The characteristics of three-phase (gas-liquid-solid) circulating uidized beds (TPCFBs) are discussed in order to visualize the unique features and advantages thereof due to the intrinsic ow and contacting behaviors of multi-phases, providing a better understanding of the state of art of TPCFBs and their feasible applications as multi-phase reactors and contactors. The hydrodynamics such as individual phase holdups, bubbling ow behaviors, bubble properties and liquid phase dispersions, and heat and mass transfer characteristics in the riser were examined based on the previous investigations. (k L a), gas-liquid interfacial area (a) and liquid side mass transfer coe cient (k L ) were determined. The information on the heat and mass transfer, however, were extremely limited comparing with those of hydrodynamics. Some correlations were suggested to predict the hydrodynamic parameters, and the values of h, k L a, a, and k L in the riser of the TPCFBs to provide insights for the present and future studies. The mechanism of heat and mass transfer and their modeling should be conducted for the better prediction of the performance of the TPCFB-reactors and contactors in the future. Although the information in the riser of various kinds of TPCFBs deviated from each other depending on the solid circulation modes and experimental conditions, they were summarized and consociated for the elucidation of the present states and views of the investigations. Rational guides to predict the hydrodynamics and heat and mass transfer phenomena in the riser of the TPCFB were possible by analyzing and synthesizing the results reported in the literatures presently available. Especially, the e ects of operating variables including gas (U G ) and liquid (U L ) velocities, properties of uidized solid particles and continuous liquid media, and solid circulation rate (Gs) on the hydrodynamic parameters and the heat and mass transfer characteristics such as heat transfer coe cient (h) and resistance, volumetric mass transfer coe cient
− Effects of operating variables on the solid circulation rate were investigated in a three-phase circulating fluidized bed, of which inside diameter was 0.102m and height was 3.5m, respectively. Gas velocity, primary and secondary liquid velocities, particle size and height of solid particles piled up in the solid recycle device were chosen as operating variables. The solid circulation rate increased with increasing primary and secondary liquid velocities and height of solid particles piled up in the solid recycle device, but decreased with increasing particle size. The value of solid circulation rate decreased only slightly with increasing gas velocity in the riser. The values of solid circulation rate were well correlated in terms of dimensionless groups within the experimental conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.