Question

A single acting two-stage air compressor deals with 4 m³/min of air at 1.013 bar and 15°C with a speed of 250 rpm. The delivery pressure is 80 bar. If the inter cooling is complete, the intermittent pressure after first stage will be 

(a) 9 bar 

(b) 8 bar 

(c) 7 bar 

(d) 6 bar

Answer 1

Correct option is (a) 9 bar 

For two stage air compressor

P_i =  \(\sqrt{p_1p_2}\) = \(\sqrt{80}\) 

= 9 bar