Arrangement and design of the charging inlet apertures on a screw compressor

摘要

The invention relates to the arrangement and design of the charging inlet apertures on a screw compressor for refrigeration systems for the feeding of refrigerant gas under intermediate pressure into tooth gap cavities of two rotors at a point at which they are closed off from the intake and pressure side. The invention is intended to improve the efficiency of refrigeration systems with screw compressors due to the feeding of relatively large quantities of gas under intermediate pressure, in that the charging inlet apertures are so arranged and designed that large flow cross-sections are provided with low pressure loss and a charging inlet aperture is also created for that part of the tooth gap cavity formed by the main rotor. To this end the invention proposes that the charging inlet aperture be arranged in the pressure-side boundary wall of the compressor housing axially to the rotors. The charging inlet apertures are equal to or smaller than the end face of the secondary rotor tooth and equal to or less than half the end face of the main rotor tooth. The resulting possibility of feeding large quantities of gas under intermediate pressure improves the efficiency of a refrigeration system.