Patent ID: 8197188

Claim:
A compressor for compressing a gas, the compressor comprising: a housing having an inlet and an outlet; an impeller wheel including a plurality of vanes rotatably mounted within the housing between said inlet and outlet; the housing having an inner wall defining a surface located in close proximity to radially outer edges of impeller vanes which sweep across said surface as the impeller wheel rotates about its axis; the inlet comprises an outer tubular wall extending away from the impeller wheel in an upstream direction and forming a gas intake portion of the inlet and an inner tubular wall of diameter extending away from the impeller wheel in an upstream direction within the outer tubular wall and defining an inducer portion of the inlet and an annular gas flow passage defined between the inner and outer tubular walls, the annular gas flow passage being in fluid communication with the impeller wheel; and wherein there is provided a plurality of blind noise attenuation apertures defined in an inside surface of a part of the housing that defines said inlet, along the length of the inlet, upstream of said impeller vanes.