Cold model investigations into the effects of bottom blowing in metallurgical reactors

Cold model investigations were performed into bottom blowing involving two-phase and three-phase systems. The investigations – performed with interrelated variation of the test parameters: bottom nozzle arrangement, number of nozzles, eccentricity of the nozzles, blowing rate, geometry of the model reactor and addition of a slag simulation phase – reveal a series of specific vortex patterns in the bath. The most favourable overall degree of mixing is achieved with an eccentric triangular arrangement of the bottom nozzles. Increasing the number of nozzles on the one hand, and spacing the bottom nozzles further apart on the other, improves the flow conditions and thus the degree of mixing in the bath. Upwards of a certain critical blowing rate, sloshing occurs at the bath surface. This sloshing limit increases with increasing eccentricity of the bottom nozzles. The presence of slag reduces the mixing times while at the same time increasing the torus angular frequencies.