Process Simulation Analysis And Optimal Design Of Desulphurization Devices For KR Molten Iron Pretreatment

KR(Kambara Reactor)desulphurization technology is a kind of pretreatment desulphurization technology for molten iron,which is used widely and has some advantages,such as low cost,high desulfurization efficiency and excellent dynamic conditions.In recent years,a number of iron and steel metallurgical enterprises have put forward higher requirements on efficiency of desulfurization.In addition,they want to produce high-quality and low-sulfur steel.Therefore,more and more attention has been paid to desulfurization by KR method.This paper demonstrates and analyzes the pretreatment project of molten iron.Several methods of molten iron pretreatment desulfurization are introduced.In terms of desulfurization kinetic conditions,type of desulfurization,cost,iron loss and temperature drop,according to the comparison and analysis between the KR method and spray method,it is found that KR method is superior to spray method.Based on the method of KR molten iron pretreatment desulfurization,the selection design of key processing equipment is carried out,including feeding and feeding system of desulphurization station,tilting slag system and mechanical mixing system.What is more,the main technical parameters and specification are given in this paper.The desulfurization process of KR molten iron pretreatment is simulated and analyzed.First of all,the fluent module based on ANSYS is used for simulation.Moreover,numerical simulation analysis is carried out by establishing a three-dimensional model of molten iron region and dividing mesh for finite element analysis.Secondly,the melted iron single-phase flow field is simulated and analyzed.The continuity equation and momentum equation are given.Furthermore,the appropriate turbulence model,discrete format,solution method of discrete format,and boundary conditions are selected.The influences of different depths of the agitator immersed in molten iron and speeds of the agitator on the iron flow field are analyzed respectively.According to the simulation results,this mathematical model has great applicability,because the dead zone and circulation zone of molten iron can be captured by using the melted iron single-phase flow.The comparison and analysis of agitator speed and immersion depth show that the desulfurization efficiency is the highest when the agitator speed is 120 rpm and the immersion depth is 1200 mm.The equipment and processing parameters of KR molten iron desulfurization pretreatment are optimized from three aspects that are vibration of the lifting frame of agitator head,desulfurization efficiency and system environment.Among them,in terms of desulfurization efficiency,the on-line slag cleaner of the agitator head,the slip pipe for feeding,slag scraping system,the cart for quickly changing agitator,and pipelines for carrying desulfurizer are optimized.Finally,the optimal desulfurization project of molten iron pretreatment is studied experimentally.According to the simulation results,after desulfurization by KR mechanical stirring method,the proportion of sulfur in molten iron can reach below 0.005%,and the amount of slag is large and easy to clean.Therefore,it meets the requirements of the pretreatment of molten iron in modern metallurgical enterprises.