改进的光衍射式颗粒粒径测量系统的设计及研究

Design and research on modified optical diffraction particle measuring system

主要研究用不扩束激光进行粉尘粒度分布在线测量的方法,提出采用不扩束激光的颗粒群衍射光强分布信号测定粉尘粒度分布的新思路,将激光的扩束系统去除,建立了不扩束激光粉尘衍射光角分布实验测量装置.该装置避免了由于光源的扩束而带来的杂散光以及系统体积增加等问题,提高了信号的信噪比,使系统更加稳定可靠.采用四种不同粉体进行实验研究,得到各自的衍射图像及沿水平方向经过中心直线上的光强分布曲线,对比了其相同点和不同点,结果表明建立的不扩束激光粉尘粒度分布测试系统是可行的.

The on-line detection technique for the particles distribution in radius without laser beam expansion is studied. A method for detecting the collective particles distribution in intensity by optical diffraction technique without laser beam expansion is proposed and expanding light is removed. Meanwhile, the experimental measuring device is set up based on non-expanding light. The conventional system for particles detection based on fore-scattering principle is simplified and some practical problems, such as the stray light induced by beam expansion and the volume increase are resolved. In this way, the signal-to-noise ratio of the detection system is greatly increased and the stability of the whole system is enhanced. Four different powder are studied and the diffraction images and light intensity distribution curve along the horizontal are gotten and the same and different points are Compared. The results show that the dust size distribution measurement system without laser expansion is feasible.