| 摘要 |
PURPOSE:To reduce NOx without increasing unburnt matter in exhaust gas by a method wherein straight forward air is supplied from the central part of an after-air feeding device, while swirl air is supplied from its outer peripheral part. CONSTITUTION:A part of the air supplied from a wind box 3 is past through a swirler 5 and turned to be swirl air stream 6A, which is past through an outside air passage 42 and jetted from an after-air port 4 into a furnace 1, whereby the stream 6A is expanded in the directions of the periphery of the furnace and of a water wall 2 due to its swirling force. On the other hand, the remaining air is regulated its flow rate by a damper 22 and then introduced in an inside air passage 23 so as to be turned in straight forward air 23 in order to be jetted from the after-air port 4 in the central part of the furnace. Consequently, because the unburnt matter in the center part of the furnace can be reduced by the jetted straight forward air with a large penetrating power and the unburnt matter in the vicinity of the furnace wall can be reduced by the jetted swirl air stream with a widely expanding power, the generation of NOx can be suppressed without accompanying the increase of unburnt matter in exhaust gas. |
