Numerical investigation on behaviors of interlaced jets and their interaction with bath in BOF steelmaking

The jet behavior of interlaced multiple nozzles and the impingement of multiple jets onto the surface of the molten metal bath in a steelmaking converter are numerically studied. The interlaced jet hydrodynamic behaviors such as jet profile, coalescence characteristics, and dynamic parameter distributions penetration depth and impact area, as well as time-dependent evolution of liquid bath are discussed. The results are compared with traditional nozzles. It is found that the single nozzle characteristics of staggered jet are similar to those of traditional jet. However, two sets of staggered nozzles with different flow rate and inclination angle having a less disturbance flows, cause weaker coalescence of the jets and larger area surrounded by isovelocity in the molten pool. In the initial stage of the interaction between the interlaced nozzles and the molten pool, the “low stirring zone” is more likely to concentrate in the outer side near the furnace wall than in the center of the molten pool. Two cavities, one deep and one shallow, are formed on the bath surface. The average depth of the two cavities is similar to traditional nozzles, and the diameter of the cavity is increased by about 11% compared to traditional nozzles.