Effect of charged desulfurization wastewater droplet evaporation on the agglomeration of fine particles

Abstract The evaporation of desulfurization wastewater (DW) using hot flue gas is an effective treatment method for DW. However, its application is limited owing to a slow evaporation rate and formation of fine crystalline particles. To increase the evaporation rate of DW and the agglomeration efficiency of fine particles, a technology for the evaporation of charged DW droplets was proposed and investigated. The influence of factors such as induction electrode voltage, atomization pressure, and Cl¯ concentration on the agglomeration of fine particles and the charge transfer characteristics between droplets and particles was studied. The results showed that increasing the induction electrode voltage and atomization pressure and reducing Cl¯ concentration improved the agglomeration efficiency of fine particles. Compared to the uncharged droplet conditions, the agglomeration efficiency of fine particles increased by 57.12% under conditions of 12 kV induction electrode voltage, 0.3 MPa atomization pressure, and 20 g/L Cl¯ concentration. The relative agglomeration efficiency of the ultra-fine particles and particles in the 0.1–1 μm size range also increased. After evaporation of the charged DW droplets, most of the electric charge of the droplets remained on the dry agglomerated particles. Agglomerated particles exhibited characteristics of chains and irregular clusters, and were tightly connected by solid bridges. The study results confirmed the feasibility of using the atomization of charged droplets to treat DW more effectively and improve the agglomeration efficiency of fine particles. .