MECHANISM OF MASS-TRANSFER IN THE ADSORPTION CONTACT DRYING OF MATERIALS

The mechanism of moisture transport in adsorption contact drying is st udied. It is shown that, when the moisture content is above the critic al value, the moisture is transferred both through the contact zone fi lled with the liquid phase condensed in capillaries and through the ga s phase. When the moisture content is below the critical value, the mo isture is only transferred through the gas phase. Equations to determi ne the critical moisture content, the effective section of a contact s ite, and the number of contacts between granules are obtained. A mathe matical model to describe the drying kinetics for rigid (strain-free) and deformable materials is proposed.