Theoretical Fundamentals of Drying Operation

Throughout the author's research on “Drying Theory”, emphasis has been placed on the observation of phenomena. Regarding the simultaneous transport of mass (water and water vapor)-heat-momentum during drying. it is represented by “drying basic equations” which take the form of simultaneous differential equations, while the mass transport flux within the material and the accompanying water distribution within the material are represented by “drying equations” which take the form of Fick's law of diffusion. To solve these interconnected equations, models for the structure of the solid material and for the Copyright 8 1996 hy Marcel Dekker. Inc. transport of water vapor are set up, and efforts are devoted to the generalization of the values of transport properties contained in the models. For the cases in which it is necessary to rely on particular values of the material, full attempt is made to not obtain these values from drying experiments but simply from small-scalephysico-chemical experiments. Finally the applicability of the models is substantiated by comparing the mathematical solutions thus obtained with experimental results.