GB1334853A - Pumps - Google Patents

Abstract

1334853 Centrifugal pumps JOSEPH LUCAS (INDUSTRIES) Ltd 19 April 1971 [10 March 1970] 11405/70 Heading F1C [Also in Division H2] A pump comprises a rotor, 35 including a chamber formed as a pair of aligned passages 11, 12 having impeller blades 13 between them, at least one of the passages including a tapered portion having its larger diameter adjacent the impeller blades, and a casing 34 containing a volute passage 44 communicating with the impeller blades and with an outlet for the pump, the rotor and the casing respectively forming parts of the rotor and stator of an electric induction motor. The pump is submersed in a fuel tank. The conical form of the passages 11, 12 causes the fuel to be urged centrifugally towards the impeller blades 13, vapour in the fuel separating centrifugally from the liquid and remaining in the centre. The rotor 35 is journalled in bearings 15, 16 and driven by an induction motor 14, 18. As shown, axial-flow impellers 45, 46 driven via a spider 36 and a shaft 37 journalled in bearings 38, 39 supplied with fuel under pressure via pipes 42, 43 may be provided in front of the inlet sleeves 32, 33. Fuel-vapour mixture resulting from cavitation and vapourization at the periphery of the impeller 45, 46 passes via annular spaces 47b, 48b between the sleeves 32, 33 and cowls 47, 48 and thence via parts 47a, 48a to the fuel within the tank. The pump is mounted with the cowl 48 adjacent the bottom of the tank and can continue to operate under conditions of low fuel depth, negative gravity or inverted flight.