Axial velocity profiles of single bubbles in water/frother solutions

Sam, Abbas; Gómez, C.O.; Finch, J.A.

doi:10.1016/0301-7516(95)00088-7

Cited by 137 publications

(77 citation statements)

References 34 publications

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“…The maximum value of the magnitude of the velocity can be close to the value for pure water even though the ultimate bubble speed may be smaller than this value by a factor roughly equal to two. These findings are qualitatively consistent with the experimental observations of Sam et al (1) and Zhang and Finch (26).…”

Section: Resultssupporting

confidence: 95%

“…Recently, Sam et al (1) and Zhang et al (2) reported experimental results for the velocity of single bubbles as a function of height above the point of release in a vertical column. The bubble velocity was determined for aqueous solutions of various surfactants over a broad range of concentrations.…”

Section: Introductionmentioning

confidence: 98%

“…The bubble velocity was determined for aqueous solutions of various surfactants over a broad range of concentrations. They found that, although the bubbles eventually reached terminal velocities that were typical of contaminated water, they attained velocities 1 To whom correspondence should be addressed.…”

Section: Introductionmentioning

confidence: 98%

See 2 more Smart Citations

Bubble Motion in Aqueous Surfactant Solutions

Liao

McLaughlin

2000

Journal of Colloid and Interface Science

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Section: Resultssupporting

confidence: 95%

Section: Introductionmentioning

confidence: 98%

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Bubble Motion in Aqueous Surfactant Solutions

Liao

McLaughlin

2000

Journal of Colloid and Interface Science

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“…The volume of the equivalent spherical bubble is 4/3πr eq 3 , where r eq is equivalent radius r eq 3 = r h 2 r v . The last parameter is widely used in literature describing gas bubbles and their behavior in the water column (Sam et al 1996). The ratio of the horizontal radius to the vertical radius is an aspect ratio (AR = r h /r v ), which indicates how much a particular bubble is vertically flattened.…”

Section: Assessmentmentioning

confidence: 99%

Quantifying gas ebullition with echosounder: the role of methane transport by bubbles in a medium‐sized lake

Ostrovsky

Mcginnis

Lapidus

et al. 2008

Limnology & Ocean Methods

155

165

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In lakes and reservoirs with variable water level, gas ebullition can play a substantial role in methane transport in the water column and to the atmosphere. However, measuring methane ebullition from sediment is difficult as releases are highly heterogeneous and intermittent on macro- and micro-scales. In contrast to conventional gas traps and optical methods, hydroacoustic technology allows rapid scanning over large volumes of the water column synoptically to quantify gas bubble abundance. A 120-kHz dual beam downward-looking echosounder was used to measure the size distributions of bubbles that do not resonate at the sonar frequency. Data obtained with this sonar permit accurate calculation and evaluation of ebullition flux from the bottom. A robust relationship was established between gas volumes and backscattering cross-section of individual bubbles in experimental conditions, and rise velocities of bubbles were precisely measured. The volume backscattering coefficient was shown to be a good gauge of the total volume of bubbles per cubic meter of water, allowing the use of a single-beam sonar for measuring volumetric bubble concentrations. Data obtained from hydroacoustic surveys on Lake Kinneret, where gaseous methane is emitted from randomly dispersed sediment sources, indicated that ~90% of bubbles escaping from soft sediments ranged from 1.3 mm to 4.5 mm and ~50% ranged from 2.0 mm to 3.2 mm in equivalent radius. In summer-fall 2001, the gaseous methane fluxes from hypolimnetic sediments was ~10 mmol m-2 d-1, accounting for one-third of the observed methane accumulation in the hypolimnion. This relatively high ebullition rate could be attributed to the gradual decreasing of the mean water level in preceding years

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“…The value of the terminal velocity of the bubble depends on the solution concentration. The impact of the surfactant concentration on the profiles of bubble velocities is described in detail elsewhere (e.g., [2,3,[11][12][13][14][15][16][17][18][19][20][21][22]). In short, it depends on the mass transfer rate, molecular orientation and packing at the liquid/gas interface, surface activity and mobility, surface tension gradients, surface viscosity, as well as hydration effects.…”

Section: Terminal Bubble Velocitymentioning

confidence: 99%

Concentration at the Minimum Bubble Velocity (CMV) for Various Types of Flotation Frothers

2017

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This paper presents the determination of a concentration at the minimum bubble velocity (CMV) for different types of frothers, such as straight and branched alkyl chain aliphatic alcohols, 1,ω-diols, poly(propylene glycol) and poly(ethylene glycol) alkyl ethers, n-alkyltrimethylammonium bromides, commercial frothers and others. The values of terminal rise bubble velocity were reviewed from the experimental data published in the literature for two different types of columns, i.e., a short PAS (used in Polish Academy of Sciences) of height (35 cm) and a long McGill of height (350 cm). The obtained empirical equation is universal and allows one to rapidly and accurately determine the CMV for all surfactants. The proposed empirical model can also be used to predict the terminal bubble velocity-frother concentration curve by knowing the maximum and minimum terminal velocities, as well as the values of CMV. Assessment and usefulness of frother characterization parameters (i.e., concentration at the minimum bubble velocity (CMV), dynamic frothability index (DFI) and critical coalescence concentration (CCC)) were shown in the flotation of coal.

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Axial velocity profiles of single bubbles in water/frother solutions

Cited by 137 publications

References 34 publications

Bubble Motion in Aqueous Surfactant Solutions

Bubble Motion in Aqueous Surfactant Solutions

Quantifying gas ebullition with echosounder: the role of methane transport by bubbles in a medium‐sized lake

Concentration at the Minimum Bubble Velocity (CMV) for Various Types of Flotation Frothers

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