Study of the effect of water mist particle characteristics on the dust reduction efficiency of respirable dust
To effectively remove respirable dust in industrial production and improve the efficiency of water mist particles in capturing respirable dust,a numerical model of single-particle mist-dust collision coupling in high-speed airflow is established based on the three-phase flow theory.The effect of the mist-dust particle size ratio and relative velocity on the surface line integral wetting humidity of dust particles is analyzed.The study shows that for different particle size classes of respirable dust,the particle size ratios of fog to dust to achieve the optimum wetting humidity are different when the high-velocity aerosol acts with them.k(PM1)=15,k(PM2.5)=2 andk(PM5)=1,and the optimum dust-catching water mist is less than 15 μm.When the relative motion of mist-dust is different in the high-speed airflow,the optimum moisture of dust particles increases with the increase of the relative velocity U.A simulation model is built to study the dust capture efficiency of the water mist particles under different conditions and to compare and analyze the dust particle capture capacity of different particle sizes of the water mist particle field.The results show that the dust reduction efficiency of supersonic atomizing nozzles for respirable dust is 95.95%,the dust reduction eficiency of single fluid nozzles is 82.98%,and the dust reduction efficiency decreases by 1.38%by reducing the relative velocity of mist-dust particles under the same conditions.Combined with the comparative analysis of field tests,the influence law of the ratio of mist-dust particle size and relative velocity on the linear integral moisture of dust particle surface is verified.The results show that the better the optimal particle size ratio of the nozzle is,the higher the dust removal efficiency is.Increasing the collision velocity of dust particles can improve the capture efficiency of dust particles and lay a theoretical foundation for the treatment of respirable dust and clean industrial production.