Aeration Control System Design

THOMAS E. JENKINS, PE, is an owner and President of JenTech Inc., where he provides consultation services to the wastewater treatment industry, including control systems, aeration systems, energy conservation, blower systems, and process equipment design. He also cofounded Energy Strategies Corporation in 1984. Mr. Jenkins is a Professor of Practice in the Department of Civil and Environmental Engineering at the University of Wisconsin-Madison. He also teaches water and wastewater treatment classes in the University's Department of Engineering Professional Development.

• Preface xiAcknowledgments xiiiList of Figures xvList of Tables xxi1 Introduction 11.1 Basic Concepts and Objectives 21.2 Safety 91.3 The Importance of an Integrated Approach 101.4 Importance of Operator Involvement 131.5 The Benefits of Successful Aeration Process Automation 14Example Problems 192 Initial System Assessment 212.1 Define Current Operations 242.2 Evaluate Process and Equipment 372.3 Benchmark Performance 402.4 Estimate Potential Energy Savings and Performance Improvement 422.5 Prepare Report 45Example Problems 473 Aeration Processes 493.1 Process Fundamentals 493.2 Loading Variations and Their Implications 683.3 Process Limitations and Their Impact on Control Systems 70Example Problems 744 Mechanical and Diffused Aeration Systems 774.1 Oxygen Transfer Basics 784.2 Types of Aerators 874.3 Savings Determinations 106Example Problems 1115 Blowers and Blower Control 1135.1 Common Application and Selection Concerns 1145.2 Positive Displacement Blowers and Control Characteristics 1345.3 Dynamic Blowers 143Example Problems 1576 Piping Systems 1616.1 Design Considerations 1626.2 Pressure Drop 1786.3 Control Valve Selection 182Example Problems 1877 Instrumentation 1917.1 Common Characteristics and Electrical Design Considerations 1927.2 Pressure 2027.3 Temperature 2057.4 Flow 2097.5 Analytic Instruments 2167.6 Motor Monitoring and Electrical Measurements 2247.7 Miscellaneous 226Example Problems 2308 Final Control Elements 2338.1 Valve Operators 2348.2 Guide Vanes 2388.3 Motor Basics 2398.4 Motor Control 2478.5 Variable Frequency Drives 251Example Problems 2599 Control Loops and Algorithms 2619.1 Control Fundamentals 2649.2 Dissolved Oxygen Control 2809.3 Aeration Basin Air Flow Control 2879.4 Pressure Control 2889.5 Most-Open-Valve Control 2919.6 Blower Control and Coordination 2939.7 Control Loop Timing Considerations 3029.8 Miscellaneous Controls 303Example Problems 30510 Control Components 30910.1 Programmable Logic Controllers 31010.2 Distributed Control Systems 32310.3 Human Machine Interfaces 32310.4 Control Panel Design Considerations 328Example Problems 33011 Documentation 33311.1 Specification Considerations 33511.2 Data Lists 33811.3 Process and Instrumentation Diagrams 34111.4 Ladder and Loop Diagrams 34211.5 One-Line Diagrams 34411.6 Installation Drawings 34511.7 Loop Descriptions 34711.8 Operation and Maintenance Manuals 348Example Problems 34912 Commissioning 35112.1 Inspection 35412.2 Testing 35712.3 Tuning 36112.4 Training 36512.5 Measurement and Verification of Results 368Example Problems 36913 Summary 37113.1 Review of Integrated Design Procedure 37113.2 Potential Problem Areas 37413.3 Benefits 375Example Problems 375Appendix A: Example Problem Solutions 377Appendix B: List of Equations and Variables 447Bibliography 485Index 487