Identification of a non-linear dynamic model of the bubble size distribution in a pilot flotation column

In this study, a new jet-stirring coupling flotation device that incorporates the advantages of three conventional flotation machines (specifically, Jameson cell, mechanical flotation cell, flotation column) was designed based on jet suction. The suction capacity of a double cosine self-aspirated nozzle utilized by the device was analyzed under different feeding pressures, and the effects of frother concentration, feeding pressure, suction capacity, and height of sampling location on the bubble size distribution (BSD) were investigated using a high-speed video system. It was found that a large amount of air was sucked into the flotation cell by the self-aspirated nozzle arranged in a non-submerged manner, which met the requirements of flotation in terms of the suction amount of air. The suction capacity showed a positive linear correlation with negative pressure inside the nozzle. When the Methyl isobutyl carbinol (MIBC) concentration reached the critical coalescence concentration (CCC), the bubble size stabilized at approximately 0.31 mm, which was smaller than the bubble size produced by the conventional flotation machine. This indicated that bubbles suitable for flotation were generated. D32 linearly decreased with increasing of feeding pressures and conversely increased with increasing suction capacities and sampling location heights, independent of the frother concentration.

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Bubble size distribution in a flotation column

The Canadian Journal of Chemical Engineering ◽

10.1002/cjce.5450720123 ◽

1994 ◽

Vol 72 (1) ◽

pp. 148-152 ◽

Cited By ~ 15

Author(s):

S. K. Biswal ◽

P. S. R. Reddy ◽

S. K. Bhaumik

Keyword(s):

Size Distribution ◽

Bubble Size ◽

Bubble Size Distribution ◽

Flotation Column

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Bubble size distribution in surface wave breaking entraining process

Science in China Series D Earth Sciences ◽

10.1007/s11430-007-0116-7 ◽

2007 ◽

Vol 50 (11) ◽

pp. 1754-1760 ◽

Cited By ~ 3

Author(s):

Lei Han ◽

YeLi Yuan

Keyword(s):

Surface Wave ◽

Size Distribution ◽

Bubble Size ◽

Wave Breaking ◽

Bubble Size Distribution

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Physiochemical properties and reproducibility of air-based sodium tetradecyl sulphate foam using the Tessari method

Phlebology The Journal of Venous Disease ◽

10.1177/0268355516655078 ◽

2016 ◽

Vol 32 (6) ◽

pp. 390-396 ◽

Cited By ~ 2

Author(s):

Mike R Watkins ◽

Richard J Oliver

Keyword(s):

Size Distribution ◽

Bubble Size ◽

Bubble Size Distribution ◽

Foam Density ◽

Physiochemical Properties ◽

Significant Difference ◽

Experienced Operator ◽

Sodium Tetradecyl Sulphate ◽

Foam Production ◽

Made In

Objectives The objectives were to examine the density, bubble size distribution and durability of sodium tetradecyl sulphate foam and the consistency of production of foam by a number of different operators using the Tessari method. Methods 1% and 3% sodium tetradecyl sulphate sclerosant foam was produced by an experienced operator and a group of inexperienced operators using either a 1:3 or 1:4 liquid:air ratio and the Tessari method. The foam density, bubble size distribution and foam durability were measured on freshly prepared foam from each operator. Results The foam density measurements were similar for each of the 1:3 preparations and for each of the 1:4 preparations but not affected by the sclerosant concentration. The bubble size for all preparations were very small immediately after preparation but progressively coalesced to become a micro-foam (<250 µm) after the first 30 s up until 2 min. Both the 1% and 3% solution foams developed liquid more rapidly when made in a 1:3 ratio (37 s) than in a 1:4 ratio (45 s) but all combinations took similar times to reach 0.4 ml liquid formation. For all the experiments, there was no statistical significant difference between operators. Conclusions The Tessari method of foam production for sodium tetradecyl sulphate sclerosant is consistent and reproducible even when made by inexperienced operators. The best quality foam with micro bubbles should be used within the first minute after production.

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Development of Bubble Characteristics on Chute Spillway Bottom

Water ◽

10.3390/w10091129 ◽

2018 ◽

Vol 10 (9) ◽

pp. 1129

Author(s):

Ruidi Bai ◽

Chang Liu ◽

Bingyang Feng ◽

Shanjun Liu ◽

Faxing Zhang

Keyword(s):

Size Distribution ◽

Bubble Size ◽

Dissipation Rate ◽

Bubble Diameter ◽

Bubble Size Distribution ◽

Impact Zone ◽

Air Bubble ◽

Air Supply ◽

Bubble Characteristics ◽

The Impact

Chute aerators introduce a large air discharge through air supply ducts to prevent cavitation erosion on spillways. There is not much information on the microcosmic air bubble characteristics near the chute bottom. This study was focused on examining the bottom air-water flow properties by performing a series of model tests that eliminated the upper aeration and illustrated the potential for bubble variation processes on the chute bottom. In comparison with the strong air detrainment in the impact zone, the bottom air bubble frequency decreased slightly. Observations showed that range of probability of the bubble chord length tended to decrease sharply in the impact zone and by a lesser extent in the equilibrium zone. A distinct mechanism to control the bubble size distribution, depending on bubble diameter, was proposed. For bubbles larger than about 1–2 mm, the bubble size distribution followed a—5/3 power-law scaling with diameter. Using the relationship between the local dissipation rate and bubble size, the bottom dissipation rate was found to increase along the chute bottom, and the corresponding Hinze scale showed a good agreement with the observations.

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