Portable Air Compressors

Portable compressors too; we started talking about portable compressors here.

More information on portable air compressors continues.

Oil Carryover

Almost all oil-lubricated air compressors will have some oil carryover. Oil coming out with the air stream is a problem for most folks. If this is critical to what you are doing with compressed air, then you will want to add a coalescing filter downstream of your compressor, to remove oil from the air stream.

To increase the life of the coalescent element in the oil-removing filter, ensure that you install a 5 Micron general purpose compressed air filter upstream from the coalescent unit. This will remove free water and larger (relatively speaking) particulates from the air stream, freeing the coalescent element to work on oil removal.

If your compressor duty cycle is high - as in you are using the compressor all day - you might also add a 40 Micron general purpose filter upstream from the 5 Micron unit. This will extend the life of both the 5 micron and coalescent filter elements.

Air preparation is a continuum. You keep adding equipment to the compressed air stream to condition the compressed air to the level your equipment needs. That may mean that you have to throw quite a bit of money at it, others can get by with just a general purpose 40 micron filter. The application for compressed air dictates the level of treatment.

Sometimes the air-using equipment demands a larger compressor, and there are a variety that are still portable compressors, but not carry. These portable air compressors ar on wheels.

Power Supply

Portable compressors usually are configured with an electrical cord and plug to connect the unit to a 120 VAC outlet.

Some compressors are dual voltage, and can be wired to run on a 220 Volt circuit and a 120 volt circuit.

If you are not an electrician, make sure you have a professional deal with the rewiring. Be safe! Leave electrical work to persons that are qualified!

When powered by 220 volts, compressors are more efficient and have greater capacity than when supplied by 120 VAC. The air compressor is a converter, turning electrical voltage into stored compressed air energy. A 120 volt circuit has less energy available for conversion than the 220 volt circuit, so the 220 can generate higher flows of compressed air from the compressor.

Portability of compressors knows no bounds! Compressors are routinely flown into to remote sites all over the world.

How often do you drive down a highway and see a work crew using a portable compressor on road construction? Since construction usually slows traffic (almost always when you are in a hurry and trying to get somewhere quickly it seems) you will have the opportunity to check out the portable compressor as you drive by.

The compressor in the adjacent photo is a rotary screw, continuous run, with a 100% duty cycle, and is powered by diesel fuel.

Compressor Selection

When it comes to portable compressors, the same rules for selection apply as they do to in-plant compressors.

• capacity required in flow and pressure
• how the unit is to be powered (what voltage or what type of fuel)
• air treatment to rid the compressed air stream of dust, water and oil
• dealing with oil carryover if an oil-lubed compressor
• compressed air pressure regulation to eliminate pulsation as the compressor kicks on and off