GB262753A - Improvements in means for heating by oil circulation - Google Patents

Abstract

262,753. Manufacture de Machines Auxiliaires pour l'ElectricitÚ et l'Industrie. Dec. 10, 1925, [Convention date].. Heating by circulation of fluids.-An apparatus for heating by the circulation of hot oil is. provided with an expansion vessel having a level indicator, and with thermostatic means for controlling the circulation either by thermo-siphon or by a pump. An oil heater 1 is connected by pipes 2 to a device 3 to be heated, and by pipes 5, 4 to the atmosphere. An expansion vessel 7 has a level indicator 8 and is directly connected to the boiler by a pipe 9. The valve 6 is closed during working, and oil is forced by expansion in the system to in the pipe 9. Oil is supplied to the system from a tank 10, and any overflow from the vessel 7 returns through pipe 13 to the tank 10. The temperature in the heater 1 may be controlled by a thermostat. A pump 14 may be connected in a by-pass 15 so that it may be employed to assist circulation of the oil by opening valve 19 and closing valves 17, 18. The circulation is then in the direction of the arrows, but when the pump is not operating it is in the opposite direction. The two methods may be alternated to effect a uniform heating of the device 3. A device for automatically changing over on accidental stopping of the pump is shown in Fig. 3. A thermometer with an indicator 21 is placed at the point of highest temperature of the heater ], and contacts with a conductor 22 to complete an electric circuit which includes electromagnets 23, 24 so that the valves 17, 18 are opened, and the valve 19 closed. In an alternative form, the thermometer may be placed at the bottom of the device 3, so that if, during thermo-siphon circulation the pointer 21 falls below the contact 22, the electromagnets are no longer energized, and the pump is brought into operation.