GB691362A - Improvements in self-priming pumps - Google Patents

Abstract

691,362. Centrifugal pumps. MARLOW PUMPS. Dec. 15, 1949 [Nov. 3, 1949], No. 32274/49. Class 110(i) In a self-priming centrifugal pump, the pump housing includes a reservoir through which the pump discharge passes on its way to the discharge outlet, and the diffuser. which is intermediate the impeller and the reservoir, contains a series of continuous repetitive groups of flow passages of unequal size. To facilitate priming, the disturbing effect of counterflow from the diffuser passages 20 towards the impeller 11 is increased by making every alternate passage 20 about twice the width of the other passages 20, and providing alternate diffuser vanes 24 with a larger clearance from the impeller periphery than the remaining vanes 24: At least one priming hole 20<SP>1</SP> communicating with a liquid reservoir 10 is provided in each larger diffuser passage and, it may be, in each smaller diffuser passage also. Check valves 16 and 22 are provided in the suction and discharge respectively. The diffuser passages may be arranged in repetitive groups of three or more passages instead of groups of two as shown. There may be a float-operated ventilating air separator in series with the pump. The Specification as open to inspection under Sect. 91, comprises also the statement that the liquid reservoir may be separate from the pump housing. This subject-matter does not appear in the Specification as accepted.