GB1178651A - Self-Priming Centrifugal Pumps - Google Patents

Abstract

1,178,651. Centrifugal pumps; jet pumps. L.W. JAMES, L. JAMES and W.H. GONYEA. Jan.1, 1968, No.137/68. Headings F1C and F1E. A centrifugal pump is primed by a gas-operated ejector. In the embodiment shown the ejector 60, Figs. 1 and 2, is carried by a rotory member 10 having radial pumping passages 18 therein communicating with a stationary suction pipe 28 via a central opening 22. During priming, rotation of the member 10 causes air within stationary casing 32 to pass through a venturic passage 70 in the ejector and thereby create a sub-atmospheric pressure in a cavity 74 to withdraw gas from the interior of the pump via passages 78, 83, 86, 84 and port 82. Thus liquid is drawn into the suction pipe and passes centrifugally through radial pumping passages 18 and ports 24 into pumping chamber 16 containing a stationary liquid pick-up and discharge tube 40. The U-shaped arrangement of the passages 83, 86, 84 prevents liquid from being ejected should any accidently enter these passages through the port 82. In another embodiment, Fig. 3 (not shown), the ejector is instead arranged on a hollow stationary arm within the pumping chamber and is operated, during priming, by air discharged into the pumping chamber by the radial pumping passages, the sub-atmospheric pressure created being communicated directly to the interior of the stationary suction pipe. In a final embodiment, Figs. 4 and 5 (not shown), comprising a centrifugal pump having a bladed rotary impeller arranged within a stationary circular casing having a central inlet and a tangential outlet, the ejector is arranged at the entrance to the tangential outlet and is operated, during priming, by air discharged by the rotating impeller, and the subatmospheric pressure created is communicated directly to the interior of the inlet.