Oscillatory flow in the steelmaking vessel

Abstract

Physical modelling of the basic oxygen furnace (BOF) was undertaken with the object of developing an overall flow pattern within the vessel as a function of fluid-flow dynamics/vessel geometry interaction. The study was initiated as the result of localised refractory wear occurring in the knuckle region of a BOF vessel. The occurrence of the wear coincided with a change in lance tip design. This preferential wear limited the campaign life of the vessel. Modelling the fluid dynamics of the system was to examine any possible relationship between fluid-flow patterns and this refractory wear pattern. The 4-fold symmetry of the newer lance tip allowed the application of a quadrant sector model of the bath. This simplified the flow to the effect of an individual nozzle. A scale of 1/6th was chosen on the basis of the bath depth and flow rates required.Results from this work indicate that waves may have a role in this localised wear.The multiphase system of the BOF involving supersonic gas jets, molten iron and slag, and the interaction between these, ensure that there is no single model, in which all facets of similarity may be satisfied simultaneously. This is the major problem in modelling the BOF.

Modelling of gas injection into a viscous liquid through a top-submerged lance

“…(12). This is consistent with the finding by Lee et al (2003), where the wave motion was constant and only dependent on the vessel size when the liquid height or submerged depth is large enough. Since the sloshing wave becomes stable quickly, less than 4 s as shown in Fig.…”

Behavior of Gas–Slag–Metal Emulsion with Nozzle‐Twisted Lance in Converter Steelmaking Process

“…In addition, the slag surface is not stable, and the propagation of surface waves on the slag surface formed during the oxygen impact on molten pool aggravates the instability of the slag surface. [24] Investigation of the coverage area of the slag phase is the key to elucidate the influence of the swirl angle on the gas-slag-metal behavior. The variation in the coverage area of the slag phase of different nozzle-twisted lances with the blowing time is shown in Figure 6.…”

Model Development for Refining Rates in Oxygen Steelmaking: Impact and Slag-Metal Bulk Zones

“…In this study, the impact zone is defined as the smooth surface of the cavities formed by the supersonic jets from the lance, where the oxygen comes in contact with the metal bath. Previous studies [61][62][63][64] indicated that the cavity surface is rough, resulting in the generation of "splash sheets" [64] or "metal-bath spraying effect" [61]. However, the surface area enhancement due to splash sheet formation is difficult to estimate.…”