Pore Structure and Diffusibility in Packed Bodies of Fine Particles

Abstract

In this investigation, the pore structure and the tortuosity factors with respect to gas flow and diffusion were studied for glass bead sintered pellets (GB) and several practical porous materials.
The above three characterizing properties were measured by a marcury penetration method, a permeation method and a Wicke-Kallenbach type diffusion apparatus.
The obtained results are as follows:
(1) On the basis of Parallel Pore Model, the effective diffusion coefficient D_e for a practical porous material can be estimated well from both the pore diameter and the tortuosity factor τ_D of 2.35 obtained for GB.
(2) The difference between τ_F and τ_D seems to be attributable to the difference in each effective pore space for flow and diffusion.