Wicking fiber with solid particulates for a high surface area odor removing filter and method of making

• US 5,902,384 A
• Filed: 10/23/1997
• Issued: 05/11/1999
• Est. Priority Date: 12/23/1994
• Status: Expired due to Term

• Current Assignee: FRAM Group IP, LLC
• Original Assignee: Alliedsignal Inc.
• Inventors: Rohrbach, Ronald, Xue, Lixin, Jones, Gordon, Unger, Peter, Bause, Daniel, Dondero, Russell
• Primary Examiner(s): Chiesa, Richard L.
• Application Number:
  US08/956,549
• Time in Patent Office: 565 Days
• Field of Search: 261/104, 261/107, 261/99, 261/80, 261/94, 261/DIG. 17, 261/DIG. 65, 55/302, 55/303, 55/DIG. 5, 96/290, 96/294, 96/296, 96/181, 96/143, 96/144, 96/FOR 123, 96/FOR 124, 95/210-212, 95/159, 95/170, 95/171, 428/397, 428/398, 264/259, 264/241, 264/271.1, 264/273, 264/279, 264/279.1, 264/257, 264/DIG. 48
• US Class Current: 96/296
• CPC Class Codes: B01D 2253/304 Linear dimensions, e.g. particle shape, diameter
• CPC Class Codes: B01D 2257/90 Odorous compounds not provided for in groups B01D2257/00 - B01D2257/708
• CPC Class Codes: B01D 2259/40086 by using a purge gas B01D2259/4009 takes precedence
• CPC Class Codes: B01D 2259/4009 using hot gas
• CPC Class Codes: B01D 39/1623 of synthetic origin
• CPC Class Codes: B01D 47/028 by directing the gas through a wetted wire mesh or a perforated plate B01D47/14 takes precedence
• CPC Class Codes: B01D 50/60 Combinations of devices covered by groups B01D46/00 and B01D47/00
• CPC Class Codes: B01D 53/025 with wetted adsorbents; Chromatography analytical chromatography G01N30/00 - G01N30/96; for liquids B01D15/08
• CPC Class Codes: B01D 53/14 by absorption
• CPC Class Codes: B01J 20/28014 characterised by their form
• CPC Class Codes: B01J 20/28021 Hollow particles, e.g. hollow spheres, microspheres or cenospheres
• 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: B60H 2003/0691 Adsorption filters, e.g. activated carbon
• CPC Class Codes: B60H 3/06 Filtering B60H3/0078 takes precedence
• CPC Class Codes: B60H 3/0658 Filter elements specially adapted for their arrangement in vehicles B60H3/0608 takes precedence
• CPC Class Codes: Y10S 264/48 Processes of making filters
• CPC Class Codes: Y10S 55/05 Methods of making filter

Abstract

A unique filtration device (10) which continuously removes gas phase contaminants from an air stream through the use of partially hollow wicking fibers (20) impregnated with a fine solid powder and a selected chemisorptive liquid (18) which can capture the gas phase contaminants. The wicking fibers (20) are generally disposed to extend in the same direction and are formed into a filter element (12). The air stream to be cleaned is directed through filter element (12). The wicking fibers (20) include internal longitudinal cavities (22) filled with a fine powder and each having a relatively small longitudinal extending opening (24). The wicking fibers (20) are filled with the selected contaminant removing chemisorptive liquid through capillary action by which the individual wicking fibers (20) rapidly draw the selected chemisorptive liquid, with which they come into contact, through the internal cavities (22). The chemisorptive liquid and fine powder remains within the wicking fiber cavities (22) and generally does not enter the space between the wicking fibers yet through the longitudinal openings (24) the chemisorptive liquid is in full fluid communication with the air stream flowing past the fibers (20).

Claims

1. A filter using a fiber mat for removal of molecules from a fluid stream comprising:

a plurality of elongated fibers each having a longitudinally extending internal cavity including an opening from the internal cavity to the outer fiber surface;

a fine powder made from particles which are smaller than the opening disposed within the internal cavities of said plurality of elongated fibers;

said fine powder particles being of such a size, shape and makeup that they are securely retained within the internal cavity; and

,

a liquid chemisorptive agent having an affinity for the molecules to be removed from the fluid stream also disposed within the internal cavities of said plurality of elongated wicking fibers.

2. A filter as claimed in claim 1 wherein each elongated fiber is less than 250 microns in diameter and the majority of fine powder particles are less than 20 microns in size.

3. A filter as claimed in claim 1 wherein the longitudinally extending internal cavity in each of said plurality of elongated fibers is sized so that said liquid chemisorptive agent is retained within the cavity by capillary forces.

4. A filter as claimed in claim 1 wherein a plurality of internal cavities, each including an opening to the outer fiber surface, are formed in each fiber.

5. A filter as claimed in claim 1 wherein the diameter of said elongated fibers is less than 250 microns, the width of said elongated opening is less than one half the strand diameter and the average diameter of said plurality of solid particles is less than 10 microns.

6. A filter as claimed in claim 1 wherein said liquid chemisorptive agent comprises sodium permanganate in combination with either sodium carbonate or sodium phosphate.

7. A filter for removing a selected type of odor molecules from an air stream comprising:

a plurality of elongated fibers, each having an elongated open channel extending into the interior of the fiber, disposed to form a fiber filter mat;

a fine powder disposed within the elongated open channels of said plurality of elongated fibers; and

,

a liquid chemisorptive agent which has an affinity for the selected type of odor molecules to be removed from the air stream also disposed within the elongated open channels and having an exposed portion near the exterior of the fiber for absorbing the selected types of odor molecules as the air stream passes through the filter.

8. A device for continuously removing undesirable odor vapors from a first air stream and releasing them into a second air stream comprising:

a plurality of wicking fibers each including a longitudinally extending channel with a longitudinally extending opening;

a fine powder disposed within the longitudinally extending channels of said plurality of wicking fibers;

a liquid chemisorptive agent having an affinity for the undesirable odor vapors disposed within the longitudinally extending channels of said plurality of wicking fibers;

means for directing the first air stream across a part of said plurality of wicking fibers into contact with said liquid chemisorptive agent along said longitudinally extending openings whereby said liquid chemisorptive agent absorbs the undesirable odor vapors; and

,

said plurality of wicking fibers disposed to extend from the first air stream into the second air stream which strips away the undesirable odor vapors.

9. A device for continuously removing undesirable odor vapors as claimed in claim 8 wherein each elongated wicking fiber is less than 250 microns in diameter and the majority of fine powder particles are less than 20 microns in size.

10. A device for continuously removing undesirable odor vapors as claimed in claim 8 wherein the longitudinally extending internal cavity in each of said plurality of elongated fibers is sized so that said liquid chemisorptive agent is retained within the cavity by capillary forces.

11. A device for continuously removing undesirable odor vapors as claimed in claim 8 wherein a plurality of internal cavities, each including an opening to the outer fiber surface, are formed in each fiber.

12. A device for continuously removing undesirable odor vapors as claimed in claim 8 wherein the diameter of said elongated fibers is less than 250 microns, the width of said elongated opening is less than one half the strand diameter and the average diameter of said plurality of solid particles is less than 10 microns.

13. A device for continuously removing undesirable odor vapors as claimed in claim 8 wherein liquid chemisorptive agent comprises sodium permanganate in combination with either sodium carbonate or sodium phosphate.

14. A method of manufacturing a fiber strand impregnated with solid particles and a liquid chemisorptive agent for a filter comprising the steps of:

a. forming a fiber strand with an internal longitudinally extending cavity having a longitudinally extending opening, smaller than the cavity width, extending from the cavity to the fiber strand outer surface;

b. applying a plurality of solid particles to the strand;

c. forcing many of the solid particles into the internal longitudinally extending cavity where they are securely retained; and

,

d. bringing the fiber strand into contact with a liquid chemisorptive agent whereby the liquid chemisorptive agent is by capillary action drawn into the longitudinally extending cavity.

15. A method as claimed in claim 14 wherein the liquid chemisorptive agent comprises sodium permanganate in combination with sodium carbonate.

16. A method as claimed in claim 14 wherein the liquid chemisorptive agent comprises sodium permanganate in combination with sodium phosphate.

17. An air filtration system for removing gas phase contaminants comprising:

a plurality of fibers each having at least one longitudinally extending open channel projection into the interior of the fiber;

a plurality of small solid particles and a liquid chemisorptive agent which can adsorb the gas phase contaminants being disposed within the open channels in said plurality of fibers, and,

an air flow path containing the gas phase contaminants directed over a portion of said plurality of fibers whereby said plurality of small solid particles and said liquid chemisorptive agent disposed in the open channels communicates with the air flow path and adsorbs the gas phase contaminants.