Hysteresis and packing in gas-fluidized beds
Hysteresis and packing in gas-fluidized beds
复制标题
气体流化床中的滞后和堆积
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
Durian
中科院分区：
文献类型：
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作者：
Ojha;Menon;Durian
填充分数和压降跨越气体流化床的颗粒介质表现出滞后的气体流量是循环向上和向下跨越流化过渡。据推测，这是由于接触力和应力转移到周围的墙壁，因此应该随着样品的纵横比而变化。在这里，我们提出了系统的测量滞后与颗粒尺寸和样品的纵横比的变化。值得注意的是，滞后尺度在一个平凡的方式与这些参数，没有证据表明的长期影响的墙壁。我们的测量还表明，填充分数变为0。590+/-0.004，与颗粒尺寸和容器形状无关，当气流的流化流被缓慢移除时。
The packing fraction and the pressure drop across gas-fluidized beds of granular media exhibit hysteresis as the gas-flow rate is cycled up and down across the fluidization transition. Presumably this is due to contact forces and transfer of stress to the surrounding walls, and hence should vary nontrivially with the aspect ratio of the sample. Here we present systematic measurements of the variation of hysteresis with particle size and aspect ratio of the sample. Remarkably, the hysteresis scales in a trivial way with these parameters, showing no evidence of long-range effects of the wall. Our measurements also show that the packing fraction becomes 0. 590+/-0.004, independent of particle size and container shape, when the fluidizing flow of gas flow is slowly removed.