Centrifugal pump impellers

摘要

A centrifugal pump impeller includes front and back shrouds and a plurality of pumping vanes therebetween, each pumping vane having a leading edge in the region of an impeller inlet and a trailing edge, the front shroud has an arcuate inner face in the region of the impeller inlet, the arcuate inner face having a radius of curvature (Rs) in the range from 0.05 to 0.16 of the outer diameter of the impeller (D2) The back shroud includes an inner main face and a nose having a curved profile with a nose apex in the region of the central axis which extends towards the front shroud, there being a curved transition region between the inner main face and the nose. Fr is the radius of curvature of the transition region and the ratio Fr/D2 is from 0.32 to 0.65. Other ratios of various dimensions of the impeller are also described.

主权项

1. An impeller which includes a front shroud and a back shroud, the back shroud including a back face and an inner main face with an outer peripheral edge and a central axis, a plurality of pumping vanes projecting from the inner main face of the back shroud to the front shroud, the pumping vanes being disposed in spaced apart relation on the inner main face providing a discharge passageway between adjacent pumping vanes, each pumping vane including a leading edge portion in the region of the central axis and a trailing edge portion in the region of the peripheral edge, the back shroud further including a nose having a curved profile with a nose apex in the region of the central axis which extends towards the front shroud, there being a curved transition region between the inner main face and the nose, wherein Fr is the radius of curvature of the transition region and D2 is the diameter of the impeller, and the ratio Fr/D2 a being from 0.20 to 0.75, wherein one or more of the passageways have associated therewith one or more discharge guide vanes, the or each discharge guide vane being located at a main face of at least one of the shrouds and wherein the or each discharge guide vane is a projection from the main face of the shroud with which it is associated, and which extends into a respective passageway.