Study On Desulfurization Wastewater Charged Evaporation Coupled With Particle Moisture Absorption To Promote Fine Particle Agglomeration And Removal

The typical combination of limestone-gypsum wet desulphurization technology and electrostatic dust removal technology for pollutant control of coal-burning flue gas achieves ultra-low emission,but at the same time,it is difficult to treat desulfurization wastewater and the removal efficiency of fine particles is not high.The technology of fine particle agglomeration promoted by charged desulfurization wastewater evaporation can improve the evaporation rate of desulfurization wastewater,promote the agglomeration of fine particles and improve the removal efficiency of fine particles,and realize the cooperative treatment of desulfurization wastewater evaporation crystallization and fine particles.However,the increase of chloride ion concentration will increase the number of fine particles in flue gas,which affects the efficient removal of fine particles to a certain extent.In order to solve the above problems,based on the previous research on charged desulfurization wastewater evaporation to promote fine particle agglomeration,this paper proposed the technology of desulfurization wastewater charged evaporation coupled with particle moisture absorption to promote fine particle agglomeration and removal,and established a pilot test system to explore the particle agglomeration characteristics of desulfurization wastewater before charged evaporation.Combined with force analysis and molecular dynamics simulation,the influence of different factors on agglomeration and removal efficiency of fine particles were studied.The main results were as follows:(1)Through the division of the whole research process and force type analysis and order of magnitude calculation,it is determined that the main forces in the movement of particles were the drag force,gravity and buoyancy,electrostatic force,thermophoresis force,diffusiophoresis force,liquid bridge force and van der Waals force.In the charged evaporation stage,electrostatic force,thermal force and diffusion force played a major role in promoting the agglomeration of fine particles.In the particle moisture absorption stage,thermal force played a leading role in the removal and agglomeration of fine particles.(2)Molecular dynamics simulation was used to study the interaction between hygroscopic particles and fine particles surface model,and the results showed that the interactions between hygroscopic particles and fine particles mainly came from the van der Waals force,the higher temperature,increased the content of calcium chloride,and increased the amount of water molecules could enhance the interactions between hygroscopic particles and fine particles.Combined with the results of thermos-gravimetric analysis on the hygroscopic characteristics of hygroscopic particles,the increase of temperature and humidity was beneficial to the agglomeration of hygroscopic particles and fine particles.(3)Using pilot experiment system for particle moisture absorption to promote fine particles agglomeration and removal research,the results showed that the increased charged voltage and cooling water flow rate were beneficial to promote the fine particle removal and agglomeration,although weakened the increased concentration of chloride ion for the promotion of fine particle removal effect,but from the whole process point of view on charged evaporation and particle moisture absorption,it greatly promoted the agglomeration and removal efficiency of fine particles,and the reduction of fine particles was up to 66.4%in the experiment.The above conclusions provided experimental data and theoretical support for the study on the desulfurization wastewater charged evaporation coupled with particle moisture absorption to promote fine particle agglomeration and removal,which was of great significance for promoting the efficient treatment of desulfurization wastewater and the removal of fine particles.