What is Gas compressor?
[[File:2017-09-14 (129) Atlas Copco portable compressors for construction work at Bahnhof Rekawinkel.jpg|thumb|A portable air compressor for construction work]] [[File:Compressor Danfoss SC18CL.jpg|thumb| A compressor like you would see inside a [[Refrigerator]].]] A '''gas compressor''' is a mechanical device that increases the [[pressure]] of a [[gas]] by reducing its [[volume]]. Compression of a gas naturally increases its [[temperature]]. When the gas is [[air]], the machine is called an '''air compressor'''. Compressors are similar to [[pump]]s: both increase the pressure on a [[fluid]] and both can transport the fluid through a [[pipe (material)|pipe]]. As gases are compressible, the compressor also reduces the volume of a gas. Liquids are relatively incompressible, so the main action of a pump is to transport liquids. == Types of compressors == There are many different types of gas compressors. The two primary categories are: * '''Positive displacement''' compressors with two sub-categories: ** '''''Reciprocating''''' ** '''''Rotary''''' * '''Dynamic''' compressors also with two sub-categories: ** '''''Centrifugal''''' ** '''''Axial''''' The more important types in each of the four sub-categories are discussed below. === Centrifugal compressors === [[File:CentrifugalCompressor.jpg|thumb|right|250px|Figure 1: A single stage centrifugal compressor]] '''Centrifugal compressors''' use a vaned rotating disk or [[impeller]] in a shaped housing to force the gas to the rim of the impeller, increasing the velocity of the gas. A [[diffuser]] (divergent duct) section converts the velocity energy to pressure energy. They are primarily used for continuous, stationary service in industries such as [[oil refinery|oil refineries]], [[chemical plant|chemical]] and [[petrochemical]] plants and [[natural gas processing]] plants. Their application can be from 100&nbsp;hp (75&nbsp;kW) to thousands of horsepower. With multiple staging, they can achieve extremely high output pressures greater than 10,000 psi (69 MPa). Man