GB191203866A - Improvements in and relating to Regulating Devices for Pumps. - Google Patents

Abstract

3866. Warwick Machinery Co., [Allgemeine Elektricitõts Ges.]. Feb. 15. Regulating delivery of two or more combined pumps.-A boiler-feed system comprises a main feed-pump capable of supplying the normal requirements of the boiler, and an auxiliary feedpump which comes into operation at times of exceptional demand, each pump being controlled by a differential piston subject on the larger area to the steam pressure of the boiler and on the smaller area to the water pressure in the pump delivery pipes. The arrangement is such that an increase of steam pressure tends so open the steam throttle valves controlling the pumps, while an increase of water pressure tends to close such valves. In the arrangement shown in Fig. 5, the differential piston l controlling the main feed-pump k has a greater difference of area on opposite sides than the piston m controlling the auxiliary pump n, so that the piston l is normally in its lower position in which the throttle valve controlled by it is open and the pump k therefore working, while the throttle valve controlled by the piston m is normally closed and the auxiliary pump out of action. When the steam pressure in the boiler becomes considerably in excess of the pressure in the pump delivery pipes, which are in communication one with the other, the piston m is depressed and the auxiliary pump brought into operation. In alternative arrangements, the pistons l, m are controlled by springs or weights or by throttle valves upon the steam and water inlet pipes.