Flow Distribution and Mass Transfer in a Parallel Microchannel Contactor Integrated with Constructal Distributors
Résumé
Flow distribution and mass transfer characteristics during CO2-water flow through a parallel microchannel contactor integrated with two constructal distributors have been investigated numerically and experimentally. Each distributor comprises a dichotomic tree structure that feeds 16 microchannels with hydraulic diameters of 667 lm. It was found that constructal distributors could ensure a nearly uniform gas–liquid distribution at high gas flow rates where the ideal flow pattern was slug-annular flow. Nevertheless, at small gas flow rates where the ideal flow pattern was slug flow, a significant flow maldistribution occurred primarily due to the lack of large pressure barrier inside each distributor, indicating that dynamic pressure fluctuation in parallel microchannels greatly disturbed an otherwise good flow distribution therein. It was further shown that the present parallel microchannel contactor could realize the desired mass transfer performance previously achieved in one single microchannel under relatively wide operational ranges due to the integration of constructal distributors. VVC 2009 American Institute of Chemical Engineers AIChE J, 56: 298–317, 2010 Keywords: microchannel, numbering-up, flow distribution, gas–liquid mass transfer, constructal theory