Abstract
The permeability of gaseous molecule through pores in the Knudsen region was numerically calculated by considering the geometrical arrangements and distances of the spheres in the packing model of simple cubic lattice type or hexagonal closest packing type of particles. The results of the theoretical calculations agreed approximately with those obtained by the Kundsen diffusion equation (eq. (14)) where a radius equivalent to the neck in pore (c. f. Table 3) was selected as an effective pore radius. These results showed that the diffusion in pores is con trolled by the neck. From the calculation of the diffusivity of the gaseous molecule with diameter a, the effect of molecular diameter on the permeability through these packing models of particles was found to be greater than that predicted through the cylindrical pores (c. f. Fig.5).
