Experimental Study On Charged Spray Dust Removal Based On Desulfurization Tower Model Device

With the country’s emphasis on air pollution prevention,the emission control policies of coal-fired power plants are becoming more and more stringent.Wet flue gas desulfurization(WFGD)is used as the end-process of flue gas treatment,with the function of synergistically removing fine particles.The technology of trapping fine particles during wet desulfurization process has attracted people’s attention.Previous research has proven that charged droplets can actively adsorb particulate matter,which can in addition enhance the removal efficiency of particulate matter.It is one of the most promising technology for enhancing the removal of fine particles and is expected to reduce the concentration of particulate matter in the desulfurization tower.Based on the desulfurization tower structure,a model desulfurization tower dust removal experimental device was built.The charge characteristics of electrostatic spray and fine particle removal characteristics were experimentally studied.It could lay a foundation for the application of charged spray to remove particulate matter in desulfurization tower.The main research work is as follows:1.Based on the test bench of measuring droplet charge,the charge-to-mass ratio,droplet size and charge decay characteristics under different conditions were analyzed.The conditions and installation positions of electrostatic atomizing nozzle used in the model desulfurization tower were determined.The results show that compared with inductive charging,the corona charging is unstable but can make droplets get better charging effect.The droplet charging effect is related to the diameter of the electrode ring and the electrode spacing.The best charging effect is that the electrode ring diameter is 80 mm and the electrode spacing is 40 mm.As the transport distance increases,the charge carried by the droplet will decrease.Considering the change of droplets charge and the spatial distribution,it is decided that the electrostatic atomizing nozzle is installed 50 cm above the entrance of the model desulfurization tower.2.Based on the wet desulfurization technology of coal-fired power plants,the experimental platform of the desulfurization tower dust removal system was designed.The effect of different operating conditions on the particulate removal efficiency was investigated.The characteristics of particulate removal by charged and uncharged sprays were analyzed.The results show that the particulate removal efficiency increases with increasing particle size,the removal efficiency increases first and then decreases with the increase of spray flow.The best dust removal effect can be obtained when the spray flow is 50L/h.The removal efficiency increases with the increase of dust concentration,and the influence of flue gas velocity on it is more complicated.Compared with the uncharged droplets,the charged droplets have a better removal effect on the particles,especially for small particles,the maximum removal efficiency can be increased by 14.1%.3.In order to solve the problem of stable charging in high humidity environment,a purge type electrostatic atomizing nozzle was designed.The charged effect of droplets in a closed high humidity environment and the characteristics of particulate removal in a model desulfurization tower were tested.The results show that the designed purge type electrostatic atomizing nozzle can stably charge in high humidity environment,the charging voltage can be loaded above 14 kV.As the loading voltage increases,the particulate removal efficiency can be further improved.Then a technical scheme of applying charged spray in the desulfurization tower is given.