Physical Simulation Study On Side Blowing Of C-H₂ Smelting Reduction Furnace

Iron and steel industry is one of the most important components in China's industrial field,and iron-making is a vital and indispensable part of the iron and steel industry.As countries around the world pay more and more attention to the concept of resource conservation and environmental friendliness,the coking and sintering process,which are essential for traditional blast furnace iron-making,have cased huge negative impacts on resources and environment,and have been widely concerned and criticized.Under this background,the concept of non-blast furnace iron-making,especially smelting reduction iron-making,came into being.After 100years of development,COREX,FINEX,HIsmelt,and other processes in the smelting reduction iron-making process have stepped into the industrialization stage.However,in the existing relatively mature smelting reduction process,C is still the primary reducing agent,which is not ideal for the purpose and effect of CO₂emission reduction.This paper is based on a new generation of iron bath C-H₂smelting reduction.Its H₂,as the main reducing agent,can effectively reduce the emission of CO_2,which is consistent with the long-term development concept of comprehensive resource utilization and environmental friendliness.In this paper,a 1:1 water model is set up using Plexiglas based on a 200kg thermal simulation iron bath C-H₂smelting reduction furnace.Based on the similarity principle,the modified Froude number of both are made equal to ensure that the model and the prototype are geometrically and dynamically similar.In the physical simulation process,water is used to simulate molten iron,high vacuum oil is used to simulate slag liquid,and oxygen-enriched air is used to simulate O₂,N₂,H₂,and other blowing gases.Through the physical simulation study of five different working conditions,the influences of the blowing conditions on the different mixing effects in the molten pool were explored,and the optimal process parameters were obtained.The experimental data are further refined into empirical formulas through dimensional analysis,providing a reference for the design and optimization of related process parameters of the C-H₂smelting reduction furnace in the future.The main research results are as follows.1.The paper investigated the overall mixing efficiency and uniformity,through the physical simulation study of single-row and double-row side blowing under the conditions of the single side blowing and the top-bottom-side blowing.The best process parameters and significant level ranking were obtained under their respective conditions.The mixing efficiency of double-row side blowing is far better than that of single-row side blowing under the single-side blowing conditions and the top-bottom-side blowing.In terms of mixing uniformity,the single-row side blowing has a better effect under the condition of single side blowing.In comparison,the double-row side blowing has a better effect under the condition of the top-bottom-side blowing.In the orthogonal experiment,each factor's significant difference is closely related to the total number of influencing factors.The more the total influencing factors,the smaller the difference in the influence degree of each factor on the overall mixing result.2.In the physical simulation research of different materials feeding positions in iron bath C-H₂smelting reduction furnace,four different materials(tracers)feeding positions were arranged.Physical simulation results show that the mixing effect of the molten pool is much better when the tracer feeding position is located 2 cm above the slag interface than when the tracer feeding position is inside the slag,and the dispersion of the mixing time is minimal at this time.The mixing effect of asymmetric side blowing is better than that of symmetrical side blowing.When the relative angle of upper side nozzle and lower side nozzle is 60°,the entire pool's mixing effect is the best.Through physical simulation under different working conditions,the optimum process parameters of the various influence factors when different materials(tracers)feeding positions are obtained.3.For the physical simulation results at the different materials(tracers)feeding positions,dimension analysis was carried out further.Based on the similarity principle,the dimensionless group empirical formulas of upper side nozzle and lower side nozzle were respectively obtained by means of multiple linear regression fitting.The empirical formulae for the relations of the mixing time?,slag physical properties,material feeding position,and side-blowing related parameters were obtained as follows:By fitting the calculated value and the experimental value,it shows a positive correlation,which reflects a better fitting effect.