IC Engine and Energy Engineering
The reciprocating type compressor consists of a piston which is enclosed within the cylinder & equipped with suction & discharge valves.The piston receives power from the main shaft through the crankshaft and connecting rod. A flywheel/belt wheel is fitted on the crankshaft which is driven by electric motor or diesel engine.Double stage or two stage reciprocating air compressors consists of two cylinders. One is called low-pressure cylinder and another is called high-pressure cylinder. When piston in a low-pressure cylinder is at its outer dead centre (ODC) the weight of air inside a cylinder is zero (neglecting clearance volume), as piston moves towards inner dead centre (IDC) pressure falls below atmospheric pressure & suction valves open due to a pressure difference. The fresh air is drawn into the low-pressure cylinder through air suction filter. This air is further compressed by piston and pressure inside & outside the cylinder is equal, at this point suction valves closed. As the piston moves towards ODC compression of air took place and when the pressure of air is in a range of 1.5 kg/cm² to 2.5 kg/cm² delivery valves opens & this compressed air is then entered into a high-pressure cylinder through the intercooler. This called low-pressure compression. If suction & discharge stroke took place on both sides of the piston then it is called Double Acting Low-pressure compression. Suction valves of a high-pressure cylinder open when the air pressure in a high-pressure side is below to the receiver pressure & air from low-pressure cylinder drawn into the high-pressure cylinder. As piston moves towards the ODC, first stage air is further compressed. When air pressure from the low-pressure cylinder and inside the high-pressure cylinder is equal, suction valves closed. Now the air is further compressed by piston until the pressure in the High-Pressure Cylinder exceeds that of the receiver & discharge valves open. This desired high-pressure air is then delivered to a receiver. The Same procedure is repeated in every cycle of operation.
Two stage reciprocating air compressors are used in automotive service and body shops, fleet maintenance, machine shops, production and manufacturing lines, wood working shops, dry cleaners, car washes, general maintenance/repair shops and farms.