GB775623A - Improvements in or relating to a self-priming centrifugal pump - Google Patents

Abstract

775,623. Centrifugal pumps. GORMANRUPP CO. June 6, 1955, No. 16173/55. Class 110 (1). A self-priming centrifugal pump comprises a partition dividing the pump casing into a pumping chamber and a combined discharge and separating chamber, the partition partly defining a priming passage leading from the lower part of the combined chamber into the pumping chamber, and partly defining a discharge passage of progressively increasing cross-sectional area leading from the pumping chamber into the upper part of the combined chamber, and the liquid-containing space in the pumping and combined chambers below the intersection of .the inlet conduit with the pumping chamber exceeding the combined liquid-containing space in the pumping chamber and in the priming and discharge passages whereby, when the impeller is rotated, the last-mentioned space will be filled with liquid.. A partition 20, Figs. 1 and 2, divides the pump casing into a pumping chamber 2 and a combined discharge and air separating chamber 3. Water discharged by the impeller 9 flows through the progressively widening space 17 between the partition 20 and the upper wall of the casing to enter the chamber 3 and finally flows to the outlet pipe 4. When the pump is stopped, the water in the casing drains out through the inlet pipe 5, down to the level of the lowest point of intersection of the pipe 5 with the casing wall; the latter may be cut away as at 27 to facilitate drainage. When the pump is started, the water remaining in the casing feeds through a passage 25 and a priming passage 26 to fill the chamber 2 and the discharge passage 17, thereby priming the pump. Instead of extending vertically, passage 26 may be inclined to the vertical or even be substantially horizontal. In a modification, the passage 26 is replaced by a hole through the partition 20. Alternatively, a gap is left between the casing wall and the right-hand end of the partition 20. In the pump shown in Figs. 6 and 7, the pumping chamber 48 and the combined discharge and air separation chamber 49 are separated by a radially extending wall 47 and axially extending walls 46, 56, the chambers being connected by a priming passage 55 formed between wall 56 and the bottom wall of the casing. Water is discharged through a passage 48a to an outlet pipe fitted into either one of two openings 51, 52. A tubular intake 43 extends horizontally but may instead be bent downwards so as to open through the bottom wall of the casing.