| 摘要 |
PROBLEM TO BE SOLVED: To suppress the lowering of denitration performance by a denitration catalyst bed due to the nonuniformity of the gaseous NH3 distribution in a waste gas treating line. SOLUTION: A denitration catalyst bed 3 consisting of a parallel-flow catalyst unit 6 obtained by laminating a honeycomb or plate catalyst element or a plurality of the catalyst blocks 2 obtained by laminating a plurality of the catalyst units 6 are arranged on the downstream side of an ammonia injection part 4 in a waste gas duct 1. At least two denitration catalyst beds 3 are set in the duct 1, a gap 13 is formed between the denitration catalyst beds 3, and a mixer 8 for mixing the waste gas and ammonia is set in the gap 13. The waste gas and NH3 are mixed at the inlets of the respective catalyst beds by the mixer 8 set in the gap 13, the unbalance of distribution of the molar ratio of NH3 to NOx is reduced, and the denitration performance is enhanced. |
