Numerical simulation of liquid fall induced gas entrainment and its mitigation

Satpathy, Kamalakanta; Velusamy, K.; Patnaik, B.S.V.; Chellapandi, P.

doi:10.1016/j.ijheatmasstransfer.2013.01.006

Cited by 25 publications

(7 citation statements)

References 22 publications

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“…The most commonly used impellers are those with standard configurations, for example, disk turbine (DT) and the like, pitched blade downflow turbine or pitched blade upflow turbine (PBTU), and so forth. The existing work mainly covers two aspects: (1) mechanism of the aeration process, (2) effect of the impeller configurations and the operation parameters (e.g., rotational speed, immersion depth of the impeller, and aspect ratio of the vessel) on the mass transfer performance.…”

Section: Introductionmentioning

confidence: 99%

Gas‐liquid mass transfer behavior in a surface‐aerated vessel stirred by a novel long‐short blades agitator

Luo

Pan

et al. 2015

AIChE Journal

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in Wiley Online Library (wileyonlinelibrary.com)For a recently developed long-short blades (LSB) agitator, its critical rotational speed for the onset of gas entrainment, power number, and gas-liquid mass transfer behavior in the case of surface aeration is investigated. The effect of the LSB configurations and the liquid level on the agitator performance has been studied in details. The obtained results clearly show several advantages of the LSB agitator in gas-liquid mass transfer with respect to the agitators in the literature. It is found that its gas-liquid volumetric mass-transfer coefficient at a given specific power can be several times larger than those shown in the literature. It can also avoid decrease in the gas-liquid mass transfer rate as the liquid level increases. In addition, the bubble distribution in the system is more uniform with respect to conventional agitators, resulting from better distribution of the dissipated energy for the LSB agitator. Figure 2. Schematic diagram of the reactor configuration.(a) reactor; (b) LSB agitator with long blades fixed on the outer ring and (c) on the inner ring. (1) Fixer; (2) Long blades; (3) Outer and inner connector rings; (4) Short blades.

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Section: Introductionmentioning

confidence: 99%

Gas‐liquid mass transfer behavior in a surface‐aerated vessel stirred by a novel long‐short blades agitator

Luo

Pan

et al. 2015

AIChE Journal

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“…In fact, the gas entrainment phenomenon is beneficial to increase the activated gas/ steel interface in the vacuum chamber, which accordingly improves refining efficiency of degassing and decarburization. The formation mechanism of gas entrainment has been clarified by Satpathy et al 27) This type of entrainment occurs when two local conditions are available: (i) the liquid rises above the mean free surface forming a local hump, (ii) there is a high interfacial velocity of falling liquid from hump. The interaction between the falling liquid and the free wall of snorkel by rising plume, then returns into the ladle along the left wall of snorkel.…”

Section: Effect Of Bubble Expansionmentioning

confidence: 99%

Numerical Simulation of Multiphase Flow and Mixing Behavior in an Industrial Single Snorkel Refining Furnace: Effect of Bubble Expansion and Snorkel Immersion Depth

Dai

Cheng

et al. 2019

ISIJ Int.

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A coupled mathematical model is used to simulate the multiphase flow in an industrial Single Snorkel Refining Furnace (SSRF). Based on the present model, the evolution characteristics of bubble size, density, and velocity are analysed during the long-distance rising process. The comparative studies indicate that the expansion of bubbles has an enormous impact on the circulation rate and free surface in the vacuum chamber. Furthermore, the effect of snorkel immersion depth (SID) on the circulation rate, mixing time, and fluid flow are investigated. The results indicate that the circulation rate decreases with the increase of SID, while the mixing time shows an uptrend with the increase of SID. Particularly, when the SID exceeds 0.4 m, the scope of dead zone around the snorkel dramatically increases, which further decreases the flow velocity of slag layer in the ladle.

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“…In sodium-cooled fast reactors (SFRs), an inert cover gas such as argon is used and maintained above the sodium surface to accommodate the volume changes of sodium and prevent the contact of sodium with air [11,12]. Several mechanisms could lead this cover gas to entrain the sodium region, including the entrainment driven by a free-surface vortex [12]. The gas entrainment may cause safety and operational problems and, for this reason, becomes an essential issue in SFR safety analyses [13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Modeling of the Free-Surface Vortex-Driven Bubble Entrainment into Water

Putra

Lucas

2020

Water

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The recently developed GENTOP (Generalized Two Phase Flow) concept, which is based on the multifield Euler‒Euler approach, was applied to model a free-surface vortex—a flow situation that is relevant for hydraulic intake. A new bubble entrainment model has been developed and implemented in the concept. In general, satisfactory agreement with the experimental data can be achieved. However, the gas entrainment can be significantly affected by several parameters or models used in the CFD (Computational Fluid Dynamics) simulation. The scale of curvature correction C s c a l e in the turbulence model, the coefficient in the entrainment model C e n t , and the assigned bubble size to be entrained have a significant influence on the gas entrainment rate. The gas entrainment increases with higher C s c a l e values, which can be attributed to the stronger rotation captured by the simulation. A smaller bubble size gives higher gas entrainment, while a larger bubble size leads to a smaller entrainment. The results also show that the gas entrainment can be controlled by adjusting the entrainment coefficient C e n t . Based on the modeling framework presented in this paper, further improvement of the physical modeling of the entrainment process should be done.

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Numerical simulation of liquid fall induced gas entrainment and its mitigation

Cited by 25 publications

References 22 publications

Gas‐liquid mass transfer behavior in a surface‐aerated vessel stirred by a novel long‐short blades agitator

Gas‐liquid mass transfer behavior in a surface‐aerated vessel stirred by a novel long‐short blades agitator

Numerical Simulation of Multiphase Flow and Mixing Behavior in an Industrial Single Snorkel Refining Furnace: Effect of Bubble Expansion and Snorkel Immersion Depth

Modeling of the Free-Surface Vortex-Driven Bubble Entrainment into Water

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