Continuous separation of suspensions containing light and heavy particle species

Continuous separation of bidisperse suspensions containing particles of significantly different size and density in a vertical settler was examined. The effects of the feed total solids volume fraction, composition, and flow rate on the performance of the settler were investigated. For feed total solids volume fractions less than 0.1, a kinematic model based on the Patwardhan and Tien (1985) expression for relative velocity was found to predict the experimental measurements fairly well over a wide range of parameters. For feed total solids volume fractions greater than 0.2, a strong local instability was observed in the settler. This local instability significantly improved the performance of the settler in some cases. On a examine la separation continue de suspensions bidisperses contenant des particules de taille et de densite significa-tivement differentes dans un decanteur vertical. Les effets de la fraction volumique de solides totale dans l'alimentation, de la composition et du debit sur la performance du decanteur ont ete etudies. Pour des fractions volumiques inferieures a 0,1, on a trouve qu'un modeale cinetique s'appuyant sur l'expression de Patwardhan et Tien (1985) sur la vitesse relative predisait plutǒt bien les mesures experimentales pour une vaste gamme de parameatres. Pour des fractions volumiques superieures a 0,2, une forte instabilite locale a ete observee dans le decanteur. Cette instabilite locale ameliore grandement la performance du decanteur dans certains cas.

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