Study Of The Erosion Of Hearth Based On The Transient Mathematical Model Of Blast Furnace

Based on the damage status of the blast furnace hearth of the effective volume of1750m~3 in a steel mill,the transient model of the blast furnace was established with the FLUENT software to study flow field during the tapping process of blast furnace.In the simulation,the effects of changing the dead man state,dead man porosity and depth of salamander are researched,and the simulation results under different conditions,i.e.the shear stress,pressure and so on,are obtained and are analyzed.The molten iron flow field in the hearth is studied to discover the effects of flow of molten iron to the erosion area and mechanism of erosion at furnace bottom.The main conclusions are as follows:(1)The maximum shear stress at the bottom with A1 type deadman is the smallest of the four dead man types,and the maximum shear stress fluctuates with the change of the iron time.The maximum shear stress at the bottom is the smallest in the four dead man states.The smallest,the formation of such dead man state in these several most conducive to long blast furnace.(2)The dead man filled with hearth when the furnace has a certain role in the protection of the dead man around the existence of hot metal free area will greatly increase the pressure on the bottom and side walls,the existence of slag can effectively reduce the molten iron on the furnace cylinder side slag layer covering area.(3)The high incidence of the circulation phenomenon is located at the bottom of the hearth.The position of the bottom maximum shear stress is mainly distributed on both sides of the hearth and the bottom of the furnace,The location of the fit.Circulation phenomenon will gradually disappear with the progress of the iron out of the process,the heart of the molten iron flow rate as a whole will drop with the time;the bottom of the shear stress,pressure with the time and decline.(4)When the porosity e = 0.3 in the suspended material,the maximum flow rate in the hearth is less and the maximum velocity of the bottom molten iron is the smallest at different times,and the flow field is more stable.With the increase of porosity,The(5)maximum shear stress position is gradually moved from the sides of the outlet to the center of the furnace bottom.The greater of the porosity,the greater the shear stress at t <500s,the smaller of the shear stress at the bottom porosity after t> 500s;and at t <500s,under the same porosity,When the dead man is floated,the shear stress is smaller than that of the dead man.(6)When the depth of the dead iron layer is the same,the flow rate of the dead man is smaller than that of the bottom.