霍 枫,常 颖,陆晓霞,刘英莉,李 聪,鲍邵衡
(国民核生化灾害防护国家重点实验室,北京 102205)
DOI:10.13732/j.issn.1008-5548.2022.02.005
收稿日期: 2021-10-09,修回日期:2021-10-19,在线出版时间:2022-01-30。
基金项目:国民核生化灾害防护国家重点实验室科研基金项目,编号:SKLNBC2020-16。
第一作者简介:霍枫(1996—),男,硕士研究生,研究方向为特种粉体包装技术。E-mail:h7uofeng@163.com。
通信作者简介:常颖(1971—),女,高级工程师,博士,硕士生导师,研究方向为特种粉体包装技术。E-mail:chying01@sina.com。
摘要: 以危险化学品泄漏处置为背景,研究粉体洗消剂离心压缩装填过程;选用二氧化硅球形颗粒作为模拟介质,进行粉体颗粒离心压缩过程的离散元模拟及实验研究;对比分析压缩前、后粉体柱高度变化,研究不同阶段粉体柱密度分布规律;进一步分析粒径对密度分布的影响规律和粉体层密度随时间变化规律。结果表明:模拟与实验结果偏差不大于5.82%,证明离散元模型及参数设置是可靠性的;离心压缩和液压压缩在密度分布趋势上有明显不同,离心压缩后粉体柱密度沿料筒轴向对称分布,底部中下位置密度最大,总体向四周逐渐减小;颗粒单位体积密度的变化趋势是随压缩时间先迅速增大,之后趋于固定值;减小颗粒粒径或适当添加部分小颗粒有助于增大压缩后的粉体密度,使密度分布更加均匀。
关键词: 粉体颗粒;离心压缩;离散元法;压缩密度
Abstract:Based on the background of hazardous chemicals decontamination,the research on the centrifugal compression loading process of the powder-decontamination-agent was conducted.Spherical silica particles were selected as the analog media,and based on discrete element method (DEM),simulations of the centrifugal compression process of the powder particles were carried out.The height of the powder column before and after compression was compared and analyzed,and the density distribution law of the powder column at different stages was studied.The influence of particle size on density distribution and the change of powder density with time were further analyzed.The results show that the height values of the powder column before and after the centrifugal compression calculated by the DEM simulation agree well with the experimental results,and the deviation is not greater than 5.82%.The density distribution regularities after the centrifugal compression are obviously different from that after the hydraulic compression.After the centrifugal compression,the distribution of compacted powder particles density is axisymmetric,the density of powder particles in the lower middle part near the bottom is largest,and the overall density decreases gradually toward the barrel wall.The change trend of particle density per unit volume increases rapidly with the compression time,and then tends to a fixed value.Reducing the particle size or adding some smaller particles appropriately are able to help increase the total density of powder column and make the density distribution more uniform.
Keywords:powder particles;centrifugal compression;discrete element method;density of compression
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