Novel concept for 3D-printed, baffled micro-fluidized beds for the regulation of bubble behavior and the suppression of solid back-mixing: Experiments and simulations

Abstract

In Micro-Fluidized Beds (MFBs), large bubbles (or slugs) and strong solid back-mixing might hinder good mixing, heat and mass transfer, while reducing conversion rates, and limiting selectivity in certain gas–solid reactions. In this study, a series of novel baffled MFBs were produced using 3D-printing. The influence of the number and position of baffles on the regulation of bubble performance and solid back-mixing in MFBs was investigated through fluidization experiments and Two-Fluid Model (TFM) simulations. The results show that the introduction of baffles effectively suppress slug formation and expand the bubbling regime. Baffles placed at mid-height disrupt fully developed slugs more effectively than those at the bottom. Increasing the number of baffles enhances bubble-breaking efficiency. Numerical simulations suggest that baffles positioned in the lower portion of the bed are more effective for the inhibition of global solid back-mixing. This study shed new light on the design and optimization of baffled MFBs.