FAULT-DETECTION FOR PRESSURE SCREENS

Malfunctions on pressure screens are usually detected in pulp mills by measuring the differential pressure between the feed line and the acc ept line of the screen as a warning signal. This method has several dr awbacks. Tests performed in a pilot plant have shown the potential for using a mathematical model of the pressure screen as a fault detectio n tool. The objective of this approach is to monitor the process param eters of the screen included in the model to detect incipient malfunct ions and to prevent screen failure. The pressure screen model, based o n mechanistic principles, is part of a general strategy for diagnosing and controlling pressure screens which is being developed at the Pulp and Paper Centre in The University of British Columbia, in collaborat ion with Paprican.