LG l PITBULL

Air compressor supplies air into a nail gun

An air compressor is a device that converts power (usually from an electric motor, a diesel engine or a gasoline engine) into kinetic energy by compressing and pressurizing air, which, on command, can be released in quick bursts. There are numerous methods of air compression, divided into either positive-displacement or negative-displacement types.^[1][2]

Types of air compressor:

1. According to the design and principle of operation
   1. Reciprocating compressor
   2. Rotary compressor
2. According to the number of stages
   1. Single stage compressor
   2. Multi stage compressor
3. According to the pressure limits
   1. Low pressure compressors
   2. Medium pressure compressors
   3. High pressure compressors
   4. Super high pressure compressors
4. According to the capacity
   1. Low capacity compressors
   2. Medium capacity compressors
   3. High capacity compressors
5. According to the method of cooling
   1. Air cooled compressor
   2. Water cooled compressor

Positive-displacement air compressors work by forcing air into a chamber whose volume is reduced to compress the air. Piston-type air compressors use this principle by pumping air into an air chamber through the use of the constant motion of pistons. They use unidirectional valves to guide air into a chamber, where the air is compressed.^[1] Rotary screw compressors also use positive-displacement compression by matching two helical screws that, when turned, guide air into a chamber, the volume of which is reduced as the screws turn. Vane compressors use a slotted rotor with varied blade placement to guide air into a chamber and compress the volume.

Negative-displacement air compressors include centrifugal compressors. These devices use centrifugal force generated by a spinning impeller to accelerate and then decelerate captured air, which pressurizes it.^[1]

Conventional air compressors are used in several different applications:

• To supply high-pressure clean air to fill gas cylinders
• To supply moderate-pressure clean air to a submerged surface supplied diver
• To supply moderate-pressure clean air for driving some office and school building pneumatic HVAC control system valves
• To supply a large amount of moderate-pressure air to power pneumatic tools
• For filling tires
• To produce large volumes of moderate-pressure air for macroscopic industrial processes (such as oxidation for petroleum coking or cement plant bag house purge systems).

Most air compressors either are reciprocating piston type, rotary vane or rotary screw. Centrifugal compressors are common in very large applications. There are two main types of air compressor's pumps: Oil lubed and oil-less. The oil-less system has more technical development, but they are more expensive, louder and last for less time than the oiled lube pumps. However, the air delivered has better quality.

See also

• Gas compressor

References