Application of process simulation to operator training and startup of a high-speed paper machine

Because of the complexity of operation of a paper machine, a simulation of operation would provide three avenues through which better startup and operation could be obtained: (1) engineering evaluation, (2) operator training, and (3) control-program evaluation.

Prior to the startup of a new high-speed paper machine, a simulation of the stock system where the suspended fibers are formed into a sheet of paper was undertaken. Basic information on the steady-state and dynamic be havior of such a system was obtained on a highly instru mented paper machine having components similar to those of the new machine. The system was analyzed one component at a time to fit available theoretical equations with minor modifications. This allowed reasonable extrap olation and reassembly of the system to describe the new machine.

An important factor in describing such a system was the transport lag in the pipelines. This facet of the simulation was accomplished with prewired Padé approximations of these lags. A second important characteristic in describing a paper machine in real time is the long time-constants involved in the rates of change. These may run as long as 10 minutes.

A replica of the main control panels was constructed for use as a training aid for the operating crews of the new machine. The panels were programmed on the computer to respond to upsets and grade changes as part of an inten sive training program for the operators.

Exploitation of the simulation system is still in progress. It is evident, however, that the smooth startup resulted from careful planning and effective operator training.