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对顶吹、中心底吹及复合吹三种工艺,在不同的气体流量条件下,用铝粉示踪法研究了熔池内的流谱,用频闪光照象法测定了涡环中的速度分布。流谱试验指出:熔池内形成一个封闭的涡环,三者都可当作轴对称二维流场。由测定结果计算出涡环中心的位置为(Z_0)/H=0.57,(2R_0)/D=0.83。还计算出不同的顶吹沈量和不同的底吹流量条件下的循环流量,回归出它们之间的定量关系武为:Q_c=0.659Q_r+5.175Q_B-0.051Q_T~2-4.975Q_B~2-0.22Q_TQ_B。依此对熔池内的搅拌规律进行了分析。在试验的参数值范围内,循环流量与顶吹气体流量之间的关系为具有一极大值的曲线,循环流量和底吹气体流量之间的关系为一条逐渐变缓的上升曲线。复合吹炼的循环流量小于单纯顶吹和单纯底吹时间两者循环流量的代数和。附加底吹所增加的循环流量随顶吹量的增加而减小。
The top blowing, center bottom blowing and composite blowing three kinds of technology, under different gas flow conditions, the aluminum flow tracing method was used to study the flow in the molten pool, and the stroboscopic ring was used to measure the velocity distribution . Fluid spectrum test indicates that a closed vortex ring is formed in the weld pool, and all three can be regarded as two-dimensional axial flow field. From the measurement results, the center of the vortex ring is calculated as (Z_0) /H=0.57, (2R_0) /D=0.83. Also calculate the different top blow-down volume and different bottom-blow flow under the conditions of the circulating flow, return to the quantitative relationship between them Wu: Q_c = 0.659Q_r +5.175Q_B-0.051Q_T ~ 2-4.975Q_B ~ 2- 0.22Q_TQ_B. Based on this analysis of the mixing law within the pool. The relationship between circulating flow and top-blown gas flow is a curve with a maximum value within the range of experimental parameter values, and the relationship between circulating flow and bottom-blown gas flow is a gradual slowing up curve. The combined flow of the blowing is less than the algebraic sum of the circulating flow of pure top blowing and pure bottom blowing. Additional bottom blowing increased circulation flow with the increase of the amount of blowing decreased.