WO2006084106A1 - Filtre de ventilation permettant de reduire la diffusion de contaminants - Google Patents

Filtre de ventilation permettant de reduire la diffusion de contaminants Download PDF

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Publication number
WO2006084106A1
WO2006084106A1 PCT/US2006/003803 US2006003803W WO2006084106A1 WO 2006084106 A1 WO2006084106 A1 WO 2006084106A1 US 2006003803 W US2006003803 W US 2006003803W WO 2006084106 A1 WO2006084106 A1 WO 2006084106A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
breather filter
valve
filter
filter assembly
Prior art date
Application number
PCT/US2006/003803
Other languages
English (en)
Inventor
Brian Babcock
Amy Butterfield
Katsushi Isogawa
Carl Soldner
Original Assignee
Donaldson Company, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Donaldson Company, Inc. filed Critical Donaldson Company, Inc.
Priority to CN2006800073190A priority Critical patent/CN101137426B/zh
Priority to JP2007554232A priority patent/JP2008528286A/ja
Publication of WO2006084106A1 publication Critical patent/WO2006084106A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/10—Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
    • B01D46/106—Ring-shaped filtering elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/0027—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with additional separating or treating functions
    • B01D46/0036—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with additional separating or treating functions by adsorption or absorption
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/42—Auxiliary equipment or operation thereof
    • B01D46/4272—Special valve constructions adapted to filters or filter elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
    • B01D53/04—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with stationary adsorbents
    • B01D53/0407—Constructional details of adsorbing systems
    • B01D53/0431—Beds with radial gas flow
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B33/00—Constructional parts, details or accessories not provided for in the other groups of this subclass
    • G11B33/14—Reducing influence of physical parameters, e.g. temperature change, moisture, dust
    • G11B33/1446—Reducing contamination, e.g. by dust, debris
    • G11B33/146—Reducing contamination, e.g. by dust, debris constructional details of filters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/10—Inorganic adsorbents
    • B01D2253/102—Carbon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/25—Coated, impregnated or composite adsorbents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/80—Water
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/26—Drying gases or vapours
    • B01D53/261—Drying gases or vapours by adsorption

Definitions

  • the present invention relates to a filter for an electronic enclosure. More specifically, the present invention relates to breather filters that can reduce or prevent ingress of contaminants by diffusion.
  • Hard disk drives and other electronic equipment are often placed within enclosures to provide a clean environment that is necessary for optimal operation of the equipment.
  • contaminants may still enter the electronic enclosure from an external source or may be generated from within the enclosure during use.
  • Contaminants, including particles, gases such as water vapor, and liquids can gradually damage the drive, cause deterioration in performance, and in certain situations can even cause sudden and complete drive failure.
  • the air in the enclosure When a disk drive or other electronic equipment is in operation, the air in the enclosure often heats up and increases the air pressure in the enclosure. As a result of increased air pressure, air escapes from the enclosure if it has a breather hole or if it is not sealed airtight. Conversely, when a disk drive or other electronic equipment ceases to be in operation, the air in the enclosure cools down and decreases the air pressure in the enclosure. As a result of the decreased air pressure, air moves into the drive if it is has a breather hole or if it is not sealed airtight. If contaminants are present in the air moving into the enclosure, the interior of the enclosure can become contaminated.
  • Breather filters are frequently used to prevent contaminants carried by exchanged air from entering electronic enclosures. Breather filters can be positioned over a breather hole to remove contaminants from air entering the enclosure.
  • Many breather filter designs include a fluid communication path between the exterior environment and the interior of the electronic enclosure that is always open to the passage of air. Thus, air can move through the breather filter to equalize any air pressure differential that may arise between the inside and the outside of the electronic enclosure.
  • the fluid communication path is always open, contaminants can move through the path by the process of diffusion even absent the ingress or egress of air.
  • the present invention relates to breather filters that can reduce or prevent ingress of contaminants into an electronic enclosure.
  • the invention includes a breather filter assembly including a valve.
  • the valve including a first layer defining a first aperture, a second layer defining a second aperture, and a third layer disposed between the first and second layers, the third layer including filtration media.
  • the third layer can be attached to one of the first and second layers.
  • the first layer can be configured to flex away from the second layer creating an air gap between the first layer and the third layer.
  • the invention includes a breather filter for an electronic enclosure including a first layer, a second layer, a filter element disposed between the first layer and the second layer, and a valve assembly comprising a first side and a second side.
  • the valve assembly has an open configuration and a closed configuration.
  • the valve assembly is configured to change from the closed configuration to the open configuration when an air pressure differential between the first side and the second side exceeds a threshold amount.
  • the invention includes a valve assembly for a breather filter including a first layer defining a plurality of pores, and a second layer also defining a plurality of pores.
  • the valve assembly can be configured to assume a closed position and an open position; such that the first layer and the second layer are adjacent to each other with the pores unaligned in the closed position. In the open position, an air gap separates a portion of the first layer from a portion of the second layer.
  • the invention includes a breather filter assembly including a base layer, a valve layer, and a filtration media layer. The filtration media layer can be disposed between the base layer and the valve layer.
  • the valve layer can include a first layer defining a plurality of inner pores and a second layer defining an outer flap.
  • the first layer can be adjacent the second layer and the outer flap can be disposed over the inner pores.
  • the outer flap can be configured to flex away from the inner pores.
  • FIG. 1 is a perspective view of a filter in accordance with an embodiment of the invention.
  • FIG. 2 is a top schematic view of the filter of FIG. 1.
  • FIG. 3 is cross-sectional view of the filter of FIG. 1, taken along line A-A' of FIG. 2.
  • FIG. 4 is a cross-sectional view of a passive valve in a closed state in accordance with an embodiment of the invention.
  • FIG. 5 is a cross-sectional view of the passive valve of FIG. 4 in an open state.
  • FIG. 6 is a perspective view of a filter in accordance with an embodiment of the invention.
  • FIG. 7 is a top schematic view of the filter of FIG. 6.
  • FIG. 8 is cross-sectional view of the filter of FIG. 6, taken along line B-B' of FIG. 7.
  • FIG. 9 is a cross-sectional view of the filter of FIG. 6, showing the passage of air through the filter.
  • FIG. 10 is a cross-sectional view of a filter in accordance with an embodiment of the invention attached to the outside of an electronic enclosure.
  • FIG. 11 is a cross-sectional view of a filter in accordance with an embodiment of the invention attached to the inside of an electronic enclosure.
  • FIG. 12 is a perspective view of the filter shown in FIG. 11.
  • FIG. 13 is a cross-sectional view of another filter in accordance with an embodiment of the invention.
  • FIG. 14 is an enlarged cross-sectional view of a portion of the filter of FIG. 13.
  • FIG. 15 is a cross-sectional view of a portion of the filter of FIG. 13 showing the passage of air through the filter.
  • FIG. 16 is another cross-sectional view of a portion of the filter of FIG. 13 showing the passage of air through the filter.
  • FIG. 17 is a cross-sectional view of another filter in accordance with an embodiment of the invention.
  • valve as used herein shall refer to a device by which the flow of a fluid may be started and stopped, or at least moderated, by a movable part that opens, shuts, or obstructs one or more fluid flow ports or passageways.
  • active valve shall refer to a valve wherein opening and closing of the valve is actuated by a means external to the valve itself, such as by mechanical, hydraulic, pneumatic, electric, or electromagnetic actuation.
  • Passive valve shall refer to a valve wherein opening and closing of the valve is directly actuated by pressure forces in the fluid flow stream that the valve controls.
  • adsorbent and "absorbent” as used herein shall both refer to either absorbent or adsorbent materials, unless the specific context indicates to the contrary. That is, the specific nature of the interaction between the captured contaminant and the filter material, is not referenced.
  • Embodiments of the present invention include breather filters that can reduce or prevent ingress of contaminants by diffusion. Some embodiments of the invention include valves that open when a threshold air pressure differential exists so that air pressure can be equalized but close when a threshold air pressure differential does not exist so that ingress of contaminants into the breather filter and/or the electronic enclosure by diffusion is prevented or reduced.
  • FIG. 1 is a perspective view of a filter 100 in accordance with an embodiment of the invention.
  • the filter 100 has a top layer 104 and an air valve assembly 102.
  • the top layer 104 is made of a substantially fluid impermeable material, such as a barrier film.
  • the air valve assembly 102 opens when the pressure differential between the two sides of the valve reaches a threshold.
  • the air valve assembly 102 can be constructed so that the threshold is set at a desired pressure differential.
  • FIG. 2 is a top view of the filter of FIG. 1.
  • the air valve assembly 102 is disposed in the middle of the top layer 104. However, it will be appreciated that the air valve assembly 102 can also be offset from the middle of the top layer 104.
  • FIG. 3 is a cross-sectional view of the filter 100 of FIG. 1, taken along line A-A' of FIG. 2 and attached to an electronic enclosure 112. It will be appreciated that the filter 100 can be attached to the electronic enclosure 112 using any conventional technique including the use of adhesives or mechanical fasteners.
  • the air valve assembly 102 is aligned with a breather port 110 in the electronic enclosure 112.
  • the top layer 104 of the filter is adjacent to the inner surface 114 of the electronic enclosure 112.
  • the filter is attached to the inside of the electronic enclosure 112.
  • the filter can also be attached to the outside of the electronic enclosure 112 in alternative embodiments.
  • the peripheral edges of the top layer 104 are attached to the peripheral edges of a bottom layer 106.
  • the air valve assembly 102 only opens when the air pressure on the top side 116 of the air valve assembly 102 is greater than the air pressure on the bottom side 118 of the air valve assembly 102 by a threshold amount. In other embodiments, the valve assembly 102 only opens when the air pressure on the top side 116 of the air valve assembly 102 is less than the air pressure on the bottom side 118 of the air valve assembly 102 by a threshold amount. In still other embodiments, the valve assembly 102 opens when the air pressure on the top side 116 of the air valve assembly 102 is either greater than or less than the air pressure on the bottom side 118 of the air valve assembly 102 by a threshold amount.
  • the bottom layer 106 can be a fluid permeable membrane.
  • the bottom layer 106 is an expanded polytetrafluoroethylene (PTFE) membrane.
  • the bottom layer 106 is made of a substantially fluid impermeable material but has one or more apertures (not shown).
  • a filter element 108 is disposed between the top layer 104 and the bottom layer 106.
  • the filter element 108 can include various types of filter media (including activated carbon) depending on what types of contaminants are to be removed by the breather filter. Various types of filter media are described in more detail below.
  • the filter element 108 can optionally be contained inside a scrim. In some embodiments, the filter element 108 can absorb water vapor.
  • the total thickness of the breather filter is less than about 5 millimeters. In a particular embodiment, the total thickness of the breather filter is less than about 3 millimeters, optionally less than 2 millimeters, and in some embodiments less than 1 millimeter.
  • the filter shown in FIG. 3 can function to allow air to pass through as necessary to prevent a large pressure differential from building up between the inside and the outside of the electronic enclosure.
  • the air pressure on the bottom 118 of the air valve assembly 102 when the air pressure on the bottom 118 of the air valve assembly 102 is greater than on the top 116 of the air valve assembly, air can pass through the bottom layer 106, filter element 108, and the air valve assembly 102 and then out of the breather port 110 in the electronic enclosure 112. When the air flows out in this manner, the pressure differential across the air valve assembly 102 is reduced and the air valve assembly 102 closes once the differential is below the threshold amount. Conversely, when the air pressure on the top 116 of the air valve assembly 102 is greater than on the bottom 118 of the air valve assembly, air can pass through the breather port 110, the air valve assembly 102, the filter element 108, the bottom layer 106, and into the electronic enclosure 112 equalizing the air pressure across the valve assembly 102.
  • the filter shown in FIG. 3 can reduce the amount of contaminants that diffuse into the electronic enclosure from the outside in comparison to breather filters that contain a fluid flow path that is always open.
  • One reason for this is because when the air valve assembly 102 is in a closed state, the amount of contaminants that can pass into the inside of the electronic enclosure is relatively small because the air valve assembly 102 physically blocks the pathway. Further, the filter element 108 can act to adsorb any contaminants that may diffuse through the air valve assembly 102 even when it is in a closed state.
  • the air valve assembly 102 can take on various forms.
  • the air valve assembly 102 may be either an active valve or a passive valve. Passive air valves can generally be manufactured less expensively than active valves.
  • the filter of the invention includes a passive air valve. Many different types of passive air valves can be used.
  • FIG. 4 illustrates a cross section one example of a passive valve 200.
  • the passive valve 200 includes a first layer 202 and a second layer 206.
  • the first layer 202 has a plurality of pores 204 that are sufficiently large in diameter to allow the passage of air.
  • the second layer 206 has a plurality of pores 208 that are sufficient large in diameter to allow the passage of air.
  • the pores 204 of the first layer 202 and the pores 208 of the second layer 206 are at least about 0.5 millimeter in diameter.
  • the passive valve 200 has a closed configuration shown in FIG. 4 and an open configuration shown in FIG. 5.
  • the first layer 202 and the second layer 206 are disposed against one another in a manner such that the pores 204 of the first layer do not line up with the pores 208 of the second layer. Accordingly, the flow of air is blocked across the first layer 202 and the second layer 206 when the passive valve 200 is in the closed configuration.
  • the valve 200 includes a liquid composition (not shown) in between the first layer 202 and the second layer 206.
  • the liquid composition can enhance the ability of the filter to block airflow across the valve 200 when the valve 200 is in the closed position.
  • the liquid composition can also help to control the amount of force necessary to shift the valve 200 from the closed position to the open position.
  • the first layer 202 of the passive valve 200 can be made from a material that deforms (or flexes) when a force is applied to it.
  • the passive valve can assume an open position. Specifically, when the air pressure is greater on the second side 212 of the valve than on the first side 214, the first layer 202 flexes away from the second layer 206 and an airflow path between the pores 208 of the second layer and the pores 204 of the first layer is created. In the open position, air can flow through the passive valve in the direction of arrows 210.
  • the first layer 202 may be made of any material that can be formed with pores for the passage of air and that has sufficient flexibility to assume an open position when incorporated as part of a passive valve.
  • the first layer 202 of the passive valve can be made of a deformable polymeric film.
  • the first layer can comprise polyurethane, polypropylene, polyester, or polytetraflouroethylene (PTFE).
  • the second layer 206 is less flexible than the first layer 202. This can be achieved in many ways.
  • the second layer 206 can be made thicker than the first layer 202.
  • the second layer 206 can be made of a material that is less flexible than the material used to make the first layer 202.
  • both the first layer 202 and second layer 206 are sufficiently flexible so as to allow airflow in either direction (into or out of an enclosure) depending upon the direction of the pressure differential between the first and second sides 214 and 212 of the enclosure.
  • FIG. 6 is a perspective view of a filter 300 in accordance with an embodiment of the invention.
  • the filter 300 is shown with a top layer 304 that defines two top ports 302.
  • the top ports 302 can provide fluid communication between the interior of the filter and the exterior of the electronic enclosure or they can provide fluid communication between the interior of the filter and the interior of the electronic enclosure.
  • the filter includes only one top port.
  • the filter can also include more than two top ports 302. If the top ports are too small, they may undesirably impede the flow of air.
  • FIG. 7 is a top schematic view of the filter 300 of FIG. 6, including aspects of the interior and bottom of the filter 300.
  • a bottom port 306 is shown in dotted lines.
  • the bottom port can provide fluid communication between the interior of the filter and the exterior of the electronic enclosure or between the interior of the filter and the interior of the electronic enclosure.
  • Embodiments of the invention can include more than one bottom port. If the bottom port is too small, it may undesirably impede the flow of air.
  • FIG. 7 shows a filter element 308 inside the filter.
  • the filter element 308 can function to remove contaminants from the air inside the filter.
  • the filter element can be annular (or ring shaped). However, the filter element can also assume other shapes.
  • the filter element 308 can optionally be contained within a scrim.
  • the filter element 308 can include filter media that removes contaminants from air flowing through the breather filter 300.
  • the filter element 308 can also remove contaminants that otherwise diffuse into the breather filter 300.
  • the filter element 308 can be made of a material that swells in the presence of water vapor.
  • the filter element 308 can include activated carbon, silica gel, a water-absorbing swellable polymer, or combinations thereof.
  • the filter element 308 includes a superabsorbent polymer.
  • the superabsorbent polymer can be AQUAKEEP SA60N Type II from Sumitomo Seika Chemical or NAFION from DuPont, Wilmington, DE.
  • FIG. 8 is cross-sectional view of the filter 300 of FIG. 6, taken along line B-
  • FIG. 9 is a cross-sectional view of the filter of FIG. 6, taken along line B-B' of FIG. 7, showing the passage of air through the filter when the pressure differential across the filter exceeds a threshold level.
  • the top layer 304 flexes such that a gap is created in between the top layer 304 and the filter element 308.
  • an airflow path is opened between the top ports 302 and the bottom port 306 and air flows is the direction of arrows 312.
  • the filter element 308 can be attached to the top layer 304 instead of the bottom layer 310.
  • the filter element 308 is made of a material that swells in the presence of water or water vapor, as described above, the filter element 308 can serve to more effectively block the airflow path through the filter 300 over time as it is exposed to more water vapor.
  • the filter element 308 since the filter element 308 would swell after exposure to water vapor, it would more tightly contact the top layer 304 and the bottom layer 310 and therefore form a better seal and more effectively block airflow.
  • the swelling of the water-absorbing swellable polymer can also prevent water vapor from diffusing through the polymer itself because of the phenomenon known as gel-blocking.
  • filters of the invention can be affixed to an electronic enclosure over the breather hole on either the outside or inside of the electronic enclosure.
  • a filter in accordance with an embodiment of the invention is shown attached to the exterior surface 322 of an electronic enclosure 318.
  • the filter can be attached to the electronic enclosure 318 using any conventional technique including the use of adhesives or mechanical fasteners.
  • the electronic enclosure 318 has a breather hole 320.
  • the filter is arranged so that the bottom port 306 fits over the breather hole 320 of the electronic enclosure.
  • FIG. 11 shows a cross-sectional view of a filter in accordance with an embodiment of the invention attached to the interior surface 324 of an electronic enclosure.
  • a spacer pad 326 provides an air gap in between the surface 324 of the electronic enclosure 318 and the top ports 302.
  • the air gap formed by the spacer pad 326 is large enough that the top layer 304 can flex sufficiently to create an airflow path through the filter.
  • FIG. 12 shows a top perspective view of the filter in FIG. 11. In this view, the spacer pad 326 can be seen disposed on the top layer 304 of the filter.
  • FIG. 13 a cross-sectional view of a filter 400 in accordance with another embodiment of the invention is shown attached to the inner surface of an electronic enclosure 430. It will be appreciated that the filter 400 can be attached using any conventional technique including the use of adhesives or mechanical fasteners.
  • the filter has a top layer 410 which defines a top port 434.
  • the filter has a valve layer 442 including a first layer 423 and a second layer 422.
  • the first layer 423 includes a plurality of pores 402 (not drawn to scale) and a flap portion 420.
  • the flap portion 420 is flexible and can move.
  • the second layer 422 includes a plurality of pores 403 (not drawn to scale) and a flap portion 418.
  • FIG. 15 illustrates how the filter 400 of FIG. 13 operates to allow the passage of air from one side of the electronic enclosure to the other side of the electronic enclosure.
  • the first layer flap 420 flexes open to allow air to flow through the filter in the direction of arrow 426.
  • FIG. 16 illustrates how the filter 400 of FIG. 13 operates to allow the passage of air from the outside of the electronic enclosure to the inside of the electronic enclosure.
  • the second layer flap 418 flexes open to allow air to flow through the filter in the direction of arrow 428.
  • the filter of FIG. 13 allows air to flow back and forth between the inside 436 and the outside 438 of the electronic enclosure 430, but only when a pressure differential exists that is sufficient to cause one of the flaps 418, 420 to flex into an open position.
  • the magnitude of the pressure differential that is necessary to cause the flaps 418, 420 to flex into an open position will vary based on factors such as the flexibility of the material used to make the flaps, the thickness of the flaps, the size of the flaps, and the like. However, it will be appreciated that the properties of the flaps can be changed such that the pressure differential necessary to open them is as desired for the particular application.
  • the first layer 423 and the second layer 422 of the valve layer 442 can be made of a polymeric film that is substantially impermeable to fluid flow (in the absence of pores 402, 403). In some embodiments, the first layer 423 and the second layer 422 of the valve layer 442 include a barrier film.
  • the top port 434 is disposed over a breather port in an electronic enclosure 430 such as depicted in FIG. 13.
  • the configuration is reversed, such as that shown in FIG. 17, so that the top port 434 of the filter is on the opposite side of the filter that is adjacent to the breather port 440 of the electronic enclosure 430.
  • valve layer can also be made having only flaps on the first layer and only pores on the second layer. This type of valve layer configuration would provide for the one-way passage of air. Similarly, a valve layer can be made having only flaps on the second layer and only pores on the first layer.
  • the breather filter can contain filter media in a filter element or filter layer.
  • Filter media can include particulate filter media and/or adsorbent filter media.
  • Particulate filter media used with the invention can have efficiency over a wide range of particle sizes including submicron to macroscopic sizes (preferably greater than or equal to 0.02 micrometers).
  • Suitable particulate filter media materials include microfiberglass media, high efficiency electrect materials, and membrane materials such as, but not limited to, expanded polytetrafluoroethylene membrane, polypropylene membrane, polycarbonate and polyester membranes, mixed-esters of cellulose membrane, polyvinyl chloride membrane, cellulose triacetate membrane, and thin film composite membranes and/or laminates thereof.
  • An especially suitable particulate filtering media is expanded polytetrafluoroethylene (expanded PTFE or ePTFE) because of its good filtration performance, conformability to cover adsorbent layers, and cleanliness.
  • a preferred expanded PTFE membrane has a filtration efficiency of 99.99% at 0.1 micrometer diameter sized particles with a resistance to airflow of approximately 20 mm water column at an airflow of 10.5 feet per minute face velocity.
  • Expanded PTFE is commercially available as GORE-TEX® from W.L. Gore & Associates, Inc. Millipore PVDF can also be used in certain embodiments as a particulate filter media.
  • Adsorbent media used in some embodiments of the invention may be selected from a broad range of adsorbents and is tailored to the particular gas or gases that are of concern. These gases include water vapor, dioctyl phthalate, silicone, chlorine, hydrogen sulfide, nitrogen dioxide, mineral acid gases, hydrocarbon compounds and any other gas that can oxidize or cause corrosion of any critical element or that can condense onto critical elements so as to effect their operation.
  • the adsorbent media selected may be of a single type of a combination of different media types. It may be a specifically selected adsorbent that targets a specific gas or may be one that has good adsorption properties over a wide range of gases.
  • Adsorbent media used in embodiments of the invention can include physisorbers such as, but not limited to silica gel, activated carbon, activated alumina, molecular sieves, or drying agents such as clays; or chemisorbents such as, but not limited to calcium carbonate, calcium sulfate, potassium permanganate, sodium carbonate, potassium carbonate, sodium phosphate, powdered or activated metals or other reactants for chemically reacting and scavenging gas phase corrosive materials or contaminants.
  • physisorbers such as, but not limited to silica gel, activated carbon, activated alumina, molecular sieves, or drying agents such as clays
  • chemisorbents such as, but not limited to calcium carbonate, calcium sulfate, potassium permanganate, sodium carbonate, potassium carbonate, sodium phosphate, powdered or activated metals or other reactants for chemically reacting and scavenging gas phase corrosive materials or contaminants
  • adsorbents may be individual layers that are positioned on top of each other, or mixed into one layer.
  • the adsorbent media may be one that has been impregnated with one or more additional adsorbents such as, but not limited to, activated carbons, silica gels or aluminas that have been impregnated with one or more chemisorbents as mentioned above.
  • a preferred broad range adsorbent is activated carbon with a wide pore size distribution that has been impregnated with one or more chemisorbents such as calcium carbonate or sodium carbonate.
  • a wide pore size distribution may be used to provide for a broad range of gasses to be adsorbed.
  • the carbonates are typically good impregnation candidates because the compounds being released due to the chemical reaction of the chemisorbents are carbon dioxide, oxygen, and water.
  • a preferred adsorbent for a given contaminant depends upon the contaminant, the pore size of the physisorbent and chemical composition of the chemisorber that is selected so as to optimize performance on that particular contaminant.
  • the adsorbent media may include, but is not limited to, one or more of the following constructions: 100% adsorbent material such as a granular adsorbent, a carbonized woven or nonwoven material, and adsorbent impregnated nonwoven material such as a cellulose or polymeric nonwoven that may include latex, acrylic or some other binder system, porous cast adsorbents that may include polymers or ceramics to keep their porous structure, adsorbent impregnated polymers or polymer membranes that serve as a porous scaffold in which void spaces within the scaffold are filled with an adsorbent.
  • 100% adsorbent material such as a granular adsorbent, a carbonized woven or nonwoven material, and adsorbent impregnated nonwoven material such as a cellulose or polymeric nonwoven that may include latex, acrylic or some other binder system
  • porous cast adsorbents that may include polymers or ceramics to keep their porous
  • Polymeric scaffolds include, but are not limited to, expanded PTFE membranes, polypropylene membranes, polyethylene membranes, polypropylene membranes, polyethylene membranes, polyvinylidene fluoride membranes, polyvinyl alcohol membranes, polyethylene terephthalate membranes and membranes form any other polymer that can be made to have a node and fibril structure.
  • the adsorbent material may be entirely of one type or a mixture of any number of physisorbers and/or chemisorbers.
  • the adsorbent media can include a water-swellable component.
  • the adsorbent media includes a water-swellable absorbent polymer. Water-swellable absorbent polymers are also known as superabsorbent polymers.
  • Water-swellable absorbent polymers can include anionic polymers, such as the alkali metal and ammonium salts of poly(acrylic acid), poly(methacrylic acid), isobutylene-maleic anhydride copolymers, polyvinyl acetic acid), poly(vinyl phosphonic acid), poly(vinyl sulfonic acid), carboxymethyl cellulose, carboxymethyl starch, carrageenan, alginic acid, polyaspartic acid, polyglutamic acid, and combinations and copolymers thereof, cationic polymers, such as salts of polyvinyl amine), poly(ethylene imine), poly(amino propanol vinyl ether), poly(allyl amine), poly(quaternary ammonium), poly(diallyl dimethyl ammonium hydroxide), polyasparagins, polyglutamines, polylysines, polyarginines, and combinations and copolymers thereof, mixtures of the anionic and cationic polymers described above.
  • the water-swellable absorbent polymer includes one of sodium polyacrylate, polyvinyl amine salt, polyacrylic acid, polyvinyl amine, and combinations and derivatives thereof.
  • the water-swellable absorbent polymer includes AQUAKEEP SA60N available from Sumitomo Seika Chemicals.
  • the water-swellable absorbent polymer can include NAFION available from DuPont, Wilmington, DE.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Filtering Of Dispersed Particles In Gases (AREA)

Abstract

L'invention concerne des filtres de ventilation (400) aptes à réduire ou à empêcher la transmission de contaminants par diffusion. Dans un mode de réalisation, l'invention concerne un ensemble filtre de ventilation (400) comprenant un clapet. Ce clapet comprend une première couche (420) définissant une première ouverture (403), une deuxième couche (422) définissant une deuxième ouverture (402), et une troisième couche disposée entre les première et deuxième couches, cette troisième couche (408) contenant un milieu de filtration. La première couche (420) peut être configurée pour se courber en s'éloignant de la deuxième couche (422), ce qui crée une lame d'air entre la première et la troisième couche. Dans un mode de réalisation, l'invention concerne un filtre de ventilation (400) comprenant une première couche (420), une deuxième couche (422), un élément de filtre (408) disposé entre la première et la deuxième couche, et un ensemble clapet comprenant un premier côté et un deuxième côté. Cet ensemble clapet peut être configuré pour passer d'une position fermée à une position ouverte lorsque la différence de pression d'air entre le premier côté et le deuxième côté dépasse une valeur seuil.
PCT/US2006/003803 2005-02-03 2006-02-03 Filtre de ventilation permettant de reduire la diffusion de contaminants WO2006084106A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN2006800073190A CN101137426B (zh) 2005-02-03 2006-02-03 用于降低污染物扩散的通气过滤器
JP2007554232A JP2008528286A (ja) 2005-02-03 2006-02-03 汚染物質の拡散を低減するためのブリーザフィルタ

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US64971105P 2005-02-03 2005-02-03
US60/649,711 2005-02-03

Publications (1)

Publication Number Publication Date
WO2006084106A1 true WO2006084106A1 (fr) 2006-08-10

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2006/003803 WO2006084106A1 (fr) 2005-02-03 2006-02-03 Filtre de ventilation permettant de reduire la diffusion de contaminants

Country Status (3)

Country Link
JP (1) JP2008528286A (fr)
CN (1) CN101137426B (fr)
WO (1) WO2006084106A1 (fr)

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US7655070B1 (en) 2006-02-13 2010-02-02 Donaldson Company, Inc. Web comprising fine fiber and reactive, adsorptive or absorptive particulate
US7988860B2 (en) 2007-03-15 2011-08-02 Donaldson Company Inc. Superabsorbent-containing web that can act as a filter, absorbent, reactive layer or fuel fuse
WO2014066683A1 (fr) * 2012-10-26 2014-05-01 Donaldson Company, Inc. Ensemble de filtre de transmission de vapeur à humidité régulée pour des boîtiers électroniques
US8885291B2 (en) 2012-08-10 2014-11-11 Donaldson Company, Inc. Recirculation filter for an electronic enclosure
US10010822B2 (en) 2012-08-10 2018-07-03 Donaldson Company, Inc. Recirculation filter for an electronic enclosure
US10482928B2 (en) 2014-02-13 2019-11-19 Donaldson Company, Inc. Recirculation filter for an electronic enclosure
US20210299601A1 (en) * 2020-03-24 2021-09-30 Mann+Hummel Gmbh Particle Discharge Device, Filter Assembly, and Method

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Cited By (19)

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Publication number Priority date Publication date Assignee Title
US9610523B2 (en) 2006-02-13 2017-04-04 Donaldson Company, Inc. Web comprising fine fiber and reactive, adsorptive or absorptive particulate
US7655070B1 (en) 2006-02-13 2010-02-02 Donaldson Company, Inc. Web comprising fine fiber and reactive, adsorptive or absorptive particulate
US10058807B2 (en) 2006-02-13 2018-08-28 Donaldson Company, Inc. Web comprising fine fiber and reactive, adsorptive or absorptive particulate
US8211218B2 (en) 2006-02-13 2012-07-03 Donaldson Company, Inc. Web comprising fine fiber and reactive, adsorptive or absorptive particulate
US8246730B2 (en) 2006-02-13 2012-08-21 Donaldson Company, Inc. Web comprising fine fiber and reactive, adsorptive or absorptive particulate
US8343264B2 (en) 2006-02-13 2013-01-01 Donaldson Company, Inc. Web comprising fine fiber and reactive, adsorptive or absorptive particulate
US8048210B2 (en) 2006-02-13 2011-11-01 Donaldson Company, Inc. Web comprising fine fiber and reactive, adsorptive or absorptive particulate
US8263214B2 (en) 2007-03-15 2012-09-11 Donaldson Company, Inc. Super absorbent containing web that can act as a filter, absorbent, reactive layer or fuel fuse
US8556089B2 (en) 2007-03-15 2013-10-15 Donaldson Company, Inc. Super absorbent containing web that can act as a filter, absorbent, reactive layer or fuel fuse
US7988860B2 (en) 2007-03-15 2011-08-02 Donaldson Company Inc. Superabsorbent-containing web that can act as a filter, absorbent, reactive layer or fuel fuse
US10010822B2 (en) 2012-08-10 2018-07-03 Donaldson Company, Inc. Recirculation filter for an electronic enclosure
US9153291B2 (en) 2012-08-10 2015-10-06 Donaldson Company, Inc. Recirculation filter for an electronic enclosure
US8885291B2 (en) 2012-08-10 2014-11-11 Donaldson Company, Inc. Recirculation filter for an electronic enclosure
US9114349B2 (en) 2012-10-26 2015-08-25 Donaldson Company, Inc. Controlled moisture vapor transmission filter assembly for electronic enclosures
WO2014066683A1 (fr) * 2012-10-26 2014-05-01 Donaldson Company, Inc. Ensemble de filtre de transmission de vapeur à humidité régulée pour des boîtiers électroniques
US10482928B2 (en) 2014-02-13 2019-11-19 Donaldson Company, Inc. Recirculation filter for an electronic enclosure
US11183222B2 (en) 2014-02-13 2021-11-23 Donaldson Company, Inc. Recirculation filter for an enclosure
US11918944B2 (en) * 2020-03-24 2024-03-05 Mann+Hummel Gmbh Particle discharge device, filter assembly, and method
US20210299601A1 (en) * 2020-03-24 2021-09-30 Mann+Hummel Gmbh Particle Discharge Device, Filter Assembly, and Method

Also Published As

Publication number Publication date
CN101137426A (zh) 2008-03-05
CN101137426B (zh) 2012-02-22
JP2008528286A (ja) 2008-07-31

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