Water modeling test for a 25 t four-strand tundish with bottom blowing gas has been carried out by using porous plug with different performance parameters and combined with RTD curves and standard deviation analysis to study the effect of porous plug area (210 ~ 105 mm x 56 ~28 mm)

4 gas blowing location and gas rate (60 ~ 120 L/h) on characteristics of fluid flow in tundish and compare with that without bottom blowing gas. Results show that with using bottom blowing gas

the flow characteristics of liquid steel in tundish are improved to balance the residence time of liquid steel at different outlet

prolong the peak concentration time and reduce the dead volume fraction. Gas blowing location near baffle

using smaller gas flow rate and smaller area of porous plug are available to improve the characteristics of fluid flow field of present tundish.