Research On Jet Flow And Macro-instability Inside Oxygen Coal Combustion Melting And Separating Furnace

The domestic iron and steel process is mainly blast furnace-converter long process.Although COREX,HIsmelt and FINEX have been industrialized,there are still restrictions such as high cost of hot metal and unable to completely get rid of coke.In order to solve the above problems,a new process of rotary kiln prereduction and oxygen coal combustion melting and separating furnaces was developed.The process takes pulverized coal and powder ore as raw materials,uses coal-based rotary kiln as prereduction reactor,and furnace as final reduction reactor.The physical simulation study of the rectangular molten pool area inside the furnace was conducted.Based on the similarity principle,a 5:1 model of the reactor was built,supplemented by the real-time shooting of the high-speed camera system.Based on the comprehensive analysis of bubble motion,jet behavior and macro-instability,the interaction between jet behaviors in furnace and macro-instability fluctuation of molten pool was discussed with bubble motion as the link and breakthrough point.The research shows that the bubbles play a key role in promoting the bubble movement in local area and the macro-instability of liquid level.The longitudinal fluctuation of liquid level first occurs in the molten pool.The injection of molten pool is stable,the fluctuation period of liquid level under different flow rates fluctuates up and down in a small time interval.The fluctuation frequency of the positive liquid level is 23 Hz,and that of the side liquid level is 14 Hz.By establishing the mathematical equations describing the bubble aggregation frequency,it was proved that the aggregation and fragmentation of large bubbles and the random collision of small bubbles was the key to the macro-instability.The parameters of the oxygen lance arrangement of the developed new ironmaking process were optimized,with the optimal oxygen lance immersion depth of 15 mm,the optimal oxygen lance diameter of 4 mm,and the optimal oxygen lance inclination angle of-15°.Figure 81;Table 2;Reference 66...