Intelligent Compressed Air: 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
Application Engineer
Twitter: @EXAIR_TD

Compressor Image courtesy of Compressor1 via Creative Commons License

Non Hazardous Purge Cabinet Cooler Systems

Last fall, when our youngest “flew the coop” and moved into a dormitory to begin his college experience, my lovely bride and I also embarked upon an exciting adventure: finding, purchasing, and moving in to our “empty nest” dream house.  While packing up the contents of the house where we had raised a United States Marine AND a hippie college student, I moved my trusty laptop from its perch on a desk in a dark basement corner, where it had resided, in that one spot, for more than a couple years.

As I was looking for its carrying case, I noticed the fan grill was almost completely obscured with more than a couple years’ worth of environmental contamination (or dust).  I vacuumed out the grill, but wondered how much more environmental contamination (dust) had made its way into the deep recesses of the laptop…and more importantly, what might it be doing to the sensitive electronics inside my trusty internet browsing device?

If a computer’s fan in a residential environment can get this dusty, imagine how much worse a control panel on a factory floor can get.

I know I’m not telling you anything you don’t already know, but electronics and dust don’t mix.  We have this conversation a LOT with callers inquiring about our Cabinet Cooler Systems.  The protection they offer against environmental contamination is integral with the protection they offer against heat.  In the panel cooling market, our Cabinet Cooler Systems are unique in that respect: a total protection solution.

When properly installed on a sealed enclosure, the only thing the inside of that enclosure is ever exposed to is cold, clean, moisture free air.  But what if the enclosure can’t be completely sealed?  One option is to use a Continuous Operation Cabinet Cooler System.  It works just as the name implies:  cold air is continuously flowing into the enclosure, creating a constant purge flow…if that cold air is blowing out of any openings in the enclosure, there’s no way for environmental contamination to get in.  Problem solved.

Well…almost.  Something else I’m sure you already know is, compressed air is costly.  Organizations like the Compressed Air & Gas Institute (CAGI) and the Compressed Air Challenge (CAC), who are devoted to optimizing industrial use of compressed air, have lists of “inappropriate uses of compressed air”, and panel cooling is on that list…EXCEPT when they’re thermostatically controlled.  At EXAIR, we couldn’t agree more, and if a caller asks any of us Application Engineers about a Continuous Operation Cabinet Cooler System, they’re inviting us in to a conversation about that.

Sometimes, the initial question is cost…well, we have to pay for the components that make up the Thermostat Controls, so we ask our customers who want those products to as well.   A quick conversation about the operating cost of continuous operation vs thermostat control is usually all that’s required in those cases.

Other times, a panel that can’t be sealed is installed in a particularly dusty or dirty environment, and they want the continuous flow of cold air, as described above, to keep those contaminants out.  A Continuous Operation Cabinet Cooler System will, of course, do that.  But EXAIR wants you to get the most out of your compressed air use, so we developed a “best of both worlds” solution: Non-Hazardous Purge Cabinet Cooler Systems.  Here’s how they work:

  • Based on a few key pieces of data that you can submit in our Cabinet Cooler Systems Sizing Guide, we’ll specify the appropriate Cabinet Cooler System to manage that heat load.
  • The system will be thermostatically controlled: a bimetallic Thermostat, mounted inside the panel, will open and close the Solenoid Valve plumbed in the compressed air supply to operate the Cabinet Cooler as needed to maintain temperature inside the panel.
  • The Solenoid Valve is modified to pass a small amount of air flow (1 SCFM) even when it’s closed.  This saves you from using the full rated air consumption of the Cabinet Cooler when cold air isn’t required, and still maintains enough purge air flow to prevent environmental contaminants from entering a less-than-ideally-sealed enclosure.

Whatever you do, DON’T do THIS to your panel.

The Non-Hazardous Purge option is just one way that EXAIR Corporation can help you address specific environmental challenges that may be presented in electrical and electronic panel cooling applications.  If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Super Blast Safety Air Gun Improves Cleanup Process

I had the pleasure of helping a caller out with a cleanup problem not long ago.  Normally, calls involving cleanups involve a discussion of how our Industrial Housekeeping Products might replace an electric shop vacuum or sump pump, but this one was about replacing a broom…with a Super Blast Safety Air Gun.

Now, I need to mention that the folks at Compressed Air Challenge have a list of Inappropriate Uses Of Compressed Air.  Using compressed air for cleaning is on that list, and I couldn’t agree more…as a blanket statement, that is.  Of course, the last paragraph of their document makes it clear that good judgement can, and should, always rule the day: “if safety enhancements, significant productivity gains, or labor reductions will result,” they say, a compressed air solution is certainly worth considering.

That’s exactly what the caller and I did.

See, he works in an equipment service shop.  Their technicians make the company money through billable labor – the time they spend fixing their customers’ equipment.  Of course, they have to spend time on tasks that aren’t billable to jobs…like tool maintenance, paperwork, and keeping a clean shop.  A particular item from a shop audit that caught his attention was the amount of time spent sweeping the floor in the welding area.  Not only did slag & dust get all over the floor out in the open, it accumulated under tables and behind the welding machines themselves.  This meant that technicians had to get down on their hands & knees, and reach brooms under those tables.  Not only was this cumbersome; it wasn’t even 100% effective…when replacing a machine recently, they discovered a surprising amount of debris in a “blind spot” that the broom just couldn’t reach.

After a discussion of the engineered Super Air Nozzles that are available on the Super Blast Safety Air Guns, the caller liked the idea of the Model 1213-7-3.  The hard hitting, tight air flow pattern of the Super Air Nozzle Cluster at the end of a 3 foot extension gave the perfect combination of power & reach for his application.

Super Blast Safety Air Gun makes short work of large area cleanup.

So, at the end of the day, (literally…that’s cleanup time, right?) a task that previously took about 10 minutes for them was reduced to just under two minutes.  Of course, that doesn’t figure in the cost of the compressed air.  The Department of Energy uses a thumbrule that states it costs $0.25 to generate 1,000 Standard Cubic Feet of compressed air.  At 98 SCFM @80psig, the Super Blast Safety Air Gun’s Cluster DOES use a decent amount of compressed air, so we did the math:

98 SCFM X 2 minutes X $0.25/1,000 SCF =   $0.049

We didn’t need to get in to payroll records, employee benefit packages, etc., to realize that an 80% reduction in labor, improved cleanup (air reaches where the brooms couldn’t,) and worker satisfaction (no more crawling along the floor beside the tables) was worth a nickel a day.

The Super Blast Safety Air Gun can be fitted with a variety of Super Air Nozzles, from our Model 1112 3/4 NPT Super Air Nozzle (4.5lbf at 12″) , to our Model 1120 1-1/4 NPT Super Air Nozzle (23lbf at 12″).

As an Application Engineer, I’m always looking for the best ways to apply our products, and quantify the benefits.  If you call me to discuss an application and the math doesn’t prove it out, I’ll let you know.  If you have a task you’re considering a compressed air solution for, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Exploring Optimization: Standards And Certifications For Compressed Air Audits

EXAIR Corporation has devoted almost 37 years to manufacturing engineered products aimed at the most efficient, quietest, and safest use of compressed air.  Sometimes, a caller has recognized that an open pipe blow off, for example, is loud, wasteful, and unsafe, and just wants to install an engineered product that they know will be an improvement.  They may not be interested in precisely quantifying the savings…they’ll just notice that their lone air compressor runs less, and their electric bill isn’t as high anymore.

Others, however, may have a compressed air system that comprises multiple compressors, with advanced controls, and they may have specific operational goals in regard to how the individual compressors are loaded and controlled, or maybe even eliminating the need to run particular compressors all the time…or at all.

The skills & knowledge necessary to handle such a task are within the confines of discipline of mechanical engineering, but oftentimes, specialized training is needed to effectively conduct an audit in order to formulate an execute such an optimization plan.  If you’re interested in pursuing this training, or working with trained personnel, here’s a brief description of the training that’s available, and how you can find people that have been through it:

  • The American Society of Mechanical Engineers (ASME) publication “Guidance for ASME EA-4, Energy Assessment for Compressed Air Systems” details the requirements for performing an audit.  Since there are so many configurations of compressed air systems, it’s not a “step by step” procedure, but it IS handy for developing one, if you know how.  Speaking of which…
  • The Compressed Air & Gas Institute (CAGI) offers training & certification in two categories:
    • Certified Compressed Air System Specialists (CCASS) – these are qualified experts who have demonstrated competence (by means of a comprehensive examination) in skills and abilities relating to the design, service, sales, and installation of compressed air systems & equipment.
    • Certified Compressed Air System Assessors (CCASA) – in addition to CCASS certification, these individuals has passed another comprehensive examination, verifying their knowledge and skills as practitioners performing assessments (audits) of compressed air systems.

Both of these certifications comply with the ISO 17024 Conformity Assessment standard, which governs General Requirements for Bodies Operating Certification of Persons in any field of endeavor.  This means that, not only have certified personnel all passed the same tests regardless of where they are, but the tests they’ve passed meet stringent standards for examining knowledge level and competence in these fields.

Bottom line: if you want an in-depth, accurate evaluation of the efficiency of your compressed air system, experts are available.  The Compressed Air & Gas Institute even publishes directories so you can find them in your area.

Russ Bowman
Application Engineer
EXAIR Corporation
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