封闭空间内细水雾去除微细粉尘的影响因素实验研究

为研究细水雾去除悬浮在空气中的微细粉尘的影响因素,自行设计了小型封闭腔体并进行了不同工况条件下的细水雾降尘实验。首先采用阴影法对5种工作压力下的细水雾特性进行了测量表征,在此基础上开展了不同雾化特性细水雾对不同质量浓度PM5粉尘的降尘实验,实验中考虑了喷雾时长为5和10s两种情况,所测试粉尘为面粉;此外,还测试研究了不同粉尘粒径分布对细水雾降尘效果的影响研究。研究结果表明:细水雾对PM5粉尘的降尘效率随粉尘初始质量浓度的增加而提高,但当初始质量浓度增加到一定值后,降尘效率的提高不再明显;细水雾雾滴越细越密,其对PM5粉尘的降尘效率越高;延长细水雾喷雾时长,在一定程度上能够提高细水雾对PM5的降尘效率,且低质量浓度PM5比高质量浓度PM5受喷雾时长影响更大;针对平均粒径相差无几的粉尘,细水雾对粒径分布范围小的粉尘的降尘效率比对粒径分布范围大的粉尘的降尘效率高,预测细水雾降尘效率使用粉尘粒径分布范围比使用平均粒径更准确。

Experimental study on factors analysis of particulate matter removal by water mist in an enclosed chamber

In order to investigate the removal efficiency of particulate matter filled in an enclosed experimental chamber using water mist, a series of experiments are conducted in a lab-scale experimental chamber. Frist of all, the characterization of water mist produced at five different operating pressure was measured by Particle-Master Shadow system. Then, the experiments of particulate matter removal using water mist were conducted. Effect of initial particulate matter concentrations, 5 second and 10 second of time period of water mist application, the polydispersity of dust particles, and water mist characteristic including droplet diameter and liquid flow rate on the removal efficiency were investigated. The results show that the initial PM5 concentrations and time of water mist application have positive effects on increasing the removal efficiency, while with the increase of PM5 concentration, the increasing trend of removal efficiency became slow. The droplets with small size may also increase the ef?ciency due to their larger surface area and denser sprays. When PM5 at low concentration, the time of water mist application have more effects than that at high concentration. Compared with broad polydispersity of dust particles, the narrow polydispersity of dust particles has a higher removal efficiency used by water mist. The prediction of removal efficiency with the use of polydispersity of dust particles is more accurate than that with the use of average size of dust particles.