Study On Gas Flow And Mass Transfer Characteristics Of Structured Packing Based On CFD

Mass transfer and flow resistance in structured packing determine the size of chemical equipments and energy consumption. If we modify the structured packing passage to improve mass transfer efficiency, it might result in higher flow resistance; if we reduce the flow resistance might result in the lower mass transfer efficiency. However, flow resistance and mass transfer efficiency are determined by tow different regions-main stream and boundary layer. So it’s the base theory to solve the problem.It is difficult to get flow detail in structured packing. The chromo-chemical reaction is taken to get the local mass transfer coefficients to complete the visualization over the surface of the corrugated wave passages without interfering the flow region.In the paper, we try to use the Computational Fluid Dynamic(CFD) to get flow and local mass transfer coefficients. One CFD model is developed to study mass transfer behavior in structured packing, which contains the low Reynolds number κ-ε model to simulate the turbulence flow behavior in the near wall region and surface reaction model to obtain mass transfer coefficient. The simulation results are verified from both experimental data and data published in the literature.Flow resistance in complex passages consists of frictional resistance in the wall region, resistance of bend flow and cross-flow resistance according to gas flow characteristics. Putting forward a partition between two pieces of corrugated wave passage is provided to reduce flow resistance of gas-gas intersection at the interface created between crossing gas flows. Mass transfer behavior and flow resistance characteristics of the new passage are studied with CFD approach. The contrast of these two passages is completed by comparison of the flow lines, local distribution of mass transfer coefficients, the average mass transfer coefficients and pressure drop. Comparison found that distribution of local mass transfer coefficients is more uniform after adding partitions, and the average mass transfer coefficient increases and pressure drop decreases to some extent.All of these jobs have provided a new and convenient method for studying other packing and exploring new kinds of packing.