According to the bad performance of traditional PID controller in big time-delay and model-free system,for keeping the residual moisture content and the thickness on the material conveyor of vacuum-pyroair dehydrated nitrocellulose in a reasonable range,then suggest to introduce multiple-value logic control algorithm in head tank discharge flux control.Introduce the description of multiple-value logic control arithmetic and the system structure,and put it in the trial run.Practice shows that this controller...