Patent GB-551887-A (GB)
Title: Improvements in temperature regulating and ventilating systems
IPC: B61D27/00
Filed: 1941-07-07
Abstract: 551,887. Valves. VAPOR CAR HEATING CO., Inc. July 7, 1941, No. 8570. Convention date, July 5, 1940. [Class 135] [Also in Groups XXXV and XIII] The temperature in each of separate compartments A, A<SP>1</SP> ... of a steam-heated railway vehicle is maintained at a selected maximum by adjustable thermostats J electrically controlling the normally open valves 29 of floor heaters L. The temperature in a passageway may be similarly controlled by a thermostat N which is not provided with adjustment. The compartments are supplied from an overhead conduit with air circulated by an electrically driven fan D and maintained at a constant temperature by thermostats G, H controlling electrically the admission of steam or cooled water to radiators E, F. The fan D is controlled by a switch which in the off position modifies the temperature control so that the valves of the floor heaters remain open but the steam supply to all is then controlled by a separate thermostat in the coolest part of the vehicle so that at least a minimum temperature is maintained. An air conditioning switch provides selective operation for ventilation only or for heating or cooling of the circulated air in each case at three selected temperatures. All heating steam is cut off during cooling periods but by operating an emergency switch steam may be made available at the floor heaters, the valves of which may be opened manually as desired. The heating system comprises a steam main 30 supplying, through separate reducing valves 33 and pressure regulators 0, 0<SP>1</SP>, 0<SP>11</SP> respectively, low pressure pipes 42 for the floor heaters, 421 for a passage heater M and 431 for the radiator E. The pressure regulators comprise a normally open valve 44, Fig. 3, adjusted by a thermostatic element 53 to throttle the steam from a medium pressure, say 20 pounds per sq. in., to a constant low pressure, say 5 pounds per sq. in. The thermostatic element is contained in a chamber 50 cooled by fins 52 and supplied with steam from the pipe 42 through a valve P having a valve member 79, Fig. 11, loaded by a spring determining the steam pressure. The valves 79 can be held open by solenoids 85 under control of an air conditioning switch when set for cooling whereby heating steam is cut off, and also under the control of the thermostat when the fan is not running whereupon the supply of heating steam is cut off until a minimum temperature is reached. An emergency switch may be used when the fan is running to permit heating steam to be taken at will by manually opening a radiator valve. Condensate issues from drip pipes 122, after passing thermostatic steam traps 61, without entering the regulators 0. Each radiator valve 29 is opened by a spring and closed by solenoid but may be manually closed or opened by a hand lever which in its medium position frees the valve to the other controls. The radiator E is controlled by a spring-closed valve opened by a solenoid 136 and thermostat G. To ensure rapid filling with steam, this radiator is supplied through a reserve tank 134 with steam at say 10 pounds per sq. inch. The cooling radiator F is supplied with cooled water from a tank 142 through an electrically-driven pump 144 controlled by thermostat H. The heating control thermostats are of the mercury column type and with the exception of the thermostat in the coolest part have auxiliary electric heaters in series with resistances for adjustment of response temperature. Each is arranged to short circuit the winding of a relay which controls a valve solenoid and has an auxiliary contact in series with a resistance in parallel with the selected resistance to cause periodic operation when the selected temperature is reached. The thermostat H controlling cooling comprises three alternative mercury column elements in series with a relay winding controlling the water-pump switch and has no periodic characteristic. The electrical circuits are fully described.