Flow Field Analysis In Rotary Injection Desulfurization Process

In the production process of steel,the excessive content of sulfur will have many adverse effects on the performance of steel,and ultimately affect the quality of steel products.Controlling the content of sulfur in steel has become an urgent problem to be solved.At present,the methods used in hot metal pretreatment desulfurization mainly include KR mechanical stirring method and injection method,but there are great shortcomings between the two methods.In this these,by combining the advantages of the two methods,a rotary injection method is proposed.Through the combination of water model experiment and numerical simulation,the variation law of internal flow field in hot metal ladle is explored,which provides reference value for the actual production of iron and steel enterprises.In this these,according to the similarity principle,the water model is established according to the ratio of 1:5,and the experimental results of the water model are verified by numerical simulation.The final conclusion is that the experimental results of the water model are consistent with the numerical simulation results,which proves the accuracy of the simulation.On this basis,aiming at the prototype of 125 T hot metal ladle in a domestic steel plant,the simulation and prediction of different spray gun speed,different insertion depth,different jet speed,different insertion position and different spray gun shape are carried out,which provides a new idea for the research of hot metal pretreatment desulfurization direction.In the simulation and prediction of 125 T ladle prototype in a domestic steel plant,it is found that :(1)The increase of jet velocity can increase the velocity of molten iron,improve the distribution of desulfurizer particles and accelerate the dispersion of bubbles.However,excessive rotation speed will cause entrainment of desulfurizer particles and bubbles,reduce the reaction opportunity between desulfurizer particles and sulfur in molten iron,which is not conducive to the desulfurization reaction and affects the desulfurization efficiency.(2)The flow field and particle dispersion can reach the best state only when the mixing depth of the spray gun is moderate.The excessive depth after the spray gun will lead to the discontinuous distribution of bubbles and the uneven distribution of the flow field.The small insertion depth of the spray gun will lead to the poor hydrodynamic conditions of the molten iron in the lower part of the spray gun and the uneven distribution of the desulfurizer particles,which is not conducive to the desulfurization reaction.(3)The increase of jet volume can also improve the movement of molten iron and increase the disturbance of molten iron.However,after increasing to a certain extent,continuous increase can only increase the distribution range of nitrogen in the molten iron ladle,and has no significant effect on the volume of gas.(4)In the case of central stirring,the dispersion of particles is better than that of eccentric stirring,and the velocity of molten iron is greater,which is more conducive to the desulfurization reaction,but eccentric stirring can solve the problem of dead zone.(5)The increase in the number of nozzle gun can significantly improve the movement of molten iron,while the amount of nitrogen injected into the molten iron ladle increases,the disturbance of molten iron is more intense,but in the wall of the molten iron below the location of particle accumulation.