叶广朋1， 刘振峰2， 周国发1
（1. 南昌大学资源环境与化工学院， 江西南昌 330031；2. 宜春万申制药机械有限公司， 江西宜春 336000）
DOI:10.13732/j.issn.1008-5548.2021.04.016
收稿日期： 2020-08-20， 修回日期：2020-09-09，在线出版时间：2021-06-02 16:54。
基金项目：国家自然科学基金项目，编号：21464009。
第一作者简介：叶广朋(1994—)，男，硕士研究生，研究方向为绿色高效过程装备。E-mail：1105955783@qq.com。
通信作者简介：周国发(1962—)，男，博士，教授，博士生导师，研究方向为绿色高效过程装备。E-mail：ndzgf@163.com。
摘要：建立一种连续化啮合反向旋转双螺杆物料混合机三维模拟模型，利用混合机出口处颗粒体积分数的相对标准偏差作为混合均匀性评价指标，建立螺杆转速与相对标准偏差的关系式，并阐述颗粒混合过程机理，为实现粉体混合均匀性的实时检测、评价与控制提供了理论基础。结果表明:在不同转速条件下，在混合工作区混合粉体均匀性沿螺杆轴向离进口距离增大而增大;随着螺杆转速增加，粉体出口处的相对标准偏差减小，混合粉体停留时间方差δ2减小;混合粉体在矩形出口的均匀性随螺杆转速增大而增强;当螺杆转速由400 r/min增至800 r/min，出口处的相对标准偏差由48.08%减少至5.34%，相对标准偏差减幅高达89%，粉体混合均匀性大幅提高;粉体出口处相对标准偏差随混合时间增加而趋于减小，增加混合时间有利于提高粉体混合的均匀性。
关键词：双螺杆；粉体混合机；混合均匀性；三维模拟；评价指标；相对标准偏差
Abstract：A three-dimensional simulation model of continuous meshing counter-rotating twin-screw material mixer was established. The relative standard deviation of particle volume fraction at the outlet of mixer was used as the evaluation index of mixing uniformityand relationship between screw speed and the relative standard deviation was established. The mechanism of particle mixing process was expounded. The formula provides a theoretical basis for real-time detection,evaluation and control of powder mixing uniformity. The results show thatthe uniformity of mixed powder in mixing work zone increases as the distance from the inlet along the screw axis increases under different speed conditions. As the screw speed increases,relative standard deviation at the powder outlet decreasesand the variance of mixed powder residence time δ2 decreases. The uniformity of mixed powder at rectangular outlet increases as the screw speed increases. When screw speed is increased from 400 r/min to 800 r/min,relative standard deviation at outlet is reduced from 48. 08% to 5. 34%,relative standard deviation reduction is up to 89% and the uniformity of powder mixing is greatly improved. Relative standard deviation at the powder outlet tends to decrease as the mixing time increases. Increasing the mixing time is beneficial to improve the uniformity of powder mixing.
Keywords：twin screw; powder mixer; mixing uniformity; three-dimensional simulation; evaluation index; relative standard deviation
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