Experimental Parametric Study of Frequency and Sound Pressure Level on the Acoustic Coagulation and Precipitation of PM_(2.5) Aerosols

Mohsen Amiri ； Asghar Sadighzadeh ； Cavus Falamaki

《Aerosol and Air Quality Research》 16卷12期 (2016/12) Pp. 3012-3025

https://doi.org/10.4209/aaqr.2015.12.0683

摘要

The efficiency of particle removal for PM_(2.5) aerosols using conventional separation systems is generally low. In this paper, acoustic precipitation and coagulation of aerosols as a preconditioning system is investigated experimentally. The results of experimental study concerning the effect of frequency and sound pressure level (SPL) on the acoustic coagulation and precipitation of PM_(2.5) aerosols are presented. An acoustic particle conditioning setup was used to perform experiments at the resonance frequencies of 204, 550, 650 and 749 (Hz), and SPLs 140, 150, 155, 162 dB. All experiments were performed under ambient condition and similar initial concentration. The experimental results showed that the effect of acoustics on filtration efficiency is amplified by increasing the frequency and intensity. Eventually, at the frequency of 749 (Hz) and 162 (dB) the acoustic coagulation and precipitation efficiency reaches about 83% which is significant. The results of this study (experimentally and theoretically) prove the existence of a threshold in SPL (≥ 155 dB) at which the acoustic precipitation and coagulation efficiency increase rapidly, implying the importance of turbulence coagulation interactions at high intensity acoustic waves. In addition, a new empirical correlation was developed for the acoustic coagulation and precipitation efficiency with reasonable accuracy.

關鍵字

Aerosol coagulation ； Precipitation ； Acoustic wave ； Coagulation kernels ； Turbulence interactions