Computational Fluid Dynamics Analysis in a Corn Air Flow Paddy Dryer with Two Types of Passing Air Flow of Lateral and Central Pattern

Document Type : Research Paper

Authors

1 Department of Agricultural Engineering Research, Fars Research and Education Center for Agriculture and Natural Resources, Agricultural Research, Education and Extension Organization (AREEO), Shiraz, P.O. Box:71555-617, Iran

2 Graduated Student, Engineering College, Bafgh Branch, Islamic Azad University, Bafgh, Iran

3 Agricultural Engineering Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran

Abstract

Drying process is not uniform in the common rice dryers (batch type dryers). In order to decrease this problem, two types of passing hot air dryer consisted of the lateral and central patterns has been defined and method of air distribution in the rice porous media modeled by Fluent software in transient condition. In the lateral pattern, air enters through the side walls of the dryer chamber and in the central pattern, air enters through the central channel of the dryer chamber. The air temperature is 40 oc and air flow rate is 550 m3/h in all models. The results of simulation illustrate, the air flows more rapidly in the central pattern and penetrates into all parts of the dryer chamber. There is not any central passing air channel in the lateral pattern so, it caused to produce an irregular temperature field with high distortion. Models were verified in steady state condition. Results show the final temperature of model was near the measured data with 2% deviation.

Keywords

Main Subjects


Achenbach, E., (1995). Heat and flow characteristics in packed beds. Experimental Thermal and Fluid Science. 10:17-21.
Aghkhani, M.H., Abbaspourfard, M.H., Bayati, M.R., Mortezapour, H., Saedi, S.I. and Moghimi, A. (2013). Review of the solar dryer operating equipped by a recirculation air flow system and a moisture absorbent chamber. Journal of Agricultural Machinery. 3 (2): 92-103. (In Farsi).
Aubin, J., Fletcher, D. F. and Xuereb, C. (2004). Modeling turbulent flow in stirred tanks with CFD: The influence of the modeling approach, turbulence model and numerical scheme. Experimental Thermal and Fluid Science. 28: 431–445.
Chen, C.K., Hung, C.I. and Horng, H.C. (1987). Transient Natural Convection on a Vertical Flat Plate Embedded in a High-Porosity Medium. Journal of Energy Resources Technology, 109 (3): 112-118.
Farokhfar, P. (2007). CFD analysis in a fluidized bed dryer- PVC unit. Thesis report. Isfahan University of Technology. (In Farsi).
Fosberg, J. (2011). Geometry development of the internal duct system of a heat pump tumble dryer based on fluid mechanic parameters from a CFD software. Applied Energy, 1956-1605.
Fu, X., Viskanta, R. and Gore, J.P. (1998). Measurement and correlation of volumetric heat transfer coefficients of cellular ceramics. Experimental Thermal and Fluid Science. 17: 285-293.
Hsu, P.F., Hoewll, J.R. and Mettews, R.D. (1993). A numerical investigation of premixed combustion within porous inert media. ASME Journal of Heat Transfer, 115: 744-750.
Jahanian, R. (2016). Optimization of air channel conditions in conventional paddy dryer using fluid dynamics flow. Thesis report. Islamic Azad University, Bafgh Branch. (In Farsi).
Jambhekar, V.A. (2011). Forchheimer Porous-media Flow Models - Numerical Investigation and Comparison with Experimental Data. Thesis report. University of Stuttgart.
Kanani, H., Shams, M. and Ebrahimi, R. (2006). Numerical simulation of flow in a U- shape dryer. 14th Annual Conference of Mechanical Engineering, Isfahan University of Technology. (In Farsi).
Kazemi, F. (2016). Numerical Modeling of Airflow in a Cabinet Dryer and Determination the Effect of Using Air Deflector Plates on Airflow Pattern and Drying Rate in the Dryer Chamber. Thesis report. Islamic Azad University, Bafgh Branch. (In Farsi).
Kothandaraman, C.P. and Subramanyan, S. (1989). Heat and Mass Transfer Data Book. 4th Edn, New Delhi, India.
Macdonald, L.F., EL-Sayed, M.S., Mow, K. and Dullien, F.A.L. (1979). Flow through porous media-the Ergun equation revisited. Industrial Engineering Chemical Fundamental, 18(3): 199-208.
Mirade, P.S. (2006). Prediction of the air velocity field in modern meat dryers using unsteady computational fluid dynamics (CFD) models. Journal of Food Engineering, 60: 41–48.
Mohsenin, N. (1980). Thermal Properties of Foods and Agricultural Materials. Gordon and Breach, Science Publishers Ins. One Park Avenue New York, NY10016.
Mozaffari, K. (2013). Numerical modeling of air flow in the chamber of an active solar dryer in order to flow optimization by using some elements in the dryer chamber. Thesis report. Islamic Azad University, Shiraz Branch. (In Farsi).
Mujumdar, A.S. (2000). Drying Technology in Agriculture and Food Sciences; Science Publishers: Enfield, NH.
Patankar, S.V. (1994). Numerical Heat Transfer and Fluid Flow. Translated by: Esmailzadeh, E., Tabriz University, Iran.
Roustapour, O.R., Hosseinalipour, M., Ghobadian, B., Mohaghegh, F. and Maftoon-Azad, N. (2009). A proposed numerical-experimental method for drying kinetics in a spray dryer. Journal of Food Engineering, 90(1): 20-26.
Roustapour, O.R., Mozaffari, K. and Tahhavor, A.R. (2014). Optimization of energy consumption in a solar dryer by numerical modeling of flow in the chamber with air deflectors. Journal of Agricultural Machinery Science, 10 (1): 43-47.
Niven, R.K. (2002). Physical insight into the Ergun and Wen & Yu equations for fluid flow in packed and fluidized beds. Chemical Engineering Science, 57: 527–534.
Zhang, H.Y. and Huang, X.Y. (2000). Volumetric heat transfer coefficients in solid–fluid porous media: closure problem, thermal analysis and model improvement with fluid flow. International Journal of Heat and Mass Transfer, 43 (18): 3417-3432.