Length of Bubble Dispersion Region in a Cylindrical Bath Subjected to Side Gas Injection through an L-shaped Lance

摘要

Dissolved oxygen in liquids plays an important role in a variety of fields such as materials engineering. For example, the dissolution rate of oxygen into a molten metal bath is responsible for the efficiency of decarburization in the steelmaking industry. Oxygen is commonly introduced into the bath using many kinds of injection devices. The dynamic behavior of oxygen bubbles mainly governs the oxygen dissolution rate. Water model experiments were carried out in a previous study to understand the oxygen bubble behavior and dissolution rate for basic three (bottom, side, and top) gas injection systems. The side gas injection was found to be most effective for oxygen dissolution. This is probably because the oxygen dissolution rate is closely associated with the length of bubble dispersion region in the bath. In this study air was injected horizontally into a cylindrical water bath through an immersed L-shaped lance. The dispersion pattern of bubbles and related bath surface oscillations were observed with a high-speed video camera and a still camera. An empirical equation was proposed for the length of bubble dispersion region, L _(BS), based on the data on L _(BS) measured in this study.