Abstract The reliable prediction of the pressure drop of packed-beds requires an accurate understanding of the packing characteristics. Therefore, packings of spheres, cylinders and hollow cylinders are studied: firstly, developing a reproducible and easily achievable packing generation method by single particle dropping; secondly, evaluating and correlating the average bed porosity as a function of the tube-to-particle diameter ratio λ, the diameter-to-height aspect ratio and the inner-to-outer diameter aspect ratio. The packed-bed pressure drop was measured, thoroughly evaluating the influence of particle filling speed, the error propagation from porosity deviations resulting in a multiplication factor of 3.1–3.9 for spheres and 2.4–3.0 for cylinders depending on material characteristics, and the influence of particle surface roughness, with rough particles increasing the packing friction by 17.5%. A novel Carman-type pressure drop correlation for smooth equilateral cylinder packings valid for Rep = 10–3000 is described.

中文翻译：

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随机填充球体、圆柱体和环的实验表征及其对压降的影响

摘要 填充床压降的可靠预测需要准确了解填充特性。因此，对球体、圆柱体和空心圆柱体的填料进行了研究：首先，开发了一种可重复且易于实现的单颗粒滴落填料生成方法；其次，评估平均床孔隙度并将其关联为管与颗粒直径比 λ、直径与高度纵横比和内径纵横比的函数。测量填充床压降，彻底评估颗粒填充速度的影响，孔隙度偏差的误差传播导致球体的倍增因子为 3.1-3.9，圆柱体的倍增因子为 2.4-3.0，具体取决于材料特性，以及颗粒表面粗糙度，粗颗粒使填料摩擦增加 17.5%。描述了一种适用于 Rep = 10–3000 的光滑等边圆柱填料的新型 Carman 型压降相关性。