First, let’s think about a gas station. When the fuel delivery truck fills the stations’ tank, the fuel is passed through a filter to make sure it’s free of water and debris. Then, as you are pumping it into your car, it passes through another filter! And then, in your car, the fuel is passed though another filter before it goes to your engine! Filtering your compressed air supply at several points is just as important, and a single filter at the compressor isn’t enough! That is where the point of use filters comes into play!
Dry Particulate Filters: Dry particulate filters are usually employed to remove desiccant particlesafter an adsorption dryer. They can also be implemented at point of use to remove any corrosion particles from the compressed air. Dry particulate filters operate similarly as a coalescing filter, capturing and retaining particles within the filter media.
The particulate element captures solids larger than 5 microns, and the centrifugal element eliminates moisture.
Coalescing Filters: Coalescing filters are used for removing water and aerosols. Small droplets are caught in a filter media and merged into larger droplets that are then taken out of the filter. A re-entrainment barrier prevents these droplets from reentering the air. Most of the liquid coalescing filters remove is water and oil. These filters also remove particulates from compressed air, trapping them within the filter media, which can lead to pressure drops if not changed regularly. Coalescing filters remove most contaminants very well.
The coalescing element catches oil and very fine particulates
Adsorption Filters: Vapor removal filters are typically used to remove gaseous lubricants that will go through the coalescing filter. Because they use an adsorption process, vapor removal filters should not be used to capture lubricant aerosols. Aerosols will quickly saturate the filter, rendering it useless in a matter of hours. Sending air through a coalescing filter prior to the vapor removal filter will prevent this damage. The adsorption process uses activated carbon granules, carbon cloth or paper to capture and remove contaminants. Activated charcoal is the most common filter media because it has a large open pore structure; a handful of activated charcoal has the surface area of a football field.
Knowing the needs of your compressed air system can help you chose the right filter. If your air needs a high level of filtration or basic contaminants removed, cleaning your air is an important step in the compressed air process. Check out our compressed air filter optionshere!
The first new car I ever bought was a 1995 Ford Escort Wagon. It got GREAT gas mileage (which was important for my 25 mile one-way commute to the day job), and had ample room to haul my keyboards & amplifier rig (which was just as important to my side hustle as a potential rock star). Since it only had four miles on the odometer – and, it was the first purchase I ever financed over a period of YEARS, I decided to follow the owner’s manual’s maintenance schedule religiously. And it paid off: I got eleven years and just shy of 200,000 miles out of one of the least expensive cars ever made. It was actually still running like a top when I sold it to “upgrade” to a minivan, which suited my needs at the time for a vehicle that fitted the car seats for our little boys (who are now a U.S. Marine and a hippie college student, respectively). I actually followed the maintenance schedule for that minivan too, and got 14 years & almost 180,000 miles out of it, without a major breakdown.
Whether you call it “preventive”, “preventative”, “scheduled”, or “planned” maintenance, there’s an old adage that applies in any case:
“If you don’t plan maintenance, it’ll plan itself without regard to your schedule.”
While following the proverbial “owner’s manual’s maintenance schedule” doesn’t guarantee against catastrophic failures, it’s awfully good insurance against them. For your privately owned vehicles, I encourage you to follow the owner’s guide as best you can. For your compressed air system – from the compressor to the devices it provided compressed to (and everything in between) – there’s likely similar documentation to follow, and for good reason. Consider:
Air compressor maintenance. Failure to properly maintain a compressor can increase energy consumption by not keeping it operating as efficiently as possible. For example, just like not periodically replacing your car engine’s air filter will impact your gas mileage, failure to do the same for your compressor’s intake air filter will impact its production of compressed air.
Air leaks are costly. Not only do they waste the money you spent on running the compressor (a leak that’s equivalent to a 1/16″ diameter hole costs you over $700.00 annually – let me know if you want to do the math on that), your system pressure takes a hit too. Pressure drop caused by those leaks (plural because there’s rarely just one) can create what’s known as “false demand”, which costs you money as well: every 2psi increase in compressor discharge pressure makes for a 1% increase in power consumption. So, it’s really important to stay on top of them. Regularly scheduled surveys with an instrument like EXAIR’s Model 9207 Ultrasonic Leak Detector allows you to quickly find – and then fix – those leaks.
EXAIR Model 9207 Ultrasonic Leak Detector comes with everything you need to find out if you have a leak (with the parabolic disc, lower right) and then zero in on its exact location (with the tubular extension, bottom).
Filters, part 1: I already mentioned the compressor intake filter above, but the rest of the filters in the system need attention from time to time as well. Filter manufacturers typically call for replacing the element in a filter when pressure drop reaches a certain point. I’ve seen published values of 2-5psi for that. Of course, that may not occur at a convenient time to shut down everything downstream of that filter, so lots of folks replace those elements as part of planned maintenance evolutions that require depressurization of that particular part of the system anyway. Dirty filters mean you have to increase their inlet pressure to maintain the same outlet pressure you had when they were clean – and the same 1% increase in power consumption for a 2psi pressure increase applies here too.
Filters, part 2: most compressed air operated products have small passages that the air has to flow through, and without filtration, those can get clogged with dirt that the intake filter doesn’t catch, solid particulate from compressor ‘wear & tear’, and rust from header pipe corrosion, just to name the “usual suspects”. An argument could be made that installation & upkeep of properly rated Filter Separators at the point of use of these devices is part of those devices’ planned maintenance. In any case, it’s akin to the awfully good insurance against catastrophic failures I mentioned earlier.
Good engineering practice calls for point of use filtration and moisture removal, such as that provided by EXAIR Filter Separators.
Again, many of the components that make up a typical industrial compressed air system will have a manufacturer’s recommended maintenance schedule, but if they don’t, how can you properly plan for it? Monitoring of certain system parameters can be a valuable tool for determining how often some planned maintenance should be performed:
Power consumption of the compressor. The benefit of measuring & logging this on a regular basis is, if you see sudden changes, you can start looking for what’s causing them. Maybe a bearing or belt is wearing out, some leaks have popped up, or a filter’s clogged. In any case, it’s an indication that SOMETHING needs attention. Large industrial compressors might even have power monitoring in their control scheme. If not, there ARE other parameters you can measure…like:
Pressure and flow. EXAIR’s Pressure Sensing Digital Flowmeters make monitoring these parameters quick and easy. Managing the readings can be done with our USB Data Logger, or you can get it on your computer, via a Zigbee Mesh Gateway, with our Wireless Models.
Compressed Air Filters are a necessary thing in modern manufacturing, and here at EXAIR we provide them in most kits. But what filter do you use, cleanliness standards require a variety of impurities to be removed, including oil mist, vapors and particulate matter. Impurities can enter the compressed air stream in several different ways. Intake air can introduce dust or debris particulates, rusted pipes can introduce rust and scale particulates. Oil and liquid vapors are often a consequence of using oiled compressors and must be filtered out before the compressed air can be used. There are distinct cleanliness standards for different compressed air applications, but the presence of impurities can exceed those standards, leading to damaged products or unsafe air. Filters fall into three categories: coalescing filters, absorption filters and the dry particulate filters. While each type ultimately produces the same result, they each operate on different principles.
Dry particulate filters are commonly used to remove desiccant particles after an in process dryer. But here at EXAIR we recommend using them at the point of use also to remove any rust particles from the compressed air before It’s used to clean, dry or cool in your process. Dry particulate filters function similar to a coalescing filter, catching particles within the filter media / or element.
The particulate element captures solids larger than 5 microns, and the centrifugal element eliminates moisture.
Coalescing filters are primarily used for removing liquids and aerosols, if used in line with a particulate filter is the coalescing filter should be second in line. Small condensations are caught in a filter media and merged into larger drops that are then taken out of the filter typically into a bowl. Most of the liquid coalescing filters remove is water and oil. Coalescing filters remove most impurities, reducing particulate levels down to 0.1 micron in size and liquids down to 0.03 micron.
The coalescing element catches oil and very fine particulate
Adsorption Filters: Vapor removal filters are typically used to remove gaseous lubricants that will go through the coalescing filter. Because they use an adsorption process, vapor removal filters should not be used to capture lubricant aerosols. Aerosols will quickly saturate the filter, rendering it useless in a matter of hours. Sending air through a coalescing filter prior to the vapor removal filter will prevent this damage. The absorption process uses activated carbon granules, carbon cloth or paper to capture and remove contaminants. Activated charcoal is the most common filter media because it has a large open pore structure; a handful of activated charcoal has the surface area of a football field.
Knowing the needs of your compressed air system can help you chose the right filter. If your air needs a high level of filtration or basic contaminants removed, cleaning your air is an important step in the compressed air process. Check out EXAIRS filter options here!
When you are using compressed air to Clean, Cool, and or Dry products in production the quality of compressed air you are using is very important. You wouldn’t want to be blowing oil or condensation from your compressed air onto a surface you are trying to dry. Or blowing debris on a surface you are trying to clean.
The most common type of oil removal filter uses a coalescing element. Oil entrained in pressurized gas flow isn’t as dense as water – so centrifugal elements won’t remove it – and it tends to act like particulate…but very fine particulate – so typical sintered particulate elements won’t remove it. Coalescing elements, however, are made of a tight fiber mesh. This not only catches any trace of oil in the air flow, but also much finer particulate than those sintered elements. EXAIR Oil Removal Filters, like the Model 9027 , provide additional particulate filtration to 0.03 microns. That’s some pretty clean air.
Dry Particulate Filters: Dry particulate filters are usually employed to remove desiccant particles after an adsorption dryer. They can also be implemented at point of use to remove any corrosion particles from the compressed air. Dry particulate filters operate in a similar manner as a coalescing filter, capturing and retaining particles within the filter media.
The particulate element captures solids larger than 5 microns, and the centrifugal element eliminates moisture.
Coalescing Filters: Coalescing filters are used for removing water and aerosols. Small droplets are caught in a filter media and merged into larger droplets that are then taken out of the filter. A re-entrainment barrier prevents these droplets from reentering the air. Most of the liquid coalescing filters remove is water and oil. These filters also remove particulates from compressed air, trapping them within the filter media, which can lead to pressure drops if not changed regularly. Coalescing filters remove most contaminants very well.
The coalescing element catches oil and very fine particulate
Adsorption Filters: Vapor removal filters are typically used to remove gaseous lubricants that will go through the coalescing filter. Because they use an adsorption process, vapor removal filters should not be used to capture lubricant aerosols. Aerosols will quickly saturate the filter, rendering it useless in a matter of hours. Sending air through a coalescing filter prior to the vapor removal filter will prevent this damage. The adsorption process uses activated carbon granules, carbon cloth or paper to capture and remove contaminants. Activated charcoal is the most common filter media because it has a large open pore structure; a handful of activated charcoal has the surface area of a football field.
Knowing the needs of your compressed air system can help you chose the right filter. If your air needs a high level of filtration or basic contaminants removed, cleaning your air is an important step in the compressed air process. Check out EXAIRS filter options here!
