INTRODUCTION

Compressors are mechanical devices used for increasing the pressure of a gas. Compressors used for producing high pressure air are called air compressors. Air is drawn from the atmosphere by suction process, which is then compressed to the required pressure and delivered to the receiver. Air compressors may be classified as shown in Fig. 12.1.

Figure 12.1 Classification of compressors

If compression is done in a conventional cylinder with a closely fitted piston making reciprocating motion, then the compressor is called a reciprocating compressor. External work must be supplied from a prime mover to the compressor to achieve the required compression. The general arrangement of the compressor and prime mover used to run the compressor is shown in Fig. 12.2.

Figure 12.2 Energy flow in an air-compressor