A study of wavy falling film flow on micro-baffled plate

作者：Ishikawa Hideaki^*; Ookawara Shinichi; Yoshikawa Shiro

来源：Chemical Engineering Science, 2016, 149: 104-116.

DOI：10.1016/j.ces.2016.04.021

• Falling film
• Microreactor
• Flow visualization
• CFD
• VOF

The effects of baffles, flow conditions and fluid properties on wavy motion of falling film were examined experimentally and numerically. Visualization showed that the liquid film became wavier by increasing the baffle distance and by changing liquid from water to methanol in the range of Reynolds number less than 42. Subsequently, the falling film behavior was numerically investigated by adopting VOF method. The qualitative agreements under similar flow conditions well validated both of visualization and numerical methods. The numerical results showed that a higher baffle tended to cause film break-up while the break-up was prevented by increasing the flow rates. As Reynolds number increases, the liquid film became wavier and further surface deformation became obvious. Those results demonstrated that properly-baffled reaction plate could form a noticeably wavy and deformed but quasi-stable falling film at a given flow rate for an organic solvent. The amplitude of wavy falling film on the baffled plates was correlated with Reynolds number, Bond number and non-dimensional geometrical factors, while the thickness of the wavy falling film was correlated with the non-dimensional geometrical factors. It was finally suggested that the possible enhancement of gas absorption due to the surface deformation of liquid film is of further interest targeting process intensification.

• 出版日期2016-7-31