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 tuyere for an iron making furnace, including a body unit having a blast passage passing through a central axis thereof, wherein the body unit includes: a frusto-conical body having a main body cooling passage; and a protruding part protruding from the body, wherein the tuyere further includes: a cover unit combined with the protruding part and defining a tip body cooling passage between the cover unit and the outer circumferential surface of the protruding part; and an outer unit combined with the cover unit while surrounding the cover unit and defining an outer cooling passage therein. When the outer unit is partially damaged, although the cooling water supply to the damaged part is cut off, the function of the tuyere can be continuously performed both by the remaining part of the outer unit and by the body unit, thereby providing a tuyere having a lengthened life span.

Abstract: A tuyere for an iron making furnace, including a body unit having a blast passage passing through a central axis thereof, wherein the body unit includes: a frusto-conical body having a main body cooling passage; and a protruding part protruding from the body, wherein the tuyere further includes: a cover unit combined with the protruding part and defining a tip body cooling passage between the cover unit and the outer circumferential surface of the protruding part; and an outer unit combined with the cover unit while surrounding the cover unit and defining an outer cooling passage therein. When the outer unit is partially damaged, although the cooling water supply to the damaged part is cut off, the function of the tuyere can be continuously performed both by the remaining part of the outer unit and by the body unit, thereby providing a tuyere having a lengthened life span.

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.

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. In the tuyere, a reverse-turning part, at which the flowing direction of cooling water is reversed at an angle of 180°, is eliminated from a cooling passage defined in the nose of the tuyere. Thus, cooling water can circulate in a single direction in the tuyere, resulting in efficient circulation of cooling water, reducing pressure loss and enabling cooling water to reach the nose of the tuyere, thereby providing maximum cooling performance.