To prevent the discharge of dust, to use very fine raw material and to reduce equipment cost by making the diameter of a shaft larger than that of a hearth and forming layers of the raw iron ore and the coke above tuyeres of a furnace lower part to provide an empty tank inside the shaft.
Tuyeres 7 are provided in a belly 4 to surround an upper part of a hot metal floor 2 and a slag floor 3 of a hearth 1, a shaft 5 is provided on their upper parts, and a raw material charging port 25 is installed in a furnace top and a transverse side as necessary. In a vertical shaft cupola, blast furnace and melting and reducing furnace, the diameter D of the shaft is ≥1.5 times the diameter (d) of the hearth, layers of raw iron ore and the coke are formed above the tuyeres 7 of the furnace lower part to provide an empty tank 26 inside the shaft. Hot air is fed from the tuyeres 7 into the raw material charging layer 24 to form a raceway, and the iron ore is reduced to obtain the hot metal. The speed of the combustion gas is reduced to approximately 1/3 to 1/10 of a conventional vertical shaft blast furnace to prevent the dust blow-up.
TAKAHASHI REIJIRO
KUME SHOICHI
KOJIMA KITOKU
KANEKO KOZO
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