Chapter
1.5. Automation Functions Required for Batch
1.5.1. Basic Regulatory Control
1.5.2. Discrete Device Drivers
1.5.6. Production Control
1.6. Automation Equipment
1.6.3. Distributed Control System (DCS)
1.6.4. Programmable Logic Controller (PLC)
2: Measurement Considerations
2.1. Temperature Measurement
2.1.1. Resistance Temperature Detectors (RTDs)
2.1.5. Accuracy versus Repeatability
2.2. Pressure Measurement
2.2.3. Establishing Vacuum
2.2.4. Flow to Vacuum System
2.2.5. Pressure as a Function of Time
2.2.6. Valve Opening as a Function of Pressure
2.2.7. Leaking Agitator Seal
2.3.5. Material Transfers
2.3.6. Noise on Vessel Weight Measurement
2.3.7. Moving Average Filter
2.3.8. Vessel Weight during a Material Transfer
2.3.9. Least Squares Filter
2.4.4. Heating or Cooling Media Flows
2.4.5. Coriolis Meters versus Load Cells
2.5. Loss-in-Weight Application
2.5.2. Exponential Smoothing
2.5.3. Least Squares Filter
2.5.4. Control Alternatives
3: Continuous Control Issues
3.1. Loops That Operate Intermittently
3.1.3. Final Control Element Issues
3.1.4. Flow Measurement Issues
3.1.6. Windup in Flow Controller
3.2.2. Ascertaining That a Vessel Is Empty
3.2.3. Driving Force for Fluid Flow
3.3. Terminating a Co-Feed
3.3.1. Ratio to Master Flow Set Point
3.3.2. Terminating Master Flow But Not Co-feed Flows
3.4. Adjusting Ratio Targets
3.4.1. Interval for Taking Corrective Actions
3.4.2. Flow Meter Deemed to Be Most Accurate
3.4.3. Weight Measurement Deemed to Be Most Accurate
3.4.4. Compensating Ratio Targets
3.4.5. Flow Correction Factors
3.4.6. Terminate All Feeds at Same Time
3.5. Attaining Temperature Target for the Heel
3.5.1. Mixing Hot and Cold Fluids
3.5.2. Contribution of Vessel and Jacket
3.5.3. Two-Stage Addition of the Heel
3.6. Characterization Functions in Batch Applications
3.6.1. Throughput in a Batch Process
3.7. Scheduled Tuning in Batch Applications
3.7.1. Re-Tuning Controllers
3.7.2. Components of Scheduled Tuning
3.7.3. Limits of Scheduled Tuning
3.8. Edge of the Envelope
3.8.1. Behavior at the Edge of the Envelope
3.8.3. Invoking Windup Protection Other Than at the Output Limits
3.8.4. Recognizing Why Loops Cease to Function
3.9. No Flow Through Control Valve
3.10. No Pressure Drop across Control Valve
3.10.1. Flow through Control Valve
3.10.3. Windup Protection
3.10.4. Advantage of the Cascade Configuration
3.11. Attempting to Operate above a Process-Imposed Maximum
3.11.1. Maximum Cooling Rate
3.11.2. “Edge of the Envelope” for Control with Cooling Water Flow
3.11.4. Vessel Temperature to Cooling Water Temperature Rise Cascade
3.11.5. Vessel Temperature to Cooling Water Return Temperature Cascade
3.11.6. Consequences for Vessel Temperature
3.12. Attempting to Operate Below a Process-Imposed Minimum
3.12.2. Alternate Configuration
3.13.1. Jacket with Four Heating/Cooling Modes
3.13.3. Instrumentation Considerations
3.13.4. Implementing the Logic for Jacket Switching
3.14. Smooth Transitions between Heating and One Cooling Mode
3.14.2. Steam Heating; One Cooling Mode
3.14.3. Control Configuration
3.14.4. Split-Range Control Logic
3.14.5. Practical Considerations
3.14.6. Implementing Split Range
3.14.7. Exchanger Configurations
3.14.8. Control Valve on Steam Supply versus Condensate
3.14.10. Maximum Recirculation Water Temperature
3.15. Smooth Transitions between TWO COOLING MODES
3.15.1. Split-Range Logic
3.15.2. Getting the Most from the Available Glycol
3.15.3. Heat Addition By Tower Water Exchanger
3.15.4. Freezing in Tower Water Exchanger
3.15.5. Alternate Exchanger Configurations
3.15.6. Reactor Temperature Control
3.15.7. Issues Pertaining to Bypass
4.1.1. Normally Open/Normally Closed
4.2.1. Output Configurations
4.2.2. Latched Configurations
4.2.3. Momentary Configurations
4.2.4. Latched/Momentary Configurations
4.2.5. Role of Programmable Logic Controllers (PLCs)
4.3.2. Final Control Element States
4.3.4. Discrete Device Driver
4.3.5. Valves on a Piping Header
4.3.6. Ignoring a Limit Switch
4.4. Associated Functions
4.4.4. Local or Maintenance Mode
4.5. Beyond Two-State Final Control Elements
4.5.2. Three-State Devices
5.1. Multiple-Source, Single-Destination Material Transfer System
5.1.1. Key Characteristics
5.1.4. Impact on Production Operations
5.2. Single-Source, Multiple-Destination Material Transfer System
5.2.1. Key Characteristics
5.2.4. Impact on Production Operations
5.3. Multiple-Source, Multiple-Destination Material Transfer System
5.3.1. Key Characteristics
5.3.2. Pneumatic Conveyers
5.3.6. Impact on Production Operations
5.4. Validating a Material Transfer
5.4.1. Flow Measurement Issues
5.4.2. Transfer Amount from Vessel Weight
5.5.3. Single Positioning Valve
5.5.4. Dribble Flow for Solids
5.6. Simultaneous Material Transfers
6: Structured Logic for Batch
6.1. Structured Programming
6.1.1. Table-Driven Software
6.1.2. Structured Logic for Batch
6.2. Product Recipes and Product Batches
6.2.3. Standard Batch Size
6.3.1. Designating Materials
6.4.1. Parallel Operations within a Product Batch
6.4.2. Parallel Product Batches
6.4.3. Transitions from One Product to Another
6.5.1. Definition of Phases
6.5.3. List of Available Phases
6.5.4. Simple versus Complex Phases
7: Batch Unit or Process Unit
7.1. Defining a Batch Unit
7.1.1. Reactor with Three Feed Tanks
7.1.2. Complex Batch Units
7.2. Supporting Equipment
7.2.4. Implications for Phase Logic
7.2.5. Between Product Batches
7.3.1. Field Device States
7.3.3. Enhancements to Drum Timer
7.4. Failure Considerations
7.4.1. Indications of a Problem
7.4.3. Bypassing or Overriding Process Interlocks
7.4.4. Implementation of Process Interlocks
7.4.5. Discrete Logic Only
7.4.6. Discrete Device Driver Coupled with Discrete Logic
7.4.8. Implications for Sequence Logic
7.4.9. Failures Initiated by Momentary Events
7.6. Shared Equipment: Exclusive Use
7.7. Shared Equipment: Limited Capacity
7.8. Identical Batch Units
8.1. Features Provided by Sequence Logic
8.2. Failure Monitoring and Response
8.2.1. Normal Logic and Failure Logic
8.2.2. Defining the Requirements
8.2.4. Process Operator Issues
8.2.7. Avoiding False Failures
8.2.8. Field Device Transitions
8.3. Relay Ladder Diagrams
8.3.1. Gas-Fired Furnaces
8.3.2. Issues with Relay Ladder Diagrams
8.3.3. Issues with Electricians
8.4. Procedural Languages
8.4.3. Issues with Procedural Languages
8.5.1. Parsing Procedural Languages
8.5.2. Access to Real-Time Data
8.5.3. Avoiding Endless Loops
8.6.3. Excessive Number of States
8.7. Grafcet/Sequential Function Charts (SFCs)
8.7.1. Step-Transition-Step
8.7.2. Initial Step and Terminal Step
8.7.3. Divergent OR/Convergent OR
8.7.4. Divergent AND/Convergent AND
8.7.6. Discrete Logic Implementation
9.1. Organization of Recipes
9.1.1. Origin of Product Recipes
9.1.2. Organization of Product Recipes
9.1.3. Phases in an Operation
9.2.1. Tailoring Recipes to a Site
9.2.2. Versions of a Product Recipe
9.2.3. Issues with the Corporate Recipe
9.2.4. What Constitutes a Recipe
9.2.5. Getting a New Product into Production
9.3. Executing Product Batches Simultaneously
9.3.1. Separate Program for Each Product
9.3.2. Example from the Chemical Industry
9.3.3. Examples from Food Processing
9.4. Managing Product Batches
9.4.1. Duration of a Product Batch
9.4.2. Making a Product Batch
9.4.4. Opening a Product Batch
9.5. Executing Operations
9.5.1. Activating an Operation
9.5.2. State of an Operation
9.5.4. Consequences of the Hold Command
9.6.1. Issues with Backup Equipment
9.6.2. Data to be Collected
9.6.3. Retrieving Data for a Product Batch
9.6.4. Special Considerations for Batch
9.7. Performance Parameters
9.7.1. Product Profit Issues
9.7.2. Computing a Performance Parameter
Control of Batch Processes
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