GB944372A - Improvements in or relating to an industrial burner and method of operating same - Google Patents

Abstract

944,372. Burners. SELAS CORPORATION OF AMERICA. July 30, 1962 [Aug. 14, 1961; Nov. 24, 1961], No. 29256/62. Heading F4T. An industrial burner comprises a burner block forming a portion of a furnace wall 1 and provided with a central opening 17 surrounded by a plurality of furnace gas passages 5, a refractory recuperator chamber 16 through which a portion of the products of combustion are withdrawn and an element 23 with gas and combustion air passages 24 and 25 received in the opening 17. A gas supply pipe 27 and a helically coiled air pre-heating tube 32 pass through the chamber 16 to the element 23 and an aspirating air pipe 37 is disposed in an exhaust opening 12 at the near end of the chamber 16. The burner block comprises a refractory block 2 having a central cup-shaped depression 3 surrounded by a ring of segments 4. The cup 3 terminates in an axial portion 3A at its outer edge and has a ridge at its inner edge. The gas passages 24 are radially disposed and parallel to the wall of the cup 3 and the air passages 25 are formed by helical ribs 26. A sleeve 18 in the opening 17 houses the element 23 and has an enlargement 19 to which the coiled air tube 32 is connected. The latter has a sealed connection cap 35 outside the chamber 16. The gas pipe 27 is screwed at its ends to the element 23 and to a connection cup 31 halted to a metal cover 15 at the back of the chamber 16. A further gas tube 48 extends through the gas supply pipe 27 and one end is received in a hole in the element 23. A tube 21 surrounding the gas pipe 27 carries a refractory insulating sleeve 36 and passes through a refractory disc 14 into the cover 15 containing a sealing ring 22. The recuperator chamber 16 is formed by two dense refractory cylinders 7 and 8 and intermediate porous refractory rings 41. Each ring is connected to an air supply 45, 46, 47 and has a manifold recess 43. In operation, gas and air regulated by a ratio controller 54 are supplied through pipes 52 and 53 for air deficient combustion in the burner cup 3 and a portion of the combustion products are withdrawn through the passages 5 into the chamber 16. The latter is supplied with air through the porous rings 41 and combustion takes place in the chamber 16. The air supply to the rings 41 and to the pipe 37 can be regulated either manually or by a valve responsive to the ratio controller or to the pre-heated air temperature. In a further modification the porous rings 41 are omitted from the construction of the chamber 16. In a final modification, the air to be pre-heated is brought to the front of the chamber 16 and flows backwardly through the coil 32 before supply to the element 23. A plurality of burners of varying fuel-air ratios may be arranged in one furnace.