Based on similarity principle

the flow performance of liquid in 60 t tundish for 230 mm x 130 mm slab casting has been studied by 1：3 water modeling test

and the average residence time

and the volume of dead area

plug area and mixed flow area are calculated by measured curves of residence time distribution (RTD) of liquid in modeling ladle. It is obtained that dam with holes is available to improve the flow field in tundish

the optimum combined device of inhibitors to improve the flow of liquid in tundish is turbulence inhibitor + dam with holes

of which the height of dam is 133 mm and the distance between dam and pouring region is 765 mm. As compared with original ladle

the average residence time of liquid in improved ladle increases by 24 s

and the dead area decreases to 6. 7% from original 14. 8%.