A Numerical Study On The Characteristics Of Fluid On The Agitaors

Stirring in chemical,pharmaceutical and food industries is an essential process flow in production,so the mixing equipment is widely used in many industries.In the past,the design and selection of the agitator completed by empirical method because of no a complete set of theory system.And experience provides a simple reference at the first stage.The factory must do a lot of experiments to test its performance before putting into production.The operation process is quite complicated,and the funding of the process is very high.For very huge agitators,it is unlikely that the factory want to test its performance.Nowadays,computational fluid dynamics(CFD)method has arisen,and can get a reliable data for flow field simulation of the agitator.Since the advantage is that the theory simulation only need a computer and CFD software,it is a effective way in engineering to test problems of performance parameters of large mixers,CFD software can provide several fluid parameters for fluid models,for example turbulent distribution,velocity distribution and pressure distribution etc.In this paper,it simulates and studies the process of mixing in mixing tank using computational fluid dynamics software Ansys CFX and use relevant literature for reference to verify the simulation results.This paper contains the following several aspects:establishing fluid domain of the agitator,meshing for fluid domain,establishing the flow field model of the pure water,particles in solution and CCl4 in solution with Euler-Euler method and solve the fluid model by the way of finite element volume.In stirring water model,through the analysis of speed contour of the flow field of different sections,turbulent eddy dissipation contour,shear rate contour and so on,two better kinds of stirrers are selected from four kinds of stirrers.Then comparing them in the process of mixing of particles in solution under critical stirring speed power,the article picks out the best agitator.Finally,the article furtherly explores the effect of mixing CCl4 in solution.Through the analysis of CCl4 volume fraction of sample points under different rotational speeds,the agitators cannot mix CCl4 and water.