GB719819A - Improvements in or relating to heating systems - Google Patents

Abstract

719,819. Fluid-pressure servomotor-control systems. ARMSTRONG MACHINE WORKS. April 23, 1952 [Oct. 1, 1951], No. 10208/52. Class 135. [Also in Group XIII] In a heating system, a pump 7 circulates hot water derived from a boiler 1, through a radiator 2 and a valve, 8 of which a feed port 19, Fig. 2, is connected to a feed conduit 4, and a bye-pass port 20 is connected by a bye-pass conduit 16 to a return conduit 5. Moreover, a double valve member 24 coacts with both ports which communicate with the inlet 9 to the pump 7, a pressure bellows 32 actuating the valve member and having a valved connection 36 to the discharge of the pump, the bellows being subject to the pressure in the feed conduit 4 (by way of an opening 29) so that the valve member 24 is operated by the difference in pressure between the intake and the discharge of the pump when the valve 37 in the connection 36 is open. A spring 31 biases the valve 24 to the closure position of port 19 shown in Fig. 2. The valve 37 may be manually operated or solenoid-actuated under the control of a thermostat 3 in the space to be heated by the radiator 2 ; the valve, in turn, controls the bellows 32 and the movement of the valve member 24. Thus it is determined whether fresh hot water is drawn through the feed port 19 from the boiler 1 or water is drawn from the return conduit 5 and bye-pass conduit 16 without re-heating in the boiler. Manual valves 11 are provided in the feed conduit 4, bye-pass conduit 16 and the discharge conduit 10 from the pump 7. There is a connection 6 from the return line 5 to an expansion tank. The valve member 24 is moved, to close either of the ports 19, 20, by a stem 25 guided at its ends by a narrow portion 34 and a spider 35 respectively and is connected to the bellows 32. When the temperature of the heated space drops, the valve 37 is opened by the thermostat 3 and the pressure in the pump discharge conduit 10 acts by way of the connection 36 to depress the bellows 32 in a pressure chamber 26 to open the port 19. When the fresh heated water from the conduit 4 raises the space temperature, the thermostat 3 closes the valve 37 and the pressure inside and outside the bellows is equalized by leakage through an opening 39 at the top of the bellows. The spring 31 then closes the port 19.