CFD modeling of gas-liquid-solid mixing characteristics in stirred tank for water-suspension granulation

doi:10.16085/j.issn.1000-6613.2025-0293

Abstract

Abstract:

The gas-liquid interface evolution and solid dispersion in a gas-liquid-solid three-phase stirred tank for energetic material water-suspension granulation were investigated using an Eulerian multi-fluid VOF model. This study systematically examined the effects of rotational speed and liquid-phase viscosity on the free surface morphology, the distributions of the concentration and velocity of solid phase were investigated. The results showed that the model effectively captured the gas-liquid-solid three-phase stirring process involving a free surface. Within the stirring speed range of 250—350r/min, increasing stirring speed reduced the accumulation of solids in the regions near the free surface and the vessel walls and thus enhanced its uniform distribution. When the stirring speed was greater than 350r/min, the entrainment of air was intensified, leading to the existence of large bubbles inside the suspension liquid. Regarding viscosity effects, increasing viscosity could enhance turbulent shear effects within 0.001—0.1Pa·s, which effectively suppressed solid sedimentation and improved suspension homogeneity. When the liquid-phase viscosity increased from 0.1Pa·s to 0.5Pa·s, the reduced solid-phase mobility adversely affected the stability and efficiency of the stirring process. This study provided theoretical insights for the operation and optimization of the water-suspension granulation process.

Key words: energetic materials, water-suspension, stirred tank, computational fluid dynamics (CFD), multiphase flow

摘要：

针对含能材料水悬浮造粒工艺气液固三相搅拌过程，采用Eulerian多相流流体体积（VOF）模型对搅拌釜内气液相界面变化及固相分散行为进行了数值模拟，考察了转速和液相黏度对自由液面形态、固相浓度分布及固相速度分布变化的影响。结果表明，该模型能够合理预测具有自由液面的气液固三相搅拌过程；在250~350r/min转速内，提升转速有助于减少自由液面及边壁区域的固相富集，促进固相的均匀分散；当转速超过350r/min时，空气卷吸效应增强，大量气泡进入悬浮液。在0.001~0.1Pa·s液相黏度范围内，提高黏度可增强湍流剪切作用，抑制固相沉降，有利于固相的均匀悬浮；当液相黏度由0.1Pa·s增至0.5Pa·s时，固相流动性降低，不利于搅拌过程的稳定运行。本文为水悬浮造粒工艺的操作和优化提供了理论参考。

关键词: 含能材料, 水悬浮, 搅拌釜, 计算流体力学, 多相流

CLC Number:

TQ027

LU Yucheng, HUANG Tao, LUO Yajun, LIU Jiahui, GONG Feiyan, YAN Chaoyu, LIU Xiaoxing. CFD modeling of gas-liquid-solid mixing characteristics in stirred tank for water-suspension granulation[J]. Chemical Industry and Engineering Progress, 2025, 44(8): 4556-4566.

卢玉成, 黄涛, 罗亚军, 刘佳辉, 巩飞艳, 严超宇, 刘晓星. 水悬浮造粒搅拌釜内气液固三相混合特性CFD模拟[J]. 化工进展, 2025, 44(8): 4556-4566.

Figures/Tables 14

References 30

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参数	设置
颗粒黏度（granular viscosity）	Syamlal等^[24]
颗粒体积黏度（granular bulk viscosity）	Lun等^[25]
固相压力（solid pressure）	Lun等^[25]
颗粒碰撞黏度（granular collisional viscosity）	Gidaspow等^[20]
摩擦黏度（frictional viscosity）	Schaeffer^[26]
摩擦压力（frictional pressure）	Johnson等^[27]
摩擦堆积极限（friction packing limit）	0.61
内摩擦角（angle of internal friction）	30
堆积极限（packing limit）	0.63
径向分布函数（radial distribution）	Lun等^[25]

参数	设置
颗粒黏度（granular viscosity）	Syamlal等^[24]
颗粒体积黏度（granular bulk viscosity）	Lun等^[25]
固相压力（solid pressure）	Lun等^[25]
颗粒碰撞黏度（granular collisional viscosity）	Gidaspow等^[20]
摩擦黏度（frictional viscosity）	Schaeffer^[26]
摩擦压力（frictional pressure）	Johnson等^[27]
摩擦堆积极限（friction packing limit）	0.61
内摩擦角（angle of internal friction）	30
堆积极限（packing limit）	0.63
径向分布函数（radial distribution）	Lun等^[25]