Tag: intake filter

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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Compressed Air Pipe

Intelligent Compressed Air: System Equipment

Published on by Russ BowmanLeave a comment

At the end of Naval Nuclear Power School, students who’ve just spent two years learning how to boil water must pass a comprehensive examination board before they’re released into the fleet as real live “Navy Nucs.” One popular question at these boards (in 1987 anyway) was to describe, in detail, the path a drop of seawater takes to become reactor coolant (a warship at sea must be self-reliant, and that includes making our own pure water.) A correct answer would prove the student’s knowledge of various piping systems, the steam distilling and water purification processes, reactor coolant chemistry maintenance, and, if you were lucky, a deep dive into the Six Factor Formula which mathematically defines the six events* that affect the probability of neutron multiplication, and hence, the sustainability of nuclear fission in the reactor core:

*Two of these six events relate to the thermalization of neutrons by the coolant. That’s why it’s considered to be a valid part of the ‘seawater-to-reactor-coolant’ question.
The block on the left represents a cubic foot of air at atmospheric pressure. The one on the right represents how much space the first one takes up when compressed to 100psig.

In that same vein, for today’s EXAIR blog, I thought I’d trace a Standard Cubic Foot (SCF) of air from the compressor room, through a typical industrial compressed air system, to its point of use. First, let’s define what that is: Imagine a cubic foot of air in front of you. If the atmospheric pressure is 14.5psia (average for sea level elevation), the ambient temperature is 68°F, and relative humidity is 0%, then that’s one Standard Cubic Foot of air. Now, let’s say this air is in an ideal compressor room – ‘ideal’ meaning those atmospheric conditions apply – and follow its path to an EXAIR Super Air Knife:

  • Filter, Part 1 (intake): When the air compressor draws our SCF in, it passes through filtration media to remove impurities like dust, oil, and moisture. It’s important to remember that this filter is there to PROTECT THE COMPRESSOR from those contaminants, not to provide any measure of cleanliness to the compressed air itself.
  • Compression: This is where our SCF gets compressed by reciprocal or rotating elements imparting energy to it, and it now occupies considerably less space than it did in the atmosphere. This also raises the temperature. When all the molecules that comprise our SCF get closer together, they run into each other more often, and that increased friction makes them hotter. Which can be bad, unless we do something about it.
  • After cooler: Hot compressed air can cause unsafe surface temperatures and can damage gaskets, seals, or other components in the downstream system. Cooling our SCF down is the first thing we want to do after compressing it.
  • Filter, Part 2 (discharge): While the Intake Filter takes care of impurities that could have damaged the compressor, the compressor itself can add some back into our SCF – like oil, wear particulate from meshing gears or seals on moving parts, etc. You’ll want to remove those as well, before letting them go any further in the system. Contaminants like that can really do a number on the operation and effectiveness of some types of dryers.
  • Dryer: While the intake filter removes some finite amount of moisture from our SCF before compression, the compression cycle increases the moisture concentration of it. Dryers come in different types and configurations, each with their own pros & cons, and certain types are more suitable for certain situations. Here’s a link to a blog on the subject by Jordan Shouse that’s both informative and entertaining!
  • Primary Storage: Once our SCF gets cooled, cleaned, and dried, it can take a little break if it’s not needed right away, in a receiver tank. Such a tank, like EXAIR’s Model 9500-60 60 Gallon Receiver Tank (right), near the compressor discharge, serves several purposes:
    • It maintains header pressure during any load transients that happen too quickly for the compressor to keep up in real time.
    • It provides further moisture removal, as any water that condenses in this receiver can be drained from a valve on the bottom.
    • It also allows the compressed air to cool further.
  • Distribution Header Piping: This is the “highway,” if you will, that our SCF travels to where it’ll be used. It’s not alone, either – there are sometimes hundreds, if not thousands, of other SCF’s passing through every minute. And if it’s not appropriately sized, there’ll be problems akin to traffic jams on crowded roads. The appropriate size and layout of the header piping will be determined by a number of factors – here’s a link to a blog with more details on that.
  • Airdrops: These are the branches from the distribution header that lead to the various points of use in the facility. Our SCF will take whichever one it gets directed to…in this case, the aforementioned EXAIR Super Air Knife. The proper size of the drop piping or hose will be determined by the compressed air consumption of the load(s) serviced by the drop, and its length from the header. In the case of our EXAIR Super Air Knife that our SCF is heading towards, the recommended in feed pipe sizes are listed in the Installation/Maintenance Guide:
The longer the drop length, the larger the diameter needs to be to compensate for line loss due to friction.
  • Filter, Part 3 (point of use): Good engineering practice calls for point-of-use filtration. Our SCF has already been through two filters, I know, but it’s also potentially picked up some more contamination along the way. Rust from the inside walls of iron pipes is the most common culprit. The EXAIR Super Air Knife that our SCF is heading towards needs its supply to be filtered for particulate to a level of 10 microns or less. EXAIR Automatic Drain Filter Separators have 5-micron particulate elements, and centrifugal elements that ‘spin’ out any remaining moisture. Depending on the needs of the application, we also have Oil Removal Filters with coalescing elements for oil/oil vapor. They also provide additional particulate filtration to 0.03 microns.
  • Regulator: It’s taken a good deal of effort and expense to get our SCF to this point, so it only makes sense to use it as efficiently as possible. A Pressure Regulator allows us to precisely ‘dial in’ the supply pressure so that we don’t use it (or any of the other SCF’s that it’s traveling with) any more than needed.
EXAIR Automatic Drain Filter Separators (left) can be directly coupled to Oil Removal Filters (center) and Pressure Regulators (right) for a compact installation, free from threaded connections.
EXAIR’s award-winning EFC Electronic Flow Control is a ‘plug and play’ system that can save you THOUSANDS of dollars in compressed air costs.
  • Shutoff valve: Years ago, I talked to an engineer at a company that was using one of our Super Air Knives to blow off parts that were passed in front of it by a robot. The robot’s arm turned & rotated the part in the air curtain to ensure it got completely blown off. This only took a couple of seconds, as the operators had ‘tweaked’ the arm movement to do it as quickly as possible. However, there were about 15 seconds between parts…and the Super Air Knife WAS BLOWING THAT WHOLE TIME. Since they’d already told me how great their automation techs were at programming the robot, I suggested that they go one more step and install a Solenoid Valve in the supply line to the Super Air Knife and use the robot’s logic to open it right before the robot got there, and close it right after the robot left. Step Four of our Six Steps To Optimizing Your Compressed Air System is to “turn off the compressed air when it’s not in use,” and by doing so, they reduced the compressed air consumption of this one Super Air Knife by about 80%. THAT’S optimized. If you don’t have existing logic to do this, our EFC Electronic Flow Control will do it for you.
  • The Super Air Knife: At long last, our SCF is ready to fulfill its purpose, and the Super Air Knife will help it do so in the most efficient way possible. It uses that SCF of air, along with all the others that pass through, to entrain a WHOLE BUNCH of SCF’s from the surrounding environment. The amplification ratio for EXAIR Super Air Knives is 40:1, making them the most efficient compressed air-blowing products on the market.
EXAIR Super Air Knives come in lengths from 3″ to 108″, and are available from stock in aluminum, 303SS, 316SS, or PVDF.

It’s been a LONG time since I’ve used the Six Factor Formula for the neutron life cycle in nuclear fission (and honestly, I haven’t missed it all that much), but every day, I use formulas and figures related to:

Just to name a few. If you’d like to “math something out,” (just not the Six Factor Formula, please), give me a call.

Russ Bowman, CCASS

Application Engineer
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Downtime: It Isn’t Always BAD

Published on by Brian FarnoLeave a comment

When you say Downtime in an industrial or manufacturing setting, it may easily carry a negative connotation. This means that the output of production is not happening and input to production has halted as well. If this is not planned, it is absolutely a worst-case scenario. In our personal lives, though, downtime generally doesn’t have a negative meaning behind it. That’s the time to disconnect and recharge to maximize your output after you return to production and that is exactly what I had the luxury to do recently. This is also a message I received from a person I look up to and trust in their experiences. Vacation time can be looked at similar to a preventative and planned downtime of equipment. Without it we just wear down and eventually productivity grinds to a halt. While hanging out at a lake with my daughters this past week, I helped them hone their fishing skills. They each baited their own hooks with worms and chose their spots. We completely slayed some bluegills, and released every single one of them.

The calm of a storm rolling in when you have nothing to do is serene.

Prescribed maintenance, preventative maintenance, vacations all help to build back into the production of whatever good or service the company provides. The entire production of a facility all starts with the utilities, energy, water, compressed air, steam, other compressed gases, and the personnel. If your power input isn’t maintained, monitoring connections and disconnects, you can find yourself with a lack of service, resulting in dangerous situations. City water is often required for processes or for the facility to function properly, even an office building needs it for plumbing, fire suppression, and drinking. Steam, compressed gases and compressed air may all be required by the processes.

Servicing the compressed air where it starts is one of the most critical steps in operating a compressed air system. Making sure that your compressor has the minimum downtime, all starts with the preventative and prescriptive maintenance. One of the first tasks should always be changing and monitoring the intake air filter. Like Russ Bowman said a while back in his blog, take a deep breath, if you sneeze or smell something that is from the intake air your nose just took in from the surrounding area. That’s even after your nose hair has already partially filtered air intake. Your compressor is no different. If you let it suck up debris, dust, and pollen, then it is eventually going to have a failure. Instead of sneezing, it may burn up a vane, valve, scroll or screw. That is going to be a considerably higher cost and longer downtime than just performing the manufacturer’s listed items to maintain optimal performance.

The compressor shown above according to the caretaker receives a regular change on the airfilter every month. This is just before the cleaning and changeover. Not only do they change the filter, they make sure to clean the entire housing inside and out. That’s one of the ways this compressor has lasted with minimal downtime over the past 20 years.

If you want to learn more about other key maintenance items in your compressed air system, please contact an Application Engineer today.

Brian Farno, MBA – CCASS
National Business Development Manager

BrianFarno@EXAIR.com
@EXAIR_BF

Air Compressors: Maintenance and Optimization

Published on by John BallLeave a comment

In one of my previous jobs, I was responsible for the operation of the facility, and one of my biggest jobs was the operation of our air compressor.  Like with many industries, the compressor system is the lifeblood of the company.  If the compressor fails, the whole facility will stop.  In this blog, I will share some maintenance items and schedules for air compressors.

Because the cost to make compressed air is expensive, the compressed air system is considered to be a fourth utility.  With such an important investment, you would like to keep it operating as long and efficiently as possible.  To do this, it is recommended to get your air compressor a “checkup” every so often.  I will cover some important items to check.  Depending on the size and type, some items may or may not apply.  But please, always check with the manufacturer of your air compressor.

Intake filter: The intake filter is used to clean the air that is being drawn into the air compressor.  Better filtration results in less debris getting into your system.  Particles can damage the air pump mechanisms over time as well as plug filters and heat exchangers downstream.  If they are not properly monitored and cleaned, the air flow can be restricted.  This will cause the compressor motor to operate harder and hotter.

Compressor Oil: This would be for flooded screws and reciprocating compressors that use oil to lubricate the bearings and sleeves in the air pump.  Most systems have an oil sight to verify levels.  The oil can also be checked for acidity, which will tell the degree at which the oil is breaking down.  Just like the motor oil in your car, you will have to replace it after so many hours of operation.

Belts & couplings: These items transmit the power from the motor to the air pump.  Check their alignment, condition, and tension (belts only) as specified by the manufacturer.  You should have spares on hand in case of any failures.

Electric Motors: A mechanical device that turns electric energy into rotational energy.  It is the main component that uses a lot of energy to make compressed air.  So, some checks are required to foresee any potential issues and major shutdowns.  For the windings inside, the resistance should be measured with a multi-meter, and it should fall within the motor’s specifications.  Another check should be on the start capacitor.  The start capacitor stores energy to give the motor a powerful boost to get it turning.  One other item is the centrifugal switch.  Just like the name states, it will disconnect the start capacitor when the motor starts spinning.  One other item for large electric motors is the phase converter.  These are typically capacitors, and they are designed to keep the direction of three-phase motors going in the correct rotation.  Both types of capacitors can be checked with a multi-meter.

Air/Oil Separators: This filter removes as much oil from the compressed air before it travels downstream.  It returns the oil back to the sump of the air compressor.  If the Air/Oil Separator builds too much pressure drop, excess oil can travel downstream.  Not only will the air pump lose the required oil level, but it will affect the performance of downstream parts like air dryers and after-coolers.  Also, the pressure drop is a waste and can rob your air system of workable energy. 

Internal filters: Many air compressors will come with an attached refrigerated air dryer.   With this type of air compressor, they will place coalescing filters to remove any residual oil.  These filters should be checked for pressure drop.  If the pressure drop gets too high, then it will rob your compressed air system of pressure, and you will not get the required performance.  Some filters come with a pressure drop indicator which can help you to determine the time to change the element.   

Unloader valve: When the air compressor unloads, this valve helps to remove any of the compressed air that is trapped in the cavity.  When the air compressor restarts, it does not have to “work” against this air pressure.  If they do not fully unload, the air compressor will have to work harder to start, wasting energy.

Preventative maintenance is very important.  As for a schedule, I created a rough sequence to check, change, or clean certain items that are important to your air compressor.  You should also check with your local compressor representative for a more detailed maintenance schedule.

Daily:

  • After stopping, remove any condensate from the receiver tank.
  • Check the oil level.

Monthly:

  • Inspect the cooling fins on the air pumps.  Clean if necessary
  • Inspect the oil cooler. Clean if necessary

Quarterly:

  • Inspect the inlet air filter.  Clean or replace if necessary.
  • Check the belt for tension and cracks.  Tighten or replace.
  • Check differential pressure indicators on outlet compressed air filters.
  • Ohm check on the electric motor

Yearly:

  • Replace Air Inlet Filter
  • Replace the air-oil separator
  • Test safety valves and un-loader valve
  • Replace compressed air filters
  • Change oil
  • Grease bearings if required

Keeping your air compressor running optimally is very important for pneumatic operations.  But there is much more than an air compressor in your system.  To help, there are steps that can be used on the demand side.  EXAIR created a Webinar – “Optimizing Your Compressed Air System In 6 Simple Steps”.  With this combination, you can keep a healthy compressed air system.  You can always contact an Application Engineer at EXAIR to see how much money can be saved by energy reduction, safety, and monitoring.  

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Image courtesy of Compressor1 – Creative commons license