A large number of investigations can be found in the literature which examine the effect of mixing parameters in both solid-liquid and liquid-liquid systems. However, very little is currently available for solid-liquid-liquid systems. It is the intent of this study to look at the various parameters affecting the point of complete dispersion for a liquid and the point of complete suspension for a solid phase, in a three phase liquid-liquid-solid system.
A model has been developed for the dispersion of each phase based on a momentum balance of forces on an individual particle of solid or an individual droplet of liquid. Kolmogoroff's theory of isotropic turbulence has been utilized to predict the behavior of the system. Similar equations have been previously applied successfully to two phase systems. A wide variety of agitation systems with both radial and axial discharge was employed in this investigation to experimentally validate the model prediction. In particular, the disk turbine (representative of radial flow impellers) and the pitched blade turbine (representative of axial flow impellers) were studied in greater detail. All of the experiments conducted in this work involved three phase systems.
A comparison between the experimental results obtained in this work and those predicted by the model equations is provided. The agreement was found to be very good. In addition, comparisons between the current work and previously reported data on two phase systems is given. Again, good agreement was obtained. These results indicate that for systems involving only moderate concentrations of solid and dispersed liquid, the role of the key variables can be successfully predicted by considering each phase independently.
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