A novel drift eliminator enhanced by Voronoi-based porous foam applied to liquid desiccant system: Separation performance and preliminary design

Abstract

A novel drift eliminator enhanced by Voronoi-based porous foam (VPF-enhanced drift eliminator) is proposed for the control of salt-spray aerosol in liquid desiccant systems. The gas-liquid flow characteristics though VPF-enhanced drift eliminator under different conditions are examined numerically and verified by the experimental results in the literature. Additionally, a new prediction model of separation efficiency is obtained based on response surface methodology. The results show that 3-D modeling of porous foam based on Voronoi technology can well characterize the structure properties of actual porous foam in terms of meso-scale (i.e. pore shape, strut orientation and cell topology) and macro-scale (i.e. strut diameter and porosity), which provides support for more accurate analysis of separation performance from the microscopic aspect of droplet. Separation performance exhibits a strong dependence on the structure properties of porous foam and operating conditions. Moreover, the interaction of thickness and porosity has a significant impact on separation efficiency. For porous foams with relatively low resistance (i.e. smaller thickness and higher porosity), separation efficiency can be simply quantified by the specific surface area of the porous foam. For relatively high resistance, it is jointly determined by the specific surface area and resistance. It is concluded that prediction model combined with multi-objective optimization can provide guidance for the structural design and selection of VPF-enhanced drift eliminator. Meanwhile, Voronoi-based porous foam can be conveniently processed by the additive manufacturing techniques, which provides engineering significance for the development of VPF-enhanced drift eliminator under specific needs.