| 摘要 |
<p>PURPOSE:To perform the denitration of exhaust gas generated by the surface treatment of a metal, by a method wherein exhaust gas generated by the surface treatment of a metal is reacted with and absorbed by a limestone powder slurry and the generated nitrite and nitrate are removed while the unreacted limestone powder slurry in conc. and recirculated to be reused. CONSTITUTION:Exhaust gas reaches an absorbing tower A through piping 1 and subjected to gas-liquid contact with a limestone powder slurry herein while the treated gas enters an absorbing tower B through piping 2 and again subjected to gas-liquid contact herein and, thereafter, discharged into the atmosphere through an eliminator F and an exhaust fan 15. On the other hand, the limestone powder slurry receives the addition of a limestone powder 17 in a slurry conditioning tank E to be adjusted to a definite solid concn. and the conditioned slurry is successively sent to adsorbing towers B, A by a pump and absorbs NOx to dissolve the same in water as nitrite and nitrate. The slurry after gas-liquid contact is concn. by a cyclone D and sent to a slurry conditioning tank where again conditioned as the limestone powder slurry which is, in turn, recirculated to be reused.</p> |
