GB491368A - - Google Patents

Abstract

491,368. Thermally-actuated valves; pilot-jets. JUNKERS & CO. GES. Feb. 17, 1938, No. 4959. Convention date, Feb. 17, 1937. [Class 135] [Also in Group XI] A safety-ignition device for gas heated apparatus in which the main gas valve is controlled by a heat-sensitive member heated exclusively by a pilot flame has the pipe supplying the pilot burner branched off from the point of minimum cross-section of a Venturi pipe traversed by the flow of gas to the main burner or by a proportionate flow diverted from the main stream. In the form shown in the Figure the cut-off valve 12 is actuated by a bi-metallic loop 15 subject to the heat of a pilot flame 16. The pilot burner is supplied through a conduit 27 fitted with a throttle adjusted to maintain a minimum flame and through a conduit 18 connected through a thermally actuated valve 25 and non-return valve 28 to the neck of a Venturi tube 21 arranged in a byepass 23 to the main gas conduit 20. The valve 25 may be controlled by the temperature of the liquid being heated. When this valve is open an increased flow in the main conduit reduces the supply to the pilot burner so causing the bi-metallic strip to move the valve 12 towards its seat to throttle the main flow. In a modification the valves 25, 28 are dispensed with and the Venturi tube is arranged in the main gas conduit.