(EN) PROBLEM TO BE SOLVED: To provide a denitration device capable of reducing costs and optimizing an ammonia consumption when a denitration catalyst is renewed.
SOLUTION: A denitration device includes: an ammonia injection device 11A which is installed in a flue 3 where the waste gas flows and injects ammonia into waste gas from an injection nozzle; a mixer which mixes the ammonia and waste gas; a denitration catalyst 30 by which nitrogen oxide and ammonia are reacted with each other and then decomposed mainly into water and nitrogen; an ammonia concentration measuring device 60 which sequentially measures ammonia concentrations by irradiating a sampling gas, acquired from a plurality of predetermined positions downstream from the denitration catalyst 30 in a cross section of the flue 3, with laser light; a nitrogen oxide concentration meter 51 which measures a nitrogen oxide concentration; and an opening setting section 40A which sets opening of a total flow rate control valve of an ammonia main system based upon the nitrogen oxide concentration, and sets opening of flow rate control valves provided to a plurality of ammonia supply systems branching off from the ammonia main system based upon the ammonia concentrations at a plurality of positions.
COPYRIGHT: (C)2013,JPO&INPIT
【課題】脱硝触媒の更新に伴うコストの低減やアンモニア消費量の最適化を実現できる脱硝装置を提供する。
【解決手段】排ガスを流す煙道３内に設置されて注入ノズルから排ガス中にアンモニアを注入するアンモニア注入装置１１Ａと、アンモニアと排ガスとを混合させる混合器と、窒素酸化物とアンモニアとを反応させた後に主として水と窒素とに分解する脱硝触媒３０と、煙道３の断面内で脱硝触媒３０の下流側の所定の複数位置から入手したサンプリングガスに対してレーザ光を照射してアンモニア濃度を順次測定するアンモニア濃度計測装置６０と、窒素酸化物濃度を計測する窒素酸化物濃度計５１と、窒素酸化物濃度に基づいてアンモニア主系統の総流量制御弁の開度設定を行い、複数位置のアンモニア濃度に基づいてアンモニア主系統から複数分岐したアンモニア供給系統に設けた流量制御元弁の開度設定を行う開度設定部４０Ａと、を備える。
【選択図】図１