Water Model Study on Bottom Gas Blowing Processin Continuous Casting Tundish

Bottom gas blowing process in continuous casting tundish was studied with water model, prototype of which is the one in Meishan Iron and Steel Cooperation. Air is blown into the tundish from the bottom with an air-supply equipment, with which tiny and steady bubbles can be produced in tundish. The results show that, without bottom gas blowing, water flowing through the weir flows close to the bottom of tundish bath in a laminar type, and flows out from the outlet directly, so that the average residence time is short and the dead-zone volume fraction is large, which is unfavorable for inclusion removal. With bottom gas blowing, water is uplifted by up-going gas acting as gas baffle, and flows close to the bath surface. Bottom gas blowing is benefit to increasing average residence time and reducing the dead-zone volume fraction. In addition, the ascending gas flow has a role of cleaning, which is in favor of inclusion removal. Inclusions can be removed with a relative small amount of low gas flow rate. It has similar influence of different locations on the average residence time, dead-zone volume fraction and the shortest residence time. But, on the whole, blowing at location in the middle of bath has a better effect.