Experimental Hydrodynamic Investigation of a Rotating Packed Bed with Different Packings

Rotating packed beds (RPBs) represent a key process intensification technology for enhancing gas–liquid mass transfer. This study presents a comprehensive hydrodynamic investigation of a fully transparent, laboratory-scale, counter-current RPB using an air–water system. Six rotor configurations were evaluated, including stainless-steel wire mesh, knitted mesh, and metal foam packings with different geometries. The dry pressure drop was successfully decoupled into centrifugal and frictional components, introducing geometry-specific centrifugal correction factors (ACH ranging from 0.56 to 2.20), and packing form factors (φ ranging from 0.13 to 0.73). Results showed that the denser metal foam rotor with shorter packing height exhibited the greatest frictional pressure drop. Furthermore, evaluating five nozzle configurations revealed that atomizing spray nozzles mitigate channeling, expanding the stable operating window by over 20–25% compared to mist nozzles. The hydraulic operating limits showed a strong dependence on rotational speed. Wet pressure drop was also investigated, with its magnitude shown to be strongly dependent on the liquid-to-gas ratio and the specific packing material. Finally, power consumption is modeled using a modified correlation that explicitly decouples nonlinear dry losses from liquid acceleration, fitting the experimental data with high accuracy (R2 > 0.99) while gas flow had negligible influence on power consumption.