Vacuum expression belt tracking and control apparatus for rotary drum vacuum filter

摘要

A rotary drum vacuum filter suitable for processing pulp slurries is provided with a vacuum expression belt. The invention provides a method and apparatus for tracking and controlling the belt during operation. The belt is positioned by a moveable frame for expressing filtrate from the pulp web and in operation a control unit monitors lateral movement of the belt with respect to the drum. When drifting occurs the belt is adjusted horizontally during operation to counter drift. The adjustment can be repeated as necessary. If continued drift cannot be corrected then the belt is moved vertically to an inoperative position.