Abstract The behaviour of a traced alumina particle lying on limestone powders with similar features has been studied in a test tube agitated by a vortex shaker aiming at studying dust emissions from powders. PEPT (Positron Emission Particle Tracking) was used for measuring the particle's position. Population densities were computed as the frequency of the particle's presence in different regions dividing the two horizontal axes and the vertical axis, respectively. The velocities of the particle were calculated by filtering out all displacements inferior to a critical distance dcrit so as not to consider spurious movements caused by experimental noise. After its validation, the methodology was applied to the standard condition of a vortex shaker experiment (ω = 1500 rpm, 2 g of powder and open test tube). While the horizontal coordinates and velocity components follow a symmetric distribution, the vertical coordinate is characterised by a large asymmetrical plateau. The heights reached by the particle (up to 24.3 mm) are small in comparison to that of the test tube (150 mm). The greatest velocities are found near the inner wall of the test tube and at the highest heights where the population densities are the lowest. The median velocity of the particle is 0.0613 m.s −1 whereas its median kinetic energy is 8.4E-12 J. The method explicated in the present study is directly applicable to any other sets of data obtained through PEPT, especially if the system is of small dimension.

中文翻译：

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涡激振动器引起的粒子运动的研究

摘要 为了研究粉末的粉尘排放，在涡旋振荡器搅拌的试管中研究了位于具有相似特征的石灰石粉末上的痕量氧化铝颗粒的行为。PEPT（Positron Emission Particle Tracking）用于测量粒子的位置。人口密度被计算为粒子在分别划分两个水平轴和垂直轴的不同区域中出现的频率。通过滤除低于临界距离 dcrit 的所有位移来计算粒子的速度，以便不考虑由实验噪声引起的虚假运动。验证后，该方法应用于涡旋振荡器实验的标准条件（ω = 1500 rpm，2 g 粉末和打开试管）。虽然水平坐标和速度分量遵循对称分布，但垂直坐标的特点是大的不对称平台。与试管的高度（150 毫米）相比，粒子达到的高度（高达 24.3 毫米）很小。在试管内壁附近和人口密度最低的最高高度处发现最大速度。粒子的中值速度为 0.0613 ms -1 而其中值动能为 8.4E-12 J。 本研究中说明的方法直接适用于通过 PEPT 获得的任何其他数据集，特别是当系统较小时尺寸。3 毫米）比试管（150 毫米）小。在试管内壁附近和人口密度最低的最高高度处发现最大速度。粒子的中值速度为 0.0613 ms -1 而其中值动能为 8.4E-12 J。 本研究中说明的方法直接适用于通过 PEPT 获得的任何其他数据集，特别是当系统较小时尺寸。3 毫米）比试管（150 毫米）小。在试管内壁附近和人口密度最低的最高高度处发现最大速度。粒子的中值速度为 0.0613 ms -1 而其中值动能为 8.4E-12 J。 本研究中说明的方法直接适用于通过 PEPT 获得的任何其他数据集，特别是当系统较小时尺寸。