1Department of Agrotechnology, College of Abouraihan, University of Tehran, Pakdasht, I.R. IRAN
2Department of Chemical Engineering, Tarbiat Modares University, Tehran, I.R. IRAN
3Department of Agricultural Machinery Engineering, Faculty of Agriculture Engineering and Technology, University of Tehran, Karaj, I.R. IRAN
Computational Fluid Dynamics (CFD) is a computational technology that enables researchers to study the dynamics of things that flow. By using CFD, it is possible to build a computational model that represents a system under study. It not only predicts fluid flow behavior, but also the transfer of heat, mass, phase change, chemical reaction, mechanical movement, and stress or deformation of related solid. In this study, hydrodynamics behavior of a laboratorial fluidized bed dryer containing carrot cubes as well as heat transfer in the dryer was simulated using CFD. In addition, to understand the energy utilization the system was optimized using the Taguchi technique. Simulations were planned based on L9 orthogonal array of Taguchi, and they were conducted at inlet air temperatures 50, 60 and 70 ºC, bed depths 3, 6 and 9 cm and carrot cube dimensions 4, 7 and 10 mm. Results show that cube size and bed depth have the maximum and minimum contribution on the energy utilization ratio, respectively. According to the results inlet air temperature 70°C, cube size 4mm and bed depth 9cm were obtained as optimum conditions. Finally, a verification test was performed to confirm the validity of the used statistical method.
 Sumnu G., Turabi E., Oztop M., Drying of Carrots in Microwave and Halogen Lamp Microwave Combination Ovens, Lebensmittel Wisst- Food Science and Technology, 38, p. 549 (2005).
 Kaya A., Aydın O., Demirtas C., Experimental and Theoretical Analysis of Drying Carrots, Desalination, 237, p. 285 (2009).
 Hatamipour M.S., Mowla D., Shrinkage of Carrots During Drying in an Inert Medium Fluidized Bed, Journal of Food Engineering, 55, p. 247 (2002).
 Bialobrzewski I., Zielinska M., Mujumdar A.S., Markowski M., Heat and Mass Transfer During Drying of a Bed of Shrinking Particles Simulation for Carrot Cubes Dried in a Spout-Fluidized-Bed Drier, International Journal of Heat and Mass Transfer, 51, p. 4704 (2008).
 Mujumdar A.S., "Hand Book of Industrial Drying", 3rdEd, Marcel Dekker, New York (2006).
 Syahrul S., Hamdullahpur F., Dincer I., Exergy Analysis of Fluidized Bed Drying of Moist Particles, Exergy, an International Journal, 2, p. 87 (2002).
 Tiza C., Liasakis G., "Extraction Optimization in Food Engineering", Marcel Dekker, New York (2003).
 Simpson R., Almonacid S., López D., Abakarov A., Optimum Design and Operating Conditions of Multiple Effect Evaporators: Tomato Paste, Journal of Food Engineering, 89, p. 488 (2008).
 Taguchi G., Yokoyama Y., Wu Y., "Taguchi Methods/Design of Experiments", American Supplier Institute (ASI) Press, Tokyo, Japan (1993).
 Mousavi S.M., Jafari A., Chegini S., Turunen I., CFD Simulation of Mass Transfer and Flow Behaviour Around a Single Particle in Bioleaching Process, Process Biochemistry, 44, p. 696 (2009).
 Jafari A., Zamankhan P., Mousavi S.M., Pietarinen K., Modeling and CFD Simulation of Flow Behavior and Dispersivity Through Randomly Packed Bed Reactors, Chemical Engineering Journal, 144, p. 476 (2008).
 Semnani Rahbar M., Alizadeh Dakhel A., Pressure Drop Prediction in Fluidized Bed Dryer of Sodium Perborate Using Computational Fluid Dynamics, Iran. J. Chem. Chem. Eng., 28 (2), p. 33 (2009).
 Gorji M., Bozorgmehry Bozzarjomehry R., Kazemeini M., CFD Modeling of Gas-Liquid Hydrodynamics in a Stirred Tank Reactor, Iran. J. Chem. Chem. Eng., 26 (2), p. 85 (2007).
 Irani M., Bozorgmehry Boozarjomehry R., Pishvaie S.M.R., Investigating the Effects of Mass Transfer and Mixture Non-Ideality on Multiphase Flow Hydrodynamics Using CFD Methods, Iran. J. Chem. Chem. Eng., 29 (1), p. 51 (2010).
 Alamprese C., Datei L., Semeraro Q., Optimization of Processing Parameters of a Ball Mill Refiner for Chocolate, Journal of Food Engineering, 83, p. 629 (2007).
 Corzo O., Bracho N., Va´squez A., Pereira A., Optimization of a Thin Layer Drying Process for Coroba Slices, Journal of Food Engineering, 85, p. 372 (2008).
 Erbay Z., Icier F., Optimization of Hot Air Drying of Olive Leaves Using Response Surface, Journal of Food Engineering, 91 (4), p. 533 (2009).
 Hodali R., Bougard J., Integration of Desiccant Unit in Crops Solar Drying Installation: Optimization by Numerical Simulation, Energy Conversion and Management, 42, p. 1543 (2001).
 Oztop M.H., Sahin S., Sumnu G., Optimization of Microwave Frying of Potato Slices by Using Taguchi Technique, Journal of Food Engineering, 79, p. 83 (2007).
 SrinivasaRao P., Bal B., Goswami T.K., Modelling and Optimization of Drying Variables in Thin Layer Drying of Parboiled Paddy, Journal of Food Engineering, 78, p. 480 (2007).
 Souza J.S., Medeiros M.F.D., Magalha˜es M.M.A., Rodrigues S., Fernandes, F.A.N., Optimization of Osmotic Dehydration of Tomatoes in a Ternary System Followed by Air-Drying, Journal of Food Engineering, 83, p. 501 (2007).
 Tasirin S.M., Kamarudin S.K., Ghani J.A., Lee K.F., Optimization of Drying Parameters of Bird’s Eye Chilli in a Fluidized Bed Dryer, Journal of Food Engineering, 80, p. 695 (2007).
 Uysal N., Sumnu G., Sahin S., Optimization of Microwave-Infrared Roasting of Hazelnut, Journal of Food Engineering, 90 (2), p. 255 (2009).
 Volpato G., Michielin E.M.Z., Ferreira S.R.S., Petrus JCC, Optimization of the Chicken Breast Cooking Process, Journal of Food Engineering, 84, p. 576 (2008).
 Zomorodian A., Zare D., Ghasemkhani H., Optimization and Evaluation of a Semi Continuous Solar Dryer for Cereals (Rice, etc), Desalination, 209, p. 129 (2007).
 Aghbashlo M., Kianmehr M.H., Arabhosseini A., Energy and Exergy Analyses of Thin Layer Drying of Potato Slices in a Semi-Industrial Continuous Band Dryer, Drying Technology, 26, p. 1501 (2008).
 Syahrul S., Dincer I., Hamdullahpur F., Thermodynamic Modeling of Fluidized Bed Drying of Moist Particles, International Journal of Thermal Sciences, 42, p. 691 (2003).
 Ceylan I., Aktas M., Dogan H., Energy and Exergy Analysis of Timber Dryer Assisted Heat Pump, Applied Thermal Engineering, 27, p. 216 (2007).
 Corzo O., Bracho N., Vasquez A., Pereira A., Energy and Exergy Analyses of Thin Layer Drying of Coroba Slices, Journal of Food Engineering, 86, p. 151 (2008).
 Topic R, Mathematical Model for Exergy Analysis of Drying Plants, Drying Technology, 13 (1-2),p. 437 (1995).
 Akpinar E.K., Energy and Exergy Analyses of Drying of Red Pepper Slices in Convective Type Dryer, International Journal of Heat and Mass Transfer, 31 (8), p. 1165 (2004).
 Akpinar E.K., Midilli A., Bicer Y., Energy and Exergy of Carrots Drying Process via Cyclone Type Dryer, Energy Conversion and Management, 46 (15/16), p. 2530 (2005).
 Akpinar E.K., Midilli A., Bicer Y., The First and Second Law Analyses of Thermodynamic of Pumpkin Drying Process, Journal of Food Engineering, 72 (4), p. 320 (2006).
 Nazghelichi T., Kianmehr M.H., Aghbashlo M., Thermodynamics Analysis of Fluidized Bed Drying of Carrot Cubes, Energy, 35 (12), p. 4679 (2010).