粒径分布可控的单分散气溶胶发生器研究

Study on Monodisperse Aerosol Generator with Controllable Particle Size Distribution

气溶胶发生器已广泛应用于高效过滤器测试、仪器校准、粒子动力学研究、吸入毒理学研究和核安全分析等领域。针对现有气溶胶发生器预热时间长、稳定性差、发生性能不易控制等缺点,作者设计了一种冷凝型单分散气溶胶发生器,对进气系统、进液系统和混合结构等进行了优化。文章使用邻苯二甲酸二辛酯(DOP)的乙醇溶液作为气溶胶来源,采用单因素法探究了DOP浓度、进液速度、雾化压力、加热电压和稀释流量对发生性能的影响。用扫描迁移率粒径谱仪对发生器进行性能测试,结果表明,DOP浓度和加热电压是数量中值粒径(CMD)和几何标准偏差(GSD)的主要影响因素,而数量浓度主要通过稀释流量进行调节,其他参数用作微调。通过调节不同的控制参数可以得到CMD为100~700 nm,GSD为1.20~1.40,Cn不低于106 cm^(-3)的单分散或准单分散气溶胶,并能达到200 min的连续发生,且具有很好的稳定性和可重复性。

Aerosol generators are used in high-efficiency filter testing,instrument calibration,particle dynamics research,inhalation toxicology research and nuclear safety analysis.Aiming at the shortcomings of the existing aerosol generators,such as long preheating time,poor stability,and difficult to control the generation performance,a condensing type monodisperse aerosol generator was designed,and the air intake system,liquid feeding system and mixing structure were optimized.Using the ethanol solution of dioctyl phthalate(DOP)as the aerosol source,the effects of DOP concentration,liquid feeding speed,atomization pressure,heating voltage and dilution flow rate on the generation performance were investigated by single factor method.The performance of the generator is tested by SMPS.The results showed that DOP concentration and heating voltage were the main influencing factors of CMD and GSD,while Cn was mainly regulated by dilution flow,and other parameters were used as fine-tuning.By adjusting different control parameters,a monodisperse aerosol or quasi-monodisperse aerosol with CMD of 100~700 nm,GSD of 1.20~1.40,and Cn of not less than 106 cm^(-3) can be obtained,which can generate continu⁃ously for 200 min with good stability and repeatability.