Numerical Simulation Study On Air Distribution Of Electric Bag Composite Dust Collector

With the social development, the importance of the survival of mankind from environmental issues have been attracted more attention. The composite Electrostatic Fabric Filter, as an effective control of emissions of fine dust, has a good development prospect. The dust stream in Electrostatic Fabric Filter is a complex three-dimensional flow. It is very difficult to make out the internal flow field by the conventional test precipitator. Using computer simulation can analyze the distribution of internal airflow in the dust removal device, and numerical simulation methods have the advantage of reproducibility when compared with the experimental research methods. With a wide application, numerical simulation technology attracts more and more attention. The purpose of this thesis is to deepen people's understanding of the electric bag filter performance in theory, improve the effect of electric bag filter dust through the guidance of the CFD simulation and the solution of the optimization problem of the structure of the Electrostatic Fabric Filter.This thesis a study of the distribution of the flow field in the electric bag filter, based on the electrostatics and fluid dynamics theory. Establish a simulation model of the electric bag filter prototype experimental device use the GMBIT software. On the basis of this simulation experiment, an in-depth analysis of the distribution of the internal flow field is done, using the Fluent software. Discuss the affection of electric bag composite dust removal device to the airflow distribution from the collecting plate opening rate, airflow initial conditions and so on.The results show that, in the original physical model, the electric area is a relatively asymmetrical distribution, while the air flow near the entrance is a large air distribution, the one far away from the entrance is weak, bag flow distribution is more uniform, flow field of the bottom of the bag is in a relative disorder, between the ash bucket and the bottom of the bag there forms a clear swirl. By increasing the opening rate, reduce flow velocity improved the original model, the internal airflow of the electric field area distributed evenly through the judgment of the homogeneity in the electric field. Due to the static pressure difference of the inside and outside of the bag, there is an clear pressure jump at the border of the filter bag, and the local pressure of the parts below the top of the bag is high, the velocity of the filter in the vertical direction of the single filter bag is gradually increasing, this part of the bag can give a thickening processing in engineering design.The study found that the internal circular collecting plate in the cylindrical electric bag filter with diversion holes can be a precipitating electrode plate collecting the dust, meanwhile distribute the air flow and protect the filter bag from the direct airflow and the corona discharge. The air velocity distribution of the precipitating electrode plate inside and outside the circular ring electric field is a gradient distribution, which is conducive to prolonged time of the dust particles in the field area, so that dust can fully charge.