Penetration of Water-Soluble Material through Gas-Cleaning Filters

August 12, 2022

Almuth D. Schwarz (1), Jorg Meye (1), Achim Dittler (1)
Membranes. Volume 12, Issue 8 (12 August 2022). DOI:


Surface filtration, salts, water mist, soluble particles, gas, gas cleaning


To predict the behavior of gas-cleaning filters during real-world operation, it is essential to understand their response to ambient conditions. The temporary presence of water droplets in gas-cleaning filtration systems due to fog, spray rain, or condensation, as examples of irregular events, has an impact on the filters’ operating performance, especially when soluble particles are present. In this work, surface filters were loaded with mixtures of water-soluble salt particles and insoluble glass spheres. These were, subsequently, exposed to water mist and dried by a particle-free gas stream. A novel approach to analyze the drainage of solution on filters with soluble filter cakes is presented, which allows the detection of solubles on the clean gas side of the filter. As a result, this work, for the first time, presents a sighting of the penetration of soluble filter cake material through gas-cleaning filters. Furthermore, filter performance, in terms of differential pressure and fractional separation efficiency, was determined and a characteristic differential pressure evolution for hydrophilic filters during exposure to water mist was also identified. The fractional separation efficiency of gas-cleaning filters decreases due to exposure to water mist. The findings are supported by scanning electron microscopy (SEM) images, energy-dispersive X-ray (EDX), and X-ray microtomography (µ-CT analysis) images.

How Our Software Was Used

Dragonfly’s Deep Learning Tool was used to train a semantic segmentation model for separating particles.

Author Affiliation

(1) Institute of Mechanical Process Engineering and Mechanics, Karlsruhe Institute of Technology, Straße am Forum 8, 76131 Karlsruhe, Germany