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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What Makes A Compressed Air System “Complete”?

It’s a good question.  When do you know that your compressed air system is complete?  And, really, when do you know, with confidence, that it is ready for use?

A typical compressed air system. Image courtesy of Compressed Air Challenge.

Any compressed air system has the basic components shown above.  A compressed air source, a receiver, dryer, filter, and end points of use.   But, what do all these terms mean?

A compressor or compressed air source, is just as it sounds.  It is the device which supplies air (or another gas) at an increased pressure.  This increase in pressure is accomplished through a reduction in volume, and this conversion is achieved through compressing the air.  So, the compressor, well, compresses (the air).

A control receiver (wet receiver) is the storage vessel or tank placed immediately after the compressor.  This tank is referred to as a “wet” receiver because the air has not yet been dried, thus it is “wet”.  This tank helps to cool the compressed air by having a large surface area, and reduces pulsations in the compressed air flow which occur naturally.

The dryer, like the compressor, is just as the name implies.  This device dries the compressed air, removing liquid from the compressed air system.  Prior to this device the air is full of moisture which can damage downstream components and devices.  After drying, the air is almost ready for use.

To be truly ready for use, the compressed air must also be clean.  Dirt and particulates must be removed from the compressed air so that they do not cause damage to the system and the devices which connect to the system.  This task is accomplished through the filter, after which the system is almost ready for use.

To really be ready for use, the system must have a continuous system pressure and flow.  End-use devices are specified to perform with a required compressed air supply, and when this supply is compromised, performance is as well.  This is where the dry receiver comes into play.  The dry receiver is provides pneumatic capacitance for the system, alleviating pressure changes with varying demand loads.  The dry receiver helps to maintain constant pressure and flow.

In addition to this, the diagram above shows an optional device – a pressure/flow control valve.  A flow control valve will regulate the volume (flow) of compressed air in a system in response to changes in flow (or pressure).  These devices further stabilize the compressed air system, providing increased reliability in the supply of compressed air for end user devices.

Now, at long last, the system is ready for use.  But, what will it do?  What are the points of use?

Points of use in a compressed air system are referred to by their end use.  These are the components around which the entire system is built.  This can be a pneumatic drill, an impact wrench, a blow off nozzle, a pneumatic pump, or any other device which requires compressed air to operate.

If your end use devices are for coating, cleaning, cooling, conveying or static elimination, EXAIR Application Engineers can help with engineered solutions to maximize the efficiency and use of your compressed air.  After placing so much effort into creating a proper system, having engineered solutions is a must.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Intelligent Compressed Air: Refrigerant Dryers and How They Work

We’ve seen in recent blogs that Compressed Air Dryers are an important part of a compressed air system, to remove water and moisture to prevent condensation further downstream in the system.  Moisture laden compressed air can cause issues such as increased wear of moving parts due to lubrication removal, formation of rust in piping and equipment, quality defects in painting processes, and frozen pipes in colder climates.  The three main types of dryers are – Refrigerant, Desiccant, and Membrane. For this blog, we will review the basics of the Refrigerant type of dryer.

All atmospheric air that a compressed air system takes in contains water vapor, which is naturally present in the air.  At 75°F and 75% relative humidity, 20 gallons of water will enter a typical 25 hp compressor in a 24 hour period of operation.  When the the air is compressed, the water becomes concentrated and because the air is heated due to the compression, the water remains in vapor form.  Warmer air is able to hold more water vapor, and generally an increase in temperature of 20°F results in a doubling of amount of moisture the air can hold. The problem is that further downstream in the system, the air cools, and the vapor begins to condense into water droplets. To avoid this issue, a dryer is used.

Refrigerated Dryer
Fundamental Schematic of Refrigerant-Type Dryer

Refrigerant Type dryers cool the air to remove the condensed moisture and then the air is reheated and discharged.  When the air leaves the compressor aftercooler and moisture separator (which removes the initial condensed moisture) the air is typically saturated, meaning it cannot hold anymore water vapor.  Any further cooling of the air will cause the moisture to condense and drop out.  The Refrigerant drying process is to cool the air to 35-40°F and then remove the condensed moisture.  The air is then reheated via an air to air heat exchanger (which utilizes the heat of the incoming compressed air) and then discharged.  The dewpoint of the air is 35-40°F which is sufficient for most general industrial plant air applications.  As long as the compressed air stays above the 35-40°F temperature, no further condensation will occur.

The typical advantages of Refrigerated Dryers are-

  1.  – Low initial capital cost
  2.  – Relatively low operating cost
  3.  – Low maintenance costs

If you have questions about getting the most from your compressed air system, or would like to talk about 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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Don’t Waste Your Money (or Compressed Air)

This week I worked with a customer trying to separate a 135” wide paper sheet from a fabric used for commercial paper towel machines. They were using 45 spray nozzles, spaced 3” apart on a manifold, to blow off the sheet which then would fall into a chute below. The nozzles were doing the job but they were growing more concerned with their compressed air expense for this process.

Competitor Nozzle
45 pcs. of this nozzle were replaced with EXAIR’s Super Air Knife to save $87,000 annually!

The current nozzle setup was also causing another issue – there were “empty voids or gaps” in the airflow between the nozzles, which resulted in creases in the fabric. They were considering adding more nozzles and spacing them 2” apart but that was only going to increase their compressed air expense, so I asked them to consider our Super Air Knife. They were intrigued but were concerned that they would consume more compressed air, you’ll see below that the Super Air Knife uses less air and eliminates the creasing problem because the Super Air Knife provides a continuous airflow from end to end.

After reviewing the specs, I determined that each nozzle was consuming 29.6 SCFM @ 90 PSIG of compressed air, meaning they were consuming 1,332 SCFM for the process (29.6 SCFM x 45 nozzles).

I recommended using (2) 48” and (1) 42” Aluminum Super Air Knives, coupled together, to provide a 138” laminar sheet of airflow. I chose these In Stock – Ready to Ship lengths, so the customer wouldn’t have to order a special length even though that lead time would have only been 3 days. The Super Air Knife only consumes 2.9 SCFM @ 80 PSI (per inch of knife), and provides a laminar sheet of uniform airflow with a 40:1 air amplification rate, which would not only perform in the application, but also provide the needed compressed air savings.

SAK
What a great replacement for multiple nozzle manifolds! How SAK works

Using the above air consumption for our Super Air Knife, 2.9 SCFM @ 80 PSI (per inch of knife or 2.9 SCFM x 138”), I calculated the Super Air Knife consuming 400.2 SCFM @ 80 PSIG.

Since their process is a 24 hour operation, Monday – Friday, every week of the year, I calculated the following (* Using $ 0.25 per 1000 SCF used):

  • 45 nozzles x 29.6 SCFM = 1,332 SCFM @ 90 PSIG
  • 1332 SCFM (current) – 400.2 SCFM (EXAIR proposed) = 931.8 SCFM saved
  • 931.8 SCFM x 60 minutes x $ 0.25 / 1000 SCF = $ 13.98 saved per hour
  • $ 13.98 per hour x 24 hours = $ 335.52 saved per working day
  • $ 335.52/day x 5 days = $ 1,677.60 saved per week
  • $ 1,677.60 week x 52 weeks = $ 87,235.20 in yearly savings

After reviewing this savings with the customer, they mentioned they were glad they called because they were looking at increasing their air compressor size or purchasing another auxiliary unit. Now, they were not only going to save money on their current process, but they were eliminating the need to spend major funding on another compressor – not to mention the saved compressed air being available for future growth and processes.

At EXAIR, we commit to providing our customers with solutions to optimizing their current compressed air system.

Please contact an Application Engineer for optimizing your system today.

Justin Nicholl
Application Engineer
justinnicholl@EXAIR.com
@EXAIR_JN

 

Ionizing Point Best Thing for Static on Trim Scrap in Cyclone Separator

This application came in from our distributor (AYRFUL) in Argentina. They had a customer who is recycling film scraps. The scrap material is conveyed into a cyclone separator. The problem is that the scrap becomes charged with static as a result of the motions and interactions within the conveying pipe. This results in the scrap sticking to itself and to the parts of the cyclone separator inside. The problem is so bad that it becomes almost impossible to separate the material when it comes time to clear it out of the cyclone separator once clogged.

After discussing the challenges the customer faced in trying to keep their cyclone up and running, we decided to recommend that the customer utilize 4 pieces of EXAIR’s Model 7199 Ionizing Point and 1 piece of Model 7941 (4 outlet Power Supply) to neutralize the static within the cyclone.

The ionizing Points would be attached by means of inserting through the wall of the inlet pipe of the cyclone separator.

Ion Point

cyclone

The existing blower moving air into the cyclone separator will do the job of carrying the positive and negative ions into the cyclone separator and keep it and the contents at a neutral state.

If you have a similar problem, contact us to discuss the application. We would be glad to help with our full range of static eliminators to address your application issues.

Neal Raker, Application Engineer
nealraker@exair.com