Fundamental experimental investigation on operating and cleaning behaviour of a reversibly stretchable filter medium for particle separation from the gas phase

• Applicant: Professor Dr.-Ing. Achim Dittler
• Subject Area: Mechanical Process Engineering
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 565284851

In the field of gas-particle separation technology, surface filters are used to separate particles from solid-laden gas flows. Particle separation takes place on the surface of the filter medium, where a so-called "filter cake" is formed. To maintain filtration operation, the filters are periodically regenerated - usually by pressure flow reversal. In order to optimise the regeneration process of the filter medium, a new type of excitation is to be introduced by uniaxial stretching of the medium. In this way, the detachment of the filter cake is to be initiated gently and extreme pressure peaks are to be prevented without flow reversal or a breakdown of particle material into the clean gas. The established processes have in common that the filter media used are largely rigid, i.e. hardly elastically expandable. Elastically expandable media, as they are available today, could be advantageous for improving the filtration and regeneration behaviour. Results of initial preliminary tests show that the use of knitted filter media with high elastic stretchability enables the detachment of particle structures at practical filtration rates. The results show that purely strain-induced filter cake detachment can occur at a flow velocity of 3 cm/s, i.e. in the relevant range of filtration velocities. The present research project aims to fundamentally investigate and evaluate the filtration and regeneration behaviour of a purely strain/relaxation regenerated elastic filter medium. The novel process eliminates the periodic flow reversal, which is the cause of undesired emissions. In addition to an (energetic) improvement of the filtration operation, a better emission behaviour is therefore also expected.

• DFG Programme: Research Grants