Evaluation of flow regimes in a semi-cylindrical spouted bed through statistical, mutual information, spectral and Hurst's analysis

Authors

  • W.P. Oliveira,

    1. Universidade de São Paulo, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Av. do Café S/N., BL. Q, 14040-903, Ribeirão Preto, SP, Brazil
    2. Post-doctoral fellow of the Brazilian Council for Scientific and Technological Development (CNPQ) at the University of the British Columbia, Vancouver, BC, Canada
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  • C.R.F. Souza,

    1. Universidade de São Paulo, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Av. do Café S/N., BL. Q, 14040-903, Ribeirão Preto, SP, Brazil
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  • C.J. Lim,

    Corresponding author
    1. Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC, Canada V6T 1Z3
    • Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC, Canada V6T 1Z3
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  • J.R. Grace

    1. Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC, Canada V6T 1Z3
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Abstract

Hydrodynamic studies were conducted in a semi-cylindrical spouted bed column of diameter 150 mm, height 1000 mm, conical base included angle of 60° and inlet orifice diameter 25 mm. Pressure transducers at several axial positions were used to obtain pressure fluctuation time series with 1.2 and 2.4 mm glass beads at U/Ums from 0.3 to 1.6, and static bed depths from 150 to 600 mm. The conditions covered several flow regimes (fixed bed, incipient spouting, stable spouting, pulsating spouting, slugging, bubble spouting and fluidization). Images of the system dynamics were also acquired through the transparent walls with a digital camera. The data were analyzed via statistical, mutual information theory, spectral and Hurst's Rescaled Range methods to assess the potential of these methods to characterize the spouting quality. The results indicate that these methods have potential for monitoring spouted bed operation.

Abstract

Des études hydrodynamiques ont été menées dans une colonne à lit jaillissant semi cylindrique de 150 mm de diamètre, de 1000 mm de hauteur, ayant un angle d'ouverture de la base conique de 60° et d'un diamètre d'orifice intérieur de 25 mm. On a employé des capteurs de pression à différentes positions axiales dans le but d'obtenir des séries temporelles de fluctuation de pression, avec des billes de verre de 1,2 et 2,4 mm, à U/Ums de 0,3 à 1,6 et des profondeurs de lit statique de 150 à 600 mm. Les conditions couvrent plusieurs régimes d'écoulement (lit fixe, jaillissement naissant, jaillissement stable, jaillissement pulsatoire, pistonage, jaillissement à bulles et fluidisation). Des images de la dynamique des systèmes ont également été obtenues à travers des parois transparentes avec un appareil photo numérique. Les données ont été analysées au moyen de diverses méthodes (méthodes statistiques, théorie des informations mutuelles, méthodes spectrales, méthode à amplitude renormalisée de Hurst) afin d'évaluer le potentiel de ces méthodes pour caractériser la qualité du jaillissement. Les résultats indiquent que ces méthodes sont potentiellement intéressantes pour la surveillance du fonctionnement en lit jaillissant.

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