Foam Engineering

About the Editor xv Contributors xvii Preface xix 1 Introduction 1 Paul Stevenson 1.1 Gas-Liquid Foam in Products and Processes 1 1.2 Content of This Volume 2 1.3 A Personal View of Collaboration in Foam Research 3 Part I Fundamentals 5 2 Foam Morphology 7 D. Weaire, S.T. Tobin, A.J. Meagher and S. Hutzler 2.1 Introduction 7 2.2 Basic Rules of Foam Morphology 7 2.3 Two-dimensional Foams 11 2.4 Ordered Foams 15 2.5 Disordered Foams 19 2.6 Statistics of 3D Foams 20 2.7 Structures in Transition: Instabilities and Topological Changes 21 2.8 Other Types of Foams 22 2.9 Conclusions 24 3 Foam Drainage 27 Stephan A. Koehler 3.1 Introduction 27 3.2 Geometric Considerations 29 3.3 A Drained Foam 33 3.4 The Continuity Equation 35 3.5 Interstitial Flow 36 3.6 Forced Drainage 38 3.7 Rigid Interfaces and Neglecting Nodes: The Original Foam Drainage Equation 41 3.8 Mobile Interfaces and Neglecting Nodes 43 3.9 Neglecting Channels: The Node-dominated Model 46 3.10 The Network Model: Combining Nodes and Channels 48 3.11 The Carman-Kozeny Approach 50 3.12 Interpreting Forced Drainage Experiments: A Detailed Look 51 3.13 Unresolved Issues 53 3.14 A Brief History of Foam Drainage 54 4 Foam Ripening 59 Olivier Pitois 4.1 Introduction 59 4.2 The Very Wet Limit 59 4.3 The Very Dry Limit 61 4.4 Wet foams 65 4.5 Controlling the Coarsening Rate 69 5 Coalescence in Foams 75 Annie Colin 5.1 Introduction 75 5.2 Stability of Isolated Thin Films 76 5.3 Structure and Dynamics of Foam Rupture 78 5.4 What Are the Key Parameters in the Coalescence Process? 81 5.5 How Do We Explain the Existence of a Critical Liquid Fraction? 86 5.6 Conclusion 89 6 Foam Rheology 91 Nikolai D. Denkov, Slavka S. Tcholakova, Reinhard Höhler and Sylvie Cohen-Addad 6.1 Introduction 91 6.2 Main Experimental and Theoretical Approaches 93 6.3 Foam Visco-elasticity 95 6.4 Yielding 103 6.5 Plastic Flow 105 6.6 Viscous Dissipation in Steadily Sheared Foams 106 6.7 Foam-Wall Viscous Friction 112 6.8 Conclusions 114 7 Particle Stabilized Foams 121 G. Kaptay and N. Babcsán 7.1 Introduction 121 7.2 A Summary of Some Empirical Observations 123 7.3 On the Thermodynamic Stability of Particle Stabilized Foams 125 7.4 On the Ability of Particles to Stabilize Foams during Their Production 131 7.5 Design Rules for Particle Stabilized Foams 135 7.6 Conclusions 138 8 Pneumatic Foam 145 Paul Stevenson and Xueliang Li 8.1 Preamble 145 8.2 Vertical Pneumatic Foam 145 8.3 Horizontal Flow of Pneumatic Foam 158 8.4 Pneumatic Foam in Inclined Channels 162 8.5 Methods of Pneumatic Foam Production 162 9 Non-aqueous Foams: Formation and Stability 169 Lok Kumar Shrestha and Kenji Aramaki 9.1 Introduction 169 9.2 Phase Behavior of Diglycerol Fatty Acid Esters in Oils 173 9.3 Non-aqueous Foaming Properties 174 9.4 Conclusion 203 10 Suprafroth: Ageless Two-dimensional Electronic Froth 207 Ruslan Prozorov and Paul C. Canfield 10.1 Introduction 207 10.2 The Intermediate State in Type-I Superconductors 208 10.3 Observation and Study of the Tubular Intermediate State Patterns 211 10.4 Structural Statistical Analysis of the Suprafroth 215 Part II Applications 227 11 Froth Phase Phenomena in Flotation 229 Paul Stevenson and Noel W.A. Lambert 11.1 Introduction 229 11.2 Froth Stability 233 11.3 Hydrodynamic Condition of the Froth 235 11.4 Detachment of Particles from Bubbles 236 11.5 Gangue Recovery 238 11.6 The Velocity Field of the Froth Bubbles 241 11.7 Plant Experience of Froth Flotation 242 12 Froth Flotation of Oil Sand Bitumen 251 Laurier L. Schramm and Randy J. Mikula 12.1 Introduction 251 12.2 Oil Sands 251 12.3 Mining and Slurrying 253 12.4 Froth Structure 265 12.5 Physical Properties of Froths 272 12.6 Froth Treatment 274 12.7 Conclusion 278 13 Foams in Enhancing Petroleum Recovery 283 Laurier L. Schramm and E. Eddy Isaacs 13.1 Introduction 283 13.2 Foam Applications for the Upstream Petroleum Industry 284 13.3 Foam Applications in Wells and Near Wells 287 13.4 Foam Applications in Reservoir Processes 289 13.5 Occurrences of Foams at the Surface and Downstream 298 13.6 Conclusion 299 14 Foam Fractionation 307 Xueliang Li and Paul Stevenson 14.1 Introduction 307 14.2 Adsorption in Foam Fractionation 310 14.3 Foam Drainage 315 14.4 Coarsening and Foam Stability 316 14.5 Foam Fractionation Devices and Process Intensification 317 14.6 Concluding Remarks about Industrial Practice 324 15 Gas-Liquid Mass Transfer in Foam 331 Paul Stevenson 15.1 Introduction 331 15.2 Non-Overflowing Pneumatic Foam Devices 334 15.3 Overflowing Pneumatic Foam Devices 336 15.4 The Waldhof Fermentor 338 15.5 Induced Air Methods 340 15.6 Horizontal Foam Contacting 341 15.7 Calculation of Specific Interfacial Area in Foam 342 15.8 Hydrodynamics of Pneumatic Foam 343 15.9 Mass Transfer and Equilibrium Considerations 345 15.10 Towards an Integrated Model of Foam Gas-Liquid Contactors 347 15.11 Discussion and Future Directions 349 16 Foams in Glass Manufacturing 355 Laurent Pilon 16.1 Introduction 355 16.2 Glass Foams in Glass Melting Furnaces 363 16.3 Physical Phenomena 365 16.4 Experimental Studies 373 16.5 Modeling 386 16.6 Measures for Reducing Glass Foaming in Glass Melting Furnaces 395 16.7 Perspective and Future Research Directions 400 17 Fire-Fighting Foam Technology 411 Thomas J. Martin 17.1 Introduction 411 17.2 History 413 17.3 Applications 415 17.4 Physical Properties 416 17.5 Chemical Properties 430 17.6 Testing 448 Concentration (CMC) 451 17.7 The Future 453 18 Foams in Consumer Products 459 Peter J. Martin 18.1 Introduction 459 18.2 Creation and Structure 463 18.3 Sensory Appeal 470 18.4 Conclusions 473 Index