| OCR Text |
Show 3.3.3 Combustion characteristics In a 104m wide x 1.4m high x 6m long ! castable refractory furnace, coke oven gas £ was burned as a fuel at a combustion rate of ~ 800,000kcal/h, an air temperature of 450°C, ~ an excess air ratio of 1.05, and a 21-30% E oxygen density range in air oxygen enrich- ~ ment. 9 3 2 sse burner Combu'tion rate : 80x104 kcaJ/h 0, in combustion a ir : 23% (1) NOx was greatly reduced to one third or less that of the conventional type burner, and the higher the oxygen enrichment ratio becomes the larger the NOx reduction ratio becomes. (Fig. 13) Primary Secondary 10 4 10 10 10 10 4 10 o (2) Flame length adjustment in the range of I-3m is possible by moving a flame length adjusting valve. A stable flame is formed at any valve position. A turndown ratio up to one tenth is possible. (Fig. 14 and Fig. 15) (3) The diameter of flame is larger than that of the conventional type. The flame temperature at the burner center axle is generally lower than that of the conventional type. With the conventional type, the highest flame temperature becomes extremely high in the vicinity of burner, but with the sse burner, it is smooth and its maximum temperature is as low as 2000 e or less . (4) When the oxygen enrichment ratio is increased, the combustion rate in the vicinity of the burner is reduced. However, the combustion ending point is almost in the same position as in other cases, and flame formation change is not observed. (Fig. 17) 500 400 E 0. 0. 0 300 Cl~ .= 200 x 0 2 100 a / / I If 21 I I I ) I I 23 I f' I I ,'''' Conventional type " burner Combustion rllte: 80xl0' kcal/h 25 27 29 Ol % in combustion lIir Air valve for pr ima ry and secondary a ir: 1010 . Flame length 1 m (SNT ty pe flame) U ~ III 5 ~ 0. E ~ j u.. Position of air valve Fig. 14 Relationship between flame length and position of air valve 1700 1600 1500 1400 1300 1200 1 100 ~ ~ \ \ \ \ )\ / Conventional type \ burner , '\. ~ '\. '\. 2 '\. , , ~ 3 '\. '\. 4 '\. , b. '\. , Distance from the burner Quarl 1m) '\. '\. ~ 5 Fig. 16 Temperature distribution of combustion flame Air va lve fo r p rimary and second;)ry a ir: 2/10 . Flame lengt h 2 .5 m |
