SPRAY OVERLAP AND HEAT TRANSFER COEFFICIENT UNIFORMITY IN THE CONTINUOUS CASTING

Continuous casting is an efficient method of producing large volumes of semi-finished steel products. Uniform and efficient heat removal is required to ensure the steel is produced without any cracks while meeting the high steel production target. One of the challenges in the continuous casting process is providing uniform spray cooling rate as needed based on the casting production rate. Improved control of steel cooling rate is critical. The heat removal rate is dependent on the spray nozzle configurations (nozzle spray angle, distance between spray nozzles, nozzle stand-off distance, and water flow rate). The current study presents a computational fluid dynamics (CFD) analysis of spray cooling for two nozzles with overlapping sprays. The Lagrangian approach is adopted to track the droplets. In order to predict the slab cooling accurately in the overlap region, droplet breakup and collision are included in the model. The effects of different spray overlap region sizes on the heat transfer coefficient are evaluated by changing the nozzle-to-nozzle distance. The results show that there is an optimum size of spray overlap which provides uniform heat transfer between the two adjacent nozzles. Further increase of the overlap increases heat transfers in the overlap region, which could lead to overcooling of the slab.