Numerical Simulation Of Hot Metal Circumferential Flow In Blast Furnace Hearth

Carbon bricks with high thermal conductivity are used for the side wall of blast furnace hearth. However, the temperature of the side wall is continuously rising after some time, which affects the production stability of blast furnace and restricts the blast furnace campaign life. During the past few years, the investigations on the blast furnace overhaul show that one of the main reasons is the scouring caused by hot metal circumferential flow which induce the hearth erosion, the temperature increase of the side wall and short campaign life of blast furnace.Because it is difficult to measure and evaluate the flowing state of hot metal directly due to the special structure of blast furnace hearth, numerical simulation method is useful to investigate the flowing situation inside blast furnace hearth in order to make the treating technology and operating measurement of controlling the hot metal circumferential flow, which can reduce the flushing to the side wall of blast furnace hearth and prolong the blast furnace campaign life.Based on the commercial computational fluid dynamics software, FLUENT, with the two different kinds of deadman (floating deadman and sitting deadman), the flowing situations for different taphole lengths, taphole angles, hot metal flow rates and double taphole, hot metal flow are simulated, and the velocity vector as well as streamline of hot metal of and streamline chart and the shear stress distribution on the hearth side wall and bottom are obtained. The conclusions are as follows.(1) Owing to the nonuniform void distribution of deadman inside the blast furnace hearth (the void of deadman in central region is smaller, and the void of deadman in peripheral region is bigger), more hot metal tends to flow to the taphole through the region with bigger void region, which leads to the generation of hot metal circumfluence. For the floating deadman, the hot metals far from the taphole flow to the hearth bottom firstly, and then to the taphole.(2) The maximum of shear stress is near the taphole because of hot metal circumfluence. For floating deadman, the flushing erosion areas locate on the taphole plane and one third plane under the taphole respectively. (3) The shear stresses of the side wall and hearth bottom decrease with the increase of taphole depth. Increasing taphole depth is proper to reduce the flushing.(4) The shear stresses of the side wall and hearth bottom change insignificantly for sitting deadman, which reach the minimum at the angle12°for floating deadman.(5) The shear stresses of the side wall increase with the increase of the hot metal flow rates. Decreasing of the hot metal flow rates can reduce the flushing.(6) The shear stresses of the side wall and hearth bottom increase with the increase of the viod of deadman. The increase of the void of deadman can reduce the flushing.(7) Comparing with one taphole, the shear stresses of the side wall and hearth bottom decrease under the condition of double taphole,...