Tag: compresser

The Importance Of Planned Maintenance

Published on by Russ BowmanLeave a comment

“If it ain’t broke, don’t fix it” is a common phase that we’ve all heard. It’s also a recipe for disaster. Think about it:

  • Corrective maintenance is ALWAYS more expensive. An oil change in your car might set you back $50 and an hour or so, but when (not if) emulsified, contaminated oil causes your engine to seize, that’s a four (if not five) figure repair bill.
  • Corrective maintenance is also ALWAYS more inconvenient. “If you don’t schedule time for maintenance, your equipment will schedule it for you.” ’nuff said.

Anything with moving parts is going to live its best life if you maintain it properly, and your air compressor has a LOT of moving parts that are CONSTANTLY under a good deal of mechanical stress. Your compressor’s manufacturer almost certainly has a published list of recommended maintenance items, with a schedule of when they should be performed. While that list is going to vary, depending on the type of compressor you have, some of the more common items include:

  • Intake Filter: This is what removes environmental contamination from the air that the compressor is drawing in. When (not if) it gets dirty, your compressor works harder. That means higher power consumption, which means higher operating costs. It also means more heat is generated, which can wear machinery out WAY faster than it should.
  • Lubricating Oil: If your compressor is oil lubed, that oil needs to be changed periodically. The schedule for this is always going to be a certain number of hours of operation, or a certain period of time, whichever comes first. That first one is because the amount of particulate contamination is going to be roughly proportional to the amount of time the lubricated parts spend in motion. The latter is because oil just loses some of its critical lubricating properties over time.
  • Drive Equipment: The two main methods of connecting a motor to a compressor are direct drive shaft coupling, or a system of pulleys and belts. Making sure they stay aligned is critical to their operation. Depending on the nature of the drive, lubrication, tension, and physical condition are all important maintenance points as well.
  • Safety (Pressure Relief) Valve: This valve releases excess pressure if the pressure switch fails and the compressor keeps running. At the very least, this keeps your operating costs in line — the higher the discharge pressure, the higher the power consumption. And, worst case, it makes sure you don’t over pressurize the system. If your receiver tank blows up, that’s a bad day.
  • Receiver Tank Condensate Drain: While there are a number of automatic condensate drains available for industrial air compressors, many owners choose to manually drain condensate from the wet receiver. This should be done AT LEAST once a day, with some manufacturers recommending it more frequently than that. This is critical because standing water can corrode the tank from the inside over time. It can also lead to moisture carryover into the header, and it reduces the volume of available air storage in the tank.
  • Keep Clean To Keep Cool: Air compressors generate heat, both from the friction between the moving parts, and the compression itself (Gay-Lussac’s Law states that the pressure of a given mass of gas is directly proportional to its temperature as long as the volume is constant.) Some compressors are air cooled; others are water cooled. Whichever yours is, keep the heat transfer surfaces — like the fins on the air end housing (air cooled) or fins of the heat exchanger (water cooled) — clean & free of debris to maximize the heat transfer, keeping your compressor as cool as possible.

Again, these are just some of the more common maintenance items for an air compressor. If you want yours to live its best life, keep up with the manufacturer’s recommendations. Oftentimes, maintenance records are required for warranty consideration, should something fail. If you have questions about getting the most out of your compressed air system, give me a call.

Russ Bowman, CCASS

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

Published on by Jordan T ShouseLeave a comment

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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German Cockroach image courtesy of Sarah Camp , Creative Commons License.

Intelligent Compressed Air®: Compressor Motors And Controls

Published on by Russ BowmanLeave a comment

Use of compressed air has gone hand in hand with manufacturing for centuries. From manually operated bellows devices that stoked fires to generate the high temperatures needed for forging metals in ancient times, to the massive steam or oil driven compressors used in the 1800’s on projects like the Mont Cenis Tunnel drills, to the sophisticated electric-powered compressors used widely across modern industry, compressed air has actually been “the fourth utility” longer than the other three (electricity, gas, and water) have been in existence.

Diesel & gas powered compressors offer advantages like higher power ratings, portability, and freedom from reliance on local electric power grids, but most air compressors in industrial use are powered by electric motors. They’re plentiful, reliable, and easily adaptable to a range of control schemes that offer efficient operation across a wide variety of operations.

Which control method is right for you will depend on a number of factors specific to your operation. Here’s a brief run-down that may help you narrow down the selection:

  • Compressors in smaller facilities that supply intermittent loads like air guns, paint sprayers, tire inflators, etc. (like the one shown on the right) are oftentimes controlled via Start/Stop. This turns the compressor motor on and off, in response to a pressure signal. This is the simplest, least expensive method, and is just fine for smaller reciprocating compressors that aren’t adversely affected by cycling on & off.
  • Some compressors ARE adversely affected by Start/Stop control…like rotary screw models. These take a finite amount of time to start back up, which could allow header pressure to drop below usable levels. If they cycle too often, heat from the starting current can build up & overheat the motor. If that’s not bad enough, the screw elements & bearings of the compressor itself are oil lubricated…every time they start up, there’s a finite amount of time where metal-to-metal contact occurs before the oil flow is providing rated lubrication. With Load/Unload control, the motor turns continuously, while a valve on the intake of the compressor is cycled by the compressor discharge pressure: it opens (loads) to build or maintain pressure, and closes (unloads) when rated pressure is achieved. When unloaded, the motor uses about 1/3 of the energy it uses while loaded.
  • While turning down energy use to 1/3 of full load is a great way to cut operating cost while maintaining operational integrity of your compressed air system, and physical integrity of your compressor, it doesn’t necessarily make sense when demand may be low enough to be serviced by existing system storage over long periods of time. That’s where Dual/Auto Dual control comes in. It allows you to select between Start/Stop and Load /Unload control modes.  Automatic Dual Control incorporates an over-run timer, so that the motor is stopped after a certain period of time without a demand. This method is most often used in facilities where different shifts have substantially different compressed air load requirements.

When any of the above control schemes are used, they will necessarily rely on having an adequate storage capacity…the compressor’s receiver, and intermediate storage (like EXAIR’s Model 9500-60 60 Gallon Receiver Tank, shown on right) must be adequately sized (and strategically located) to ensure adequate point-of-use pressures are maintained while the compressor’s motor or intake valve cycle. Other methods use variable controls to “tighten up” the cycle bands…these don’t rely on as much storage volume, and in some (but not all) cases, result in higher energy efficiency:

  • A variation of Load/Unload control, called Modulation, throttles the intake valve instead of opening & closing it, to maintain a specific system pressure. This method is limited in range from 100% to 40% of rated capacity, though, so it’s fairly inefficient in many cases.
  • Slide, spiral, or turn valves are built in to certain compressor designs to control output by a method called Variable Displacement, which (as advertised) changes the physical displacement volume of the air end. When header pressure rises, it sends a signal which repositions the valve progressively, reducing the working length of the rotors. This allows some bypass at the inlet, limiting the volume of air that’s being compressed with each turn of the rotor. Since the inlet pressure & compression ratio remain constant, the power draw from the partial load is considerably lower…so it costs less to operate. The normal operating range for this method is from 100% to 40% of rated capacity, but when used in conjunction with inlet valve Modulation, it’s effective & efficient down to 20% of rated capacity.
  • Of course, the most significant advance in efficient control of rotating industrial equipment since Nikola Tesla invented 3-phase AC is the Variable Speed Drive. When the frequency of the AC power supplied to an electric motor is changed, the speed at which it rotates changes in direct proportion. By applying this type of control to an air compressor, the motor’s speed is continuously controlled to match the air demand. Energy costs can be greatly reduced, as this method allows efficient turn down to as low as 20% of rated capacity.

As mentioned a couple times above, multiple control schemes can be applied, depending on user specific needs. Adding accessories, of course, adds cost to your capital purchase, but discussions with your air compressor dealer will lay out the pros, cons, and return on investment. While we don’t sell, service, or even recommend specific air compressors, EXAIR Corporation is in the business of helping you get the most out of your compressed air system. If you’d like to talk more about it, give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Intelligent Compressed Air®: Common Compressor Room Mistakes, And How To Avoid Them

Published on by Russ BowmanLeave a comment

While we don’t sell, install, or service air compressors, EXAIR Intelligent Compressed Air Products run on compressed air, so helping you get the most out of your compressed air system is important to us. Today, we’re starting where it all begins: the compressor room.

Some of the mistakes that are commonly made in the compressor room are by design, and others are operational. My colleague Tyler Daniel wrote a great blog on design considerations recently, so I’m going to focus on the operational aspects, which include maintenance…and maybe some minor design stuff:

  • 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), to all that friction and you come up with a TREMENDOUS amount of heat. An industry thumbrule, 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.
  • 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. We’ve written…again and again…about the importance of dryers, and which type might be best for you.
  • Tolerating 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.
EXAIR Model 9061 Ultrasonic Leak Detector “finds them all, big or small!”
  • 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.

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, CCASS

Application Engineer
EXAIR Corporation
Visit us on the Web
Follow me on Twitter
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Image courtesy of PEO ACWA Some rights reserved Creative Commons Attribution 2.0 Generic (CC BY 2.0)