(54y) 3D CFD-DEM Simulation of Particle Separation By Porous Media

Porous media are widely used to separate solid particles or droplets from gases or liquids. Common applications are raw materials production and processing, industrial wastewater or exhaust cleaning and breathing air conditioning. Nonwoven fleece, knitted or woven wire meshes, open-pored foams or sinter materials can serve as porous filter medium.

The particle separation process in the 3D porous structure of the filter medium can be simulated by computational fluid dynamics (CFD) and the discrete element method (DEM) and by coupling these methods where applicable. The required 3D model of the porous structure can be obtained either by microtomography (µ-CT) or by generation with mathematical models. The interactions of particles and particles with the filter medium can be included in the simulations to predict the developing of the pressure drop and the separation efficiency during the filtration process.

In our contribution we show recent applications of these methods to fundamental examples from the fields of aerosol filtration and solid-liquid separation. We use the in-house developed simulation environment DNSlab which ist based on CFD and DEM methods. Particle deposition mechanisms like inertia, interception and diffusion are included in the simulation as well as electrical and adhesive forces between particles and the porous structure. The simulation results such as permeability and filter efficiency of the porous filter medium are compared with pressure drops and separation efficiencies which were measured or obtained by applying empirical formulas from the literature.

References:
[1] Schmidt, K.; Ripperger, S.; Antonyuk, S.: 3D DEM-CFD Simulation of the Formation of a Fixed Bed of Activated Carbon Grains, Air and Toluene Permeation and Toluene Adsorption. Chemie Ingenieur Technik 88 (2016), Nr. 3, S. 307-312
[2] Hellmann, A.; Pitz, M.; Schmidt, K.; Haller, F.; Ripperger, S.: Characterization of an Open-Pored Nickel Foam with Respect to Aerosol Filtration Efficiency by Means of Measurement and Simulation. Aerosol Science and Technology 49 (2015), Nr. 1, S. 16-23
[3] Schmidt, K.; Becker, J.: Generating Validated 3D Models of Microporous Ceramics. Advanced Engineering Materials 15 (2013), Nr. 1-2, S. 40-45