Apparatus for manufacturing molten metal

Patent metadata

Field	Value
Publication number	US-9453678-B2
Application number	US-201013500790-A
Country	US
Kind code	B2
Filing date	Oct 8, 2010
Priority date	Oct 8, 2009
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

Disclosed is a production device of which secondary combustion efficiency can be further improved when a molten metal is produced by directly reducing and melting a metal agglomerate raw material layer in an electric heating furnace. Specifically, material charging chutes ( 4, 4 ) are disposed at either end portion ( 2, 2 ) of a furnace in the width direction of the furnace. Electrodes ( 5 ) are disposed in a central region in the furnace width direction. Secondary combustion burners ( 6 ) are disposed in an upper portion ( 1 ) of the furnace having stepped portions descending from both end portions ( 2, 2 ) in the furnace width direction to the electrodes ( 5 ). Raw material layers ( 12 ) each having a downslope inclined to lower portions of the electrodes ( 5 ) are formed in advance by charging a carbonaceous material (A) from the chutes ( 4, 4 ), and metal agglomerate raw material layers ( 13 ) are formed on the slopes of the raw material layers ( 12 ) by charging metal agglomerate raw material (B). Molten iron is produced by sequentially melting lower end portions of the metal agglomerate raw material layers ( 13 ) by arc heating at the electrodes ( 5 ). At the same time, an oxygen containing gas (C) is blown from the secondary combustion burners ( 6 ) so as to cause the combustion of a CO containing gas generated from the metal agglomerate raw material layers ( 13 ) while the metal agglomerate raw material layers ( 13 ) descend along the slopes of the raw material layers ( 12 ), and the metal agglomerate raw material layers ( 13 ) are heated by the radiant heat of the combustion.

First claim

The invention claimed is:

1. An apparatus for manufacturing molten metal, comprising:
a stationary non-tilting electric furnace including an electric heating device and having a furnace top;
a secondary combustion burner provided in the furnace top;
an exhaust gas duct connected to the furnace top; and
a raw material charging chute connected to the furnace top and provided on one end of the furnace in a width direction of the furnace,
wherein the electric heating device is provided such that an electric heating region heated with the electric heating device is on the other end of the furnace in the width direction,
the furnace top includes a sloping furnace top having a portion that generally slopes downward from the one end of the furnace in the width direction to a lowest position of the furnace top,
the secondary combustion burner is provided in the sloping furnace top and positioned between the one end of the furnace and the lowest position of the furnace top,
the sloping furnace top has a stepped structure, and the secondary burner is positioned horizontally in the stepped structure.

2. An apparatus for manufacturing molten metal, comprising:
a stationary non-tilting electric furnace including an electric heating device and having a furnace top;
a secondary combustion burner provided in the furnace top;
an exhaust gas duct connected to the furnace top; and
a plurality of raw material charging chutes connected to the furnace top and provided on both ends of the furnace in a width direction of the furnace,
wherein the electric heating device is provided such that an electric heating region heated with the electric heating device is in a center position of the furnace in the width direction,
the furnace top includes a sloping furnace top that generally slopes downward from both ends of the furnace in the width direction to the center position of the furnace in the width direction,
the secondary combustion burner is provided in the sloping furnace top and positioned between the one end of the furnace and the center position of the furnace,
the sloping furnace top has a stepped structure, and the secondary burner is positioned horizontally in the stepped structure.

3. The apparatus for manufacturing molten metal according to claim 1 , wherein the sloping furnace top has a sloping angle in a range of θ 1 or more and θ 2 or less,
the raw material charging chute is configured such that a metal agglomerate raw material is supplied to the furnace in manufacturing molten metal in the apparatus, θ 1 equals to a collapse angle of the metal agglomerate raw material minus 15°, and θ 2 equals to a static angle of repose of the metal agglomerate raw material plus 15°.

4. The apparatus for manufacturing molten metal according to claim 1 , wherein the electric heating device includes an electrode inserted through the furnace top into the furnace and the secondary combustion burner is provided in the sloping furnace top at an angle such that an oxygen-containing gas blown through the secondary combustion burner flows away from the electrode.

5. The apparatus for manufacturing molten metal according to claim 1 , wherein the secondary combustion burner has a gas blowing portion configured such that an oxygen-containing gas blown through the secondary combustion burner swirls about an axis of the secondary combustion burner.

6. The apparatus for manufacturing molten metal according to claim 1 , further comprising a shock generator that is disposed, within the stationary non-tilting electric furnace, between a furnace bottom of the furnace and a surface of a metal agglomerate raw material layer to be formed by a metal agglomerate raw material supplied through the raw material charging chute to the furnace in manufacturing molten metal in the apparatus.

7. The apparatus for manufacturing molten metal according to claim 6 , wherein the shock generator includes a shaft having a rotational axis lying in a longitudinal direction of the furnace and a disintegrating member protruding from a surface of the shaft.

8. The apparatus for manufacturing molten metal according to claim 7 , wherein the shock generator is configured to rotate about the rotational axis in one direction only in which the metal agglomerate raw material layer descends or alternately in the direction in which the metal agglomerate raw material layer descends and in a direction opposite to the direction.

9. An apparatus for manufacturing molten metal, comprising:
a stationary non-tilting electric furnace including an electric heating device, the furnace having a furnace top and a furnace bottom;
a secondary combustion burner provided in the furnace top;
an exhaust gas duct connected to the furnace top; and
a raw material charging chute connected to the furnace top,
wherein the raw material charging chute is provided on one end of the furnace in a width direction of the furnace, the electric heating device is provided such that an electric heating region heated with the electric heating device is on the other end of the furnace in the width direction,
the furnace bottom of the furnace includes a sloping furnace bottom having a portion that generally slopes downward from the one end of the furnace in the width direction to a lowest position of the furnace bottom where a molten metal is to be formed, and the sloping furnace bottom has an access hole at a position higher than the lowest position of the furnace bottom,
the sloping furnace bottom includes a slanting-surface portion and a stepped portion that are alternately located in a longitudinal direction of the furnace,
a plurality of shock generators are disposed at least in the longitudinal direction of the furnace, within the furnace, between the sloping furnace bottom that generally slopes downward and a surface of a metal agglomerate raw material layer to be formed by a metal agglomerate raw material supplied through the raw material charging chute to the furnace in manufacturing molten metal in the apparatus,
the shock generators include a shaft having a rotational axis lying in the longitudinal direction of the furnace and a disintegrating member protruding from a surface of the shaft, at least one end of the shaft is supported by a bearing disposed, outside the furnace, below the slanting-surface portion of the sloping furnace bottom, and a portion of the shaft from which the disintegrating member is protruded is disposed, inside the furnace, above the stepped portion of the sloping furnace bottom.

10. The apparatus for manufacturing molten metal according to claim 9 , wherein the sloping furnace bottom has a sloping angle in a range of θ 3 or more and θ 4 or less,
the raw material charging chute is configured such that a metal agglomerate raw material is supplied to the furnace in manufacturing molten metal in the apparatus, θ 3 equals to a collapse angle of the metal agglomerate raw material minus 25°, and θ 4 equals to a static angle of repose of the metal agglomerate raw material plus 5°.

11. An apparatus for manufacturing molten metal, comprising:
a stationary non-tilting electric furnace including an electric heating device, the furnace having a furnace top and a furnace bottom;
a secondary combustion burner provided in the furnace top;
an exhaust gas duct connected to the furnace top; and
a plurality of raw material charging chutes connected to the furnace top,
wherein the raw material charging chutes are provided in both ends of the furnace in a width direction of the furnace, the electric heating device is provided such that an electric heating region heated with the electric heating device is in a center position of the furnace in the width directi

Assignees

• Tetsumoto Masahiko
• Kobe Steel Ltd

Inventors

• Tetsumoto Masahiko

Classifications

• C21B13/026

  heated electrically · CPC title

• F27B3/205

  Burners · CPC title

• C21B13/10 Primary

  in hearth-type furnaces · CPC title

• F27B3/08 Primary

  heated electrically, with or without any other source of heat · CPC title

• C21B13/12

  in electric furnaces · CPC title