ABSTRACT
Mass transfer through a flat sheet boundary can be described with the Fick equation. A rectangular coordinate system (x, y , z) is chosen; x is defined in the direction perpendicular to the flat sheet. If convection is absent and concentration differences in the y and z direction are absent, the Fick equation becomes:
1 iJx (mol m2 S-l) 11.la
in which F{I ID i C i
molar flux of component i diffusion coefficient of i concentration of i
(mol m-2 s-l) (m2 S-l)
The mass transfer through a sheet with surface a and thickness dx can be determined from a microbalance. It is assumed that the y and z dependencies can be neglected.
