FILTECH 2022, The Filtration Event

Cologne, Germany

08.-10.03.2022

C. Straube, J. Meyer, A. Dittler

Fibrous coalescence filters consisting of micro glass fibers and sometimes small amounts of synthetic fibers are widely applied in gas cleaning processes to separate liquid droplets from a gas flow (e.g. oil mists). When separated on the fibers of the filter media, the deposited oil can take different shapes dependent on the oil saturation, wettability, roughness and diameter of the fibers and fiber arrangement (e.g. axisymmetric barrel-shaped droplets, axially asymmetric clam-shell droplets or oil sails between adjacent fibers). To understand the initial state of the coalescence filtration process as well as the impact of the deposited oil structures within the filter matrix on the separation efficiency, it is essential to characterize these structures. Using X-Ray microtomography (μ-CT) and an artificial intelligence tool for segmentation, this work presents a novel approach to visualize, identify and analyze deposited oil structures down to sizes in the micrometer region. For a first time, the droplet distribution of deposited oil droplets on filter fibers of an oleophilic filter medium is presented. Furthermore, the liquid distribution of the oil in the direction of the flow, determined by calculating the volume fractions of the different phases (air, oil, fibers), is evaluated and discussed.