Claims
- 1. In a housing for a honeycomb body, the improvement comprising:
a jacket tube having an inner wall surface with sections; and a passivation layer disposed in at least one of said sections of said inner wall surface for deliberately preventing joining of said jacket tube to the honeycomb body.
- 2. The housing according to claim 1, wherein said passivation layer is an oxide surface layer.
- 3. The housing according to claim 1, wherein said passivation layer is an applied ceramic layer.
- 4. The housing according to claim 1, wherein said ceramic layer has aluminum oxide.
- 5. The housing according to claim 1, wherein said passivation layer is an all-round strip.
- 6. The housing according to claim 1, wherein said jacket tube has a shape selected from the group consisting of oval and elliptical, and said jacket tube has a more-sharply-curved jacket-tube section in which said passivation layer is disposed.
- 7. The housing according to claim 1, wherein said passivation layer has an axial length of from 5 mm to 50 mm.
- 8. The housing according to claim 1, wherein said passivation layer has a thickness of from 30 μm to 120 μm.
- 9. The housing according to claim 1, wherein said passivation layer is an applied ceramic layer, and an adhesive layer is disposed between said jacket tube and said applied ceramic layer.
- 10. The housing according to claim 1, including a layer of brazing material disposed on said passivation layer.
- 11. The housing according to claim 10, wherein said layer of brazing material is an all-round layer on said passivation layer.
- 12. A catalyst carrier body, comprising:
a honeycomb body having an axial partial region and layers of sheet metal being at least partly structured to form channels in said honeycomb body through which an exhaust gas can flow; a housing having a jacket tube at least partially surrounding said honeycomb body and joined to said honeycomb body at least in said axial partial region, said jacket tube having an inner wall surface with sections; and a passivation layer disposed in at least one of said sections of said inner wall surface for deliberately preventing joining of said jacket tube to said honeycomb body in said at least one section.
- 13. The catalyst carrier body according to claim 12, wherein said honeycomb body has an end surface, and said passivation layer is disposed in the vicinity of said end surface.
- 14. The catalyst carrier body according to claim 12, wherein said layers of sheet metal of said honeycomb body have radially outer end regions resting against said passivation layer.
- 15. The catalyst carrier body according to claim 14, wherein said end regions resting against said passivation layer are joined to one another.
- 16. The catalyst carrier body according to claim 12, wherein said honeycomb body is brazed to said jacket tube.
- 17. The catalyst carrier body according to claim 12, wherein said honeycomb body is brazed to said jacket tube by high-temperature vacuum brazing.
- 18. A method for the production of a catalyst carrier body, which comprises:
forming a honeycomb body with an axial partial region by at least one of stacking and winding layers of sheet metal being at least partly structured to form channels in the honeycomb body through which an exhaust gas can flow; producing a jacket tube having an inner wall surface with sections; forming a passivation layer on at least one of the sections of the inner wall surface of the jacket tube, for deliberately preventing a brazed joint between the jacket tube and the honeycomb body; supplying at least partial regions of the inner wall surface of the jacket tube with brazing material; introducing the honeycomb body into the jacket tube and at least partially surrounding the honeycomb body with the jacket tube; and forming brazed joints between the jacket tube and the honeycomb body at least in the axial partial region.
- 19. The method according to claim 18, which further comprises producing the passivation layer by selective, spatially limited heating of the at least one section.
- 20. The method according to claim 19, which further comprises inductively heating the at least one section.
- 21. The method according to claim 18, which further comprises supplying the at least one section with a stream of oxygen-containing gas during the production of the passivation layer.
- 22. The method according to claim 18, which further comprises supplying the jacket tube with a stream of a noble gas outside the at least one section during the production of the passivation layer.
- 23. The method according to claim 18, which further comprises supplying the jacket tube with a stream of argon gas outside the at least one section during the production of the passivation layer.
- 24. The method according to claim 18, which further comprises producing the passivation layer by chemical treatment of the at least one section.
- 25. The method according to claim 18, which further comprises producing the passivation layer by forming an applied ceramic layer to the at least one section of the inner wall surface.
- 26. The method according to claim 18, which further comprises producing the passivation layer by forming an applied aluminum oxide layer to the at least one section of the inner wall surface.
- 27. The method according to claim 25, which further comprises applying an adhesive layer to the at least one section before the formation of the applied ceramic layer.
- 28. The method according to claim 27, which further comprises flame-spraying the passivation layer as the applied ceramic layer formed on the jacket tube.
- 29. The method according to claim 18, which further comprises applying an adhesive before supplying the inner wall surface of the jacket tube with brazing material, to produce a layer of the brazing material.
- 30. The method according to claim 29, which further comprises applying the adhesive to the passivation layer.
- 31. The method according to claim 18, which further comprises applying powdered brazing material to an end of the honeycomb body before introducing the honeycomb body into the jacket tube.
- 32. The method according to claim 18, which further comprises applying powdered brazing material to an end of the honeycomb body after introducing the honeycomb body into the jacket tube.
- 33. The method according to claim 18, which further comprises producing the passivation layer by roughening the inner wall surface in the at least one section.
- 34. The method according to claim 33, which further comprises performing the roughening step by at least one of sandblasting and brushing.
Priority Claims (2)
Number |
Date |
Country |
Kind |
100 18 641.6 |
Apr 2000 |
DE |
|
100 26 697.5 |
May 2000 |
DE |
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of copending International Application No. PCT/EP01/04220, filed Apr. 12, 2001, which designated the United States and was not published in English.
Continuations (1)
|
Number |
Date |
Country |
Parent |
PCT/EP01/04220 |
Apr 2001 |
US |
Child |
10271421 |
Oct 2002 |
US |