| With the rapid development of modern industrial production and science and technology,the increasing requirements for steel quality have forced the continuous upgrading and improvement of hot metal desulfurization equipment.Improving desulfurization efficiency has become a concern of the steel industry and related researchers.This paper also starts research from three aspects:research on the way of adding desulfurizer particles based on KR method,research on baffle plate to improve the stirring effect of KR method desulfurization,and numerical research on flow field based on KR method new agitator.First,the dispersion of desulfurizer particles and the free liquid surface vortex were analyzed with the cross-type stirrer head commonly used in KR mechanical stirring as the research object.The main areas that affect the desulfurization efficiency are clarified:the forced vortex area and the low-velocity area at the bottom of the molten iron tank.At the same time,the particle flow characteristics of several desulfurizing agent addition methods based on the KR method were studied,and it was analyzed that the injection feeding can reduce the low flow rate area at the bottom of the molten iron tank.The dispersion effect of different desulfurizing agent addition methods in the fluid will be different.The performance is:injection feeding>continuous feeding>one-time feeding>evenly flat feeding.Next,in order to reduce the forced vortex area during the KR desulfurization process and improve the central agglomeration of the desulfurizer,a flow control device was added to the molten iron tank to improve the stirring effect of molten iron desulfurization.From the perspectives of gas-liquid distribution,streamline distribution,average velocity of the flow field and average turbulent kinetic energy,the flow field characteristics when the number and width of the baffle are different are analyzed for the presence or absence of the baffle,the arrangement of the baffle,and the number and width of the baffle.It is concluded that the setting of baffles in the molten iron tank can suppress the formation of the central vortex,expand the dispersion of the desulfurizing agent particles in the tank,and have little effect on the low flow rate area at the bottom of the molten iron tank;the height of 4 blocks is 1/2 of the height and width of the molten iron tank.When it is a short baffle with a diameter of 1/10 of the hot metal tank,the forced vortex area in the tank is basically eliminated,and the bottom of the hot metal tank still retains a large flow field velocity,and the mixing effect is the best.Finally,in order to improve the overall desulfurization efficiency,referring to the traditional KR desulfurization method,the advantages of the agitator and the spray gun are combined to form a new type of agitator that both stirs and sprays.Through numerical simulation calculation,the influence of the different eccentricity of the stirrer,the stirring speed,and the ventilation flow rate on the desulfurization effect in the molten iron tank is studied from the two aspects of flow field velocity and gas distribution.The use of a new type of agitator can enhance the flow of the flow field,and the desulfurization gas sprayed from the nozzle at the bottom of the agitator will spiral upward,which will make the desulfurization gas distributed in the molten iron tank wider and more uniform.When the new agitator has a stirring speed of 150 r/min,an air flow of 5.0 m~3/h and an eccentricity of 0.3,the distribution and density of the gas is the best,and the flow field has a large average flow rate,which is conducive to the reaction of iron and desulfurizer.The research results of this paper are helpful to systematically understand the fluid flow characteristics of KR hot metal desulfurization,provide a theoretical basis for the optimal design of KR mechanical stirring,and provide a reference for optimizing hot metal pretreatment technology and equipment. |
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