| 摘要 |
PURPOSE:To prevent the abrasion of a tuyere pipe and to prolong its life, by covering the outer surface of the inner pipe and the inner surface of the outer pipe of a double-ply pipe tuyere of oxygen bottom blown blast furnace using a fluid mixed with solid powder as a tuyere coolant, with films having high hardness. CONSTITUTION:In the oxygen bottom blowing tuyere of double-ply pipe structure for refining molten steel 5 provided at the furnace bottom made of refractory materials 1 and iron shells 2, a mixture of solid powder containing carbon and CO2 is supplied as a tuyere coolant from a feeding pipe 6 into the gap between the tuyere inner pipe 8 and the outer pipe 9. The outer surface of said inner pipe 8 and the inner surface of the pipe 9 are covered with the uniform films 10, 11 having uniform thickness made of a metal and ceramic, etc. having film hardness higher than that of said solid powder. Even if said covered film is used as only the film 10 at the outer surface of the pipe 8 or as a local cover at a part adjacent to an inlet of the coolant 7 at the tuyere gap in which the severest abrasion occurs, said film has distinct effects on prolongation of the tuyere life. |
