Fluidization regimes in different spouted bed apparatus constructions

Piskova, Elka; Mörl, Lothar

doi:10.1016/j.cep.2006.09.005

Cited by 16 publications

(16 citation statements)

References 11 publications

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“…This frequency range includes the range, 5-7.5 Hz, found by Freitas et al (2004) and is also similar to the dominant frequency of 4-10 Hz reported by Piskova and Morl (2007) Multiple spouts and their merging were also observed for low bed heights and low gas velocities. Normally two spouts appeared, one at each end of the slot, both oscillating.…”

Section: Flow Regimessupporting

confidence: 74%

“…Spectral analysis of pressure fluctuations has been used to identify flow regimes of spouted beds (Taranto et al, 1997;Rocha et al, 1998;Xu et al, 2004;Piskova and Morl, 2007). This method was also employed by Freitas et al (2004) to characterise the flow regimes in a slot-rectangular column with˛= 150 mm, = 100 mm, and 1.4 mm diameter glass beads.…”

Section: Flow Regimesmentioning

confidence: 99%

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Stability of slot‐rectangular spouted beds: Effect of slot configuration

Chen¹,

Lim²,

Grace³

2011

Can J Chem Eng

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Experiments were carried out to determine the flow stability of slot-rectangular spouted beds of 300 × 100 mm cross-section with slots of different widths, lengths, and depths. The effects of slot expansion angle and diverging base were also investigated. Dependent variables included the minimum spouting velocity, bed pressure drop and standard deviation of pressure fluctuations. Based on the flow regimes and spout termination mechanisms, instability was found to be mainly due to the interaction of multiple spouts. Criteria were identified relating stable spouting to slot dimensions and particle size. Slots of limited cross-sectional area can provide sustainable and symmetric spouting with little fluctuation, as long as the slot length-to-width ratio and depth are within certain limits, related to those for conventional spouted beds.On a mené uneétude expérimentale sur la stabilité de l'écoulement dans un lità jet rectangulaire ayant une section transversale de 300 mm × 100 mm, dont les fentes ont différentes largeurs, longueurs et hauteurs. On a aussiétudié les effets de l'angle interne et d'une base divergente sur la vitesse minimum de giclage, la chute de pressionà travers le lit, et les fluctuations de pression. Basée sur les régimes d'écoulement et le mécanisme de terminaison du jet, l'instabilité aété attribuée aux interactions entre les jets avoisinants. On a identifié les critères reliant la stabilité du jet aux dimensions de la fente et de la taille des particules. Des fentes ayant une section transversale restreinte peuvent engendrer un giclage stable et symétrique avec peu de fluctuations, pourvu que le ratio longueur sur largeur et la profondeur de la fente soient tous les deux en dedans de certaines limites, reliéesà celles des litsà jet classique.

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Section: Flow Regimessupporting

confidence: 74%

Section: Flow Regimesmentioning

confidence: 99%

Stability of slot‐rectangular spouted beds: Effect of slot configuration

Chen¹,

Lim²,

Grace³

2011

Can J Chem Eng

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“…The main drawbacks refer to the identification of the dominant frequency, which may differ depending on the observer. Although widely used in fluidization, spectral analysis has rarely been applied to spouted beds (Wang et al, 2001;Freitas et al, 2004;Xu et al, 2004a;Piskova and Morl, 2007). The results reported so far are inconclusive and specific for the system configuration, inert material and operating conditions.…”

Section: Spectral Analysismentioning

confidence: 86%

“…Fan et al, 1990;Kage et al, 1991;Bai et al, 1997;He et al, 1997;Briens et al, 1997a,b;Ohara et al, 1999;Briens and Briens, 2002;Chaplin et al, 2004Chaplin et al, , 2005. However, the application of these methods in spouted beds is scarce, with only a few attempts reported in the literature (Wang et al, 2001;Freitas et al, 2004;Xu et al, 2004a,b,c;Piskova and Morl, 2007).…”

Section: Introductionmentioning

confidence: 93%

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

et al. 2008

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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/U ms 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.Desétudes hydrodynamiques ontété menées dans une colonneà 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 pressioǹ a 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, a U/U ms de 0,3à 1,6 et des profondeurs de lit statique de 150à 600 mm. Les conditions couvrent plusieurs régimes d'écoulement (lit fixe, jaillissement naissant, jaillissement stable, jaillissement pulsatoire, pistonage, jaillissementà bulles et fluidisation). Des images de la dynamique des systèmes ontégalementété obtenuesà travers des parois transparentes avec un appareil photo numérique. Les données ontété analysées au moyen de diverses méthodes (méthodes statistiques, théorie des informations mutuelles, méthodes spectrales, méthodeà 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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“…Hydrodynamics of the spouted bed was investigated by Verma et al [3], Piskova and Mörl [4], Duarte et al [5], Shirvanian et al [6,7] and Kazdobin et al [8]. The positive effect of draft tube existence on the performance of the spouted bed reactor used for waste water treatment is obvious.…”

Section: Introductionmentioning

confidence: 99%

Optimization of Draft Tube Position in a Spouted Bed Reactor using Response Surface Methodology

Baghban¹,

Mehrabani-Zeinabad²

2012

AMPC

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Optimization of draft tube position in a spouted bed reactor used for treatment of wastewater containing low concentration of heavy metals is investigated in this paper. Response surface methodology is used to optimize the draft tube height, the draft tube width and the gap between the bottom of the draft tube and the inlet nozzle. It is observed that the draft tube with a height of 60 millimeter, width of 12 millimeter and the gap of 13 millimeter between its bottom and inlet nozzle, results in optimum value of minimum spouting velocity, measured 45 cubic centimeter per second (2.7 Liter per minute).

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Fluidization regimes in different spouted bed apparatus constructions

Cited by 16 publications

References 11 publications

Stability of slot‐rectangular spouted beds: Effect of slot configuration

Stability of slot‐rectangular spouted beds: Effect of slot configuration

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

Optimization of Draft Tube Position in a Spouted Bed Reactor using Response Surface Methodology

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