The Design and Layout of Vertical Thermosyphon Reboilers
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 THE DESIGN PROBLEM
5 COMPUTER PROGRAMS
6 GENERAL CONSIDERATIONS
6.1 Heating Medium Temperature
6.2 Fouling Resistance
7 DESIGN PARAMETERS
7.1 Overall Arrangement and Specifications
7.2 Geometry Elements
8 ANALYSIS OF COMMERCIALLY AVAILABLE
PROGRAM RESULTS
8.1 Main Results
8.2 Supplementary Results
8.3 Error Analysis
8.4 Adjustments to Design
9 OPERATING RANGE
10 CONTROL
10.1 Control of Condensing Heating Medium Pressure
10.2 Control of The Condensate Level
10.3 Control of Sensible Fluid Flow Rate
11 LAYOUT
11.1 Factors Influencing Design
11.2 A Standard Layout
12 BIBLIOGRAPHY
Low Temperature Shift Catalyst Reduction Procedure
VSG-C111 as supplied contains copper oxide; it is activated for the low temperature shift duty by reducing the copper oxide component to metallic copper with hydrogen. The reaction is highly exothermic. In order to achieve maximum activity, good performance and long life, it is essential that the reduction is conducted under correctly controlled conditions. Great care must be taken to avoid thermal damage during this critical operation.
This document describes gas sweetening processes used to remove acid gases like H2S and CO2 from natural gas. It focuses on chemical absorption processes using alkanolamine solvents like MEA, DGA, DEA, and MDEA in aqueous solutions. The general process involves absorbing acid gases from the feed gas in an absorber column, regenerating the solvent in a regenerator column, and recycling the regenerated solvent. Key unit operations discussed include the absorber, flash drum, amine/amine heat exchanger, regenerator, reboiler, and condenser. Process conditions and equipment details are provided for the typical operation of each unit.
This document summarizes the key steps in designing liquid pipelines according to API 14E standards. It discusses important considerations like ensuring velocity is below 15 feet per second to avoid erosion and pressure drop is below 1 psi per 100 feet. The document then provides an example calculation for sizing a water pipeline using schedule 40 and 80 steel pipes. It determines that an 8-inch schedule 40 pipe meets both velocity and pressure drop requirements and has the lowest annual operating costs.
This presentation summarizes the hydrotreating process. Hydrotreating reduces sulfur, nitrogen and aromatics in petroleum feeds using hydrogen. It has various applications including desulfurizing naphtha, kerosene, gas oil and fuel oils. The process involves reacting feeds over catalysts in fixed beds to hydrogenate contaminants like sulfur, nitrogen and olefins. Typical hydrotreating removes these through reactions like desulfurization and denitrogenation. The presentation describes specific hydrotreating processes for distillate desulfurization and kerosene smoke point improvement.
Low Temperature Shift Catalyst Reduction Procedure
VSG-C111 as supplied contains copper oxide; it is activated for the low temperature shift duty by reducing the copper oxide component to metallic copper with hydrogen. The reaction is highly exothermic. In order to achieve maximum activity, good performance and long life, it is essential that the reduction is conducted under correctly controlled conditions. Great care must be taken to avoid thermal damage during this critical operation.
This document describes gas sweetening processes used to remove acid gases like H2S and CO2 from natural gas. It focuses on chemical absorption processes using alkanolamine solvents like MEA, DGA, DEA, and MDEA in aqueous solutions. The general process involves absorbing acid gases from the feed gas in an absorber column, regenerating the solvent in a regenerator column, and recycling the regenerated solvent. Key unit operations discussed include the absorber, flash drum, amine/amine heat exchanger, regenerator, reboiler, and condenser. Process conditions and equipment details are provided for the typical operation of each unit.
This document summarizes the key steps in designing liquid pipelines according to API 14E standards. It discusses important considerations like ensuring velocity is below 15 feet per second to avoid erosion and pressure drop is below 1 psi per 100 feet. The document then provides an example calculation for sizing a water pipeline using schedule 40 and 80 steel pipes. It determines that an 8-inch schedule 40 pipe meets both velocity and pressure drop requirements and has the lowest annual operating costs.
This presentation summarizes the hydrotreating process. Hydrotreating reduces sulfur, nitrogen and aromatics in petroleum feeds using hydrogen. It has various applications including desulfurizing naphtha, kerosene, gas oil and fuel oils. The process involves reacting feeds over catalysts in fixed beds to hydrogenate contaminants like sulfur, nitrogen and olefins. Typical hydrotreating removes these through reactions like desulfurization and denitrogenation. The presentation describes specific hydrotreating processes for distillate desulfurization and kerosene smoke point improvement.
The document outlines 11 steps for sizing a pipe line to carry water at 100 m3/hr, including: calculating the internal pipe diameter, selecting the nearest available pipe size, determining the fluid velocity, calculating the Reynolds number and friction factor, determining equivalent length, calculating pressure drop, and comparing the available and calculated pressure drops. The goal is to select a pipe size that ensures the available pressure drop is greater than the calculated pressure drop.
Design and Simulation of Continuous Distillation ColumnsGerard B. Hawkins
Design and Simulation of Continuous Distillation Columns
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 FRACTIONAL DISTILLATION
5 ROUGH METHOD OF COLUMN DESIGN
5.1 Sharp Separations
5.2 Sloppy Separations
6 DETAIL DESIGN USING THE CHEMCAD DISTILLATION PROGRAM
6.1 Sharp Separations
6.2 Sloppy Separations
7 COMPLEX COLUMNS
7.1 Multiple Feeds
7.2 Sidestream Take-Offs
8 DESIGN USING A LABORATORY COLUMN
SIMULATION
9 DESIGN USING ACTUAL PLANT DATA
9.1 Uprating or Debottlenecking Exercises
10 REFERENCES
APPENDICES
A WORKED EXAMPLE
B SLOPPY SEPARATIONS
C SIMULATION USING PLANT DATA : CASE HISTORIES
TABLES
101 Things That Can Go Wrong on a Primary Reformer - Best Practices GuideGerard B. Hawkins
This document discusses common problems that can occur in primary reformers and associated equipment. It identifies issues that can lead to plant shutdowns or efficiency losses, grouping them under catalysts, tubes, furnace boxes, burners, flue gas ducts, headers, and refractories. Some examples discussed include carbon formation, tube overheating, flame impingement, leaks in air preheaters, combustion air maldistribution, and damage to coffins. The document provides an overview of these issues to improve plant reliability over its lifespan.
This document summarizes a technical seminar on thermosyphon reboilers and their operational characteristics. It begins with an introduction to reboilers and thermosyphon reboilers. It then discusses the working principles and types of thermosyphon reboilers, including vertical and horizontal designs. The document reviews the operational characteristics of thermosyphon reboilers and how they are influenced by factors like temperature difference, operating pressure, and pipe diameter. It also compares advantages and disadvantages of vertical and horizontal designs. Finally, it discusses common industrial applications of thermosyphon reboilers and concludes with a summary of key points and references.
Amine Gas Treating Unit - Best Practices - Troubleshooting Guide Gerard B. Hawkins
Amine Gas Treating Unit Best Practices - Troubleshooting Guide for H2S/CO2 Amine Systems
Contents
Process Capabilities for gas treating process
Typical Amine Treating
Typical Amine System Improvements
Primary Equipment Overview
Inlet Gas Knockout
Absorber
Three Phase Flash Tank
Lean/Rich Heat Exchanger
Regenerator
Filtration
Amine Reclaimer
Operating Difficulties Overview
Foaming
Failure to Meet Gas Specification
Solvent Losses
Corrosion
Typical Amine System Improvements
Degradation of Amines and Alkanolamines during Sour Gas Treating
APPENDIX
Best Practices - Troubleshooting Guide
Centrifugal Compressors
SECTION ONE - ANTI-SURGE PROTECTION AND THROUGHPUT REGULATION
0 INTRODUCTION
1 SCOPE
2 MACHINE CHARACTERISTICS
2.1 Characteristics of a Single Compressor Stage
2.2 Characteristic of a Multiple Stage Having More
Than One Impeller
2.3 Use of Compressor Characteristics in Throughput
Regulation Schemes
3 MECHANISM AND EFFECTS OF SURGE
3.1 Basic Flow Instabilities
3.2 Occurrence of Surge
3.3 Intensity of Surge
3.4 Effects of Surge
3.5 Avoidance of Surge
3.6 Recovery from Surge
4 CONTROL SCHEMES INCLUDING SURGE PROTECTION
4.1 Output Control
4.2 Surge Protection
4.3 Surge Detection and Recovery
5 DYNAMIC CONSIDERATIONS
5.1 Interaction
5.2 Speed of Response of Antisurge Control System
6 SYSTEM EQUIPMENT SPECIFICATIONS
6.1 The Antisurge Control Valve
6.2 Non-return Valve
6.3 Pressure and flow measurement
6.4 Signal transmission
6.5 Controllers
7 TESTING
7.1 Determination of the Surge Line
7.2 Records
8 INLET GUIDE VANE UNITS
8.1 Application
8.2 Effect on Power Consumption of the Compressor
8.3 Effect of Gas Conditions, Properties and Contaminants
8.4 Aerodynamic Considerations
8.5 Control System Linearity
8.6 Actuator Specification
8.7 Avoidance of Surge
8.8 Features of Link Mechanisms
8.9 Limit Stops and Shear Links
APPENDICES
A LIST OF SYMBOLS AND PREFERRED UNITS
B WORKED EXAMPLE 1 COMPRESSOR WITH VARIABLE INLET PRESSURE AND VARIABLE GAS COMPOSITION
C WORKED EXAMPLE 2 A CONSTANT SPEED ~ STAGE COMPRESSOR WITH INTER-COOLING
D WORKED EXAMPLE 3 DYNAMIC RESPONSE OF THE ANTISURGE PROTECTION SYSTEM FOR A SERVICE AIR COMPRESSOR RUNNING AT CONSTANT SPEED
E EXAMPLE OF INLET GUIDE VANE REGULATION
FIGURES
2.1 TYPICAL COMPRESSOR STAGE CHARACTERISTIC PLOTTED WITH FLOW AT DISCHARGE CONDITIONS
2.2 TYPICAL COMPRESSOR STAGE CHARACTERISTIC PLOTTED WITH FLOW AT INLET CONDITIONS
2.3 PERFORMANCE CHARACTERISTICS OF A COMPRESSOR STAGE AT VARYING SPEEDS
2.4 SYSTEM WORKING POINT DEFINED BY INTERSECTION OF PROCESS AND COMPRESSOR CHARACTERISTICS
2.5 DISCHARGE THROTTLE REGULATION
2.6 BYPASS REGULATION
2.7 INLET THROTTLE REGULATION
2.8 INLET GUIDE VANE REGULATION
2.9 VARIABLE SPEED REGULATION
3.1 GAS PULSATION LEVELS FOR A CENTRIFUGAL COMPRESSOR
3.2 REPRESENTATION OF CYCLIC FLOW DURING SURGE OF LONG PERIOD
3.3 TYPICAL WAVEFORM OF DISCHARGE PRESSURE DURING SURGE
3.4 MULTIPLE SURGE LINE FOR A MULTISTAGE CENTRIFUGAL COMPRESSOR
3.5 TYPICAL MULTIPLE SURGE LINES FOR SINGLE STAGE AXIAL-FLOW COMPRESSOR
4.1 GENERAL SCHEMATIC FOR COMPRESSORS OPERATING IN PARALLEL TO FEED MULTIPLE USER PLANTS
4.2 ILLUSTRATION OF SAFETY MARGIN BETWEEN SURGE POINT AND SURGE PROTECTION POINT AT WHICH ANTISURGE SYSTEM IS ACTIVATED
4.3 ANTISURGE SYSTEM FOR COMPRESSOR WITH FLAT PERFO ..........
This document discusses catalytic reforming and isomerization processes. Catalytic reforming transforms C7-C10 hydrocarbons with low octane numbers into aromatics and iso-paraffins with high octane numbers. It is a highly endothermic process. Isomerization is a mildly exothermic process that increases octane number by changing hydrocarbon structure. Reactions involved in reforming include naphthene dehydrogenation, paraffin dehydrogenation, dehydrocyclization, isomerization, and hydrocracking. Thermodynamics, reaction kinetics, and catalyst selection influence process conditions and product distribution. Common reforming technologies are semi-regenerative fixed bed and continuous regenerative moving bed processes.
DESIGN OF VENT GAS COLLECTION AND DESTRUCTION SYSTEMS Gerard B. Hawkins
DESIGN OF VENT GAS COLLECTION AND DESTRUCTION SYSTEMS
CONTENTS
1 INTRODUCTION
1.1 Purpose
1.2 Scope of this Guide
1.3 Use of the Guide
2 ENVIRONMENTAL ISSUES
2.1 Principal Concerns
2.2 Mechanisms for Ozone Formation
2.3 Photochemical Ozone Creation Potential
2.4 Health and Environmental Effects
2.5 Air Quality Standards for Ground Level Concentrations of Ozone, Targets for Reduction of VOC Discharges and Statutory Discharge Limits
3 VENTS REDUCTION PHILOSOPHY
3.1 Reduction at Source
3.2 End-of-pipe Treatment
4 METHODOLOGY FOR COLLECTION & ASSESSMENT OF PROCESS FLOW DATA
4.1 General
4.2 Identification of Vent Sources
4.3 Characterization of Vents
4.4 Quantification of Process Vent Flows
4.5 Component Flammability Data Collection
4.6 Identification of Operating Scenarios
4.7 Quantification of Flammability Characteristics for Combined Vents
4.8 Identification, Quantification and Assessment of Possibility of Air Ingress Routes
4.9 Tabulation of Data
4.10 Hazard Study and Risk Assessment
4.11 Note on Aqueous / Organic Wastes
4.12 Complexity of Systems
4.13 Summary
5 SAFE DESIGN OF VENT COLLECTION HEADER SYSTEMS
5.1 General
5.2 Process Design of Vent Headers
5.3 Liquid in Vent Headers
5.4 Materials of Construction
5.5 Static Electricity Hazard
5.6 Diversion Systems
5.7 Snuffing Systems
6 SAFE DESIGN OF THERMAL OXIDISERS
6.1 Introduction
6.2 Design Basis
6.3 Types of High Temperature Thermal Oxidizer
6.4 Refractories
6.5 Flue Gas Treatment
6.6 Control and Safety Systems
6.7 Project Program
6.8 Commissioning
6.9 Operational and Maintenance Management
APPENDICES
A GLOSSARY
B FLAMMABILITY
C EXAMPLE PROFORMA
D REFERENCES
DOCUMENTS REFERRED TO IN THIS PROCESS GUIDE
TABLE
1 PHOTOCHEMICAL OZONE CREATION POTENTIAL REFERENCED
TO ETHYLENE AS UNITY
FIGURES
1 SCHEMATIC OF TYPICAL VENT COLLECTION AND THERMAL OXIDIZER SYSTEM
2 TYPICAL KNOCK-OUT POT WITH LUTED DRAIN
3 SCHEMATIC OF DIVERSION SYSTEM
4 CONVENTIONAL VERTICAL THERMAL OXIDIZER
5 CONVENTIONAL OXIDIZER WITH INTEGRAL WATER SPARGER
6 THERMAL OXIDIZER WITH STAGED AIR INJECTION
7 DOWN-FIRED UNIT WITH WATER BATH QUENCH
8 FLAMELESS THERMAL OXIDATION UNIT
9 THERMAL OXIDIZER WITH REGENERATIVE HEAT RECOVERY
10 TYPICAL PROJECT PROGRAM
11 TYPICAL FLAMMABILITY DIAGRAM
12 EFFECT OF DILUTION WITH AIR
13 EFFECT OF DILUTION WITH AIR ON 100 Rm³ OF FLAMMABLE GAS
This document summarizes different processes for removing carbon dioxide from ammonia plant streams. It discusses why CO2 removal is important, and describes common processes like MEA and MDEA absorption. The Benfield process uses hot potassium carbonate solution promoted by diethanolamine to physically absorb CO2. Issues with the Benfield process include foaming, corrosion, and vanadation problems. Retrofitting with a new amine promoter called LRS 10 can improve CO2 removal efficiency and reduce energy costs for the Benfield process.
Air Cooled Heat Exchanger Design
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 SUITABILITY FOR AIR COOLING
4.1 Options Available For Cooling
4.2 Choice of Cooling System
5 SPECIFICATION OF AN AIR COOLED HEAT
EXCHANGER
5.1 Description and Terminology
5.2 General
5.3 Thermal Duty and Design Margins
5.4 Process Pressure Drop
5.5 Design Ambient Conditions
5.6 Process Physical Properties
5.7 Mechanical Design Constraints
5.8 Arrangement
5.9 Air Side Fouling
5.10 Economic Factors in Design
6 CONTROL
7 PRESSURE RELIEF
8 ASSESSMENT OF OFFERS
8.1 General
8.2 Manual Checking Of Designs
8.3 Computer Assessment
8.4 Bid Comparison
9 FOULING AND CORROSION
9.1 Fouling
9.2 Corrosion
10 OPERATION AND MAINTENANCE
10.1 Performance Testing
10.2 Air-Side Cleaning
10.3 Mechanical Maintenance
10.4 Tube side Access
11 REFERENCES
Steam Reformer Surveys - Techniques for Optimization of Primary Reformer Oper...Gerard B. Hawkins
Introduction
Background Radiation and Temperature Measurement
Reformer Survey Inputs
Other Troubleshooting Tools
Safety
Preparation
Onsite Data Collection
TWT Survey
Observation/Troubleshooting
Modelling and Analysis
Results/Outputs
Case Studies
Conclusions
Case Study 1
Case Study 2
Case Study 3
Conclusions
This document provides an overview of equipment sizing and costing procedures for chemical process design. It discusses shortcuts for sizing common equipment like vessels, reactors, heat exchangers, distillation columns, and more. It also covers Guthrie's modular cost estimation method, which estimates the bare module cost of equipment based on sizing parameters, material factors, and other adjustments. The document is intended to help chemical engineers quickly size key process equipment and generate preliminary capital cost estimates during early design stages.
The document discusses air cooled heat exchangers. It describes how air cooled heat exchangers work by using air as the cooling medium, making them useful when water supply is limited. The document outlines the main components of air cooled heat exchangers, including axial fans, tube bundles, headers, fins and nozzles. It also discusses types of fans, headers, fins, factors that affect performance like fouling, and considerations for inspection and design of air cooled heat exchangers.
Study 2: Front-End Engineering Design and Project DefinitionGerard B. Hawkins
Study 2: Front-End Engineering Design and Project Definition
CONTENTS
2.0 PURPOSE
2.0.1 Team
2.0.2 Timing
2.0.3 Documentation
HAZARD STUDY 2: APPLICATION
2.1 Study of Process and Non-Process Activities
2.2 Study of Programmable Electronic Systems (PES)
2.3 Risk Assessment
2.4 Defining the Basis for Safe Operation
2.5 Review of Hazard Study 2
APPENDICES
Appendix A Hazard Study 2 Method
A.1 Significant Hazards Flowsheet
A.2 Event Guide Diagram
A.3 Consequence Guide Diagram
A.4 Typical Measures to Reduce Consequences
Appendix B Programmable Electronic Systems (PES) Guide Diagram
Appendix C Risk Assessment
C.1 Risk Assessment Procedure
C.2 Risk Matrix
C.3 Risk Matrix Guidance for Consequence Categories – Safety and Health Incidents
C.4 Risk Matrix Guidance for Consequence Categories – Environmental Incidents
Appendix D Key Hazards and Control Measures
Appendix E Content of Hazard Study 2 Report Package.
The document outlines 11 steps for sizing a pipe line to carry water at 100 m3/hr, including: calculating the internal pipe diameter, selecting the nearest available pipe size, determining the fluid velocity, calculating the Reynolds number and friction factor, determining equivalent length, calculating pressure drop, and comparing the available and calculated pressure drops. The goal is to select a pipe size that ensures the available pressure drop is greater than the calculated pressure drop.
Design and Simulation of Continuous Distillation ColumnsGerard B. Hawkins
Design and Simulation of Continuous Distillation Columns
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 FRACTIONAL DISTILLATION
5 ROUGH METHOD OF COLUMN DESIGN
5.1 Sharp Separations
5.2 Sloppy Separations
6 DETAIL DESIGN USING THE CHEMCAD DISTILLATION PROGRAM
6.1 Sharp Separations
6.2 Sloppy Separations
7 COMPLEX COLUMNS
7.1 Multiple Feeds
7.2 Sidestream Take-Offs
8 DESIGN USING A LABORATORY COLUMN
SIMULATION
9 DESIGN USING ACTUAL PLANT DATA
9.1 Uprating or Debottlenecking Exercises
10 REFERENCES
APPENDICES
A WORKED EXAMPLE
B SLOPPY SEPARATIONS
C SIMULATION USING PLANT DATA : CASE HISTORIES
TABLES
101 Things That Can Go Wrong on a Primary Reformer - Best Practices GuideGerard B. Hawkins
This document discusses common problems that can occur in primary reformers and associated equipment. It identifies issues that can lead to plant shutdowns or efficiency losses, grouping them under catalysts, tubes, furnace boxes, burners, flue gas ducts, headers, and refractories. Some examples discussed include carbon formation, tube overheating, flame impingement, leaks in air preheaters, combustion air maldistribution, and damage to coffins. The document provides an overview of these issues to improve plant reliability over its lifespan.
This document summarizes a technical seminar on thermosyphon reboilers and their operational characteristics. It begins with an introduction to reboilers and thermosyphon reboilers. It then discusses the working principles and types of thermosyphon reboilers, including vertical and horizontal designs. The document reviews the operational characteristics of thermosyphon reboilers and how they are influenced by factors like temperature difference, operating pressure, and pipe diameter. It also compares advantages and disadvantages of vertical and horizontal designs. Finally, it discusses common industrial applications of thermosyphon reboilers and concludes with a summary of key points and references.
Amine Gas Treating Unit - Best Practices - Troubleshooting Guide Gerard B. Hawkins
Amine Gas Treating Unit Best Practices - Troubleshooting Guide for H2S/CO2 Amine Systems
Contents
Process Capabilities for gas treating process
Typical Amine Treating
Typical Amine System Improvements
Primary Equipment Overview
Inlet Gas Knockout
Absorber
Three Phase Flash Tank
Lean/Rich Heat Exchanger
Regenerator
Filtration
Amine Reclaimer
Operating Difficulties Overview
Foaming
Failure to Meet Gas Specification
Solvent Losses
Corrosion
Typical Amine System Improvements
Degradation of Amines and Alkanolamines during Sour Gas Treating
APPENDIX
Best Practices - Troubleshooting Guide
Centrifugal Compressors
SECTION ONE - ANTI-SURGE PROTECTION AND THROUGHPUT REGULATION
0 INTRODUCTION
1 SCOPE
2 MACHINE CHARACTERISTICS
2.1 Characteristics of a Single Compressor Stage
2.2 Characteristic of a Multiple Stage Having More
Than One Impeller
2.3 Use of Compressor Characteristics in Throughput
Regulation Schemes
3 MECHANISM AND EFFECTS OF SURGE
3.1 Basic Flow Instabilities
3.2 Occurrence of Surge
3.3 Intensity of Surge
3.4 Effects of Surge
3.5 Avoidance of Surge
3.6 Recovery from Surge
4 CONTROL SCHEMES INCLUDING SURGE PROTECTION
4.1 Output Control
4.2 Surge Protection
4.3 Surge Detection and Recovery
5 DYNAMIC CONSIDERATIONS
5.1 Interaction
5.2 Speed of Response of Antisurge Control System
6 SYSTEM EQUIPMENT SPECIFICATIONS
6.1 The Antisurge Control Valve
6.2 Non-return Valve
6.3 Pressure and flow measurement
6.4 Signal transmission
6.5 Controllers
7 TESTING
7.1 Determination of the Surge Line
7.2 Records
8 INLET GUIDE VANE UNITS
8.1 Application
8.2 Effect on Power Consumption of the Compressor
8.3 Effect of Gas Conditions, Properties and Contaminants
8.4 Aerodynamic Considerations
8.5 Control System Linearity
8.6 Actuator Specification
8.7 Avoidance of Surge
8.8 Features of Link Mechanisms
8.9 Limit Stops and Shear Links
APPENDICES
A LIST OF SYMBOLS AND PREFERRED UNITS
B WORKED EXAMPLE 1 COMPRESSOR WITH VARIABLE INLET PRESSURE AND VARIABLE GAS COMPOSITION
C WORKED EXAMPLE 2 A CONSTANT SPEED ~ STAGE COMPRESSOR WITH INTER-COOLING
D WORKED EXAMPLE 3 DYNAMIC RESPONSE OF THE ANTISURGE PROTECTION SYSTEM FOR A SERVICE AIR COMPRESSOR RUNNING AT CONSTANT SPEED
E EXAMPLE OF INLET GUIDE VANE REGULATION
FIGURES
2.1 TYPICAL COMPRESSOR STAGE CHARACTERISTIC PLOTTED WITH FLOW AT DISCHARGE CONDITIONS
2.2 TYPICAL COMPRESSOR STAGE CHARACTERISTIC PLOTTED WITH FLOW AT INLET CONDITIONS
2.3 PERFORMANCE CHARACTERISTICS OF A COMPRESSOR STAGE AT VARYING SPEEDS
2.4 SYSTEM WORKING POINT DEFINED BY INTERSECTION OF PROCESS AND COMPRESSOR CHARACTERISTICS
2.5 DISCHARGE THROTTLE REGULATION
2.6 BYPASS REGULATION
2.7 INLET THROTTLE REGULATION
2.8 INLET GUIDE VANE REGULATION
2.9 VARIABLE SPEED REGULATION
3.1 GAS PULSATION LEVELS FOR A CENTRIFUGAL COMPRESSOR
3.2 REPRESENTATION OF CYCLIC FLOW DURING SURGE OF LONG PERIOD
3.3 TYPICAL WAVEFORM OF DISCHARGE PRESSURE DURING SURGE
3.4 MULTIPLE SURGE LINE FOR A MULTISTAGE CENTRIFUGAL COMPRESSOR
3.5 TYPICAL MULTIPLE SURGE LINES FOR SINGLE STAGE AXIAL-FLOW COMPRESSOR
4.1 GENERAL SCHEMATIC FOR COMPRESSORS OPERATING IN PARALLEL TO FEED MULTIPLE USER PLANTS
4.2 ILLUSTRATION OF SAFETY MARGIN BETWEEN SURGE POINT AND SURGE PROTECTION POINT AT WHICH ANTISURGE SYSTEM IS ACTIVATED
4.3 ANTISURGE SYSTEM FOR COMPRESSOR WITH FLAT PERFO ..........
This document discusses catalytic reforming and isomerization processes. Catalytic reforming transforms C7-C10 hydrocarbons with low octane numbers into aromatics and iso-paraffins with high octane numbers. It is a highly endothermic process. Isomerization is a mildly exothermic process that increases octane number by changing hydrocarbon structure. Reactions involved in reforming include naphthene dehydrogenation, paraffin dehydrogenation, dehydrocyclization, isomerization, and hydrocracking. Thermodynamics, reaction kinetics, and catalyst selection influence process conditions and product distribution. Common reforming technologies are semi-regenerative fixed bed and continuous regenerative moving bed processes.
DESIGN OF VENT GAS COLLECTION AND DESTRUCTION SYSTEMS Gerard B. Hawkins
DESIGN OF VENT GAS COLLECTION AND DESTRUCTION SYSTEMS
CONTENTS
1 INTRODUCTION
1.1 Purpose
1.2 Scope of this Guide
1.3 Use of the Guide
2 ENVIRONMENTAL ISSUES
2.1 Principal Concerns
2.2 Mechanisms for Ozone Formation
2.3 Photochemical Ozone Creation Potential
2.4 Health and Environmental Effects
2.5 Air Quality Standards for Ground Level Concentrations of Ozone, Targets for Reduction of VOC Discharges and Statutory Discharge Limits
3 VENTS REDUCTION PHILOSOPHY
3.1 Reduction at Source
3.2 End-of-pipe Treatment
4 METHODOLOGY FOR COLLECTION & ASSESSMENT OF PROCESS FLOW DATA
4.1 General
4.2 Identification of Vent Sources
4.3 Characterization of Vents
4.4 Quantification of Process Vent Flows
4.5 Component Flammability Data Collection
4.6 Identification of Operating Scenarios
4.7 Quantification of Flammability Characteristics for Combined Vents
4.8 Identification, Quantification and Assessment of Possibility of Air Ingress Routes
4.9 Tabulation of Data
4.10 Hazard Study and Risk Assessment
4.11 Note on Aqueous / Organic Wastes
4.12 Complexity of Systems
4.13 Summary
5 SAFE DESIGN OF VENT COLLECTION HEADER SYSTEMS
5.1 General
5.2 Process Design of Vent Headers
5.3 Liquid in Vent Headers
5.4 Materials of Construction
5.5 Static Electricity Hazard
5.6 Diversion Systems
5.7 Snuffing Systems
6 SAFE DESIGN OF THERMAL OXIDISERS
6.1 Introduction
6.2 Design Basis
6.3 Types of High Temperature Thermal Oxidizer
6.4 Refractories
6.5 Flue Gas Treatment
6.6 Control and Safety Systems
6.7 Project Program
6.8 Commissioning
6.9 Operational and Maintenance Management
APPENDICES
A GLOSSARY
B FLAMMABILITY
C EXAMPLE PROFORMA
D REFERENCES
DOCUMENTS REFERRED TO IN THIS PROCESS GUIDE
TABLE
1 PHOTOCHEMICAL OZONE CREATION POTENTIAL REFERENCED
TO ETHYLENE AS UNITY
FIGURES
1 SCHEMATIC OF TYPICAL VENT COLLECTION AND THERMAL OXIDIZER SYSTEM
2 TYPICAL KNOCK-OUT POT WITH LUTED DRAIN
3 SCHEMATIC OF DIVERSION SYSTEM
4 CONVENTIONAL VERTICAL THERMAL OXIDIZER
5 CONVENTIONAL OXIDIZER WITH INTEGRAL WATER SPARGER
6 THERMAL OXIDIZER WITH STAGED AIR INJECTION
7 DOWN-FIRED UNIT WITH WATER BATH QUENCH
8 FLAMELESS THERMAL OXIDATION UNIT
9 THERMAL OXIDIZER WITH REGENERATIVE HEAT RECOVERY
10 TYPICAL PROJECT PROGRAM
11 TYPICAL FLAMMABILITY DIAGRAM
12 EFFECT OF DILUTION WITH AIR
13 EFFECT OF DILUTION WITH AIR ON 100 Rm³ OF FLAMMABLE GAS
This document summarizes different processes for removing carbon dioxide from ammonia plant streams. It discusses why CO2 removal is important, and describes common processes like MEA and MDEA absorption. The Benfield process uses hot potassium carbonate solution promoted by diethanolamine to physically absorb CO2. Issues with the Benfield process include foaming, corrosion, and vanadation problems. Retrofitting with a new amine promoter called LRS 10 can improve CO2 removal efficiency and reduce energy costs for the Benfield process.
Air Cooled Heat Exchanger Design
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 SUITABILITY FOR AIR COOLING
4.1 Options Available For Cooling
4.2 Choice of Cooling System
5 SPECIFICATION OF AN AIR COOLED HEAT
EXCHANGER
5.1 Description and Terminology
5.2 General
5.3 Thermal Duty and Design Margins
5.4 Process Pressure Drop
5.5 Design Ambient Conditions
5.6 Process Physical Properties
5.7 Mechanical Design Constraints
5.8 Arrangement
5.9 Air Side Fouling
5.10 Economic Factors in Design
6 CONTROL
7 PRESSURE RELIEF
8 ASSESSMENT OF OFFERS
8.1 General
8.2 Manual Checking Of Designs
8.3 Computer Assessment
8.4 Bid Comparison
9 FOULING AND CORROSION
9.1 Fouling
9.2 Corrosion
10 OPERATION AND MAINTENANCE
10.1 Performance Testing
10.2 Air-Side Cleaning
10.3 Mechanical Maintenance
10.4 Tube side Access
11 REFERENCES
Steam Reformer Surveys - Techniques for Optimization of Primary Reformer Oper...Gerard B. Hawkins
Introduction
Background Radiation and Temperature Measurement
Reformer Survey Inputs
Other Troubleshooting Tools
Safety
Preparation
Onsite Data Collection
TWT Survey
Observation/Troubleshooting
Modelling and Analysis
Results/Outputs
Case Studies
Conclusions
Case Study 1
Case Study 2
Case Study 3
Conclusions
This document provides an overview of equipment sizing and costing procedures for chemical process design. It discusses shortcuts for sizing common equipment like vessels, reactors, heat exchangers, distillation columns, and more. It also covers Guthrie's modular cost estimation method, which estimates the bare module cost of equipment based on sizing parameters, material factors, and other adjustments. The document is intended to help chemical engineers quickly size key process equipment and generate preliminary capital cost estimates during early design stages.
The document discusses air cooled heat exchangers. It describes how air cooled heat exchangers work by using air as the cooling medium, making them useful when water supply is limited. The document outlines the main components of air cooled heat exchangers, including axial fans, tube bundles, headers, fins and nozzles. It also discusses types of fans, headers, fins, factors that affect performance like fouling, and considerations for inspection and design of air cooled heat exchangers.
Study 2: Front-End Engineering Design and Project DefinitionGerard B. Hawkins
Study 2: Front-End Engineering Design and Project Definition
CONTENTS
2.0 PURPOSE
2.0.1 Team
2.0.2 Timing
2.0.3 Documentation
HAZARD STUDY 2: APPLICATION
2.1 Study of Process and Non-Process Activities
2.2 Study of Programmable Electronic Systems (PES)
2.3 Risk Assessment
2.4 Defining the Basis for Safe Operation
2.5 Review of Hazard Study 2
APPENDICES
Appendix A Hazard Study 2 Method
A.1 Significant Hazards Flowsheet
A.2 Event Guide Diagram
A.3 Consequence Guide Diagram
A.4 Typical Measures to Reduce Consequences
Appendix B Programmable Electronic Systems (PES) Guide Diagram
Appendix C Risk Assessment
C.1 Risk Assessment Procedure
C.2 Risk Matrix
C.3 Risk Matrix Guidance for Consequence Categories – Safety and Health Incidents
C.4 Risk Matrix Guidance for Consequence Categories – Environmental Incidents
Appendix D Key Hazards and Control Measures
Appendix E Content of Hazard Study 2 Report Package.
Integration of Special Purpose Centrifugal Fans into a ProcessGerard B. Hawkins
Integration of Special Purpose Centrifugal Fans into a Process
0 INTRODUCTION
1 SCOPE
2 NOTATION
3 PRELIMINARY CHOICE OF NUMBER OF FANS
3.1 Volume Flow Q o
3.2 Definitions
3.3 Estimate of Equivalent Pressure Rise Δ P e
3.4 Choice of Fan Type
3.5 Choice of Control Method
4 GAS DENSITY CONSIDERATIONS
4.1 Calculation of Inlet Pressure
4.2 Calculation of Gas Density
4.3 Atmospheric Air Conditions
5 CAPACITY AND PRESSURE RISE RATING
5.1 Calculation of Fan Capacity
5.2 Calculation of Fan Pressure Rise
5.3 Multiple Duty Points
5.4 Stability
5.5 Parallel Operation
6 GUIDE TO FAN SELECTION
6.1 Effect of Gas Contaminants
6.2 Selection of Blade Type
6.3 Selection of Rotational Speed
6.4 Wind milling and Slowroll
6.5 Estimate of Fan External Dimensions
7 POWER RATING
7.1 Estimate of Fan Efficiency
7.2 Calculation of Absorbed Power
7.3 Calculation of Driver Power Rating
7.4 Motor Power Ratings
7.5 Starting Conditions for Electric Motors
8 CASING PRESSURE RATING
8.1 Calculation of Maximum Inlet Pressure ΔP i max
8.2 Calculation of Maximum Pressure Rise Δ P s max
8.3 Calculation of Casing Test Pressure
8.4 Rating for Explosion
9 NOISE RATING
9.1 Estimate of Fan Sound Power Rating LR
9.2 Acceptable Sound Power Level LW
9.3 Acceptable Sound Pressure Level L p
9.4 Assessment of Silencing Requirements
APPENDICES
A RELIABILITY CLASSIFICATION
B FAN LAWS
FIGURES
3.4 GUIDE TO FAN TYPE
4.5 VARIATION OF AIR DENSITY WITH TEMPERATURE AND ALTITUDE
6.3.1 DUTY BOUNDARY FOR SINGLE - INLET IMPELLERS
6.3.3 RELATIONSHIP BETWEEN HEAD COEFFICIENT AND SPECIFIC SIZE
6.3.6 ROTATIONAL SPEEDS FOR FAN IMPELLERS WITH BACK SWEPT VANES
6.3.7 ROTATIONAL SPEED FOR FAN IMPELLERS WITH RADIAL VANES
6.3.8 RELATIONSHIP OF IMPELLER TIP SPEED TO SHAPE
6.3.9 BOUNDARY DEFINING ARDUOUS DUTY
7.1 NOMOGRAPH FOR ESTIMATING THE EFFICIENCY OF A SINGLE STAGE FAN
7.2 GRAPH: COEFFICIENT OF COMPRESSIBILITY vs PRESSURE RATIO
7.5 GRAPH: MOMENT OF INERTIA OF FAN AND MOTOR (wR2) vs kW
EMERGENCY ISOLATION OF CHEMICAL PLANTS
CONTENTS
1 Introduction
2 When should Emergency Isolation Valves be Installed
3 Emergency Isolation Valves and Associated Equipment
3.1 Installations on existing plant
3.2 Actuators
3.3 Power to close or power to open
3.4 The need for testing
3.5 Hand operated Emergency Valves
3.6 The need to stop pumps in an emergency
3.7 Location of Operating Buttons
3.8 Use of control valves for Isolation
4 Detection of Leaks and Fires
5 Precautions during Maintenance
6 Training Operators to use Emergency Isolation Valves
7 Emergency Isolation when no remotely operated valve is available
References
Glossary
Appendix I Some Fires or Serious Escapes of Flammable Gases or Liquids that could have been controlled by Emergency Isolation Valves
Appendix II Some typical Installations
John Crane gas seals provide maximum reliability through ensuring a clean and dry seal environment. Key factors include filtering the gas to 1 micron, using coalescing filters to remove liquids, heating the gas above hydrate and liquid formation points, and using an SEPro system to provide heated filtered gas to the seals during shutdown periods. It is also important to properly monitor the outer barrier seal, ensure adequate separation from bearing oil, and have the OEM test the job seal system to validate performance matches duty conditions.
Introduction
Catalyst breakage is a well known phenomena that occurs during operation and transients such as reformer trips, whether this be due to,
• Normal in service breakage,
• Breakage due to carbon formation/removal,
• Breakage due to steam condensation or carry over,
• Breakage during a trip.
The effect of catalyst breakage can be observed in a number of ways,
• Hot bands,
• Speckling and giraffe necking,
• Catalyst breakage and settling.
Introduction to Pressure Surge in Liquid Systems
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 CAUSES OF PRESSURE SURGE
4.1 Start-up
5 CONSEQUENCES OF PRESSURE SURGES
6 PRELIMINARY CALCULATIONS
6.1 Estimation of the Sonic Velocity
6.2 Pipeline Period
7 CALCULATION OF PEAK PRESSURES
7.1 Rigid Liquid Column Theory
7.2 Sudden Changes in Flowrate
7.3 Moderately Rapid Changes in Flowrate
7.4 Reflections and Attenuations
7.5 Vapor Cavity Formation
7.6 Complex Piping Systems
8 FORCES ON PIPE SUPPORTS.
9 METHODS OF REDUCING THE EFFECTS OF
PRESSURE SURGE
9.1 Flowrate
9.2 Pipe Diameter
9.3 Valve Selection and Operation
9.4 Pump Start-up/Shut-down
9.5 Surge Tanks and Accumulators
9.6 Vacuum Breakers
9.7 Changes to Equipment
10 DETAILED ANALYSIS
10.1 Data Requirements
10.2 Interpretation of Results
11 GUIDELINES FOR CALCULATIONS
12 EXAMPLES OF PRESSURE SURGE INCIDENTS
12.1 Caustic Soda Pipeline Movement
12.2 Ammonia Pipe Movement
12.3 Propylene Reactor Start-up
12.4 Cooling Water Failure
12.5 Dry Riser Fire Sprinkler Systems
12.6 Cast Iron Fire Main Pressurization
SYNOPSIS
The principles underlying centrifugal separation of particulate species are briefly considered, and the main types of separator available are noted. The procedures available for scale-up from laboratory or semi-technical data are then discussed in detail with particular reference to perhaps the most important class of machine for fine particle processing: the disc-nozzle centrifuge.
Starting with the basic concepts behind their design, discussion follows to explain the factors which may limit centrifuge performance. It is shown how a few simple; laboratory scale tests can give a valuable insight into the design and operation of full-scale industrial machines.
Pressure Relief Systems Vol 2
Causes of Relief Situations
This Volume 2 is a guide to the qualitative identification of common causes of overpressure in process equipment. It cannot be exhaustive; the process engineer and relief systems team should look for any credible situation in addition to those given in this Part which could lead to a need for pressure relief (a relief situation).
Integration of Special Purpose Centrifugal Pumps into a ProcessGerard B. Hawkins
Integration of Special Purpose Centrifugal Pumps into a Process
CONTENTS
1 SCOPE
2 PRELIMINARY CHOICE OF PUMP
SECTION A - INLET CONDITIONS
Al Calculation of Basic Nett Positive Suction Head (NPSH)
A2 Correction to Basic NPSH for Temperature Rise at Pump Inlet
A3 Correction to Basic NPSH for Acceleration Head
A4 Calculation of Available NPSH
A5 Correction to NPSH for Fluid Properties
A6 Calculation of Suction Specific Speed
A7 Priming
A8 Submergence
SECTION B – FLOW / HEAD RATING SEQUENCE
B1 Calculation of Static Head
B2 Calculation of Margins for Control
B3 Calculation of Q-H Duty
B4 Stability and Parallel Operation
B5 Corrections to Q-H Duty for Fluid Properties
B6 Guide to Pump Type and Speed
SECTION C – DRIVER POWER RATING
C1 Estimation of Pump Efficiency
C2 Calculation of Absorbed Power
C3 Calculation of Driver Power Rating
C4 Preliminary Power Ratings of Electric Motors
C5 Starting Conditions for Electric Motors
C6 Reverse Flow and Reverse Rotation
SECTION D - CASING PRESSURE RATING
D1 Calculation of Maximum Inlet Pressure
D2 Calculation of Differential Pressure
D3 Pressure Waves
D4 Pressure due to Liquid Thermal Expansion
D5 Casing Hydrostatic Test Pressure
SECTION E – SEALING CONSIDERATIONS
E1 Preliminary Choice of Seal
E2 Fluid Attributes
E3 Definition of Flushing Arrangements
APPENDICES
A RELIABILITY CLASSIFICATION
B SYMBOLS AND PREFERRED UNITS
DOCUMENTS REFERRED TO IN THIS ENGINEERING DESIGN GUIDE
The water crisis is undeniable and the corruption challenge it faces is urgent. More than 1 billion people worldwide have no guaranteed access to water and more than 2 billion are without adequate sanitation. It is estimated that by 2025 more than 3 billion people could be living in water stressed countries.
When corruption is part of the equation, the consequences for development and poverty reduction are dire. Corruption can increase the cost of connecting a household to a water network by more than 30 percent, raising the price tag for achieving the Millennium Development Goals for water and sanitation by a staggering US $48 billion, according to expert estimates in the Global Corruption Report 2008.
The document provides information on mechanical seals used in engineering applications. It discusses the basic principles of how mechanical seals work, including balance, lubrication, materials selection and heat removal considerations. Mechanical seals are an alternative to packed glands for sealing rotating shafts, with advantages of reduced maintenance costs and leakage but also higher costs and less tolerance for misalignment than packed glands. Key factors that influence the performance of mechanical seals are proper balance to control pressures, adequate lubrication of the seal faces, suitable materials selection based on wettability and corrosion resistance, and removal of frictional heat generated during operation.
The Selection of Flocculants and other Solid-Liquid Separation AidsGerard B. Hawkins
The use of chemical additives, such as flocculants, is a common step in solid-liquid separation operations. The correct selection of agent is an essential part of the design of such processes. Many excellent reviews and guides deal with this topic, and the interested reader is referred to works such as [l-4]. In particular the Harwell-Warren Spring Report “The Use and Selection of Flocculants" provides a good overview on the application of coagulants and flocculants. This section does not attempt to reproduce a detailed treatment of that kind; instead it is our intention to state a few general rules and principles concerning methods of choosing an additive, and to illustrate briefly their application in practice.
The types of agents employed in solid-liquid separation fall into three principal classes:
Koch Modular Process Systems, LLC. (KMPS) Extraction Technology Group specializes in the design and supply of liquid-liquid extraction equipment engineered to fulfill the chemical, pharmaceutical, petrochemical, biotech and flavor & fragrance industries’ increasingly challenging purification requirements. Our extractor design expertise includes SCHEIBEL® Columns, KARR® Columns, rotating disc contactor (RDC) columns, pulsed, packed (SMVP) and sieve tray.
At KMPS, we don’t just sell extraction equipment; we supply solutions to your difficult separation applications.
KMPS also provides replacements parts, repair services and troubleshooting assistance for all types of extraction columns. A qualified technician or engineer can be provided on-site for both mechanical and process related support.
Introduction High temperature shift Catalysts
Low temperature shift catalysts
Catalyst storage, handling, charging and discharging
Health and safety precautions
Reduction and start-up of high temperature shift catalysts
Operation of high temperature shift catalysts
Reduction and start-up of low temperature shift catalysts
Operation of low temperature shift catalysts
These slides are developed for a part of the undergraduate course in Petroleum Refinery Engineering. The slides are also helpful for Masters level introductory course.
Selection and Design of Condensers
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 CHOICE OF COOLANT
5 LAYOUT CONSIDERATIONS
5.1 Distillation Column Condensers
5.2 Other Process Condensers
6 CONTROL
6.1 Distillation Columns
6.2 Water Cooled Condensers
6.3 Refrigerant Condensers
7 GENERAL DESIGN CONSIDERATIONS
7.1 Heat Transfer Resistances
7.2 Pressure Drop
7.3 Handling of Inerts
7.4 Vapor Inlet Design
7.5 Drainage of Condensate
8 SUMMARY OF TYPES AVAILABLE
8.1 Direct Contact Condensers
8.2 Shell and Tube Exchangers
8.3 Air Cooled Heat Exchangers
8.4 Spiral Plate Heat Exchangers
8.5 Internal Condensers
8.6 Plate Heat Exchangers
8.7 Plate-Fin Heat Exchangers
8.8 Other Compact Designs
9 BIBLIOGRAPHY
FIGURES
1 DIRECT CONTACT CONDENSER WITH INDIRECT COOLER FOR RECYCLED CONDENSATE
2 SPRAY CONDENSER
3 TRAY TYPE CONDENSER
4 THREE PASS TUBE SIDE CONDENSER WITH INTERPASS LUTING FOR CONDENSATE DRAINAGE
5 CROSS FLOW CONDENSER WITH SINGLE PASS COOLANT
Selection of Heat Exchanger Types
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 BACKGROUND
5 FACTORS INFLUENCING SELECTION
5.1 Type of Duty
5.2 Temperatures and Pressures
5.3 Materials of Construction 5.4 Fouling
5.5 Safety and Reliability
5.6 Repairs
5.7 Design Methods
5.8 Dimensions and Weight
5.9 Cost
5.10 GBHE Experience
6 TYPES OF EXCHANGER
6.1 Shell and Tube Exchangers
6.2 Cylindrical Graphite Block Heat Exchangers
6.3 Cubic Graphite Block Heat Exchangers
6.4 Air Cooled Heat Exchangers
6.5 Gasketed Plate and Frame
6.6 Spiral Plate
6.7 Tube in Duct
6.8 Plate-fin
6.9 Printed Circuit Heat Exchanger (PCHE)
6.10 Scraped Surface/Wiped Film Exchangers
6.11 Welded or Brazed Plate
6.12 Double Pipe
6.13 Electric Heaters
6.14 Fired Process Heaters
TABLE
(1) ADVANTAGES AND DISADVANTAGES OF DIFFERENT SHELL AND TUBE DESIGNS
FIGURES
1 ESTIMATED MAIN PLANT ITEM COSTS
2 ESTIMATED INSTALLED COSTS
3 TEMA HEAT EXCHANGER NOMENCLATURE
4 F ‘CORRECTION FACTORS' : TEMA E SHELL WITH EVEN NUMBER OF PASSE
5 SHELL AND TUBE HEAT EXCHANGER HEAD TYPES
6 GENERAL ARRANGEMENT OF A CYLINDRICAL GRAPHITE BLOCK HEAT EXCHANGER
7 EXPLODED VIEW OF A CUBIC GRAPHITE BLOCK
HEAT EXCHANGER
8 TYPICAL AIR COOLED HEAT EXCHANGER
9 GENERAL VIEW OF ONE END OF A 3-STREAM
PLATE-FIN HEAT EXCHANGER
10 TYPICAL PCHE PLATE
11 VICARB ‘COMPABLOC' EXCHANGER
12 ‘BROWN FINTUBE' MULTITUBE HEAT EXCHANGER
13 FIRED HEATER : SCHEMATICS AND NOMENCLATURE
Thermal Design Margins for Heat Exchangers
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 TERMINOLOGY
5 REASONS FOR SPECIFYING A DESIGN MARGIN
5.1 Instantaneous Rates
5.2 Future Uprating
5.3 Plant Upsets
5.4 Process Control
5.5 Uncertainties in Properties
5.6 Uncertainties in Design Methods
5.7 Fouling
6 COMBINATION OF DESIGN MARGINS
7 CRITICAL AND NON-CRITICAL DUTIES
7.1 General
7.2 Penalties of Over-design
8 OPTIMIZATION OF EXCHANGER DUTY
9 WAYS OF PROVIDING DESIGN MARGINS
9.1 The Provision of Excess Surface
9.2 Decreasing the Design Temperature Difference
9.3 Increasing the Design Process Throughput
9.4 Increasing the Design Fouling Resistance
9.5 Reducing the Design Process Outlet Temperature Approach
9.6 Adjusting the Physical Properties
10 ACCURACY OF THE DESIGN METHODS FOR SHELL AND TUBE EXCHANGERS
10.1 Pressure Drop
10.2 Heat Transfer
11 SUGGESTED DESIGN MARGINS
11.1 No Phase Change Duties
11.2 Condensers
11.3 Boilers
12 EFFECT OF UNDER- OR OVER-SURFACE ON PERFORMANCE
FIGURES
1 EFFECT OF LENGTH ON EXCHANGER DUTY COUNTERCURRENT FLOW, C* = 1.0
2 EFFECT OF NUMBER OF TUBES ON EXCHANGER PERFORMANCE COUNTERCURRENT FLOW, C* = 1.0, ALL RESISTANCE IN TUBES
3 EFFECT OF TUBE LENGTH ON NUMBER OF TUBES, AREA AND PRESSURE DROP
Batch Distillation
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 BACKGROUND TO THE DESIGN
4.1 General
4.2 Choice of batch/continuous operation
4.3 Boiling point curve and cut policy
4.4 Method of design
4.5 Scope of calculations required for design
5 SIMPLE BATCH DISTILLATION
6 FRACTIONAL BATCH DISTILLATION
6.1 General
6.2 Approximate methods
6.3 Rigorous design - use of a computer model
6.4 Other factors influencing the design
6.4.1 Occupation
6.4.2 Choice of Batch Rectification or Stripping
6.4.3 Batch size
6.4.4 Initial estimate of cut policy
6.4.5 Liquid Holdup
6.4.6 Total reflux operation and heating-up time
6.4.7 Column operating pressure
6.5 Optimum Design of the Batch Still
6.6 Special design problems
7 GENERAL ASPECTS OF EQUIPMENT DESIGN
7.1 Kettle reboilers
7.2 Column Internals
7.3 Condensers and reflux split boxes
8 PROCESS CONTROL AND INSTRUMENTATION IN
BATCH DISTILLATION
9 MECHANICAL DESIGN FEATURES
10 BIBLIOGRAPHY
APPENDICES
A McCABE - THIELE METHOD - TYPICAL EXAMPLE
The Preliminary Choice of Fan or Compressor
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 METHOD FOR PRELIMINARY SELECTION
OF COMPRESSOR
5 PROCESS DATA SHEET
5.1 Essential Data for the Completion of a
Process Data Sheet
5.2 Gas Properties
5.3 Discharge Requirements
6 PRELIMINARY CHOICE OF FAN AND
COMPRESSOR TYPE
6.1 Essential Data for Preliminary Selection
7 FAN AND COMPRESSOR APPLICATIONS
7.1 Fans
7.2 Centrifugal Compressors
7.3 Axial Compressors
7.4 Reciprocating Compressors
7.5 Screw Compressors
7.6 Positive Displacement Blowers
7.7 Sliding Vane Compressors
7.8 Liquid Ring Compressors
8 PROVISION OF INSTALLED SPARES
9 PRELIMINARY ESTIMATE OF COSTS
Distillation Sequences, Complex Columns and Heat IntegrationGerard B. Hawkins
Distillation Sequences, Complex Columns and Heat Integration
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 SEQUENCING OF SIMPLE COLUMNS
4.1 Sidestream Columns
4.2 Multi-Feed Columns
5 SIMPLE COLUMN SEQUENCING AND HEAT
INTEGRATION INTERACTIONS
5.1 Energy Quantity and Quality
5.2 Heat Integration within the Total Flowsheet
6 COMPLEX COLUMN ARRANGEMENTS
6.1 Indirect Sequence with Vapor Link
6.2 Sidestream Systems
6.3 Pre-Fractionator Systems
7 COMPLEX COLUMNS AND HEAT INTEGRATION
INTERACTIONS
FIGURES
1 DIRECT AND INDIRECT SEQUENCES
2 A SINGLE SIDESTREAM COLUMN REPLACING 2
SIMPLE COLUMNS
3 A TYPICAL MULTI-FEED COLUMN
4 TYPICAL GRAND COMPOSITION CURVE
5 TYPICAL INDIRECT SEQUENCE WITH VAPOUR LINK
6 SIDESTREAM STRIPPER AND SIDESTREAM
RECTIFIER
7 SIMPLEST PRE-FRACTIONATOR SYSTEM
8 SIMPLEST PRE-FRACTIONATOR SYSTEM
9 PETLYUK COLUMN
Heating and Cooling of Batch Processes
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
3.1 units
4 STATEMENT OF THE PROBLEM
5 DEVELOPMENT OF THE METHOD
5.1 Assumptions
5.2 Basic Equations
6 APPLICATION OF THE METHOD
6.1 Determining the Behavior of an Existing System
6.2 Specifying the Heat Transfer Duty for a New System
APPENDICES
A DERIVATION OF THE EQUATIONS
B WORKED EXAMPLES
FIGURES
1 CASES CONSIDERED
Shell and Tube Heat Exchangers Using Cooling Water
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
3.1 HTFS
3.2 TEMA
4 CHECKLIST
5 QUALITY OF COOLING WATER
6 COOLING WATER ON SHELL SIDE OR TUBE SIDE
7 COOLING WATER ON THE SHELL SIDE
7.1 Baffle Spacing
7.2 Impingement Plates
7.3 Horizontal or Vertical Shell Orientation
7.4 Baffle Cut Orientation
7.5 Sludge Blowdown
7.6 Removable Bundles
8 FOULING RESISTANCES AND LIMITING TEMPERATURES
9 PRESSURE DROP
9.1 Pressure Drop Restrictions
9.2 Fouling and Pressure Drop
9.3 Elevation of a Heat Exchanger in the Plant
10 MATERIALS OF CONSTRUCTION
11 WATER VELOCITY
11.1 Low Water Velocity
11.1.1 Tube Side Water Flow
11.1.2 Shell Side Water Flow
11.2 High Water Velocity
12 ECONOMICS
13 DIRECTION OF WATER FLOW
14 VENTS AND DRAINS
15 CONTROL
15.1 Operating Variables
15.2 Heat Load Control
15.2.1 General
15.2.2 Heat load control by varying cooling water flow
15.3 Orifice Plates
16 MAINTENANCE
Turbulent Heat Transfer to Non Newtonian Fluids in Circular TubesGerard B. Hawkins
Turbulent Heat Transfer to Non Newtonian Fluids in Circular Tubes
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 THE INTEGRATION OF THE ENERGY EQUATION
5 THE EDDY VISCOSITY FOR NON-NEWTONIAN AND DRAG REDUCING FLUIDS
6 THE CALCULATION OF HEAT TRANSFER
COEFFICIENTS FOR NON-NEWTONIAN AND DRAG
REDUCING FLUIDS IN TURBULENT PIPE FLOW
6.1 General
6.2 Drag Reducing Fibre Suspensions
6.3 Transition Delay
7 NOMENCLATURE
8 BIBLIOGRAPHY
Large Water Pumps
CONTENTS
1 SCOPE
SECTION ONE: INTEGRATION OF PUMPS INTO THE PROCESS
2 PROPERTIES OF FLUID
2.1 Cooling Water
2.2 Brine
2.3 Estuary Water
2.4 Harbor Water
2.5 Oil-field water
3 CALCULATION OF DUTY
4 CHOICE OF TYPE AND NUMBER OF PUMPS
4.1 Type of Pump
4.2 Points to Consider
4.3 Number of Pumps
5 RECOMMENDED LINE DIAGRAM
5.1 Check List for Each Pump
6 RECOMMENDED LAYOUT
SECTION TWO: CONSTRUCTION FEATURES
7 HORIZONTAL, AXIALLY SPLIT CASING PUMPS
7.1 Pressure Casing
7.2 Bolting
7.3 Flanges and Connections
7.4 Rotating Elements
7.5 Wear Rings
7.6 Running Clearances
7.7 Mechanical Seals
7.8 Packed Glands
7.9 Bearings and Bearing Housings
7.10 Lubrication
7.11 Couplings
7.12 Guards
7.13 Baseplates
7.14 Flywheels
8 VERTICAL PUMPS
8.1 General
8.2 Pressure Casing
8.3 Bolting
8.4 Flanges and Connections
8.5 Rotating Element
8.6 Packed Glands
8.7 Bearings and Bearing Housings
8.8 Pump Head
8.9 Column Pipes
8.10 Line Shaft and Couplings
8.11 Reverse Rotation
8.12 Gearboxes
9 MATERIALS
9.1 Castings
9.2 Casings
9.3 Impellers
9.4 Shafts
9.5 Shaft Sleeves
9.6 Bolts and Nuts
10 DRIVERS
10.1 Electric Motor Drives
11 BIBLIOGRAPHY
APPENDICES:
A COOLING WATER - EUROPEAN SITE
B TIDAL RIVER ESTUARY
C FLYWHEEL INERTIA FOR PRESSURE SURGE ABATEMENT
D RESIN COATING OF CASINGS FOR WATER PUMPS
E AREA RATIO METHOD
F NOTES ON PUMP IMPELLERS CASTINGS
G LIMIT ON SHAFT DIAMETER FOR HORIZONTAL PUMPS HAVING
ONE DOUBLE-ENTRY IMPELLER SUPPORTED BETWEEN BEARINGS
H FORCES AND BENDING MOMENTS ON RISING MAIN ASSEMBLY
I POWER COSTS
J PUTATIVE COST COMPARISON SHEET
K TECHNICAL COMPARISON SHEETS
FIGURES
2.1 VAPOR TEMPERATURE CURVES
2.2 DENSITY TEMPERATURE CURVES
3.1 TYPICAL HEAD OF PUMPS
3.2 TOTAL HEAD OF VERTICAL IMMERSED PUMP
3.3 TYPICAL TIDAL RIVER ESTUARY LEVELS
3.5 SUBMERGENCE LIMITS
4.1 TYPES OF PUMP
4.2 GUIDE TO PUMP TYPE AND SPEED
5.1 TYPICAL LINE DIAGRAM
6 GUIDE TO SUCTION PIPEWORK DESIGN
7 CASING AND IMPELLER DETAILS
8.1 DRY WELL AND WET WELL PUMP INSTALLATIONS
8.2 BELLMOUTH DIMENSIONS FOR VERTICAL INTAKES
8.3 MAXIMUM SPACING BETWEEN SHAFT GUIDE BUSHING
8.4 LINE SHAFT COUPLING
9 TYPICAL VOLUTE CASING
10 TYPICAL CASE WEAR RINGS
11 SEAL AREA
TABLES
1 LIQUID PROPERTIES SODIUM CHLORIDE (25% W/W)
2 LIQUID PROPERTIES SODIUM CHLORIDE (20% W/W)
3 LIQUID PROPERTIES SODIUM CHLORIDE (16.25% W/W)
4 LIQUID PROPERTIES SODIUM CHLORIDE (15% W/W)
5 LIQUID PROPERTIES SODIUM CHLORIDE (10% W/W)
6 LIQUID PROPERTIES SODIUM CHLORIDE (5% W/W)
7 GUIDE TO PUMP TYPE AND SPEED
8 RECOMMENDED CAST MATERIALS FOR USE IN THE PUMP INDUSTRY
GRAPHS
1 GUIDE TO ROTOR INERTIA
2 LIMITS BETWEEN BEARINGS
DOCUMENTS REFERRED TO IN THIS ENGINEERING DEPARTMENT DESIGN GUIDE
Boiler Water Circulation Pumps
1 SCOPE
2 CHOICE OF TYPE AND NUMBER OF PUMPS
2.1 Need for Continuous Flow
2.2 Pump Reliability
3 CHOICE OF DRIVER
4 DUTY CALCULATIONS
5 CHOICE OF SEAL
5.1 Mechanical Seals
5.2 Soft-packed Glands
5.3 Construction Features
5.4 Guarding
6 CONSTRUCTION FEATURES
6.1 Vertical Glandless Wet-stator Motor Pumps
7 LAYOUT
7.1 Non-return Valves
7.2 Reducers at Pump Connections
7.3 Glandless Pumps for System Pressures
Exceeding 60 bar abs
7.4 Access round Glandless Pumps
7.5 Cooling Water Supply
8 RECOMMENDED LINE DIAGRAMS
8.1 Horizontal Pumps in Category 1
8.2 Vertical Wet-stator Motor Pumps in Category
APPENDICES
A PROPERTIES OF WATER AT THE SATURATION LINE
B ANNEX TO API 610, 6TH EDITION 1981:
VERTICAL GLANDLESS WET-STATOR MOTOR PUMPS
C ANNEX TO API 610, 6TH EDITION 1981:
HORIZONTAL BACK PULL-OUT PUMPS FOR BOILER
WATER CIRCULATION DUTY
FIGURES
3.1 NPSH CORRECTION FOR WATER
3.2 VELOCITY OF SOUND IN WATER AT 50 BAR
(NO BUBBLES)
3.3 VELOCITY OF SOUND IN WATER AT 50 BAR
(WITH 3% VAPOR CONTENT)
8.1 RECOMMENDED LINE DIAGRAM HORIZONTAL PUMPS - CATEGORY 1
8.2 RECOMMENDED LINE DIAGRAM HORIZONTAL PUMPS - SOFT PACKED GLAND INSTALLATION
8.3 RECOMMENDED LINE DIAGRAM HORIZONTAL PUMPS - MECHANICAL SEAL INSTALLATION
8.4 RECOMMENDED LINE DIAGRAM VERTICAL WET STATOR PUMPS - CATEGORY 2
BIBLIOGRAPHY
This document provides guidance on implementing procedures for managing critical pressure systems as outlined in PEG 4. It covers the design, manufacture, repair, modification and periodic examination of pressure vessels, piping systems, and pressure relief streams. Key requirements include using recognized standards, qualified personnel, design verification, registration of equipment, and periodic inspections to ensure safety. The document is intended to support the development of detailed local engineering procedures for managing pressure equipment over its lifecycle.
How to Use the GBHE Mixing Guides
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 THE MIXING GUIDES
4.1 Mixing Guides
4.2 GBHE Mixing and Agitation Manual
5 DEVICE SELECTION
6 MIXING QUESTIONNAIRE
6.1 What is being mixed?
6.2 Why is it being mixed?
6.3 How is it to be mixed?
6.4 Is Heat Transfer Important?
6.5 Is Mixing Time Important?
6.6 Is Inventory Important?
6.7 Is Subsequent Phase Separation Important?
6.8 What Quantities?
6.9 What are the Selection Criteria?
6.10 What Data are required?
7 BASICS
7.1 Bulk Movement
7.2 Shear and Elongation
7.3 Turbulent Diffusion
7.4 Molecular Diffusion
7.5 Mixing Mechanisms
APPENDICES
A ROTATING MIXING DEVICES
B MIXING DEVICES WITHOUT MOVING PARTS
Physical Properties for Heat Exchanger Design
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 COMPONENT PROPERTIES
4.1 General
4.2 Use of Component Properties for Mixtures
5 INPUT OF MIXTURE CURVES
5.1 General
5.2 Generation of the Mixture Curves
5.3 Selection of Temperature Points
5.4 Extrapolation
6 IMMISCIBLE CONDENSATES
FIGURES
1 TEMPERATURE POINTS SELECTED FOR EQUAL ENTHALPY CHANGE
2 TEMPERATURE POINTS SELECTED FOR GOOD
FIT TO CURVE
Data Sources For Calculating Chemical Reaction EquilibriaGerard B. Hawkins
Data Sources For Calculating Chemical Reaction Equilibria
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 BACKGROUND TO THEORY
5 BIBLIOGRAPHY
Mechanical Constraints on Thermal Design of Shell and Tube ExchangersGerard B. Hawkins
Mechanical Constraints on Thermal Design of Shell and Tube Exchangers
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 STANDARD DIMENSIONS
4.1 Shell Diameters
4.2 Tube Lengths
4.3 Tube Diameters
4.4 Tube Wall Thicknesses
5 CLEARANCES
5.1 Tube Pitch
5.2 Pass Partition Lane Widths
5.3 Minimum 'U' Bend Clearance
5.4 Tube-to-Baffle Clearance
5.5 Baffle-to-Shell Clearance
5.6 Bundle-to-Shell Clearance
6 TUBESHEET THICKNESS
7 END ZONE LENGTHS
8 TUBE COUNTS
8.1 Program Correlations
8.2 Use of Tube count Tables
8.3 Graphical Layout
8.4 Use of Computer Programs
8.5 Tie Rods
TABLES
1 HEAT EXCHANGER SHELLS - GEOMETRICAL DATA
FOR INLET & OUTLET BRANCHES: PIPE WITH ANSI
150 FLANGE
2 HEAT EXCHANGER SHELLS - GEOMETRICAL DATA
FOR INLET & OUTLET BRANCHES: PIPE WITH ANSI
300 FLANGE
3 TEMA TIE ROD STANDARDS
FIGURES
1 DEFINITION OF TUBE PITCH, LIGAMENT THICKNESS & PASS PARTITION LANE WIDTH
2 DEFINITION OF PASS PARTITION LANE WIDTH FOR U-TUBES
3 BUNDLE TO SHELL CLEARANCES FOR DIFFERENT BUNDLE TYPES
4 ESTIMATED TUBESHEET THICKNESS FOR FIXED TUBE CONSTRUCTION
5 ESTIMATED TUBESHEET THICKNESS FOR U-TUBE CONSTRUCTION
6 END ZONE
7 EXAMPLE OF OPTU3 GRAPHICAL OUTPUT
Integration of Rotary Positive Displacement Pumps into a ProcessGerard B. Hawkins
Integration of Rotary Positive Displacement Pumps into a Process
This Engineering Design Guide deals with:
(a) The specification of the pump duty for enquiries to be sent to pump vendors,
(b) The estimation of the characteristics and requirements of the pumps in order to provide preliminary information for design work by others.
It applies to pumps in Group 2 and 3 as defined in GBHE-EDS-MAC-21 Series, and is also an essential preliminary step for a pump in Group 1 whose final duty is negotiated with the chosen pump supplier.
It may be used for general-purpose pumps in Group 4; their duties when used in a support role are often inadequately defined, whereupon such pumps can be specified by reference to the manufacturer's data for a pump satisfactorily fulfilling the same process need.
Gas Mixing
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 RECOMMENDATIONS FOR GAS MIXING:
PLUG FLOW
5 RECOMMENDATIONS FOR GAS MIXING:
BACKMIXED INITIAL ZONE
6 BIBLIOGRAPHY
Fixed Bed Reactor Scale-up Checklist
The purpose of this checklist is to identify the stages and potential problems associated with the scale up of fixed bed reactors from the drawing board to the full scale plant, and to determine how they should be checked.
The checking can be done using various methods. These are:
• Literature data.
• Lab testing.
• Calculation.
• Modeling.
• Semi-tech testing.
• Piloting or Sidestream testing.
Identifying the stages that need to be addressed for a particular catalyst/reactor development will help in estimating the time needed for the development of the reactor
Similar to The Design and Layout of Vertical Thermosyphon Reboilers (20)
This document provides guidelines for engineering design of pressure relief systems. It discusses key principles such as identifying potential overpressure and underpressure causes, sizing relief systems to prevent hazards, and safely disposing of relieved materials. The guidelines cover statutory requirements, recommended design procedures, and documentation standards. The overall goal is to preserve equipment integrity and prevent failure from over or under pressure during all process phases.
GAS DISPERSION - A Definitive Guide to Accidental Releases of Heavy GasesGerard B. Hawkins
GAS DISPERSION - A Definitive Guide to Accidental Releases of Heavy Gases
This Process Safety Guide has been written with the aim of assisting process engineers, hazard analysts and environmental advisers in carrying out gas dispersion calculations. The Guide aims to provide assistance by:
• Improving awareness of the range of dispersion models available within GBHE, and providing guidance in choosing the most appropriate model for a particular application.
• Providing guidance to ensure that source terms and other model inputs are correctly specified, and the models are used within their range of applicability.
• Providing guidance to deal with particular topics in gas dispersion such as dense gas dispersion, complex terrain, and modeling the chemistry of oxides of nitrogen.
• Providing general background on air quality and dispersion modeling issues such as meteorology and air quality standards.
• Providing example calculations for real practical problems.
SCOPE
The gas dispersion guide contains the following Parts:
1 Fundamentals of meteorology.
2 Overview of air quality standards.
3 Comparison between different air quality models.
4 Designing a stack.
5 Dense gas dispersion.
6 Calculation of source terms.
7 Building wake effects.
8 Overview of the chemistry of the oxides of nitrogen.
9 Overview of the ADMS complex terrain module.
10 Overview of the ADMS deposition module.
11 ADMS examples.
12 Modeling odorous releases.
13 Bibliography of useful gas dispersion books and reports.
14 Glossary of gas dispersion modeling terms.
Appendix A : Modeling Wind Generation of Particulates.
APPENDIX B TABLE OF PROPERTY VALUES FOR SPECIFIC CHEMICALS
El impacto en el rendimiento del catalizador por envenenamiento y ensuciamien...Gerard B. Hawkins
El documento describe los procesos de refinería y catalizadores, así como los efectos del envenenamiento y ensuciamiento en el rendimiento de los catalizadores. El envenenamiento reduce la actividad de los catalizadores al bloquear los sitios activos o modificar la química de la superficie, lo que afecta la actividad y selectividad. Los niveles bajos de contaminantes tienen un mayor impacto en catalizadores con menor área de superficie. El envenenamiento también puede causar cambios estructurales en el catalizador y permitir
Theory of Carbon Formation in Steam Reforming
Contents
1 Introduction
2 Underpinning Theory
2.1 Conceptualization
2.2 Reforming Reactions
2.3 Carbon Formation Chemistry
2.3.1 Natural Gas
2.3.2 Carbon Formation for Naphtha Feeds
2.3.3 Carbon Gasification
2.4 Heat Transfer
3 Causes
3.1 Effects of Carbon Formation
3.2 Types of Carbon
4 What are the Effects of Carbon Formation?
4.1 Why does Carbon Formation Get Worse?
4.1.1 So what is the Next Step?
4.2 Consequences of Carbon Formation
4.3 Why does Carbon Form where it does?
4.3.1 Effect on Process Gas Temperature
4.4 Why does Carbon Formation Propagate Down the Tube?
4.4.1 Effect on Radiation on the Fluegas Side
4.5 Why does Carbon Formation propagate Up the Tube?
5 How do we Prevent Carbon Formation
5.1 The Role of Potash
5.2 Inclusion of Pre-reformer
5.3 Primary Reformer Catalyst Parameters
5.3.1 Activity
5.3.2 Heat Transfer
5.3.3 Increased Steam to Carbon Ratio
6 Steam Out
6.1 Why does increasing the Steam to Carbon Ratio Not Work?
6.2 Why does reducing the Feed Rate not help?
6.3 Fundamental Principles of Steam Outs
TABLES
1 Heat Transfer Coefficients in a Typical Reformer
2 Typical Catalyst Loading Options
FIGURES
1 Hot Bands
2 Conceptual Pellet
3 Naphtha Carbon Formation
4 Heat Transfer within an Reformer
5 Types of Carbon Formation
6 Effect of Carbon on Nickel Crystallites
7 Absorption of Heat
8 Comparison of "Base Case" v Carbon Forming Tube
9 Carbon Formation Vicious Circle
10 Temperature Profiles
11 Carbon Pinch Point
12 Carbon Formation
13 Effect on Process Gas Temperature
14 How does Carbon Propagate into an Unaffected Zone?
15 Movement of the Carbon Forming Region
16 Effect of Hot Bands on Radiative Heat Transfer
17 Effect of Potash on Carbon Formation
18 Application of a Pre-reformer
19 Effect of Activity on Carbon Formation
Adiabatic Reactor Analysis for Methanol Synthesis Plant Note Book Series: P...Gerard B. Hawkins
The document discusses adiabatic reactor analysis for methanol synthesis from syngas. It provides the reaction kinetics and calculates conversion, temperature, and reactor volume needed at different conversions. Energy and mass balances are used to derive relationships between conversion, temperature and reaction rate. Data is generated to plot conversion versus volumetric flow rate for reactor sizing. The plot indicates a continuous stirred tank reactor (CSTR) could achieve 85% conversion before switching to a plug flow reactor (PFR) for higher conversion with less volume.
STEAMING PROCEDURE FOR VULCAN STEAM REFORMING CATALYSTSGerard B. Hawkins
The document discusses procedures for steaming Vulcan steam reforming catalysts to recover from sulfur poisoning and carbon formation incidents. It describes maintaining steam flow at 30-40% of design levels and an outlet temperature above 780°C. Gas samples should be taken hourly to monitor CO2, CH4, H2S and SO2. Steaming is complete when CO2 levels stabilize over 2-3 samples after increasing the temperature. The process typically takes 12-24 hours to complete and closely monitors pressure drop and tube conditions. After steaming, the catalyst requires reduction before restarting hydrocarbon feed.
Calculation of an Ammonia Plant Energy Consumption: Gerard B. Hawkins
Calculation of an Ammonia Plant Energy Consumption:
Case Study: #06023300
Plant Note Book Series: PNBS-0602
CONTENTS
0 SCOPE
1 CALCULATION OF NATURAL GAS PROCESS FEED CONSUMPTION
2 CALCULATION OF NATURAL GAS PROCESS FUEL CONSUMPTION
3 CALCULATION OF NATURAL GAS CONSUMPTION FOR PILOT BURNERS OF FLARES
4 CALCULATION OF DEMIN. WATER FROM DEMIN. UNIT
5 CALCULATION OF DEMIN. WATER TO PACKAGE BOILERS
6 CALCULATION OF MP STEAM EXPORT
7 CALCULATION OF LP STEAM IMPORT
8 DETERMINATION OF ELECTRIC POWER CONSUMPTION
9 DETERMINATION OF THE TOTAL ENERGY CONSUMPTION OF THE AMMONIA PLANT ISBL
10 ADJUSTMENT OF ELECTRIC POWER CONSUMPTION FOR TEST RUN CONDITIONS
11 CALCULATION OF AMMONIA SHARE IN MP STEAM CONSUMPTION IN UTILITIES
12 CALCULATION OF AMMONIA SHARE IN ELECTRIC POWER CONSUMPTION IN UTILITIES
13 DETERMINATION OF THE TOTAL ENERGY CONSUMPTION OF THE AMMONIA PLANT OSBL
14 DETERMINATION OF THE TOTAL ENERGY CONSUMPTION OF THE AMMONIA PLANT
Ammonia Plant Technology
Pre-Commissioning Best Practices
GBHE-APT-0102
PICKLING & PASSIVATION
CONTENTS
1 PURPOSE OF THE WORK
2 CHEMICAL CONCEPT
3 TECHNICAL CONCEPT
4 WASTES & SAFETY CONCEPT
5 TARGET RESULTS
6 THE GENERAL CLEANING SEQUENCE MANAGEMENT
6.6.1 Pre-cleaning or “Physical Cleaning
6.6.2 Pre-rinsing
6.6.3 Chemical Cleaning
6.6.4 Critical Factors in Cleaning Success
6.6.5 Rinsing
6.6.6 Inspection and Re-Cleaning, if Necessary
7 Systems to be treated by Pickling/Passivation
Ammonia Plant Technology
Pre-Commissioning Best Practices
Piping and Vessels Flushing and Cleaning Procedure
CONTENTS
1 Scope
2 Aim/purpose
3 Responsibilities
4 Procedure
4.1 Main cleaning methods
4.1.1 Mechanical cleaning
4.1.2 Cleaning with air
4.1.3 Cleaning with steam (for steam networks only)
4.1.4 Cleaning with water
4.2 Choice of the cleaning method
4.3 Cleaning preparation
4.4 Protection of the devices included in the network
4.5 Protection of devices in the vicinity of the network
4.6 Water flushing procedure
4.6.1 Specific problems of water flushing
4.6.2 Preparation for water flushing
4.6.3 Performing a water flush
4.6.4 Cleanliness criteria
4.7 Air blowing procedure
4.7.1 Specific problems of air blowing
4.7.2 Preparation for air blowing
4.7.3 Performing air blowing
4.7.4 Cleanliness checks
4.8 Steam blowing procedure
4.8.1 Specific problems of steam blowing
4.8.2 Preparation for steam blowing
4.8.3 Performing steam blowing
4.8.4 Cleanliness checks
4.9 Chemical cleaning procedure
4.9.1 Specific problems of cleaning with a chemical solution
4.9.2 Preparation for chemical cleaning
4.9.3 Performing a chemical cleaning
4.9.4 Cleanliness criteria
4.10 Re-assembly - general guideline
4.11 Preservation of flushed piping
PRACTICAL GUIDE ON THE SELECTION OF PROCESS TECHNOLOGY FOR THE TREATMENT OF A...Gerard B. Hawkins
PRACTICAL GUIDE ON THE SELECTION OF PROCESS TECHNOLOGY FOR THE TREATMENT OF AQUEOUS ORGANIC EFFLUENT STREAMS
CONTENTS
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
3.1 IPU
3.2 AOS
3.3 BODs
3.4 COD
3.5 TOC
3.6 Toxicity
3.7 Refractory Organics/Hard COD
3.8 Heavy Metals
3.9 EA
3.10 Biological Treatment Terms
3.11 BATNEEC
3.12 BPEO
3.13 EQS/LV
3.14 IPC
3.15 VOC
3.16 F/M Ratio
3.17 MLSS
3.18 MLVSS
4 DESIGN/ECONOMIC GUIDELINES
5 EUROPEAN LEGISLATION
5.1 General
5.2 Integrated Pollution Control (IPC)
5.3 Best Available Techniques Not Entailing Excessive Costs (BATNEEC)
5.4 Best Practicable Environmental Option (BPEO)
5.5 Environmental Quality Standards(EQS)
6 IPU EXIT CONCENTRATION
7 SITE/LOCAL REQUIREMENTS
8 PROCESS SELECTION PROCEDURE
8.1 Waste Minimization Techniques (WMT)
8.2 AOS Stream Definition
8.3 Technical Check List
8.4 Preliminary Selection of Suitable Technologies
8.5 Process Sequences
8.6 Economic Evaluation
8.7 Process Selection
APPENDICES
A DIRECTIVE 76/464/EEC - LIST 1
B DIRECTIVE 76/464/EEC - LIST 2
C THE EUROPEAN COMMISSION PRIORITY CANDIDATE LIST
D THE UK RED LIST
E CURRENT VALUES FOR EUROPEAN COMMUNITY ENVIRONMENTAL QUALITY STANDARDS AND CORRESPONDING LIMIT VALUES
F ESTABLISHED TECHNOLOGIES
G EMERGING TECHNOLOGY
H PROPRIETARY/LESS COMMON TECHNOLOGIES
J COMPARATIVE COST DATA
PRACTICAL GUIDE ON THE REDUCTION OF DISCHARGES TO ATMOSPHERE OF VOLATILE ORGA...Gerard B. Hawkins
PRACTICAL GUIDE ON THE REDUCTION OF DISCHARGES TO ATMOSPHERE OF VOLATILE ORGANIC COMPOUNDS (VOCs)
FOREWORD
CONTENTS
1 INTRODUCTION
2 THE NEED FOR VOC CONTROL
3 CONTROL AT SOURCE
3.1 Choice or Solvent
3.2 Venting Arrangements
3.3 Nitrogen Blanketing
3.4 Pump Versus Pneumatic Transfer
3.5 Batch Charging
3.6 Reduction of Volumetric Flow
3.7 Stock Tank Design
4 DISCHARGE MEASUREMENT
4.1 By Inference or Calculation
4.2 Flow Monitoring Equipment
4.3 Analytical Instruments
4.4 Vent Emissions Database
5 ABATEMENT TECHNOLOGY
5.1 Available Options
5.2 Selection of Preferred Option
5.3 Condensation
5.4 Adsorption
5.5 Absorption
5.6 Thermal Incineration
5.7 Catalytic Oxidation
5.8 Biological Filtration
5.9 Combinations of Process technologies
5.10 Processes Under Development
6 GLOSSARY OF TERMS
7 REFERENCES
Appendix 1. Photochemical Ozone Creation Potentials
Appendix 2. Examples of Adsorption Preliminary Calculations
Appendix 3. Example of Thermal Incineration Heat and Mass Balance
Appendix 4. Cost Correlations
Getting the Most Out of Your Refinery Hydrogen PlantGerard B. Hawkins
Getting the Most Out of Your Refinery Hydrogen Plant
Contents
Summary
1 Introduction
2 "On-purpose" Hydrogen Production
3 Operational Aspects
4 Uprating Options on the Steam Reformer
4.1 Steam Reforming Catalysts and Tube Metallurgy
4.2 Oxygen-blown Secondary Reformer
4.3 Pre-reforming
4.4 Post-reforming
5 Downstream Units
6 Summary of Uprating Options
7 Conclusions
Investigation of the Potential Use of (IILs) Immobilized Ionic Liquids in Sha...Gerard B. Hawkins
The document discusses using immobilized ionic liquids (IILs) in shale gas sweetening reactions. It proposes immobilizing a cobalt catalyst in the surface ionic liquid layer of a solid supported ionic liquid catalyst. This would create a "homogeneous catalyst" dissolved within the fixed IIL layer. Competing reactions like oxidation of sulfides to sulfones would need to be considered. Related work on using similar approaches for hydroformylation reactions is referenced. The concept aims to develop a solid IIL catalyst for sweetening reactions involving oxidation using techniques from other areas like hydroformylation.
El documento proporciona una descripción general de los servicios y tecnologías de procesamiento de catalizadores de GBH Enterprises Ltd. (GBHE), incluyendo refinación de petróleo, procesamiento de gas, industrias petroquímicas y venta de catalizadores. GBHE ofrece servicios de ingeniería, soporte técnico y consultoría, así como una línea de catalizadores patentados para aplicaciones como desulfuración y purificación de gas.
Burner Design, Operation and Maintenance on Ammonia PlantsGerard B. Hawkins
The document discusses burner design, operation, and maintenance on ammonia plants. It covers reformer burner types and designs, including premix and staged burners. It also addresses combustion characteristics like excess air and fuel viscosity effects. Maintenance best practices like checking burner pressures and atomizing steam temperatures are emphasized. Low NOx equipment uses techniques like staged air, fuel, and flue gas recirculation to reduce emissions. Good combustion requires attention to design, operation, maintenance, and partnership among related roles.
Debottlenecking Claus Sulfur Recovery Units: An Investigation of the applicat...Gerard B. Hawkins
Debottlenecking Claus Sulfur Recovery Units: An Investigation of the application of Zinc Titanates
1 Executive Summary
2 Claus Process
2.1 Partial Combustion Claus
2.2 Split Flow Claus
2.3 Sulfur Recycle Claus
3 Zinc Titanates
4 Application of Zinc Titanate to Debottleneck Partial Combustion Claus by 10%
4.1 Process
4.2 ASPEN Modeling Results
4.3 Cost of Zinc Titanate Bed Installation
4.3.1 Basis of Costing
4.3.2 Zinc Titanate Beds
4.3.3 Regen Cooler
4.3.4 Blowers
4.3.5 Results
4.4 Alternative Debottlenecking Technology for Partial Combustion Claus
4.5 Cost of 10% Debottlenecking Using COPE Process
5 Debottlenecking Claus Split Flow System by 10% with Zinc Titanates
6 Debottlenecking Claus Sulfur Recycle System With Zinc Titanate
7 Effect of Zinc Titanate Debottlenecking on Existing Tail; Gas Treatment Systems
7.1 Selectox
7.2 SuperClaus99
7.3 Superclaus 99.5
7.4 SCOT Process
7.5 Zinc Titanate as a Claus Tail Gas Treatment
7.6 H2S Removal Efficiency With Zinc Titanate
8 Effects on COS and CS2 Formation
9 Questions for further Investigation
FIGURES
Figure 1 Claus Unit and TGCU
Figure 2 Claus Process
Figure 3 Typical Claus Sulfur Recovery Unit
Figure 4 Two-Stage Claus SRU
Figure 5 The Super Claus Process
Figure 6 SCOT
Figure 7 SCOT/BSR-MDEA (or clone) TGCU
REFERENCES: PATENTS
US4333855_PROMOTED_ZINC_TITANATE_CATALYTIC_AGENT
US4394297_ZINC_TITANATE_CATALYST
US6338794B1_DESULFURIZATION_ZINC_TITANATE_SORBENTS
Test Case Design Techniques as chapter 4 of ISTQB Foundation. Topics included are Equivalence Partition, Boundary Value Analysis, State Transition Testing, Decision Table Testing, Use Case Testing, Statement Coverage, Decision Coverage, Error Guessing, Exploratory Testing, Checklist Based Testing
Move Auth, Policy, and Resilience to the PlatformChristian Posta
Developer's time is the most crucial resource in an enterprise IT organization. Too much time is spent on undifferentiated heavy lifting and in the world of APIs and microservices much of that is spent on non-functional, cross-cutting networking requirements like security, observability, and resilience.
As organizations reconcile their DevOps practices into Platform Engineering, tools like Istio help alleviate developer pain. In this talk we dig into what that pain looks like, how much it costs, and how Istio has solved these concerns by examining three real-life use cases. As this space continues to emerge, and innovation has not slowed, we will also discuss the recently announced Istio sidecar-less mode which significantly reduces the hurdles to adopt Istio within Kubernetes or outside Kubernetes.
Corporate Open Source Anti-Patterns: A Decade LaterScyllaDB
A little over a decade ago, I gave a talk on corporate open source anti-patterns, vowing that I would return in ten years to give an update. Much has changed in the last decade: open source is pervasive in infrastructure software, with many companies (like our hosts!) having significant open source components from their inception. But just as open source has changed, the corporate anti-patterns around open source have changed too: where the challenges of the previous decade were all around how to open source existing products (and how to engage with existing communities), the challenges now seem to revolve around how to thrive as a business without betraying the community that made it one in the first place. Open source remains one of humanity's most important collective achievements and one that all companies should seek to engage with at some level; in this talk, we will describe the changes that open source has seen in the last decade, and provide updated guidance for corporations for ways not to do it!
Enterprise Knowledge’s Joe Hilger, COO, and Sara Nash, Principal Consultant, presented “Building a Semantic Layer of your Data Platform” at Data Summit Workshop on May 7th, 2024 in Boston, Massachusetts.
This presentation delved into the importance of the semantic layer and detailed four real-world applications. Hilger and Nash explored how a robust semantic layer architecture optimizes user journeys across diverse organizational needs, including data consistency and usability, search and discovery, reporting and insights, and data modernization. Practical use cases explore a variety of industries such as biotechnology, financial services, and global retail.
Leveraging AI for Software Developer Productivity.pptxpetabridge
Supercharge your software development productivity with our latest webinar! Discover the powerful capabilities of AI tools like GitHub Copilot and ChatGPT 4.X. We'll show you how these tools can automate tedious tasks, generate complete syntax, and enhance code documentation and debugging.
In this talk, you'll learn how to:
- Efficiently create GitHub Actions scripts
- Convert shell scripts
- Develop Roslyn Analyzers
- Visualize code with Mermaid diagrams
And these are just a few examples from a vast universe of possibilities!
Packed with practical examples and demos, this presentation offers invaluable insights into optimizing your development process. Don't miss the opportunity to improve your coding efficiency and productivity with AI-driven solutions.
How to Optimize Call Monitoring: Automate QA and Elevate Customer ExperienceAggregage
The traditional method of manual call monitoring is no longer cutting it in today's fast-paced call center environment. Join this webinar where industry experts Angie Kronlage and April Wiita from Working Solutions will explore the power of automation to revolutionize outdated call review processes!
Database Management Myths for DevelopersJohn Sterrett
Myths, Mistakes, and Lessons learned about Managing SQL Server databases. We also focus on automating and validating your critical database management tasks.
Chapter 3 of ISTQB Foundation 2018 syllabus with sample questions. Answers about what is static testing, what is review, types of review, informal review, walkthrough, technical review, inspection.
CNSCon 2024 Lightning Talk: Don’t Make Me Impersonate My IdentityCynthia Thomas
Identities are a crucial part of running workloads on Kubernetes. How do you ensure Pods can securely access Cloud resources? In this lightning talk, you will learn how large Cloud providers work together to share Identity Provider responsibilities in order to federate identities in multi-cloud environments.
The "Zen" of Python Exemplars - OTel Community DayPaige Cruz
The Zen of Python states "There should be one-- and preferably only one --obvious way to do it." OpenTelemetry is the obvious choice for traces but bad news for Pythonistas when it comes to metrics because both Prometheus and OpenTelemetry offer compelling choices. Let's look at all of the ways you can tie metrics and traces together with exemplars whether you're working with OTel metrics, Prom metrics, Prom-turned-OTel metrics, or OTel-turned-Prom metrics!
MySQL InnoDB Storage Engine: Deep Dive - MydbopsMydbops
This presentation, titled "MySQL - InnoDB" and delivered by Mayank Prasad at the Mydbops Open Source Database Meetup 16 on June 8th, 2024, covers dynamic configuration of REDO logs and instant ADD/DROP columns in InnoDB.
This presentation dives deep into the world of InnoDB, exploring two ground-breaking features introduced in MySQL 8.0:
• Dynamic Configuration of REDO Logs: Enhance your database's performance and flexibility with on-the-fly adjustments to REDO log capacity. Unleash the power of the snake metaphor to visualize how InnoDB manages REDO log files.
• Instant ADD/DROP Columns: Say goodbye to costly table rebuilds! This presentation unveils how InnoDB now enables seamless addition and removal of columns without compromising data integrity or incurring downtime.
Key Learnings:
• Grasp the concept of REDO logs and their significance in InnoDB's transaction management.
• Discover the advantages of dynamic REDO log configuration and how to leverage it for optimal performance.
• Understand the inner workings of instant ADD/DROP columns and their impact on database operations.
• Gain valuable insights into the row versioning mechanism that empowers instant column modifications.
The presentation will delve into the ASIMOV project, a novel initiative that leverages Retrieval-Augmented Generation (RAG) to provide precise, domain-specific assistance to telecommunications engineers and technicians. The session will focus on the unique capabilities of Milvus, the chosen vector database for the project, and its advantages over other vector databases.
Attending this session will give you a deeper understanding of the potential of RAG and Milvus DB in telecommunications engineering. You will learn how to address common challenges in the field and enhance the efficiency of their operations. The session will equip you with the knowledge to make informed decisions about the choice of vector databases, and how best to use them for your use-cases
Tool Support for Testing as Chapter 6 of ISTQB Foundation 2018. Topics covered are Tool Benefits, Test Tool Classification, Benefits of Test Automation and Risk of Test Automation
Communications Mining Series - Zero to Hero - Session 2DianaGray10
This session is focused on setting up Project, Train Model and Refine Model in Communication Mining platform. We will understand data ingestion, various phases of Model training and best practices.
• Administration
• Manage Sources and Dataset
• Taxonomy
• Model Training
• Refining Models and using Validation
• Best practices
• Q/A
Multivendor cloud production with VSF TR-11 - there and back again
The Design and Layout of Vertical Thermosyphon Reboilers
1. GBH Enterprises, Ltd.
Process Engineering Guide:
GBHE-PEG-HEA-515
The Design and Layout of Vertical
Thermosyphon Reboilers
Information contained in this publication or as otherwise supplied to Users is
believed to be accurate and correct at time of going to press, and is given in
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(statutory or otherwise) is excluded except to the extent that exclusion is
prevented by law. GBHE accepts no liability resulting from reliance on this
information. Freedom under Patent, Copyright and Designs cannot be assumed.
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2. Process Engineering Guide:
The Design and Layout of
Vertical Thermosyphon
Reboilers
CONTENTS
SECTION
0
INTRODUCTION/PURPOSE
3
1
SCOPE
3
2
FIELD OF APPLICATION
3
3
DEFINITIONS
3
4
THE DESIGN PROBLEM
4
5
COMPUTER PROGRAMS
6
GENERAL CONSIDERATIONS
5
6.1
6.2
Heating Medium Temperature
Fouling Resistance
5
6
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3. 7
DESIGN PARAMETERS
7
7.1
7.2
Overall Arrangement and Specifications
Geometry Elements
7
7
8
ANALYSIS OF COMMERCIALLY AVAILABLE
PROGRAM RESULTS
10
8.1
8.2
8.3
8.4
Main Results
Supplementary Results
Error Analysis
Adjustments to Design
10
11
11
12
9
OPERATING RANGE
38
10
CONTROL
14
10.1
10.2
10.3
Control of Condensing Heating Medium Pressure
Control of The Condensate Level
Control of Sensible Fluid Flow Rate
15
15
15
11
LAYOUT
55
11.1
11.2
Factors Influencing Design
A Standard Layout
15
17
12
BIBLIOGRAPHY
24
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4. APPENDICES
A
ESTIMATION OF FOULING RESISTANCE FROM
PLANT DATA
25
FIGURES
1
TYPICAL SKETCH
4
2
THERMOSYPHON REBOILER EXIT HEADERS
10
3
ILLUSTRATION OF RECOMMENDED RATING PROCEDURE
WITH COMMERCIALLY AVAILABLE PROGRAMS
13
METHODS OF REBOILER CONTROL
14
4
5 (a) BASIC LINE DIAGRAM WITH INTERNAL WEIR
19
5 (b) BASIC LINE DIAGRAM WITHOUT WEIR
19
6 (a) TYPICAL DIMENSIONS WITH INTERNAL WEIR
20
6 (b) TYPICAL DIMENSIONS WITHOUT WEIR
20
7
ISOMETRIC OF TYPICAL LAYOUT WITH WEIR
21
8
FRI RECOMMENDATIONS FOR LARGE COLUMN INLETS
22
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5. 9
10
REBOILER, SUMP AND PUMPING TANK SMALL
DIAMETER COLUMNS
23
TYPICAL FOULING CURVE (VC3 HCI STILL)
26
DOCUMENTS REFERRED TO IN THIS PROCESS
ENGINEERING GUIDE
26
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6. 0
INTRODUCTION/PURPOSE
This Guide is one of a series on heat transfer produced for GBH Enterprises.
Vertical thermosyphon reboilers require care in their thermal design and layout to
avoid operational problems. This Guide describes the recommended design
method and gives advice on layout.
1
SCOPE
Vertical Thermosyphon Reboilers (VTRs) are one of several types of reboiler that
may be used on distillation columns. A review of the relative merits of the
different types is given in GBHE-PEG-HEA-507.
This Guide assumes that the decision has already been taken to specify a VTR.
It outlines recommended methods for the process design of vertical
thermosyphon reboilers, considering basic thermal design, control and layout.
2
FIELD OF APPLICATION
This Guide is intended for process engineers and plant operating personnel in
GBH Enterprises worldwide, who may be involved in the specification, design or
operation of vertical thermosyphon reboilers.
3
DEFINITIONS
For the purposes of this Guide, the following definitions apply:
FRI
Fractionation Research Incorporated. A co-operative research
organization, based in the USA, involved in research into distillation
in industrial sized equipment, and the production of design guides
and computer programs for the design of such equipment.
HTRI
Heat Transfer Research Incorporated. A co-operative research
organization, based in the USA, involved in research into heat
transfer in industrial sized equipment, and the production of design
guides and computer programs for the design of such equipment.
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7. HTFS
4
Heat Transfer and Fluid Flow Service. A co-operative
research organization, with headquarters in the, UK, involved in
research into the fundamentals of heat transfer and two phase flow
and the production of design guides and computer programs for the
design of industrial heat exchange equipment.
THE DESIGN PROBLEM
General information on VTRs is given in references [3], [4].
When the process fluid boils in the tubes of the reboiler the resulting two-phase
mixture has a lower density than the single-phase liquid in the column sump. This
density difference induces a circulation of the process fluid from the sump, up
through the boiler and back into the column shell. The resulting flow enhances
the heat transfer and is responsible for the high performance that can be
obtained from a VTR.
The basic problem in the design of thermosyphon boilers is that the heat transfer
performance is coupled to the circulation rate, which is not known a priori.
Iteration is necessary to match the driving force due to the density difference with
the pressure drop from the circulation. The iteration is best performed with the
aid of a computer program.
An additional consideration is that badly designed thermosyphon boilers may
operate in an unstable manner, with circulations and heat loads fluctuating wildly
over short time periods. Such instabilities can have a serious effect on column
performance, leading in extreme cases to alternate periods of flooding and
dumping. The exchanger and associated circulation pipework needs to be
designed to avoid this. See 7.2.4 and 7.2.5.
5
COMMERCIAL OMPUTER PROGRAMS: PROPRIETARY
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8. 6
GENERAL CONSIDERATIONS
6.1
Heating Medium Temperature
The majority of thermosyphon reboilers are heated with steam. The effective
maximum steam temperature is the saturation temperature of the steam at the
maximum pressure obtainable in the reboiler shell.
Note:
This is typically 7-10% below the boundary limits steam pressure due to line and
control valve pressure drops.
The design steam temperature should preferably be at least 20°C greater than
the column sump temperature; with lower temperature differences the reboiler
may fail to thermosyphon adequately. However, too high a steam temperature
may result in film boiling and increased fouling. Commercially available programs
will give warning of this.
Reboilers may also be heated with process fluids, a practice that is becoming
more common with the growth of process integration. If the heating medium is a
condensing fluid with a high condensing coefficient it can be considered in the
same way as steam, but if a single-phase heating medium is used, the shell side
thermal resistance is liable to be dominant. Careful attention should be given to
maximizing the shell side coefficient to take advantage of the high tubeside
coefficients normally obtained from VTRs.
Another consequence of using a single-phase fluid, or a process fluid with a wide
condensing range, as the heating medium is that its temperature will fall across
the exchanger. If the boiling fluid is a single component or a narrow boiling range
mixture, the heating medium should be arranged to be co-current to the boiling
fluid, to maximize the temperature difference at the bottom of the tubes. This will
result in earlier nucleate boiling and improved circulation. On the other hand, with
a wide boiling range mixture the boiling point may rise as the fluid passes up the
tube, in spite of the reduction in static pressure, and counter-current flow of the
heating medium may be better.
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9. 6.2
Fouling Resistance
Thermosyphon boilers are designed to achieve a high boiling coefficient. As a
result, the fouling resistance may be a major part of the total resistance, and is
thus a critical factor in the design.
The fouling resistance for condensing steam can be taken as 0.00005 - 0.0001
m2K/W. For a process fluid as heating medium, a fouling resistance appropriate
for the particular fluid should be used.
At present, the only way to get a realistic boiling fluid fouling resistance for a
design is to measure the performance of a comparable boiler, i.e. one with a
similar fluid boiling at a similar temperature and with a similar heat flux, flow
regime and velocity. The fouling resistance can then be obtained from a
comparison of the computed clean performance and the actual performance
when fouled. Appendix A details the method. Since any inaccuracies in the
program correlations are lumped into the fouling resistance, it is advisable to use
the same computer program for design as for calculating the fouling resistance.
The fouling resistance for a boiler usually increases in an approximately linear
way with time. The resistance chosen for design, therefore, besides affecting the
boiler area, also determines the interval between cleanings. Typical cycle times
vary between about 2 months for a very heavy fouling duty to 12 months or more
for a light fouling duty. As it may be difficult to produce a sensible design that will
perform adequately in both the clean and very fouled conditions, it may be worth
installing a spare reboiler, with suitable means for switching over and isolating, to
enable one boiler to be cleaned without a lengthy plant shut-down. See also
Clause 9.
Some typical fouling resistances for chlorinated hydrocarbons are:
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10. Here rdi is the fouling resistance based on the tube inside area in m2K/W and W
is the time since cleaning in weeks. These values were calculated from data in
references [6] and [9], using a proprietary program.
7
DESIGN PARAMETERS
7.1
Overall Arrangement and Specifications
The first step in a proper design procedure for a vertical thermosyphon reboiler is
a review of the operating specifications and geometric design elements.
The required duty is specified by the Process requirements:
(a)
Heat duty.
(b)
Boiling fluid pressure, temperature, composition and physical properties.
(c)
Heating medium pressure, temperature, composition and properties.
Geometric information is required by the program:
(1)
Tube length, inside and outside diameter and pitch.
(2)
Baffle spacing and cut.
(3)
Inlet piping length, diameter and details of fittings.
(4)
Outlet piping diameter, length, layout and details of fittings.
(5)
Liquid static head in the column sump, measured above the lower
tubesheet.
A sketch of the basic layout, such as shown in Figure 1, is recommended. The
major resulting dependent variables obtained from the computer calculation will
be the actual heat duty and the circulation rate/exit vapor fraction.
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11. 7.2
Geometry Elements
The major variables under the control of the designer are:
(a)
Tube diameter.
(b)
Tube length.
(c)
Liquid head.
(d)
Inlet and outlet pipework design.
Typical ranges of variables are given below as guides. These ranges may be
exceeded in special cases when required, but then more careful analysis of the
results should be made.
7.2.1 Tube Diameter
The normal range for tube outside diameter is ¾" to 2" (19.05 - 50.8 mm). Within
this range, larger values are required for vacuum operation, operation near the
critical point or high viscosity fluids. Smaller values, which usually mean lower
cost, may be used for moderate pressure and clean fluids. ¾" and 1" are the
most common sizes. See GBHE-PEG-HEA-512 for details on preferred tube
size, wail thickness and tube pitch.
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12. FIGURE 1
TYPICAL SKETCH
7.2.2 Tube Length
The normal range is 1.5 to 6 m (4 to 20 ft). Short tubes are used when required
to obtain sufficient circulation, or because of small available head. Longer tubes,
which usually mean lower cost for the exchanger, are used where possible, but
circulation should be checked carefully; watch for mist flow. The liquid velocity
into a thermosyphon boiler initially increases as the tube length is reduced, but
falls off again for short tubes. A reboiler with very short tubes may not
thermosyphon adequately.
Note:
Although a long thin exchanger is cheaper than a short fat one, it does require
the column base elevation to be greater, which may mean a higher and more
expensive skirt.
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13. 7.2.3 Liquid Head
For boilers operating from atmospheric to moderate pressures it is common
practice to design for the liquid level in the column sump to be on a level with the
top tube-plate of the reboiler. This is generally satisfactory.
For high pressure operation, it may be beneficial to increase the liquid head to
improve the liquid circulation rate.
Note:
This will require longer exit piping and a taller column skirt.
For vacuum operation a lower liquid level gives improved performance as it
reduces the length of the sub-cooled zone, where heat transfer is relatively poor.
There is an optimum liquid head for a given duty, which may be less than two
thirds of the tube length. However, as static head is reduced, the exit vapor
fraction is increased and care should be taken to prevent this rising above 0.5 if
possible.
7.2.4 Outlet Piping
Badly designed thermosyphon boilers may operate in an unstable manner, with
fluctuating circulations and heat loads. Such instabilities can have a serious
effect on column performance, leading in extreme cases to alternate periods of
flooding and dumping. Increased flow resistance in the outlet piping from the
reboiler to the column increases the tendency to unstable operation, whereas
resistance in the inlet pipework has a stabilizing effect.
According to HTRI, more operating problems are due to small exit piping than to
any other single reason. The ratio of exit piping frictional pressure drop to total
pressure drop should never exceed 0.3; the recommended value is 0.1. The ratio
of exit pipe cross-sectional area to total tube cross-sectional area should not be
less than 0.75 unless there is a very special reason and careful design. The
recommended value is 1.0.
Long radius elbows and 90° tee type exits of the same minimum cross-section
were found by HTRI to give similar overall reboiler performance. (See Figure 2
for sketches of the various types.) The 90° tee has the advantage of shorter
piping and a lower column first tray; the long radius elbow permits a higher liquid
level. For most cases the 90° tee is the cheapest solution. The mitred exit piping
("lobster back") which is sometimes used would seem to have no real
advantages.
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14. FIGURE 2
THERMOSYPHON REBOILER EXIT HEADERS
7.2.5 Inlet Piping
This can be small, giving a ratio of the inlet pipe pressure drop to the total
pressure drop of up to 0.3, provided the resulting exit vapor fraction does not
exceed the recommended maximum value (0.5 for vacuum duties, 0.35 for other
cases). Relatively high inlet resistance increases the boiler stability and reduces
inlet sub-cooling.
It is almost always possible to stabilize an otherwise unstable boiler by increasing
the inlet resistance. It is good practice to install a valve (a butterfly valve is
adequate), or at the minimum an orifice plate carrier, in the inlet pipework for this
purpose at the design stage.
8
ANALYSIS OF COMMERCIALLY AVAILABLE PROGRAM RESULTS
Results generated by commercially available programs should be studied
carefully to identify potential problems. Adjustments to the design can then be
made. An illustrated example follows:
The results of particular interest for thermosyphons are:
(a)
‘PERFORMANCE OF THE UNIT’.
(b)
‘THERMOSYPHON STABILITY ASSESSMENT’.
(c)
The ‘TUBE WALL TEMPERATURE PROFILE’.
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15. 8.1
Main Results
The following items require particular attention. The normal range for the
expected values is given.
Note:
Some of these items are not given explicitly, but have to be calculated from the
other values.
Weight fraction vapor in the exit:
0.05 – 0.35 (0.5 for vacuum)
This is the ratio of the total vapor + gas
in the outlet to the total fluid
flowing.
Design velocity:
(a) above atmospheric
(b) vacuum
This is the inlet velocity to the tubes,
obtained by dividing the volumetric liquid
flowrate entering the exchanger by the
total inside cross section of the tubes.
0.3 – 1.5 m/s
0.03 – 0.3 m/s
Average heat transfer coefficient
Design heat flux
The total heat duty divided by
the inside surface area (corrected by the
ratio of inside to outside tube diameters).
1000 – 6000 W/m2.K
10000 – 100,000 W/m2
8.2
Supplementary Results
The most important items are:
(a)
Thermosyphon Stability
Assessment
When rating a thermosyphon
boiler, commercially available programs
will always perform this assessment,
based on proprietary methods.
These programs will indicate whether or
not the system is stable. If there are
indications of stability problems, steps
should be taken to correct the design
(see below).
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16. (b)
Physical properties
These should always be checked
to see if they are within reasonable
range. When rating a thermosyphon
boiler, at least two sets of physical
properties data for the boiling fluid, at
pressures which span the expected
pressure change within the boiler,
should be given, so that the program
can take account of the variation in
properties with pressure. The program
output should include the predicted
pressure and temperature variation
through the exchanger, and
corresponding liquid and vapor
properties.
(c) Length of the liquid zone
This should be less than one quarter of
the tube length for effective design. This
item may be deduced from the TUBE
WALL TEMPERATURE PROFILE and
is the length over which the quality
remains zero.
(d) Flow regimes
The predicted flow regime (bubble,
churn, annular) is
generated for each increment of the
TUBE WALL TEMPERATURE
PROFILE. The ideal flow regime at exit
is annular.
(e) Temperature profiles
These should be checked to ensure that
no near pinch conditions are present
along the tube.
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17. 8.3
Error Analysis
Should be self explanatory, and the appropriate action should be taken.
8.4
Adjustments to Design
If a problem or inadequate performance warning is found it is usually possible to
adjust design details to prevent the problem. Some typical adjustments are given
below; where more than one solution is given, they are in order of preference.
Problem
Adjustment
Vapor fraction too high or
mist flow indication
Increase exit pipework diameter.
Increase tube diameter.
Decrease tube length.
Vapor fraction too low
Decrease tube diameter.
Increase inlet flow resistance.
Increase tube length.
Film boiling
Decrease temperature difference.
Increase tube diameter.
Instability
Decrease exit flow resistance.
Increase inlet flow resistance.
Decrease temperature difference.
Long liquid zone
Decrease static head.
Increase inlet flow resistance.
Add sparge gas.
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18. 9
OPERATING RANGE
A thermosyphon reboiler will be designed for the maximum anticipated heat duty
with the highest anticipated level of fouling. When first installed, or after periodic
cleaning, the fouling resistance will be considerably less. Moreover, it is often
required to run the boiler at rates below the design heat duty. It is good practice
to simulate the performance of the unit at likely operating conditions away from
the design point to see if any problems are evident, for example instability. This
can be done by repeated runs using commercially available programs. Such a
check should also include the design case, using the actual geometry of the
exchanger and associated pipework, which may differ from that assumed at the
design stage.
The results of such a study can be presented by plotting the heat duty against
the overall temperature difference for the clean and fouled condition, as
illustrated in Figure 3. The curves will in general have a maximum and minimum,
although these may not lie within the range of temperature difference available.
The maximum represents the onset of film boiling, with a subsequent fall-off in
performance. It can be seen that beyond this point there is a region where
increasing the driving force actually results in a fall-off in performance, which is
one reason why partial film boiling is to be avoided.
Ideally, the exchanger should perform to the left of the maximum under all
conditions. However, it may be found that film boiling results in the clean
condition if the maximum heating fluid temperature is used. Unless care is taken
to limit the temperature in these circumstances, rapid fouling is likely, which may
quickly convert the operation to the more stable, but fouled, condition.
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19. FIGURE 3 ILLUSTRATION OF RECOMMENDED RATING PROCEDURE
The results of the study may also indicate operational problems such as
instability. Sometimes it is possible to improve this by suitable changes, but in
some cases no totally satisfactory design will be found which meets all the
operating requirements under both clean and fouled conditions. In these
circumstances it is worth questioning whether a VTR is the most appropriate
design. This is particularly likely to occur for deep vacuum operation or at
pressures approaching the critical pressure.
Particular problems can occur if a boiler is required to operate on widely different
fluids at different times. This could be because at start-up, before recycle
streams have had a full effect, the composition of the column bottoms product
differs from the flowsheet case.
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20. Alternatively, the boiler may be part of a multi-purpose plant and be required to
perform different duties, depending on the product being made. Again, it is
essential to simulate all likely conditions, and again, a VTR may not be the most
appropriate choice of boiler.
10
CONTROL
There are three common ways of controlling a VTR, which are illustrated in
Figure 4.
FIGURE 4
METHODS OF REBOILER CONTROL
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21. 10.1
Control of Condensing Heating Medium Pressure
This is the most common form of control for steam heated boilers and is the
preferred method in most cases. A control valve in the steam supply line reduces
the pressure in the reboiler shelf, and hence the condensing temperature.
Start-up is typically simulated in commercially available programs by eliminating
the fouling resistances and reducing the heating medium temperature and
pressure until the design duty is matched.
Note:
If a boiler is designed for a high fouling resistance and heated with LP steam, the
required steam pressure for clean conditions may be below atmospheric
pressure, which will usually give problems in removing the condensate.
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22. 10.2
Control of the Condensate Level
In cases where it is not possible to reduce the heating medium pressure
sufficiently, such as where the condensing pressure would be below atmospheric
pressure, the condensate exit flow can be restricted to flood the lower portion of
the shell. This condensate will then cool to near the boiling fluid temperature,
effectively reducing the tube length. This method has many disadvantages and
should only be used as a last resort. It should never be used when the design
temperature difference is high enough to cause mist flow or film boiling
under clean conditions.
Start-up is simulated by eliminating the fouling resistance and decreasing the
tube length and static head until the design condition is reached. This ignores the
liquid friction loss in the flooded portion of the tubes, but this is usually negligible.
10.3
Control of Sensible Fluid Flow Rate
For a sensible heating medium, flow of the heating medium is by-passed around
the reboiler to decrease the heating medium heat transfer coefficient and exit
temperature. A potential problem is accelerated shell side fouling due to low
velocity on start-up. Start-up is simulated by eliminating the fouling factor and
reducing the heating medium flowrate until the design duty is met.
11
LAYOUT
11.1
Factors Influencing Design
(a)
The object of the thermosyphon reboiler is to save money by
having a fast circulation through the boiler tubes and hence a good
heat transfer coefficient. This is to some extent offset by the
requirement for long tubes, which increases the overall height of
the installation.
(b)
The return pipework from the boiler to the column should have a
low hydraulic resistance to reduce the possibility of instability.
However, as explained above, the tee type return is adequate for
most cases.
(c)
The vapor-liquid lift over the sump liquid level should be as low as
possible.
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23. (d)
Possible thermal degradation of the boiler contents, and increasing
concerns over large inventories of boiling liquids, require the
minimum hold-up in the system. (However, there must be adequate
residence time for control purposes.)
(e)
Provision is often required for an installed spare boiler. Even if this
is not provided initially, the layout should preferably allow for the
addition of this feature at a later stage.
(f)
Provision should be made for a valve in the liquid line to the boiler
to provide variable resistance to improve stability. This is good
practice even if the stability checks done at the design stage do not
indicate any problems; as such checks cannot be regarded as
totally reliable.
(g)
A valve or slip-plate in the liquid line, together with a slip plate in the
two-phase line to the column should be considered for isolation,
particularly if a spare boiler is to be provided.
(h)
The large carry-over of liquid in the return pipe to the column,
typically over 75% by weight, means that allowance must be made
for:
(1)
(2)
Avoiding erosion of the column wall.
(3)
(j)
Separation of the vapor-liquid mixture in the space between
the sump and the bottom tray or packing support grid.
Avoiding obstruction of the flow of liquid from the bottom tray
seal pan in plate columns.
For economic reasons it is usually better to use the column base or
skirt as a pumping tank rather than have a separate vessel,
especially as the extra height penalty has already been incurred by
using a VTR.
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24. (k)
Control problems.
There are two level control duties, associated with the base of the
column, which may be separated: the liquid head above the boiler
must be kept at its design value, and the bottoms pump-off rate
must be controlled.
Level control can be difficult because of the turbulent conditions in
the column sump. Control of the liquid level over the boiler should
be accurate and steady, particularly for vacuum duties. Some plant
operators have an established practice to carry this out by means
of a weir. This has the advantage of separating this duty from the
control of the off-take, allowing the level of the latter to fluctuate if
necessary, which may permit a shorter residence time in the sump,
with consequently less thermal degradation. The pump necessarily
requires a LIC of some sort; the requirement will be determined by
the degree of smoothing required on the outflow.
In certain cases where heavy fouling is known to occur, it is best to
avoid the use of a weir and baffle system because of the risk of
blockages. In these cases accurate instrumentation is required to
maintain the sump level at the required height over the boiler to
within ±25 mm. The system then offers little smoothing of the
bottoms flow from the column, particularly in small diameter
columns, and an external pumping tank may be required.
Some plant operators control the level for the boiler by a weir is
considered unusual, and satisfactory operation is achieved with a
single control of level for both the boiler recirculation and the
bottoms off-take.
The difference in approach between the, two aforementioned plant
operations may be attributed at least partly to the difference in
scale of operation. It is recommended that in the one case, the
approach to be adopted for columns in excess of 1.5 m in diameter,
and the other case, an approach for smaller diameter columns.
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25. (l)
11.2
Differential expansion. Provision has to be made for
differential expansion between the reboiler and the column shell.
The return vapor-liquid pipework from the top of the reboiler will be
of a relatively large diameter and should be short to reduce flow
resistance, so there is little possibility of building flexibility into it
other than with a bellows. The liquid pipework, on the other hand, is
of relatively small diameter, and extra resistance in it is of little
concern; indeed, it may help to stabilize the system. Ideally, the top
of the boiler should be supported off the column, or both of them
supported at the same level, with the liquid pipework designed to
be flexible.
A Standard Layout
The line diagrams given in Figure 5 show the basic requirements of an
installation; 5(a) shows a system with an internal baffle, and 5(b) without. These
diagrams will require elaboration to cover the requirements of the particular case
under consideration. Figure 6 gives typical dimensions of the lower part of the
distillation column and Figure 7 shows an isometric sketch of the layout. Figures
8(a) - 8(c) show the recommendations of FRI (reference [8]) for inlets to large
diameter (above 1.5 m) columns.
Points to note are as follows:
(a)
For columns below 1.5 m diameter with weir control, the vapor-liquid
return pipe is at least 100 mm above the liquid level; 200 mm or more may
be necessary to avoid froth interference. This greater height may also be
required for systems without a baffle, to allow for less precise level control.
For large diameter columns, above 1.5 m diameter, FRI recommend a
minimum height of 300 mm.
(b)
The two-phase mixture returned to the column can potentially erode the
column shell. In small diameter columns this can be avoided by the use of
an impingement plate on the column wall. For large diameter columns,
where this plate may become excessive, an inlet deflector such as shown
on Figure 8(a) may be preferable, to divert the incoming mixture down
towards the surface. In this case it is particularly important to provide
adequate clearance between the liquid level and the inlet, to avoid splash
carry-over. The deflector design type B is the most common; designs C or
E will have lower pressure drops, and thus fewer tendencies to restrict
circulation or cause instability. Some plant operators install a deflector.
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26. (c)
In Figure 5(a), the liquid level in the sump supplying the reboiler is
controlled by a weir; the level in the base of the column, acting as a
pumping tank is lower than this and is controlled by a level controller
acting on the pump discharge. In Figure 5(b), the level controller performs
both duties.
(d)
With weir control, the bottom downcomer is double sealed to cover the
start-up condition.
(e)
The vapor-liquid return to the column does not obstruct the downcomer
operation. It is desirable to arrange the vapor-liquid return to be at right
angles to the centre line of the downcomer.
(f)
For the baffled system, the internal pumping tank liquor entry is protected
by a baffle acting as an 'umbrella' to prevent spray failing into it.
(g)
Adequate space is provided for vapor-liquid disengagement. FRI (Figure
8) recommend a clearance between the top of the return pipe and the
bottom tray equal to the tray spacing, with a minimum of 18". This is
considered by GBH Enterprises to be excessive, especially for small
diameter columns, or if a deflector is used. A clearance of 2/3 of the tray
spacing, as in Figure 6, is adequate.
(h)
A second boiler can easily be added, arranged as a mirror image.
(j)
The liquid feed line to the boiler contains an isolation valve or spool piece
as well as a valve to act as a variable resistance. The latter could possibly
be combined with the isolation valve.
(k)
Note the provision of drain branches, manways and weepholes.
This layout can reasonably be used with columns down to about 0.75 m
diameter. For smaller diameter columns, the sump may become too long for a
good layout, and there are problems of access. In these cases an external
pumping tank should be used. A good layout is shown in Figure 9. Note the baffle
opposite the vapor-liquid inlet to the column to avoid erosion of the column wall.
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27. FIGURE 5 (a)
BASIC LINE DIAGRAM WITH INTERNAL WEIR
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28. FIGURE 5 (b)
BASIC LINE DIAGRAM WITHOUT WEIR
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29. FIGURE 6 (a)
TYPICAL DIMENSIONS WITH INTERNAL WEIR
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30. FIGURE 6 (b)
TYPICAL DIMENSIONS WITHOUT WEIR
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31. FIGURE 7
ISOMETRIC OF TYPICAL LAYOUT WITHOUT WEIR
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32. FIGURE 8
FRI RECOMMENDATIONS FOR LARGE COLUMN INLETS
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33. FIGURE 9
REBOILER, SUMP AND PUMPING TANK SMALL DIAMETER
COLUMNS
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34. 12
BIBLIOGRAPHY
[1]
'The layout and general arrangement of vertical thermosyphon reboilers.'
W H Orrell, September 1971.
[2]
'Process design of vertical thermosyphon reboilers. 'P D Hills, May 1982.
[3]
HTRI Design Manual Volume 2, Section D5.3.
[4]
HTFS Design Report 'The design of vertical thermosyphon reboilers.'
D Butterworth, R A W Shock, 1975.
[5]
HTFS Handbook 'Vertical thermosyphon reboilers.'
[6]
'Comparison of two computer programs used in the design and
rating of vertical thermosyphon reboilers.' R C Barker, January 1980.
[7]
‘Performance of vertical thermosyphon reboilers’. B P Richardson,
March 1973.
[8]
FRI Design Practices Manual.
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35. APPENDIX A
ESTIMATION OF FOULING RESISTANCE
FROM PLANT DATA
Plant data form the only reliable source of fouling resistances. It should be
remembered, however, that such data refer strictly only to the specific boiler from
which they were obtained and should be used with caution if the new design
differs in process composition, temperature or flowrate.
Some commercially available programs have an option, for evaluating the
‘Differential Resistance’, which enables the program to estimate the fouling
resistance necessary to match program prediction to observed plant
performance.
There are two ways to estimate fouling resistances from plant data. In
both cases it is necessary to have the heat load (obtained, for example, from the
steam flow to the boiler), the conditions in the column sump and the heating
medium temperature.
A1
MANUAL ITERATION
This method requires the user to perform repeated runs of the program, adjusting
the input fouling resistance until the predicted heat load matches the plant data.
Although this method is easy to understand and use for one or two data sets, and
gives the fouling resistance directly, it is very inefficient in computing time if many
data sets are to be analyzed, as is the case if a plot of fouling resistance against
time since cleaning is to be generated. If there are many sets of data it is better
to generate a heat duty/temperature difference curve once, using the 'available
duty' method, and obtain the fouling resistance by a simple hand calculation.
A2
AVAILABLE DUTY METHOD
If the program is run with zero fouling resistance, it will calculate the heat load
obtainable from a clean exchanger with the given temperature difference. A
series of four or five such runs covering the range of heat duty of interest can be
used to generate a curve of heat duty against temperature difference. It is
convenient to use the apparent temperature difference (steam temperature –
sump temperature) rather than the true mean difference generated by the
program, as this is readily available from the plant data. Any errors generated
from this approximation are small compared with the likely scatter of the plant
data.
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36. The procedure for estimating the fouling resistance is as follows:
We have available a set of values of heat load, Q, and apparent temperature
difference in the fouled condition ΔTd .
From the curve of heat duty vs apparent temperature difference generated as
above, find the required temperature difference for each heat duty in a clean
condition ΔT c .
The temperature difference across the fouling layer ΔT f is then given by:
The total fouling resistance, based on the inside area, is then:
Where
A i is the reboiler inside area.
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37. FIGURE 10
TYPICAL FOULING CURVE (VC3 HCI STILL)
DOCUMENTS REFERRED TO IN THIS PROCESS ENGINEERING GUIDE
This Process Engineering Guide makes reference to the following documents:
GBH Enterprises Engineering Guides
GBHE-PEG-HEA-507
Selection of Reboilers for Distillation Columns
(referred to in Clause 1)
GBHE-PEG-HEA-512
Mechanical Constraints on Thermal Design of Shell and
Tube Exchangers (referred to in 7.2.1)
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38. Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
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39. Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
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