GB570516A - Improvements in or relating to gas-fired reheating furnaces - Google Patents

Abstract

570,516. Gas-fired reheating furnaces. PRIEST, C. F. Jan. 4, 1944, No. 125. [Classes 51 (i) and 51 (ii)] A gas-fired reheating furnace having a recirculatory system for the products of combustion is provided in each side wall with vertical combustion chambers 30 each fitted with a burner 32 and communicating with a roof cavity 27 from which the passes pass through ports 29 into the heating chamber 13 to escape therefrom through openings 21 and damper-controlled passages 22 to. horizontal exhaust flues 11 below the furnace, the gases being withdrawn from these flues by fans 14 and transferred to adjacent return flues 12 from which passages 38 and vertical flues 35 lead to the upper ends of the combustion chambers 30 As shown in Fig. 4, the flues 35 are arranged on each side of the combustion chambers 30 and V-shaped blocks 37 are provided to cause intimate mixing of the returned gases with the fresh combustion products. The connections 16 between the flues 11 and the fans 14 are fitted with dampers 19 and further dampers 20 are provided in flues 18 through which gases can be passed to the stack when required. A valve-controlled vent pipe 40 may be fitted to each return flue 12 to permit gases to escape in regulated quantities as required, direct to atmosphere. When a temperature higher than that produced by the recirculatory system is desired, e.g. 700‹ C. to 1000‹ C. the burners 32 and fans 14 are shut off and high temperature burners 41 delivering into the heating chamber 13 near the roof are brought into operation, the various dampers being set to pass the waste gases direct to the stack without racirculation. The charge 43 is supported in the furnace-on a bogie 23 having a platform provided with transverse ribs 44, the charge resting on the tops of the ribs and the gases passing along the valleys between them to the escape ports 21.