Study of bubble dynamics in gas-solid fluidized beds using ultrashort echo time (UTE) magnetic resonance imaging (MRI)
Study of bubble dynamics in gas-solid fluidized beds using ultrashort echo time (UTE) magnetic resonance imaging (MRI)
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DOI：
10.1016/j.ces.2017.07.003
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发表时间：
2017-11
影响因子：
4.7
通讯作者：
Hilary T. Fabich;A. Sederman;D. Holland
中科院分区：
文献类型：
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作者：
Hilary T. Fabich;A. Sederman;D. Holland
采用超短回波时间（UTE）磁共振成像（MRI）对直径为0.44 mm、0.72 mm和1.5 mm的颗粒进行了窄柱气固流化床研究。当气泡上升通过样品时，UTE能够采集单个气泡的1D和2D图像，其空间分辨率高于以前的MRI。一维图像允许计算气泡上升速度和气泡频率。它们还显示了前导-拖尾气泡聚结。在2D中获得轴向平面中的气泡图像，其中调整图像的位置以在气泡上升时跟踪气泡。这些测量被用来观察气泡的尾流区域，气泡上升时的横向漂移，以及面内气泡聚结。垂直平面内的图像被用来研究空隙率的一维扰动的稳定性。对于直径<1 mm的颗粒，扰动迅速崩溃，但对于1.5 mm直径的颗粒，扰动通常在整个成像区域是稳定的。
A narrow column, gas-solid fluidized bed was studied using ultrashort echo time (UTE) magnetic resonance imaging (MRI) for particles of diameter 0.44 mm, 0.72 mm, and 1.5 mm. UTE enables 1D and 2D images to be acquired of an individual bubble as it rises through the sample with higher spatial resolution than has previously been possible with MRI. One-dimensional images allow calculations of bubble rise velocity and bubble frequency. They also show leading-trailing bubble coalescence. Images of bubbles in the axial plane were obtained in 2D, with the location of images adjusted to track bubbles as they rise. These measurements were used to observe the wake region of a bubble, lateral drift as the bubble rises, and in-plane bubble coalescence. Images in the vertical plane were used to study the stability of a 1D perturbation in voidage. The perturbation collapsed rapidly with particles <1 mm in diameter, but for the 1.5 mm diameter particles the perturbation was often stable throughout the imaging region.