GB697846A - Heat producing device for various applications and composition for heating same - Google Patents

Abstract

697,846. Heating by chemical action. GOURGUES, A. Feb. 1, 1950 [Feb. 5, 1949], No. 2625/50. Class 64 (ii) A device, e.g., for heating liquids or food or for footwarming, comprises a tube A containing a heating charge 1, a priming charge 2 with igniting means such as a wick 5 and closed by a plug B which includes an expansion chamber containing filtering packing 20 and means such as resistance wires 32 for firing the igniting means, the plug being removable by unscrewing for emptying and recharging of the tube for further use. To form the loading charge, a calcium silicide-iron oxide mixture for the heating, together with a calcium silicidestrontium chromate mixture for the priming, is compressed in a mould or else contained, compressed or otherwise, with the wick 5, in an auxiliary tube 3 which may also be refilled after use. The bottom closures of the tubes A, 3 may be screwed plugs removable to facilitate emptying the residue after combustion. Inert fillers such as talc or china clay may be included in the priming charge. Strontium chromate may be included, together with red lead, 5 per cent of each, in the heating mixture and may be included, together with calcium silicide, in a nitro-cellulose bath into which is dipped the wick 5 after impregnation with sodium or potassium chlorate. The filter packing 20 incorporates asbestos or glass fibres with charcoal. The tube A may be secured to a wall of the container in which food etc. is heated and may be surrounded by refractory material to retard the heat transmission. A number of resistance wires 32 are mounted on the plug B, one being used until burnt out and the remainder being spares moved into position when required. Electric current from a battery or hand-operated magneto secured to the food container is supplied to heat the wire and fire the wick 5 by way of terminals 37 one of which, in a modification, Fig. 9 (not shown), is mounted on the lower side of the plug in the region of vent holes 18 in order to make electrical contact with a member on the food container 1 and thus fire the charge when the plug is screwed home. A tube 39 surrounds the wick and protects the firing means. In one modification, Fig. 10 (not shown), the wick 5 is omitted and only its head 6 is included, to be fired directly by a resistance wire embedded in the priming charge. Another modification, Fig. 12 (not shown), has the resistance wire held in position by a disc closing the end of tube 3 and protected from the heating charge by. insulation in which the wick is embedded. In a further modification, Fig. 13 (not shown), a match head attached to the wick 5 is fired by a friction surface on the plug B. Specifications 579,046 and 581,129 are referred to.