Comparison Between Reciprocating and Rotary Compressors

Comparisons between Reciprocating and Rotary Compressors can be made in aspects like pressure ratio, handled volume, speed of the Compressor, vibrational problem, size, air supply, purity of compressed air, compression efficiency, maintenance, mechanical efficiency, lubrication, initial cost, flexibility and suitability.

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.	The discharge pressure of air is low. The pressure ratio per stage will be in the order of 3 to 5.
2	Handled Volume	The quantity of air handled is low and is limited to 50m3/s.	Extensive measures of air 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 the reciprocating section and more significant vibrational problem, the parts of the machine could be better balanced.	Rotary parts of the machine, thus, have fewer vibrational problems. The machine parts are pretty balanced.
5	Size of Compressor	The size of the Compressor is bulky for a given discharge volume.	The compressor size is small for a given discharge volume.
6	Air supply	The air supply is intermittent.	Air supply is steady and continuous..
7	Purity of compressed air	Air delivered from the Compressor is dirty since it comes in contact with lubricating oil and cylinder surface.	Air delivered from the Compressor is clean and free from dirt.
8	Compressed efficiency	Higher with a pressure ratio of more than 2.	Higher with compression ratio less than 2.
9	Maintenance	Higher due to reciprocating engine.	Lower due to less sliding parts..
10	Mechanical Efficiency	Lower due to several sliding parts.	Higher due to fewer sliding parts.
11	Lubrication	Complicated lubrication system.	Simple lubrication system.
12	Initial cost	Higher.	Lower.
13	Flexibility	Greater flexibility in capacity and pressure range.	No flexibility in capacity and pressure range.
14	Suitability	For medium and high-pressure ratios. For low and medium gas volumes.	For low and medium pressures. For large volumes.