Vacuum Pumps, Booster Compressors and Pressure Intensifiers

A booster compressor is a compressor that compresses compressed air to a much higher pressure. It may be used to compensate the pressure drop in long pipelines or for applications in which a higher pressure is required for a sub-process. Booster compressors may be single-stage or multi-stage and can be of a dynamic or displacement type, but piston compressors are the most common. The power requirement for a booster compressor increases as the pressure ratio rises, whereas the mass flow drops. The curve for power requirement as a function of the inlet pressure has the same general form as the curve for a vacuum pump.

Pressure intensifiers are a form of booster compressors, driven by the compressed air medium itself (called the propellant). They can increase the pressure in a medium for special applications: for laboratory tests of valves, pipes and hoses. A pressure of 7 bar can be amplified in a single stage to 200 bar or up to 1700 bar in multi-staged equipment. The pressure intensifier is only available for very small flows. When the propellant flows in, the low-pressure piston is pressed downwards and forces the medium in the high-pressure compression chamber out under high pressure. The intensifier can work in a cycling process, up to a pressed pressure level. All inert gases can be compressed in this way. Air can also be compressed in a pressure intensifier, but must be completely oil-free to avoid self-ignition.