Rotating vane diffuser for a centrifugal compressor

摘要

A vaned diffuser for a centrifugal compressor has provision for selectively adjusting the pitch of the vanes 21 in order to accommodate variable load conditions. Each of the vanes 21 is rotatable about a pivot pin 34 near its leading edge and is engaged with an actuation member 66 near its trailing edge 33. The actuation members 66 are attached to a common ring 62 which can be selectively rotated to move to the vanes 21 in unison. The ring 62 is supported by rollers at its outer periphery and is positioned at the outer periphery of a diffuser wall such that there is no forward facing step projecting into the flow stream. A throat 87 is defined between adjacent vanes, and the pivot pin 34 for each vane 21 is located downstream of the throat on the pressure side of the vane 21 to reduce turbulence in the flow at the throat.