| 摘要 |
PURPOSE:To enable a homogeneous dispersion of NH3 gas while preventing openings of upward nozzles for ammonia injection from being choked up with dust by arranging dust shelter plates over the nozzles of ammonia injection pipes. CONSTITUTION:Dust piled up on a vertical duct 9 or internal reinforcing members 12 during the operation of a boiler is apt to drop out and fail down at the start-up or shut-down of the boiler. By arranging a dust shelter plate 15 over every NH3 injection nozzle 11, a falling dust 13 is caught by a dust shelter plate 15 and an NH3 injection nozzle 11 underneath the plate 15 is not choked up with the falling dust 13. NH3 gas from the injection nozzle 11 collides with the dust shelter plate 15 and mixed with a flue gas homogeneously, resulting in an improvement in a denitration performance. Furthermore, the lower face of the dust shelter plate 15 is prevented from a dust adhesion, because an NH3 gas film is formed. |
