GB466054A - Improvements relating to centrifugal pumps - Google Patents

Abstract

466,054. Centrifugal pumps. LEE, HOWL, & CO.. Ltd., and CLARK, C. B. Feb. 27, 1936, No. 5870. [Class 110 (i)] A centrifugal pump of the kind having a plurality of.impellers which can operate either in series or in parallel has the impellers provided in the two end sections a, b of the pump body and arranged on a common shaft so as to be balanced against end pressure, and the inlet and outlet connections together with various ducts and valves are arranged in the middle section c, the valves being operable to give the series or parallel flow. Fig. 1 is a sectional plan of the pump and Fig. 2 is a transverse section taken through the middle section containing the ducts. The impellers are each of the two stage type. Liquid from the entrance duct d passes to the first stage of the impeller g and is fed by ducts p, q to the second stage of such impeller g which delivers it by ducts s to a chamber t opening to a valve chamber u. If the valve k is open this liquid passes to the chamber v and so to the second impeller f, the non-return valves l being automatically closed by the pressure. Ducts p<1>, q<1> lead the liquid from the first stage of this second impeller f to the second stage whence the liquid passes by ducts s<1> to a chamber t<1> opening to the delivery e. If the valve k is closed the first impeller g delivers the liquid past a non-return valve m and so directly to the delivery duct e. A branch w from the inlet duct d leads to the underside of the non-return valve l and allows liquid to pass to the chamber v and the second impeller f ; thus the two impellers act in parallel. The main valve k may be operated by hand or automatically by the pressure. The branch w may be formed so as to permit a second suction pipe being connected. The chamber v may also be arranged for attachment of a suction pipe. A water-ring air pump may be provided for priming.