METHOD FOR HEADBOX CONTROL

摘要

Headbox transient response for sheet weight and moisture are modeled as a combination of two sets of time constants and dead time delays. One set represents a shorter delay with faster respons e dynamics, the fast mode weight and moisture responses, and the other models the longer delay with slower dynamics, the slow mode weight and moisture responses. A weight and/or moisture transient model is then formed for headbox changes by combining the fast mod e weight and moisture responses and the slow mode weight and moisture responses. Stock weight and moisture dynamic and delay time models are determined for operation of stock flow of the paper making machine and the stock flow is controlled in accordance with the stock weight and/or moisture models and the headbox weight transient and/or moisture transient model to compensate f or weight and moisture changes in a web of paper being manufacture which weight and moisture changes result from headbox changes.