Abstract: The impact of the slag layer on internal macroscopic flow in tundish is frequently neglected, and there is little research on the velocity beneath the tundish slag-steel interface. This study focuses on a single-strand tundish without flow control devices. Ink and salt tracer solution were used to systematically study the macroscopic flow phenomena in a water model tundish. Particle image velocimetry (PIV) technology was utilized to measure the velocity distribution beneath the water-oil interface and internal region of the tundish. The primary objective is to investigate the influence of the oil layer on the macroscopic flow within the tundish and the flow field at the water-oil interface. The results show that in scheme of presence of the oil layer, the transport and diffusion of the tracer at the bottom of the tundish are facilitated, and the ink transfer process at the water-oil interface is slowed down. In the scheme without the oil layer, there is an obvious trend of ink upward transport, while in the scheme with the oil layer, ink primarily transports along the bottom. Compared to the scheme without the oil layer, the time for ink flow out from the outlet is reduced. For the salt tracer transport experiment, the residence time distribution (RTD) curve of the silicone oil scheme exhibits a leftward shift compared to the RTD curve of the free of oil scheme, indicating an expedited outflow of the salt tracer solution from the tundish outlet. In the scheme without the oil layer, the flow velocity near the liquid surface is generally greater than that in the scheme with the oil layer. In the area near the outlet and right wall, in some locations the velocity in the scheme with oil layer is slightly greater than that of the scheme without oil layer. In this case, the blocking effect of the oil layer on the fluid becomes weaker. Furthermore, for the oil layer scheme, the vertical velocity attains its maximum value in the vicinity of the ladle shroud area, the vertical velocity increases with increasing distance from the water-oil interface. In the region proximal to the right-side wall, the horizontal velocity attains its peak, albeit exhibiting minimal variation with the liquid surface height.

Key words: single-strand tundish, water model, slag-steel interface, PIV, velocity field

摘要： 中间包渣层对内部宏观流动的影响往往被忽略，且针对中间包渣/钢界面下方速度的研究较少。本工作以单流无控流装置中间包为研究对象，在水模型中使用墨水和盐水示踪剂研究宏观流动现象，并使用粒子图像测速(PIV)技术测定水油界面下方以及中间包内部区域的速度分布，从而探究油层对中间包内宏观流动以及水油界面处流场的影响。结果表明，油层对中间包内示踪剂在底部的传输和扩散有促进作用，油层的存在减缓了水油界面处墨水传输过程。无油层方案中墨水向上传输趋势明显，而含油层方案中墨水主要沿底部进行传输，与无油层方案相比，墨水从出口流出的时间有所缩短。在盐水示踪剂实验中，含油层方案的RTD曲线相比无油层方案整体向左偏移，盐水溶液较早地流出中间包出口。对于整体流场，无油层方案的速度基本都大于含油层方案速度。在靠近出口和右侧壁面的区域，存在局部速度含油方案略大于无油方案的情况，油层对流体的阻滞作用变弱。对于油层方案，靠近长水口区域的垂直速度最大，随着与水油界面距离增加，垂直速度有所增加。在靠近右侧壁面的区域中，水平速度最大，但其随液面高度变化较小。

关键词: 单流中间包, 水模型, 渣钢界面, 粒子图像测速, 速度场