Two-Dimensional Mathematical Modeling of Heat and Mass Transfer in Fluidized-Bed Drying of Porous Material

Abstract

A two-dimensional mathematical model of simultaneous heat and mass transfer for porous media drying was derived based on the Whitaker's theory in the present study. The cylindrical coordinate system, which is more practical than the spherical one, was adopted. The model was solved numerically under the circumstance of fluidized-bed drying. The control-volume method with the fully implicit scheme was applied for discretization of governing equations. Physical properties of apple were selected in the simulation. Under typical operating conditions, heat and mass transfer mechanisms were analyzed based on the profiles of temperature and saturation inside the particles. Effects of the temperature, humidity and inlet velocity of hot gas were examined under different operating conditions. Simulation results show that the drying process can be significantly affected by coupled heat and mass transfer between gas and solid phases. The drying time increases with the increase in temperature and velocity of inlet hot gas, and decreases with the increase in humidity and bed area factor.

Heat and Mass Transfer for a Nanofluid Flow in Fluidized Bed Dryer in Presence of Induced Magnetic Field

“…Based on their findings, they noted that the mean air velocity was minimum on the bed of the dryer's wall and highest at the center of the dryer. Furthermore, [6]'s study agrees with our findings that drying process in fluidized bed dryer is influenced by the coupled heat and mass transfer processes occurring in a fluidized bed dryer between fluid and solid particles and this process can be significantly improved by increasing dryer's temperature and inlet gas velocity.…”

“…Nevertheless, the authors determined that the CFD-DEM model was successful in forecasting the minimum fluidization velocity, and the data obtained from the investigation was advantageous in designing and improving fluidized bed dryers. A study by [6] focused on a 2D mathematical model to simulate simultaneous heat and mass transfer during porous media drying, using Whitaker's theory. The model was based on cylindrical coordinates, which were deemed more practical than spherical coordinates.…”