GB614197A - Improvements in water heating systems - Google Patents

Abstract

614,197. Thermally-actuated valves. BARNES, N., WHITAKER, A., and JESSEL. R. July 5, 1946, No. 20190. [Class 135] [Also in Group XIII] A water heater is provided with one or more thermostatic devices which are responsive to changes in the temperature of the water in the outlet section or delivery pipe of the heater and servo to control a valve which regulates the flow of water through the heater and also to control the heat supplied to the heater, the operation being such that if the temperature of the outlet water rises above a predetermined value the valve is opened progressively to the fully open position and thereafter the rate of heat supplied is progressively reduced. In an auxiliary gas-fired water heater, Figs. 1, 3 and 4, for insertion in the delivery pipe of a hot water system provided with <a> main water heater, in-flowing water enters the lower part of a valve-housing 2 containing a valve 3, and after passing through ports 5 (valve 3 being normally closed) flows to a device 8 for ensuring that gas will only be admitted to the burners when water is flowing, and then to the heat exchanger (not shown). The heated water returns to the device 8 from the heat exchanger and 'then flows successively through the parts of the housings 13 and 2 containing temperature responsive bellows 15, 4 which respectively actuate a gas valve 14 and a water inlet valve 3. In operation, a progressive rise in the water temperature at the outlet connection 20 will expand the bellows 4 and cause a corresponding opening of the water inlet valve 3 to allow more water to flow. If the outlet temperature exceeds the predetermined maximum with the inlet valve 3 fully open., the bellows 15 will operate and cause the gas valve 14 to close and reduce or cut off the heat supply. In an alternative arrangement (Fig. 7), a single thermostatic device may be used to control the water inlet and gas supply valves. Water enters the housing 28 through a port 30, passing through ports 31 and conduit 34 to the aforementioned device 8 and after passing through the heat exchanger as before described, the heated water re-enters the housing 28, and passing over the bellows thermostat 27 which controls both water inlet and gas supply valves 32 and 42 leaves through the port 38 leading to the outlet. The housing 28 is divided by a partition 48 having a central communicating aperture between the right- and left-hand portion of the bellows 27. Gas enters through port 41, the flow of gas through port 43 to the burners being controlled by valve 42. As in the previous arrangement the bellows 27 is proportioned so that the water inlet valve 32 is fully opened before the gas valve 42 commences to close. If the main heater is supplying water at the required temperature, the water inlet to the auxiliary heater will be fully open and the gas valve will remain closed. The invention may be applied to an auxiliary heater taking water from any source of supply. Other forms of thermostat may be used to control the valves.