Critical Components of Your Compressed Air System

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 after coolers, and compressed air dryers. An after cooler 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 after cooler uses a fan to blow ambient air across coils to lower the compressed air temperature.

When air leaves the after cooler, 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, CCASS

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

Compressor Image courtesy of Tampere Hacklab via Creative Commons License

Have a Plan and Stick to It: Common Compressed Air Drawing Symbols

Mike Tyson once said “everyone has a plan ‘til they get punched in the mouth”. I do believe it’s always important to have a plan, but hopefully your line of work does not involve anyone punching you in the mouth. If this plan is a Piping & Instrumentation Diagram (or P&ID), you’d be best served to follow it to the exact letter (or symbol). Otherwise, you might end up finding some facility or maintenance manager that is of the same mindset as good ol’ Mike.

The Piping & Instrumentation Diagram is a great way to illustrate the layout of your complete system. Different symbols, created by ANSI or ISO, are used to identify the specific items in the diagram and lays out the entire system, installation, and process flow.

Air compressors are the heart of the pneumatic system and have a variety of different types of symbols that can be used based on the style of compressor that you have. Below are some examples of the symbols used to denote an air compressor on a P&ID:

On the left is a generic symbol that can be used for any style of compressor. Moving towards the right we have specific, unique symbols for each: centrifugal, diaphragm, piston, rotary, and screw compressors. As the 4th utility in any industrial environment, air compressors are a critical piece of equipment in the facility. From the compressor there will be a line drawn to denote the distribution system or piping that connects the supply side (air compressors) to the demand side.

On the demand side are a variety of different available symbols for each type of equipment. EXAIR recommends installing filters and regulators at the point-of-use to keep air clean and dry as well as operating at the minimal pressure for compressed air conservation. The symbols below are used for particulate filters, oil removal filters, and pressure regulators:

The symbols on the left denote the EXAIR products on the right: Automatic Drain Filter Separator, Oil Removal Filter, and Pressure Regulator

They’re laid out in this order for a reason which is why it’s important to follow the drawing exactly as shown when installing the equipment. The particulate filter must come before the coalescing filter in the supply line. Since we can experience pressure drop across filters, it makes the most sense to include the pressure regulator AFTER the air exits the particulate and oil removal filters for the most accurate representation of point-of-use line pressure.

Oftentimes, you may encounter a situation where the product you’re looking to use doesn’t have a specified ANSI or ISO symbol. In those cases, what is recommended is to choose any shape you wish and call it out specifically by name. For our Super Air Knives, this would look something like this:

Having a plan is one thing, but it’s important to make sure this plan has been well-thought-out prior to doing any installation work. It’s not that Mike Tyson is going to come around throwing haymakers or biting off ears if you don’t, but you run the risk of wasting quite a bit of time (and money!) by not adhering to the original plan.

If your plan includes using some of EXAIR’s Intelligent Compressed Air Products, give us a call. We have a variety of products ready to ship same-day from stock to help you get the most out of your compressed air system.

Tyler Daniel, CCASS

Application Engineer

E-mail: TylerDaniel@EXAIR.com

Twitter: @EXAIR_TD

Mike Tyson photo courtesy of Abelito Roldan via Flickr Creative Commons License

Turn Your One Bedroom Fixer-upper Compressor Room into a Pent House Suite!

First lets paint a picture, by starting with my first 400 Sq.Ft Bachelor pad in Holland Michigan. It was my first time after college living on my own and paying my own room and board! So I did what every fresh out of college 25-year-old male does, I scoured the internet for the cheapest possible living arrangements! And that was a one bedroom(ish) apartment that was one of three rentals they made from a small 1,500 Sq.ft house! It was rough, I could smell the smoke from my neighbors. I could tell what they were having for dinner by the smell and I could hear EVERYTHING! Needless to say the conditions were not the best to relax and properly live my life. (Just had a little PTSD thinking about it)

Yeah, that was a problem too……… (Longest 6 months of my Life)

I said all of that just to say the Environment Matters! For me, it was my living conditions and I learned that the hard way! But for your Air compressor it’s the compressor room in which it sits! While we don’t sell compressors, pretty much all of our products use compressed air so helping you generate and use it in the best and most efficient way is important to us!

Some of the mistakes that are commonly made in the compressor room are by design, and others are operational. Let’s cover a few;

  • Poor ventilation: Air compressors get hot. They’ve got a lot of moving parts, and many of those parts are moving under a great amount of force (pressure is literally defined as force per unit area), and at a high rate of speed. Add in the heat of compression (it takes energy to compress air, and that energy has to go somewhere, (something another colleague, John Ball, explains here). Add in all that friction, and you come up with a TREMENDOUS amount of heat. An industry rule of thumb, in fact, states that over 2500 Btu/hr of heat is generated, PER HORSEPOWER, by a typical industrial air compressor. If the compressor room isn’t big enough, you’ll need an exhaust fan capable of removing all that heat. Many compressors also have optional heat recovery systems as well.
  • Lack of filtration: Take a good, full breath in through your nose, right now. Did you smell anything unpleasant or irritating? I hope not…clean air is a “must” for your lungs (and the rest of your body), and the same is true for your air compressor (and the rest of your compressed air system). Keeping up with the maintenance on the intake filter is literally “starting where it all begins”…from the 1st paragraph.
  • Not removing moisture: Water & water vapor will have an adverse effect on many components of your compressed air system: it’ll cause rust in iron pipes, damage the seals in air cylinders, motors, tools, etc., and if you use it for blow off or conveying, it’ll contaminate your product.
  • Leaks: The compressor room is loud, so leaks are going to be pretty big before you can hear them. And to add insult to injury, the vibration of a running compressor makes the compressor room a prime location for them to occur. Even one small leak that you couldn’t hear in a quieter area will cost you over $100 over the course of the year, and maybe only take minutes to fix. Good news is, even if you can’t hear them, they ALL make an ultrasonic signature, and we’ve got something for that.
  • Ignoring maintenance. If you don’t schedule planned maintenance, your equipment will schedule “corrective” maintenance for you…oftentimes at greater expense, and with no regard to your schedule.
    • Moving metal parts that make metal-to-metal contact (or that have very tight spacing tolerances) HAVE to be lubricated properly. If you run low on oil, or let it get dirty or emulsified, severe damage will follow. Keeping an eye on the oil level, and changing it (and the filter) at the manufacturer’s recommended intervals, is critical.
    • Emulsified or otherwise contaminated oil can damage seals, gaskets, and o-rings. That’s obviously a big problem for the compressor, and when it carries over into the header, it’s a big problem for pneumatic cylinders & tools as well. Periodic sampling & analysis of your oil can provide timely notice of issues that can be corrected before they become catastrophic failures.
    • Depending on the type of compressor, and its drive system, the manufacturer’s maintenance recommendations may also include:
      • Checking coupling or belt alignment of the drive.
      • Checking bolts for loosening due to vibration (a “necessary evil”, especially with reciprocating compressors).
      • Adjusting the pistons to maintain valve plate clearance.
      • Tightening or replacing the mounts & vibration pads.

Don’t put your compressor in a room that smells like a cigarette butt covered in cooking grease that is infested with cockroaches. Set it up in the pent house, and it will reward you with dependable and efficient operation for a very long time! 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.

Jordan Shouse
Application Engineer

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Twitter: @EXAIR_JS

German Cockroach image courtesy of Sarah CampCreative Commons License.

EXAIR Products Entrain FREE Ambient Air For Maximum Force and Flow

Air entrainment is a term that we bring up quite often here at EXAIR. It’s this concept that allows many of our products to dramatically reduce compressed air consumption. The energy costs associated with producing compressed air make it an expensive utility for manufacturers. Utilizing engineered compressed air products that will entrain ambient air from the environment allow you to reduce the compressed air consumption without sacrificing force or flow.

Products such as the Super Air Knife, Super Air Nozzle, Air Amplifier, and Super Air Wipe all take advantage of “free” air that is entrained into the primary supplied airstream. This air entrainment occurs due to what is known as the Coanda effect. Named after renowned Romanian physicist, Henri Coanda, the Coanda effect is used in the design of airplane wings to produce lift. As air comes across the convex surface on the top, it slows down creating a higher pressure on the underside of the wing. This creates lift and is what allows an airplane to fly.

EXAIR Super Air Nozzle entrainment

This is also the same principle which is allowing us to entrain ambient air. As the compressed air is ejected through a small orifice, a low-pressure area is created that draws in additional air. Our products are engineered to maximize this entrained air, creating greater force and flow without additional compressed air. Super Air Amplifiers and Super Air Nozzles are capable of up to a 25:1 air entrainment ratio, with just 1 part being the supplied air and up to 25 times entrained air for free!! The greatest air entrainment is achieved with the Super Air Knife at an incredible ratio of 40:1!

This air entrainment principle allows you to utilize any of these products efficiently for a wide variety of cooling, drying, cleaning, or general blowoff applications. In addition to reducing your compressed air consumption, replacing inefficient devices with engineered products will also dramatically lower your sound level in the plant. Sound level in some applications can even be reduced down to a point that would eliminate the need for hearing protection with the OSHA maximum allowable exposure limits set at 90 dBA for an 8-hour shift.

If you have inefficient blowoff devices in your facility, give us a call. An Application Engineer will be happy to help you select a product that will “quietly” reduce your compressed air consumption!

Tyler Daniel, CCASS


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