A Simulation Study of Drying Kinetics for a Natural Rubber Sheet by Convective Drying

Abstract

In this work, the drying equipments used convective flow, and the heat source is liquid petroleum gas (LPG). Inside the drying chamber, five samples of natural rubber sheets were used. The weight and temperature were controlled by two spring balances and thermocouples, respectively. The controlled temperatures inside the drying chamber for this study are 40, 50, and 60◦C, The experimental data were fitted by using different empirical mathematical models for finding an important parameter named the effective diffusion coefficients at each control temperature. After that a 2D finite elements method (FEM) simulation of drying kinetics with convective drying for a natural rubber sheet was performed. The simulation results fit and predict experimental results well, for moisture ratio of dried natural rubber sheets. However, in the case of temperature, the simulation results have instability in the first period of drying times 0-10 hr, due to the rapidly decreasing moisture ratio in this period. Then, the simulation results go to a steady state. They fit the experimental results well.

Keywords: Natural rubber sheet drying; Convective drying; and Drying kinetics.