| 摘要 |
PURPOSE:To reduce the amount of an unburned part of powdered coal without increasing NOx by a method wherein a large amount of powdered coal is supplied into a furnace through a lower stage burner and a small amount of powdered coal is supplied into the furnace through an upper stage burner. CONSTITUTION:An upper stage burner 10 is connected to a small capacity pulverizer 8 and a lower stage burner 13 is connected to a large capacity pulverizer 11. The coals pulverized and dried by the pulverizers 8 and 11 are then supplied to the burners 10 and 13 by means of a transfer medium and thrown into the furnace. The powdered coal thrown through the upper stage burner is supplied by the the small capacity pulverizer 8 and that thrown through the lower stage burner is supplied by the pulverizer 11. The total amount of the powdered coal to be thrown into the furnace is determined to correspond to the load on the furnace and the amounts of supplied powdered coal by the upper and the lower stage burner are so adjusted that the powdered coal is burned sufficiently within the furnace and the amount of an unburned part of the coal to be discharged outside the furnace is reduced. As the amount of coal thrown through the lower stage burner is small, the unburned part of the coal is reduced and so the total amount of the unburned part of the coal to be discharged outside the furnace is also reduced. |
