Abstract: The present invention relates to a method of manufacturing a slag discharge door, which is provided separately from a molten-steel discharge opening in an electric furnace and opens and closes a slag discharge opening for discharging slag. The method of manufacturing the slag discharge door, which moves up and down on the slag discharge opening to open and close the slag discharge opening, includes the steps of: forming a door body by forging, forming a coolant passage, a coolant inlet, and a coolant outlet in the door body by drilling, and then finishing a passage that blocks a portion that is open toward an outer surface of the door body.

Abstract: Provided is a method and an apparatus for manufacturing a lance nozzle comprising: a casting step for primarily manufacturing the lance nozzle comprising a plurality of discharge pipes, which discharge a gas supplied through an inlet to an outlet, and a front wall with a plurality of discharge holes, each of which is connected to the outlet of the discharge pipe; and a forging step for forming forging structure by forging a circumference of the discharge holes in a front surface of the front wall positioned on an opposite side to the discharge pipes.

Abstract: The present invention relates to a method of manufacturing a slag discharge door, which is provided separately from a molten-steel discharge opening in an electric furnace and opens and closes a slag discharge opening for discharging slag. The method of manufacturing the slag discharge door, which moves up and down on the slag discharge opening to open and close the slag discharge opening, includes the steps of: forming a door body by forging, forming a coolant passage, a coolant inlet, and a coolant outlet in the door body by drilling, and then finishing a passage that blocks a portion that is open toward an outer surface of the door body.

Abstract: A double chamber single directional spiral tuyere for blast furnaces is disclosed. The tuyere includes a body unit, a spiral unit and a cover unit, with a body chamber having a body nose passage and a body main passage defined in the body unit, and a nose chamber having first, second, third and fourth spiral passages defined in both the spiral unit and the cover unit. The tuyere further includes a tunnel, which is formed in the spiral unit and the cover unit and connects a cooling water inlet to the first spiral passage. Thus, efficient circulation of cooling water and maximum cooling performance can be provided.