Research Topic

Basic investigations into the behavior of drainage in coalescence filters

Coalescence separators are often used in industrial applications for the separation of oil mist (e.g. from compressed air systems). These consist of several layers of a fibrous material (micro glass or polymer fibers), followed by a support structure and a drainage fleece. The loading behaviour in coalescence filters is characterized by the fact that deposited droplets are moved by the air flow and the capillary forces of the filter medium. This leads to a redistribution of the droplets (coalescence) towards larger droplets and transport to locally more saturated areas (oil channels) inside the medium. Drainage of the separated oil occurs at the back of the filter.

The aim of this research project is to fundamentally clarify how the drainage behavior influences the separation efficiency as well as the pressure loss. For this purpose, the correlations between the material properties of the drainage fleece (porosity, wettability, etc.) and the process parameters (inflow velocities, oil delivery rate, etc.) on the local and temporal onset as well as the discharge rate of the drainage are to be investigated by using an optical evaluation method.