+612 9045 4394
Gas Cyclones and Swirl Tubes : Principles, Design, and Operation - Alex C. Hoffmann

Gas Cyclones and Swirl Tubes

Principles, Design, and Operation

Hardcover Published: 2nd October 2007
ISBN: 9783540746942
Number Of Pages: 422

Share This Book:


RRP $531.99
or 4 easy payments of $92.10 with Learn more
Ships in 15 business days

Other Available Editions (Hide)

  • Paperback View Product Published: 19th October 2010

Believed to be a publishing first when originally brought out, this book covers all aspects of centrifugal gas cleaning devices. These are cyclones used as gas-solid separators for dedusting and as gas-liquid separators for demisting. The optimization of cyclone performance for any given task is a sought-after goal - but it is one that is seldom achieved in practice. This second edition will help mechanical and chemical engineers to achieve this optimization.

Introductionp. 1
Some Historical Backgroundp. 1
Removal of Particles from Gasesp. 6
Filtrationp. 8
Wet Scrubbersp. 10
Centrifugal/Cyclonic Devicesp. 11
Knock-out Vessels and Settling Chambersp. 12
A Closer Look at Centrifugal Gas Cleaning Devicesp. 12
Applications of Centrifugal Separatorsp. 13
Classification of Centrifugal Separatorsp. 17
Two Main Classes-Cyclones and Swirl Tubesp. 20
Basic Ideasp. 23
Gas Flowp. 23
Swirling Flowp. 23
Static and Dynamic Pressurep. 26
Particle Motionp. 27
Particle Sizep. 32
Definitions of Particle Sizep. 32
Particle Size Distributionp. 33
Particle Densityp. 37
Ideal Vortex Laws from N-S Eqsp. 38
Model Functions for Size Distributionsp. 41
The Normal Distributionp. 42
The Log-Normal Distributionp. 42
The Rosin-Rammler Distributionp. 43
How Cyclones Workp. 45
Flow in Cyclonesp. 45
Gas Flow Patternp. 45
Particle Flowp. 49
Separation Efficiencyp. 51
Overall Separation Efficiencyp. 51
Grade-Efficiencyp. 51
Converting Between Overall Efficiency and Cut-sizep. 54
Pressure Dropp. 54
Worked Example: Calculating a Grade-Efficiency Curvep. 56
Cyclone Flow Pattern and Pressure Dropp. 59
Discussionp. 59
Flow Patternp. 60
Pressure Dropp. 61
Models for the Flow Patternp. 64
n-Type Modelp. 65
Barthp. 66
Models for the Pressure Dropp. 70
Models Based on Estimating the Dissipative Lossp. 71
Core Modelp. 72
Purely Empirical Modelsp. 77
Model Assumptions in Light of CFD and Experimentp. 78
Overviewp. 82
Worked Example for Calculating Cyclone Pressure Dropp. 83
The Meissner and Loffler Modelp. 85
Cyclone Separation Efficiencyp. 89
Discussionp. 89
Modelsp. 90
Equilibrium-orbit Models: the Model of Barthp. 90
Time-of-Flight Modelsp. 93
Hybrid Modelsp. 96
Comparing the Modelsp. 96
Comparison of Model Predictions with Experimentp. 97
Agreement with Experiment in Generalp. 97
A Case Study: the Effect of Cyclone Lengthp. 98
Overviewp. 102
Worked Example, Separation Performancep. 103
Models of Dietz and of Mothes and Lofflerp. 106
The Muschelknautz Method of Modelingp. 111
Basis of the Modelp. 112
Computation of the Inner Vortex Cut-Point, x[subscript 50]p. 118
Computation of Efficiency at Low Solids Loadingsp. 120
Determining if the Mass Loading Effect will Occurp. 122
Overall Separation Efficiency when c[subscript o] > c[subscript oL]p. 122
Computation of Pressure Dropp. 124
Example Problemsp. 125
Data from Hoffmann, Peng and Postma (2001)p. 125
Data from Obermair and Staudinger (2001)p. 128
Simulation of the Data from Greif (1997)p. 129
Incorporation of the 'Inner Feed'p. 133
Computational Fluid Dynamicsp. 139
Simulating the Gas Flow Patternp. 140
Setting up the Finite Difference Equationsp. 140
Turbulence Modelsp. 142
Simulationsp. 143
Simulating the Particle Flowp. 147
Eulerian Modelingp. 148
Lagrangian Particle Trackingp. 148
3-D particle tracksp. 148
Some Simulations of the Gas and Particle Flow in Cyclonesp. 149
LES Simulations of Derksen and van den Akkerp. 149
Some Remarks on CFD in Cyclonesp. 160
Transport Equationsp. 161
Dimensional Analysis and Scaling Rulesp. 163
Classical Dimensional Analysisp. 164
Separation Efficiencyp. 164
Pressure Dropp. 167
Scaling Cyclones in Practicep. 168
Approximately Constant Stk[subscript 50] over a Wide Range of Rep. 168
Eu Only Weakly Dependent on Rep. 171
Some other Considerationsp. 172
Stk-Eu Relationshipsp. 173
Inspecting the Equations of Motionp. 176
Equation of Motion for the Gasp. 176
Equation of Motion for a Particlep. 176
Sample Cyclone Scaling Calculationsp. 177
Inlet Velocity for Re Similarityp. 177
Prediction from Scale Modelp. 178
Other Factors Influencing Performancep. 183
The Effect of Solids Loadingp. 183
Effect on Separation Efficiency of Cyclonesp. 183
Models for Effect on Separation Efficiencyp. 185
Effect on the Separation Efficiency of Swirl Tubesp. 191
Effect on the Pressure Drop of Cyclonesp. 192
Effect on the Pressure Drop Across Swirl Tubesp. 194
Computing Performance with High Loadingp. 194
The Effect of the Natural Vortex Lengthp. 195
The Nature of the Vortex Endp. 195
Wall Velocity Due to Core Precessionp. 197
The Significance of the Vortex Endp. 199
Models for the Natural Vortex Lengthp. 203
Predicting the Effect of Solids Loading on Cyclone Efficiencyp. 205
Predicting the Effect of Loading on Cyclone Pressure Dropp. 208
Measurement Techniquesp. 213
Gas Flow Patternp. 216
Pressure Dropp. 218
Particle Flowp. 219
Overall Separation Efficiencyp. 220
On-line Sampling of Solidsp. 221
Grade-Efficiencyp. 224
On-Line vs. Off-Line Size Analysisp. 224
Sample Capture and Preparationp. 225
Methods for Size Analysisp. 226
Estimate of Errorsp. 231
Underflow Configurations and Considerationsp. 235
Underflow Configurationsp. 235
Importance of a Good Underflow Sealp. 239
Inleakage Examplep. 242
Upsets Caused by 'Too Good' an Underflow Sealp. 243
Second-Stage Dipleg Solids 'Backup'p. 246
Hopper 'Crossflow'p. 248
Hopper Venting Optionsp. 250
Dipleg Calculationp. 253
Moment Balance on Flapper Valve Platep. 253
Examplep. 256
Some Special Topicsp. 257
Cyclone Erosionp. 257
Inlet 'Target Zone'p. 257
Lower Cone Sectionp. 260
Vortex Tube Outer Surfacep. 263
Erosion Protectionp. 268
Critical Deposition Velocityp. 279
High Vacuum Casep. 281
Application to Cyclone or Swirl Tube Simulationp. 282
Worked Example for Critical Deposition Velocityp. 283
Worked Example with Slipp. 283
Demisting Cyclonesp. 287
Liquid Creep and 'Layer Loss'p. 288
Demisting Cyclone Design Considerationsp. 290
Some Vapor-Liquid Cyclone Design Geometries and Featuresp. 292
Estimating Inlet Drop Size for Two-Phase Mist-Annular Flowp. 299
Estimating Drop Size Distributionp. 301
Modeling the Performance of Vapor-Liquid Cyclonesp. 302
Computation of Cut Sizep. 302
Computation of Efficiency at Low Inlet Loadingsp. 303
Criteria for Determining if 'Mass loading' ('Saltation') Occursp. 303
Overall Separation Efficiency when c[subscript o] > c[subscript oL]p. 304
Re-entrainment From Demisting Cyclonesp. 305
Re-entrainment Mechanisms and Governing Parametersp. 305
Data for Re-entrainmentp. 308
Example Calculations of Droplet Sizes in Pipe Flowp. 311
Finding the Mean Droplet Sizep. 311
Finding the Droplet Size Distributionp. 312
Flow Distribution in Parallel Demisting Cyclonesp. 312
Calculation of Flow Distributionp. 317
Calculation of Liquid Level Differencep. 317
Method for Estimating Wall Film Thickness and Velocityp. 318
Two-Phase, Co-current, Annular Force Balance, Resolved in the Axial Directionp. 320
Friction Factors and Shear Stressesp. 321
Final Form of Void Fraction Equationp. 323
Example calculationp. 324
Foam-Breaking Cyclonesp. 327
Introductionp. 327
Some Design Considerations and Factors Influencing Behaviorp. 330
Applicationsp. 334
Estimating Submergence Required to Prevent Gas 'Blow Out'p. 334
Example Calculation of Submergence Requiredp. 340
Design Aspectsp. 341
Cylinder-on-Cone Cyclones with Tangential Inletp. 341
Some Standard Cyclone Designsp. 341
Design of the Inletp. 342
Design of the Cone Sectionp. 349
Solids Outlet Configurationsp. 350
Vortex Finder Geometriesp. 353
Cyclone Lengthp. 363
Cyclone Roofp. 364
Cyclone Operating Conditionsp. 367
Design of Swirl Tubes with Swirl Vanesp. 368
Design of the Inlet Vanesp. 368
Calculation of Inlet 'Throat' Areap. 370
Length of the Swirl Tube Body and the Solids Exitp. 372
Example Calculation of the Throat Areap. 373
Construction of Vane "Cut-out" patternp. 374
Multicyclone Arrangementsp. 381
Cyclones in Seriesp. 381
Cyclones in Parallelp. 382
Example Calculation for Multicyclone Arrangementsp. 391
List of Symbolsp. 397
List of Tradenamesp. 403
Referencesp. 405
Indexp. 411
Table of Contents provided by Ingram. All Rights Reserved.

ISBN: 9783540746942
ISBN-10: 3540746943
Audience: Professional
Format: Hardcover
Language: English
Number Of Pages: 422
Published: 2nd October 2007
Publisher: Springer-Verlag Berlin and Heidelberg Gmbh & Co. Kg
Country of Publication: DE
Dimensions (cm): 23.5 x 15.5  x 3.05
Weight (kg): 0.79
Edition Number: 2
Edition Type: Revised