扬尘源粒度组成筛分方法比较

为建立扬尘源筛分规范依据,选取F150标准砂和道路尘作为待测样品,对比国产3种振动方式(电动式、震击式和拍击式)振筛机和3个厂家试验筛的筛分性能. 结果表明:①经过拍击式振筛机和F150标准砂检验,A、B、C三厂试验筛的筛分性能差异较大,得到200目(75μm)试验筛的筛上累计含量(以质量分数计)分别为78.9%、65.9%和57.9%,B厂和C厂结果小于F150标准砂76.1%的基准值；②3种振筛机的筛分性能也存在差异,震击式振筛机筛出率略小于拍击式振筛机,但电动式振筛机筛分不彻底,其对道路尘样品中粒径≤75μm和粒径≤38μm粒子的筛出率分别只有另外2种振筛机的1/2和1/4；③3种振筛机筛分结果一致性顺序为拍击式>震击式>电动式. 建议使用拍击式振筛机或震击式振筛机与性能好的A厂试验筛组合筛分得到粒径≤75μm的样品,使用拍击式振筛机和性能好的A厂试验筛组合筛分得到粒径≤38μm的样品. 

Comparison of Screening Methods of Size Distribution of Fugitive Dust Source

In order to provide the supporting material for establishing the standard sample screening methods of fugitive dust source, F150standard sand and road dust were selected as the samples to compare screening performances of three domestic sieve machines (electrodynamic type, shock type, slap type) and three test sieves from different manufacturers. The results showed that:1) Through the test by the slap type sieve machine and the F150standard sand, the screening performances of sieves were greatly different from manufacturer A, B and C. The accumulated mass contents of 200mesh test sieves were 78.9%, 65.9% and 57.9%, respectively, showing that the later two screening results were less than the reference value of F150standard sand 76.1%. 2) The screening performances of three sieve machines were also different. The screen out rate of the shock type was slightly less than the slap one, the screening of the electrodynamic type was incomplete, since the screen out rate for road dust particles less than 75μm and 38μm using the electrodynamic type was only half and fourth of the slap type respectively. 3) The decreasing consistency order of the screening result using three sieve machines was slap type>shock type>electrodynamic type. This result suggested that using the combination of the slap type or shock type and test sieve A of good performance to get samples less than 75μm, and use the combination of slap type and test sieve A of good performance to get samples less than 38μm.