Patent ID: 8021104

Claim:
A centrifugal compressor configured to provide a flow of recirculated air for surge control, the compressor comprising: a housing defining an axial inlet passage and a radial diffuser passage; and a compressor wheel defining a plurality of blades, each blade having a leading edge adjacent the inlet passage and a trailing edge adjacent the diffuser passage, the compressor wheel rotatably mounted in the housing such that the compressor wheel is configured to receive air flowing generally axially in the inlet passage at the leading edges of the blades and deliver the air from the trailing edges of the blades in a generally radial direction to the diffuser passage, wherein the housing defines at least one injection port configured to receive compressed air from the compressor wheel and recirculate the compressed air to the inlet passage of the compressor, each injection port defining an outlet proximate to the leading edges of the compressor blades, and wherein the housing defines at least one flow channel having an inlet at the diffuser passage, the inlet being configured to receive the compressed air from the diffuser passage, and each flow channel extending in a generally axial direction from the inlet to the at least one injection port such that the injection port delivers the compressed air to the leading edges of the compressor blades.