Experimental Study On Charging Performance And Dust Removal Effect Of Water Mist

Water mist charged removal dust technology is a new dust fall technology,which can prevent the second dust emission on the premise of effectively removing the exhaled dust and better control the mass concentration of the exhaled dust.In this thesis,the gas-liquid two-phase water mist charged dust removal technology is further studied by combining theoretical analysis with experiment.Firstly,the paper extracts the independent factors affecting the charge-mass ratio of droplets by the path graph method,the orthogonal experiment was designed according to the significance of the factors,the experimental data were processed by the method of multifactor regression analysis,and the prediction equation of the charge-mass ratio under the influence of six factors was obtained.According to the prediction equation,in the range of factor level,when the charge voltage is 12 kV,the gas pressure is 0.2 MPa,the liquid pressure is 0.2 MPa,the electrode spacing is 15 mm,the electrode ring diameter is 60 mm,the nozzle diameter is 0.6 mm,the optimal value of the predicted charge to mass ratio is 441.66 μC/kg,and the error between the actual value is less than 5%;The charge-mass ratio is positively correlated with the charge voltage,gas pressure and electrode spacing,and negatively correlated with the liquid pressure,electrode ring diameter and nozzle diameter.The order of influence degree of six factors is water mist charged voltage,gas pressure,liquid pressure,electrode spacing,electrode ring diameter,nozzle diameter.Secondly,the effects of different dust removal methods on total dust and exhaled dust were experimentally studied.By comparing the experimental results,it is concluded that the gas-liquid two-phase water mist charging technology has better dust removal effect on exhaled dust.Comparing the dust removal effects of total dust and exhaust dust under different charge-mass ratios,it is concluded that the gas-liquid two-phase water mist charged dust removal technology can improve the dust removal efficiency of total dust and exhaust dust,but the dust removal effect of exhaust dust is better,and the better the charging effect of water mist,the better the dust removal effect of exhaled dust.Finally,an orthogonal experiment was designed to study the effects of charged atomization factors of gas-liquid two-phase water mist and wind velocity of dust-laden airflow on dust removal efficiency.Within the range of factor level,the regression model can predict the dust removal efficiency of exhaled dust.When the charge voltage y1 is 12 kV,the electrode spacing y2 is 15 mm,the electrode ring diameter y3 is 60 mm,the gas-liquid ratio y4 is 1.5,the nozzle diameter y5 is 0.6 mm,and the wind velocity of dust-laden airflow y6 is 4 m/s,the optimal value of exhaled dust removal efficiency is 97.26%.Through standardized regression equation,it is concluded that exhaled dust removal efficiency is positively correlated with y1,y2 and y4,and negatively correlated with y3,y5 and y6.The order of importance of factors is y1>y6>y4>y5>y3>y2.By using high-speed digital camera combined with microscopic magnification technology,the morphological changes of single charged droplet and the state of charged droplet adsorbing exhaust dust were visually analyzed with the increase of charging voltage.The effect of water mist charging and the effect of exhaled dust were analyzed from the perspective of image.Compared with traditional spray dust removal technology,gas-liquid two-phase water mist charged removal dust technology reduces the surface tension of droplets,makes droplets break up further,make the particle size smaller,and increase the contact area with the dust.Compared with electrostatic precipitation,the charging voltage requirement is lower,and the phenomenon of secondary dust can be prevented.This technology improves the efficiency of exhaled dust removal and reduces the incidence of pneumoconiosis.This thesis has 21 pictures,8 tables and 57 references.