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Canadian Forest Products Limited
(Prince George and Intercontinental Pulp and Paper Mills), Prince George, BC
Control System Modernization

Background

Canadian Forest Products (Canfor) owns and operates two pulp and paper mills in Prince George, BC. The control system upgrade project was launched to replace pneumatic field-mounted instruments and pneumatic PID controllers mounted in control panels with electronic instruments and Foxboro I/A DCS to improve the productivity and to become competitive in the market. Relay-based controls were also replaced with Allen-Bradley PLC-5's.

The Project

Andritz Automation was retained from the beginning of the project to assist Canfor personnel with preparing budgets for the master plan, preparing a realistic schedule for the projects to work around the minimal downtimes available for the system changeover, and map out a strategy on the details of the change over to minimize interruptions to the mill production.

The scope of the project covered the upgrade of all the areas of two pulp and paper mills for about 2,600 instrument control loops and 6,000 discrete input/outputs for logic controls. The plan was to start from the most critical part of the mills, fiber line, then proceed to the utilities, and then to the machine rooms. Fiber lines for both mills include the chip receiving and screening, Kamyr continuous digesters, brown stock washing and screening, bleaching, chemical preparation areas. Lime kiln and recausticizing areas were also done as part of the fiber line. Utilities include the power and recovery boilers, multi-effects evaporators as well as other support processes such as feedwater systems, river water systems, effluent treatment systems and other services essential to mill operation. The machine room included the pulp machines and dryers, bale handling systems, paper machine and dryer and paper roll handling system.

Benefits

To date, the fiber lines and most of the steam and recovery areas for both mills are complete and operational. The distributed control system provided the operators with much more process and products information than what was available to them before. The process engineers are now spending much more time implementing advanced control strategies and trying to make the mill work better. Statistics maintained for the Intercon mill, which was the first to upgrade, indicate that the percentage of the time that mill is producing " on-grade" pulp has improved by 5% for the first two years after the upgrade.