Method for producing a sintered porous body

• US 6,365,092 B1
• Filed: 06/23/1999
• Issued: 04/02/2002
• Est. Priority Date: 06/23/1999
• Status: Expired due to Term

• Current Assignee: ABB Lummus Global Inc. (ABB Limited)
• Original Assignee: ABB Lummus Global Inc. (ABB Limited)
• Inventors: Fdhila, Rebei Bel, Rissanen, Markku, Backa, Stefan
• Primary Examiner(s): Fiorilla, Christopher A.
• Application Number:
  US09/338,060
• Time in Patent Office: 1,014 Days
• Field of Search: 264/640, 264/641, 264/628, 419/2
• US Class Current: 264/628
• CPC Class Codes: B01D 53/885 Devices in general for catalytic purification of waste gases
• CPC Class Codes: B01J 35/58 Fabrics or filaments
• CPC Class Codes: B01J 37/0018 Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)
• CPC Class Codes: C04B 14/38 Fibrous materials; Whiskers
• CPC Class Codes: C04B 2111/0081 as catalysts or catalyst carriers
• CPC Class Codes: C04B 24/24 Macromolecular compounds C04B24/14 takes precedence; macromolecular compounds comprising sulfonate or sulfate groups C04B24/16
• CPC Class Codes: C04B 30/02 containing fibrous materials
• CPC Class Codes: C04B 40/006 involving the elimination of excess water from the mixture
• CPC Class Codes: C04B 40/0071 making use of a rise in pressure
• CPC Class Codes: C04B 40/0268 Heating up to sintering temperatures C04B41/0072 takes precedence
• CPC Class Codes: C04B 41/502 Water

Abstract

A shaped sintered fibrous porous body exhibits a structure with a three-dimensional corrugated or undulating shape and porosity. The structure includes inorganic fibers joined as a sintered structure and is produced in one embodiment by: dispersing and suspending a fiber mixture including inorganic fibers and organic binder, such as cellulose fibers, or other organic compounds, in a liquid to form a fibrous slurry; forming a body including the fiber mixture by depositing the slurry on a shaped screen to thereby shape the fibrous body to a three-dimensional configuration simultaneously with the formation of the body; removing at least a part of the liquid from the fibrous body through the screen by a vacuum; drying the fibrous body in the ambient atmosphere or in a furnace; heating the dried fibrous body to a first elevated temperature where the organic binder is removed from the body; subsequently heating the dried body to a second elevated temperature where the inorganic fibers are partly fused to form a sintered porous fibrous body with a three-dimensional corrugated or undulating configuration. The body is suitable for use as or included in reactor elements to provide gas/condensed phase mass transfer areas in a system involving processing or teatment of gases and/or vapors through distillation, absorption and/or catalytic reactions or the like requiring gas/condensed phase mass transfer, The body is also for enhancing fluid-catalyst mass transfer at low pressure drop and contacting between fluids or combinations thereof in single phase catalytic reactors.

Claims

1. A method for producing a shaped three-dimensional sintered porous body comprising the steps of:

dispersing and suspending a fiber mixture comprising inorganic fibers and a liquid containing an organic binder to form a fibrous slurry;

applying the slurry to a three dimensional configured mesh sheet comprising through openings distributed throughout and over the surface of the mesh sheet forming from the slurry a wet fibrous three dimensional configured fibrous body comprising the fiber mixture attached to the sheet and complementary to the sheet configuration,

the applying step including spraying the slurry onto the mesh sheet and simultaneously de-watering the sprayed sheet to form a de-watered fibrous body;

drying the fibrous body attached to the sheet;

removing the binder from the dried fibrous body; and

subsequently fusing the inorganic fibers to form a sintered porous fibrous body with the three-dimensional configuration.

2. A method for producing a shaped three-dimensional sintered porous body comprising the steps of:

dispersing and suspending a fiber mixture comprising inorganic fibers and a liquid containing an organic binder to form a fibrous slurry;

applying the slurry to a three dimensional configured mesh sheet comprising through openings distributed throughout and over the surface of the mesh sheet forming from the slurry a wet fibrous three dimensional configured fibrous body comprising the fiber mixture attached to the sheet and complementary to the sheet configuration;

the applying the slurry step including dipping the mesh sheet into the slurry, applying a suction to the mesh sheet such that the slurry is de-watered through said mesh sheet forming the fibrous body on the sheet;

drying the fibrous body attached to the sheet;

removing the binder from the dried fibrous body; and

subsequently fusing the inorganic fibers to form a sintered porous fibrous body with the three-dimensional configuration.

3. A method for producing a shaped three-dimensional sintered porous body comprising the steps of:

dispersing and suspending a fiber mixture comprising inorganic fibers and a liquid containing an organic binder to form a fibrous slurry;

applying the slurry to a three dimensional configured mesh sheet comprising through openings distributed throughout and over the surface of the mesh sheet forming from the slurry a wet fibrous three dimensional configured fibrous body comprising the fiber mixture attached to the sheet and complementary to the sheet configuration;

said applying said slurry comprising injecting the slurry into a cavity including at least one surface formed by said mesh sheet to form the fibrous body within the cavity on the at least one surface and then dewatering the slurry contained in the cavity on the sheet with a suction;

drying the fibrous body attached to the sheet;

removing the binder from the dried fibrous body; and

subsequently fusing the inorganic fibers to form a sintered porous fibrous body with the three-dimensional configuration.

4. A method for producing a shaped three-dimensional sintered porous body comprising the steps of:

dispersing and suspending a fiber mixture comprising inorganic fibers and a liquid containing an organic binder to form a fibrous slurry;

applying the slurry to a three dimensional configured mesh sheet comprising through openings distributed throughout and over the surface of the mesh sheet forming from the slurry a wet fibrous three dimensional configured fibrous body comprising the fiber mixture attached to the sheet and complementary to the sheet configuration;

drying the fibrous body attached to the sheet;

removing the binder from the dried fibrous body;

subsequently fusing the inorganic fibers to form a sintered porous fibrous body with the three-dimensional configuration;

and then coating the sintered fibrous body with a catalyst.

5. The method according to claim 4 wherein the fiber mixture is dispersed and suspended in water to form a water-based slurry, and further including the step of de-watering the fibrous body.

6. The method according to claim 4 including forming said binder of any one of the group consisting of cellulose, organic resins including polyvinyl alcohol, polyurethanes, and styrenebutadiene latex, and thermosets, including epoxies, ureaformaldehyde resins, melamine-formaldehyde resins, and polyamide-polyamine epichlorohydrin resins.

7. The method according to claim 4 including controlling the ratio of binder to inorganic fiber in the fiber mixture such that the sintered body exhibits a predetermined porosity.

9. The method according to claim 4 wherein the fusing and sintering step includes heating the three dimensional configured fibrous body at a temperature below the melting point of the inorganic fibers but sufficiently high to achieve a partial fusion and a sintering of the contact surfaces between the fibers.

10. The method of claim 4 including forming apertures and fins on said body during said forming.

11. The method of claim 4 wherein the forming step includes simultaneously forming the body as a sheet member with a plurality of undulations.

12. The method according to claim 4 wherein the porous sheet member is a steel mesh cloth.

13. The method according to claim 4 further including wetting the dried fibrous body prior to removing the binder and then forming the wet body into a three dimensional shaped body.

14. The method according to claim 4 including forming the porous sheet member into a three dimensional configuration prior to applying the slurry so that the slurry is formed into the three dimensional configuration complementary to the support configuration.

15. The method according to claim 10 wherein the porous sheet member is a screen.

16. The method according to claim 4 including storing the dried body, later wetting the stored body, shaping the wet body into a three dimensional configuration and then continuing with the subsequent steps of removing the binder and fusing the inorganic fibers.

8. The method according to claim wherein the inorganic fibers are selected from the group consisting of any one or more of metallic fibers, ceramic fibers, glass fibers, carbon fibers and coated fibers.

17. A method for producing a shaped three-dimensional sintered porous body comprising the steps of:

dispersing and suspending a fiber mixture comprising inorganic fibers and a liquid containing an organic binder to form a fibrous slurry;

dispersing and suspending a catalytic material in the slurry

applying the slurry to a three dimensional configured mesh sheet comprising through openings distributed throughout and over the surface of the mesh sheet forming from the slurry a wet fibrous three dimensional configured fibrous body comprising the fiber mixture attached to the sheet and complementary to the sheet configuration;

drying the fibrous body attached to the sheet;

removing the binder from the dried fibrous body; and

subsequently fusing the inorganic fibers to form a sintered porous fibrous body with the three-dimensional configuration.

18. A method for producing a sintered porous body comprising the steps off:

forming a fibrous slurry of dispersed and suspended fiber mixture comprising inorganic fibers and a liquid containing an organic binder;

applying the slurry to a porous sheet member support of a given configuration to simultaneously form the slurry into a wet fibrous sheet member body comprising the fiber mixture attached to the support and complementary to the support configuration;

the applying step including applying a vacuum to one side of the sheet member, dipping the sheet member in the slurry to attract a layer of the slurry to a side of the sheet member opposite the one side with the vacuum and then withdrawing the sheet member from the slurry;

drying the fibrous body attached to the support;

removing the binder from the dried fibrous body; and

subsequently fusing the inorganic fibers to form a sintered porous fibrous body with the sheet member configuration.