| 摘要 |
PROBLEM TO BE SOLVED: To provide a blast furnace tuyere complex lance enabling reduction of a basic unit of a reduction material without extremely increasing a diameter of the lance.SOLUTION: A collecting flow passage part 31 is constructed by joining to an outer peripheral surface of a circular cross section flow passage part 32 comprising a circular tube body 34, or an outer peripheral surface of an incomplete circular cross section flow passage part 33 comprising a vertical split tube body 35 with an arc-shaped cross section, both end parts in the circumferential direction of the other incomplete circular cross section flow passage 33; an outer periphery tube body 24 is fitted to an outer periphery of the collecting flow passage part 31 so as to make a gap therebetween to a supply side cooling fluid body flow passage 18; an outermost periphery tube body 25 is arranged in an outer periphery of the outer periphery tube body 24 so as to make a gap therebetween to a return side cooling fluid body flow passage part 19; and a junction type lance 4 is constructed by the passage parts. Since there is no surplus gap in the collecting flow passage part 31, and each of the flow passage parts 32 and 33 has pressure loss smaller than that of a gap between the tubes of a double tube type lance, a sufficient gas volume can be secured without extremely increasing an external diameter of the lance. |
