METHODS FOR BEATING PULP, METHODS FOR TREATING PROCESS WATERS, AND METHODS FOR PRODUCING PULP AND PAPER

摘要

A method for preparing bulky pulp at freeness levels comparable to that obtained by mechanical treatments while suppressing fiber damage and internal fibrillation comprises generating cavitation in the pulp suspension. Preferably cavitation is generated by a liquid jet and resulting fine bubbles are introduced to adjust the pulp suspension to a desired freeness by the impact force induced by collapse of the fine bubbles. Process water containing up to 50% by weight based on total solids, of long pulp fiber fractions is treated by the generated cavitation and returned to the process for stripping contaminants deposited on pulp fibers and/or inorganic particles to reduce contaminates and adhesion, and decrease microorganisms.