Support structure for a catalyst in a combustion reaction chamber

• US 6,116,014 A
• Filed: 06/05/1995
• Issued: 09/12/2000
• Est. Priority Date: 06/05/1995
• Status: Expired due to Term

• Current Assignee: General Electric Company, International Engine Intellectual Property Company, LLC (Volkswagen AG)
• Original Assignee: Catalytica, Inc. (DSM-Firmenich AG), General Electric Company, Tanaka Kikinzoku Kabushiki Kaisha
• Inventors: Cutrone, Martin Bernard, Schlatter, James C., Dalla Betta, Ralph A., Beebe, Kenneth Winston
• Primary Examiner(s): Thorpe, Timothy
• Assistant Examiner(s): Kim, Ted
• Application Number:
  US08/462,639
• Time in Patent Office: 1,926 Days
• Field of Search: 60/39.06, 60/39.822, 60/39.31, 60/39.32, 60/723, 431/7, 431/170, 431/328, 502/527
• US Class Current: 60/777
• CPC Class Codes: F23C 13/00 Apparatus in which combustion takes place in the presence of catalytic material in a fluidised bed of catalytic particles F23C10/01; radiant gas burners using catalysis for flameless combustion F23D14/18
• CPC Class Codes: F23D 2203/104 Grids, e.g. honeycomb grids
• CPC Class Codes: F23D 2203/106 Assemblies of different layers
• CPC Class Codes: F23D 2203/107 coated with catalysts
• CPC Class Codes: F23R 3/40 characterised by the use of catalytic means

Abstract

A support structure for securing a catalyst structure comprising a multiplicity of longitudinally disposed channels for passage of a flowing gas mixture within a reactor, said support structure being comprised of a monolithic open celled or honeycomb-like structure formed by thin strips or ribs of high temperature resistant metal or ceramic which abuts against one end of the catalyst structure, and extends in a direction perpendicular to the longitudinal axis of the catalyst structure to essentially cover an end face (at either the inlet end or outlet end or both) of the catalyst structure with the support structure being secured on its periphery to the reactor wall. The strips or ribs making up the support structure are bonded together to form a unitary structure having cellular openings at least as large as the catalyst structure channel openings. The cellular openings in the support structure are also positioned to be in fluid communication with the channels of the catalyst structure thus affording essentially unaltered gas flow from the catalyst structure through the support structure.

Claims

1. A support structure for securing within a combustion reaction chamber, defined by a reaction chamber wall, a monolithic catalyst structure made up of a multiplicity of longitudinally disposed channels with inlet and outlet ends for passage of a flowing gas mixture, which exerts an axial load on the catalyst structure in the direction of gas flow, with the catalyst structure having a longitudinal axis in the direction of gas mixture flow, said support structure comprising a monolithic open cellular structure wherein the walls of the cells are formed by strips of a high temperature resistant metal or ceramic material to afford cellular openings which are at least as large as the openings formed by the catalyst structure channels at their inlet and outlet ends, said monolithic open cellular structure being:

(a) placed at the outlet end of catalyst structure, or at both the inlet end and the outlet end of the catalyst structure;

(b) positioned and configured to abut against one end of the catalyst structure and extend in a direction perpendicular to the longitudinal axis of the catalyst structure to essentially cover the end face of the catalyst structure, with the cellular openings of the monolithic open cellular structure being in fluid communication with the channels of the catalyst structure; and

(c) secured on an outer periphery to the reaction chamber wall by an attachment means fixed to the reaction chamber wall which holds the monolithic open cellular structure in place while allowing for differential thermal expansion of the monolithic open cellular structure in an outward direction towards the reaction chamber wall such that the axial load which is placed on the monolithic open cellular structure by the catalyst structure on passage of the flowing gas mixture is transferred to the reaction chamber wall thereby limiting axial movement of said catalyst structure in a direction parallel to the longitudinal axis of said catalyst structure.

2. The support structure of claim 1 wherein the monolithic open cellular structure is placed at the outlet end of the catalyst structure.

3. The support structure of claim 1 wherein the monolithic open cellular structure is placed at both the inlet end and the outlet end of the catalyst structure.

4. The support structure of claim 1, 2 or 3 wherein the cells of the open cellular structure are polygonal, elliptical or circular in shape.

5. The support structure of claim 4 wherein the cells are polygonal in shape.

6. The support structure of claim 5 wherein the polygonal cells are in the shape of trapezoids, triangles, rectangles, squares, or hexagons.

7. The support structure of claim 1 wherein the flow blockage relative to unobstructed gas flow provided by any single monolithic open cellular structure at the inlet or outlet end of the catalyst structure is less than about 25 percent.

8. The support structure of claim 7 wherein the flow blockage is between about 5 and 15 percent.

9. The support structure of claim 1 wherein the metal or ceramic strips making up the monolithic open cellular structure are from about 0.5 to 20 times as thick as the walls of the longitudinally disposed channels of the catalyst structure.

10. The support structure of claim 9 wherein the catalyst structure channel walls and the strips making up the monolithic open cellular structure are both comprised of a high temperature resistant metal material.

11. The support structure of claim 9 wherein the width of the strips making up the monolithic open cellular structure is between about 0.25 and 4 inches.

12. The support structure of claim 1, 2, 3, 10 or 11 wherein the deformation index for the monolithic open cellular structure is between about 0.0001 and 0.05.

13. The support structure of claim 1 wherein the open cells of the monolithic open cellular structure have an average cell size (cross-sectional area) ranging from about 0.03 in² to 2.0 in².

14. The support structure of claim 1 wherein the attachment means is selected from (a) an inwardly protruding ledge on the interior side of the reaction chamber wall on which one face side of the periphery of the monolithic open cellular structure rests in a slideable fashion to accommodate differential thermal expansion of the monolithic open cellular structure;

or (b) a series of rivets which extend through the reaction chamber wall into cavities on the peripheral surface of the monolithic open cellular structure with the difference in the depth of the cavities and length of the rivets being such that differential thermal expansion of the monolithic open cellular structure can be accommodated.

15. A method for securing within a combustion reaction chamber defined by a reaction chamber wall, a monolithic catalyst structure made up of a multiplicity of longitudinally disposed channels with inlet and outlet ends for passage of a flowing gas mixture and having a longitudinal axis in the direction of gas mixture flow, said flowing gas mixture exerting an axial load on the catalyst structure, which comprises inserting into the reaction chamber at the outlet end of the catalyst structure or at both the outlet end and inlet end of the catalyst structure, a monolithic open cellular structure in which the walls of the cells are formed by strips of a high temperature resistant metal or ceramic material to afford cellular openings which are at least as large as the openings formed by the catalyst structure channels at their inlet and outlet ends, said monolithic open cellular structure being:

(a) positioned and configured to abut against one end of the catalyst structure and extend in a direction parpendicular to the longitudinal axis of the catalyst structure to essentially cover the end face of the catalyst structure, with the cellular openings of the monolithic open cellular structure being in fluid communication with the channels of the catalyst structure; and

(b) secured on an outer periphery to the reaction chamber wall by an attachment means fixed to the reaction chamber wall which holds the monolithic open cellular structure in place while allowing differential thermal expansion of the monolithic open cellular structure in an outward direction towards to reaction chamber wall such that the axial load which is placed on the monolithic open cellular structure by the catalyst structure on passage of the flowing gas mixture is transferred to the reaction chamber wall thereby limiting axial movement of said catalyst structure.

16. A process for the combustion of a hydrocarbonaceous or other combustible fuel to form a hot gas product wherein the fuel is at least partially combusted, the process comprising the steps of:

(a) forming a mixture of the fuel with an oxygen-containing gas; and

(b) passing the oxygen-containing gas and fuel mixture as a flowing gas stream through a monolithic catalyst structure positioned in a combustion reaction chamber defined by a reaction chamber wall, said catalyst structure made up of a multiplicity of longitudinally disposed channels for passage of said flowing gas stream and having a longitudinal as in the direction of gas mixture flow, said catalyst structure being stablized in said reaction chamber by means of a monolithic open cellular structure in which the walls of the cells are formed by strips of a high temperature resistant metal or ceramic material to afford cellular openings which are at least as large as the openings formed by the catalyst structure channels at their inlet and outlet ends, said monolithic open cellular structure being;

(i) placed at the outlet end of catalyst structure or at both the inlet end and the outlet end of the catalyst structure;

(ii) positioned and configured to abut against one end of the catalyst structure and extend in a direction perpendicular to the longitudinal axis of the catalyst structure to essentially cover the end face of the catalyst structure, with the cellular openings of the monolithic open cellular structure being in fluid communication with the channels of the catalyst structure; and

(iii) secured on an outer periphery to the reaction chamber wall by an attachment means fixed to the reaction chamber wall which holds the monolithic open cellular structure in place while allowing for differential thermal expansion of the monolithic open cellular structure in an outward direction towards the reaction chamber wall thereby limiting the axial movement of said catalyst structure parallel to the longitudinal axis of said catalyst structure.

17. The process of claim 16 wherein the monolithic open cellular structure is placed at the outlet end of the catalyst structure.

18. The process of claim 16 wherein the monolithic open cellular structure is placed at both the inlet end and the outlet end of the catalyst structure.

19. The process of claim 16, 17 or 18 wherein the cells of the open cellular structure are polygonal, elliptical or circular in shape.

20. The process of claim 19 wherein the cells are polygonal in shape.

21. The process of claim 20 wherein the polygonal cells are in the shape of trapezoids, triangles, rectangles, squares, or hexagons.

22. The process of claim 16 wherein the flow blockage relative to unobstructed gas flow provided by any single monolithic open cellular structure at the inlet or outlet end of the catalyst structure is less than about 25 percent.

23. The process of claim 22 wherein the flow blockage is between about 5 and 15 percent.

24. The process of claim 16 wherein the metal or ceramic strips making up the monolithic open cellular structure are from about 0.5 to 20 times as thick as the walls of the longitudinally disposed channels of the catalyst structure.

25. The process of claim 24 wherein the catalyst structure channel walls and the strips making up the monolithic open cellular structure are both comprised of a high temperature resistant metal material.

26. The process of claim 24 wherein the width of the strips making up the monolithic open cellular structure is between about 0.25 and 4 inches.

27. The process of claims 16, 17, 18, 25 or 26 wherein the deformation index for the monolithic open cellular structure is between 0.0001 and about 0.05.

28. The process of claim 16 therein the open cells of the monolithic open cellular structure have an average cell size (cross-sectional area) ranging from about 0.03 in² to 2.0 in².

29. A support structure for securing within a combustion reaction chamber defined by a reaction chamber wall, a multi-stage monolithic catalyst structure made up of a multiplicity of longitudinally disposed channels with inlet and outlet ends from each stage for passage of a flowing gas mixture which exerts an axial load on the catalyst structure in the direction of gas flow with the catalyst structure having a longitudinal as in the direction of gas mixture flow, said support structure comprising a monolithic open cellular structure wherein the walls of the cells are formed by strips of a high temperature resistant metal or ceramic material to afford cellular openings which are at least a large as the openings formed by the catalyst structure channels at their inlet and outlet, ends, said monolithic open cellular structure being:

(a) placed at the outlet end of each stage of the catalyst structure, or at the inlet end of the first stage of the catalyst structure and the outlet end of one or more of the catalyst stages including the final catalyst stage in the catalyst structure;

(b) positioned and configured to abut against one end of the catalyst structure and extend in a direction perpendicular to the longitudinal axis of the catalyst structure to essentially cover the end face of the catalyst structure, with the cellular openings of the monolithic open cellular structure being in fluid communication with the channels for the catalyst structure; and

(c) secured on an outer periphery to the reaction chamber wall by an attachment means fixed to the reaction chamber wall which hold the monolithic open cellular structure in place while allowing for differential thermal expansion of the monolithic open cellular structure in an outward direction towards the reaction chamber wall such that the axial load which is placed on the monolithic open cellular structure by the catalyst structure on passage of the flowing gas mixture is transferred to the reaction chamber wall thereby limiting axial movement of said catalyst structure parallel to the longitudinal axis of said catalyst structure.