Study by laser Doppler anemometry of the turbulent flow induced by a Rushton turbine in a stirred tank: Influence of the size of the units—I. Mean flow and turbulence

Costes, J.; Couderc, J.P.

doi:10.1016/0009-2509(88)80018-6

Cited by 105 publications

(53 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The continuous recycle of concentrate as feed to the cell allows for steady state conditions to be established. The design of the cell is based upon the standard mixing tank by Costes & Couderc (1988).…”

Section: Experimental Systemmentioning

confidence: 99%

The effect of particle size distribution on froth stability in flotation

Norori-McCormac

Brito-Parada

Hadler

et al. 2017

Separation and Purification Technology

View full text Add to dashboard Cite

Separation of particles of different surface properties using froth flotation is a widely-used industrial process, particularly in the minerals industry where it is used to concentrate minerals from ore. One of the key challenges in developing models to predict flotation performance is the interdependent nature of the process variables and operating parameters, which limits the application of optimising process control strategies at industrial scale. Froth stability, which can be quantified using air recovery (the fraction of air entering a flotation cell that overflows in the concentrate as unburst bubbles), has been shown to be linked to flotation separation performance, with stable froths yielding improved mineral recoveries. While it is widely acknowledged that there is an optimum particle size range for collection of particles in the pulp phase, the role of particle size on the measured air recovery and the resulting link to changes in flotation performance is less well understood. This is related to the difficulty in separating particle size and liberation effects.In this work, the effects of particle size distribution on air recovery are studied in a single species (silica) system using a continuous steady-state laboratory flotation cell. This allows an investigation into the effects of particle size distribution only on froth stability, using solids content and solids recovery as indicators of flotation performance. It is shown that, as the cell air rate is increased, the air recovery of the silica system passes through a peak, exhibiting the same froth behaviour as measured industrially. The air recovery profiles of systems with three different particle size distributions (d80 of 89.6, 103.5 and 157.1 m) are compared. The results show that, at lower air rates, the intermediate particle size distribution (103.5 m) yields the most stable froth, while at higher air rates, the finest particles (89.6 m) result in higher air recoveries. This is subsequently linked to changes in flotation performance. The results presented here highlight, for the first time, the link between particle size distribution in flotation feeds, air recovery and flotation performance. The results demonstrate that there is an optimal air rate for each particle size distribution, therefore changes in particle size distribution in the feed to flotation cells require a change in air rate in order to maximise mineral recovery.

show abstract

Section: Experimental Systemmentioning

confidence: 99%

The effect of particle size distribution on froth stability in flotation

Norori-McCormac

Brito-Parada

Hadler

et al. 2017

Separation and Purification Technology

View full text Add to dashboard Cite

show abstract

“…Pericleous and Patel [10] modelled single and multi stage radial impellers as distributed sources of momentum, on the basis of the blade fluid relative velocity and of drag coefficients taken from the literature. Costes and Couderc [11] studied the fields of the average velocities obtained by the LDV (Laser Doppler Velocimetry) in the plane of the baffles and the median plane of a stirred tank equipped by Rushton turbine. Alcamo et al [12] computed by large-eddy simulation (LES) the turbulent flow field generated in an unbaffled stirred tank by a Rushton turbine.…”

Section: Laboratory Of Electro-mechanic Systems (Lasem) National Schmentioning

confidence: 99%

A Study of Mixing Structure in Stirred Tanks Equipped with Multiple Four-Blade Rushton Impellers

Driss¹,

Karray²,

Chtourou³

et al. 2012

Archive of Mechanical Engineering

View full text Add to dashboard Cite

The effect of multiple Rushton impellers configurations on hydrodynamics and mixing performance in a stirred tank has been investigated. Three configurations defined by one, two and three Rushton impellers are compared. Results issued from our computational fluid dynamics (CFD) code are presented here concerning fields of velocity components and viscous dissipation rate. These results confirm that the multi-impellers systems are necessary to decrease the weaken zones in each stirred tanks. The experimental results developed in this work are compared with our numerical results. The good agreement validates the numerical method.

show abstract

“…• Kinetic energy balance term averaged over a control volume [21][22][23] • Integration of dissipation spectrum [24,25] • Dimensional analysis [26] In the present work, of surface aeration systems has been calculated by using commercial software Visimix [18]. The Visimix [18] program can be helpful in analyzing the mixing parameters in a stirred tanks [27,28].…”

Section: Dissipation Rate Of Turbulent Kinetic Energy εmentioning

confidence: 99%

Energy Dissipation and Shear Rate with Geometry of Baffled Surface Aerator

Kumar

2010

Chem. Eng. Res. Bull.

View full text Add to dashboard Cite

Abstract:The geometric parameters of surface aeration systems govern the process phenomena. The dissipation rate of turbulent kinetic energy (ε) and shear rate (γ) are the key process parameters for mixing in surface aerators. Present work by doing numerical computation by visimix analyzes the effect of geometric parameters (impeller diameter, cross-sectional area of the tank, liquid height, width of the baffle, rotor blade length and immersion height) on ε and γ . Analysis has been done by making the geometric parameters non-dimensionalized through rotor diameter. With an increase in liquid height and baffled width, there is an increase in the case of energy dissipation and shear rate values. In the case of tank area and blade length, it is vice versa. Energy dissipation and shear rate are not affected by the variation in immersion height of the impeller.

show abstract

Study by laser Doppler anemometry of the turbulent flow induced by a Rushton turbine in a stirred tank: Influence of the size of the units—I. Mean flow and turbulence

Cited by 105 publications

References 9 publications

The effect of particle size distribution on froth stability in flotation

The effect of particle size distribution on froth stability in flotation

A Study of Mixing Structure in Stirred Tanks Equipped with Multiple Four-Blade Rushton Impellers

Energy Dissipation and Shear Rate with Geometry of Baffled Surface Aerator

Contact Info

Product

Resources

About