A computerized pulp and paper mill instrumentation and control system

Over the past few years about a dozen computer installations have been announced and discussed in the paper industry. The acceptance of these systems has ranged from outright return to the vendor, through claims of a twenty percent increase in production. It is the opinion of the author that those systems which had improved control through better regulation of the process as their immediate goal were consistently much more successful than those installations which were keyed in a research oriented, data gathering approach. Rather than conduct another historical review of these installations, this paper will devote its attention to discussing control problems and their typical solutions. In particular, the continuous digester, stock preparation, and paper machine areas will be reviewed in some detail. A typical paper mill wood flow diagram is shown in Fig. 1.