Essentials of Fluidization Technology

John Grace is an Emeritus Professor at the University of British Columbia (Vancouver, Canada), where he has served since 1979. Prior to that he was a faculty member at McGill University (Montreal, Canada) and completed a PhD on fluidization at Cambridge University. He has published more than 590 papers, chapters and books, most of them related to the subject of the proposed book. He has chaired a number of conferences, consulted for a number of companies, and won a number of awards and honours such as the International Fluidization Award of Achievement from the Engineering Foundation, Thomas Baron Award in Fluid-Particle Systems of the AIChE, and the Particle Technology Forum Award of the AIChE. Xiaotao (Tony) Bi completed his PhD at the University of British Columbia (UBC, Canada) in 1994, then worked in industry and returned to UBC in 1997 where he rose to the rank of Full Professor. He has published more than 300 papers and has supervised dozens of graduate students, mostly related to fluidization and associated multiphase systems. His research covers many areas including hydrodynamics, flow patterns and flow regimes, heat transfer, mass transfer, reactor performance testing, modeling and simulation, scaling and scale-up, commercial reactor trouble-shooting etc. covering gas-solids, liquid-solids, gas-liquid-solids bubbling, turbulent and circulating fluidized beds. He is a Fellow of the Canadian Academy of Engineering and a recent winner of the AIChE Lectureship Award in Fluidization. Naoko Ellis completed a PhD on fluidization at the University of British Columbia (UBC, Canada) in 2003. As a faculty member at UBC (recently promoted to Full Professor and currently serving as Associate head for Graduate Programs), she has been actively engaged in research and supervision of graduate students on fluidization, chemical looping, biomass utilization, bio-oil upgrading, biochar, biodiesel and sustainability, publishing in each of these areas. With Professors Grace and Bi, she taught a recent graduate course on fluidization.

• Preface xixAcknowledgement xxi1 Introduction, History, and Applications 1John R. Grace1.1 Definition and Origins 11.2 Terminology 21.3 Applications 31.4 Other Reasons for Studying Fluidized Beds 41.5 Sources of Information on Fluidization 8References 8Problems 92 Properties, Minimum Fluidization, and Geldart Groups 11John R. Grace2.1 Introduction 112.2 Fluid Properties 112.3 Individual Particle Properties 122.4 Bulk Particle Properties 162.5 Minimum Fluidization Velocity 182.6 Geldart Powder Classification for Gas Fluidization 242.7 Voidage at Minimum Fluidization 27Solved Problem 28Notations 28References 29Problems 313 Liquid Fluidization 33Renzo Di Felice and Alberto Di Renzo3.1 Introduction 333.2 Field of Existence 333.3 Overall Behaviour 353.4 Superficial Velocity–Voidage Relationship 373.5 Particle Segregation and Mixing 403.6 Layer Inversion Phenomena 413.7 Heat and Mass Transfer 463.8 Distributor Design 48Solved Problems 48Notations 51References 52Problems 534 Gas Fluidization Flow Regimes 55Xiaotao Bi4.1 Onset of Fluidization 554.2 Onset of Bubbling Fluidization 554.3 Onset of Slugging Fluidization 574.4 Onset of Turbulent Fluidization 584.5 Termination of Turbulent Fluidization 624.6 Fast Fluidization and Circulating Fluidized Bed 624.7 Flow Regime Diagram for Gas–Solid Fluidized Beds 644.8 Generalized Flow Diagram for Gas–Solid Vertical Transport 654.9 Effect of Pressure and Temperature on Flow Regime Transitions 68Solved Problems 70Notations 71References 72Problems 745 Experimental Investigation of Fluidized Bed Systems 75Naoko Ellis5.1 Introduction 755.2 Configuration and Design 765.3 Fluidizability and Quality of Fluidization 845.4 Instrumentation and Measurements 875.5 Operation of Fluidized Beds 935.6 Data Analysis 95Solved Problem 98Notations 98References 100Problems 1046 Computational Fluid Dynamics and Its Application to Fluidization 109Tingwen Li and Yupeng Xu6.1 Two-Fluid Model 1106.2 Discrete Particle Method 1156.3 Gas–Solid Interaction 1196.4 Boundary Conditions 1226.5 Example and Discussion 1236.6 Conclusion and Perspective 126Solved Problem 126Notations 127References 1287 Hydrodynamics of Bubbling Fluidization 131John R. Grace7.1 Introduction 1317.2 Why Bubbles Form 1337.3 Analogy Between Bubbles in Fluidized Beds and Bubbles in Liquids 1347.4 Hydrodynamic Properties of Individual Bubbles 1357.5 Bubble Interactions and Coalescence 1397.6 Freely Bubbling Beds 1397.7 Other Factors Influencing Bubbles in Gas-Fluidized Beds 146Solved Problem 147Notations 147References 148Problems 1528 Slug Flow 153John R. Grace8.1 Introduction 1538.2 Types of Slug Flow 1538.3 Analogy Between Slugs in Fluidized Beds and Slugs in Liquids 1558.4 Experimental Identification of the Slug Flow Regime 1558.5 Transition to Slug Flow 1568.6 Properties of Single Slugs 1568.7 Hydrodynamics of Continuous Slug Flow 1588.8 Mixing of Solids and Gas in Slugging Beds 1598.9 Slugging Beds as Chemical Reactors 160Solved Problem 160Notations 161References 1619 Turbulent Fluidization 163Xiaotao Bi9.1 Introduction 1639.2 Flow Structure 1659.3 Gas and Solids Mixing 1689.4 Effect of Column Diameter 1729.5 Effect of Fines Content 173Solved Problem 173Notations 175References 176Problems 18010 Entrainment from Bubbling and Turbulent Beds 181Farzam Fotovat10.1 Introduction 18110.2 Definitions 18210.3 Ejection of Particles into the Freeboard 18410.4 Entrainment Beyond the Transport Disengagement Height 18510.5 Entrainment from Turbulent Fluidized Beds 19010.6 Parameters Affecting Entrainment of Solid Particles from Fluidized Beds 19110.7 Possible Means of Reducing Entrainment 195Solved Problem 195Notations 196References 197Problems 20111 Standpipes and Return Systems, Separation Devices, and Feeders 203Ted M. Knowlton and Surya B. Reddy Karri11.1 Standpipes and Solids Return Systems 20311.2 Standpipes in Recirculating Solids Systems 21211.3 Standpipes Used with Nonmechanical Solids Flow Devices 21611.4 Solids Separation Devices 22211.5 Solids Flow Control Devices/Feeders 230Solved Problem 232Notations 233References 235Problems 23712 Circulating Fluidized Beds 239Chengxiu Wang and Jesse Zhu12.1 Introduction 23912.2 Basic Parameters 24112.3 Axial Profiles of Solids Holdup/Voidage 24312.4 Radial Profiles of Solids Distribution 24612.5 The Circulating Turbulent Fluidized Bed 24912.6 Micro-flow Structure 25012.7 Gas and Solids Mixing 25612.8 Reactor Performance of Circulating Fluidized Beds 25812.9 Effect of Reactor Diameter on CFB Hydrodynamics 261Notations 262References 263Problems 26813 Operating Challenges 269Poupak Mehrani and Andrew Sowinski13.1 Electrostatics 26913.2 Agglomeration 27313.3 Attrition 27413.4 Wear 278Solved Problems 280Notations 286References 287Problem 29014 Heat and Mass Transfer 291Dening Eric Jia14.1 Heat Transfer in Fluidized Beds 29114.2 Mass Transfer in Fluidized Beds 318Solved Problem 320Notations 323References 325Problem 32915 Catalytic Fluidized Bed Reactors 333Andrés Mahecha-Botero15.1 Introduction 33315.2 Reactor Design Considerations 33415.3 Reactor Modelling 33415.4 Fluidized Bed Catalytic Reactor Models 34215.5 Conclusions 356Notations 357References 358Problems 36116 Fluidized Beds for Gas–Solid Reactions 363Jaber Shabanian and Jamal Chaouki16.1 Introduction 36316.2 Gas–Solid Reactions for a Single Particle 36416.3 Reactions of Solid Particles Alone 37716.4 Conversion of Particles Bathed by Uniform Gas Composition in a Dense Gas–Solid Fluidized Bed 37816.5 Conversion of Both Solids and Gas 38116.6 Thermal Conversion of Solid Fuels in Fluidized Bed Reactors 38616.7 Final Remarks 390Solved Problems 391Acknowledgments 398Notations 398References 401Problems 40317 Scale-Up of Fluidized Beds 405Naoko Ellis and Andrés Mahecha-Botero17.1 Challenges of Scale 40517.2 Historical Lessons 40717.3 Influence of Scale on Hydrodynamics 40817.4 Approaches to Scale-Up 41217.5 Practical Considerations 41517.6 Scale-Up and Industrial Considerations of Fluidized Bed Catalytic Reactors 419Solved Problems 424Notations 426References 426Problems 42918 Baffles and Aids to Fluidization 431Yongmin Zhang18.1 Industrial Motivation 43118.2 Baffles in Fluidized Beds 43218.3 Other Aids to Fluidization 44918.4 Final Remarks 452Notations 452References 452Problem 45519 Jets in Fluidized Beds 457Cedric Briens and Jennifer McMillan19.1 Introduction 45719.2 Jets at Gas Distributors 45719.3 Mass Transfer, Heat Transfer, and Reaction in Distributor Jets 46719.4 Particle Attrition and Tribocharging at Distributor Holes 46719.5 Jets Formed in Fluidized Bed Grinding 46919.6 Applications 47119.7 Jet Penetration 47119.8 Solids Entrainment into Jets 47119.9 Nozzle Design 47219.10 Jet-Target Attrition 47319.11 Jets Formed When Solids Are Fed into a Fluidized Bed 47519.12 Jets Formed When Liquid Is Sprayed into a Gas-Fluidized Bed 47719.13 Jet Penetration 478Solved Problems 483Notations 487References 488Problem 49720 Downer Reactors 499Changning Wu and Yi Cheng20.1 Downer Reactor: Conception and Characteristics 49920.2 Hydrodynamics, Mixing, and Heat Transfer of Gas–Solid Flow in Downers 50120.3 Modelling of Hydrodynamics and Reacting Flows in Downers 50820.4 Design and Applications of Downer Reactors 51420.5 Conclusions and Outlook 523Solved Problem 523Notations 525References 526Problems 52821 Spouted (and Spout-Fluid) Beds 531Norman Epstein21.1 Introduction 53121.2 Hydrodynamics 53221.3 Heat and Mass Transfer 53821.4 Chemical Reaction 53821.5 Spouting vs. Fluidization 53921.6 Spout-Fluid Beds 54021.7 Non-conventional Spouted Beds 54321.8 Applications 54621.9 Multiphase Computational Fluid Dynamics 547Solved Problem 547Notations 548References 54922 Three-Phase (Gas–Liquid–Solid) Fluidization 553Dominic Pjontek, Adam Donaldson, and Arturo Macchi22.1 Introduction 55322.2 Reactor Design and Scale-up 55622.3 Compartmental Flow Models 55822.4 Fluid Dynamics in Three-Phase Fluidized Beds 56222.5 Phase Mixing, Mass Transfer, and Heat Transfer 56922.6 Summary 574Solved Problems 574Notations 582References 585Problems 587Index 591