GB654854A - Liquid pumping unit - Google Patents

Abstract

654,854. Centrifugal and rotary pumps. NASH ENGINEERING CO. Feb. 27, 1948, No. 6064. Convention date, Jan. 18, 1946. [Classes 110(i) and 110(ii)] A pumping unit comprises a centrifugal pump delivering liquid to the inlet of a positive displacement rotary pump and having a vapour collecting chamber separate from the inlet of the rotary pump, and a vapour removal pump mounted between the other two pumps and connected to the collecting chamber, all the pumps being connected together for simultaneous operation. The unit may be submerged in the fuel tank of a gas turbine or reciprocating engine. A centrifugal impeller 41 delivers fuel to a sliding-vane pump 12, Vapour and gases in the fuel entering the impeller 41 collect in an annular groove 71 and pass by way of conduits 80-83 to a liquid-ring pump which discharges them through a conduit 84. The blades 73 of the liquidring pump are formed on the back of the impeller 41, the shaft 42 of which is screwed into the rotor 20 of the sliding-vane pump. The rotor 20 is splined to a floating driving shaft 16. The pump 12 is provided with an adjustable relief valve 50 and a byepass valve 52 (Fig. 2, not shown). Specifications 636,712, 637,139, 648.546 and 654,853 are referred to. The Specification as open to inspection under Sect. 91 also describes an embodiment in which the liquid-ring pump is omitted. The sliding-vane pump may be replaced by a pump of the gear, piston or other positive displacement type. There is described in connection. with Fig. 1 (Cancelled) (not shown), a shaft sealing means and ducts for returning leakage past a bearing 24 to the inlet 10 and for draining leakage past the sealing means to the atmosphere, the sealing means and ducts being identical with those shown in Fig. 1. This subject-matter does not appear in the Specification as accepted.