On the effect of liquid height on the flooding/loading transition

Hudcova, V.; Nienow, Alvin W.; Haozhung, Wang; Liu, Huoxing

doi:10.1016/0009-2509(87)85067-4

Cited by 6 publications

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cavity Shape. Visual observations using the highspeed video camera revealed that the length and shape of cavities were essentially independent of the liquid depth, which was consistent with the observations of others 19 on the flooding-loading transition for discturbines. In the region where the cavity length increased with increasing impeller tip speed, a tapered cavity developed as indicated in Figure 4.…”

Section: Methodssupporting

confidence: 89%

“…The results presented in Figures 2 and 3 are consistent with earlier studies, where the gas was introduced via a ring or porous sparger placed below the rotating impeller. For example, it has been reported 19 that large cavities reached a maximum length, which increased for higher gas ventilation rates. It was also found that once the maximum cavity length was reached the ventilation rate could be increased considerably before the impeller became flooded.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Cavity Formation, Growth, and Dispersion behind Rotating Impeller Blades

Evans

Manning

Jameson

2005

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Ventilated gas cavities were observed when air was sparged directly to the rear of one blade of a multi-bladed disc-turbine impeller. For a constant gas rate, it was found that for low impeller speeds no cavities were formed. As the impeller speed was increased, large, tapered cavities were formed and increased in length with increasing impeller speed. At a critical speed, however, the cavities reached a maximum length, beyond which the cavity length decreased with increasing impeller speed. For each gas ventilation rate, it was found that the internal pressure of the cavity decreased only slightly for speeds up to the corresponding critical value. Beyond this point the internal pressure decreased significantly with further increases in impeller speeds. A gas flow model was developed based on the assumption that the gas exited the cavity through an opening (orifice) located randomly on the gas-liquid interface.

show abstract

Section: Methodssupporting

confidence: 89%

Section: Methodsmentioning

confidence: 99%

Cavity Formation, Growth, and Dispersion behind Rotating Impeller Blades

Evans

Manning

Jameson

2005

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

Gas–liquid dispersion with dual Rushton impellers

Hudcova

Machoň

Nienow

1989

Biotech & Bioengineering

127

View full text Add to dashboard Cite

Aerated and unaerated power consumption and flow patterns in a 0.56 m diameter agitated vessel containing water with dual Rushton turbines have been studied. Under unaerated conditions with a liquid height-to-diameter ratio of 2, an impeller spacing of 2 to 3 times the impeller is required for each to draw an amount of power equal to a single impeller. For aerated conditions, if a similar spacing is used, equations for the flooding-loading transition and for power consumption for a single Rushton impeller can be extended relatively easily to dual systems. All results for this spacing are explained by reference to bulk flow patterns and gassed-filled cavity structures and the proportion of sparged gas flowing through the upper impeller is also estimated. Such a spacing is generally recommended since it maximizes the power draw and hence the potential for oxygen mass transfer. Data are presented for other spacings but the results do not fit in easily with single agitator studies because strong impeller-impeller flow pattern interactions occur.

show abstract

Mixing and Hydrodynamics in Flotation Cells

Mavros

1992

Innovations in Flotation Technology

View full text Add to dashboard Cite

On the effect of liquid height on the flooding/loading transition

Cited by 6 publications

References 1 publication

Cavity Formation, Growth, and Dispersion behind Rotating Impeller Blades

Cavity Formation, Growth, and Dispersion behind Rotating Impeller Blades

Gas–liquid dispersion with dual Rushton impellers

Mixing and Hydrodynamics in Flotation Cells

Contact Info

Product

Resources

About