1. School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China; 2. Institute for Frontier Technologies of Low-Carbon Steelmaking, Northeastern University, Shenyang 110819, Liaoning, China; 3. Liaoning Province Engineering Research Center for Technologies of Low-Carbon Steelmaking, Shenyang 110819, Liaoning, China
Abstract:Preheating scrap in hot metal ladle by burning low calorific value gas is one of the effective measures to increase the amount of scrap entering the converter. Based on the standard k-ε turbulence model coupled with vortex-dissipative combustion model, numerical simulation research on oxy-fuel combustion process in hot metal ladle was conducted, and the gas flow distribution characteristics and its influence on baking effect was discussed. The result showed that under the condition of pure oxygen combustion, the velocity of high-temperature flue gas increased and entered from the center of the material pile and discharges from the edge, making a large heat exchange distance, which could greatly improve the heat utilization efficiency of low calorific value gas combustion. During the combustion process, air entrainment and flue gas overflow occurred in the gap between the ladle and its cover. By adjusting the BOF gas flow rate or outlet negative pressure, the overflow of flue gas could be reduced, the flue gas recovery temperature could be adjusted, and the optimal gas flow distribution and the effect of scrap baking could be realized. In this preheating device, the comprehensive effect was better when the outlet negative pressure was -50 Pa and the BOF gas flow rate was about 3 500 m3/h.
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