US 12,077,911 B2 · Predictive control system and method for brown washing treatment in pulp mills

Abstract

A system and method are provided for predictive control of brown stock treatment at a pulp mill. Various online sensors generate output signals representative of actual values for respective process characteristics, each of which are directly or indirectly affected by adjustments to corresponding process variables. A controller uses the output signals or associated measurement data to dynamically set target values for the process characteristics based on a predicted impact of control responses for corresponding process variables. The controller further generates control signals to actuators associated with the respective process variables based on detected variations between the respective actual values and target values. Exemplary brown stock washing control systems may optimize various types of brown stock washing configurations, including for example vacuum drum washers, compaction baffle washers, chemiwashers, direct displacement washers and wash presses. Cloud-based analytics and machine learning may also be implemented to improve the control algorithms over time.

Claims11

Dependent claims

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.

3 more elements

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.

5 more elements

Dependencies are inferred from the claim text.

Predictive control system and method for brown washing treatment in pulp mills

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Predictive control system and method for brown washing treatment in pulp mills

Life of this patent

Abstract

Claims11