Abstract A low cost, easy-to-manufacture particle classification device for coarse mode, supermicrometer particles and droplets remains important for a variety of industries and environmental measurements, including agricultural sprays, pharmaceutical powders, spray drying processes, precipitation, and dust storms. While optical techniques can typically be used to analyze particle sizes in this range (20 μm–100 μm), there are few instruments available for size-segregated particle collection. Here, we demonstrate that a horizontal, parallel-plate sheathed elutriator can be designed and 3D printed, enabling modest-to-high resolution size segregated particle and droplet collection in the supermicrometer size range. In such elutriators, gravitational settling drives sampled particles vertically down the device (between two plates), while a clean sheath flow drives motion orthogonally; the net result is aerodynamic diameter-specific particle and droplet trajectories. In designing a sheathed elutriator, we develop both an analytical deposition location distribution function, similar to the transfer function of sheath mobility analyzers, as well as a 3D computational fluid dynamics model of a prototype instrument. The prototype is built solely from 3D printed parts (and PVC sheath lines) without any high voltage sources or high power pumps required. The performance of the prototype is tested by examining the deposition location distribution of monodisperse uranine-doped oleic acid droplets in the 26 μm–81 μm size range. Uranine signal intensity was determined using both traditional fluorometric analysis and via yellow-color intensity analysis from a digital camera, with both measurements in good agreement with one another. Overall excellent agreement is observed between the analytical model, computational fluid dynamics simulations, and experimental measurements, demonstrating that inexpensive elutriators provide a means to collect coarse-mode particles in a size selective manner, and further suggesting that they can be designed for aerodynamically monodisperse particle selection.

中文翻译：

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3D 打印带护套的淘析器，用于微粒和液滴的尺寸分辨收集

摘要 一种低成本、易于制造的粗模式、超微米颗粒和液滴的颗粒分类装置对于各种行业和环境测量仍然很重要，包括农业喷雾、药物粉末、喷雾干燥过程、降水和沙尘暴。虽然光学技术通常可用于分析此范围内 (20 μm–100 μm) 的粒径，但很少有仪器可用于收集粒径分离的颗粒。在这里，我们证明了可以设计和 3D 打印水平、平行板护套的淘析器，从而能够在超微米尺寸范围内实现中等至高分辨率尺寸的分离颗粒和液滴收集。在这种淘析器中，重力沉降将采样颗粒垂直向下驱动到设备（在两个板之间），而干净的鞘流驱动正交运动；最终结果是特定于空气动力学直径的粒子和液滴轨迹。在设计护套淘析器时，我们开发了类似于护套迁移率分析仪的传递函数的分析沉积位置分布函数，以及原型仪器的 3D 计算流体动力学模型。该原型完全由 3D 打印部件（和 PVC 护套线）构建，不需要任何高压电源或大功率泵。通过检查 26 μm-81 μm 尺寸范围内的单分散铀掺杂油酸液滴的沉积位置分布来测试原型的性能。使用传统的荧光分析和数码相机的黄色强度分析来确定尿信号强度，两种测量结果相互吻合。在分析模型、计算流体动力学模拟和实验测量之间观察到总体上非常一致，表明廉价的淘析器提供了一种以尺寸选择方式收集粗模式颗粒的方法，并进一步表明它们可以设计用于空气动力学单分散颗粒选择。