Evaporation and dry products characteristics of charged desulfurization wastewater

The SO2 can be removed effectively by the traditional limestone-gypsum wet flue gas desulfurization technology,but some desulfurization wastewater can be produced simultaneously. At present,using the hot flue gas to evaporate desulfurization wastewater is one of effective ways,but in practical applications,because of the slow evaporation rate of desulfurization wastewater,it is easy to cause scaling and corrosion of the flue. For achieving a better flue gas evaporation treatment of desulfurization wastewater,accelerating the evaporation rate of desulfurization wastewater in the flue,a charged desulfurization wastewater evaporation technology was proposed based on the electrostatic induction charge theory. The flue gas temperature distribution,the particle size distribution of the dried products and the change of charge amount were investigated using a thermal experiment system of charged desulfurization wastewater evaporation under different charge voltages and atomization pressures. The results show that the evaporation rate is limited and the fine particle concentration of dried flue gas is increased due to the presence of salt such as CaCl2 in the desulfurization wastewater. Compared with no charge, the concentration of fine particle is still unimodal distribution after charged desulfurization wastewater evaporation,the charged atomization can raise the evaporation rate of desulfurization wastewater,the dried fine particles can be charged by the charge transfer,and the electric charge quantity of the particle is higher with larger particle size. Affected by the evaporation and fragmentation mechanism of charged droplets,the measurable dried fine particle number decreases with the increase of the charge voltage after desulfurization wastewater evaporation,but the electric charge quantity of dried fine particle increases. While the measurable dried fine particle number increases with the increase of the atomization pressure,but the electric charge quantity of dried fine particle decreases. The polarity of charged voltage has no effect on the particle size distribution of dried product. The feasibility of charged desulfurization wastewater evaporation is proved,and the basic data and theoretical support for the combined evaporation of charged desulfurization wastewater with particles agglomeration are provided.