1971 Volume 4 Issue 4 Pages 336-339
Liquid film coefficients of mass transfer have been measured for dilute packed beds of irregular (εf=0.392) or regular (εf =0.313) packing, applying the diffusion current method. The data obtained show clearly the transition from the region of molecular diffusion controlling to that of concentration boundary layer controlling, both in Stokes flow.
With increasing flow rate of fluid from zero velocity, the film coefficient starts to transfer from the region of molecular diffusion controlling at Pe*pe≈ 20 for both gas and liquid systems. The transition ends at Re*h ≈ 20 for gas systems, and at Peh ≈ 20 for liquid systems.
Mass transfer behaviour is approximately expressed as follows for the region of molecular diffusion controlling under Stokes flow: