Patent ID: 7942625

Claim:
A housing for a compressor that compresses fluid, the compressor having blades that impart to a fluid a momentum having components along a main gas flow direction and a swirl direction, said housing comprising: a channel defining an axis substantially aligned with the main gas flow direction, said channel being configured to duct the fluid and having at least one channel wall, said at least one channel wall defining an internal cavity that extends axially and circumferentially within said at least one channel wall; and a bleed passage connecting and providing fluid communication between said channel and said cavity; wherein said at least one channel wall defines an array of injection passages providing fluid communication between said cavity and said channel at a location spaced from both said bleed passage and the blades in a direction opposite the main gas flow direction, wherein said array comprises injection passages spaced apart circumferentially and axially, and wherein each of said injection passages comprises a tubular hole through said at least one channel wall, said injection passages being oriented to direct fluid from the cavity into said channel with a component along the main gas flow direction and a component opposed to the swirl direction.