NUMERICAL CONTROL OF A CONTINUOUS INFRARED DRYER

This study compares the relative performance of distinct microcomputer control aigorithms for drying a textile sheet in an infrared oven. Th e process responses to changes in the set point as well as perturbatio ns in the traveling velocity of the sheet and the inlet humidity of th e sheet are analyzed. Feedback, feedforward, and hybrid control algori thms are considered. The results indicate that the performance of the feedback control algorithm is negatively affected by the time delay as sociated with the traveling of the sheet in the dryer. The feedforward control algorithm exhibits more rapid dynamics, but falls short of re aching the set point because of model imperfection. The hybrid control algorithm, combining the feedback and feedforward controls, gives the best results overall.