Distribution of bleaching chemicals (ClO₂, Hydrogen Peroxide (H₂O₂), Sodium Hydroxide (NaOH), O₃) into pulp slurries at medium consistency (3–15%). Uniform distribution critical for even bleaching.
Minimum open vane area >40% to prevent plugging with fibre. Non-Newtonian pulp rheology — standard Hagen-Poiseuille ΔP correlations not applicable. VN open geometry essential for plug flow prevention. Mixing intensity (Velocity Gradient (G-value)) sufficient to disperse chemical into fibre mass.
Preferred MOC: FRP or rubber-lined CS for ClO₂ and Hydrogen Peroxide (H₂O₂) service. 316SS with FRP injection nozzle for Sodium Hydroxide (NaOH). Avoid bare carbon steel for ClO₂.
VN open LPD vane geometry ONLY — helical elements will plug with pulp fibres. Minimum vane open area >40% of cross-section. Position immediately upstream of bleaching tower. Injection nozzle in FRP or PVDF for ClO₂ service.