Patent GB-696710-A (GB)
Title: Space heating system
IPC: F24D19/10
Filed: 1951-05-17
Abstract: 696,710. Space-heating systems. VAPOR HEATING CORPORATION. May 17, 1951 [April 5, 1951], No. 11587/51. Classes 64 (i) and 64 (ii) A space-heating system particularly for railway vehicles, in which water continuously circulated by a pump 26 Fig. 1 through a closed primary circuit B containing a plurality of water heaters, such as 23, 25, arranged between the hot water delivery pipe 19 and the cold water return pipe 21, has in addition an auxiliary branch circuit C for heating the space A, this circuit receiving water from the primary circuit delivery pipe 19 by pipe 36, the water being forced by a pump 41 through a heater 10 for air discharged by blower 46 through a duct 11 and then through radiators 12, and the water being discharged at syphonnozzle 35 into the delivery side of the primary circuit. As shown in Fig. 1, the heating means for the primary circuit includes an independent boiler 23 with fuelpump 61, combustion air blower 64 and spark ignition 63 for combustion chamber 60, the entry of water to jacket 23 being controlled by thermostat 68 which opens at 160F. and closes at 120F. An alternative combined steam and electric heating device 25 receives steam through a thermostatically-controlled reducing valve 33a from the train steam pipe 31. Excessive steam leaving the heater 25 enters a chamber 33c and causes the thermal element 33b to close the valve 33a. Alternatively, an electric heating coil 29 may be used. A check valve 16a, fully open when the boiler 23 is in use, is partly closed when the water is steam heated, the pump 26, though out of use, still permitting circulation of water by thermal action. Supply of hot water to basin 71 is obtained either through heat exchanger 24, when the boiler 23 is working, or through a heat exchanger 75 having a steam coil supplied from the train steam pipe 31 through a pressure-reducing valve 33a<SP>1</SP>. Fig. 2 shows electric circuits for controlling the boiler 23 when switch 82 is closed and the space-heating circuit C when switch 82a is closed. The switch 82 energises a circuit through water pump motor 27, and motor 65 for driving the air blower 64 and boiler fuel pump 61, these motors being wired in parallel. Closing of a press button switch 99 brings the boiler into operation by energising coil 100 to move relay-contactor 92 and close the circuit through switch arm 112 of the boiler temperature control 68 and then through coil 113 to move a second relay-contactor 95 that energises the coils 115, 116 for effecting respectively the fuel supply and ignition for the boiler. The winding 100 is arranged to hold the relay 92 energised for 45 seconds after the push button is released. A temperature limit switch 107 is adjusted to say 200F. to open the circuits through the relays and shut down the boiler if the temperature of the delivery water is excessive. A signal horn 89 is then energised and the boiler will not resume automatic operation until the push-button 99 is again operated. Switch 82a, which controls the flow of water through the space-heating circuit C by means responsive to the temperature of the space, energises branch circuits through a motor 42 driving the water pump 41, a motor 47 driving the hot-air blower 46, a coil 130 for heating a mercurycolumn thermostat 131, and a coil 142 operating a relay-contactor 151 which controls the circuit through the normally-open solenoid coils 39, 49 controlling the flow of water through the space heaters 10, 12. When the mercury column rises in the thermostat 131, the relay coil 142 is de-energised and contactor 151 closes the circuit through coils 39, 49 to stop the flow of water.