OPTIMIZING PAPER-MACHINE DRYER CONTROL - A CASE-STUDY

The tuning of paper machine dryer section control loops represents one of the most complex tasks facing the paper machine control engineer. Improper tuning frequently causes substantial increases in machine dow ntime and product moisture variation, and is often responsible for chr onic flooding of dryers on high speed machines. Good process design an d control strategy design are shown to be fundamental requirements for successful tuning and control. The primary objectives are to minimize the non-linearities inherent in the process and to develop a tuning s trategy that will optimize dryer section performance. Computer simulat ion can play a key role in achieving these objectives.