Improvement in performance of double-flow laminar countercurrent mass exchangers

A laminar counterflow mass exchange device is an open duct divided into two subchannels of uniform wall concentration by inserting a permeable barrier , in which only the composition of the flow stream varies along the channel s. Efficiency improvement in mass transfer has been investigated analytical ly by using an eigenfunction expansion in power series. The results of enhancement in mass-transfer efficiency are represented grap hically and compared with those in a single-flow device (without a permeabl e barrier inserted). Analytical results show that suitable adjustment of th e permeable-barrier position can effectively enhance the mass transfer effi ciency compared with the efficiency in single-flow operations.