GB716579A - Radiant-heating elements for furnaces - Google Patents

Abstract

716,579. Furnace radiant heating-elements. INTERNATIONAL FURNACE EQUIPMENT CO., Ltd., and BAILLY, L. March 17, 1953 [March 27, 1952], No. 7856/52. Class 51 (1) In a furnace radiant-heating element comprising inner and outer metal or refractory tubes hot gases are fed from a burner through a nozzle such that they flow through the inner tube and thence through the annular space between the tubes. As shown (Fig. 1) the outer tube a is closed at one end and attached to the furnace structure at the other, hot gas outlet ports d being provided at this end such that they communicate with an exhaust gas duct i in the furnace structure whi'st the tube a extends into the furnace working chamber j. Within the tube a is mounted a metal tube k which is open at both ends and is provided along part of its length with a venturi tube shaped refractory lining m. The tube k is supported at its ends by radial lugs n and o. A refractory nozzle q for conveying combustion products from a burner r to the entrance end of the tube k is provided in the end of the tube a. In operation, hot gases pass from the nozzle q along the tube k and back along the annular space between the tubes to the out'et ports d from which point some of the gases return to the entrance end of the tube k for recirculation. In a modification (Fig. 2) the inner tube k<SP>1</SP> is of re'ractory whilst a nozzle q<SP>1</SP> is mounted in the end of the tube a' this nozzle being formed with a spigot which fits tightly within the entrance end of the tube k<SP>1</SP>. The nozzle bore is flared at t<SP>2</SP> to form a chamber in which the fuel and air mixture issuing from the tube r<SP>2</SP> of the burner r<SP>1</SP> may ignite such ignition being effected by passing a lighted taper. down the bore u' of the nozzle q'. A cylindrical en closure v' is secured around the end of the tube a<SP>1</SP> provided with ports d<SP>1</SP>. Extending 'rom one side of v' is an exhaust gas duct i<SP>1</SP> and in the other are formed air admission openings x<SP>1</SP>. Either of the above forms of element may be mounted vertically (with gas entrance and out'et at the upper or lower end), horizontally or in any other desired position.