| In the field of chemical industry, biotechnology, pharmaceutical engineering, materials processing and food processing, stirring equipment has been widely used. When the fluid viscosity is large or when the media is shear-sensitive, mixing is required in a laminar flow with low Reynolds number. There have many researches that concentrate on the aspect of standard impeller. This paper will simulate the flow characteristics of the standard impeller and the staggered impeller, and find impeller of different layout of the flow field. This thesis also uses PIV technology as the research onΦ200 mm diameter tank of agitation.The flow of radial impeller is simulated with FLUENT software. Compared with the standard radial impeller, staggered impeller has greater high-speed area and enhanced the efficiency of the flow field.Analyzing the flow of different axial impeller which include of 45°oblique impeller, 4-blade CBY and staggered 45°oblique impeller. Comparison of three axial impeller speed changes, find that staggered impeller improved the flow field of the oblique impeller. Arrangement of impeller and the number of impeller have a great effect on the impact of mixing.Combination impeller of the tank and propeller shaft in the concentric and eccentric are simulated. The situation of oars and the eccentric groove break the symmetry of the flow field and the dead space of the stirred tank is decreased. However, the side away from the stirring shaf stirring is weakened, reducing the overall mixing effect. When the upper blade and lower blade relative shift, the flow field symmetry is broken. The superposition between two blades is strengthened. Staggered agitators increase the mixing efficiency.Using PIV technique to study combination of impeller, analyzing the experimental results and simulation results to receive that the simulation results agreed well with experimental results. |
