Exercises.............................................................................53
References ..........................................................................55
7 Optimizing Product Quality Performance.............57
Learning Objectives ...........................................................57
7.1 Quality Performance Measurement ..........................58
7.2 Frequency of Failure .................................................59
7.3 Optimize MRT between Distillate and Bottoms
Quality .......................................................................60
7.4 Avoid Excessive Use of Steam...................................62
7.5 Reduce Variability......................................................63
7.6 Optimize with Expert System Advisor .....................65
7.7 Summary....................................................................70
Exercises.............................................................................70
References ..........................................................................71
8 PID Feedback Control Loop...................................73
Learning Objectives ...........................................................73
8.1 The Feedback Control Loop .....................................74
8.2 Proportional Action ...................................................75
8.3 Integral Action ...........................................................76
8.4 Derivative Action ...................................................... 77
8.5 Parallel and Series Algorithms ................................. 77
8.6 Summary....................................................................78
Exercises.............................................................................78
Reference ............................................................................78
9 Closed-Loop Tuning of Controllers ........................79
Learning Objectives ...........................................................79
9.1 Trial-and-Error Tuning of Control Loops..................81
9.2 Ultimate Gain Tuning of Control Loops ...................82
9.3 Troubleshooting an Oscillating Control Loop ......... 84
9.4 Quarter Decay Ratio Tuning of Control Loops ........85
9.5 Pattern Recognition Tuning of Self-Regulating
Control Loops ........................................................... 86
9.6 Effect of Proportional Gain...................................... 90
9.7 Effect of Integral (Reset) Action ................................93
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