MODELING OF THE FORMATION OF SLAG-METAL SUPPORTS ON THE TRUNK OF TWO-TIER OXYGEN TUYERES DURING PURGING IN HEAVY-DUTY CONVERTERS

The main technological features of converter melting when used for purging two-tier hydrogen tuyeres are considered. The reasons for the formation of metal slag deposits on the tuyere trunk during upper purging of the melt in heavy-duty converters are analyzed, depending on the specifics of the organization of the blast regime and the different level of foamed slag-metal emulsion in the working space of the unit. A conjugated three-dimensional mathematical model of hydrodynamic and mass transfer processes in the slag and metal phases of the converter is proposed, which can be used to study the patterns of formation and direction of melt circulation flows in a bath at the positions of a two-tier tuyere, the number of nozzles in the lower and upper tiers, the angles of inclination of the nozzles, oxygen consumption through the tiers of nozzles and other design and technological parameters. A physical model is formulated and numerical simulation of the metal purging process in a 350 ton converter is performed using a two-tiered tuyere with four Laval nozzles in the lower tip and twelve nozzles in the upper tier. The presented data make it possible to obtain reliable information about the nature of the movement of the metal and slag phases during purging in the converter and the mechanism of formation of slag-metal deposits on the tuyere trunk.

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