A study of solid behavior in spouted beds using 3‐D particle tracking

A non-invasive γ-ray emission system, employing eight NaI detectors, has been developed to follow the motion of a single radioactive particle in a three-dimensional spouted bed reactor. The count-rates measured simultaneously by the detectors are converted into tracer coordinates (x, y, z) using a pre-established calibration model which accounts for every physical and geometrical aspects involved in the spouting facility. Typically four hundred thousands successive coordinates, obtained over 3.5 hours of particle tracking, are used for determining the average particle velocity field and other hydrodynamic quantities such as the cycle time distribution, the spout shape and the solid exchange distribution at the spout boundary, which could not be evaluated accurately using any available techniques. Une methodologie nucleaire non-intrusive, employant huit detecteurs a scintillation, a ete mise au point pour l'etude de la circulation du solide dans les lits a jet tridimensionnels par la poursuite d'une particule radioactive. Les comptages de photons mesures simultanement par les detecteurs sont convertis en coordonnees cartesiennes (x, y, z) avec un modele preetabli de calibration qui decrit les interactions des photons avec les detecteurs et le reacteur. Apres avoir accumule typiquement quatre cent mille coordonnees successives sur une periode de 3.5 heures, ces donnees sont utilisees pour quantifier une variete de proprietes hydrodynamiques du solide jusque la inaccessible non-intrusivement. Cet article presente les resultats preliminaires obtenus sur le champ moyen de vitesse du solide, les distributions des temps de circulation des particules et d'echange du solide a la paroi du jet et la morphologie du jet.

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