GB986700A - Improvements in or relating to centrifugal or other roto dynamic pumps - Google Patents

Abstract

986,700. Priming centrifugal &c. pumps. GOODENOUGH PUMPS Ltd. June 12, 1963 [Sept. 12, 1962], No. 34853/62. Heading F1C. The casing of the centrifugal pump shown is initially filled with water. When the impeller 18 is rotated, water returns from the discharge chamber 30 to the suction pipe 8 via a tube 32 and a bypass 35, and entrains air from the suction pipe 8 and extension pipe 10 as it enters the impeller eye 28. The air tends to separate out from the water and be discharged through the pump outlet 6 while the main bulk of the initial charge of water stays in the pump casing and is continuously recirculated. On completion of priming, the discharge pressure, communicated through a passage 40 to the left-hand side of a flexible diaphragm 36, reaches its normal value and moves the diaphragm against the action of a spring 42 to close the end of the tube 32 and stop the recirculation of fluid. Since only a small central area of the right-hand face of the diaphragm 36 is exposed through the tube 32 to the discharge pressure, the remainder of this face being exposed through the passage 35 to the suction pressure, while the whole of the left-hand face is exposed to the discharge pressure, there is a net force holding the diaphragm against the end of the tube 32 during normal operation of the pump. A filter may be provided between the discharge chamber 30 and the end of the tube 32 adjacent the diaphragm to remove solid particles which might prevent the diaphragm from seating properly on the end of the tube. The diaphragm may be replaced by a piston working in a cylinder. The Provisional Specification describes an arrangement in which the priming device is separate from the pump and is connected to the latter through pipes.