Unit Operations of Chemical Engineering

front.pdf......Page 1
Table of Contents......Page 0
Table of Contents......Page 2
What Are "Unit Operations"?......Page 5
Shell-and-Tube Hxer......Page 7
Log-Mean Driving Force......Page 9
Resistances in Series......Page 14
Correlations to Estimate h’s......Page 17
hi for Turbulent Flow In Long Pipes......Page 19
Baffles......Page 20
ho for Shell-and-Tube Exchanger......Page 21
Appendix: Derivation for Sb and Sc......Page 23
Multipass Construction......Page 25
"True" Mean Temperature Difference......Page 26
Equipment for Evaporation......Page 31
Long-Tube Vertical Evaporator......Page 32
Example: Simple Evaporator Problem......Page 33
Steam Economy......Page 37
Overview of Evaporator Design......Page 38
Boiling-Point Elevation......Page 39
Heat of Dilution......Page 41
Multiple Effects......Page 42
Performance......Page 45
Vapor Recompression......Page 46
Two Components......Page 50
Ideal Binary Mixtures......Page 52
xy and Txy Diagrams......Page 55
Nonideal Behavior......Page 56
Approximate Solution......Page 57
Inverse Lever-Arm Rule on Txy Diagram......Page 59
Rigorous Solution......Page 60
Batch (Differential) Distillation......Page 63
Multistage Operations......Page 68
Counter-Current Cascade......Page 69
Equipment for Tray Towers......Page 71
Analysis of a C-C Cascade......Page 74
Constant Molal Overflow......Page 75
A Rectifying Cascade......Page 77
A Stripping Cascade......Page 80
Steam Distillation......Page 83
McCabe-Thiele Method......Page 84
Location of Feed Plate......Page 86
Convergence of Operating Line and Equilibrium Curve......Page 87
Choosing the Reflux Ratio......Page 92
1) Existence of Rmin......Page 93
2) Total Reflux: R?? gives Minimum Stages......Page 94
Calculating Flowrates and Condenser/Reboiler Heat Duties......Page 96
Role of q-Line......Page 98
Plate Efficiency......Page 99
Determining Number of Real Stages......Page 102
Multi-Component Distillation......Page 103
Product Distribution for a Sharp Split......Page 104
Minimum Number of Trays......Page 106
Method 1) Psuedo-Binary Method......Page 111
Method 2) Underwood's Method......Page 113
Method 3) Rigorous Solution of MESH Equations......Page 117
Computer Simulation of Distillation......Page 120
Some Preliminary Steps......Page 121
Loading a File (Problem)......Page 123
Plotting the McCabe-Thiele Diagram......Page 134
Printing the Graphs......Page 136
Testing the McCabe-Thiele Method......Page 137
Degrees of Freedom......Page 141
Equipment for Absorption/Stripping......Page 143
A Typical Absorber Design Problem......Page 145
Solution Overview:......Page 146
Equilibrium Curve......Page 147
Operating Line......Page 148
Approx. #1: Only One Transferable Component......Page 149
Interfacial Mass Transfer: Review......Page 152
Definitions of Transfer Coefficients......Page 154
Determining the Interfacial Concentrations: (xi,yi)......Page 155
Equimolar Counter-Diffusion vs. Diffusion through Stagnant Fluid......Page 158
Height of a Packed Tower......Page 160
Transfer Unit......Page 164
Evaluation of NTU's......Page 166
Analogy with Double-Pipe HXer......Page 168
Relationships among HOx, HOy, Hx and Hy......Page 169
Pressure Drop in Pack Beds......Page 171
Tower Diameter......Page 173
Gases......Page 177
Equipment......Page 178
Porous Membranes......Page 181
Nonporous Polymer Membranes......Page 182
Example: Production of Enriched Air......Page 183
Stage Cut......Page 186
Liquid-Liquid Extraction......Page 188
Equipment......Page 189
Triangle Diagrams......Page 190
Nomenclature......Page 191
Flash Mixing of Two Liquids......Page 192
Single-Stage Extractor......Page 194
Multi-Stage Extractor......Page 195
Difference-Point Method......Page 197