Aerosol Technology

William C. Hinds, ScD, was Emeritus Professor in the Department of Environmental Health Sciences at the UCLA Fielding School of Public Health. His research studied aerosols and industrial control of airborne contaminants. Yifang Zhu, PhD, is Professor in the Department of Environmental Health Sciences at the UCLA Fielding School of Public Health. Her research focus is on air pollution, environmental exposure assessment, and aerosol science and technology.

• Preface to the First Edition xiPreface to the Second Edition xiiiPreface to the Third Edition xvList of Principal Symbols xvii1 Introduction 11.1 Definitions 21.2 Particle Size, Shape, and Density 51.3 Aerosol Concentration 8Problems 11References 122 Properties of Gases 152.1 Kinetic Theory of Gases 152.2 Molecular Velocity 182.3 Mean Free Path 202.4 Other Properties 212.5 Reynolds Number 242.6 Measurement of Velocity, Flow Rate, and Pressure 27Problems 35References 363 Uniform Particle Motion 373.1 Newton’s Resistance Law 373.2 Stokes’s Law 393.3 Settling Velocity and Mechanical Mobility 403.4 Slip Correction Factor 423.5 Nonspherical Particles 443.6 Aerodynamic Diameter 463.7 Settling at High Reynolds Numbers 473.8 Stirred Settling 543.9 Instruments that Rely on Settling Velocity 563.10 Appendix: Derivation of Stokes’s Law 58Problems 60References 634 Particle Size Statistics 654.1 Properties of Size Distributions 654.2 Moment Averages 714.3 Moment Distributions 724.4 The Lognormal Distribution 774.5 Log-Probability Graphs 804.6 The Hatch-Choate Conversion Equations 844.7 Statistical Accuracy 884.8 Appendix 1: Distributions Applied to Particle Size 894.9 Appendix 2: Theoretical Basis for Aerosol Particle Size Distributions 904.10 Appendix 3: Derivation of the Hatch-Choate Equations 90Problems 92References 945 Straight-Line Acceleration and Curvilinear Particle Motion 975.1 Relaxation Time 975.2 Straight-Line Particle Acceleration 985.3 Stopping Distance 1015.4 Curvilinear Motion and Stokes Number 1045.5 Inertial Impaction 1055.6 Cascade Impactors 1105.7 Virtual Impactors 1155.8 Time-of-Flight Instruments 117Problems 119References 1206 Adhesion of Particles 1216.1 Adhesive Forces 1216.2 Detachment of Particles 1236.3 Resuspension 1246.4 Particle Bounce 126Problems 127References 1277 Brownian Motion and Diffusion 1297.1 Diffusion Coefficient 1297.2 Particle Mean Free Path 1327.3 Brownian Displacement 1347.4 Deposition by Diffusion 1377.5 Diffusion Batteries 141Problems 144References 1458 Thermal and Radiometric Forces 1478.1 Thermophoresis 1478.2 Thermal Precipitators 1518.3 Radiometric and Concentration Gradient Forces 153Problems 155References 1559 Filtration 1579.1 Macroscopic Properties of Filters 1579.2 Single-Fiber Efficiency 1639.3 Deposition Mechanisms 1659.4 Filter Efficiency 1699.5 Pressure Drop 1749.6 Membrane Filters 174Problems 176References 17610 Sampling and Measurement of Concentration 17910.1 Isokinetic Sampling 17910.2 Sampling from Still Air 18510.3 Transport Losses 18810.4 Measurement of Mass Concentration 18910.5 Direct-Reading Instruments 19210.6 Measurement of Number Concentration 19510.7 Sampling Pumps 197Problems 199References 20011 Respiratory Deposition 20311.1 The Respiratory System 20311.2 Deposition 20611.3 Deposition Models 21011.4 Inhalability of Particles 21311.5 Respirable and Other Size-Selective Sampling 215Problems 223References 22412 Coagulation 22712.1 Simple Monodisperse Coagulation 22712.2 Polydisperse Coagulation 23312.3 Kinematic Coagulation 238Problems 240References 24113 Condensation and Evaporation 24313.1 Definitions 24313.2 Kelvin Effect 24613.3 Homogeneous Nucleation 24713.4 Growth by Condensation 24813.5 Nucleated Condensation 25113.6 Condensation Particle Counters 25513.7 Evaporation 257Problems 261References 26314 Atmospheric Aerosols 26514.1 Natural Background Aerosol 26514.2 Urban Aerosol 26914.3 Global Effects 274Problems 275References 27515 Electrical Properties 27715.1 Units 27715.2 Electric Fields 27815.3 Electrical Mobility 28015.4 Charging Mechanisms 28315.5 Corona Discharge 28915.6 Charge Limits 29115.7 Equilibrium Charge Distribution 29215.8 Electrostatic Precipitators 29415.9 Electrical Measurement of Aerosols 297Problems 301References 30216 Optical Properties 30516.1 Definitions 30616.2 Extinction 30716.3 Scattering 31316.4 Visibility 31716.5 Optical Measurement of Aerosols 322Problems 329References 33017 Bulk Motion of Aerosols 333Problems 338References 33818 Dust Explosions 339Problems 344References 34419 Bioaerosols 34519.1 Characteristics 34519.2 Sampling 347Problems 350References 35120 Microscopic Measurement of Particle Size 35320.1 Equivalent Sizes of Irregular Particles 35320.2 Fractal Dimension of Particles 35820.3 Optical Microscopy 36220.4 Electron Microscopy 36520.5 Asbestos Counting 36920.6 Automatic Sizing Methods 371Problems 371References 37221 Production of Test Aerosols 37521.1 Atomization of Liquids 37521.2 Atomization of Monodisperse Particles in Liquid Suspensions 38021.3 Dispersion of Powders 38221.4 Condensation Methods 387Problems 388References 389Appendices 391Appendix A1. Useful Constants and Conversion Factors 391Appendix A2. Some Basic Physical Laws 393Appendix A3. Relative Density of Common Aerosol Materials (Multiply Values by 1000 for Density in kg/m 3 and by 1.0 for Density in g/cm 3) 394Appendix A4. Standard Sieve Sizes 394Appendix A5. Properties of Gases and Vapors at 293 K [20 ∘ C] and 101 kPa [1 atm] 395Appendix A6. Viscosity and Density of Air versus Temperature 395Appendix A7. Pressure (a), Temperature (b), Density (c), and Mean Free Path (d) of air versus altitude 396Appendix A8. Properties of Water Vapor 397Appendix A9. Properties of Water 398Appendix A10. Particle Size Range of Aerosol Properties and Measurement Instruments: (a) Application Range for Aerosol Size Measuring Instruments and (b) Size Range of Aerosol Properties (See Also Fig. 1.6) 398Appendix A11. (a) Properties of Airborne Particles at Standard Conditions (SI Units) 400Appendix A12. Slip Correction Factor for Standard and Nonstandard Conditions: (a) Slip Correction Factor Minus One versus Particle Diameter and Standard Conditions; (b) Slip Correction Factor versus Particle Diameter Times Pressure (per atm) for Temperatures from 233 to 893K [–40 to 600 ∘ C] 402Appendix A13. Properties of Selected Low-Vapor-Pressure Liquids 403Appendix A14. Reference Values for Atmospheric Properties at Sea Level and 293.15Ki20 ∘ C] 404Appendix A15. Greek Symbols Used in This Book 405Appendix A16. SI Prefixes 405References 405Index 407