GB299103A - Improvements in centrifugal pumps - Google Patents

Abstract

299,103. Drysdale &. Co., Ltd., and Drysdale, J. W. W. July 25, 1927. Multi-stage centrifugal pumps. -A pumping unit comprises a two-stage low-pressure pump e, f and a multi-stage high-pressure pump arranged above it, all the impellers being carried by a common shaft b. The eye of the impeller e is arranged at the upper side of the impeller while that of the impeller f is at its lower side. The liquid travels downwards from the suction d to the eye of the impeller e and upwards through the passage h from the impeller e to the impeller f. This arrangement prevents the formation of air looks, and a chamber i is formed above the suction d to entrap air or gas which enters the suction pipe. An annular passage s collects any air from the impeller eye and conveys it to the chamber i. The gas is conveyed from the chamber i by the pipe k. The discharge r of the low-pressure pump may be connected directly to the suction n of the high pressure pump or it may be connected to the tank or heater from which the high-pressure pump draws its supply. This pump is shown having three impellers m each arranged with its eye uppermost and the lowest pressure stage is at the top. The last impeller discharges into the channel o. The shaft b passes through one gland p only, and this is arranged at the top of the casing where the pressure is that of the suction side of the highpressure pump. Specification 201,842 is referred to.