Morphology of particulate deposits formed on a single filter fibre by exposure to mixed aerosol flow

Single fibre experiments are commonly used to obtain a deeper understanding of particle deposition in fibrous filters. Most studies on particle deposition on single fibres in literature use monodisperse particles of a single particulate species. In this study, a single filter fibre was exposed to aerosols containing two particulate species, namely glass spheres and/or soot particles, in order to compare the morphology of the resulting particulate deposits. The glass spheres alone build compact deposits on the front/windward side of the fibre and the soot particles alone formed particle dendrites on the front of the fibre, which reached wide to the sides perpendicular to the flow. Exposure of the fibre to an aerosol containing both, glass spheres and soot particles, resulted in bigger particulate structures on the front of the fibre. If the fibre was exposed to an aerosol containing only soot particles first and to an aerosol containing only glass spheres afterwards, the glass spheres deposited on the front of the soot dendrites. The reversed procedure resulted in soot dendrites on the top of the compact glass sphere deposits, which were located on the front of the fibre.