Abstract The particle velocity distributions in the liquid-solid countercurrent nylon 6 extraction tower equipped with different types of inserts were investigated by both cold-model experiments and 2D-DEM simulations. The cold-model experiment results near the insert were well interpreted by the distribution of the particle contact force acquired from the DEM simulation. Compared with the disordered particle flow caused by a conventional single-funnel insert, the uniform particle flow could be realized by a special combination of single-funnel inserts with 53° and 35° dip angles of the upper and lower parts, respectively. In addition, a new type of insert, the multi-funnel insert, was found to be more beneficial in improving the uniformity of the particle velocity distribution because it made the particle contact force near the insert uniform. Furthermore, the mass flow state could be maintained in a wider range of discharge rate, which implied an enhancement of the operating flexibility of the tower equipped with the multi-funnel insert. These developed inserts have the potential to be applied in large-scale liquid-solid countercurrent extraction processes.

中文翻译：

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通过插入结构优化改善液固逆流萃取塔中的颗粒流动：实验与DEM模拟的结合研究

摘要 通过冷模型实验和2D-DEM模拟研究了配备不同类型插件的液固逆流尼龙6萃取塔中的颗粒速度分布。通过从 DEM 模拟中获得的颗粒接触力的分布，可以很好地解释刀片附近的冷模型实验结果。与传统单漏斗嵌件造成的颗粒流动紊乱相比，上下两部分倾角分别为53°和35°的单漏斗嵌件的特殊组合可以实现均匀的颗粒流动。此外，发现一种新型插入件，即多漏斗插入件，更有益于提高粒子速度分布的均匀性，因为它使插入件附近的粒子接触力均匀。此外，质量流量状态可以在更宽的排放率范围内保持，这意味着配备多漏斗插件的塔的操作灵活性的增强。这些开发的插入物有可能应用于大规模的液固逆流萃取过程。