WO2001008781A2 - Materiaux filtrants a base de cellulose et cartouche associee - Google Patents

Materiaux filtrants a base de cellulose et cartouche associee Download PDF

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Publication number
WO2001008781A2
WO2001008781A2 PCT/US2000/020282 US0020282W WO0108781A2 WO 2001008781 A2 WO2001008781 A2 WO 2001008781A2 US 0020282 W US0020282 W US 0020282W WO 0108781 A2 WO0108781 A2 WO 0108781A2
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WO
WIPO (PCT)
Prior art keywords
media
filtration
filter
corrugation
filter media
Prior art date
Application number
PCT/US2000/020282
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English (en)
Other versions
WO2001008781A3 (fr
Inventor
Bruce A. Johnson
James D. Benson
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 AU63753/00A priority Critical patent/AU6375300A/en
Publication of WO2001008781A2 publication Critical patent/WO2001008781A2/fr
Publication of WO2001008781A3 publication Critical patent/WO2001008781A3/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
    • B01D46/24—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies
    • B01D46/2403—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies characterised by the physical shape or structure of the filtering element
    • B01D46/2411—Filter cartridges
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
    • B01D39/1607—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous
    • B01D39/1623—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous of synthetic origin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
    • B01D39/18—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being cellulose or derivatives thereof
    • 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
    • B01D46/52—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material
    • B01D46/521—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material using folded, pleated material
    • 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
    • B01D46/54—Particle separators, e.g. dust precipitators, using ultra-fine filter sheets or diaphragms
    • B01D46/546—Particle separators, e.g. dust precipitators, using ultra-fine filter sheets or diaphragms using nano- or microfibres
    • 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
    • B01D46/66—Regeneration of the filtering material or filter elements inside the filter
    • B01D46/70—Regeneration of the filtering material or filter elements inside the filter by acting counter-currently on the filtering surface, e.g. by flushing on the non-cake side of the filter
    • B01D46/71—Regeneration of the filtering material or filter elements inside the filter by acting counter-currently on the filtering surface, e.g. by flushing on the non-cake side of the filter with pressurised gas, e.g. pulsed air
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2275/00—Filter media structures for filters specially adapted for separating dispersed particles from gases or vapours
    • B01D2275/10—Multiple layers

Definitions

  • the present invention relates generally to filtration, and more particularly to improved air filter medias and their use in an air filtration cartridges.
  • cellulosic material as the material of choice for forming the media or core material of air filters.
  • cellulosic materials can be relatively easily handled and shaped to accommodate filter configurations of varied shapes, sizes and configurations, and can be made in a wide variety of grades to accommodate a broad range of basic filtration needs.
  • Corrugated cellulosic filtration media in the configuration of pleated sheets or panels are popular throughout the industry.
  • a corrugated configuration provides increased filtration surface area for any defined cross-sectional area of filtration media, provides stiffhess to the media, and generally aids in the collection of large amounts of filtered particles by the media before clogging or before demonstrating undesirable increased pressure drops though the media.
  • the air filtration properties of a base media can be enhanced by applying or adhering a layer of thin or "fine" fibers to the surface of the media.
  • Such fibers form an overlying web or mat of such fibers that entrap submicron-sized dust at the media surface, allowing it to rapidly build into a dust cake, providing improved long term filter efficiency.
  • the dust cake builds on top of the fine fiber layer and can be quickly removed by a back flow pulsing or purging process, without decreasing the filtration efficiency of the underlying substrate material.
  • Such fine fiber layers provide for more thorough pulse cleaning of the media and help maintain low pressure drop through the media, since they stop the pore clogging dust particles at the media surface, preventing the dust from becoming embedded within the media substrate that would otherwise clog the pores of the cellulosic based media. Since the base substrate does not become "saturated" with dust, filter life is dramatically extended.
  • the present invention addresses these issues by providing cellulose filter media configurations that are cheaper to produce, are more durable, and have longer useful lives and higher initial efficiencies for submicron particles, as compared with prior filter media.
  • the present invention provides a new all cellulose media formulation that has a stiffer cellulose substrate and a new corrugation pattern than heretofore known.
  • the stiffer media reduces restriction, thereby increasing filter life.
  • the media corrugation pattern is characterized by corrugations of increased height, which increases the moment of inertia of the pleats of a filter panel using the media.
  • the stiffer media reduces pleat bagging caused by pressure forces induced by dust loading, and provides a more desirable media for sustaining the forces applied to it during pulse cleaning cycles.
  • the enlarged corrugation channel areas improves airflow through the pleats. Filter panels constructed by this media costs less to produce than those using prior cellulose media of similar stiffhess by eliminating a manufacturing step. By using a non-phenolic resin, the curing step following pleating required by prior phenolic resin formed cellulose medias, is eliminated.
  • the invention also provides a new layered media, having an all cellulose corrugated substrate material that may include the above described media produced with non-phenolic resins, that also includes a layer of fine fibers applied to and adhered on one or more surfaces thereof.
  • the corrugated substrate is also characterized by a low corrugation cycle and deep corrugations to provide a stiff material that increases the moment of inertia of the pleats of a filter panel formed by the media.
  • the fine fiber layer is formed from fibers having an average diameter of no greater than 15 microns, and preferably of no greater than 1 micron. The fine fiber layer extends the life of the filter, increases its start up efficiency, and enhances cleaning filters in pulsed cleaning filtration assemblies.
  • Filter media having such layered configuration has been shown to meet a BIA-C standard initial filtration efficiency of 99.9% for 0.2 to 2 micron particles, and may also be provided with a flame retardant.
  • a filter media for air filters comprising: (a) a substrate layer of all cellulose material, said substrate being corrugated with a corrugation cycle of no greater than 6.7 cycles per inch and a corrugation height of no less than 18 mils; and (b) a fine fiber filtration layer deposited on and adhering to at least one broad surface area of said cellulose material, said fine fiber filtration layer comprising fibers having an average fiber diameter of no greater than 15 microns.
  • the fine fibers more preferably have an average diameter of no greater than 5 microns, and even more preferably an average diameter of no greater than 1 micron.
  • the corrugation cycle of the media is preferably no greater than 6 cycles per inch, and even more preferably no greater than 5 cycles per inch.
  • the corrugation height of the media is no less than 20 mils, and more preferably, no less than 25 mils.
  • the filter media has a substrate layer basis weight of from about 60 to 95 pounds per 3,000 square feet, and more preferably from about 65 to 75 pounds per 3,000 square feet.
  • the filter media is configured with parameters selected in combination so as to provide performance characteristics of the media as a filter for air, with an LEFS of not less than 70% and displaying an initial filtration efficiency of at least 99.9% for 0.2 to 2 micron dust particles, satisfying the BIA-C standard.
  • the filter media may include a flame retardant applied to the substrate which preferably comprises of from about 3% to 15% by weight of the substrate material.
  • the fine fiber layer has a thickness of no less than 0.05 microns, and more preferably a thickness of from 0.05 to 80 microns.
  • a filter media for filters comprising a corrugated layer of all cellulose fibers formed with a non-phenolic resin requiring no cure after corrugation, having a corrugation cycle of no greater than 6.3 cycles per inch and a corrugation height of no less than 18 mils.
  • the cellulose filter media preferably is formed with a latex thermoplastic resin and has a basis weight of no greater than 75 pounds per 3,000 square feet.
  • a filtration panel suitable for use in a filter apparatus, comprising a pleated sheet of corrugated media material, wherein the media material comprises all cellulose material of a type requiring no cure after pleating, having a corrugation cycle no greater than 6.3 cycles per inch and a corrugation height of no less than 18 mils.
  • the media material may be fabricated with a non-phenolic resin such as a latex thermoplastic resin and the pleated sheet may be shaped in various configurations such as flat or curved configurations, including cylindrical configurations.
  • the filtration panel may include edge members cooperatively engaging one or more edges of the media material to form filtration cartridges and may further include one or more liner member supported by the edge members and extending adjacent the pleated sheet.
  • a filtration panel suitable for use in a filter apparatus comprising: (a) a pleated sheet of corrugated media material comprising a substrate layer of all cellulose material, said substrate being corrugated with a corrugation cycle of no greater than 6.7 cycles per inch and a corrugation height of no less than 18 mils; and (b) a fine fiber filtration layer deposited on and adhering to at least one broad surface area of said cellulose material, said fine fiber filtration layer comprising fibers having an average fiber diameter of no greater than 15 microns, and preferably a diameter of no greater than one micron.
  • Filtration panel preferably has a substrate layer with a basis weight of from about 60 to 95 pounds per 3,000 square feet. Further, the filtration panel preferably displays a combination of parameters for the pleated sheet, selected in combination so as to provide filtration performance characteristics for filtering air, with an LEFS from not less than 70% and to meet the BIA-C filtration standard of initial filtration efficiency of at least 99.9% for 0.2 to 2 micron dust particles. The media meeting such performance could also include a flame retardant.
  • Fig. 1 is a view in top elevation of a portion of a pleated filter media configured according to the principles of this invention
  • Fig. 2 is an enlarged cross-sectional view illustrating the corrugation pattern of the substrate material forming the pleated filter of Fig. 1 generally taken along the Line 2-2 of Fig 1;
  • Fig. 3 is a diagrammatic cross-sectional view of the corrugation pattern of Fig. 2, illustrating a layer of fine fiber applied to one surface of the corrugated base media;
  • Fig. 4 is a diagrammatic cross-sectional view of a corrugation pattern, illustrating deformation caused by pressure force (Fig. 4A), and by dust loading (Fig. 4B);
  • Fig. 5 is a perspective view of a filter cartridge constructed with media configured according to the present invention;
  • Fig. 6 is a sectional view of the filter cartridge of Fig. 5, generally taken a long the line 6-6 of Fig 5;
  • Fig. 7 is a bar graph illustrating the efficiencies of media of the present invention as compared to prior art filter media.
  • Fig. 8 is a comparative graph illustrating life test results for a filter using the media of the present invention as compared to a prior art filter.
  • a blend of additional materials have typically been added to the cellulose to produce a fiberblend substrate media.
  • Such blends are typically comprised of 80% cellulose and 20% polyester fibers and significantly increase the cost of the media material.
  • Such all-cellulose materials of the prior art have, however, used resins in their fab ⁇ cation that require additional processing steps that add to the manufactu ⁇ ng cost of the media.
  • the present invention provides a filter media having an all cellulose based substrate material, that is made with resins that allow reduced manufacturing processing steps for filters made with such media, thereby reducing the filter cost.
  • Fig. 4A diagrammatically illustrates how pressure forces deform the pleats of a filter.
  • Fig. 4B illustrates pleat deformation caused by dust loading.
  • the smaller arrows represent the pressure force applied to the pleats, and the larger arrows represent the air flow through the media.
  • the deformed pleats result in decreased flow area that increases the restriction through the flow channels between the pleats.
  • the present invention provides an all cellulose media having a corrugation pattern that increases the stiffness of the pleat, reduces pleat bagging and keeps the air flow area open - all resulting in lower restriction and longer filter life.
  • a pleated configuration of a typical filter panel is illustrated at 10, wherein the pleats are generally indicated at 11.
  • the base media material from which the pleated panels are formed is preferably of corrugated construction, which provides a degree of stiffhess to the pleats.
  • the base media material is in the preferred embodiment, a corrugated cellulose material.
  • This invention provides a new base cellulose media for filtration purposes as well as a new combination layered media of a base substrate and fine fiber material.
  • the cellulose media material can be made by various means known to those skilled in the art, and generally uses a wet layed process.
  • a typical manufacturing process of the prior art might include manufacturing and drying of a paper layer, impregnating the paper with a resin of from about 20% to 30% of the paper weight, curing the paper, corrugating the paper and finally curing the corrugated sheet.
  • Prior art methods for making cellulose filtration media have used phenolic resins that require a final curing step after the media is pleated.
  • This invention provides a new all-cellulose base media material made with a non-phenolic resin preferably comprising a latex thermoplastic, such as a latex suspension or acrylic, that is functionally cross-linked between 2%-8% with an amine-based resin.
  • a latex thermoplastic resin does not require a final curing step after formation of the filter panel pleats, as was required by prior art phenolic resins. Therefore, the cellulose media material of this invention can be made at lower cost than those of prior known processes.
  • the base thickness of the media is from about 0.010 to 0.025 inches thick, has a basis weight from about 60-90 pounds per 3,000 square feet, and preferably a maximum pore size of from about 30-60 microns.
  • the base media of all cellulose fiber construction, is formed into a corrugated sheet generally represented by corrugations 12, repeatedly alternating between peaks 14 and valleys 16.
  • the distance "C” between two consecutive peaks or two consecutive valleys, is referred to as a "cycle" of the corrugation pattern.
  • the vertical distance between the bottom of a valley and the top of a peak is typically referred to as the depth or height "FT of the corrugations.
  • Corrugation cycles of prior art-cellulose media with non-phenolic resins have generally not been below about 6.3 cycles per inch.
  • Such prior art large corrugation cycle configurations have limited the corrugation height "H" to about 0.015 to 0.020 inches (15 to 20 mils), thereby limiting the stiffhess able to be obtained by the resultant pleated filter material constructed form the media.
  • the present invention uses base medias having significantly lower corrugation cycles which allows for a higher corrugation height in the media, without damaging the media (i.e. fracturing the media during the corrugation process).
  • an all-cellulose substrate media having a corrugation cycle of less than 6.7 cycles per inch is used for a layered filter, that includes a coating layer of fine fibers.
  • a filtration base media material that will not necessarily be coated with fine fibers, and having a non- phenolic resin has a corrugation cycle of less than 6.3 cycles per inch. More preferably, the present invention uses a corrugation cycle for both media for layered or unlayered applications of about 4.5 cycles per inch is used.
  • This lower corrugation cycle provides for an accompanying increase in the corrugation height "Ft" to greater than 18 mils, and preferably from about 20 to 24 mils. Decreasing the corrugation cycle and increasing the corrugation height results in a better performing media, by increasing the media stiffhess and air channel area. With prior medias of higher corrugation cycles, there was a tendency to lose the corrugation depth, stiffhess and pleat separation throughout the lifetime of the pleated filter element. It will be appreciated, therefore, that the media configuration of this invention, tends to provide lower initial pressure and lower pressure drop at a given time than the prior standard medias. These qualities are particularly important in layered media wherein fine fibers (hereinafter described) are applied to the media.
  • the pressure drop is a function of the loading and air channel area.
  • Increasing the corrugation height and pattern has the effect of increasing the moment of inertia of the pleat of the filter formed by the media, thus increasing its stiffhess. Therefore, for both pulsed self-cleaning and non-pulsed filtration systems, the medias of the present invention allow utilization of more surface area than with those having higher corrugation cycles and lower corrugation depth. Further, as a result of the higher corrugation depth and media rigidity, there is less loss of media due to collapse of the pleats, which is particularly important in pulsed cleaning air filtration systems.
  • an all cellulose base media, of reduced corrugation cycles of less than 6.7 cycles per inch, whether or not constructed with non-phenolic resins can be coated with a fine fiber layer to provide an improved layered filter media.
  • fine fibers having an average fiber diameter of no greater than 15 microns are deposited in a layer 20 on at least one of the broad surfaces 13 of the cellulose substrate (Fig. 3) and are self-adhering thereto. More preferably the average fiber diameter will be no greater than 5 microns, and even more preferably no greater than 1 micron. Typically such fine fibers have an average fiber diameter in the range from about 0.001 to 1 micron.
  • the fine fibers are preferably deposited on that side of the substrate that will first encounter the air to be filtered, such that submicron particles will first be removed from the air flow before they can clog the substrate media, and a removable dust cake will build up on the fine fiber layer.
  • the fine fiber layer could in certain applications, however, be deposited on the exit surface of the media, or even on both surfaces of the media.
  • the fine fiber layer is responsible for enhancing efficiency with minimal additional flow restriction, which will depend in part on the thickness of the fine fiber layer. Increasing the thickness of the fine fiber layer provides greater capture of submicron contaminant particles.
  • the desired thickness of the fine fiber layer will depend on the intended use for the media as discussed above and upon the diameter of the fine fibers.
  • the thickness of the fine fiber layer can widely vary and is generally no less than about 0.05 microns and is typically in the range of from about 0.05 to 80 microns, but can be much thicker as for example up to 0.1 inches for large diameter fibers. Rapid accumulation of particles on the media surface builds a permeable, dust-stopping cake and ensures high filtration efficiencies by eliminating premature filter plugging. Further, the layer of ultra- fine fibers greatly facilitates dust release during the collector's cleaning cycle.
  • the layer 20 of fine fibers can be formed and deposited on the surface 13 of the substrate material 10 by various known methods, including melt blowing, solution blowing and electrostatic spinning. While the present invention applies to any of these fiber producing methods, the electrostatic spinning method is preferred and may, for example, be of the type described in the cross-referenced U.S. Patent 4,650,506. Further, it is currently believed that the fine fibers could be formed from a wide variety of materials that would serve the filtration purposes of this invention and be compatible with an underlying cellulose substrate material. It should be understood that the specific type of fine fiber, or its method of fabrication and application to the substrate, is not as significant to this invention as is the fact that a fine fiber layer is applied to a substrate layer to provide certain enhanced filtration properties.
  • any of a wide variety of polymer materials could be used to form the fibers such as polytetrafluoroethylene (PTFE) or other flurochemical polymers.
  • Other polymers such as described in the 4,650,506 patent could be used. They include polyacrylonitriles, polyvinylide chlorides, polysulfones, sulfonated polysulfones, polyimides, polyvinylidene fluorides, polyvinyl chlorides, chlorinated polyvinyl chlorides, polycarbonates, nylons, aromatic nylons, cellulose esters, acyrlates, polystyrenes, polyvinyl butyrals and copolymers of each of these polymers.
  • the material used for the fine fiber will depend upon the selected technology used for applying the fibers to the substrate. It will also be appreciated that the thickness of the fiber layer deposited on the base media 10 can be controlled and varied to produce a fine fiber layer 20 exhibiting desired efficiency and flow restriction characteristics.
  • a fine fiber layer 20 thick enough to produce a particle efficiency of the fine fiber coated media in the LEFS (Low Efficiency Flat Sheet) rating range of 60% to 85% and preferably not less than 70%o, and a permeability of from about 10-50 feet per minute (Frazier air) is preferred.
  • the layered media preferably meets the BIA-C filtration standard initial filtration efficiency of at least 99.9% for 0.2 to 2 micron dust particles.
  • a flame retardant may be added to the layered filter material meeting the LEFS and BIA-C performance standards.
  • Such flame retardants are particularly applicable to use situations wherein the airborne particulates are combustible or in which the environment in which the filter is used as highly combustible.
  • the flame retardant substance is preferably added to the resin during manufacture of the media, but could also be applied to the media after it is made.
  • Such flame retardants may be of any type well- known in the art.
  • "halogen-type" flame retardant materials i.e.
  • the media of this invention can be shaped and configured into filter cartridges or panels for use in filtration apparatus as is well-known in the industry.
  • the filter portion of cartridges could assume any type of geometrical shapes most common of which are flat panel filters elements or cylindrically shaped filter elements.
  • the filter cartridge 30 is of the type generally described in cross-referenced U.S. Patents 4,171,963, and 4,395,269 with the improved filter media of this invention.
  • the filter cartridge of the preferred embodiment is generally of a cylindrical shape that it easy to mount on yoke assemblies, such as the type described in U.S. Patent 4,395,269, wherein portions of the filter element slide along portions of the yoke during mounting. Further, the cartridge is preferably of a type that is easy to crush for disposal after use. In many dust collector filtration systems a plurality of such filter cartridges are coaxially mounted, end-to-end, on a common yoke assembly.
  • the filter cartridge generally has a layer of filter media 31 of the type previously described with respect to Figs. 1-3, having an all-cellulose fiber substrate formed with as described above, with a corrugation pattern of less than 6.7 cycles per inch and a corrugation height of greater than 18 mils, coated with a layer of fine fibers.
  • the media 31 is formed into a cylindrical shape and is maintained in such shape between a pair of end caps 33 and 34.
  • the end caps are preferably constructed of a soft polymeric material in which the ends of the filter media are potted.
  • the polymeric material is preferably of a type that can withstand the forces exerted on the end caps of the filter element while in use, that can maintain their integrity when exposed to contaminated air, and that allows the filter element to be easily crushed with the filter cartridge is disposed after use.
  • the filter media 31 is preferably used in association with one or a combination of liner members. As illustrated in Figs. 5 and 6, the filter media 31 is positioned between inner and outer protective liners 35 and 36 respectively that extend in conventional manner between the end caps 33 and 34 and provide physical protection for the filter media.
  • the inner and outer liners comprise perforated materials such as perforated metal sheets or expanded metal screen, cylindrically arranged in close proximity to the cylindrical surfaces of the media.
  • At least one of the end caps generally contains an appropriate seal, such as illustrated by the sealing ring 40 of end cap 33.
  • Sealing ring 40 extends axially outward from the end surface 41 of the filter cartridge.
  • the sealing ring 40 is configured for providing a seal between the filter cartridge and the mounting yoke assembly of the dust collector or filtration apparatus, or to an adjacent filter cartridge, as is known in the art.
  • the inner annular surface 42 of the end cap 33 provides a first slidable surface for sliding the filter cartridge over the mounting yoke assembly of a dust collector.
  • the second end cap 34 is similar to the first end cap 33, but does not have a sealing ring such as 40.
  • the second end cap is generally sealed by whatever structure secures the filter element 30 in place in a dust collector or air filtration system.
  • the end cap 34 would be sealed by a sealing ring 40 of the second filter cartridge.
  • the second end cap could be sealed by a securing mechanism included in the dust collector or filtration system, as is well- known in the art, and as fully described in U.S. Patent 4,395,269.
  • the inner surface 44 of the end cap 34 defines a sliding mounting surface similar in function to surface 42 of the first end cap 33.
  • the filter cartridge 30 receives air to be filtered through its outer cylindrical surface area 46, which then passes through the filter media 31 and out through its inner cylindrical surface 48.
  • the filtered air passes into central cavity 50 of the filter cartridge and leaves the cartridge through the aperture 52 formed by the first end cap 33.
  • a filter cartridge of cylindrical shape has been illustrated, those skilled in the art will readily recognize that other filter configurations, such as for example, generally planar filter panels could equally well be configured using the novel media of this invention.
  • a particular configuration of dust collector assembly has been used to describe a filter cartridge of this invention, those skilled in the art will readily recognize many other variations of dust collectors and air filtration assemblies that can benefit from use of filters incorporating the novel media of this invention.
  • Fig. 7 illustrates the results of efficiency testing of a filter panel constructed according to the principles of this invention, as compared to an all- cellulose filter media representing the best known media of the prior art that is also produced by the assignee of this invention.
  • a comparison of the base substrate parameters for the two medias is listed in Table 1.
  • the Fig. 7 graph shows that the base substrate cellulose material, by itself (i.e. without a fine fiber layer), provides an LEFS (Low Efficiency Flat Sheet) rating of less than 40% based on the discontinued ASTM spec 1215.
  • LEFS Low Efficiency Flat Sheet
  • the media of this invention tests at a significantly higher 70%-75% LEFS efficiency level.
  • the test results of Fig. 7 were obtained using an efficiency quality control bench at Donaldson Corporation, using 0.7 micron latex beads at a velocity of 20 feet per minute.
  • the graph also illustrates that a minimum efficiency of 70% on this bench is required to meet the BIA class C requirements, and that the filter media of this invention meets those requirements.
  • the Fig. 7 test illustrates that the media of the present invention meets the BIA-C industry standard for start-up or initial clean air efficiency.
  • a filter media For filtering very fine and/or hazardous dust, it is necessary for a filter media to feature high initial efficiency to avoid air stream contamination at the start-up of the collector.
  • the BIA or "Berufsartenschaftliches Institute Fuer Häriol” is the German/European Institute for Health and Safety at work that provides internationally recognized and accepted tests for evaluating and rating media efficiency.
  • the test procedure comprises a series of status tests used to rate filter media when air is to be returned to the work place.
  • the BIA-C certification states highest initial efficiency at 99.9% on 0.2-2 micron dust particles. This is the current limit of their measuring capabilities.
  • This test guarantees less than 0.1 % dust penetration through the media when using dust in the size range of 0.2-2 microns.
  • the media of this invention passes this test, which allow for filtration of many fine dusts and fumes without additional HEPA filtration.
  • Test 1 Several field tests have been conducted to date on the new media of this invention, and have shown and continue to show positive results of longer filter life. Three of such tests are briefly outlined below. Test 1
  • the filter application for the first test was an industrial application for thermal spraying of zinc coating materials.
  • the filtration apparatus was operated 24 hours per day, six days a week.
  • the dust collector model used was a model DFT3- 24 down flow dust collector with a drop-out box for pre-cleaning manufactured by Donaldson Corporation.
  • the dust collector had previously used a filter of the type generally described as the prior art filter of Table 1.
  • the prior art filter demonstrated an AMR (Air to Media Ratio) of 0.9:1. Under such conditions of use, the collector never realized more than three months of filter life, and the DeltaP (i.e. pressure differential) across the filter was terminal (i.e. the final or maximum amount of permissible pressure drop across the filter) at the three month interval.
  • the prior art filter was replaced by a filter having media of this invention, as described in Table 1, with an AMR of 0.9: 1. After three months of operation, the new filter media was still operating well within specifications and had a very low DeltaP of 1.6 inches of water. Test 2
  • the filter application for the second test was an industrial application for heavy duty electric arc zinc spraying.
  • the dust collector model used was a DFT4-96 down flow dust collector manufactured by Donaldson Corporation wherein the filter cartridges of the dust collector were preceded in the flow path by a Cyclone pre-separator for removing large particles.
  • the dust collector had previously used a filter of the type generally described as the prior art filter of Table 1.
  • the prior art filter initially demonstrated an AMR of 0.63 : 1.
  • the DeltaP fluctuated daily with pressure differentials of to 3.5 inches of water with down time pulsing.
  • the prior art filter was replaced by a filter having media of this invention, as described in Table 1.
  • the new filter demonstrated an AMR of 0.7:1, an 11% improvement in airflow.
  • the new filter also showed a stabilized DeltaP at 2 inches of water.
  • Test 3 The filter application for the third test was an industrial application for grinding steel panel boxes.
  • the dust collector model used was a DFT2-8 down flow dust collector manufactured by Donaldson Corporation.
  • the dust collector previously used a filter of the type generally described as the prior art filter of Table 1 and demonstrated an AMR of 2.2:1.
  • the DeltaP for the prior art filter was extremely high, and the filter was on a four month maintenance schedule for replacement due to the high pressure drop.
  • the prior art filter was replaced by a filter having media of this invention, as described in Table 1.
  • the AMR for the new filter was 2.2:1. After nine months of operation in the system, the new filter had a DeltaP of 3.0 inches of water.
  • the replacement filters configured according the principles of this invention consistently demonstrated longer filter life and improved operating characteristics over the prior filter, at significantly lower pressure drops.
  • a comparative testing of the filter media of this invention with a prior art filter media were formed into filter cartridges and tested in a Downflow collector using a test dust with a mean particle size of 2.5 microns, which was fed at a rate of 35 pounds per hour into the collector.
  • the test results are shown in the graph of Fig. 8.
  • One way of measuring filter life is by comparing pressure drop over time. The graph illustrates that the media of this invention has a 15% lower pressure drop at 500 hours of operation than that of the prior art media. This co ⁇ elates to a 15%) increase in filter life for this particular application.
  • a second method of comparing filter life is to compare the time it takes for a filter to reach a specific pressure drop. Using this approach, the new filter media of this invention took 300%) longer to reach two inches of water than the prior art cartridge media.
  • the filter medias of this invention provide a significant improvement over prior art medias.
  • the medias of this invention provides relatively low cost medias for dust collection which display longer filter life at a significantly lower pressure drop; increased rigidity, higher durability and superior cleanability; start-up efficiency of 99.9% on 0.2-2 micron dust particles, satisfying the industry BIA-C standard; and superior particle release due to surface filtration and improved pulse cleaning capabilities.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • Geometry (AREA)
  • Engineering & Computer Science (AREA)
  • Nanotechnology (AREA)
  • Filtering Materials (AREA)

Abstract

L'invention concerne des matériaux filtrant l'air et leur utilisation dans des applications de filtration. L'un de ces matériaux filtrants utilise un substrat, constitué de fibres de pure cellulose, cannelé au moyen d'une résine non phénolique ne nécessitant aucun traitement post plissage, le cycle d'ondulation étant inférieur à 6,3 cycles par pouce et les ondulations ayant une hauteur ou une profondeur supérieure à mils. Un autre de ces matériaux utilise une substrat cannelé pure cellulose dont les ondulations sont caractérisées par un cycle inférieur à 6,7 cycles par pouce et une hauteur ou une profondeur supérieure à 18 mils. On dépose une couche de fibres fines sur le matériau de base du substrat pour conférer un pouvoir filtrant efficace aux particules inférieures au micron à la surface desdits matériaux. Cette couche de fibres fines favorise la formation de gâteaux de poussière à la surface des matériaux et facilite ainsi le nettoyage pulsé desdits matériaux. Les matériaux selon l'invention permettent de fabriquer des panneaux filtrants renfermant des feuilles pliées de différentes configurations, qui peuvent être utilisés dans des cartouches filtrantes et dans le cadre de diverses applications de filtration. L'invention concerne des panneaux filtrants répondant à la norme de filtration BIA-C pour les rendements de filtration de 99,9 % sur des particules de poussière ayant une taille comprise entre 0,2 et 2 microns, lesquels panneaux peuvent être ignifugés.
PCT/US2000/020282 1999-07-30 2000-07-26 Materiaux filtrants a base de cellulose et cartouche associee WO2001008781A2 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU63753/00A AU6375300A (en) 1999-07-30 2000-07-26 Cellulose based filter media and cartridge apparatus

Applications Claiming Priority (2)

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US36452599A 1999-07-30 1999-07-30
US09/364,525 1999-07-30

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Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10150073A1 (de) * 2001-10-10 2003-04-24 Mann & Hummel Filter Mehrlagiges Filtermedium und Herstellprozess
EP1355714A2 (fr) 2000-09-05 2003-10-29 Donaldson Company, Inc. Dispositif filtrant plisse et procede associe
EP1713558A1 (fr) * 2004-02-02 2006-10-25 Nanosys, Inc. Substrats poreux, articles, systemes et compositions comprenant des nanofibres et procedes pour les utiliser les produire
EP1733776A2 (fr) * 2000-09-05 2006-12-20 Donaldson Company, Inc. Matériau filtrant comprenant un support filtrant et une couche de fibres fines
EP1775006A1 (fr) 2005-10-14 2007-04-18 General Electric Company Dispositif et média de filtration, et méthodes de fabrication
EP1795250A1 (fr) * 2000-09-05 2007-06-13 Donaldson Company, Inc. Élément de filtration utilisant une construction plissée
US8206484B2 (en) 2008-08-13 2012-06-26 Dow Global Technologies Llc Process for producing micron and submicron fibers and nonwoven webs by melt blowing
US8365925B2 (en) 2008-08-13 2013-02-05 Dow Global Technologies Llc Filter medium
US8584871B2 (en) 2007-05-30 2013-11-19 Dow Global Technologies Llc High-output solvent-based electrospinning
EP2620205A3 (fr) * 2007-02-28 2013-12-18 Hollingsworth & Vose Company Éléments et supports de filtre ondulé
US8882875B2 (en) 2007-02-28 2014-11-11 Hollingsworth & Vose Company Waved filter media and elements
US9718012B2 (en) 2000-09-05 2017-08-01 Donaldson Company, Inc. Fine fiber media layer
US10279341B2 (en) 2004-02-02 2019-05-07 Oned Material Llc Porous substrates, articles, systems and compositions comprising nanofibers and methods of their use and production
US10441909B2 (en) 2014-06-25 2019-10-15 Hollingsworth & Vose Company Filter media including oriented fibers
US10449474B2 (en) 2015-09-18 2019-10-22 Hollingsworth & Vose Company Filter media including a waved filtration layer
US10490817B2 (en) 2009-05-19 2019-11-26 Oned Material Llc Nanostructured materials for battery applications
US10561972B2 (en) 2015-09-18 2020-02-18 Hollingsworth & Vose Company Filter media including a waved filtration layer
US11020689B2 (en) 2012-04-27 2021-06-01 Sartorius Stedim Biotech Gmbh Filter element with improved testability after dry steaming

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4246066A (en) * 1975-02-12 1981-01-20 Mitsubishi Paper Mills, Ltd. Method for producing fibrous sheet
US4623462A (en) * 1984-10-29 1986-11-18 The Bf Goodrich Company Oil filters using water-based latex binders
US5427597A (en) * 1992-07-07 1995-06-27 Donaldson Company, Inc. Layered air filter medium having improved efficiency and pleatability
DE19752143A1 (de) * 1997-11-25 1999-05-27 Mann & Hummel Filter Filterelement

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1085529A (ja) * 1996-09-19 1998-04-07 Gun Ei Chem Ind Co Ltd フィルター用濾紙及びその製造方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4246066A (en) * 1975-02-12 1981-01-20 Mitsubishi Paper Mills, Ltd. Method for producing fibrous sheet
US4623462A (en) * 1984-10-29 1986-11-18 The Bf Goodrich Company Oil filters using water-based latex binders
US5427597A (en) * 1992-07-07 1995-06-27 Donaldson Company, Inc. Layered air filter medium having improved efficiency and pleatability
DE19752143A1 (de) * 1997-11-25 1999-05-27 Mann & Hummel Filter Filterelement

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 1998, no. 09, 31 July 1998 (1998-07-31) & JP 10 085529 A (GUN EI CHEM IND CO LTD;TOWA KK), 7 April 1998 (1998-04-07) *

Cited By (30)

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EP1820553A3 (fr) * 2000-09-05 2007-11-21 Donaldson Company, Inc. Polymère, microfibre polymère, nanofibre polymère et applications incluant des structures filtrantes
EP1733776A3 (fr) * 2000-09-05 2007-11-28 Donaldson Company, Inc. Matériau filtrant comprenant un support filtrant et une couche de fibres fines
EP1733776A2 (fr) * 2000-09-05 2006-12-20 Donaldson Company, Inc. Matériau filtrant comprenant un support filtrant et une couche de fibres fines
US10272374B2 (en) 2000-09-05 2019-04-30 Donaldson Company, Inc. Fine fiber media layer
EP1795250A1 (fr) * 2000-09-05 2007-06-13 Donaldson Company, Inc. Élément de filtration utilisant une construction plissée
EP1355714A2 (fr) 2000-09-05 2003-10-29 Donaldson Company, Inc. Dispositif filtrant plisse et procede associe
US10967315B2 (en) 2000-09-05 2021-04-06 Donaldson Company, Inc. Fine fiber media layer
US9718012B2 (en) 2000-09-05 2017-08-01 Donaldson Company, Inc. Fine fiber media layer
DE10150073A1 (de) * 2001-10-10 2003-04-24 Mann & Hummel Filter Mehrlagiges Filtermedium und Herstellprozess
US8025960B2 (en) 2004-02-02 2011-09-27 Nanosys, Inc. Porous substrates, articles, systems and compositions comprising nanofibers and methods of their use and production
AU2005210654B2 (en) * 2004-02-02 2010-04-01 Oned Material Llc Porous substrates, articles, systems and compositions comprising nanofibers and methods of their use and production
EP1713558A4 (fr) * 2004-02-02 2009-01-28 Nanosys Inc Substrats poreux, articles, systemes et compositions comprenant des nanofibres et procedes pour les utiliser les produire
US10279341B2 (en) 2004-02-02 2019-05-07 Oned Material Llc Porous substrates, articles, systems and compositions comprising nanofibers and methods of their use and production
EP1713558A1 (fr) * 2004-02-02 2006-10-25 Nanosys, Inc. Substrats poreux, articles, systemes et compositions comprenant des nanofibres et procedes pour les utiliser les produire
EP1775006A1 (fr) 2005-10-14 2007-04-18 General Electric Company Dispositif et média de filtration, et méthodes de fabrication
EP2620205A3 (fr) * 2007-02-28 2013-12-18 Hollingsworth & Vose Company Éléments et supports de filtre ondulé
US10758858B2 (en) 2007-02-28 2020-09-01 Hollingsworth & Vose Company Waved filter media and elements
US9718020B2 (en) 2007-02-28 2017-08-01 Hollingsworth & Vose Company Waved filter media and elements
US8882875B2 (en) 2007-02-28 2014-11-11 Hollingsworth & Vose Company Waved filter media and elements
US9687771B2 (en) 2007-02-28 2017-06-27 Hollingsworth & Vose Company Waved filter media and elements
US8584871B2 (en) 2007-05-30 2013-11-19 Dow Global Technologies Llc High-output solvent-based electrospinning
US8365925B2 (en) 2008-08-13 2013-02-05 Dow Global Technologies Llc Filter medium
US8206484B2 (en) 2008-08-13 2012-06-26 Dow Global Technologies Llc Process for producing micron and submicron fibers and nonwoven webs by melt blowing
US10490817B2 (en) 2009-05-19 2019-11-26 Oned Material Llc Nanostructured materials for battery applications
US11233240B2 (en) 2009-05-19 2022-01-25 Oned Material, Inc. Nanostructured materials for battery applications
US11600821B2 (en) 2009-05-19 2023-03-07 Oned Material, Inc. Nanostructured materials for battery applications
US11020689B2 (en) 2012-04-27 2021-06-01 Sartorius Stedim Biotech Gmbh Filter element with improved testability after dry steaming
US10441909B2 (en) 2014-06-25 2019-10-15 Hollingsworth & Vose Company Filter media including oriented fibers
US10449474B2 (en) 2015-09-18 2019-10-22 Hollingsworth & Vose Company Filter media including a waved filtration layer
US10561972B2 (en) 2015-09-18 2020-02-18 Hollingsworth & Vose Company Filter media including a waved filtration layer

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AU6375300A (en) 2001-02-19

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