Evolution and fluidization behaviors of wet agglomerates based on formation-fragmentation competition mechanism. (16th January 2022)

• Record Type: Journal Article
• Authors: Cheng, Jianan; Fan, Xiaoqiang; Sun, Jingyuan; Yang, Yao; Huang, Zhengliang; Wang, Jingdai; Yang, Yongrong
• Is Part Of: Chemical engineering science. Volume 247(2022)
• Publication Date: 2022-01-16
• Subjects: Fluidized bed -- Formation-fragmentation -- Competition mechanism -- Wet agglomeration evolution -- Liquid holdup; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2021.116933
• Languages: English
• ISSNs: 0009-2509

Abstract

Highlights: An agglomeration evolution model based on the formation-fragmentation competition mechanism was proposed. A simulation method of fluidization with wet agglomerates was proposed with the combination of particle agglomeration mechanism and EMMS model. The vertical solid velocity simulated by CFD was in good agreement with the PIV measurement results. The influence of different liquid holdup on the agglomeration and fluidization behaviors of wet agglomerates was explored.. Abstract: When the liquid is injected into a gas-solid fluidized bed, particles are easily wetted and prone to form liquid bridges among them, further leading to particle agglomeration. Wet particle agglomeration induced by liquid bridge is dynamic and unstable, and its evolution behavior affects the stable operation of fluidized bed reactor. Therefore, based on the formation-fragmentation competition mechanism, a wet agglomeration evolution model is proposed to predict the evolution characteristics of wet agglomerates under different conditions. Furthermore, a modified drag force model which attributed the effect of wet agglomerates into the drag force was established and applied to the CFD simulation of a fluidized bed with wet agglomerates under the liquid spray-evaporation equilibrium state. Meanwhile, the particle image velocimetry (PIV) technology is applied in this work, and it was found that the vertical solid velocity simulated by CFD is in good agreement with the PIV measurement results.