A mathematical model for moisture movement during continous and intermittent drying of Eucalyptus saligna

Abstract

A modified diffusion-based mathematical model is proposed to describe the moisture movement during continuous and intermittent drying of Eucalyptus saligna. This model includes the temperature change, the surface drying coefficient (β _n ) and 2 diffusion coefficients [from green to FSP (D _f ) and from FSP to dry condition (D _o )] as important parameters. The final model expression obtained was M = exp (− 25 β _n ² D _t /l²) with the β _n used was 1.5807 kg m⁻² s⁻¹, the D _f was 2.26 × 10⁻¹¹ m² s⁻¹, and the D _o was 5.85 × 10⁻¹² m² s⁻¹. The range of temperature change between heating and non-heating phases in the intermittent drying regimes was from 24.9 to 31.8 °C. The R² values obtained when the model was fitted into the drying data of different intermittent regimes ranged from 71.5 to 85.9%. The R² value was 87.4% when the model was fitted into continuous trial data. The high values of R² indicate that the model can be used to understand the moisture reduction both in intermittent and continuous regimes.