Effects of micron-sized particles on hydrodynamics and local heat transfer in a slurry bubble column

Li, H; Prakash, Anand; Margaritis, Argyrios; Bergougnou, M.A.

doi:10.1016/s0032-5910(03)00118-9

Cited by 34 publications

(26 citation statements)

References 23 publications

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“…In addition, solid is to be added in the small diameter column to study the influence of an increase in solid concentration on heat transfer, as results in the literature are confusing. Some authors observed an increase in the value of the heat transfer coefficient with increasing solid concentration (Deckwer et al, 1980;Fazeli et al, 2008), while others reported a decrease (Li and Prakash, 1997;Li et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Heat transfer metrology issues in two‐phase bubble column reactors

et al. 2010

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The metrology and the impact of various parameters and operating conditions on the bulk-to-tube heat transfer coefficients in two-phase bubble columns are investigated on a small-scale mock-up. It is shown that (1) quasi-adiabatic conditions can be reached in the column; (2) the bulk-to-tube heat transfer coefficients for each U-tube downward and upward sections may or may not differ significantly, depending on the way uncertainty of the measurements is estimated; (3) using the different measurements and uncertainty estimates for given conditions, a mean heat transfer coefficient over all tubes is estimated within ±5%. The consequences for bulk-to-tube heat transfer coefficient prediction in a larger column are discussed.La métrologie et les répercussions de divers paramètres et différentes conditions d'utilisation sur les coefficients de transfert de chaleur de la calandre aux tubes dans des colonnesà bulles en deux phases sontétudiées sur une maquetteà petiteéchelle. Il est démontré que (1) l'on peut parvenirà des conditions quasi adiabatiques dans la colonne; (2) les coefficients de transfert de chaleur de la calandre aux tubes pour les parties descendante et ascendante de chaque tube en << U >> peuvent différer considérablement ou non, selon la façon dont l'incertitude des mesures est estimée; (3) par l'utilisation des différentes mesures et estimations de l'incertitude pour des conditions données, un coefficient de transfert de chaleur moyen pour tous les tubes est estiméà ±5%. Les conséquences pour la prédiction des coefficients de transfert de chaleur de la calandre aux tubes dans une colonne plus grande sont discutées.

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Section: Introductionmentioning

confidence: 99%

Heat transfer metrology issues in two‐phase bubble column reactors

et al. 2010

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“…Furthermore, if gas velocity is maintained at constant level, the gas momentum per unit mass of slurry would decrease with increasing solid concentration and thus, the total gas holdup is expected to decrease with increasing solid concentration [4]. In addition, the slurry viscosity with solid concentration tends to decrease gradually by the increase of liquid viscosity, since the interfacial tension of bubbles has increased and the boundary layer thickness of the bubbles has increased [6].…”

Section: Resultsmentioning

confidence: 99%

“…For the SBCR design, the understanding on the mixing among gas, liquid and particles, individual phase holdup and heat and mass transfer in the column are certainly essential. In addition, the flow behavior of gas phase is known to act a pivotal role in determining the heat transfer coefficient, since the gas bubbles, which exist as a dispersed phase, flow stochastically and randomly in the viscous slurry medium which is composed of solvent with particles [4]- [6]. Gas holdup is directly affected by gas velocity and particle concentration and is generally found to decrease with an increase of particle concentration in a SBCR [7]- [9].…”

Section: Introductionmentioning

confidence: 99%

Bubble and Heat Transfer Phenomena in Viscous Slurry Bubble Column

Kim¹,

Kim²,

Lee³

et al. 2014

ACES

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Heat transfer and bubble phenomena were investigated by adopting the drift flux model in a viscous slurry bubble column reactor (SBCR), having a diameter of 0.0508 m (ID) and height 1.5 m. The effects of superficial gas velocity (0.002-0.164 m/s), solid concentration (0-20 wt%) and liquid viscosity (paraffin oil; 16.9 mPa•s and squalane; 25.9 mPa•s) on the gas holdup and heat transfer characteristics were examined. It was observed that the gas holdup increased with increasing superficial gas velocity (UG), but decreased with increasing solid concentration (SC) or slurry viscosity. The degree of non-uniformity in a SBCR could be determined by the modified drift flux model at the heterogeneous flow regime. The local heat transfer coefficient (h) between the immersed heater and the bed decreased with increasing liquid viscosity and SC, but it increased with increasing UG. The modified Nusselt number including the gas holdup and local heat transfer coefficient was well correlated in terms of dimensionless groups such as Reynolds and Prandtl numbers.

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“…In this figure, the value of heat transfer coefficient decreases slowly with increasing solid concentration and slurry viscosity. This can be attributed to an increase in apparent slurry viscosity and corresponding increase in average boundary layer thickness at the tube surface for heat transfer, with increasing slurry concentration [9,25]. The value of the heat transfer coefficient decreases gradually with increasing liquid viscosity, since the bubble size in- …”

Section: July 2008mentioning

confidence: 99%

“…For the commercial design or scale-up of the SBCR, an understanding of the characteristics such as mixing among gases, liquid and particles, gas holdup and heat and mass transfer in the SBCR are essential [5,6]. In addition, the flow behavior and characteristics of gas phase are known to play critical roles in determining the heat transfer coefficient, since the gas bubbles, which exist as a dispersed phase, are flowing stochastically and randomly in the viscous liquid as solvent with particles at high pressure [4,[7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Effect of pressure fluctuations on the heat transfer characteristics in a pressurized slurry bubble column

Kang

Son

Kang

et al. 2008

Korean J. Chem. Eng.

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The hydrodynamics and heat transfer characteristics were investigated in a slurry bubble column reactor whose diameter was 0.0508 m (ID) and 1.5 m in height. Effects of gas velocity (0.025-0.1 m/s), pressure (0.1-0.7 MPa), solid concentration (0-20 vol%) and liquid viscosity (1.0-38.0 mPa s) on the hydrodynamics and heat transfer characteristics were examined. The pressure difference fluctuations were analyzed by means of attractor trajectories and correlation dimension to characterize the hydrodynamic behavior in the column. The gas holdup increased with increasing gas velocity or pressure, but decreased with increasing solid concentration or liquid viscosity. It was found that the attractor trajectories and correlation dimension of pressure fluctuations were effective tools to describe the hydrodynamic behaviors in the slurry bubble column. The heat transfer coefficient increased with increasing pressure or gas velocity, but decreased with increasing solid concentration or viscosity of slurry phase in the slurry bubble column. The heat transfer coefficient value was well correlated in terms of operating variables and correlation dimension of pressure fluctuations in the slurry bubble column.

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Effects of micron-sized particles on hydrodynamics and local heat transfer in a slurry bubble column

Cited by 34 publications

References 23 publications

Heat transfer metrology issues in two‐phase bubble column reactors

Heat transfer metrology issues in two‐phase bubble column reactors

Bubble and Heat Transfer Phenomena in Viscous Slurry Bubble Column

Effect of pressure fluctuations on the heat transfer characteristics in a pressurized slurry bubble column

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