Physical Modeling Of Vortex Formation During Ladle Drainage

A 1 :7 scale plexiglas model of a steelmaking ladle (315 tons, ArcelorMittalTubardo) was built in order to assess the conditions of vortex formation during the final stages of draining. The vortex was detected by a photo-electric sensor and the mass of residual liquid inside the ladle was evaluated after weighing. The influence of the type of residual flow, as dictated by routes of processing such as: RH degasser, IRUT reactor, as well as the drainage flow rate, in addition to anti-vortex devices, was assessed Residual flow due to RH or IRUT processing as well as the initial level of liquid did not affect the results. The mass of residual liquid at vortex onset was influenced by the flow rate only. At the final stages of drainage, the liquid surface collapse was dictated by the bottom ladle capacity of supplying liquid in the radial direction to the outlet. As a consequence vortex breakers were found deleterious under these set of conditions. A rotational flow was induced in order to increase the likelyhood of vortex formation. In this case gas injection through the pouring nozzle, vortex breakers, slopped bottoms have been found effective.