Flow field distribution of stirring tank for hydrometallurgical vanadium extraction
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摘要: 为提高湿法提钒浸出率、掌握机械搅拌反应釜内液相流动和固相分布的规律，使用Fluent软件，基于计算流体力学理论，利用多重参考系法对浸钒搅拌釜内计算区域进行处理，建立多相流欧拉-欧拉模型和标准k-ε湍流模型，研究了搅拌速度v、桨叶离底高度L和带孔挡板对搅拌釜内流场分布的影响。结果表明：随着搅拌速度v的增大，搅拌釜内液相速度先逐渐增大，然后基本保持不变；根据桨叶离底高度L高低对搅拌釜内液相速度分布的影响，将最适宜离底高度选作L=0.4D1；安装带孔挡板有助于消除流场的漩涡现象，改善流场分布。Abstract: In order to improve the leaching rate of vanadium and understand the liquid flow and solid distribution in the mechanical stirring tank for hydrometallurgical vanadium extraction, the software Fluent was used to establish the Euler-Euler model of multi-phase flow and the standard k-ε turbulence model, by dealing with the calculation area in the stirring tank via multi-reference system method based on the theory of computational fluid dynamics. The influences of stirring speed v, the height of blade from the bottom L and the perforated baffle on the flow field distribution in the stirring tank were investigated. The results show that the liquid phase velocity in the stirring tank gradually increases first and then basically stabilizes with the increase of stirring velocity v. Based on the influence of the height of the blade from the bottom L on the liquid velocity distribution, the most suitable value was determined at L=0.4D1, where D1 refers to the blade diameter. The perforated baffle is helpful to eliminate the vortex in the flow field and improve the flow field distribution.
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图 2 4种搅拌速度下液相速度分布
Figure 2. Velocity distribution of liquid phase under four stirring speeds
图 4 4种离底高度下液相速度分布
Figure 4. Distribution of liquid velocity at four different heights from the bottom
图 5 4种离底高度下固相体积分数
Figure 5. Solid volume fraction diagrams at four different heights from the bottom
图 6 不同结构下y=0平面速度分布
Figure 6. Vector diagram of y=0 plane velocity distribution under different structures
图 7 不同结构下搅拌釜纵截面速度分布曲线
Figure 7. Velocity distribution in longitudinal section of stirring tank under different structures
表 1 搅拌釜结构参数
Table 1. Structure parameters of stirring tank
搅拌釜直径
D/mm搅拌釜高度
H/mm桨叶直径
D1/mm桨叶离底高度
L/mm轮毂直径
D2/mm搅拌轴直径
D3/mm桨叶个数/
个纵向高度
Z/mm110 105 60 0.25D1,0.4D1,0.55D1,0.7D1 20 10 3 52.5 
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表 2 基本物性参数
Table 2. Main material parameters
物料 直径dp/μm 密度$\rho $/（kg∙m−3） 粘度$\eta $/（Pa∙s） 体积分数α/% 钒钛磁铁矿颗粒 75～150 4500～6000 5～20 NaOH溶液 1000 0.001～0.007 80～95
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