Fluidization and slugging in large-particle systems

Noordergraaf, Inge-Willem; Dijk, Albert van; Bleek, C.M. van den

doi:10.1016/0032-5910(87)80007-4

Cited by 44 publications

(14 citation statements)

References 7 publications

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“…13 also shows that most natural frequency equations listed in Table 2 underestimate the natural frequency data in the literature, but agree reasonably well with the dominant frequency data. Based on the analysis of synchronized video images and visual observations, it was found (Baeyens and Geldart, 1974;Broadhurst and Roy et al (1990), Catalyst A Roy et al (1990), Vermiculite Roy et al (1990), Glass beads Musters (1974), Catalyst Musmara et al (1995), Glass beads Bi et al (1995), catalyst Kobayashi et al (1969) Wong and Baird (1971) Dominant Frequency Baskakov et al (1986) 1976; Noordergraaf et al, 1987;Kage et al, 1991;M'chirguiet al, 1997) that the dominant frequency from absolute pressure fluctuations generally corresponds to the bubble eruption frequency detected at the bed surface. The local pressure drops almost simultaneously in the upper and lower sections of the bed as bubbles break through the bed surface (Baskakov et al, 1986).…”

Section: Dominant Mechanisms Of Local Pressure Fluctuationsmentioning

confidence: 99%

A critical review of the complex pressure fluctuation phenomenon in gas–solids fluidized beds

Bi¹

2007

Chemical Engineering Science

211

107

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Section: Dominant Mechanisms Of Local Pressure Fluctuationsmentioning

confidence: 99%

A critical review of the complex pressure fluctuation phenomenon in gas–solids fluidized beds

Bi¹

2007

Chemical Engineering Science

211

107

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“…Absolute pressure fluctuations also originate from pressure waves, mainly coming from surface fluctuations due to slug eruption (Noordergraaf et al, 1987). The amplitude of surface height oscillations in deep slugging beds can be estimated (Kehoe and Davidson, 1972b) by:…”

Section: Simplified Analysismentioning

confidence: 99%

Pressure and voidage fluctuations in slugging fluidized beds

1999

Can J Chem Eng

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In fully developed slugging fluidized beds, the maximum amplitude of absolute pressure fluctuations is reached with increasing superficial gas velocity when the slug length reaches a maximum, and the separation distance between successive slugs starts to decrease. Uc, the superficial gas velocity at which absolute pressure fluctuations reach a maximum, thus indicates the early stage of transition from slugging to core-annular flow. U,, identified based on standard deviations of differential pressure fluctuations or local voidage fluctuations, can be predicted by slug flow models and does not signify a transition to turbulent fluidization.Dans les lits fluidisCs bouchonnants pleinement dbveloppks, I'amplitude maximale des fluctuations de pression absolues est atteinte avec l'augmentation de la vitesse de gaz lorsque la longueur du bouchon atteint un maximum, et quand la distance de sbparation entre les bouchons successifs commence h diminuer. U,, la vitesse de gaz superficielle

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“…Various phenomena with different scales occur in a fluidized bed which are characterized by their frequencies and can be identified by Fourier transform and the related power spectral density function (PSDF). As indicated by many researchers 25–27, the dominant frequency in the PSDF generally corresponds to the bubbles and their eruption.…”

Section: Resultsmentioning

confidence: 85%

Investigation of Hydrodynamics of High‐Temperature Fluidized Beds by Pressure Fluctuations

2016

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Hydrodynamics of a gas-solid fluidized bed at elevated temperatures was investigated by analyzing pressure fluctuations in time and frequency domains. Sand particles were fluidized with air at various bed temperatures. At a constant gas velocity, the standard deviation, power spectrum density function, and wide-band energy of pressure fluctuations reach a maximum at 300°C. Increasing the temperature to this value causes larger bubble sizes and after the bubbles reach their maximum size, they break into smaller bubbles. The Archimedes number decreases with higher temperature and the type of fluidization becomes closer to that of Geldart A boundary at this maximum temperature. Based on estimation of the drag force acting on the emulsion phase, it was concluded that 300°C was a transition temperature at which the drag force reaches a minimum due to a significant change of interparticle and hydrodynamic forces.

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Fluidization and slugging in large-particle systems

Cited by 44 publications

References 7 publications

A critical review of the complex pressure fluctuation phenomenon in gas–solids fluidized beds

A critical review of the complex pressure fluctuation phenomenon in gas–solids fluidized beds

Pressure and voidage fluctuations in slugging fluidized beds

Investigation of Hydrodynamics of High‐Temperature Fluidized Beds by Pressure Fluctuations

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