# US 6,719,947 B1 · Composite porous media > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,719,947 B1 - Document ID: US6719947B1 - Status: Granted - Kind: B1 - Application number: 09/578,118 - Filed: 2000-05-24 - Granted: 2004-04-13 - Earliest claimed: 1998-05-08 - Assignees: Mott Metallurgical Corporation - Inventors: Sunil C. Jha; Kenneth L. Rubow; Cathy L. Cowan; Mark R. Eisenmann - Web page: https://patentgrep.com/patent/US6719947B1 ## CPC - B22F 3/114: {the porous products being formed by impregnation (B22F3/1137, B22F3/26 take precedence)} - B01D 39/2051: {Metallic foam} - B01D 39/2093: {Ceramic foam} - C04B 41/4582: {Porous coatings, e.g. coating containing porous fillers} - B22F 2998/10: Processes characterised by the sequence of their steps - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE ## Abstract A composite porous media for either gas or liquid flow is strong and efficient, and can readily be formed in or into a wide range of different shapes and configurations. In particular, the porous media is a composite of a metal, aerogel or ceramic foam (i.e., a reticulated inter-cellular structure in which the interior cells are interconnected to provide a multiplicity of pores passing through the volume of the structure, the walls of the cells themselves being substantially continuous and non-porous, and the volume of the cells relative to that of the material forming the cell walls being such that the overall density of the intercellular structure is less than about 30 percent theoretical density) the through pores of which are impregnated with a sintered powder or aerogel. The thickness, density, porosity and porous characteristics of the final composite porous media can be varied to conform with what is demanded by the intended use. ## Claims ### Claim 1 The method of making a composite porous media filter comprising: providing a foam having a reticulated, inter-cellular structure with a multiplicity of interconnected pores extending therethrough; impregnating pores of the foam with a powder to provide a composite; sintering said composite to form said media; and providing said media into a conduit to form a filter, the conduit including an inlet for receiving a fluid and an outlet for providing a filtered fluid. ### Claim 2 (depends on 1) The method of claim 1 wherein said foam is a ductile metal foam. ### Claim 3 (depends on 1) The method of claim 1, wherein the pores of the foam are impregnated with a powder in dry form, the method further comprising providing powder in dry form on a surface of the foam, said composite after sintering including a layer of sintered powder defining a surface of the composite. ### Claim 4 (depends on 1) The method of claim 1, wherein said foam has a density less than about 15 percent of theoretical density. ### Claim 5 (depends on 4) The method of claim 4, further comprising compressing said foam with said impregnated pores to increase the density thereof before sintering said composite. ### Claim 6 The method of making a composite porous media comprising: providing a foam having a reticulated, inter-cellular structure with a multiplicity of interconnected pores extending therethrough; impregnating pores of the foam with a powder to provide a composite; sintering said composite to form said media; and compressing said foam with said impregnated pores to increase the density thereof before sintering said composite wherein said compressing reduces the thickness of the foam with the pores thereof impregnated with powder to a thickness in the range of ⅓ to ⅔ of the thickness thereof before said compressing. ### Claim 7 The method of making a composite porous media comprising: providing a metal foam having a multiplicity of interconnected pores extending therethrough; impregnating pores of the foam with a powder and providing powder on a surface of the foam to provide a composite; compressing the foam to reduce the thickness of the foam to a thickness in the range of ⅓ to ⅔ of the thickness thereof before said compressing; and sintering said composite to form said media, said composite including a layer of sintered metal defining a surface of the composite; wherein said powder is a metal powder, wherein said layer has a thickness in the range of about 25% to about 75% of the total thickness of said composite. ### Claim 8 (depends on 1) The method of claim 1, wherein said foam is formed into a cylindrical tube before the impregnating. ### Claim 9 The method of making a composite porous media comprising: providing a foam having a reticulated, inter-cellular structure with a multiplicity of interconnected pores extending therethrough; impregnating pores of the foam with a powder to provide a composite; and sintering said composite to form said media, said composite including a layer of sintered metal defining a surface of the composite; wherein said foam is formed into a cylindrical tube before the impregnating, wherein said layer defines the outer cylindrical surface of said composite and has a thickness in the range of about 25% to about 75% of the total wall thickness of said tube. ### Claim 10 (depends on 9) The method of claim 9 wherein said thickness is in the range of about 50% to about 70%. ### Claim 11 (depends on 1) The method of claim 1, wherein said foam has in the range of 10 to 150 pores per inch. ### Claim 12 (depends on 11) The method of claim 11, wherein the composite is sintered to provide a porous structure having pores with a nominal size in the range of about 100 micrometers to about 0.1 micrometers. ### Claim 13 (depends on 1) The method of claim 1, including providing powder on a surface of said foam before said sintering, and wherein said composite includes a layer of sintered powder defining a surface of said composite. ### Claim 14 (depends on 1) The method of claim 1, wherein the foam and powder are made of metal. ### Claim 15 (depends on 1) The method of claim 1, where one of the foam and powder is made of ceramic. ### Claim 16 (depends on 1) The method of claim 1, where one of the foam and powder is made of an aerogel. ### Claim 17 (depends on 4) The method of claim 4, wherein the density of the foam is less than 15%. ### Claim 18 (depends on 17) The method of claim 17, wherein the density of the foam is less than 10%. ### Claim 19 (depends on 1) The method of claim 1, further comprising providing said powder in a dry state to a surface of said foam, and using vibration to cause the powder to impregnate the pores. ### Claim 20 (depends on 19) The method of claim 19, further comprising shaping the foam into a cylinder before providing said powder. ### Claim 21 (depends on 1) The method of claim 1, wherein the conduit includes a cylindrical tube.