关键词: 不锈钢, AOD转炉, 侧顶复吹过程, 流体流动, 数学模拟

Abstract: The fluid flows in the bath of a 120 t AOD converter and its water model with a 1/4 linear scale in the combined side and top blowing have been treated and analyzed from the superposition of the computed results of those during the simple side and top blowing processes respectively by the side and top blowing components of the mathematical model developed for the molten steel flow in an AOD bath under the conditions of combined blowing. The results demonstrate that the mathematical model can be used to simulate the fluid flow in an AOD bath with the combined blowing. The liquid flow in the bath with the combined blowing results from the gas side blowing streams under the influence of a gas top blowing jet, the gas side streams play a governing role for it, and the liquid is equally in vigorous stirring and circulatory motion during the combined blowing also without obvious dead zone in the whole bath. Compared with those in a simple side blowing, the impinging of a gas top blowing jet does not change the essential features of gas agitation and fluid flow in the bath, but can make the local flow pattern of the liquid vary evidently. The changes in the angle between each tuyere and the tuyere number have similarly not altered the basic characteristics and patterns of gas stirring and liquid flow and turbulent kinetic energy distribution in the bath. However, at a given tuyere number and gas side blowing rate or a given angular separation between each tuyere and gas side blowing rate, the variation of the number or the angle can change locally them. Using 6 tuyeres with 27° for blowing can reach more uniform flow field and turbulent energy distribution of the liquid in the AOD bath with the combined blowing than that taking 7 tuyeres with 18° or 22.5° and 6 tuyeres with 22.5°.

Key words: stainless steel, AOD refining, combined side and top blowing, fluid flow, mathematical modeling