Paper Mill Headbox Consistency Control System Design with Deadtime Compensation

One very important component of the paper making process is the headbox. The inflow of the stock is accumulated up to an appropriate height in the headbox. The regulation of this height is to be strictly regulated to sustain an optimum pressure so that the stock jet is released with the preferred speed. The present work addresses the control system design of headbox consistency. The controllers using ZN and LQG techniques have been developed for it and their performance is compared. Further, the undesired effects of deadtime are compensated by designing Smith predictor. The output response, after deadtime compensation, is compared with the previous responses. All the results have been obtained by MATLAB simulations.