Effect of salt addition on the coalescence process of droplets on fiber. (15th June 2023)

• Record Type: Journal Article
• Authors: Zhang, Yan; Yan, Shenglin; Bai, Zhishan
• Is Part Of: Chemical engineering science. Volume 274(2023)
• Publication Date: 2023-06-15
• Subjects: Coalescence -- Salt -- Fiber -- DLVO -- Morphological evolution; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2023.118628
• Languages: English
• ISSNs: 0009-2509

Abstract

Highlights: The increase of salt concentration weakens the double-layer force and reduces the pressure barrier. The effect of salt concentration on droplet convergence morphology was obtained. The effect of salt concentration on the oscillation attenuation process was studied. The presence of salt and fiber reduces the production of secondary droplets. Abstract: Fiber coalescence is an economical and effective technology for the treatment of oily wastewater. In this paper, the microscopic coalescence process of salt droplets on the fiber is studied using a high-speed camera and PIV, and the effect of salt on hydrodynamics and morphological evolution is discussed. The results show that the increase of salt concentration leads to a decrease of double layer force, a larger liquid bridge expansion, and a higher capillary wave propagation velocity. When the salt concentration is too high, the capillary wave propagation velocity decreases. A catchment region with a high velocity is formed near the traveling region of the capillary wave, and the velocity can reach 0.03 m/s. The attenuation coefficient of the oscillation process increases with the increase of salt content. By combining fiber and salt, the rate of droplet coalescence can be increased, and the production of secondary droplets can be reduced.