An Analysis of Drying Rate Mechanism in Complex Solids
In the falling rate period drying of solids, a new drying model which results in a linear partial differential equation is introduced. The main assumption of this model is that the capillary flow mechanism controls the liquid motion inside the solid body and evaporation takes place at the surface only. The analytical solution is possible by using Laplace Transformation technique for the simplified boundary conditions. The resultant drying equation reveals that the contribution of moisture concentration change due to convection is considerable besides the contribution of moisture concentration change due to diffusion. The applicability of this model is checked with the experimental data of coal and sunflower seed dried in a tunnel dryer. It is concluded that experimental results are in good aggreement with the theoretical values of coal. But in the case of sunflower seed, it is observed that the theory and experimental results do not aggree very well which is due to the complex structure of sunflower seeds.
KeywordsPermeability Porosity Hydrate Convection Mercury
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