Modelling of the Filtration Behaviour Using Coupled DEM and CFD
Modelling of the Filtration Behaviour Using Coupled DEM and CFD
复制标题
使用耦合 DEM 和 CFD 进行过滤行为建模
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
J. Tomas
中科院分区：
文献类型：
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作者：
S. Stein;J. Tomas
通过滤饼形成的过滤是排出颗粒悬浮液的有效方法。改进过滤过程的一种可能性是形成絮凝物，其存款更快。本文采用离散元法和计算流体力学相结合的方法，在微米级范围内对多孔超细颗粒填料的过滤行为、絮凝效果以及生成和压缩过程中的流速进行了二维预测。一个压力剪切细胞被用来调查的固结颗粒填料的过滤行为，并测量最重要的材料性能。
结果表明，该方法可以预测絮凝和非絮凝悬浮液的比滤液体积和滤饼高度的时间依赖性。
据观察，絮凝导致滤饼的孔隙率和渗透性增加。这导致滤饼阻力降低和渗透率增加。过滤时间在减少。具有主导斥力的稳定悬浮液产生具有小孔隙度、大滤饼阻力和差渗透性的致密滤饼。与稳定悬浮液相比，絮凝饼的可压缩性更高，并且可以被归类为非常可压缩。
The filtration by cake formation is an effective method to drain a particle suspension. One possibility to improve the filtration process is the formation of flocs, which deposit faster. The aim of this work is to predict the filtration behavior, the effects of flocculation and simulate the flow rate during generation and compression of the porous ultrafine particle packings by coupling Discrete Element Method and Computational Fluid Dynamics in two dimensions within the micron range. A Press-Shear-Cell was used to investigate the filtration behaviour of the consolidated particle packings and to measure the most important material properties.
It was shown that the time dependency of specific filtrate volume and cake height for the flocculated and non-flocculated suspension can be predicted by this method.
It is observed that a flocculation causes an increase in porosity and permeability of the filter cake. This results in decreasing filter cake resistances and increasing permeabilities. The filtration times are decreasing. A stable suspension with dominant repulsion produces a compact filter cake with small porosity, large filter cake resistance and poor permeability. The compressibility of the flocculated cake is higher compared to the stable suspension and can be categorized as very compressible.