High cleanliness molten steel production method and refining device

Patent metadata

Field	Value
Publication number	US-9752202-B2
Application number	US-201314400908-A
Country	US
Kind code	B2
Filing date	May 13, 2013
Priority date	May 14, 2012
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

Provided are a method and a refining device for producing molten steel of outstanding cleanliness, and more particularly provides a method and device for refining inclusions by forming droplets from molten steel and dropping same into slag during pre-processing in a continuous casting process in a steel-making process. Also, provided is a method for producing high cleanliness molten steel comprising a molten-steel supply device for supplying molten steel and a molten-steel refining device for containing and refining molten steel poured into the molten-steel supply device, wherein the method comprises: a molten-steel pouring step in which molten steel is poured from the molten-steel supply device into the molten-steel refining device; a droplet-forming step in which the molten steel which has been poured in is formed into droplets in the molten-steel refining device; a slag-pass-through step in which the molten steel which has been formed into droplets is dropped so as to pass through slag; and an inclusion-removing step in which residual inclusions in the molten steel, which has been formed into droplets, are removed while passing through the slag.

First claim

The invention claimed is:

1. A high cleanliness molten steel refining device, comprising:
a first container adapted to receive molten steel poured from a molten steel supply device; and
a droplet forming device positioned within the first container and comprising a second container comprising:
a sidewall separate from any sidewall of the first container; and
a droplet forming portion having a plurality of droplet holes for forming molten steel into droplets at a central part of the second container,

wherein the first container is a tundish, the droplet forming device is within a tundish body of the tundish, and the droplet forming device is adjacent to a lower region where molten steel is poured,
wherein the droplet forming device further comprises a molten steel accommodating portion at a lower portion of a molten steel pouring region in the tundish body to accommodate the molten steel poured from the molten steel supply device and is configured to move the poured-in molten steel to the droplet forming portion via the molten steel accommodating portion, and
wherein the droplet forming portion further comprises an opening on an opposite side of a region where the plurality of droplet holes are formed is coupled so that an upper portion of the molten steel accommodating portion is passed through via the opening or located at an upper portion of an outer circumference surface of the molten steel storage space of the molten steel accommodating portion so that an upper portion of the molten steel accommodating portion is passed through via the opening.

2. The device of claim 1 , wherein the molten steel accommodating portion is adjacent to an inner side surface and a lower side surface of the tundish body at a lower region of the molten steel pouring region.

3. The device of claim 2 , wherein the droplet forming portion is supported by a weir provided in the tundish body.

4. The device of claim 3 , wherein a portion of the sidewall of the second container on one side of the droplet forming portion is supported by the weir and a portion of the sidewall of the second container on another side is supported by the molten steel accommodating portion.

5. The device of claim 3 , wherein a portion of the sidewall of the second container on the one side of the droplet forming portion is supported by the weir and a portion of the sidewall of the second container on the another side is supported by being coupled to an inner side surface of the tundish body.

6. A high cleanliness molten steel refining device, comprising:
a first container adapted to receive molten steel poured from a molten steel supply device; and
a droplet forming device positioned within the first container and comprising a second container comprising:
a sidewall separate from any sidewall of the first container; and
a droplet forming portion having a plurality of droplet holes for forming molten steel into droplets at a central part of the second container,

wherein the first container is a tundish,
wherein the droplet forming device is within a tundish body of the tundish, and wherein the droplet forming device is adjacent to a lower region where molten steel is poured,
wherein the droplet forming device further comprises a molten steel accommodating portion at a lower portion of a molten steel pouring region in the tundish body to accommodate the molten steel poured from the molten steel supply device and is configured to move the poured-in molten steel to the droplet forming portion via the molten steel accommodating portion,
wherein a portion of the sidewall of the second container adjacent to the molten steel accommodating portion is formed lower than a portion of the sidewall on another side.

7. The device of claim 1 , wherein the droplet hole is 6.5 mm or less in diameter.

8. A high cleanliness molten steel refining device comprising:
a tundish including a tundish body and a tundish cover for covering a side of the tundish body; and
a droplet forming device comprising:
a molten steel accommodating portion formed by blocking the tundish body with a first weir; and
a droplet forming portion provided adjacent to the molten steel accommodating portion in the tundish body comprising:
a container comprising:
a sidewall separate from any sidewall of the tundish; and
a droplet forming portion having a plurality of droplet holes for forming molten steel into droplets at a central part of the container.

9. The device of claim 8 , wherein the molten steel accommodating portion is a space between the first weir and an inner side wall of the tundish body.

10. The device of claim 8 , wherein the droplet forming portion and the molten steel accommodating portion are on opposite sides of the first weir.

11. The device of claim 8 , further comprising a second weir supported on an inner sidewall of the tundish body and supporting the droplet forming portion.

12. The device of claim 11 , wherein the droplet forming portion is supported by the first weir and the second weir in a space between the first weir and the second weir.

13. The device of claim 12 , wherein a lower portion of the second weir is open.

14. The device of claim 8 , wherein the molten steel, overflown from the molten steel accommodating portion, is transferred to the droplet forming portion.

15. The device of claim 8 , wherein the molten steel formed into droplets by passing through the droplet forming portion is stored in a molten storage portion formed on an opposite side of the molten steel accommodating portion of the tundish body.

16. The device of claim 15 , wherein the molten steel formed into droplets by passing through the droplet forming portion is stored in the molten steel storage portion in a state in which the molten steel is refined by passing through slag.

17. The device of claim 8 , wherein the droplet forming portion comprises stepped parts, wherein a height of a stepped part adjacent to the molten steel accommodating portion is lower than a height of another stepped part that is more distanced away from the molten steel accommodating portion than the adjacent stepped part.

18. The device of claim 8 , wherein the molten steel accommodating portion is configured to receive the molten steel supplied from a ladle via a long nozzle.

19. The device of claim 8 , wherein the droplet hole is 6.5 mm or less in diameter.

Assignees

• Posco

Inventors

• Choi Ja Yong
• Han Seung Min
• Kim Sun Koo
• Lee Hee Ho
• Jung Sang Yuel
• Seo Young Jong

Classifications

• Y02P10/242

  Cross-Sectional Technologies · mapped topic

• B22D41/08

  for bottom pouring (B22D41/14, B22D41/50 take precedence) · CPC title

• C21C7/0075

  Treating in a ladle furnace, e.g. up-/reheating of molten steel within the ladle · CPC title

• C21C7/076 Primary

  Use of slags or fluxes as treating agents (C21C7/06, C21C7/064, C21C7/068 take precedence) · CPC title

• B22D11/118

  by circulating the metal under, over or around weirs (B22D11/119 takes precedence) · CPC title