Nkk Corporation

Masahiro Matsuo

Genji Kanatani

Shinichi Isozaki

Tatsuro Ariyama

Kenzo Yamada

Haruhito Tsuboi

Hitoshi Kawata

Yoshiyuki Kitano

Jirou Mase

Tatsurou Ariyama

A method for controlling a flow rate of gas for prereducing ore comprises the steps of prereducing ore in a prereduction furnace having a fluidized bed with a gas generated in a smelting reduction furnace and controlling a pressure of gas generated in the smelting reduction furnace and introduced into the prereduction furnace, thereby controlling the actual flow rate of gas introduced into the prereduction furnace. An apparatus for controlling a flow rate of gas for prereducing ore comprises a flow passage for introducing gas generated in a smelting reduction furnace into a prereduction furnace and a gas pressure control valve positioned in the flow passage.

Method for controlling a flow rate of gas for prereducing ore and

A prereduction furnace of a smelting reduction facility of iron ore includes a fluidizing prereduction chamber installed at an upper part of the prereduction furnace wherein iron ores are fed and prereduced, a gas blowing chamber installed at a lower part of the prereduction furnace wherein a reducing gas is fed, a distributor installed between the fluidizing prereduction chamber and the gas blowing chamber, a first plurality of nozzles passing through the distributor for injecting the reducing gas in the gas blowing chamber into the fluidizing prereduction chamber, a discharge pipe for discharging prereduced iron ores installed at a bottom center portion of the fluidizing prereduction chamber and extending through the distributor, wherein a cooling fluid flows, at least two horizontally movable gas purging pipes arranged below the distributor, and a second plurality of nozzles attached to the horizontally movable gas purging pipes for injecting a purging gas to a bottom surface of the distributor to prevent clogging of lower ends of the first plurality of nozzles.

Prereduction furnace of a smelting reduction facility of iron ore

A prereduction furnace of a smelting reduction facility of iron ore includes of a fluidizing prereduction chamber at an upper part of the prereduction furnace wherein iron ores are fed and prereduced, a gas blowing chamber at a lower part of the prereduction furnace wherein a reducing gas is fed, a ceramic main body of a distributor mounted between the fluidizing prereduction chamber and the gas blowing chamber, a metal box attached to the bottom side of the ceramic main body, which prevent adhesion of dust in the reducing gas, nozzles passing through the ceramic main body and through the metal box for injecting the reducing gas in the blowing chamber, into the prereduction chamber and a discharge pipe for discharging prereduced iron ores mounted at a bottom center portion of the prereduction chamber and extending through the ceramic main body, through the metal box, and through a bottom of the gas blowing chamber.

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Kawasaki, Japan

Masahiro Matsuo