Influence of microstructures on liquid spreading on inclined plates: A CFD based study

• Flow analysis on microstructured inclined surfaces. • CFD study based on explicit geometrical reconstruction of the microstructures. • Proper microstructure design can drastically improve the column efficiency. • Orientation of microstructures has a strong influence on the liquid flow. Efficiency of separation columns strongly depends on the geometrical properties of column internals. The surface of structured packing is often covered by microstructures, as this is expected to enhance separation. Since the size of the interfacial area between the contacting fluids is a key factor for the separation efficiency, the influence of microstructures on the packing surface wetting has to be understood. In this work, several microstructures applied on inclined plates are studied by CFD methods to investigate their influence on the liquid spreading over the surface. Liquid flow rate and momentum as well as the size, shape and orientation of the microstructures are varied. Along with size and shape, especially the orientation of microstructures is found to have the strongest influence on the liquid flow pattern and the size of the wetted area. Therefore, a reasonable adjustment of the microstructure and its orientation can increase the interfacial area and hence the efficiency of the column.