Investigating the effect of food trays porosity on the drying process

Improving the dynamics of airflow behavior in the drying system is essential for improving its efficiency. In this study, the impact of the porosity of the plum-filled drying trays on the airflow behavior inside the chamber is investigated. Three configurations of constant porosity (30%, 50%, 70%), and 4 additional configurations of porosity varying linearly along trays 1 and 2 as a function of the x-axis are evaluated. To model the trays as a porous medium, the Power-low mathematical model was used, with the built-in parameters C₀ and C₁ were given experimentally. Both were formed as a subroutine in C++ and integrated into the CFD code, as was done for the integration of unsteady weather parameters. The CFD method used for visualizing and analyzing the airflow behavior in the drying chamber has been previously validated with the experimental result. The obtained results indicate that the average temperature of the drying trays reaches a maximum of 316,91 k at tray 1 for a porosity of 50% and an inlet velocity of 0.1 m/s. For the case of non-uniform trays porosity, it was found that for low air inlet velocity of 0.1 m/s, the velocity difference ΔV is generally low in cases (b) and (d), where it is equal respectively to 0.02 m/s and 0.01 m/s for tray 1, and 0.01 in both cases for tray 2. While for high air inlet velocity of 1 m/s the difference ΔV in both trays reaches 0.17 m/s.