Investigation of Eccentric Open Eye Formation in a Slab Caster Tundish

Abstract

Inert gas shrouding in tundish can result in the formation of a tundish open eye (TOE) due to the presence of reversed flows on the upper surface of the tundish. Prolonged presence of open eyes promotes reoxidation of liquid steel and creates harmful inclusions, which can ultimately result in clogging of SENs. In spite of its importance, not much work has been performed on TOEs. In our series of recent works (Chattopadhyay in Modelling of Transport Phenomena for Improved Steel Quality in a Delta-Shaped Four Strand Tundish, 2011; Chattopadhyay et al. in ISIJ Int 51: 573–580, 2011; Chatterjee and Chattopadhyay in ISIJ Int 55: 1416–1424, 2015; Metall Mater Trans B 41: 508–521, 2016; Metall Mater Trans B 47: 3099–3114, 2016; Chatterjee et al. in ISIJ Int 56: 1889–1892, 2016), although substantial efforts have been made to understand the basics of TOE formation process, a lot still remains to be deciphered. The current work deals with investigating a strange phenomenon observed during tundish operations: eccentric open eye formation. It is essential to gain proper insights of this matter in order to improve the operations, enhance liquid metal cleanliness, and generate more revenues. A mathematical model was developed using ANSYS-FLUENT 16.2. The standard k-e turbulence model and the discrete phase method, coupled with the discrete random walk model was employed. Three different causes for eccentric open eye formation viz., unbalanced throughput, biased argon injection, and misalignment of ladle shroud have been analyzed. The predicted results correspond to both water model experiments and real plant observations.