Page 12 - PNEUMATIC AND HYDRAULIC

1.1 Air generation system

1.1.1 Types of air compressor

Compressor converts the mechanical energy of an electric or combustion motor into
the potential energy of a compress air.

Electrical Energy Potential Energy

Figure 1.4: Energy Conversion

Compressors are broadly classified as: Positive displacement compressor and

Dynamic compressor.

a) Positive Displacement
i. Reciprocating

ii. Rotary Screw

Positive displacement compressors increase the pressure of the gas by reducing the

volume. Positive displacement compressors are further classified as reciprocating and

rotary compressors.

b) Dynamic
i. Centrifugal

ii. Axial flow

Dynamic compressors increase the air velocity, which is then converted to increased

pressure at the outlet. Dynamic compressors are basically centrifugal compressors and
are further classified as radial and axial flow types. The flow and pressure

requirements of a given application determine the suitability of a particulars type of
compressor.

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