| 摘要 |
<p>PURPOSE:To prevent the deterioration of the alkali metal in a catalyst, by steadily adding a catalyst comprising heavy metal oxide in a denitration system. CONSTITUTION:A tank 8 for adding an active metal is provided between the ammonia-air mixer 7 and an ammonia injection nozzle 4 of an ammonia injection system and an ammonium salt of the active metal is stored in the tank 8 as an aqueous solution with a constant concn. Because the active metal is added as an aqueous solution, concn. control and the control of an injection amount can be easily performed by a control valve 13 and the aqueous solution of the ammonium salt containing the active metal in an amount more than that of an alkali metal exerting influence upon a denitration catalyst is injected in a state accompanied by ammonia gas from an ammonia injection nozzle 4. The injection region is of a high temp. with a temp. of 300 deg.C or more and the ammonium salt is vaporized, uniformly diffused and effectively acts.</p> |
