Numerical investigation of the particle circulation characteristics in a tapered fluidized bed
Numerical investigation of the particle circulation characteristics in a tapered fluidized bed
复制标题
锥形流化床颗粒循环特性的数值研究
DOI：
10.1108/ec-01-2022-0001
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发表时间：
2022-10
影响因子：
1.6
通讯作者：
Tang Chen
中科院分区：
文献类型：
--
作者：
Hanqiao Che;Tang Chen
研究目的探讨流化床内颗粒循环的几个问题，包括颗粒循环时间的量化方法，不同操作参数对颗粒循环时间的影响，以及颗粒混合和颗粒循环之间的关系。设计/方法/途径计算流体动力学与离散元法耦合（CFD-DEM）研究了锥形流化床的颗粒循环特性。提出了一种考虑颗粒水平运动的颗粒循环量的计算方法，并对颗粒循环时间进行了估算，结果表明，提高气流速度和壁面倾角可以加速颗粒循环，而颗粒粒径的增大和颗粒间凝聚力的增大则会减缓颗粒循环;空气分配器的中心区域的开口面积比的增加将使颗粒循环减速。此外，颗粒循环时间和混合速率是独立的变量，从不同的角度描述的颗粒的流动动力学。实际implicationsA大部分的流化床在工业应用中可以归类为TFB。本研究提出了一种数值方法来获得有关TFB中颗粒循环的详细信息，这对于相关过程的设计、优化和控制至关重要。独创性/价值TFB中的颗粒循环很重要，但很少研究，而且很难使用现有的实验方法进行量化。建议的数值工作流程揭示了颗粒循环的特点，从颗粒尺度的角度来看。
PurposeThe objective of this study is to investigate several issues related to particle circulation within the TFB, including exploring an appropriate method to quantify particle circulation time, the effects of different operational parameters on particle circulation time, and the relationship between particle mixing and particle circulation.Design/methodology/approachThe computational fluid dynamics coupled with the discrete element method (CFD-DEM) is applied to investigate the particle circulation characteristics of a tapered fluidized bed (TFB). An approach for defining particle circulation, which accounts for the horizontal motion of each particle, is proposed to estimate particle circulation time.FindingsIt is found that the overall particle circulation in a TFB could be accelerated by increasing air velocity and wall inclination angle, while an increase in particle size and an increase in inter-particle cohesive forces decelerate particle circulation; the increase in the open area ratio of the central region of the air distributor would decelerate the particle circulation. Moreover, the particle circulation time and mixing rate are independent variables that describe the flow dynamics of particles from different perspectives.Practical implicationsA large part of fluidized beds in industrial applications can be classified as TFB. This study presents a numerical method to obtain detailed knowledge about particle circulation in a TFB, which is essential for the design, optimization, and control of related processes.Originality/valueThe particle circulation in a TFB is important but rarely investigated, and it is hard to be quantified using existing experimental approaches. The proposed numerical workflow reveals the characteristics of particle circulation from a particle-scale perspective.
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影响因子：
3
作者：
W. Lang;S. Sokhansanj
通讯作者：
W. Lang;S. Sokhansanj
影响因子：
3.3
作者：
Huolong Liu;Seongkyu Yoon;Mingzhong Li
通讯作者：
Huolong Liu;Seongkyu Yoon;Mingzhong Li
影响因子：
3.7
作者：
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通讯作者：
Zongyan Zhou;S. Kuang;Kaiwei Chu;A. Yu
影响因子：
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作者：
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通讯作者：
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影响因子：
3.4
作者：
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通讯作者：
P. Lacey