多因素对内混式气动雾化喷头雾化及降尘特性影响

Influence of various factors on the atomization and dust suppression characteristics of internal mixing pneumatic atomization nozzles

为了掌握内混式气动雾化喷嘴喷雾特性及降尘性能,借助自主研发的雾化角及内混式气动雾化雾滴粒径测试平台和尘雾耦合试验平台,对内混式气动雾化喷头雾化特性与降尘特性进行了实测及分析。结果表明,在气动压力为0.2~0.4 MPa、水流量为10~16 L/h的情况下,内混式气动雾化雾滴体积中值粒径(V_(50))和索特尔平均直径(Sauter Mean Diameter,SMD)均随着气动压力的增大而减小,随着水流量的增大而增大,且气动压力对内混式气动雾化雾滴粒径的影响比水流量对雾滴粒径的影响更大。粉尘运动速度在1~3 m/s范围内,气雾运动速度分别为2~5 m/s、>5~11 m/s时,内混式气动雾化雾滴粒径分别在>40~50μm处、>30~40μm处取得最大降尘效率。设定气雾运动速度为>8~11 m/s、粉尘运动速度为1 m/s,并使雾滴粒径SMD大致均匀地在20~40μm范围内分布,则可以较好地与0~50μm内各粒径区间的粉尘耦合沉降,且降尘效率最高。研究为内混式气动雾化技术在粉尘耦合领域提供了理论基础和试验支撑。

To investigate the spray characteristics and dust reduction performance of internal-mix pneumatic atomizing nozzles,we measured their atomization and dust suppression capabilities using an independently developed test platform.This platform assesses atomization angle and droplet size,as well as coupling tests for dust and mist.The test results were analyzed to elucidate the effects of the volume median diameter(V 50)and Sauter Mean Diameter(SMD)of internal-mix pneumatic atomizing droplets on pneumatic pressure and water flow rate.We also summarized the corresponding droplet size range for internal-mix pneumatic atomization that maximized dust reduction efficiency at various aerosol movement speeds.Additionally,we established a general trend regarding dust reduction efficiency across different aerosol velocities,along with the relationship between dust movement speed and droplet size(SMD).We summarized the relationships among dust movement speed,dust size,and the SMD of internal-mix pneumatic atomizing droplets in order to achieve optimal coupling effects.The results indicate that,within a pneumatic pressure range of 0.20.4 MPa and a water flow rate of 1016 L/h,both the V 50 and SMD of the internal mixing pneumatic atomization decrease as pneumatic pressure increases,while they increase with rising water flow rate.Furthermore,the impact of pneumatic pressure on droplet size is more significant than that of water flow rate.When the dust movement speed ranges 13 m/s,and the aerosol movement speeds are between 25 m/s and>511 m/s,the droplet size of internal mixing pneumatic atomization achieves maximum dust removal efficiency at>4050μm and>3040μm,respectively.Additionally,dust removal efficiency increases with larger SMD droplets,demonstrating a consistent overall trend of increasing and decreasing efficiency.At an aerosol velocity of 25 m/s,dust reduction efficiency exhibits a“decrease-increase-decrease”pattern with increasing SMD of the droplets.At aerosol velocities of>58 m/s,the trend generally shifts to an“increase-decrease”pattern,while at velocities of>811 m/s,the dust reduction efficiency shows a consistent upward trend.When the aerosol velocity is set between>811 m/s,the dust velocity at 1 m/s,and the SMD of droplets evenly distributed within the range of 2040μm,optimal coupling occurs with dust particles across the size range of 050μm,resulting in the highest dust reduction efficiency.This study offers both theoretical foundations and experimental support for the application of internal mixing pneumatic atomization technology in dust coupling scenarios.