Cleanable high efficiency filter media structure and applications for use

• US 7,008,465 B2
• Filed: 06/16/2004
• Issued: 03/07/2006
• Est. Priority Date: 06/19/2003
• Status: Active Grant

• Current Assignee: Donaldson Company Incorporated
• Original Assignee: Donaldson Company Incorporated
• Inventors: Grafe, Timothy H., Gogins, Mark A., Graham, Kristine M.
• Primary Examiner(s): Chiesa, Richard L.
• Application Number:
  US10/869,459
• Publication Number:
  US 20040255783A1
• Time in Patent Office: 629 Days
• Field of Search: 555/24, 555/27, 555/28, 555/21, 554/97, 554/98, 55486-488, 553/00, 553/02, 553851-3856, 55D/IG.3, 55D/IG.33, 55D/IG.35, 96/67, 96/69, 962/26, 95/74, 95/78, 952/73, 95278-280, 952/86, 952/87, 210/767, 210/798, 210/411, 210/493.5, 210/501, 210/503, 210/505, 977/DIG.1
• US Class Current: 95/78
• CPC Class Codes: A47L 9/122 flat
• CPC Class Codes: A47L 9/127 tube- or sleeve-shaped
• CPC Class Codes: B01D 2271/027 Radial sealings
• CPC Class Codes: B01D 2275/10 Multiple layers
• CPC Class Codes: B01D 39/1623 of synthetic origin
• CPC Class Codes: B01D 39/18 the material being cellulose or derivatives thereof cork or peat B01D39/1646 ; making filter paper D21F11/14
• CPC Class Codes: B01D 39/2017 the material being filamentary or fibrous
• CPC Class Codes: B01D 46/0032 using electrostatic forces to remove particles, e.g. electret filters
• CPC Class Codes: B01D 46/10 Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
• CPC Class Codes: B01D 46/2411 Filter cartridges
• CPC Class Codes: B01D 46/4281 Venturi's or systems showing a venturi effect
• CPC Class Codes: B01D 46/521 using folded, pleated material
• CPC Class Codes: B01D 46/525 which comprises flutes
• CPC Class Codes: B01D 46/546 using nano- or microfibres
• CPC Class Codes: B01D 46/71 with pressurised gas, e.g. pulsed air
• CPC Class Codes: Y10S 55/03 Vacuum cleaner
• CPC Class Codes: Y10S 55/33 Gas mask canister
• CPC Class Codes: Y10S 55/35 Respirators and register filters

Abstract

An improved cartridge, typically in cylindrical or panel form that can be used in a dry or wet/dry vacuum cleaner. The cartridge is cleanable using a stream of service water, or by rapping on a solid object, or by using a compressed gas stream, but can provide exceptional filtering properties even for submicron particulate in the household or industrial environment. The cartridge has a combination of nanofiber filtration layer on a substrate. The nanofiber and substrate are engineered to obtain a maximum efficiency at reasonable pressure drop and permeability. The improved cartridge constitutes at least a substrate material and at least a layer including a non-woven, fine fiber separation layer.

Claims

1. A filter media comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of about 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5</sup> gm-cm<sup>−

2</sup>, an average pore size of about 0.01 to 100 microns and a thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd² to 350 lb-3000 ft², a layer thickness of about 0.001 to 0.2 inch, the overall filter substrate having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99.99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%.

2. The media of claim 1 wherein the substrate layer is electrostatically charged.

3. The media of claim 1 wherein the media is pleated and comprises a non-woven comprising spunbond fiber, cellulose fiber, melt blown fiber, glass fiber or blends thereof.

4. The media of claim 1 wherein the media comprises a scrim layer between the nanofiber layer and the substrate layer.

5. The media of claim 1 wherein the polymer comprises an addition polymer.

6. The media of claim 1 comprising a condensation polymer.

7. The media of claim 6 comprising a nylon polymer.

8. The media of claim 5 also comprising a resinous additive comprising an oligomer having a molecular weight of about 500 to 3000 and an aromatic character wherein the additive is miscible in the condensation polymer.

9. The media of claim 8 wherein the additive comprises an oligomer comprising a phenol.

10. The media of claim 6 wherein the polymer comprises the polymeric reaction product of a nylon 6 and a nylon copolymer comprising a cyclic lactam, a C_6-10 diamine monomer and a C_6-10 diacid monomer and a resinous additive comprising an oligomer having a molecular weight of about 500 to 3000 and an aromatic character wherein the additive is miscible in the condensation polymer.

11. A media composition of claim 10 wherein the polymeric reaction product comprises nylon 6,6 and the nylon copolymer.

119. The media of claim 1 wherein when tested under conditions of exposure for a test period of 16 hours to test conditions of 140°

F. air at a relative humidity of 100%, retains greater than 30% of the fiber changed for filtration purposes.

120. The media of claim 5 wherein the polymer is crosslinked.

121. The media of claim 5 wherein the polymer is a polyvinyl alcohol.

122. The media of claim 121 wherein the polyvinyl alcohol is crosslinked.

129. The filter of claim 1 wherein tested under conditions of exposure for a test period of 16 hours to test conditions of 140°

F. air at a relative humidity of 100%, retain greater than 30% of the fiber changed for filtration purposes.

130. The media of claim 1 wherein the polymer is crosslinked.

131. The media of claim 1 wherein the polymer is polyvinylalcohol.

132. The media of claim 131 wherein the polyvinylalcohol is crosslinked.

172. The media of claim 1 wherein the media is treated with an anti-microbial, anti-viral, or anti-mycotic agent.

12. A filter cartridge comprising a filter element comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of about 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5</sup> gm-cm<sup>−

2</sup>, an average pore size of about 0.01 to 100 microns and a thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup>, a layer thickness of about 0.001 to 0.2 inch, the overall filter substrate having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%, the cartridge having an overall design flow rate between about 5 and 10000 cubic feet per minute.

13. The cartridge of claim 12 wherein the cartridge comprises a flat panel cartridge.

14. The cartridge of claim 12 wherein the filter element is pleated.

15. The cartridge of claim 14 wherein the pleated filter element has pleats having a depth of about 0.25 to about 4 inches.

16. The cartridge of claim 12 wherein the cartridge comprises a cylindrical cartridge.

17. The cartridge of claim 16 wherein the cylindrical cartridge has a circumference of about 3 to about 50 inches.

18. The cartridge of claim 12 wherein the polymer comprises an addition polymer.

19. The cartridge of claim 12 comprising a condensation polymer.

20. The cartridge of claim 19 comprising a nylon polymer.

21. The cartridge of claim 18 also comprising a resinous additive comprising an oligomer having a molecular weight of about 500 to 3000 and an aromatic character wherein the additive is miscible in the condensation polymer.

22. The cartridge of claim 21 wherein the additive comprises an oligomer comprising a phenol.

23. The cartridge of claim 19 wherein the polymer comprises a polymeric composition of a polymeric reaction product of a nylon 6 and a nylon copolymer comprising a cyclic lactam, a C_6-10 diamine monomer and a C_6-10 diacid monomer, and a resinous additive comprising an oligomer having a molecular weight of about 500 to 3000 and an aromatic character wherein the additive is miscible in the condensation polymer.

24. The cartridge of claim 23 wherein the polymeric reaction product comprises nylon 6,6 and the nylon copolymer.

123. The cartridge of claim 18 wherein the polymer is crosslinked.

124. The cartridge of claim 18 wherein the polymer is a polyvinyl alcohol.

125. The cartridge of claim 124 wherein the polyvinyl alcohol is crosslinked.

133. The cartridge of claim 12 wherein the polymer is crosslinked.

134. The cartridge of claim 12 wherein the polymer is polyvinylalcohol.

135. The cartridge of claim 134 wherein the polyvinylalcohol is crosslinked.

173. The cartridge of claim 12 wherein the cartridge is treated with an anti-microbial, anti-viral, or anti-mycotic agent.

25. A vacuum cleaner comprising a 0.25 to 500 HP motor driving an air stream having a flow rate of 5 to 600 ft-min⁻

1 through a filter, the filter comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymeric material and having a fiber diameter of 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5</sup> gram-cm<sup>−

2</sup>, an average pore size of about 0.01 to 100 microns and a layer thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup>, a thickness of about 0.001 to 0.2 inch, the overall filter having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%.

174. The vacuum cleaner of claim 25 wherein the filter is treated with an anti-microbial, anti-viral, or anti-mycotic agent.

182. The vacuum cleaner according to claim 25 that further comprises a pulse-jet cleaning system to remove particulate collected in the filter.

183. The vacuum cleaner according to claim 182 wherein the pulse is directed in a direction opposite to the flow direction of the air in normal operation.

184. The vacuum cleaner according to claim 183 wherein the pulse removes greater than 50% of the particulate in the filter.

185. The vacuum cleaner according to claim 25 that further comprises a vibration cleaning system to remove particulate collected in the filter.

186. The vacuum cleaner according to claim 184 wherein the vibration is directed in a direction opposite to the flow direction of the air in normal operation.

187. The vacuum cleaner according to claim 185 wherein the vibration removes greater than 50% of the particulate in the filter.

26. A filter arrangement comprising a media pack having an element comprising first and second opposite flow faces and a plurality of flutes wherein in said media pack;

(a) each of said flutes have a first end portion adjacent to said first flow face and a second end portion adjacent to said second flow face;

(b) selected ones of said flutes being open at said first end portion and closed at said second end portion; and

selected ones of said flutes being closed at said first end portion and open at said second end portion

(c) said element comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5</sup> gram-cm<sup>−

2</sup>, an average pore size of about 0.01 to 10 microns and a thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup>, a layer thickness of about 0.001 to 0.2 inch, the overall filter having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%.

27. The filter of claim 26 wherein when tested under conditions of exposure for a test period of 16 hours to test conditions of 140°

F. air at a relative humidity of 100%, retains greater than 30% of the fiber changed for filtration purposes.

28. The filter of claim 26 wherein the polymer comprises an addition polymer.

29. The filter of claim 26 comprising a condensation polymer.

30. The filter of claim 29 comprising a nylon polymer.

31. The filter of claim 28 also comprising a resinous additive comprising an oligomer having a molecular weight of about 500 to 3000 and an aromatic character wherein the additive is miscible in the condensation polymer.

32. The filter of claim 31 wherein the additive comprises an oligomer comprising a phenol.

33. A filter according to claim 26 further including:

(a) a sealing system including a frame construction and a seal member;

(i) said frame arrangement including an extension projecting axially from one of said first and second flow faces;

(A) said extension comprises a hoop construction having an outer radial surface;

(ii) said seal member being supported by said extension of said frame arrangement;

(A) said seal member comprising a resilient seal; and

(B) said seal member being oriented against at least said outer radial surface.

34. A filter according to claim 33 wherein:

(a) said media pack and said frame construction have a circular cross-section.

35. A filter according to claim 33 wherein:

(a) said media pack and said frame construction have a race track shaped cross-section; and

(b) said frame construction includes radially supporting cross braces.

36. A filter according to claim 33 further including:

(a) a panel structure;

said media pack being mounted within said panel structure.

37. A filter according to claim 33 further including:

(a) a handle projecting from the first face of the media pack said handle being sized to accommodate a human hand.

38. A filter according to claim 33 further including:

(a) a sleeve member secured to and circumscribing said media pack;

(i) said sleeve member being oriented relative said media pack to extend at least 30% of said axial length of said media pack; and

(b) a seal member pressure flange at least partially circumscribing said media pack.

(i) said seal member pressure flange extending radially from said sleeve member and fully circumscribing said sleeve member.

126. The filter of claim 28 wherein the polymer is crosslinked.

127. The filter of the claim 28 wherein the polymer is a polyvinyl alcohol.

128. The filter of claim 127 wherein the polyvinyl alcohol is crosslinked.

136. The filter of claim 26 wherein the polymer is crosslinked.

137. The filter of claim 26 wherein the polymer is polyvinylalcohol.

138. The filter of claim 137 wherein the polyvinylalcohol is crosslinked.

175. The filter of claim 26 wherein the filter is treated with an anti-microbial, anti-viral, or anti-mycotic agent.

176. The method of claim 36 wherein the media is treated with an anti-microbial, anti-viral, or anti-mycotic agent.

39. A method for filtering air, the method comprising;

(a) directing air through a media pack at a rate of 5 to 10,000 cfm, the pack comprising a substrate having first and second opposite flow faces, the element comprising a plurality of flutes wherein in said media pack;

(i) said flutes have a first end portion adjacent to the first flow face and a second end portion adjacent to the second flow face;

(ii) selected ones of the flutes being open at the first end portion and closed at the second end portion; and

selected ones of the flutes being closed at the first end portion and open at the second end portion;

(iii) the element comprises a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5</sup> gram-cm<sup>−

2</sup>, an average pore size of about 0.01 to 100 microns and a layer thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup>, a thickness of about 0.001 to 0.2 inch, the overall filter having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%.

40. The method of claim 39 wherein the nanofiber, when tested under conditions of exposure for a period of 16 hours to test conditions of 1400°

F. air at a relative humidity of 100%, retains greater than 30% of the fiber unchanged for filtration purposes.

41. A method according to claim 40 wherein the method comprises a step of directing a pulse of air through the media pack to remove particulate collected in the pack.

42. A method according to claim 41 wherein the pulse is directed in a direction opposite to the flow direction of the air in normal operation.

43. A method according to claim 42 wherein the pulse removes greater than 50% of the particulate in the pack.

44. A method according to claim 39 wherein:

(a) the step of directing the air through a media pack includes directing the air into an air intake conduit of an engine rated at an engine intake air flow of about 50 to 500 cfm.

45. A method according to claim 39 wherein:

the step of directing the air through a media pack includes directing the air through a filter element including the media pack and a sealing system;

the sealing system comprising a frame arrangement and a seal member;

(i) the frame arrangement including an extension projecting axially from one of the first and second flow faces;

(ii) the seal member being supported by the extension of the frame arrangement; and

(iii) the seal member forming a radial seal between and against the extension and a duct in the engine air intake.

46. A method according to claim 39 wherein:

(a) the step of directing the air through a media pack includes directing the air into an air intake conduit of a gas turbine system.

47. A method according to claim 42 wherein:

(a) the step of directing the air into an air intake conduit of a gas turbine system includes directing the air into the air intake conduit of the gas turbine system including;

(i) a tube sheet having at least a single through hole;

(ii) a sleeve member removably and replaceably mounted trough the hole;

the media pack being held by the sleeve member;

(iii) a flange at least partially circumscribing the sleeve member; and

(iv) a seal member pressed between and against the flange and the tube sheet to form a seal therebetween.

48. A method according to claim 40 wherein:

(a) the step of directing the air through a media pack includes directing the air into an air intake of a fuel cell system including a filter assembly and a downstream fuel cell.

49. A method according to claim 48 wherein:

(a) the step of directing the air through a media pack includes directing the air into the air intake of the fuel cell system including the filter assembly upstream of the fuel cell, the filter assembly including;

(i) a housing having an inlet and an outlet, the inlet receiving dirty atmospheric air to the filter assembly, and the outlet receiving clean air from the filter assembly;

(A) the media pack being operably installed in the housing;

(ii) a sound suppression element within the housing;

the sound suppression element construction and arranged to attenuate at least 6 dB; and

the fuel cell having an air intake port;

the filter assembly constructed and arranged to provide clean air from the outlet of the filter assembly to the intake port of the fuel cell.

139. The method of claim 39 wherein the polymer is crosslinked.

140. The method of claim 39 wherein the polymer is polyvinylalcohol.

141. The method of claim 140 wherein the polyvinylalcohol is crosslinked.

188. The method of claim 40, wherein the method comprises a step of directing a vibration of air through the media pack to remove particulate collected in the media pack.

189. The method of claim 40 wherein the method comprises a step of directing a reverse pressure pulse of air through the media pack to remove particulate collected in the media pack.

190. The method of claim 189 wherein the vibration removes greater than 50% of the particulate in the media pack.

50. An air filter assembly comprising:

(a) a housing including an air inlet, an air outlet, a spacer wall separating said housing into a filtering chamber and a clean air chamber;

said spacer wall including a first air flow aperture therein;

(b) a first filter construction positioned in air flow communication with said first air flow aperture in said spacer wall;

said first filter construction including an extension of a pleated filter media composite defining a filter construction inner clean air chamber;

(i) said first filter construction being oriented with said filter inner clean air chamber in air flow communication with said spacer wall first air flow aperture;

(ii) said pleated filter media composite comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10^{31 5} gram-cm<sup>−

2</sup>, an avenge pore size of about 0.01 to 100 microns and a thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup>, a thickness of about 0.001 to 0.2 inch, the overall filter having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%; and

(c) a cleaning system comprising at least one of a pulse-jet cleaning system oriented to direct a pulse of air through said filter construction into said inner clean air chamber or a vibration cleaning system oriented to vibrate said filter construction inner clean air chamber.

51. The air filter assembly according to claim 50 that after exposure for a test period of 16 hours to test conditions of 140°

F. air and a relative humidity of 100% retains greater than 30% of the fiber unchanged for filtration purposes.

53. Au air filter assembly according to claim 50 wherein the polymer comprises an addition polymer.

56. An air filter assembly according to claim 50 further including:

(a) a first Venturi element mounted in said spacer wall first air flow aperture and positioned to project into said first filter construction inner clean air chamber; and

wherein

(i) said pulse-jet cleaning system includes a first blowpipe oriented to direct a pulse of air into said first Venturi element from said clean air chamber and toward said first filter construction.

57. An air filter assembly according to claim 50 wherein:

(a) said first filter construction includes a first end cap having a central aperture;

said extension of filter media being embedded within said first end cap.

58. An air filter assembly according to claim 50 wherein:

(a) said first filter construction includes first and second filter elements in axial alignment;

(i) said extension of a pleated filter media composite comprising a first extension of media in said first filter element and a second extension of media in said second filter element.

59. An air filter assembly according to claim 50 wherein;

(a) said spacer wall includes a second air flow aperture therein; and

wherein the assembly further includes;

(i) a second filter construction positioned in air flow communication with said second air flow aperture in said spacer wall;

said second filter construction including an extension of a pleated filter media composite defining a second filter construction inner clean air chamber;

(A) said second filter construction being oriented with said second filter inner clean air chamber in air flow communication with said spacer wall second air flow aperture; and

(B) said pleated filter media composite of said second filter construction including a substrate at least partially covered by a layer of fine fiber.

60. An air filter assembly according to claim 50 wherein:

(a) said spacer wall includes a second air flow aperture therein; and

wherein the assembly further includes;

(i) a second filter construction positioned in air flow communication with said second air flow aperture in said spacer wall;

said second filter construction including an extension of a pleated filter media composite defining a second filter construction inner clean air chamber;

(A) said second filter construction being oriented with said second filter inner clean air chamber in air flow communication with said spacer wall second air flow aperture; and

(B) said pleated filter media composite of said second filter construction including a substrate at least partially covered by a layer of fine fiber;

(ii) a second Venturi element mounted in said spacer wall second air flow aperture and positioned to project into said second filter construction inner clean air chamber;

(iii) a second blowpipe oriented to direct a pulse of air into said second Venturi element from said clean air chamber and toward said second filter construction.

142. The assembly of claim 50 wherein the polymer is crosslinked.

143. The assembly of claim 50 wherein the polymer is polyvinylalcohol.

144. The assembly of claim 143 wherein the polyvinylalcohol is crosslinked.

177. The air filter assembly of claim 50 wherein the filter is treated wit an anti-microbial, anti-viral, or anti-mycotic agent.

191. The air filter assembly of claim 51, wherein the pulse is directed in a direction apposite to the flow direction of the air in normal operation.

192. The air filter assembly of claim 191, wherein the pulse removes greater than 50% of the particulate in the filter.

52. An air filter assembly according to 50 wherein the polymer comprises a condensation polymer.

54. The air filter assembly according to claim 52 wherein the polymer comprises a nylon, other than a copolymer formed from a cyclic lactam and a C_6-10 diamine monomer or a C_6-10 diacid monomer, and a resinous additive comprising an oligomer having a molecular weight of about 500 to 3000 and an aromatic character wherein the additive miscible in the condensation polymer.

55. The air filter assembly of claim 52 wherein the condensation polymer comprises a nylon.

193. The air filter assembly according to claim 55, wherein the vibration is directed in a direction opposite to the flow direction of the air in normal operation.

194. The air filter assembly according to claim 193 wherein the vibration removes greater than 50% of the particulate in the filter.

61. A method for filtering air, the method comprising;

(a) directing the air through an inlet of a housing and into a filtering chamber;

the housing including a spacer wall separating the filtering chamber from a clean air chamber;

the spacer wall including a first air flow aperture therein;

(b) after directing the air into the filtering chamber, directing the air through an extension of a pleated filter composite of a first filter construction and into a filter construction inner clean air chamber;

the first filter construction being positioned in air flow communication wit the first air flow aperture in the spacer wall;

the extension of a pleated filter media composite defining the filter construction inner clean air chamber;

(i) the first filter construction being oriented with the filter inner clean air chamber in air flow communication with the spacer wall first air flow aperture;

(ii) the filter composite comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5</sup> gram-cm<sup>−

2</sup>, an avenge pore size of about 0.01 to 100 microns and a thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup>, a layer thickness of about 0.001 to 0.2 inch, the overall filter having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%; and

(e) after directing the air through an extension of a pleated filter media composite of a first filter construction and into a filter construction inner clean air chamber, directing the air into the clean air chamber and out of the housing.

62. The method of claim 61 wherein after exposure for a test period of 16 hours to test conditions of 140°

F. air and a relative humidity of 100% retains greater than 30% of the nanofiber is unchanged for filtration purposes.

63. A method according to claim 61 further including directing a pulse of air into the filter construction inner clean air chamber to at least partially remove particulates collected on the pleated filter media composite.

64. A method according to claim 63 wherein said step of directing a pulse of air into the filter construction inner clean air chamber to at least partially remove particulates collected on the pleated filter media composite includes directing the pulse of air into a Venturi element mounted to project into the first filter construction inner clean air chamber.

65. A method according to claim 61 wherein said housing spacer wall includes a plurality of extensions of pleated filter media composites of a plurality of filter constructions wherein each of the extensions of a pleated filter media composites define a respective filter construction inner clean air chamber.

66. A method according to claim 61 further including directing a series of pulses of air into each of the filter construction inner clean air chambers to at least partially remove particulates collected on each of the pleated filter media composites.

67. A method according to claim 63 wherein said step of directing a series of pulses of air into each of the filter construction inner clean air chambers to at least partially remove particulates collected on each of the pleated filter media composite includes directing the pulse of air into a plurality of Venturi elements each mounted to project into a respective filter construction inner clean air chamber.

68. A method according to claim 61 further Including vibrating the media to at least partially remove particulates collected on the pleated filter media composite.

145. The method of claim 61 wherein the polymer is crosslinked.

146. The method of claim 61 wherein the polymer is polyvinylalcohol.

147. The method of claim 146 wherein the polyvinylalcohol is crosslinked.

150. The filter of claim 147, wherein the polyvinylalcohol is crosslinked.

178. The method of claim 61 wherein the filter is treated with an anti-microbial, anti-viral, or anti-mycotic agent.

69. A filter structure for filtering air in a gas turbine intake system, the intake air having an ambient temperature and a humidity of at least 50% RH, the structure comprising, in an air intake of a gas turbine system, at least one filter element, the filter element having a media pack forming a tubular construction and construction defining an open filter interior, the open filter interior being a clean air plenum, the media pack including a pleated construction of a media composites the media composite including a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

1</sup> gram-cm<sup>−

2</sup>, an average pore size of about 0.01 to 100 microns and a thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup>, a layer thickness of about 0.001 to 0.2 inch, the overall filter having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%.

70. The structure of claim 69 wherein the fine fibers comprise a polymeric composition comprising an addition polymer or a condensation polymer.

71. The structure of claim 69 wherein the substrate comprises a cellulosic fiber, a synthetic fiber or mixtures thereof.

72. The structure of claim 70 wherein the condensation polymer comprises additive comprising an oligomer having a molecular weight of about 500 to 3000 and an aromatic character free of an alkyl moiety wherein the additive is miscible in the condensation polymer.

73. The structure of claim 70 wherein the condensation polymer comprises a nylon homopolymer, a nylon copolymer or mixtures thereof.

148. The filter of claim 69 wherein the polymer is crosslinked.

149. The filter of claim 69 wherein the polymer is polyvinylalcohol.

74. A method for filtering air in a gas turbine intake system, the turbine operating at a temperature of about 120°

F. to about 220°

F., the intake air having an ambient temperature and a humidity of at least 50% RH, the method comprising the steps of;

(a) installing a filter proximate an air intake of a gas turbine system, the filter comprising at least one filter element, the filter element having a media pack forming a tubular construction defining a open filter interior;

the open filter interior being a clean air plenum, the media pack including a pleated construction of a media composite, the media composite, comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5</sup> gram-cm<sup>−

2</sup>, an average pore size of about 0.01 to 100 microns and a thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup>, a thickness of about 0.001 to 0.2 inch, the overall filter having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%; and

(b) directing intake air into an air intake of a gas turbine system.

75. The method of claim 74 wherein the fine fibers comprise an addition polymer or a condensation polymer.

76. The method of claim 74 wherein the fine fiber comprises a condensation polymer and additive comprising an oligomer having a molecular weight of about 500 to 3000 and an aromatic character free of an alkyl phenolic moiety wherein the additive is miscible in the condensation polymer.

77. The method of claim 75 wherein the condensation polymer comprises a nylon polymer.

78. The method according to claim 75 wherein, said step of directing air into an air intake of a gas turbine system having at least one filter clement includes directing air into an air intake of a gas turbine system having a plurality of filter element pairs, each of the filter element pairs including a first tubular filter element with the media pack sealed against an end of a second tubular filter element with the media pack;

each of the first and second tubular filter elements defining the clean air plenum.

79. A method according to claim 74 wherein said step of directing air into an air intake of a gas turbine system having a plurality of filter element pairs includes directing air into the first tubular filter element and the second tubular filter element;

wherein the first tubular filter element is cylindrical and the second tubular filter element is conical.

80. A method according to claim 74 further including directing a pulse of air into each of the clean air plenums of each of the filter element pairs to at least partially remove particulates collected on each of the media packs.

151. The method of claim 74, wherein the polymer is crosslinked.

152. The method of claim 74, wherein the polymer is polyvinylalcohol.

153. The method of claim 152, wherein the polyvinylalcohol is crosslinked.

195. The method according to claim 74 further including directing a vibration of air into each of the clean air plenums of each of the filter element pairs to at least partially remove particulates collected on each of the media packs.

196. The method according to claim 195, wherein the vibration is directed in a direction opposite to the flow direction of air in normal operation.

197. The method according to claim 196, wherein the vibration removes greater than 50% of the particulate in the filter.

198. The method according to claim 79, wherein the pulse is directed in a direction opposite to the flow direction of air in normal operation.

199. The method according to claim 198, wherein the pulse removes greater than 50% of the particulate in the filter.

81. A method for filtering air in a gas turbine intake system, an intake air having an ambient temperature and a humidity of at least 50% RH,

(a) directing intake air into an air intake of a gas turbine system having at least one filter element, the filter element having a media pack forming a tubular construction and construction defining a open filter interior;

the open filter interior being a clean air plenum, the media pack including a pleated construction of a media composite, the media composite including a substrate at least partially covered by a layer of fine fibers, comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5</sup> gram-cm<sup>−

2</sup>, an average pore size of about 0.01 to 100 microns and a layer thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup>, a layer thickness of about 0.001 to 0.2 inch, the overall filter having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%; and

(b) directing the air through the media pack of the filter element and into the open filter interior to clean the air.

82. The method of claim 81 wherein the fine fibers comprising an additive polymer or a condensation polymer.

83. The method of claim 82 wherein the condensation polymer comprises a nylon.

84. The method according to claim 81 wherein, said step of directing air into an air intake of a gas turbine system having at least one filter element includes directing air into an air intake of a gas turbine system having a plurality of filter element pairs, each of the filter element pairs including a first tubular filter element with the media pack sealed against an end of a second tubular filter element with the media pack;

each of the first and second tubular filter elements defining the clean air plenum.

85. A method according to claim 81 wherein said step of directing air into an air intake of a gas turbine system having a plurality of filter element pairs includes directing air into the first tubular filter element and the second tubular filter element;

wherein the first tubular filter element is cylindrical and the second tubular filter element is conical.

86. A method according to claim 81 further including directing a pulse of air into each of the clean air plenums of each of the filter element pairs to at least partially remove particulates collected on each of the media packs.

154. The method of claim 81, wherein the polymer is crosslinked.

155. The method of claim 81, wherein the polymer is polyvinylalcohol.

156. The method of claim 155, wherein the polyvinylalcohol is crosslinked.

200. The method according to claim 81 further including directing a vibration of air into each of the clean air plenums of each of the filter element pairs to at least partially remove particulates collected on each of the media packs.

201. The method according to claim 200, wherein the vibration is directed in a direction opposite to the flow direction of air in normal operation.

202. The method according to claim 201, wherein the vibration removes greater than 50% of the particulate in the filter.

203. The method according to claim 86, wherein the pulse is directed in a direction opposite to the flow direction of air in normal operation.

204. The method according to claim 203, wherein the pulse removes greater than 50% of the particulate in the filter.

87. A filtration system for an enclosed locus of human habitation, the system comprising a filter cartridge comprising a filter element comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of about 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5</sup> gm-cm<sup>−

2</sup>, an average pore size of about 0.01 to 100 microns and a thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft^{31 2} a layer thickness of about 0.001 to 0.2 inch, the overall filter substrate having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%, the cartridge having an overall design flow rate between about 5 and 10000 cubic feet per minute.

88. The system of claim 87 wherein the cartridge comprises a flat panel cartridge.

89. The system of claim 87 wherein the filter media is pleated.

90. The system of claim 89 wherein the pleated filter media has pleats having a depth of about 0.25 to about 4 inches.

91. The system of claim 87 wherein the cartridge comprises a cylindrical cartridge.

92. The system of claim 91 wherein the cylindrical cartridge has a circumference of about 3 to about 90 inches.

93. The system of claim 87 wherein the system is in a military structure.

157. The method of claim 87, wherein the polymer is crosslinked.

158. The method of claim 87, wherein the polymer is polyvinylalcohol.

159. The method of claim 158, wherein the polyvinylalcohol is crosslinked.

179. The filtration system of claim 87 wherein the filter element is treated with an anti-microbial, anti-viral, or anti-mycotic agent.

205. The system according to claim 87 that further comprises a pulse-jet cleaning system to remove particulate collected in the filter.

206. The system according to claim 205 wherein the pulse is directed in a direction opposite to the flow direction of the air in normal operation.

207. The system according to claim 206 wherein the pulse removes greater than 50% of the particulate in the filter.

208. The system according to claim 87 that further comprises a vibration cleaning system to remove particulate collected in the filter.

209. The system according to claim 208 wherein the vibration is directed in a direction opposite to the flow direction of the air in normal operation.

210. The system according to claim 209 wherein the vibration removes greater than 50% of the particulate in the filter.

94. A filtration system for an enclosed portion of a human transportation conveyance, the system comprising a filter cartridge comprising a filter element comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of about 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5</sup> gm-cm<sup>−

2</sup>, an average pore size of about 0.01 to 100 microns and a thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup>, a layer thickness of about 0.001 to 0.2 inch, the overall filter substrate having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%, the cartridge having an overall design flow rate between about 5 and 10000 cubic feet per minute.

95. The system of claim 94 wherein the cartridge comprises a flat panel cartridge.

96. The system of claim 94 wherein the filter media is pleated.

97. The system of claim 96 wherein the pleated filter media has pleats having a depth of about 0.25 to about 4 inches.

98. The system of claim 94 wherein the cartridge comprises a cylindrical cartridge.

99. The system of claim 98 wherein the cylindrical cartridge has a circumference of about 3 to about 90 inches.

100. The system of claim 94 wherein the system is in a military vehicle.

101. The system of claim 100 wherein the vehicle is a tank, an armored personnel carrier, a truck, an ambulance, a self-propelled howitzer, a self-propelled missile launcher, an aircraft, a ship, or a High Mobility Multipurpose Wheeled Vehicle (HMMWV).

102. The system of claim 94 wherein the vehicle is an aircraft.

160. The system of claim 94, wherein the polymer is crosslinked.

161. The system of claim 94, wherein the polymer is polyvinylalcohol.

162. The system of claim 161, wherein the polyvinylalcohol is crosslinked.

180. The filtration system of claim 94 wherein the filter element is treated wit an anti-microbial, anti-viral, or anti-mycotic agent.

211. The system according to claim 94 that further comprises a pulse-jet cleaning system to remove particulate collected in the filter.

212. The system according to claim 211 wherein the pulse is directed in a direction opposite to the flow direction of the air in normal operation.

213. The system according to claim 212 wherein to pulse removes greater than 50% of the particulate in the filter.

214. The system according to claim 94 that further comprises a vibration cleaning system to remove particulate collected in the filter.

215. The system according to claim 214 wherein the vibration is directed in a direction opposite to the flow direction of the air in normal operation.

216. The system according to claim 215 wherein the vibration removes greater than 50% of the particulate in the filter.

103. A filtration system for a personal respirator, the system comprising a mask enclosing at least the mouth and nose, the mask comprising at least one air intake the intake, the intake comprising a filter cartridge comprising a filter element comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of about 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5 gm-cm31 2</sup>, an average pore size of about 0.01 to 100 microns and a thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup>, a layer thickness of about 0.001 to 0.2 inch, the overall filter substrate having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%, the cartridge having an overall design flow rate between about 0.2 and 3 cubic feet per minute.

104. The system of claim 103 wherein the cartridge comprises a flat panel cartridge.

105. The system of claim 103 wherein the filter media is pleated.

106. The system of claim 105 wherein the pleated filter media has pleats having a depth of about 0.125 to about 2 inches.

163. The system of claim 103, wherein the polymer is crosslinked.

164. The system of claim 103, wherein the polymer is polyvinylalcohol.

165. The system of claim 164 wherein the polyvinylalcohol is crosslinked.

181. The filtration system of claim 103 wherein the filter element is treated with an anti-microbial, anti-viral, or anti-mycotic agent.

108. A filtration system for a liquid having entrained particulate loading, the system comprising a conduit for a stream of the liquid and placed across the strem a filter cartridge comprising a filter element comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of about 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5</sup> gm-cm<sup>−

2</sup>, an average pore size of about 0.01 to 100 microns and a thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup>, a layer thickness of about 0.001 to 0.2 inch, the overall filter substrate having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%, the cartridge having an overall design flow rate between about 5 and 10000 cubic feet per minute.

107. The system of claim 108 wherein the system is in a military mask.

109. The system of claim 108 wherein the cartridge comprises a flat panel cartridge.

110. The system of claim 108 wherein the filter media is pleated.

111. The system of claim 110 wherein the pleated filter media has pleats having a depth of about 0.25 to about 4 inches.

112. The system of claim 108 wherein the cartridge comprises a cylindrical cartridge.

113. The system of claim 112 wherein the cylindrical cartridge has a circumference of about 3 to about 30 inches.

166. The system of claim 108, wherein the polymer is crosslinked.

167. The system of claim 108, wherein the polymer is polyvinylalcohol.

168. The system of claim 167, wherein the polyvinylalcohol is crosslinked.

217. The system according to claim 108 that further comprises a pulse-jet cleaning system to remove particulate collected in the filter.

218. The system according to claim 217 wherein the pulse is directed in a direction opposite to the flow direction of the air in normal operation.

219. The system according to claim 218 wherein the pulse removes greater than 50% of the particulate in the filter.

220. The system according to claim 108 that further comprises a vibration cleaning system to remove particulate collected in the filter.

221. The system according to claim 220 wherein the vibration is directed in a direction opposite to the flow direction of the air in normal operation.

222. The system according to claim 221 wherein the vibration removes greater than 50% of the particulate in the filter.

114. A filtration system for a liquid having entrained particulate loading, the system comprising a stream of the liquid having a crossflow path across filter surface, the filter comprising a filter element comprising a nanofiber layer and a high efficiency substrate layer;

the nanofiber layer comprising a polymer material and having a fiber diameter of about 0.01 to 0.5 micron, a basis weight of about 3×

10<sup>−

7</sup> to 6×

10<sup>−

5</sup> gm-cm<sup>−

2</sup>, an average pore size of about 0.01 to 100 microns and a thickness of about 0.05 to 50 microns;

the high efficiency substrate layer comprising a non-woven layer comprising a basis weight of about 0.2 oz-yd<sup>−

2</sup> to 350 lb-3000 ft<sup>−

2</sup> a layer thickness of about 0.001 to 0.2 inch, the overall filter substrate having a permeability of about 1 to 200 ft-min<sup>−

1</sup> at 0.5 inch (water) Δ

P, an efficiency in removing a 0.1 micron particle at 10 ft-min<sup>−

1</sup> of about 35 to 99,99995% and an efficiency in removing a 0.76 micron particle at 20 ft-min<sup>−

1</sup> of about 80 to greater than 98%, the cartridge having an overall design flow rate between about 5 and 10000 cubic feet per minute;

the filter passing a portion of the fluid and retaining the particulate.

115. The system of claim 114 wherein the cartridge comprises a flat panel cartridge.

116. The system of claim 114 wherein the particulate is recovered.

117. The system of claim 114 wherein the cartridge comprises a cylindrical cartridge.

118. The system of claim 117 wherein the cylindrical cartridge has a circumference of about 3 to about 30 inches.

169. The system of claim 114, wherein the polymer is crosslinked.

170. The system of claim 114, wherein the polymer is polyvinylalcohol.

171. The system of claim 170, wherein the polyvinylalcohol is crosslinked.

223. The system according to claim 114 that further comprises a pulse-jet cleaning system to remove particulate collected in the filter.

224. The system according to claim 223 wherein the pulse is directed in a direction opposite to the flow direction of the air in normal operation.

225. The system according to claim 224 wherein the pulse removes greater than 50% of the particulate in the filter.

226. The system according to claim 114 that further comprises a vibration cleaning system to remove particulate collected in the filter.

227. The system according to claim 226 wherein the vibration is directed in a direction opposite to the flow direction of the air in normal operation.

228. The system according to claim 227 wherein the vibration removes greater than 50% of the particulate in the filter.