1. School of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063000, Hebei, China; 2. Hebei High Quality Steel Continuous Casting Engineering Technology Research Center, Tangshan 063000, Hebei, China; 3. Handan Branch, HBIS Group, Handan 056002, Hebei, China; 4. Guangdong Xinxing Ductile Iron Pipes Co., Ltd., Yangjiang 629500, Guangdong, China
Abstract：The top and bottom composite blowing converter steelmaking method is the mainstream steelmaking method at present. The type, number, arrangement mode and bottom blowing gas supply intensity of the bottom gas supply element directly affect the mixing effect of the converter molten pool. The reasonable flow field can not only reduce the production cost, but also shorten the smelting cycle and increase the enterprise benefit. Based on the research characteristics of cold water simulation and CFD numerical simulation, a 300 t converter in a steel plant was taken as the prototype, and the mixing time, dead zone and weak flow zone volume of the molten pool under different bottom blowing conditions were evaluated. The bottom lance arrangement, bottom blowing gas supply mode (non-uniform gas supply and uniform gas supply), and bottom blowing gas supply intensity of 300 t converter are systematically studied. The results show that when the position of the bottom lance is from 0.3D (D is the diameter of furnace bottom) to 0.5D, the stirring capacity of the bottom blowing system on molten steel at the furnace wall is obviously enhanced, but the volume of the dead zone and weak flow zone in the molten pool increases obviously, which makes the mixing time of the whole bath increase. It is found that when the critical value of bottom blowing strength is 0.28 m3 / (t·min), the stirring effect is the best. The stirring effect of the bottom blowing system on the molten pool will change with the different gas supply modes. When the bottom blowing flow distribution is 2:1, the bottom blowing system has the best stirring effect, followed by the uniform gas supply mode (1:1). When the distribution ratio is 3:1 and 4:1, the stirring effect of the bottom blowing system on the molten pool will be greatly affected due to the relatively large gas supply intensity on the large flow side of the bath.
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2021, Vol. 56 
