Experimental Study On Collection Of Fine Particle From Coal-fired Power Plants By Wet Electrostatic Precipitator

The emissions of fly ash from coal-fired plants are one of main sources of fine particulate matter pollution in the air. To solve this problem, adding wet electrostatic precipitator(WESP) after wet desulphurization system is designed to remove fine particulate matter. Spray atomization system as an important part of WESP, the atomization characteristics have great influence on dust collection efficiency. Through exploring the nozzle atomization mechanism, and testing the nozzle atomization performance, the effects of spray atomization characteristics and other work conditions on V-I curve and the collection efficiency of WESP has studied in order to achieve high collection efficiency of WESP.Fistly, fly ash is characterized to analyze the apparent morphology, chemical composition and particle size distribution characteristics. Secondly, atomizing nozzle parameters are measured, aiming at the droplets diameter and spraying quantity at different water pressure. In addition, the V-I curve is test to analyze its impact on WESP.Finally, using fly ash from coal-fired plants as the dust source, the collection efficiency at different conditions is obtained. Results show that:(1) The fly ash mainly consists of oxide, and the organized structure is scattered ball and irregular dust with the median diameter of 16.66 μm.(2) The best water pressure is 0.6 MPa of when WESP works while the atomizing performance is best.(3) Using fly ash from coal-fired plants as the dust source, the collection efficiency increases with the droplets diameter decreases or spraying quantity increases as in the same other conditions. The highest collection efficiency can be99.57% while droplets diameter is 70 μm. The WESP can satisfy the efficient removal of fine particulate matter from coal-fired plants.The experimental researches above show that wet electrostatic precipitator is applied to removal of fly ash from coal-fired plants, which is able to make the dust concentration down to 10 mg/m3 or less. The study is of great theoretical and practical significance for the design of wet electrostatic precipitator spray system in engineering and high collection efficiency of fine particulate matter.