The definition of a dry vacuum pump is a pump that does not use any fluids to create a vacuum or contact the process gas and can also discharge to atmosphere. … Timing gears with essential oil reservoirs and close clearances between the rotors and casing are extra attributes that define a dry vacuum pump.
Principle of Operation
Dried out screw vacuum pumps operate with two screw rotors rotating in reverse directions. This traps the medium to become pumped between your cylinder and the screw chambers and transports it to the gas discharge. … It also results in a lower heat load of the compressed gas.