GB730668A - Improvements in or relating to two-stage combustion furnace - Google Patents

Abstract

730,668. Metal-heating furnaces. NESS, H. J., and RUSCIANO, F. A. Oct. 31, 19 [Nov. 10, 1951], No. 27403/52. Classes 51 (1) and 51 (2). A metal-heating furnace comprises a workheating chamber with refractory walls, means for introducing a mixture of fuel and air into the chamber for reaction therein, means for conducting the reaction products from the chamber, means for adding air to said reaction products and producing combustion of said air and reaction products externally of the work-heating chamber and means for supplying the heat generated in said combustion to the said work-heating chamber. As shown in Figs. 3 and 4 the work-heating chamber is provided with burners 21 and additional burners 48 through which gas or an air-gas mixture is supplied. Each billet 24 to be heated is surrounded by exhaust passages 22 or 23 from which the reaction products from the workchamber pass to exhaust tunnels 25 and vertical combustion-chambers 29, 30 wherein the reaction products are burnt with an air-gas mixture introduced through a further burner not shown and with air introduced at 40 and 42; the burnt gases then pass through a chamber 31 and are discharged above the furnace through flues not shown. The chamber 31 also receives combustion products from a group of vertical radiant combustion tubes 39 extending upwardly through the work-chamber and supplied with reaction products from the exhaust tunnels: the tubes 39 each have an air supply nozzle 45 and a pilot burner 46. Lithium vapour from a lithium generator 51 may be introduced into the work-chamber through a tube 56. Specification 728,085 is referred to.