AN INVESTIGATION OF THE BOUNDARY-CONDITIONS FOR A VACUUM DRYING PROBLEM - INTRODUCING THE TRANSITION LAYER CONCEPT

In this work a new derivation of the boundary conditions for a vacuum drying process is postulated. The theoretical and numerical investigat ions performed in this research reveal that a dynamic Transition Layer exists at the interface between the porous material and the vacuum ch amber. This hypothesis has been confirmed by the similar theory discus sed in several works devoted to freeze drying and, by using a simulati on package which performs fluid dynamic numerical simulations. A simul ation program of the one dimensional drying of wood is under developme nt in order to validate this research.