CFD Numerical Simulation Of The Flow In The Slurry Mixing Cabin

As land mineral resources tend to become exhausted due to long-term exploitation,the exploitation of marine mineral resources has become an important way to alleviate the problem of resource shortage and insufficient energy supply in the future.The development of marine mining equipment is the key to expanding the capacity of marine mining,in which the mining ship as an important carrier of marine mining is the focus of development.Mining ships will be affected by wind,waves,and swells during mining operations,so the slurry concentration will fluctuate,which will affect the working efficiency of the beneficiation system.In order to eliminate this effect,it is necessary to set up a slurry mixing cabin for stabilizing the slurry concentration,so as to maintain the output slurry concentration in the concentration range with the highest efficiency of the beneficiation system.The solid-liquid mixing in the slurry mixing cabin is a two-phase flow problem.It is difficult to verify the effectiveness of the mixing cabin through model tests.Therefore,this paper uses ANSYS FLUENT to perform numerical simulation calculations on the mixing process.The paper investigates the role of the slurry mixing cabin in stabilizing the output slurry concentration of the mining system,as well as the capacity of the mixing cabin to stabilize the fluctuation of the slurry concentration.At the same time,It study the power consumption which is required to achieve the suspension effect.In this paper,through theoretical analysis and CFD numerical simulation,the following conclusions are drawn on the design schemes of open slurry mixing cabin and closed slurry mixing cabin.The suspension effect of the cylindrical mixing cabin is the best,and the bottom of the mixing cabin can be filled with angles or cones to facilitate particle suspension.At the same time,the length and width of the mixing tank should be reduced as much as possible to reduce the loss of radial flow.The mixing effect of the axial flow agitator is the best.Its size is usually designed based on a certain proportion based on the size of the mixing cabin.Increasing the distance from the bottom of the agitator can increase the suspension height of the particles,but will increase the critical speed of the particles suspended from the bottom.And when the distance from the bottom is too small,the impeller may be damaged when restarting the agitator.The position of the inflow pipe should minimize the influence of the mainstream stirring and outflow pipe.The position of the outflow pipe should be selected around the agitator and stir evenly.According to the simulation results,the open slurry mixing cabin composed of the optimized mixing cabin model and the CBY mixer with a rotation speed of 40 rpm,a distance of 1.325 m from the bottom and a diameter of 4m can stabilize the slurry concentration and minimize the power consumption.Although the closed slurry mixing cabin is simple in structure and convenient to install,the ore suspension effect is poor.