Research On Material Transfer In Gas DRI Shaft Furnace And Temperature Field

With the development of short steel-making instead of traditional BF-BOF process inthe world and the increasing shortage of appropriate scraps as iron resource, the directreduction iron production technology as an alternative method has attracted researchersmore and more concern day by day.First of all, the minimum requirement of direct reduction gas was calculated andanalyzed on the basis of dominant gas-based HYL and MIDREX technology, duringwhich the main factors of influencing the speed of direct reduction were also analyzed, theways to increase its speed were raised, and thermodynamics reaction gibbs free energy,equilibrium constant, theoretical maximum output and thermodynamic temperature werestudied.Secondly, a numerical model was established for simulating the reduction section ofthe DRI shaft furnace through ANSYS software. The FLUENT software was adopted toget the numerical solution for heat transfer between gas and solid during its reductionprocess. In this way, the temperature distribution in the shaft furnace, thermal efficiencyand reduction gas distribution in DRI shaft furnace were obtained. The affect of volume,temperature, and the pressure of the reducing gas on its temperature distribution wasanalyzed.At last the materials movement in the furnace was analyzed because it played a vitalrole in the gas flow distribution, which was directly related with the efficiency ofreduction gas and metallization ratio of DRI. Research showed that the movement wascontrolled by the discharge device of the furnace. Materials motion under different screwstructures conditions were compared, and the most suitable one of which was selected tobe the discharge device.The wearing rate of the screw was very rapid because of the high environmenttemperature up to850℃in a continuous long time, even though the screw blade wasmade of heat-resisting material. In order to improve the service life of the device, thecooling water was prepared for cooling the equipment. The heat-force interaction method was adopted to analyze the cooling effect.