Claims
- 1. A method for sealing an end of a ceramic filter element, comprising the steps of:
(a) providing a porous ceramic filter element comprising a first end portion and a second end portion and comprising filtering channels therethrough wherein said filter element comprises a substantially continuous network of open porosity; (b) contacting a portion of said first end of said filter element with a molten metal comprising from about 1.5 weight percent to about 10 weight percent oxygen, to infiltrate said metal into the continuous network of open porosity in said first end portion of said filter element by capillary action without substantially infiltrating said filtering channels; (c) cooling said infiltrated portion to form a filter element having an internally sealed end comprising a ceramic-metal composite portion.
- 2. The method of claim 1, further comprising attaching a connecting means to said ceramic-metal composite portion.
- 3. The method of claim 2, wherein said connecting means permits sealable attachment of said ceramic filter element to a dissimilar material.
- 4. The method of claim 2, wherein said connecting means permits sealable attachment of said ceramic filter element to another ceramic filter element.
- 5. The method of claim 2, wherein said connecting means comprises a swage fitting or a compression fitting.
- 6. The method of claim 2, wherein said connecting means is a braze.
- 7. The method of claim 2, wherein said connecting means is a weld.
- 8. The method of claim 7, wherein said weld attaches said ceramic-metal composite portion to a metal member.
- 9. The method of claim 2, wherein said step of attaching said connecting means to said ceramic-metal composite portion comprises the step of brazing said connecting means to said ceramic-metal composite portion.
- 10. The method of claim 9, wherein said step of brazing said connecting means to said ceramic-metal composite is performed using a copper-silver brazing alloy.
- 11. The method of claim 2, wherein said connecting means comprises threads.
- 12. The method of claim 2, wherein said connecting means comprises a metal bellows.
- 13. The method of claim 1, further comprising forming threads into said ceramic metal composite portion before or after metal infiltration.
- 14. The method of claim 1, wherein said molten metal comprises copper metal.
- 15. The method of claim 1, wherein said ceramic filter element comprises a porous ceramic support having from about 30 volume percent to about 50 volume percent open porosity.
- 16. The method of claim 11, wherein said porous ceramic support has an average pore size of from about 0.01 micrometers to about 2 millimeters.
- 17. The method of claim 1, further comprising the step of coating at least a portion of said filtering channels with a membrane layer.
- 18. The method of claim 13, wherein said membrane layer comprises three different layers.
- 19. a ceramic filter element for a filtration device, comprising:
(a) a substantially cylindrical sintered ceramic porous support having channels therethrough; and (b) a metal comprising from about 1.5 weight percent to about 10 weight percent oxygen infiltrated into an end portion of said ceramic filter element by capillary action to form a ceramic-metal composite portion wherein said ceramic metal composite portion creates a substantially hermetic internal seal within said porous support and wherein said channels are not substantially filled with said metal.
- 20. The ceramic filter element of claim 19, further comprising a connecting means, wherein said connecting means is attached to said ceramic-metal composite portion.
- 21. The ceramic filter element of claim 20, wherein said connecting means comprises a swage fitting or a compression fitting.
- 22. The ceramic filter element of claim 20, wherein said connecting means comprises a weld.
- 23. The ceramic filter element of claim 20, wherein said connecting means comprises a braze.
- 24. The ceramic filter element of claim 20, wherein said connecting means comprises a metal bellows.
- 25. The ceramic filter element of claim 20, wherein said connecting means comprises threads formed into said ceramic-metal composite portion before or after metal infiltration for screwing said ceramic filter element into a threaded member.
- 26. The ceramic filter element of claim 19, further comprising a supporting ring, wherein said supporting ring is attached to said ceramic-metal composite portion.
- 27. The ceramic filter element of claim 26, wherein said supporting ring is a stainless steel ring.
- 28. The ceramic filter element of claim 19, wherein said filter element comprises alumina ceramic.
- 29. The ceramic filter element of claim 19, wherein said filter element has an open porosity of from about 30 volume percent to about 50 volume percent.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 08/220,558, filed Mar. 31, 1994, now U.S. Pat. No. 5,700,373, issued on Dec. 23, 1997, which is a continuation-in-part of Patent Cooperation Treaty Application No. PCT/US93/08835, filed Sep. 17, 1993, which designates the United States and is a continuation-in-part of U.S. patent application Ser. No. 07/946,972, filed Sep. 17, 1992, now abandoned.
Continuations (1)
|
Number |
Date |
Country |
Parent |
08996680 |
Dec 1997 |
US |
Child |
09803440 |
Mar 2001 |
US |
Continuation in Parts (3)
|
Number |
Date |
Country |
Parent |
08220558 |
Mar 1994 |
US |
Child |
08996680 |
Dec 1997 |
US |
Parent |
PCT/US93/08835 |
Sep 1993 |
US |
Child |
08220558 |
Mar 1994 |
US |
Parent |
07946972 |
Sep 1992 |
US |
Child |
08220558 |
Mar 1994 |
US |