Cloud chamber experimental study for acoustic fog elimination technology

Scholars have previously shown that sound waves can promote the collision and growth of cloud droplets. To determine the optimal acoustic parameters for fog removal, a cloud chamber with a diameter of 1.0 m and a height of 7.5 m was constructed in this study. The effects of low-frequency (<100 Hz) sound waves on the dispersion of dense fog at different sound pressure levels (SPLs) were studied and compared with those of traditional hygroscopic salt. Experiments showed that low-frequency sound waves can effectively promote the collision and growth of droplet particles in the cloud chamber and accelerate the evolution process of droplets in the cloud chamber. Moreover, sound waves with relatively low frequencies (<50 Hz) and high sound pressure levels (>125 dB) have a highly significant effect; the low-frequency sound waves defogging effect is better than that of traditional artificial defogging with hygroscopic salts. Importantly, experiments indicated that there are two mechanisms for low-frequency sound waves fog removal in different frequency bands: (1) the collision and dissipation mechanism under the action of 40 Hz sound waves and (2) the evaporation and dissipation mechanism under the action of 25 Hz sound waves. The results of this study objectively verify the feasibility of sound waves fog removal technology. Considering its advantages of low cost, no chemical pollution production, strong mobility, and good environmental adaptability, sound waves defogging has broad application potential in the field of artificial fog removal.