According to the actual structure of sand silo, an experimental model is made with the scale of 1:30. By dyeing the sand into different colors, the flowability of molding sand in sand silo is studied. 40 mesh and 50 mesh sands are dyed and mixed with other mesh unstained. The sand grain distribution is studied during adding sand into sand silo. By setting up different inlet positions and different number of flow pipes, grain distribution of sand is studied at different stages flowing out of the sand silo. The results show that the sand outflow does not follow first-in first-out(FIFO) principle. Actually, sand sequentially flows out from bottom, middle, top, middle and then bottom. As added into the silo, the coarse sand flows far from the inlet, while the fine sand is close to the inlet. The slanting guide path below the silo will affect the sand flowing condition inside the model, and worsen the grain segregation inside the silo. By adding sand from the center, with 16 pieces of flow pipes, it is beneficial to reducing the sand grain segregation.%根据砂库实际结构,按1:30比例制作了试验模型.通过将砂粒染成不同的颜色,研究了石英砂在流出砂库过程中的流动特性.将砂子的40目和50目染上颜色,与未染色的其他目数混合,研究了砂库加砂时的砂子分布.通过设置不同的加砂位置、不同的流砂管数量,研究了不同时期流出砂库石英砂的粒度分布情况.结果表明,砂子流出不是遵循"先进先出"原则,而是底部→中部→上部→中部→底部;在加砂过程中粗砂都流向了加入口的远端,细砂靠近加入口;砂库下方的斜向导出槽会影响石英砂在模型内流动状态,加剧砂库中砂子的偏析;采用中心加砂,16根管出砂对降低砂子粒度偏析现象有利.
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