GB864168A - Improvements in or relating to rotary fluid pumps - Google Patents

Abstract

864,168. Circumferential flow pumps; gas turbine plant. WESTINGHOUSE ELECTRIC CORPORATION. Sept. 28, 1959 [Oct. 3, 1958], No. 32838/59. Classes 110 (1) and 110 (3). A circumferential flow pump comprises an impeller 25 having a circumferential row of radially-extending blades 26, a housing structure 27 surrounding the impeller, the housing structure defining a main inlet 31 and outlet 34, a secondary inlet 39 and outlet 37, means for driving the impeller 25 in one direction at varying speeds, the main inlet and outlet being angularly displaced in the direction of rotation to a greater degree than the secondary outlet and inlet, valve means for blocking and unblocking the secondary inlet and outlet and means responsive to the rotational speed of the impeller for controlling the valve means. In Fig. 1, the pump supplies fuel to a gas turbine engine and rotates at the same speed as the engines. At low speeds, solenoid valves 41, 42 are closed with a manual switch 48 either opened or closed and fuel enters the pump housing 27 through the main inlet 31 to be discharged at the main outlet 34 after about 250 degrees rotation. The switch 48 is provided for setting the circuit for automatic operation. At about 5000 r.p.m. a speed-responsive switch 46 closes thereby opening the solenoid valves 42, 41. Fuel enters the pump housing through inlet 31, and via a conduit 40 through inlet 39 and is discharged through outlets 37, 34 after 90 degrees rotation. Thus at low speeds the fuel flow rate is moderate with relatively high pressure and at high speeds the flow rate is considerably higher with reduced pressure.