GB1287309A - Screw rotor compressor - Google Patents

Abstract

1287309 Screw motor compressors KUHIAUTOMAT VEB 29 Oct 1970 51586/70 Index F4H G2T HG2L HG2F HG2C HF2J In an externally meshing screw rotor compressor for a refrigeration process (not described) in a ship's installations, refrigerant vapour is sucked in at the low pressure side and partly compressed before oil, from an oil separator (2), Fig. 3 (not shown), is injected via a pump (7), filter (9) and connection (10) Fig. 3 (not shown) into the refrigerant vapour compression chamber, for the purpose of sealing, cooling, lubrication and noise absorption, via ducts 15, a subsequent injection of liquid refrigerant at condensation pressure into the compression chamber via axial and/or radial ducts 17, 18 further taking place at a point shortly before the screw rotor grooves come into communication with the high-pressure outlet at the end of the compression stage, whereby the oil is cooled by the liquid refrigerant which is accordingly vaporized by the heat, the arrangement obviating the necessity for a separate oil cooler and thus reducing the overall size of the operational refrigerator unit. The liquid refrigerant is supplied from a condenser (3) Fig. 3 (not shown) via a thermostatic expansion valve (11) and connection (12), the injected quantity of refrigerant being regulated by the valve (11) and directed against the pump delivery flow to ensure good distribution and mixing for rapidly cooling the oil whereby the entire compression work generated heat is conducted away in the condenser (3). The major part of the refrigerant liquified in the condenser (3) is fed to the normal refrigerant cycle in that is passes through an expansion valve (4) into a vaporizer (5), is vaporized there by a heat supply and is sucked by the compressor 1, which is driven by an electric motor (8), through suction filters (6).