Mixing Time in a Bath in the Presence of Swirl Motion Induced by Horizontal Gas Injection with an L-Shaped Lance

Abstract

Water model experiments are carried out to understand the mixing behavior of the steel refining processes agitated by horizontal gas injection. Mixing time in a cylindrical water bath agitated by horizontal air injection through an L-shaped top lance is measured with an electric conductivity meter. Several types of bath surface oscillations are induced by the gas injection depending on the operation parameters such as the vessel diameter and gas flow rate. Particular emphasis is placed on the condition that a swirl motion of the deep-water wave type appears in the bath. This is because the swirl motion plays a practically important role for bath mixing. The diameter of the bath, lance exit position, bath depth, and gas flow rate are varied over a wide range. An empirical equation is proposed for the mixing time in the presence of the swirl motion.