Collect. Czech. Chem. Commun. 2006, 71, 1320-1332

Gas Permeability of Porous Substances

Jiří Medek*, Lukáš Kovář and Zuzana Weishauptová

Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, V Holešovičkách 41, 182 09 Prague 8, Czech Republic


A dependence of the amount of gas passed Q on the input pressure Pin has been derived for turbulent flow in a model material with an artificially prepared porous texture. For the ratio Q/∆P, where ∆P is the pressure gradient equal to the difference of an input Pin and output Pout pressures, the dependence on Pin is linear with a positive slope value, while for Q/∆P2 for the pressure gradient expressed by Pin2 - Pout2 it is linear as well, but with a negative slope value, which contradicts the experimental results. The ratio Q/∆P has been introduced as a quantity determining the permeability. The dependence of permeability on the path length of the flow L satisfied the power function Q/∆P = CL-b, where the constant C corresponds to the value (Q/∆P)(1) for L = 1, C is characteristic of a given system. Helium has been chosen as a standard gas for studying gas permeability in real porous systems.

Keywords: Gas permeability; Real porosity; Turbulent flow.

References: 13 live references.