Novel Liquid Distributor Concept for Rotating Packed Beds
Tobias Pyka, Manuel Brunert, Jörg Koop, André Bieberle, Christoph Held, Gerhard Schembecker
Abstract
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 n rot of the rotor. High-speed camera analyses showed that a minimum n rot 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 ( F G ) was set up to 2.3 Pa 0.5 and n rot 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 n rot ≥ 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.