TWO-STAGE SCREW COMPRESSOR

摘要

A two-stage screw compressor is provided with a low-stage compression mechanism that compresses a fluid, a high-stage compression mechanism that further compresses the fluid compressed by the low-stage compression mechanism, and a screw shaft that drives the low-stage compression mechanism and the high-stage compression mechanism. The low-stage compression mechanism has a low-stage screw rotor, a pair of low-stage gate rotors, and a low-stage casing. The high-stage compression mechanism has a high-stage screw rotor, one high-stage gate rotor, and a high-stage casing. The low-stage screw rotor and the high-stage screw rotor have the same radius. A compression groove of the low-stage screw rotor is formed in such a manner that a rotation angle of a stroke from the start of a compression to the completion of a discharge is smaller than 180°. A compression groove of the high-stage screw rotor is formed in such a manner that a rotation angle of a stroke from the start of a compression to the completion of a discharge falls within 180°to 360°.