In accordance with the status of high reject rate in nondestructive test of third strand bloom casting with a 35-t tundish for five-strand 280 mm x 350 mm blooms

the effect of different flow control device on flow characteristics of liquid in tundish has been studied by numerical simulation and water model simulation with geometrical similarity ratio 1: 3 to optimize the tundish flow field. Results show that the structure of flow control device of original tundish is not reasonable

each strand is out of step especially the short circuit flow in No3 strand is obvious; after using 2# baffle with two diversion holes at wall middle + round B type turbulence controller with eaves

each strand is in step and the short circuit flow in No3 strand is eliminated its average residence time is prolonged by 242. 1 s

and in tundish the plug zone flow volume increases by 5. 7%

the dead zone volume decreases by 1. 1 %

the impact zone flow is steady and smooth.