Capturing liquid aerosols with thin fibrous filter

Various filters are used to recover liquid aerosols from the air. Filtering liquid droplets from the exhaust flow of a power plant, reduce the noxious emission of aerosol from chemical plants and also capturing the morning fog in a deserted area to get drinking water are samples of liquid filtering. Fig. 1 shows a liquid-based aerosol filterwhich consists of 3D networks of fibers: the droplets are collected by the solid fibrous part of the filter while the gaseous phase passes through it. It is of obvious practical interest to improve the efficiency of filters especially when it is needed to capture as much as toxic liquid aerosols from a media. 

Fig 1: sample liquid filter

In order to gain a detailed understanding of the complex physical phenomena in filtering, it is useful and reasonable to start with a simple situation. Therefore, a single droplet impacting on a thin fiber is modeled. The effect of droplet velocity and radius, centered and off-centered impact, size and wettability property of the fiber on the ability to capture the droplet are investigated. Fig. 2 shows experimental results for trapped and non-trapped silicon oil. 

Fig. 2: top panel: The drop of silicon oil falling at 20 cm/s is entirely captured by the fiber, bottom panel:a drop of silicon oil impacting at V = 95 cm/s a horizontal fiber of radius is not trapped by the fiber. (Lorenceau, É., Clanet, C. and Quéré, D., 2004. J. colloid and interface science, 27, pp.192-197.)

A FORTRAN code based on the multiphase lattice Boltzmann technique is used for simulations. This project is available from September 2016.



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