The diaphragm compressor for process gas uses a pair of flexible membranes to pump gas in a closed chamber. This eliminates metal-to-metal friction between the piston and crankshaft, making it perfect for toxic or explosive gas compression applications. This type of compressor also offers higher efficiency and a lower purchase, operating, and maintenance cost than traditional compressors with metal pistons.
The motor-driven eccentric mechanism oscillates a flexible diaphragm set to alternately expand and compress the compression chamber volume. The movement of the diaphragms ensures that only the process gas comes in contact with hydraulic fluid (or oil from the compressor). This prevents lubricant contamination of the process gas and maintains high purity levels. In addition, the eccentric rotor prevents the process head from coming in contact with the abrasive process gas.
The Power of Precision: Exploring Diaphragm Compressors for Process Gas Applications
A cam-driven injection pump provides make-up hydraulic fluid to the system during the compression stroke. This ensures the hydraulic system is fully charged with a fresh supply of hydraulic oil during each cycle. The oil relief valve limits maximum oil pressure and assures that the diaphragms completely “sweep” the upper and lower cavity contours to maximize displacement.
The elastomeric O-ring seals of the process side of the diaphragm are matched to the chemical properties of the process gas. This ensures that the elastomeric O-ring seals are not degraded by the abrasive process gas. This is an important feature because frequent diaphragm rupture in diaphragm compressors is a common problem at hydrogen refueling stations. This problem is usually caused by the violent collision of the diaphragm with the piston and can be predicted using dynamic pressure monitoring.