旋转雾化器液滴破碎过程及颗粒分布的数值研究

Numerical Study on Droplet Breakage and Particle Distribution in Rotating Nebulizers

以脱酸塔内旋转雾化器为研究对象,基于VOF(Volume of fluid)和DPM(Discrete particle model)方法,采用Fluent软件模拟了石灰浆液的一次破碎过程和雾化后的粒径分布特征,分析了雾化盘转速、单喷孔、平行双/3喷孔及孔间距对喷孔射流一次破碎效果和粒径分布的影响。结果表明,高速射流条件下的液滴破碎主要由周向表面波和轴向波叠加导致,并呈现出关于主流对称的形态;多喷孔射流的聚合射程与孔间距成正比关系,增加喷孔数将导致射流提前聚合;提高雾化盘转速、喷孔间距和喷孔数目均有利于减小雾化后液滴平均直径;多喷孔结构下的液滴平均直径与孔间距呈简单的线性关系。

Taking a rotary atomizer in a deacidification tower as an object,based on VOF model and DPM models,the primary crushing process of lime slurry and the particle size distribution characteristics after atomization were simulated by Fluent,and the influences of the rotating speed of atomizing disk,single nozzle,parallel double/triple nozzles and nozzle spacing on the primary crushing and particle size distribution of nozzle jet were analyzed.The results show that the droplet breakup under the condition of high-speed jet is mainly caused by the superposition of circumferential surface waves and axial waves,and presents a symmetrical shape with respect to the main flow.The polymerization range of multi-hole jet is proportional to the nozzle spacing,and increasing the number of nozzles leads to the early polymerization of jet.Increasing the rotating speed of atomizing disk,nozzle spacing and nozzles is benefit for reducing the average diameter of atomized droplets.A simple linear correlation of average diameter of droplets and nozzle spacing is obtained for the multi-nozzles.