Screw compressor with a shunt pulsation trap

摘要

A shunt pulsation trap for a screw compressor reduces gas pulsation and NVH, and improves off-design efficiency, without using a traditional serial pulsation dampener and a sliding valve. A screw compressor has a pair of multi-helical-lobe rotors that are housed in a compressor chamber that propel gas flow from a suction port to a discharge port of the compressor chamber. The shunt pulsation trap includes an inner casing as an integral part of the compressor chamber, and an outer casing oversized and surrounding the inner casing. The shunt pulsation trap houses at least one gas pulsation dampening device, and includes at least one injection port (trap inlet) branching off from the compressor chamber into the pulsation trap chamber and a feedback region (trap outlet) communicating with the compressor outlet.

主权项

1. A screw compressor, comprising:
a. a housing structure having an inner casing with a flow suction port, a flow discharge port, and a compressor chamber there-between; b. two parallel multi-helical-lobe rotors rotatably mounted on two parallel rotor shafts respectively inside said compressor chamber for propelling flow from said suction port to said discharge port in a flow direction; and c. a shunt pulsation trap apparatus comprising an outer casing oversized and surrounding said inner casing to cooperatively form a pulsation trap chamber therebetween, at least one pulsation dampening device positioned within the pulsation trap chamber, at least one trap inlet branching off from said compressor chamber before said flow discharge port in said flow direction and connecting said compressor chamber to said pulsation trap chamber so that at least a portion of said compressor chamber and said pulsation trap chamber are arranged in parallel, and at least one trap outlet connecting said pulsation trap chamber to said compressor discharge port;wherein said screw compressor is capable of achieving high gas pulsation and NVH reduction at said pulsation trap chamber and improving compressor off-design efficiency.