Solucionario Operaciones Unitarias en Ingenieria Quimica Mccabe 6 Ed

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P R E FA C E

This sixth edition of the text on the unit operations of chemical engineering has been extensively revised and updated, with much new material and considerable condensation of some sections. Its basic structure and general level of treatment, however, remain unchanged. It is an introductory text, written for undergraduate students in their junior or senior years who have completed the usual courses in mathematics, physics, chemistry, and an introduction to chemical engineering. An elementary knowledge of material and energy balances and of thermodynamic principles is assumed. Separate chapters are devoted to each of the principal unit operations, grouped into four sections: fluid mechanics, heat transfer, mass transfer and equilibrium stages, and operations involving particulate solids. One-semester or one-quarter courses may be based on any of these sections or combinations of them. The order of the first 16 chapters has not been changed; later ones, dealing with mass transfer and operations involving solids, have been rearranged in a more logical order. Nearly all equations have been written for SI units, and the Newton’s law conversion factor gc has been eliminated except in the few instances where it must be included. Symbols for dimensionless groups have been changed to Re for NRe, for example, Pr for NPr, and so forth. Many new examples and problems have been added, some reflecting the importance of biochemical engineering processes. Material on handling, mixing, and grinding particulate solids has been greatly condensed and dealt with in a single chapter. The number of appendixes is reduced from 22 to 19. Derivations of the differential equations for continuity and momentum balances, leading to the Navier-Stokes equation, have been added, as well as the differential forms of Fourier’s law and Fick’s law, emphasizing the analogies among momentum, heat, and mass transfer. The chapter on adsorption has been expanded to include new material on chromatography and ion exchange, and renamed “Fixedbed Separations.” Other new material has been added on viscoelastic fluids, laminar flow in annuli, drag coefficients, affinity laws for pumps, high-efficiency agitators and motionless mixers, plate-type heat exchangers, boiling by submerged tube bundles, cooling towers, aqueous phase extraction, cross-flow filtration, and many other topics. Many of the problems at the ends of the chapters are new or revised. Most are expressed in SI units. Nearly all the problems can be solved with the aid of a pocket calculator; for a few, a computer solution is preferable. McGraw-Hill and the authors thank Dr. N. T. Obot for his many suggestions regarding fluid mechanics and heat transfer, and Professor Charles H. Gooding of Clemson University for his detailed and helpful review of the manuscript. Julian C. Smith Peter Harriott xvii

iii

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Preface

SECTION I

1

xvii

Introduction Definitions and Principles

3

Unit Operations Unit Systems

4 4

Physical Quantities / SI Units / CGS Units / Gas Constant / FPS Engineering Units / Conversion of Units / Units and Equations

Dimensional Analysis Basic Concepts

16 20

Equations of State of Gases

Symbols Problems References

SECTION II

2

3

24 25 27

Fluid Mechanics Fluid Statics and Its Applications

31

Hydrostatic Equilibrium

32

Applications of Fluid Statics Symbols Problems References

34

Fluid Flow Phenomena

44

Laminar Flow, Shear Rate, and Shear Stress Rheological Properties of Fluids Turbulence Boundary Layers Symbols Problems References

45

41 42 43

46 51 59 63 64 65 vii

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4

5

6

7

8

Basic Equations of Fluid Flow

67

Mass Balance in a Flowing Fluid; Continuity Differential Momentum Balance; Equations of Motion Macroscopic Momentum Balances Mechanical Energy Equation Symbols Problems References

67

Incompressible Flow in Pipes and Channels

94

Shear Stress and Skin Friction in Pipes Laminar Flow in Pipes and Channels Turbulent Flow in Pipes and Channels Friction from Changes in Velocity or Direction Symbols Problems References

94

72 77 82 90 92 93

97 104 117 123 124 127

Flow of Compressible Fluids

128

Definitions and Basic Equations Processes of Compressible Flow Isentropic Flow through Nozzles Adiabatic Friction Flow Isothermal Friction Flow Symbols Problems References

128

Flow Past Immersed Bodies

150

Drag and Drag Coefficients Flow through Beds of Solids Motion of Particles through Fluids Fluidization Symbols Problems References

150

Transportation and Metering of Fluids

187

Pipe, Fittings, and Valves Pumps

187

133 134 140 145 147 148 149

157 162 171 182 183 185

194

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ix

Positive-Displacement Pumps / Centrifugal Pumps

Fans, Blowers, and Compressors

209

Fans / Blowers and Compressors / Comparison of Devices for Moving Fluids

Measurement of Flowing Fluids

219

Full-Bore Meters / Insertion Meters

9

SECTION III

10

11

Symbols Problems References

234

Agitation and Mixing of Liquids

238

Agitated Vessels Blending and Mixing Suspension of Solid Particles Dispersion Operations Agitator Selection and Scaleup Symbols Problems References

239

236 237

259 265 270 278 281 282 284

Heat Transfer and Its Applications Heat Transfer by Conduction

291

Basic Law of Conduction Steady-State Conduction Unsteady-State Conduction Symbols

291

Problems References

312

Principles of Heat Flow in Fluids

315

Typical Heat-Exchange Equipment Energy Balances Heat Flux and Heat-Transfer Coefficients

315

293 300 311 314

319 321

Overall Heat-Transfer Coefficient / Individual Heat-Transfer Coefficients

Symbols Problems References

333 334 335

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12

Heat Transfer to Fluids Without Phase Change

336

Boundary Layers Heat Transfer by Forced Convection in Laminar Flow Heat Transfer by Forced Convection in Turbulent Flow

336 339 346

Transfer by Turbulent Eddies and Analogy Between Transfer of Momentum and Heat

Heat Transfer in Transition Region Between Laminar and Turbulent Flow Heat Transfer to Liquid Metals Heating and Cooling of Fluids in Forced Convection Outside Tubes Natural Convection Symbols Problems References

13

14

15

358 360 362 365 371 373 375

Heat Transfer to Fluids with Phase Change

377

Heat Transfer from Condensing Vapors Heat Transfer to Boiling Liquids Symbols Problems References

377

Radiation Heat Transfer

406

Emission of Radiation Absorption of Radiation by Opaque Solids Radiation Between Surfaces

407

Radiation to Semitransparent Materials Combined Heat Transfer by Conduction-Convection and Radiation Symbols Problems References

423

Heat-Exchange Equipment

431

Shell-and-Tube Heat Exchangers Plate-Type Exchangers Extended-Surface Equipment Scraped-Surface Exchangers

432

389 401 403 404

410 413

425 427 428 430

446 449 455

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16

xi

Condensers and Vaporizers Heat Transfer in Agitated Vessels Heat Transfer in Packed Beds Symbols Problems References

456

Evaporation

473

Types of Evaporators

475

Performance of Tubular Evaporators

479

459 463 467 469 471

Evaporator Capacity / Evaporator Economy

Vapor Recompression Symbols Problems References SECTION IV

17

498 500 500 502

Mass Transfer and Its Applications Principles of Diffusion and Mass Transfer Between Phases Theory of Diffusion Prediction of Diffusivities Mass-Transfer Theories

511 512 518 523

Film Theory / Boundary Layer Theory / Penetration Theory / Two-Film Theory

Mass-Transfer Coefficients

530

Experimental Measurements / Coefficients for Mass Transfer through Known Areas

18

Symbols Problems References

540

Gas Absorption

546

Packings and Packed Tower Design Principles of Absorption Absorption from Rich Gases Mass-Transfer Correlations

546

542 544

557 574 580

Absorption in Plate Columns

Absorption with Chemical Reaction

588

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19

Symbols Problems References

590

Humidification Operations

596

Definitions Humidity Chart Wet-Bulb Temperature Cooling Towers

596

592 594

600 604 608

Theory of Counterflow Cooling Towers

20

Symbols Problems References

618

Equilibrium-Stage Operations

622

Equipment for Stage Contacts Principles of Stage Processes

622

619 621

625

Equilibrium-Stage Calculations for Multicomponent Systems

21

Symbols Problems References

639

Distillation

641

Flash Distillation Continuous Distillation with Reflux

641

639 640

645

Material Balances in Plate Columns / Number of Ideal Plates; McCabe–Thiele Method

Enthalpy Balances Design of Sieve-Plate Columns Plate Efficiencies

672 681 689

Theory of Plate Efficiency

22

Distillation in Packed Columns Batch Distillation Symbols Problems References

699

Introduction to Multicomponent Distillation

713

Phase Equilibria in Multicomponent Distillation Flash Distillation of Multicomponent Mixtures

713

700 704 706 711

717

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23

xiii

Fractionation of Multicomponent Mixtures Azeotropic and Extractive Distillation Symbols Problems References

718

Leaching and Extraction

739

Leaching

739

734 735 736 738

Leaching Equipment / Principles of Continuous Countercurrent Leaching

Liquid Extraction

747

Extraction Equipment / Principles of Extraction

Special Extraction Techniques

766

Supercritical Fluid Extraction

24

Symbols Problems References

768

Drying of Solids

773

Principles of Drying

775

769 772

Phase Equilibria

Cross-Circulation Drying Through-Circulation Drying

782 790

Drying of Suspended Particles

Freeze-Drying Drying Equipment

793 794

Dryers for Solids and Pastes / Dryers for Solutions and Slurries / Selection of Drying Equipment

25

Symbols Problems References

807

Fixed-Bed Separations

812

Adsorption Adsorption Equipment

812

809 810

813

Equilibria; Adsorption Isotherms / Principles of Adsorption / Basic Equations for Adsorption / Solutions to Mass-Transfer Equations / Adsorber Design / Continuous Operation

Ion Exchange Equilibria / Mass-Transfer Rates / Operation of Ion Exchangers

839

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26

Chromatography Symbols Problems References

845

Membrane Separation Processes

857

Separation of Gases Separation of Liquids

857

852 854 855

878

Dialysis / Membranes for Liquid-Liquid Extraction / Pervaporation / Reverse Osmosis

27

Symbols Problems References

896

Crystallization

902

Crystal Geometry Equilibria and Yields Nucleation Crystal Growth Crystallization Equipment Crystallizer Design: Crystal Size Distribution

903

898 900

904 911 918 921 927

MSMPR Crystallizer

Crystallization from Melts Symbols Problems References

SECTION V

28

936 937 939 941

Operations Involving Particulate Solids Properties and Handling of Particulate Solids

945

Characterization of Solid Particles Properties of Masses of Particles

945 951

Storage and Conveying of Solids

Mixing of Solids

955

Mixers for Noncohesive Solids / Mixers for Cohesive Solids

Size Reduction Computer Simulation of Milling Operations / Equipment for Size Reduction

965

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29

xv

Ultrafine Grinders Symbols Problems References

977

Mechanical Separations

986

Screening

986

981 983 984

Screening Equipment

Filtration; General Considerations

991

Cake Filters

993

Centrifugal Filters / Filter Media / Filter Aids / Principles of Cake Filtration

Clarifying Filters

1018

Liquid Clarification / Gas Cleaning / Principles of Clarification

Crossflow Filtration; Membrane Filters

1021

Type of Membranes / Permeate Flux for Ultrafiltration / Concentration Polarization / Microfiltration

Gravity Sedimentation Processes Centrifugal Sedimentation Processes Symbols Problems References Appendix 1 Conversion Factors and Constants of Nature Appendix 2 Dimensionless Groups Appendix 3 Dimensions, Capacities, and Weights of Standard Steel Pipe Appendix 4 Condenser and Heat-Exchanger Tube Data

1035

Appendix 5 Appendix 6 Appendix 7 Appendix 8 Appendix 9 Appendix 10 Appendix 11

1070

Tyler Standard Screen Scale Properties of Liquid Water Properties of Saturated Steam and Water Viscosities of Gases Viscosities of Liquids Thermal Conductivities of Metals Thermal Conductivities of Various Solids and Insulating Materials Appendix 12 Thermal Conductivities of Gases and Vapors Appendix 13 Thermal Conductivities of Liquids Other Than Water Appendix 14 Specific Heats of Gases

1045 1056 1058 1061 1063 1066 1068 1069 1071 1072 1074 1076 1079 1080 1082 1083 1084

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Appendix 15 Appendix 16 Appendix 17 Appendix 18

Specific Heats of Liquids Prandtl Numbers for Gases at 1 atm and 100°C Prandtl Numbers for Liquids Diffusivities and Schmidt Numbers for Gases in Air at 0°C and 1 atm Appendix 19 Collision Integral and Lennard-Jones Force Constants

1085

Index

1091

1086 1087 1088 1089

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