Numerical Simulation Of Flow Field In Box - Type Mixed Clarification Extraction

Box mixer-settlers in extraction tank is an important equipment widely used in extraction metallurgy. Using the numerical simulation methods to study the fluid dynamics in tank at different stirring, under the conditions of mixed with equal conditions of numerical simulation methods, plays an important role in guiding the optimization of equipment structure design and process conditions.The construction of box type mixed settler extractor geometry model by Gambit software, based on the Fluent simulation software, the multiphase flow model, standard k-e turbulence model, multiple reference frame model, first order upwind discretization method for numerical simulation of three-dimensional flow field, mixing process of mixing chamber; using Eulerian multiphase flow model, Laminar model, first order upwind discretization method, numerical simulation of the process of phase separation settling chamber.With simulating the mixing chamber, we studied the effect of different factors of impeller type, different stirring speed on the mixing chamber flow field; in the clarification chamber simulation, we studied the effect of mixed phase feeding velocity, dispersion degree and other factors on the separation effect, in addition to the heavy phase entrance high degree of fining phase interface the effects of altitude. Output the mixing chamber and a settling chamber of velocity vector diagram, phase volume fraction distribution, stress nephogram.Contact in the mixing chamber and compared under the condition of1:1, when the stirring speed was1OOrpm, two kinds of impeller type reached a better mixing effect, the mixing chamber in each region of the liquid-liquid phase volume fraction is basically the same; when the turbine impeller, two feeding tube liquid level degree greater than the flat paddle, shows that the stirring pumping ability than the flat paddle. Cyclone enhanced when the stirring speed increased to260rpm, the mixing chamber, the surface of the liquid is concave parabolic shape, easy to cause the liquid splash.In the clarification chamber volume, this study set, when the mixed phase feeding speed is less than0.12m/s, phase separation effect is good; with the increase of feed speed, the effect of declining phase, when the mixing phase feeding speed is up to0.2m/s, no demixing effect.This study used the light phase dispersed particles mixing intensity, phase of the corresponding mixed results, phase separation effect with light dispersion particle size decreases (increases the corresponding mixing intensity) and drop, so in extraction and separation, mixing chamber mixing intensity is not too large, otherwise it will seriously affect the phase effect.