GB361990A - Improvements in or relating to steam power plants - Google Patents

Abstract

361,990. Feedwater regulators for steam-boilers. JACKSON, L. MELLERSH-, 28, Southampton Buildings, London.-(Doble Steam Motors, Ltd. ; 4053, Harlan Street, Emeryville, California, U.S.A.) Sept. 3, 1930, No. 26304. [Class 123 (ii).] An electrically-controlled steam-boiler plant comprises a thermostatically-operated switch for controlling successively the feedwater and fuel supply and a pressure-operated switch for interrupting the operation of the entire plant when the pressure of the steam in the boiler exceeds a predetermined value. On starting up the boiler 2, a switch 58 is closed and current flows from a battery 56 to the motor 16 which drives the fan 17 to deliver air and fuel. As the temperature of the boiler rises, and steam is generated, a thermostat 23 in the steam space of the boiler operates a switch lever 25 to open normally closed contacts 30, 33 in the circuit of the solenoid 57 and thus de-energize the latter to open the valve 15 to permit feedwater to pass from the tank 13 to the pump 3, which is also driven by the motor 16, and be supplied through the valve-controlled pipe 7 to the bottom of the boiler. Further rise in temperature of the boiler causes the thermostat to operate the lever 25 to close contacts 31, 34, energize the solenoid 56a and open the valve 10 to permit feedwater to flow to the steam space of the boiler through the pipes 9, 11. Should this supply of feedwater be insufficient to lower the temperature to that desired, the switch lever 25 is further operated to close contacts 39, 40 and permit current to flow to a solenoid 55 to close a valve 54 in the conduit 18 and thus stop the fuel supply. In the event of the pressure in the boiler exceeding a predetermined limit, a spring-pressed diaphragm 46 operates a switch 49 and breaks the circuit of the motor 16 and other electrical apparatus in the system. The counter contacts 33, 34, 40 of the thermostatically operated switch are mounted on pivoted levers adapted to yield against the action of springs.