The nature of the flow just above the perforated plate distributor of a gas-fluidised bed, as imaged using magnetic resonance
The nature of the flow just above the perforated plate distributor of a gas-fluidised bed, as imaged using magnetic resonance
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DOI：
10.1016/j.ces.2006.05.006
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发表时间：
2006-09
影响因子：
4.7
通讯作者：
A. Rees;J. Davidson;J. S. Dennis;P. Fennell;L. Gladden;A. Hayhurst;M. Mantle;C. Müller;A. Sederman
中科院分区：
文献类型：
--
作者：
A. Rees;J. Davidson;J. S. Dennis;P. Fennell;L. Gladden;A. Hayhurst;M. Mantle;C. Müller;A. Sederman
利用磁共振成像（MRI）首次观察到了由氮气流化的含油种子的三维床内的流动模式。注意力集中在床的下部区域，就在多孔分配器上方：孔直径为1.0或1.5mm，具有正方形或三角形布局，间距为7- 10 mm。使用两种尺寸的种子：1.2和0.50 mm。每个MRI图像是超过105分钟的时间平均值，并测量了粒子的局部浓度。U/Umf的值在0.0-3.6的范围内，其中U是表观气速，U=Umfat初始流化。图像显示：无量纲组之间的简单相关性很好地总结了测量结果，给出了气体速度和其他变量的“射流”的长度和半角。这些相关性与已发表的结果是一致的，包括依赖于孔的间距，这被认为是重要的。
Flow patterns within a 3D bed of oil-containing seeds fluidised by nitrogen have been observed for the first time using magnetic resonance imaging (MRI). Attention was focused on the lower region of the bed, just above the multi-orifice distributor: the orifices were 1.0 or 1.5mm in diameter with square or triangular layouts, of pitch 7–10mm. Two sizes of seeds were used: 1.2 and 0.50mm. Each MRI image was a time-average over ∼5min and measured the local concentration of seeds. Values of U/Umfwere in the range 0.0–3.6, where U is the superficial gas velocity and U=Umfat incipient fluidisation. The images revealed: Simple correlations between dimensionless groups summarise the measurements well, giving the length and half angle of a ‘jet’ in terms of the gas velocity and other variables. These correlations are consistent with published results and include a dependence on the pitch of the orifices, which was found to be important.