Investigation of Non-Newtonian pseudo plastic fluid behavior in gas-liquid agitated tank

A non-Newtonian pseudo plastic fluid is investigated in two phase gas-liquid system in agitated vessel equipped with ASI (Axial-Radial) impeller, by using a noninvasive flow visualization technique, electrical resistance tomography. The main goal of this study is to investigate the effect of gas dispersion on the behavior of non-Newtonian fluid. In this work, xanthan gum solution in different concentration is used as yield-pseudo plastic fluid and air is used for gas phase which dispersed to liquid from the bottom of vessel by a sparger. The experiments are carried out in gassed condition with different gas flow rate, and the effect of impeller speed, xanthan gum concentration and gas flow rate on mixing time, and power consumption is explored and the results compared with the performance of Rushton turbine and pitch blade impeller. The analysis of experimental results shows that ASI impeller is more effective than the two other impellers from the point of mixing time, unlike the power consumption in two phases non-Newtonian agitated system. We found a linear relationship between power consumption and Re for our non-Newtonian gas- liquid agitation system by using ASI impeller as p/v=c .Re.Fr which C is a logarithmic function of concentration as C=5×10^10 e^(-0.02ρ) where ρ is the density of solution.