広幅スラブ連続鋳造用旋回流ノズルの吐出角度設計

抄録

We have proposed a technology of swirling flow formation in submerged entry nozzle as a fundamental and effective measure for controlling flow pattern in continuous casting mold. A joint study started in 1997 with Nippon Institute of Technology, Osaka University, Kyushu Refractories and Sumitomo Metal Industries to develop a swirling flow submerged entry nozzle with a swirling blade for steel casting. As a result of the collaboration, the swirling flow submerged entry nozzle for wide slab casting has developed in Wakayama Works, which improve productivity and surface quality of slabs and coils.
Swirling flow formation in the submerged entry nozzle can be effective for controlling flow pattern in the mold in the case with optimum design of outlet port. The outlet port of the swirling flow submerged entry nozzle should be designed adapting a characteristic of swirling downward flow in the nozzle.
As a result of full-scale water model experiment, we achieved a conclusion of optimum outlet port design that the narrow width of the outlet port is optimum for the swirling flow submerged entry nozzle.
In addition to that, we got another conclusion of the outlet port design relation to the outlet flow angle that the optimum downward angle of outlet flow is 30-40 degree for stable flow formation in the wide slab mold.