Chapter | three - Air Compressors, Air Treatment and Pressure Regulation

Abstract

The vast majority of pneumatic systems use compressed atmospheric air as the operating medium. Pneumatic systems use a compressible gas, hydraulic systems an incompressible liquid, and this leads to some significant differences. Pressure in a hydraulic system can be quickly and easily controlled by devices such as unloading and pressure-regulating valves. Fluid is thus stored at atmospheric pressure and compressed to the required pressure as needed. Like hydraulic pumps, air compressors can be split into positive displacement devices and dynamic devices such as centrifugal or axial blowers. The vast majority of air compressors are of the positive displacement type. This chapter discusses an air receiver, which is used to store high-pressure air from the compressor. Its volume reduces pressure fluctuations arising from changes in load and from compressor switching. Control of the compressor is necessary to maintain pressure in the receiver.