GASEOUS DIFFUSION IN POROUS MEDIA AT UNIFORM PRESSURE

Journal Article · Fri Dec 01 04:00:00 EST 1961 · Journal of Chemical Physics (U.S.)

OSTI ID:4810289

Watson, G M; Mason, E A; Evans, III, R B

A model is presented for the diffusion of gases in porous media in the absence of pressure gradients, in which the porous medium is visualized as a collection of uniformly distributed dust particles which are constrained to be stationary. By formally considering the dust particles as giant molecules, it is possible to derive all the desired resuits very simply from rigorous kinetic theory as special cases of multicomponent mixtures. By formally varying the mole fractions of the real gas molecules, the entire pressure range from the Knudsen region to the normal diffusion region can be covered. This model permits the first satisfactory theoretical derivation of the experimentally discovered fact that the flux ratio for binary mixtures ts equal to (m/sub 2//m/sub 1/)sup 1/2/ at all pressures (not just in the Knudsen region). It also permits a rigorous theoretical treatment of the entire transition region for the first time, from which is obtained the usual Bosanquet interpolation formula and a differential equation for diffusion which covers the entire range (and appears to be new). The model gives no quantitativ-e a priori characterization of the porous medium itself, but if one gas mixture is measured in a given medium, then the behavior of other gas mixtures in the same medium can be predicted. (auth)

• Research Organization: Oak Ridge National Lab., Tenn.
• NSA Number: NSA-16-010000
• OSTI ID: 4810289
• Journal Information: Journal of Chemical Physics (U.S.), Journal Name: Journal of Chemical Physics (U.S.) Vol. Vol: 35; ISSN JCPSA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AERODYNAMICS
CHEMISTRY
CIRCUITS
DIFFERENTIAL EQUATIONS
DIFFUSION
DUSTS
FISSION
FLUID FLOW
GAMMA DETECTION
GAMMA RADIATION
GAMMA SPECTROMETERS
GAS FLOW
GASES
GOLD 185
GOLD 186
GOLD 187
GOLD 188
GOLD 189
GOLD 190
JOURNAL
KNUDSEN EFFUSION
KNUDSEN NUMBER
MEASURED VALUES
MECHANICAL STRUCTURES
MECHANICS
MERCURY 185
MERCURY 186
MERCURY 187
MERCURY 188
MERCURY 190
MIXING
MOLECULES
NUCLEAR REACTIONS
PARTICLE MODELS
PARTICLES
PLATINUM 185
PLATINUM 186
PLATINUM 187
PLATINUM 188
PLATINUM 189
PLATINUM 190
POROSITY
PRESSURE
REACTION KINETICS
SCINTILLATION COUNTERS
SPECTRA
STABILITY
VARIATIONS
VELOCITY