Two basic principles
Two basic principles There are two basic principles for the compression of air (or gas), the displacement principal and dynamic compression. Among displacement compressors are, for example, piston compressors and different types of rotary compressors. They are the most common compressors in most countries. On a piston compressor for example, the air is drawn into a compression chamber, which is closed from the inlet. Thereafter the volume of the chamber decreases and the air is compressed. When the pressure has reached the same level as the pressure in the outlet manifold, a valve is opened and the air is discharged at a constant pressure, under continued reduction of the compression chamber's volume. In dynamic compression air is drawn into a rapidly rotating compression impeller and accelerates to a high speed. The gas is then discharged through a diffuser, where the kinetic energy is transformed to static pressure. There are dynamic compressors with axial or radial flow. All are suitable for large volume rates of flow.