Zhang Guangxue, Ma Zhenfang, Shen Jian, Zhang Kai, Wang Jinqing, Chi Zuohe
The Institute for Energy Engineering, China Jiliang University, Hangzhou, 310000, China.
The Institute for Energy Engineering, China Jiliang University, Hangzhou, 310000, China.
J Hazard Mater. 2020 Jan 15;382:121089. doi: 10.1016/j.jhazmat.2019.121089. Epub 2019 Aug 23.
Acoustic agglomeration is a process in which an intense sound field is applied to promote relative motion and rapid agglomeration among aerosol particles. This technology is able to improve significantly and rapidly the visibility of the smoke in a fire situation, and therefore assists the quick evacuation of evacuees. In this paper, the elimination effect of polystyrene smoke using acoustic agglomeration technology is experimentally investigated. The results show that the smoke transmittance will be increased to 0.75 from the initial value of 0.24 in only 0.5 min, in a 1.5 kHz acoustic field at a sound pressure level of 141 dB. The agglomeration rate is sensitive to acoustic frequency and there is an optimal operation frequency, which indicates that the predominant mechanism is orthokinetic interaction. Under the conditions of our experiments, the optimal frequency for eliminating soot particles is determined to be 1.5 kHz. As an energy consuming process, the agglomeration efficiency increases proportionally with the acoustic power until the corresponding nonlinear acoustic effects become significant. Moreover, it is found that the agglomeration rate of thicker smoke is much higher than thin ones at the early stage of the process, but the discrepancy tends to vanish at the later stage.
声团聚是一种通过施加强声场来促进气溶胶颗粒间相对运动和快速团聚的过程。该技术能够显著且迅速地提高火灾场景中烟雾的能见度，从而有助于疏散人员快速撤离。本文通过实验研究了声团聚技术对聚苯乙烯烟雾的消除效果。结果表明，在1.5 kHz声场、声压级为141 dB的条件下，仅需0.5分钟，烟雾透过率就能从初始值0.24提高到0.75。团聚率对声频敏感，存在一个最佳工作频率，这表明主要机制是同向运动相互作用。在我们的实验条件下，确定消除 soot 颗粒的最佳频率为1.5 kHz。作为一个耗能过程，团聚效率与声功率成正比增加，直到相应的非线性声学效应变得显著。此外，发现较浓烟雾在该过程早期的团聚率远高于稀薄烟雾，但在后期差异趋于消失。
