State necessity of multistaging and Intercooling of air compressor.
Necessity of multistaging –
For producing high pressure i.e. more than 8 bar, single stage air compressor suffers fallowing drawbacksi) Size of cylinder is too large
ii) Rise in temperature of air is very high.
To avoid this difficulty multi-staging is necessary.
Necessity of intercooling –
In two stage air compressor air is compressed in first cylinder and the temperature of air is increased. If this high temperature air is not passed through intercooler and sent directly to second stage then because of high temperature volume of air increases so amount of air taken inside decreases and pressure is also automatically decreased and volumetric efficiency is also decreases. To avoid this intercooling is necessary.