The storage of granular materials is a critical process in industry, which has driven research into flow in silos. Varying material properties, such as particle size, can cause segregation of mixtures. This work seeks to elucidate the effects of size differences and determine how using a flow-correcting insert mitigates segregation during silo discharge. A rotating table was used to collect mustard seeds discharged from a three-dimensional (3D)-printed silo. This was loaded with bidisperse mixtures of varying proportions. A 3D-printed biconical insert was suspended near the hopper exit to assess its effect on the flow. Samples were analysed to determine the mass fractions of small particle species. The experiments without the insert resulted in patterns consistent with segregation. Introducing the insert into the silo eliminated the observed segregation during discharge. Discrete element method simulations of silo discharge were performed with and without the insert. These results mirrored the physical experiment and, when complimented with coarse graining analysis, explained the effect of the insert. Most of the segregation occurs at the grain–air free surface and is driven by large velocity gradients. In the silo with an insert, the velocity gradient at the free surface is greatly reduced, hence, so is the degree of segregation.

中文翻译：

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带和不带插入物的筒仓中的粒度分离

颗粒材料的储存是工业中的一个关键过程，这推动了对筒仓流动的研究。不同的材料特性，例如粒度，会导致混合物的分离。这项工作旨在阐明尺寸差异的影响，并确定使用流量校正插件如何减轻筒仓卸料过程中的离析。使用旋转台收集从 3D (3D) 打印筒仓排出的芥菜籽。这装有不同比例的双分散混合物。一个 3D 打印的双锥形插入物悬挂在料斗出口附近，以评估其对流动的影响。分析样品以确定小颗粒物质的质量分数。没有插入物的实验产生与分离一致的模式。将插入物引入筒仓消除了卸料过程中观察到的离析。使用和不使用插件对筒仓排放进行离散元方法模拟。这些结果反映了物理实验，当与粗粒度分析相辅相成时，可以解释插入的效果。大多数偏析发生在颗粒-空气自由表面，并且是由大的速度梯度驱动的。在带有插入件的筒仓中，自由表面的速度梯度大大降低，因此偏析程度也大大降低。大多数偏析发生在颗粒-空气自由表面，并且是由大的速度梯度驱动的。在带有插入件的筒仓中，自由表面的速度梯度大大降低，因此偏析程度也大大降低。大多数偏析发生在颗粒-空气自由表面，并且是由大的速度梯度驱动的。在带有插入件的筒仓中，自由表面的速度梯度大大降低，因此偏析程度也大大降低。