CFD analysis of gas flow characteristics in a rotating packed bed with randomly arranged spherical packing

摘要

In recent years, some unit operations such as absorption and rectification in rotating packed beds (RPBs) have drawn great attention, and single-phase hydrodynamics characteristics became the basis to understand the multiphase flow and mass transfer process. In this work, the 3D steady-state gas flow in the RPB with randomly arranged spherical packing was investigated by computational fluid dynamics (CFD). The gas flow field and the effects of operational parameters were analyzed. Results showed that the errors between the simulated and the experimental data of the total pressure drop were within +/- 20%. The pressure drop of packing zone and tangential velocity increased with the increase of rotational speed, while the rising of the gas flow rate could result in the increase in the radial velocity, the pressure drop of the inner or outer cavity. The turbulent kinetic energy was predominantly affected by the tangential slip velocity, and the higher values of turbulent kinetic energy were illustrated near the outer edge of the rotor. Furthermore, a semi-empirical correlation based on the numerical simulation was proposed to predict the dry pressure drop of the packing zone combining the wall effect.