Depth filters are used in air-conditioning, cleanroom technology and process industry for removal of particles in gases. The particles deposit inside the filter media and accumulate causing increasing separation efficiency, pressure drop and hence energy consumption. Introduction of smart materials in gas-particle-filtration could be an opportunity to reduce pressure drop while maintaining high separation efficiency. Smart materials are able to adapt themselves to required conditions. For instance, they can be used as actuator in an electronic control system.
In gas filtration, the filter media itself could be such a smart material. Aforesaid filter could adapt its fiber diameter and porosity to operation conditions, like particle load, particle diameter and flow velocity, in order to attain the necessary collection efficiency with minimal pressure loss and energy consumption. Elastic filter fibers, which have become available yet, are a candidate for smart filter media in gas-particle-filtration. Their properties like porosity, fiber length and thickness could be controlled through stretching and therefore adapted to operation conditions. Smart filter media could improve digitalization of filtration processes and industry 4.0.
Figure: picture of break-up and flaking of particles on a single fiber during oncoming flow and stretching
