Inert pump leg adapted for immersion in molten metal

• US 6,168,753 B1
• Filed: 10/19/1998
• Issued: 01/02/2001
• Est. Priority Date: 08/07/1998
• Status: Expired due to Term

• Current Assignee: Alphatech, Inc.
• Original Assignee: Alphatech, Inc.
• Inventors: Morando, Jorge A.
• Primary Examiner(s): KASTLER, SCOTT R
• Application Number:
  US09/174,624
• Time in Patent Office: 806 Days
• Field of Search: 266/233, 266/235, 266/236, 266/239, 266/286, 266/287, 222/590, 222/591, 222/594, 417/360, 428/408
• US Class Current: 266/233
• CPC Class Codes: F04D 7/065 for liquid metal

Abstract

A graphite support leg for positioning an object, such as a pump, in a bath of molten metal. The leg is enclosed in a ceramic sleeve, and an inert material is disposed in a clearance between the leg and the sleeve to protect the leg from the heat of the molten metal.

Claims

1. A support structure having a lower end suited for positioning an object such as a pump housing below the surface of a bath of molten metal, and an upper end suited for connection to structure above the bath of molten metal, comprising:

an elongated support leg of a graphite material, a sleeve housing said support leg, said sleeve being formed of a ceramic that is resistant to the heat of the molten metal, both the leg and the sleeve having a length suited for connection to a support structure above the bath of molten metal and a lower end suited for connection to a structure immersed below the metal level of the bath of molten metal;

means forming a helical groove between the interface of the graphite leg and the ceramic sleeve extending from the upper end of the leg to a location proximate said immersed structure; and

a source of an inert gas, and means for connecting said source of inert gas to said helical groove to fill the groove.

2. A support structure as described in claim 1, where the groove is axially located on the interface of the leg and the ceramic sleeve to generate an inert gas protective chamber.

3. A support suited for positioning a pump or other similar device disposed in a bath of molten metal, beneath an overhead support structure disposed above the metal level of the bath, comprising:

a graphite leg having an upper end and a lower end, the leg having a sufficient compressive strength to prevent an object from rising in molten metal, the leg having a tendency to be combustible in the presence of oxygen, and non-combustible in the presence of an inert material;

first means for connecting the graphite leg to an overhead support structure, and second means for connecting the graphite leg to an object disposed in a bath of molten metal;

structure enclosing that portion of the graphite leg disposed in the bath of molten metal, including a ceramic sleeve telescopically enclosing the leg, the ceramic sleeve being resistant to the heat of molten metal;

third means forming a clearance between the graphite leg and the ceramic sleeve; and

an inert non-gaseous material disposed in said clearance to form a non-combustible barrier between the graphite leg and the molten metal.

4. A support as defined in claim 3, in which the inert material includes a nylon tape, and a coating of refractory cement mixed with boron nitride paint to form a gas-free environment between the graphite leg and the ceramic sleeve.

5. A support as defined in claim 4, in which the nylon tape is wrapped in a helical wrapping around the graphite leg.

6. A support as defined in claim 3, in which the lower end of the leg is capable of being connected to a pump housing.

7. A support suited for positioning a pump or similar device disposed in a bath of molten metal, beneath an overhead support structure disposed above the metal level of the bath;

comprising;

a leg of a material capable of being penetrated by a gas, having an upper end and a lower end, the leg having a sufficient compressive strength to prevent an object from rising in molten metal, the leg having a tendency to be combustible in the presence of oxygen, and non-combustible in the presence of an inert gas;

first means for connecting the leg to an overhead support structure; and

second means for connecting the leg to an object disposed in a bath of molten metal;

structure enclosing that portion of the leg disposed in the molten metal to form a sealed chamber, including a ceramic sleeve telescopically enclosing the leg, the ceramic sleeve being resistant to the heat of molten metal; and

a source of an inert gas, and means for introducing the gas into the sleeve to so penetrate the leg as to prevent it from burning when disposed in molten metal.

8. A support as defined in claim 7, in which the leg is formed of a graphite material.

9. A support as defined in claim 7, in which the gas is nitrogen.

10. A support as defined in claim 7, in which the lower end of the leg is connected to a pump housing.

11. A support as defined in claim 7, in which the leg has an axial passage, and including a source of an inert gas connected to said axial passage to impregnate the leg with the inert gas.

12. A support suited for positioning a pump or other similar device disposed in a bath of molten metal, beneath an overhead support structure disposed above the metal level of the bath, comprising:

a graphite leg having an upper end and a lower end, the graphite having a sufficient compressive strength to prevent an object from rising in molten metal, the leg having a tendency to be combustible in the presence of oxygen, and non-combustible in the presence of an inert material, at

first means for connecting the graphite leg to an overhead support structure, and second means for connecting the graphite leg to an object disposed in a bath of molten metal; and

structure enclosing that portion of the graphite leg disposed in a bath of molten metal to form a barrier between the graphite leg and the molten metal including a ceramic sleeve having a lower end telescopically enclosing the leg, the ceramic sleeve being resistant to the heat of molten metal.

13. A support as defined in claim 12, including structure in the opening in the pump housing for joining the leg to the pump housing and for preventing molten metal from entering the lower end of the ceramic sleeve.

14. A support suited for positioning a pump having a housing disposed in a bath of molten metal, beneath an overhead support structure disposed above the metal level of the bath, comprising:

a pump housing having an opening;

a graphite leg having an upper end and a lower end, the graphite leg having a sufficient compressive strength to prevent the pump housing from rising in molten metal, the graphite leg having a tendency to be combustible in the presence of oxygen, and non-combustible in the presence of an inert material at such times as the graphite leg is disposed in a bath of molten metal;

first means for connecting the graphite leg to an overhead support structure, and second means for connecting the graphite leg in the opening in the pump housing; and

structure forming a barrier between the graphite leg and the molten metal including a ceramic sleeve telescopically enclosing the leg, the ceramic sleeve being resistant to the heat of molten metal.

15. A support as defined in claim 14, in which the lower end of the graphite leg extends through the opening in the pump housing, and including a fastener threadably connected to the leg to join the leg to the pump housing.

16. A support as defined in claim 14, in which the pump-housing opening has a frusto-conical configuration, and the graphite leg has a frusto-conical end mated with the opening in the pump housing.