Patent GB-544605-A (GB)
Title: Improvements in steam heating systems
IPC: F24D1/02
Filed: 1941-05-19
Abstract: 544,605. Valves. VAPOR CAR HEATING CO., Inc. May 19, 1941, No. 6442. Convention date, May 17, 1940. [Class 135] [Also in Group XIII] In a steam heating system in which the steam admission valve to a radiator is controlled in response to the temperature of the heated space, a supply of steam is stored between the source and the admission valve sufficient to fill the radiator rapidly when the valve is opened. As applied to a railway vehicle, steam passes from the train pipe A through reducing valve 11 to a regulator B and thence to a storage vessel E, thermostatic inlet valve D and radiator C. The regulator B is controlled by a pressure-limit switch G when the vessel E is being filled, and is controlled by steam and condensate in the return main H when in normal operation. The radiator C and a heat exchange device K of a cooling system are arranged in the path of air from a blower L, and the thermostat F is in the same conduit. Steam pressure is reduced by the valve 11 from about 250 pounds per sq. inch to about 20 pounds per sq. inch. The regulator B is similar to that described in Specification 543,480, and the valve G is a spring-pressed lift valve adapted to open at about 10 pounds per sq. inch, which is similar to that described in Specification 543,480 but with the addition of an actuating solenoid. If no steam is returning through main H and if the solenoid is not energised, the valve B remains open until the pressure in the system rises to 10 pounds per sq. inch, after which valve G opens to allow steam to flow through pipe 42 to the thermostat of valve B which partly closes the valve. If the outflow of steam to the vessel E is unrestricted, the above pressure is not reached, the valve G remains closed, and the valve B is controlled by fluid returned through main H. The radiator inlet valve D, which may be hand or solenoid operated, is similar to that described in Specification 543,480. Fig. 2 shows the circuit connections for the thermostatic control of valve D. Thermostat F is provided with an auxiliary heater 119 to secure quick opening and closing of the thermostat contacts. When the relay 123 is energized, switches 133 and 134 are closed, solenoid 94 is energized, and valve D is open to heat the radiator. Closing of the contacts of thermostat F is expedited by heater 119, the circuit of which is closed by switch 134 simultaneously with the opening of valve D. Relay 123 is de-energized, switches 133 and 134 open, solenoid 94 is de-energized and valve D closed, and heater 119 is de-energized and valve D closed and heater 119 is de-energized to open the thermostat circuit. The cycle is then repeated, admitting steam to the radiator in bursts until the ambient temperature is sufficient to maintain the thermosat circuit closed. The vessel E in combination with pressure limit valve G ensures quick filling of the radiator. If valve D is closed and there is no return of steam through main H, valve B opens to admit steam to the inlet piping and valve G, until filled to the pre-determined pressure. Valve G then opens and valve D partly closes so that the steam flow is just sufficient to keep the inlet piping filled. When valve D opens on one of its cycles, the stored steam rapidly fills the radiator, pressure falls and valve G closes so that valve B is fully opened. When steam returns through pipe H, valve B is partly closed, and the system operates at atmospheric pressure as in the usual vapourheating system. When valve D closes, steam return through pipe H ceases, valve B remains open, and inlet piping is again filled. The circuit, Fig. 2, includes a control switch N which may provide for several degrees of heating or cooling. In the " Off " or " Cool " positions, the solenoid of valve G is energized, the valve is open, and steam flows through it to valve B to close it except for a sufficient steam flow to keep its thermal element expanded. No steam can then flow through the heating system. In the " Heat" position of switch N, the solenoid of valve G is de-energized, and the valve operates only under its spring control. A water seal M, constructed as described in Specification 543,480 prevents heating of the inlet piping if valve D is closed for a considerable time.