Rotary compressor is used in those cases where:

 S.no

 Aspect

 Reciprocating Compressors

 Rotary Compressors

 1

 Pressure Ratio

Discharge Pressure of air is high. The pressure ratio per stage will be in the order of 4 to 7

Discharge pressure of air is low. The pressure ratio per stage will be in the order of 3 to 5

 2

 Handled Volume

Quantity of air handled is low and is limited to 50m3/s

Large measure of air handled can be handled and it is about 500 m3/s

 3

 Speed of Compressor

Low speed of compressor

High speed of compressor

 4

 Vibrational Problem

Due to reciprocating section, greater vibrational problem, the parts of machine are poorly balanced

Rotary parts of machine, thus it has less vibrational problems. The machine parts are balanced

 5

 Size of compressor

Size of Compressor is bulky for given discharge volume

Compressor size is small for given discharge volume

 6

 Suitability

For medium to high-pressure ratio

For low and medium gas volume

For low to medium pressures

For large volumes