Submerged entry nozzle was development in 1960s. At first time, it was produced from quartz. With the development of continuous casting, it can not meet the requirement of high level continuous casting and special steel casting.
With the improvement of the level of casting, especially special steel casting, quartz submerged entry nozzle can not meet requirement of casting life and steel quality. Therefore, aluminum carbon and aluminum carbon-zirconium carbon combined submerged entry nozzles came out. Compared to quartz submerged entry nozzle, this nozzle is of much longer service life. In order to adapt to low carbon steel casting, the inner layer of the refractory nozzle uses special materials like aluminum magnesium, ceramics, etc. For casting aluminum killed steel, nozzle would easy to get block out of caking. Against this condition, both blowing argon in the way of ventilation and using non-carbon-containing and calcium zirconate material have achieved a good result. To solve some emergency working conditions, non-baking submerged entry nozzle was developed. By the methods of designing the trapezoidal submerged nozzle, and mounting impeller in the nozzles, we can make slag floating, in which way blocking can be well prevented.