High-resolution imaging of depth filter structures using X-ray computed tomography
High-resolution imaging of depth filter structures using X-ray computed tomography
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DOI：
10.1007/s10853-021-06238-w
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发表时间：
2021-06-18
影响因子：
4.5
通讯作者：
Bracewell, D. G.
中科院分区：
文献类型：
--
作者：
Johnson, T. F.;Iacoviello, F.;Bracewell, D. G.
描述了使用X射线计算机断层扫描对深度滤波器进行成像和测量的多长度尺度方法。在3D中可视化不同标称截留率的三种不同过滤器等级，并基于孔隙率、孔径和弯曲度进行定量比较。过滤器内基于位置的分析显示，上游四分位数的空隙率和平均孔径较大，然后通过过滤器从中心到下游四分位数逐渐减小，这些结果在每种情况下都得到空隙距离图的直观支持。流动模拟显示曲折的路径，流动可能通过内部空隙率进行了检查。数字重建能够识别空隙率，纤维素和每个深层过滤器等级内的纤维素的个别成分，与上游和下游表面的元素分析确认纤维素的存在。实现适当的像素大小是特别重要的，当优化成像条件的所有等级检查。3 lm像素大小能够表示每个过滤器结构的内部大孔;然而，对于最精细的等级，需要改进到1 μ m像素大小，以便解析微孔和小碎片。提高像素大小导致所有等级的平均孔隙度测量值为70%至80%。
A multiple length scale approach to the imaging and measurement of depth filters using X-ray computed tomography is described. Three different filter grades of varying nominal retention ratings were visualized in 3D and compared quantitatively based on porosity, pore size and tortuosity. Positional based analysis within the filters revealed greater voidage and average pore sizes in the upstream quartile before reducing progressively through the filter from the center to the downstream quartile, with these results visually supported by voidage distance maps in each case. Flow simulation to display tortuous paths that flow may take through internal voidage were examined.Digital reconstructions were capable of identifying individual constituents of voidage, cellulose and perlite inside each depth filter grade, with elemental analysis on upstream and downstream surfaces confirming perlite presence. Achieving an appropriate pixel size was of particular importance when optimizing imaging conditions for all grades examined. A 3 lm pixel size was capable of representing internal macropores of each filter structure; however, for the finest grade, an improvement to a 1 mu m pixel size was required in order to resolve micropores and small perlite shards. Enhancing the pixel size resulted in average porosity measurements of 70% to 80% for all grades.