MULTISTAGE AIR COMPRESSION WITH INTERCOOLING

In Multi - Stage Compressor, The Compression of the air from the initial pressure to the final pressure is carried out in more than one cylinder. It is used to get high pressure air. In a compressor, when compression ratio exceeds 5 , generally multistage compression is adopted.

In Two stage reciprocating air compressor. It consists of a low-pressure Cylinder (LP), an intercooler and a high - pressure cylinder (HP). Fresh air is sucked from the atmosphere in low - pressure cylinder during its suction stroke at intake pressure p1 and Temperature T1. The air after compression in L.P cylinder is delivered to the intercooler at pressure p2 and Temperature T2. In the intercooler, the air is cooled at constant pressure by circulating cold water. The cooled air from intercooler is then taken to the high - pressure cylinder. In the high pressure cylinder, air is further compressed to the final delivery pressure (p3) and discharge to the receiver.

Assumptions Made In Multistage Compression :

1. Suction and Delivery pressures remain constant during each stage.

2. The Index of compression is same in each stage.

3. The inter cooling in each stage is at constant temperature.

4. The mass of air handled by the low pressure and high pressure cylinders are same.

Advantages Of Multistage Air Compressor

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