Experimental research on aerosol deposition phenomenon in single-sized rising bubble

摘要

Bubble filtration in pool scrubbing is an important physical process to reduce the release of aerosol in gas during a severe accident. In this paper, experimental research on the phenomenon of aerosol deposition in single-sized bubbles was carried out. Also, the characteristic parameters of bubble dynamics, such as bubble diameter, and rising velocity, are synergistically studied with the deposition efficiency, and the quantitative relationship between them was analyzed. The experiments have also revealed the presence of a most penetrating particle size between 125 and 150 nm. The results show that bubble size is a sensitivity factor affecting the deposition efficiency of aerosol, and the deposition efficiency is negatively correlated with bubble size. Under the bubbling condition with nozzle sizes of 0.8 mm and 1.26 mm, the deposition efficiency may decrease from 95% to 81% when the bubble diameter change from 3.1 mm to 6.1 mm. The effect of bubble size on efficiency is mainly reflected in the change in retention time and aerosol migration distance, and this change is caused by the rising velocity instead of the bubble aspect ratio. Moreover, the entrance effect of the bubble formation process is also found in the study, in which the aerosol deposition efficiency caused by the centrifugal effect is positively correlated with the injection velocity and bubble formation frequency.