Abstract We investigated a spray-drying aerosol generator that can generate micro-particles at high concentration using an ultrasonic nozzle. Unlike a conventional spray-drying aerosol generator that uses vertical spray with co-current sheath flow, we designed a new aerosol generator by using horizontal spray with co-current sheath flow combined with clean counter flow to increase particle generation efficiency. A drying chamber was designed using the ANSYS Fluent solver to complete the evaporation of droplets and to minimize the loss of post-evaporation particles inside the chamber. Both numerical prediction and experimental data showed that droplets would completely evaporate at a temperature of 353 K. Both KCl aqueous solution and silica powder suspension were sprayed using an ultrasonic nozzle to generate micro-sized particles with a size range of 1–10 μm. When horizontal spray with co-current sheath flow was operated with clean counter flow the loss of particles on the chamber wall was minimized and thus the total particle number concentration was 2.4 times higher than when the clean counter flow was inactive. The particle generator in the present study can generate larger particles than a Collison atomizer which generates particles up to 3 μm.

中文翻译：

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使用具有清洁逆流的超声波喷嘴的水平喷射喷雾干燥气溶胶发生器

摘要 我们研究了一种喷雾干燥气溶胶发生器，它可以使用超声波喷嘴产生高浓度的微粒。与传统的喷雾干燥气溶胶发生器使用垂直喷雾并流鞘流不同，我们设计了一种新型气溶胶发生器，通过使用水平喷雾并流鞘流结合清洁逆流来提高颗粒生成效率。使用 ANSYS Fluent 求解器设计了一个干燥室，以完成液滴的蒸发并最大限度地减少室内蒸发后颗粒的损失。数值预测和实验数据均表明，液滴会在 353 K 的温度下完全蒸发。使用超声波喷嘴喷洒 KCl 水溶液和二氧化硅粉末悬浮液，以产生尺寸范围为 1-10 μm 的微米级颗粒。当具有并流鞘流的水平喷雾以清洁逆流操作时，室壁上的颗粒损失最小化，因此总颗粒数浓度比清洁逆流不活动时高 2.4 倍。本研究中的粒子发生器可以生成比 Collison 雾化器更大的粒子，后者可生成高达 3 μm 的粒子。