GB727649A - Improvements in or relating to overspeed control for air turbine driven pump - Google Patents

Abstract

727,649. Turbines; centrifugal pumps. BORG-WARNER CORPORATION. May 9, 1951 [May 16, 1950], No. 10894/51. Classes 110 (1) and 110 (3). In an air-turbine-driven pump having a pressure-operated motor for actuating a control valve for restricting the supply of air to the turbine, means are provided within the motor for assuring partial opening of the valve to maintain a minimum flow of air to the turbine. In the event of interruption of the supply of fluid to a centrifugal pump 17, the resultant depression of the suction pressure is communicated from the inlet 13 by way of a duct 40 to a piston 34. The resultant upward movement of the piston 34 under the action of a spring 37 causes partial closure of a valve 25 which controls the supply of air to the driving turbine 15, whereby overspeeding is prevented. Complete closure is prevented by a piston extension 34A. Instead of the suction pressure, the pump discharge pressure may be used as the controlling factor. The stop 34A may be supplemented by a stop against which the valve 25 abuts. The upper part of valve 25 may be made greater or less in area than the lower part, as by notching or drilling or by eccentrically mounting the valve on its pivot 27. The spring 37 may be replaced by a light spring and a heavy spring in series, so that the heavy spring comes into operation only after the light spring has been fully compressed. The pump may be used to inject fuel or water into the reheat burner of a jet-propulsion engine. The control means may comprise a separate unit for attachment to an existing turbine-driven pump. Specification 608,963 is referred to.