Novel Liquid Distributor Concept for Rotating Packed Beds

Multi-rotor RPBs (MR-RPBs) are a promising way to intensify mass transfer by exploiting the centrifugal field while achieving high separation performance. Reaching the full potential of the separation performance of MR-RPBs requires a uniform liquid distribution in each rotor. As conventional liquid distributors like nozzles can only be used at the pressurized inlet of the liquid, a new concept is needed for distribution on additional rotors. For this r eason, a novel liquid distribution concept named rotating baffle distributor (RBD) was developed. It has a compact design and exploits the rotational speed nrot of the rotor. High-speed camera analyses showed that a minimum nrot of 600 r min-1 was required for axial liquid distribution with water at ambient conditions. CT scans revealed a uniform liquid distribution in the circumferential direction using RBD with 36 baffles. Furthermore, RBDs with 12, 24, and 36 baffles were applied to the distillation of ethanol-water at atmospheric pressure under total reflux using a one-rotor RPB (1R-RPB). The F-factor (FG) was set up to 2.3 Pa0.5 and nrot up to 1200 r min-1. The results were compared to the same distillation experiment in the 1R-RPB using the conventional liquid distribution, i.e., spraying the liquid on the packing via a full-jet nozzle. The distillation study revealed that the RBD with 36 baffles showed one theoretical stage higher separation performance at nrot >= 900 r min-1 compared to the conventional liquid distribution. Those results suggest that the RBD is not only multi-rotor-compatible but also provides uniform liquid distribution while being easier to adjust and operate than the conventional nozzle setup.