doiSerbia

Modeling of intermittent convective drying of walnuts in single layer and its influence on deep bed drying simulation

Doder Đorđije D. (Department of Energy and Process Engineering, Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia )
Đaković Damir D (Department of Energy and Process Engineering, Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia )

This research concerns the convective intermittent drying of in-shell walnuts, as well as the comparison between intermittent and continuous regimes. The collected data from the continuous drying experiment served as the basis for the modeling of intermittent drying, where the kinetic semi-theoretical model was implemented. Mathematical model for the intermittent drying precedes the computer simulation and experimental procedure for a single layer. As the validity of the proposed model is confirmed, deep fixed bed drying simulation was included as well. Intermittent drying regimes with shorter tempering periods gave better results compared to the longer ones. Deep bed simulations showed that a fixed bed of walnuts should not be bigger than 15-20 cm.

Keywords: intermittent drying, walnuts, modeling, heat and mass transfer