AN ANALYTICAL MODEL FOR MOISTURE DIFFUSION IN SOLID OBJECTS DURING DRYING

An analytical model is proposed to determine the moisture diffusivities in geometrical solid objects (namely, infinite slab, infinite cylinder, sphere) subjected to drying applications. The analysis for moisture diffusion is carried out on the basis of two important criteria: 0.1<Bi<100 and Bi>100. New correlations for the roots of the characteristic equations corresponding these objects are developed. For a drying application, Using the similarity between cooling and drying profiles, drying coefficient and lag factor are obtained. The model is then verified using available data from literature. Results show that the presented model can be used to determine the moisture diffusion coefficients in such solid objects in a simple and accurate manner in a variety of drying applications.