夹杂物在渣层运动上浮的水模型研究

Study on Water Model of Inclusions Floating up in Slag Layer

为研究夹杂物在去除过程中,在钢–渣界面的运动,基于相似原理,用Al2O3和聚丙烯PP (poly-propylene)粒子模拟夹杂物,水模拟钢液,硅油模拟钢渣,建立了一个水模型。通过改变粒子尺寸、种类,以及油层黏度等因素,观察粒子在不同条件下在水–油界面上浮的运动过程,从而分析实际炼钢生产过程中各种因素对夹杂物去除的影响。实验结果表明,粒子在水中只需不到1 s的时间,即可加速至终端速度,其到达水–油界面时的速度主要与粒子密度及尺寸有关。当粒子到达水–油界面时,会与界面发生能量交换。只有当粒子的动能超过了界面变形所需能量,粒子才可以顺利穿过界面。否则,粒子只能滞留在水–油界面。当油层一定时,PP粒子的无量纲位移大于密度更小的Al2O3粒子的无量纲位移,说明密度大的更容易穿过界面。而油层黏度也对粒子运动有一定影响,油层黏度越大,对粒子穿越过程的阻碍也越大,越不利于粒子穿过界面。主要影响因素是粒子与界面间的相互作用关系,即总润湿性。

In order to study the movement of inclusions at the steel-slag interface during the removal process, based on the similarity principle, a water model was established. In the model, Al2O3 and PP particles were used to simulate inclusions, water was used to simulate molten steel, and silicone oil was used to simulate steel slag. By changing the size and type of the particles, and the viscosity of the oil layer, the movement process of the particles floating up through the water-oil interface under different conditions was observed, so as to analyze the influence of the above-mentioned factors on the removal of inclusions in the actual steelmaking production process. The experimental results show that the particles can be accelerated to the terminal velocity in less than 1s in water. Therefore, the velocities when they reach the water-oil interface are mainly related to the particles’ density and size. When the particles reach the water-oil interface, they exchange energy with the interface. Only when the kinetic energy of the particle exceeds the energy required to deform the interface, the particles can pass through the interface. Otherwise, the particles can only stay at the water-oil interface. When the oil layer is fixed, the dimensionless displacement of the PP particles is greater than that of the Al2O3 particles whose density is much smaller, indicating that the denser ones are easier to pass through the interface. The viscosity of the oil layer also has a certain influence on the movement of the particles. The greater the viscosity of the oil layer, the greater the obstacle for the particle to pass, and the less favorable for the particles to pass through the interface. The main influencing factor is the interaction between the particles and the interface, that is, the total wet ability.