Intermittent Drying of Soybeans in Conical Spouted Beds: Modeling Approach

Abstract

Intermittent drying is a promising methodology to conventional drying which offers benefits related to energy and better-quality products. However, modeling of this technique remains a challenge. Thus, this study aims to propose a fully predictive model for intermittent drying in conical spouted bed dryers. A single-phase model is used to account for the heat and mass transfer on the soybean surface and their inside, and the predictions are compared with the experimental results. The proposed model provides physically consistent results and is coherent with the experimental data, mainly for drying under moderate air temperatures with moderate and long resting periods. As the average moisture content and the average particle temperature are estimated based on the spatial discretization used in the numerical solution, as well as on the boundary conditions adopted, the internal gradients of moisture and temperature are also estimated by the model, thus providing a physically consistent representation of the internal gradient behavior. Therefore, this study describes the successful application of an accurate model for continuous and intermittent drying. Accordingly, it contributes to obtain optimal drying parameters in order to minimize drying costs and improve product quality.