To enhance compressor flexibility it is desirable to design into the compressor the capability of operating at other than the original design conditions. If it is desired to provide flexibility to operate at lower suction pressures: * Add the ability to increase speed or * Add variable clearance initially, when the suction pressure is high; …
Read More…Category: Cylinder Sizing
Reciprocating Compressors – Cylinder Throughput Capacity
Using a known piston displacement and efficiency, the gas throughput can be calculated from:
Read More…Reciprocating Compressors – Volumetric Efficiency
The flow rate is not directly equal to the piston displacement. Volumetric efficiency is the ratio of actual volumetric flow at inlet temperature and pressure conditions to piston displacement. It is given by: where Ev = stage volumetric efficiency, % R = compression ratio (Pd/Ps) of the compressor stage (based on absolute pressure) C = …
Read More…Reciprocating Compressors – Piston Displacement
The actual volume of the cylinder that is swept by the piston per minute is piston displacement. It can be calculated from: Single acting cylinder (head end displacement) Single acting cylinder (crank end displacement) Double acting cylinder (sum of head end and crank end displacement) Throughput can be changed directly by changing the piston displacement. …
Read More…Reciprocating Compressors – Cylinder Sizing
Typically, in specifying a unit, the suction and discharge pressures, capacity (MMscfd), inlet temperature, and gas properties are given. The actual sizing of the cylinders is left to the manufacturer from his specific combinations of standard cylinders, pistons, and liners. However, once a proposal is received from a manufacturer, sometimes it is beneficial to check …
Read More…