基于空气动力学的环缝气流雾化制粉喷嘴设计

Design on Girth Airflow Atomized Powder Nozzle Based on Aerodynamics

气流雾化制粉技术在生产冶金粉末领域应用非常广泛,为了提高气流对金属流的剪切作用,根据压缩空气膨胀所形成的高速气流动力学原理,设计了一种环缝气流雾化制粉喷嘴,并对影响环缝气流雾化制粉喷嘴粉末破碎过程中的参数进行了分析。推导出了压缩空气在进气管内流动时不产生紊流的管径计算式;分析了R_0/re及pe/p_0比值对环缝出口处气流速度的影响,通过增加R_0/re比值或降低pe/p_0比值,将提高粉末的破碎效果;建立了雾化锥角设计计算的函数关系式。通过仿真得到喷嘴内部流场分成4个区域:涡流区、回流区、分离区和混合区。仿真效果验证了参数选取的准确性,为环缝气流雾化制粉喷嘴的设计提供了理论依据。

Airflow atomized powder technology is widely applied in the field of production of powder metallurgy,in order to improve the shearing action of airflow on metal flow,according to the compressed air which is formed by the expansion of the high-speed airflow dynamics principle,a girth airflow atomized powder nozzle is designed. The influence of parameters in the crushing process of girth airflow atomized powder nozzle was analyzed. The mathematical expression of the diameters that compressed air flowing in the intake pipe without turbulence was given out. And the ratio of the R0/reand pe/p0 that affected airflow velocity of girth exports were analyzed,and the crushing effect of powder was improved by increasing the ratio of the R0/reor reducing the ratio of the pe/p0. The mathematical expression of the design computation for atomizing cone-angle was established. Inside the nozzle flow field obtained by simulation was divided into four areas： eddy zone,reflux area,separation area and mixed area. The simulation results verify the accuracy of parameters selection,which provides a theoretical basis for the design of girth airflow atomized powder nozzle.