| 摘要 |
PROBLEM TO BE SOLVED: To reduce heat load in the vicinity of a side wall of a combustion furnace and increase the excess air ratio of a burner provided on a wall surface of the furnace, which is suitable for preventing formation of a reducing atmosphere. SOLUTION: Among coal feeding pipes 5 which connect a mill 4 and a burner 7, the radius of a coal feeding pipe 5a extending to a burner 7a which is arranged in the vicinity of a side wall 8b adjoining a furnace wall 8a of a furnace 8, where the burner 7 is located, is made smaller than that of a coal feeding pipe 5b which extends to a burner 7b at the central portion of the wall 8a. Accordingly, the amount of fuel supplied to the burner 7a is reduced compared with that supplied to the burner 7b at the central portion of the wall 8a where the burner 7 is located. Thus the excess air ratio of the burner 7a positioned adjacent to the side wall 8b is increased, the amount of air in the vicinity of the side wall 8b is increased, slagging caused by the reduction of heat load is suppressed and incomplete combustion of the fuel is suppressed to suppress production of CO. Further, the amount of sulfide produced by combustion of the fuel is suppressed by suppressing generation of uncombusted fuel and permitting reducing atmosphere in the flames to decrease, thereby preventing the wall surface of the furnace from being corroded.
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