Verification of diffusion mathematical model for long-term materials drying

Abstract

The paper deals with a design of a diffusion mathematical model describing the drying processes for longlasting desiccation of dried substances prototypically shaped as plane, cylinder, and sphere. A decrease in the substance humidity shrinkage is derived from the result in deterministic model of desiccation. The long-term desiccation of the dried substances has been simulated on the basis of COMSOL MULTIPHYSICS programme and MAPLE, where initial and marginal conditions were defined. The functional program application in MATLAB has been created in order to draw a contrast among particular results obtained from the COMSOL programme.The application enables delineating the moisture extent in substances, 3D graph of moisture extent, and a decrease in the substance humidity degree. By means of the mentioned application, it is achievable to evaluate the results even in terms of changes in some of the set parameters. The shrinkage in substance moisture can be predicted in relation to suggested mathematical models. This fact has been confirmed bythe results of long-lasting desiccation of green coffee-beans in the warehouse.