Gas permeability in rarefied flow conditions for characterization of mineral membrane support

Gas Permeability Measurement Technique (GPMT) has the advantage of being a non-destructive method, which is efficient in characterizing filtration membranes. Ceramic filtration membranes consist of successive layers of micro (support) to nano size (skin) pores. When gas flows through such a small scale structure, the molecular mean free path becomes comparable to the pore size. The Slip flow model, validated to describe the gas transport properties under rarefied flow conditions in a microchannel, is extended to porous media. The porous structure is modeled as a cluster of several identical cylindrical channels. By measuring the pressure drop ∆P at several different mean pressures, the pore radius and the porosity on square tortuosity ratio /τ 2 of the porous model structure that have the same flow property were estimated. Nomenclature G Geometric factor (m −1) H Effective length of hollow fiber (m) J Mass flux density (kg.s −1 .m −2) K Hydraulic conductivity (s) Kn Knudsen number L p Channel length / Gas path length through the porous media (m) N Channel number P Gas pressure (Pa) P 0 Pressure upstream the nozzle (bar) P 1 Pressure upstream the porous sample (bar) P 2 Pressure downstream the porous sample (bar) P c Nozzle critical pressure (bar) P m Mean pressure (Pa)

C. Savaro, J.P. Bonnet, M.V. Johansson, Pierre Perrier, Irina Martin Graur, et al.. Gas permeability in rarefied flow conditions for characterization of mineral membrane support. European Journal of Mechanics - B/Fluids, 2020, 79, pp.44-53. ⟨10.1016/j.euromechflu.2019.07.005⟩. ⟨hal-02904990⟩

Journal: European Journal of Mechanics - B/Fluids

Date de publication: 01-01-2020

Auteurs:
  • C. Savaro
  • J.P. Bonnet
  • M.V. Johansson
  • Pierre Perrier
  • Irina Martin Graur
  • P. Moulin

Digital object identifier (doi): http://dx.doi.org/10.1016/j.euromechflu.2019.07.005


x >