Patent ID: 8226353
Filing Date: 2012-07-24
Classification: F01D,F02C,F04D,F05D,Y02T

Abstract:
1. A system for ventilating a downstream cavity of an impeller of a centrifugal compressor in a turbomachine, said downstream cavity being delimited by a downstream radial face of the impeller and by a downstream annular end-piece of an annular diffuser arranged at the outlet of the compressor, said downstream annular end-piece having an L-shaped axial section and comprising a substantially radial upstream portion which extends along the downstream radial face of the impeller and which is connected by its outer end to an inlet of the annular diffuser and by its inner end to an upstream end of a substantially cylindrical downstream portion, said downstream cavity being ventilated by tapped-off air from the outlet of the compressor, the tapped-off air circulating downstream in the cavity and toward the axis of rotation of the compressor, wherein at least one annular deflector is mounted in said downstream cavity and extends between said downstream radial face of the impeller and said downstream annular end-piece of the annular diffuser in order to oppose a return of hot air along said downstream radial face of the impeller, to accelerate the tapped-off air from the outlet of the compressor, and to cause said hot air to be driven by the accelerated tapped-off air from the outlet of the compressor, wherein the annular deflector has a square, rectangular or triangular shape in axial section, and is situated radially at a junction between the substantially radial upstream portion and the substantially cylindrical portion of the downstream annular end-piece, the junction having a rounded shape in axial section and including a concave annular surface oriented downstream and outward and a convex annular surface oriented upstream and inward.