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CIMExcel Software Inc. Slide 1

Advanced Drystock Control (ADC) to reduce the ‘residual’ basis weight, moisture, and caliper profiles. CIMExcel Software Inc. Control Systems Engineering company located in Vancouver, Canada. Provides Simulators, Advanced Control and Optimization Systems for, Pulp and Paper Industry

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CIMExcel Software Inc. Slide 1

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  1. Advanced Drystock Control (ADC) • to reduce the ‘residual’ basis weight, moisture, and caliper profiles • CIMExcel Software Inc. • Control Systems Engineering company located in Vancouver, Canada. • Provides Simulators, Advanced Control and Optimization Systems for, • Pulp and Paper Industry • Energy and Power Industry • Mineral Processing Industry • Nuclear Industry • Pulp and Paper: • Advanced Paper Machine Control (APMC) • Roll Quality Optimization (RQO) and Trim Optimization • Pulp Quality Analysis (PQA) • Advanced Boiler Control (ABC) • Energy Management System (EMS) CIMExcel Software Inc. Slide 1

  2. Space - Time Control of Paper Machine • Basis Weight, Moisture, Caliper and Coat Weight • Advanced Paper Machine Control (APMC) significantly reduces the variability of basis weight, moisture, caliper and coat weight for all grades and speeds. • APMC improves grade transition performance. • APMC consists of two parts, • Advanced Drystock Control (ADC) for MD Control • Modal Profile Control (MPC) for CD Control • Advanced Drystock Control (ADC) consists of two parts, • ADC - Thickstock • ADC - Thinstock CIMExcel Software Inc. Slide 2

  3. Space - Time Control of Paper Machine • Basis Weight, Moisture, Caliper and Coat Weight unconditioned CD Scans ‘flat’ actuators ‘Residual’ CD Reel average CD improvement ~ 0.55 % total improvement ~ 1.27 % ‘optimized’ actuators • The ‘noisy / residual’ CD scans are actually aliased MD variability which is within the scanner scanning time. • Approximately 80-90 % of the variability of headbox consistency and total head is in the 2 - 50 second range, • and 30-60 % of this variability is in the 2 - 5 second range, and is completely aliasing the scanner CD profile. • Feedforward ADC (thinstock and thickstock) is required in order to reduce the ‘residual’ CD profile. CIMExcel Software Inc. Slide 3

  4. MD to CD Aliasing Problem and Variability Analysis • strong correlation of short term (2 – 5 seconds) variability spatially filtered single point scanner operation 8 scan average 100 boxes 8 scan average 100 boxes headbox consistency 8 scan average 100 boxes 30 scan average 440 boxes headbox total head ~ 50 second CD scan time ~ 50 seconds CIMExcel Software Inc. Slide 4

  5. Variability Analysis Single Point Dry Weight (gsm) Time Series Data (sampled at 1 cps) Power Spectrum Highest Frequency (0.5 cps, 2 second period) Lowest Frequency (0.000116 cps, 832 second period) Recirculation Flow Control 2 – 3 second period (0.33 – 0.50 cps) Possible Wet-End Sources Total Head Control 6 – 3 second period (0.17 – 0.33 cps) Headbox Consistency Control 6 – 15 second period (0.07 – 0.17 cps) Drystock Feedforward Control 15 – 25 second period (0.04 – 0.07 cps) Drystock Feedback Control 25 – 250 second period (0.004 – 0.04 cps) CIMExcel Software Inc. Slide 5

  6. Variability Analysis (for variables with 2 - 50 second periods of variation - within the CD scanning time) MD Variables Thinstock Variables Thickstock Variables • Size Press / Reel Basis Weight • Size Press / Reel Dry Weight • Coater Basis Weight • Rush - Drag • Vertical Slice • Horizontal Slice • Press Section PLI • Couch Pressure • Scanner Beta Signal • Scanner IR Signals • Scanner Basis Weight • Scanner Dry Weight • Scanner Moisture • Scanner Water • Basis Weight Valve • Furnish LD Consistency • Furnish LD Dilution Valve • Broke Chest Consistency • Broke Chest Dilution Valve • Blend Chest Consistency • Blend Chest Dilution Valve • Machine Chest Consistency • Machine Chest Dilution Valve • Stuff Box Consistency • Thickstock Consistency • Total Head • Headbox Consistency • Front-Back Differential Pressure • Stream Valve • Stream Flow • Stock Flow • Cleaner Reject Flows • Screen Reject Flow • Fan Pump Speed CIMExcel Software Inc. Slide 6

  7. Performance Analysis Toolkit for Variability Analysis of MD, Thinstock and Thickstock Variables High Speed NI-DAQ Time Series Analysis Power Spectral Analysis Backlash - Transport Signal Processing and Filtering CIMExcel Software Inc. Slide 7

  8. Advanced Drystock Control Advanced Drystock Control signal analysis multi-actuator response coordination and optimization Feedforward Control: Headbox Consistency Total Head Thinstock Flows Thinstock Consistencies Thickstock Flows Thickstock Consistency Main Dilution Individual Dilution Main Slice Individual Actuators Basis Weight Valve New Devices CIMExcel Software Inc. Slide 8

  9. Advanced Drystock Control - Thickstock transport model, backlash compensator, discrete time control, additives and consistency feedforward • requires high speed data acquisition and signal processing equipment. • requires some instrumentation - control device, and possible process reconfiguration. • new thickstock control programming and tuning services. CIMExcel Software Inc. Slide 9

  10. Advanced Drystock Control - Thinstock Advanced Drystock Control consistency feedforward transport multi actuator response optimization Main Dilution Individual Dilution Main Slice Individual Actuators New Devices Headbox Consistency Total Head Thinstock Flows Thinstock Consistencies • Requires an optical thinstock consistency transmitter strategically located on the headbox approach. • Requires high speed data acquisition and signal processing equipment. • Thinstock and headbox analysis and control tuning services. • Identification of process related variability. • Possible process-related variability reduction solutions. • Response analysis testing of potential actuators. • Possible process equipment and control additions. • Coordination and optimization of multiple actuators. • Scanner single point operation required for tuning and optimization. CIMExcel Software Inc. Slide 10

  11. Scanner Basis Weight βSignal Corrections • The scanner basis weight β voltage has a noisy and lagged response as shown in the above displays. • Some scanner β noise filtering be may be applied which increases the scanner basis/dry weight response lag. • For a scanner CD speed of 20 cm/s, • the lagged response (without filtering) affects 4 cm of the basis/dry weight CD width and needs to be corrected, • the lagged response (with filtering) affects 10 cm of the basis/dry weight CD width and needs to be corrected. • In single point mode, some attenuation will occur for the 2.0 second period basis/dry weight variability. CIMExcel Software Inc. Slide 11

  12. Advanced Drystock Control Project Activities to reduce the ‘residual’ basis weight, moisture, and caliper profiles • Overview Analysis and Report - Proposal • > Scanner Signal Analysis and Correction. • > Scanner MD-CD Basis Weight , Dry Weight, and Water baseline performance. • > Survey of Thinstock, Thickstock Instrumentation, DCS Loops and Control Devices. • > Thinstock and Thickstock Variability Analysis. • > Thickstock Control Device Analysis. • > Thinstock Control Device Analysis. • 2. Thickstock - Detailed Analysis, Design, and Report • 3. Thickstock - ADC System (PC-> DCS) • 4. Thinstock - Detailed Analysis, Design, and Report • 5. Thinstock - ADC System (PC -> DCS) CIMExcel Software Inc. Slide 12

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