Experiments and meso-scale modeling of phase holdups and bubble behavior in gas-liquid-solid mini-fluidized beds

Li, Xiangnan; Liu, Mingyan; Ma, Yong-li; Dong, Tingting; Yang, Dedong

doi:10.1016/j.ces.2018.08.005

Cited by 16 publications

(10 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The bubble diameter increased with U G and decreased with the superficial liquid velocity U L . According to previous studies, 23 the bubble diameter in the gas–liquid mini‐bubble column was generally smaller than that in the three‐phase mini‐fluidized bed. For gas–liquid two‐phase flow, the bubble diameter variation trend is similar to that of three‐phase mini‐fluidized bed.…”

Section: Resultsmentioning

confidence: 67%

“…Among the researches on the mini-scale multiphase flow systems, there have been some reports on the micro-or mini-scale fluidized beds. The main topics are to determine the hydrodynamic parameters of the mini-fluidized bed, such as flow regime, minimum fluidization velocity, minimum bubble velocity, bubble size, bubble terminal velocity, and so on, [16][17][18][19][20][21][22][23][24][25] by means of pressure drop measurement and high-speed photography. Compared with conventional fluidized beds, it is found that some factors negligible in macro flow play a major role in mini-flow systems, such as flow regime transitions influenced by the ratio of bed to particle diameter, which can be attributed to local heterogeneous fluidization caused by wall effect.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Characteristics of flow fields in the gas–liquid mini‐bubble columns with particle image velocimetry measurements

Liu

et al. 2022

AIChE Journal

Self Cite

View full text Add to dashboard Cite

As a new type of gas-liquid microreactors, the gas-liquid mini-bubble column has potential applications. However, few studies on the flow fields in the mini-bubble column can be found at present. In this work, particle image velocimetry (PIV) was used to visually study the velocity fields, vorticity fields and bubble dynamics in the gas-liquid mini-bubble columns with column inner diameters of 1-3 mm and minibubble diameters ranged from 0.7 to 1.3 mm. It is found that with the increase of superficial liquid velocity, bubbles rose from almost straight line to Z-shaped or S-shaped trajectory, and the bubble trajectory changed from one-dimension to three-dimension; when the bubble velocity changed, the bubble size and gas holdup decreased; bubble terminal velocity was controlled by bubble buoyancy and flow resistance, and increased slightly with bubble coalescence. These findings may provide basic reference for the design and scale-up of such a mini-bubble column reactor.

show abstract

Section: Resultsmentioning

confidence: 67%

mentioning

confidence: 99%

Characteristics of flow fields in the gas–liquid mini‐bubble columns with particle image velocimetry measurements

Liu

et al. 2022

AIChE Journal

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the three-phase turbulent flow field, the bubbles and particles have parallel movement and rotation during the movement [38], and at the same time, the instantaneous vortex generated by the bubble burst causes the particles to rotate [39][40][41]. Using the above models, the flow field profiles can be obtained.…”

Section: Name Symbol Equationmentioning

confidence: 99%

Dynamic Characteristics and Wall Effects of Bubble Bursting in Gas-Liquid-Solid Three-Phase Particle Flow

Wang

et al. 2020

Processes

View full text Add to dashboard Cite

The bubble bursting process existing in the particle flow is a complex gas-liquid-solid three-phase coupling dynamic problem. The bubble bursting mechanism, including dynamic characteristics and wall effects, is not clear. To address the above matters, we present a modeling method for the piecewise linear interface calculation-volume of fluid (PLIC-VOF) based bubble burst. The bubble bursting process near or on the wall is analyzed to reveal the dynamic characteristics of bubble bursting and obtain the effect of a bubble bursting on the surrounding flow field. Then a particle image velocimetry (PIV) based self-developed experimental observation platform is established, and the effectiveness of the proposed method is verified. Research results indicate that, in the high-speed turbulent environment, a large pressure difference existed in the bubble tail, which induces the bubble burst to occur; the distance between the wall and the bubble decreases; the higher the flow velocity is, the less time is acquired for bubble bursting, but when the flow velocity exceeds the critical velocity 50 m/s, more time is needed; the coalescence-burst process of double bubbles increases the bubble bursting time, which causes the acceleration of particle motion to reduce.

show abstract

“…Bubbling behavior of gas–liquid two‐phase flow widely exists in chemical, biological, environmental industries, etc . Especially for various multiphase reactor applications, such as gas–liquid bubble column reactor, gas–liquid–solid fluidized reactor, and sieve‐plate column reactor, the initial detachment state of the bubbles is critical to the shape, size, oscillation, interaction, dissolution of bubbles during the subsequent migration. The floating bubbles make significant convection and mixing inside the reactor, which influences the gas–liquid contact time and contact area, thus affects the heat and mass transfer process between gas and liquid phases.…”

Section: Introductionmentioning

confidence: 99%

Bubble dynamics and mass transfer characteristics from an immersed orifice plate

Shi

Jiang

Liu

et al. 2020

J of Chemical Tech & Biotech

View full text Add to dashboard Cite

BACKGROUND: Bubble dynamics plays an important role in performance enhancement of multiphase reactor. The formation of the bubbles at the orifice is critical for the dynamics of bubbles and the mass transfer process during the rising stage. However, few studies have focused on the detailed changing characteristic of bubble formation and its relationship with mass transfer.RESULTS: The evolution of the bubble dynamics from millimeter to micrometer-sized immersed orifice plates is in situ visualized. Bubble inrush is observed from the orifices with diameters below 421 ∼m, resulting in significant fluctuation on the gas-liquid interface. The base of the leading bubble varies with the orifice diameter. Smaller orifice is preferred to produce more trailing bubbles with smaller size. The inrush time of the trailing bubble is prolonged with decreasing orifice diameter and increasing gas velocity. The inrush time and diameter of the latter trailing bubble are higher than the former at a certain gas velocity. The volumetric mass transfer coefficient (K L a) is obtained by measuring the bubble volume during the rising process using chemical absorption of carbon dioxide (CO 2 ) with sodium hydroxide (NaOH). Increasing gas velocity, decreasing orifice diameter and bubble inrush make an apparent positive impact on the K L a.CONCLUSIONS: The bubble inrush happens at micrometer orifice. Decreasing orifice diameter and increasing gas velocity are important to intensify oscillation of the leading bubble and increase the frequency of bubbles with high specific interfacial area, which are conducive to the enhancement of the volumetric mass transfer coefficient.

show abstract

Experiments and meso-scale modeling of phase holdups and bubble behavior in gas-liquid-solid mini-fluidized beds

Cited by 16 publications

References 34 publications

Characteristics of flow fields in the gas–liquid mini‐bubble columns with particle image velocimetry measurements

Characteristics of flow fields in the gas–liquid mini‐bubble columns with particle image velocimetry measurements

Dynamic Characteristics and Wall Effects of Bubble Bursting in Gas-Liquid-Solid Three-Phase Particle Flow

Bubble dynamics and mass transfer characteristics from an immersed orifice plate

Contact Info

Product

Resources

About