10th European Conference on Mixing (eBook)

Harry E.A. van den Akker, J.J. Derksen (Herausgeber)

eBook Download: PDF

2000 | 1. Auflage
572 Seiten
Elsevier Science (Verlag)
978-0-08-052579-2 (ISBN)

Infos

Traditionally, fluid mixing and the related multiphase contacting processes have always been regarded as an empirical technology. Many aspects of mixing, dispersing and contacting were related to power draw, but understanding of the phenomena was limited or qualitative at the most.
In particular during the last decade, however, plant operation targets have tightened and product specifications have become stricter. The public awareness as to safety and environmental hygiene has increased. The drive towards larger degrees of sustainability in the process industries has urged for lower amounts of solvents and for higher yields and higher selectivities in chemical reactors. All this has resulted in a market pull: the need for more detailed insights in flow phenomena and processes and for better verifiable design and operation methods.
Developments in miniaturisation of sensors and circuits as well as in computer technology have rendered leaps possible in computer simulation and animation and in measuring and monitoring techniques.
This volume encourages a leap forward in the field of mixing by the current, overwhelming wealth of sophisticated measuring and computational techniques. This leap may be made possible by modern instrumentation, signal and data analysis, field reconstruction algorithms, computational modelling techniques and numerical recipes.

Inhalt

Cover 1
Contents 4
Preface 10
Mixing: Terms, Symbols, Units 14
PART I: TURBULENCE CHARACTERISTICS IN STIRRED TANKS 32
Chapter 1. Trailing vortex, mean flow and turbulence modification through impeller blade design in stirred reactors 32
Chapter 2. Turbulence generation by different types of impellers 40
Chapter 3. Limits of fully turbulent flow in a stirred tank 48
PART II: MEASUREMENTS IN CHEMICALLY REACTING FLOWS 56
Chapter 4. Spatially resolved measurements and calculations of micro-and macromixing in stirred vessels 56
Chapter 5. Characterisation and modelling of a two impinging jet mixer for precipitation processes using laser induced fluorescence 66
Chapter 6. Four-dimensional laser induced fluorescence measurements of micromixing in a tubular reactor 76
PART III: MODELLING OF MICRO-MIXING 84
Chapter 7. Simulation with validation of mixing effects in continuous and fed-batch reactors 84
Chapter 8. A computational and experimental study of mixing and chemical reaction in a stirred tank reactor equipped with a down-pumping hydrofoil impeller using a micro-mixing-based CFD model 92
Chapter 9. Mixing with a Pfaudler type impeller: the effect of micromixing on reaction selectivity in the production of fine chemicals 100
Chapter 10. Comparison of different modelling approaches to turbulent precipitation 108
Chapter 11. Application of parallel test reactions to study micromixing in a co-rotating twin-screw extruder 116
Chapter 12. Solid liquid mixing at high concentration with SMX static mixers 124
PART IV: EFFECTS OF VISCOSITY AND RHEOLOGY ON MIXING 132
Chapter 13. Influence of viscosity on turbulent mixing and product distribution of parallel chemical reactions 132
Chapter 14. Mixing of two liquids with different rheological behaviour in a lid driven cavity 140
Chapter 15. Mobilization of cohesive sludge in storage tanks using jet mixers 148
PART V: SLURRY SYSTEMS 156
Chapter 16. CFD simulation of particle distribution in a multiple-impeller high-aspect ratio stirred vessel 156
Chapter 17. Power consumption in slurry systems 164
PART VI: LIQUID-LIQUID DISPERSIONS 172
Chapter 18. Drop break-up and coalescence in intermittent turbulent flow 172
Chapter 19. Measurement and analysis of drop size in a batch rotor-stator mixer 180
Chapter 20. The impact of fine particles and their wettability on the coalescence of sunflower oil drops in water 188
Chapter 21. Influence of impeller type and agitation conditions on the drop size of immiscible liquid dispersions 196
Chapter 22. Experimental findings on the scale-up behaviour of the drop size distribution of liquid/liquid dispersions in stirred vessels 204
Chapter 23. Investigations of local drop size distributions and scale-up in stirred liquid-liquid dispersions 212
PART VII: GAS-LIQUID SYSTEMS 220
Chapter 24. Gas-liquid mass transfer in a vortex-ingesting, agitated draft-tube reactor 220
Chapter 25. Modelling of the interaction between gas and liquid in stirred vessels 228
Chapter 26. Experimental investigation of local bubble size distributions in stirred vessels using Phase Doppler Anemometry 236
Chapter 27. Void fraction and mixing in sparged and boiling reactors 244
PART VIII: PARTICLE COLLISIONS IN CRYSTALLISATION 252
Chapter 28. A numerical investigation into the influence of mixing on orthokinetic agglomeration 252
Chapter 29. An experimental method for obtaining particle impact frequencies and velocities on impeller blades 262
PART IX: ADVANCED CFD 270
Chapter 30. Comparison between direct numerical simulation and ke prediction of the flow in a vessel stirred by a Rushton turbine 270
Chapter 31. The use of large eddy simulation to study stirred vessel hydrodynamics 278
Chapter 32. Compartmental modelling of an 1100L DTB crystallizer based on large eddy flow simulation 286
PART X: POSTERS 296
Chapter 33. Detailed CFD prediction of flow around a 45° pitched blade turbine 296
Chapter 34. Comparison of CFD methods for modelling of stirred tanks 304
Chapter 35. Predicting the tangential velocity field in stirred tanks using the Multiple Reference Frames (MRF) model with validation by LDA measurements 312
Chapter 36. Numerical simulation of flow of Newtonian fluids in an agitated vessel equipped with a non standard helical ribbon impeller 320
Chapter 37. A contribution to simulation of mixing in screw extruders employing commercial CFD-software 328
Chapter 38. Experimental and CFD characterization of mixing in a novel sliding-surface mixing device 336
Chapter 39. An investigation of the flow field of viscoelastic fluid in a stirred vessel 344
Chapter 40. Flow of Newtonian and non-Newtonian fluids in an agitated vessel equipped with a non-standard anchor impeller 352
Chapter 41. Characterization of convective mixing in industrial precipitation reactors by real-time processing of trajectography data 360
Chapter 42. Characterization of flow and mixing in an open system by a trajectography method 368
Chapter 43. Characterization of the turbulence in a stirred tank using particle image velocimetry 376
Chapter 44. Turbulent macroscale of the impeller stream of a Rushton turbine 384
Chapter 45. Analysis of macro-instabilities (MI) of the flow field in stirred tank reactor (STR) agitated with different axial impellers 392
Chapter 46. Local dynamic effect of mechanically agitated liquid on a radial baffle 400
Chapter 47. Interpretation of macro- and micro-mixing measured by dual-wavelength photometric tomography 408
Chapter 48. Effect of tracer properties (volume, density and viscosity) on mixing time in mechanically agitated contactors 416
Chapter 49. Mixing, reaction and precipitation : an interplay in continuous crystallizers with unpremixed feeds 426
Chapter 50. Simulation of a tubular polymerisation reactor with mixing effects 438
Chapter 51. Mixing equipment design for particle suspension - generalized approach to designing 446
Chapter 52. Characterization and rotation symmetry of the impeller region in baffled agitated suspensions 454
Chapter 53. Solids suspension by the bottom shear stress approach 462
Chapter 54. A phenomenological model for the quantitative interpretation of partial suspension conditions in stirred vessels 470
Chapter 55. A self-aspirating disk impeller – an optimization attempt 478
Chapter 56. A novel gas-inducing agitator system for gas-liquid reactors for improved mass transfer and mixing 486
Chapter 57. Hold-up and gas-liquid mass transfer performance of modified Rushton turbine impellers 492
Chapter 58. A simple method for detecting individual impeller flooding of dual-Rushton impellers 500
Chapter 59. Numerical simulation of gas-liquid flow in a parallelepiped tank equipped with a gas rotor-distributor 508
Chapter 60. Experimental and modelling study of gas dispersion in a double turbine stirred tank 516
Chapter 61. Local heat transfer in liquid and gas-liquid systems agitated by concave disc turbine 524
Chapter 62. Effect of the viscosity ratio .d/.c on the droplet size distributions of emulsions generated in a colloid mill 532
Chapter 63. Experimental measurement of droplet size distribution of a MMA suspension in a batch oscillatory baffled reactor of 0.21 m diameter 540
Chapter 64. Power consumption in mechanically stirred crystallizers 548
Chapter 65. Fluid dynamic studies of a large bioreactor with different cooling coil geometries 556
Author index 564

Produkt-Details

• Erscheint lt. Verlag: 14.6.2000
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Chemie ► Technische Chemie
• Themenwelt: Naturwissenschaften ► Physik / Astronomie ► Strömungsmechanik
• Themenwelt: Technik ► Bauwesen
• Themenwelt: Technik ► Maschinenbau
• Themenwelt: Technik ► Umwelttechnik / Biotechnologie
• ISBN-10: 0-08-052579-2 / 0080525792
• ISBN-13: 978-0-08-052579-2 / 9780080525792