Mass Transport by Surface and Pore Diffusion in Drying Processes

• Autorzy: Silva M. , Kerkof P. , Coumans J.
• Języki publikacji: EN

Abstrakty

EN

In this work the effective diffusivity of Won clay was obtained by considering the mass transfer mechanisms ocurring in the pores and on the surface. The binary friction model was used to evaluate the effective gas diffusivity and the Maxwell-Stefan approach to mass transfer was applied to the surface diffusion. Different expressions for the effective diffusivity for porous solids were used considering parallel diffusion, series diffusion and the Clausius-Mossoti model. Numerical results were compared with experimental data and showed that the Maxwell-Stefan approach, used earlier for surface diffusion in microporous solids, is also a strong tool for evaluating surface diffusion of absorbed species as bound water. In the pore diffusivity, when both present, capillary flow showed dominance over gas diffusion. The best results were obtained for the parallel model, considering the occurrence of discontinuous capillary flow.

Słowa kluczowe

EN

Knudsen diffusion; bulk diffusion; surface diffusion; bound water; Won Clay; Maxwell-Stefan approach

• Wydawca: Polska Akademia Nauk, Wydział IV Nauk Technicznych
• Czasopismo: Bulletin of the Polish Academy of Sciences. Technical Sciences
• Rocznik: 2000
• Tom: Vol. 48, nr 3
• Strony: 339--355
• Opis fizyczny: 12 rys., 3 tabele, bibliogr. 24 poz.

Twórcy

autor

Silva M.

autor

Kerkof P.

autor

Coumans J.

• Thermo Fluid Dynamics Department - FEQ - State University of Campinas (Unicamp), PO BOX 6066, 13081-970 CAMPINAS-SP, Brazil