Blast Cleaning Technology

3540736441......Page 1
Contents......Page 5
1.2 Introductory Remarks......Page 13
1.3 Blast Cleaning Methods and Applications......Page 15
2.2.1 Structural Aspects of Abrasive Materials......Page 19
2.2.2 Hardness of Abrasive Materials......Page 25
2.3.2 Relative Proportions of Particles......Page 29
2.3.3 Geometrical Forms of Particles......Page 30
2.4.1 Particle Size Distribution......Page 36
2.4.3 Alternative Abrasive Particle Size Assessment Methods......Page 39
2.6.1 Abrasive Particle Number and Frequency......Page 42
2.6.2 Kinetic Energy of Abrasive Particles......Page 43
2.6.3 Power Availability......Page 44
2.7 Impurities......Page 46
2.8 Global Abrasive Evaluation Parameter......Page 48
2.9.1 Fracture Zones......Page 49
2.9.2 Fracture Probability of Abrasive Particles......Page 53
2.9.3 Effects of Abrasive Material Structure......Page 57
2.9.4 Debris Size......Page 58
2.9.5 Disintegration Numbers......Page 59
2.9.6 Particle Shape Modification During Abrasive Fragmentation......Page 61
2.9.7 Energy Absorption During Abrasive Fragmentation......Page 63
2.9.8 Chemical Degradation......Page 65
3.1 Properties of Compressed Air......Page 66
3.2.1 Air Mass Flow Rate Through Nozzles......Page 70
3.2.2 Volumetric Air Flow Rate......Page 72
3.2.3 Air Exit Flow Velocity in Nozzles......Page 77
3.2.4 Air Flow in Laval Nozzles......Page 79
3.2.5 Power, Impulse Flow and Temperature......Page 81
3.3.1 General Aspects......Page 83
3.3.3 Abrasive Flux Rate......Page 86
3.3.4 Abrasive Particle Spacing......Page 87
3.4.1 Structure of High-speedAir Jets......Page 88
3.4.2 Structure of Air-particle Jets......Page 89
3.4.3 Design Nozzle Pressure......Page 91
3.5.2 Particle Velocity Distribution Function......Page 96
3.5.3 Radial Abrasive Particle Velocity Distribution......Page 100
3.5.5 Stream Density......Page 101
3.6.2 Effects of Abrasive Mass Flow Rate on Particle Velocity......Page 105
3.6.3 Effects of Abrasive Particle Size on Particle Velocity......Page 108
3.6.5 Effects of Abrasive Material Density on Particle Velocity......Page 111
3.6.6 Effects of Stand-off Distance on Particle Velocity......Page 112
3.6.8 Effects of Nozzle Design on Particle Velocity......Page 114
3.6.9 Effects of Nozzle Wall Roughness on Particle Velocity......Page 115
3.6.10 Scaling Laws for Abrasive Particle Velocity......Page 116
3.7 Abrasive StreamEnergy Flow and Nozzle Efficiency......Page 118
4.2.1 General Aspects......Page 120
4.2.2 Working Lines......Page 122
4.2.3 Power Rating......Page 123
4.2.4 Economic Aspects......Page 125
4.2.5 Aspects of Air Quality......Page 127
4.3.1 Basic Parts......Page 129
4.3.2 Abrasive Metering......Page 130
4.4.1 Materials and Technical Parameters......Page 139
4.4.2 Air Hose Diameter Selection......Page 140
4.4.3 Pressure Drop in Air Hose Lines......Page 141
4.5.1 Conveying Modes in Abrasive Hoses......Page 149
4.5.2 Critical Conveying Flow Velocities in Abrasive Hoses......Page 151
4.5.3 Optimum Flow Velocities in Abrasive Hoses......Page 156
4.5.4 Pressure Drop in Abrasive Hoses......Page 158
4.6.1 Nozzle Types......Page 165
4.6.2 Nozzle Wear......Page 166
5.2.1 Relevant Mechanical Properties......Page 177
5.2.2 Mechanical Properties of Oxides......Page 184
5.2.3 Mechanical Properties of Organic Coatings......Page 185
5.3.2 Coefficient of Restitution......Page 192
5.3.3 Energy Absorption......Page 195
5.3.4 Damage Number......Page 199
5.3.5 Friction Effects......Page 201
5.4.1 Loading Parameters......Page 202
5.4.2 Material Response to Particle Impingement......Page 204
5.4.3 Formation of Radial and Lateral Cracks......Page 206
5.5.1 General Aspects of Modelling......Page 210
5.5.2 Erosion of Plastically Responding Materials......Page 211
5.5.3 Erosion of Elastically Responding Materials......Page 215
5.6.1 Brittle Erosion Approach......Page 216
5.6.2 Removal Mechanisms and Modelling......Page 217
5.6.3 Removableness of Mill Scale......Page 219
5.7.1 Material Removal Mechanisms for Bulk Polymers......Page 220
5.7.2 Material Removal Mechanisms for Elastomers......Page 223
5.7.3 Erosion Resistance of Bulk Polymers......Page 224
5.7.4 Erosion Resistance of Elastomers......Page 227
5.8.1 Material Removal Mechanisms......Page 231
5.8.2 Erosion Resistance......Page 233
5.8.3 Erosion Durability......Page 238
5.9.1 Indentation Debonding......Page 239
5.9.2 Impact Debonding......Page 243
5.10.1 Ploughing/Delamination Model......Page 246
5.10.2 Debonding Model......Page 247
5.10.3 Effects of a Second Phase in the Coating......Page 249
6.1.1 Process Parameters......Page 250
6.1.2 Target Parameters......Page 251
6.2.1 Effects of Air Pressure......Page 252
6.2.2 Effects of Nozzle Diameter and Nozzle Length......Page 258
6.2.3 Effects of Nozzle Design......Page 260
6.3.1 Effects of Stand-off Distance......Page 265
6.3.3 Effects of Impact Angle......Page 268
6.3.4 Effects of Exposure Time......Page 270
6.3.5 Effects of Number of Passes......Page 272
6.4.1 Effects of Abrasive Mass Flow Rate......Page 273
6.4.2 Effects of Abrasive Flux Rate......Page 277
6.4.3 Effects of Abrasive Particle Diameter......Page 279
6.4.4 Effects of Abrasive Particle Shape......Page 286
6.4.5 Effects of Abrasive Material Hardness......Page 288
6.5 Removal Models......Page 290
6.6.1 Erosion Efficiency......Page 292
6.6.2 General Aspects of Process Efficiency......Page 293
6.6.3 Aspects of Site Management......Page 295
6.6.4 Aspects of Operators\' Fatigue......Page 296
6.7 Weld Seam Cleaning......Page 298
6.8 Underwater Applications......Page 299
6.9 Cost Aspects......Page 301
7.1.1 General Safety Aspects......Page 304
7.1.2 Risk of Explosion......Page 305
7.2 Emission of Air Sound......Page 306
7.3 Emission of Body Sound......Page 310
7.4 Emission of Dust......Page 311
7.5.1 Airborne Lead......Page 319
7.5.2 Other Airborne Metals......Page 323
7.6.1 Asbestos Fibres......Page 325
7.6.2 Organic Compounds......Page 326
7.7 Vibrations to the Operator......Page 327
7.8 Personal Protective Equipment......Page 329
7.9 Confined Spaces......Page 330
7.10 Soil Contamination......Page 333
7.11.1 General Disposal Problems......Page 334
7.11.2 Abrasive Material Disposal......Page 337
7.11.3 Contamination of Abrasive Material and Leachable Metals......Page 340
7.11.4 Paint Waste......Page 341
7.12.1 Contamination with Residue......Page 342
7.12.2 Use for Construction Materials......Page 343
8.1 Surface Quality Features......Page 346
8.2.1 Visual Standards......Page 347
8.2.2 Initial Conditions......Page 348
8.2.3 Preparation Grades......Page 350
8.2.4 Special Remarks......Page 355
8.3.1 Definitions and Measurement......Page 358
8.3.2 Effects of Dissolved Substances on Coating Performance......Page 360
8.3.3 Substrate Cleanliness After Blast Cleaning......Page 366
8.4.1 Definitions and Measurement......Page 371
8.4.2 Effects of Oil and Grease on Coating Performance......Page 372
8.4.3 Substrate Cleanliness After Blast Cleaning......Page 375
8.5.1 Definitions and Measurement......Page 376
8.5.2 Effects of Dust and Particle Embedment on Coating Performance......Page 379
8.5.3 Substrate Cleanliness After Blast Cleaning......Page 383
8.5.4 Fine Cleaning......Page 388
8.6.1 Definitions and Measurement......Page 389
8.6.2 Effects of Roughness on Coating Performance......Page 393
8.6.3 Profile Parameters of Blast Cleaned Metal Substrates......Page 403
8.6.5 Profiles of \"Overblasted\" Steel Substrates......Page 418
8.7.1 Introduction......Page 422
8.7.2 Substrate Hardness......Page 423
8.7.3 Residual Stresses......Page 426
8.7.4 Substrate Fatigue Strength......Page 429
8.7.7 Tribological Parameters......Page 432
8.7.9 Near-surface Layer Chemical Composition......Page 434
8.7.10 Corrosion Resistance......Page 438
8.8.1 Definitions and Measurement......Page 443
8.8.2 Effects of Substrate Surface Energy on Corrosion and Coating Performance......Page 446
8.8.3 Surface Energies of Blast Cleaned Substrates......Page 447
8.9.1 Definitions and Measurement......Page 450
8.9.2 Effects of Wettability on Coating Performance......Page 454
8.9.3 Wettability of Blast Cleaned Metal Substrates......Page 456
8.10 Electron Transport Properties......Page 460
9.1.1 Definitions and Methods......Page 462
9.1.2 Coating Performance After Blast Cleaning......Page 465
9.2.1 Definitions and Measurement......Page 473
9.2.2 Adhesion of Coatings andAdhesives to Metal Substrates......Page 477
9.2.3 Blast Cleaning Parameters Effects on Adhesion......Page 492
9.3 Mechanical Behaviour of Coatings......Page 498
9.4 Corrosion Protection Performance of Coatings......Page 501
9.5 Deposition and Transport Phenomena......Page 503
9.6 Wire Embedment in Polymer Matrices......Page 504
9.7.1 Spreading and Splashing......Page 505
9.7.2 Powder Solidification......Page 507
9.7.3 Nucleation Processes......Page 508
References......Page 511
List of Symbols......Page 539
D......Page 547
N......Page 548
W......Page 549
Z......Page 550