Control of Swirl Motion of Bottom Blown Bubbling Jet Using an Immersion Cylinder

Abstract

Gas injection techniques have extensively been used in the steelmaking industry. When gas is injected into a reactor, for example, through a bottom nozzle at a relatively high gas flow rate, a jet of a mixture of gas and liquid is formed above the nozzle exit. This jet, called a bottom blown bubbling jet, swirls under a certain gas injection condition. The appearance of the swirl motion of bubbling jet is not expected in the steelmaking industry, as it causes dangerous splashing and slopping of molten steel. In this study, we focus on the control of the swirl motion using an immersion cylinder. The cylinder is immersed concentrically from the bath surface after a steady swirl motion is observed. Empirical equations are proposed for identifying the boundary of the regime in which the swirl motion survives even if the cylinder is immersed in the bath.