Effect of Tunnel Filters on Flow Characteristics in an Eight-strand Tundish

Abstract

Fluid flows in an eight-strand tundish with tunnel filters have been investigated with physical modeling and mathematical simulation methods. This paper mainly studies the effect of tunnel filters install location and turning corner angle on the flow characteristics. In 1/3 scale tundish model experiments, RTD curves were used to study the flow characteristics in tundish with different configurations. The molten steel flow velocity and temperature fields were calculated by the commercial CFD package FLUENT. The result shows that tunnel filters play an important role in promoting flow characteristics. Suppose the tundish was divided into two regions by baffles, defined as sub-tundish a and sub-tundish b. The tunnel filters distinguished and enhanced the metallurgical function of each region, that is sub-tundish a is the inclusion collision and aggregation region and the main metallurgical function of sub-tundish b is uniform the temperature and remove large inclusions. The corner angle of tunnel filters has a great influence on the dead volume fraction, and the install location plays a key role in the assignment proportion of plug volume between sub-tundish a and sub-tundish b. By overall evaluation and contrast analysis, the tundish equipped with 120° tunnel filters long distance to the pouring point, was identified as the optimal tundish configuration. Industrial experiment verified the simulation results and had proved that the tundish with tunnel filters can effectively improve the removal efficiency of small inclusion(>5 µm).