洁净钢精炼中气泡去除夹杂物机理及模型研究

Inclusion removal from liquid steel is very important in production of clean steel. In present, bigger inclusions can be removed by argon blowing in liquid steel. However, the mechanism problem has not been solved until now and smaller inclusions can not be removed effectively. Thus, it is very important to study the mechanism of inclusion removal from liquid steel. In present project,the bubble shape is investigated by studying the evolution behavior of bubble during its flotation process. The process and mechanism of inclusion removal by inclusion-bubble adhesion and bubble trailing vortex in liquid steel are investigated. And the correlation for inclusion removal probability is obtained by probability statistics. The multi-scale mathematical model concerning inclusion removal in argon blowing reactors is developed by integrating inclusion removal microcosmic model and multiphase transmission. Moreover, the inclusion removal experiment in bottom-blown ladle is conducted to investigate the effect of different parameters on inclusion removal process, and the key factors for inclusion removal rate can be discovered consequently. In order to increase inclusion removal rate, the processing parameters are optimized, which will lay a foundation for the application of inclusion removal by bubble flotation in industry.

去除钢液中非金属夹杂是洁净钢生产的重要任务，目前吹氩可去除钢液中较大尺寸夹杂物，但由于机理性问题迄今未能全面解决，较小尺寸夹杂物仍不能有效去除，因而气泡去除夹杂物机理是目前需要研究的重点问题。本课题通过考察气泡上浮过程变形行为，建立气泡形状与相关参数的关系；通过研究钢液内气泡粘附及尾涡去除夹杂物机理，基于概率统计获得气泡粘附及尾涡去除夹杂物概率与影响因素的函数关系；通过将气泡去除夹杂物微观模型与吹氩钢包内多相传输相结合，建立吹氩钢包内气泡去除夹杂物的多尺度数学模型，并结合底吹钢包内去除夹杂物实验研究不同工艺参数对夹杂物去除过程的影响，找到影响夹杂物去除率关键因素，从而提高夹杂物去除率，优化钢包吹氩工艺，进而为气泡去除夹杂物理论应用于工业实际奠定基础。

去除钢液中非金属夹杂是洁净钢生产的重要任务，目前吹氩可去除钢液中较大尺寸夹杂物，但由于机理性问题未能解决，较小尺寸夹杂物仍不能有效去除。与此同时，气泡去除夹杂物存在气泡粘附与尾涡带动夹杂物两种去除方式，但已有机理模型多从气泡粘附夹杂物出发，忽略了气泡尾涡对夹杂物去除的影响。因此，阐明气泡去除夹杂物机理是目前需要研究的重点问题。本课题开展了以下几方面的研究，一、针对气泡长大、脱离及上浮过程中形状演化行为进行了研究，开发了用于测量气泡参数的单电导及双电导探针装置，基于相似原理及数值模拟手段，通过对气泡长大、脱离及上浮过程中的受力进行分析，阐述了气泡高宽比、上浮速度及阻力系数的变化规律；二、针对钢液内气泡-夹杂物作用过程，基于物理模拟及数值模拟方法，研究了不同气泡尺寸、夹杂物尺寸等参数对气泡粘附去除及尾涡带动夹杂物上浮去除的影响，阐明了上浮气泡对夹杂物的作用机理；三、针对钢液内夹杂物碰撞长大为聚合团簇的过程，基于颗粒轨迹模型及颗粒随机行走模型，建立了团簇夹杂物碰撞长大行为模型，分析了夹杂物颗粒运动过程中的受力，阐述了初始夹杂物尺寸对团簇夹杂物长大行为的影响；四、针对吹氩反应器内夹杂物去除过程进行了多尺度模拟及物理模拟，建立了综合考虑夹杂物碰撞长大、气泡粘附的多尺度数学模型，分别针对吹氩钢包、RH精炼装置、侧底复吹RH及SSF单管真空精炼装置内的夹杂物去除行为进行了研究，分析了不同工艺参数对夹杂物整体去除率、夹杂物空间分布及不同尺寸夹杂物去除率的影响规律，为工业生产过程中参数优化提供了理论支撑。