Nittetsu Plant Designing Corporation

Nippon Steel Corporation

Nippon Steel Engineering Co., Ltd.

Masahide Nagatomi

Shinji Shima

Toshitaka Nakayama

Yuichi Sakurai

A reduced iron discharging screw conveyer is provided in a rotary hearth furnace and discharges reduced iron out of the rotary hearth furnace. The rotary hearth furnace produces the reduced iron by charging and heating a pellet including metallic oxide and coal material onto a rotary hearth rotating in a horizontal plane. The reduced iron discharging screw conveyer has a rotary shaft and a screw blade which is spirally formed on an outer surface of the rotary shaft. A lead angle &#x3b8; of the screw bladesatisfies a condition of '0.46 rad &#x2266;&#x3b8;&#x2266;0.79 rad'. A ratio (h/D) between height h of the screw blade and an outer diameter D of the screw conveyer is smaller than 0.2, and a ratio (t/h) between thickness t and height h of the screw blade is larger than or equal to 0.12.

Screw conveyor of rotary hearth furnace for discharging reduced iron

The invention provides a raw materials feeding apparatus capable of uniformly dispersing and feeding into a furnace agglomerated raw materials that are likely to undergo dusting, deformation and mutual adhesion. In a raw material feeding apparatus for a rotary hearth furnace, for feeding raw materials to a rotary hearth furnace by using a flat belt conveyor, the invention employs a construction in which a scraper for guiding the raw materials on the flat belt conveyor to a side surface of the flat belt conveyor is arranged obliquely to a traveling direction of the flat belt conveyor. Preferably, the scraper is arranged in such a manner as to guide the raw materials to both sides of the flat belt conveyor.

Growing community of inventors

Fukuoka, Japan

Masahide Nagatomi