SCREW CONVEYOR FOR DISCHARGING REDUCED IRON FROM ROTARY HEARTH REDUCTION FURNACE

Title:

SCREW CONVEYOR FOR DISCHARGING REDUCED IRON FROM ROTARY HEARTH REDUCTION FURNACE

Document Type and Number:

WIPO Patent Application WO/2007/116878

Kind Code:

A1

Abstract:

A screw conveyor for discharging reduced iron from a rotary hearth reduction furnace in which the rate of operation of the rotary hearth reduction furnace can be enhanced by prolonging the abrasion life of the screw blades of screw conveyor thereby reducing maintenance frequency of the screw conveyor. In the screw conveyor (5) which is disposed in the rotary hearth reduction furnace for producing reduced iron by loading a pellet composed of a metal oxide and a carbon material onto a rotary hearth rotating in a horizontal plane and then by heating (reduction), and which discharges reduced iron to the outside of the furnace, a rotating shaft and screw blades formed spirally on the outer circumference of the rotating shaft are provided, and the lead angle θ (rad) of the screw blade (5a) is set to satisfy the condition 0.6 rad≤θ≤0.79 rad. Furthermore, the ratio (h/D) between the height (h) of the screw blade and the outside diameter (D) of the screw conveyor is set smaller than 0.2, and the ratio (t/h) between the thickness (t) and the height (h) of the screw blade is set at 0.12 or above.

Inventors:

SHIMA SHINJI (JP)
NAKAYAMA TOSHITAKA (JP)
NAGATOMI MASAHIDE (JP)

Application Number:

PCT/JP2007/057442

Publication Date:

October 18, 2007

Filing Date:

April 03, 2007

Export Citation:

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Assignee:

NIPPON STEEL ENG CO LTD (JP)
NITTETSU PLANT DESIGNING CORP (JP)
SHIMA SHINJI (JP)
NAKAYAMA TOSHITAKA (JP)
NAGATOMI MASAHIDE (JP)

International Classes:

F27D3/08; C21B13/10; F27B9/16; F27B9/39

Foreign References:

JP2001304766A	2001-10-31
JPS4519569B1
JPH0320482B2	1991-03-19
US4636127A	1987-01-13
JP2005061651A	2005-03-10

Other References: