GB824578A - Improvements in or relating to gas burners - Google Patents

Abstract

824,578. Gas burners. FAURE & CIE. Aug. 23, 1957 [Sept. 14, 1956], No. 26709/57. Classes 75(1) and 75(3) [Also in Group XXIX] A gas burner safety device comprises one or more pilot flame orifices the size and disposition of which are such that the flame becomes unstable and extinguished when the oxygen of the combustion air falls below a critical value, which value is such that the air still supports animal life, and the pilot flame controls a thermostat controlling the gas supply to the burner. On turning lever 22, Fig. 4, anticlockwise sector 19 is rotated against return spring 25 through arm 23 and abutment 24 so that mercury switch 18 closes and an electric igniter 17 is energized and brought adjacent ignition gas nozzles 8. Lever 22 also sets a cock 21 adjusting the gas supply to a cut-off valve 13 controlling the gas to the burner pipe 14. Cock 13, Fig. 3, is opened by turning lever 16 against spring 15 and is held open by bimetal 9 engaging roller 10 when a pilot burner 4 heats the bimetal. Valves 13, 21 may be operated by a single lever. The burner consists of a lower chamber 1 and upper chamber 2 separated by a ported partition 5 whereby gas entering chamber 1 at venturi 3 has a static pressure at ignition nozzles 8 and main burner nozzles 6 to give a stable flame, but is led directly to pilot burner nozzle 4 where it has a dynamic pressure so that the flame is in a retractable condition, i.e. at the limit of its detachment from the nozzle so that should the atmosphere surrounding the burners become deficient in oxygen, the flame becomes detached and extinguished, and bimetal 9 releases the roller to close cock 13. The flames at nozzles 8 and 6 and pilot burner ignition nozzles 7 are not metastable. In alternative embodiments the main and pilot flames are separate and the main gas cock is shut off when a catch is released by a thermal ball and bellows, a bimetal or a thermocouple and solenoid heated by the pilot flame.