CFD MODELLING OF DRY PRESSURE DROP IN STRUCTURED PACKING

Abstract

In the present work the pressure drop in Flexipac lY, Sulz packing and newly proposed zigzag pattern packing predicted using commercial fluid dynamic software, FLUENT 6.3, ANSYS. The geometry was pre-processed and constructed using GAMBIT software, ANSYS. The dry pressure drop in the structured packing was predicted using different turbulence models and compared with the results reported in the literature. The different viscous models used to estimate dry pressure drop are laminar, realizable k-s, realizable k-c with pressure gradient effect and the SST k-a. It is observed that the present simulated predictions using realizable k-c model considering pressure gradient effects is in good agreement with the results reported in the literature. The prediction were analysed in terms of resistance factor (sir) versus Reynolds number for the comparison of different models and literature results. A new packing is developed to give the better efficiency as compared to the Sulz EX. It has been observed that the zigzag pattern structured packing resulted into small pressure drop as compared to the Sulz EX packing. Also the wall effects of the column with the zigzag patterned geometry are reduced, which is one of the reason that the pressure drop is less as compared to the other structured packings. The flow is developed only in the inner channels for the sulz packing while it is developed in the entire computational domain of the zigzag packing leading to the less pressure drop as compared to the sulz packing. Mixing is more in the zigzag packing as compared to sulz packing due to the zigzag orientation where the flow will experience maximum directional changes. The residence time of the fluid particles will be more in the zigzag packing resulting in the good mixing. The realizable k-c model considering pressure gradient effects is further extended for newly developed packing module for the future work in the CO2 absorption process