| CPC D21C 3/228 (2013.01) [D21C 3/24 (2013.01); D21C 9/02 (2013.01); D21C 9/06 (2013.01); G01N 33/343 (2013.01)] | 11 Claims |
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1. A computer-implemented method for predictive control of brown stock treatment at a pulp mill, the method comprising:
continuously measuring, via a plurality of online sensors, actual values for respective process characteristics comprising an entrained air level, a vat level, and a washer speed, wherein the entrained air level is directly affected by adjustments to at least a defoamer flow rate, and the vat level is directly affected by adjustments to at least a vat dilution rate;
dynamically setting target values for the entrained air level and the vat level, respectively, based on a predicted impact of corresponding control responses for at least the defoamer flow rate and the vat dilution rate; and
generating control signals for actuators associated with defoamer flow rate and the vat dilution rate based on detected variations between the respective actual values and target values for the entrained air level and vat level; and
generating control signals to the actuator associated with washer speed based on detected variations between the actual and target values for the vat level.
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8. A system for predictive control of brown stock treatment at a pulp mill, the system comprising:
a plurality of online sensors configured to generate output signals representative of actual values for respective process characteristics comprising an entrained air level, a vat level, and a washer speed;
wherein the entrained air level is directly affected by adjustments to at least a defoamer flow rate, and the vat level is directly affected by adjustments to at least a vat dilution rate;
a plurality of actuators configured to regulate actual values for the defoamer flow rate, the vat dilution rate, and the washer speed, respectively;
a controller configured to
dynamically set target values for the entrained air level and the vat level, respectively, based on a predicted impact of corresponding control responses for at least the defoamer flow rate and the vat dilution rate;
generate control signals to the actuators associated with defoamer flow rate and the vat dilution rate based on detected variations between the respective actual values and target values for the entrained air level and vat level; and
generate control signals to the actuator associated with washer speed based on detected variations between the actual and target values for the vat level.
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