State the methods to improve efficiency of air compressor. Explain two stage air compressor with perfect intercooling with neat sketch.
Following are the methods to improve efficiency of air compressor 1. Cooling cylinder by spraying water during compression stroke. 2. Circulation of water surrounding to cylinder by providing jackets 3. Installing inter cooler between two cylinders 4. Providing greater fins on cylinder 5. By selecting suitable material for cylinder 6. By providing suitable choice of cylinder proportions i.e. short stroke and large bore in construction with sleeve valve Two stage reciprocating air compressor :
Two stage reciprocating compressor
Multistage compression refers to the compression process completed in more than one stage i.e. a part of compression occurs in one cylinder ( L.P. cylinder) and subsequently compressed air is sent to subsequent cylinders ( H.P. cylinder) for further compression. Figure shows the schematic of two stage compressor with intercooler between stages. The total work requirement for running this shall be algebraic summation of work required for low pressure (LP) and high pressure (HP) stages. The size of HP cylinder is smaller than LP cylinder as HP cylinder handles high pressure air having smaller specific volume. Intake temp of air at LP =intake temp of air at HP for perfect intercooling.