GB397035A - Improvements in or relating to means for priming centrifugal pumps - Google Patents

Abstract

397,035. Centrifugal pumps. HOLDEN & BROOKE, Ltd. and McNAIR, D. G., Sirius Works, West Gorton, Manchester. Feb. 24, 1933, No. 5697. [Class 110 (i).] A centrifugal pump is primed by means of an ejector operated by the residual water in the pump, part of the water being used as a seal to prevent the vacuum from being broken as formed. The main casting 1 has a flanged inlet 2 connected to the suction pipe and a flanged outlet 3 connected to the pump 4 to be primed. An ejector 5 with air and water inlets 6, 7 respectively is connected to the delivery branch 8 of the pump by a pipe 9 and a hand-operated valve 10. The chamber formed by the casing 1 is divided into two compartments by the weir 15 ; one compartment 14 communicates through the opening 16 with the inlet 2 and outlet 3 while the compartment 13 receives water from the ejector. After use the pump contains water to the level shown, and when the pump is restarted with its delivery valve 11 closed, water is forced through the pipe 9 and the ejector 5 to the compartment 13. Air from the suction pipe is entrained by the ejector and escapes through the port 17 while the water flows from the compartment 13 to the compartment 14, through the opening 16 back to the pump. The water in the casing 1 thus forms a seal which prevents air from reaching the suction pipe. When the pump is primed the valve 10 is closed, the valve 11 is opened, and the pump works normally. In a modification the hand-operated valve 10 is replaced by a spring-controlled valve 18, Fig. 4. After the pump is primed and the valve 11 opened, the drop in pressure on the delivery side permits the spring 19 to raise the valve to shut off the ejector circuit. In another modification the valve 11 is operated automatically as well as the valve 18.