Infodoc : Sciences, Techniques et Culture

CHAPTER 1 Introduction
1.1 Dimensions
1.2 Engineering Units
1.2.1 Base Units
1.2.2 Derived Units
1.2.3 Supplementary Units
1.3 System
1.4 State of a System
1.4.1 Extensive Properties
1.4.2 Intensive Properties
1.5 Density
1.6 Concentration
1.7 Moisture Content
1.8 Temperature
1.9 Pressure
1.10 Enthalpy
1.11 Equation of State and Perfect Gas Law
1.12 Phase Diagram of Water

CHAPTER 1 Introduction
1.1 Dimensions
1.2 Engineering Units
1.2.1 Base Units
1.2.2 Derived Units
1.2.3 Supplementary Units
1.3 System
1.4 State of a System
1.4.1 Extensive Properties
1.4.2 Intensive Properties
1.5 Density
1.6 Concentration
1.7 Moisture Content
1.8 Temperature
1.9 Pressure
1.10 Enthalpy
1.11 Equation of State and Perfect Gas Law
1.12 Phase Diagram of Water
1.13 Conservation of Mass
1.13.1 Conservation of Mass for an Open System
1.13.2 Conservation of Mass for a Closed System
1.14 Material Balances
1.15 Thermodynamics
1.16 Laws of Thermodynamics
1.16.1 First Law of Thermodynamics
1.16.2 Second Law of Thermodynamics
1.17 Energy
1.18 Energy Balance
1.19 Energy Balance for a Closed System
1.19.1 Heat
1.19.2 Work
1.20 Energy Balance for an Open System
1.20.1 Energy Balance for Steady Flow Systems
1.21 A Total energy Balance
1.22 Power
1.23 Area
Problems
List of Symbols
Bibliography
CHAPTER 2 Fluid Flow in Food Processing
2.1 Liquid Transport Systems
2.1.1 Pipes for Processing Plants
2.1.2 Types of Pumps
2.2 Properties of Liquids
2.2.1 Terminology Used in Material Response to Stress
2.2.2 Density
2.2.3 Viscosity
2.3 Handling Systems for Newtonian Liquids
2.3.1 The Continuity Equation
2.3.2 Reynolds Number
2.3.3 Entrance Region and Fully Developed Flow
2.3.4 Velocity Profile in a Liquid Flowing Under Fully Developed Flow Conditions
2.3.5 Forces Due to Friction
2.4 Force Balance on a Fluid Element Flowing in a Pipe-Derivation of Bernoulli Equation
2.5 Energy Equation for Steady Flow of Fluids
2.5.1 Pressure Energy
2.5.2 Kinetic Energy
2.5.3 Potential Energy
2.5.4 Frictional Energy Loss
2.5.5 Power Requirements of a Pump
2.6 Pump Selection and Performance Evaluation
2.6.1 Centrifugal Pumps
2.6.2 Head
2.6.3 Pump Performance Characteristics
2.6.4 Pump Characteristic Diagram
2.6.5 Net Positive Suction Head
2.6.6 Selecting a Pump for a Liquid Transport System
2.6.7 Affinity Laws
2.7 Flow Measurement
2.7.1 The Pitot Tube
2.7.2 The Orifice Meter
2.7.3 The Venturi Meter
2.7.4 Variable-Area Meters
2.7.5 Other Measurement Methods
2.8 Measurement of Viscosity
2.8.1 Capillary Tube Viscometer
2.8.2 Rotational Viscometer
2.8.3 Influence of Temperature on Viscosity
2.9 Flow Characteristics of Non-Newtonian Fluids
2.9.1 Properties of Non-Newtonian Fluids
2.9.2 Velocity Profile of a Power Law Fluid
2.9.3 Volumetric Flow Rate of a Power Law Fluid
2.9.4 Average Velocity in a Power Law Fluid
2.9.5 Friction Factor and Generalized Reynolds Number for Power Law Fluids
2.9.6 Computation of Pumping Requirement of Non-Newtonian Liquids
2.10 Transport of Solid Foods
2.10.1 Properties of Granular Materials and Powders
2.10.2 Flow of Granular Foods
2.11 Process Controls in Food Processing
2.11.1 Processing Variables and Performance Indicators
2.11.2 Input and Output Signals to Control Processes
2.11.3 Design of a Control System
2.12 Sensors
2.12.1 Temperature
2.12.2 Liquid Level in a Tank
2.12.3 Pressure Sensors
2.12.4 Flow Sensors
2.12.5 Glossary of Terms Important in Data Acquisition
2.13 Dynamic Response Characteristics of Sensors
Problems
List of Symbols
Bibliography
CHAPTER 3 Resource Sustainability
3.1 Generation of Steam
3.1.1 Steam Generation Systems
3.1.2 Thermodynamics of Phase Change
3.1.3 Steam Tables
3.1.4 Steam Utilization
3.2 Fuel Utilization
3.2.1 Systems
3.2.2 Mass and Energy Balance Analysis
3.2.3 Burner Efficiencies
3.3 Electric Power Utilization
3.3.1 Electrical Terms and Units
3.3.2 Ohm's Law
3.3.3 Electric Circuits
3.3.4 Electric Motors
3.3.5 Electrical Controls
3.3.6 Electric Lighting
3.4 Energy, Water and Environment
3.4.1 Life Cycle Assessment
3.4.2 Food System Applications
3.4.3 Sustainability Indicators
Problems
List of Symbols
Bibliography
CHAPTER 4 Heat Transfer in Food Processing
4.1 Systems for Heating and Cooling Food Products
4.1.1 Plate Heat Exchanger
4.1.2 Tubular Heat Exchanger
4.1.3 Scraped-Surface Heat Exchanger
4.1.4 Steam-Infusion Heat Exchanger
4.1.5 Epilogue
4.2 Thermal Properties of Foods
4.2.1 Specific Heat
4.2.2 Thermal Conductivity
4.2.3 Thermal Diffusivity
4.3 Modes of Heat Transfer
4.3.1 Conductive Heat Transfer
4.3.2 Convective Heat Transfer
4.3.3 Radiation Heat Transfer
4.4 Steady-State Heat Transfer
4.4.1 Conductive Heat Transfer in a Rectangular Slab
4.4.2 Conductive Heat Transfer through a Tubular Pipe
4.4.3 Heat Conduction in Multilayered Systems
4.4.4 Estimation of Convective Heat-Transfer Coefficient
4.4.5 Estimation of Overall Heat-Transfer Coefficient
4.4.6 Fouling of Heat Transfer Surfaces
4.4.7 Design of a Tubular Heat Exchanger
4.4.8 The Effectiveness-NTU Method for Designing Heat Exchangers
4.4.9 Design of a Plate Heat Exchanger
4.4.10 Importance of Surface Characteristics in Radiative Heat Transfer
4.4.11 Radiative Heat Transfer between Two Objects
4.5 Unsteady-State Heat Transfer
4.5.1 Importance of External versus InternaI Resistance to Heat Transfer
4.5.2 Negligible Internal Resistance to Heat Transfer (NBi < 0.l)-A Lumped System Analysis
4.5.3 Finite InternaI and Surface Resistance to Heat Transfer (0.1 ≤ NBi ≤ 40)
4.5.4 Negligible Surface Resistance to Heat Transfer (NBi ≥ 40)
4.5.5 Finite Objects
4.5.6 Procedures to Use Temperature- Tirne Charts
4.5.7 Use of fh and j Factors in Predicting Temperature in Transient Heat Transfer
4.6 Electrical Conductivity of Foods
4.7 Ohmic Heating
4.8 Microwave Heating
4.8.1 Mechanisms of Microwave Heating
4.8.2 Dielectric Properties
4.8.3 Conversion of Microwave Energy into Heat
4.8.4 Penetration Depth of Microwaves
4.8.5 Microwave Oven
4.8.6 Microwave Heating of Foods Problems
List of Symbols
Bibliography
CHAPTER 5 Preservation Processes
5.1 Processing Systems
5.1.1 Pasteurization and Blanching Systems
5.1.2 Commercial Sterilization Systems
5.1.3 Ultra-High Pressure Systems
5.1.4 Pulsed Electric Field Systems
5.1.5 Alternative Preservation System
5.2 Microbial Survivor Curves
5.3 Influence of External Agents
5.4 Thermal Death Time F
5.5 Spoilage Probability
5.6 General Method for Process Calculation
5.6.1 Applications to Pasteurization
5.6.2 Commercial Sterilization
5.6.3 Aseptic Processing and Packaging
5.6.4 Combined Processes
5.7 Mathematical Methods
5.7.1 Pouch Processing
Problems
List of Symbols
Bibliography
CHAPTER 6 Refrigeration
6.1 Selection of a Refrigerant
6.2 Components of a Refrigeration System
6.2.1 Evaporator
6.2.2 Compressor
6.2.3 Condenser
6.2.4 Expansion Valve
6.3 Pressure-Enthalpy Charts
6.3.1 Pressure-Enthalpy Tables
6.3.2 Use of Computer-Aided Procedures to Determine Thermodynamic Properties of Refrigerants
6.4 Mathematical Expressions Useful in Analysis of Vapor-Compression Refrigeration
6.4.1 Cooling Load
6.4.2 Compressor
6.4.3 Condenser
6.4.4 Evaporator
6.4.5 Coefficient of Performance
6.4.6 Refrigerant Flow Rate
6.5 Use of Multistage Systems
6.5.1 Flash Gas Removal System
Problems
List of Symbols
Bibliography
CHAPTER 7 Food Freezing
7.1 Freezing Systems
7.1.1 Indirect Contact Systems
7.1.2 Direct-Contact Systems
7.2 Frozen-Food Properties
7.2.1 Density
7.2.2 Thermal Conductivity
7.2.3 Enthalpy
7.2.4 Apparent Specific Heat
7.2.5 Apparent Thermal Diffusivity
7.3 Freezing Time
7.3.1 Plank's Equation
7.3.2 Other Freezing-Time Prediction Methods
7.3.3 Pham's Method to Predict Freezing Time
7.3.4 Prediction of Freezing Time of Finite-Shaped Objects
7.3.5 Experimental Measurement of Freezing Time
7.3.6 Factors Influencing Freezing Time
7.3.7 Freezing Rate
7.3.8 Thawing Time
7.4 Frozen-Food Storage
7.4.1 Quality Changes in Foods during Frozen Storage
Problems
List of Symbols
Bibliography
CHAPTER 8 Evaporation
8.1 Boiling-Point Elevation
8.2 Types of Evaporators
8.2.1 Batch-Type Pan Evaporator
8.2.2 Natural Circulation Evaporators
8.2.3 Rising-Film Evaporator
8.2.4 Falling-Film Evaporator
8.2.5 Rising/Falling-Film Evaporator
8.2.6 Forced-Circulation Evaporator
8.2.7 Agitated Thin-Film Evaporator
8.3 Design of a Single-Effect Evaporator
8.4 Design of a Multiple-Effect Evaporator
8.5 Vapor Recompression Systems
8.5.1 Thermal Recompression
8.5.2 Mechanical Vapor Recompression
Problems
List of Symbols
Bibliography
CHAPTER 9 Psychrometrics
9.1 Properties of Dry Air
9.1.1 Composition of Air
9.1.2 Specific Volume of Dry Air
9.1.3 Specific Heat of Dry Air
9.1.4 Enthalpy of Dry Air
9.1.5 Dry Bulb Temperature
9.2 Properties of Water Vapor
9.2.1 Specific Volume of Water Vapor
9.2.2 Specific Heat of Water Vapor
9.2.3 Enthalpy of Water Vapor
9.3 Properties of Air-Vapor Mixtures
9.3.1 Gibbs-Dalton Law
9.3.2 Dew-Point Temperature
9.3.3 Humidity Ratio (or Moisture Content)
9.3.4 Relative Humidity
9.3.5 Humid Heat of an Air-Water Vapor Mixture
9.3.6 Specific Volume
9.3.7 Adiabatic Saturation of Air
9.3.8 Wet Bulb Temperature
9.4 The Psychrometric Chart
9.4.1 Construction of the Chart
9.4.2 Use of Psychrometric Chart to Evaluate Complex Air-Conditioning Processes
Problems
List of Symbols
Bibliography
CHAPTER 10 Mass Transfer
10.1 The Diffusion Process
10.1.1 Steady-State Diffusion of Gases (and Liquids) through Solids
10.1.2 Convective Mass Transfer
10.1.3 Laminar Flow Over a Flat Plate
10.1.4 Turbulent Flow Past a Flat Plate
10.1.5 Laminar Flow in a Pipe
10.1.6 Turbulent Flow in a Pipe
10.1. 7 Mass Transfer for Flow Over Spherical Objects
10.2 Unsteady-State Mass Transfer
10.2.1 Transient-State Diffusion
10.2.2 Diffusion of Gases
Problems
List of Symbols
Bibliography
CHAPTER 11 Membrane Separation
11.1 Electrodialysis Systems
11.2 Reverse Osmosis Membrane Systems
11.3 Membrane Performance
11.4 Ultrafiltration Membrane Systems
11.5 Concentration Polarization
11.6 Types of Reverse-Osmosis and Ultrafiltration Systems
11.6.1 Plate-and-Frame
11.6.2 Tubular
11.6.3 Spiral-Wound
11.6.4 Hollow-Fiber
Problems
List of Symbols
Bibliography
CHAPTER 12 Dehydration
12.1 Basic Drying Processes
12.1.1 Water Activity
12.1.2 Moisture Diffusion
12.1.3 Drying-Rate Curves
12.1.4 Heat and Mass Transfer
12.2 Dehydration Systems
12.2.1 Trayor Cabinet Dryers
12.2.2 Tunnel Dryers
12.2.3 Puff-Drying
12.2.4 Fluidized-Bed Drying
12.2.5 Spray Drying
12.2.6 Freeze-Drying
12.3 Dehydration System Design
12.3.1 Mass and Energy Balance
12.3.2 Drying-Time Prediction
Problems
List of Symbols
Bibliography
CHAPTER 13 Supplemental Processes
13.1 Filtration
13.1.1 Operating Equations
13.1.2 Mechanisms of Filtration
13.1.3 Design of a Filtration System
13.2 Sedimentation
13.2.1 Sedimentation Velocities for Low-Concentration Suspensions
13.2.2 Sedimentation in High-Concentration Suspensions
13.3 Centrifugation
13.3.1 Basic Equations
13.3.2 Rate of Separation
13.3.3 Liquid-Liquid Separation
13.3.4 Particle-Gas Separation
13.4 Mixing
13.4.1 Agitation Equipment
13.4.2 Power Requirements of Impellers
Problems
List of Symbols
Bibliography
CHAPTER 14 Extrusion Processes for Foods
14.1 Introduction and Background
14.2 Basic Princip les of Extrusion
14.3 Extrusion Systems
14.3.1 Cold Extrusion
14.3.2 Extrusion Cooking
14.3.3 Single Screw Extruders
14.3.4 Twin-Screw Extruders
14.4 Extrusion System Design
14.5 Design of More Complex Systems
Problems
List of Symbols
Bibliography
CHAPTER 15 Packaging Concepts
15.1 Introduction
15.2 Food Protection
15.3 Product Containment
15.4 Product Communication
15.5 Product Convenience
15.6 Mass Transfer in Packaging Materials
15.6.1 Permeability of Packaging Material to "Fixed" Gases
15.7 Innovations in Food Packaging
15.7.1 Passive Packaging
15.7.2 Active Packaging
15.7.3 Intelligent Packaging
15.8 Food Packaging and Product Shelf- Life
15.8.1 Scientific Basis for Evaluating Shelf Life
15.9 Summary
Problems
List of Symbols
Bibliography
Appendices
A.l SI System of Units and Conversion Factors
A.1.1 Rules for Using SI Units
Table A.1.1 SI Prefixes
Table A.1.2 Useful Conversion Factors
Table A.1.3 Conversion Factors for Pressure
A.2 Physical Properties of Foods
Table A.2.1 Specific Heat of Foods
Table A.2.2 Thermal Conductivity of Selected Food Products
Table A.2.3 Thermal Diffusivity of Some Foodstuffs
Table A.2.4 Viscosity of Liquid Foods
Table A.2.5 Properties of !ce as a Function of Temperature
Table A.2.6 Approximate Heat Evolution Rates of Fresh Fruits and Vegetables When Stored at Temperatures Shown
Table A.2.7 Enthalpy of Frozen Foods
Table A.2.8 Composition Values of Selected Foods
Table A.2.9 Coefficients to Estimate Food Properties
A.3 Physical Properties of Nonfood Materials
Table A.3.1 Physical Properties of Metals
Table A.3.2 Physical Properties of Nonmetals
Table A.3.3 Emissivity of Various Surfaces
A.4 Physical Properties ofWater and Air
Table A.4.1 Physical Properties of Water at the Saturation Pressure
Table A.4.2 Properties of Saturated Steam
Table A.4.3 Properties of Superheated Steam
Table A.4.4 Physical Properties of Dry Air at Atmospheric Pressure
A.5 Psychrometric Charts
Figure A.5.1 Psychrometric chart for high temperatures
Figure A.5.2 Psychrometric chart for low temperatures
A.6 Pressure- Enthalpy Data
Figure A.6.1 Pressure-enthalpy diagram for Refrigerant 12
Table A.6.1 Properties of Saturated Liquid and Vapor R-12
Figure A.6.2 Pressure-enthalpy diagram of superheated R-12 vapor
Table A.6.2 Properties of Saturated Liquid and Vapor R-717 (Ammonia)
Figure A.6.3 Pressure-enthalpy diagram of superheated R-717 (ammonia) vapor
Table A.6.3 Properties of Saturated Liquid and Vapor R-134a
Figure A.6.4 Pressure-enthalpy diagram of R-134a
Figure A.6.5 Pressure-enthalpy diagram of R-134a(expanded scale)
A.7 Symbols for use in Drawing Food Engineering Process Equipment
A.8 Miscellaneous
Table A.8.1 Numerical Data and Area/Volume of Objects
Figure A.8.1 Temperature at the geometric center of a sphere (expanded scale)
Figure A.8.2 Temperature at the axis of an infinitely long cylinder (expanded scale)
Figure A.8.3 Temperature at the midplane of an infinite slab (expanded scale)
A.9 Dimensional Analysis
A.9.1 Buckingham π Theorem
Table A.9.1 Dimensions of Selected Experimental Variables