GB698377A - Pump priming mechanism - Google Patents

Abstract

698,377. Centrifugal pumps. TRINITY PUMPS, Ltd. Sept. 19, 1951, No. 21986/51. Class 110(i) [Also in Group XXIX] The control member or members of the priming mechanism of a centrifugal pump 10 are operated by a fluid motor under the control of a valve 32 which is responsive to the delivery. pressure of the pump and is adapted to connect a motor port 34 alternatively with a fluid supply port 35 or a fluid return port 36. As shown the delivery pressure of the pump 10 acts through a pipe 42 on a spring- loaded diaphragm 40 connected to a piston valve 32 controlling the connections between the ports 34, 35, 36. The fluid motor comprises a cylinder 43 containing a spring-loaded servopiston 44. In the case of a pump driven by an internal combustion engine the exhaust gases of which may be passed through an ejector such as 19 which exerts a suction effect to raise liquid to the level of the pump impeller, the piston 44 through a linkage 49, 26, 27 operates a valve 25 in a pipe 20 connecting the suction pipe 12 of the pump to the low pressure point 21 of the ejector and also operates a hinged valve 18 by which the gases from the exhaust manifold 16 may be passed directly to the exhaust pipe 17 or by-passed through the ejector 19. The pipe 20 is fitted with a water trap 22. Until the pump is primed, the valve 32 is in its raised position and the piston 44 maintains the valves 18, 25 in the positions shown so that a suction effect is exerted through the pipe 20 to prime the pump. When priming is completed, the pump delivery pressure causes the valve 32 to be depressed so that the piston 44 moves to close the valve 25 and open the valve 18. The diaphragm or diaphragms 40 may be replaced by a piston. Where a priming pump is employed, the valve 18 and the ejector 19 are omitted and the priming pump is connected to the pipe 20 so that it is cut off when the valve 25 is closed.