Spouted Beds

Spouted Beds is a comprehensive 13-chapter book that covers the spouting phenomenon and the special features and applications of spouted beds. After briefly discussing the history and features of spouted bed compared to fluidized bed, the book deals with the fluid and solid dynamics of spouted beds. The book then gives a description of the internal geometrical structure of a stable bed, as well as the estimation of maximum spoutable bed depth. The subsequent chapters examine the attrition and heat and mass transfer in spouted beds, both between fluid and particles and within particles. The book further discusses theoretical aspects on using a spouting bed in carrying out gas phase chemical reaction. It also describes the application of spouted bed to a large variety of mechanical, thermal, diffusional, and chemical processes, whether on the bench, pilot, or commercial scale. This is followed by a discussion on the various process and equipment modifications to a standard spouted bed that have been devised to achieve specific ends. The final chapter outlines some practical hints for the benefit of the spouted bed designer and operator. This book is an ideal resource text to spouted bed designers, operators, and manufacturers.

Preface

Acknowledgments

1 Introduction

1.1 The Spouted Bed

1.2 History

1.3 Requirements for Spouting

1.4 Spouted Beds in the Gas-Solids Contacting Spectrum

1.5 Spouting versus Fluidization

1.6 Layout of Subject Matter

2 The Onset of Spouting

2.1 Mechanism

2.2 Pressure Drop

A Interpretation of Pressure Drop Measurements

Β Peak Pressure Drop

C Spouting Pressure Drop

2.3 Minimum Spouting Velocity

A Maximum Value

Β Correlations

C Prediction for Large Beds

3 Flow Pattern of Gas

3.1 Experimental Findings

3.2 Prediction of Flow Pattern

3.3 Residence Time Distribution

4 Flow Pattern of Solids

4.1 Particle Motion in Spout

A Measurement Techniques

Β Longitudinal Profile

C Radial Profile

4.2 Particle Motion in Annulus and Recirculation

A Experimental Findings

Β Theoretical Predictions

4.3 Gross Mixing Behavior

A Experimental Findings

Β Modeling

5 Bed Structure

5.1 Spout Shape

A Experimental Observations

Β Empirical Correlations

C Theoretical Models

5.2 Voidage Distribution

A Annulus

Β Spout

6 Spouting Stability

6.1 Experimental Observations

A Effect of Column Geometry

Β Effect of Solids Properties

C Effect of Gas Flow Rate

6.2 Maximum Spoutable Bed Depth

A Controlling Mechanisms

Β Prediction Methods

7 Particle Attrition

8 Heat Transfer

8.1 Between Fluid and Particles

A Transfer Mechanism

Β Experimental Findings

C Design Equations

8.2 Between Wall and Bed

A Transfer Mechanism

Β Experimental Findings

C Proposed Theoretical Model

8.3 Between Submerged Object and Bed

A Transfer Mechanism

Β Experimental Findings

9 Mass Transfer and Drying

9.1 Mass Transfer under External Control Conditions

A Transfer Mechanism

Β Experimental Findings

9.2 Mass Transfer under Internal Control Conditions

9.3 Design Equations for Solids Drying

A Constant Rate Drying

Β Falling Rate Drying

C Intermediate Case

10 Vapor Phase Chemical Reaction

10.1 The Spouted Bed as a Chemical Reactor

10.2 Theoretical Model for Predicting Catalytic Conversion

10.3 Predicted Reactor Performance

10.4 Comparison with Fixed and Fluidized Beds

10.5 Experimental Support

11 Applications

11.1 Introduction

Physical Operations

11.2 Diffusional

A Drying of Granular Solids

Β Drying of Suspensions and Solutions

C The Spouted Bed as a Reactor-Granulator

D Particle Coating

Ε Sorption

F Potential Diffusional Operations

11.3 Thermal

A Solids Heating

Β Solids Cooling

C Food Processing

11.4 Mechanical

A Solids Blending

Β Comminution

C Potential Mechanical Operations

11.5 Solids as Reactants

A Low-Temperature Coal Carbonization

Β Shale Pyrolysis

C Iron Ore Reduction

D Cement Clinker Production

Ε Charcoal Activation

11.6 Solids as Heat Carrier or Catalyst

A Thermal Cracking of Petroleum

Β Solid Catalysis

12 Modifications and Variations

12.1 Multiple Spouting

12.2 Multistage Spouting

12.3 Pulsed Flow Spouting

12.4 Spouting with Tubular Inserts

12.5 Derivative Techniques

A Ring Spouted Bed

Β Slot Spouted Bed

C Spouting with Reverse Gas Flow in Annulus

D Spout-Fluid Bed

Ε Two-Fluid-Phase Spouting

13 Design

13.1 General Considerations

13.2 Experiments Required and Scale-Up Criteria

A Spouting Behavior

Β Rate and Equilibrium Data

C Pilot Plant Work

13.3 Some Practical Suggestions

A Gas Entrance

Β Feed and Discharge of Solids

C Bed Level Control

D Bed Support

Ε Spout Deflector

Appendix

Nomenclature

Conversion Factors

References

Subject Index