Experimental And Numerical Simulation Study On Burden Distribution Of COREX Melter Gasifier In Bayi Steel

COREX is the earliest industrialized smelting reduction ironmaking process.Compared to the traditional blast furnace,COREX is featured with shorter route,less operation and lower environmental pollution.Baosteel has moved COREX-3000 to one of its subsidiaries,i.e.,Bayi Steel in Xijiang autonomous region of China.Due to the changes in raw materials and charging scheme,operational difficulties are encountered and the conventional adjusting measures are usually in lack of pertinence and effectiveness.Therefore,it is urgently needed to clarify and understand the burden pattern under a variety of charging schemes,which would provide theoretical guidance for determining operational parameters of COREX melter gasifier in the situation of new raw materials.Based on similarity laws,an experimental charging distributor of COREX-3000 melter gasifier,of which the geometric ratio is 1:7.5,is built in the present study.The particles employed in the experiments are actual materials of coal,coke and pellet and the size is scaled by 1:2.Under the condition of utilizing the gimbal distributor alone,the DRI-flap distributor alone and both of them simultaneously for mixing charging,the effect of charging radius,chute rotating speed,ratio of pellet powder,charging scheme and cycle time on burden pattern is investigated.Also,a DEM based mathematical model for simulating the charging process of the melter gasifier is developed and verified by the experimental results.Some significant information related to the charging process,such as burden trajectory,particle segregation in the burden pile,velocity and voidage distribution,is provided by the mathematical model.The results in the present thesis indicate that as the gimbal or the DRI-flap distributor is employed alone,segregation is obvious in the burden pile where the voidage shows a U shaped distribution in the radial direction.As pellet and coke are charged simultaneously,the average voidage of the burden pile slightly decreases as coke is charged.As pellet and coal particles are charged at the same time,the burden pile structure and ore to coal ratio are influenced by the charging scheme to a big extent.However,the burden pile voidage varies within a narrow range in the radial direction.