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Mixing (process engineering)

About: Mixing (process engineering) is a research topic. Over the lifetime, 26736 publications have been published within this topic receiving 162697 citations. The topic is also known as: combining & blending.


Papers
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Journal ArticleDOI
TL;DR: A three-dimensional serpentine microchannel design with a "C shaped" repeating unit is presented in this paper as a means of implementing chaotic advection to passively enhance fluid mixing.
Abstract: A three-dimensional serpentine microchannel design with a "C shaped" repeating unit is presented in this paper as a means of implementing chaotic advection to passively enhance fluid mixing. The device is fabricated in a silicon wafer using a double-sided KOH wet-etching technique to realize a three-dimensional channel geometry. Experiments using phenolphthalein and sodium hydroxide solutions demonstrate the ability of flow in this channel to mix faster and more uniformly than either pure molecular diffusion or flow in a "square-wave" channel for Reynolds numbers from 6 to 70. The mixing capability of the channel increases with increasing Reynolds number. At least 98% of the maximum intensity of reacted phenolphthalein is observed in the channel after five mixing segments for Reynolds numbers greater than 25. At a Reynolds number of 70, the serpentine channel produces 16 times more reacted phenolphthalein than a straight channel and 1.6 times more than the square-wave channel. Mixing rates in the serpentine channel at the higher Reynolds numbers are consistent with the occurrence of chaotic advection. Visualization of the interface formed in the channel between streams of water and ethyl alcohol indicates that the mixing is due to both diffusion and fluid stirring.

1,218 citations

Book
01 Jan 2006
TL;DR: In this paper, the authors present an overview of the history of the field of polymers in terms of elementary steps and shaping methods, and present and future perspectives of this field.
Abstract: 1 History, Structural Formulation of the Field Through Elementary Steps, and Future Perspectives 11 Historical Notes 12 Current Polymer Processing Practice 13 Analysis of Polymer Processing in Terms of Elementary Steps and Shaping Methods 14 Future Perspectives: From Polymer Processing to Macromolecular Engineering 2 The Balance Equations and Newtonian Fluid Dynamics 21 Introduction 22 The Balance Equations 23 Reynolds Transport Theorem 24 The Macroscopic Mass Balance and the Equation of Continuity 25 The Macroscopic Linear Momentum Balance and the Equation of Motion 26 The Stress Tensor 27 The Rate of Strain Tensor 28 Newtonian Fluids 29 The Macroscopic Energy Balance and the Bernoulli and Thermal Energy Equations 210 Mass Transport in Binary Mixtures and the Diffusion Equation 211 Mathematical Modeling, Common Boundary Conditions, Common Simplifying Assumptions, and the Lubrication Approximation 3 Polymer Rheology and Non-Newtonian Fluid Mechanics 31 Rheological Behavior, Rheometry, and Rheological Material Functions of Polymer Melts 32 Experimental Determination of the Viscosity and Normal Stress Difference Coefficients 33 Polymer Melt Constitutive Equations Based on Continuum Mechanics 34 Polymer Melt Constitutive Equations Based on Molecular Theories 4 The Handling and Transporting of Polymer Particulate Solids 41 Some Unique Properties of Particulate Solids 42 Agglomeration 43 Pressure Distribution in Bins and Hoppers 44 Flow and Flow Instabilities in Hoppers 45 Compaction 46 Flow in Closed Conduits 47 Mechanical Displacement Flow 48 Steady Mechanical Displacement Flow Aided by Drag 49 Steady Drag-induced Flow in Straight Channels 410 The Discrete Element Method 5 Melting 51 Classification and Discussion of Melting Mechanisms 52 Geometry, Boundary Conditions, and Physical Properties in Melting 53 Conduction Melting without Melt Removal 54 Moving Heat Sources 55 Sintering 56 Conduction Melting with Forced Melt Removal 57 Drag-induced Melt Removal 58 Pressure-induced Melt Removal 59 Deformation Melting 6 Pressurization and Pumping 61 Classification of Pressurization Methods 62 Synthesis of Pumping Machines from Basic Principles 63 The Single Screw Extruder Pump 64 Knife and Roll Coating, Calenders, and Roll Mills 65 The Normal Stress Pump 66 The Co-rotating Disk Pump 67 Positive Displacement Pumps 68 Twin Screw Extruder Pumps 7 Mixing 71 Basic Concepts and Mixing Mechanisms 72 Mixing Equipment and Operations of Multicomponent and Multiphase Systems 73 Distribution Functions 74 Characterization of Mixtures 75 Computational Analysis 8 Devolatilization 81 Introduction 82 Devolatilization Equipment 83 Devolatilization Mechanisms 84 Thermodynamic Considerations of Devolatilization 85 Diffusivity of Low Molecular Weight Components in Molten Polymers 86 Boiling Phenomena: Nucleation 87 Boiling-Foaming Mechanisms of Polymeric Melts 88 Ultrasound-enhanced Devolatilization 89 Bubble Growth 810 Bubble Dynamics and Mass Transfer in Shear Flow 811 Scanning Electron Microscopy Studies of Polymer Melt Devolatilization 9 Single Rotor Machines 91 Modeling of Processing Machines Using Elementary Steps 92 The Single Screw Melt Extrusion Process 93 The Single Screw Plasticating Extrusion Process 94 The Co-rotating Disk Plasticating Processor 10 Twin Screw and Twin Rotor Processing Equipment 101 Types of Twin Screw and Twin Rotor-based Machines 102 Counterrotating Twin Screw and Twin Rotor Machines 103 Co-rotating, Fully Intermeshing Twin Screw Extruders 11 Reactive Polymer Processing and Compounding 111 Classes of Polymer Chain Modification Reactions, Carried out in Reactive Polymer Processing Equipment 112 Reactor Classification 113 Mixing Considerations in Multicomponent Miscible Reactive Polymer Processing Systems 114 Reactive Processing of Multicomponent Immiscible and Compatibilized Immiscible Polymer Systems 115 Polymer Compounding 12 Die Forming 121 Capillary Flow 122 Elastic Effects in Capillary Flows 123 Sheet Forming and Film Casting 124 Tube, Blown Film, and Parison Forming 125 Wire Coating 126 Profile Extrusion 13 Molding 131 Injection Molding 132 Reactive Injection Molding 133 Compression Molding 14 Stretch Shaping 141 Fiber Spinning 142 Film Blowing 143 Blow Molding 15 Calendering 151 The Calendering Process 152 Mathematical Modeling of Calendering 153 Analysis of Calendering Using FEM Appendix A: Rheological and Thermophysical Properties of Polymers Appendix B: Conversion Tables to the International System of Units (SI) Appendix C: Notation Author Index Subject Index

1,163 citations

Journal ArticleDOI
12 Aug 2003-Langmuir
TL;DR: In this article, an experimental characterization of a simple method for rapid formation of droplets, or plugs, of multiple aqueous reagents without bringing reagents into contact prior to mixing is presented.
Abstract: This paper reports an experimental characterization of a simple method for rapid formation of droplets, or plugs, of multiple aqueous reagents without bringing reagents into contact prior to mixing. Droplet-based microfluidics offers a simple method of achieving rapid mixing and transport with no dispersion. In addition, this paper shows that organic dyes at high concentrations should not be used for the visualization of flow patterns and mixing of aqueous plugs in multiphase flows in this system (fluorinated carrier fluid and PDMS microchannels). It reports an inorganic dye that can be used instead. This work focuses on mixing in plugs moving through straight channels. It demonstrates that, when traveling through straight microchannels, mixing within plugs by steady recirculating flow is highly sensitive to the initial distribution of the aqueous reagents established by the eddy flow at the tip of the forming plug (twirling). The results also show how plugs with proper distribution of the aqueous reagents could be formed in order to achieve optimal mixing of the reagents in this system.

765 citations

Journal ArticleDOI
TL;DR: In this paper, the authors measured the interfacial area in gas-liquid dispersions and correlated the data with other published data for heat and mass transfer in liquid-liquid and solid-gas dispersions in which the dispersed phases are free to move under the action of gravity.

742 citations

Book
01 Jan 2000
TL;DR: In this article, the authors discuss the structural and functional hierarchy of microreactors and the potential of using micro-reactors in analytical analysis and reaction systems, as well as their application in the field of micro-reactor realisation.
Abstract: 1 State of the Art of Microreaction Technology 1.1 Definition 1.1.1 Microsystems Termed Microreactor 1.1.2 Structural Hierarchy of Microreactors 1.1.3 Functional Classification of Microreactors 1.1.4 Dividing Line Between Analysis and Reaction Systems 1.2 Fundamental Advantages of Microreactors 1.2.1 Fundamental Advantages of Miniaturized Analysis Systems 1.2.2 Fundamental Advantages of Nano-Scale Reactors 1.2.3 Advantages of Microreactors Due to Decrease of Physical Size 1.2.4 Advantages of Microreactors Due to Increase of Number of Units 1.3 Potential Benefits of Microreactors Regarding Applications 1.4 References 2 Modern Microfabrication Techniques for Microreactors 2.1 Microfabrication Techniques Suitable for Microreactor Realization 2.2 Evaluation of Suitability of a Technique 2.3 Anisotropic Wet Etching of Silicon 2.4 Dry Etching of Silicon 2.5 LIGA Process 2.6 Injection Molding 2.7 Wet Chemical Etching of Glass 2.8 Advanced Mechanical Techniques 2.8.1 Surface Cutting with Diamond Tools 2.8.2 Milling, Turning and Drilling 2.8.3 Punching 2.8.4 Embossing 2.9 Isotropic Wet Chemical Etching of Metal Foils 2.10 Electro Discharge Machining (EDM) of Conductive Materials 2.10.1 Wire-Cut Erosion and Die Sinking 2.10.2 -EDM Drilling 2.11 Laser Micromachining 2.12 Interconnection Techniques 2.12.1 Microlamination of Thin Metal Sheets 2.13 Functional Coatings 2.13.1 Functional Coatings for Corrosion Prevention 2.13.2 Functional Coatings for Fouling Prevention 2.14 References 3 Micromixers 3.1 Mixing Principles and Classes of Macroscopic Mixing Equipment 3.2 Mixing Principles and Classes of Miniaturized Mixers 3.3 Potential of Miniaturized Mixers 3.4 Contacting of Two Substreams, e.g. in a Mixing Tee Configuration 3.4.1 Mixing Tee-Type Configuration 3.4.2 Double Mixing Tee-Type Configuration 3.5 Collision of High-Energy Substreams for Spraying/Atomizing 3.5.1 Collision of Three Substreams in a Microjet Reactor 3.6 Injection of Many Small Substreams of One Component into a Main Stream of Another Component 3.6.1 Injection of Multiple Microjets 3.7 Manifold Splitting and Recombination of a Stream Consisting of Two Fluid Lamellae of Both Components 3.7.1 Multiple Flow Splitting and Recombination Combined with Channel Reshaping 3.7.2 Multiple Flow Splitting and Recombination Using Fork-Like Elements 3.7.3 Multiple Flow Splitting and Recombination Using a Separation Plate 3.7.4 Multiple Flow Splitting and Recombination Using a Ramp-Like Channel Architecture 3.8 Injection of Many Substreams of Both Components 3.8.1 Multilamination of Fluid Layers in an Interdigital Channel Configuration 3.8.2 Vertical Multilamination of Fluid Layers Using a V-type Nozzle Array 3.8.3 Multilamination Using a Stack of Platelets with Microchannels 3.8.4 Multilamination Using a Stack of Platelets with Star-Shaped Openings 3.9 Decrease of Diffusion Path Perpendicular to the Flow Direction by Increase of Flow Velocity 3.9.1 Decrease of Layer Thickness by Hydrodynamic Focusing 3.10 Externally Forced Mass Transport, e.g. by Stirring. Ultrasonic Wave, Electrical and Thermal Energy 3.10.1 Dynamic Micromixer Using Magnetic Beads 3.11 References 4 Micro Heat Exchangers 4.1 Micro Heat Exchangers with Wide and Flat Channels 4.1.1 Cross-Flow Heat Exchange in Stacked Plate Devices 4.1.2 Cross-Flow Heat Exchange Based on Cross-Mixing 4.1.3 Counter-Flow Heat Exchange in Stacked Plate Devices 4.1.4 Electrically Heated Stacked Plate Devices 4.2 Micro Heat Exchangers with Narrow and Deep Channels 4.2.1 Heat Exchanger with One-Sided Structured Channels 4.2.2 Heat Exchanger with Double-Sided Structured Channels 4.3 Micro Heat Exchangers with Breakthrough Channels 4.4 Axial Heat Conduction 4.4.1 Numerical Calculations of the Influence of Material on Heat Transfer Efficiency 4.4.2 The Use of Thermal Blocking Structures 4.5 Permanent Generation of Entrance Flow by Fins 4.6 Generation of a Periodic Flow Profile by Sine-Wave Microchannels 4.7 Microtechnology-Based Chemical Heat Pumps 4.8 Performance Characterization of Micro Heat Exchangers 4.8.1 Temperature Profiles of Micro Heat Exchangers Yielded by Thermograms of Infrared Cameras 4.9 References 5 Microseparation Systems and Specific Analytical Modules for Microreactors 5.1 Microextractors 5.1.1 Partially Overlapping Channels 5.1.2 Wedge-Shaped Flow Contactor 5.1.3 Contactor Microchannels Separated by a Micromachined Membrane 5.1.4 Contactor Microchannels Separated by Sieve-Like Walls 5.1.5 Micromixer - Settler Systems 5.2 Microfilters 5.2.1 Isoporous-Sieve Microfilters 5.2.2 Cross-Flow Microfilters 5.3 Gas Purification Microsystems 5.4 Gas Separation Microdevices 5.5 Specific Analytical Modules for Microreactors 5.5.1 Analytical Modules for In-Line IR Spectroscopy 5.5.2 Analytical Module for Fast Gas Chromatography 5.6 References 6 Microsystems for Liquid Phase Reactions 6.1 Types of Liquid Phase Microreactors 6.2 Liquid/Liquid Synthesis of a Vitamin Precursor in a Combined Mixer and Heat Exchanger Device 6.3 Acrylate Polymerization in Micromixers 6.4 Ketone Reduction Using a Grignard Reagent in Micromixers 6.5 Laboratory-Scale Organic Chemistry in Micromixer/Tube Reactors 6.6 Dushman Reaction Using Hydrodynamic Focusing Micromixers and High-Aspect Ratio Heat Exchangers 6.7 Synthesis of Microcrystallites in a Microtechnology-Based Continuous Segmented-Flow Tubular Reactor 6.8 Electrochemical Microreactors 6.8.1 Synthesis of 4-Methoxybenzaldehyde in a Plate-to-Plate Electrode Configuration 6.8.2 Scouting Potentiodynamic Operation of Closed Microcells 6.9 References 7 Microsystems for Gas Phase Reactions 7.1 Catalyst Supply for Microreactors 7.2 Types of Gas Phase Microreactors 7.3 Microchannel Catalyst Structures 7.3.1 Flow Distribution in Microchannel Catalyst Reactors 7.3.2 Partial Oxidation of Propene to Acrolein 7.3.3 Selective Partial Hydrogenation of a Cyclic Triene 7.3.4 H 2 /O 2 Reaction 7.3.5 Selective Partial Hydrogenation of Benzene 7.3.6 Selective Oxidation of 1-Butene to Maleic Anhydride 7.3.7 Selective Oxidation of Ethylene to Ethylene Oxide 7.3.8 Reactions Utilizing Periodic Operation 7.4 Microsystems with Integrated Catalyst Structures and Heat Exchanger 7.4.1 Oxidative Dehydrogenation of Alcohols 7.4.2 Synthesis of Methyl Isocyanate and Various Other Hazardous Gases 7.4.3 H 2 /O 2 Reaction in the Explosion Regime 7.5 Microsystems with Integrated Catalyst Structures and Mixer 7.5.1 Synthesis of Ethylene Oxide 7.6 Microsystems with Integrated Catalyst Structures. Heat Exchanger and Sensors 7.6.1 Oxidation of Ammonia 7.6.2 H 2 /O 2 Reaction 7.7 Microsystems with Integrated Mixer, Heat Exchanger, Catalyst Structures and Sensors 7.7.1 HCN Synthesis via the Andrussov Process 7.8 References 8 Gas/Liquid Microreactors 8.1 Gas/Liquid Contacting Principles and Classes of Miniaturized Contacting Equipment 8.2 Contacting of Two Gas and Liquid Substreams in a Mixing Tee Configuration 8.2.1 Injection of One Gas and Liquid Substream 8.2.2 Injection of Many Gas and Liquid Substreams into One Common Channel 8.2.3 Injection of Many Gas and Liquid Substreams into One Packed Channel 8.2.4 Injection of Many Gas Substreams into One Liquid Channel with Catalytic Walls 8.2.5 Injection of Many Gas and Liquid Substreams into Multiple Channels 8.3 Generation of Thin Films in a Falling Film Microreactor 8.4 References 9 Microsystems for Energy Generation 9.1 Microdevices for Vaporization of Liquid Fuels 9.2 Microdevices for Conversion of Gaseous Fuels to Syngas by Means of Partial Oxidations 9.2.1 Hydrogen Generation by Partial Oxidations 9.2.2 Partial Oxidation of Methane in a Stacked Stainless Steel Sheet System 9.2.3 Partial Oxidation of Methane in a Microchannel Reactor 9.3 Microdevices for Conversion of Gaseous Fuels to Syngas by Means of Steam Reforming 9.3.1 Steam Reforming of Methanol in Microstructured Platelets 9.4 References 10 Microsystems for Catalyst and Material Screening 10.1 Parallel Screening of Heterogeneous Catalysts in a Microchannel Reactor 10.2 Parallel Screening of Heterogeneous Catalysts in Conventional Mini-Scale Reactors 10.3 References 11 Methodology for Distributed Production 11.1 The Miniplant Concept 11.1.1 Miniplant Concept for HCN Manufacture 11.1.2 The Disposable Batch Miniplant 11.2 Paradigm Change in Large-Scale Reactor Design Towards Operability and Environmental Aspects Using Miniplants 11.3 References Index

661 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202217
2021367
2020927
20191,434
20181,841
20171,500