Spark discharge nanoparticle generators (SDGs) employ the method of spark ablation to generate nanoparticles (NPs) in the gas phase. The material plume ablated from two bulk electrodes is quenched and carried away by a controlled gas flow. The electrical circuit needed to maintain sparking and the gas/aerosol handling are usually rather simple to implement, therefore many different SDG designs exist in the literature. Since the carrier gas plays an important role in particle formation, the actual flow field inside the SDG chamber might also affect the properties of the generated particles. In this technical note we systematically investigate the size distribution of Ag NPs in various flow conditions. Size distribution measurements are used to compare cross-, coaxial-, and mixed flow geometries at different gas inlet to aerosol outlet distances, flow directions and volumetric flow rates and complemented with steady flow field simulations. The mechanisms behind the results are also briefly discussed.

火花放电纳米颗粒发生器（SDG）采用火花消融的方法在气相中产生纳米颗粒（NPs）。从两个块状电极烧蚀掉的材料羽流被淬灭并通过受控的气流带走。维持火花和气体/气溶胶处理所需的电路通常很容易实现，因此在文献中存在许多不同的SDG设计。由于载气在颗粒形成中起着重要作用，因此SDG腔室内的实际流场也可能会影响所生成颗粒的性质。在本技术说明中，我们系统地研究了各种流动条件下Ag NP的尺寸分布。尺寸分布测量用于比较不同进气口到气溶胶出口距离处的交叉，同轴和混合流几何形状，流向和体积流率，并辅以稳定的流场模拟。还简要讨论了结果背后的机制。