Study On Flow Field Simulation And Parameter Improvement Of Agitator Blade

Agitator is a kind of common process equipment.There are certain requirements for mixing efficiency in daily scientific research and production.In view of this demand,this paper studies the parameters of improving the efficiency of agitator.The radial diffusion ability and axial pushing capacity of impeller of agitator directly affect the stirring efficiency.The most direct way to improve the mixing efficiency of agitator is to improve its radial diffusion ability and axial pushing flow ability.It is of great significance to study the blade structure,analyze the flow field characteristics and improve the impeller parameters of the agitator.The main contents of this paper are as follows:(1)The interaction between a rotating blade and a stationary stirred tank is dealt with by the method of multiple reference systems.The theory of blade system is calculated and analyzed from the aspects of helix lift line theory,helix lift surface theory,induction velocity of singularity system,discretization and circulation theory.(2)The bubble like sequencing method was used to simulate and compare the external flow field under different parameters,such as blade opening,central axis opening,blade rotation angle,blade speed,auxiliary blade and so on.The influence of flow field velocity characteristics,radial diffusion capacity,axial pushing capacity on the mixing efficiency of agitator was analyzed.According to the results of numerical simulation,the best parameters are six blades without holes,no auxiliary blades,rotation angle of 40 degrees and rotating speed of 400 R/min.(3)In order to improve the structural strength of the blade,based on the best parameters of the agitator,the buckling analysis of the agitator structure is carried out,and the weak part of the structure strength is obtained.By changing the connection mode of the joint between the blade and the central shaft from half contact to full contact,the displacement and stress situation are improved by more than 60%.(4)The best parameter model,flow velocity meter,torque sensor and stirrer were selected as experimental devices.Sodium nitrite solution and p-aminobenzenesulfonic acid were used as experimental materials to verify the simulation data of pushing force and velocity.The results showed that the error between the experimental data and the simulation data was less than 5%.The velocity data is in good agreement with the simulation data.Overall,the accuracy of the numerical simulation is verified.