Slug behavior in dense pneumatic conveying affects system stability and efficiency, which raises the urgent need for an in-depth understanding of this phenomenon. This investigation employs computational fluid dynamics coupled with a discrete element method to comprehensively analyze the behavior and properties of slugs and particles within a horizontal dense-phase pneumatic conveying system. Based on the validated model, this study explores slug velocity, volume, particle trajectory, dispersion, and other properties under diverse operating conditions, examining their characteristics and variation patterns. The findings indicate that the superficial gas velocity is a key factor affecting the efficiency of pneumatic conveying. As the superficial gas velocity increases from 8 to 12 m/s, a 53.60% increase in the slug velocity and a 70.12% decrease in the volume are observed at the midpoint of the pipe. Higher particle flow rate significantly increases the slug velocity while reducing the frequency and volume. The particle-scale information has an obvious effect on slug behavior. The lower density of particles makes them more easily caught and discarded by the slugs. Consequently, the maximum dispersion and displacement of foamed polypropylene (FPP) particles reach 1.64 m²/s and 0.30 m, respectively, whereas those of ceramic particles are only 0.71 m²/s and 0.13 m. These findings provide a valuable basis for optimizing the horizontal dense-phase pneumatic conveying system through an in-depth analysis of the slug.

中文翻译：

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深入了解密集水平气力输送过程中的中尺度段塞特性


密集气力输送中的段塞行为会影响系统的稳定性和效率，这就迫切需要深入了解这一现象。这项研究采用计算流体动力学与离散元方法相结合，全面分析了水平密相气力输送系统中段塞和颗粒的行为和特性。基于经过验证的模型，本研究探索了不同操作条件下的段塞速度、体积、颗粒轨迹、分散和其他特性，检查了它们的特性和变化模式。研究结果表明，气体表观速度是影响气力输送效率的关键因素。当表面气体速度从 8 m/s 增加到 12 m/s 时，在管道中点观察到段塞速度增加 53.60%，体积减少 70.12%。较高的颗粒流速会显著提高段塞速度，同时降低频率和体积。粒子比例信息对 slug 行为有明显影响。颗粒的密度较低，因此更容易被蛞蝓捕获和丢弃。因此，泡沫聚丙烯 （FPP） 颗粒的最大分散和置换分别达到 1.64 m²/s 和 0.30 m，而陶瓷颗粒的最大分散和置换仅为 0.71 m²/s 和 0.13 m。这些发现为通过对段塞的深入分析来优化水平密相气力输送系统提供了宝贵的基础。