In the following paper, experimental data represent mixing time in a stirred tank. Electrical conductivity methods are used to obtain results of mixing time. Weight percent of CMC solution, which indicates pseudo plastic behavior of the fluid, was deemed 0.5%. What is more, it was used as continuous phase and air as the dispersed phase. The effect of blade angle and length were investigated with 7 concave impellers. The experimental results demonstrate that the mixing time will decrease by increasing rotation speed. The impeller No. 6 is favorable to reduce mixing time in constant power consumption because of the maximumangle between the other impellers. Consequently, an equation to predict mixing time by using four independent parameters is suggested; moreover, this equation can be utilized as a predictor relation in comparison with the experimental data.