Chemical Process Equipment - Selection and Design (Walas)(1) PDF

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BUTTERWORTH-HEINEMANN SERIES IN CHEMICAL ENGINEERING SERIES EDITOR ADVISORY EDITORS HOWARD BRENNER ANDREAS ACRIVOS Massachusetts Institute of Technology The City College of CUNY JAMES E. BAILEY California Institute of Technology MANFRED M O R A R I California Institute of Technology E. BRUCE NAUMAN...

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BUTTERWORTH-HEINEMANN SERIES IN CHEMICAL ENGINEERING ADVISORY

SERIES EDITOR HOWARD BRENNER Massachusetts Institute of

ANDREAS ACRIVOS The City College of CUNY JAMES E. BAILEY California Institute of Technology MANFRED M O R A R I California Institute of Technology E. BRUCE NAUMAN Rensselaer Polytechnic Institute ROBERT K. PRUD’HOMME Princeton University

Technology

SERIES TITLES Chemical Process Equipment St anley M . W alas Constitutive Equations for Polymer Melts and Solutions Ronald G. Larson

Gas Separation by Adsorption Processes Ralph T. Yang Heterogeneous Reactor Design Hong H. Lee Molecular Thermodynamics of Nonideal Fluids Lloy d L. Lee Phase Equilibria in Chemical Engineering Stanley M . Walas Transport Processes in Chemically Reacting Flow Systems Daniel E. Rosner

Viscous Flows: The Practical Use of Theory St uart W ins t o n Churchill

RELATED TITLES Catalyst Supports and Supported Catalysts Alvin B. Enlargement and Compaction of Particulate Solids Nayland

Stiles

St anley - W o o d

Fundamentals of Fluidized Beds John G. Yates Liquid and Liquid Mixtures J.S. Rowlimon and F. L. Sw inton Mixing in the Process Industries N . Harnby , M . F. Edw ards , and A . W . Nieno w

Shell Process Control Workshop

D av id M . Prett and

Manfred M orari

Solid Liquid Separation Ladislav Svarovsky Supercritical Fluid Extraction M ark A. M cHugh and Val .I. Krukonis

EDITORS

Chemical Process Equipment Selection and Design

Stanley M. Walas Department of Chemical and Petroleum Engineering University of Kansas

To the memory of my parents, Stanklaus and A polonia, and to my w ife, Suzy Belle

Copyright 0 1990 by Butterworth-Heinemann, a division of Reed Publishing (USA) Inc. All rights reserved. The information contained in this book is based on highly regarded sources, all of which are credited herein. A wide range of references is listed. Every reasonable effort was made to give reliable and up-to-date information; neither the author nor the publisher can assume responsibility for the validity of all materials or for the consequences.of their use. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher.

Library of Congress Cataloging-in-Publication Data Walas, Stanley M. Chemical process equipment. (Butterworth-Heinemann series in chemical engineering) Includes bibliographical references and index. 1. Chemical engineering-Apparatus and supplies. I. Title. II. Series. TP157.w334 1988 660.2’83 87-26795 ISBN 0-7506-9385-l (previously ISBN o-409-90131-8)

British Library Cataloguing in Publication Data Walas, Stanley M. Chemical process equipment.-(ButterworthHeinemann series in chemical engineering). series in chemical engineering). 1. Chemical engineering-Apparatus and supplies I. Title TP157 660.2’8 ISBN 0-7506-9385-l (previously ISBN o-409-90131-8) Butterworth-Heinemann 3 13 Washington Street Newton, MA 02158-1626 10 9 8 7 Printed in the United States of America

Contents LIST OF EXAMPLES ix

CHAPTER 5 TRANSFER OF SOLIDS 69

PREFACE xi

5.1. 5.2.

RULES OF THUMB: SUMMARY

... xiii

CHAPTER 1 INTRODUCTION

1

1.1. Process Design I 1.2. Equipment 1 Vendors’ Questionnaires 1 Specification Forms 1 1.3. Categories of Engineering Practice 1 1.4. Sources of Information for Process Design 2 1.5. Codes, Standards, and Recommended Practices 1.6. Material and Energy Balances 3 1.7. Economic Balance 4 1.8. Safety Factors 6 1.9. Safety of Plant and Environment 7 1.10. Steam and Power Supply 9 1.11. Design Basis 12 Utilities 1 2 1.12. Laboratory and Pilot Plant Work 12 References 1 5 CHAPTER 2 FLOWSHEETS 19 2.1. 2.2. 2.3. 2.4. 2.5.

Block Flowsheets 19 Process Flowsheets 19 Mechanical (P&I) Flowsheets 19 Utility Flowsheets 19 Drawing of Flowsheets 20 References 31 Appendix 2.1 Descriptions of Example Process Flowsheets 33

CHAPTER 3 PROCESS CONTROL 39 3.1. Feedback Control 39 Symbols 39 Cascade (Reset) Control 42 3.2. Individual Process Variables 4.2 Temperature 42 Pressure 42 Level of Liquid 43 Flow Rate 43 Flow of Solids 43 Flow Ratio 43 Composition 43 3.3. Equipment Control 43 Heat Transfer Equipment 44 Distillation Equipment 47 Liquid-Liquid Extraction Towers 50 Chemical Reactors 53 Liquid Pumps 55 Solids Feeders 55 Compressors 55 References 60

5.3.

5.4. 2

CHAPTER 6 FLOW OF FLUIDS 91 6.1. Properties and Units 91 6.2. Energy Balance of a Flowing Fluid 92 6.3. Liquids 94 Fittings and Valves 95 Orifices 95 Power Requirements 98 6.4. Pipeline Networks 98 6.5. Optimum Pipe Diameter 100 6.6. Non-Newtonian Liquids 100 Viscosity Behavior 100 Pipeline Design 106 6.7. Gases 109 Isentropic Flow 109 Isothermal Flow in Uniform Ducts 110 Adiabatic Flow 110 Nonideal Gases 111 6.8. Liquid-Gas Flow in Pipelines 111 Homogeneous Model 113 Separated Flow Models 114 Other Aspects 114 6.9. Granular and Packed Beds 117 Single Phase Fluids 117 Two-Phase Flow 118 6.10. Gas-Solid Transfer 119 Choking Velocity 119 Pressure Drop 119 6.11. Fluidization of Beds of Particles with Gases Characteristics of Fluidization 123 Sizing Equipment 123 References 127

120

CHAPTER 7 FLUID TRANSPORT EQUIPMENT 129 7.1. 7.2. 7.3. 7.4. 7.5.

CHAPTER 4 DRIVERS FOR MOVING EQUIPMENT 61 4.1. Motors 61 Induction 61 Synchronous 61 Direct Current 61 4.2. Steam Turbines and Gas Expanders 62 4.3. Combustion Gas Turbines and Engines 6 5 References 68

Slurry Transport 69 Pneumatic Conveying 71 Equipment 72 Operating Conditions 73 Power Consumption and Pressure Drop 7 4 Mechanical Conveyors and Elevators 76 Properties of Materials Handled 76 Screw Conveyors 76 Belt Conveyors 76 Bucket Elevators and Carriers 78 Continuous Flow Conveyor Elevators 82 Solids Feeders 83 References 88

7.6.

Piping 129 Valves 129 Control Valves 129 Pump Theory 131 Basic Relations 131 Pumping Systems 133 Pump Characteristics 134 Criteria for Selection of Pumps 140 Equipment for Gas Transport 143 Fans 143 Compressors 145 Centrifugals 1 4 5 Axial Flow Compressors 146 Reciprocating Compressors 146 Rotary Compressors 149 Theory and Calculations of Gas Compression 153 Dimensionless Groups 153 Ideal Gases 153 Real Processes and Gases 156 Work on Nonideal Gases 156

vi

CONTENTS

Efficiency 1.59 Temperature Rise, Compression Ratio, Volumetric Efficiency 159 7.7. Ejector and Vacuum Systems 162 Ejector Arrangements 162 Air Leakage 164 Steam Consumption 165 Ejector Theory 166 Glossary for Chapter 7 166 References 167 CHAPTER 8 HEAT TRANSFER AND HEAT EXCHANGERS 169 8.1. Conduction of Heat 169 Thermal Conductivity 169 Hollow Cvlinder 170 Composite Walls 170 Fluid Films 170 8.2. Mean Temperature Difference 172 Single Pass Exchanger 172 Multipass Exchangers 173 F-Method 173 O-Method 179 Selection of Shell-and-Tube Numbers of Passes Example 179 8.3. Heat Transfer Coefficients 179 Overall Coefficients 180 Fouling Factors 180 Individual Film Coefficients 180 Metal Wall Resistance 18.2 Dimensionless Groups 182 8.4. Data of Heat Transfer Coefficients 182 Direct Contact of Hot and Cold Streams 185 Natural Convection 186 Forced Convection 186 Condensation 187 Boiling 187 Extended Surfaces 188 8.5. Pressure Drop in Heat Exchangers 188 8.6. Types of Heat Exchangers 188 Plate-and-Frame Exchangers 189 Spiral Heat Exchangers 194 Compact (Plate-Fin) Exchangers 194 Air Coolers 194 Double Pipes 19.5 8.7. Shell-and-Tube Heat Exchangers 195 Construction 195 Advantages 199 Tube Side or Shell Side 199 Design of a Heat Exchanger 199 Tentative Design 200 8.8. Condensers 200 Condenser Configurations 204 Desien Calculation Method 205 The Silver-Bell-Ghaly Method 206 8.9. Reboilers 206 Kettle Reboilers 207 Horizontal Shell Side Thermosiphons 207 Vertical Thermosiphons 207 Forced Circulation Reboilers 208 Calculation Procedures 208 8.10 Evaporators 208 Thermal Economy 210 Surface Requirements 211 8.11. Fired Heaters 211 Description of Eauinment 211 Heat Transfer 213 Design of Fired Heaters 214 8.12. Insulation of Equipment 219 Low Temperatures 221 Medium Temperatures 221

179

Refractories 221 8.13. Refrigeration 224 Compression Refrigeration 224 Refrigerants 226 Absorption Refrigeration 229 Cryogenics 229 References 229 9 DRYERS AND COOLING TOWERS 231 9.1. Interaction of Air and Water 231 9.2. Rate of Drying 234 Laboratory and Pilot Plant Testing 237 9.3. Classification and General Characteristics of Dryers 237 Products 240 Costs 240 Specification Forms 240 9.4. Batch Dryers 241 9.5. Continuous Tray and Conveyor Belt Dryers 242 9.6. Rotary Cylindrical Dryers 247 9.7. Drum Dryers for Solutions and Slurries 254 9.8. Pneumatic Conveying Dryers 255 9.9. Fluidized Bed Dryers 262 9.10. Spray Dryers 268 Atomization 276 Applications 276 Thermal Efficiency 276 Design 276 9.11. Theorv of Air-Water Interaction in Packed Towers 277 Tower Height 279 9.12. Cooling Towers 280 Water Factors 285 Testing and Acceptance 285 References 285 CHAPTER 10 MIXING AND AGITATION 287 10.1. A Basic Stirred Tank Design 287 The Vessel 287 Baffles 287 Draft Tubes 287 Impeller Types 287 Impeller Size 287 Impeller Speed 288 Impeller Location 288 10.2. Kinds of Impellers 288 10.3. Characterization of Mixing Quality 290 10.4. Power Consumption and Pumping Rate 292 10.5. Suspension of Solids 295 10.6. Gas Dispersion 296 Spargers 296 Mass Transfer 297 System Design 297 Minimum Power 297 Power Consumption of Gassed Liquids 297 Superficial Liquid Velocity 297 Design Procedures 297 10.7. In-Line-Blenders and Mixers 300 10.8. Mixing of Powders and Pastes 301 References 304 CHAPTER 11 SOLID-LIQUID SEPARATION 305 11.1. Processes and Equipment 305 11.2 Theory of Filtration 306 Compressible Cakes 310 11.3. Resistance to Filtration 313 Filter Medium 313 Cake Resistivity 313

CONTENTS

11.4. 11.5.

11.6. 11.7.

Compressibility-Permeability (CP) Cell Measurements 314 Another Form of Pressure Dependence 315 Pretreatment of Slurries 315 Thickening and Clarifying 315 Laboratory Testing and Scale-Up 317 Compression-Permeability Cell 317 The SCFT Concept 317 Scale-Up 318 Illustrations of Equipment 318 Applications and Performance of Equipment 320 References 334

CHAPTER 12 DISINTEGRATION, AGGLOMERATION, AND SIZE SEPARATION OF PARTICULATE SOLIDS 335 12.1. Screening 335 Revolving Screens or Trommels 335 Capacity of Screens 335 12.2. Classification with Streams of Air or Water 337 Air Classifiers 337 Wet Classifiers 339 12.3. Size Reduction 339 12.4. Eauiument for Size Reduction 341 Crushers 3 4 1 Roll Crushers 341 12.5. Particle Size Enlargement 351 Tumblers 351 Roll Compacting and Briquetting 354 Tabletting 357 Extrusion Processes 358 Prilling 361 Fluidized and Spouted Beds 362 Sintering and Crushing 363 References 370 CHAPTER 13 DISTILLATION AND GAS ABSORPTION 371 13.1.

13.2.

13.3. 13.4.

13.5. 13.6.

13.7.

Vapor-Liquid Equilibria 371 Relative Volatility 374 Binary x-y Diagrams 375 Single-Stage Flash Calculations 375 Bubblepoint Temperature and Pressure 376 Dewpoint Temperature and Pressure 377 Flash at Fixed Temnerature and Pressure 377 Flash at Fixed Enthalpy and Pressure 377 Equilibria with KS Dependent on Composition 377 Evaporation or Simple Distillation 378 Multicomponent Mixtures 379 Binary Distillation 379 Material and Energy Balances 380 Constant Molal Overflow 380 Basic Distillation Problem 382 Unequal Molal Heats of Vaporization 382 Material and Energy Balance Basis 382 Algebraic Method 382 Batch Distillation 390 Material Balances 391 Multicomponent Separation: Generali Considerations 393 Sequencing of Columns 393 Number of Free Variables 395 Estimation of Reflux and Number of Travs (FenskeUnderwood-Gilliland Method) 395 Minimum Trays 395 Distribution of Nonkeys 395 Minimum Reflux 397 Operating Reflux 397 Actual Number of Theoretical Trays 397 Feed Tray Location 397

13.8. 13.9.

13.10.

13.11.

13.12.

13.13.

13.14.

Tray Efficiencies 397 Absorption Factor Shortcut Method of Edmister 398 Seoarations in Packed Towers 398 Miss Transfer Coefficients 399 Distillation 401 Absorption or Stripping 401 Basis for Computer Evaluation of Multicomponent Separations 404 Specifications 405 The MESH Equations 405 The Wang-Henke Bubblepoint Method 408 The SR (Sum-Rates) Method 409 SC (Simultaneous Correction) Method 410 Special Kinds of Distillation Processes 410 Petroleum Fractionation 411 Extractive Distillation 412 Azeotropic Distillation 420 Molecular Distillation 425 Tray Towers 426 Countercurrent Trays 426 Sieve Trays 428 Valve Trays 429 Bubblecap Trays 431 Packed Towers 433 Kinds of Packings 433 Flooding and Allowable Loads 433 Liquid Distribution 439 Liauid Holdup 439 Pressure Drop 439 Efficiencies of Trays and Packings 439 Trays 439 Packed Towers 442 References 456

CHAPTER 14 EXTRACTION AND LEACHING 459 14.1. Equilibrium Relations 459 14.2. Calculation of Stage Requirements 463 Single Staee Extraction 463 Crosscurrent Extraction 464 Immiscible Solvents 464 14.3. Countercurrent Operation 466 Minimum Solvent/Feed Ratio 468 Extract Reflux 468 Minimum Reflux 469 Minimum Stages 469 14.4. Leaching of Solids 470 14.5. Numerical Calculation of Multicomponent Extraction 473 Initial Estimates 473 Procedure 473 14.6. Equipment for Extraction’ 476 Choice of Disperse Phase 476 Mixer-Settlers’ 477 Spray Towers 478 Packed Towers 478 Sieve Tray Towers 483 Pulsed Packed and Sieve Tray Towers 483 Reciprocating Tray Towers 485 Rotating Disk Contactor (RDC) 485 Other Rotary Agitated Towers 485 Other Kinds of Extractors 487 Leaching Equipment 488 References 493 CHAPTER 15 ADSORPTION AND ION EXCHANGE 495 15.1. Adsorption Equilibria 495 15.2. Ion Exchange Equilibria 497 15.3. Adsorption Behavior in Packed Beds 500 Regeneration 504

V ii

Viii

CONTENTS

15.4. Adsorption Design and Operating Practices 504 15.5. Ion Exchange Design and Operating Practices 506 Electrodialysis 508 15.6. Production Scale Chromatography 510 15.7. Equipment and Processes 510 Gas Adsorption 511 Liquid Phase Adsorption 513 Ion Exchange 517 Ion Exchange Membranes and Electrodialysis 5 1 7 Chromatographic Equipment 520 References 522

Homogeneous Liquid Reactions 595 Liquid-Liquid Reactions 595 Gas-Liquid Reactions 595 Noncatalytic Reactions with Solids 595 Fluidized Beds of Noncatalytic Solids 595 Circulating Gas or Solids 596 Fixed Bed Solid Catalysis 596 Fluidized Bed Catalysis 60 1 Gas-Liquid Reactions with Solid Catalysts 604 References 609 CHAPTER 18 PROCESS VESSELS

CHAPTER 16 CRYSTALLIZATION FROM SOLUTIONS AND MELTS 523 16.1. Solubilities and Equilibria 523 Phase Diagrams 523 Enthalpy Balances 524 16.2. Crvstal Size Distribution 525 16.3. The Process of Crystallization 528 Conditions of Precipitation 528 Supersaturation 528 Growth Rates 530 16.4. The Ideal Stirred Tank 533 Multiple Stirred Tanks in Series 536 Applicability of the CSTC Model 536 16.5. Kinds of Crystallizers 537 16.6. Melt Crystallization and Purification 543 Multistage Processing 543 The Metallwerk Buchs Process 543 Purification Processes 543 References 548 CHAPTER 17 CHEMICAL REACTORS 549 17.1. Design Basis and Space Velocity 549 Design Basis 549 Reaction Times 549 17.2. Rate Equations and Operating Modes 549 17.3. Material and Energy Balances of Reactors 555 17.4. Nonideal Flow Patterns 556 Residence Time Distribution 556 Conversion in Segregated and Maximum Mixed Flows 560 Conversion in Segregated Flow and CSTR Batteries 560 Dispersion Model 560 Laminar and Related Flow Patterns 5 6 1 17.5. Selection of Catalysts 562 Heterogeneous Catalysts 562 Kinds of Catalysts 563 Kinds of Catalvzed Organic Reactions 563 Physical Characteristics of Solid Catalysts 564 Catalyst Effectiveness 565 17.6. Types and Examples of Reactors 567 Stirred Tanks 567 Tubular Flow Reactors 569 Gas-Liquid Reactions 571 Fixed Bed Reactors 572 Moving Beds 574 Kilns and Hearth Furnaces 575 Fluidized Bed Reactors 579 17.7. Heat Transfer in Reactors 582 Stirred Tanks 586 Packed Bed Thermal Conductivity 587 Heat Transfer Coefficient at Walls, to Particles, and Overall 587 Fluidized Beds 589 17.8. Classes of Reaction Processes and Their Equipment 592 Homogeneous Gas Reactions 592

611

18.1. Drums 611 18.2. Fractionator Reflux Drums 6 12 18.3. Liquid-Liquid Separators 612 Coalescence 613 Other Methods 613 18.4. Gas-Liquid Separators 613 Droplet Sizes 613 Rate of Settling 614 Empty Drums 615 Wire Mesh Pad Deentrainers 6 1 5 18.5. Cyclone Separators 616 18.6. Storage Tanks 619 18.7. Mechanical Design of Process Vessels 6 2 1 Design Pressure and Temperature 623 Shells and Heads 624 Formulas for Strength Calculations 624 References 629 CHAPTER 19 OTHER TOPICS

631

19.1. Membrane Processes 631 Membranes 632 Equipment Configurations 632 Applications 632 Gas Permeation 633 19.2. Foam Separation and Froth Flotation 635 Foam Fractionation 635 Froth Flotation 636 19.3. Sublimation and Freeze Drying 638 Equipment 639 Freeze Drying 639 19.4. Parametric Pumping 639 19.5. Seoarations bv Thermal Diffusion 642 19.6. Electrochemical Syntheses 645 Electrochemical Reactions 646 Fuel Cells 646 Cells for Synthesis of Chemicals 648 19.7. Fermentation Processing 648 Processing 650 Operating Conditions 650 Reactors 654 References 660 CHAPTER 20 COSTS OF INDIVIDUAL EQUIPMENT 663 References 669 APPENDIX A UNITS, NOTATION, AND GENERAL DATA 671 APPENDIX B EQUIPMENT SPECIFICATION FORMS 681 APPENDIX C QUESTIONNAIRES OF EQUIPMENT SUPPLIERS 727 INDEX 747

List of Examples

1.1 1.2 1.3 1.4 1.5 3.1 4.1 4.2

5.1 5.2 5.3 5.4

6.1 6.2 6.3 6.4 6.5 6.6

6.7 6.8 6.9 6.10 6.11 6.12 6.13 6.14 6.15 6.16 7.1 7.2 7.3 7.4

E 717 7.8 7.9 7.10 7.11 7.12 7.13

i:: 8.3 8.4

Material Balance of a Chlorination Process with Recycle 5 Data of a Steam Generator for Making 250,000 lb/hr at 450 psia and 650°F from Water Entering at 220°F 9 Steam Plant Cycle for Generation of Power and Low Pressure Process Steam 11 Pickup of Waste Heat by Generating and Superheating Steam in a Petroleum Refinery 11 Recovery of Power from a Hot Gas Stream 1 2 Constants of PID Controllers from Response Curves to a Step Input 42 Steam Requirement of a Turbine Operation 65 Performance of a Combustion Gas Turbine 67 Conditions of a Coal Slurry Pipeline 70 Size and Power Requirement of a Pneumatic Transfer Line 77 Sizing a Screw Conveyor 80 Sizing a Belt Conveyor 83 Comparison of Redler and Zippered Belt Conveyors 88 Density of a Nonideal Gas from Its Equation of State 9 1 Unsteady Flow of an Ideal Gas through a Vessel 93 Units of the Energy Balance 94 Pressure Drop in Nonisothermal Liquid Flow 9 7 Comparison of Pressure Drons in a Line with Several Sets of Fittings Resistances 101 A Network of Pipelines in Series, Parallel, and Branches: the Sketch, Material Balances, and Pressure Drop Equations 101 Flow of Oil in a Branched Pipeline 101 Economic Optimum Pine Size for Pumping Hot Oil with a Motor or Turbine Drive 102 Analysis of Data Obtained in a Capillary Tube Viscometer 107 Parameters of the Bingham Model from Measurements of Pressure Drops in a Line 107 Pressure Drop in Power-Law and Bingham Flow 110 Adiabatic and Isothermal Flow of a Gas in a Pipeline 112 Isothermal Flow of a Nonideal Gas 113 Pressure Drop and Void Fraction in Liquid-Gas Flow 116 Pressure D r p in Flow of Nitrogen and Powdered Coal 120 Dimensions of a Fluidized Bed Vessel 125 Application of Dimensionless Performance Curves 132 Operating Points of Single and Double Pumps in Parallel and Series 133 Check of Some Performance Curves with the Concept of Specific Speed 136 Gas Compression, Isentropic and True Final Temp...