摘要
螺旋分选流液面因失稳所产生的滚波,势必会扰乱分选流场,对矿物分选造成影响。为了解决螺旋分选流稳定性机制复杂、难以调控的问题,借助CFD(Computation fluid dynamics)技术对不同流动阻力条件下螺旋分选流稳定性的影响规律进行研究。结果表明:在螺旋分选流流动过程中,惯性力具有不稳定性,对流动稳定性起到破坏作用,而表面张力则能抑制小扰动的进一步发展,增强流动稳定性;随着槽面粗糙度的增大、流体黏度的增大以及槽面刻槽数量的增多,流动阻力逐渐增大,螺旋分选流所能达到的最大雷诺数有所降低;流动阻力的增大同样使得弗劳德数和韦伯数有所降低,当粗糙度由0.1 mm增加至0.5 mm和1.0 mm时,弗劳德数分别下降了4.8%和14.0%;当黏度由0.010 Pa·s增加至0.020 Pa·s和0.025 Pa·s时,弗劳德数分别下降了8.9%和20.7%;当槽面刻槽数量由0增加至10和19时,弗劳德数分别下降了13.6%和16.7%,即流动阻力的增大可增强流动稳定性。研究结果可为螺旋溜槽的设计及矿浆黏度的选择提供参考。
The spiral concentrator is a type of gravity-based beneficiation equipment extensively utilized in the processing of hematite,specular iron ore,chromite,and ilmenite,owing to its advantages of minimal environmental impact,low production costs,and straightforward configuration.In industrial applications,surface instabilities,known as roll waves,are frequently observed in spiral concentrators due to fluctuations in the free surface,with flow resistance being a primary factor influencing flow stability.This study focuses on three key factors affecting flow resistance:wall roughness,fluid viscosity,and trough surface grooving.Utilizing computational fluid dynamics(CFD)technology,we investigated the influence patterns of these parameters on the stability of separation flows in spiral concentrators.Analysis based on the liquid film evolution equation reveals that the inertial forces within the spiral sorting stream are unstable and contribute to destabilizing the flow.In contrast,surface tension mitigates the development of minor disturbances,thereby enhancing flow stability.A CFD model of a spiral concentrator was employed to simulate the flow field under varying flow resistance conditions.The simulation results indicate that an increase in wall roughness,fluid viscosity,or the number of grooves on the surface results in a gradual increase in flow resistance,subsequently reducing the maximum achievable Reynolds number of the spiral separation flow.Furthermore,the increase in flow resistance led to a decrease in both the Froude number and the Weber number,with reductions of 4.8%and 14.0%observed when the roughness was increased from 0.1 mm to 0.5 mm and 1.0 mm,respectively.Similarly,when the viscosity was elevated from 0.010 Pa·s to 0.020 Pa·s and 0.025 Pa·s,the Froude number decreased by 8.9%and 20.7%respectively.Additionally,increasing the number of engraved grooves on the surface from 0 to 10 and 19 resulted in a reduction of the Froude number by 13.6%and 16.7%,respectively.These findings demonstrate that increased flow resistance contributes to enhanced flow stability.
作者
朱合钧
刘惠中
邓华军
刘嘉虎
刘茜茜
ZHU Hejun;LIU Huizhong;DENG Huajun;LIU Jiahu;LIU Xixi(Ganzhou Vocational and Technical College,Ganzhou 341000,Jiangxi,China;School of Mechanical and Electrical Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China)
出处
《黄金科学技术》
北大核心
2026年第1期231-242,共12页
Gold Science and Technology
基金
江西省研究生创新专项基金“螺旋选矿机分选槽截面形状对矿物颗粒运动轨迹影响研究”(编号:YC2023-S650)资助。
关键词
螺旋溜槽
流动阻力
数值模拟
流动稳定性
滚波
spiral concentrator
flow resistance
numerical simulation
flow stability
rolling wave
