PULP AND BLEACHING REAGENT MIXER AND METHOD

摘要

A contacting apparatus (50) for providing intimate contact between pulp and a gaseous bleaching reagent has an elongate substantially cylindrical chamber (60) having an inside diameter proportional to a mixing capacity and an inlet (52) for pulp and for the carrier gas and the gaseous bleaching reagent; a rotatable shaft (54) extending through the chamber along an axial centerline of the chamber; provisions, mounted on the rotatable shaft, for radially tossing the pulp within successive transverse planes to maintain a substantially uniform distribution of pulp across the radial extent of the cylindrical chamber (60) with a minimum of axial mixing; and further provisions for regulating gas flow through the inlet (52) to transport the pulp through the mixing apparatus, the flow being proportioned to provide a predetermined pulp residence time within the chamber as determined by dimensions of the chamber, rotation speed of the shaft, concentration of the bleaching reagent, pulp consistency, and pulp production requirements.