Helical screw type compressor - has oil trap on outlet to increase efficiency when inlet throttle is closed

摘要

The compressor has two rotors (1) with helical threads on them meshing with each other and rotating in opposite directions inside a casing (3). A gas is admitted at one axial end (4) and discharged at the other (11). Oil for cooling and lubrication is injected in the inlet and removed in a separator after the compressor. A throttle (5) in the inlet controls the volume throughput. The connection (13) between the outlet opening and the discharge non return valve (15) is constructed as a liquid trap (14). When the throttle is closed this fills with oil and prevents reverse flow of gas and thus reduces no load pumping losses.