Electrical resistance of gas fluidized natural flake graphite

Le résumé fourni par la source

Resistance and bulk resistivity of three commercial grades of fluidized natural flake graphite were determined with a high-frequency data acquisition system at ambient conditions and low voltage. Resistance was measured for up to 5 h over a wide range of superficial gas velocities up to 7 times the minimum fluidization velocity. Resistivities between 1 and 5 Ω∙m were measured for the two largest flake graphite populations used while fully fluidized. The relationship of resistance as a function of flow rate is influenced by the fluidized bed geometry and the particle population used. Resistance was found to fluctuate at frequencies between 3 and 10 Hz and demonstrate a strong link between physical particle properties, fluid-dynamic properties of the bed and the resistive behaviour of the fluidized flakes. When poor quality or partial fluidization occurs, as evidenced by a low relative pressure drop across the bed at steady state, 100 min or more of data is insufficient to capture the probability distribution. When the bed is well fluidized, 3 min or less are required for a representative sample. To operate a direct ohmic heating electric fluidized bed (DOH-ERB) purification reactor for natural graphite, pseudo-steady resistances are achievable with larger natural flake graphite sizes and at flow rates above the full fluidization velocity.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.