摘要：通过实验测试和理论分析,找到不同管径突变比和镜头保护效果的关系,以解决散射传感器监测粉尘浓度的镜头污染问题,实验分析8套不同突变比的变径分离管段在引入保护风量吹洗传感器嵌入镜头后的不同效果,并结合突变管段局部进行理论推导。结果表明,选择突变截面比为1.6～2.0,不仅使管段压损更大,而且引入保护流的吹洗效果同样不佳;管径突变比D2/D1为1.1～1.4时,相对于大突变比管段的保护气流,流速提高了25%以上,压力损失也低于16 Pa,使传感器镜头污染效果减轻。

关键词：散射传感器；分离管段；突变比

Abstract：To solve the lens pollution problem of scattering sensors monitoring dust concentration,a relationship between different mutation ratio and lens protection effect was found by experimental test and theory analysis.The test analyzed the different effects of 8 separated pipe sections with different mutation ratios after blow washing sensors embedded lens by introducing protected airflow,the theory deduction of local mutation pipe segment was done.It is concluded that when mutation ratio D2/D1 is 1.1 to 1.4,airflow speed improves more than 25% relative to protected airflow of large mutation ratio pipe.The pressure loss is less than 16 Pa as well.So that the pollution effect on lens is greatly reduced.

Keywords：scattering sensor；separated pipe section；mutation ratio