Manufacturing’s 4th Utility: Compressed Air System Components

In any manufacturing environment, compressed air is critical to the operation of many processes. You will often hear compressed air referred to as a “4th utility” in a manufacturing environment. The makeup of a compressed air system is usually divided into two primary parts: the supply side and the demand side. The supply side consists of components before and including the pressure/flow controller. The demand side then consists of all the components after the pressure/flow controller.

The first primary component in the system is the air compressor itself. There are two main categories of air compressors: positive-displacement and dynamic. In a positive-displacement type, a given quantity of air is trapped in a compression chamber. The volume of which it occupies is mechanically reduced (squished), causing a corresponding rise in pressure. In a dynamic compressor, velocity energy is imparted to continuously flowing air by a means of impellers rotating at a very high speed. The velocity energy is then converted into pressure energy.

Still on the supply side, but installed after the compressor, are aftercoolers, and compressed air dryers. An aftercooler is designed to cool the air down upon exiting from the compressor. During the compression, heat is generated that carries into the air supply. An aftercooler uses a fan to blow ambient air across coils to lower the compressed air temperature.

When air leaves the aftercooler, it is typically saturated since atmospheric air contains moisture. In higher temperatures, the air is capable of holding even more moisture. When this air is then cooled, it can no longer contain all of that moisture and is lost as condensation. The temperature at which the moisture can no longer be held is referred to as the dewpoint. Dryers are installed in the system to remove unwanted moisture from the air supply. Types of dryers available include: refrigerant dryers, desiccant dryers, and membrane dryers.

Also downstream of the compressor are filters used to remove particulate, condensate, and lubricant. Desiccant and deliquescent-type dryers require a pre-filter to protect the drying media from contamination that can quickly render it useless. A refrigerant-type dryer may not require a filter before/after, but any processes or components downstream can be impacted by contaminants in the compressed air system.

Moving on to the demand side, we have the distribution system made up of a network of compressed air piping, receiver tanks when necessary, and point of use filters/regulators. Compressed air piping is commonly available as schedule 40 steel pipe, copper pipe, and aluminum pipe. Some composite plastics are available as well, however PVC should NEVER be used for compressed air as some lubricants present in the air can act as a solvent and degrade the pipe over time.

Receiver tanks are installed in the distribution system to provide a source of compressed air close to the point of use, rather than relying on the output of the compressor. The receiver tank acts as a “battery” for the system, storing compressed air energy to be used in periods of peak demand. This helps to maintain a stable compressed air pressure. It improves the overall performance of the system and helps to prevent pressure drop.

Finally, we move on to the point-of-use. While particulate and oil removal filters may be installed at the compressor output, it is still often required to install secondary filtration immediately at the point-of-use to remove any residual debris, particulate, and oil. Receiver tanks and old piping are both notorious for delivering contaminants downstream, after the initial filters.

Regulator and filter

In any application necessitating the use of compressed air, pressure should be controlled to minimize the air consumption at the point of use. Pressure regulators are available to control the air pressure within the system and throttle the appropriate supply of air to any pneumatic device. While one advantage of a pressure regulator is certainly maintaining consistent pressure to your compressed air devices, using them to minimize your pressure can result in dramatic savings to your costs of compressed air. As pressure and flow are directly related, lowering the pressure supplied results in less compressed air usage.

EXAIR manufactures a wide variety of products utilizing this compressed air to help you with your process problems. If you’d like to discuss your compressed air system, or have an application that necessitates an Intelligent Compressed Air Product, give us a call.

Tyler Daniel, CCASS

Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

Compressor Image courtesy of Compressor1 via Creative Commons License

The Importance of Compressed Air Filters

The last home I purchased had an all-seasons room, but the sellers told me the air conditioner that controlled the room temperature wasn’t working. When I moved in and tested the unit, the sellers were correct that it did not run. I started breaking it down and thought that maybe it could use a good cleaning. During this I found the filter, black and covered with pet fur. It was a washable filter so I cleaned it and let it air dry as I continued to clean remaining areas of the unit. When I put the filter back in and tried running the unit it was a miracle, it was running and producing cool air. I did nothing other than clean and clear the filter, no replacement parts, no tweaking and no repairmen.

I tell this story to many people now as it also relates to appliances, cars, lawn mowers and now I emphasize filters for compressed air systems. Using auto drain filters and oil removal filters is imperative to keeping your air clean before it gets to your tooling and equipment. Keeping water condensate and particulates contained to your filters is critical to the operation and life of your tooling and equipment. Older compressed air lines can begin to rust or corrode inside, creating scale which can jam and cause inefficiencies. Sediment and other contaminants will build up and could cause damage to your compressed air systems.

Good engineering practice calls for point of use filtration and moisture removal, such as that provided by EXAIR Filter Separators.

EXAIR carries multiple sizes and types of compressed air filters available from stock. Our Particulate and Coalescing filters can be found in our catalog and online (use the link above). If you have an application and need help selecting and sizing the right filter for your needs please contact one of our application engineers by calling 800.903.9247.

Eric Kuhnash
Application Engineer
E-mail: EricKuhnash@exair.com
Twitter: Twitter: @EXAIR_EK

Optimize Your Intelligent Compressed Air® Products with EXAIR’s Accessories

EXAIR offers a wide variety of various accessories that can help you to better control and fine-tune any of your compressed air operated products. Most of EXAIR’s line of Intelligent Compressed Air Products have no moving parts and require no maintenance. The caveat to the “no maintenance” aspect is proper filtration at the point of use. Many products have very tight orifices that could get clogged from any contaminants such as particulate, condensate, and lubricant. EXAIR recommends point of use filtration to be installed just upstream of any EXAIR Product for this purpose.

EXAIR has a line of Automatic Drain Filter Separators and Oil Removal Filters, available from stock, to make sure the quality of your air supply is sufficient for proper operation of any EXAIR product. Particulate filters remove any suspended solids from the airstream, ensuring the tight orifices in the products remain free of debris. If your system has residual oil, this should also be removed with a coalescing filter. Check out this short video from my colleague, Brian Farno, that demonstrates these filters in action:

Controlling your compressed air pressure at the point of use is an excellent way of minimizing your compressed air usage. Pressure regulators are available to control the air pressure within the system and throttle the appropriate supply of air to any pneumatic device. As the last of the six steps to optimizing your compressed air system, controlling air at the point of use can often be overlooked. using them to minimize your pressure can result in dramatic savings to your costs of compressed air. As pressure and flow are directly related, lowering the pressure supplied results in less compressed air usage. EXAIR recommends operating your Intelligent Compressed Air Products at the minimum pressure necessary to achieve a successful application. If you notice a desirable result at a pressure of 60 PSIG, or even less, there’s no need to run full line pressure. In-line point of use pressure regulators are the simplest and most reliable way to allow you to dial down to the pressure to any compressed air operated product.

Taking this idea of minimizing air usage one step further, you can achieve even greater savings by simply turning the air off when not needed. The most basic option for turning off the air supply is a simple manual valve. EXAIR offers a range of various sized valves to allow you to do just that.

This process can also be automated as well. If you’d like to automate the control of your blowoff, EXAIR offers solenoid valves that can tie into your existing PLC and eliminate unnecessary air usage. For those that want a solution ready to go right out of the box, EXAIR’s Electronic Flow Controller utilizes a photoelectric sensor and solenoid valve tied to a timer that allows you to shut off the air supply when a part or component is not present. This can lead to dramatic air savings in many applications where parts are traveling along a conveyor.

Once you’ve selected an engineered compressed air nozzle for your blow off application, you’ll likely need a solution to mount and position it as well. Here’s where EXAIR’s Stay Set Hoses and Magnetic Bases come into play. EXAIR’s Stay Set Hoses are available from 6”-36” in length with ¼ NPT male threads on each end, or a ¼ NPT male on one end and 1/8 NPT female on the other. The Stay Set Hoses are rigid and allow you to maintain precise positioning of the blow off nozzle. The hoses have “memory” and will not creep or bend. They’re easily repositionable as well, making them an ideal solution for applications that may require frequent repositioning due to varying parts.

In addition to the Stay Set Hoses, EXAIR also has Magnetic Bases available as well. The powerful magnet permits both horizontal and vertical mounting. A manual valve is also included that will allow you to vary the force and flow. Magnetic bases are available with one or two outlets and can be combined with any of our nozzles and Stay Set Hoses to create your own customized blowoff system.

Regardless of your application, EXAIR has the products available from stock to help optimize your processes. These accessories allow you to help optimize the use of your blowoff products and ensure reliable, repeatable performance. If you’d like to discuss an application, give us a call.

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

Preventative Maintenance for EXAIR Filters

Good engineering practice calls for point of use filtration and moisture removal, such as that provided by EXAIR Filter Separators.

I read a white paper from Parker Hannifin about compressed air filters.  The idea behind the paper was to remember your filter replacements.  Compressed air can be dirty with water, oil, pipe scale, etc.  As the filters capture the contamination, it will start to build pressure drop.  Remember, pressure drop is a waste of energy in your compressed air system.

Majority of EXAIR products use compressed air for cleaning, cooling, conveying, static elimination, coating and more.  To help keep them running efficiently, it is important to supply them with clean, dry, pressurized air.  EXAIR offers a line of Filter Separators and Oil Removal Filters to supply quality air to your equipment.  In this blog, I will explain the two types of filters that we carry and the maintenance requirements.  Filters and preventative measures can play an important part in your compressed air system.

Filter Separators are used to remove bulk liquid and contamination from the compressed air stream.  They utilize a 5-micron filter with a mechanical separation to help remove large amounts of dirt and water.  This type of filter would be considered the minimum requirement for filtration.  Most of the Filter Separators come with an auto-drain to automatically dispense the collection of oil and water.  EXAIR offers a variety of port sizes and flow ranges to meet your pneumatic flow requirement.  For maintenance, the filter elements should be changed once a year or when the pressure drop reaches 10 PSID (0.7 bar), whichever comes first.  I created a list in Table 1 below showing the correct replacement element kits for each model number.  And for any reason, if the bowl or internal components get damaged, we also have Rebuild Kits as well.  Just remember, the air quality is very important for longevity and functionality of your pneumatic systems and even for EXAIR products.

The Oil Removal Filters can make your compressed air even cleaner.  They work great at removing very small particles of dirt and oil.  They are made from glass fibers and can remove particles down to 0.03 micron.  They are designed to collect small particles and to coalesce the liquid particles into a large droplet for gravity to remove.  Because of the fine matrix, Oil Removal Filters are not great for bulk separation.  If you have a system with lots of oil and water, I would recommend to use the Filter Separator upstream of the Oil Removal Filter.  As with the Filter Separator, the filter element should be changed once a year or at a pressure drop of 10 PSID (0.7 bar).  EXAIR also offers a variety of port sizes and flow ranges.  Table 1 below shows the replacement Element Kits as well as the Rebuild Kits.  If the application requires very clean compressed air, the Oil Removal Filter should be used.

Table 1

By using EXAIR filters, they will clean your compressed air to prevent contamination on parts, performance issues, and premature failures.  As an ounce of prevention, you should add the replacement elements in stock and enter them in your preventative maintenance program.  With quality air, your pneumatic system and EXAIR products will provide you with effective, long-lasting performance without any maintenance downtime.  If you would like to discuss the correct type of filters to use in your application, you can speak with an Application Engineer.  We will be happy to help you.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb