IMPROVEMENTS RELATING TO CENTRIFUGAL PUMP IMPELLERS

摘要

A centrifugal pump impeller (40) includes front and back shrouds (50, 51) and a plurality of pumping vanes (42) therebetween, each pumping vane having a leading edge (43) in the region of an impeller inlet (48) and a trailing edge (44), the front shroud has an arcuate inner face in the region of the impeller inlet, the arcuate inner face having a radius of curvature (R s ) in the range from 0.05 to 0.16 of the outer diameter of the impeller (D 2 ). 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. I nr is the radius of curvature of the curved profile of the nose and the ratio I nr /D 2 is from 0.17 to 0.22. Other ratios of various dimensions of the impeller are also described.