摘要
采用离散元法(DEM)对变振幅等厚筛分过程进行模拟试验,探究了不同生产率条件下粒群的时空分布规律,通过变振幅模型机筛分试验,研究了不同生产率条件下筛面各段粒群透筛分布规律。模拟试验结果表明,筛下产品中细颗粒的质量随着时间的变化呈现上升趋势。当激振频率为16 Hz、平均振幅为2.75 mm、筛分时间为3.0 s时,筛上料层近似等厚;在筛分时间为8.97 s时,粗细物料颗粒基本完成粒度分离。当生产率为14.73 t/(m^2·h)时,数值模拟试验的筛分效率为83.56%,错配物总量为17.21%;筛分试验研究的筛分效率为85.24%,错配物总量为16.42%。随着生产率逐渐增加,粒群基本在Ⅱ段进行松散和分层,在Ⅲ段大量透筛且筛分效果最好,在Ⅰ段(入料端)和Ⅳ段(出料端)物料会出现堆积现象,筛分效果较差。
Numerical simulation is made of the operating process of the variable-amplitude equal-bed-thickness screen using descrete element method ( DEM) to explore the law governing the spatiotemporal distribution of particle groups under the conditions that the screen operates with varying productivities. Whereas, the law of the distribution of the particle groups passing through various sections of the screen at different productivity of the screen is investigated through model screening test. Simulation test shows that: the mass of fine particles in undersize product tend to become increased with time;at an exciting frequency of 16 Hz, a mean amplitude of 2.75 mm and a screening time of 3.0 s, the material bed on sieve tends to become equal in thickness;and at a screening time of 8.97 s, the separation process of the coarser and finer sizes is basically finished. When the screen operates with a unit capacity of 14.73 t/m^2·h, the screening efficiency and the total of misplaced materials are found to be 83.56% and 17.21% respectively through simulation test, and 85.24% and 16.42% respectively through screening test. With the increase of the screen′s productivity, the particles tend to basically undergo loosening and stratifying process at the screen′s 2nd section. At the 3rd section, as the bulk bed material passes the screen, a best screening effect can be expected, and at the 1st section (feed end ) and the 4th section (discharge end ) the screening effect is relatively poor because of the presence of the phenomenon of heaping up of materials.
作者
黄龙
潘淼
江海深
乔金鹏
王中轩
HUANG Long;PAN Miao;JIANG Haishen;QIAO Jinpeng;WANG Zhongxuan(School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou 221116, China)
出处
《选煤技术》
CAS
2019年第3期23-29,共7页
Coal Preparation Technology
基金
国家自然科学基金项目(U1508210)
关键词
等厚筛分
数值模拟试验
筛分试验
生产率
筛分效率
错配物总量
equal-thickness screening
numerical simulation test
screening test
productivity
screening efficiency
total amount of misplaced material
作者简介
黄龙(1994-),男,安徽宿松人,硕士研究生,研究方向:煤炭的高效深度筛分;通信作者:江海深(1990-),男,博士,讲师,研究方向:煤炭的干法分选与深度筛分。E-mail:haishen_jiang2015@163.com,Tel:15162136936。
