| 摘要 |
PURPOSE:To reduce NOX in a discharged gas by a method wherein a sub-burner is transferred from a conventional mounting side wall to its opposing side wall and its position is set at a level lower than a mounting height of the second stage main burner. CONSTITUTION:Reducing gas generated in a combustion area in a sub-burner 51 is contacted with NOX produced in a combustion area of the first stage main burner 3 and the second stage main burner 4 and ascended up while reducing NOX and is reached up to the position where the second stage main burner 4 is located. Since a distance 10 between this position and an after-air port 6 is long, no production of NOX is caused by an interference with air fed from the after- air port 6. Thus, a concentration of NOX in the exhaust gas can be reduced. |
