GB252136A - Improvement in hydraulic pumps - Google Patents

Abstract

252,136. Worthingtan Pump & Machinery Corporation, (Assignees of Benson, H. F.). May 18, 1925, [Convention date]. Multi-stage helico centrifugal pumps; casings; impeller blades.-In a centrifugal pump,. more particularly adapted to work as a deep well multi-stage pump, the impeller of each stage delivers the stream, in an advancing flow rotating about the pump axis, to an annular vane-free whirl chamber from which it passes to a vane-equipped diffuser giving an axial outflow. Two stages are shown in Fig. 1, the impellers 12 being carried by the shaft 10 which extends down through the drop pipe 11. Guide vanes 15 are provided below the pump sections to impart a true axial flow to the water rising to the impeller. Each impeller has a conical core 17 and a peripheral shroud 18 with vanes 21 between them. The vanes 21 start at the inlet end 19, Fig. 3, in a plane at right-angles to the axis, their inlet edges being curved as shown; the vane surfaces pass gradually towards. the outlet end 21 with a gradually increasing warp until the outlet edges 21<1> are presented at oblique angles to the axis. The largest radius of the inlet 19 is approximately equal to the smallest radius of the outlet 21. The difference between the maxmum and minimum radii at the outlet is less than at the inlet. The water passes from the impeller into the vaneless whirl chamber 14 formed by the casing unit 29; from that chamber it passes to the fixed diffuser 13, which has an increasing cross-sectional area in the direction of flow and is provided with vanes 40, Fig. 6, with the entering edges 40<1> bent into the direction of the approaching liquid and the leaving edges 41 arranged to give an axial flow. The vanes are secured to the central conical portion 34 and an outer ring 35.