单颗粒质谱仪进样装置的设计与模拟

Design and Simulation of Sampling Device in Single Particle Mass Spectrometer

摘要: 目前，广泛采用空气动力学透镜喷嘴作为单颗粒质谱仪的进样装置。针对大气环境污染物PM2.5的研究需要，对单颗粒质谱仪进样装置中空气动力学透镜喷嘴（聚焦颗粒的空气动力学直径在0.3~3 μm范围内）进行优化设计，并选用Fluent软件对颗粒运动进行数值模拟。仿真结果表明：优化设计的进样装置对粒径0.3~3 μm范围的颗粒聚焦效果较好，在距离装置出口24 cm处的颗粒束宽在0.03 mm以内。因此，优化设计的进样装置能满足单颗粒质谱仪对PM2.5颗粒进样聚焦的要求。

Abstract: Aerodynamic lens-nozzle is widely used as sampling device in single particle mass spectrometer recently. For the analysis need of PM2.5, aerodynamic lens-nozzle with a focusing ability from 0.3 to 3 μm was optimally designed. Fluent software was chosen to numerically simulate the particle motion in the aerodynamic lens-nozzle. Simulation results demonstrate that the performance of particle in the range of 0.3—3 μm in the optimal design sampling device is very well. Particle beam diameter at a distance of 24 cm downstream of the nozzle exit is less than 0.03 mm. Accordingly, the optimal design sampling device can satisfy the requirement of tightly focusing PM2.5 in single particle mass spectrometer.