Compressed Air Filters: What They Are, And Why They Matter

The first time I ever bought a brand new car was in 1995…it was a Ford Escort Wagon. My plan was to pay it off quick and run the tires off it. Well, I DID actually put new tires on it several times over the 11 years and 200,000 miles I had it. But, aside from fuel & tires, that car cost me less than $2,000 in repairs over all that time…an achievement that my mechanic said was due largely to the aforementioned planned maintenance, which largely consisted of regular oil changes, which, of course, included a new oil filter, every 3,000 miles. For the record, I didn’t run the wheels off it; I sold it when I took a job that included a company vehicle. Also for the record, I found out the fellow I sold my car to was still driving it after I left that job (and company vehicle.) He, too, believed in regular oil changes, and he might still have that 1995 Escort on the road for all I know.

So, yeah, I’m a big believer in the importance of fluid filtration.  If you’re a regular reader of the EXAIR Blog page, you likely are too.  The two main culprits that cause the most problems in a compressed air system are solid particulates and water.  These are easily addressed with a Filter Separator, like EXAIR Model 9004 Automatic Drain Filter Separator.  It has a 5 micron particulate element, and a centrifugal element that imparts a spinning motion to the air flow.  Since water is denser than air, any droplets of moisture are “flung” to the inside wall of the bowl, while the moisture-free air continues on through the discharge.

 

The particulate element captures solids larger than 5 microns, and the centrifugal element eliminates moisture.

Another common impurity in compressed air is oil.  Since oil-less compressors came along, this is easy to eliminate at the source…literally.  However, for other types of compressors (piston types in particular,) as they age, the oil that lubricates the moving parts can seep by the piston rings and get to the air side.  Oil doesn’t carry the same wear and corrosion problems that dirt & water do, but it causes particular problems in air conveyance and blow off applications: anything in your air is going to get on your product.  Ask any paint booth operator, for example, what happens when a metal surface hasn’t been cleaned of all traces of oil.  It really does look a “fish eye.”

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 shown below, provide additional particulate filtration to 0.03 microns.  That’s some pretty clean air.

The coalescing element of an Oil Removal Filter catches oil and very fine particulate.

For best results, we recommend both the Filter Separator and Oil Removal Filter.  Make sure you install the Filter Separator upstream of the Oil Removal Filter…that way, its 5 micron element catches all the “big” particles that would quickly clog the very fine coalescing element, necessitating an element replacement.  In fact, this arrangement will allow the Oil Removal Filter to operate darn near indefinitely, maintenance free.

If you have questions about keeping your compressed air clean, moisture free, and oil free, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
Visit us on the Web
Follow me on Twitter
Like us on Facebook

EXAIR Products: The Importance of Oil Removal Filters

Oil Removal Filter
Oil Removal Filters

EXAIR’s Intelligent Compressed Air Products have no moving parts and require no maintenance. Most EXAIR products require no direct maintenance, and will continue to require no maintenance if the supplied air is clean. Keeping air clean, in EXAIR’s case, can be done with a simple water/dirt or oil filter separator close to the application of the product – usually within 10 feet. The reason for the filters is that many products have very tight orifices that could get clogged from contaminants such as particulate, condensate, and lubricant.

Oil is commonly present in a compressed air supply, whether that’s intentional or not. Many air compressors are lubricated by a constant supply of oil, inevitably some of this oil ends up in the air supply. As the compressor wears, more oil is permitted to pass and ends up in the distribution system. While this is kept to a minimum with proper maintenance, it is impossible to prevent unless using an oil-free compressor.

Sometimes oil is present in the air supply intentionally. Many pneumatic devices require a precise amount of oil to keep the internal moving parts lubricated. In the case of EXAIR Intelligent Compressed Air Products, we recommend particulate-free, moisture-free, and oil-free air.

EXAIR offers a line of Oil Removal Filters. These coalescing style filters are used to remove very fine water vapor as well as any residual oil. These filters are highly recommended to be installed just prior to dryers that contain a media that would be compromised by 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 filter bowl. With a coalescing filter, the most common cause of pressure drop increase is due to particulate clogging the element. Because of this, a particulate filter should always be installed just prior to coalescing filters. Check out this video demonstrating an Auto-Drain Filter and Oil-Removal Filter in action:

Without filtration, oil in the air supply will pass through the point of use device and into your product or process. The elimination of this problem is such a simple solution. Don’t neglect your compressed air system and ensure you’re delivering clean, dry, oil-free air to all of your EXAIR Intelligent Compressed Air Products.

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

EXAIR Chip Trappers Make Short Work of Coolant Maintenance

“Build a better mousetrap, and the world will beat a path to your door,” words attributed to Ralph Waldo Emerson, means that even if there are established methods of doing something, an improved method will garner success.  It may or may not be true with mousetraps – there are over 4,400 U.S. patents for various designs. The tried-and-true spring loaded bar on a small wood plank seems to still be the most popular by far, however. Likely due to its simplicity, availability, and low cost.

There are also a good many machines on the market to clean & filter machine tool coolant.  Some are made to be permanent attachments to the coolant sump for continuous filtration.  Others are made for portability, and are used to pump out the sump, filter the coolant, and pump it back in.  These can be impressively comprehensive, and that’s often reflected in the knowledge required to operate them, as well as the price tag.

Like anything else, if you need all the “bells and whistles,” I’m sure those machines are worthy every penny.  If you just want clean coolant and you have a few minutes to spare every week or so, look no further than the EXAIR Chip Trapper System.  Here’s how it works:

  • Roll the Chip Trapper to your machine.
  • Pump the coolant out of your sump, stirring it with the pickup wand to get chips & debris sucked up with the coolant.
  • Pump the filtered coolant back in to your sump.
  • If you’ve got another machine tool, roll the Chip Trapper over to it, and repeat.  If not, you’re done.  Unless the Filter Bag’s full, in which case, you’ll want to empty it for the next time.

The vacuum hose (1) is attached to the barbed connection of the Chip Trapper (2). The directional flow control valve on the top of the drum (3) and knob on the pump (4) are set to the “fill” position. The air supply valve is opened to permit compressed air at 80-100 psig (5.5-6.9 BAR) to flow through the pump which pulls the liquid through the hose, then into the reusable filter bag (5). When all liquid is in the drum, the air supply is turned off. The filtered liquid can then be pumped out by setting the directional flow control valve on top of the drum and the knob on the pump to the “empty” position. Once the air supply valve is opened, the air pushes the liquid back through the hose while all solids remain in the reusable filter bag.

There’s no moving parts, and it’s compressed air operated, so there’s nothing to wear out or burn out.  If you keep on top of emptying and cleaning the Filter Bag, the Chip Trapper will operate darn near indefinitely, maintenance free.  Oh, and to explain why I started this blog with the quote I referenced, the folks at Design News Magazine thought it was so innovative, they gave it their “Golden Mousetrap” Award when we rolled them out.  Since then, we’ve incorporated three sizes for 30, 55, and 110 gallon drums.  We also developed a High Lift version that generates 180″ H2O suction lift, for when the standard Chip Trapper‘s 96″ H2O lift isn’t enough.

EXAIR Corporation has a long history of making compressed air products that help a wide variety of industries get the most out of their processes, and the Chip Trapper is one of the most visible, and successful, examples of that.  If you’d like to find out more, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
Visit us on the Web
Follow me on Twitter
Like us on Facebook

How to Manage Condensate in Your Compressed Air System

If you operate an air compressor, you’re drawing water vapor into your compressed air system.  Factors like climate control (or lack thereof,) and humidity will dictate how much.  If (or more to the point, when) it condenses, it becomes an issue that must be addressed.  There are several types of dryer systems to choose from, usually when you buy your compressor…we’ve covered those in a number of blogs.  Some of these can leave a little more water vapor than others, but remain popular and effective, when considering the cost, and cost of operation, of the different types.

So, how do you handle the condensate that the dryer doesn’t remove?

  • Receivers, or storage tanks (like EXAIR Model 9500-60, shown to the right,) are commonly used for several reasons:
    • By providing an intermediate storage of compressed air close to the point of use, fluctuations across the system won’t adversely affect an application that needs a constant flow and pressure.
    • This also can keep the air compressor from cycling rapidly, which leads to wear & tear, and additional maintenance headaches.
    • When fitted with a condensate drain (more on those in a minute,) they can serve as a wet receiver.  Condensate collects in the bottom and is manually, or automatically emptied.
  • Condensate drains, while popularly installed on receivers, are oftentimes found throughout larger systems where the vapor is prone to condense (intercoolers, aftercoolers, filters and dryers) and where the condensation can be particularly problematic (drip legs or adjacent to points of use.) There are a couple of options to choose from, each with their own pros & cons:
    • Manual drains are self explanatory: they’re ball valves; cycled periodically by operators.  Pros: cheap & simple.  Cons: easy to blow down too often or for too long, which wastes compressed air.  It’s also just as easy to blow down not often enough, or not long enough, which doesn’t solve the condensate problem.
    • Timer drains are self explanatory too: they cycle when the timer tells them to. Pros: still fairly cheap, and no attention is required.  Cons: they’re going to open periodically (per the timer setting) whether there’s condensate or not.
    • Demand, or “zero loss” drains collect condensate until their reservoir is full, then they discharge the water.  Pros: “zero loss” means just that…they only actuate when condensate is present, and they stop before any compressed air gets out.  Cons: higher purchase price, more moving parts equals potential maintenance concerns.
  • The “last line of defense” (literally) is point-of-use condensate removal.  This is done with products like EXAIR Automatic Drain Filter Separators.  They’re installed close to compressed air operated devices & products, oftentimes just upstream of the pressure regulator and/or flow controls…the particulate filter protects against debris in these devices, and the centrifugal element “spins” any last remaining moisture from the compressed air flow before it gets used.

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

Efficient and safe use of your compressed air includes maintaining the quality of your compressed air.  If you’d like to find out more about how EXAIR Corporation can help you get the most out of your compressed air system, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
Visit us on the Web
Follow me on Twitter
Like us on Facebook