Study On Power Consumption And Mixing Performance Of Granular Materials In The Mixing Process

Experiments were carried out in an elliptical based stirred tank with a diameter of 0.476 m to measure the power demand and mixing performance of four different impeller combinations.The impellers used were double helical ribbon(HR)+bottom HR,Paravisic impeller+bottom HR,inner and outer HR+bottom HR,Frame impeller+bottom frame impeller,respectively.Silica gel particles with the diameter of 75μm were used as the materials in the power measurement experiments.The quantitative correlations among the rotational speed,fill level and power consumption from impeller I to impellerⅣ were obtained.Two kinds of silica gel particles with a particle size of 75μm and 1 mm,respectively,were used as raw materials for the mixing performance measurements.The effects of agitation speed,filling level and material loading methods on the mixing performance with different impellers were experimentally measured.The power experiment results show that when the filling level is constant,the power consumption of the four combined impellers is almost linear with the rotation speed.Given the agitation speed,the power consumption and the specific power consumption for four combined impellers increase with the increase of the filling level,and the greater the relative loading height,the faster the growth rate of the power consumption is.At the same speed and filling level,the power consumption of the frame-type combined impeller is much higher than those of other experimental combined impellers.The agitation speed,filling level and loading method have a significant effect on the mixing performance of four impeller combinations.The agitation speed has different effects on the mixing performance of different impeller combinations,and each combination has its own optimal mixing agitation speed.The mixing performance of the four impeller combinations will change at different filling levels:When the filling level H/T=0.6,the mixing performance of the frame impeller is the best among the four combined impellers,and the local unmixing problems of the other three impellers will have an adverse effect on industrial production;But whenH/T=0.8,the mixing performance of the inner and outer ribbon impeller is the best,and the frame impeller is the worst.The material loading method has an effect on the power characteristics and mixing performance of the four impeller combinations.When H/T=0.6,the loading method 2 has advantages of convenient operation,low power consumption,and good mixing effect.The experimental results can guide the selection and development of mixing equipment in the powder mixing applictions.