Refractories for the Cement Industry (eBook)

Prasunjit Sengupta (Autor)

eBook Download: PDF

2019 | 1st ed. 2020
XIII, 240 Seiten
Springer International Publishing (Verlag)
978-3-030-21340-4 (ISBN)

Infos

This book provides process engineers with all of the information necessary for installation, maintenance and management of refractory in a cement industry. It describes how to characterize the refractory material and select refractories for various equipments in the cement plant. The author explains refractory installation, in general, and the rotary kiln specifically, as it is distinct from static furnaces used in metallurgical or process industries. It also details the chemical and physical factors that influence refractory performance and has discussed the mechanism of degradation of refractories with special emphasis on thermo-chemical and thermo-mechanical aspects. The heat transfer calculation and energy loss from the equipment surfaces has been addressed. A chapter in the book is dedicated for the management of refractory quality and the installation quality at the site.

• Maximizes reader understanding of the operating conditions in different equipments and how those are related to selection of refractories;
• Details  the process variables and their influences on the performance of the refractories;
• Elucidates  subtle points of refractory installation to ensure optimal performance;
• Presents heat transfer calculations and quality management protocols of refractory installation. Reinforces the concepts with many illustrations and tables.

Mr. Prasunjit Sengupta is Technical Director, SKG Refractories Ltd in Nagpur, India

Inhalt

Preface 6
Contents 8
Chapter 1: Characterization of Refractories 13
1.1 Introduction 13
1.2 Refractory Materials 14
1.3 Refractory Properties 16
1.3.1 Specific Gravity 16
1.3.2 Bulk Densities 16
1.3.3 Apparent Porosity 17
1.3.4 Permeability 18
1.3.5 Mechanical Properties 19
1.3.5.1 Cold Crushing Strength (CCS) 19
1.3.5.2 Modulus of Rupture 19
1.3.5.3 Modulus of Elasticity, Poisson’s Ratio, Hardness 19
1.3.5.4 Fracture 20
Wedge-Splitting Test 22
1.3.5.5 Abrasion Resistance 23
1.3.6 Thermal Properties 25
1.3.6.1 Pyrometric Cone Equivalent (PCE) 25
1.3.6.2 Reversible Thermal Expansion (RTE) 26
1.3.6.3 Permanent Linear Change (PLC) on Reheating 26
1.3.6.4 Thermal Conductivity 26
1.3.6.5 Heat Capacity (Cp) 27
1.3.6.6 Thermal Diffusivity (D) 28
1.3.7 Thermo-mechanical Properties 28
1.3.7.1 Hot Modulus of Rupture (HMOR) 28
1.3.7.2 Refractoriness Under Load (RUL) 28
1.3.7.3 Creep 29
1.3.7.4 Thermal Shock Resistance 29
1.3.7.5 Structural Spalling 31
1.3.8 Corrosion Resistance 31
1.3.8.1 Static Test Method 32
1.3.8.2 Dynamic Test Method 32
1.3.9 Alkali Resistance Test 32
1.3.10 Microstructure Study 33
1.3.10.1 Optical Microscopy 33
1.3.10.2 SEM and EDAX 34
1.3.10.3 X-Ray Diffraction 35
1.3.10.4 XRF 36
References 36
Chapter 2: Classification and Features of Different Types of Refractories 37
2.1 Classification of Refractories 37
2.2 Basis of Classification 37
2.2.1 By Basicity 37
2.2.2 By Form 38
2.2.2.1 Shaped Refractories 38
Pressed Shape 38
Hand Molded 39
Precast 40
Fused Cast 40
Vacuum-Formed 40
Advantage and Disadvantage of Shaped Products 40
2.2.2.2 Unshaped Refractories 41
Mortars 41
Ramming Masses 41
Plastic Refractories 42
Castable 42
Conventional Castable 43
Low and Ultra-low Cement Castable 43
No-Cement Castable 44
Pumpable 44
Shotcreting 45
Gunning 45
Special Features of Unshaped Products 46
2.2.3 Insulating Property 46
2.2.4 Special Chemistry 47
Chapter 3: Manufacturing and Properties of Refractories 48
3.1 Introduction 48
3.2 Shaped Refractories 48
3.2.1 Aluminosilicate Refractories 48
3.2.1.1 Fireclay Refractories 49
3.2.1.2 High Alumina Refractories 49
3.2.2 Basic Refractory 51
3.2.2.1 Magnesia-Chrome Refractories 53
3.2.2.2 Magnesia-Alumina Spinel 53
3.2.2.3 Magnesia Hercynite 54
3.2.2.4 Magnesia Zirconia 55
3.2.2.5 Dolomite 55
3.3 Unshaped Refractories 57
3.3.1 Castable 58
3.3.1.1 Conventional Castable 59
3.3.1.2 Low Cement Castable (LCC) 59
3.3.1.3 Ultra-low Cement Castable (ULCC) 59
3.3.1.4 No Cement Castable (NCC) 60
3.3.1.5 Gunning Mass 61
3.3.1.6 Shotcrete and Pumpable Material 62
3.3.2 Ramming Mass 63
3.3.3 Plastic 64
3.3.4 Mortar 65
3.4 Insulation Refractory 65
3.4.1 Insulation Shapes 66
3.4.2 Calcium Silicate 66
3.4.3 Ceramic Fiber Products 67
3.4.4 Insulation Castable 67
References 69
Chapter 4: Cement Manufacturing and Process Control 71
4.1 Cement Manufacturing: Basic Process and Operation 71
4.2 Raw Material 72
4.3 Fuel 73
4.4 Different Plant Design 73
4.4.1 Suspension Preheater (SP) Kiln 74
4.4.2 Line Calciner Using Excess Air 74
4.4.3 In-Line Calciner (ILC) 74
4.4.4 Separate Line Calciner Downdraft (SLC-D) 74
4.4.5 Separate Line Calciner (SLC) 75
4.4.6 Separate Line Calciner with In-Line Calciner (SLC-I) 75
4.5 Rotary Kiln 76
4.6 Kiln Control Parameters 77
4.6.1 Burning Zone Temperature (BZT) 78
4.6.1.1 Pyrometer 79
4.6.1.2 NOx 79
4.6.1.3 Kiln Torque 80
4.6.1.4 Secondary Air Temperature (SAT) 80
4.6.2 Back-End Temperature (BET) 81
4.6.3 Oxygen Control 81
4.7 Control Variables 82
4.7.1 Fuel Rate 82
4.7.2 Feed Rate 83
4.7.3 Kiln Draft 83
4.7.4 Kiln Speed 84
4.8 Chemical Parameters 84
4.9 Start-Up and Shutdown 85
4.9.1 Heat Up 85
4.9.2 Shutdown 86
References 86
Chapter 5: Selection of Refractory 87
5.1 Introduction 87
5.2 Refractory Selection 89
5.2.1 Cyclones and Ducts 89
5.2.2 Calciner 92
5.2.3 Riser Duct 93
5.2.4 Smoke Chamber 93
5.2.5 Meal Pipes 94
5.2.5.1 Insulation 94
5.2.6 Kiln Hood 94
5.2.6.1 Insulation 95
5.2.7 Tertiary Air Duct and Cooler 96
5.2.7.1 Grate Cooler 96
5.2.8 Kiln 96
5.2.8.1 Inlet Cone 97
5.2.8.2 Preheating Zone 97
5.2.8.3 Transition Zone 98
5.2.8.4 Burning Zone 100
5.2.8.5 Outlet Area (Retainer Ring and Nose Ring) 101
5.2.8.6 Brick Shapes for the Kiln Lining 103
5.2.8.7 Calculation of Combination of Two Different Brick Sizes 105
5.2.9 Burner Pipe 106
References 107
Chapter 6: Refractory Design, Installation, and Maintenance 108
6.1 Introduction 108
6.2 Refractory Lining in Rotary Kiln 108
6.2.1 Storage 109
6.2.2 Tools and Tackles 109
6.2.3 Preview of Drawings 110
6.2.4 Kiln Shell Inspection 110
6.2.5 Reference Line: Longitudinal 110
6.2.6 Reference Line: Circumferential 111
6.2.7 Brick Shapes and Size 112
6.2.8 Lining Thickness 113
6.3 Laying of Bricks 113
6.3.1 Mortar Joints 114
6.3.2 Expansion Joints 115
6.4 Vertical Wall Lining 117
6.4.1 Basic Rules of Refractory Lining 118
6.5 Installation of Monolithics 120
6.5.1 Conventional Castables 120
6.5.2 Low Cement/Ultra-Low Cement /No Cement Castables 120
6.5.2.1 Precautions to Be Taken During Installation to Get Best Performance 121
6.5.3 Shotcreting 122
6.5.4 Gunning 123
6.5.5 Pumping 124
6.5.5.1 Monitoring and Safety 124
6.5.6 Joints 125
6.5.6.1 Expansion Joints 125
6.5.6.2 Separation Joints 125
6.6 Choice of Installation Method 126
6.6.1 Location and Site Condition 126
6.6.2 Environmental Condition and Equipments 127
6.6.3 Volume of the Refractory That Need to Be Installed 127
6.6.4 Ease and Speed of Installation 127
6.6.5 Storage Condition 127
6.6.6 Skill of Installation Team 127
6.6.7 Budget 128
6.7 Anchor 128
6.7.1 Anchor Construction Material 128
6.7.2 Anchor Shape and Size Design 129
6.7.2.1 Fixing of Metal Anchors 131
6.7.2.2 Fixing of Ceramic Anchors 132
6.7.3 Spacing 132
6.7.3.1 Support Spacing Based on Strength of Anchors 133
6.7.3.2 Support Spacing Based on the Strength of the Castable 133
6.8 Drying and Preheating 135
6.8.1 Preheating of Bricks 137
6.8.2 Preheating of Castable 138
6.9 Carbonation 140
References 142
Chapter 7: Refractory Performances and Mechanism of Damages 144
7.1 Introduction 144
7.2 Thermo-chemical Effects 147
7.2.1 Aluminosilicate Refractories 149
7.2.1.1 Interaction with Alkalis 150
7.2.1.2 Interaction with Sulfur 152
7.2.1.3 Interaction with Chlorides 154
7.2.1.4 Interaction with Vanadium Oxides 154
7.2.2 Basic Refractories 156
7.2.2.1 Alkali Reaction 156
7.2.2.2 Interaction with SO2 / SO3 /Cl 157
7.2.2.3 Reactions with clinker 159
7.2.2.4 Effect of Vanadium Oxides 159
7.2.2.5 Hydration 159
7.2.2.6 Redox Reactions 162
7.2.2.7 Attack of the liquid phase 164
7.3 Thermal Load 165
7.3.1 Overheating 165
7.4 Flame 166
7.5 Thermo- mechanical Aspect 168
7.5.1 Ovality 168
7.5.1.1 Determination of Ovality 173
7.5.2 Cranking 177
7.5.3 Creep and Migration of Tires 178
7.5.4 Thermal Distribution 180
7.5.5 Strain-Controlled Load 181
7.5.6 Thermal Shock 182
7.6 Abrasion of Clinker and Dusts 182
7.7 Ring Formation and Buildup 183
7.8 Refractory Failure Due to Anchor 185
7.8.1 Sigma Phase Embrittlement 186
7.8.2 Schaeffler-De Long Diagram 187
7.9 Kiln Diameter 188
7.10 Lining Failure Statistics 188
References 190
Chapter 8: Coating and Burnability of Clinker 193
8.1 Coating and Its Function 193
8.2 Formation 194
8.3 Mechanism of Coating Formation 195
8.4 Coating Destabilization and Destruction 196
8.5 Test for Coatability 196
8.6 Effect of Composition and Microstructure 198
8.7 Coating Collapse 198
8.8 Burnability 199
8.8.1 Burnability Test 199
References 200
Chapter 9: Heat Transfer 201
9.1 Introduction 201
9.2 Mechanism of Heat Transfer 202
9.2.1 Conduction 202
9.2.2 Convection 203
9.2.2.1 Vertical Wall 205
9.2.2.2 Horizontal Wall 206
9.2.2.3 Vertical Cylinder 206
9.2.2.4 Horizontal Cylinder 206
9.2.3 Radiation 207
9.2.4 Heat Loss Calculation 208
9.3 Combined Heat Loss by Conduction, Convection, and Radiation 208
9.3.1 Energy Loss Norm Through Different Equipments 209
9.3.2 Use of Insulation in Rotary Kiln 210
9.3.3 Criteria of the Use of Insulation 212
References 213
Chapter 10: Management of Quality and Inspection 215
10.1 Introduction 215
10.2 Quality Management 215
10.3 Inspection Plan: General 217
10.3.1 Inspection Plan for Procurement of Material 217
10.3.2 Inspection of Materials 217
10.3.2.1 Shaped Refractory Materials 218
Inspection by Attributes 218
Sampling for nondestructive tests 219
Sampling plan 220
Inspection by Variables 221
Sampling for Destructive Tests 222
The Sampling Plan 222
10.3.2.2 Unshaped (Monolithic) Refractory Materials 223
Drawing the Sample 224
Reduction in Sample Size 224
Test Sample Preparation 226
Evaluation 227
Mortars 227
10.4 Inspection of Installation 227
10.4.1 Inspection Plan for Installation of Refractory Materials 227
10.4.1.1 Technical Documentation and Installation Manual 229
10.4.1.2 Preliminary Inspection of the Construction Part 229
10.4.1.3 Inspection of Incoming Material, Its Storage, and Transportation to the Site 229
10.4.1.4 Readiness of the Equipments and Utilities 230
10.4.1.5 Qualification of Personnel 230
10.4.1.6 Compliance with Engineering Requirements 231
10.4.1.7 Compliance with Application Guideline 231
10.4.2 Inspection of Preheating Arrangements 231
10.4.3 Final Inspection and Acceptance 232
References 233
Appendix 234
Glossary 236
Further Reading 238
Index 239

Produkt-Details

• Erscheint lt. Verlag: 26.8.2019
• Zusatzinfo: XIII, 240 p. 111 illus., 50 illus. in color.
• Sprache: englisch
• Themenwelt: Technik ► Bauwesen
• Themenwelt: Technik ► Maschinenbau
• Schlagworte: Cement manufacturing and process control • Characterization of Refractories • Classification and features of different Refractory materials • Coating and burnability of clinker • Manufacturing and properties of refractories • Refractory design, Installation and Maintenance • Refractory performances and mechanism of damage • Selection of Refractories
• ISBN-10: 3-030-21340-4 / 3030213404
• ISBN-13: 978-3-030-21340-4 / 9783030213404