Experimental Research On Reducing Fume Emission From Electrostatic Precipitator In Sintering Machine Head

China as a large steel country,there are a mass of exhaust emissions and industrial dust emissions in it every year,and these emissions also caused serious air pollution problems,of which fine particulate matter are the major factor of haze.electrostatic precipitators,as the mainstream equipment for dealing with dust in sintered flue gas,has the advantages of no secondary pollution and high collection efficiency,but the treatment effect of fine particulate matter is not good.In order to reduce the dust emissions of the sintering machine,this paper will make full use of the overall structure of the existing electrostatic precipitators,by changing the electrode structure,reordering the air flow state in the electrostatic precipitators,to improving the collection efficiency of fine dust in sintered flue gas.In this study,the dust in the flue gas of a steel mill sintering machine was selected,The actual working environment of the dust remover was replaced by the laboratory environment,two kinds of corona wires(circular linear electrode,barbed electrode)and collecting electrodes(traditional plate,perforated plate)were used to form a variety of electrodes configurations to explore the best conditions for removing fine dust of the sintering machine head.Firstly,the small particle dust of the fourth-felid of the sintering machine head ESPs were selected in the experiment.,The particle size distribution and physical characteristics of the dust were analyzed.Corona dust removal experiments were carried out under different working voltages and different electrode distributions,and the respective dust removal results were studied.It was found that dust in the fourth-felid has large porosity,large specific surface area,and large proportion of dust in the small particle size range.It is easy to escape from the dust collecting space with a primary flow in the work process.The dust attached to the collecting plate will also be scrubbed by a primary flow or in the process of mechanical dust rap cause secondary dust,affecting the dust removal effect.Dust with irregular shape and rough surface is not conducive to uniform charge in corona electric field.Comparing the total efficiency of collection in the best working conditions of 5 extremely electrode distributions,it is found that the total efficiency of the applied perforated plate is higher than that of the traditional plate.By analyzing the distribution of the number of dusts collected by each electrode distribution and the mass distribution,it can be learned that the perforated plate has an obvious positive effect on the collection of fine dust.The dust particle size distribution collected at barbed electrodeperforated plate(the projection of the barbed electrode on the perforated plate coincides with the center of the hole)electrodes configuration and 45 k V working voltage is closest to the original dust at the entrance of the fourth-field,and combined with collection efficiency can be known,this electrode distribution is the best one for collecting fourth-field dust.Secondly,Analyze the force of charged particles in the electric field,and use fluid simulation software to simulate the fluid in the electric field.It was found that small diameter size particles compared to large diameter size particles saturated charged is smaller,It is less affected by electric field forces;with the increase of voltage,ion wind speed grows exponentially,more susceptible to ion wind disturbance,deviation from the original direction of motion,along the direction of ion wind air flow,or from the collecting plate to re-enter the dust collection space by ion wind.Large diameter size particles may not be disturbed by ion wind within a certain working voltage range,but as the voltage continues to rise,it will eventually be affected by ion wind.Reasonable application of the perforated plate can change the flow field structure of the ion wind,effectively reduce the disturbance effect of the ion wind,reduce the negative effect of the ion wind to the collecting plate and the primary flow,The fine particle,which is greatly affected by the ion wind,will be bounded to the back of the perforated plate along the direction of ion wind air flow,and the large diameter size particle will arrive in the collecting plate under the combined action of the electric field force and the ion wind.Finally,the transformation direction of first electric field of sintering machine head ESPs is explored.It was found that though the first field inlet dust is large particle size dust,it also obtains a higher removal efficiency than the traditional plate-matching method when the perforated plate is used,and does not affect the removal of large particle size at the same time improve the removal of fine particle,thereby reducing the subsequent electric field on the working pressure of fine particle,so the perforated plate is very suitable for the first field of the sintering machine head ESPs,too.In addition,according to the different flue gas reasonable set the length of the electric field,to avoid waste,reduce costs.