Two Basic Compression Principles: Displacement Compression and Dynamic Compression

Two basic principles of compression? displacement and dynamic compression

There are two generic principles for the compression of air (or gas):

In positive displacement compression, the air is drawn into one or more compression chambers, which are then closed from the inlet. Gradually the volume of each chamber decreases and the air is compressed internally. When the pressure has reached the designed build-in pressure ratio, a port or valve is opened and the air is discharged into the outlet system due to continued reduction of the compression chamber's volume.

for example, reciprocating (piston) compressors, orbital (scroll) compressors and different types of rotary compressors (screw, tooth, vane)

In dynamic compression, air is drawn between the blades on a rapidly rotating compression impeller and accelerates to a high velocity. The gas is then discharged through a diffuser, where the kinetic energy is transformed into static pressure.

Most dynamic compression are turbo compressors with an axial or radial flow pattern.