The Experimental Study On Collection Effect Of Fine Dust For A Novel Plate

The seriousness of the current air pollution problem has aroused extensive attention from all walks of life, especially the fine particulate pollutants PM2.5 which are harmful to the health of the human. Now the state and the provinces governments have begun to monitor and control the air pollution.In order to improve the collecting efficiency of the fine dust for electrostatic precipitator, especially the dust PM2.5, taking the construction dust which is coming from one of the three main sources of PM2.5 as the research object, the force conditions of the charged particles in the discharge space were analyzed, and the motion states under the action of these forces were studied to analyze the reason of low collecting efficiency for fine dust.Considering the reason and the development direction of dust collector, a new type of metal net-bag collection plate for the electric-bag composite device was designed. The voltage current characteristic of the novel device was analyzed to prove the rationality of the design. Besides, the collection effect of fine dust was studied by using the new type of electric-bag composite experimental device, compared with the traditional one.It is concluded that the metal net-bag structure of the new plate is in line with the characteristic of the wire plate corona discharge, and it is better than the traditional electrode, which proves the rationality of the design of the new plate.Ion wind which is advanced with the increasing discharge voltage becomes the main reason that fine dust collecting efficiency is low for electrostatic precipitator. Weakening the influence coming from the ion wind is the basis of the reform of the dust collector.The strong role in binding of metal net-bag for fine dust has reduced the disturbance effect coming from the ion wind and its good air permeability has destroyed the double helix structure of ion wind and weakened the strength of the helical fluid structure formed by the ion wind in the electric field. The cumulative percentage of fine dust collected by the new type electrode plate is higher than that of the traditional electrode plate, that is to say, the collecting effect of the fine dust is enhanced relative to traditional plate.In addition, under the premise of the metal net-bag area of the new plate being placed upright to the corona wire, metal net-bag structure increased the wind speed of the diverted ion wind which is pointed upright from corona wire to the metal net-bag area and reduced the speed of ion wind pointing to the adjacent metal net-bag area which is inclined to the corona wire.The distribution of fine dust on collecting plate was changed due to the changes of ion flow field, the cumulative percentage of the fine dust collected on the new metal net-bag which is uprightness the corona wire is larger than that of the area inclined to the corona wire.In addition, with the increase of discharge voltage, shunt for ion flow is more obvious, and the difference about collection effect is larger between the areas which are upright and inclined to the corona wire. Therefore, it is reasonable to carry out the metal net-bag structure arrangement, which can further improve the collection efficiency of the electrostatic precipitator to the fine dust.The collection effect of fine dust for the new metal net-bag plate combined with the advantages of electrostatic precipitator and bag filter is obviously enhanced, which realizes the integrated design of the two kinds of precipitators and provides the experimental and technical support for the updating of the transformation of the existing electrostatic precipitator.