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摘要: 对离心粒化后高温熔渣的飞行过程建立数学模型，通过Runge-Kutta方法对建立的数学模型进行离散求解。结果表明，熔渣液滴沿x方向飞行距离与液滴直径和初始速度成正比；由于空气绕流阻力和重力作用，熔渣液滴速度先降低后增加。对熔渣液滴撞壁后过剩反弹能进行分析，获得了熔渣液滴的临界撞击速度。结果表明，临界撞击速度为区间，存在上界和下界，且上界和下界同时随直径增加而降低。对初始速度为10、12和14 m·s‒1三种粒化工况进行实验，结果表明，由于熔渣液滴从粒化盘抛出时速度小于粒化盘边缘线速度，熔渣液滴实际下降距离大于其理论值；三种工况下熔渣液滴撞击速度在临界撞击速度区间内，均未产生粘结。Abstract: The mathematical model was established for the flight process of the molten blast furnace slag after the centrifugal graining, and the model was discretely solved by the Runge-Kutta method. The results show that, the flight distance of the slag droplets along the x direction is proportional to the diameter and the initial velocity of droplets. Due to the air flow resistance and gravity, the velocity of droplets decreases with time, and then increases slightly. Critical impact velocity of the droplets was proposed by analyzing the excess rebound energy of the slag droplets after collision with wall. The results indicate that, the critical impact velocity is an interval, and the larger the droplets, the lower the bounds. The experiments were performed with the initial droplet velocities of 10, 12, and 14 m·s‒1. The results indicate that, the actual falling distance of the slag droplets is greater than the theoretical values, because the initial velocity of the slag droplets is less than the linear velocity of the granulation plate. Meanwhile, the impact velocity of the slag droplets is between the upper and lower bound, thus no adhesion occurs.
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Key words:
- blast furnace slag /
- flight dynamics /
- collision /
- mathematical model
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图 1 粒化过程示意图（a）和熔渣液滴受力分析（b）
Figure 1. Schematic diagram of the granulating (a) and the force analysis for the slag droplets (b)
图 3 熔渣液滴沿x轴飞行距离（t=1 s）
Figure 3. Flight distance of the slag droplets along x direction (t=1 s)
图 4 熔渣液滴速度随时间变化图（d=2 mm）
Figure 4. Velocity of the slag droplets with the different times (d=2 mm)
图 5 熔渣液滴撞击过剩反弹能与撞击速度关系（T=1400 ℃，α=60°）
Figure 5. Dependence between the excess rebound energy and the impact velocity (T=1400 ℃, α=60°)
图 7 熔渣液滴沿y轴下降距离（x=1 m）
Figure 7. Falling distance of the slag droplets along y direction (x=1 m)
表 1 熔渣化学成分（质量分数）
Table 1. Chemical composition of the blast slag
% SiO2 CaO Al2O3 MgO FeO MnO TiO2 S 其他 33.92 40.15 14.50 8.17 0.33 0.30 0.50 1.03 1.10 
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表 2 熔渣液滴直径与临界撞击速度关系
Table 2. Relationship between the slag droplet diameter and the critical impact velocity
d / mm v* / (m·s‒1) 0.5 0.45～227.32 1.5 0.33～75.75 2.5 0.27～45.44 3.5 0.24～32.45 4.5 0.22～25.23
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表 3 实验工况
Table 3. Experimental condition
序号 Dm / m D / m N / (r·min‒1) v0 / (m·s‒1) 1 2 0.25 764 10 2 2 0.25 917 12 3 2 0.25 1069 14
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