Combination centrifugal-turbine pump

Claim 1

An improved centrifugal-turbine pump capable of pumping liquids and liquified gases at or near the boiling point thereof with suction heads not greater than about 1 foot, having a pump casing with a first pumping channel and a second pumping channel disposed laterally of said first pumping channel, a drive shaft disposed axially of said pumping channels, a high-pressure regenerative turbine impeller fixed for rotation with said driving shaft, said second pumping channel extending generally angularly about and spaced outwardly from the periphery of said turbine impeller and having a discharge opening generally radially from said turbine impeller, said casing having a suction entrance for the turbine stage opening laterally from said first pumping channel to said second pumping channel, and a centrifugal impeller fixed for rotation within said first pumping channel and with said driving shaft and turbine impeller, said centrifugal impeller having a large diameter axial inlet opening of substantially the same as a suction inlet for the centrifugal stage defined by said casing, said centrifugal impeller comprising a plurality of equally spaced blades for said centrifugal impeller inwardly from the periphery of said first pumping channel, each of said blades having an outer curved portion of constant axial width and an inner curved portion gradually increasing in axial width from the center of said centrifugal impeller in a diverging outward direction towards the opposite ends of said outer curved portion, each of said outer curved portion having a first arcuate segment concentric with said center and a second arcuate extending inwardly from one end of said first arcuate segment a short distance leaving a space between its innermost end and said center, where a plurality of equally spaced discharge outlets for said centrifugal impeller is defined by openings provided between the adjacent ends of said first arcuate segments.