Agro-Product Processing Technology

Professor B. K. Bala is the dean of the Faculty of Engineering,Bangabandhu Sheikh Mujibur Rahman Science and TechnologyUniversity, Gopalganj, Bangladesh, and was a professor in theDepartment of Farm Power and Machinery, Bangladesh AgriculturalUniversity, Mymensingh, Bangladesh, where he was engaged in teachingand research for over 42 years starting from 1970. He has supervisedmore than a dozen PhD students in the areas of drying and storageof agro products, modeling of food security, modeling of integratedenergy systems and energy policy, renewable energy, modeling of climatechange impacts, and emerging technologies such as neural network,exergy, genetic algorithm, and computational fluid dynamics.Professor Bala received a B.Sc. (Eng.) degree from BangladeshUniversity of Engineering and Technology, Dhaka, Bangladesh, in1969 and an M.Eng. degree from the Asian Institute of Technology, Bangkok, Thailand, in 1975.Professor Bala also received a Ph.D. degree from the University of Newcastle upon Tyne, UK, in1983 and worked on modeling and simulation of heat and mass transfer during industrial deep-beddrying of malt and provided the foundation and basis for energy conservation and online control ofindustrial deep bed drying of malt. He also worked on solar drying as an EC postdoctoral fellow atthe University of Newcastle upon Tyne, UK, from 1992 to 1993. He was on a DAAD study visit atthe Institute of Agricultural Engineering in the Tropics and Subtropics, University of Hohenheim,Germany, for research on solar drying in 1995. Professor Bala also served as a research fellow at theInstitute of Agricultural and Food Policy Research, Universiti Putra Malaysia from 2012 to 2014.Professor Bala has published 207 scientific papers mostly in high-impact factor journals, andhe is also the author of nine textbooks. He is the author of Drying and Storage of Cereal Grainspublished by Wiley-Blackwell in 2017, and he is the co-author of System Dynamics Modeling andSimulation published by Springer in 2017.

• ContentsForeword ..........................................................................................................................................xvPreface............................................................................................................................................xviiAuthor .............................................................................................................................................xixChapter 1 Introduction ..................................................................................................................11.1 Introduction .........................................................................................................11.2 Impotence of Postharvest Technology .................................................................21.3 Importance of Postharvest Losses .......................................................................21.4 Postharvest Technology .......................................................................................3References ....................................................................................................................5Chapter 2 Physical, Thermal, and Chemical Properties of Food and Biological Materials .........72.1 Introduction .........................................................................................................72.2 Physical Properties ..............................................................................................72.2.1 Physical Dimensions ................................................................................72.2.2 1000-Grain Weight ..................................................................................72.2.3 Bulk Density ............................................................................................82.2.4 Shrinkage .................................................................................................82.2.5 Friction ....................................................................................................92.2.5.1 Angle of Internal Friction and Angle of Repose ......................92.2.5.2 Coefficient of Friction ............................................................. 102.3 Thermal Properties ............................................................................................ 112.3.1 Specific Heat .......................................................................................... 112.3.2 Thermal Conductivity ........................................................................... 132.3.2.1 Theory ..................................................................................... 132.3.2.2 Apparatus and Measurement .................................................. 142.3.3 Latent Heat of Vaporization .................................................................. 152.3.3.1 Determination of Latent Heat of Vaporization ....................... 162.3.4 Heat Transfer Coefficient of Product Bed ............................................. 182.3.4.1 Dimensional Analysis ............................................................. 192.3.4.2 Comparison of Theory and Experiment ................................. 192.3.4.3 Theory .....................................................................................202.3.4.4 Determination of Volumetric Heat Transfer Coefficient ........222.4 Chemical Properties ..........................................................................................242.4.1 Starch .....................................................................................................242.4.2 Protein ...................................................................................................242.4.3 Fat ..........................................................................................................242.4.4 Vitamin ..................................................................................................24Key to Symbols ..........................................................................................................24Exercises .....................................................................................................................26References ..................................................................................................................27Chapter 3 Cleaning, Grading, and Sorting .................................................................................293.1 Grade Factor ....................................................................................................293.2 Washing ...........................................................................................................303.3 Sorting Fruits and Vegetables ..........................................................................303.4 Sorting Grain ...................................................................................................303.5 Spiral Separator ............................................................................................... 323.6 Indent Cylinder Separator ............................................................................... 333.7 Color Separator ................................................................................................ 333.8 Centrifugal Separation ....................................................................................343.8.1 Stokes’ Equation .................................................................................343.9 The Centrifuge................................................................................................. 353.10 The Cream Separator ....................................................................................... 353.11 Cyclone Separator ............................................................................................363.12 Machine Vision................................................................................................ 393.12.1 Image Acquisition ............................................................................. 393.12.1.1 Computer Vision System .................................................. 393.12.1.2 Ultrasound and Infrared ...................................................403.12.1.3 Tomographic Imaging ......................................................403.12.2 Preprocessing ....................................................................................403.12.3 Segmentation ..................................................................................... 413.12.4 Feature Extraction ............................................................................. 423.12.4.1 Color Features .................................................................. 423.12.4.2 Morphological Features.................................................... 433.12.4.3 Texture Features ............................................................... 433.12.5 Classification .....................................................................................44Bibliography ............................................................................................................... 45Chapter 4 Psychrometry .............................................................................................................. 474.1 Introduction ..................................................................................................... 474.2 Psychrometric Terms ....................................................................................... 474.2.1 Humidity Ratio ..................................................................................484.2.2 Relative Humidity .............................................................................484.2.3 Specific Volume ................................................................................494.2.4 Vapor Pressure ..................................................................................494.2.5 Dry-Bulb Temperature ......................................................................494.2.6 Dew Point Temperature.....................................................................494.2.7 Wet-Bulb Temperature ......................................................................494.2.8 Enthalpy ............................................................................................504.2.9 Adiabatic Wet-Bulb Temperature ...................................................... 514.2.10 Psychrometric Wet-Bulb Temperature .............................................. 524.3 Construction of Psychrometric Chart ..............................................................544.4 Use of Psychrometric Chart ............................................................................544.4.1 Sensible Heating and Cooling ........................................................... 554.4.2 Heating with Humidification ............................................................. 554.4.3 Cooling with Humidification ............................................................564.4.4 Cooling with Dehumidification.........................................................564.4.5 Drying ............................................................................................... 574.4.6 Mixing of Airstreams ....................................................................... 594.4.7 Heat Addition with Air Mixing .......................................................... 614.4.8 Drying with Recirculation .................................................................. 62Key to Symbols ..........................................................................................................66Exercises .....................................................................................................................68Bibliography ...............................................................................................................68Chapter 5 Drying of Agro Products ............................................................................................695.1 Principles of Drying ..........................................................................................695.2 Importance of Drying ........................................................................................695.3 Moisture Content ............................................................................................... 705.3.1 Moisture Content Representation .......................................................... 705.3.2 Determination of Moisture Content ...................................................... 725.3.2.1 Direct Methods ....................................................................... 735.3.2.2 Indirect Methods ..................................................................... 755.4 Equilibrium Moisture Content .......................................................................... 765.4.1 Determination of Static Equilibrium Moisture Content ........................775.4.2 Static Equilibrium Moisture Content Models .......................................775.5 Mechanism of Drying........................................................................................825.6 Thin-Layer Drying ............................................................................................845.6.1 Thin-Layer Drying Equations ...............................................................845.6.1.1 Empirical Drying Equations ...................................................845.6.1.2 Theoretical Drying Equations ................................................845.6.1.3 Semi-Theoretical Drying Equations .......................................855.6.2 Drying Rate ...........................................................................................875.6.3 Drying Parameters .................................................................................875.6.4 Drying Rate Constant and Diffusion Coefficient ..................................885.6.4.1 Drying Rate Constant .............................................................885.6.5 Half Response Time .............................................................................. 915.7 Deep-Bed Drying ..............................................................................................925.7.1 Logarithmic Model ................................................................................925.7.2 Partial Differential Equation Model ......................................................985.7.2.1 Method of Solution ............................................................... 1025.7.2.2 Comparisons of Simulated and Observed Results ................ 1035.8 Fluidized Bed Drying Model .......................................................................... 1035.8.1 Heat Balance Equation ........................................................................ 1045.8.2 Drying Rate Equation .......................................................................... 1045.8.3 Mass Balance Equation ....................................................................... 1055.9 Agro-Product Drying Systems ........................................................................ 1065.9.1 Solar Drying Systems .......................................................................... 1065.9.1.1 Solar Dryers .......................................................................... 1065.9.2 Batch Drying Systems ......................................................................... 1105.9.2.1 Flatbed Dryer ........................................................................ 1115.9.3 Continuous Flow Drying Systems ....................................................... 1135.9.3.1 Cross-Flow Dryer ................................................................. 1135.9.3.2 Cross-Flow Batch Dryer ....................................................... 1135.9.3.3 Concurrent Flow Dryer ......................................................... 1145.9.3.4 Counterflow Dryer ................................................................ 1145.9.3.5 Mixed-Flow Dryer ................................................................ 1165.10 Safe Temperature for Drying Grain .............................................................. 1175.11 Selection of Dryers ........................................................................................ 117Key to Symbols ........................................................................................................ 118Exercises ................................................................................................................... 119Bibliography ............................................................................................................. 120Chapter 6 Parboiling of Rice .................................................................................................... 1236.1 Introduction ................................................................................................... 1236.2 Principles of Parboiling .................................................................................1246.3 Soaking ..........................................................................................................1246.3.1 Kinetics of Soaking ........................................................................... 1266.3.2 Finite Element Modeling of Soaking of Water by Paddy .................. 1326.3.3 Half Response Time .......................................................................... 1376.3.4 Kinetics of Water Diffusion and Starch Gelatinization .................... 1376.4 Steaming ........................................................................................................ 1406.5 Drying ............................................................................................................ 1406.6 Effect of Parboiling on Milling, Nutritional, and Cooking Qualitiesof Rice ........................................................................................................... 1416.7 Parboiling Methods ....................................................................................... 1426.7.1 Traditional Methods .......................................................................... 1426.7.1.1 Single Stage Parboiling ...................................................... 1426.7.1.2 Double Stage Parboiling ..................................................... 1426.7.2 Modern Methods ............................................................................... 1426.7.2.1 CFTRI (Central Food Technological ResearchIndustries) Method ............................................................. 1436.7.2.2 Jadavpur University Method .............................................. 1436.7.2.3 Malek Process .................................................................... 1436.7.2.4 Schule Process .................................................................... 1436.7.2.5 Crystal Rice Process .......................................................... 1446.7.2.6 Rice Conversion Process .................................................... 1446.7.2.7 Avorio Process .................................................................... 1446.7.3 Estimation of Heat Required for Parboiling ...................................... 1446.7.3.1 Soaking Operation.............................................................. 1446.7.3.2 Steaming Operation............................................................ 1446.7.3.3 Drying Operation ............................................................... 145Exercises ................................................................................................................... 159Bibliography ............................................................................................................. 160Chapter 7 Milling of Rice and Wheat ....................................................................................... 1637.1 Introduction ................................................................................................... 1637.2 Rice Milling .................................................................................................. 1637.3 Traditional Methods ...................................................................................... 1637.3.1 Home Pounding ................................................................................. 1637.3.2 Huller Mills ....................................................................................... 1647.3.3 Sheller Mills ...................................................................................... 1647.3.4 Rubber Roll Sheller Mills .................................................................. 1647.4 The Modern Rice Milling Process ................................................................ 1657.5 Modern Rice Milling Machinery .................................................................... 1677.5.1 Paddy Cleaner ...................................................................................... 1677.5.2 Stoner ................................................................................................... 1677.5.3 Rubber Roll Sheller ............................................................................. 1677.5.4 Paddy Separator ................................................................................... 1697.5.5 Whitening or Polishing........................................................................ 1717.5.5.1 Cone-Type Polisher ............................................................... 1717.5.5.2 Horizontal Abrasive-Type Polisher ....................................... 1727.5.5.3 Friction-Type Polisher ........................................................... 1727.5.6 Bran and Polished Rice Separator ....................................................... 1737.5.7 Rice Grader ......................................................................................... 1737.5.8 Rice Mixing ......................................................................................... 1747.6 Wheat Milling ................................................................................................. 1747.6.1 Conditioning/Hydrothermal Treatment ............................................... 1747.6.2 Milling ................................................................................................. 1747.6.3 Storage of Finished Products ............................................................... 1757.7 Size Characteristics ......................................................................................... 1757.7.1 Sieve ..................................................................................................... 1757.7.2 Fineness Modulus ................................................................................ 1767.7.3 Energy Requirements .......................................................................... 177Bibliography ............................................................................................................. 179Chapter 8 By-Product Utilization ............................................................................................. 1818.1 Introduction ..................................................................................................... 1818.2 Fuels and Combustion ..................................................................................... 1818.2.1 Furnaces .............................................................................................. 1828.3 Pyrolysis and Gasification ............................................................................... 1838.3.1 Pyrolysis (Destructive Distillation) and Gasification .......................... 1838.3.2 Types of Gasifiers ................................................................................ 1848.3.2.1 Countercurrent Moving Bed Gasifiers .................................. 1858.3.2.2 Concurrent Moving Bed Gasifiers ........................................ 1858.3.2.3 Crosscurrent Moving Bed Gasifiers ..................................... 1858.3.2.4 Fluidized Bed Gasifiers ........................................................ 1858.3.3 Gasification Process ............................................................................ 1858.3.3.1 Oxidation .............................................................................. 1868.3.3.2 Reduction .............................................................................. 1868.3.3.3 Drying ................................................................................... 1868.3.4 Gasifier Units ....................................................................................... 1868.4 Liquefaction ..................................................................................................... 1878.5 Hydrolysis Followed by Fermentation ............................................................. 1898.6 Biochar Production and Utilization ................................................................. 1908.6.1 Biochar Carbonizer ............................................................................. 1908.6.2 Types of Carbonizers ........................................................................... 1918.6.2.1 Application............................................................................ 1928.7 Rice Husk Pelletizing and Briquetting ............................................................ 1928.7.1 Need for Briquetting ............................................................................ 1938.7.2 Principle and Technology .................................................................... 1938.7.3 Types of Briquetting Machines ....................................................... 1938.7.3.1 High- and Medium-Pressure Compaction .......................1948.7.3.2 Screw Press ...................................................................... 1948.7.3.3 Piston Press ...................................................................... 1958.7.3.4 Low-Pressure Compaction ............................................... 1958.7.3.5 Hand-Molded Briquettes .................................................. 1958.7.4 Applications ..................................................................................... 1958.7.5 Limitations....................................................................................... 1968.7.6 Future Prospective ........................................................................... 1968.8 Biogas Digesters ............................................................................................ 1968.8.1 Anaerobic Digestion Process ........................................................... 1978.8.2 Indian-Type Biogas Digester ........................................................... 1978.8.3 The Chinese Biogas Digester .......................................................... 1988.8.4 Digester Sizing ................................................................................ 1998.9 Composting ....................................................................................................2028.9.1 Process of Composting ....................................................................2038.9.2 Mixing of Materials in the Compost ...............................................2038.9.3 Starting a Composter .......................................................................2048.9.4 Operating a Compost .......................................................................2048.9.5 Simple Thermophile Composting Procedure ..................................2048.9.6 Types of Composters .......................................................................2058.10 Utilization of Rice Bran – Stabilizer Design and Oil Extraction ..................2078.11 Bran – Stabilizer Design ...............................................................................2078.12 Oil Extraction ................................................................................................2078.12.1 Batch Extraction Method .................................................................208Bibliography .............................................................................................................208Chapter 9 Storage of Agro Products .........................................................................................2099.1 Principles of Storage ......................................................................................2099.2 Interactions of Physical, Chemical, and Biological Variables in theDeterioration of Stored Grains ...................................................................... 2119.3 Computer Simulation Modeling for Stored Grain Pest Management ........... 2129.4 Grain Storage Systems .................................................................................. 2139.4.1 Traditional Storage Systems ............................................................ 2139.4.2 Modern Storage Systems ................................................................. 2149.4.2.1 Bagged Storage System .................................................... 2149.4.2.2 Silo Storage System ......................................................... 2159.4.2.3 Airtight Grain Storage ..................................................... 2169.4.2.4 Aerated Storage System ................................................... 2189.4.2.5 Low-Temperature Storage System (Grain Chillingby Refrigeration) .............................................................. 2219.4.2.6 Controlled Atmosphere Storage Systems ........................2249.4.2.7 Damp Grain Storage System with Chemicals .................2269.5 Design of Grain Storages...............................................................................2289.5.1 Structural Requirements ..................................................................2289.5.2 Janssen’s Equation ...........................................................................2299.5.3 Rankine’s Equation.......................................................................... 2329.5.4 Airy’s Equation ................................................................................ 2339.5.5 Construction Materials ....................................................................236Key to Symbols ........................................................................................................240Exercises ................................................................................................................... 241Bibliography ............................................................................................................. 241Chapter 10 Heating and Cooling of Agro Products ....................................................................24510.1 Introduction ....................................................................................................24510.2 Heat Conduction ............................................................................................24610.2.1 The Differential Equation of Heat Conduction in Cartesianand Cylindrical Coordinate Systems ...............................................24610.2.1.1 The Differential Equation ofHeat Conduction in Cartesian Coordinate System ..........24610.2.1.2 The Differential Equation ofHeat Conduction in Cylindrical Coordinate System .......24810.2.2 The Composite Wall ........................................................................24910.2.3 Cylinder and Sphere ......................................................................... 25110.3 Convection ..................................................................................................... 25210.3.1 Forced Convection ........................................................................... 25210.3.2 Natural or Free Convection .............................................................. 25510.3.3 Heat Exchangers ..............................................................................25610.4 Radiation ........................................................................................................ 26110.4.1 Radiation Intensity and Shape Factor ..............................................26310.4.2 Radiation Exchange between Black Surfaces ..................................26410.4.3 Heat Exchange by Radiation between Gray Surfaces......................26510.5 Cooling ........................................................................................................... 26710.5.1 Cooling Rate .................................................................................... 26710.6 Freezing .........................................................................................................26910.6.1 Freezing Point Depression ...............................................................26910.7 Heating ........................................................................................................... 27110.7.1 Boiling-Point Elevation .................................................................... 272Key to Symbols ....................................................................................................... 275Exercises ................................................................................................................. 276Bibliography ............................................................................................................277Chapter 11 Refrigeration and Cold Storage ................................................................................ 27911.1 Introduction .................................................................................................... 27911.2 Vapor Compression Refrigeration Cycle .......................................................28011.3 Pressure–Enthalpy (p-h) Chart ......................................................................28011.3.1 Unit of Refrigeration ........................................................................ 28111.4 Refrigerants .................................................................................................... 28111.4.1 Desirable Characteristics of Refrigerants ........................................ 28111.5 Construction of Psychrometric Chart ............................................................28711.6 Moisture Control and Storage of Vegetables Crops ....................................... 29111.6.1 Potatoes ............................................................................................ 29111.6.1.1 Adequate Volume ............................................................. 29111.6.1.2 Adequate Strength ........................................................... 29111.6.1.3 Storage Environment .......................................................29211.6.1.4 Suberization Period ..........................................................29211.6.1.5 Short-Term Storage ..........................................................29211.6.1.6 Long-Term Storage ..........................................................29211.7 Cooling Requirement .....................................................................................293Exercises ...................................................................................................................297Bibliography .............................................................................................................298Chapter 12 Separation .................................................................................................................29912.1 Introduction ....................................................................................................29912.2 Contact Equilibrium Process .........................................................................29912.2.1 Absorption........................................................................................29912.2.2 Extraction .........................................................................................30012.2.2.1 Rate of Extraction ............................................................30012.2.2.2 Leaching .......................................................................... 30112.2.3 Distillation .......................................................................................30312.2.3.1 Vapor-Liquid Equilibrium ...............................................30312.2.3.2 Flash Vaporization ...........................................................30512.2.3.3 Batch Distillation .............................................................30612.2.3.4 Fractionation ....................................................................30712.2.3.5 Steam Distillation ............................................................ 31112.3 Mechanical Separation Process ..................................................................... 31212.3.1 Filtration ........................................................................................... 31212.3.2 Sedimentation .................................................................................. 31412.3.2.1 Sedimentation for Low Concentration Suspensions .......... 31412.3.2.2 Sedimentation for High Concentration Suspensions ......... 31512.3.3 Centrifugation .................................................................................. 31612.3.3.1 Rate Separation ................................................................ 31612.3.3.2 Liquid-Liquid Separation ................................................ 31712.3.3.3 Particle Gas Separation ................................................... 318Exercises ................................................................................................................... 319Bibliography ............................................................................................................. 319Chapter 13 Materials Handling and Conveying ......................................................................... 32113.1 Introduction .................................................................................................... 32113.2 Principles of Materials Handling ................................................................... 32213.3 Classification of Materials Handling Equipment ........................................... 32213.4 Belt Conveyors ............................................................................................... 32313.4.1 The Capacity of the Conveyor Belt Needed..................................... 32513.4.2 Belt Width ........................................................................................ 32513.4.3 Belt Speed ........................................................................................ 32613.4.4 Belt Tension ...................................................................................... 32613.4.5 Selection of Belt Carcass ................................................................. 32713.4.6 Selection of Driving and Other Pulleys ........................................... 32713.4.7 Motor Power ..................................................................................... 32713.4.8 Selection of Idlers ............................................................................ 32813.5 Chain Conveyors ............................................................................................ 32913.5.1 Trolley Chain Conveyor ................................................................... 32913.5.2 Scraper Chain Conveyor .................................................................. 33013.5.3 Apron Chain Conveyor .................................................................... 33013.6 Screw Conveyors ......................................................................................... 33113.6.1 Power Requirement for Screw Conveyors ..................................... 33213.7 Bucket Conveyors ........................................................................................ 33313.8 Pneumatic Conveyors .................................................................................. 33413.9 Hydraulic Conveyors ................................................................................... 33713.10 Gravity Conveyors ....................................................................................... 33813.11 Cranes.......................................................................................................... 33813.12 Lift and Carrying Trucks and Cart ............................................................. 33813.13 Robotic Handling System ........................................................................... 338Exercises ...................................................................................................................348Bibliography .............................................................................................................349Chapter 14 Process Dynamics and Control ................................................................................ 35114.1 Introduction ................................................................................................. 35114.2 Feedback Control Systems .......................................................................... 35114.3 Block Diagrams ........................................................................................... 35114.4 Dynamic Behavior of First- and Second-Order Systems ............................ 35214.4.1 First-Order System ........................................................................ 35214.4.2 Step Input ....................................................................................... 35314.4.3 Ramp Input .................................................................................... 35414.4.4 Sinusoidal Input ............................................................................. 35414.4.5 Second-Order System .................................................................... 35514.5 The Laplace Transform ............................................................................... 35614.6 Transfer Function ........................................................................................ 35814.6.1 Routh–Hurwitz Stability Criterion ................................................ 35914.7 Transient Response...................................................................................... 36114.7.1 Performance of Second-Order System .......................................... 36114.7.2 Performance Indices ...................................................................... 36214.8 Frequency Response .................................................................................... 36214.8.1 Bode Plot ....................................................................................... 36314.8.1.1 First-Order Process K(τs+1) ............................................... 36314.8.1.2 Integrating Process G(s) Ks= ........................................36414.8.1.3 Second-Order Process G(s) K2s2 2 s 1 = + □ + ........................36414.8.1.4 Process Zero s +1 ........................................................36514.8.1.5 Time Delay e−j- ...........................................................36614.8.1.6 Bode Stability Criterion ................................................ 36714.8.1.7 Gain Margin and Phase Margin ................................... 36714.8.2 Nyquist Criterion ...........................................................................36814.8.2.1 Gain Margin and Phase Margin ...................................36914.9 Frequency Response of Controllers ............................................................36914.9.1 Proportional Controller .................................................................36914.9.2 Proportional–Integral Controller ...................................................36914.9.3 Ideal Proportional–Derivative Controller...................................... 37014.9.4 Proportional–Derivative Controller with Filter ............................. 37014.9.5 Parallel PID Controller .................................................................. 37014.9.6 Series PID Controller .................................................................... 37114.9.7 Series PID Controller with a Derivative Filter .............................. 371Exercises ................................................................................................................... 373Bibliography ............................................................................................................. 374Chapter 15 Emerging Technologies ............................................................................................ 37515.1 Introduction .................................................................................................... 37515.2 Neural Network Modeling ............................................................................. 37515.2.1 Structure of ANN Model of a Dryer ................................................ 37615.2.2 Training of ANN Model .................................................................. 37715.3 Energy and Exergy Analysis of Drying Process ........................................... 37815.3.1 Drying Efficiency ............................................................................. 37815.3.2 Exergy Analysis through the Analysis of Second Lawof Thermodynamics ......................................................................... 37815.3.3 Exergy Calculation for Dryer ........................................................... 37915.4 Finite Element Modeling of Single Kernel ....................................................38015.5 Computational Fluid Dynamics (CFD) Modeling ......................................... 38515.5.1 CFD Model Formulation ................................................................. 38515.5.1.1 Continuity Equation ........................................................38615.5.1.2 Momentum Conservation Equations ............................... 38615.5.1.3 Energy Conservation Equation ........................................ 38615.5.1.4 User-Defined Function .....................................................38615.5.2 CFD Analysis ................................................................................... 38715.5.2.1 Preprocessing ................................................................... 38715.5.2.2 Processing ........................................................................ 38815.5.2.3 Post-processing ................................................................ 38815.6 Optimal Design Using Genetic Algorithm ....................................................39015.6.1 Optimal Design of Agro-Product Processing Systems ....................39015.6.2 Genetic Algorithm ...........................................................................39015.6.2.1 Basic Principles of Genetic Algorithm ............................ 39115.6.2.2 Fitness Function ............................................................... 39115.6.2.3 Genetic Algorithm Procedure for OptimalDrying Parameters ........................................................... 391Key to Symbols ........................................................................................................ 393Bibliography ............................................................................................................. 394Index ..............................................................................................................................................397