Experimental and Numerical Investigation of Particle Separation in Electret Filters
Results of the ElekSim project in cooperation with the Institute for Environment & Energy, Technology & Analytics (IUTA)
Electrostatic effects play a central role in the functioning of modern filter media and significantly determine their efficiency and performance. In particular, in applications such as air and liquid filtration, particle separation, and in medical and industrial contexts, electrostatic charges enable the effective binding and separation of particles that are far smaller than the pore size of the filter.
Through the targeted use of electrostatic forces, filter media can achieve high filtration performance with low flow resistance. This is crucial not only for improving energy efficiency but also for meeting demanding environmental protection and health standards. In this context, electrostatic effects are increasingly being regarded as a key technology for the development of innovative and sustainable filtration solutions.
Reasons for choosing the GeoDict solution
Digital simulations with GeoDict enable precise investigation of the interactions between electrostatic forces and particles in a filter medium. They provide insights into the mechanisms of charge interaction, particle movement, and separation efficiency, which are difficult to access experimentally. This enables detailed investigation of the electrostatic charging of filter fibers and its influence on particle separation. With the help of GeoDict, filter efficiency can be predicted and optimized.
- Detailed investigation of operating conditions
- Effects of electrostatic forces on separation efficiency
- Consideration of filter effects on different scales
- Testing of novel materials with combined electrostatic and mechanical separation mechanisms
Verification with ANSYS Fluent
- The new feature was verified using ANSYS Fluent with a complex fiber structure generated with FiberGeo.
- Separation mechanism used:
- Mechanical
- Diffusion
- Coulomb
- Dielectrophoresis
Mechanical validation of initial efficiency
- Validation of purely mechanical separation (filter medium A)
Measurements performed by IUTA
Mechanical and electrostatic validation of initial efficiency
- Electrostatic and mechanical validation (filter medium A)
- Various particle charge distributions and electrostatic deposition mechanisms tested and implemented in GeoDict
- Locally flexible surface distributions
- Triboelectrically charged
- Corona-loaded
- Hydro-charged
Further information can be found on the validation subpage.
- Material design of electrostatically supported filter media
- Analysis of existing products with regard to electrostatic influences such as
- Particle charge
- Electrical potential
- Electrical field
- Electrostatic and dielectrophoretic force
- Avoidance of expensive prototypes through realistic simulation
- Time and cost savings in research and development
To deepen our understanding of electrostatic charge, GeoDict can be used to apply different charges to the fibers under consideration, thereby revealing the exact effects of electrostatic forces on the filter's performance.
- Digital testing of different electrical charge distributions
- different colors = different charges = different values for ξ0
- Comparison with (actual) measurements of electrical potential
The GeoDict solution for electret filters
In addition to GeoDict Base, the GeoDict package includes all necessary modules for research and development of electret filters and analysis of electrostatic influences on filter media.
Module Recommendations
| Image Processing & Image Analysis | ImportGeo-Vol | |
| Characterization & Analysis | FiberFind-AI | |
| Modeling & Design | FiberGeo | |
| Simulation & Prediction | FilterDict | FlowDict |
Which modules are best suited to you depends on the type of application you have.
