GB828502A - Improvements in or relating to furnace burner system - Google Patents

Abstract

828,502. Burners. BLOOM ENGINEERING CO. Inc. Nov. 25, 1957, No. 36670/57. Class 75(1) A burner comprises a body 15 extending at its front end through a refractory block forming part of a furnace wall 11 into a combustion recess 12 thereof to which combustion recess the air and fuel in gaseous or spray form pass by two sets of passages 25, 26 in the peripheral wall of the burner body the front end wall 21 forming a closure and the fuel and air respectively passing along the interior and exterior of an open-ended sleeve 30 the front end of which can be positioned so that only air passed to the rearmost set of passages 26 and only gaseous fuel to the foremost set of passages 25. The sleeve end can thus be set so that mixing of the fuel and combustion air does not occur till they are discharged from the burner end, or the sleeve end can be set slightly back to allow mixing of the air and gaseous fuel in the small space 22 below the passages or can be set a little further forward to allow air and gaseous fuel to enter the foremost passages 25 in a low proportion of air/gas, the complementary air for complete combustion entering by the rearmost passages 26. This prevents backfiring when a fast burning gas such as coke oven gas or hydrogen is used. For a sprayed fuel from a nozzle 35 shown disposed within the sleeve the latter is retracted so that its front end lies behind such nozzle 35 the mixing then being effected in the main space of the body 15. The sleeve is shown in Fig. 4 as flanged at the front end to slide on the interior wall of the body and will prevent mixing of the air and fuel until discharged into the recess 12 when the flange 41 is positioned between the two rows of passages 25<SP>1</SP>, 26<SP>1</SP>, Figs. 4 and 6, or will allow a variation of the air/fuel ratio when the flange 41 cuts across the front row of passages 25<SP>1</SP>. The front end of the burner body which is exposed to the high temperature may be a renewable one screwed on or welded, as shown in Fig. 9, at 64<SP>11</SP>, to the main burner body 60<SP>11</SP> and the end face 62<SP>11</SP> may have a refractory cover 98 cast thereon. The furnace wall 89 is in this form shown convex to the burner and the two sets of passages 80", 81<SP>11</SP> are arranged to converge their jets and cause the mixing air and gas to be directed parallel to the convex surface; no mixing of the air and gas occurs until the jets discharge from the passages since the sleeve engages a bore in an inward shoulder portion 91 of the burner body. Adjustment of the burner body to position its front end appropriately projecting into the furnace may be effected by inserting shims between the back plate 115, Fig. 10 (not shown), of the burner body and the outer wall plate 116 of the furnace.