GB129830A - Improvements relating to the Construction of Furnaces and other Heating Appliances. - Google Patents

Abstract

129,830. Roberts, G. H., and Booth, W. N. Jan. 27, 1919. Muffle furnaces; crucible furnaces; metal-heating furnaces.-In a furnace of the type in which the outer walls are separated from the walls of the heating-chamber by a space through which the waste gases circulate before passing to recuperators, the recuperators are situated in a flue below the furnace and surrounded by the outer walls. The waste gases flow in the opposite direction to that of the air or gas, or both, being heated. In the gas-heated muffle furnace shown ia Fig. 5, combustion gases pass around a chamber A, and the waste gases pass by openings a to the space b and thence to a flue below the furnace, where they heat the air for combustion in pipes G, G<1> provided with radiating-gills, and the gas in a pipe N with branches leading to two burner nozzles. A layer of heat-insulating material E may be disposed within an outer casing F. In a modification provided with a single burner, the fuel gas and air are preheated together in a single gilled pipe. Fig. 9 shows a crucible tilting furnace wherein combustion gases from burners M ascend around a crucible A, pass through holes a, and descend a jacket flue b<1>, heating the gas in an annular tube 0, and the air in a pipe G branched in the flue D to give greater heating-surface. Fig. 11 shows a billet-heating oven furnace supplied with hot gas from producers through an intake Q, the waste gases, aftet passing through the jacket b, heating air in pipes G<2> within a flue having an outlet R. The air supply is regulated by a slide g<5>. The invention may be applied to furnaces using solid or liquid fuel.