Experimental Study On Submicron Particles Agglomeration Enhanced By Charged Droplets

China is the country with the maximal coal yield and consumption. Particulate matter is one of the main sources of atmospheric particulate pollutants in China.33percent of total suspended particles in the air are generated by coal fired, including35percent submicron particles, which are hazard to the atmospheric environment and people’s health. Urgent to control the submicron particles has aroused a world-wide attention. China will gradually raise the standard of coal-fired power plant dust concentration to30mg/Nm3. The key to achieve that goal is the control of submicron particles.90%of coal-fired power plants in China adopt ESP. However, submicron particles are too small for electrostatic precipitators to remove. It is necessary that we should find an effective way to deal with submicron particles and improve the traditional precipitators.Physical or chemical agglomerations of submicron particles can make the size of particles big enough to be removed by traditional precipitators, which will increase the separation efficiency of submicron particles effectively. The technology of submicron particle agglomeration will be one of the trends on flue gas dust removal in the future. This thesis presented a method of submicron particles agglomeration enhanced by charged droplets. Experimental systems were designed and built. Under the condition of power plant dust control temperature, studies were taken which focus on submicron particles agglomeration enhanced by charged droplets. At last this paper gave the application project and feasibility analysis on droplets charged technology applied to traditional precipitators.Firstly, droplets size distribution was investigated and analyzed under induction charged. This paper investigated and analyzed impacts of factors including atomizing air pressure, water volume, which is the foundation for the next step for experimental study on submicron particles agglomeration enhanced by charged droplets. Secondly, particles size distribution was investigated and analyzed under induction charged. This paper investigated and analyzed impacts of factors including atomizing air pressure, water volume and the influence of electrostatic voltage on the experiment. According to the above two rules, the best water spray quantity is8L/h, the best atomizing air pressure is0.35MPa.Finally, pilot experimental system was designed and built. According to the atomizing pressure of0.35MPa, water volume of8.0L/h, the charged voltage of12kV and other parameters, we verified the efficiency of submicron particles agglomeration enhanced by charged droplets. The removal efficiency of droplets under10μm was studied. The mass concentration removal efficiency was54.80%, obviously better than30.60%of the mass concentration under the action of only electrostatic precipitator removal efficiency. Combining research results and theoretical analysis, this thesis presented the application project and feasibility analysis on the technology of submicron particle agglomeration enhanced by charged droplets.