Control Loop Foundation: Batch and Continuous Processes reviews the fundamental principles of industrial process control in a clear and practical way. Designed for engineers, technicians and operators new to the field, this book explains how modern control systems monitor and regulate processes like temperature, flow, pressure and level using real-world plant examples, diagrams and hands-on web-based workshops. It covers measurement devices, final control elements (such as valves and drives), field wiring and communications, operator graphics, process characterization, single-loop PID control, tuning and an introduction to advanced model-predictive control.
The authors focus on practical skills rather than complex math. The chapters teach readers how to interpret standard plant documents (plot plans, PIDs, loop diagrams), and tune and test controllers and design operator interfaces for safety and efficiency. Interactive web exercises allow readers to run simulated processes, perform step tests and practice tuning controllers. This book also discusses control system goals, including economics, safety and environmental compliance and offers practical examples, such as boiler draft control and ammonia synthesis, to emphasize the importance of good control.
Table of Contents:
About the Authors ix
Foreword xvii
Chapter 1 INTRODUCTION 1
Chapter 2 BACKGROUND AND HISTORICAL PERSPECTIVE 7
2.1 Plant Structure, 7
2.2 Plant Organization, 10
2.3 Early Control Systems, 18
2.4 Distributed Control Systems (DCS), 22
2.5 Operator Interface, 27
2.6 System Installation, 30
2.7 External System Interfacing, 34
2.8 Modern Control Systems, 36
2.9 The Impact of Standards, 39
Chapter 3 MEASUREMENTS 45
3.1 Magnetic Flowmeter, 46
3.2 Vortex Flowmeter, 48
3.3 Flow Based on Differential Pressure, 50
3.4 Coriolis Mass Flowmeter, 53
3.5 Pressure Measurement, 54
3.6 Temperature Measurement, 55
3.7 Level Measurement, 57
3.8 Other Measurement Techniques, 59
Chapter 4 ON-LINE ANALYZERS 61
4.1 Sampling vs. In-situ Analyzers, 61
4.2 Flue Gas O2, 62
4.3 Liquid Stream pH and ORP, 65
4.4 On-line Estimator, 65
Chapter 5 FINAL CONTROL ELEMENTS 67
5.1 Regulating Valves, 67
5.2 Damper Drives, 75
5.3 Variable Speed Drives, 76
5.4 Blocking Valves, 77
Chapter 6 FIELD WIRING AND COMMUNICATIONS 79
6.1 Traditional Device Installation, 79
6.2 HART Device Installation, 81
6.3 Fieldbus Device Installation, 83
6.4 WirelessHART Installation, 85
Chapter 7 CONTROL AND FIELD INSTRUMENTATION DOCUMENTATION 89
7.1 Plot Plan, 90
7.2 Process Flow Diagram, 91
7.3 Piping and Instrumentation Diagram, 92
7.4 Loop Diagram, 96
7.5 Tagging Conventions, 99
7.6 Line and Function Symbols, 106
7.7 Equipment Representation, 109
7.8 Documentation Examples, 110
Chapter 8 OPERATOR GRAPHICS 117
8.1 Display of Alarm Conditions, 120
8.2 Dynamic Elements, 121
8.3 Displays, 122
8.4 Process Performance Monitoring, 124
8.5 Process Graphic Data Interfaces, 125
Chapter 9 PROCESS CHARACTERIZATION 127
9.1 Process Structure, 127
9.2 Process Definition, 130
9.3 Pure Gain Process, 136
9.4 Pure Delay Process, 138
9.5 Pure Lag Process, 142
9.6 First Order Plus Deadtime Process, 144
9.7 Integrating Process, 146
9.8 Inverse Response Process, 149
9.9 Process Linearity, 150
9.10 Workshop Exercises – Introduction, 152
9.11 Workshop – Process Characterization, 154
Chapter 10 CONTROL SYSTEM OBJECTIVES 159
10.1 Economic Incentive, 160
10.2 Safety, Environmental Compliance, Equipment Protection, 171
10.3 Balancing Complexity with Benefits, 173
Chapter 11 SINGLE-LOOP CONTROL 175
11.1 Manual Control, 175
11.2 Feedback Control, 191
11.3 PID Block Implementation, 204
11.4 Pulsed Outputs, 211
11.5 Process Action, 216
11.6 Workshop – Feedback Control, 217
Chapter 12 TUNING AND LOOP PERFORMANCE 221
12.1 Initial Loop Tuning, 221
12.2 Manual Tuning, 223
12.3 Automatically Establishing Tuning, 227
12.4 Commissioning – Sticky Valves and Other Field Challenges, 232
12.5 Characterizing Loop Gain, 237
12.6 Pairing of Parameters, Decoupling, 241
12.7 Workshop – PID Tuning, 243
12.8 Workshop Discussion, 245
Chapter 13 MULTI-LOOP CONTROL 247
13.1 Feedforward Control, 247
13.2 Cascade Control, 260
13.3 Override Control, 268
13.4 Control Using Two Manipulated Parameters, 275
Chapter 14 MODEL PREDICTIVE CONTROL 309
14.1 MPC Replacement of PID, 310
14.2 Commissioning MPC, 311
14.3 MPC Replacement for PID with Feedforward, 316
14.4 MPC Replacement for PID Override, 318
14.5 Using MPC to Address Process Interactions, 319
14.6 Layering MPC onto an Existing Strategy, 321
14.7 MPC Applications, 324
14.8 Workshop – Model Predictive Control, 324
Chapter 15 PROCESS SIMULATION 327
15.1 Process Simulation Techniques, 328
15.2 Developing a Process Simulation from the P&ID, 330
15.3 Simulating Process Non-linearity, 337
15.4 Other Considerations, 342
15.5 Workshop – Process Simulation, 343
Chapter 16 APPLICATIONS 347
16.1 Inventory Control, 347
16.2 Batch Processes, 352
16.3 Continuous Processes, 359
16.4 Combustion Control, 364
16.5 Distillation Control, 370
16.6 Coordination of Process Areas, 372
16.7 Difficult Dynamics, Process Interaction, 375
APPENDIX A 379
A.1 Accessing the Web Site, 380
A.2 Download Selection, 390
A.3 Book Selection, 390
GLOSSARY OF TERMS 391
INDEX 401
About the Author :
Terrence "Terry" Blevins has been actively involved in the application and design of process control systems throughout his career. For more than 15 years, he worked as a systems engineer and group manager in the design and startup of advanced control solutions for the pulp and paper industry. Terry was instrumental in the establishment of Emerson Process Management's Advanced Control Program. From 1998–2005, Terry was the team lead for the development of DeltaV advanced control products. He is the Fieldbus Foundation™ team lead for the development and maintenance of the Function Block Specification and editor of the SIS Architecture and Model Specifications. In this capacity, Terry is involved in the movement of Fieldbus Foundation function block work into international standards. Terry is the U.S. expert to the IEC SC65E WG7 function block committee that is responsible for the IEC 61804 function block standards. He is a voting member and chairman of ISA104-EDDL (Electronic Device Description Language) committee and is the technical advisor to the United States Technical Advisory Group (USTAG) for the IEC65E subcommittee. He is also a member of the USNC TAG (IEC/SC65 and IEC/TC65). Terry authored "An Overview of the ISA/IEC Fieldbus," Section 11, Standards Overview, Fifth Edition of the Process/Industrial Instruments and Controls Handbook and coauthored four sections in the Fourth Edition of the Instrumentation Engineer's Handbook, Process Control and Optimization. He coauthored the ISA bestselling book Advanced Control Unleashed. He has 36 patents and has written over 65 papers on process control system design and applications. Terry received a Bachelor of Science in Electrical Engineering from the University of Louisville in 1971 and a Master of Science in Electrical Engineering from Purdue University in 1973. In 2004, he was inducted into Control Magazine's Process Automation Hall of Fame. Presently, Terry is a principal technologist in the future architecture team of DeltaV Product Engineering at Emerson Process Management.
Mark Nixon has been involved in the design and development of control systems throughout his career. Mark started his career as a systems engineer working on projects in oil & gas, refining, chemicals, and pulp & paper. He moved from Canada to Austin, TX in 1998 where he has held a variety of positions in both research and development. From 1995–2005, Mark was lead architect for DeltaV. In 2006, he joined the wireless team, taking a very active role in the development of the ixWirelessHART specifications and the development of the IEC 62591 standardization. Mark's current research includes control using WirelessHART devices, data analytics for batch process, use of wireless technology the process industry, mobile users, operator interfaces, and advanced graphics. He is currently active in the Center for Operator Performance (http://www.operatorperformance.org), WirelessHART, ISA-88 standard, Foundation Fieldbus standards (http:// www.fieldbus.org/), and ISA-101 standard. He has written numerous papers and currently holds more than 45 patents. He coauthored WirelessHART: Real-Time Mesh Network for Industrial Automation and has made contributions to the Industrial Instruments and Controls Handbook and Essentials of Modern Measurements and Final Elements in the Process Industry. Mark received his Bachelor of Science in Electrical Engineering from the University of Waterloo in 1982.
