Herein, the fluid flow pattern in a continuous casting slab strand with varied degree of clogging of the submerged entry nozzle is measured using nail boards in industrial trials. The influence of clogging on meniscus velocity, top surface position, surface level fluctuation, and slag entrainment of the strand is investigated. The number density and area fraction of nonmetallic inclusions including Na₂O and K₂O‐bearing entrained slag ones within the subsurface of steel slabs are inspected using an automatic scanning electron microscope (SEM). The flow pattern in the strand periodically transforms from a double roll flow to a complex flow and/or a single roll flow. The fluid field in the continuous casting mold is unstable and asymmetric under the condition of varied degree of clogging with time. The variation of the meniscus velocity and the surface level fluctuation with time is stochastic. The percentage of >3 mm level fluctuation increases from 4.7% to 10.6% with a serious clogging of the submerged entry nozzle. The amount of entrained slag inclusions with serious clogging is approximately 1.6 times than that with slight clogging. In addition, slag entrainment mechanisms of the shear‐layer instability and the vortex formation are discussed.

中文翻译：

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用钉板测量的连续铸造板坯中的阻塞引起的不对称和瞬态流型

在此，在工业试验中，使用钉板来测量具有不同程度的浸入式注口的连铸板坯铸坯中的流体流动模式。研究了堵塞对弯液面速度，顶面位置，表面液位起伏和钢渣夹带的影响。Na ₂ O和K ₂等非金属夹杂物的数量密度和面积分数使用自动扫描电子显微镜（SEM）检查钢坯表面下含O的夹渣。股线中的流动模式周期性地从双辊流转变为复流和/或单辊流。在随时间变化的堵塞程度下，连铸结晶器中的流场不稳定且不对称。弯月面速度和表面高度随时间的变化是随机的。高度超过3毫米的波动百分比从4.7％增加到10.6％，其中浸入式喷嘴严重堵塞。严重堵塞的夹带渣夹杂物数量约为轻微堵塞的夹杂物数量的1.6倍。此外，还讨论了夹渣层剪切不稳定性和涡流形成的机理。