Study on performance of wave-plate mist eliminator with porous foam layer as enhanced structure. Part I: Numerical simulation

Wave-plate mist eliminator with porous foam layers as enhanced structures on vanes to improve separation efficiency for tiny droplets was proposed in this paper. Overall separation efficiency, grade separation efficiency and pressure drop of the mist eliminators were systematically studied by using Computational Fluid Dynamics (CFD) method. The Shear Stress Transport (SST) k-ω turbulence model and Discrete Phase Model (DPM) were adopted to describe the motion of gas phase and liquid phase, respectively. The computational field was simplified by introducing an assumption that the real 3D structure of porous foam can be equivalent to 2D layout with randomly arranged circles. The CFD results showed that the separation efficiency was enhanced by increasing the foam layer thickness. Moreover, a gradual increase in the foam porosity at fixed PPI (pores per inch) value made the separation efficiency increased to a maximum value, then fall to a lower level, while by decreasing the PPI value of the foam at fixed porosity, the separation efficiency increased. Pressure drop was increased both with the increase in the foam layer thickness and PPI value as well as the decrease of the porosity. Furthermore, the flow field and the droplet trajectories were also analyzed.