Water Model Experimental Method And Application Of KR Hot Metal Desulfurization

KR desulfurization method as one of the hot metal pretreatment methods that has high desulfurization,efficiency desulfurization effect and low cost of desulfurization and many other advantages is widely used in major iron and steel enterprises to produce low sulfur content steel now.Therefore the study of KR desulfurization has become the research topic of many scholars.The research of KR desulfurization in laboratory main methods has physical simulation and numerical simulation.With the development of computer the numerical simulation study is relatively mature,because of the complexity of KR mixing process the experimental methods and test parameters of physical model of water model experiment need to be improved.Based on the insufficient kinetics of KR desulphurization in Baosteel,this paper combined with experimental studies on solid-liquid mass transfer in the mixing tank and the experimental method of hot metal pretreatment,and put forward a comprehensive experimental method and test parameter of KR desulfurization water model.The optimization experiment of KR desulfurization kinetics of Baosteel was carried out and the reasonable mixing parameters were obtained.The experimental method is similar to the kinetic method using the modified Fred criterion and the simulated desulfurizer medium is derived according to the Stokes formula.The parameters of the test parameters include the height of the free liquid,surface the depth of the center whirlpool,the dispersion criterion,the mixing time,the proportion of the weak flow area,the mass transfer coefficient,and the number of particles scattered and so on.Then the numerical simulation method and the formula method are used as the auxiliary method to verify the reliability of the experimental results.Baosteel KR hot metal desulfurization kinetics optimization experiments show that the stirring blade speed 120 r / min and sneak into the depth of 1650 mm,the fluid in the agitation tank the best dynamic conditions.As Baosteel actually produces the motor power limit to make the stirring blade speed 100r/min or so under this condition the experiment achieves the optimum parameters of the stirring blade depth of 1.35 m.In a certain range of appropriate increase in the radius of the mixing pad and hot metal diameter ratio improve the efficiency of desulfurization.Experiments measured kinetic conditions more than 0.46 diameter ratio better in low sneak and depth high speed.Deep into the depth and low speed diameter 0.41 better than the performance diameter ratio of 0.41 for Baosteel existing technology.Compared with the four leaves,the three-leaf stirring blade increases the angle between the stirred blade and reduces the weight of the stirring blade.Under the same conditions,the stirring efficiency of the three-blade stirring blade is improved the forced strength of the fluid increased,the agglomeration of the desulfurizer reduced and the desulfurization efficiency improved.The baffle in the flow control device can effectively change the rotational motion fluid into axial vertical inversion movement and eliminated the desulfurize aggregation in the central vortex and increased the amount of the desulfurizer in the fluid and increase the utilization rate of the desulfurizer.2 long baffle can effectively improve the distribution of plastic particles and improve the utilization of desulfurization agent and reduce the consumption of refractories.In the case of no baffle the dispersing effect of the desulfurizer in the fluid is as follows 1-time feeding continuous feeding and feeding.In the absence of baffle the effect of batch addition and continue addition and powder blasting addition on the dispersion of the desulfurizer in the fluid is as follow powder blasting addition is best and batch addition is the worst.The three feeding methods on the desulfurization agent dispersion was not significant difference after adding the baffle.In a feeding mode,there is a baffle desulfurizer dispersion effect is greater than no baffle.The baffle affects the agglomeration of the particles more than the injection and the continuous feeding.