
- **LOWER THE PRESSURE** We all know that working under pressure can be hard! Every additional bar of pressure can increase your power consumption by 7%. Set your air compressor at the lowest possible pressure for a specific application. Remember that increasing pressure does not compensate for a pressure drop in the system due to leaks, faulty piping, or choked filters. Install a pressure regulator for better control. It’s also important to calibrate your pressure gauges at quarterly intervals.
- **CHANGE FILTERS ON TIME** While replacing air filters is mandatory to maintain the quality of air, it is also an energy saving opportunity. Delaying an air filter change costs you more than you think! Clogged filters can lead to pressure drops and hamper efficiency. Ensure on-time service for a healthy compressed air system.
- **INVEST IN PRE-FILTERS** Not only do pre-filters (also known as coalescing filters) help purify air by removing oil and water but also particulate matter to a certain extent. Installing pre-filters for suction air and cooling air can extend the life of your compressor and its consumables.
- **CLEAN UP** Besides keeping your air clean, ensure that you give your compressed air system a thorough dusting every few months. Presence of sludge, dust or grime can have a big impact on the efficiency of the compressed air system. Pay special attention to compressor coolers and heat exchangers. Consider investing in a dedicated low pressure air compressor and air line for cleaning to save power.
- **PICK THE RIGHT DRYER** Selection of the right sized air dryer for your compressed air system is crucial. Make sure the energy consumption of the dryer is in proportion to the demand. An oversized dryer can add to your electricity bill significantly.
- **CONSIDER A VFD** Screw compressors should run under full load. If the usage pattern varies, consider a Variable Frequency Drive (VFD) for upto 35% reduction in energy cost. A VFD helps regulate the energy consumption based on demand fluctuations, ensuring energy efficiency. ELGi’s VFD has helped clients realize up to 215% savings in maintenance and energy cost with payback as low as 7 months.
- **PERFORM QUARTERLY MAINTENANCE CHECKS** The importance of maintenance cannot be overemphasized. Regular maintenance can help you identify and accurately measure leaks in the circuit. They also reduce the chances of breakdowns leading to maximum uptime and productivity.
- **PREVENT MISUSE OF AIR** Wasted air is wasted money. Invest time and money in training employees for efficient compressed air management. Create maintenance logs and update them on a regular basis, recording abnormalities or leaks in the systems. Systematically label leaks with proper tagging and prioritize repairs and plugging of leaks.
- **RECOVER HEAT** It’s common knowledge that heat is produced during the process of air compression. If not used judiciously, all the heat energy goes to waste. Over 90% of the heat produced can be recovered and utilized for heating air or water at the facility.
- **GET AN AIR AUDIT** Air audits enable companies to work with experts in the field and get valuable insights into their plant’s compressed air utilization. ELGi’s air audits chart out a customized and comprehensive energy management plan for your needs. Over the years, we have helped save millions of dollars in energy costs. Request an air audit now
    


It’s a proven fact that about 70% of an air compressor’s lifetime cost comes from power consumption. Have you assessed what compressed air is costing you? Here are 10 expert insights to help you keep a tab on the electricity bill.
    

10 Tips For Energy Savings


#### STOP AND START CHECK POINTS FOR YOUR ELGi OIL FLOODED SCREW AIR COMPRESSORS

#### STOP CHECK POINTS

- Disconnect compressors main power line to avoid short circuit
- Keep the compressor doors closed to avoid dust entry
- Cable entry points need to be closed to avoid rat entry
- Avoid moisture and dust entry:
- Close air outlet valve (After de-pressurizing the system & line)
- Close dryer & downstream filters IN & OUT valves
- Keep the manual drain valve of the receiver tank in open condition.
- Ensure there is no moisture in the downstream filters
- Drain water from water coolers to avoid scale formation and close the IN & OUT valves (water cooled air compressor)

#### START UP CHECK POINTS (WHILE MACHINE IS IN POWER OFF CONDITION)
- Clean the cooler, pre filter, air filter & complete machine (Use dry air with pressure below 2.5 bar). Ensure cleanliness of control panel.
- Ensure tightness of power cable, control wiring, connectors, transmitters, motor terminal connections and VFD cables - Check for damages
- Check for free rotation of airend and motor
- Ensure oil levels are as recommended in the manual
- Ensure oil condition is good and there is no de-colourisation, emulsification, solidification or dust contamination
- Drain moisture from separator tank and air receiver
- Clean moisture separator ADV and air receiver ADV
- Ensure no service over due (Oil and consumables change, Motor greasing must have not crossed beyond recommended hours / months whichever earlier, as given in manual)
- Disconnect the air outlet pipe and ensure there are no rust particles

#### START UP CHECK POINTS (AFTER POWER ON)
- Check incoming voltage as per specification and change the transformer tapping accordingly
- Ensure there are no alarm and trip messages in the PLC
- Ensure earth voltage ≤ 3 volts
- Check direction of motor rotation (as per the sticker in motor)
- START UP CHECK POINTS (AFTER COMPRESSOR START)
- Check for smooth running without abnormal sound
- Ensure there is no air and oil leakages in the compressor
- Ensure there is no water leakage (applicable for water cooled compressors)

#### START UP CHECK POINTS (APPLICABLE ONLY FOR VFD)
- Physical check for foreign particles, condensation, insects inside panel and VFD. Clean the drive with dry air (air pressure less than 3 bar)
- Tightness check of all wirings (L1, L2, L3, U, V, W)
- Corrosion on bus bars and earthing (Applicable for standalone VFD)
- Insulation of motor and cables
- Cleaning of heat sink, cooling fan and duct channels
- Check for alarm and warning during power up
- Check cooling fan operations
- Check the healthiness of monitoring parameters on display
- Start VFD and run in manual unload mode
- Run system with load
    


#### PRECAUTIONS FOR YOUR BUSINESS DURING COVID 19

While businesses focus on optimising production and reducing unnecessary costs, air compressor breakdown due to incorrect start-stop might lead to huge operational losses. Here is the need to work on a business continuity plan capable of handling the fast-moving variables of an outbreak like COVID-19.

As some countries across the world are going into lockdown while others are resuming business activities, it is important to follow few steps to ensure proper shut down and start-up of your air compressor and related accessories.

Re-evaluate your energy cost during operation and invest in energy saving products like ELGi Heat Recovery System.

![PRECAUTIONS FOR YOUR BUSINESS DURING COVID 19](/consultant/screw-compressor/maintenance/000023.jpg)
    

Surviving the lockdown


#### Types of maintenance:

##### 1. Reactive Maintenance:

Fix the defect after it occurs to restore the air compressor to its normal operating condition.

##### 2. Preventive Maintenance:

Carry out maintenance based on how the air compressor runs over hours or days and eliminate the defect before it occurs. The goal here is to prevent the defect.

Example: Changing oil, filter, separator, and valve kits as per manufacturer recommendations.

##### 3. Predictive maintenance:

Prevent failure by time/condition-based monitoring to plan and schedule regular checks. The goal is to predict failures in advance (based on certain conditions) and resolve them.

Predictive maintenance can be done using conventional methods and IoT Technology.

Furthermore, you can take a look at :

#### Conventional Methods:

- **Health check-up:**

Health check-ups are performed at regular intervals to monitor the condition of the components of the air compressor. If any abnormalities are found, a solution will be provided immediately to avoid failure.

Health check-ups include:

- Monitoring the condition of the air filter, oil filter, oil, separator elements, and ventilation
- Checking air and oil leakages at various locations
- Monitoring the inlet and outlet temperatures of air and oil
- Monitoring the condition of electrical contactors, overload relays, transformers, sensors, cables, and PLC
- Checking the functioning of PLC
- Checking the functioning of the control valves

- **Oil sampling:**

![Oil sampling](/consultant/screw-compressor/maintenance/000020.jpg)

Oil sampling is a process of collecting a volume of oil from the air compressor for analysis. It helps monitor oil properties, condition of the oil, change in viscosity water content, and identify contamination.

Oil analysis helps understand:

- If the air compressor is running consistently within the correct temperature range
- If there is adequate filtration
- If there is any wear and tear of rotors and gears

- **Shock Pulse Method:**

The Shock Pulse Method is a signal processing technique. It measures the metal impact and rolling noise as found in rolling bearings and gears.

This is a preferred method for predictive maintenance throughout the world.

Rolling element bearings are the most common measurement for shock pulse, but the technique has several other applications such as gear conditioning, compressor conditioning, and others where metal to metal contact takes place.

- **Vibration Analysis:**

This helps measure the vibration levels of the air compressor. The data from the analysis is then used to evaluate the health of the machine.

#### IoT Technology:

IoT-enabled devices are fitted in the compressors to acquire operation and performance data from the controller and transmit the encrypted data to a secure cloud server. The air-alert server collects the data, analyses it, and sends alerts to correct any abnormalities.

![IoT Technology](/consultant/screw-compressor/maintenance/000021.jpg)
    


Compressed air is considered to be the fourth most important utility after electricity, water, and natural gas. However, it is also the most expensive of the four. This is why organizations look for efficiency and reliability while looking for air compressors. One way to ensure this is to select the right maintenance plan, to ensure higher productivity and savings.
    

A 3-step approach to maintain an air compressor for optimum performance


#### Oil levels and colour

![Oil levels and colour](/consultant/screw-compressor/maintenance/000015.jpg)

Oil levels in the air compressor must be maintained as per the manufacturer's recommendations. Once it is below the stipulated level, the machine starts showing symptoms of a disorder. Oil levels can easily be checked by looking at the oil level indicator. The oil should only be topped up when the machine is down.

The colour of the oil is an important factor. Regularly monitor the oil and do not ignore if the colour of the oil changes to dark grey or black.

Oil storage and the container used for topping up must also be as per the manufacturer's guidelines.

#### Air filter

![Air filter](/consultant/screw-compressor/maintenance/000016.jpg)

The condition of the air filter can determine the exact problem. Normally, filters are found to be dusty and require immediate attention through cleaning or replacement. Choked filters lead to increased power consumption or a dusty entry which needs to be replaced immediately.

Filters must be cleaned regularly and kept in good condition.

#### Motor

![Motor](/consultant/screw-compressor/maintenance/000017.jpg)

By checking the temperature of the motor with a temperature gun, you can determine if the machine is running normally or not. The temperature of the motor must be within the recommended limits, otherwise the chances of a failure become high.

The compressor room must be properly ventilated, as per the recommendation of the manufacturer. The customer must ensure that there is no obstruction in the airflow path.

By inspecting the hot air dissipated from the machine or by checking the air temperature by hand, the operator can easily determine if there is any problem. The operator must also look out for dust accumulations in the fins of the cooler, which can lead to hot airflow and inefficient cooling.

#### Coolers

![Coolers](/consultant/screw-compressor/maintenance/000018.jpg)

The coolers must be cleaned regularly to ensure that there is no clogging or dust accumulation between its fins.

Apart from this, the health of the machine must also be checked and recorded. This will give you a detailed picture of the immediate history. Almost 90% of the problems lie in these basic diagnoses and can be carried out by anyone.

Well, prevention is better than cure. By following proactive steps stated above, customers can avoid breakdowns and downtime, improving overall productivity. If you see anything beyond what was stated above, you must connect with their compressor manufacturer immediately and rectify the faults.
    


Your air compressor will show enough symptoms before breaking down. These symptoms, if not attended on time, can lead to erratic behaviour, inefficient compression processes and (or) higher power consumption, leading to eventual premature machine breakdown.

Issues such as oil carryover, air leaks, filter clogs, and inadequate lubrication are all warning signs of a gradually failing system. While all air compressor manufacturers recommend carrying out scheduled maintenance checks mandatorily, not recognizing the symptoms associated with certain issues can also lead to system failures.

So, does that mean that it is possible to identify the exact problem by simply observing the preliminary symptoms? In most cases, yes, it is.

For a customer, it is important that the functioning of a downstream equipment that relies on compressed air is not disturbed. Hence, efficient and smart troubleshooting is mandatory to save time and money. By closely observing the symptoms, we can anticipate the nature of the problem. Data must be collected, verified, and ascertained properly in order to arrive at a conclusion.

The most reported issues of an air compressor are:

- Pressure not building up or not loading
- High temperature and tripping
- Not understanding alarming and warning signals in the controller
- Tripping with high sump pressure
- Oil leakages
- Moisture condensation observed at utility point

Most of the problems can be identified through self-diagnosis of the following:
    

Smart solutions for troubleshooting your compressed air system


##### Best practices for resourceful use and efficient maintenance

Air compressors consume significant amounts of energy while fuelling industrial applications. If you take into account all the costs of running a facility, you will realise that any savings therein will lead to a positive impact on your overall cost management.

To make compressed air a more affordable utility, all you need to do is root out the inefficiencies, and maintain a sound maintenance regimen. Here are five effective ways to derive more value from your compressed air systems and reduce the related operating expenditure:

- **Turn off when not in use**

Many business users do not realise the amount of energy wasted when air compressors stay on idle mode.

Except in cases where a compressor must operate nonstop, like in critical application, it should be turned off during non-business hours or when the underlying application is not required. By ensuring that it is used judiciously for concerned applications, you can reduce the power consumption, leading to significant cost savings!

- **Fix the leaks**
Another way to reduce spending on compressed air energy bills is to regularly check for and eliminate any leakage. In air compressor systems, worn or improper connections can promote air leakage and forcing the system to run in full capacity compress air. This system inefficiency can increase power consumption of the system and the user might not experience a reliable air flow.

Some leaks may be in spots that are not easy to access. In other cases, the crack may not be big enough to know if air is leaking from it. In such cases, we recommend an ultrasonic leak detector that helps you find most of those small and faint trickles before they get bigger and lead to costly issues. Get in touch with and ELGi air expert to get your system checked

- **Reduce the air pressure**

At many sites, users set air pressure levels to the highest limit for applications that need maximised-pressure. However, such high-pressure requirements often account for just a small part of the setup.

If you use high-pressure applications only on some days, do not hesitate to segregate them from the remaining equipment. This enables you to run the compressor at average pressure, resulting in more energy saving. The pressure should be increased only when required. To run a large facility with several compressors, you can designate a separate machine for various pressure levels.

- **Examine the drains, make necessary replacements**

Even though condensate drains are key features of an air compressor, their malfunctioning can cause significant harm to the system. If it does not open as intended, it begins to deteriorate the working of the air compressor.

Also, if the timer drain is jammed in an open position and does not get noticed before the next scheduled maintenance, it may cause compressed air to leak through the setup.

You can avoid such issues by adopting preventive maintenance practices and subscribing to an annual maintenance plan that will ensure efficient functioning of the system.

- **Redesign piping infrastructure**

The piping system design should be adequately wide for optimal airflow at the required pressure. It should allow the air to move the smallest possible length because the likelihood of pressure drop increases with long and/or complicated routing.

Shortening the distance travelled by air also reduces pressure drops by 20-40%. Such design changes in the piping infrastructure improve the efficiency of pneumatic processes and help save on operating expenditure.

In the past few years, manufacturers have customised piping for more effective use of modern compressed air systems. If your existing pipes were used with an older, smaller compressor, investment in a new arrangement would be worthwhile.
    

Top 5 ways to reduce your compressed air costs


##### Benefits you enjoy when you purchase only genuine parts:

- Warranty – for repair, replacement or refund if the part fails to function optimally
- High product quality
- Longer lifespan
- Higher productivity
- More energy savings
- High reliability
- Ease of service and maintenance

Let’s take a look at the parts that need to be replaced or replenished for the commonly used rotary screw air compressors:

##### Dust filters and oil separators

The air & oil filters and the oil separators are critical parts of air compressors as they prevent damage and performance loss caused by dirt in the internal system.

Dust particles from inlet air can damage your air compressor’s rotors. This can reduce the quantity of compressed air delivered to associated tools, with continuous energy consumption.

Dust also lowers the lifespan of the air compressor element and the oil separator. When it gets mixed with the oil that lubricates the rotary screw air compressor, the oil becomes impure and less effective.

Additionally, dust harms the bearings and the bearing housing, negatively impacting the air compressor element and may even lead to element seizure.

Therefore, it is essential to use only genuine air compressor filters and oil separators when it is time to replace the originally-fitted units. Such filters have strong dirt reduction capabilities. They are devised to endure high operating pressures and fluctuating temperatures while maintaining efficient performance with low power consumption.

##### Airline filter cartridge

If you replace your air compressor’s line filter cartridge with a counterfeit piece, it will reduce the filter’s efficiency and allow dirt particles to enter the air network. This will result in pressure drops and high energy consumption by the compressed air system.

Using a non-genuine filter cartridge will also result in more frequent replacements or repairs, leading to a higher total lifecycle cost of the air compressor. Hence, always insist on buying genuine airline filters.

##### Lubricating oil

A key consumable in oil-based air compressors, is that the lubricating oil absorbs heat while also safeguarding the unit from dust accumulation and rusting.

While some users have a notion that ‘any oil’ can be used for lubrication, the fact is that a poor quality oil reduces the durability of an air compressor. If oil greases the system components ineffectively, it can cause the formation of sediment in oil circuits and over the moving parts. Such developments increase the risk of oil oxidation and corrosion of metal parts in the compressed air system.

Using genuine oil or lubricating fluid offered by your air compressor supplier can ensure effective lubrication, prevent equipment breakdown and derive better performance from your rotary screw air compressor.

Authentic air compressor oil combines the finest quality of case oil with required amounts of additives that make the product suitable for lubricating an industrial compressed air system.  It is viscous at low temperatures and has high oxidation resistance.

With a genuine lubricating oil, you will need to top-up less frequently, have lower disposal cost, require less maintenance and face lesser downtime incidents.

##### Important points for you to take note:

Besides procuring spare parts and consumable fluids from OEMs and recognised suppliers, it is also critical to have a proper service kit comprising the hand tools for safe replacement of parts, and for best results, you should get your compressed air system serviced only by experienced repair personnel.
    


##### Reasons to buy spares and consumables from certified suppliers

Like any other machine, air compressors need regular maintenance and periodic replacement of parts that get strained with continuous use. By changing the worn-out components in time, you can ensure optimal functioning and better durability of your unit while also saving time and money on unnecessary repairs.

While these spare parts are often available in the market, and in many instances even come at attractive price-points, it is critical to procure your air compressor’s components only from Original Equipment Manufacturers (OEMs).
    

Understanding servicing & maintenance of air compressors


##### B) You’ve got the eagle’s eye – now inspect for leaks

After you’ve cleaned your air compressors, ensure that there are no air leaks.

Air leaks waste close to 20-30% of the energy generated by compressed air systems. Due to this, the performance of the tools weakens, and the efficiency of the operations reduces. This results in higher operating and maintenance costs.

The problems associated with air leaks can be identified easily and do have solutions. Regular inspection can help prevent these issues.

##### C) Don’t let your compressor buckle under pressure – avoid over pressurization

Adhering to the tips mentioned above is important. Apart from the tips mentioned above, the air compressor load needs to be optimised as well. For this, use the lowest operating pressure suited for your requirements. According to the industrial standards, if you drop the system pressure by 2 PSI, the operating costs reduce by **1%**.

Installing pressure regulators to your compressed air system is also recommended. This will decrease the machine wear-and-tear and save up to 15% of the energy generated!

![Don’t let your compressor buckle under pressure – avoid over pressurization](/consultant/screw-compressor/maintenance/000011.jpg)

##### D) Free-falling? Reduce pressure drops

Sometimes, when compressed air travels from the compressor discharge to the actual point of use, the pressure drops. Consequently, the operators increase the generator pressure or turn up the regulators. This can increase the energy consumption.

There are two causes for this – a complicated pipework system and an inept filtration process. To counter this, the pipework should be simplified, and filters should be changed regularly. The energy will be conserved, and pressure drops reduced.

##### E) You’ll never run out of steam – conserve heat energy

Over 50% of compressed air systems can ensure low-cost energy conservation if used efficiently.

One way to achieve efficient use of energy is to conserve heat.

The heat released during the process of air compression can be reused in warehouses to warm water or produce steam for industrial processes.

With a proper energy system in place, like ELGi’s Heat Recovery System, a lot of energy can be saved.

To mitigate such situations, it’s important to ensure that the air compressors are functioning properly and are always reliable.
    


With growing pressure to reduce carbon footprint, lower energy costs and implement sustainable manufacturing processes, it is imperative that we optimise our compressed air use.

Here are 5 essential tips to improve the efficiency of your compressed air system:

##### A) Start with a Clean Slate – Clean Your Compressor

If you want an efficient compressor, you need to have a clean filtration system.

Through a given cycle, air and oil should be sufficiently filtered out. This results in the production of cool air in constant volumes and ensures a seamless performance of the machine.

If the filters are dirty, the pressure can drop. This will make the air compressor consume more energy and exert harder just to perform the basic functions. Ultimately, this would result in the untimely wear-and-tear of the compressor.

In case, the dirt stays on for several seasons the air quality could decline.

![Start with a Clean Slate – Clean Your Compressor](/consultant/screw-compressor/maintenance/000010.jpg)
    

Top 5 Tips to improve the efficiency of your air compressor


Based on the application requirement, contaminants are to be removed from the compressed air by using the suitable downstream equipment.

For instance, using downstream filters particle, water and oil contaminants can be removed from the compressed air.

**Bulk moisture separators** are recommended for removing the water from the compressed air.

- It is mandatory to have proper automatic drain along with the moisture separator, as they are mostly used after the cooler. The optimal removal of condensate will ensure that no bulk water carry over to the downstream equipment’s. It is recommended to use Level sensing zero loss drain along with moisture separator to get this done with minimum loss of air.

Downstream filters are available in various configuration/types. These can be categorized as per the the residual oil and particle after filtration and are, as follows:

- **Coalescing filters** are recommended to remove the wet particles and aerosols (water and oil) from the compressed air. Different types of coalescing filters are available based on residual oil and particle content at the filter outlet after filtration. Coalescing filter are mainly classified into two types:With the
  - Pre-filter, class 3 or 2 purity of particles and oil can be achieved, i.e. ISO 8573-1:2010 [2: - :2]
    - The recommended sequence of installation is the bulk moisture separator followed by pre-filter
  - With the fine-filter, class 2 or 1 purity of particles and oil can be achieved, i.e. ISO 8573-1:2010 [1: - :2]
    - The recommended sequence of installation is bulk moisture separator, pre-filter, dryer followed by fine filter

**2. The particulate filter** is specialized to remove the dry particle and microorganisms from compressed air. This filter is mostly used after a desiccant dryer to ensure that the desiccant particles are not carried to the compressed air line.

- The class of purity of particles made possible with this filter is 3,4,5&6, i.e. ISO 8573-1:2010 [3: - : - ]
  - The recommended sequence of installation is the bulk moisture separator, pre-filter, Desiccant dryer followed by particulate filter

**3. Carbon filters** are recommended to remove the oil vapour and other gases present in the compressed air which are not removed by coalescing filters

- The class of purity achievable with carbon filter is ‘’1’’ , i.e. ISO 8573-1:2010 [-: - :1]
  - The recommended preceding with carbon filter would be pre-filter, dryer, fine filter, followed by carbon filter

![Carbon filters** are recommended to remove the oil vapour and other gases present in the compressed air which are not removed by coalescing filters](/consultant/screw-compressor/maintenance/000006.jpg)

##### Important factors to consider for the right selection of filters and ensuring their optimal performance

- The filter capacity is based on the operating pressure of 7bar (nominal condition). In case the operating pressure is different, it is important to use the correction factor and select the filter model accordingly.
- The correct sequence of installing filters must be followed, so that the performance is optimal. As a thumb rulem the level of filteration should be in sequence, ranging from 20 ppm to 5 micron or from 10 micron to 1 micron to 0.01 micron. Carbon filters should always follow after the 0.01 micron filter. In absence of this sequence, it will choke up faster, and reduce the lifespan.
- Please note that the lowest pressure drop across filters happens when the filter elements are dry. If the filter element gets wet, delta P will increase. This is another reason why we should follow the above mentioned sequence.
- It is recommended to have a proper drain along with the pre-filter, since the pre-filter is mostly used before the dryer. The regular removal of condensate will ensure that no moisture carries over to the downstream equipment.
- The replacement of filter element at the recommended service interval is important. The filters have an indicator of saturation level and it is recommended to replace the filter element incase of indication. saturated filter element will not give the required class of purity. This will have higher pressure drop, creating an extra load on the compressor. As a thumb rule, 0.14bar/2 psi pressure drop will have 1% additional load on the compressor. Carbon filters function on the adsorption method and need to be replaced on a timely basis.

The oil emulsified condensate is collected from various downstream equipment and the compressor. After this, the condensate needs to proceed for oil removal before discharging to the sewage

If the oil emulsified condensate is discharged to the ground, the water will eventually evaporate, leaving the oil behind.

##### How to select an oil water separator to remove the oil from the oil emulsified condensate before it discharging to the sewage:

- Selecting the correct oil water separator and element is important for removing oil from the condensate within the permissible limits allowed in the region. This is expressed in terms of ppm units. Usually it is set from 10 to 15ppm.
- It is important to see that the oil water separator selected is compatible to operate with the compressed air and condensate mixture flowing through the condensate line.
- The PPM level after separation needs to be monitored thoroughly. If the PPM level is above the recommended level, then the element needs to be replaced. Some of the oil water separators also have a life indicator for elements to ensure ease in identification

![How to select an oil water separator to remove the oil from the oil emulsified condensate before it discharging to the sewage](/consultant/screw-compressor/maintenance/000007.jpg)

Best practices for removing contaminants from compressed air are, as follows:

- Selection of the correct size of moisture separators, so that maximum bulk moisture is removed from the system and is not carried over to the downstream equipment
- Selection of the correct coalescing filter type, rating, size and appropriate preceding level for the selected filters. Here, it is important to replace the filter element at proper service intervals.
- Electronic drains play an important role in removing the condensate from the compressor and downstream equipment. Here, it is important to properly maintain and replace an electronic drain regularly, as per recommendations.
- Dryers are a must before the fine filter and carbon filter so that the compressed air is free from water vapour. This is critical, as the vapor can choke the filter element. A particulater filter is recommended after the desiccant dryer before fine and carbon filter
- In case a small part of the application requires more stringent air quality, it is recommended to have an additional dryer and filter set near the point of use. Usually, this dryer could be a membrane or dessicant type giving a lower dew point.
- Monitor and check for leakage in the compressed air pipelines. A leakage can give a chance for the outside contaminants to get into the compressed air line. These leakages allow outside air to creep inside the piping when the compressor is stopped (when there is no positive pressure inside the pipe). This leak allows moisture to rust and carries other impurities inside the pipe, which, in turn, may get carried forward when the compressor restarts.

![Best practices for removing contaminants from compressed air are, as follows](/consultant/screw-compressor/maintenance/000006.jpg)

Conclusion: Once you have attained the purity class that is suitable for your application, it is important to maintain the same and not add any further impurity. Sometimes, this can happen with the usage of mild steel pipes and fitments  shedding out rust in the line, which can reach your application. Therefore, it is recommended to use suitable piping like aluminium, or a suitable rust preventive coating like galvanized iron. Moreover, it is also recommended to check and replace these pipes based on their life and corrosion level.
    


The atmospheric air comprises of moisture, particle contaminants, microorganisms and gases. When this air gets compressed, the concentration of such particles these increases by 6-10 times. However, when this atmospheric air gets compressed by a compressor, other contaminants like oil & traces of metal get added during the compression process. This is why, it is important to remove these contaminants from the compressed air before it is used for any application.

These contaminants can be categorized into:

1. Particles
2. Water (Liquid, vapor and aerosol)
3. Oil (Liquid, vapor and aerosol)
4. Microorganisms
5. Other gases

According to the International Standard, ISO 8573-1:2010, compressed air contaminants like particles, water and oil are segregated as per purity classes. In this standard, microorganisms and other gases are not included. As a result, the air purity is indicated as [P,W,O] and is ordered as per the amount of particles, water and oil.

![ISO 8573-1:2010, compressed air contaminants like particles](/consultant/screw-compressor/maintenance/000005.jpg)
    

How to remove contaminants from your compressed air system?


##### Simple calculation to assess leaks

One simple way to estimate how much leakage a system has is to turn off all of the point-of-use devices / pneumatic tools, then start the compressor and record the average time it takes for the compressor to cycle on and off. The total percentage of leakage is calculated as follows:

```
% Percentage = [(T x 100) / (T + t)]

T = on time in minutes
t = off time in minutes
```

The percentage of the compressor's capacity that is lost should be under 10% for a system that is properly maintained.

The below table may be helpful to identify, quantify, and assess the cost of the leaks in the system.

|SN|Machine description|Location|Approx. leak (cfm)|Approx. energy cost of air leak|Photos|Parts required to rectify leak|Approx. cost of components required to rectify leak|Status |
|--|--|--|--|--|--|--|--|--|
|1|--|--|--|--|--|--|--|--|
|2|--|--|--|--|--|--|--|--|

##### Leak Detection

- There are various methods to detect the leak in the system. The best way is with the use of an **Ultrasonic leak test**. The instrument uses high-frequency sound and is very sensitive to sound. It will help to identify the minimal leak in the system within the blink of an eye. Of course, the result of the instrument is affected by background conditions.
- The simplest method is to use soap solution at the joints or any suspected area. It is cost-effective, but time-consuming and involves extra work.

##### Fixing the leaks

- Fixing the leaks can be as simple as tightening the joints, fittings
- Replace faulty components such as pressure regulators, quick fittings, hoses, valves
- Replace service kits of actuators as per schedule
- Another approach is to identify the pressure required for equipment to operate and supply the required pressure using local pressure regulating components. This will reduce the pressure in the system, thereby improving the life of pneumatic components.

Re-check the % percentage leak as per the formula and assess the improvement in energy cost.

##### Few other points to consider

- Most leaks may occur in the machines that are not being operated. Cutting off the air supply to those machines will save some energy, and cost of components.
- Training the employees regarding the importance of air leaks will help to identify quick
- Documentation - Tagging of the leak, tracking, repair, and verification of the leak will help to create a repository for future reference and pave the way for improvements.

ELGi’s Air audit may help users identify leakages and deploy solutions to address the air compressor leak. Our Audit Report includes identifying all the Big, Medium, and Small leaks in the compressed air system network and providing recommendations on short, medium, and long-term measures for energy conservation, along with financial estimates and analysis for their implementation. The audit involves a wide range of sophisticated, portable diagnostic and measuring instruments to generate refined data and facilitate complex analysis to give a more reliable basis for identifying leaks, evaluating performance, energy saving measures, and economic viability.

To Know more, get an air audit to identify and stop Air Compressor leakages.

![Few other points to consider](/consultant/screw-compressor/maintenance/000003.jpg)
    


##### Importance

Leaks in a compressed air system can waste your operating budget on high electricity consumption every year. In many manufacturing and processing plants, the leakage can account for up to 20% of the total operational cost of the compressor. The most common areas where you might find leaks are connection joints like valves, unions, couplings, fittings, etc. This can also cause the compressed air system to lose pressure which reduces the efficiency of the pneumatic tools or machines that make use of compressed air in the system, like an air-operated actuator being unable to close a valve, for instance, and may cause rejections in the end product.

![Leaks in a compressed air system can waste your operating budget on high electricity consumption every year](/consultant/screw-compressor/maintenance/000002.jpg)
    

A Comprehensive Guide on Finding and Fixing Air Compressor Leakages


##### 1. Location

The most important aspect is the location. During installation, we need to ensure there is sufficient area available for the unloading, installation, operation, and maintenance of the compressor. The designated area must be equipped with enough clearance around it.

Please note that, for rotary screw compressors, however, no special foundation or anchoring is required. The compressor must be placed on a level surface that can withstand the load of the compressor and the equipment used to move it.

Furthermore, we must make sure the compressor is protected from natural elements like rain, sunlight, hot air, and other deterrents like toxic or flammable materials and corrosive agents like ammonia, chlorine, salt spray, and other chemicals as they erode the internal components, contaminate the oil and damage the filters.

##### 2. Ventilation

Next up is ventilation. A lack of ventilation and cooling is the leading cause for trouble in air compressors. The electricity delivered to your compressor is completely transformed into heat during compression and that heat is dissipated into the compressor room.

To make sure your compressor is sufficiently cooled, the following measures can be adopted:

**Natural ventilation:**

If the temperature inside the compressor room doesn’t exceed 5 ˚C when compared with the ambient temperature, the natural ventilation is sufficient.

You may also ensure ventilation through alternatives such as:

**Forced ventilation with an exhaust fan:** Install an exhaust fan if the temperature inside the compressor room exceeds 5 ˚C.

**Forced ventilation with ducts:** Ensure the hot air exhaust from the compressor is diverted through ducts when it is installed in an enclosed area.

Install a cabinet heater if the air inlet temperature drops below ambient temperature. Use the cold start kit and heater in the compressor room to maintain the temperature at 0˚C - 50˚C.

##### 3. Electricals

Make sure that the electrical service voltage matches the voltage on the compressor nameplate (located inside the electrical cabinet) before installing the compressor.

The compressor should be:

- Properly grounded

- Properly equipped: The appropriately sized fuse or circuit breaker should be installed between the compressor and the main electric service.

The actual operating voltage must be within +/- 10% of the compressor nameplate voltage. Insufficient or excessive voltage will directly affect the compressor's electrical system.

For variable speed drive units, make sure that the power supply transformer has a symmetrical, three-phase supply. In a symmetrical three-phase supply, the phase angles and voltage are all the same.

Here’s an additional tip: provide the power supply to the compressor through a dedicated switch disconnector fuse (SDF). Mount a suitable SDF unit of rating within 5 meters of the compressor. This helps to carry out maintenance without stopping more than one compressor.

##### 4. Air storage

An air receiver tank is an integral and important part of any compressed air system. The selection of an air-receiver is crucial to meet the demand of the plant and the effective operation of the compressor (load / unload).

In a compressed air system, a receiver tank provides the following benefits:

- The receiver tank acts as a reservoir of compressed air for peak demand.
- The receiver tank helps remove water from the system by allowing the air to cool.
- The receiver tank minimises pulsation in the system caused by a reciprocating compressor or a cyclic process downstream.

Receiver tanks are required to have a pressure relief valve and a pressure gauge. The relief valve should be set to 10% higher than the working pressure of the system.

It is also important to install a manual or automatic drain on the receiver tank to remove water from the system.

##### 5. Piping

The correct size of pipework is important to provide sufficient flow and steady pressure to all points of use. Pipe diameter directly impacts the pressure drop. Discharge piping must be at least the same diameter as the compressor discharge outlet.

Pipe selection directly affects three key elements of a compressed air system (flow, pressure, and air quality). Poor choice of pipe materials, diameter, and layout causes flow restrictions and frequently results in a significant pressure drop.

Pipe bends are an additional source of friction losses in compressed air piping. The pressure drops due to an increase in friction with the flow. Friction loss is also affected by the pipe type and the length of the pipeline.

The compressor air outlet must be on top of the common/main header pipe to avoid condensed water entry when the compressor is idle. Make sure the air inlet to the receiver is at the bottom, and the outlet from the receiver is on the top to avoid moisture-free air to the dryer or customer equipment.

The pipelines must be flushed before downstream filters like the prefilter, fine filter, and carbon filters are assembled. Make sure the water drain is in provision with the auto drain for the air receiver, downstream filters, and dryers. We must also provide a bypass for piping arrangements of the dryer and downstream filters in case of isolation.

A good installation of a compressor system makes all the difference in performance, efficiency, and the overall lifecycle of the system and prevents direct or indirect expenses in the future.
    


Once a compressor is purchased, we get ready for the installation. During this stage, it is very important to make sure that the compressor is installed as per the manufacturer's guidelines. This will make sure that the compressor lasts long, provides optimum performance, and reduces energy costs.

Take a look at the key points to focus on a compressor’s installation.
    

5 essential steps for a successful air compressor installation


##### A brief overview of water well drilling applications

Water well drilling equipment consists of a water well rig, air compressors & accessories like drilling rods, casing pipes, and a hammer. In most cases, for deeper water well drilling, DTH drilling is adopted. DTH Drilling is an efficient way of drilling for deeper holes in medium or hard formations as hammering action is provided right on the drill bit at the bottom of the hole.

To fulfill the requirements of water well drilling applications, ELGi manufactures efficient and rugged compressors.

Here is look at the typical mounting of the equipment in water well drilling application:

![A brief overview of water well drilling applications](/consultant/screw-compressor/application/000091.jpg)

*Both Compressor and Rig in the same truck.*

##### The process of drilling

Typically, a water well drill consists of the following activities:

- A large hole is drilled to insert casing pipe (anywhere between 20-200 ft) using the Over Burden hammer

- Which removes the top layer of the earth's crust to prevent any collapsing materials into the well.

- Then, a hole of the actual size is drilled.

Today in India, the average depth ranges from 800-1200 ft depending on the water table in the zone under consideration.

##### Different stages of Drilling

For water well compressors, there are 2 very important aspects in any compressors.

**Drilling state:** In this phase, compressed air is needed at the required pressure for efficient hammer performance. The drilling state forms 75-80% of the overall drilling cycle. Compressor performance is critical in ensuring profits for the Drill rig owner.

ELGi compressors deliver the required amount of compressed air to ensure optimum drilling.

**Flushing State:** This phase requires the maximum flow of compressed air to remove the cuttings/debris from the hole. This state plays a critical role in determining the fuel consumption of the compressor overall, as generally, the compressor consumes more fuel if flushing is too much. Typically, flushing ranges from 10-15 % of the overall drilling cycle.

Another state is **idling** where the compressor delivers no air, however, it remains in that state, as the rig will undergo rod change activity.

A water well depth depends on water yield or until a customer wants to try for water. Finding a drilling point is a different topic for discussion as there are multiple ways, be it using a scientific method of using a geologist or a traditional method like using a water diviner.

![Different stages of Drilling](/consultant/screw-compressor/application/000092.jpg)
    


Water is a precious resource and drinking water, more precious. Humankind needs drinking water today more than ever.

In most places, water is dug out of the earth for drinking. In the olden days, wells used to be dug, but as the water table receded, depths increased, and today water wells of 4.5”-4.75”, and 6” – 6.5” are very common. Tube wells have become the order of the day to access potable water from the earth’s crust.

![Water is a precious resource and drinking water, more precious. Humankind needs drinking water today more than ever](/consultant/screw-compressor/application/000090.jpg)
    

Using Air Compressors for Water Well Drilling


##### Compressed air in the packaging industry.

Compressed air plays a crucial role in the manufacturing and packaging processes in many different industries around the world. It is used to clean, align, shape, and seal packaging products of all kinds.

##### Food and Beverage:

Last year, the global food packaging market crossed over US$ 302 billion in market value. Compressed air plays a vital role in safely transporting food items and other products around the factory or to their desired location, without any contamination or deterioration in quality. Compressed air is used to shape and seal cartons and boxes, manufacturing products like PET bottles and thoroughly clean all containers before they can be filled with liquids.

##### Pharma Industry:

In the pharma industry, oil-free compresses are used to manufacture products including pills and tablets. These tablets or pills are then safely placed in bottles, after the moisture has been removed, and then sealed airtight- maintaining the highest level of clean and sterile compressed air

![One can easily call the supermarket a Disneyland for adults](/consultant/screw-compressor/application/000086.jpg)

##### Benefits of compressed air in packaging.

Compressed air has made life easier for businesses all over the world. From small bakeries to large production plants, its multiple applications have made it an indispensable tool for industries today. It is safe to operate, affordable, and reliable. Thus, rightfully earning its name as the ‘fourth utility’ in the manufacturing and packaging world.

##### Compressed Air and Sustainability in the packaging industry

In 2020, sustainability is not an option, but a must. Industries all around the globe are looking for solutions to reduce operational costs as well as their carbon footprint. With global warming levels at an all-time high, it is the need of the hour.
At ELGi, sustainability is not just a feature of our products, it is our mission. We have set a global standard in providing environmentally friendly and sustainable solutions to all our partners.
Our oil-free and sustainable air compressors play a big part in reducing the carbon footprint of manufacturing plants around the world. With low operational and maintenance costs, our compressors are reliable and trusted everywhere, making the lives of our customers and the planet, Always Better!

![Compressed Air and Sustainability in the packaging industry](/consultant/screw-compressor/application/000087.jpg)

##### EG series screw air compressors

A trusted solution for partners from across the globe, the EG series air compressors from ELGi are highly efficient, reliable, and have a long life. These features of the air compressors support the packaging industry in maintaining quality, safety, and reliability. You can reach out to our air experts for support with your business.

![EG series screw air compressors](/consultant/screw-compressor/application/000088.jpg)
    


One can easily call the supermarket a Disneyland for adults.

You would find literally everything you need or did not know you needed at a supermarket. Choices of brands, products, sizes, weights, you name it! And while you find yourself spoilt for choice, there is one thing common with all these offerings and that is the packaging. Each of these products is ready and safe for use because of compressed air.
    

Compressed Air – The Complete Package!


#### What are the quality standards in compressed air?

The International Organization for Standardization (ISO) publishes the standard for compressed air quality, globally. This standard, ISO 8573:2010 is commonly used for compressed air applications.

In the absence of specified standards governing compressed air quality testing in the manufacturing process or production of pharmaceutical, medical devices, and food applications, it is often best to use site-specific testing programs. **Direct Product Contact, Indirect Product Contact, USP and ISO 8573 air standards can be considered reference points for testing.**

A routine testing schedule for your compressed air quality program should provide the appropriate verification and compliance each facility will need.

![What are the quality standards in compressed air?](/consultant/screw-compressor/application/000083.jpg)

#### What are the applications of compressed air in the pharmaceutical industry?

Oil-free compressed air is crucial in powering the following applications:

##### Bottling and Packaging

Medicines are packaged in multiple ways. Bottles, lightweight plastic containers, cartons, blister packs, etc. Depending on the nature of the manufacturing need, compressed air is utilised to clean and remove moisture from these packages.

##### Capsule and Tablet Manufacturing

Compressed air meets almost every need in the manufacturing process. From mixing, hardening and granulation to drying, pressing, coating and packaging.

##### Fermentation

Compressed air helps aerate the fermenters with sterile air.

##### Instrumentation Air

Tools used in the manufacturing processes need to be pure and oil-free, compressed air helps fuel these tools.

##### Drying.

Vacuum pumps are used to evaporate liquids from the solids, in the process of drying medicines to remove any solvents or water from the product.

##### Wastewater Treatment.

To prevent contamination of the product, water must be treated at various stages- before and after the manufacturing. Blowers are generally used to treat wastewater.

##### Fluid filling machines

Fluid pumps are used to move liquid products in the production and filling process.

#### Oil-free compressed air

There is a growing industrial need for compressed air free of oil in the manufacturing process. While an oil flooded screw compressor will satisfy multi-stage filtration, oil-free compressors are ideal- owing to the hassle of pressure drops and added maintenance, stemming from filter equipped lubricated compressors.

Oil free screw compressors are used extensively without any contact with oil.

The air cooler removes the heat from the compression chamber. Without oil, the rotors rotate at high speeds to get volumetric efficiencies equivalent to oil injected screw compressors. Timing gears synchronise rotor rotation to ensure no contact. A separate lubrication system lubricates the timing gears. This calls for an efficient sealing system to prevent the entry of lubricating oil into the compression chamber.

ELGi's oil-free rotors employ a two-layer non-metallic coating and coating process to preserve the rotors. This comprises PTFE + PFA((Poly Tetra Fluoro Ethylene + Per Fluoro Alkoxy), with PTFE on the first layer and PFA on the top.

![Oil-free compressed air](/consultant/screw-compressor/application/000084.jpg)

PFA has layering and formation properties which ensure homogeneous coating and avoid the formation of pin holes. This in turn enhances the coating reliability and provides highly efficient corrosion protection. In addition; the coating serves as a dry lubricant. The coating's food and medical grade certification ensures its safety for pharmaceutical applications. Though there is no oil injected into the compression chamber, the timing gears and bearings need lubrication which is taken care of by a separate lubrication system. The oil used for this purpose needs to be prevented from entering the compression chamber.

ELGI employs an efficient internally designed sealing system comprising of floating carbon seal and viscose on each rotor to prevent the oil from entering the compression chamber. These seals are non-contact seals and their reliability is significantly higher than any contact seals; hence ensuring continuous clean air supply.

With a visible shift in acceptance of oil free equipment, ELGi will continue to support sustainable initiatives with innovation and design contributing towards cost and efficiency. Data will serve as a key enabler in the process, where compressor suppliers and manufacturers partner to eliminate quality concerns.

At ELGi, we know that compressors must be dependable, to prevent unwanted downtime loses in repair and misses in maintenance can have a significant impact on the company’s business. For manufacturers in the pharma industry, it is essential to have reliable compressed air systems for profitable production lines. ELGi keeps this in mind while building its compressed air solutions.
    


A sterile environment is essential in the pharmaceutical industry, demanding the highest quality standards always. Manifold rise in public healthcare spending, rising patient awareness, expanding insurance coverage across the income pyramid and the emergence of new hospital formats, have contributed to a period of bloom in the pharma sector, globally.

However, with increased supervision, global pharmaceutical markets are also amidst major discontinuities; providing opportunities for emerging markets in the coming decade.

The Indian pharmaceuticals market, along with the markets of China, Brazil and Russia, will spearhead growth within these markets.

![Compressed air supports the manufacturing of critical drugs to combat virus outbreak](/consultant/screw-compressor/application/000082.jpg)
    

Compressed air supports the manufacturing of critical drugs to combat virus outbreak


#### What is a Concrete Batching Plant?

Concrete batching plant is an equipment in which all the aggregates such as sand, gravel, crushed stone, and slag, are batched, mixed with water, cement and other additives homogeneously to obtain a concrete of desired strength and quality.

![What is a Concrete Batching Plant?](/consultant/screw-compressor/application/000079.jpg)

#### Layout of a Concrete Batching Plant
1. The aggregate bins contain sand, gravels and other aggregates
2. The cement silo is a container used for the storage of bulk cement on site.
3. The mixer is the heart of a batching plant, where ingredients are mixed together to form the concrete.

#### Operating Cycle of a Concrete Batching Plant

**Charging:** A cyclic process of continuously feeding all ingredients to the mixer. It ensures that the mixer is not idle and proportion of all ingredients are appropriate.

**Mixing:** Mixing is the complete blending of materials required for production of a homogeneous concrete.

**Discharging:** After mixing, the concrete mixture is evacuated from the mixing chamber to the RMC (Ready Made Concrete) truck via a discharge chute.

#### Compressed Air in Concrete Batching Plant

Compressed air is used in the control system typically during charging and discharging cycles to actuate pneumatic valves in the aggregate bins and the mixer. As charging, mixing & discharging are a part of a continuous operation in a concrete batching plant, the compressor must be up and running to ensure a seamless operation. Compressed air is also used to clean the silos so that the right proportion of cement and fly ash is charged ensuring desired output quality.

#### Criticality of Compressed Air in Concrete Batching Plant

In Aggregate Bins, valves are controlled by load sensing cells and PLC. Compressed air is required for opening these valves based on the signals from load cells for discharging aggregates to the hopper/ conveyor belt.

In the Mixer, compressed air is used for operating the pneumatic delivery valves. This aids in unloading the mixed concrete onto the ready mix concrete (RMC) truck. Concrete typically sets in from 30 to 40 minutes. If it is not delivered on time from the mixer, the concrete will set inside the mixer and leave the customer with no other option than replacing the entire mixer.

Compressed air is utilized for cleaning the silos and also for dusting the deposits in the silo walls/lining during operation. If silos are not cleaned at regular intervals, the holding capacity of silos will be reduced due to the accumulated residues resulting in decreased output quantity.

Compressed air is used as an alternative for water to clean the silos. If water is used for cleaning, the silo must be dried before loading. This process takes ample time, thereby reducing productivity.

---

Productivity is key for a batching plant and as compressed air plays a critical role in this, choosing the right partner for compressor is imperative.

ELGi’s range of reciprocating compressors, designed with oil bath filters as a standard part of the machine to suit batching plants, has proven to be the right product for this application’s dusty environment. The oil bath air filters are designed to offer an excellent degree of filtration, capacity for prolonged use and minimum maintenance ensuring seamless compressor performance in any external environment.

![Criticality of Compressed Air in Concrete Batching Plant](/consultant/screw-compressor/application/000080.jpg)
    


The infrastructure sector is a key driver for any economy, especially for a developing country like India. It includes power projects, dams, bridges, roads, and urban infrastructure development.

As per industry reports, India is expected to become the world’s 3rd largest construction market by 2022. Furthermore, increasing the development of the National Highways and initiatives like “Smart City Mission” provide attractive opportunities and drives the growth of this sector.

Concrete batching plants have become an essential machinery and we can’t imagine any construction site without it. In the construction industry, producing high quality concrete in the right amount and delivering it on time is a challenging task. The right quality of concrete increases the reliability of any construction and this is being achieved with concrete batching plants.

Have we ever thought what is driving the concrete batching plants to deliver the right quality concrete on time? Yes, it’s compressed air!

Let us understand the concrete batching plant briefly before going into the usage of compressed air in its operation.

![Powering growth and development in infrastructure](/consultant/screw-compressor/application/000078.jpg)
    

Powering growth and development in infrastructure


The ready-made garment production industry is labor-intensive and has a fragmented supply chain. At a broader level, it starts with fiber selection, yarn and fabric production, and then, garment manufacturing.

Major operations of the ready-made garment industry fall under these three categories:

- Pre-production
- Production
- Post-production

**Pre-production:** This phase involves arranging materials, line planning, sample development and approval, sourcing, and production scheduling.

**Production:** During production, fabrics are spread, cut, bundled, and sewn.

**Post-production:** Post-production includes inspection, pressing, folding, and packing, making the garment ready to sell.

The labour dependent nature of cutting and sewing makes the readymade garment expensive. Fabric costs and cut-and-sew costs are two of the largest expenses in garment manufacturing. While raw materials contribute up to 50 to 60% of the total product cost, sewing contributes approximately 35% of the total cost.

Efforts have been made to lower labour costs through supply chain management by locating production facilities in developing countries like India, Bangladesh, etc. However, this strategy is becoming complex and difficult to sustain, forcing the industry to find alternative solutions. Thus, automating ready-made garment manufacturing processes are becoming the need of the hour!

Automation not only improves productivity, but also the quality of the finished product by minimising human intervention and preventing errors. Some of the automated techniques adopted by the industry includes:

- Mechanised fabric handling
- Computerised cutting
- Automatic sewing
- Use of robots

#### Compressed Air and the Garment Industry

“Compressed Air” plays a critical role in ensuring effectiveness of sophisticated automated machinery, helping manufacturers overcome persistent challenges like:

- Maximising uptime and productivity to meet demands
- Reducing operational and maintenance costs
- Preventing contamination due to air, water, and oil mixture

###### Automation in Sewing:

Sewing is the most important process but is still dependent on highly skilled labour for operations. With increase in labour costs, shortage of skilled labour, and ever-changing consumer behaviour pushed by fast fashion trends, the garment manufacturing industry is forced to strive for automated sewing.

Compressed air is critical for seamless sewing operations in functions like:

- **The Presser Foot:** It works with the feed to move fabric evenly through the machine. Air is used for lifting and lowering the presser foot for quicker action and improved productivity compared to manual control.
- **Thread Trimmer:** Excess thread must be trimmed post a stitching, before proceeding to further operations. Controlled by the compressed air system, a pneumatic chain-off thread suction device cuts the thread chain and collects dust. Compared to the conventional system of cutting the thread with scissors, these devices dramatically increase operational efficiency.
- **Cleaning: **Air is used for cleaning the stitching points at regular intervals to remove lint and dust from building up in the oil ports which form the lubrication system for the needle and presser foot.
- **Needle Cooling:** Needle cooling with compressed air increases productivity by facilitating continuous operation, unlike conventional machines which have to be stopped at regular intervals to let the stitching point cool.

###### How critical is Compressed Air in a sewing unit?

The stitching industry is moving towards three important aspects:

- Quality
- Productivity
- Energy Efficiency

It is imperative to invest in the right compressed air system to achieve the right quality of finished garment, improve productivity to maximise revenue and reduce energy costs and increase return on investment.

The quality of compressed air directly affects the end product. Missed stitches, damages to cloth, oil stains and lint are key sources of quality inhibitors.

Higher temperature of compressed air leads to slipped and staggered stitch.

Presence of moisture in compressed air causes corrosion over a period, leaving the stitching unit with no choice than to replace the entire system.

Contaminated compressed air causes oil stains to mix with the fabric and thread, leading to oil patches in the product and lint deposits in the needle.

Without compressed air cooling the stitching point, the machine must be stopped at regular intervals before resuming stitching. In the absence of compressed air, excess thread must be trimmed manually, costing 40% to 50% additional time for each piece of clothing.

###### Productivity can be increased considerably with the aid of compressed air.

![](/consultant/screw-compressor/application/000075.jpg)

Stitching units are growing in size, in terms of the number of stitching cells and have started looking at energy efficiency as one of the key parameters during machine procurement. For smaller stitching units using piston compressors, the energy consumed accounts to at least 30% of their total electricity cost.

![](/consultant/screw-compressor/application/000076.jpg)

ELGi’s reciprocating compressors are highly reliable; ensuring highest air quality, minimum downtime, and low life cycle costs.

With ELGi’s two-stage reciprocating compressor, a sewing unit operating 25 sewing machines can easily save up to 9% of their annual energy cost!

A leading Textile Company in Tiruppur uses ELGi’s reciprocating compressors in their cutting, sewing, embroidery, and printing division.

They claim that their production is now “seamless and without any niggles” and that they are clearly able to differentiate ELGi’s product quality compared to the compressor that they were using earlier. They consider ELGi as a “partner” offering not only a reliable product, but also excellent after-sales support.

With the right equipment, even the most difficult challenges can be turned into a profit-generating opportunity. By selecting the right brand and type of compressor to meet air demand and air quality; coupled with proper downstream equipment and FRL units, ready-made garment manufacturers can eliminate the root causes affecting the quality of the garment, improve productivity, and save considerable energy cost.
    

A stitch in time indeed saves nine!


The country’s pharmaceutical industry is expected to reach $55 billion by 2020.

![The country’s pharmaceutical industry is expected to reach $55 billion by 2020](/consultant/screw-compressor/application/000070.jpg)

As we can see above, India has a great role to play in this industry with skyrocketing progress in the near future. Quality consistency will be paramount to realise this growth.

#### The Cost of Poor Quality

In 2010, the US Justice Department ordered GlaxoSmithKline (GSK), the British pharmaceutical giant, to pay $750 million dollars for failing to prevent contaminations in their products Kytril, Bactorban, Paxil Controlled Release (CR), and Avandamet. The Department found that Bactroban, Kytril and Avandamet could be infected with microorganisms stemming from a contaminated production facility. For Paxil CR, an antidepressant drug, missteps in the manufacturing process resulted in the pills splitting into two, offering no therapeutic effect, while others did not have the controlled release effect.

In 2012, Schering-Plough paid USD 500 million towards settlement for violation of product quality norms arising out of poor manufacturing practices for its allergy medication Claritin. In September 2013, the FDA imposed a ban on Ranbaxy's drugs that may have included human hair and oil spots in tablets. While the punitive amounts may seem large, the damage is irreversible as it is impossible to trace consumers who may have suffered from these mishaps, thus making prevention paramount. Given that such manufacture involves compressed air at every juncture, oil and contamination free air is critical to making risk free products.

#### Applications of Compressed Air in the Pharmaceutical Industry

Compressed air is vital to the industry and its usage can be classified into two categories; Process Air and Direct Contact. Process applications employ compressed air for a specific kinetic activity. For example, during pill production, the uncoated are churned in a large drum as part of the coating process. Compressed air often drives the drum. Similarly, it plays a large role in the conveyance process. Direct contact entails the direct contact of compressed air with the application, thus making air quality critical. For example, compressed air is used to coat tablets to ensure their structural integrity. Impurities in this air will compromise the integrity and worse, contaminate the product. It is also critical in jet milling, where nitrogen is used to reduce active ingredients. Specifically, the powder is fed into a milling chamber where compressed air or nitrogen, usually in a vortex motion, promotes particle-to-particle collisions. Particle classification is made by inertia, following reduction via impaction and abrasion.

Compressed air is used for bottle cleaning to safely remove dust and small particles from containers before filling. The system is particularly suitable for removing loose contaminants that may have accumulated during shipping or storage. Containers first enter the rinsing area and are then bathed with ionized air generated by special transvector air flow amplifiers. The static charge that attracts debris to the surface of the containers is neutralized. Rinsing heads use a blast of compressed air to clean them. A vacuum collects the loose particles which are then disposed. As a final direct application, membrane technology with nitrogen generators uses compressed air forced through a polymeric hollow fibre to selectively permeate oxygen, water vapour and other impurities out of its side walls while allowing nitrogen to flow through its centre and emerge as high purity N2 gas.

#### Compressed Air Standards in the Pharmaceutical Industry

The amount of allowable oil in compressed air depends on its application. ISO 8573-1 (2010) classifies the quality of air based on oil content as Class 0 to Class 4. The table below is used as a guide for selecting the compressor based on the application requirement.

![Compressed Air Standards in the Pharmaceutical Industry](/consultant/screw-compressor/application/000071.jpg)

The following graphic summarizes the data collected from various industries in India and neighboring countries on the quality class of oil in compressed air. It depicts that industries such as foundry and sand blasting use lower quality (class 3 or 4) air, where air quality doesn’t affect the process or the product. Industries such as food and beverage, pharmaceutical and photography demand higher quality (class 1) as the quality of air directly affects the product quality. Though Class 0 is not figured in this list, industries are moving towards using this standard to improve and safeguard their product and process quality.

![The following graphic summarizes the data collected from various industries](/consultant/screw-compressor/application/000072.jpg)

*Table: 1.2. Details of application requirements vs Quality class of oil*

#### Generating Oil-Free Compressed Air

There is a growing industrial need for compressed air, free of entrained oil. For many requirements oil flooded screw compressors do the job with multi stage filtration. However, oil-free compressors are ideal owing to the hassle of pressure drops and added maintenance stemming from filter equipped lubricated compressors.

Popular compressed air systems include piston driven reciprocating compressors, screw or rotary compressors and centrifugal compressors. The rotary screw is the most widely used owing to its inherent reliability. These machines are available in a wide range of oil lubricated and oil-free versions. To understand the generation of oil-free compressed air, one must understand the role of oil in regular compressed air. Focusing on screw compressors, the heart of the compressor or the ‘airend’ works by two rotors or screws in an enclosed housing moving in opposite directions, sucking air from the atmosphere and compressing it for use in the end application.

As air travels through the airend, it is compressed to high pressure. Oil is injected into the compressed air and discharged from the compressor mixed with the air. The oil and air mixture is discharged into a gas and oil separator. After separation, the oil is cooled and filtered, then pumped back into the compressor housing, gears and bearings. In the prevailing (reciprocating and rotary) systems, oil serves as lubricant, sealant and coolant. So how do oil-free systems function without oil serving these critical functions?

In an oil-free screw compressor, an air cooler removes the heat from the compression chamber. Without oil, the rotors rotate at high speeds to get volumetric efficiencies equivalent to oil injected screw compressors. Timing gears synchronize rotation to ensure no contact. A separate lubrication system lubricates the timing gears. And finally, an efficient sealing system prevents the entry of lubricating oil into the compression chamber.

![Generating Oil-Free Compressed Air](/consultant/screw-compressor/application/000073.jpg)

*Typical assembly cut view of ELGi Oil-free airend used in oil-free compressor*

#### Quality By Design (QbD)

Pioneered by Joseph M. Juran, Quality by Design is an approach that helps prevent the occurrence of quality lapses in high risk industries such as drug manufacture. Design for quality and innovation is one of the three universal processes of the Juran Trilogy. The focus of this concept is on quality that should be built into a product with an understanding of the product and process by which it is developed and manufactured along with a knowledge of the risks involved in manufacturing and how best to mitigate them.

Applying this to oil-free air in the pharmaceutical industry, QbD principles would dictate design measures to prevent contamination in the delivered air. As an example, ELGi’s oil-free rotors employ a two-layer non-metallic coating and coating process to preserve the rotors. This coating comprises of PTFE + PFA (Poly Tetra Fluoro Ethylene + Per Fluoro Alkoxy), with PTFE on the first layer and PFA on the top.

PFA has layering and formation properties which ensure homogeneous coating and avoid the formation of pin holes. This enhances the coating reliability and provides highly efficient corrosion protection. In addition the coating serves as a dry lubricant. The coating’s food and medical grade certification ensures its safety for pharmaceutical applications. Though there is no oil injected into the compression chamber, the timing gears and bearings need lubrication through a separate system. This oil is prevented from entering the compression chamber with ELGi’s efficient internally designed sealing system comprising of floating carbon seal and viscose on each rotor. These are non-contact seals and their reliability is significantly higher than any other, hence ensuring continuous clean air supply.

#### The Future of Oil-Free Air

Rough estimates indicate that oil flooded screw compressors have expelled nearly 10 million liters of oil into the atmosphere over the past ten years. The amount is humbling given the growing stresses placed on the planet. Thus it is clear that oil-free air is set to grow in relevance not just for the pharmaceutical industry but for all applications. The current oil-free technology struggles to compete with traditional oil flooded machines. Given the higher rotor speeds, rotor complexity and increased parts for cooling, they’re typically more expensive and less efficient, causing crippling barriers for their adoption. To overcome this, companies such as ELGi are taking a two pronged approach. The first is a philosophical shift to no longer look at oil flooded and oil-free as distinct segments.  Secondly, to simplify current oil-free technology to reduce cost and improve efficiency, ELGi is working on water injection processes.

To reduce risks, ELGi has started delivering compressors with data transmitters. The sensors pick up variations in volume, pressure, temperature, moisture, etc., and feed this data back to the service and quality team to proactively address issues in the line. This technology will likely be extended to detecting air contamination, which can allow ELGi to partner closely with its customers in ensuring quality.

Compressed air will be relevant to the pharmaceutical industry for the foreseeable future. Oil-free compressed air will become more prevalent supported by design initiatives to improve cost and efficiency. Data will serve as a key enabler but more importantly, the suppliers and manufacturers need to work as a team to eliminate quality concerns.
    

Oil-Free Air in Medicine Manufacture


The reason for this is food. Fish, worms, snails and other aquatic creatures and water plants such as algae and reeds abound, an entire food web flourishing in the water. But the water also contains unappealing material of mineral and biological origin, making water bodies of wastewater.

#### WASTEWATER AND ITS TREATMENT

Wastewater refers to any water that contains pollutants as a result of human activity, subsequently possessing undesirable qualities such as colour, odour, turbidity and the presence of pathogens. There is industrial wastewater and domestic wastewater. Normally, the sanitary sewers in a city carry a combination of these wastewaters, called municipal wastewater. Sewage is wastewater from residences only. Rainwater, is usually carried in storm drains that are not connected to the sewer system, but a small portion of the runoff tends to leak into sewers.

![WASTEWATER AND ITS TREATMENT](/consultant/screw-compressor/application/000064.jpg)

*Wastewater being released directly into larger water bodies*

Laws in most countries prohibit the discharge of untreated wastewater directly into rivers, lakes or oceans. Toxic chemicals can kill or cause genetic defects in aquatic life. Heavy metals such as mercury accumulate in fish and affect the health of human beings who consume them. Pathogens cause illnesses when the water is used for recreational activities. They enter a city's water supply, which is not adequately treated and cause mass outbreaks, like the deadly 1993 Cryptosporidium outbreak in Milwaukee, USA , which sickened 400,000 residents and led to the death of over 100 people.

Organic materials serve as nutrients for bacteria, which consume dissolved oxygen in receiving streams, reducing their ability to support aquatic life. Wastewater must be treated to reduce the level of pollutants to within acceptable limits. Statutory bodies such as the Environmental Protection Agency (EPA) in the USA and the Central Pollution Control Board (CPCB) in India set the maximum levels allowed for various pollutants in the effluent from wastewater treatment plants.

Toxic inorganic chemicals in municipal wastewater are cyanides, asbestos and metals like chromium, lead and mercury, which are not biodegradable. Non-toxic inorganic chemicals are important because they alter the chemical properties of wastewater such as acidity or alkalinity and salinity.

![](/consultant/screw-compressor/application/000065.jpg)

*Toxic pollutants escaping a mine*

Organic materials are a mixture of many different carbon-containing compounds, and so the tests to measure them are non-specific. The three most commonly used tests are total organic carbon (TOC), chemical oxygen demand (COD) and biochemical oxygen demand (BOD). BOD is the primary measure, being the oxygen required by microorganisms to oxidise the organic material present.

There are many processes that can be used to remove pollutants from wastewater. These involve physical, chemical or biological methods. Processes that use only physical methods are called unit operations (UO) while those using chemical or biological methods are called unit processes (UP). They always contain primary and secondary treatment stages, while a tertiary treatment stage may be present if a higher-quality effluent is desired.

![](/consultant/screw-compressor/application/000066.jpg)

*An aerial shot of a wastewater treatment plant*

#### PRIMARY TREATMENT

##### Screening (UO):

Screening is usually the first step where coarse screens are used to remove large objects such as cans, bottles and sheets of paper which are not biodegradable and which could damage equipment.

##### Flow equalization:

Flow equalization involves the use of a basin in which wastewater is stored and provided with adequate aeration and mixing (to prevent odour formation and sedimentation).

##### Sedimentation (UO):

Sedimentation is used to remove suspended solids by means of gravity settling, using basins so the solids accumulate into a sludge at the bottom. Liquids that are lighter than water, such as oil, are skimmed from the surface.

![](/consultant/screw-compressor/application/000067.jpg)

*Air pumping stations at treatment plant*

#### SECONDARY TREATMENT

Secondary treatment removes organic material by biological treatment. Bacteria convert organic matter into carbon dioxide and water. Suspended growth treatment processes are those in which the microorganisms remain suspended in wastewater. In attached growth treatment processes, microorganisms are bound to a solid medium and remove nutrients as wastewater flows over them.

##### Suspended Growth Treatments

##### Activated sludge process (UP):

This is the most commonly used process. “Activated sludge” refers to the microbial culture that metabolises organic matter in the aeration tank. Part of the sludge is returned to the aeration chamber to continue the process. Air is supplied to the aeration tank by diffusion (using compressed air) or mechanical aeration.

##### Treatment ponds and aerated lagoons (UP):

Treatment ponds are forms of biological wastewater treatment. There are shallow aerobic ponds with only bacteria and algae, facultative ponds with layers based on oxygen content and deep anaerobic ponds with a lot of organic matter but hardly any oxygen as you go deeper. Aerated lagoons are ponds that are oxygenated by surface aeration or diffused air aeration.

##### Attached Growth

##### Trickling filters (UP):

These consist of a shallow layer of stones, covered by slime containing the microorganisms. Wastewater trickles from the top as the organic matter is removed from it. Oxygen comes from circulating air. The effluent contains biological solids which are separated in a secondary clarifier.

##### Rotating biological contactors (UP):

Using a similar principle as the trickling filter, they contain rotating discs covered by a layer of microorganisms. This process is said to be more efficient than the activated sludge process.

##### Nitrification/denitrification (UP):

Nitrogen is also an important pollutant that could cause algal blooms and needs to be removed. A nitrification stage may be a separate stage or combined with suspended or attached growth treatment. Here, bacteria convert nitrogen in the form of ammonia to nitrates which are removed by converting them to nitrogen gas. Other means of nitrogen removal include ammonia stripping, breakpoint chlorination, and ion exchange.

![](/consultant/screw-compressor/application/000068.jpg)

*Sludge separation at the treatment plants*

Now the water is clean enough to be discharged into waterways. The effluent may be reused for purposes such as drinking water, agriculture, non-potable water and so forth. Depending on use, higher-quality water may be required, so a tertiary treatment is performed by using processes such as filtration, carbon adsorption, reverse osmosis and electrodialysis.

##### Sludge digestion:

At treatment plants, disposal of the large amount of sludge created is an expensive task. The steps involved in sludge disposal are concentration, stabilisation, conditioning, dewatering, drying and combustion. Stabilisation or digestion may be carried out as an aerobic process – which is easier – or anaerobic process – which is cheaper.

Compressed air finds a number of uses in the treatment of effluents and wastewater. Air compressors connected to tubular diffusers provide dissolved oxygen for microorganisms in an aeration tank. The dissolved air flotation process uses air at a high pressure to bring impurities to the surface, where they are skimmed. A belt filter press is used for dewatering sludge, and the belts are pneumatically controlled. Air compressors are used to operate all valves and actuators in a wastewater treatment plant.
    


Water birds are among the easiest birds to observe, mostly frequenting open stretches of water with no obstructions, so they stand out. Sometimes water birds turn up in large numbers in urban areas. Remarkable looking flamingos, pink, long-necked and long-legged, flock to Sewri mudflats in Mumbai almost every winter. Pelicans, among the largest birds capable of flight and with extraordinarily large and extensible bills, have been sighted in recent years in the Pallikaranai marshes of Chennai. These large cities with intense human activity have water courses that are polluted. Why then do birds such as pelicans, flamingos and others congregate here?

![Water birds are among the easiest birds to observe](/consultant/screw-compressor/application/000063.jpg)

*Flamingos wade through muddy waters*
    

Wild Wild Waste!



These upgrades are not just about performance. These help reduced service downtime by half. And since we replaced two machines with one, it ensured additional space as well.

One of the key points from the feedback received was that the ELGi air compressors could operate in any environment and the newer compressor only elevated the belief because of better thermal management by:

- Providing a larger cooler that considerably lowers the oil temperature.
- The pre-filters fitted at air entry points into the compressors helping prevent entry of dust into the canopy and subsequently choking the cooler faster.

The upgraded controllers also offered better safety features over the older machines and operate with lesser noise.

Overall upgrading your older compressor with the newer premium series of EG compressors helps save power, better operational efficiency and reduces maintenance costs.

![Overall upgrading your older compressor with the newer premium series](/consultant/screw-compressor/application/000061.jpg)
    


#### CHALLENGE:

One of our partners in the paper manufacturing industry was looking for ways to reduce their energy consumption. They identified that their air compressor was a major contributor to their energy bill.

#### SITE ANALYSIS:

They had many decade-old compressors placed in various locations of their plant. The older compressors consumed higher energy. The machines were also becoming difficult to maintain due to short consumable replacement cycles and an increase in maintenance costs. And any new compressor would have to be rugged in to run in harsh temperatures with minimal maintenance checks.

#### SOLUTION:

After a comprehensive study, we recommended that two of their existing 75kW machines be replaced with newer, larger 160kW compressors as a preliminary change to accommodate their budget and to increase efficiency.

#### RESULT:

It has been 1 month since we replaced the machines, and the paper manufacturer has recovered over 55% of their investment only through power. The newer compressors which offer more features also operate with less noise and are built to handle harsh temperatures and conditions of the site.

Every equipment in use needs an upgrade. Not only does an upgrade bring changes to the equipment in terms of performance but also features.

When it comes to the environment, both the consumer and the manufacturer understand the impact of a product on the environment. Hence, there is significant effort taken to reduce the environmental impact of products.

Over the past decade, a lot has changed in compressors. The air-ends which are the heart of the compressors have been improved to provide higher compressed air flow and consume lower power. The primary mover of the air-ends, the electric motor’s minimum efficiency has been incrementally upgraded as well. The unload power and power consumed by the cooling fan has also been reduced significantly by controlling the flow of oil into the air-ends and the cooler. The controllers have become smarter and can identify running patters. They can also control multiple other compressors as well.

After analysis, ELGi recommended replacing 2 machines with a larger one as a preliminary effort.

Two 75kW units were replaced with one 160kW improved state of the art oil lubricated screw compressor. Not only did it help increase the compressed air output but also helped save electricity. this effort helped reduce CO2 emission (in tonnes). The details of the savings are as below:

![recommended replacing 2 machines with a larger one as a preliminary effort](/consultant/screw-compressor/application/000060.jpg)
    

ELGi helps a paper manufacturer save on power costs by replacing an old air compressor


Compressed air finds application in the finishing stages of leather at the company’s state-of-the-art tannery. A spray of compressed air is used to sanitize the leather surface by removing dust particles and other impurities. The dew point of compressed air is crucial here. “Any moisture in the compressed air can be detrimental to the leather. It could result in poor color or a patchiness that is undesirable. We have very strict specifications for the quality of air that comes in contact with our leather,” adds Mr. Ambarish.

Moving on to the production plant where the actual shoe is put together, the clockwork-like assembly line is composed of state-of-the-art machines and backed by expert leather craftsmen. The ideal production capacity of the plant is 7 million pairs of shoes per annum and the plant manages to reach 70-80% of its capacity –– at a whopping number of 6 million pairs a year, this is no mean feat. 90% of the tools and machines are controlled pneumatically. Consequently, the supply of compressed air is critical to the functioning of the plant.

![Sole stitching done by the hands of seasoned leather craftsmen](/consultant/screw-compressor/application/000057.jpg)

*Sole stitching done by the hands of seasoned leather craftsmen.*

“Our conveyors deliver over 2100 pairs of finished leather shoes per hour. If air compressors break down, production would stop immediately. Today, Red Tape shoes are available in over 300 prime outlets and 1200 shop windows all over the world, in addition to prominent e-commerce websites. The demand is high and we simply cannot afford to have any hold-ups,” Mr Ambarish points out.

Established in 1979, Mirza International Limited (formerly known as Mirza Tanners) has trusted ELGi for its compressed air supply. The company sources the machines from exclusive ELGi dealers in Kanpur, Auto Service Equipment. Mr Ambarish elaborates: “The plant utilizes 35 compressed air systems. We are extremely happy with the service. In case of downtime, air supply is restored within 90 minutes which is remarkable. It ensures smooth running of the plant and maximum output which is very important for us. In my 23 years of working here, we have never felt the need to hire in-house technical staff to inspect our compressed air systems. The ELGi team is always there to help us out.”

In 2016, after performing a thorough analysis of the ELGi compressed air systems installed, the technical team at ELGi recommended a brand new facelift for Mirza International Limited. ELGi set up their latest “Global Series” air compressors (EG75) at the plant. “After the installation, we have charted about 75,000-80000 INR of energy savings a month. That’s 15-20% of our total energy costs…a significant achievement,” says Mr. Ambarish.

![Seat lasting is a crucial step in shoe making that gives the ‘upper’ its shape](/consultant/screw-compressor/application/000058.jpg)

*Seat lasting is a crucial step in shoe making that gives the ‘upper’ its shape.*

Since the launch of the brand in 1996, Red Tape has garnered a premium brand status, both in Indian and international markets, especially in Europe. The brand boasts of a 25% market share in the middle-segment category for men’s shoes in the UK. With fashion experts, footwear and leather technologists as part of the team, the brand is known worldwide for its lasting quality, and compelling designs.

On being quizzed about the number of years ELGi has been in business with Mirza International Limited, Mr. Ambarish smiles and signs off, “Many, many years. ELGi was the first compressor installed at the tannery right at its inception around the 1980s. There has been no looking back ever since.” He hurries back to work as the air resonates with a low hum of the machines relaying one spectacular shoe after the other. The clockwork of the plant keeps ticking. Time, after all, is of the essence.
    


The air is heavy with the unmistakable scent of leather. Both man and machine move in tandem with a precision that is hard to fathom. In less than a minute, 24 conveyor belts churn out the Summer Spring 2017 collection of impeccably crafted Red Tape shoes. We’re in “Leather City of India”, Kanpur at the production plant and tannery of Mirza International Limited. One thing is immediately obvious –– time is of the essence.

The shoe business is serious business. With fashion trends changing at the drop of a hat, one cannot afford to blink and miss. From the runways of Milan to street style in Durban, international brands must keep their designs relevant across the globe. Mirza International Limited is India’s leading manufacturer and exporter of leather footwear and finished leather. Red Tape is their flagship brand of premium footwear with a strong presence in over 30 countries. At this level, the exigencies of the business are incessant.

“UK, USA, Europe, New Zealand, South Africa, Middle East….retailers everywhere keep changing collections to match global trends and demand new designs with a quick turnaround time. Enter the market too late and you could end up with dead stock,” says Plant Manager, Mr. Ambarish Srivastava.

Mr. Ambarish Srivastava has been working with Mirza International Limited since 1994. As  Plant Manager of their Kanpur unit, he helps keep a watertight system in place; ensuring maximum efficiency at every step of production from ‘raw to retail’. With more than two decades of experience in the leather industry, Mr. Ambarish knows the nitty gritties of the business. “Handling leather is an art in itself. The textures, the surface finishes, the natural imperfections are all hallmarks of genuine leather. We strive to preserve this quality during the process of treating the leather,” Mr. Ambarish elucidates.

![Strips of exotic leathers are artfully cut to in various shapes to form the top part of the shoe, called the ‘upper’](/consultant/screw-compressor/application/000056.jpg)

*Strips of exotic leathers are artfully cut to in various shapes to form the top part of the shoe, called the ‘upper’.*
    

It’s Shoe Business


Distilled from barley that comes from both Scotland and India, Amrut Fusion is a delectable marriage of the east and west. Named after India’s mythological elixir of life, the whiskey creates a symphony of flavours in the palate and has won the hearts of many a connoisseur.

Amrut is now available in 43 countries that includes famous retailers such as Harrods, Selfridges, Fortum and Mason in London, and Park Avenue Liquor Store in New York. As the single malt jostles for space among other whiskey greats in bars and collectors’ homes around the world, the Amrut distillery in Bangalore is modernising itself to cater to increased demand.

Located in Kambipura, along the Bangalore-Mysore highway, Amrut’s distillery produces four million cases of liquor a year, of which about 25 percent is blended whiskey and around 25,000 cases are single malts. Besides Amrut Fusion, the company produces 30 different expressions of single malts that are export oriented.

The company relies heavily on ELGi air compressors across the various automated processes in its distillery to speed up production, reduce inefficiencies and maintain quality standards. “To make a world-class product, our processes must have high accuracy, quality and reliability. It is critical for us to meet our production targets so that our products reach our customers around the world on time. ELGi compressors that power our hydraulic and pneumatic based automated systems have helped us a great deal in achieving these targets,” says KP Sushanth, Deputy General Manager, Maintenance, Amrut Distilleries.

![Located in Kambipura, along the Bangalore-Mysore highway](/consultant/screw-compressor/application/000054.jpg)

Earlier workers would manually rotate the control values during production, with the result that the quality of the output varied from batch to batch. With automated systems, the company can now be assured of consistent quality.

Amrut’s relationship with ELGi goes back 20 years, when it acquired its first ELGi compressor. Today, the company employs a range of ELGi products in its facility including EG 22-10 and EG 11-10 from ELGi’s Global Series screw compressor range, TS 05 HN 220 industrial reciprocating compressors, and E 11-10 from the Horizon Series screw compressors.

“Advanced screw compressors from ELGi are highly energy saving and have helped us reduce our operating costs. We can keep the compressor in an unload mode which consumes minimal power and load it back up on demand. It is of particular importance in a distillery like ours that is operational 24 hours, 365 days a year,” said Mr. Sushanth.

The company is now planning to automate its packaging process and is considering upgrading some of the older compressors with more advanced versions. With ELGi’s innovative compressed air solutions keeping up with the times, we’re more than happy to raise the bar!
    


*“Too much of anything is bad, but too much good whiskey is barely enough.” - Mark Twain*

Blended with the finesse of an artist and aged in oak, whiskey evokes a kind of romanticism that no other drink (except wine, perhaps) can match. This golden liquid attracts collectors from across the world; some willing to spend over $500,000 on a single bottle! It is no wonder that distilleries across the world are competing to craft the perfect glass of whiskey that could be destined for greatness. Air compressors are aiding in modernisation, helping distilleries increase production and achieve higher quality standards.

When you think of the world’s finest distilleries, the mind wanders to the highlands of Scotland and Ireland. But that changed over the last decade when an unlikely contender emerged in the global market — Amrut Whisky. The company’s flagship single malt, Amrut Fusion has won accolades for its distinctive aromas: American magazine, Whisky Advocate, called it the “world whiskey of the year” and acclaimed whiskey writer Jim Murray rated it the world’s third best single malt in 2010.

![Blended with the finesse of an artist and aged in oak](/consultant/screw-compressor/application/000053.jpg)
    

Raising the Bar


##### What is urea?

Also known as carbamide, carbonyldiamine or amino methanamide, Urea is an organic compound with two amides joined by a carbonyl functional group.

In smaller amounts, urea is present in the blood, liver, lymph nodes and serous fluids, and in the waste of fish and many other lower species.

Urea was first produced industrially by the hydration of calcium cyanimide. When combined with carbon dioxide, it resulted in the formation of ammonium carbamate which could then be dehydrated to urea.

#### AGRICULTURE

- **Fertilizer:** 90% of the urea produced is used as fertilizer. It is added to the soil to provide nitrogen to plants. Low-biuret (less than 0.03%) urea is used as a foliar fertilizer. It dissolves in water and is applied to the leaves of plants that yield fruit, especially citrus.
- **High nutrient content:** Urea’s rich nutrients are essential for metabolism in plants. It helps in the absorption of light during photosynthesis.
- **Multiple applications:** Urea is added to the soil after harvest to help retain its nutrient content. In the soil, it hydrolyses back to ammonia and carbon dioxide. The ammonia is oxidized by the bacteria in soil to nitrate, which can be easily absorbed by plants.

![What is urea?](/consultant/screw-compressor/application/000050.jpg)

#### CHEMICAL INDUSTRY

Urea finds application as a raw material in the manufacturing of many important chemicals including:

- Various plastics, especially the urea-formaldehyde resins
- Adhesives, such as urea-formaldehyde or the urea-melamine-formaldehyde used in marine plywood
- Urea nitrate, which is used as an explosive

#### AUTOMOBILE SYSTEMS

Urea is used in SCR (selective catalytic reduction) and SNCR (selective noncatalytic reduction) to reduce the nitrogen pollutants in exhaust gases from combustion, eg: in power plants and diesel engines.

#### COMMERCIAL USES

- A component of animal feed, providing a relatively cheap source of nitrogen to promote growth
- An ingredient in many tooth whitening products
- An ingredient in dish soap
- An ingredient in some hair conditioners, facial cleansers, bath oils, skin softeners, and lotions
- A reactant in some ready-to-use cold compresses for first-aid use, due to the endothermic reaction it creates when mixed with water
- As a solubility-enhancing and moisture-retaining additive to dye baths for textile dyeing or printing laboratory uses

#### DE-ICE

Urea is a safe, non-corrosive fertilizer alternative for de-icing. The chemical is easy to use on runways and walkways as well as on landing gears and other vital parts located on the under-carriage of aircraft that must always be protected from corrosion.

However with compressed air at 160-180 Bar pressure this stainless-steel layer, which generally contains up to 24% chrome, forms a very resistant brownish Cr03 layer which keeps the oxidation and corrosion in equilibrium and protects the inner layer of the reactor from getting corroded.

#### Passivation air compressors – ELGi Sauer

ELGi Sauer has recently supplied 2 x 100 m3/hr Passivation Air Compressors to 2 Fertilizer projects coming up in the north of India having production capacities of 2200 TPD ammonia and 3850 TPD urea.

![Passivation air compressors – ELGi Sauer](/consultant/screw-compressor/application/000051.jpg)
    


Population expansion, excessive resource utilisation and reclamation of land for settlement have primarily resulted in the loss of nutrient content in ground soil. Owing to this change in composition, it has become impossible to cultivate land for crop without the use of fertilizers*.

**The most well-known is urea, a white crystalline substance, made up of 46% nitrogen.*

![](/consultant/screw-compressor/application/000049.jpg)
    

Compressors support increased production capacity of your fertilizer plant


The passion for chocolate led the Bramardi management to select the best cocoa qualities like Criollo and Trinitario from Central and South America, Madagascar and Ghana to create a blend that gives the chocolate a unique and distinct flavour.

#### But how is chocolate made?

**We start with the mixing process:** The cocoa paste, obtained from the processing of seeds selected by the master Chocolatier, is mixed with other ingredients to obtain the dark, milk or white varieties.

#### We then move on to CONCHING:

The ingredients’ blend is mixed for a long duration in special mixers called conches. This process takes place at a controlled temperature, just enough to keep the mixture liquid, taking care to smoothen out the lumps and make a perfectly smooth and homogeneous mass. Conching among other things, also helps oxidize the tannins.

#### Then comes the TEMPERING process:

Since cocoa butter tends to crystallize in a polymorphic and irregular way, the mass of melted chocolate must be cooled cautiously to get the desired crystallization. This helps produce chocolate that breaks, but also melts softly.

![Then comes the TEMPERING process:](/consultant/screw-compressor/application/000046.jpg)

The resulting chocolate can be used to make molds with a classic tablet shape, used for coverings or in case of Bramardi chocolates, to coat an even more precious filling. The heart of chocolates is prepared by slowly grinding toasted hazelnuts first, then the cocoa and sugar in the old cold- mixing stone mill. The result is a paste with a tempting fragrance that is further refined, conched and tempered to make it velvety and pleasing to the palate.

The chocolates are produced by extrusion: The chocolate structure is placed on the ribbon of the production line by a nozzle similar to the classic pastry bag of the pastry chef. The chocolate mixture has to be perfect, to make it stand.

![And what role does compressed air play in this process?](/consultant/screw-compressor/application/000047.jpg)

#### And what role does compressed air play in this process?

Compressed air is used to operate various machines reliably and constantly. Like in the case of conching- where a single operation goes on for days.

Mr. Franco Beccaria, heir of Founder Bramardi and owner says, “I am an artisan and am concentrated on making savory chocolates. I know nothing of compressed air. For me, a good compressor is a machine that you install and forget. ELGi has been a good choice, it performs and stays quiet at work. So, I can concentrate on my craft.”

The experience, the careful selection of raw materials, the knowledge of the gestures necessary to obtain a superlative result, in order to transfer the gesture in the machine and feel its correctness during the process are important to making chocolate. The artisans may rely on machines for these. For other processes, like the tempering on a marble table, the skilled hand of the craftsman does not want to be replaced.
    


Who hasn’t dreamed of finding the Golden Ticket to enter Willie Wonka’s Chocolate Factory? Well, while most us know of Roald Dahl’s book or the popular film with Johnny Depp, the first version with Gene Wilder came out years ago.

Our Chocolate Factory is a large, award-winning artisan laboratory located in Cervasca in the Province of Cuneo, North-West of Italy. A land that, like Switzerland and Belgium, boasts of a century-old tradition of chocolate making. The famous Gianduiotto was also born on the slopes of the Alps, on the Italian side. The founder Giovanni Bramardi, after a long experience as a confectioner in Paris, opened this workshop for chocolate production.

![](/consultant/screw-compressor/application/000045.jpg)
    

ELGi and the Chocolate Factory


##### Coffee is a form of art

Coffee beans are grown in over 80 countries, making this beverage extremely diverse in flavour and texture. From Colombia and Ethiopia to Brazil and Jamaica, these countries possess adequate climatic conditions to produce the highest quality of coffee. After harvest, coffee undergoes numerous cleaning and sorting operations until it is finally ready for market.

Coffee making is a form of art, let's go to the origins of where it all began.

##### The origins of coffee

Coffee is a wonderfully popular beverage that dates back centuries to its origins in Ethiopia. Here, it flourishes as undergrowth in cool and shady woods at altitudes of 1,300 to 1,800 m above sea level.

Raw coffee grows on the branches of the coffee plant in tropical and sub-tropical regions. It can grow up to 10 m in height. The fruit of these plants contains two kernels, which are the coffee beans. The main varieties are Arabica and Robusta.

Coffee roasting began in the 13th century. It is a heat process that causes chemical changes in the beans, bringing out the aroma, colour and flavour. Depending on the desired flavour and aroma required in a coffee blend, coffee roasters mix together coffees of different origins, types and quality. They also preserve coffee either as whole beans or granulated powder in specialised packaging, to create -lasting freshness, for whenever you brew a pot of this roasted beverage.

![The origins of coffee](/consultant/screw-compressor/application/000042.jpg)

##### Packaging is key

Oxygen is excluded from the packs either by evacuation or by replacing it by an inert gas (nitrogen) in normal air, since the greatest threat of coffee is oxygen and humidity.

##### Nitrogen generators in coffee packaging

An essential aspect of the coffee packaging process is flushing the bag with nitrogen. Nitrogen in its gaseous form is injected into the bag, where the coffee beans are placed, displacing the oxygen and moisture from within. Nitrogen plays a key role because of its inert properties, which means it does not interact with the oils in the coffee as oxygen would.

This flushing of coffee is performed with the help of compressed air

Since this process eliminates any presence of gases in the packaging, the freshness of the coffee is preserved, offering the fresh and invigorating experience even for months after it is packaged in the factory. Another benefit of this process is its ability to provide the same aromatic experience, which is especially anticipated by coffee connoisseurs.

![Nitrogen generators in coffee packaging](/consultant/screw-compressor/application/000043.jpg)

##### What about the carbon-dioxide released by the coffee beans?

In the process of roasting coffee beans, the carbon dioxide from the beans is released. However, most of the carbon dioxide remains intact and is slowly discharged over the next couple of weeks after baking.

In the packaging process, freshly roasted coffee beans are placed in a bag containing a button-like object at the back of the packaging, which may have a hole called a gas valve. The purpose of this is to let the carbon dioxide out of the packaging and reduce the aging process of the beans.

The gas valve is a one-way air valve and hence prevents any outside air from penetrating into the bean bag and affecting the quality of beans. The trick to that freshly roasted aroma when you open the bag is the removal of all oxygen, humidity and air that may destroy its quality.

##### Whipping up a Dalgona coffee

The Dalgona coffee trend which became a craze around the world, has an interesting knack to it! The top layer of the coffee is made by repeatedly beating coffee, sugar and hot water, until it becomes airy, which makes the resultant mix super light, sitting atop the milk.

So, as it turns out the key to your perfect Dalgona coffee is air!

The next time you pour yourself a nice hot (or cold) brew, let the aroma sink in, let the taste fill your senses and then you'll know your coffee has been in good hands, courtesy compressed air.
    


t is a beautiful October morning and you wake up to the smell of wild lilies porched in your little garden space, with young birds announcing the break of day. You draw the curtains and allow the morning rays to warm your face, before you turn on the coffee machine, pick a cup with a happy quote – “Be kind” and pour yourself an extra generous cup of freshly roasted coffee.

“Umm I'm ready to take on the day!”

There is nothing more inviting than the aroma of coffee, a wake-up call to the morning chaos, fuel to keep you going for the rest of the day. This conversational beverage will warm you up to every social interaction, whether an important business presentation or a quick catch up with your buddies!
    

The key to your perfect brew is air!


With ease in operations, ELGi's models of electric portable compressors come with a globally patented eta-V screw profile airend. This ensures maximum energy efficiency and significant savings in energy cost.

The compressor's unified oil cooling system offers quick and easy oil circulations for operations of longer duration with less static restriction and a higher transfer rate.

Power-packed with reliable control ensuring smaller footprint design, its service-friendly motors assure 30% to 40% savings over operational costs with reduced maintenance intervals. What's more, this series of compressors, with an energy-efficient screw profile, is built for high performance and greater airflow to drive applications.

Additionally, this machine is also equipped with an integrated pre-cleaner feature, which is best suited to withstand the dusty environment in blue metal, granite, and marble quarry applications.

![Sandblasting - Blue metal quarry](/consultant/screw-compressor/application/000037.jpg)

![Granite quarry - Marble quarry](/consultant/screw-compressor/application/000038.jpg)

#### Here are some pictures of the application on site:

![LD 4 drilling - Jack hammer](/consultant/screw-compressor/application/000039.jpg)

![Sandblasting - Crawler drilling](/consultant/screw-compressor/application/000040.jpg)

When it comes to emission concerns, electric portables are always superior since they generate lesser emissions and noise. On the other hand, diesel-powered portable compressors produce extra toxic gases and other pollutants, leading to a variety of climate changes and health issues.
    


ELGi's eco-friendly electric compressors set a new standard in the portable air segment. With advanced technology and a compact footprint, ELGi's Electric Series is an environmentally friendly product that ensures minimal emissions.

![Portable electric air compressors](/consultant/screw-compressor/application/000036.jpg)
    

Portable Electric Air Compressors - versatile machines for mining applications


#### Pump Storage Plants

At times of low electrical demand, excess generation capacity is used to pump water into the upper reservoir.

When the demand rises, the water is released into the lower reservoir through a turbine which generates electricity. This reversible turbine/generator assembly plays the dual role of a pump and turbine generator.

Once the evaporation losses from the exposed water surface and conversion losses are taken into consideration, close to 70-80% of recovery can occur. This technique is currently the most cost-effective means of storing large amounts of electrical energy.

Apart from generating hydroelectricity, pumped storage units find their application in pumping stations to supply river water for upland irrigation, industrial use and, generating drinking water.

#### Use of Compressed Air in Pump Storage Plants

In pump storage plants, the turbine and generator are operated in the reverse direction of the pump water from the lower reservoir to the upper reservoir during lean periods of power consumption.

This is achieved by the **Draft Tube Water Depression System.**

This process utilizes the high-pressure compressed air to depress the water below the runner of the turbine. Thereby, this compressed air allows the unit to motor with minimum power consumed from the system as it is spinning in the air as opposed to the water. Then, the wicket gates are opened to begin the pumping action as indicated below:

![Air forcing the water down - Power generation mode](/consultant/screw-compressor/application/000032.jpg)

![Wicket gates closed - Wicket gates open power generation mode](/consultant/screw-compressor/application/000033.jpg)

#### ELGi Sauer Compressors

ELGi Sauer is a joint venture between ELGi Equipments India and JP Sauer & Sohn Germany. This conglomerate caters to the needs of high-pressure applications in India and the subcontinent regions.

Over its 12 years, ELGi Sauer has developed a range of compressors suited for hydro power generation and has spearheaded installations with all the major hydro power companies in India and executed key projects locally and internationally.

![ELGi Sauer Compressors](/consultant/screw-compressor/application/000034.jpg)
    


Globally, India stands 5th in the installed hydroelectric power capacity.

According to the report, ‘All India installed capacity (in MW) of power stations' published on 31st March 2020, India's installed utility-scale hydroelectric capacity was 46,000 MW. This accounted for 12.3% of its total utility power generation capacity.

In the future, it is estimated that India's hydroelectric potential shall reach up to 148,701 MW. Furthermore, it is said that an additional 6,780 MW from smaller hydro schemes which have capacities of less than 25 MW can be deemed as exploitable.

Apart from this, a total of 56 sites for pumped storage schemes with an aggregate installed capacity of 94,000 MW have also been identified.
    

The future of hydro power generation


![](/consultant/screw-compressor/application/000026.jpg)

**Compressed air in the textile industry** A reliable source of compressed air is needed at all levels of the supply chain in a textile manufacturing industry for effective and smooth operations.

- Power looms, spinning machines and other equipment used to process fabric require varying degree of compressed air
- Compressed air also powers tools to keep the equipment clean and in good and working condition
- The use of oil-free compressed air ensures safety standards are met and the output is free from contaminants.

![Compressed air in the textile industry](/consultant/screw-compressor/application/000027.jpg)

##### Oil-free compressed air

There is a growing demand for protective textile products, and therefore the need to maintain quality and sterility in these processes. Selecting the right compressed air systems becomes crucial here to meet the ISO standards and legal requirements while ensuring savings of cost and energy. Class 0 Oil-Free air guarantees 100% clean air for your systems, without any contaminants and disruptions.

#### Benefits of ELGi's compressed air systems

We understand the functioning of your processes and the need for prompt action and support.

While ELGi's air compressors come with multiple benefits for your industrial applications, our services and maintenance solutions are a great way to safeguard your compressor against untimely and costly repairs, and to ensure that it runs with maximum efficiency.

![While ELGi's air compressors come with multiple benefits](/consultant/screw-compressor/application/000028.jpg)

Maximum uptime for your equipment, without any process disruptions.

![Maximum uptime for your equipment, without any process disruptions.](/consultant/screw-compressor/application/000029.jpg)

With low cost of ownership and emphasis on productivity and efficiency, when your compressed air system works at its optimal best, you make savings in cost and energy in the long-term.

![With low cost of ownership and emphasis on productivity and efficiency](/consultant/screw-compressor/application/000030.jpg)

ELGi air accessories and genuine spare parts come with an added sustainable advantage. The waste from the compressed air system is treated before it is released into the environment, minimising waste treatment costs. We work together with businesses to help them achieve their sustainable and cost-saving goals. Technology and innovation at ELGi have enabled us to evolve with changing trends. While our products undergo continuous improvements, our service team is also ready to help you restart your business, while maintaining strict safety and sanitization measures.
    

The year 2020 has seen unprecedented times, and while most manufacturing setups and production facilities are still trying to revive their processes and capacities, they must prioritise safety, sanitization, and social distancing over optimising output. In our fight against the Coronavirus, PPE products have become an essential requirement for the protection of every individual at the frontline, from doctors & medical staff, to policemen, cleaning staff and security & delivery personnel. Textile units have started allocating their resources towards the production of such protective gear, adjusting to the needs of a changing world.

Protective textiles for the safety of frontline workers


##### Let's take a look at each of these methods:

- **Air-atomized applicators** are highly flexible and can be used on almost any kind of substrate, as the equipment can be adjusted and customized to suit the needs of the operator. Air-atomized applicator consists of a traditional spray gun that combines compressed air with liquid paint to create a pressurized mist that coats the surface.
- **Airless spray** propels paint particles at a lower velocity than conventional air-atomized equipment, so there is less loss of paint through overspray. In this method, rather than mixing liquid paint with compressed air, airless application equipment simply forces the liquid coating through a narrow opening to create pressure.
- **In High-volume, Low-pressure (HVLP) technique** the paint is released at a lower velocity, yielding less overspray and blowback than conventional air-atomized equipment. The HVLP spray equipment utilizes spray gun atomization technology that propels large quantities of low-pressure air to the gun applicator.

While there are clear visible benefits in Airless and HVLP spraying, they require advanced skill on the part of the operator, making Air-atomized spraying technique the widely preferred one.

##### Design of a spray gun

Paint applied by a spray gun must be even and should not drip, hence the nozzles of spray guns are designed for handling expanding, non-turbulent volume flow with high exit speed.
Spray guns can also have flat, broad or round spray nozzles to suit different applications.

##### Types of spray guns & the compressed air requirement

Type of spray, consistency and quantity of paint to be applied determines the operating pressure and the nozzle diameter of the spray gun which in turn determines the compressed air requirement. Typically, spray guns require compressed air in the pressure range of 2 to 6 bar with an average air consumption ranging between 10 to 20 cfm.

##### Factors to be considered when sizing your compressor:

A reliable compressor is key to achieving high quality paint finish consistently.

- When it comes to sizing air compressors for painting, **operating pressure** and **flow** offered by the compressor, are the critical factors to be considered.
- The next critical factor to consider is the **compressed air quality** that the painting application demands. Quality of air is defined based on accepted levels of contaminants such as water, particles and oil. The air produced by any compressor, contains the same substances as the ambient air. This means that apart from dust particles, the RH factor in the ambient air contributes to water vapor and the oil used in the compressor for lubrication purpose also gets carried along with the compressed air.

It is recommended that the humidity is reduced by drying the compressed air with a refrigerant dryer, and particulate filters are installed, to reduce the amount of dust particles present in the compressed air.

An activated carbon filter can also be used to ensure there is no oil in the compressed air system. When supplementing other filters with an activated carbon filter, one achieves a quality called "technically oil-free" compressed air.

ELGi offers a wide range of oil lubricated and oil free Reciprocating and to choose from, along with the downstream equipment to suit vast range of applications. Our extensive network of authorized channel partners across the world can help to choose the best compressor model suiting your painting applications.
    


Your first impression always leaves a lasting impression on your customer!

In business, visual cues play a key role in creating customer delight and facilitating purchase decisions. While performance & utility of the product is important on one end, aesthetics can in fact make or break your product's future.

One such method of “selling an aesthetic experience” to customers is Spray Painting- making it the most prevalent paint application technique due to its versatility and economic viability.

Compressed air plays a vital role in spray painting and there are multiple methods involved in the spray painting process including Air-atomized applicators, Airless spray, and High-volume, low-pressure (HVLP) spraying.
    

'Spraying' the impact of compressed air in manufacturing


#### What are PSA oxygen plants and how do they function?

The air around us is composed of 78% Nitrogen, 21% Oxygen and 0.9%of Argon among trace elements of other gases. To separate oxygen from the other components of air, oxygen plants play an instrumental role.

To put it simply, oxygen plants are systems, which are designed to produce oxygen by separating it from other components of air.

In PSA oxygen plants, a technique called 'adsorption' is used to make this separation. This relies on the phenomenon that each gas is attracted to different solid surfaces in varying degrees.

For supplying medical oxygen, PSA oxygen plants compress the atmospheric air with an air compressor. This compressed air is then pushed under pressure through a vessel, which has a bed of zeolite, a material to which other air components have a higher degree of attraction towards, as compared to oxygen. The gas, which then comes out of the vessel, is oxygen viable for utilization on patients.

![What are PSA oxygen plants and how do they function?](/consultant/screw-compressor/application/000023.jpg)

#### The key advantages of PSA Oxygen Plant in critical times

In the current scenario, PSA Oxygen Plants provide essential assistance in the following ways:

##### Transportation

One of the biggest challenges faced by healthcare centers is transporting oxygen from one place to another. In situations where patients need critical air supply, if delivery of the oxygen cylinders is delayed, it could be too little, too late. However, with an in-house oxygen plant, healthcare institutions can save on the transportation time and take care of the essential supply of oxygen, as and when required.

##### Safety

Due to their high potential for inflammability, taking care of oxygen cylinders can also be a safety issue and can be risky for healthcare centers. In comparison to that, oxygen plants are a safer solution as the risk of high-pressure inflammability is much lower.

##### Sustainability

With ambient air as its raw material, PSA Oxygen Plants are a sustainable option for healthcare centers and can be set up in a short span of time.

##### Savings

Apart from the initial set-up cost, the PSA Oxygen Plants are a cost-effective option as they ensure higher savings on monthly medical oxygen bills, unlike oxygen cylinders which are costlier.

#### Conclusion

At ELGi, we're always committed to aid the healthcare sector at every step of the way. Currently, in addition to ensuring smooth flow of services to our customers across the globe, we are providing assistance to supply air compressors for such oxygen plants, so that critical patients receive timely supply of oxygen. We are working closely with several manufacturers of oxygen plants to ensure on-time delivery and maintenance of the system.
    


In India, the second wave of the COVID-19 pandemic had brought with it an unprecedented set of challenges to the healthcare sector.

From constraints in providing adequate treatment, to a lack of supply of medicines- Hospitals across the country were reeling from the impact of a cataclysmic crisis. The biggest challenge that the COVID-19 pandemic had brought with it, is the lack of oxygen supply to patients who need utmost critical care. More than the lack of oxygen cylinders, hospitals faced difficulty in transportation due to logistical constraints.

This is why, as a timely solution to mitigate the severe crisis, the Defence Research and Development Organisation (DRDO) had committed to set up PSA oxygen plants, which would resolve the issue of the supply constraints.
    

A commitment to providing critical solutions in times of need


An aspiration or a necessity, we've all grown up with the idea that being independent also meant possessing a plush four or two-wheeler to carry the enthusiasm of our dreams and take us on an adventure around the world!

But what makes an automobile the thing of dreams?

#### High-quality equipment for a high-quality vehicle

Automobiles have been engineered into the modern-day way of life, which is what has driven many manufacturing feats and innovations and changed the face of the entire industry for the better. Manufacturers today can supply consumers with safer, more fuel-efficient and reliable vehicles owing to the improved manufacturing practices through the use of compressed air systems.

![High-quality equipment for a high-quality vehicle](/consultant/screw-compressor/application/000020.jpg)

#### Application of compressed air in the automotive industry

Compressed air is used in almost every process in the auto industry, from engine construction to vehicle assembly, painting, and cleaning.

The typical uses of compressed air in automotive manufacturing include:

- Air operated robots
- Cutting and welding
- Painting and finishing
- Tire inflation
- Assembly

Today, automobiles are manufactured with lightweight materials, including plastics.

During assembly, compressed air tools power various processes including lifting, positioning, moving, stamping, etc.

- Assembling of the components of the vehicle is done using machinery, which does most of the heavy lifting. Multiple tasks can be completed efficiently and effectively, including small tasks like fastening component screws.
- Once assembled, the cleaning and painting processes are completed with the help of compressed air. The assembled vehicles move along the production line on conveyor systems using compressed air, as well.

#### Auto body shops & garages

In smaller auto body shops and garages, compressed air finds application in the process of painting and cleaning. Low pressure oil-free compressed air is utilised to operate spray guns, which provide a smooth finish across the body of the vehicle.

Body shops may also use a compressed air dryer and coalescing filters to remove any naturally occurring moisture.

#### Compressed air solutions from ELGi

A trusted solution for partners from across the globe, the EG series air compressors from ELGi are highly efficient, reliable and have a long life. These features of the air compressors support the automobile industry in manufacturing top of the line vehicles!

![Compressed air solutions from ELGi](/consultant/screw-compressor/application/000021.jpg)
    

Need a ride?


Automotive production
In automobile manufacturing, air compressors are primarily used for:

Operation of pneumatic robots
Welding and plasma cutting
Tyre inflation
Driving machines that lift, move, position and fasten auto parts
Body painting
You need to determine the total load profile of such applications to select an air compressor that can effectively power them. The factors that help in making correct calculations are:

Review of historical power consumption records
Checking the load on pneumatic systems
Counting the number of equipment that need compressed air
Being mindful of future plans for purchasing new compressed air operated machines and their collective requirement.
Such observations help determine the average airflow (CFM) and air pressure (bar ) required for daily operations, the maximum possible demand and requirement during a low production phase.

Automotive servicing and repair
Workshops need air compressors to paint vehicles, inflate tyres and operate equipment such as nibblers, power grinders, wrenches and sanders.

The amount of air volume essential to perform such tasks varies widely. While some processes need merely 2.5 CFM of airflow, there are others that demand 20 CFM  or higher airflow from an air compressor. Usually, heavy-duty jobs such as sanding and painting have higher airflow requirements, whereas vehicle body cleaning and tyre inflation need lower volume.

In terms of pressure range, most air operated tools need 6.2 bar for proper functioning. Paint guns have a lower requirement, ranging between 2.4-4.1 bar. On the higher side, tyre inflation demands around 8.9 bar and truck jacks demand 11.4 bar.

Generally, air compressors with the highest standard operating pressure settings of7 bar, 8 bar, 10 bar or 12 bar can be used to manage the different mechanical tasks in automotive workshops.

You should also remember that air compressor systems offer higher airflow at low pressures and lower airflow at high pressures. Therefore, choosing the correct pressure is essential to ensure that you have an adequate airflow metric to power all your equipment. For example, if you have a tyre inflating machine that needs  8.9 bar while all other air tools need just 6.2 bar, consider buying a unit that can compress air to 10 bar or higher. Additionally, use a pressure regulator to help feed the air tools with the required 6.2 bar.

Applications that need oil-free air compressors in the automotive industry
In many pneumatic tool operations and applications such as tyre inflation, where a minor presence of oil particles is not detrimental to the job, an oil-lubricated air compressor serves the purpose. Also, modern oil-based air compressors come with custom filters and dryers that purify and drain the compressed air to keep the associated tools free from traces of oil and dirt.

However, when you need the air to be absolutely dry and clean, it is better to opt for oil-free air compressors tailored for specific industrial uses. The major applications that need oil-free compressed air systems in the automotive industry include:

Vehicle assembly - Pressurised air helps operate vehicle assembly robots and pneumatic equipment like nutrunners.

Car surface cleaning - Dirt-free and dry compressed air is used to clean the metal surface of a car's body before coating it with paint.

Spray painting - Clean compressed air also enables spray painting through paint guns and robots onto the pre-cleaned surfaces of a vehicle's body.

Using an oil-free air compressor for such processes, you will avoid damaging the equipment and costly replacements or downtime that follow such damage. In painting jobs, oil-free air compressors prevent the adhesion, beading and cracking of paint on the car's surface to give a smooth and corrosion-free finish.

To sum up, while air compressors are the multitaskers of the automotive industry, choosing the right unit will depend on the existing scale of operations and your plans for expanding in the future.

![](/consultant/screw-compressor/application/000018.jpg)
    


The global automotive industry has undergone significant transformation over the past two decades. From the electrification of cars and two-wheelers, to self-driving and connected vehicles - technology is changing the way we drive and maintain our automobiles.

However, the basic vehicle manufacturing practice has largely remained the same. Different parts of a car, passing through production lines, are assembled by skilled workers or automated robotic processes. Air compressors are key devices that power the equipment used in vehicle assembly and the servicing and maintenance of finished products.

Choosing a suitable compressed air system for automotive applications depends on the volume and air pressure required for the concerned tools. These can vary widely across manufacturing plants and workshops:
    

Choosing an air compressor for automotive applications


##### Operation theatre

Medical-grade compressed air, free from contaminants such as oil, dust particulates, bioburden and water vapour, is administered to patients for anaesthesia and inhaled medications during surgeries. It keeps them with breathing and makes them feel comfortable during invasive procedures. Air compressors also help run several handheld medical tools and pneumatic devices in the OT.

##### Treatment of severe respiratory conditions in the ICU

Life support systems in Intensive Care Units (ICUs) are powered by air compressors. Medical grade air compressors deliver clean and dry air while running ventilators. They also power the incubators that provide a safe space to new-born babies as their vital organs develop. The controlled flow of air helps reduce unsafe levels of oxygen exposure and enables easy breathing for patients.

##### Dentistry

Air compressors are also at the core of dental treatments and surgeries. They help operate drills, scalers and other handhelds used by dentists in tooth extraction, root canal process, teeth cleaning and other invasive procedures.

Besides providing the cleanest of air for equipment, dental air compressors must also function without making much noise - this is necessary to enable dentists to focus on their work and the patients to stay relaxed. Small air compressors with filter silencers can significantly reduce the noise a unit makes.

##### Hospital maintenance

Compressed air is the best resource to clean dusty surfaces in any facility, making it useful for hospitals that must be kept very clean. Air compressors also power a number of other tools used in the repair and maintenance of medical equipment such as nail-guns, impact hammers and others.

Hospital maintenance teams also use air compressors to inflate mattresses and the tyres of wheelchairs, stretchers and service carts.

##### Air compressors that supply medical-grade air

Medical air compressors are specially designed to distribute air that does not have any traces of fine particles, oil, odour or moisture. Such air is used only for patient care and calibration of devices for respiratory applications.

Oil-free air compressors are the best models to supply medical-grade air Since they use materials like Teflon for lubrication, there is no trace of harmful oil in the air output of these compressed air systems.

It is also critical to eliminate water from healthcare compressed air systems because moisture is corrosive and can cause significant harm to the units. Besides damaging distribution pipelines and air receivers, it may lead to mould growth on equipment used in medical treatments. Water can also freeze in control lines during cold weather, resulting in faulty operation of associated applications.

Regardless of airborne moisture or vapour from system condensation, water in any form is harmful to systems run by medical air compressors and can lead to multiple breakdowns and repair bills.

More alarmingly, any bacterial contaminant or pathogens mixed with moisture, put patients' lives in danger, defeating the very purpose of using compressed air in medical facilities.

##### Smooth functioning of air compressors

The key component requiring maintenance to avoid water in medical air compressors is the air dryer. While buying accessories, ensure that you choose the right size of dryers and fit them carefully, considering the amount of moisture that they can hold.

Service or replace the dryers when required because, in time, they tend to lose their ability to stop vapour from passing through the air compressor.

As part of your routine air compressor maintenance, check the condensate drains to prevent them from carrying moisture downstream into the linked medical systems. Get the clogged drains cleaned thoroughly and if there are any other signs of damage, contact a professional to make necessary repairs or replacements.

ELGi offers air compressors and accessories for the healthcare industry for select applications and to support your facility maintenance tasks. To know more about these models or to sign up for an annual maintenance package, contact our team at 1800-425-3544 (India tollfree) or write to us at communications@elgi.com .
    


The use of air compressors in typical industrial applications such as manufacturing, spray painting, food processing and packaging is commonly known.

However, not many are aware that compressed air is a major power source in the healthcare sector and saves many lives. It is a key component that enables the functioning of modern medical equipment. Be it artificial respirators or surgical instruments, air compressors power a number of systems in hospitals and dental clinics.

Let us look into some of these in more detail:
    

Compressed air applications in the healthcare sector


The largest portion of earth's surface covered by the blue carpet in the form of ocean, rivers, lakes and ponds often fascinate human beings around the world to think, explore and get awed by its magnificence. One of the best ways to get under water, whether for professional purpose or for recreational purpose, is Scuba diving.

SCUBA stands for “Self Contained Underwater Breathing Apparatus” and it is the paramount element of marine exploration.

The major aspect that confines our time and experience underwater is the air that we carry in our SCUBA tanks.  Air, Ah!! It's simple when we hear it as a term in itself. But when it comes to using air in SCUBA, we must understand its forms first.

Right from our early schooling we have learnt that the air we breathe is a composition of nitrogen and oxygen majorly, as well as water, carbon dioxide, ozone, and many other compounds in small traces. But little did we know that the same atmospheric air is compressed, to utilize as a fourth form of energy in many industrial applications. The pressure range in which air is compressed depends on the use case. While for SCUBA, normal atmospheric air is compressed and filtered, so the divers can take more of it with on their underwater trip.

Compressed air is the typical gas used for recreational diving, while Nitrox, Trimix and Heliox gas mixes are used for technical diving in deep waters. Divers use a pressure regulator (in their mouth-piece) to bring back the air from high pressure to atmospheric pressure (when at the surface) or the local underwater pressure, depending on the depth.

While underwater, compressed air is utilized at varied levels which is a factor of the depth it is breathed at. For us to visualize - If you are a diver descending into the ocean, for each foot you will experience an increase in pressure by 0.44 psi roughly for sea water and this is a tad bit less for freshwater SCUBA as both the air pressure at the water's surface, and the water pressure, will act.

The scuba diver uses a mouthpiece with a pressure regulator to retrieve the air from high pressure to atmospheric pressure, or to the required pressure based on the depth.

SCUBA tank filling air compressors are similar to the ones used to deliver air for firefighters and for oxygen tanks in hospitals but the vital difference is the pressure and compressed air quality output from the compressor.

- **Pressure**

For SCUBA, when compressed air is being used, based on the way air is carried, a low pressure or a high pressure compressor is chosen.

##### a. Low-Pressure Compressors

For surface supplied diving, low-pressure compressors are used. These compressors are lighter in weight compared to the conventional compressors so as to carry in flotation rings that float on the surface of water and they supply underwater divers with air via a hose. Typically pressure range for surface- supplied diving compressors range from 15 psi to 130 psi maximum.

##### b. High-Pressure Compressors

Divers carry compressed air in Aluminium or Steel tanks for breathing underwater, in this scenario air is compressed in ranges between 3,200 and 5,000 psi.

The compressor's Free Air delivery/ output flow is a factor of the tank size and number of tanks that needs to be filled.

##### Compressed air quality

For SCUBA it is mandatory that the compressed air is of breathing quality. A compressed air system can contain contaminants that affect the quality of breathing air from sources like compressor oil, system leaks, inadequate filtration and environmental variables. Hence filtration plays a crucial role.

Mostly the filtration and moisture separation system is separated from the compressor system, hence downstream filters, moisture separator and dryers are preferred, to ensure the compressed air complies with breathing air standards. Apart from regular filtration, the compressed air is passed through a sequence of activated carbon filters that gets rid of hydrocarbons and carbon monoxide (CO).

We must keep in mind it is important to choose the right compressor that inherently does not pass over excess moisture, oil, dust particles and other contaminants as excess moisture can cause overloading of the drier, and moisture separator. If left unnoticed, it may lead to deprivation of compressor filtration, fault in regulators, corrosion and oxidation of scuba tanks. While excess oil could increase excess CO, CO2 and hydrocarbon levels in compressed air.

In order for humans to have a safe and fun underwater experience, making sure you have the right tank and air supply is essential for a successful dive. At ELGi, all our compressors are built with best in class features unique to our brand for keeping moisture and oil carryover as much within the limits as possible. We study the application in-depth before suggesting the compressed air system with the suitable air quality and right size.
    

Dive into the world of compressed air underwater!


#### Clean air for precision machining

The performance of a vehicle's engine relies heavily on the smooth function of its fuel injection system. These systems are integral for delivering fuel to the engine systems, controlling the injecting timing and releasing the right amount of fuel for the power demand.

With innovations in injection system designs, there have been great improvements in the amount of fuel consumed for given power requirements. These include high injection pressures and electronic control systems. However, to successfully replicate these highly sophisticated designs on shop floor, extreme care and precision is of utmost importance.

With this backdrop, the fuel management system provider in this case study, enlisted ELGi's help for a clean and controlled environment in their Sharjah plant. This was critical as the manufacturing process requires moisture-free air at 4-6 bars of pressure at every stage.

##### These stages, are as below:

1. Washing booth - All the machine parts are cleaned with compressed air before they enter the assembly line.

2. Assembly line - Compressed air is used to operate pneumatic equipment used for pressing, tightening, and bolting the parts of oil pumps being assembled.

3. Testing - Once the pumps have been assembled, compressed air is forced into them to test for leakages.

#### ELGi's solution for ensuring highest quality standards

Apart from providing clean air, the company needed its compressed air solution to be cost-effective and energy efficient. This is why, the ELGi team in UAE spent considerable time with the plant management to understand its current requirements and goals with its growth plans.

According to the plant management, “When we started planning for this facility, our main focus was to acquire reliable machinery that is of global standards with local presence and suitable for local conditions. ELGi's strong presence in the Middle East for over a decade strengthened our purchase decision. ELGi was our natural choice also due to our prior satisfactory experience with them.”

They further added that the ELGi compressor's low energy consumption and integrated VFD has helped them to save 50% of their power cost. Furthermore, these air compressors are also compact, which uses minimal floor space.

Apart from the EG series compressor, the company also took ELGi's UPTIME assurance plan for the airend, main motor, cooler, and separator time. This plan helps them to mitigate the losses from machine downtime.

With a goal to ensure the highest quality standards and energy efficiency, the fuel management system provider and ELGi were successful in providing a sustainable solution for the business.

![ELGi's solution for ensuring highest quality standards](/consultant/screw-compressor/application/000014.jpg)
    


For automotive companies, ensuring enhanced fuel efficiency and higher vehicle emission standards is paramount. Manufacturers of vehicles and vehicle components spend millions of dollars every year on research and development, driving innovation in fuel management systems.

Today, let us read more about a leading fuel management system provider, which enlisted the help of ELGi's EG series compressor for their facility in Sharjah, UAE.
    

Compressed air fuels efficiency for automotive industries


#### Modern Technology in Tablet Making

Today's laboratories and manufacturing plants of pharmaceutical companies follow strict quality guidelines to ensure every one of the millions of tablets they produce possess the same properties. The sterile environments encourage the higher use of automation and less human intervention, thus making the reliability of the equipment a top priority.

After reliability comes quality. Compressed air is used in production where air is directly sprayed into the contents of a tablet for various applications.

In fact, one of India's biggest pharmaceutical company has been using ELGi's air compressor since the last 25+ years. This equipment is working well for a variety of applications at its plants in Goa, Ankleshwar in Gujarat, and Hyderabad. In a year, the plant produces four billion tablets and capsules of over 100 different varieties.

According to the Associate Director - Technical of the pharmaceutical company, **“For a pharma manufacturing facility, compressed air is the second most important component after electricity. Most of our processes are fully automated and any break in the supply of compressed air will bring the plant to a standstill.”**

ELGi's air compressor is now being used in the following processes:

- **Dispensing:** Chemicals in powder form that go into making a tablet are transferred from storage containers to the production area with the help of vacuums. Air compressors are used to operate the vacuums as the substance is taken to the processing unit.
- **Granulation:** For the even distribution of chemicals in a tablet, the powder is slowly granulated through a purging process. The compressor is used as a purging device to break the seal that holds the chemicals and spread it evenly.
- **Drying/hardening:** Air is sprayed on the granules to dry the content. A binding solution is also sprayed on the granules.
- **Shaping:** The granules are then pressed in a compression machine to give the substance the desired shape and size.
- **Coating:** Compressed air is used on the tablets to give it a lustrous coat and colour.
- **Packaging:** The tablets are then punched into a strip (blister packaging) with the help of compressed air.

**"Besides quality and reliability, we now look at air compressors not from a singular, one-time capital investment but its total cost of ownership. For that, energy consumption, the availability of spares, and long-time assurance become critical. This is one of the main reasons behind our decision to go with ELGi,"** the Associate Director added.

The energy-efficient air compressors from ELGi help ensure the pharmaceutical company meets its business targets and maintains a strict focus on product quality.
    


Over the years, India has become the third-largest producer of drugs and the largest producer of generic drugs. The country also has the distinction of having the highest number of manufacturing plants approved by the US-based Food and Drug Administration (FDA) outside the US. Such progress has been possible because of the investments pharmaceutical companies have made in research, talent development, quality standards, and state-of-the-art technologies.

Compressed air is required for the tablet manufacturing process, coming into direct contact with the product. This direct product contact occurs after the tablet press where compressed air is utilised to remove dust particles or faulty products are sorted out. Preferably, oil-free, dry air is crucial to maintain the highest standards of quality and compliance.
    

A Dose of Healing Air


##### Choosing your compressor:

Compressors and sandblasters are sized based on:

- **Flow:** Defined as the volume of air that the system can move in a minute, the flow is dictated by
  - Number of users
  - Hose length
  - Hose diameter
  - Nozzle size and type
- **Pressure:** The pressure generated by the system is dictated by media, hose length, & diameter
  -
  One must consider both numbers to make sure the compressor and sandblaster will work together. The size of the sandblaster and nozzle will determine what size of the compressor should be used for the operation.

##### How sandblasters work:

To select the right size of the compressor for the operation; it is necessary to understand how exactly a sandblaster works. They clean out rough surfaces by abrading them with sand that is fired out of an air-powered gun at high velocity.

- Different types of projection systems that can throw abrasive using compressed air:
  - In pressurised projection systems, both abrasive pot and air mixing champers are under the same pressure, sweeping the abrasive material along in the blast hose.
- In suction systems, compressed air is injected into the gun through a nozzle which creates a partial vacuum that sucks a mix of air and abrasive materials from the pot.
- In gravity systems, the abrasive material enters the mixing chamber by gravity and is then pushed by compressed air into the nozzle.

![In gravity systems](/consultant/screw-compressor/application/000008.jpg)

![In suction systems](/consultant/screw-compressor/application/000009.jpg)

##### Nozzle Chart - Air Consumption:

Air and Abrasive consumption per blast nozzle

![Nozzle Chart - Air Consumption:](/consultant/screw-compressor/application/000010.jpg)

Air is CFM of air consumption per blast nozzle. All figures are estimates that may vary according to field conditions and density (pounds per cubic foot) of the type of abrasive material used*

There are many factors to consider when you're sandblasting. Do check the guidelines of your sandblaster to make sure it's compatible with your nozzle. You will also require a nozzle that is durable enough to withstand the pressure from your chosen sandblaster. After that, please check the PSI and CFM levels of your sandblaster and increase the size of your compressor accordingly in line with other equipment.

With the right compressor, you can power any sandblasting project efficiently. To know more about the compressors suited for sandblasting applications,

![Air is CFM of air consumption per blast nozzle](/consultant/screw-compressor/application/000011.jpg)
    


Ever wondered what sandblasting is all about? How it works and what it's used for? If you have, this blog will address everything you need to know about sandblasting as a whole.

According to historians, it is believed that sandblasting was first patented after the observation of what appeared to be sand-laden winds. Apparently, this seemed to significantly affect objects or surfaces they met. This observation was made by none other than Benjamin Chew Tilghman - the person who invented the first air compressor.

Sandblasting is also known as abrasive blasting. It is the operation of forcibly propelling a stream of abrasive materials against a surface. It is done under high-pressure to smooth out a rough surface, roughen a smooth surface or shape the same to remove its contaminants.

The abrasive material for this operation is chosen based on the finish required on the surface.

To get the best performance from your sandblaster, you need to select the right compressor for the job.
    

How to size an air compressor for sandblasting


#### Manufacturing

With its multifaceted nature, compressed air is used most widely in the manufacturing domain. From food, beverage, and pharmaceutical packaging to glass moulding and plastic fabrication - it is at the core of production efficiency. Steady and robust air streams offer optimal product finishes while supporting the casting processes and cleaning.

Rotary screw air compressors are used in manufacturing that trap air between two meshed rotors and reduce its volume as the trapped air moves down through the rotors.

These compressed air systems are commonly used to deliver a clean seal for products that need contaminant-free and tightly sealed packages. They also power the conveyor systems, actuators, sprayers, and clamping equipment used in factories.

![Manufacturing](/consultant/screw-compressor/application/000002.jpg)

#### Construction

For construction, air compressors power several pneumatic tools such as buffing equipment, nailing, stapling and riveting guns, grinders, drillers, jackhammers, and sanders.

Portable screw air compressors are also used for safe lugging and lowering of heavy loads in construction and demolition works.

They are also used for road digging, cutting, and cleaning. They help to keep the tarmac, pavements, and other hard surfaces even and debris-free.

Compressed air is also used for tunnel-digging by countering hydrostatic pressure from the ground, making excavation work feasible.

![Construction](/consultant/screw-compressor/application/000003.jpg)

#### Agriculture

Here, compressed air underpins a variety of activities, including pruning and fruit harvesting, crop fertilising, seed sprinkling, and spraying of herbicides. This is because air compressors power the machines that are integral to modern agricultural practices. These include tractors, sprayers, conveyors and pneumatic fruit pickers. They also facilitate hydraulic pump operations and make it easier to transport agricultural products and machinery.

Tractor-mounted air compressors are particularly beneficial as they use compressed air contained in the receiver, which helps in certain farming activities even if the engine is shut off. Here, the air compressor acts as an energy storage system.

Compressed air is also used to maintain a clean and steady airflow in greenhouse and dairy farm ventilation.

![Agriculture](/consultant/screw-compressor/application/000004.jpg)

#### Healthcare

Medical-grade compressed air and air compressors are used in different areas of the air industry. It is administered to patients who need anesthesia, inhaled medications, ventilators, and surgical machines in operation theatres. It is also used in air filtration systems for treatment of respiratory disorders.

The compressed air used in hospitals does not have any contaminants, particles, odors or oil. It is also kept dry to prevent water build-up in the pipelines used for supply.

Air compressors also power the tools for repair, replacement, and maintenance of hospital equipment. It is used for impact hammers, nail guns, and other air-driven hand tools. Additionally, compressed air inflates emergency mattresses and the wheels that drive service carts and wheelchairs.

In medical textile manufacturing, it has a key role in spinning and weaving operations. Air compressors also drive the mechanical operations in the bandage production process. They also help in colour sorting the cotton to eliminate impurities, interlocking of carding machine doors, loading of scanner rollers, and pressing of rollers in the drafting process.

![Healthcare](/consultant/screw-compressor/application/000005.jpg)

#### Automotive

In the automative industry, compressed air is used for engine construction, assembling, and providing finishing touches to cars. Compressed air based pneumatic tools and air operated bots also help build different parts of a vehicle that handle equipment to life, transport, position, and fasten their intricate components.

Additionally, compressed air is also used for plasma cutting, welding, and tire inflation.

Once a vehicle is assembled, it is cleaned and painted using dry, oil-free compressed air to prevent fisheyes, bubbles or spattering on the painted layer.

Many body shops are also adopting compressed air-powered pneumatic tools that are lighter to use and have lower operating costs compared to traditional electric-powered tools.

![Automotive](/consultant/screw-compressor/application/000006.jpg)
    


Even though it isn't as ubiquitous as water, electricity, or gas, compressed air plays a critical role in powering a myriad equipments and mechanical operations across consumer, business, and industrial segments.

Air compressors convert normal air into its high-pressure, denser form for uses in a wide range of environments.

From small, portable models for safe supply on-the-go, to huge commercial installations that fuel complex industrial processes, they vary considerably in size and configuration to best suit all kinds of needs.

ELGi offers compressed air solutions to multiple industries, and here's a list to name a few:
    

Compressed air - the fourth utility of the modern world


While there is significant awareness in industries about energy efficiency and carbon reduction, we tend to overlook a massive opportunity right under our proverbial noses.

Compressed air can certainly save your pocket a fair bit of change but inefficiency and negligence can make it a saving liability. Alarming news, considering market studies indicate that in various industries compressed air accounts for 10 to 30 percent of the entire energy consumed.

#### How much is wasted energy costing me?

A 100 hp air compressor can incur a cost of $40000 annually in energy alone. And up to 50% of that may be wasted. On average, the share of electricity in the operating cost of a compressed air system amounts to 76 percent.

Leaks in the compressed air system are a significant part of the problem but a greater issue is a mismatch in the demand and supply within the system. Therefore, to optimize a compressed air system one should start with optimizing the demand and the supply. Here's how to do it -

Six Steps To Optimise Your Compressed Air System -

#### Demand

1. Establish the correct air requirements (flow and pressure) of each point-of-use.

#### Distribution

2. Establish the leakage points in your system and manage them.
3. Analyse the system capacity and optimise it.
4. Analyse the fluctuations in demand and manage them efficiently.
5. Track the pressure profiles across the plant for supply-demand mismatches and minimise the pressure drops.

#### Supply

Evaluate the health of each compressor and the support systems. Optimise the controls to match the system dynamics.

#### Demand

Step 1 on optimizing demand is to plug up the leaks! These are typically located at the point-of-use connections, filter-regulator lubrication units, solenoid banks and hoses. Nothing that regular maintenance can't fix.

Maintenance is also important to prevent pressure drops.  The nominal pressure drop in the system from the compressor to the farthest end of the facility should be less than 10 psig. Common culprits of this are - plugged filters, old dryers, inadequately sized pipes and excessive or sharp bends in pipes.

![How much is wasted energy costing me?](/consultant/screw-compressor/general/000043.jpg)

Using appropriate pressure settings at the end users is essential, because an unwarranted high pressure results in an increased use of air, creating an artificial demand on the compressor.

Solenoid valves must be installed to shut off air. These valves can be interlocked with machine operations so that when a machine or line shuts down, the air flow to that machine or line is shut off, thus eliminating leaks.

#### Supply

The supply side refers to how the compressed air is generated.

#### The discharge pressure set point must be reduced as much as possible.

There is a 1% reduction in power consumption for every 2 psig reduction at the compressor. This also reduces the leakage losses.

#### Efficient part-load compressors and controls need to be installed.

If a facility has a constant requirement then one compressor is efficient but for fluctuating loads a combination of compressors is more prudent.

#### A large storage capacity is desirable.

For load/unload-type compressors, the storage capacity should optimally be in the range of 3 to 10 gallons/cfm. This protects the compressor and dryers from sudden-demand events and prevents false loading.

#### Efficient dryers can be installed.

The drying technology that offers the maximum allowable pressure dew point must be used.

#### The use of demand flow controllers is crucial.

The higher the pressure delivered to the plant, the higher the artificial demand and, therefore, higher the leakage losses. Demand flow controllers help isolate the supply side from the demand side and provide a steady flow of low pressure air.

#### The replacement of timer drains with float type traps.

Timers tend to discharge compressed air wastefully along with condensate. Float type traps discharge condensate alone once they fill up with water, avoiding the loss of compressed air.

A compressed air audit helps optimize productivity, reduce operating costs and improve quality. At ELGi, we believe in a systems thinking approach to help our clients deliver the best. Our team of industry-leading personnel conduct complimentary air audits, enabling our clients to save millions of dollars in energy costs annually. ELGi air audits range from full system audits to specific procedures, such as leak detection and power and flow rate measurements.
    

Compressed Air Isn't Free


##### The Evolution of Air Compressors

The use of compressed air spans rudimentary mechanic shops powered by decades-old reciprocating compressors to large scale textile units powered by high volume centrifugal compressors.  While the basic technology has remained fairly simple — powered pistons, screws, or impellers compress a volume of atmospheric air to a required pressure  — the design and use of compressed air systems have evolved to suit the industry needs.

#### Compressed air and power consumption

For manufacturers, achieving optimal efficiency is always a challenge as compressed air is inherently inefficient. Fossil fuels are more efficient in getting work done for the same amount of energy.  However, compressed air is among the best ways to safely store and use energy.  Thus, compressed air has remained a prevalent energy source for industry.  Manufacturers have innovated to reduce lifecycle cost, improve reliability, and improve air quality.

*The Table below shows the typical lifecycle of a compressor.  Nearly 75% of the cost incurred over a ten year period comes from the power consumption.*

![Compressor lifecycle cost breakdown](/consultant/screw-compressor/general/000037.jpg)

Here are 5 simple steps that can ensure that your compressed air system brings you maximum ROI during its lifetime:

#### Step 1: Size up Your Needs

Bigger is not better for compressed air.  A screw compressor should continuously “load” or produce air for maximum efficiency.  A compressor will continuously load when its air production capacity matches the air requirement.  For example, if a compressor produces 500 CFM but the air requirement is only 300 CFM, then the compressor will be in unload condition for a significant portion of time.  Screw compressors are inefficient in the unload condition and thus a larger compressor will consume more energy than a right sized compressor for a given air requirement.

*The table below illustrates the difference in power consumption between a right sized compressor and one that is too large for the requirement.*

![Size up your needs](/consultant/screw-compressor/general/000038.jpg)

To be appropriately sized, customers should demand a sizing audit from manufacturers so that the recommended machine matches the requirement.

#### Step 2: Match Your Frequency

Right sizing is sufficient for those customers with stable air demand, but how about those customers who have varying demand patterns during the day or those customers who anticipate an increase in manufacturing capacity requiring more air?  Variable Frequency Drives (VFDs) can address both situations.  A VFD works by reducing the compressor motor's speed to lower flow to match the actual air demand of the customer and thereby consume lower power when compared to a fixed speed machine; thus significantly reducing unload energy consumption.  A few manufacturers offer compressors with in-built VFDs while other manufacturers offer systems that can be retrofitted.

*The table below illustrates the power savings with a VFD*

![Benifits of a VFD](/consultant/screw-compressor/general/000039.jpg)

To evaluate the need for a VFD, customers should demand a sizing audit from manufacturers along with relating a fairly accurate view of upcoming changes in air demand.  With this information, manufacturers should provide a lifecycle cost comparison of a VFD solution along with a payback period based on the energy savings.

##### Managing a Dynamic Air Distribution System

Thus far, the discussion has centered on compressed air generation.  Specifically, best practices in selecting a machine for energy efficiency.  However, the biggest area for air wastage and thus energy inefficiency is the distribution system.   Specifically, the way in which the compressed air is transported and used in the end application.

#### Step 3: Ensure a Smooth Flow

##### Line Design

Simply, the shorter the distance from the compressor to the application the better.  In addition, minimizing bends and kinks en route to the application, reduces pressure drops and thus improves the efficiency of the system

*The diagram below compares an inefficient line design vs an efficient design.*

![Best practices for compressed air line design](/consultant/screw-compressor/general/000040.jpg)

##### Line Material

Plastic, aluminum, and steel are used for piping, with steel and aluminum being the most popular in India.  While steel is cheaper than aluminum aluminum offers benefits such as lower weight and corrosion resistance.  Compressed air contains trace amounts of oil and water, which can cause line corrosion, which in turn result in pressure drops and thus degrades the efficiency of the system.  Also, compressed air lines are dynamic in that they are constantly vibrating owing to the passage of compressed air.  Over time, these movements weaken joints and can result in leaks.  Leaks lead to higher energy consumption owing to air wastage.

#### Step 4: Evaluate and Overhaul

Air audits evaluate the efficiency of use of compressed air in an operation.  Air audits can identify energy savings from better compressor selection, improved line design, arresting leaks, and optimizing usage.  Compressor manufacturers and independent air audits are capable of conducting air audits.  While methods vary, an air audit expert will use flow meters and leak detection devices to evaluate an operation's air usage.  Typically, they will spend sufficient time to gain a representative understanding of varying demand conditions.  Following the analysis, they will issue a report with a summary of the potential savings along with recommended changes and associated costs to realize the savings.  While compressor selection, line design, and line monitoring have been discussed, air auditors will also review the nature of use.  For instance, operators in compressed air intensive operations such as textiles will often use a higher than required pressure to operate their machinery.  An air auditor might test these machines at lower pressures, and if there is no disruption, the mill operators can continue to operate at a lower pressure, thereby enjoying energy savings.  In addition, an air auditor may also recommend against using compressors for energy wasting applications such as cleaning.

The report below is an example of a summary air audit report that shows a textile operation's before and after energy cost following an air audit.

![Air audit report](/consultant/screw-compressor/general/000041.jpg)

#### Step 5: Do a Regular Check-Up

Setting up and sustaining an efficient compressed air system requires a monitoring process.  Following intelligent compressor selection and delivery design, customers should assign an in-house air expert who is sufficiently trained to monitor the operation's compressed air usage.  Specifically, the expert should work with the compressor manufacturer or an independent air auditor to periodically review the company's air usage to identify areas for improvement.
    

5 Best Practices to get Maximum ROI on your Air Compressor


#### 1. Fix leaks
It is estimated that up to 30% of the compressed air usage can be attributed to leaks from the system. If you can hear a leak, you should get it fixed!

However, approximately 80% of the leaks are inaudible, that is where the need for an air audit arises. Besides conducting an air audit, it is also recommended to invest in good piping material. Aluminium is the best option; it is anti-corrosive and durable.

Once you have fixed the leaks in the system, make sure that you allocate a team to conduct regular and timely checks. Be proactive and look inside the piping system. A clean, dry pipe indicates good quality air and no corrosion issues.

![A clean, dry pipe indicates good quality air and no corrosion issues.](/consultant/screw-compressor/general/000035.png)

#### 2. Choosing the right compressor

Bigger is not better for compressed air. Evaluate the needs of your business and the use of compressed air in that application. Inappropriate uses of compressed air will only result in wastage and further energy consumption.

- Selection of your air compressor as per the demand of your business
- Do not over size your compressor for future projects, you will end up wasting more power than your capital investment

#### 3. Reduce Pressure

Evaluate your system requirements and use only the necessary amount of pressure. Avoid turning up the pressure to compensate for leaks or drops due to piping problems or clogged filters. Having less pressure in the system also reduces flow from unnoticed air leaks or leaks that cannot be immediately repaired.

The compressor pressure should be set as per that of the equipment pressure requirement. With increase of pressure by 1 bar your compressor consumes 7-8% more energy.

#### 4. Proper maintenance

All industrial machinery run more efficiently when properly maintained. Proper maintenance cuts energy costs by one percent and helps prevent breakdowns that may result in loss of production. Most issues that may arise from time to time are fixable, if caught quickly.

ELGi helps you identify the energy saving opportunities for your compressed air and your organisation. Schedule an AIR AUDIT  for your business with ELGi and make energy a priority to ensure big gains for your business.
    


Energy is the most expensive component of a compressed air system, and while it may seem insignificant, over the lifespan of your system, the energy typically costs several times that of the purchase price of your compressor.

Hence, one of the first measures you can take to reduce compressed air energy costs is to measure and monitor your energy consumption regularly to optimize usage.

![Manage your energy for optimum productivity](/consultant/screw-compressor/general/000034.png)

**90% of the cost incurred by the customer is energy**

Small adjustments can help reduce your operating costs and improve output:
    

Manage your energy for optimum productivity


#### Introducing the ELGi AB series air compressors:

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#### What are Technical oil-free compressors?

In applications where compressed air directly comes in contact with the product being processed, throughout the process, manufacturers must ensure there are absolutely no impurities. In such cases Oil-free screw compressors are the preferred choice as they compress the air inside an oil-free compression chamber, which is effectively sealed to prevent lubrication oil from contaminating the compressed air.

Traditional oil-lubricated compressors or oil injected compressors are predominantly used in oil free applications with downstream filters. This arrangement delivers “Class 1” oil quality standards, which means the air will have about 0.01 mg/m3 of oil residue.

This does not meet the global compliance requirements of ISO 8573-1:2010 and ISO 8573-7. To ensure that no residual oil, airborne particulates or vapour can enter the downstream system, they must be connected with downstream air dryers and double line filters to further purify the air. This is termed as “Technical Oil Free”.

This approach appears to be cost-effective, but in reality, it results in high operation cost and higher life cycle costs.

#### Technical Oil Free systems also have an environmental impact

- Approximately, 2-3ppm of oil will be continuously carried into the application and into the atmosphere. This loss of oil must be continuously topped up for the entire operating life of the compressor & is a hidden cost.
- The condensate from the compressor and the downstream filters will contain traces of oil. Due to strict environmental regulations, additionally, an oil/water separator must be used, to remove the oil before letting the condensate into the atmosphere.


#### What are the alternatives available for us?

Owing to oil carryover and the downstream filtration, there are a lot of indirect costs associated with a Technical Oil-Free set-up: higher operating pressure, periodic cleaning of pipes & valves, disposal of oil & filters, and downtime for maintenance.

From an initial investment perspective, Technical Oil Free systems will look very lucrative. But owing to the hidden costs, indirect costs, and operating arrangements, they will also have a higher total cost of ownership. Oil Free compressor systems will easily have a 6-7% reduction in the total cost of ownership compared to Technical Oil Free systems.

Further, if not maintained periodically, there is a very high chance of oil contaminants in the compressed air system. This might result in the manufacturers scrapping or disposing of their in-process inventory or the finished goods; recalling their products; legal proceedings or safety concerns in the facility.

It might even lead to authorities revoking production permits.

It is hence strongly recommended that you reach out to compressed air experts who can evaluate your needs, understand statutory regulations, and propose a cost-effective comprehensive Compressed Air Solution for you.
    


Compressed air is termed as the “Fourth Utility” for any industry. In industries like Food & Beverage or Pharmaceuticals, it is not just the compressed air, but the quality of compressed air which also plays an important role, since the multiple stages in the manufacturing process affect the quality of output.

While on one hand we see, there is an increase in operating costs, we have also to be mindful of the impact a process/ product has on the environment. Delivering quality and superiority of product, is the need of the hour!

Hence industries are challenging existing norms and looking for innovative solutions to their quality compressed air needs. From this perspective, Oil Free Compressors are emerging as a preferred solution & ideal choice.
    

“Technical Oil-Free” is not Oil Free


#### EG series air compressors from ELGi

EG Series, screw air compressor, is a highly reliable and energy-efficient series of air compressors. With multiple installations across 120+ countries and various industries, the EG Series has proven to be a reliable and dependable partner with its high uptime. EG Series rotary air compressor is also supported by an industry-leading warranty plan. Please check with your nearest ELGi representative for warranty plans available in your region.

With high performance and reduced energy costs, the EG series delivers consistent performance while ensuring maximum uptime and increased savings.

Want to know more about the EG series and its technology-edge? [Speak to our air experts!](/contact)

![EG series air compressors from ELGi](/consultant/screw-compressor/general/000031.jpg)
    


Many opportunities exist to reduce the energy used by compressed air systems, beginning with air assessment and air audit. Here are 10 expert tips to help you keep a tab on your electricity bill.

- **LOWER THE PRESSURE:** We all know that working under pressure can be hard. Every additional bar of pressure can increase your power consumption by 7%. Set your air compressor at the lowest possible pressure for a specific application. Remember that increasing pressure does not compensate for a pressure drop in the system caused due to leaks, faulty piping, or choked filters. Install a pressure regulator for better control. It's also important to calibrate your pressure gauges at quarterly intervals.
- **CHANGE FILTERS ON TIME:** While replacing air filters, it is mandatory to maintain the quality of air, it is also an energy-saving opportunity. Delaying an air filter change may cost you a lot. Clogged filters can lead to pressure drops and also hamper efficiency. Ensure on-time service for a healthy compressed air system.
- **INVEST IN PRE-FILTERS:** Not only do pre-filters (also known as coalescing filters) help purify the air by removing oil and water, but they also help remove the particulate matter to a certain extent. Installing pre-filters for suctioning the air, and for its cooling, can extend the life of your compressor and its consumables.
- **CLEAN UP:** Besides keeping your air clean, ensure that you give your compressed air system a thorough dusting every few months. The presence of sludge, dust, or grime can have a big impact on the efficiency of the compressed air system. Pay special attention to compressor coolers and heat exchangers. Consider investing in a dedicated low-pressure air compressor, and airline for cleaning, to save power.
- **PICK THE RIGHT DRYER:** Selection of the right sized air dryer for your compressed air system is crucial. Make sure the energy consumption of the dryer is in proportion to the demand. An oversized dryer can add to your electricity bill significantly.

![Many opportunities exist to reduce the energy used by compressed air systems](/consultant/screw-compressor/general/000029.jpg)

- **CONSIDER A VFD:** Screw compressors should run under full load. If the usage pattern varies, consider a Variable Frequency Drive (VFD) for up to 35% reduction in energy cost. A VFD helps regulate energy consumption based on demand fluctuations, ensuring energy efficiency. ELGi's VFD has helped clients save up to 25% savings in maintenance and energy cost with payback as low as 7 months.
- **PERFORM QUARTERLY MAINTENANCE CHECKS:** The importance of maintenance cannot be overemphasized. Regular maintenance can help you identify and accurately measure leaks in the circuit. They also reduce the chances of breakdowns, leading to maximum uptime and productivity.
- **PREVENT MISUSE OF AIR:** Wasted air is wasted money. Invest time and money in training employees for efficient compressed air management. Create maintenance logs and update them on a regular basis and record abnormalities or leaks in the systems. Systematically label leaks with proper tagging and prioritize repairs and plugging of leaks.
- **RECOVER HEAT:** It's common knowledge that heat is produced during the process of air compression. If not used judiciously, all the heat energy can go to waste. Over 90% of the heat produced can be recovered and utilized for heating air or water at the facility.
- **GET AN AIR AUDIT:** Air audits enable companies to work with experts in the field and get valuable insights into their plant's compressed air utilization. ELGi's air audits chart out a customized and comprehensive energy management plan for your needs. Over the years, we have helped save millions of dollars in energy costs.

![ELGi's air audits chart out a customized and comprehensive energy management plan for your needs](/consultant/screw-compressor/general/000030.jpg)
    


Compressed air is critical to the smooth operation of plants and factories. Contributing to a great deal of convenience and efficiency, compromised compressed air can result in forced shutdowns, poor output, and significant costs.

It is a proven fact that about 70% of an air compressor's lifetime cost comes from power consumption, which then increases your overall power consumption However, due to the effectiveness and capacity of production support extended by compressed air systems, that it is now an indispensable part of the factory setup, especially in the case of sensitive industries including healthcare, pharma, food & beverage, etc.
    

Energy saving tips for your air compressor


#### TYPICAL CALCULATION OF SYSTEM STORAGE

- Most systems have undersized wet air receivers
  - Wet side storage can overload the air treatment equipment and hence should always be lower than the dry storage capacity.
  - Avoid the use of rules of thumb (1 gallon / cfm or as a general rule of thumb air receivers should be about 25% of the FAD is inadequate in most systems) Receiver size should be Engineered to meet customer requirements.

Let's check if the rule of thumb helps the system for a compressor breakdown, followed by an auto-standby startup – which for screw compressors will be a delay of 45 seconds before it starts to generate airflow ( Typical sequence of a start is: Star to delta time delay, Stabilization, Unload run and then load run)

```
V   =   T   x   D x Pa

                P1-P2
```

##### Where:

```
V          = Receiver Volume

T          = Time allowed for Pressure drop P1 to P2 to occur (or a disruptive event)

D          = Air demand for this period

Pa         = Atmospheric pressure absolute

P1         = Initial pressure in the receiver (typically the load pressure)

P2         = Lowest useful pressure required for the demand to function properly.
```

##### Assumed condition of a compressor room:

- One working compressor with one standby, with built-in automation to start immediately (within 45 sec) when compressor 1 fails. Each compressor is 500 cfm (14.2 m3/min) FAD capacity with setting of 100 psi ( 7barg) load 110 psi (7.7 barg) unload type control.
- T time available before the pressure drop affects the application is 45 sec or 0.75min
- D Air demand at the time of event/breakdown is also say 500 cfm ( 14.2 m3/min)
- Atmospheric pressure is 1 bar (14.5 psi) absolute
- P1 initial pressure in the receiver is say 100 psi, 7 bar when the compressor 1 has a breakdown.
- P2 is the lowest pressure for the application to run is 85 psi ( 5.9 bar)

##### Applying the formula to get the storage volume, we get

```
V   =   T   x   D x Pa

                P1-P2
```

```
V   =   0.75min   x   500cfm    x   14.5

                                    (100-85)psig
```

Calculated Storage for 45 sec backup  = 362.5 cu ft or 10.3 m3

1 gallon /cfm Rule of thumb storage = 500Gal or 66 cu ft or 1.9 m3

25% of the FAD Rule of thumb storage = 25% of 14.2 m3/min = 3.55 m3 or 125 cu ft.

If in another situation, the time to restore the standby compressor is 90 sec the storage required will be twice the above: ie

Calculated Storage for 90 sec backup = 725 cu ft or 20.6 m3

#### What events/ items can affect the Receiver storage sizing:
- Real events that can happen from the supply side, like compressor failures, dryer purge, power outage, are a few possibilities.
- Real events are unique to application on the demand side like, a sudden spike in demand which is more than the compressor capacity for shorter durations. These can be spotted in Air system audits.
- Useful pressure available: This is the difference between the average pressure maintained in the system to the lowest pressure it can take.
- Application and its criticality: Some processes can handle the loss of air supply for short periods, but in some cases, it will result in loss of production or complete breakdown.
- While the rule of thumb takes care of some of the intended functions like stabilization of dryer and compressor, it may fall short of others like compressor shutdown, demand spikes, etc.

The receiver tank is one of the least acknowledged champions in the compressed air system. What is also noteworthy is that, the receiver is the least expensive item that can give a return on investment in the short run!

The ease and flexibility of adding a receiver in a series at any time, makes it convenient to upgrade and improve the system, whenever necessary.

When looking to invest in any accessory for your compressed air system, it is always better to consult the experts, follow the local design codes and safety recommendations and do not deviate from the manufacturers recommended specifications.
    


##### What are the benefits of Air receivers?

- **Stored Energy:** The primary role of an air receiver tank is to provide temporary storage for compressed air. It stores compressed air that can be used for short spikes in demand, also referred to as ‘events of sudden demand'. It also acts as a standby supply system, when tricky situations may arise at a factory including, power outage for a short period (typically switching from a grid to generator), a sudden unplanned loss of supply from a compressor (typically from breakdown), etc. Think of the importance of a battery with UPS supplying power for a computer to function without disruptions, the air receiver is that reliable battery source which enables smooth functioning of your business.
- **Stabilizer:** Fluctuating compressed air utilization causes uneven demand on the air compressor, resulting in rapid cycling of the air compressor controls as the air compressor turns on and off to meet moment-by-moment demand.

Each time the system turns on and off (or loads/unloads) it is called a “cycle.” It is better for the air compressor motor and other components to keep these cycles as long as possible. This is true for all upstream equipment like dryers, particle filters etc. The stabilized flow through these systems allows the equipment to function to its intended performance.

- **Improves Efficiency for Air Compressors:** As the air compressor cycles on and off, compressed air can be wasted. Every time a rotary screw air compressor cycles to unload, the Separator tank is blown-off from its operating pressure typically from 7 bar to near atmospheric pressure. Compressed air is released during the venting.

With cycling once every few seconds (typically under a minute) this adds up to the loss of a sizeable percentage.

- **Improves Efficiency for Dryers:** If used as a wet Tank (or receiver before the dryer) the receiver acts as a heat exchanger, cooling off the air and thus condensing some moisture before it reaches the dryer. The water drains out of a valve at the bottom of the tank. By removing some moisture in advance, the air receiver tank reduces the amount of work the air dryer needs to do. This is true for any dryer type from refrigerated air dryer to desiccant dryers.
- **Improves efficiency for Coalescing filters:** The moisture removal to some extent allows the filters to be relatively dry, in comparison to the direct handling of compressed air coming from the compressor, for the same reason as mentioned above.

#### TYPES OF RECEIVER TANKS

There are two types of compressed air storage: wet and dry. The tanks are the same; the difference is in where they are installed within the system.

Wet receiver tanks are located before the compressed air dryer. Some functions of the wet receiver include:

- Isolating the compressor from demand events
- Reduces/eliminates compressor cycling
- Allows the compressor to remain unloaded for a longer time
- Acts as a backup for compressor failure

Dry receiver tanks are located after the air dryers, to store compressed air that has already been dried to its desired level of the application.

- Dry compressed air is available closer to the application and is hence available in the case of a high-demand event or supply failure.
- Dry storage reduces the burden on the air dryer during high-demand events. Without a dry air receiver (but having a wet receiver only), during sudden spikes in demand, the dryer can be subject to higher volumes than the dryer is designed/rated for. This leads to lower drying efficiency and may also result in sudden pressure drops, leading to unwanted water in the air lines and the application desiring of pressure.

It is recommended that the dry receiver is larger than the wet receiver by 2 to 3 times to take care of the points mentioned above. Most applications require a combination of wet and dry storage for optimal efficiency and performance.

![Capacity control graph - Show the effect of higher storage on part load-power consumed](/consultant/screw-compressor/general/000027.jpg)
    


#### How many industries pay attention to their storage/receiver capacity design as much as it deserves? Probably only a few.

That is because, most would have gone with the rule of thumb, the usual recommendation for a typical compressed air system. But the reality is that there is more to receiver tank sizing, customized to the application than just one size fits all

Imagine a water tank at an elevated height, supplying water to residences in an area. This is analogous to an air receiver supplying to various industrial demands. Let's understand the need for an air receiver and its function in the compressed air system.
    

The importance of an air receiver tank to improve system efficiency


#### Air accessories for the effective operation of your plant

To complete your compressed air system, you will need to analyse the requirements of your equipment, and accordingly choose the accessories which deliver the best quality and quantity of compressed air for the effective operation of your plant.

- Line filters - Compressed air will contain dirt, moisture, scales, and other impurities. The purity of air plays a significant role in the sterility of processes, especially in sensitive industries including food, beverage, and pharma. Installation of filters will ensure that your application remains oil and dir free.

It is also necessary to replace the cartridges at recommended intervals to maintain air quality.

- Dryer - The presence of moisture in the compressed air system, will damage pipelines, tools, and equipment that utilise compressed air. You must select a dryer for your system depending on the moisture tolerance level of the equipment. Dryers are effective in removing moisture and delivering moisture free air for further processes within the system.
- Drain valves - Zero loss drain valves are highly efficient and reliable. The condensate level is sensed and the moisture/condensate is drained completely, with no loss of air.
- Condensate treatment - A mix of oil-water (condensate) is bound to be present in the system. It is always recommended to treat this mixture before releasing it to the sewage-disposal phase. A Condensate treatment unit (Oil-water separator) will help you carry out this activity to dispose of the condensate.
- Measure the effectiveness of your compressed air system periodically- This can be done by simple visual checks for leakage, monitoring the condition of filters for a pressure drop, analyzing the application pressure, and finally, adjusting and adapting to the changing needs.

Air audit data is the most reliable source of information for reducing the operation cost. Depending on the demand pattern, you can arrive at a solution which will decide on the use of VFD or sizing of your compressor.
    


#### Impact of faulty component selection

A faulty layout, design, and selection of pipe material will cut down profits by:
- Increasing the energy consumed in your air compressor
- Resulting in the failure of the equipment
- Reducing production efficiency
- Increasing maintenance costs

#### What should be the key focus points in a pipe layout and design?

Fixing leaks is the first thought that pops up in your head! But there is a lot more to your compressed air system.
Here is a list of additional components to be considered for efficient transmission and better quality of compressed air:

1. Air-receiver - It is the primary storage for compressed air to balance the output pressure and application need. The selection of an air-receiver is crucial to meet the demands of the plant, along with the effective operation of the compressor (load / unload).
2. Size - Appropriate selection of the size of the pipe, based on CFM of the compressor, will minimize the pressure drop, thereby reducing energy consumption. The larger the size of the pipe, the lower is the pressure drop.
3. Bends - A straight path for the air is the most efficient. When it comes to bends, a large radius bend is the most preferred. It reduces turbulence, thereby reducing the pressure drop. Note: Avoid short bends as much as possible.
4. Drop-line - Drop line tapping should always be from the top of the main header line, curved down to the application point.
5. Moisture drain points - Moisture drain points at the right place with Auto drain valve, will drain the water from the system.
6. Closed-loop design - It is the most efficient piping layout. There is no beginning or end for the header line, just a continuous loop.

Planning for the long-term is always crucial for the continuity of your business. Hence, when you follow structure, recommendations and timely upgrades in your expansion plans, you are at a better place, avoiding any expensive modifications.

#### What compressor piping systems are available for businesses?

- Aluminum pipes - The latest technology, Aluminum, is light-weight, making it easy to handle, and is highly recommended for clean air applications. It is non-corrosive and remains leak-free.
- Galvanized pipes - Galvanized steel pipes are widely used in compressed air systems. However, over time, the galvanizing coating flakes off and affects the application equipment in the line.
- PVC pipes - PVC pipes are commonly used in compressed air systems, mostly because they are readily available, inexpensive, and easy to install.

![What compressor piping systems are available for businesses?](/consultant/screw-compressor/general/000025.jpg)
    

Generally, for a compressor owner, the pipeline selection, layout, and accessories, are among the lesser significant sections of their air compressor. However, it is these components that support the optimum air supply, pressure, volume, and eventually, quality of output in your compressed air system.

Compressed Air Piping Systems


##### Fixed Speed or Variable Speed?

In addition to the airflow demand, another parameter to consider while choosing a fixed speed or VFD compressor is the duration of the airflow demand. If the airflow demand is relatively constant i.e if the flow demand does not fluctuate and remains relatively constant for a significant duration in a shift, the choice will be that of a fixed speed compressor. This is because fixed speed units deliver constant airflow and will meet the demands. The increased cost of a VFD unit is not justified in such a constant airflow demand scenario.

If the airflow demand is varying for a significant duration in a shift between the minimum and maximum flow capacity, then the choice will be compressors with VFD. The compressors equipped with VFD will vary the speed of the motor and ensure excess energy is not consumed by the compressor. Compressors with VFD can save up to 35% in energy costs compared to fixed speed compressors.

If a fixed speed compressor is chosen for a varying airflow demand, it will result in higher energy consumption. When the demand fluctuates significantly, fixed speed compressors will run on “un-load” mode where no compressed air is delivered but energy is consumed. The increase in the duration of unload mode of operation can result in significant loss of energy.
    


##### Fixed Speed Compressors
Fixed speed compressors are designed to deliver a fixed or constant flow (cfm or m3/min) of compressed air for a rated operating pressure. This is achieved by the electrical motor in a compressor running at a constant speed (rpm), which in turn drives the air end of a compressor.

##### Variable Speed Compressors

Variable speed compressors or compressors equipped with variable frequency drive (VFD) are designed to deliver varying flow of compressed air depending on the airflow demand by the applications in a production facility. This is achieved by varying the speed of the motor which in turn varies the speed of the air end of the compressor. The speed of the motor is proportional to the flow delivered by the compressor.
As the demand for airflow increases, the speed of the motor is increased up to the maximum rated speed, and when the demand for airflow decreases, the speed of the motor is decreased up to the minimum rated speed of the motor. The VFD also allows the motor to operate at frequencies between the maximum and minimum speeds.
To understand better on when to use a fixed speed compressor and when a VFD compressor will be beneficial, we will discuss further about, airflow demand.

![Variable Speed Compressors](/consultant/screw-compressor/general/000022.jpg)

##### What is “airflow demand”?

Airflow demand is the rate of volume of compressed air (cfm or m3/min) required by applications in a production facility.
For example, a manufacturing facility with machining centers and a few pneumatic actuators need 100 cfm (2.8 m3/min) of compressed air at a rated pressure of 7 bar g. If these applications run continuously together in a shift, the flow demand is considered to be constant.
In the same example, if the machining centers and the pneumatic actuators are operated separately and for different durations during the shift, the airflow demand will fluctuate depending on the number of applications run at a given time.
An example of a relatively constant and variable airflow demand is shown in the graphs below.

![What is “airflow demand”?](/consultant/screw-compressor/general/000023.jpg)
    


One of the important decisions to make while investing in an air compressor is to decide whether a production facility needs a fixed speed or a variable speed compressor.

Typically, energy costs contribute to more than 75% of the total life cycle costs of a compressor. Appropriate selection of compressors will result in optimal energy utilization, thereby reducing energy costs significantly for the user.

![The Thrill of Speed!](/consultant/screw-compressor/general/000021.jpg)
    

The Thrill of Speed!


Air compressors are among the most important equipment used for varied applications across industries. Air compressors come in different types, sizes and makes. From its utility perspective, air compressors are machines which consume power. Every kW of power consumed is money spent / cost incurred.

Apart from the electricity cost, there is also the cost associated with maintenance and upkeep of the equipment. These are recurring costs incurred through the life of the compressors, to keep them in operation. Hence it is important to understand the different costs associated with air compressors and their contribution towards expenditure.

The overall cost incurred in procuring, maintaining and operating the equipment is often called as the “Total Cost of Ownership (TCO)” or “Life Cycle Cost (LCC)”. There are three main elements of cost used in calculating the life cycle cost, they are (1) Power /electricity cost (2) Overall maintenance cost, and (3) Initial investment

##### (1) Power Cost:

The electricity charges to operate the compressors are termed as power cost. The duty cycle of the compressor (i.e. full load or partial load) is an important factor while computing the power cost. Since air compressors are capital equipment, they should be operated on its full load capacity to reap its full benefits. Partial load cycle means the equipment will blow off air during the unload phase, which is (economically) undesirable. Power cost is always calculated as cost of power when the compressors run in loaded and unloaded condition. This is by far the most significant component of compressor life cycle cost.

##### (2) Maintenance Cost:

The cost associated with keeping the compressor in good working condition is called maintenance cost. The key costs included are the cost of consumables like air filter, oil filter, oil, separator elements, refrigerants, desiccants, and valves which must be replaced at regular intervals as recommended by the manufacturer. The cost of regular spares, kit parts and critical parts should also be included. Labour is the additional cost incurred along with compressor maintenance when hiring a professional. In most of the cases, cost of the annual maintenance contract (AMC) would also be involved.

##### (3) Initial investment:

The cost of purchasing the air compressors, its accessories and associated installation costs are referred to as the initial investment. During each purchase & installation, decision makers will evaluate all possible options to ensure optimum investment in procurement.

Hence life cycle cost is the sum of the three factors mentioned above. This can mathematically be expressed as:

#### Life Cycle Cost = Power Cost+ Maintenance Cost + Initial Investment

![Life Cycle Cost = Power Cost+ Maintenance Cost + Initial Investment](/consultant/screw-compressor/general/000019.jpg)

The above figure illustrates the contribution of the three elements in calculating the overall life cycle cost of the compressor. As can be observed, the power cost plays a vital role.

It is essential to understand the maintenance costs and the power consumption of the compressor during the procurement phase itself. The reason is that equipment costing less might involve frequent maintenance and consume higher power.
    


“Cost is king…” is a popular saying among the business circles and there could not be a better time than now to understand its implications.

The current pandemic situation has reiterated the significance of cost. Decisions regarding capital expenditure are being critically reviewed, as every organization is looking at ways for better cash management. In such scenarios, where expenditure is essential, there, every penny saved is equal to cash earned.

![The current pandemic situation has reiterated the significance of cost](/consultant/screw-compressor/general/000018.jpg)
    

Identify the real life cycle costs of your air compressor


##### Oil-lubricated air compressors

The oil injected into the compression chamber helps in keeping the system cool by dissipating the heat and also acts as a lubricant to lower the friction between the moving parts. It also offers sealing and helps in noise reduction.

In addition to rotary screw type, oil-injected or oil-flooded air compressors are also available in piston technology. Their efficiency, robustness and ability to work quietly make them effective for a variety of pneumatic tools and accessories.

Oil carryover, being a concern with many users, ELGi's lubricated rotary screw air compressors are designed to deliver air with the lowest oil carryover. By using ELGi's downstream filters the oil carryover can be further reduced to achieve high quality output air suitable for industrial applications. This process enables you to get industrial grade air for industrial use such as manufacturing, construction, recycling, waste management and quarrying.

##### Oil-free air compressors

As the name suggests, such units do not need oil on their cylinder walls or compression chamber. They have pre-lubricated cylinders coated with a material like PTFE, inside which the piston can slide easily.

Owing to permanent lubrication, the quality of pressurised air generated by these oil-free air compressors is similar to that of the input air; therefore, the air output remains oil-free.

Oil-less air compressors are recommended for industries where air must be completely free from oil vapour and moisture. They are used for the most sensitive applications that commonly include:

- Food & beverage processing
- Pharmaceutical manufacturing
- Operating ventilators, surgical machines, inhaled medication systems (only for breathing air certified machines) and other critical equipment in hospitals
- Semiconductor and electronics manufacturing
- Automotive spray painting
- Textile manufacturing

The oil-free mechanism of these air compressors helps users reduce their carbon footprint.

##### The advantages and disadvantages of oil-free and oil-lubricated compressors:

The oil-lubricated units are more efficient, durable and less noisy. The oil in these air compressors also helps lubricate and cool down the compressed air. Such models are recommended for industries that do not have stringent requirements for maintaining air quality. A majority of heavy-duty manufacturing plants and workshops using pneumatic tools can opt for oil-lubricated air compressors. Their only downsides are that they need more maintenance owing to regular oil changes.

On the other hand, oil-free air compressors produce clean air, helping organisations maintain optimal product quality and get class 0 certified air for their critical applications. These air compressors have low carbon footprint and need lower maintenance.

While both the technologies are superior and can ensure reliable delivery of compressed air, your choice of air compressors will be influenced by the intended use and the facility where they will be deployed.
    


##### Which system is better for your industrial application?

There are several parameters to keep in mind while buying an air compressor. Apart from deciding the size, rating expressed in CFM (for airflow), and bar (for air pressure), you also have to choose between an oil-free and oil-lubricated system.

The choice depends on the kind of applications where you intend to operate your air compressor. This is why, it is good to understand how these compressed air systems work and the applications that they're used for.
    

Oil-lubricated or oil-free air compressors - which one should I pick?


##### Drilling machines

While the commonly used electric drills can penetrate only softer surfaces such as wood or fibreglass, air compressor based pneumatic tools can also drill through hard materials such as rocks and metals. For this application, compressed air powered drills, both reversible and straight-line, need between 3-6 CFM at **6.2 bar**.

##### Chiselling tools

Air chisel is a handheld pneumatic tool with a narrow and flat cutting edge. It is used to cut into wood and stone, for construction and home renovation applications. It is particularly handy in carving out mortises and dovetail joints while building adjacent walls and shelves.

Normally, air chisels need between 3-11 CFM at **6.2 bar**.

##### Angle grinders

Air compressor powered angle grinders find use in car repairs and metalwork where they are used for grinding, buffing and cutting. When supported by an appropriate sanding disc, angle grinders can also be used to smoothen the surface and edges of some materials. For most applications, a basic 7-inch portable angle grinder needs between 5-8 CFM at **6.2 bar**.

##### Cut-off tools

Cut-off tools need considerable power to sever metal sheets in the building and maintenance of vehicles, industrial applications, and artistic works. With air-powered tools, it becomes easier and quicker to slice metal sheet corners and cut out panels from large metal walls.. An air compressor between 4-10 CFM at **6.2 bar** can effectively power cut-off tools.

##### Riveting

Contrary to what some people believe, riveting has not become obsolete after the advent of welding. As permanent clasps, rivets are still used in numerous mechanical applications, such as aircraft construction that needs strong and reliable fastening with minimum weight. Air riveting tools are also used in construction work - commonly used to set up corrugated metal roofs. They do not consume much power, and 4 CFM at **6.2 bar** is their standard requirement.

##### Shearing equipment

Air shears are good for heavy-duty metal cutting that cannot be done with nibblers. They are used to shave, trim, slice and outline metal sheets for handicrafts and industrial works. Modern pneumatic tools are equipped with pistol-grip shears that can make up to 2600 cuts in a minute. Also, a standard air compressor powered shear is capable of cutting into sheet metals with a thickness of 16 gauge, 20-gauge cold-rolled steel and 14-gauge aluminium. Air compressors of between 8-16 CFM at **6.2 bar** can power such shearing equipment.

##### Painting tools

One of the most useful pneumatic equipment is the airbrush that prevents bubbles, fisheyes, splotches and other inconsistencies in painting vehicle, wall and furniture surfaces. Air-operated paintbrushes also keep the flow of colour free from any moisture and dirt. They make it easier to apply coats of paint for a smooth finish and glaze that cannot be offered by regular brushes, rollers or aerosol spray dispensing systems. Normally, these devices need air compressors rated between 3-11.3 CFM at **6.2 bar**.

***

Please note that the figures mentioned here are for specific make and range of tools. This may vary between manufacturers and application requirement.

ELGi builds air compressors with different airflow rates to suit multiple pneumatic tools used in a facility. If you still have questions about the optimal CFM or free air delivery for your applications,
    


What is CFM or airflow, and what are the requirements of some common pneumatic tools?

If you plan to buy an air compressor for your industrial application, you need to mull over several factors that best suit your needs. One important consideration is the air pressure requirement of the equipment that the air compressor will operate.

The free air delivery in an air compressor is measured in **cubic feet per minute (CFM)**. It is the amount of air generated by the air compressor at a certain pressure level. Another parameter considered along with CFM is the amount of pressure that the air compressor can offer, which is measured in bar, kg/cm2 or PSI.

For instance, small pneumatic tools usually need up to 5 CFM at 4.8-**6.2 bar**. Larger equipment, on the other hand, demand more than 10 CFM at 6.9-8.2 bar. Remember that when you have multiple applications with different airflow demands, you should add up their individual requirement and consider the total usage to be 40-50% higher than the obtained number. This is to ensure the air compressor doesn't run at full capacity at all times.

Take a look at the airflow required for some common air compressor applications:
    

How to calculate the right CFM or airflow for air compressors


##### System design

Rotary screw air compressors have a couple of meshing spiral screws called rotors for compressing the input air. While reciprocating air compressors employ pistons moved by a crankshaft for compressing the air.

##### Components involved

With just two moving parts (screws) that have a small gap between them, screw air compressors are not subject to much wear and tear. Even in models where the two screws come in contact with each other, they don't encounter any friction, which is why they are less likely to break down.

On the other hand, reciprocating air compressors have several moving parts like pistons, piston rings, connecting rods, and inlet-outlet valves due to which they are noisier and may need stocking of spares.

##### Temperature

The internal heat produced by screw air compressors during operation is between 80 - 99 degrees celsius. The heat production is limited, as there is no friction between the screws. The oil or lubricant used between the rotors and casing creates a non-wearing seal that can eliminate the heat with the help of a thermostatically managed fluid circuit.

In reciprocating air compressors, the pistons operate at temperatures between 150-200 degrees celsius. The high temperatures are due to the friction caused by the movement of piston rings against the cylinder walls.

#####  Oil filtration
The chances of finding residual oil in an oil-lubricated screw air compressor are very low, because this unit has a three-stage oil filtration system. The oil content is typically below three particles per million (PPM).
However, a reciprocating air compressor does not have an oil filtration system, which is why, its outlet air can be more contaminated than a screw air compressor. The oil content in the air also increases when piston rings and oil rings deteriorate, allowing oil to move up to the compression side.

##### Air-receiver tanks

It's often tricky to choose the appropriate size of an air-receiver tank when you use a rotary screw air compressor, as most of the associated applications don't need a tank at all. This unit is devised to deliver a continual stream of compressed air without any disruption or pulsation. If the airflow requirement of your tool is less than what is produced by the air compressor, then you wouldn't need a tank at all.

On the other hand, piston-based compressors come with air-receiver tanks in which they store air and remove pulsation before it runs the connected applications. Once the tank is full, one can operate the equipment.

##### Individual benefits of both the models

*The top advantages of choosing a screw air compressor are:*

- Continuous air supply
- Higher duty cycle
- Better durability
- Higher overall efficiency
- Lower ambient noise
- Higher airflow per rated power

*Few reasons why some operators still prefer a reciprocating air compressor are:*

- Very high pressure requirements
- Spare parts management
- Lower duty cycle

At ELGi, we offer both rotary screw and piston-based reciprocating air compressors. Although reciprocating air compressors make for a good option for low capacity requirements, your facility may need more energy-efficient units when the demand for associated applications increase. Rotary screw air compressors are compact, quiet, and reliable with a consistent airflow. They will give you a stable air supply for a variety of applications across industries.
    


The key difference between Rotary Screw Air Compressors and Reciprocating Air Compressors is the mechanism in which they compress air.

Their distinct features can be understood in terms of:
    

The difference between rotary screw air compressors and reciprocating air compressors


##### Q1. I am setting up a new pharmaceutical bulk drug manufacturing plant. Which compressor should I select?

The quality of compressed air is critical in applications where the air comes in direct contact with the end product. It should not contain contaminants like oil particles. One more requirement of the pharma segment is uninterrupted operation. Hence, the most suitable solution will be an Oil-Free screw air compressor which is best suited for continuous duty application and delivers compressed air, free from oil contaminants.

##### Q2. How is an Oil-Free compressor different from a lubricated compressor?

In the lubricated compressor, oil is injected into the compression chamber, also called the Airend, during the compression process. This lubricating oil mixes with air, and this Air-Oil mixture is further treated.

Whereas in an Oil-Free compressor, during compression, there is no injection of oil into the Airend.  Hence, the compressed air does not contain any traces of oil.

Additionally, Oil-Free air compressors are also eco-friendly since there is no oil spillage from the compressor drain or oil carryover in compressed air.

##### Q3.I have fluctuating airflow demand. How can I reduce my operating cost?

While some setups have a fixed airflow requirement, many factories might be experiencing fluctuating demand. This situation allows us to reduce our operating costs significantly.

As a best practice, if your airflow demand is not constant, we recommend installing a VFD-equipped air compressor. If you have a fixed air compressor installed already, you can opt for a Retrofit VFD kit matched to your compressor power, which can help regulate the airflow as per plant requirements and reduce power costs.

##### Q4. What are the different cooling methods used in Oil-Free air compressors?

Electrical energy is converted into thermal energy during the compression process. Cooling systems are designed to maintain the system temperature within acceptable limits.

ELGi offers Oil-Free air compressors in both Air-cooled & Water-cooled variants.

##### Q5. My application is critical. How can I be sure that the compressor delivers Oil-Free air all the time?

The compression process occurs in the compressor chamber called the Airend. An Airend has two sides, the airside and the oil side, which are completely isolated by air & oil seals, which prevent oil from mixing with air.

ELGi Airends have an additional safety arrangement, wherein even if the seals, for some reason, malfunction, the oil will go back into the sump and not mix with air. Thereby always guaranteeing 100% Oil-Free compressed air.

##### Q6.  What all industries use Oil-Free compressors?

Specific industries require air that directly contacts the end product or is used for sophisticated machines. The presence of oil traces in such scenarios is highly undesirable.

ELGi offers 100% Oil-Free compressed air solutions to Pharmaceuticals, Food & Beverage, Textile, Automobile, Electronics, FMCG, Oil & Gas, Power, and many more.

##### Q7. How does ELGi ensure the high quality of its air compressors?

Air compressors from ELGi are designed to offer the highest product quality & system reliability to our customers.

We are one of the very few manufacturers in the world who have their Airend design and build them entirely in-house.

Another example of our efforts to go the extra mile is our state-of-the-art foundry set-up to achieve the highest quality in casting.

##### Q8. How do I select a suitable air compressor for my application?

Air compressor selection depends on several factors. A few questions to ask before finalizing one for yourself are -

- What is the airflow or SCFM required by your pneumatic machines?

- What is the operating pressure?

- Does your application need Oil-Free air?

- Is your airflow demand fluctuating?

With so many factors to consider, the selection process might seem overwhelming. ELGi offers a wide range of air compressors - Oil-Free and lubricated piston and screw air compressors.

ELGi's compressed air experts can help you identify the right solution for your application. We also conduct extensive air audits to map airflow demand accurately to get the most efficient solution.
    

Frequently asked questions while selecting an oil-free air compressor


##### Reclaim The Heat You're Wasting

Energy costs account for approx. 30% of a production facility's operating budget. That means nearly a third of all the money organizations invest into their plant, goes straight to the power bill. Power cost is a pivotal determinant of the overall cost to companies.

Globally, business owners have embraced sustainable techniques to ensure   convenience, and efficiency in their facility, but is it possible to go too green? Absolutely.

Considering the implications of global warming, ELGi introduced a Heat Recovery System, which enables the reuse of heat energy generated during the compression process for tasks like heating water.

##### Refine Your Compressed Air System with ELGi's Heat Recovery System

ELGi's Heat Recovery System can assist in using 78% of the waste heat generated by the compressor for other facility operations, such as heating water. As a result, there is no longer a need to purchase additional equipment to heat water, thus lowering CO2 emissions. The Heat Recovery System is an accessory which can be used with the ELGi EG Series rotary air compressor. Customers can easily plug the HRS into an air compressor to warm water and air for use in showers and boilers by using the heat produced by the air compressor.

![Heat recovery systems](/consultant/screw-compressor/general/000012.jpg)

In a typical compression system, the theoretical recoverable heat is 96% of the overall electrical energy consumption. It consists of heat dissipated in the oil cooler (78%), the after cooler (13%) and the heat radiated from the drive motor (5%). The heat dissipated by the oil cooler can be used for heating water and the heat dissipated by the after cooler and drive motor can be used for supplemental space heating. The remaining 4% heat cannot be recovered, since 2% radiates through the canopy and the other 2% vents inside the canopy.

##### Robust Operations Across Industries

The Heat Recovery System finds its operation in industries like automotive, textiles, cement, paper & pulp, machine tool shops, steel making and the food processing industry where there is a need to heat / pre-heat water to a certain temperature ELGi's HRS can significantly reduce energy costs by eliminating the use of special heating equipment or by offering the initial heat to start the heating process where higher temperatures are required.

Elgi is a global air compressor manufacturer with an expansive line of innovative and technologically superior compressed air systems. ELGi has consistently ensured that its customers achieve their productivity goals while keeping the environmental impact low. Our product innovation for the Heat Recovery System is driven by the potential for savings and by examining the carbon footprint of an air compressor. ELGi firmly believes that sustainable technology is at the heart of positive environmental change.
    

Recover Waste Heat Energy for Better Savings


**Energy Efficiency:** Energy costs contribute to over 75% of the total life cycle cost (LCC) of a compressor, and is therefore the key factor in upgrading an air compressor. Once the energy cost of the existing compressor is determined (through air audit or a simpler total input power measurement), the benefits of a new compressor, in terms of energy costs, can be evaluated. In cases where the user's duty cycle of the air compressor has increased significantly over time due to additional production activities, the savings will be more beneficial with shorter return on investment. Additionally, if the plant needs a higher flow for expansion, it is an opportunity to consolidate the need and evaluate for upgradation. The size of the machine (in kW) should also be considered, as the larger the size of the unit, the higher the savings potential.

**Advanced features:** Significant improvement in controller features, more intelligence through additional sensors, and evolution of IoT capability are further reasons to consider an upgrade. These features result in improved uptime, insights for improvement in energy efficiency, and inputs for optimized operational settings in addition to 24x7 remote monitoring from anywhere in the world. In plants where the failure of a compressed air system can result in heavy losses in productivity, these features are particularly critical. Improvement in consumables' life and/or reliability is another factor. Recently, ELGi had doubled the life of oil filters used in its oil lubricated rotary screw compressors in several models. All these features not only make the compressors more efficient but also significantly more reliable and advanced.

**Breakthrough products:** Compressor users must also look out for breakthrough products that will result in superior performance. ELGi has recently launched a product, AB Series with a disruptive oil-free technology that will bring down the life cycle cost of an oil-free compressor significantly. Such breakthrough improvements provide an opportunity to improve overall plant efficiency and performance while meeting the users' needs effectively. Growing production needs in a plant will also need a different compressor technology such as the transition to centrifugal compressors for larger volumes of compressed air as an example.

**Unplanned maintenance costs:** As compressors age and when they need frequent attention to keep them running reliably, the unplanned maintenance or repair costs will also increase. If the cost of repairs reaches a certain level (~40-50% of the compressor value), along with the lower energy efficiency of older products, it is an appropriate time to evaluate and upgrade your air compressor.

**Return of Investment (RoI):** Another important factor to be considered while upgrading the compressor is the RoI. With improv energy costs, the RoI can be evaluated to meet the customer's target.

![To evaluate if an upgrade of the compressor will help you](/consultant/screw-compressor/general/000010.jpg)
    


As technology evolves at a rapid pace and with every version of a product getting more efficient in meeting customer needs, it is necessary to understand the efficient life of any product. Air compressors are no exception to such technological and product improvements.

With continuous efforts by compressor manufacturers to lead the market on energy efficiency, superior performance, and reliability, it is critically important that the users of air compressors are aware of the advanced product options available in the market. The technological advances in control systems and the evolution of the Internet of Things (IoT) provide further motivation to upgrade the air compressors at the right time. Typically, air compressors are upgraded every 3-4 years by manufacturers to improve energy efficiency, reliability, advanced features, etc., and it is worth the while to evaluate the need for upgrading your compressors.

In this article, we will highlight the key factors to be considered for upgrading your air compressor.
    

Factors to Consider While Upgrading Your Air Compressors


##### Why ELGi Airmate Filters?

Here are the three key values that the customers gain with the ELGi's AF Series Filters.

- **Best-in-class performance:** These filters are third-party tested for performance of residual oil as per the class stated and handle capacity they are rated for with high efficiency (99.99%).
- **Best-in-class energy efficiency:** The AF series filters have the lowest pressure drop in their class and significantly save energy wastage. The lowest pressure drop of 0.35 bar (combination of wet saturated pre-filter, fine-filter, and dry carbon filter) at rated capacity with next-gen elements is about 30% lower than average competition.
- **Best-in-class ten years warranty for housing:** The common problem with most housing is corrosion. While this corrosion doesn't affect the filter's performance itself, it adds particles of its corroded body (Al or Fe) to the air, thus making it unfit for sensitive applications. With this warranty, customers can have a reliable, pure operation for the entire life of the filter.

The above value proposition is backed by tests (as per ISO 12500 standard), validation data, and third-party certification. The maintenance of these filters for changing the elements is made reliable and simple. The differential pressure gauge gives the actual condition of the element, i.e., three coloured indicator helps in easy identification of filter element life and planning the maintenance activity. They also come with an element-time strip indicator that helps alert the user for on-time replacement of elements, thus never missing the reliability and quality of air needed by any user. You can contact ELGi application engineers or the nearest sales representative to select the right product for your application.

![Best pratices to keep your compressed air system running efficiently](/consultant/screw-compressor/general/000004.jpg)

** *Application of Downstream Filters* **

##### How to remove contaminants from your compressed air system?

The atmospheric air comprises of moisture, particle contaminants, microorganisms, and gases. When this air gets compressed, the concentration of such particles increases by 6-10 times. However, when an air compressor compresses this atmospheric air, other contaminants like oil and metal traces get added during the compression process. This is why it is important to remove these contaminants from the compressed air before using them for any application.

![How to remove contaminants from your compressed air system?](/consultant/screw-compressor/general/000005.jpg)

These contaminants can be categorized into:

- Particles
- Water (Liquid, vapour, and aerosol)
- Oil (Liquid, vapour, and aerosol)
- Microorganisms
- Other gases

According to the International Standard, ISO 8573-1:2010, compressed air contaminants like particles, water, and oil are segregated as per purity classes. In this standard, microorganisms and other gases are not included. As a result, the air purity is indicated as [P, W, O] and is ordered as per the number of particles, water, and oil.

![International Standard, ISO 8573-1:2010, compressed air contaminants](/consultant/screw-compressor/general/000006.jpg)

Based on the application requirement, contaminants are to be removed from the compressed air using suitable downstream equipment. For instance, particle, water, and oil contaminants can be removed from the compressed air using downstream filters.

**Bulk moisture separators** are recommended for removing the water from the compressed air. It is mandatory to have a proper automatic drain along with the moisture separator, as they are mostly used after the cooler. The optimal removal of condensate will ensure that no bulk water carry over to the downstream equipment. It is recommended to use a level sensing zero loss drain along with a moisture separator to get this done with minimum loss of air.

Downstream filters are available in various configurations/types. These can be categorized as per the residual oil and particle after filtration and are as follows:

- **The Coalescing filters** are recommended to remove the wet particles and aerosols (water and oil) from the compressed air. Different types of coalescing filters are available based on residual oil and particle content at the filter outlet after filtration. Coalescing filters are classified into pre filters and fine filters.
  - With the Pre-filter, class 3 or 2 purity of particles and oil can be achieved, i.e., ISO 8573-1:2010 [2:-:2]
- The recommended sequence of installation is the bulk moisture separator followed by pre-filter
- With the fine-filter, class 2 or 1 purity of particles and oil can be achieved, i.e., ISO 8573-1:2010 [1:-:1]
  - The recommended sequence of installation is bulk moisture separator, pre-filter, dryer followed by a fine filter
- **The particulate filters** are specialized to remove the dry particle and microorganisms from compressed air. This filter is mostly used after a desiccant dryer to ensure that the desiccant particles are not carried to the compressed air line.
- The class of purity of particles made possible with this filter is 3,4,5&6, i.e. ISO 8573-1:2010 [3:-: - ]
  - The recommended installation sequence is the bulk moisture separator, pre-filter, desiccant dryer, followed by the particulate filter.
- **The Carbon filters** are recommended to remove the oil vapor and other gases present in the compressed air that are not removed by the coalescing filters.
- The class of purity achievable with carbon filter is "1", i.e., ISO 8573-1:2010 [-:-:1]
  - The recommended preceding with carbon filter would be pre-filter, dryer, fine-filter, followed by carbon filter

![image](/consultant/screw-compressor/general/000007.jpg)

##### Important factors to consider for having the right selection of filters to ensure optimal performance

- The filter capacity is based on the operating pressure of 7 bar/100 psi (nominal condition). In case the operating pressure is different, it is important to use the correction factor and select the filter model accordingly.
- The correct sequence of installing filters must be followed so that the performance is optimal. As a thumb rule, the level of filtration should be in sequence, ranging from 20 ppm to 5 microns or from 10 microns to 1 micron to 0.01 micron. Carbon filters should always follow after the 0.01 micron filter. Absence of this sequence will reduce the life of the filters.
- Please note that the lowest pressure drop across filters happens when the filter elements are dry. If the filter element gets wet, delta P will increase. This is another reason why we should follow the above sequence.

- It is recommended to have a proper drain along with the pre-filter since the pre-filter is mostly used before the dryer. The regular removal of condensate will ensure that no moisture carries over to the downstream equipment.

- The replacement of the filter element at the recommended service interval is important. The filters have an indicator of saturation level, and it is recommended to replace the filter element in case of indication. Saturated filter elements will not give the required class of purity. This will have a higher pressure drop, creating an extra load on the compressor. As a thumb rule, 0.14bar/2 psi pressure drop will have 1% additional load on the compressor. Carbon filters function on the adsorption method and need to be replaced on a timely basis.

![Important factors to consider for having the right selection of filters to ensure optimal performance](/consultant/screw-compressor/general/000008.jpg)
    

The ELGi's Airmate Filters (AF) are suitable for applications that require filtered air for reliable performance. The AF series filters provide customers with best-in-class filtration and the lowest pressure drop. These filters are manufactured in compliance with applicable international standards ASME(USA), CE (Europe), CRN (Canada), AS 1210(Australia), and are designed as per the international quality standards.

Introducing ELGi's AF Series Downstream Filters.


#### An indispensable utility for your compressed air system

Water vapor in the compressed air needs to be eliminated to prevent damage & corrosion to the compressed air line & your pneumatic tools. The operational expenses may go up significantly, if this moisture is not eliminated from the system.  That is why compressed air dryers are critical to industrial manufacturing processes as they help in removal of moisture from the compressed air lines.


Different dryers for diverse applications

#### Depending on the application, compressed air dryers come in different capacities and types. Each of these dryers is unique, with its benefits and disadvantages:

1. Refrigerated air dryers

Out of all the compressed air dryers, the refrigerated air dryer is the most popular and used across several applications.

##### Functions:

- Cools compressed air to very low temperatures, allowing moisture suspended in it to condense into its liquid form.
- Once the water has been removed, a dry stream of air can flow towards the application.

##### Application:

Useful in manufacturing & service applications that require compressed air with no detectable condensable moisture.

##### Benefits:

- Cost-efficient - both in purchase and maintenance.
- Resistant to airborne oil particles.

##### Considerations:

- Not ideal for sub-freezing temperatures.
- Have a limited dew point capacity.

2. Desiccant air dryers

They are usually the second step after a primary dryer like a refrigerated dryer.

##### Functions:

Utilize a porous hygroscopic medium like activated alumina, molecular sieve and silica gel to extract moisture from the air and dry it.

##### Applications:

Useful in moisture-sensitive industrial and commercial applications:

- Mold & bacteria prevention.
- Healthcare/medication prescription environments.
- Food processing.
- Textile manufacturing.

##### Benefits:

- Constant, low dew points.
- Moderate operating costs.
- Suitable for use in harsh, isolated environments.

##### Considerations:

- High setup costs.
- Air filtration needed to prevent desiccant degradation from suspended oils.
- Purge air is often required.

3. Deliquescent air dryers

Single Tower Desiccant dryers are used in smaller, more specialized applications where a continuous supply of clean, dry compressed air is not required.

##### Functions:

Utilize a porous hygroscopic medium like activated alumina, molecular sieve and silica gel to extract moisture from the air and dry it.

##### Applications:

Useful in moisture-sensitive industrial and commercial applications:

- Mold & bacteria prevention.
- Healthcare/medication prescription environments.
- Food processing.
- Textile manufacturing.

##### Functions:

- The deliquescent desiccant type of dryer uses a hygroscopic desiccant material having a high affinity for water.
- The desiccant absorbs the water vapor and is dissolved in the liquid formed.
- These hygroscopic materials are blended with ingredients to control the pH of the effluent and to prevent corrosion, caking and channeling.

##### Benefits:

- Low initial capital and installation cost.
- Low pressure drops.
- No moving parts.
- Requires no electrical power.
- Can be installed outdoors.
- Can be used in hazardous, dirty or corrosive environments.

##### Consideration:

- Limited suppression of dew point.
- Desiccant bed must be refilled periodically.
- Drainage of dissolved solution.
- Regular periodic maintenance.
- Desiccant material can carry over into down-stream piping if there is no after-filter and if the dryer is not drained regularly. Certain desiccant materials may have a damaging effect on down- stream piping and equipment.
- Some desiccant materials may melt or fuse together at temperatures above 80°F.

4. Membrane air dryers

Efficient option for compressed air drying.

##### Functions:

- Utilize specialized membranes containing microtubules to filter moisture.
- The microtubules retain water while a stream of the dried air is permitted to flow through to a collection unit or required application.

##### Applications:

Used in applications requiring dehumidification, food processing, and gas separation.

##### Benefits:

- Remote operation without the need for electricity.
- Quiet operation, no moving parts.
- Easy maintenance.

##### Considerations:

- Only be operated with uncontaminated air.
- Require regular filter changes to prevent blockages.

#### ELGi's solution for moisture sensitive industries

**ELGi's Airmate Desiccant Dryer:** is a heatless twin tower desiccant dryer that removes moisture through absorption onto a granular desiccant bed from the air supply. As compressed air flows up through a packed bed of desiccant in tower 1, water vapor is absorbed. Meanwhile, tower 2 is rapidly depressurized, and dry purge air from the outlet of tower 1 is fed through a purge valve, expanded to near atmospheric pressure, and counter-flowed down through tower 2 to affect the regeneration of its granular desiccant bed. When the desiccant in tower 1 becomes saturated with water vapor, the air supply is switched back to tower 2 after it has been re-pressurized, and the cycle continues.

#### As default, all HLD models above 5X come with the following options.

**Dew Point Stretch Cycle:** It stretches the moisture loading time of the desiccant bed by increasing the drying time. A dew point meter at the outlet with a required dew point setting provides the signal for the stretch cycle. This reduces the purge of air per the air flow and dew point chosen. The purge occurs for the pre-programmed time during this time.

Note - Dew point meter not in dryer scope.

**Purge Optimizer:** It reduces the percentage of regeneration flow based on the front panel setting. It has 4 options 40%, 60%, 80% & 100% purge optimization cycles respectively. The settings correspond to flow or moisture load through the dryer. Separate LED Indicators for Tower Status, Purge Optimizer & Condensate Drain.

To make sure that you choose the ideal air dryer for your system, here are some things to keep in mind:

- Select the air quality your business requires.
- Invest in high-quality systems, resulting in cost & time efficiency.
- Get in touch with an ELGi expert; they can assist you while navigating ELGi's range of air dryers.
    

How to select the right air dryer for compressors?


#### Duty Cycle & Utilization

Duty cycle refers to the time a compressor is expected to run in a given hour at full capacity. Reciprocating compressors are designed to operate between 60-80% duty cycles and screw compressors are designed to operate at 100% duty cycle.

Life cycle cost of a compressor constitutes Initial Cost + Maintenance Cost + Energy Cost

(In a screw compressor, energy cost contributes to over 75% of the life cycle cost over 10 years' operation time).

It is critical to understand the life cycle cost of a compressor before making the purchase decision.

For more understanding on the life cycle cost of a compressor, refer to:
https://blog.elgi.com/knowledge-center/identify-the-real-life-cycle-costs-of-your-air-compressor/

#### The amount of time a compressor runs in a day influences the energy cost. While looking to select a compressor with optimal life cycle cost, follow these guidelines:

- When utilization is < 4 hours/day select a reciprocating compressor
- When utilization is between 4 and 8 hours/day, a belt driven screw compressor is preferred
- When the utilization exceeds 8 hours/day, a direct driven screw compressor is the best fit.

You can also use the product selector on our website, to match the products for your requirements.
    


#### Factors to consider when selecting an air compressor:

- Quality of air
- Capacity of the compressor
- Duty cycle & utilization

#### Quality of Air

Industrial compressors have oil as the medium that cools, lubricates and seals gaps between the moving parts. As a result of this, compressed air is exposed to the oil and a part of it is carried over.

In specific applications, compressed air comes in direct contact with products such as food and pharma, this is where oil free air is preferred.

The quality of air based on the amount of this oil carried is represented by ISO 8573:2010. Class 3 allows for < 1 mg/m3 of oil carry over and a higher quality can be achieved through downstream filtration equipment.

Depending on your application requirement, the selection of the air compressor will vary.

#### Capacity of the Compressor Required

The capacity of an air compressor is a function of volumetric flow of air and the pressure to which it is compressed. This also determines the power rating (typically in kW or HP) of the air compressor.

Eg. A 22 kW (30 HP) air compressor can provide a flow of about 140 cfm (3.96 m3/min) at 7 bar g. (102 psi) pressure.

Few ways to determine the capacity requirement of a plant is through the OEM recommendation, past equipment experience or through air audit. Air audits enable companies to get valuable insights into their plant's compressed air utilization.

ELGi's air audits chart out a customized and comprehensive energy management plan for your needs. Reciprocating compressors are well suited for flow below < 50 cfm and for higher flow capacities, screw compressors are better suited, when comparing the two technologies.
    


With increase in automation across industries, the need for compressed air in the industrial sector is also increasing - and this dependency will only grow, going forward.

Having said that, the need for compressed air are many, based on various application in several industries.

Selection of the right compressor can be a daunting challenge with several technologies and options available in the market. In this article, we attempt to simplify the process of selecting the industry's most widely used air compressors; reciprocating and screw compressors for any given application.

But remember, when in doubt, always reach out to our Compressed Air Experts!
    

How to choose the right air compressor for your business?

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