Abstract In this paper, lignite and glass beads with different particle size were selected as experimental materials. These powder materials were discharged from hoppers in the situations of without insert (No In), with confined insert (Con In) and with unconfined insert (Ucon-In), respectively. The discharge processes were first discussed in detail and consequently, the solid flow rate of powders was obtained and analyzed. The flow zones in hoppers were divided based on the radial flow model of powder flow and the effects of inserts on the flow zone evolution were revealed. Experimental results show that both confined and unconfined inserts are beneficial to the increase of the solid flow rate, especially for the weaker flowability powders. The lignite, with the worst flowability, shows the largest increment of solid flow rate giving a value of 58% under Con In. Considering characteristics of the inserted hopper structure as well as the development of flow zones, a modified model derived from the minimum energy theory was developed. The model was able to predict the solid flow rate through both the traditional hoppers and the inserted hoppers, with the deviation below than 10%.

中文翻译：

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带插件料斗排出粉体的流动机理和固体流量预测

摘要 本文选用不同粒径的褐煤和玻璃珠作为实验材料。这些粉状物料分别在无插入（No In）、有限制插入（Con In）和无限制插入（Ucon-In）的情况下从料斗中排出。首先详细讨论了放电过程，从而获得并分析了粉末的固体流速。基于粉体流动的径向流动模型划分料斗中的流动区，揭示了插入件对流动区演变的影响。实验结果表明，有限制和无限制的嵌件都有利于提高固体流速，特别是对于流动性较弱的粉末。褐煤，流动性最差，显示固体流速的最大增量，在 Con In 下给出 58% 的值。考虑到插入式料斗结构的特点以及流动区的发展，建立了一个基于最小能量理论的修正模型。该模型能够预测通过传统料斗和插入料斗的固体流量，偏差小于 10%。