Diffuser

Claim 2

A centrifugal compressor comprising a rotor discharging radially and tangentially of the axis of the rotor and a diffuser body having a first set of diffuser passages with entrances adjacent the periphery of the rotor, said first plurality of diffuser passages each having arcuate cross sections and merging adjacent the rotor so that the body defines approximately elliptical leading edges at the intersections of the passage boundaries, each diffuser passage including a first converging portion with a spiral center line terminating at a throat region and a second diverging portion beginning at and extending in a continuous spiral downstream from the throat region, a divider rib located between each of said first plurality of diffuser passages, each of said ribs including a pressure surface thereon and a suction surface thereon, a bleed passage directed through each of said ribs having an inlet intersecting one of said diffuser passages at a pressure surface and an outlet intersecting an adjacent one of said first plurality of diffuser passages at a suction surface, each of said inlets being located downstream of one of said throat regions and operative to direct subsonic flow downstream of one of said throat regions from a pressure surface through one of said bleed passages to a suction surface for improving boundary flow at the suction surface and to increase the diffuser exit area between the entrance of each of said first plurality of diffuser passages and the exterior periphery of said diffuser body.

Claim 3

A centrifugal compressor comprising a rotor discharging radially and tangentially of the axis of the rotor, a diffuser body located radially outwardly of said rotor including an inner circumferential surface thereon having a plurality of circumferentially arranged primary diffuser passages each having entrances adjacent the outer periphery of the rotor, each of said primary diffuser passages having an arcuate cross section and merging adjacent the rotor to form an approximately elliptical leading edge into each of said primary diffuser passages, each of said primary diffuser passages including a converging portion terminating at a throat region and a second diverging portion beginning at and extending downstream from the throat region, a divider rib located between each of said passages including a pressure surface thereon and a suction surface thereon, an intersecting passageway through said rib communicating adjacent ones of said primary diffuser passages, said intersecting passage including an inlet located at a pressure surface on said rib within one of said diffuser passages and including an outlet thereon at a suction surface in an adjacent one of said primary diffuser passages, said intersecting passage directing subsonic flow downstream of the throat region in one of said passages into an adjacent one of said primary diffuser passages to increase the flow area through said diffuser body from the inner periphery to the outer periphery thereof for improved conversion of kinetic energy to pressure energy, said intersecting passage serving to direct flow from a pressure surface to a suction surface to improve boundary layer flow through adjacent ones of said primary diffuser passages.

Claim 4

A centrifugal compressor comprising a rotor discharging radially and tangentially of the axis of the rotor, a diffuser body located radially outwardly of said rotor including an inner circumferential surface thereon having a plurality of circumferentially arranged primary diffuser passages each having entrances adjacent the outer periphery of the rotor, each of said primary diffuser passages having an arcuate cross section and merging adjacent the rotor to form an approximately elliptical leading edge into each of said primary diffuser passages, each of said primary diffuser passages including a converging portion terminating at a throat region and a second diverging portion beginning at and extending downstream from the throat region, a divider rib located between each of said passages including a pressure surface thereon and a suction surface thereon, an intersecting passageway through said rib communicating adjacent ones of said primary diffuser passages, said intersecting passage including an inlet located at a pressure surface on said rib within one of said diffuser passages and including an outlet thereon at a suction surface in an adjacent one of said primary diffuser passages, said intersecting passage directing subsonic flow downstream of the throat region in one of said passages into an adjacent one of said primary diffuser passages to increase the flow area through said diffuser body from the inner periphery to the outer periphery thereof for improved conversion of kinetic energy to pressure energy, said intersecting passage serving to direct flow from a pressure surface to a suction surface to improve boundary layer flow through adjacent ones of said primary diffuser passages.