Continuous casting of materials using pressure differential

Patent metadata

Field	Value
Publication number	US-2016167121-A1
Application number	US-201615051812-A
Country	US
Kind code	A1
Filing date	Feb 24, 2016
Priority date	Sep 28, 2012
Publication date	Jun 16, 2016
Grant date	—

Abstract

A system and method for continuous casting. The system includes a melt chamber, a withdrawal chamber, and a secondary chamber therebetween. The melt chamber can maintain a melting pressure and the withdrawal chamber can attain atmospheric pressure. The secondary chamber can include regions that can be adjusted to different pressures. During continuous casting operations, the first region adjacent to the melt chamber can be adjusted to a pressure that is at least slightly greater than the melting pressure; the pressure in subsequent regions can be sequentially decreased and then sequentially increased. The pressure in the final region can be at least slightly greater than atmospheric pressure. The differential pressures can form a dynamic airlock between the melt chamber and the withdrawal chamber, which can prevent infiltration of the melt chamber by non-inert gas in the atmosphere, and thus can prevent contamination of reactive materials in the melt chamber.

First claim

1 . A method for casting material, the method comprising:
controlling the pressure in a melt chamber, a secondary chamber, and a withdrawal chamber to a melting pressure; passing cast material cast from molten material in the melt chamber into the secondary chamber, wherein the secondary chamber comprises a plurality of regions, and wherein the plurality of regions comprises a first region adjacent to the melt chamber; passing the cast material from the secondary chamber into the withdrawal chamber; controlling the pressure of the first region from the melting pressure to a first differential pressure that is greater than the melting pressure; and controlling the pressure of the withdrawal chamber from the melting pressure to atmospheric pressure.

2 . The method of claim 1 , further comprising evacuating the melt chamber, secondary chamber, and withdrawal chamber to a substantial vacuum before controlling the pressure therein to the melting pressure.

3 . The method of claim 2 , further comprising, after evacuating the melt chamber, secondary chamber, and withdrawal chamber to a substantial vacuum, filling the melt chamber, secondary chamber, and withdrawal chamber with an inert gas.

4 . The method of claim 1 , wherein the plurality of regions of the secondary chamber further comprises a second region adjacent to the first region, the method further comprising controlling the pressure of the second region to a second differential pressure that is less than the first differential pressure.

5 . The method of claim 4 , wherein the plurality of regions of the secondary chamber further comprises a final region operably positioned adjacent to the withdrawal chamber, the method further comprising controlling the pressure of the final region to a final differential pressure that is greater than atmospheric pressure.

6 . The method of claim 5 , wherein the plurality of regions of the secondary chamber comprises an intermediate region, the method further comprising controlling the pressures in regions of the plurality of regions positioned between the second region and the intermediate region, wherein the pressures are adjusted from the melting pressure to pressures that sequentially decrease from the second region to the intermediate region.

7 . The method of claim 6 , wherein the pressures in the regions positioned between the second region and the intermediate region sequentially decrease by approximately 10 Torr to approximately 100 Torr between adjacent regions.

8 . The method of claim 5 , further comprising controlling the pressures in regions of the plurality of regions positioned between the intermediate region and the final region, wherein the pressures are adjusted from the melting pressure to pressures that sequentially increase from the intermediate region to the final region.

9 . The method of claim 1 , further comprising applying energy to material in the melt chamber to melt the material.

10 . The method of claim 1 , further comprising moving a withdrawal mechanism to move the cast material through the secondary chamber and into the withdrawal chamber.

11 . The method of claim 1 , further comprising releasing the withdrawal chamber from the secondary chamber to control the pressure of the withdrawal chamber from the melting pressure to atmospheric pressure.

12 . The method of claim 1 , further comprising extending a set of rollers to contact the cast material.

13 . The method of claim 1 , further comprising cutting the cast material with a cutting device.

14 . The method of claim 13 , further comprising unloading a cut segment of the cast material onto a cart.

15 . The method of claim 1 , wherein the melting pressure is greater than atmospheric pressure.

16 . The method of claim 1 , wherein the pressure in each region of the plurality of regions of the secondary chamber is adapted to be separately controlled.

17 . The method of claim 16 , wherein pressures in the plurality of regions of the secondary chamber are controlled via a plurality of pumps.

18 . The method of claim 17 , further comprising recovering and recycling gas withdrawn by the plurality of pumps.

19 . The method of claim 18 , wherein the gas comprises inert gas.

20 . The method of claim 18 , wherein the recovered gas is compressed and purified before returning to a gas source.

21 . A casting method, the method comprising:
controlling the pressure in a melt chamber, a secondary chamber, and a withdrawal chamber to a melting pressure; passing cast material made from material in the melt chamber into the secondary chamber, wherein the secondary chamber comprises a plurality of regions, and wherein the plurality of regions comprises a first region adjacent to the melt chamber; passing cast material from the secondary chamber into the withdrawal chamber; controlling a pressure of the first region from the melting pressure to a first differential pressure that is greater than the melting pressure, to form a dynamic airlock and protect the melt chamber from non-inert gas in the atmosphere; and controlling a pressure of the withdrawal chamber from the melting pressure to atmospheric pressure.

22 . The method of claim 21 , wherein the plurality of regions further comprises a final region and an intermediate region intermediate the first region and the final region, the method further comprising controlling the pressure of the final region to a final differential pressure that is greater than atmospheric pressure, and decreasing the pressure in the intermediate region to direct gas toward the intermediate region.

23 . The method of claim 22 , wherein pressures in regions of the secondary chamber are adjusted to sequentially decrease from the first region to the intermediate region.

24 . The method of claim 22 , wherein pressures in regions of the secondary chamber are adjusted to sequentially increase from the intermediate region to the final region.

25 . The method of claim 21 , wherein pressures in the plurality of regions of the secondary chamber are controlled via a plurality of pumps.

Assignees

• Ati Properties Inc

Inventors

• Arnold Matthew J

Classifications

• B22D11/117

  by treating with gases (B22D11/118, B22D11/119 take precedence) · CPC title

• B22D11/20

  for removing cast stock · CPC title

• B22D11/113 Primary

  by vacuum treating · CPC title

• B22D11/142

  for curved casting · CPC title

• B22D27/003

  by using inert gases · CPC title