Patent ID: 8808615

Claim:
A tuyere for an iron making furnace having a blast passage passing through a central axis thereof, comprising: a body unit having a frusto-conical body, a main body cooling passage therein, the main body cooling passage configured as a spiral cooling passage, and a protruding part protruding from the tip of the body and having an outer circumferential surface; a cover unit having an outer circumferential surface and combined with the protruding part to define a tip body cooling passage between the cover unit and the outer circumferential surface of the protruding part, the tip body cooling passage being configured as a spiral passage and communicating with the main body cooling passage; and a first outer unit having an outer circumferential surface and combined with the cover unit and surrounding the cover unit to define a first outer cooling passage between the first outer unit and the outer circumferential surface of the cover unit, the first outer cooling passage being configured as a spiral passage and being isolated from the tip body cooling passage; wherein the first outer cooling passage defines: a first outer inlet of the tuyere such that a cooling water may be supplied through the first outer inlet; and a first outer outlet of the tuyere such that the cooling water supplied through the first outer inlet may be discharged from the first outer outlet, and wherein the first outer unit includes a tip thereof with a first outer passage groove defining a lowest course of the first outer cooling passage, the first outer passage groove connecting the first outer inlet cooling passage to the first outer outlet.