Abstract
Experiments were made using imperfect pulses at low Reynolds numbers to study mass transfer behaviour in packed beds. Two types of measurements were devised: those using non-porous particles coated with a thin liquid film of methyl silicone, and those using porous alumina particles. With the non-porous particles, a series of runs at Reynolds numbers ranging from about 0.025 to 0.25 gives conclusive evidence of a limiting Sherwood number of about 2. With the porous particles, mass transfer coefficients could not be measured. An effective diffusivity was measured, but its dependence on velocity in the bed at low Reynolds numbers suggests that the Kubin-Kucera model may be an inadequate description of the bed under these conditions.
