Kim Hyungsu, Lee Jaegeun, Won You-Yeon
Department of Chemical Engineering, Dankook University, Yongin-si, Gyunggi-do 448-701, Republic of Korea.
School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA.
Ultrasonics. 2015 Aug;61:20-4. doi: 10.1016/j.ultras.2015.04.007. Epub 2015 Apr 25.
A simple model is proposed for the ultrasonic atomization of polymer solutions. In this model, the atomization process is approximated as an equilibrium process. It is shown that the minimum attainable droplet size is determined by two parameters, the (Rayleigh) acoustic pressure acting on the surface of the liquid, and the surface tension of the liquid. Increasing the viscosity of the liquid suppresses the formation of small-sized droplets because of increased attenuation of the sound wave and thus decreased acoustic pressure. Lowering the surface tension of the liquid (e.g., by spreading a surfactant film on the liquid surface) has the opposite effect of enhancing the formation of smaller droplets. Also, there exists a maximum limit for the droplet size, because when the produced droplet is too large, the aspiration flow is unable to carry the droplet against sedimentation. These predictions are supported by experimental observations.
提出了一种用于聚合物溶液超声雾化的简单模型。在该模型中，雾化过程近似为一个平衡过程。结果表明，可达到的最小液滴尺寸由两个参数决定，即作用于液体表面的（瑞利）声压和液体的表面张力。由于声波衰减增加从而声压降低，液体粘度的增加会抑制小尺寸液滴的形成。降低液体的表面张力（例如，通过在液体表面铺展一层表面活性剂薄膜）具有促进形成更小液滴的相反效果。此外，液滴尺寸存在一个最大极限，因为当产生的液滴过大时，抽吸流无法携带液滴抵抗沉降。这些预测得到了实验观察结果的支持。
