Experimental Study on Liquid-Liquid Macromixing in a Stirred Tank

In this paper, the experimental data on the mixing time ad power consumption of two immiscible liquids in a mechanically agitated baffled tank are presented. The electric conductivit method was taken for the measurement of the mixing time and the shaft-torque method for the power consumption measurer lent. Tap water was used as the continuous phase and kerosene the dispersed phase. The effects of the agitation speed, type of impeller, clearance of the impeller off the tank bottom, volume fraction of the dispersed phase, physical properties of the liquids, and probe position on the macromixing of the liquid-liquid system were studied. The phenomena of macromixing are largely similar to those of single-liquid and gas-liquid stirred tanks. The experiment indicates that the flow field and turbulence c in be dampened at high volume fraction of the dispersed phase while enhanced at low percentage. The mixing time becomes longer with increasing viscosity of the dispersed phase. The results show that the pitched blade turbine downflow is more efficient for macromixing than the others tested in this work.

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