颗粒密度对声发射法粒径测量的影响

Effects of Particle Density on Particle Sizing by Acoustic Emission Methods

基于单颗粒碰撞声发射信号的粒径测量研究是实现声发射法粒径在线测量的基础,有助于进一步理解声发射粒径测量的机理。设计并搭建了单颗粒碰撞实验装置,分别采用0.4 mm、0.6 mm和0.8 mm的玻璃珠和钢珠撞击波导杆,分析不同密度颗粒碰撞产生的声发射信号特征。分析结果表明,颗粒密度增大,相同颗粒粒径和碰撞速度下产生的声发射信号的幅值与持续时间也增加。同时,根据非弹性碰撞理论,建立颗粒粒径的反演模型,并比较了不同密度颗粒的粒径测量结果。实验结果表明,颗粒密度对声发射法粒径测量结果的影响较小,大部分测量结果的平均相对误差在8%以内。

Particle size measurement based on single particle collision acoustic emission signal is the basis of on-line measurement of particle size by acoustic emission method,which is helpful to further understand the mechanism of particle size measurement by acoustic emission.A single-particle test rig was designed and built to enable experimental tests with glass beads and steel balls both with a mean diameter of 0.4 mm,0.6 mm and 0.8 mm,respectively.The AE signals from the particles impinging onto a waveguide were then analyzed.The results of signal analysis show that,with the same particle size and impact velocity,the increasing density of a particle leads to a higher amplitude and duration of the AE signal.Meanwhile,a theoretical model considering the plastic deformation during the impact was developed for particle size inversion.The results of particle size measurement for particles of different densities were also compared.The results indicate that the density of the particle has little effect on particle sizing through the AE technique.For all the tested particles,the mean relative errors of the measured particles are mostly within 8%.