Flow Characteristics And Numerical Simulation Of Solid-Liquid Mixing In A Square Stirred Tank

Solid-liquid agitation mixing in a stirred tank is one of the important operating units for industrial production and has a common use in many industries.In order to further understand the distribution state of solid-liquid two-phase flow field,and achieve the optimal mixing and mixing effect under the premise of maximizing energy saving and consumption reduction,master the flow state of fluid in the stirring tank and the mixing of solid-liquid mixing.The effect is of great value.The research results of this thesis can provide a certain degree of reference for the optimization design,manufacturing and selection of mixing equipment in practical applications.When the physical properties such as the content and density of the solid phase particles in the stirred tank are determined to be constant,the parameters such as the diameter of the agitator blade,the height of the bottom,and the stirring speed are the main factors affecting the solid-liquid suspension effect.Therefore,this paper has carried out related numerical simulations on different speeds,different blade lengths,different blade bottom heights,etc.and reached relevant conclusions.The main research processes and results are as follows:(1)Combining the existing research results of solid-liquid mixing and mixing,using the existing equipment conditions,using a square stirring tank and a 45° six-slope open turbine agitator as the research object,using CFD software ANSYS workbench 14.0 CFX In part,first determine the shape and size of the agitation tank,the agitator paddle and other related parameters,and then complete the steps of establishing the geometric model of the analysis object,dividing the mesh,setting initial conditions and boundary conditions,and finally,the solid in the agitation tank.-Liquid two-phase flow for numerical simulation.(2)The liquid phase velocity vector diagram,solid-state ratio cloud map and turbulent flow energy cloud diagram of different cross-sections in the stirred tank under different conditions were compared and analyzed.According to the comprehensive analysis results,the flow law of the fluid in the square stirred tank was obtained,and the optimality for the square stirred tank was determined.Parameter groups for optimal solid-liquid suspension.(3)The conclusion shows that when the bottom length of the square agitating tank is 500*500mm,the liquid level height is 500 mm,the blade diameter is 250 mm,the blade bottom height is 200 mm,and the stirring speed is 400 rpm,the solid-liquid mixing effect is the best.(4)By analyzing the solid-state rate cloud diagram of the bottom and side of the stirring tank and the horizontal plane of the blade under the optimal parameters,it is concluded that the solid-liquid suspension effect in the square stirring tank is better under the optimal parameters,and the conclusions from the different angles are verified.Consistent.