Modeling coupled transport phenomena and mechanical deformation of shrimp during drying in a jet spouted bed dryer

Heat and mass transfer in highly shrinkable and irregular-shape biomaterials such as shrimp during convective drying represents a complicated phenomenon since it is important to consider not only the transport phenomena occurring during drying but also the various changes of the drying materials. In order to describe drying of biomaterials adequately, a mathematical model that considers both of the above-mentioned aspects is needed. In this study, the formulation and validation of a mathematical model describing coupled transport phenomena and mechanical deformation of shrimp undergoing drying in a representative convective dryer, i.e., a jet spouted bed dryer, was conducted. The model consists of coupled heat conduction and mass diffusion equations along with the elastic solid mechanics equations. Governing equations and initial as well as boundary conditions were solved numerically using a finite element method via COMSOL Multiphysics (TM) Software (version 3.3a). The simulated results, in terms of the shrimp moisture content, mid-layer temperature and shrinkage, were compared with the experimental results also obtained in this study and good agreement between the theoretical simulation and experimental results was observed in general. The model was also used to predict the principal stress distributions within shrimp during drying. Moreover, the effect of including deformation in the model was also illustrated by comparing the simulated results with those obtained from the model assuming no deformation. (c) 2008 Elsevier Ltd. All rights reserved.