BACKGROUND & AIMS:
:In this work, particle electrification in the Turbula and horizontally oscillating mixers were investigated for adipic acid, microcrystalline cellulose (MCC), and glycine particles. MCC and glycine particles acquired positive electrostatic charges, while adipic acid particles attained negative charges in both mixers. Adipic acid (of sieved size larger than 500 microm), MCC, and glycine particles were monotonically charged to saturated values, and had negligible wall adhesion. On the contrary, the adipic acid particles, both unsieved and sieved but of smaller sieved size fraction, exhibited very different charging kinetics in the horizontally oscillating mixer. These adipic acid particles firstly acquired charges up to a maximum value, and then the charges slowly reduced to a lower saturated value with increasing mixing time. Furthermore, these particles were found to adhere to the inner wall of the mixer, and the adhesion increased with mixing time. Surface specific charge densities for adipic acid particles were estimated based on particle size distribution, and were found to increase with particle mean diameters under the conditions investigated. The results obtained from the current work suggested that electrostatic force enhanced particle-wall adhesion, and the adhered particles can have a significant impact on particle electrification.
背景与目标:
: 在这项工作中,研究了湍流和水平振荡混合器中己二酸,微晶纤维素 (MCC) 和甘氨酸颗粒的颗粒带电。MCC和甘氨酸颗粒在两个混合器中均获得正电荷,而己二酸颗粒则获得负电荷。己二酸 (筛分尺寸大于500微米) 、MCC和甘氨酸颗粒单调带电至饱和值,并且具有可忽略的壁粘附力。相反,未过筛和过筛但过筛尺寸分数较小的己二酸颗粒在水平振荡混合器中表现出非常不同的充电动力学。这些己二酸颗粒首先获得的电荷达到最大值,然后随着混合时间的增加,电荷逐渐降低到较低的饱和值。此外,发现这些颗粒粘附在混合器的内壁上,并且粘附力随混合时间而增加。根据粒径分布估算了己二酸颗粒的表面比电荷密度,并发现在所研究的条件下随着颗粒平均直径的增加而增加。从当前工作中获得的结果表明,静电力增强了颗粒壁的附着力,并且粘附的颗粒会对颗粒的起电产生重大影响。