Formation and Analysis of Aerosol Clusters Consisting of Ultrafine Primary Particles

本研究的目的是开发在线测量和分析燃烧、干燥洗涤过程中形成的硫酸铵和硝酸盐颗粒以及硅烷热解产生的硅颗粒的实验和理论程序。在硅生产中，通过在低于均质成核温度和低核浓度的温度下操作来选择防止团簇形成的条件。在电子束洗涤过程中，操作和安装成本非常昂贵，因此要求在高剂量下短时间照射。这些条件产生相对较高的水蒸气浓度，至少部分补偿，并且可以预期致密的颗粒。煤烟结构为延伸链状结构。具体研究方向为：(1)团簇气动直径的实验测量及其与初级粒径和分形维数的关系；(2)建立了基于Kaplan晶格方法的混凝模型；(3)团簇的扩散充电，特别是它们作为离子汇的作用。

The objectives of this research are to develop experimental and theoretical procedures for online measurement and analysis of combustion, ammonium sulphate and nitrate particles formed in dry scrubbing processes, and silicon particles from the pyrolysis of silane. In silicon production, conditions are chosen to prevent cluster formation by operating at temperatures below where homogeneous nucleation occurs and with low concentration of nuclei. In the electron beam scrubbing processes, operating and installation costs are so expensive that short irradiation times at high doses are mandated. These conditions yield comparatively high water vapor concentrations will at least partially compensate, and a compact particle can be expected. The soot structures are extended chain-like structures. The specific research areas are: (1) the experimental measurement of the aerodynamic diameter of clusters and their correlation with primary particle size and fractal dimension; (2) the development of a coagulation model based on the Kaplan lattice approach; and (3) the diffusional charging of clusters and especially their role as a sink for ions.