Abstract: This invention is proposed to increase the efficiency of all vaned diffusers used in centrifugal compressors, without in itself further increasing the overall diameter. The invention is to curve in a radial plane, the axial cross-sections of vanes from tip to near the throat, so as logically to accommodate the heretofore deleterious effect of the long-recognized highly-arched relative velocity traverse across the impeller exit annulus, a recognition seldom reflected in diffuser structure over the past approximately 49 years of vaned diffuser development.

Abstract: This invention is proposed as an aerodynamically more efficient vaned diffuser for centrifugal compressors than heretofore achieved, while still respecting the usual diffuser requirement of a limited overall diameter. The invention is so to shape the early entering portion of the diffuser side-walls and the vanes as to achieve for the first time, isobars across the so-called throat which are highly oblique to the flow direction there, instead of heretofore always an isobar which is very nearly normal or normal across the passage at that throat. This is more understandably but still briefly explained in the two sections following, on Background, and Summary, of the Invention.