The University of British Columbia

Macmillan Bloedel Limited

Fpinnovations

Bruce James Allison

Guy A Dumont

Brennan Dubord

Patrick J Tessier

Wei Ren

Joe E Ciarniello

Jason Johnson

Methods and systems for controlling operation of a smelt dissolving tank receiving a flow of smelt and having a vent stack in fluid communication are provided. A dissolving liquid is injected into the smelt dissolving tank at a predetermined injection rate. A temperature of a flow of vapour in the vent stack is measured with a sensor. The injection rate of the dissolving liquid is controlled based on the temperature of the flow of vapour.

Vent stack temperature as a feedforward variable for smelt dissolving tank TTA control

The load on a refiner motor is controlled by adjusting the motor load setpoint by monitoring load applied by the refiner and the plate gap between the refiner plates to define the curve of the load versus plate gap relationship. This slope of load versus plate gap relationship is estimated and when the sign of the slope of the curve changes sign indicating operation in an unstable zone of pad collapse and based on the tendency for the refiner to be in the unstable operation zone over a selected period of time exceeding a preset limit adjusting the setpoint lower to approach more closely the maximum load applied over the selected time.

Automatic refiner load control

Growing community of inventors

Vancouver, Canada

Bruce James Allison