Category: Rotary Air Compressors

The comparison of rotary and reciprocating compressors is given in Table 13.1.   Table 13.1 Comparison of rotary and reciprocating compressors Example 13.3 Free air of 30 m3/min is compressed from 101.3 kPa to 2.23 bar in roots blower. Determine the power required and the isentropic efficiency. Solution The p − V diagrams for roots blower is shown in Fig.…

A rotary vanes blower works between the pressure limits of 1 bar and 1.8 bar, and gives 5 m3/min of free air delivered when running at 240 rpm. Determine the power required to drive the blower when (a) ports are so placed that there is no internal compression and (b) when the ports are so…

Free air of 25 m3/min is compressed from 1 bar to 2.5 bar. Calculate the indicated power required if the compression is carried out in (a) roots blower and (b) vanes blower. Assume that there is 20% reduction in volume before the backflow occurs. Also, calculate the isentropic efficiency in each case. Solution The p−V diagrams for…

In positive displacement type rotary compressors, the air is compressed by entrapping it between the reduced space of two sets of engaging surfaces. The pressure rise is either by backflow of air, as in the case of roots blower, or by both squeezing action and backflow of air, as in the case of vane type.…

In a rotary compressor, the compression of air is achieved due to the rotating blades fitted in a rotor. It requires less starting torque as compared to reciprocating compressors because of direct coupling with the prime over. Usually, rotary compressors operate at high speed and supplies higher quantity of air than reciprocating compressors. Rotary compressors…