GB1011708A - Pumping unit - Google Patents

Abstract

1,011,708. Rotary pumps. SUNDSTRAND INTERNATIONAL CORPORATION S.A. May 22, 1963, No. 20367/63. Heading F1F. A pumping unit for supplying air-free oil to the burner nozzles of an oil-fired furnace or boiler, comprises a casing 10, Fig. 1, housing first and second gear-crescent type rotary pumps 16, 22 mounted on a common driving shaft 29. Oil admitted to an inlet space 12 within the casing passes through a screen 14 into a reservoir 15 connected to the first pump 16 through a kidney-shaped inlet port 21, Fig. 2, in a spacer plate 23. The oil on being discharged from the first pump passes through passages 31, 32, to the interior of a burner shut-off valve 33, as described in Specification 703,051, connected by a passage 34 to the inlet space 12. Oil from the reservoir 15 then passes through an inlet 28 to the second pump 22 and the discharge from this pump passes into a pressure conduit 35 controlled by the valve 33 and connected to the burner nozzle. To prevent air being entrained in the oil to the second pump, the spacer plate is formed with duct 40, 41 extending oppositely from the port 21 and connected with the reservoir 15. The size of the ducts are such that they are not large enough to meet the suction demand at the port 21 so that when oil flows through the duct 41 vacuum exists in the duct 40 whence oil is drawn into the reservoir up to the level of the upper end of the duct 40 to provide a head of oil h to the inlet of the second pump. The pumps 16, 22, together with the spacer plate 23 and end-plates can be rotated as a single unit with respect to the shaft. If through 180 degrees, the duct 41 will be uppermost with the inlet 28 located laterally on the other side of the shaft. The head h will then be the height of the upper end of the duct 41 above the inlet 28. With the pumps rotated through 90 degrees clockwise from the Fig. 2 position, the ducts 40, 41 will be disposed laterally on either side of the shaft 29 with the inlet 28 pointing downwards so that ends of the ducts 40, 41 will still be at a height h above the inlet 28. Thus in every position of the pumps from the Fig. 2 position to 180 degrees clockwise position, air will be excluded from the second pump inlet.