出口直径对内混式空气雾化喷嘴雾化特性及降尘性能的影响

Influence of outlet diameter on atomization characteristics and dust removal properties of internal-mixing air atomizing nozzle

为了掌握喷嘴出口直径对气水喷雾降尘的影响,基于自行设计的气水喷雾降尘实验平台,对不同出口直径的空气雾化喷嘴流量、雾化特性及降尘性能进行了实测,并对实验结果作对比分析。研究结果表明:随着出口直径的增加,喷嘴耗水量几乎保持线性增长,而耗气量呈现指数增长的变化趋势;喷雾射程和雾滴体积分数均随着出口直径的增大不断增大,而雾化角先增大后减小;出口直径为2. 0 mm的喷嘴雾化质量最好,所形成的雾滴索太尔平均直径D[3,2]最小,且雾滴粒径呈现正态分布,雾滴尺寸较为集中;雾滴速度沿喷嘴轴线方向不断衰减,且喷嘴直径越大雾滴速度衰减越缓慢;随着喷嘴直径的增加,雾滴速度呈现先增大后减小的变化规律;全尘和呼吸性粉尘降尘效率随着喷嘴出口直径的增加均有所提高,但增幅较小;综合考虑喷嘴降尘性能、耗水量和耗气量等因素,在采掘作业场所进行气水喷雾降尘时,选择出口直径为2. 0～3. 0 mm的空气雾化喷嘴较为合适。

In order to understand the effect of nozzle outlet diameter on dust removal using air-water spray,based on experimental system designed by authors for air-water spray and dust suppression,the spray performance parameters and dust removal efficiency of the nozzle with different outlet diameters were measured.The study results indicate that the water consumption of nozzle appears a linear growth with the increase of outlet diameter,and the air consumption increases in an exponential way.With the increase of outlet diameter,the spray range and droplet volume concentration of air atomizing nozzle increase,but the spray angle increases first and then decreases.It can gain the best quality atomization with the outlet diameter of 2 mm.Under this outlet diameter of air cap,the sauter mean diameter(SMD)of droplets is smallest,and the particle size presents a normal distribution.The droplet’s velocity falls continuously along the axial line,and it will slow down with the increase of outlet diameter.The droplet’s velocity firstly increases and then decreases with the increase of outlet diameter.As the nozzle out diameter increases,the total dust suppression efficiency and the respirable dust suppression efficiency increase.Taking into consideration of the dust suppression efficiency and the nozzle flow,the nozzle with the outlet diameter of 2-3 mm should be adopted in air-water spray and dust suppression at mine operation site.