EXPERIMENTAL STUDY OF THE BUBBLE-BURST PHENOMENON AT THE SURFACE OF A LIQUID STEEL BATH

摘要

We have developed an experimental device for studying the main mechanism of dust formation in electric arc furnace steelmaking: the burst of gas bubbles at the liquid steel surface. As in the case of the air-water system, the bubble-burst process takes place in three steps: breaking of the film cap, projection of film drops, and projection of jet drops. The film break and the jet drop formation are observed with high-speed video. The film drop aerosol enters a particle counter, which characterizes the drops in size and number. Results are presented and discussed. The quantification of both types of projections leads to the conclusion that the film drop projections represent the major source of dust. We currently are investigating the influence of the bubble size on the amount of film drop projections, with the aim of checking the theoretical existence of an optimal bubble size that minimizes dust emission.