Nashrieh Shimi va Mohandesi Shimi Iran

Nashrieh Shimi va Mohandesi Shimi Iran

CFD Simulation and Investigation of the Effect of Baffle Angle in the Drying Process of Gypsum Boards

Document Type : Research Article

Authors
Department of Chemical Engineering, Faculty of Chemical, Oil and Gas Engineering, Semnan University, Semnan, IR. IRAN
Abstract
For various reasons, including the improper structure of tunnel dryers, uniform drying does not occur in the panels, and there is a need to correct the flow structure in these dryers. Baffles are among the equipment that helps to improve the drying process by adding to the dryer structure. The purpose of this study is to attempt to identify a conceptual design to improve airflow for more uniform drying of gypsum panels. The effect of baffle angle and change in dryer geometry on pressure reduction, flow distribution and temperature distribution, and the moisture content of the body on the surface of the panels in the hot air chamber of the dryer was investigated using computational fluid dynamics. In this study, rectangular baffles with different angles were used to help the flow uniformity. The realizable k-ε model simulated turbulent flow with low Reynolds number modeling (LRNM) and wall function for the boundary layer region. A higher angle (90 degrees) increases the speed, mixing and airflow on the panel plates compared to the case with a baffle with a lower angle (30 degrees). The higher angle of the baffle also increased the amount of pressure (179%), the average velocity (150%), and the kinetic energy of the turbulence (11.5%) compared to the baffle mode with a lower flow angle. The lower angle baffle in this design also caused the amount of moisture and relative humidity on the surface (for the 90 degrees angle baffle =3.7952% and for the 30 degrees angle baffle =3.7828%). Still, the uniformity created in the humidity of this design was lower than the 90-degree angle. This study leads to the creation of knowledge about the effect of the baffle on various airflow parameters to improve the uniform moisture content of the product, which can lead to better optimization of drywall designs in future designs.
Keywords

Subjects


[1] Pabis S., Jayas D., Cenkowski S., Grain Drying: Theory and Practice. (1998).
[2] Law C.L., Tasirin S.M., Daud W.R,W., Geldart D., Effect of Vertical Baffles on Particle Mixing and Drying in Fluidized Beds of Group D Particles. China Particuology, 1(3): 115-118 (2003).
[3] Amanlou Y., Zomorodian A., Applying CFD for Designing a New Fruit Cabinet Dryer. Journal of Food Engineering, 101(1): 8-15 (2010).
[5] Böhner M., Barfuss I., Heindl A., Müller J., Improving the Airflow Distribution in a Multi-Belt Conveyor Dryer for Spice Plants by Modifications Based on Computational Fluid Dynamics. Biosystems Engineering, 115(3): 339-345 (2013).
[6] Chokphoemphun S., Pimsarn M., Thianpong C., Promvonge P., Heat Transfer Augmentation in a Circular Tube with Winglet Vortex Generators. Chinese Journal of Chemical Engineering, 23(4): 605-614 (2015).
[7] Zhang H., Deng S., Numerical Simulation of Moisture-Heat Coupling in Belt Dryer and Structure Optimization. Applied Thermal Engineering, 127: 292-301 (2017).
[8] Rezaei H., Lim C.J., Sokhansanj S., A Computational Approach to Determine the Residence Time Distribution of Biomass Particles in Rotary Drum Dryers. Chemical Engineering Science, 247: 116932 (2022).
[9] Afshari F., Khanlari A., Doğuş Tuncer A., Sözen A., Şahinkesen İ., Di Nicola G., Dehumidification of Sewage Sludge Using Quonset Solar Tunnel Dryer: An Experimental and Numerical Approach. Renewable Energy, 171: 784-798 (2021).
[10] Zannouni K., El Abrach H., Dhahri H., Mhimid A., Study of Heat and Mass Transfer of Water Evaporation in a Gypsum Board Subjected to Natural Convection. Heat and Mass Transfer, 53(6): 1911-1921 (2016).
[11] Hinze J.O., Uberoi M.S., Turbulence. Journal of Applied Mechanics, 27(3): 601-601 (1960).
[12] Thorpe G.R., The Application of Computational Fluid Dynamics Codes to Simulate Heat and Moisture Transfer in Stored Grains. Journal of Stored Products Research, 44(1): 21-31 (2008).
[13] Versteeg H.K. Malalasekera W., An Introduction to Computational Fluid Dynamics : The Finite Volume Method. 2nd ed. ed. 2007: Harlow.
[14] Defraeye T., Blocken B., Carmeliet J., An Adjusted Temperature Wall Function for Turbulent Forced Convective Heat Transfer for Bluff Bodies in the Atmospheric Boundary Layer. Building and Environment, 46(11): 2130-2141 (2011).
[15] Defraeye T., Houvenaghel G., Carmeliet J., Derome D., Numerical Analysis of Convective Drying of Gypsum Boards. International Journal of Heat and Mass Transfer, 55(9-10): 2590-2600 (2012).