Aluminum scrap reclamation

• US 4,128,415 A
• Filed: 12/09/1977
• Issued: 12/05/1978
• Est. Priority Date: 12/09/1977
• Status: Expired due to Term

• Current Assignee: Aluminum Company of America (Howmet Aerospace, Inc.)
• Original Assignee: Aluminum Company of America (Howmet Aerospace, Inc.)
• Inventors: van Linden, Jan H. L., Herrick, Joseph R., Ormesher, Robert J., Claxton, Raymond J.
• Primary Examiner(s): Andrews, M. J.
• Application Number:
  US05/859,060
• Time in Patent Office: 361 Days
• Field of Search: 75/68 R, 75/65 R, 266/901, 266/44
• US Class Current: 75/687
• CPC Class Codes: C22B 21/0092 Remelting scrap, skimmings or any secondary source aluminium
• CPC Class Codes: C22B 7/003 only remelting, e.g. of chips, borings, turnings; apparatus used therefor
• CPC Class Codes: C22B 9/16 Remelting metals liquating C22B9/02
• CPC Class Codes: Y02P 10/20 Recycling
• CPC Class Codes: Y10S 266/901 Scrap metal preheating or melting

Abstract

An improved system for melting metal scrap in a molten melting media includes a housing generally cylindrical in cross section and having upper and lower portions. Metal scrap is introduced to a body of molten melting media contained in the upper portion of the housing. A supply of molten melting media is added to the upper portion of the housing through a volute located in the lower portion. The molten melting media is supplied or added by action of an impeller located in the lower portion and mounted on a drive shaft extending through the upper portion. Vanes are mounted on the drive shaft to control the flow motion of the body of molten melting media and metal scrap in the upper portion of the housing by creating a vortex in this body for purposes of mixing the melting media and metal scrap. An opening is provided in the upper portion to remove melted scrap and melting media at a rate substantially commensurate with their rate of introduction.

Claims

1. An improved method of melting metal scrap in a molten melting media comprising:

(a) providing a body of molten melting media in a housing for purposes of melting metal scrap therein, the housing being generally circular in cross section and having upper and lower portions;

(b) introducing a supply of scrap metal to the melting media contained in the upper portion of said housing;

(c) adding a supply of molten melting media to said body through a volute located in the lower portion of said housing, said adding being accomplished by action of an impeller mounted on a drive shaft extending through the upper portion of the housing, and rotating in the lower portion of the housing, the impeller having a substantially circular disc having blades extending substantially downwardly therefrom to a flat ring member having a circular shaped opening in the center thereof, the opening adapted to permit molten melting media to enter the impeller axially, the disc, blades and ring member cooperating to discharge the molten melting media therefrom radially at a relatively high velocity;

(d) controlling the motion of the body of molten melting media and the metal scrap in the upper portion of the housing by action of vanes mounted on said shaft to create a vortex in said body for mixing said scrap in said melting media; and

(e) removing melted scrap and molten melting media at a rate substantially commensurate with their rate of introduction to the housing, the melted scrap and molten melting media removed through an opening located in the upper portion of the housing.

2. The method according to claim 1 wherein the impeller is fabricated from a zinc borosilicate frit.

3. The method according to claim 1 wherein the upper portion of the housing is downwardly converging.

4. The method according to claim 1 wherein the metal scrap is aluminum or aluminum alloys.

5. The method according to claim 1 wherein the molten melting media is molten aluminum.

6. The method according to claim 1 wherein the temperature of the melting media being added to said body is in the range of 1325°

to 1475°

F.

7. In an improved method of melting metal scrap in a recirculating system having a heating bay and a pumping bay wherein molten melting media is circulated from the heating bay to the pumping bay and back to the heating bay, the pumping bay having a housing having upper and lower portions therein of generally circular cross section, the upper portion containing a body of molten melting media, the improvement comprising:

(a) introducing a supply of scrap metal to the melting media contained in the upper portion of said housing;

(b) adding a supply of molten melting media to said body through a volute located in the lower portion of said housing, said adding being accomplished by action of an impeller mounted on a drive shaft extending through the upper portion of the housing, and rotating in the lower portion of the housing, the impeller fabricated from a zinc borosilicate frit;

(c) controlling the flow motion of the body of molten melting media and the metal scrap in the upper portion of the housing by action of vanes mounted on said shaft to create a vortex in said body for mixing said scrap in said melting media; and

(d) removing melted scrap and molten melting media at a rate substantially commensurate with their rate of introduction to the housing, the melted scrap and molten melting media removed through an opening located in the upper portion of the housing.

8. An improved method of melting aluminum scrap in molten aluminum comprising:

(a) providing a body of molten aluminum in a housing for purposes of melting aluminum scrap therein, the housing being generally circular in cross section and having upper and lower portions, the upper portion having a downwardly converging wall;

(b) introducing a supply of scrap aluminum metal to the molten aluminum contained in the upper portion of said housing;

(c) adding supply of molten aluminum at a temperature in the range of 1325°

to 1475°

F. to said body through a volute located in the lower portion of said housing, said adding being accomplished by action of an impeller mounted on a drive shaft extending through the upper portion of the housing, and rotating in the lower portion of the housing, the impeller fabricated from a zinc borosilicate frit and having a substantially circular disc having blades extending substantially downwardly therefrom to a flat ring member having a circular shaped opening in the center thereof, the opening adapted to permit molten melting media to enter the impeller axially, the disc, blades and ring member cooperating to discharge the molten melting media therefrom radially at a relatively high velocity;

(d) controlling the flow motion of the body of molten aluminum and the aluminum scrap in the upper portion of the housing by action of vanes mounted on said shaft to create a vortex in said body for mixing said scrap in said molten aluminum; and

(e) removing melted scrap and molten melting media at a rate substantially commensurate with their rate of introduction to the housing, the melted scrap and molten melting media removed through an opening located in the upper portion of the housing.