Fundamental Study on the Stirring of Liquid Iron and the Liquid-Liquid Mass Transfer in Gas Injection System.

为了了解铁液的搅拌和气体喷射的液液传质的基本知识，进行了水的模型实验及其分析。系统内流动：在氮气搅拌的水-苯体系中，观察到水中的流态和液滴的形成。证实了水中存在较大的回流，苯滴中的苯数随气体流量的增加而增加。液液传质：测定了不同气速、苯水高度、容器半径等条件下苯乙酮从苯到水的传质速率。结果用两个经验公式关联--在低气体流量和高气体流量下。在高气体流量下，由于苯滴的形成，气体流量对体积系数的影响很大。利用经验公式，结合水中液滴数量和平均直径的测量结果，估算了低气体流量下液滴的形成贡献。&lt；k_LA&gt；的计算值与观测值吻合较好。系统中的湍流特性：利用热线风速仪和FFT分析仪组成的湍流分析系统测量时均速度分布和湍动能分布。该系统还可用于湍流功率谱分析。研究发现，该系统中的湍流特性与各向同性湍流的特性非常相似。流动模拟：采用最基本的湍流模型--0方程模型来估计局部气含率和流型的时间平均分布。

Model experiments by the use of water and its analysis were made in order to obtain fundamental knowledge on the stirring of liquid iron and the liquid-liquid mass transfer by gas injection.1. Flow in the system: Flow pattern in water and appearance of droplet formation were observed in the water-benzene system stirred by nitrogen. The existence of large recirculating flow in water and the increase in number of benzene of benzene droplets with gas-flow rate were confirmed.2. Liquid-liquid mass transfer: Transfer rate of acetophenone from benzene to water were measured under the various conditions of gas-flow rate, the height of benzene and water, and the radius of vessel. The results were correlated by two empirical equations-at low gas-flow rate and at high gas-flow rate. At high gas-flow rate, the effect of gas-flow rate on the volumetric coefficient, <k_LA> , was very large because of the benzene-droplet formation. Contribution of droplet formation was estimated by using the empirical equation at low gas-flow rate and the measured results of the amount of droplet in water and its average diameter. Calculated values of <k_LA> agreed well with observed ones.3. Characteristics of turbulence in the system: Turbulence-analysing system composed of a hot wire anemometer and a FFT analyser was used for the measurements of the distributions of time-averaged velocities and the turbulent kinematic energies. This system was also used for the analysis of power-spectrum of turbulence. It was found that the characteristics of turbulence in the present system was very similar to those of the isotropic turbulence.4. Simulation of flow: The 0-equation model which is the most fundamental model of turbulence was used for the estimation of the time-averaged distributions of local gas holdup and flow pattern.