Experimental Research On The Influence Of Ionic Wind On The Internal Flow In Wire-plate Electrostatic Precipitator

The electrostatic precipitator plays an important role in industrial dust control with its low pressure loss,treatment of large volume flue gas and high collection efficiency.However,collection efficiency of submicron particles is low in ESP,because the collecting of submicron particles is affected not only by the difficulty of charging but also by the ionic wind disturbed.In order to improve the collecting efficiency of submicron particles,it is necessary to analyze the ionic wind motion in the electrostatic precipitator.In this research,the C480 collecting plates and RS spiked electrodes is used,combining with PIV technology,to study the effect of ionic wind on the internal flow field of the electrostatic precipitator during corona discharge.This study also explores the speed of ionic wind in the area of mainstream and near the ground plate by changing the number of RS spiked electrodes,voltage and the speed of airflow.The main conclusions are as follows:(1)The maximum ionic wind velocity will appear at 25 ± 3mm obliquely below the tip of electrodes.The relation between ionic wind velocity V,distance L and voltage U was obtained as V=-(0.0005U+0.0013)(L-L0)2+0.0342U+0.018.From the motion law of ionic wind near the ground plate,the influence of velocity z-component is the largest,and velocity y-component is the smallest.The variation trend of ionic wind velocity near the plates indicates that increasing the distance between plates will reduce the disturbance of ionic wind to the airflow,which is beneficial to improve the submicron particle collecting efficiency.(2)When the single electrode wire is discharged,the increase of voltage will make the particle motion in the composite field more complicated.When the secondary voltage is too high,the vortices generated in the channel and caused some particles which is near the ground plate flow out of the electric field following the airflow and affect particle collecting.Increasing the speed of the airflow will weaken the vortex motion in the channel.When the voltage is 65kV and the electric field wind speed exceeds 1.0m/s,the ionic wind will only change the direction of the airflow near the spiked electrode’s tip,making it slightly deflected.At the same time,the velocity x-component ratio of particles near the plate decreased,and the velocity z-component ratio of particles near the plate increased.When the airflow velocity is 0.8m/s,he velocity z-component ratio reaches the maximum.(3)When the several electrode wires are discharged,the results show that the increasing of wire distance will reduce the intensity of vortex,at this time,the deflection degree of air flow will be weakened,resulting in the decrease of air flow velocity near the plate.Influenced by the decrease of vortex intensity,the velocity y-component along the direction of electric field force increases gradually,and the displacement of particles moving towards the plate increases,which is conducive to particle collection.