Integrated Control of Stock Preparation Technology and Benefits for the Paper Mill, 1991 Papermakers Conference Proceedings

The modern Distributed Control System can provide integration of previously independent information and control packages and therefore can provide integrated optimized operation for the separate Stock Preparation processes. Examples are provided for pulping, refining, and furnish blending. Control strategies consider not only the optimum operation of these individual areas, but also their coordination within the overall stock prep area and with the paper machine operation. The strategies incorporate sensor and operator inputs, process models, and feedforward-feedback controls. Sequencing of startups and shutdowns, including safety interlocking, is automated to the degree desired by the mill. To assist operators during grade change and on-grade conditions, as well as during upset situations, customized pictorial video displays provide both overview and detail information. Sensor data and control status of all the processes is available in a global data base, both for current real time use and as a historical record. Mill personnel have immediate, precise and easily interpreted information about all processes at all times. The result is improved efficiency and convenience, fewer process upsets, reduced material costs, and improved uniformity of furnish supplied to the paper machine.