空气雾化喷嘴雾化机理及影响因素实验分析

Experimental analysis of atomization mechanism and influencing factors of air atomizing nozzle

为分析空气雾化喷嘴雾化特性,采用一次雾化和二次多级雾化理论得出影响喷嘴雾化性能的主要因素,设计喷嘴雾化实验分析各因素对喷嘴雾化性能的影响。研究结果表明:空气雾化喷嘴的雾化特性受喷嘴的水流量、气流量、气压和水压影响;水流量随着水压的增大而增大,随着气压增大而减小,气流量随着气压的增大而增大,随着水压增大而减小,气液流量比(Qg/Ql)与液气压力比(pl/pg)存在幂函数关系,指数为?1.09;随着喷射距离的增大,一次雾化向二次雾化转变直至雾化结束,对应的雾滴粒径由大变小再变大,随水压的增大,雾滴粒径呈现出“增大—减小”的变化规律,随气压的增大而减小,最佳的液气压力比为0.8~1.0,对应的最佳气液流量比为115~146;雾滴粒径D50与pl/pg存在三次函数关系,由函数关系可知喷嘴雾化后的雾滴粒径理论上的最小值为18.23 μm,验证了喷嘴雾化最小粒径的存在,但在实际应用中该最小粒径无法实现。

In order to study the atomization characteristics of air atomizing nozzle, the main factors affecting the atomization performance of the nozzle were analyzed with primary atomization and secondary multi-stage atomization theory, and the atomization experiment of the nozzle was designed to analyze the influence of various factors on the atomization performance of the nozzle. The results show that the atomization characteristics of the air atomizing nozzle are affected by the water flow, air flow, air supply pressure and water supply pressure. The water flow increases with the increase of the water supply pressure and decreases with the increase of the air supply pressure. The air flow increases with the increase of the air supply pressure, and decreases with the increase of water pressure. The gas-liquid flow ratio(Qg/Ql) has a power function relationship with the liquid-gas pressure ratio(pl/pg), and the index is ? 1.09. As the jetting distance increases, the primary atomization changes to the secondary atomization until the atomization ends, and the corresponding droplet size changes from being large to small and then large. The atomized particle size of nozzle increases first and then decreases with the increase of water supply pressure, and decreases with the increase of air supply pressure. The optimum liquid-gas pressure ratio is between 0.8 and 1.0, and the corresponding optimum gas-liquid flow ratio is 115?146. There is a cubic function relationship between droplet particle size (D50) and pl/pg. With the increase of pl/pg, the theoretical minimum value of the atomized droplet size is 18.23 μm, which verifies the existence of the minimum atomized particle size of the nozzle. However, this minimum value can not be achieved in the practical application.