Air-permeable filtration media, methods of manufacture and methods of use

• US 8,609,191 B2
• Filed: 02/10/2011
• Issued: 12/17/2013
• Est. Priority Date: 09/03/2004
• Status: Active Grant

• Current Assignee: Point Source Solutions Incorporated
• Original Assignee: Point Source Solutions Incorporated
• Inventors: Raetz, James A., Raetz, Gregory J.
• Primary Examiner(s): LAWRENCE JR, FRANK M
• Application Number:
  US13/024,597
• Publication Number:
  US 20110129603A1
• Time in Patent Office: 1,041 Days
• Field of Search: 961/34, 961/53, 961/54, 555/24, 55D/IG.5, 210/502.1, 210503-505, 428/221, 428/323, 427/180, 427/244, 427/294, 427/350
• US Class Current: 427/244
• CPC Class Codes: B01D 2239/0407 comprising particulate additives, e.g. adsorbents apparatus incorporating gas filtering material B01D46/0036
• CPC Class Codes: B01D 2239/0435 Electret apparatus incorporating such gas filtering material B01D46/0032
• CPC Class Codes: B01D 2239/0485 on particles
• CPC Class Codes: B01D 2239/10 Filtering material manufacturing
• CPC Class Codes: B01D 2239/1216 Pore size
• CPC Class Codes: B01D 2239/1233 Fibre diameter
• CPC Class Codes: B01D 2239/1241 Particle diameter
• CPC Class Codes: B01D 2253/102 Carbon
• CPC Class Codes: B01D 2253/106 Silica or silicates
• CPC Class Codes: B01D 2253/108 Zeolites
• CPC Class Codes: B01D 2253/202 Polymeric adsorbents
• CPC Class Codes: B01D 2253/206 Ion exchange resins
• CPC Class Codes: B01D 2253/304 Linear dimensions, e.g. particle shape, diameter
• CPC Class Codes: B01D 39/083 of organic material
• CPC Class Codes: B01D 39/1623 of synthetic origin
• CPC Class Codes: B01D 39/2055 Carbonaceous material solid sorbent compositions comprising free carbon B01J20/20
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: B01J 20/20 comprising free carbon; comprising carbon obtained by carbonising processes
• CPC Class Codes: B01J 20/28004 Sorbent size or size distribution, e.g. particle size
• CPC Class Codes: B01J 20/28019 Spherical, ellipsoidal or cylindrical
• CPC Class Codes: B01J 20/28023 : Fibres or filaments fibres or filaments in the form of membranes B01J20/28038; B01J20/28007 takes precedence
• CPC Class Codes: B01J 20/28028 : Particles immobilised within fibres or filaments
• CPC Class Codes: B01J 20/2803 : Sorbents comprising a binder, e.g. for forming aggregated, agglomerated or granulated products
• CPC Class Codes: B01J 20/28033 : Membrane, sheet, cloth, pad, lamellar or mat
• CPC Class Codes: B01J 20/28038 : Membranes or mats made from fibers or filaments
• CPC Class Codes: B01J 20/28078 : Pore diameter
• CPC Class Codes: Y10T 442/2861 : Coated or impregnated synthetic organic fiber fabric

Abstract

The present invention provides an air-permeable filtration media that includes an air-permeable backing and an adsorbent. The adsorbent is at least partially embedded in the air-permeable backing. The present invention also provides a method of manufacturing an air-permeable filtration media. The present invention also provides a method of substantially removing contaminants form air, employing the air-permeable filtration media.

Claims

1. A method of manufacturing an air-permeable filtration media, the method comprising:

entraining adsorbent particles, having an average particle size of about 1 micron or less across, in a gaseous carrier;

maintaining a pressure drop across a thickness of an air-permeable backing including a plurality of fibrous elements, sufficient to partially or substantially embed at least some of the entrained adsorbent particles within the air-permeable backing, without the use of a binding or adhesive composition, wherein the adsorbent particles substantially coat the plurality of fibrous elements;

enhancing an electrostatic filtration charge, wherein enhancing the electrostatic filtration charge consists of contacting an outer surface of an air-permeable backing with the gaseous carrier and entrained adsorbent particles; and

applying a negative pressure to the air-permeable backing, sufficient to remove excess adsorbent particles from the air-permeable backing and thereby retaining fixed adsorbent within the air-permeable backing.

2. The method of claim 1, wherein entraining the adsorbent particles in the gaseous carrier includes entraining adsorbent particles in the gaseous carrier in the substantial absence of fibrous material.

3. The method of claim 1, wherein entraining adsorbent particles in the gaseous carrier includes entraining substantially planar adsorbent particles in the gaseous carrier.

4. The method of claim 3, wherein each of the substantially planar adsorbent particles define a length and a width, and wherein a ratio of the length to the width is greater than about 20.

5. The method of claim 1, wherein the adsorbent particles include a material selected from a group consisting of:

activated carbon fiber, activated carbon particles, carbonized basil planes, carbonized particles, sodium silicate, zeolite particles, molecular sieves, porous polymer adsorbers, carbonized ion-exchangers, and combinations thereof.

6. The method of claim 1, wherein the absorbent particles substantially coat the plurality of fibrous elements on all sides of the fibrous elements.

7. The method of claim 1, wherein the absorbent particles substantially coat the plurality of fibrous elements and are evenly distributed throughout the air permeable filtration media.

8. The method of claim 1, wherein the air-permeable filtration media includes a pre- manufactured filtration media.

9. The method of claim 1, wherein the air-permeable filtration media includes raw bulk media.

10. The method of claim 3, wherein each of the substantially planar adsorbent particles define a length and a width, and wherein a ratio of the length to the width is greater than about 1.