Patent ID: 8038392

Claim:
An axial diffuser for a centrifugal compressor, comprising a plurality of axial diffuser passages arranged around an impeller of the centrifugal compressor at a prescribed circumferential interval so that a radial fluid flow from the impeller is directed into an axial fluid flow substantially in parallel with a central axial line of the impeller, and kinetic energy of the fluid flow entering each diffuser passage is converted into pressure energy, wherein: each axial diffuser passage includes an upstream end communicating with an outlet part of the impeller and a downstream end extending substantially in parallel with an axial line of the impeller, and defines a cross section progressively increasing in area from the upstream end to the downstream end thereof, the cross section of each axial diffuser passage being configured such that a relatively high velocity fluid flow in an upstream part of the diffuser passage is directed toward a negative pressure side of a cross section thereof.