粒径对激光诱导煤粉流等离子体特性的影响

摘要

为了明确在应用激光诱导击穿光谱技术进行煤粉流物质成分在线检测过程中,煤粉粒径大小对激光诱导煤粉流等离子体特性的影响,利用螺杆给料机搭建煤粉颗粒流检测平台,分析了粒径不同的6种煤粉流等离子体的光谱数据.结果表明,在相同的实验条件下,随着煤粉颗粒粒径减小,等离子体的电子密度和温度升高,粒径小于50μm与粒径为250μm～300μm的样品的等离子体电子密度和温度分别升高了19.89％和13.13％;煤粉粒径大小对激光诱导煤粉流等离子体特性有很大影响,选取合适的煤粉粒径不仅可以提高光谱强度而且元素检出限也得到改善,更有利于检测样品中含量低的元素.%In order to further clarify the influence of pulverized coal particle size on the laser-induced plasma flow characteristics in the process of detecting the composition of pulverized coal by using laser induced breakdown spectroscopy,the screw feeder was used to build coal particle flow detection platform.Spectral datas of 6 kinds of pulverized coal flow plasmas with different particle sizes were analyzed.Under the same experimental conditions,the electron density and temperature of plasma would increase with the decrease of coal particle size.The electron density and temperature of plasma were increased by 19.89％and 13.13％respectively when the sample sizes were < 50μm and 250μm～300μm correspondingly.The results show that,the particle size of pulverized coal has a great influence on the plasma characteristics of laser induced pulverized coal flow.Choosing the appropriate size of pulverized coal can not only improve the spectral intensity but also improve the elements detection limit.It is more favorable for the detection of the low content of elements in the sample.