| 摘要 |
<p>PURPOSE:To carry out an excellent suppression of NOx by providing an exhaust gas blow-in nozzle for blowing at high speed a combustion exhaust gas toward the interior of the furnace from the periphery of a secondary fuel supply nozzle, at the outer peripheral portion of the secondary fuel supply nozzle. CONSTITUTION:In a case where a combustion load is high and the flow speed of secondary air is large, the amount of the supply of a combustion exhaust gas to an exhaust gas blow-in nozzle 10 is increased so as to increase the attracting force of a secondary fuel supply nozzle 3, thus maintaining the secondary fuel ratio to a constant value. Further, even in a case where, by a head difference between the primary supply nozzle 7 of a primary combustion burner 2 and the secondary fuel supply nozzle 3 thereof, a pulverized coal flow amount ratio varies, the amount of the combustion exhaust gas to be supplied to the exhaust gas blow-in nozzle 10 is adjusted so as to remove the influences caused thereby. As a result, even if there are a load and a head difference, it is possible to constantly obtain a predetermined secondary fuel ratio and to satisfactorily control NOx.</p> |
