Lee Dukyoung, Kang Jumin, Son Younggyu
Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea.
Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea; Department of Energy Engineering Convergence, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea.
Ultrason Sonochem. 2023 Oct 24;101:106659. doi: 10.1016/j.ultsonch.2023.106659.
The effects of violent mixing and reactor geometric conditions were investigated using the overhead stirrer and high-speed homogenizer in 28-kHz sonoreactors. The sonochemical oxidation activity was quantified using the KI dosimetry method, and the sonochemical active zone was visually observed using the luminol method. Higher mixing rates resulted in a significant enhancement of the sonochemical oxidation activity, primarily due to a significant change in the sonochemical active zone. When using the overhead stirrer (0-2,000 rpm), the highest activity for 2λ and 3λ occurred at 500 rpm, whereas the highest activity for 4λ was obtained at 250 rpm. For the high-speed homogenizer (0-12,000 rpm), the highest activity was consistently obtained at 3,500 rpm across all liquid height conditions. The impact of mixing position (Top, Mid, and Bot positions) on sonochemical activity was analyzed. The results revealed that the lowest activity was obtained for the bottom position, likely attributed to significant ultrasound attenuation. The reactor size effect was investigated using the high-speed homogenizer in five cylindrical sonoreactors with different diameters (12-27 cm). It was found that very low activity could be observed due to unexpected geometric conditions, and the application of mixing (3,500 rpm in this study) could result in high sonochemical activity regardless of geometric conditions.
在28kHz声化学反应器中，使用顶置式搅拌器和高速均质器研究了剧烈混合和反应器几何条件的影响。采用KI剂量法对声化学氧化活性进行定量，并采用鲁米诺法对声化学活性区进行可视化观察。较高的混合速率导致声化学氧化活性显著增强，这主要是由于声化学活性区发生了显著变化。使用顶置式搅拌器（0 - 2000转/分钟）时，2λ和3λ的最高活性出现在500转/分钟，而4λ的最高活性出现在250转/分钟。对于高速均质器（0 - 12000转/分钟），在所有液位条件下，3500转/分钟时始终能获得最高活性。分析了混合位置（顶部、中部和底部位置）对声化学活性的影响。结果表明，底部位置的活性最低，这可能是由于显著的超声衰减所致。使用高速均质器在五个不同直径（12 - 27厘米）的圆柱形声化学反应器中研究了反应器尺寸效应。结果发现，由于意外的几何条件，活性非常低，而应用混合（本研究中为3500转/分钟）无论几何条件如何都能产生高声化学活性。
