Multiple-Pass Flow Mass Transfer in a Parallel-Plate Channel by inserting permeable Barriers for Improved Device Performance

摘要

A multi-pass alaminar counterflow mass exchange device is an open conduit divided into four subchannels with uniform wall concentration,by inserting three permeable barriers.Only the composition of the flow stream varies along the channels.The Sherwood numbers as well as the improvement of mass transfer efficiency have been investigated analytically by using an Engenfunction power series expansion.The device peformance results in multi-pass operatons are represented graphically and ocmpared withthose in a single-poass device(without permeable barriers inserted).Analytical results show that there exists a best permeable-barrier position when both themass transfer improvement and the increment of power consumptionare considered and thus can effectively enhance the mass transfer efficinecy compared with that of single-pass operations.