GB657191A - Improvements in or relating to boiler feed systems - Google Patents

Abstract

657,191. Feedwater supply systems. WEIR, Ltd., G. & J., and HILLIER, H. Jan. 28, 1949, No. 2400. [Class 123(ii)] In a closed feedwater supply system for a boiler 21, the extraction pump 6 of the condenser 2 is provided with a direct discharge to the boiler feed pump 10, through, for example, an air ejector 7, feed heater 8 and pipe 25, and also a connection 26, from a point 9 in the pipe 25, to a de-aerator 11 which is provided with an extraction pump 22 discharging into the suction of the pump 10 at a point 24 in the pipe 25. Preferably the pressure capacity characteristic of the pump 22 is above that of the pump 5 through the normal range of water flow. The condenser 2 is fitted with floatcontrolled inlet and overflow valves 13, 14, adapted to permit, respectively, make-up water to flow thereto from an external feed-tank 17 and to discharge surplus water to said tank 17 through a pipe 15; the deaerator 11 also has a float-controlled valve 27 in its inlet 26, the valve opening on a fall of water level and vice versa. The arrangement is such that the feed pump 10 normally takes its supply from the deaerator and, if necessary, alternatively from the condenser direct. The system may include an auxiliary feed pump 39 and, in an outlet from the tank 17, a de-aerator supply pump 40 for use when the main condenser 2 is shut down; also a connection 50, fitted with a non-return valve 49, from the tank 17 to the pump 10 so that the boiler may be operated should the main system become deranged. An installation comprising two or more of the above systems operating in parallel, with cross connections provided between the respective feed tanks and also the discharges of the condenser and de-aerator extraction pumps, is also described.