Charge And Movement Of PM2.5 In Electrostatic-Bag Precipitator

Coal-fired flue gas emitted from industrial boilers is the main source of fine particulates in the atmosphere,and these fine particulates are the main factors affecting the air quality and visibility.Dust removal equipment commonly used in coal-fired boilers includes electrostatic precipitators and bag filters.In recent years,the appearance of electrostatic-bag precipitators(EBP)has made a significant contribution to the development of the dust removal business.As a combination of electrostatic precipitators and bag filters,EBP has the advantages of high dust removal efficiency,low filtration pressure and so on.Research on the EBP has become a hot spot for a long time,but the charge and movement mechanism of the fine particles need to be further studied.In this paper,the experimental platform of EBP was designed and set up.The charge effect and movement state of fine particles in the precipitator were studied,and the performances of precipitator under the different working conditions were compared and analyzed after the formulation of a reasonable experimental program,and the selection of experimental equipment and materials.The corona ion wind in the electric field has an important influence on the charge trapping of the dust particles.In this experiment,the particle motion state in the electric field was visually tested by PIV,and the influence law of ion wind on the particle motion under different electric field voltage was obtained.At the same time,the motion state of charged particles in the part of bag filter was studied,and the force situation and movement of charged particles in bag filter were revealed.The charge amount,porosity and pressure drop of dust layer on the surface of filter media were studied in the experiment,which provided a theoretical basis for further study on the trapping mechanism of fine particles in EBP.The experimental study on the capture effect and charge situation of particles was conducted by ELPI+.The influence of electric field voltage,filtration speed and electric field structure on the charge and trapping efficiency of fine particles was studied.With the rise of the voltage,the charge and trapping effect are both improved.The increase of filtration speed is harmful to the charge capture of the particles,so it is essential to set an appropriate filtration speed.In addition,the structure of electric field can cause certain effect on the performance of precipitators,the prickle electrode can discharge better than wire electrode and spiral electrode,which is beneficial to the fully charged of particles,and the trapping efficiency can be improved by the reasonable addition of the electric field series.It's not significant that the influence of filtration time on the charge trapping effect.