System and method for degassing molten metal

• US 8,753,563 B2
• Filed: 01/31/2013
• Issued: 06/17/2014
• Est. Priority Date: 06/21/2007
• Status: Active Grant

• Current Assignee: Molten Metal Equipment Innovations Incorporated (Molten)
• Original Assignee: Paul V. Cooper
• Inventors: Cooper, Paul V.
• Primary Examiner(s): KASTLER, SCOTT R
• Application Number:
  US13/756,468
• Publication Number:
  US 20130140748A1
• Time in Patent Office: 502 Days
• Field of Search: 266/239, 266/275, 266/234, 266/217, 266/235
• US Class Current: 266/217
• CPC Class Codes: C22B 21/0084 melting and handling molten aluminium C22B21/02, C22B21/04 and C22B21/06 take precedence
• CPC Class Codes: C22B 21/064 using inert or reactive gases C22B21/066 and C22B21/068 take precedence
• CPC Class Codes: C22B 21/066 Treatment of circulating aluminium, e.g. by filtration C22B21/068 takes precedence
• CPC Class Codes: C22B 9/05 Refining by treating with gases, e.g. gas flushing also refining by means of a material generating gas in situ
• CPC Class Codes: F27D 2003/167 the fluid being a neutral gas
• CPC Class Codes: F27D 27/005 Pumps
• CPC Class Codes: F27D 3/14 Charging or discharging liquid or molten material
• CPC Class Codes: F27D 3/16 Introducing a fluid jet or current into the charge porous elements for gas flushing of molten metals B22D1/005
• CPC Class Codes: F27D 99/00 Subject matter not provided for in other groups of this subclass

Abstract

A system for adding gas to and transferring molten metal from a vessel and into one or more of a ladle, ingot mold, launder, feed die cast machine or other structure is disclosed. The system includes at least a vessel for containing molten metal, an overflow (or dividing) wall, a device or structure, such as a molten metal pump, for generating a stream of molten metal, and one or more gas-release devices.

Claims

1. A system for releasing gas into molten metal, the system comprising:

(a) a vessel for containing molten metal, the vessel comprising a bottom interior surface;

(b) a raised chamber in fluid communication with the vessel, the raised chamber comprising;

(i) a bottom interior surface positioned at least partially above the bottom interior surface of the vessel; and

(ii) a discharge for expelling molten metal from the raised chamber; and

(c) a plurality of degassers positioned in the raised chamber, the plurality of degassers releasing gas into the molten metal in the raised chamber;

(d) a dividing wall between each of the degassers, each dividing wall including an opening through which molten metal can pass; and

a pump positioned in the vessel for pumping the molten metal from the vessel to the raised chamber.

2. The system of claim 1 wherein the pump positioned in the vessel is selected from the group consisting of:

a circulation pump and a gas-release pump.

3. The system of claim 1 wherein the degassers are in line.

4. The system of claim 1 wherein the degassers are mounted on a top wall of the raised chamber.

5. The system of claim 4 wherein the raised chamber has side walls and the top wall of the raised chamber is removably attached to the side walls.

6. The system of claim 1 wherein the degassers are rotary degassers, each rotary degasser comprising:

(a) a shaft that extends into the raised chamber; and

(b) an impeller positioned on the shaft.

7. The system of claim 1 wherein each dividing wall extends between a front interior surface of the raised chamber to a rear interior surface of the raised chamber.

8. The system of claim 7 wherein each dividing wall extends from a top interior surface of the raised chamber to a bottom interior surface of the raised chamber.

9. The system of claim 1 further comprising a plurality of openings in each dividing wall, the one or more openings for allowing molten metal to flow through the raised chamber.

10. The system of claim 1 further comprising a dividing wall between the vessel and the raised chamber, the dividing wall comprising an overflow opening for allowing molten metal to return to the vessel from the raised chamber.

11. The system of claim 10 wherein at least a portion of the overflow opening has a height H1, wherein at least a portion of the discharge in the raised chamber has a height H2, and H2 is less than H1.

12. The system of claim 11 wherein the overflow opening comprises a lower edge having the height H1, and wherein the discharge comprises a lower edge having the height H2.

13. The system of claim 10 wherein the dividing wall includes an opening positioned beneath the height H1, the opening configured to at least partially receive a base of a pump.

14. The system of claim 13 further comprising a pump positioned in the vessel, the pump comprising a base, the base positioned in the opening in the dividing wall for pumping the molten metal from the vessel to the raised chamber.

15. The system of claim 14 wherein the pump positioned in the vessel is selected from the group consisting of:

a circulation pump, and a gas-release pump.

16. The system of claim 14 further comprising a seal between the base of the pump positioned in the vessel and the opening.

17. The system of claim 14 wherein the pump positioned in the vessel is a variable speed pump.

18. The system of claim 1, wherein the bottom interior surface of the raised chamber is sloped backward to allow molten metal to flow back into the vessel when the flow of molten metal from the pump ceases.