喂料方式对粉体气力分级性能的影响及成因分析  

Influence of feeding methods on classification performance of powder pneumatic classification and cause analyses

作　　者：于源[1] 刘克润 刘晓勇 刘家祥[2] 焦志伟[1] 付俊杰[1] YU Yuan;LIU Kerun;LIU Xiaoyong;LIU Jiaxiang;JIAO Zhiwei;FU Junjie(College of Mechanical and Electical Engineering,Beijing University of Chemical Technology,Beijing 100029,China;Beijing Key Laboratory of Materials Electrochemical Process and Technology,Beijing University of Chemical Technology,Beijing 100029,China)

机构地区：[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

出　　处：《中国粉体技术》2024年第2期36-44,共9页China Powder Science and Technology

基　　金：国家自然科学基金项目,编号:52174234。

摘　　要：【目的】为了提高粉体气力分级设备的分级性能,研究螺旋喂料和振动喂料2种不同喂料方式对气力分级性能的影响。【方法】采用高速摄像机对不同喂料方式下粉体下落运动(喂料)进行图像采集,运用图像处理技术对采集到的图像进行处理,通过图像观察法和引入喂料时连续时刻粉体面积分布变异系数分析喂料方式对粉体分散性的影响;通过碳酸钙粉体分级实验方法探讨喂料方式对分级性能的影响。【结果】相较于螺旋喂料,振动喂料有利于粉体解团,提升粉体喂料时的均匀性和分散性;相较于螺旋喂料方式,振动喂料有助于提升气力分级机的分级性能,尤其在较高的喂料速度下,分级性能提升效果显著,喂料速度为18 kg/h时,分级精度提升185%,旁路值减小75%,“鱼钩效应”峰值点高度降低29%;粒径小于10μm的超细颗粒在粗粉中占比从螺旋喂料时的11.4%减小到振动喂料时的4.4%,粗粉中细粉占比大幅减小,粗细颗粒分离效果得到改善。【结论】螺旋喂料不适合输运黏性较强、流动性较差的粉体,如碳酸钙;振动喂料可改善粉体材料的喂料均匀性和分散程度,有利于提高气力分级机分级性能。Objective The feeding method is crucial factors influencing the classification performance of the pneumatic classifier. Spiral feeding and vibration feeding are popular feeding method for powder preparation. This study aims to comparatively analyze their effects on the classification performance, providing valuable insights for the theoretical guidanceof structural optimization in the pneumatic classifier.Methods In this paper, firstly, the image acquisition of the falling motion of material particles(feeding process) with different feeding methods was carried out using a high-speed camera.The collected images were processed using image processing technology. The influence of feeding methods on powder dispersion was analyzed through image observation and the variation coefficient of the powder distribution area of continuous moments. Then the influence of feeding methods on the classification performance was explored through the CaCO_(3) powder classification experiments.Results and Discussion According to the image processing results, there are significant differences in the falling state and dispersion of powder at different feeding methods.Atthe feeding speed of 5 kg/h, the variation coefficients of spiral feeding and vibration feeding are 1.73 and 0.16, respectively. This trend continued at higher feeding speeds, with values forspiral feeding and vibration feeding at the feeding speed of 12 kg/h being 1.38 and 0.15, and at 18 kg/h being 0.90 and 0.12, respectively. Remarkably, the variation coefficient of vibration feeding is smaller than that of spiral feeding at the same feeding speed. According to the CaCO_(3) powder classification experimental results, the vibration feeding is conducive to improving classification performances of the pneumatic classifier, especially under the operating condition with high feeding speed, ascompared to the spiral feeding method. At the feeding speed of 18 kg/h, the pneumatic classifier exhibits substantial improvements in classification metrics when utilizing vibration feed

关 键 词：粉体 气力分级 喂料方式 鱼钩效应 

分 类 号：TQ028[化学工程] TB4[一般工业技术]