Drying in the Process Industry

DRYING IN THE\nPROCESS INDUSTRY......Page 3
Contents......Page 7
Preface......Page 11
1 Introduction......Page 15
2.1 Residual Moisture......Page 23
2.3 Process Changes to Simplify Drying......Page 24
2.4 Combination of Drying and Other Process Steps......Page 26
2.5 Nonthermal Drying......Page 29
2.6 Process Changes to Avoid Drying......Page 31
2.7 No Drying......Page 33
3.1 Selection Schemes......Page 35
3.2 Processing Liquids, Slurries, and Pastes......Page 45
3.3 Special Drying Techniques......Page 47
3.4 Some Additional Comments......Page 48
3.5 Testing on Small-Scale Dryers......Page 51
3.6 Examples of Dryer Selection......Page 52
4 Convective Drying......Page 55
4.1 Common Aspects of Continuous Convective Dryers......Page 56
4.2 Saturated Water Vapor Pressure......Page 57
4.3 Wet-Bulb Temperature......Page 58
4.4 Adiabatic Saturation Temperature......Page 60
4.5 Humidity Chart......Page 61
4.6 Water–Material Interactions......Page 63
4.7 Drying with an Auxiliary Material......Page 66
4.8 Gas Velocities......Page 68
4.9 Heat Losses......Page 69
4.10 Electrical Energy Consumption......Page 71
4.11 Miscellaneous Aspects......Page 73
4.13 Heat Balance (kJ·h-1)......Page 75
4.14 Specific Heat of Solids......Page 77
4.15 Gas Flows and Fan Power......Page 78
4.16 Direct Heating of Drying Air......Page 79
5.1 General Description......Page 81
5.2 Fluidization Theory......Page 84
5.3 Drying Theory for Rectangular Dryers......Page 90
5.4 Removal of Bound Moisture from a Product in a Rectangular Dryer......Page 102
5.5 Circular Fluid-Bed Dryers......Page 104
6.1 General Description......Page 113
6.2 Design Methods......Page 117
7.1 General Description......Page 131
7.2 Design Methods......Page 134
7.3 Drying in Seconds......Page 136
7.4 Application of the Design Methods......Page 140
8.1 General Description......Page 147
8.2 Single-Fluid Nozzle......Page 152
8.3 Rotary Atomizer......Page 157
8.4 Pneumatic Nozzle......Page 159
8.5 Product Quality......Page 163
8.6 Heat of Crystallization......Page 167
8.8 Product Transportation......Page 168
8.9 Design Methods......Page 169
9 Miscellaneous Continuous Convective Dryers and Convective Batch Dryers......Page 177
9.1 Conveyor Dryers......Page 178
9.2 Wyssmont Turbo-Dryer......Page 183
9.3 Nara Media Slurry Dryer......Page 184
9.4 Anhydro Spin Flash Dryer......Page 186
9.5 Hazemag Rapid Dryer......Page 188
9.6 Combined Milling and Drying System......Page 190
9.7 Batch Fluid-Bed Dryer......Page 192
9.8 Atmospheric Tray Dryer......Page 196
9.9 Centrifuge–Dryer......Page 198
10.1 Plate Dryers......Page 203
10.2 Mildly Agitated Contact Dryers (Paddle Dryers)......Page 207
10.3 Vigorously Agitated Contact Dryers......Page 212
10.4 Vertical Thin-Film Dryers......Page 216
10.5 Drum Dryers......Page 218
10.6 Steam-Tube Dryers......Page 222
10.7 Spiral Conveyor Dryers......Page 226
10.8 Agitated Atmospheric Batch Dryers......Page 227
11 Vacuum Drying......Page 231
11.1 Vacuum Drying......Page 233
11.2 Freeze-Drying......Page 246
11.3 Vacuum Pumps......Page 256
12 Steam Drying......Page 265
12.1 Sugar Beet Pulp Dryer......Page 266
12.2 GEA Exergy Barr–Rosin Dryer......Page 269
12.4 Disadvantages of Continuous Steam Drying......Page 271
12.6 Eirich Evactherm Dryer......Page 272
13 Radiation Drying......Page 277
13.1 Dielectric Drying......Page 278
13.2 Infrared Drying......Page 292
14.1 Product Quality......Page 303
14.2 Safeguarding Drying......Page 305
15.1 Continuous Moisture-Measurement Methods for Solids......Page 327
15.2 Continuous Moisture-Measurement Methods for Gases......Page 335
15.3 Dryer Process Control......Page 341
15.4 Energy Recovery......Page 349
16 Gas–Solid Separation Methods......Page 353
16.1 Cyclones......Page 354
16.2 Fabric Filters......Page 357
16.3 Scrubbers......Page 360
16.4 Electrostatic Precipitators......Page 363
17 Dryer Feeding Equipment......Page 371
17.1 Fluid-Bed Dryers......Page 372
17.3 Flash Dryers......Page 374
17.5 Conveyor Dryers......Page 375
17.6 Hazemag Rapid Dryer......Page 377
17.10 Vertical Thin-Film and Drum Dryers......Page 379
Notation......Page 383
Index......Page 391