距径比调整时螺旋溜槽中二次环流演变过程及颗粒分离效率预测  

Evolution of secondary circulation and prediction of particles separation efficiency in spirals with regulation of pitch-diameter ratio

作　　者：高淑玲[1] 周孝洪 王乾 刘春雨 GAO Shuling;ZHOU Xiaohong;WANG Qian;LIU Chunyu(School of Resources&Civil Engineering,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110819

出　　处：《中南大学学报（自然科学版）》2024年第11期4100-4110,共11页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(52274257,51974065)。

摘　　要：为研究距径比对螺旋溜槽中流场及颗粒分离过程的影响,本文基于计算流体力学方法进行数值试验。首先,系统考察距径比调整时螺旋溜槽中二次环流的纵向演变过程;其次,考察赤铁矿和石英颗粒的迁移行为,探讨颗粒运动随流体演变的变化及距径比的影响;最后,预测分离效率并查明距径比对颗粒分离过程及结果的影响机制。研究结果表明:增大距径比能更快形成整体连续的二次环流空间分布,增大中部区域的内环流速度,削弱外缘区域的内、外环流平衡速度,降低外环流径向通量的相对稳定值和波动性;距径比越大,赤铁矿向外迁移量越多,但在r=100 mm处,迁移趋向平衡,在中部形成富集,石英在r=100 mm以外区域的向外迁移量不断升高,石英和赤铁矿富集区的位置差异扩大;分离效率预测值与距径比呈正相关,当距径比为0.8时在第3.0圈末最大分离效率可达75.03%,最佳截矿器位置在94 mm处,预测结果与二次环流演变特性及颗粒迁移规律相吻合。Numerical experiments based on computational fluid dynamics methods were carried out to investigate the effect of pitch-diameter ratio on the flow field and particle separation process in spirals.Firstly,the longitudinal evolution of the secondary circulation in spirals was systematically investigated when pitch-diameter ratio was adjusted.Secondly,the migration behaviour of hematite and quartz particles was investigated.The variation of particle motion with fluid evolution and the influence of pitch-diameter ratio were discussed.Finally,The separation efficiency was predicted and the influence mechanism of pitch-diameter ratio on the particle separation process and results was identified.The results show that the increase of the pitch-diameter ratio can form the overall continuous secondary circulation spatial distribution faster,enhance the inner circulation velocity in the central region,weaken the equilibrium velocity of the inner and outer circulation in the outer area,and reduce the relative stability and volatility of the radial flux in the outer circulation.The larger the pitch-diameter ratio,the more the outward migration of hematite.However,at r=100 mm,the migration tends to be balanced,and the enrichment is formed in the middle.The outward migration of quartz in the area outside r=100 mm increases,and the position difference between quartz and hematite enrichment areas expands.The predicted separation efficiency is positively correlated with the pitch-diameter ratio.The maximum separation efficiency reaches 75.03%at the trough of the end of the third turn when the pitch-diameter ratio increases to 0.8,and the optimal splitter position is 94 mm.It is consistent with the evolution characteristics of the secondary circulation and the migration law of particles.

关 键 词：距径比 二次环流连续性 纵向行程 颗粒径向通量 最大分离效率 

分 类 号：TD455[矿业工程—矿山机电]