The Study On Charging And Agglomeration Of Micro-particles In ESP Flue

Entering 21st century,the dust pollution in China will be more and more serious for the large consumption of energy with high speed of economic development.In order to achieve sustainable development,there will be a wide application of ESP in thermal power plant,steel plant and cement plant.But the existing ESP has the problem of large volume, high investment and low efficiency of micro-particles removal.To improve the problem, the author,combined with National Natural Science Foundation of China:Basic Study on Ionic Kinetic Laws and Application in Strong Electric Field at Atmospheric Pressure(No.60471036) and Study on Ionic Charge and Agglomerate in AC Strong Electric Field of Electrostatic Precipitation(No.50578020),carried out the experiment of particles agglomeration under the circumstance that the pre-charge facility is installed in the soot channel of electrostatic precipitator.There will be high plasma density in the soot channel of electrostatic precipitator because the particles can charge sufficiently by adding pre-charge facility in the high gas velocity.The agglomeration field is high voltage alternating current and the particles is produced by silicon powder and talcum powder.The result shows that the equipment has agglomeration effect to all the particles.Different agglomeration field has been chosen with different particles in the experiment.The best agglomeration electrode is strip-to-strip,plate-to-plate and plate-to-strip when the particles are silicon powder,talcum powder and the mixture,respectively.When the electric-field intensity is 5～5.5kV/cm and the frequency is 80～110Hz,the agglomeration effect of particles is the best.The percentage of micro-particles can decreased by 23.4%,30.9% and 28.7%,respectively,which is the foundation of increasing micro-particles collection efficiency.Ion concentration tester made by principle of ion direct motion in electric-field can get rid of the limitation of air velocity when flat-plate tester is used.The tester we developed can test the ion concentration when the air velocity is 5～40m/s.In addition,the tester has the advantage of simple structure,small volume,little influence to environment,so it is suitable for point measurement.The tester provide suitable equipment for the study of ion distribution in ESP. In the foundation of result above,the pre-charge facility can be installed in front of sootwhere the air velocity is about 20m/s.through this way,we can enhance the function and decrease the volume of ESP.So the volume,energy consume and expense can all be decreased.