PARTICLE SHAPE AND INFERENCE OF SIZE FROM SIEVING
PARTICLE SHAPE AND INFERENCE OF SIZE FROM SIEVING
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DOI：
10.1111/j.1365-3091.1968.tb00853.x
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发表时间：
1968-01-01
期刊：
影响因子：
3.5
通讯作者：
HENDERSO.PL
中科院分区：
文献类型：
--
作者：
LUDWICK, JC;HENDERSO.PL
通过筛分进行精确的粒度测量需要考虑颗粒形状和筛孔尺寸的变化。通过实验确定通过35个不同mm尺寸椭球体的5个编织丝网筛中的每一个的概率，研究了颗粒形状的影响。它们的形状范围为T/D= 0.2 - 1.0和mL/D= 1.125 - 2.625，其中T是颗粒厚度，L是颗粒长度，D是颗粒中间直径。通过对静态和动态筛分条件下的通过试验，提出了基于颗粒通过概率思想的数学筛分理论。该理论通过简单形状组成的理想化输入样本的计算机模拟筛选来使用。当筛选近球体时，发现条形直方图是合理的描述。对于其他一些更真实的形状输入，所获得的是广泛的，重叠的钟形分数分布，大大偏离了限制屏幕的标称开口。对于这些分布，传统的直方图表示法是不协调的。所提出的处理方法包含了筛孔尺寸变化的容差。一些明显的多峰分布可能是由于所用的屏幕和理想屏幕系列之间的意外差异而解释的。
Accurate particle‐size measurement by sieving requires that consideration is given to particle shape and screen opening size variations. The effect of particle shape has been studied by determining experimentally the probability of passage through each of five woven‐wire screens of 35 different mm‐sized ellipsoids. These range in shape fromT/D= 0.2 to 1.0 and fromL/D= 1.125 to 2.625, whereTis particle thickness,Lis particle length, andDis particle intermediate diameter. Passage tests were performed for both static and dynamic conditions of sieving.A mathematical sieving theory stemming from the idea of particle passing probability is developed. The theory is put to use by computer‐simulated sieving of idealized input samples of simple shape make‐up. When near‐spheres are sieved it is found that a bar‐type histogram is a justifiable depiction. For some other more realistic shape inputs, what is obtained are broad, overlapping bell‐shaped fraction distributions considerably offset from the nominal openings of the limiting screens. For these distributions, conventional representation in histogram form is incongruous.The treatment presented contains allowance for screen opening size variations. Some apparently polymodal distributions are probably explainable as a result of unsuspected differences between the screens used and an ideal screen series.