Speaker
Description
Steel industry, even with best operating practices, has reported a minimum of 2 to 3 ppm nitrogen absorption, during transfer of molten steel from a ladle to tundish; up to 20 ppm of nitrogen absorption is not uncommon and have also been reported in literature. These imply that ladle shroud- collector plate nozzle (LS-CN) in practice is never perfectly secured and air ingression during ladle to tundish transfer, despite all precautions and improvements, takes place to varied degree in steel industry. Thus, to investigate the circumferential delivery and distribution of argon gas around LS-CN joint for various argon delivery arrangements, a non-isothermal, two component turbulent flow model has been developed and the resultant equations, in conjunction with appropriate boundary conditions, solved via ANSYS Fluent™. These indicate that at any given argon flow rate, gas delivery design influences distribution of argon and hence the effectiveness of the overall inert gas shrouding of LS-CN joint. Present work has clearly indicated that currently employed gas delivery designs function sub-optimally and do not ensure homogeneous, 360o shielding LS-CN joint. To improve argon distribution and attendant shielding of LS-CN joint further, a novel inert gas delivery design has been developed and is being tried in the industry. Preliminary industrial trials indicate that the new gas delivery design provides better shielding of the LS-CN assembly leading to reduced nitrogen pick-up from the atmosphere.