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
CHAPTER 2 FLUID DYNAMICS......Page 29
CHAPTER 7 REFRACTORIES......Page 30
CHAPTER 10 HIGH FREQUENCY HEATING......Page 31
CHAPTER 14 TEMPERATURE MEASUREMENT......Page 32
HANDBOOKS FOR GENERAL REFERENCE AND DATA......Page 33
1.1 IN THE BEGINNING......Page 34
1.2 HEATING SYSTEM CLASSIFICATION......Page 36
1.3 CLASSIFICATION OF HEATING MODES......Page 40
1.4 AUXILLIARY TECHNIQUES......Page 43
CONTENTS......Page 45
2.2 SOURCES OF GASES IN FURNACES......Page 46
2.3 FLOW OF GASES......Page 47
2.4 IMPORTANCE OF FLUID FLOW IN HEATING......Page 49
2.5 CLASSIFICATION OF FLUID FLOW......Page 50
2.6 FLOW OVER OBJECTS......Page 53
2.7 FLOW SEPARATION......Page 54
2.8 FORCED CIRCULATION IN ENCLOSURES......Page 59
2.10 NATURAL GAS CIRCULATION INSIDE FURNACES......Page 61
2.11 BERNOULLI’S THEOREM OF FLUID FLOW......Page 64
2.12 FRICTIONAL LOSSES IN FLOW......Page 67
2.13 LOCAL LOSSES......Page 76
2.13.1 Common Local Features......Page 78
2.13.2 Gas Flow through Ports......Page 80
2.13.3 Pump Power......Page 81
2.14 STACK EFFECT......Page 83
2.15 PRACTICAL FLUE SYSTEM......Page 85
CONTENTS......Page 89
3.1 INTRODUCTION......Page 90
Single Layer Wall......Page 92
3.3 THE SHAPE FACTOR......Page 104
3.4 GRAPHICAL METHOD FOR WALL HEAT TRANSFER AND DESIGN......Page 107
3.5 CONVECTION......Page 112
Determination of Convective Heat Transfer Coefficient......Page 115
3.6 FORCED CONVECTION......Page 117
3.6.1 Boundary Layer and Convection......Page 118
3.6.2 Forced Convection over Flat Plate......Page 120
3.6.3 Forced Convection inside Tubes......Page 129
3.6.3A Laminar Flow......Page 130
3.6.3B Turbulent Flow......Page 131
3.6.4 Heat Transfer in Coils......Page 140
3.7 NATURAL CONVECTION (FLAT WALLS)......Page 145
3.7.1 Free Convection over Horizontal Pipes......Page 148
3.7.2 Free Convection inside Enclosures......Page 153
3.8 RADIATIVE HEAT TRANSFER......Page 156
3.9 RADIATION EXCHANGE BETWEEN BODIES......Page 160
3.9.1 Radiative Exchange between Two Parallel Surfaces......Page 161
3.9.2 Radiative Exchange between Article and Enclosure......Page 164
3.10 RADIATION SCREENS......Page 165
3.11 RADIATION EXCHANGE INSIDE AND OUTSIDE FURNACES......Page 169
3.12 RADIATION IN ABSORBING MEDIA......Page 172
Heat exchange between gray bodies in a closed space filled by absorbing gas......Page 176
3.13 RADIATION LOSS FROM FURNACE OPENINGS......Page 178
3.14 EXTENDED SURFACES......Page 193
CONTENTS......Page 201
4.1 INTRODUCTION......Page 202
4.2 SOLUTION BY USING CHARTS......Page 203
4.3 HEATING OF BODIES OF FINITE SIZE......Page 212
4.4.1 Instantaneous Temperature Change at Surface......Page 221
4.4.3 Surface Heating by Convection......Page 224
4.4.4 The Late Regime......Page 226
4.5 TRANSIENT CONDUCTION — FINITE DIFFERENCES METHOD......Page 231
4.6 APPLICATION OF THE FINITE DIFFERENCE METHOD TO A MULTILAYERED WALL......Page 237
4.7 CONCENTRATED HEAT SOURCES......Page 243
4.7.1 Instantaneous Point Source......Page 244
4.7.2 Continuous Sources......Page 245
4.8 TRANSIENT CONDUCTION GRAPHICAL METHOD (SCHMIDT’S METHOD)......Page 251
CONTENTS......Page 257
5.2 PROPERTIES OF FUELS......Page 258
5.3 LIQUID FUELS......Page 263
5.4 GASEOUS FUELS......Page 264
5.5 BIOGAS......Page 265
5.5.1 Single Stage Generation......Page 267
5.5.2 Two Stage Generator......Page 268
5.6 HEATING (CALORIFIC) VALUE......Page 270
5.7 CALCULATION OF CALORIFIC VALUE......Page 272
5.8 COMBUSTION AIR REQUIREMENTS AND PRODUCTS......Page 275
5.8.1 Combustion Air and Practical Requirements......Page 277
5.8.2 Preheating of Air......Page 278
5.9 SOLID WASTE AND GARBAGE......Page 279
5.10 INCOMPLETE COMBUSTION......Page 281
5.11 COMBUSTION AND POLLUTION......Page 284
CONTENTS......Page 306
6.2 COMBUSTION OF LIQUID FUELS......Page 307
6.3 CLASSIFICATION OF OIL BURNERS......Page 311
6.3.2 Low Pressure Burners......Page 312
6.4 BURNERS FOR DISTILLATE FUELS......Page 313
6.5 PREHEATING OF OILS......Page 315
6.6 KINETICS OF COMBUSTION OF GASES......Page 316
6.7 BURNING PROPERTIES OF GASES......Page 318
6.8 CLASSIFICATION OF GAS BURNERS......Page 320
6.9 FLAME STABILIZATION, IGNITION, AND DETECTION......Page 322
6.10 ATMOSPHERIC GAS BURNERS......Page 324
6.11 NOZZLE MIXING GAS BURNERS......Page 327
6.12 RADIANT TUBES......Page 329
6.13 DUAL FUEL BURNERS......Page 331
6.14 PACKAGED BURNERS......Page 333
6.15 COMBUSTION OF SOLID WASTE AND GARBAGE......Page 334
6.16.1 Burner Blocks......Page 336
6.16.3 Flame Protection Devices......Page 338
CONTENTS......Page 339
7.2 CLASSIFICATION OF REFRACTORIES......Page 340
7.2.1 Fire Clay Refractories......Page 341
7.2.2 High Alumina Refractories......Page 342
7.2.4 Carbon and Graphite Refractories......Page 343
7.2.7 Zirconia Refractories......Page 344
7.3 INSULATING REFRACTORIES AND MATERIALS......Page 345
7.4.1 Raw Materials......Page 346
7.5 REFRACTORY SHAPES......Page 349
7.6 UNSHAPED REFRACTORY PRODUCTS......Page 351
7.7 REFRACTORY FIBERS......Page 352
7.8 PROPERTIES OF REFRACTORIES......Page 353
7.8.1 Room Temperature Properties......Page 355
7.8.2 High Temperature Properties......Page 356
7.9.1 Thermal Requirements......Page 358
7.9.2 Mechanical and Chemical Requirements......Page 362
CONTENTS......Page 363
8.2 MECHANICAL PROPERTIES OF METALS AT HIGH TEMPERATURE......Page 364
8.3 OXIDATION AND CORROSION......Page 370
8.3.1 Corrosion by Other Gases......Page 373
8.4 MELTING POINT AND PHYSICAL STABILITY......Page 375
8.5 LINEAR EXPANSION......Page 376
8.6 CAST IRONS......Page 377
8.8 SELECTION OF METALS FOR HIGH TEMPERATURE APPLICATION......Page 379
CONTENTS......Page 386
9.2.1 Principles of Indirect Electric Heating......Page 387
9.2.2 Material for Heaters......Page 388
9.2.3 Special Insulating Materials in the Construction of a Heater......Page 390
9.3 CONSTRUCTION AND PLACEMENT OF HEATERS......Page 397
9.4 DESIGN OF METALLIC ELEMENTS......Page 402
9.4.1 Determination of Wire or Strip Size......Page 406
9.5.1 Silicon Carbide Heating Elements......Page 412
9.5.2 MoSi2 Heating Elements......Page 414
9.6 DESIGN CALCULATIONS FOR NONMETALLIC ELEMENTS......Page 416
9.7.1 Principle of DRH......Page 430
9.7.2 Design for DRH......Page 432
9.7.3 Advantages and Limitations of DRH......Page 434
9.8 STORED ENERGY HEATING (SEH)......Page 437
9.8.1 Principle of Stored Energy Heating......Page 438
9.8.3 Some Peculiarities of SEH......Page 440
9.9.1 Introduction......Page 443
9.9.2 Construction and Working of Electrode Furnaces......Page 444
9.9.3 Bath Salts......Page 445
9.9.5 Applications of Salt Baths......Page 448
9.9.6 Other Bath Furnaces......Page 450
CONTENTS......Page 451
10.1.1 Introduction......Page 452
10.1.3 Advantages and Disadvantages of Induction Heating......Page 453
10.1.4 Skin Effect......Page 456
10.1.5 Ferrous and Nonferrous Heating......Page 460
10.1.6 Choice of Frequency......Page 461
10.1.8 Mains Frequency Generators......Page 465
10.1.10 Motor Generators......Page 466
10.1.11 Solid State Generators......Page 468
10.1.13 Radio Frequency (RF) Power Generators......Page 470
10.1.15 Generator and Coil Matching......Page 472
10.1.16 Thermal Requirements......Page 475
10.1.17 Design of the Coil......Page 477
10.1.18 Electrical Design of Coil......Page 478
10.1.19 Equivalent Circuit Method of Coil Design......Page 481
10.1.20 Physical Design of Coils......Page 484
10.2.3 Review of Related Electric Properties......Page 494
10.2.4 Some Noteworthy Points about Dielectric Heating......Page 498
10.2.5 Applications of Dielectric Heating......Page 499
10.3.1 Nature and Generation of Microwaves......Page 500
10.3.2 Heat Generation by Microwaves......Page 501
10.3.3 Heat Produced in Microwave Heating......Page 505
10.3.4 Some Peculiarities of Microwave Heating......Page 506
CONTENTS......Page 512
11.1.1 Introduction......Page 515
11.1.2 Generation of Laser Beam......Page 516
11.1.3 Noteworthy Points about Lasers......Page 519
11.1.4 Limitations of Lasers......Page 522
11.1.5 CO2 Laser......Page 523
11.1.6 Nd-YAG Lasers......Page 526
11.1.7 Ruby Lasers......Page 528
11.1.8 Longitudinal Modes of Laser Beam......Page 529
11.1.9 Focusing Properties of Lasers......Page 531
11.1.10 Collimation......Page 534
11.1.12 Depth of Focus......Page 535
11.1.13 Transverse Modes in Lasers......Page 541
11.1.14 Temporal Characteristics of Lasers......Page 542
11.1.15 Q Switching of the Laser Beam......Page 544
Continuous Output......Page 546
11.1.16 Application of Lasers for Material Processing......Page 547
11.1.17 Laser-Material Interaction......Page 550
11.1.18 Reflectivity and Absorptivity......Page 553
11.1.19 Laser Penetration......Page 556
11.1.20 The Temperature Field......Page 558
11.2.1 Introduction......Page 560
11.2.2 Generation of Electron Beam......Page 561
11.2.3 Characteristics of EB......Page 564
11.2.4 EB — Noteworthy Points......Page 565
11.2.5 EB — Material Interaction......Page 566
11.2.6 Commercial EB Equipment......Page 568
CONTENTS......Page 569
12.1 INTRODUCTION......Page 570
12.2 UNITS FOR VACUUM......Page 571
12.3 VACUUM PUMPS......Page 572
12.3.1 Positive Displacement Pump......Page 573
Limitations and Advantages of Mechanical Pumps......Page 575
12.3.2 Roots Pump......Page 576
12.3.3 Diffusion Pumps......Page 580
Noteworthy points about diffusion pumps......Page 581
12.3.4 Molecular Pumps......Page 583
12.4.1 Selection of Vacuum Pumps......Page 584
12.4.2 Calculation of Pumping Speed......Page 588
12.5 CONDUCTANCE AND PUMPING SPEED......Page 590
12.6 BAFFLES AND TRAPS......Page 594
12.7 OUTGASSING......Page 595
12.8 VACUUM PUMPING (PRESSURE–TIME RELATIONS)......Page 600
12.9 CALCULATION OF PUMPING TIME......Page 613
12.10 MEASUREMENT OF VACUUM......Page 616
12.10.1 Mechanical Gauges......Page 617
12.10.2 Conductivity Gauges......Page 618
Cold Cathode (Penning) Gauge......Page 620
‘‘Alphatron” Ionization Gauge......Page 622
Choice and Installation of Gauges......Page 623
CONTENTS......Page 626
13.1 INTRODUCTION......Page 627
13.2 MANUFACTURED ATMOSPHERE......Page 628
13.3.2 Hydrogen......Page 629
13.4 HEATING OF PROTECTIVE ATMOSPHERE FURNACE......Page 633
13.5 DETERMINATION OF ATMOSPHERE CONSUMPTION......Page 635
13.5.1 Batch Type......Page 636
13.5.2 Continuous Type......Page 637
13.6.1 Dew Point Measurement......Page 649
13.6.2 Measurement of CO, CO2, CH4, and NH3......Page 652
13.6.3 Detection of Oxygen......Page 653
13.6.4 Selection of Analytical Instruments......Page 655
CONTENTS......Page 656
14.1 INTRODUCTION......Page 657
14.2 THERMOCOUPLE PYROMETERS......Page 659
Corollary 1......Page 660
14.3 PROPERTY REQUIREMENTS OF THERMOCOUPLE MATERIALS......Page 661
14.4 PRACTICAL THERMOCOUPLES......Page 662
14.5 COLD JUNCTION COMPENSATION......Page 666
14.7 CONSTRUCTION OF THERMOCOUPLES......Page 668
14.8 SELECTION OF THERMOCOUPLES......Page 670
14.9.1 Principle of Radiation......Page 672
14.9.2 Practical Problems......Page 674
14.10 DISAPPEARING FILAMENT PYROMETER......Page 680
14.11 RADIATION PYROMETERS......Page 682
14.11.2 Limitations......Page 686
14.12.2 Bimetallic Devices......Page 687
14.12.3 Bimetallic Energy Regulators......Page 688
14.13 TEMPERATURE INDICATORS......Page 691
14.14 TEMPERATURE CONTROLLERS......Page 693
CONTENTS......Page 697
15.1 INTRODUCTION......Page 698
15.2.1 Rotating Hearth Furnace......Page 699
15.2.2 Automatic Integral Quench Furnace......Page 701
15.2.3 Vacuum Gas Furnace......Page 704
15.2.4 Linear Continuous Furnaces......Page 707
15.3 INCINERATORS......Page 709
15.3.1 Large Scale Municipal Incinerator......Page 711
15.3.3 Domestic or Office Incinerator......Page 713
15.4 HEAT EXCHANGERS......Page 715
15.4.1 Classification of Heat Exchangers......Page 717
15.4.2 Convective Heat Transfer over Tube Banks......Page 723
15.4.3 Heat Exchanger Calculations......Page 726
15.5 DRYING OVENS......Page 734
15.6 BAKING OVENS......Page 737
15.7 FANS......Page 742
Effect of Rotational Speed (N rpm)......Page 746
15.8.2 Alumina Refractory Adhesive......Page 747
15.8.3 Cast Basalt......Page 748
Appendix A: Pressure......Page 749
Appendix B: Viscosity......Page 752
Appendix C: Thermal Diffusivity......Page 755
Appendix D: Humidity......Page 759
Appendix E: Error Function......Page 767
Appendix F: Properties of Air, Water, Gases......Page 770
Appendix G: Emissivity......Page 775