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
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
Steam ejector working principle
An ejector is a device used to suck the gas or vapour from the desired vessel or system. An ejector is similar to an of vacuum pump or compressor. The major difference between the ejector and the vacuum pump or compressor is it had no moving parts. Hence it is relatively low-cost and easy to operate and maintenance free equipment.
Types of Distillation & column internalsBharat Kumar
More:- https://chemicalengineeringworld.com
Distillation is a method of separating the components of a solution which depends upon distribution of the substances between a gas and liquid phase, applied to cases where all components are present in both phases.
* What is distillation ?
* Types of Distillation
* Batch Distillation
* Azeotropic Distillation
* Flooding
* Priming
* Coning
* Weeping
* Dumping
* Packed Column
* Tray column
* Reflux Ratio
* Relative volatility
* Distillation column
Distillation is a method of separating mixtures based on differences in volatility (volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure.) of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction
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
Steam ejector working principle
An ejector is a device used to suck the gas or vapour from the desired vessel or system. An ejector is similar to an of vacuum pump or compressor. The major difference between the ejector and the vacuum pump or compressor is it had no moving parts. Hence it is relatively low-cost and easy to operate and maintenance free equipment.
Types of Distillation & column internalsBharat Kumar
More:- https://chemicalengineeringworld.com
Distillation is a method of separating the components of a solution which depends upon distribution of the substances between a gas and liquid phase, applied to cases where all components are present in both phases.
* What is distillation ?
* Types of Distillation
* Batch Distillation
* Azeotropic Distillation
* Flooding
* Priming
* Coning
* Weeping
* Dumping
* Packed Column
* Tray column
* Reflux Ratio
* Relative volatility
* Distillation column
Distillation is a method of separating mixtures based on differences in volatility (volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure.) of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction
Design Considerations for Plate Type Heat ExchangerArun Sarasan
A plate heat exchanger is a type of heat exchanger that uses metal plates to transfer heat between two fluids. This has a major advantage over a conventional heat exchanger in that the fluids are exposed to a much larger surface area because the fluids spread out over the plates. This facilitates the transfer of heat, and greatly increases the speed of the temperature change. Plate heat exchangers are now common and very small brazed versions are used in the hot-water sections of millions of combination boilers. The high heat transfer efficiency for such a small physical size has increased the domestic hot water (DHW) flowrate of combination boilers. The small plate heat exchanger has made a great impact in domestic heating and hot-water. Larger commercial versions use gaskets between the plates, whereas smaller versions tend to be brazed.
Control of Continuous Distillation Columns
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 GENERAL DESCRIPTION OF A DISTILLATION COLUMN
5 REGULATORY CONTROL
5.1 Composition Control
5.2 Mass Balance Control
5.3 Design of Feedback Control Systems
5.4 Pressure and Condensation Control
5.5 Reboiler Control
6 DISTURBANCE COMPENSATION
6.1 Feed-forward Control
6.2 Cascade Control
6.3 Internal Reflux Control
7 CONSTRAINT CONTROL
7.1 Override Controls
7.2 Flooding
7.3 Limiting Control
8 MORE ADVANCED TOPICS
8.1 Temperature Position Control
8.2 Inferential Measurement
8.1 Floating Pressure Control
8.2 Model Based Predictive Control
8.1 Control of Side-streams
8.2 Extractive/Azeotropic Systems
9 REFERENCES
TABLES
1 SYMPTOMS OF IMBALANCE AND THE REGULATORY VARIABLES
2 PRACTICAL LINKAGES BETWEEN CONTROL
(P, R, B, C) AND REGULATION VARIABLES
(h, r, d, b, c, v)
3 COMPOSITION REGULATION
4 COMPOSITION REGULATION - VERY SMALL FLOWS
Reactor and Catalyst Design
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 CATALYST DESIGN
4.1 Equivalent Pellet Diameter
4.2 Voidage
4.3 Pellet Density
5 REACTOR DESIGN
6 CATALYST SUPPORT
6.1 Choice of Support
TABLES
1 CATALYST SUPPORT SHAPES
2 SECONDARY REFORMER SPREADSHEET
FIGURES
1 GRAPH OF EFFECTIVENESS v THIELE MODULUS
2 VARIATION OF COSTS WITH CATALYST SIZE
3 VARIATION OF COSTS WITH CATALYST BED VOIDAGE
4 VARIATION OF COSTS WITH VESSEL DIAMETER
• Types of heat exchangers
• Classification of heat exchangers
• components of heat exchanger
• Materials of heat exchanger
• troubleshooting of heat exchanger
The Design and Layout of Vertical Thermosyphon ReboilersGerard B. Hawkins
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
The processing technique employing a suspension or fluidization of small solid particles in a vertically rising stream of fluid usually gas so that fluid and solid come into intimate contact. This is a tool with many applications in the petroleum and chemical process industries. Suspensions of solid particles by vertically rising liquid streams are of lesser interest in modern processing, but have been shown to be of use, particularly in liquid contacting of ion-exchange resins. However, they come in this same classification and their use involves techniques of liquid settling, both free and hindered (sedimentation), classification, and density flotation.
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
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 ..........
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
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
Design Considerations for Plate Type Heat ExchangerArun Sarasan
A plate heat exchanger is a type of heat exchanger that uses metal plates to transfer heat between two fluids. This has a major advantage over a conventional heat exchanger in that the fluids are exposed to a much larger surface area because the fluids spread out over the plates. This facilitates the transfer of heat, and greatly increases the speed of the temperature change. Plate heat exchangers are now common and very small brazed versions are used in the hot-water sections of millions of combination boilers. The high heat transfer efficiency for such a small physical size has increased the domestic hot water (DHW) flowrate of combination boilers. The small plate heat exchanger has made a great impact in domestic heating and hot-water. Larger commercial versions use gaskets between the plates, whereas smaller versions tend to be brazed.
Control of Continuous Distillation Columns
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 GENERAL DESCRIPTION OF A DISTILLATION COLUMN
5 REGULATORY CONTROL
5.1 Composition Control
5.2 Mass Balance Control
5.3 Design of Feedback Control Systems
5.4 Pressure and Condensation Control
5.5 Reboiler Control
6 DISTURBANCE COMPENSATION
6.1 Feed-forward Control
6.2 Cascade Control
6.3 Internal Reflux Control
7 CONSTRAINT CONTROL
7.1 Override Controls
7.2 Flooding
7.3 Limiting Control
8 MORE ADVANCED TOPICS
8.1 Temperature Position Control
8.2 Inferential Measurement
8.1 Floating Pressure Control
8.2 Model Based Predictive Control
8.1 Control of Side-streams
8.2 Extractive/Azeotropic Systems
9 REFERENCES
TABLES
1 SYMPTOMS OF IMBALANCE AND THE REGULATORY VARIABLES
2 PRACTICAL LINKAGES BETWEEN CONTROL
(P, R, B, C) AND REGULATION VARIABLES
(h, r, d, b, c, v)
3 COMPOSITION REGULATION
4 COMPOSITION REGULATION - VERY SMALL FLOWS
Reactor and Catalyst Design
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 CATALYST DESIGN
4.1 Equivalent Pellet Diameter
4.2 Voidage
4.3 Pellet Density
5 REACTOR DESIGN
6 CATALYST SUPPORT
6.1 Choice of Support
TABLES
1 CATALYST SUPPORT SHAPES
2 SECONDARY REFORMER SPREADSHEET
FIGURES
1 GRAPH OF EFFECTIVENESS v THIELE MODULUS
2 VARIATION OF COSTS WITH CATALYST SIZE
3 VARIATION OF COSTS WITH CATALYST BED VOIDAGE
4 VARIATION OF COSTS WITH VESSEL DIAMETER
• Types of heat exchangers
• Classification of heat exchangers
• components of heat exchanger
• Materials of heat exchanger
• troubleshooting of heat exchanger
The Design and Layout of Vertical Thermosyphon ReboilersGerard B. Hawkins
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
The processing technique employing a suspension or fluidization of small solid particles in a vertically rising stream of fluid usually gas so that fluid and solid come into intimate contact. This is a tool with many applications in the petroleum and chemical process industries. Suspensions of solid particles by vertically rising liquid streams are of lesser interest in modern processing, but have been shown to be of use, particularly in liquid contacting of ion-exchange resins. However, they come in this same classification and their use involves techniques of liquid settling, both free and hindered (sedimentation), classification, and density flotation.
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
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 ..........
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
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
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
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
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
Selection and Use of Printed Circuit Heat ExchangersGerard B. Hawkins
Selection and Use of Printed Circuit Heat Exchangers
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 CONSTRUCTION
5 HEAT TRANSFER AND PRESSURE DROP
6 FOULING
7 MECHANICAL AND MATERIALS ASPECTS
8 COMPACTNESS
9 FLEXIBILITY
10 COST
11 GBHE EXPERIENCE 5
12 BIBLIOGRAPHY
APPENDICES
A HEAT TRANSFER AND PRESSURE DROP IN
WAVY PASSAGES
Electric Process Heaters
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 ADVANTAGES OF ELECTRIC HEATERS
4.1 Safety
4.2 Environment
4.3 Location of Equipment
4.4 Low Temperature Applications
4.5 Cross Contamination
4.6 Control
5 DISADVANTAGES OF ELECTRIC HEATERS
6 POTENTIAL APPLICATIONS FOR ELECTRIC
PROCESS HEATERS
7 GENERAL DESIGN AND OPERATING CONSIDERATIONS
8 TYPES OF PROCESS ELECTRIC HEATERS
8.1 Pipeline Immersion Heaters
8.2 Tank Heaters and Boilers
8.3 Indirect (Fluid Bath) Heaters
8.4 Radiant Furnaces
8.5 Induction Heaters
8.6 Hot Block Heaters
9 CONTROL
10 REFERENCES
FIGURES
1 ELECTRIC HEAT EXCHANGER CONSTRUCTION
2 SHEATHED HEATING ELEMENTS
Fouling Resistances for Cooling Water
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 GENERAL
5 COOLING WATER FOULING
6 CHROMATE SYSTEMS
6.1 General
6.2 Constraints
6.3 Requirements
6.4 Fouling resistances
7 NON-CHROMATE SYSTEMS
7.1 General
7.2 Requirements and Constraints
7.3 Fouling resistances
8 UNTREATED COOLING WATER
9 MATERIALS OTHER THAN MILD STEEL
APPENDICES
A FOULING RESISTANCES FOR COOLING WATER
B FOULING FILM THICKNESS
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
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
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
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
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
Integration of Special Purpose Reciprocating Compressors into a ProcessGerard B. Hawkins
1 SCOPE
2 CHOICE OF COMPRESSOR TYPE
2.1 Parameters
2.2 Preliminary Choice of Machine Type
2.3 Review of Other Types of Compressor
3 CHOICE OF NUMBER OF COMPRESSORS
3.1 Influence of Reliability Classification
3.2 Driver Considerations
3.3 Deterioration of Standby Machines
4 EFFECTS OF PROCESS GAS COMPOSITION
4.1 Particulate Contamination
4.2 Droplets in Suspension
4.3 Polymer Deposit
4.4 Molecular Weight Variation
4.5 Compressibility Variation
4.6 Gas Dryness
4.7 Gas Solution in Lubricating Oil for Cylinder and Gland
5 THROUGHPUT REGULATION
5.1 Inlet Line Throttle Valve
5.2 Inlet Line Cut-off Valve
5.3 Compressor Inlet Valve Lifter
5.4 Clearance Volume Variation
5.5 Speed Variation
5.6 Bypass
5.7 Hybrid Regulation Systems
6 PRINCIPAL FEATURES
6.1 Calculate Discharge Gas Temperature
6.2 Choice of Number of Stages
6.3 Configuration
6.4 Valve Operation Limit on Piston Speed
6.5 Limits for Mean Piston Speed
6.6 Estimation of Volumetric Efficiency
6.7 Estimation of Crankshaft Rotational Speed
6.8 Calculation of Piston Diameter
6.9 Choice of Number of Cylinders
7 DRIVER TYPE
7.1 Electric Motors
7.2 Steam Turbines
7.3 Special Drivers
8 VESSELS
APPENDICES
A RELIABILITY CLASSIFICATION
B CONDITIONS FOR LUBRICATED CYLINDERS AND GLANDS
C ESTIMATE OF LUBE OIL CONTAMINATION OF PROCESS GAS
D INFLUENCE OF GAS COMPOSITION AND MACHINE CONSTRUCTION
ON FILLED PTFE PISTON RING SEALS
E LIMITS ON GAS TEMPERATURES
FIGURES
1 SELECTION CHART
2 DESIGN SEQUENCE 1 - ESTIMATE NUMBER OF STAGES
3 DESIGN SEQUENCE 2 - ESTIMATE CYLINDER SIZES
Pressure Systems
CONTENTS
0 INTRODUCTION
1 SCOPE
2 DEFINITIONS ADDITIONAL TO THOSE IN THE EP GLOSSARY
2.1 PRESSURE VESSEL
2.2 ATMOSPHERIC PRESSURE STORAGE TANK
2.3 VESSEL
2.4 PIPING SYSTEM
2.5 NON-PRESSURE PROTECTIVE DEVICE
2.6 ASSOCIATED RELIEF EQUIPMENT
3 APPLICATION OF PRINCIPLES
3.1 IMPLEMENTATION OF PEG 4
3.2 DESIGN, MANUFACTURE, REPAIR AND MODIFICATION
3.3 VERIFICATION OF DESIGN
3.4 GBHE REGISTRATION AND RECORDS
3.5 PERIODIC EXAMINATION
4 AUDITING
4.1 General
4.2 Scope of Audit
APPENDICES
A EQUIPMENT WHICH MAY BE EXEMPTED FROM GBHE REGISTRATION
C DOCUMENTATION FOR INCLUSION IN FILES OF REGISTERED EQUIPMENT
D ADDITIONAL REQUIREMENTS FOR THE PERIODIC EXAMINATION OF SPECIAL CATEGORIES OF EQUIPMENT
E DIAGRAMMATIC REPRESENTATION OF PRESSURE SYSTEMS PROCEDURES
F DECISION TREE FOR REGISTRATION OF PIPING SYSTEMS
G REGISTERED EQUIPMENT WHICH MAY BE EXEMPTED FROM DESIGN VERIFICATION
TABLES
1 REGISTERED VESSELS AND PIPING SYSTEMS: MAXIMUM EXAMINATION INTERVALS
2 EQUIPMENT TO BE CONSIDERED FOR CATEGORY LLT
FIGURES
1 SIMPLE PRESSURE RELIEF ARRANGEMENT
2 COMPLEX PRESSURE RELIEF ARRANGEMENT
DOCUMENTS REFERRED TO IN THIS INFORMATION FOR ENGINEERS DOCUMENT
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
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
Similar to Selection and Design of Condensers (20)
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).
Pressure Relief Systems
BACKGROUND TO RELIEF SYSTEM DESIGN Vol.1 of 6
The Guide has been written to advise those involved in the design and engineering of pressure relief systems. It takes the user from the initial identification of potential causes of overpressure or under pressure through the process design of relief systems to the detailed mechanical design. "Hazard Studies" and quantitative hazards analysis are not described; these are seen as complementary activities. Typical users of the Guide will use some Parts in detail and others in overview.
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
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
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
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
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
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
"Impact of front-end architecture on development cost", Viktor TurskyiFwdays
I have heard many times that architecture is not important for the front-end. Also, many times I have seen how developers implement features on the front-end just following the standard rules for a framework and think that this is enough to successfully launch the project, and then the project fails. How to prevent this and what approach to choose? I have launched dozens of complex projects and during the talk we will analyze which approaches have worked for me and which have not.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
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- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
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Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
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Selection and Design of Condensers
1. GBH Enterprises, Ltd.
Process Engineering Guide:
GBHE-PEG-HEA-508
Selection and Design of Condensers
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
good faith, but it is for the User to satisfy itself of the suitability of the information
for its own particular purpose. GBHE gives no warranty as to the fitness of this
information for any particular purpose and any implied warranty or condition
(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.
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com
2. Process Engineering Guide:
Selection and Design of
Condensers
CONTENTS
SECTION
0
INTRODUCTION/PURPOSE
3
1
SCOPE
3
2
FIELD OF APPLICATION
3
3
DEFINITIONS
3
4
CHOICE OF COOLANT
4
5
LAYOUT CONSIDERATIONS
5
5.1
5.2
Distillation Column Condensers
Other Process Condensers
5
5
6
CONTROL
5
6.1
6.2
6.3
Distillation Columns
Water Cooled Condensers
Refrigerant Condensers
5
5
6
7
GENERAL DESIGN CONSIDERATIONS
6
7.1
7.2
7.3
7.4
7.5
Heat Transfer Resistances
Pressure Drop
Handling of Inerts
Vapor Inlet Design
Drainage of Condensate
6
7
7
8
8
8
SUMMARY OF TYPES AVAILABLE
9
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com
3. 8.1
8.2
8.3
8.4
8.5
8.6
8.7
8.8
Direct Contact Condensers
Shell and Tube Exchangers
Air Cooled Heat Exchangers
Spiral Plate Heat Exchangers
Internal Condensers
Plate Heat Exchangers
Plate-Fin Heat Exchangers
Other Compact Designs
9
11
15
15
16
16
16
16
9
BIBLIOGRAPHY
17
FIGURES
1
DIRECT CONTACT CONDENSER WITH INDIRECT COOLER
FOR RECYCLED CONDENSATE
9
2
SPRAY CONDENSER
10
3
TRAY TYPE CONDENSER
10
4
THREE PASS TUBE SIDE CONDENSER WITH INTERPASS
LUTING FOR CONDENSATE DRAINAGE
12
CROSS FLOW CONDENSER WITH SINGLE PASS COOLANT
13
5
DOCUMENTS REFERRED TO IN THIS PROCESS
ENGINEERING GUIDE
18
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com
4. 0
INTRODUCTION/PURPOSE
This Process Engineering Guide is one of a series on heat transfer prepared for
GBH Enterprises.
1
SCOPE
This Guide is designed as an aid to the selection of condensers for process
duties. It describes the various factors which influence the choice of exchanger,
giving some of the options and detailing their merits and draw-backs. For more
general information on selection of heat exchanger type see GBHE-PEG-HEA506.
The Guide also gives advice on design methods for condensers. It does not
attempt to give detailed design procedures, most of which are in any case
performed by computer programs, but points the reader to sources of
information. It does give advice on many of the additional design features which
are not covered by the programs. General recommendations on computer
programs for exchanger design are given in GBHE-PEG-HEA-502.
2
FIELD OF APPLICATION
This Guide is intended for process engineers and plant operating personnel in
GBH Enterprises world-wide, who may be involved in the specification or design
of condensers.
3
DEFINITIONS
For the purposes of this Guide, the following definitions apply:
HTFS
Heat Transfer and Fluid Flow Service. A co-operative research
organization, 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.
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com
5. 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.
TEMA
The Tubular Exchanger Manufacturers’ Association. An
organization of US manufacturers of shell and tube exchangers.
Their publication ‘Standards of the Tubular Exchanger
Manufacturers Association’ is widely accepted as the basis
specification of heat exchangers
4
CHOICE OF COOLANT
The choice of coolant is obviously Influenced by the condensing temperature of
the process stream. In the case of multi-component systems, which condense
over a temperature range, the key temperature is the final temperature to which
the product is to be cooled.
For temperatures above ambient the choice is usually between air and cooling
tower water. GBHE-PEG-HEA-513 discusses the relative merits of air and water
cooling. This indicates that water is likely to be more economic if the condensing
temperature is less than 20°C above the design air temperature, and air if it is
more than 30°C above. These figures are ‘rules of thumb’, and may be
influenced by layout considerations. See Clause 5.
For condensing temperatures less than 5 - 10°C above the supply temperature of
the cooling water the size of a water cooled exchanger may become excessive,
and it will be economical to use some form of refrigeration. The cold service fluid
used in the process exchangers may be either a single phase liquid or a boiling
liquid.
For single phase liquid coolants, chilled water can be provided at down to 2 5°C; below that, either a brine such as 25% CaCl2, or an organic liquid such as
trichloroethylene or kerosene is used.
With boiling liquid coolants, the working fluid of the refrigeration plant is generally
used directly as the coolant, the process exchanger becoming the evaporator of
the refrigeration cycle, and the vapor being returned to the suction of the
compressor. Typical fluids are halocarbons, such as R22 or KLEA 134A, or
ammonia. On some plants, e.g. olefins, process fluids such as ethylene may be
used as the boiling refrigerant.
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com
6. For condensers for fluids with a wide condensing range, cooling to low
temperatures, it may prove more economic to perform the condensation in two
stages, taking out most of the heat load in an air or water cooled unit, and
following it with a refrigerated condenser for the final cooling. This will reduce the
load on the refrigeration system, which is an expensive form of cooling.
A combination of air cooling followed by water cooling is sometimes used for
wide temperature ranges above ambient. However, GBHE-PEG-HEA-513
suggests that this is often not economic.
In recent years there has been an increased tendency to heat integration on
plants. If a suitable process stream is available, it can be used as the coolant.
However, it should be remembered that the control requirements of the plant may
impose a fluctuating demand on the coolant, which may influence the operability
of the total exchanger network.
A special case of heat integration in distillation columns is mechanical vapor
re-compression, where the overhead vapor is compressed and condensed at a
higher temperature to provide the heat input to the column reboiler.
5
LAYOUT CONSIDERATIONS
5.1
Distillation Column Condensers
One of the major factors influencing the layout, and sometimes the choice, of the
condenser for a distillation column is whether the reflux liquid is to return to the
column under gravity, or a pumped reflux system is to be used. In the former
case, the condenser has to be mounted above the top plate of a trayed column
or the distributor of a packed column. The use of a gravity reflux return may also
impose a lower design pressure drop for the condenser than is necessary for a
pumped system.
With a pumped reflux system, the designer has more flexibility. However, the
potential savings in mounting the condenser near grade level must be offset
against need for a pump and the increased cost of vapor and liquid pipework to
link the condenser with the top of the column. Moreover, a pumped reflux system
usually requires a reflux drum; for a gravity return system, particularly if the top
product is to be removed as vapor, it may be possible to dispense with this.
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com
7. With a free standing column, a pumped reflux system has to be used unless
either the column is located close to a structure as high as the column on which
the condenser can be mounted, or the condenser is supported directly from the
column. The latter favors either an internal condenser or a reflux condenser
(dephlegmator), where the condensate flows counter-current to the vapors. See
GBHE-PEG-HEA-516 for a discussion of reflux condensation.
Air cooled exchangers require a relatively large plot area. Because of this, it may
be difficult to find a suitable location for one which would allow gravity
condensate return.
5.2
Other Process Condensers
For most other plant condenser duties, layout does not have a major influence on
the choice of condenser: the structure is usually present to support any design at
a suitable elevation.
6
CONTROL
6.1
Distillation Columns
The operation of a distillation column is usually coupled to the column
pressure control. There are many ways in which this can be done. The
choice of method depends amongst other factors on whether the vapor is
totally condensed, or the top product leaves as a vapor. Some of the
methods can be applied to any type of condenser, but others are specific
to certain designs. Reference [1] and GBHE-PEG-MAS-608 give good
reviews of alternative methods, discussing their advantages and
drawbacks.
6.2
Water Cooled Condensers
It is often necessary to control the heat load on a condenser, for example
if it is a partial condenser. With a single phase coolant the obvious way to
do this is to throttle back the supply of coolant. However, if the coolant
side is prone to fouling which is velocity dependent, this can cause
problems. Cooling water is particularly bad in this respect; low
velocities may lead to both high fouling and corrosion of metals.
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8. It is preferable to control the heat load either by bypassing the hot fluid or
by recycling the cooling water round the exchanger, thus maintaining an
optimum velocity. See GBHE-PEG-HEA-511 for more details.
6.3
Refrigerant Condensers
When using a boiling refrigerant as coolant, it is usually necessary to ensure that
complete evaporation of the liquid refrigerant takes place, to avoid returning
liquid to the compressor suction. This requires control of the refrigerant feed rate
to match the varying plant demands. Partly because of this, most process
refrigerant cooled exchangers are designed as shell and tube exchangers with
shell side boiling, usually as kettle boilers, as this allows easy control of the liquid
level and disengagement of the vapor. Control of heat load can be effected by
varying the pressure, and hence evaporation temperature, of the refrigerant.
7
GENERAL DESIGN CONSIDERATIONS
7.1
Heat Transfer Resistances
The heat transfer resistance on the condensing side of an exchanger is made up
from two parts (apart from fouling): the resistance of the condensate film and the
resistance of the vapor film between the bulk vapor and the vapor-condensate
interface. For a single component, there is no vapor film resistance, but for multicomponent systems, including single condensables with inerts, it can be
substantial.
The value of the condensate film resistance depends on the geometry of the
condensing surface, and on whether the process is dominated by gravity or
vapor shear. In the absence of vapor shear, on vertical surfaces the condensate
film resistance initially rises with increased condensate loading, and then falls
again. On the outside of horizontal tubes, or inside horizontal passages, the
resistance generally rises with increased loading. Vapor shear effects reduce the
resistance, unless the vapor is flowing counter-current to the condensate, when
they may increase it. Further information on the condensate film
resistance can be found in References [2], [3] and [4]
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9. The vapor phase resistance for multi-component condensation arises from the
difference in composition between the bulk vapor and the interface, and is
complicated by mass transfer effects. The full analysis for other than binary
systems is extremely complex; even for binary mixtures the calculations are
tedious. It is therefore usual for engineering calculations to use an approximate
method known as either the Silver or Bell and Ghally method, which is given in
Reference [5] In its simplest form, this relates the local vapor film heat transfer
coefficient α f to the heat transfer coefficient that the gas/vapor phase
would have at that point in the exchanger in the absence of liquid film and
condensation α g by the equation:
Later workers refined this approach, introducing additional correction terms.
Details of the modified method as used in the HTFS computer programs may be
found in Reference [6].
It can be seen from the above that high condensing side coefficients are favored
by high vapor velocities, both to improve the condensate film coefficient and to
give a good gas phase coefficient. Unfortunately, pressure drop also rises with
vapor velocity, limiting the velocity that can be used. During the course of
condensation, the vapor flow falls, causing a reduction in coefficients. This can
be particularly important in the latter stages of a condensation with small
quantities of non-condensables present, where very poor coefficients can result.
These effects can be reduced in some designs of condenser by reducing the flow
area as the condensation proceeds. For example, the number of channels per
pass in a multi-pass exchanger can be reduced for the later passes. For a
shell and tube exchanger with condensing on the shell side, the baffle pitch can
be decreased at the cold end of the exchanger. Where it is not practical to
reduce the flow area, it may be worth considering dividing the duty into two, with
a small vent condenser following the main unit.
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10. Although experience indicates that the Silver/Bell and Ghally method, as used in
most computer programs, generally results in a reasonable estimate of the heat
duty of the exchanger, it cannot give accurate information on non-equilibrium
effects. In practice, the exit condensate is generally at a lower temperature than
the vapor, and the vapor may be super- or sub-saturated with respect to one or
more components. This can be particularly important when the vent from a
condenser is exiting to the environment. Unfortunately, suitable reliable programs
for calculating these cases are not available and hand calculations are difficult. If
this is important, a heat transfer specialist should be consulted.
7.2
Pressure Drop
A high pressure drop is usually undesirable in a condenser; the condensing
temperature falls with reducing pressure, lowering the temperature driving force
for the condensation. Moreover, for a given flowrate the pressure drop rises as
the pressure falls. This can be particularly critical for vacuum condensers. As the
high velocities which tend to give high pressure drops also result in good heat
transfer, some compromise may be necessary, but particular attention should be
given to minimizing the parasitic pressure losses which occur in regions away
from the heat transfer surface, such as the nozzle pressure drops.
The acceleration component of the pressure gradient in a condenser is positive,
due to momentum recovery. The maximum accelerational pressure rise is equal
to two inlet velocity heads. Depending on the magnitude of the frictional terms,
the static pressure in a condenser can actually rise as the condensation
proceeds.
7.3
Handling of lnerts
Many process fluids, even when nominally totally condensable, contain trace
quantities of non-condensable gases, often referred to as ‘inerts’. Unless some
care is taken at the design stage these may build up in the exchanger and, by
lowering the local dew point, result in significant loss of performance. lnerts can
generally be removed from an exchanger by a suitable purge, either continuous
or intermittent, depending on the inlet concentration.
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11. Bell in Reference [7] claims that more than half of all the operational troubles with
condensers are caused by poor venting. He states the four principles of
condenser venting as:
(a)
All vapors to be condensed contain non-condensable gases
(b)
Condensers must be constructed positively to guide the non-condensable
gases to a convenient. identifiable point or region in the condenser.
(c)
The vent must be located in that region.
(d)
A vent condenser may be required.
7.4
Vapor Inlet Design
Because the volume flow rate decreases as the condensation proceeds, it is
economical to employ a high vapor velocity at the inlet. However, this may
present problems:
(a)
High velocities may result in excessive pressure drop.
(b)
There may be erosion damage due to impingement of liquid droplets in the
incoming vapor. An impingement plate is ALWAYS required for the inlet
nozzle of a shell and tube condenser with shell side condensation unless it
can be guaranteed that the vapor is always significantly superheated, say
by 50°C or more. Even then, a plate will be necessary if the product of the
fluid density and the square of the nozzle velocity exceeds the TEMA
recommended maximum of 2200 kg/m.s2.
(c)
Vibration damage may occur, particularly with shell and tube exchangers.
For shell and tube exchangers, a vibration analysis should always be
performed using either the methods within the computer programs or a
suitable hand method such as Reference [8].
(d)
Mal-distribution may occur. This problem is particularly important for
condensers with a large number of parallel flow channels, such as shell
and tube exchangers with tube side condensation. It arises if the jet of
vapor issuing from the inlet nozzle has a momentum that is high relative to
the pressure drop in the tubes. If the nozzle is parallel to the tubes, the
flowrate in the tubes immediately opposite the nozzle can be well above
the mean flowrate, giving severe mal-distribution.
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12. This can result in accumulation of non-condensable gases in the tubes
subjected to lower flow rates, resulting in severe downgrading of the
condenser performance. To avoid severe mal-distribution, the total
pressure drop across the tubes should be at least five times the inlet
nozzle pressure drop. Mal-distribution can be reduced by fitting restriction
devices into each tube inlet, by the use of a perforated deflector plate in
the inlet header, by increasing the size of the inlet nozzle or by using a
radial nozzle.
7.5
Drainage of Condensate
If condensate and uncondensed vapors and gases are to be withdrawn from the
condenser through a single nozzle, this must be adequately sized for the flow,
remembering that two phase pressure drops are considerably greater than single
phase ones. It is more usual to arrange for vapor-liquid disengagement within the
exchanger, with separate outlet nozzles for the two phases. If liquid carry-over
with the vapors is undesirable, a demister before the vapor outlet, or a separate
separator may be necessary.
The liquid outlet should be designed to avoid carry under of the vapors, using the
recommendations in GBHE-PEG-FLO-301 for self-venting flow. A vortex breaker
is recommended; for shell side condensation in a shell and tube exchanger this is
not necessary provided that the bottom tubes are close to the outlet, but is
required if tubes have been removed in this region to aid condensate drainage.
8
SUMMARY OF TYPES AVAILABLE
8.1
Direct Contact Condensers
Direct contact condensers are the simplest and cheapest form of condenser.
They are also less prone than other types to problems associated with dirty or
corrosive fluids. However, they are only suitable where there is no objection to
mixing the process fluid and the coolant.
They are mainly used in vacuum or low pressure applications, particularly for
condensing steam; a typical example is for the final condenser in a multi-effect
evaporation train in the production of salt. For vacuum duties, it is usual to mount
the condenser at a sufficient elevation to enable the coolant and condensate to
flow by gravity through a ‘barometric leg’, thus obviating the need for a pump.
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13. Another area of use for direct contact condensers is as a quench condenser for a
hot corrosive gas. Although principally used for condensing steam, organic
vapors can also be condensed. If water is used as the coolant and the organic
material is immiscible with water, a phase separator will be necessary. Often,
however, the product itself is used as the coolant, the mixture of freshly
condensed material and recycled cold product being passed through a separate
single phase cooler and a portion returned to the condenser. See Figure 1. This
may enable a large surface condenser to be replaced by a simple direct
condenser and a small cooler.
FIGURE 1
DIRECT CONTACT CONDENSER WITH INDIRECT
COOLER FOR
The most common form of direct contact condenser is the spray chamber shown
in Figure 2. The key to this design is to produce fine sprays which are positioned
so that the liquid is well distributed. This produces a large surface area for heat
and mass transfer. The liquid pressure must be considerably above that of the
vapor to ensure a good spray. However, too fine a spray results in excessive
liquid carryover. Design methods for spray condensers are given in References
[9] and [10].
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14. FIGURE 2
SPRAY CONDENSER
The spray condenser has the disadvantage that the nozzles can block if using a
dirty coolant such as river water. The tray type of direct condenser shown in
Figure 3 does not have this limitation. Unfortunately, it does not produce a very
high interfacial area. References [9] and [10] can be used for design of this type
also.
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15. FIGURE 3
TRAY TYPE CONDENSER
Reference [11] describes a design of direct contact condenser in which the
interfacial area is created by feeding the liquid over a set of V-notch weirs
mounted at the top of the chamber. This design probably produces an interfacial
area between that of the tray and spray designs.
A packed column gives the highest thermal efficiency of all types of direct contact
condenser, with evenly distributed counter-current flow of vapor and liquid, a high
interfacial area and a good heat transfer coefficient. However, it is more
expensive than the other designs, and gives a larger pressure drop.
The simplest method of contacting a high pressure vapor with a liquid is to
bubble it through the liquid in some sort of sparge device. The major drawbacks
of such devices are the noise and possible cavitation damage associated with
collapse of the vapor bubbles. In can be particularly difficult to design equipment
to operate reasonably over a wide turndown range. Reference [12] gives some
useful advice on design of sparging systems for condensable vapors or very
soluble gases.
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16. 8.2
Shell and Tube Exchangers
With shell and tube condensers, there is a choice between shell side or tube side
condensation. Tube side condensation is favored when the condensing fluid is at
high pressure, is corrosive or prone to cause fouling. Shell side condensation is
generally used for low pressures, and almost always for vacuum duties. There
are two basic types of shell side condenser, cross-flow condensers and baffled
exchangers where the overall flow direction is along the shell.
Shell and tube condensers can be rated using commercially available computer
programs.
8.2.1 Tube Side Condensation
Vertical tube side condensers are almost always designed as single pass
units, usually with co-current downwards flow of condensate and vapor. It
is feasible to design a two pass condenser with vertical up-flow in the first
pass and down-flow in the second, provided that it can be guaranteed that
the vapor velocity at the top of the first pass is sufficient to carry the
condensate upwards, but this is not recommended. Some condensers are
built in which substantially all the condensation takes place in a down-flow
pass with condensate removal from the base. The non-condensables then
flow back up a second pass having far fewer tubes to effect a final cooling.
This second pass operates with a counter-current flow of condensate and
vapor. The design of such units cannot be performed directly with
computer programs. See GBHE-PEG-HEA-516 for a discussion of reflux
condensers (dephlegmators) in which the condensate and vapors flow
counter-current.
For single pass down flow, the cheapest designs are generally obtained
by using the maximum allowable tube length, subject to pressure drop
constraints. Use of shorter tubes may result in a substantial increase in
required heat transfer surface, particularly for condensation with inerts.
Horizontal tube side condensers give the designer more flexibility in
principle, as multi-pass units are possible. However, except for two pass
U-tube designs, problems can arise in distribution of the two phase
mixture after the first pass. Computer programs for the rating of
condensers generally assume a uniform distribution of liquid and vapor,
but in practice, most of the liquid will flow in the lower tubes of the second
and subsequent passes. For a multi-component mixture, this means that
the vapor in the upper tubes will contain less of the heavier components,
and so be more difficult to condense.
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17. There are also problems with assessing the pressure drop, as different
tubes will have different flow rates and vapor fractions.
Reference [13] recommends the removal of condensate from the end of each
pass in a multi-pass exchanger, with suitable luting where the individual
condensate streams are combined to prevent vapor bypassing. (See Figure 4).
Although this does get round the problem of phase distribution, because the
composition and flowrate will vary from pass to pass, each pass will have to be
modeled separately; conventional computer programs are not suitable directly for
this task, although they can assist, given some skill on the part of the designer. If
this approach is used, there is a possibility that the mixed stream from the
different passes will flash when the mixing takes place. A check on the vaporliquid equilibrium of the mixture should be made.
FIGURE 4
THREE PASS TUBE SIDE CONDENSER WITH INTERPASS
LUTING FOR CONDENSATE DRAINAGE
A multi-pass design allows the number of tubes per pass to be reduced in later
passes, to maintain the vapor velocity, and hence heat transfer coefficient.
However, none of the computer programs available is able directly to model
exchangers with differing numbers of tubes per pass, so some ingenuity is
necessary on the part of the designer.
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18. 8.2.2 Cross-flow Shell Side Condensers (TEMA X Shell Type)
This type of condenser is used for condensing large volume flowrate vapors
containing only small quantities of incondensable gases where only a low
pressure drop can be tolerated, particularly in vacuum duties. The most common
application is steam turbine exhaust condensers in the power industry.
The main problems in the design are:
(a)
Avoiding a very high cross flow velocity in the inlet region, which could
lead to tube damage from erosion or vibration. This is usually done by
providing multiple inlet nozzles to spread the vapor along the shell.
Suitable impingement devices should be provided for each nozzle. There
should be an adequate number of support plates along the shell to prevent
serious tube vibration. These must be shaped to support all the tubes, but
cut clear of the upper and lower spaces where there are no tubes, to allow
longitudinal flow of vapor and condensate.
(b)
Minimizing the pressure drop, to avoid loss of temperature difference.
(c)
Avoiding stagnant regions where inerts can accumulate. There should be
a positive flow of vapor towards the vent region, which should be
maintained as cold as possible to reduce the condensable components as
far as possible. In some designs, particularly with a single pass coolant,
inclined longitudinal baffles running the full length of the shell are used in
the region near the vents, as shown in Figure 5. Because of the high
concentration of incondensable gases in the region of the vent, the heat
flux to these tubes will be low, so the coolant in these tubes will not heat
up much, thus reducing the temperature of the vent stream.
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19. FIGURE 5
CROSS FLOW CONDENSER WITH SINGLE PASS COOLANT
8.2.3 Baffled Shell Side Condensers
The most common type of condenser in the process industries is the horizontal
shell side condenser. Vertical shell side condensation is normally limited to the
heating of vertical boilers etc., usually with condensing steam. For process
duties, a nominally horizontal design is more usual, although the exchanger is
generally inclined at a small angle, say 5°, to assist drainage.
The baffles should have a vertical cut, and have a triangular notch in the bottom
to assist in the drainage of condensate. This should have a minimum size of 20
mm for clean fluids and 40 mm for dirty fluids. At the cold end of the shell, the
baffle spacing can be reduced to maintain an adequate vapor velocity.
Note:
Commercially available programs can presently model variable baffle pitch.
An impingement plate in the shell opposite the inlet nozzle just above the first
row of tubes is mandatory unless using a vapor belt inlet. With small nozzles, this
should be slightly bigger than the nozzle; with large nozzles it should extend to
the shell to avoid a high velocity stream impacting the outer tubes.
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20. Tubes are removed from the top of the shell (assuming a top vapor inlet) to avoid
excessive pressure drop of the incoming fluid and to reduce the velocities off the
impingement plate. Tubes may be removed from the bottom of the shell to assist
condensate drainage. The spaces left by the removal of tubes and the pass
partition lanes for multi-pass designs represent by-pass routes for the vapor.
Sealing devices or longitudinal baffles may be necessary to reduce by-passing.
A vent should be provided on the top of the shell at the cold end, opposite the
liquid nozzle. The liquid nozzle should be sized for self venting flow as in GBHEPEG-FLO-301, with a vortex breaker unless the tubes extend to close to the
liquid nozzle. The exchanger should be mounted to give a slight downwards
slope to the cold end, to assist in drainage.
Most process shell and tube exchangers are of TEMA E-type, with a single side
pass. For large volumes of vapors or low pressure drops, it may be preferable to
use a split flow arrangement (TEMA J-shell). See GBHE-PEG-HEA-506 for more
information on the TEMA designations.
8.2.4 Extended Surfaces
If the heat transfer resistance on the condensing side is dominant, it may be
worth considering the use of extended surfaces. The most common form of this
is the use of low-finned tubing. This is produced by rolling from a thick walled
base tube to give fin heights typically around 1 mm and frequencies from 400 1500 fins per meter. The ends of the tubes are left plain for joining to the tubesheets, and sometimes a plain section is left at each baffle position. The tubes
come in standard fin sizes and frequencies; consult manufacturers’ brochures for
exact dimensions. The finned tubing typically has an outside area from 1.5 to 4
times that of the plain tube.
Finned tubing is normally used in horizontal exchangers, as this gives good
condensate drainage. The fins provide additional surface, and also may give
some direct increase In local coefficient. This is evidenced by the fact that the
enhancement in the condensing heat transfer coefficient, based on the plain tube
area, may be even greater than the increase in area, but generally it is less, due
to flooding of the lower portion of each tube by condensate. This flooding is the
result of hold-up of condensate by capillary forces. There is a theoretical
optimum fin spacing for a given fluid which will result in the smallest
exchanger. The optimum depends on the surface tension of the fluid. Finned
tubes are likely to be of most benefit for low surface tension fluids which have
less tendency to flood.
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21. Low-fin tubing is more expensive per meter than plain tubing. However, its use
will result in a smaller exchanger. Whether there is an overall saving can only be
determined by performing designs for both plain and enhanced tubes.
8.2.5 Subcooling
It is often desired to subcool the condensate from a condenser. The condensate
from a vertical tube side exchanger is usually subcooled to some extent, and
designs can be performed to give reasonable levels of subcooling.
Note:
Caution: some commercially available programs severely underestimates the
performance in the subcooling zone, as their model is based on full bore pipe
flow rather than the film flow which usually occurs.
In horizontal tube side condensers, subcooling can be achieved by arranging for
the last pass to run full of condensate. It may be advantageous to reduce the
number of tubes in this pass to give a reasonable velocity.
Note:
The computer programs cannot directly model exchangers with different numbers
of tubes per pass.
Subcooling can be done in shell side condensation by arranging for the
condensate to maintain a level in the shell above the bottom few rows of tubes.
However, it must be remembered that this is not a very efficient way of
performing the subcooling. The liquid velocities in the bottom of the shell are low,
so that cooling is performed mainly by natural convection. It is not possible to
predict with any certainty what level of subcooling will be achieved, and the
calculations of subcooling in the thermal rating programs are based on a
physical model of the system which does not correspond to reality. If shell side
subcooling is used, it will usually be necessary to arrange for level control of the
condensate in the shell. Any level control device should preferably be adjustable.
Designs have been produced in which the lower’ part of the shell is separated
from the condensing region by a horizontal baffle, open to the upper part in the
last baffle space from the vapor inlet end. Condensate is then directed back
along the shell below this baffle. Extra cross baffles are used to give a good flow
pattern and hence heat transfer to subcool the condensate. This type of design is
frequently used for the design of boiler feed water heaters, and has been used
for process condensers.
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22. There are no computer programs that we are aware of suitable for modeling this
design except for the special case of steam condensation. If it is essential to
guarantee a given level of subcooling, it is preferable to perform this part of the
heat duty in a separate exchanger designed for the purpose.
Vertical shell side condensers, such as steam heated vaporizers, are sometimes
designed to have a variable level of condensate as a means of controlling the
heat duty (see GBHE-PEG-HEA-515). This will lead to some subcooling of the
condensate. Again, it is not possible to predict this with great accuracy.
8.3 Air Cooled Heat Exchangers
Consult GBHE-PEG-HEA-513 for full information on air cooled heat exchangers,
including their use as condensers.
Note:
Commercially available programs: air cooled exchanger rating subroutines
allows for different numbers of tubes per pass. It is normal design practice to
have fewer tubes in the subcooling pass(es) than in the condensing pass(es).
8.4 Spiral Plate Heat Exchangers
There are several forms of exchanger based on the spiral plate concept. All of
these are suitable for condensation duties, but have different merits.
The first of these, referred to as Type I by Alfa Laval, one of the principal
manufacturers of spiral plate exchangers, has spiral flow on both sides. This
results in almost pure countercurrent flow, and is thus suitable for duties which
require a long flow path, such as wide condensing range mixtures.
The Alfa Lava1 Type II has spiral flow on the coolant side, but the condensate
flows in cross flow, with a relatively short flow path. It is normally used where
there is a very large volume of vapor to be handled with low pressure drop. It will
be better suited to single component systems than wide condensing range
mixtures. It can also be mounted directly onto a distillation column to act as a
dephlegmator. See GBHE-PEG-HEA-516 for more details.
The Alfa Lava1 Type III offers on the process side a combination of cross flow for
the initial bulk condensation followed by counter-current spiral flow to subcool the
condensate and non-condensables.
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23. The Alfa Lava1 Type G is designed specifically as a condenser for mounting
directly onto distillation columns or reactors. Unlike the Type II, it is not a
dephlegmator. Instead, the incoming vapor is directed up a central tube and can
then be allowed to flow back down the spiral, in cross flow to the coolant and cocurrent with the condensate, outward in spiral flow counter-current to the coolant
as in Type I or a combination as in Type III.
As explained in GBHE-PEG-HEA-506, spiral plate exchangers are considered
proprietary items, and are designed by the manufacturers.
8.5
Internal Condensers
Rather than provide a separate heat exchanger, it is possible to mount a cooling
bundle inside the top of a distillation column. In large diameter columns this can
be in the form of a horizontal tube bundle. For smaller columns a vertical bundle
is used, generally in the form of a set of U tubes. The latter is a more common
arrangement. This design acts as a dephlegmator. The design of such a unit is
discussed in GBHE-PEG-HEA-516.
In some cases, to avoid the problems with dephlegmators such as flooding,
internal baffling is used to direct the vapor past the bundle and back in
downwards flow.
8.6
Plate Heat Exchangers
Experience of the use of plate heat exchangers for condensing duties, other than
using steam for heating, is limited. Brazed plate exchangers are used as
condensers in some small refrigeration units. The relatively high pressure drop
usually associated with plate exchangers will reduce their applicability. However,
some of the plate manufacturers are pursuing a policy of extending the use of
plate exchangers into new areas, developing modified forms of plate where
necessary, so this situation could change.
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24. 8.7
Plate-Fin Heat Exchangers
Plate-fin exchangers are well established as condensers in the cryogenics
industry, but the restriction until recently to aluminium as a material of
construction has limited their applications elsewhere. With the development of
the large brazed stainless steel units from various manufacturers, recently, and
the continuing work by others to produce an all stainless exchanger, other outlets
should be considered.
8.8
Other Compact Designs
Experience in the use of other compact exchangers in condensing duties is at
present very limited. As condensing duties are usually non-fouling, the small
passage size of many compact designs should not be a limitation, although
fouling from the coolant side, especially cooling water could be a problem.
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26. DOCUMENTS REFERRED TO IN THIS PROCESS ENGINEERING GUIDE
This Process Engineering Guide makes reference to the following documents:
PROCESS ENGINEERING GUIDES
GBHE-PEG-FLO-301
Overflows and Gravity Drainage Systems
(referred to in 7.5 and 8.2.3)
GBHE-PEG-HEA-502
Computer Programs for the Thermal Design of Heat
Exchangers (referred to in Clause 1)
GBHE-PEG-HEA-506
Selection of Heat Exchanger Type
(referred to in Clause 1, 8.2.3 and 8.4)
GBHE-PEG-HEA-511
Shell and Tube Heat Exchangers Using Cooling
Water (referred to in 6.2)
GBHE-PEG-HEA-513
Air Cooled Heat Exchanger Design
(referred to in Clause 4 and 8.3)
GBHE-PEG-HEA-515
The Design and Layout of Vertical Thermosyphon
Reboilers (referred to in 8.2.5)
GBHE-PEG-HEA-516
Refluxing Condensation Systems (Dephlegmators)
(referred to in 5.1, 8.2.1, 8.4 and 8.5)
GBHE-PEG-MAS-608
Control of Continuous Distillation Columns (referred to
in 6.1)
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