| OCR Text |
Show Figure 9 shows deviation of temperature in the furnace in several conditions of the divided COO supply. The longitudinal temperature uniformity is improved only when 20-300/0 of total COO is blown in the downstream direction 2m apart from the burner. The position of 2m from the burner is just after the maximum temperature point without auxiliary gas, and it is around the top of the burner flame. Figure 10 indicates longitudinal temperature distributions normalized by each mean temperature in the case of COG blown in the downstream direction 2m apart from the burner, and Figure 11 indicates normalized heat flux data in the same condition. These figures tell that feeding 20% of total COG reduces each peak value and improves uniformity, and that feeding 300/0 COG makes each peak position move in the direction of downstream. Figure 12 shows deviation of temperature in the furnace in the conditions of the divided oxygen supply. The divided oxygen supply system also gives the least deviation of temperature under the same condition as in the case of the divided COO supply system, that 20-300/0 of total gas is suppled in the downstream direction 2m apart from the burner. The difference is the uniformity appears even in the condition of feeding at the point 1. 25m from the burner. Feeding COG in the centre of the burner possibly causes the difference, because the auxiliary oxygen gas can change the carolification pattern of the burner reacting with COG at the point in the divided oxygen supply system. Figure 13 shows longitudinal temperature distribution, and it tells the system can not only establish the thennal uniformity but also control temperature distribution in the furnace widely. Figure 14 indicates NOx emission in the oxygen/COG dispersed supply system. It shows the oxygen dispersed supply system can decrease standardized NOx concentration down to less than 100ppm . ....-.. ~ 90 ...... . ..................... !...................................... .............. ......... ... .... .. -.. ,,'- ...... . Q) 2 ~ 'Q"") c.. e .Q..) 'o c:: .9 .~ . : 80 ............. : ........................... ~ .. ....................... .;.. ................................. . ~ 0 1 0 20 30 40 50 "'0 ratio of auxiliary 02 to total 02 (0/0) Figure 12 Deviation of temperature in the divided 02 supply system ~ 1.20,-----.....----,-----r---1""1 := ~ ~ r.. QJ 0.. E QJ ~ 1.00 .... "0 QJ .-N~ E r.. g 0.800 - _ . - ~ L..:~::=.....J...;u.ua1 -:...-. .: -~ -0 ~ '"' ........................•... _ .. - " . --- -- {J 1 2 3 4 distance from burner ( m ) Figure 13 Normalized temperature in the furnace (the divided 02 supply 2m apart from the burner) |
