Research And Analysis Of 3D Flow Field And Mixing Process Of Stirred Tank With NdFeB Boron

Stirring and mixing devices are commonly used in many industrial fields such as medicine and waste recycling.Many scholars currently study fluid flow mixing characteristics through numerical calculations.In this paper,numerical simulation methods are used to simulate and analyze the fluid mixing characteristics of the neodymium-iron-boric acid agitating tank with the standard k-?model and the multiple reference frame method to improve the mixing performance of the agitating tank as an evaluation index and optimize its structural parameters.The main results are as follows:(1)Numerical simulation was used to analyze the fluid flow characteristics of the presence or absence of a flow tube in a 10 m~3 stirred tank.The axial flow paddles combined with the flow tube enhanced the fluid flow in the upper and lower parts of the mixing tank,and the fluids were strongly mixed in the flow tube,Axial circulation flow of the fluid in the agitating tank was determined,and the phenomenon of fluid follow-up near the blade in the agitator tank without a guide tube was improved.(2)Taking the diameter of the blade,the angle of the blade,the height of the draft tube,and the distance from the bottom of the blade as the research variables,the comparative analysis of the flow field and power consumption of the agitation tank with single-layered draft tube with different structural parameters was carried out.Obtaining reasonable structural parameters helps to improve the flow field inside the mixing tank and reduce the stirring power.Comparing the flow fields in the agitator tank with single/double blades,the power consumption of the agitator tank with double-layer propeller was increased,but the flow field distribution was better and the effective mixing volume of the fluid was increased.(3)Based on the simulation of the flow field,the tracer method was used to numerically simulate the mixing process of the mixing tanks of single-layer propellers with different structural parameters,and the diffusion process of the tracer in the stirred tank was observed.The mixing time and the mixing energy per unit volume are used as the evaluation indexes,and the structure of the mixing tank is optimized.The numerical analysis of the improved mixing tank is compared with the stirring tank before the change,the results show that suitable structural parameters can reduce the mixing time,reduce the mixing energy per unit volume,improve the overall mixing effect and reduce energy consumption.