METHOD OF REFINING WOOD CHIPS OR PULP IN A HIGH CONSISTENCY CONICAL DISC REFINER

摘要

A method is proposed for improving pulp quality at high production rates on conical disc refiners. It permits a reduction in refining intensity by enabling fibre residence time to increase by increasing consistency, while avoiding the problem of plate plugging normally associated with high discharge consistency. In practice, inlet consistency is increased by the in-feed dilution, flat zone dilution or both, but without allowing the discharge consistency to rise. Instead, the discharge consistency is controlled at a fixed optimum value by the addition of dilution water within the conical zone. The result is that residence time is increased, and refining intensity decreased, by raising the consistency in the inner region of the refining zone, while avoiding the plate plugging caused by excessive consistency in the outer region of the refining zone.