Homogeneous distribution of ammonia or urea across the flue gas duct ahead of Selective Catalytic Reduction (SCR) catalyst beds for NOₓ reduction. Uneven distribution causes NH₃ slip and poor deNOₓ.
Coefficient of Variation (CoV) ≤0.05 at Selective Catalytic Reduction (SCR) catalyst bed inlet for Ammonia (NH₃)/NO molar ratio. Operating temperature 200–450°C. Duct geometry typically rectangular or square — custom vane design required. Ammonia (NH₃) slip target <5 ppm (parts per million) at stack.
Preferred MOC: Alloy steel (P91 or P22) for high-temperature service. Stainless steel 316 or 321 for moderate temperature. Differential thermal expansion between flanges and mixer body must be accommodated.
Custom rectangular duct vane mixer design required for non-circular ducts. Multi-lance ammonia injection grid upstream of mixer for pre-distribution. High-temperature insulation on mixer flanges to prevent differential thermal expansion cracking. Soot blower compatible design.