气力分级粉体团聚表征及其影响因素的研究
Powder agglomeration characterization of pneumatic classification and the factors influencing agglomeration
曹迎妮 1李兴帅 1焦志伟 1刘家祥 2杨卫民 1于源1
作者信息
- 1. 北京化工大学 机电工程学院,北京 100029
- 2. 北京化工大学 材料电化学过程与技术北京市重点实验室,北京 100029
- 折叠
摘要
粉体团聚对气力分级设备的分级性能有着重要的影响,是制约机械法制备超细粉体的瓶颈问题.为表征气力分级制备超细粉体时的粉体团聚特性并分析其影响因素,利用筛分法和激光粒度分析法测得的粉体平均粒径比值,提出了团聚参数F,并以此为基础分析了粉体颗粒形貌、平均粒径、粒度分布以及粉体流动性对粉体团聚的影响.结果表明:当不同粉体之间的形貌(包括长扁度、球度、棱角度和粗糙度)差异不显著时,颗粒形貌不是引起粉体团聚有所差异的主要因素.粉体平均粒径越大,团聚程度越小;粒度分布指数对团聚的影响取决于粉体整体粗细程度,粗颗粒占比较高的情况下,颗粒不易团聚.因此,对于形貌相似的不同粉体而言,粉体平均粒径和粒度分布是影响粉体团聚的主要因素.此外,通过分析休止角和Hausner值发现,粉体流动性越差,团聚程度越强.
Abstract
Powder agglomeration has an major influence on the performance of pneumatic classification equipment.It is a bottleneck in the preparation of ultrafine powders by mechanical methods.In order to characterize powder ag-glomeration during pneumatic classification and analyze the factors which influence its extent,an agglomeration pa-rameter F is proposed based on the ratio of the average particle size measured by the sieve method to that measured by the laser particle analyzer method.Based on the agglomeration parameter F,the effects of particle morphology,average particle size,the spread of particle size and powder fluidity on powder agglomeration were analyzed.The results show that when there is little difference in particle morphology between different powders,including long flatness,sphericity,angularity and roughness,the particle morphology is not the main factor influencing powder ag-glomeration.Larger average particle sizes result in less powder agglomeration.The effect of the spread of particle size on the powder agglomeration depends on the overall coarseness of the powder.If the percentage of coarse parti-cles is high,the extent of particle agglomeration is relatively low.Therefore,for different powders with similar par-ticle morphology,the average particle size and the spread of particle size are the main factors influencing powder agglomeration.In addition,analysis of the relationship between the angle of repose,the Hausner value and the ag-glomeration parameter shows that increased powder fluidity results in less powder agglomeration.
关键词
粉体/团聚/平均粒径/粒度分布/颗粒形貌Key words
powder/aggregation/average particle size/spread of particle size/particle morphology引用本文复制引用
出版年
2024
NETL
NSTL
万方数据