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AssigneeW. L. Gore & Associates, Inc.
InventorsMarc Plinke, Robert L. Sassa, William P. Mortimer, Jr., Glenn A. Brinckman
Estimating the term…
A method of using an improved catalytic filter material for removing contaminants such as NO.sub.x from a fluid stream. The filter employs composite fibers of expanded polytetrafluoroethylene (PTFE) filled with catalytic particles. The composite fibers are chopped into staple fibers and made into a felt material. Preferably, the felt material is then laminated on at least one side with a protective microporous membrane. The combined filter removes both macro-particles, such as dust, from the filter stream before the dust can clog active catalytic sites and effectively catalytically coverts undesirable contaminants in the fluid stream to acceptable end products.
A method of using a catalytic filter comprising a coherent catalytic filter material and microporous membrane, said method comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Filter cloth, i.e. woven, knitted or interlaced material: of organic material
The material being particulate: of synthetic origin
Of organic material, e.g. synthetic fibres: other shaped material, e.g. perforated or porous sheets
Handling or mounting catalysts: devices in general for catalytic purification of waste gases
Term ended 15 Aug 2015 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
1. Field of the Invention
The present invention relates to a chemically and/or catalytically active particulate and gas filtration materials, such as those used in flue gas cleaning processes.
2. Description of Related Art
The operation of the present invention should become apparent from the following description when considered in conjunction with the accompanying drawings, in which:
FIG. 1 is a scanning electron micrograph (SEM) of a number of catalyst loaded expanded polytetrafluoroethylene (ePTFE) fibers employed in the present invention, enlarged 100 times;
FIG. 2 is a scanning electron micrograph (SEM) of a catalyst loaded fiber employed in the present invention, enlarged 1,000 times;
The current invention is an improved catalytic filter material. With this filter, pollutant gas components, such as NOx, Dioxin/Furan, CO, and others, can be catalytically altered (i.e., reduced or oxidized) into non-polluting or less polluting gas components. In addition, particulates in the gas stream can be separated and collected in the filter with high efficiencies.
The present invention is directed to a wide variety of filter applications. The terms "filter" and "filtration" as used in the present application is intended to encompass any device that blocks or traps particles and/or modifies particles or molecules passing through the device. The use of the term "fluid" in the present invention is intended to encompass any form of readily flowing material, including liquids and gases.
FIGS. 1 through 3 show catalytic fibers 10 of the present invention at three different magnification levels. The fiber 10 comprises an expanded polytetrafluoroethylene (ePTFE) that is composed of polymeric nodes 12 and interconnecting fibrils 14. The production of this basic expanded PTFE structure is taught in a number of patents, including U.S. Pat. Nos. 3,953,566, 3,962,153, 4,096,227, and 4,187,390, all incorporated by reference. By the terms "fibrils" and "nodes," it is intended to define a wide variety of materials such as those made in accordance with these patents and improvements thereto. "Fibrils" are intended to define small polymeric strands (such as, on the order of a few microns or less in diameter). "Nodes" are intended to define any structure attached to such fibrils, from relatively large polymer masses or particles (such as, up to 10 to 50 microns or more across) to mere intersect points of two or more fibrils.