Effect of magnetic field on the mesoscale structure evolution process in a wet particle fluidized bed

被引：0
作者：
Tang T. [1 ,2 ]
He Y. [1 ,2 ]
机构：
[1] School of Energy Science and Engineering, Harbin Institute of Technology, Heilongjiang, Harbin
[2] Heilongjiang Key Laboratory of New Energy Storage Materials and Processes, Harbin Institute of Technology, Heilongjiang, Harbin
来源：
Huagong Xuebao/CIESC Journal | 2022年 / 73卷 / 06期
关键词：
discrete element method; magnetic field; mesoscale structure; wet particle;
D O I：
10.11949/0438-1157.20220158
中图分类号：
学科分类号：
摘要：
Wet particle systems are very common in nature and industrial processes, such as spray granulation, mineral bonding in reactors, pharmaceutical and catalyst. Due to the presence of liquid, the flow, heat and mass transfer characteristics are significantly changed compared with dry particle systems. For example, a large number of typical mesoscale structures, including particle agglomeration, clusters and bubbles, form and lead to different flow regime. Thus, mesoscale structure flow and evolution behaviors have attracted more and more attention, which might affect the design and operation of industrial reactors. In this paper, typical mesoscale structures are investigated in a bubbling fluidized bed by discrete element method (DEM), and effect of external magnetic field on mesoscale structure evolution process is explored. First, the numerical model for describing dry and wet particle system flow behaviors were established with magnetic field introduced. The numerical model has been validated and shown in our previous published investigations. Then, mesoscale structure flow behaviors were analyzed in dry and wet particle system without magnetic flied. Bubble evolution process was found clearly in a dry particle system, and the trajectory of the bubble was almost along the midline of fluidized bed. With the cohesive liquid introduced, that of bubble center was offset from the midline. Next, an external magnetic field was introduced based on DEM to study the evolution mechanism of the mesoscale structure in the wet particle system under the action of the magnetic field. We compared the dominant role of liquid bridge force, contact force, magnetic force and drag force in fluidized beds, and tried to analyze and explore the relationship among different forces. The study found that without considering the magnetic field, particles are easy to form agglomeration and have irregular bubble boundaries. After the introduction of an external uniform magnetic field, the magnetic field force will destroy and inhibit the bubble structure in the bubbling fluidized bed. © 2022 Chemical Industry Press. All rights reserved.
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页码：2636 / 2648
页数：12
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