Comparing the Different Styles of Compressed Air Filters

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.

There are three primary types of compressed air filters: particulate, coalescing, and adsorption. Each have their own inherent characteristics and can be used in conjunction with one another. Each style is used to handle a different form of contaminant that’s present within the distribution system of your compressed air supply.

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EXAIR Model 9001 Auto-Drain Filter

Particulate filters – Particulate filters are available with different filtering mechanisms that allow you to control the particulate size that will be filtered out. The higher the level of filtration, the greater the pressure drop you’ll experience at the outlet of the filter. Styles are also available with either a polycarbonate bowl or metal bowls, depending on the application and environment.

Any filter with a polycarbonate bowl should have a metal guard on the outside to provide protection for personnel should a failure occur. In these styles of filters, compressed air is forced through a filter element that blocks any particulate contained within the air supply.

These filter elements are generally a sintered bronze material with filtration levels from 40-5 micron possible. Over time, the filter elements can clog and increase the pressure drop at the discharge of the filter. They’re relatively inexpensive and should be replaced yearly to maintain optimum performance and mitigate pressure drop. They also remove liquid drops as well from the air supply, containing them within the bowl. Styles with both manual-drains and automatic-drains are available that will drain the bowl of excess moisture automatically through the bottom of the filter.

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EXAIR Model 9005 Oil Removal Filter

Coalescing Filters – The coalescing filter is used to remove very fine water vapor as well as any residual oil. These filters are highly recommended to be installed just prior to any dryer that contains a media that would be compromised by any lubricant passing through it. Coalescing filters utilize an element typically made up of glass fibers that “coalesce”, or combine, the fine water vapor and oil aerosols until the droplet size becomes large enough that it drops off into the bowl or filter housing. With a coalescing filter, the most common cause of pressure drop increase is due to particulate clogging the filter element. Because of this, a particulate filter should always be installed just prior to any coalescing filters.

Adsorption Filters – The final type of compressed air filter is the adsorption filter. Where the particulate filters can remove the majority of contaminants and the coalescing filters the residual oil, they are not capable of removing lubricant vapors or oil. That’s where the adsorption filter comes in. In addition to removing the finest oil vapors, they also can eliminate odors from the compressed air supply. The oil vapors and odors adhere to activated carbon within the filter, removing them from the air supply. These filters are commonly found within the food processing industry, where any contaminants in the air supply could impact the integrity of the product.

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. Feel free to give us a call and any of our Application Engineers will be happy to assist you.

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

The Importance of Compressed Air Filtration

In this blog, I would like to turn your attention to our accessories that support our Intelligent Compressed Air® Products; the Filter Separator and the Oil Removing Filter.  EXAIR products use compressed air to coat, conserve, cool, convey and clean.  So, to keep our products running properly and efficiently, we need to supply them with clean, pressurized air.  If we look at the two types of filters that we offer, we can see how they can play an important part in your compressed air system.

Filter Separators

Filter separators are used to remove bulk liquid and contamination from the compressed air stream.  They have a 5-micron filter and work very well if you get a slug of liquid in your compressed air system.  They use mechanical separation to remove the large particles of dirt and water from the air stream.

Most facilities use some type of compressed air dryer in their system to dry and condition the compressed air.  But, if a system failure occurs, then water, oil, and dirt can be pushed into the compressed air lines and perhaps into your EXAIR products.

Even if you have good quality air, it is still important to keep your products protected.  I would consider the Filter Separator as a minimum level of protection that should be used.

Oil Removal Filters

The Oil Removal Filters are used to keep the compressed air even cleaner yet.  They work great at removing very small particles of dirt and oil.  The 0.03-micron media of the Oil Removal Filter is designed to “coalesce” the fine liquid particles into large droplets.

Thus, allowing gravity to remove it from the compressed air stream.  Some common issues allow for dirt and oil particles to collect in “dead” zones within the air lines.  As it piles up and grows, portions can break off and get into the air stream affecting pneumatic devices.

The Oil Removal Filter will be able to help eliminate this long-term problem in your compressed air system.  As a note, Oil Removal Filters are not great for bulk separation.  If you have a system with lots of water, you should use a Filter Separator in front of the Oil Removal Filter to optimize the filtration.

Now that we went through each type, how do we use them together to get the best supply of compressed air?  We always want them to be installed upstream of a Regulator.  This is because the velocity is lower at higher pressures.

Lower velocities mean lower pressure drops which is great for supplying the proper amount of compressed air to EXAIR products.  If you are using a combination of both filters, the Filter Separator will be upstream of the Oil Removal Filter.  The Filter Separator will knock down the large particles and liquid slugs allowing the Oil Removal Filter to remove the smaller droplets and particles.

EXAIR offers a range of sizes to help support our products.  They range from ¼” NPT ports up to 1 ½” NPT ports.  The size of the ports determines the flow rating for each unit.  EXAIR also has Mounting Brackets to mount the filters to walls or frames.

To support each type of filter, we have replacement elements and bowl kits.  Since the function of the filter is to remove debris, we recommend to change the filter element once a year or when it reaches 10 PSID pressure drop; whichever comes first.

If we can analyze the compressed air systems, I would like to categorize it into a good and premium quality.  For the good quality of compressed air, you can have the compressed air run through the Filter Separator.  For the premium quality of compressed air, you can have your compressed air run through the Filter Separator and then through the Oil Removal Filter.

With clean quality air, your EXAIR products will provide you with effective, long-lasting performance without maintenance downtime.

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

What’s The Big Deal About Clean Air?

Compressed air isn’t called manufacturing’s “Fourth Utility” (the first three being electricity, water, and natural gas) for nothing. Pneumatic tools are popular because they’re often so much lighter than their electric counterparts. Compressed air can be stored in receiver tanks for use when other power supplies are unavailable or not feasible. Many compressed air operated products can be made to withstand environmental factors (high/low temperature, corrosive elements, atmospheric dust, oil, other contaminants, etc.,) that would make electric devices very expensive, unwieldy, or impractical.

One of the most valuable considerations, though, is that your compressed air system is, by and large, under your control.  The type and capacity of your air compressor can be determined by your specific operational needs.  The header pressure in your supply lines is based on the applications that your air-operated devices are used for.  And the performance & lifespan of every single component in your compressed air system is determined by the care you take in maintaining it.

I covered the importance of compressed air system maintenance in a blog a while back…today, I want to focus on clean air.  And, like the title (hopefully) makes you think, it’s a REALLY big deal.  Consider the effects of the following:

Debris: solid particulates can enter your air system through the compressor intake, during maintenance, or if lines are undone and remade.  If you have moisture in your air (more on that in a minute,) that can promote corrosion inside your pipes, and rust can flake off in there.  Almost all of your air operated products have moving parts, tight passages, or both…debris is just plain bad for them.  And if you use air for blow off (cleaning, drying, etc.,) keep in mind that anything in your compressed air system will almost certainly get on your product.

Your compressed air system may be equipped with a main filter at the compressor discharge.  This is fine, but since there is indeed potential for downstream ingress (as mentioned above,) point-of-use filtration is good engineering practice.  EXAIR recommends particulate filtration to 5 microns for most of our products.

Water: moisture is almost always a product of condensation, but it can also be introduced through faulty maintenance, or by failure of the compressor’s drying or cooling systems.  Any way it happens, it’s also easy to combat with point-of-use filtration.

EXAIR includes an Automatic Drain Filter Separator in our product kits to address both of these concerns.  A particulate filter element traps solids, and a centrifugal element “spins” any moisture out, collecting it in the bowl, which is periodically drained (automatically, as the name implies) by a float.

Point of use filtration is key to the performance of your compressed air products, and their effectiveness. Regardless of your application, EXAIR has Filter Separators to meet most any need.

Oil: many pneumatic tools require oil for proper operation, so, instead of removing it, there’s going to be a dedicated lubricator, putting oil in the air on purpose.  Optimally, this will be as close to the tool as possible, because not all of your compressed air loads need oil…especially your blow offs.  If, however, a blow off device is installed downstream of a lubricator (perhaps due to convenience or necessity,) you’ll want to do something about that oil. Remember, anything in your system will get blown onto your product.

If this is the case, or you just want to have the cleanest air possible (keep in mind there is no downside to that,) consider an EXAIR Oil Removal Filter.  They come in a range of capacities, up to 310 SCFM (8,773 SLPM,) and the coalescing element also offers additional particulate filtration to 0.03 microns.

In closing, here’s a video that shows you, up close and personal, the difference that proper filtration can make:

If you’d like to discuss or debate (spoiler alert: I’ll win) the importance of clean air, and how EXAIR can help, give me a call.

Russ Bowman
Application Engineer
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Oil Removal Filters – Keeping Compressed Air Clean

Compressed air filters help to keep the air clean and condensate free to protect equipment from dust, dirt, pipe scale, oil and water. Even though the compressed air system will typically have a main dryer, additional treatment is often necessary. For this discussion, we will focus on the oil removal process and filter type.

After the compressed air has passed through a particulate filter, the dirt, dust and water droplets have been removed.  Oil that is present is much smaller in size, and mostly passes though the particulate filter.  The installation of a coalescing filter will provide for the removal of the majority of the fine oil aerosols that remain. The coalescing filter works differently than the particulate filters. The compressed air flows from inside to outside through the coalescing filter media. The term ‘coalesce’ means to ‘come together’ or ‘form one mass.’  The process of coalescing filtration is a continuous process where the small aerosols of oil come in contact with fibers of the filter media. As other aerosols are collected, they will join up and ‘come together’ and grow to become an oil droplet, on the downstream or outside surface of the media.  Gravity will then cause the droplet to drain away and fall off the filter element.

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Example of a 0.03 Micron Coalescing Oil Removal Filter

Some important information to keep in mind –

  • Change the filter regularly, not just when the differential pressures exceeds recommended limits, typically 5 PSI
  • Coalescing filters will remove solids too, at a higher capture rate due to the fine level of filtration, using a pre-filter for solids will extend the life
  • Oil free compressors do not provide oil free air, as the atmospheric air drawn in for compression contains oil vapors that will cool and condense in the compressed air system.

If you would like to talk about oil removal filters or any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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EXAIR Accessories – We’ve Got you Covered

When you work with us here at EXAIR, we strive to have all the ancillary items that you might need to make your installation a success, without having to find components at the last minute or perhaps using the wrong sized components. Each specific product line such as Super Air Knives or Line Vac air operated conveyors have specific accessories such as mounting brackets or plumbing kits which EXAIR has made to simplify the installation of those particular products. We also carry generalized accessories which work across all of the product lines so you do not have to use multiple vendors or purchase orders.

Silencing Mufflers – Per OSHA Standard 1910.95(a), a worker must not be exposed to sounds levels above 90 dBA for any eight hour shift of a 40 hour work week.  EXAIR offers several types of mufflers including – Reclassifying, Sintered Bronze, Straight-Through and Heavy Duty.  For reducing the noise associated with an EXAIR E-Vac Generator, Vortex Tube, Cabinet Cooler System, or the exhaust air from cylinders, valves and other air powered equipment, we’ve got a muffler that will help to keep the noise level at an acceptable level.

Mufflers

Solenoid and Manual Valves – The easiest way to reduce compressed air usage and save on operating expense is to turn off the compressed air to a device when it isn’t needed. EXAIR carries a wide assortment of solenoid valves, with offerings in the NEMA 4/4X classification, and supply voltages of 24VDC, 120VAC, and 240VAC.  We also have manual ball valves from 1/4 NPT to 1-1/4 NPT and a foot operated valve, with 1/4 NPT connections.

Valves

Swivel Fittings, Stay Set Hoses and Magnetic Bases – To provide a great degree of flexibility for positioning an EXAIR Super Air Nozzle, Air Jets or Air Amplifiers, EXAIR offers several items.  The Swivel Fittings have 25 degree of movement from the center axis, providing a total of 50 degree of adjustability.  The position is locked in place and holds until adjustment is needed. For applications where frequent re-positioning of the air device is required, the Stay Set Hoses are ideal.  Simply mount the hose close to the application, bend it to the shape preferred, and because the hose has “memory”, it will not creep or bend.  Lastly, the Magnetic Bases are another option for flexible, movable installations.  The base has a on/off valve, and a powerful magnet to hold in any vertical or horizontal mounting arrangement.

Swivels, StaySets,MagBases2

 

Hoses – EXAIR can provide hoses for your application.  For the Line Vac air operated conveyor applications, we offer conveyance hose – a durable, clear reinforced PVC hose, in diameters of 3/8″ to 3″ ID, and lengths up to 50′. On the compressed air side, we can provide 12′ Coiled Hoses with 1/8, 1/4, and 3/8 NPT connections, and also 3/8″ and 1/2″ ID hose in lengths to 50′.

Hoses

Filter Separators, Oil Removal Filters and Pressure Regulators – Perhaps the most important accessories for use on a compressed air device are filters and regulators. Filtering the compressed air of dirt, debris, moisture and oil will help to prevent build up inside the EXAIR products, leading to longer service life, and less time spent cleaning, while providing optimum performance. Regulating the air pressure allows for tuning of the performance, using the proper amount of compressed air to obtain satisfactory results.

Filter and Regualtors

If you have questions regarding accessories for use with any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Compressed Air Filtration – Particulate, Coalescing, and Adsorption Types

Compressed air systems will contain contaminants that can lead to issues and increased costs through contamination of product, damage to the air operated devices, and air line clogging and restriction. Proper air preparation is critical to optimizing performance throughout the plant operations.

Because there are different types of contaminants, including solid particles, liquid water, and vapors of water and oil, there are different methods of filtration, each best suited for maximum efficiency in contaminant removal.

Particulate Filters – The compressed air flows from outside to inside of the filter element. The compressed air first passes through a baffle arrangement which causes centrifugal separation of the largest particles and liquid drops (but not liquid vapors), and then the air passes through the filter element.  The filter element is usually a sintered material such as bronze.  The filter elements are inexpensive and easy to replace. Filtration down to 40-5 micron is possible.

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Particulate Type Filter with Sintered Bronze Element

Coalescing Filters – This type operates differently from the particulate type.  The compressed air flows from inside to outside through a coalescing media. The very fine water and oil aerosols come into contact with fibers in the filter media, and as they collect, they coalesce (combine) to form larger droplets towards the outside of the filter element. When the droplet size is enough the drops fall off and collect at the bottom of the filter housing.  The filter element is typically made up of some type glass fibers.  The coalescing filter elements are also relatively inexpensive and easy to replace. Filtration down to 0.01 micron at 99.999% efficiency is possible.

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Coalescing Type Filter with Borosilicate Glass Fiber Element

Adsorption Filters – In this type of filtration, activated carbon is typically used, and the finest oil vapors, hydrocarbon residues, and odors can be be removed.  The mechanism of filtration is that the molecules of the gas or liquid adhere to the surface of the activated carbon.  This is usually the final stage of filtration, and is only required for certain applications where the product would be affected such as blow molding or food processing.

When you work with us in selecting an EXAIR product, such as a Super Air Knife, Super Air Amplifier, or Vortex Tube, your application engineer can recommend the appropriate type of filtration needed to keep the EXAIR product operating at maximum efficiency with minimal disruption due to contaminant build up and unnecessary cleaning.

If you have questions regarding compressed air filtration or any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Oil And Water Don’t Mix, But Oil And Air Sure Do

Do you have oil in your compressed air system? It may be there on purpose…air operated tools require it, and there are a number of devices on the market that provide a precise amount of oil to keep the moving parts in these tools well lubricated and properly operating.

If it’s not there on purpose, it’s not necessarily a problem, though, and it’s hardly uncommon. Many air compressors are oil lubricated, which means there’s oil being pumped at a constant rate, directly towards the piston rings, and a little bit is always going to end up in the air. As the rings wear, even more makes it past…this is impossible to prevent, but, with proper maintenance, it’s kept to a very minimal amount. There are, of course, oil-less compressor designs, which can eliminate this entirely, but they’ve been known to carry a little heavier price tag. Some situations, though, make them worth every penny.

Trace amounts of oil like this don’t affect a lot of compressed air applications, including the performance of most of our products. There are times, however, when oil needs to be addressed…for instance:

*Blow off prior to painting or coating. Even trace amounts of oil on a surface to be painted can cause big problems.
*Electrical enclosure cooling. Oil won’t affect the heat removal performance of an EXAIR Cabinet Cooler System, but it can indeed cause serious issues with electrical/electronic components and devices if it’s present in the cold air that’s blowing on them.
*Air operated conveyors. Likewise, oil won’t hurt the performance of a Line Vac, but keep in mind that anything in the air supply will get on the material or product you’re conveying.
*Static Eliminators. Here’s a situation where oil in the air WILL have an effect on product performance…the emitter points of your EXAIR Static Eliminator need to be kept clean (including oil free) for proper operation. And, again, anything in your air is going to get onto your product.

This is where proper filtration comes in: properly installed downstream of a Filter Separator, EXAIR’s coalescing Oil Removal Filters take out even trace amounts of oil from the air flow, ensuring your process doesn’t see anything but clean, dry air.

EXAIR Model 9027 Oil Removal Filter, installed between Model 9004 Filter Separator and 9008 Pressure Regulator, using our Modular Coupling Kits
EXAIR Model 9027 Oil Removal Filter, installed between Model 9004 Automatic Drain Filter Separator and 9008 Pressure Regulator, using our Modular Coupling Kits.

Again, oil in your air isn’t always a problem. If you have questions about your application, though, give us a call…if it IS a problem, we’ve got a solution.

Russ Bowman
Application Engineer
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