低浓度细颗粒物声波团聚及喷雾优化实验

常规除尘器无法有效去除PM_2.5，而声波能有效增加颗粒物之间的碰撞、团聚，使PM_2.5粒径增大，是一种非常有前景的除尘预处理技术。主要研究了声波频率、声压级、初始浓度及停留时间对声波团聚效率的影响，发现在低频声波作用下效果更好，而纯声波作用下最佳团聚效率为44.84%。并对粉尘进行扫描电镜分析，对比了实验前后的粉尘形态，验证了声波对气溶胶颗粒的团聚作用。利用喷雾作为辅助手段，可以进一步提高团聚效率，降低声波团聚的能耗。在相同情况下，添加喷雾可以使团聚效率从43.07%增加到66.48%，说明喷雾联合声波作用是非常有效的除尘预处理技术。

EXPERIMENTAL STUDY ON ACOUSTIC AGGLOMERATION AND COMBINED SPRAY OPTIMIZATION OF FINE PARTICLES AT LOW CONCENTRATION

Fine particles are inflicting great harm on human health due to their small particle size and absorption of hazardous components on them. But the conventional dust remover cannot remove it effectively. Sound wave can effectively increase the collision and agglomeration of particles and increase the particle size of PM_2.5, which is a promising dust removal pretreatment technology. The acoustic frequency, sound pressure level (SPL), initial concentration and residence time are the main factors for the acoustic agglomeration efficiency. It was found that the effect was better under the action of low frequency sound wave, but the best agglomeration efficiency was only 43.07% under the action of pure acoustic agglomeration. The dust morphology before and after the experiment was compared by scanning electron microscope, and the agglomeration effect of acoustic wave on aerosol particles was verified. Then this study used spray as an auxiliary means to further improve the agglomeration efficiency and reduce the energy consumption of acoustic agglomeration. The effects of frequency, SPL and spray volume on the agglomeration efficiency were investigated. The agglomeration efficiency increased to 66.48% after spray. It showed that spray combined with acoustic agglomeration was an effective dust removal pretreatment technology.