板坯中间包内钢液流动特性

Flow characteristic of molten steel in slab casting tundishes

通过开展中间包控流装置布置的正交试验，研究了反应器结构对钢水流动行为的影响.着重探讨了不同尺寸中间包的控流装置布置规律及其对钢液流动行为和夹杂物去除的影响，定量化得到了双流板坯中间包控流装置布置与死区体积和结构影响因子D的关系.实验结果分析表明：中间包内部分活塞流体积不利于夹杂物去除，死区体积可准确反映钢液的洁净度水平；出水口抽吸作用对钢液流动行为影响较大，挡坝布置在距出水口1000-1300 mm时钢液流动形态较好，夹杂物聚集导致的水口结瘤率低至7.5%；0.0035〈D〈0．0085时，可获得板坯中间包在普通拉速下的流场特征与挡坝相对位置的关系；中间包内钢液与夹杂物的相对运动速度为大于6×10^-5m·s^-1时，夹杂物的上浮速度较大．

Orthogonal experiments of control device arrangement in different slab casting tundishes were carried out to study the influence of the reactor＇s structure on the flow characteristic of molten steel. The optimal arrangement rule of control devices and its effect on the flow characteristic of molten steel and inclusion removal were mainly analyzed. A quantificational relation of control devices, dead volume and the structure factor D was determined. The results indicate that the steel cleanness can be reflected by dead volume while the piston flow volume is disadvantageous to inclusion removal. There is a great influence of outlet pumping action on the fluid flow pattern, so the best distance between the dam and outlet is 1000 to 1300 mm, which results in the decrease of nozzle blocking rate to 7.5%. The relation between the flow characteristic of molten steel and the dam＇s relative location is obtained at normal casting speed when 0.0035 〈 D 〈 0. 0055. As the relative speed of inclusions to molten steel reaches to 6 ×10^-5m·s^-1, the floating speed of inclusions becomes faster.