The tundish is a buffer for liquid steel during the continuous casting of steel. There is another important aspect of the tundish operation - the need to cast different grades of steel sequentially through the same caster. The tundish allows changing of the ladle (and hence of the steel grade) but there is an unavoidable mixing of two different grades of steel in the tundish. This produces cast slabs of intermixed grades that are difficult to classify. Keeping the intermixed grade volume to a minimum is a plant target. CFD is used to estimate the grade change over time for a particular tundish. Flow distribution in the tundish has very critical influence on the casting process in terms of quality, productivity and economics. Use of CFD is becoming increasingly popular in designing and optimizing tundish internals (weirs, dams, and baffles). It is also possible to study the effects of various process parameters and practices and thereby optimize the process to achieve the minimum amount of intermixed grade steel. The image here shows a snap shot during the progress of grade change over the course of the operation.

Spanshot of concentration contours in a continuous casting tundish during the grade change operation, simulated using CFD. Red was the old grade that is almost replaced, by the intermediate grades and blue is the new grade