Contents
Preface………………………………………………………………………………………………………..xi
List of Symbols…………………………………………………………………………………………. xiii
Chapter 1 Dust and Air Mechanics of Bulk Material Transfer………………………..1
1.1 Transfer Groups as Air Pollution Sources…………………………….1
1.1.1 Intensity of Dust Emissions…………………………………….1
1.1.2 Primary Means of Dust Emission Control ……………….8
1.2 Theoretical Models of Air Suction with a Gravitational
Solid Stream………………………………………………………………….. 12
1.2.1 Butakov–Hemeon Model and Its Development……….. 14
1.2.2 Semiempirical Models…………………………………………22
1.2.3 Dynamic Theory and Research Methodology for
Injection Properties of a Particle Stream ……………….24
1.2.3.1 Mathematical Modeling………………………….25
1.2.3.2 Experimental Studies……………………………..26
1.2.3.3 Industrial Evaluation………………………………28
1.3 Classification of Bulk Material Streams…………………………….29
Chapter 2 Aerodynamic Properties of Particles in the Gravitational
Flow of a Chuted Bulk Material…………………………………………………. 33
2.1 Peculiarities of Bulk Material Motion in Chutes………………… 33
2.1.1 Modes of Motion………………………………………………… 35
2.1.2 Particle Distribution…………………………………………….38
2.1.3 Motion Speed…………………………………………………….. 41
2.2 Aerodynamic Characteristic of a Single Particle………………… 45
2.2.1 Geometric Shape…………………………………………………48
2.2.2 Dynamic Shape of Particles………………………………….50
2.2.3 Resistance Coefficient…………………………………………. 53
2.3 Sedimentation of Particles……………………………………………….. 55
2.3.1 Particle Motion in the Air Stream…………………………. 55
2.3.2 Aerodynamic Drag of a Particle Moving at an
Increasing Rate…………………………………………………… 57
2.4 Method for Evaluating the Aerodynamic Characteristic
of Particle Gravitational Flow ………………………………………….65
2.4.1 Channel Pressure Variation…………………………………..66
2.4.2 Experimental Evaluation of the Method for
Determining the Particle Drag Factor……………………. 72
Chapter 3 Air Injection in Chutes………………………………………………………………75
3.1 Isothermal Flow………………………………………………………………75
3.1.1 Averaged Aerodynamic Characteristic of Particles…….78
3.1.1.1 Monofractional Stream ………………………….78
3.1.1.2 Polyfractional Stream ……………………………81
3.1.2 Air Injection with a Stream of Particles in a Prismatic Chute…………………………………………………..84
3.1.2.1 Pressure Distribution …………………………….86
3.1.2.2 Induced Air Velocity …………………………….95
3.1.3 Peculiarities of the Dynamic Interaction of Air and a Bulk Material Stream in Laminar Flow in a Chute…………………………………………………101
3.1.4 Air Injection in a Bin Chute with a Uniform Distribution of Particles……………………………………..104
3.1.5 Air Mechanics of a Stream of Particles with High Bulk Concentrations…………………………………..107
3.2 Effect of Heat and Mass Exchange…………………………………..110
3.2.1 Inter-Component Heat Exchange in an Inclined Chute…………………………………………………..111
3.2.2 Thermal Head……………………………………………………113
3.2.3 Air Velocity in the Chute……………………………………116
3.2.4 Influence of Mass Exchange on the Volumes of Induced Air…………………………………………………..118
3.3 Aerodynamics of an Unsteady Particle Flow in the Chute……120
3.3.1 Sudden Change in the Material Flow……………………120
3.3.2 Smooth Change in the Material Flow…………………..129
Chapter 4 The Aerodynamics of Solid-Particle Jets……………………………………133
4.1 Air Injection in a Jet of Freely Falling Particles………………..134
4.1.1 Initial Equations………………………………………………..134
4.1.1.1 Changes in Volumetric Particle Concentration in a Jet of Material………….134
4.1.1.2 Volumetric Forces of Interaction between Components……………………………137
4.1.1.3 Fluid Dynamics Equations……………………139
4.1.2 Structure of Air Streams in a Flat Jet of Loose Matter…………………………………………………….144
4.1.2.1 Self-Similar Motion Equations ……………..144
4.1.2.2 Approximate Solution of Self-Similar Motion Equation………………………………….152
4.1.2.3 Uniformly Distributed Particles…………….154
4.1.2.4 One-Dimensional Problem …………………..157
4.1.2.5 Exponentially Distributed Particles ……….169
4.1.2.6 Effect of Pressure Gradient…………………..175
4.1.3 Injection of Air in an Axially Symmetric Jet of Freely Falling Particles………………………………………184
4.1.3.1 Self-Similar Motion Equations………………185
4.1.3.2 Solving the Self-Similar Equation …………190
4.2 The Aerodynamics of a Jet of Particles in a Channel…………196
4.2.1 Plane-Parallel Flow……………………………………………197
4.2.2 One-Dimensional Flow………………………………………200
Chapter 5 Engineering Solutions for Dust Release Containment and Air Dedusting………………………………………………………………………………213
5.1 Basic Premises for Calculating Local Suction Capacity……..214
5.1.1 Initial Equations………………………………………………..214
5.1.2 Determining the Minimum Negative Pressure………215
5.1.2.1 Interaction between an Injected Air Jet and Suction Spectrum of a Local Suction Unit …….215
5.1.2.2 Compressive Effect………………………………219
5.1.2.3 Thermal Pressure in the Cowl……………….221
5.1.2.4 Optimizing the Choice of Negative Pressure………………………………………………221
5.1.3 Choosing an Aspiration Layout and Calculating the Performance of Local Suction Units at Handling Facilities…………………………………………….222
5.1.3.1 Conveyor-to-Conveyor Transfers……………224
5.1.3.2 Conveyor (Feeder)–Crusher–Conveyor…..229
5.1.3.3 Conveyor–Screen–Conveyor…………………232
5.1.3.4 Dry Magnetic Separation Assembly……….234
5.1.3.5 Cascade Installations……………………………236
5.1.3.6 Specific Issues of Injection-Driven Air Discharge Calculations for Complex Configurations of Chutes…………237
5.1.4 Calculations of Air Replacement in High-Speed Machinery………………………………………………………..242
5.1.4.1 Hammer Breakers as Fans…………………….242
5.1.4.2 Aspiration Volumes……………………………..246
5.2 Dust Release Intensity and Mitigation of Initial Dust Concentration in Aspirated Air……………………………………….251
5.2.1 Overview and Primary Features of Dust Release Sources…………………………………………………………….251
5.2.1.1 Dust Carryover from Aspiration Cowls ……251
5.2.1.2 Concentration and Particle Size Composition of Dust in Aspirated Air…….253
5.2.2 Decrease in Dust Release Intensity………………………257
5.2.2.1 Changes in Total Dust Releases Depending on Structural and Process Parameters of Load-Handling Facilities…..260
5.2.3 Techniques for Intensifying Inertial Dust Precipitation in Aspirating Cowls………………………..271
5.2.3.1 Inertial Trap Using a Plate Grid inside Cowl…………………………………………271
5.2.4 Reduction of Dust Concentration in Aspiration Funnels…………………………………………………………….279
5.2.4.1 Initial Dust Concentration as a Function of Air Velocity in Aspiration Funnels……………………………………………….279
5.2.4.2 Dust Precipitation in Dust Receivers/Separators…………………………………………..281
5.2.4.3 Dust Precipitation in a Local Cyclone-Type Suction Unit/Dust Trap…………………291
5.2.4.4 Dust Precipitation in a Local Dust-Separating Suction Unit with a Filter Element ……………………………………………..295
5.3 Sources of Fugitive Atmospheric Dust Releases in Outdoor Storage of Iron Ore Pellets…………………………………298
5.3.1 Outdoor Storage Locations as Atmospheric Emission Sources at Ore Beneficiation Plant Industrial Sites…………………………………………………..298
5.3.1.1 Storage Process Layout…………………………299
5.3.1.2 Primary Dust Emission Sources…………….301
5.3.2 Examining Dust Release Intensity at Iron Ore Pellet Storage Sites………………………………………303
5.3.2.1 Distribution of Dust Released by a Ground-Based Source…………………………..303
5.3.2.2 Field Surveys of Dust Plume Structure…..309
5.3.2.3 Intensity of Primary Dust Emission Sources……………………………………………….315
5.3.2.4 Procedure for Determining Losses of Powdered Material during Stockpiling of Fired Pellets…………………………………….318
5.3.3 Dust Release Containment in Fired Pellet Storage…321
5.3.3.1 Fencing Off the Flowing Material When Pellets Are Dumped into the Stockpile…………………………………………….321
5.3.3.2 Local Suction Units and Aspiration Systems of Storage Facilities…………………329
5.4 Fugitive Emissions and Containment of Dust during Loading of Iron-Ore Pellets in Railway Cars…………………….339
5.4.1 Dust Emission Containment Designs for Loading Bins………………………………………………………………….339
5.4.2 Performance Calculations for Local Suction Units of Pellet Loading Bins………………………………………..344
5.4.3 Improving Aspiration Efficiency for Pellet Handling in Transfer Bin Housings………………………351
Conclusion……………………………………………………………………………………………….359
Appendix Initial Aerodynamic Equations for a Bulk Material Stream…….363
A.1 Phenomenological Method of Dynamic Equation Development for Two-Component Stream………………………..363
A.1.1 Inter-Component Interaction……………………………….364
A.1.2 Accounting Equations………………………………………..367
A.2 Space–Time Method of Averaging Accounting Equations….373
A.2.1 Mass Transfer Equation………………………………………374
A.2.2 Pulse Transfer Equation……………………………………..376
A.2.3 Energy Transfer Equation…………………………………..378
References……………………………………………………………………………..379
References………………………………………………………………………………………………..383
رایگان – خرید
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