Industrial Heating: Principles, Techniques, Materials, Applications, and Design

Industrial Heating: Principles, Techniques, Materials, Applications and Design......Page 1
Dedication......Page 11
Contents......Page 12
Preface......Page 21
About the Author......Page 25
Abstract......Page 26
Acknowledgments......Page 28
1.1 IN THE BEGINNING......Page 29
1.2 HEATING SYSTEM CLASSIFICATION......Page 31
1.3 CLASSIFICATION OF HEATING MODES......Page 35
1.4 AUXILLIARY TECHNIQUES......Page 38
CONTENTS......Page 40
2.2 SOURCES OF GASES IN FURNACES......Page 41
2.3 FLOW OF GASES......Page 42
2.4 IMPORTANCE OF FLUID FLOW IN HEATING......Page 44
2.5 CLASSIFICATION OF FLUID FLOW......Page 45
2.6 FLOW OVER OBJECTS......Page 48
2.7 FLOW SEPARATION......Page 49
2.8 FORCED CIRCULATION IN ENCLOSURES......Page 54
2.10 NATURAL GAS CIRCULATION INSIDE FURNACES......Page 56
2.11 BERNOULLI’S THEOREM OF FLUID FLOW......Page 59
2.12 FRICTIONAL LOSSES IN FLOW......Page 62
2.13 LOCAL LOSSES......Page 71
2.13.1 Common Local Features......Page 73
2.13.2 Gas Flow through Ports......Page 75
2.13.3 Pump Power......Page 76
2.14 STACK EFFECT......Page 78
2.15 PRACTICAL FLUE SYSTEM......Page 80
CONTENTS......Page 84
3.1 INTRODUCTION......Page 85
Single Layer Wall......Page 87
3.3 THE SHAPE FACTOR......Page 99
3.4 GRAPHICAL METHOD FOR WALL HEAT TRANSFER AND DESIGN......Page 102
3.5 CONVECTION......Page 107
Determination of Convective Heat Transfer Coefficient......Page 110
3.6 FORCED CONVECTION......Page 112
3.6.1 Boundary Layer and Convection......Page 113
3.6.2 Forced Convection over Flat Plate......Page 115
3.6.3 Forced Convection inside Tubes......Page 124
3.6.3A Laminar Flow......Page 125
3.6.3B Turbulent Flow......Page 126
3.6.4 Heat Transfer in Coils......Page 135
3.7 NATURAL CONVECTION (FLAT WALLS)......Page 140
3.7.1 Free Convection over Horizontal Pipes......Page 143
3.7.2 Free Convection inside Enclosures......Page 148
3.8 RADIATIVE HEAT TRANSFER......Page 151
3.9 RADIATION EXCHANGE BETWEEN BODIES......Page 155
3.9.1 Radiative Exchange between Two Parallel Surfaces......Page 156
3.9.2 Radiative Exchange between Article and Enclosure......Page 159
3.10 RADIATION SCREENS......Page 160
3.11 RADIATION EXCHANGE INSIDE AND OUTSIDE FURNACES......Page 164
3.12 RADIATION IN ABSORBING MEDIA......Page 167
Heat exchange between gray bodies in a closed space filled by absorbing gas......Page 171
3.13 RADIATION LOSS FROM FURNACE OPENINGS......Page 173
3.14 EXTENDED SURFACES......Page 188
CONTENTS......Page 196
4.1 INTRODUCTION......Page 197
4.2 SOLUTION BY USING CHARTS......Page 198
4.3 HEATING OF BODIES OF FINITE SIZE......Page 207
4.4.1 Instantaneous Temperature Change at Surface......Page 216
4.4.3 Surface Heating by Convection......Page 219
4.4.4 The Late Regime......Page 221
4.5 TRANSIENT CONDUCTION — FINITE DIFFERENCES METHOD......Page 226
4.6 APPLICATION OF THE FINITE DIFFERENCE METHOD TO A MULTILAYERED WALL......Page 232
4.7 CONCENTRATED HEAT SOURCES......Page 238
4.7.1 Instantaneous Point Source......Page 239
4.7.2 Continuous Sources......Page 240
4.8 TRANSIENT CONDUCTION GRAPHICAL METHOD (SCHMIDT’S METHOD)......Page 246
CONTENTS......Page 252
5.2 PROPERTIES OF FUELS......Page 253
5.3 LIQUID FUELS......Page 258
5.4 GASEOUS FUELS......Page 259
5.5 BIOGAS......Page 260
5.5.1 Single Stage Generation......Page 262
5.5.2 Two Stage Generator......Page 263
5.6 HEATING (CALORIFIC) VALUE......Page 265
5.7 CALCULATION OF CALORIFIC VALUE......Page 267
5.8 COMBUSTION AIR REQUIREMENTS AND PRODUCTS......Page 270
5.8.1 Combustion Air and Practical Requirements......Page 272
5.8.2 Preheating of Air......Page 273
5.9 SOLID WASTE AND GARBAGE......Page 274
5.10 INCOMPLETE COMBUSTION......Page 276
5.11 COMBUSTION AND POLLUTION......Page 279
CONTENTS......Page 301
6.2 COMBUSTION OF LIQUID FUELS......Page 302
6.3 CLASSIFICATION OF OIL BURNERS......Page 306
6.3.2 Low Pressure Burners......Page 307
6.4 BURNERS FOR DISTILLATE FUELS......Page 308
6.5 PREHEATING OF OILS......Page 310
6.6 KINETICS OF COMBUSTION OF GASES......Page 311
6.7 BURNING PROPERTIES OF GASES......Page 313
6.8 CLASSIFICATION OF GAS BURNERS......Page 315
6.9 FLAME STABILIZATION, IGNITION, AND DETECTION......Page 317
6.10 ATMOSPHERIC GAS BURNERS......Page 319
6.11 NOZZLE MIXING GAS BURNERS......Page 322
6.12 RADIANT TUBES......Page 324
6.13 DUAL FUEL BURNERS......Page 326
6.14 PACKAGED BURNERS......Page 328
6.15 COMBUSTION OF SOLID WASTE AND GARBAGE......Page 329
6.16.1 Burner Blocks......Page 331
6.16.3 Flame Protection Devices......Page 333
CONTENTS......Page 334
7.2 CLASSIFICATION OF REFRACTORIES......Page 335
7.2.1 Fire Clay Refractories......Page 336
7.2.2 High Alumina Refractories......Page 337
7.2.4 Carbon and Graphite Refractories......Page 338
7.2.7 Zirconia Refractories......Page 339
7.3 INSULATING REFRACTORIES AND MATERIALS......Page 340
7.4.1 Raw Materials......Page 341
7.5 REFRACTORY SHAPES......Page 344
7.6 UNSHAPED REFRACTORY PRODUCTS......Page 346
7.7 REFRACTORY FIBERS......Page 347
7.8 PROPERTIES OF REFRACTORIES......Page 348
7.8.1 Room Temperature Properties......Page 350
7.8.2 High Temperature Properties......Page 351
7.9.1 Thermal Requirements......Page 353
7.9.2 Mechanical and Chemical Requirements......Page 357
CONTENTS......Page 358
8.2 MECHANICAL PROPERTIES OF METALS AT HIGH TEMPERATURE......Page 359
8.3 OXIDATION AND CORROSION......Page 365
8.3.1 Corrosion by Other Gases......Page 368
8.4 MELTING POINT AND PHYSICAL STABILITY......Page 370
8.5 LINEAR EXPANSION......Page 371
8.6 CAST IRONS......Page 372
8.8 SELECTION OF METALS FOR HIGH TEMPERATURE APPLICATION......Page 374
CONTENTS......Page 381
9.2.1 Principles of Indirect Electric Heating......Page 382
9.2.2 Material for Heaters......Page 383
9.2.3 Special Insulating Materials in the Construction of a Heater......Page 385
9.3 CONSTRUCTION AND PLACEMENT OF HEATERS......Page 392
9.4 DESIGN OF METALLIC ELEMENTS......Page 397
9.4.1 Determination of Wire or Strip Size......Page 401
9.5.1 Silicon Carbide Heating Elements......Page 407
9.5.2 MoSi2 Heating Elements......Page 409
9.6 DESIGN CALCULATIONS FOR NONMETALLIC ELEMENTS......Page 411
9.7.1 Principle of DRH......Page 425
9.7.2 Design for DRH......Page 427
9.7.3 Advantages and Limitations of DRH......Page 429
9.8 STORED ENERGY HEATING (SEH)......Page 432
9.8.1 Principle of Stored Energy Heating......Page 433
9.8.3 Some Peculiarities of SEH......Page 435
9.9.1 Introduction......Page 438
9.9.2 Construction and Working of Electrode Furnaces......Page 439
9.9.3 Bath Salts......Page 440
9.9.5 Applications of Salt Baths......Page 443
9.9.6 Other Bath Furnaces......Page 445
CONTENTS......Page 446
10.1.1 Introduction......Page 447
10.1.3 Advantages and Disadvantages of Induction Heating......Page 448
10.1.4 Skin Effect......Page 451
10.1.5 Ferrous and Nonferrous Heating......Page 455
10.1.6 Choice of Frequency......Page 456
10.1.8 Mains Frequency Generators......Page 460
10.1.10 Motor Generators......Page 461
10.1.11 Solid State Generators......Page 463
10.1.13 Radio Frequency (RF) Power Generators......Page 465
10.1.15 Generator and Coil Matching......Page 467
10.1.16 Thermal Requirements......Page 470
10.1.17 Design of the Coil......Page 472
10.1.18 Electrical Design of Coil......Page 473
10.1.19 Equivalent Circuit Method of Coil Design......Page 476
10.1.20 Physical Design of Coils......Page 479
10.2.3 Review of Related Electric Properties......Page 489
10.2.4 Some Noteworthy Points about Dielectric Heating......Page 493
10.2.5 Applications of Dielectric Heating......Page 494
10.3.1 Nature and Generation of Microwaves......Page 495
10.3.2 Heat Generation by Microwaves......Page 496
10.3.3 Heat Produced in Microwave Heating......Page 500
10.3.4 Some Peculiarities of Microwave Heating......Page 501
CONTENTS......Page 507
11.1.1 Introduction......Page 510
11.1.2 Generation of Laser Beam......Page 511
11.1.3 Noteworthy Points about Lasers......Page 514
11.1.4 Limitations of Lasers......Page 517
11.1.5 CO2 Laser......Page 518
11.1.6 Nd-YAG Lasers......Page 521
11.1.7 Ruby Lasers......Page 523
11.1.8 Longitudinal Modes of Laser Beam......Page 524
11.1.9 Focusing Properties of Lasers......Page 526
11.1.10 Collimation......Page 529
11.1.12 Depth of Focus......Page 530
11.1.13 Transverse Modes in Lasers......Page 536
11.1.14 Temporal Characteristics of Lasers......Page 537
11.1.15 Q Switching of the Laser Beam......Page 539
Continuous Output......Page 541
11.1.16 Application of Lasers for Material Processing......Page 542
11.1.17 Laser-Material Interaction......Page 545
11.1.18 Reflectivity and Absorptivity......Page 548
11.1.19 Laser Penetration......Page 551
11.1.20 The Temperature Field......Page 553
11.2.1 Introduction......Page 555
11.2.2 Generation of Electron Beam......Page 556
11.2.3 Characteristics of EB......Page 559
11.2.4 EB — Noteworthy Points......Page 560
11.2.5 EB — Material Interaction......Page 561
11.2.6 Commercial EB Equipment......Page 563
CONTENTS......Page 564
12.1 INTRODUCTION......Page 565
12.2 UNITS FOR VACUUM......Page 566
12.3 VACUUM PUMPS......Page 567
12.3.1 Positive Displacement Pump......Page 568
Limitations and Advantages of Mechanical Pumps......Page 570
12.3.2 Roots Pump......Page 571
12.3.3 Diffusion Pumps......Page 575
Noteworthy points about diffusion pumps......Page 576
12.3.4 Molecular Pumps......Page 578
12.4.1 Selection of Vacuum Pumps......Page 579
12.4.2 Calculation of Pumping Speed......Page 583
12.5 CONDUCTANCE AND PUMPING SPEED......Page 585
12.6 BAFFLES AND TRAPS......Page 589
12.7 OUTGASSING......Page 590
12.8 VACUUM PUMPING (PRESSURE–TIME RELATIONS)......Page 595
12.9 CALCULATION OF PUMPING TIME......Page 608
12.10 MEASUREMENT OF VACUUM......Page 611
12.10.1 Mechanical Gauges......Page 612
12.10.2 Conductivity Gauges......Page 613
Cold Cathode (Penning) Gauge......Page 615
‘‘Alphatron” Ionization Gauge......Page 617
Choice and Installation of Gauges......Page 618
CONTENTS......Page 621
13.1 INTRODUCTION......Page 622
13.2 MANUFACTURED ATMOSPHERE......Page 623
13.3.2 Hydrogen......Page 624
13.4 HEATING OF PROTECTIVE ATMOSPHERE FURNACE......Page 628
13.5 DETERMINATION OF ATMOSPHERE CONSUMPTION......Page 630
13.5.1 Batch Type......Page 631
13.5.2 Continuous Type......Page 632
13.6.1 Dew Point Measurement......Page 644
13.6.2 Measurement of CO, CO2, CH4, and NH3......Page 647
13.6.3 Detection of Oxygen......Page 648
13.6.4 Selection of Analytical Instruments......Page 650
CONTENTS......Page 651
14.1 INTRODUCTION......Page 652
14.2 THERMOCOUPLE PYROMETERS......Page 654
Corollary 1......Page 655
14.3 PROPERTY REQUIREMENTS OF THERMOCOUPLE MATERIALS......Page 656
14.4 PRACTICAL THERMOCOUPLES......Page 657
14.5 COLD JUNCTION COMPENSATION......Page 661
14.7 CONSTRUCTION OF THERMOCOUPLES......Page 663
14.8 SELECTION OF THERMOCOUPLES......Page 665
14.9.1 Principle of Radiation......Page 667
14.9.2 Practical Problems......Page 669
14.10 DISAPPEARING FILAMENT PYROMETER......Page 675
14.11 RADIATION PYROMETERS......Page 677
14.11.2 Limitations......Page 681
14.12.2 Bimetallic Devices......Page 682
14.12.3 Bimetallic Energy Regulators......Page 683
14.13 TEMPERATURE INDICATORS......Page 686
14.14 TEMPERATURE CONTROLLERS......Page 688
CONTENTS......Page 692
15.1 INTRODUCTION......Page 693
15.2.1 Rotating Hearth Furnace......Page 694
15.2.2 Automatic Integral Quench Furnace......Page 696
15.2.3 Vacuum Gas Furnace......Page 699
15.2.4 Linear Continuous Furnaces......Page 702
15.3 INCINERATORS......Page 704
15.3.1 Large Scale Municipal Incinerator......Page 706
15.3.3 Domestic or Office Incinerator......Page 708
15.4 HEAT EXCHANGERS......Page 710
15.4.1 Classification of Heat Exchangers......Page 712
15.4.2 Convective Heat Transfer over Tube Banks......Page 718
15.4.3 Heat Exchanger Calculations......Page 721
15.5 DRYING OVENS......Page 729
15.6 BAKING OVENS......Page 732
15.7 FANS......Page 737
Effect of Rotational Speed (N rpm)......Page 741
15.8.2 Alumina Refractory Adhesive......Page 742
15.8.3 Cast Basalt......Page 743
Appendix A: Pressure......Page 744
Appendix B: Viscosity......Page 747
Appendix C: Thermal Diffusivity......Page 750
Appendix D: Humidity......Page 754
Appendix E: Error Function......Page 762
Appendix F: Properties of Air, Water, Gases......Page 765
Appendix G: Emissivity......Page 770
HANDBOOKS FOR GENERAL REFERENCE AND DATA......Page 0