Experimental Investigations On Dust Particle Removal By Water Mist In An Enclosed Chamber

Dust,which widely exist in industrial and agricultural production processes,has attracted much attention due to its explosion risk and occupational health issues.In recent years,dust explosion accidents and environmental problems caused by dust have become increasingly prominent all over the world,which has brought enormous economic losses and serious impacts to the society.Therefore,it is of great significance to carry out research on dust control technology.In this context,we carried out experimental investigations on dust particle removal by water mist in an enclosed chamber.Considering the different dust collection mechanisms of TSP(dust)and PM5(respirable dust)and to improve the removal efficiency of dust particles in an enclosed chamber using water mist effectively,we investigated the factors that affect the removal efficiency of TSP(dust)and PM5 by water mist.Firstly,the effects of initial dust particle concentrations,particle size and dispersion on removal efficiency was investigated.Various concentrations of TSP and PM5 dust particles has been used in this experiment.Experimental results show that the removal efficiency keep increasing with the initial dust particle concentration increase for operating pressures of 0.4 and 0.8 MPa,while removal efficiency gradually increased with initial dust particle concentration in a certain concentration range,and became saturated thereafter for operating pressures of 1.2,1.6 and 2.0 MPa.The removal efficiency of the water mist to dust with high dispersity is higher than that with lower dispersity.The removal efficiency of water-mist to the TSP dust is higher than that to the PM5 dust under the same conditions.Secondly,in order to investigate the effect of droplet size,velocity,the time of water mist application,and liquid flow rate on removal efficiency,we carried out experiments using water mist generated under different operating pressures applied for 10 s and 5s respectively.The results show that the smaller the diameter of droplets and the greater the speed of the droplets,the higher the removal efficiency can be achieved.In addition,the larger the water mist flow,the higher the removal efficiency can be achieved.However,for the water mist of excellent atomization,increasing operating pressure has little positive effect on the increase of removal efficiency,but caused high energy consumption and water pollution.The extension of water mist application time is beneficial to improve the dust removal efficiency,especially at the low initial dust particle concentration,while has a little effect to improve the dust removal efficiency at high initial dust particle concentration.The effect of water mist duration on TSP removal efficiency is more evident than that on PM5 dust.Finally,a theoretical model for predicting removal efficiency by water mist is developed in this paper.And the theoretical calculation results and the experimental results are compared and analyzed.The maximum deviation between the two results was 15%.According to the experimental environment and the model assumptions,the deviation has been analyzed in this paper,and conclude that the theoretical calculation results is more accurate at the high dust concentration.