High temperature device for the_~tudy of the dynamic oxidation of refractory compounds Application to graphite

a high temperature reactor, and aims to blow a high temperature oxidizing gas through a tubular sample. It has been tested on graphite. The mass loss rate of graphite samples was measured for experimental conditions varying from 1 to 10% for oxygen volume concentration; from 1500 to 2200 K fQrsample temperature; from 1600 to 3500 K and 60 to 120 m s -1 for gas temperature and average stream velocity. These results can ber~ghly accounted for by a solution of the Graetz- Nusselt problem. Local Sherwood numbers are given from measurement of theil1l1_erdiameter of the sample after oxidation. Resume On decrit un dispositif experimental permettant Iʹetude de lʹoxydation dynamique de refractaires. II assode une torche a plasma souffle dʹargon et un reacteur a haute temperatue qui sert de §upport pour lʹechantillon. Ce dispositif a ete teste sur des echantillons tubulaires en graphite. On presente des vitesses de perte de masse des echantillonsel1 graphite-dans un domaine allant de 1500 a 2200 K pour la temperature de lʹechantillon; de 1600 a 3800 K et 60 it 120 m S-1 pour les temperatures et vitesse du gaz avec des concentrations dʹoxygene de 1 a 10% en volume. Pour rendre compte des resultas experimentaux, un modele analytique base sur Ie probleme de Graetz-Nusselt a ete developpe. Les nombres de Sherwood locaux sontdcmnes a partirdela mesure du diametre interieur de lʹechantillon apres oxydation