Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/11—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements
  • B01D29/13—Supported filter elements
  • B01D29/15—Supported filter elements arranged for inward flow filtration
  • B01D29/21—Supported filter elements arranged for inward flow filtration with corrugated, folded or wound sheets
  • B01D29/216—Supported filter elements arranged for inward flow filtration with corrugated, folded or wound sheets with wound sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/11—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements
  • B01D29/13—Supported filter elements
  • B01D29/15—Supported filter elements arranged for inward flow filtration
  • B01D29/21—Supported filter elements arranged for inward flow filtration with corrugated, folded or wound sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/11—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements
  • B01D29/13—Supported filter elements
  • B01D29/23—Supported filter elements arranged for outward flow filtration
  • B01D29/232—Supported filter elements arranged for outward flow filtration with corrugated, folded or wound sheets
  • B01D29/237—Supported filter elements arranged for outward flow filtration with corrugated, folded or wound sheets with wound sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/50—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition
  • B01D29/56—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition in series connection
  • B01D29/58—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition in series connection arranged concentrically or coaxially
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D39/00—Filtering material for liquid or gaseous fluids
• • 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
  • B01D39/1692—Other shaped material, e.g. perforated or porous sheets
• • 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
  • 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
  • B01D46/522—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material using folded, pleated material with specific folds, e.g. having different lengths
• • 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
  • B01D46/525—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material using folded, pleated material which comprises flutes
  • B01D46/527—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material using folded, pleated material which comprises flutes in wound arrangement
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2201/00—Details relating to filtering apparatus
  • B01D2201/04—Supports for the filtering elements
  • B01D2201/0407—Perforated supports on both sides of the filtering element
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2201/00—Details relating to filtering apparatus
  • B01D2201/04—Supports for the filtering elements
  • B01D2201/0415—Details of supporting structures
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2201/00—Details relating to filtering apparatus
  • B01D2201/12—Pleated filters
  • B01D2201/122—Pleated filters with pleats of different length
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
  • B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
  • B01D2239/065—More than one layer present in the filtering material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
  • B01D2239/12—Special parameters characterising the filtering material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
  • B01D2239/12—Special parameters characterising the filtering material
  • B01D2239/1216—Pore size
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2265/00—Casings, housings or mounting for filters specially adapted for separating dispersed particles from gases or vapours
  • B01D2265/06—Details of supporting structures for filtering material, e.g. cores

Definitions

• An aspect of the invention provides a cylindrical porous filter comprising an inner core and an outer cage, with an annular gap between the inner core and the outer cage, with a cylindrical hollow porous filter element arranged in the annular gap between the inner core and the outer cage, the annular gap having a width; wherein the cylindrical hollow porous pleated filter element has first and second end surfaces, the cylindrical hollow porous pleated filter element comprising a plurality of filter element groups, each of the plurality of filter element groups comprising a first filter element sub-group comprising a first bridge followed by a plurality of longitudinal pleats having longitudinal pleat heights, alternating with a second filter element sub-group comprising a second bridge followed by at least one longitudinal counter-pleat having a longitudinal counter-pleat height; wherein the first bridge and the second bridge each have a height greater than the width of the annular gap; wherein the plurality of longitudinal pleats in the first filter element sub-group has a first pleat with a tallest height, and a second longitudinal pleat with
• each first bridge has a front first bridge surface and a rear first bridge surface; each of the longitudinal pleats has a pair of longitudinal pleat legs, each of the longitudinal pleat legs having a first longitudinal pleat leg surface and a second longitudinal pleat leg surface; each second bridge has a front second bridge surface and a rear second bridge surface; the at least one longitudinal counter-pleat having a pair of longitudinal counter-pleat legs, each of the longitudinal counter-pleat legs having a first longitudinal counter-pleat leg surface and a second longitudinal counter-pleat leg surface; the first bridge, the longitudinal pleats, the second bridge, and the at least one longitudinal counter-pleat, being in a laid-over state in which a longitudinal pleat leg surface of one longitudinal pleat is in intimate contact with at least one of any of a longitudinal pleat leg surface of an adjoining leg of the one longitudinal pleat, a longitudinal pleat leg surface of an adjacent longitudinal pleat, a rear first bridge surface, and a front second bridge surface; and, a longitudinal counter-pleat
• a method of filtering fluid comprising passing the fluid through an aspect of a cylindrical porous filter comprising an inner core and an outer cage, with an annular gap between the inner core and the outer cage, with a cylmdncal hollow porous filter element arranged in the annular gap between the inner core and the outer cage, the annular gap having a width; wherein the cylindrical hollow porous pleated filter element has first and second end surfaces, the cylindrical hollow porous pleated filter element comprising a first filter element sub-group comprising a first bridge followed by a plurality of longitudinal pleats having longitudinal pleat heights, alternating with a second filter element sub-group comprising a second bridge followed by at least one longitudinal counter-pleat having a longitudinal counter-pleat height; wherein the first bridge and the second bridge each have a height greater than the width of the annular gap; wherein the plurality of longitudinal pleats in the first filter element sub-group has a first pleat with a tallest height, and
• a cylindrical hollow porous pleated filter element comprising a plurality of filter element groups, each of the plurality of filter element groups comprising a first filter element sub-group comprising a first bridge followed by a plurality of longitudinal pleats having longitudinal pleat heights, alternating with a second filter element sub-group comprising a second bridge followed by at least one longitudinal counter-pleat having a longitudinal counter-pleat height; wherein the plurality of longitudinal pleats in the first filter element sub-group has a first pleat with a tallest height, and a second longitudinal pleat with a shortest height, wherein the height of the first longitudinal pleat is in the range of 25% to 35% lower than the height of the first bridge, and the height of the second longitudinal pleat is in the range of 65% to 75% lower than the height of the first bridge; and wherein the at least one longitudinal counter-pleat in the second filter element sub-group has a longitudinal counter-pleat height is in the range
• FIG. 1 is a drawing showing, diagrammatically, pleats with mixed pleat heights for use in preparing a filter element according to an aspect of the invention, (wherein, for ease of reference, the pleats are shown expanded before compression to form a pleated porous filter element, and an inner core and outer cage are also shown), showing an aspect of a pleated cylindrical hollow porous filter element arranged in an annular gap between the inner core and the outer cage, the annular gap having a width; the pleated cyhndncal hollow porous filter element comprising a plurality of filter element groups, each of the plurality of filter element groups comprising a first filter element sub-group comprising a first bridge followed by a plurality of longitudinal pleats having longitudinal pleat heights, each first filter element sub-group alternating with a second filter element sub-group comprising a second bridge followed by at least one longitudinal counter-pleat having a longitudinal counter-pleat height, wherein first and second groups of longitudinal pleats facing inwardly (tips facing toward an
• Figure 2A is a photograph showing the filter element as shown in Figure 1; and Figure 2B is a photograph showing, in a partial cut-away view, a computed tomography (CT) scan of an assembled filter element with mixed pleat heights as generally shown in Figures 1 and 2A; Figure 2C is a drawing showing the filter element as shown in Figure 2A partially compressed.
• CT computed tomography
• Figure 3 is a drawing showing a cut-away perspective diagrammatic view of a filter including a filter element with mixed pleat heights shown in Figure 2B (filter element not fully compressed) according to another aspect of the invention.
• a cylindrical porous filter comprising an inner core and an outer cage, with an annular gap between the inner core and the outer cage, with a cylindrical hollow porous filter element arranged in the annular gap between the inner core and the outer cage, the annular gap having a width; wherein the cylindrical hollow porous pleated filter element has first and second end surfaces, the cylindrical hollow porous pleated filter element comprising a plurality of filter element groups, each of the plurality of filter element groups comprising a first filter element sub-group comprising a first bridge follow ed by a plurality of longitudinal pleats having longitudinal pleat heights, alternating with a second filter element sub-group comprising a second bridge followed by at least one longitudinal counter-pleat having a longitudinal counter-pleat height; wherein the first bridge and the second bridge each have a height greater than the width of the annular gap; wherein the plurality of longitudinal pleats in the first filter element sub-group has a first pleat with a tallest height
• a cylindrical hollow porous pleated filter element comprising a plurality of filter element groups, each of the plurality of filter element groups comprising a first filter element sub-group comprising a first bridge followed by a plurality of longitudinal pleats having longitudinal pleat heights, alternating with a second filter element sub-group comprising a second bridge followed by at least one longitudinal counter-pleat having a longitudinal counter-pleat height; wherein the plurality of longitudinal pleats in the first filter element sub-group has a first pleat with a tallest height, and a second longitudinal pleat with a shortest height, wherein the height of the first longitudinal pleat is in the range of 25% to 35% lower than the height of the first bridge, and the height of the second longitudinal pleat is in the range of 65% to 75% lower than the height of the first bridge; and wherein the at least one longitudinal counter-pleat in the second filter element sub-group has a longitudinal counter-pleat height is in the range
• a method of filtering fluid comprising passing the fluid through an aspect of a cylindrical porous filter comprising an inner core and an outer cage, with an annular gap between the inner core and the outer cage, with a cylindrical hollow porous filter element arranged in the annular gap between the inner core and the outer cage, the annular gap having a width; wherein the cylindrical hollow porous pleated filter element has first and second end surfaces, the cylindrical hollow porous pleated filter element comprising a first filter element sub-group comprising a first bridge followed by a plurality of longitudinal pleats having longitudinal pleat heights, alternating with a second filter element sub-group comprising a second bridge followed by at least one longitudinal counter-pleat having a longitudinal counter-pleat height; wherein the first bridge and the second bridge each have a height greater than the width of the annular gap; wherein the plurality of longitudinal pleats in the first filter element sub-group has a first pleat with a tallest height, and a second longitudinal pleat with
• aspects of the method can include outside-in flow in which a fluid to be filtered flows from the outer cage through the filter element into the inner core, or include inside-out flow in which fluid flows from the inner core through the filter element to the outer cage.
• a first impervious end cap is connected to the first end surface of the filter element.
• each first bridge has a front first bridge surface and a rear first bridge surface; each of the longitudinal pleats has a pair of longitudinal pleat legs, each of the longitudinal pleat legs having a first longitudinal pleat leg surface and a second longitudinal pleat leg surface; each second bridge has a front second bridge surface and a rear second bridge surface; the at least one longitudinal counter-pleat having a pair of longitudinal counter-pleat legs, each of the longitudinal counter-pleat legs having a first longitudinal counter-pleat leg surface and a second longitudinal counter-pleat leg surface; the first bridge, the longitudinal pleats, the second bridge, and the at least one longitudinal counter-pleat, being in a laid-over state in which a longitudinal pleat leg surface of one longitudinal pleat is in intimate contact with at least one of any of a longitudinal pleat leg surface of an adjoining leg of the one longitudinal pleat, a longitudinal pleat leg surface of an adjacent longitudinal pleat, a rear first bridge surface, and a front second bndge surface; and, a longitudinal counter-pleat having a pair
• a second (inner) longitudinal pleat leg surface of a longitudinal pleat leg of one longitudinal pleat is in intimate contact with a second (inner) longitudinal pleat leg surface of an adjoining leg of the one longitudinal pleat
• a first (outer) longitudinal pleat leg surface of a longitudinal pleat leg of one longitudinal pleat is in intimate contact with a rear first bridge surface, or a front second bridge surface
• a first (outer) longitudinal pleat leg surface of an adjacent longitudinal pleat and/or a second (inner) longitudinal counter-pleat leg surface of a longitudinal counter-pleat leg of the at least one longitudinal counter-pleat is in intimate contact with a second (inner) longitudinal counter-pleat leg surface of an adjoining leg of the at least one longitudinal counter-pleat
• a first (outer) longitudinal counter-pleat leg surface of the longitudinal counter-pleat leg of the at least one longitudinal counter-pleat may be in in intimate contact with a rear second bridge surface, or a front first bridge surface.
• the first bridges have heights that are in a range of 10% to 25% greater than the annular gap between the inner core and the outer cage and/or the second bridges have heights that are in a range of 10% to 25% greater than the annular gap between the inner core and the outer cage.
• filter elements can have lower packing densities and higher permeabilities, while maintaining desirable pressure differentials and reduced membrane area, while edge-flow resistance is reduced.
• Embodiments of filter elements according to aspects of the invention are generally hollow cylindrical in form and comprise pleated porous media including mixtures of pleat heights wherein a plurality of longitudinal pleats face inwardly (tips facing toward an inner core; heights (I)H1-(I)H2) and at least one longitudinal counter-pleat faces outwardly (tip facing toward an outer cage; counter-pleat; height (O)H1).
• FIG 1 illustrates, diagrammatically (wherein, for ease of reference, the pleats are shown expanded before compression to form the pleated porous filter element), an aspect of a pleated cylindrical hollow porous filter element 3000 is arranged in the annular gap G between a perforated inner core 800 and an outer cage 900, the annular gap having a width W; the pleated cylindrical hollow porous filter element having a longitudinal axis (see, Fig. 3) and first and second end surfaces, the cylindrical hollow porous pleated filter element comprising a plurality of filter element groups GRP,
• each of the plurality of filter element groups GRP comprising a first filter element sub-group SGI comprising a first bridge Bl (having a front first bridge surface and a rear first bridge surface) followed by a plurality of longitudinal pleats 100A, 200A having longitudinal pleat heights, each first filter element sub-group SGI alternating with a second filter element sub-group SG2 comprising a second bridge B2 (having a front second bridge surface and a rear second bridge surface) followed by at least one longitudinal counter-pleat 100B having a longitudinal pleat height;
• first bridge Bl and the second bridge B2 have respective heights BIH, B2H greater than the width of the annular gap;
• the plurality of longitudinal pleats in the first filter element sub-group SGI has a first pleat with a tallest height (I)H1 , and a second longitudinal pleat with a shortest height (I)H2, wherein the height (I)H1 of the first longitudinal pleat is in the range of 25% to 35% lower than the height BH1 of the first bridge Bl, and the height (I)H2 of the second longitudinal pleat is in the range of 65% to 75% lower than the height BH1 of the first bridge Bl; and
• the at least one longitudinal counter-pleat in the second filter element sub-group SG2 has a longitudinal counter-pleat height (O)H1 in the range of 25% to 35% lower than the height BH2 of the second bridge B2;
• the first bridge, the longitudinal pleats, the second bridge, and the at least one longitudinal pleat being in a laid-over state (shown in Figures 2B and 3).
• Each pleat comprises a pair of legs, each leg having an inner surface, and outer surface (thus, the legs have opposing interior surfaces and opposing exterior surfaces), a leg length, and a crown or tip where the legs meet (adjoined) and the pleat is folded over.
• Each leg has a root abutting the core (for longitudinal counter-pleats) or cage (longitudinal pleats), and the pleats extend axially from the core or cage, respectively.
• each leg of pleats (I)H1 are equal to each other
• lengths of each leg of pleats (I)H2 are equal to each other
• the lengths of each leg of pleats (O)H1 are equal to each other
• the lengths of each leg in the pair of pleats (I)H2 and (O)H1 are equal to each other.
• the formed filter element will have laid-over pleats. Accordingly, the first bridge, the longitudinal pleats, the second bridge, and the at least one longitudinal counter-pleats, are in a laid-over state in which a longitudinal pleat leg surface of one longitudinal pleat is in intimate contact with at least one of any of a longitudinal pleat leg surface of an adjoining leg of the one longitudinal pleat, a longitudinal pleat leg surface of an adjacent longitudinal pleat, a rear first bridge surface, and a front second bridge surface; and, a longitudinal counter-pleat leg surface of the at least one longitudinal counter-pleat is in intimate contact with at least one any of a longitudinal counter-pleat leg surface of an adj oining leg of the one longitudinal counter-pleat, a front first bridge surface, and a rear second bridge surface.
• each second (inner) longitudinal counter-pleat leg surface of one longitudinal counter-pleat is in intimate contact with a second (inner) longitudinal counter-pleat leg surface of an adjoining leg of the one longitudinal counter-pleat, and a first (outer) counter-pleat leg surface of one longitudinal counter-pleat may also be in intimate contact with a rear first bridge surface, or a front second bridge surface, and/or each second (inner) longitudinal pleat leg surface of one longitudinal pleat is in intimate contact with a second (inner) longitudinal pleat leg surface of an adjoining leg of the one longitudinal pleat, and a first (outer) pleat leg surface of one longitudinal pleat may also be in intimate contact with a first (outer) longitudinal pleat leg surface of an adjacent longitudinal pleat, a front first bridge surface, or a rear second bridge surface.
• the rear first bridge surface will be in intimate contact with the first (outer) longitudinal pleat leg surface of the first longitudinal pleat leg of the following longitudinal pleat (100 A), the second (inner) longitudinal pleat leg surface of the first longitudinal pleat leg will be in intimate contact with the second (inner) longitudinal pleat leg surface of the adjoining second longitudinal pleat leg of that longitudinal pleat (100 A).
• the first (outer) longitudinal pleat leg surface of the second longitudinal pleat leg of that longitudinal pleat (100A) will be in intimate contact with the first (outer) longitudinal pleat leg surface of the first longitudinal pleat leg of the following (adjacent) longitudinal pleat (200 A), and so on with reference to Figure 1, e.g., the front second bridge surface will be in intimate contact with the first (outer) longitudinal pleat leg surface of the second longitudinal pleat leg of the longitudinal pleat (200A) following (adjacent) longitudinal pleat (100A), and the rear second bridge surface will be in intimate contact with the first (outer) longitudinal counter-pleat leg surface of the first longitudinal counter-pleat leg of the following (adjacent) longitudinal counter-pleat (100B).
• a cylindrical perforated inner core 800 is coaxially disposed along the inner periphery of the pleated porous filter element 3000, and a cylindrical cage 900 is disposed along the outer periphery of the filter element, and an annular gap G is present between the inner core and the outer cage, with the pleated porous filter element arranged in the gap between the inner core and the outer cage, the gap having a width W.
• the first bridge Bl and the second bridge B2 have respective heights BIH, B2H greater than the width of the annular gap and thus the bridges Bl and B2 each have ends that are bent facing the outer cage and the inner core as part of the laid-over state.
• the first bridges have heights that are in a range of 10% to 25% greater than the annular gap between the inner core and the outer cage and/or the second bridges have heights that are in a range of 10% to 25% greater than the width of annular gap between the inner core and the outer cage.
• the heights of the longitudinal pleats and the longitudinal counter-pleats are each less than the width of annular gap between the inner core and the outer cage.
• adjoining legs of the pleats need not be in intimate contact over the entire axial length of the filter element, but the greater is the length in the axial direction of the region of intimate contact, the more effectively used is the space between the inner and outer periphery of the filter element 3000. Therefore, adjoining legs are in intimate contact over a continuous region which can extend for at least approximately 50%, in some aspects, at least approximately 75%, or approximately 95-100% of the axial length of the filter element 3000
• porous filter medium 500 there are no particular restrictions on the type of porous filter medium 500 (see, Fig. 3) which can be employed in the porous filter element of the present invention, and it can be selected in accordance with the fluid which is to be filtered and the desired filtering characteristics.
• the porous filter medium/filter element comprises a polymeric medium.
• the filter element/filter can be used to filter fluids such as liquids, gases, or mixtures thereof used in various industries.
• the filter element/filter can be used to filter process fluids in the microelectronic industry for wet-etch cleans (e.g., a material removal process that uses liquid chemicals or etchants to remove materials from a wafer).
• CMP chemical-mechanical planarization
• the fluids can include, for example, standard clean 1 (SCI) fluids, standard clean 2 (SC2) fluids, Isopropyl Alcohol (IP A; including hot IP A), Sulfuric Acid (H2SO4 including hot H2SO4), Tetramethyl quaternary ammonium hydroxide (TMAH; including hot TAMH), hydrogen peroxide (H2O2, including hot H2O2), Ammonium Hydroxide (NH4OH; including hot NH4OH), and Hydrogen Fluoride (HF; including hot HF), among others, used independently or mixed with each other.
• SCI standard clean 1
• SC2 standard clean 2
• IP A including hot IP A
• Sulfuric Acid H2SO4 including hot H2SO4
• TMAH Tetramethyl quaternary ammonium hydroxide
• H2O2, including hot H2O2 Ammonium Hydroxide
• NH4OH including hot NH4OH
• HF Hydrogen Fluoride
• the pleated porous fdter element comprises, or is, a membrane.
• the membranes can have any suitable pore structure, e.g., a pore size (for example, as evidenced by bubble point, or by KL as described in, for example, U.S.
• Patent 4,340,479 or evidenced by capillary condensation flow porometry
• an average pore size e.g., when characterized using a porometer, for example, a Porvair Porometer (Porvair pic, Norfolk, UK), or a porometer available under the trademark POROLUX (Porometer.com; Belgium)
• MFP mean flow pore
• a pore rating e.g., when characterized using the modified OSU F2 test as described in, for example, U.S. Patent 4,925,572
• removal rating media e.g., when characterized using the modified OSU F2 test as described in, for example, U.S. Patent 4,925,572
• the pore structure used depends on the size of the particles to be utilized, the composition of the fluid to be treated, and the desired effluent level of the treated fluid.
• the membrane has (depending on the application), an average pore size in the range of 10 nm to 150 nm.
• the porous membrane can have any desired critical wetting surface tension (CWST, as defined in, for example, U.S. Patent 4,925,572).
• the CWST can be selected as is known in the art, e.g., as additionally disclosed in, for example, U.S. Patents 5,152,905, 5,443,743, 5,472,621, and 6,074,869.
• the membrane has a CWST of in the range of 28 dynes/cm (28 x 10' 5 N/cm) to 34 dynes/cm (34 x 10' 5 N/cm).
• Exemplary membranes are disclosed in U.S. Patents 4,702,840 and 4,900,449.
• Other membranes including those disclosed in U.S. Patents 4,906,374; 4,886,836; 4,964,989; 5,019,260; 4,340,479; 4,855,163; 4,744,132; 4,707,266; 4,203,848; 4,618,533, 6,039,872; 6,780,327; 6,783,937; and 7,189,322, may also be suitable.
• Exemplary membranes include, but are not limited to, nylon membranes, polytetrafluoroethylene (PTFE) membranes, high-density polyethylene (HDPE) membranes, and highly asymmetric polyarylsulfone (HAPAS) membranes.
• PTFE polytetrafluoroethylene
• HDPE high-density polyethylene
• HPAPAS highly asymmetric polyarylsulfone
• Exemplary' membranes may be used individually or in combination with any other exemplary membranes with the same or different characteristics.
• the filter can include additional elements, layers, or components, that can have different structures and/or functions, e.g., at least one of any one or more of the following: prefiltration, support, drainage, spacing and cushioning.
• the illustrated filter in addition to a cylindrical perforated inner core 800 coaxially disposed along the inner periphery of the filter element and a cylindrical outer cage 900 disposed along the outer periphery of the filter element 3000, the illustrated filter includes a first pleated mesh 501 contacting a first (e.g., upstream) surface of the porous medium 500 of the filter element, and a second pleated mesh 502 contacting a second (e.g., downstream) surface of the porous medium 500 of the filter element, providing a three-layer composite.
• references to contact between surfaces of the pleats refers to contact between the meshes on the referenced surfaces of the filter element, e.g., a second (inner) longitudinal counter-pleat leg surface of one longitudinal counter-pleat being in intimate contact with a second (inner) longitudinal counter-pleat leg surface of an adjoining leg of the one longitudinal counter-pleat, refers to the mesh on the second (inner) longitudinal counter-pleat leg surface of one longitudinal counter-pleat being in intimate contact with the mesh on a second (inner) longitudinal counter-pleat leg surface of an adjoining leg of the one longitudinal counter-pleat.
• the components (meshes, filter medium) forming the filter element can be formed into a composite by conventional filter manufacturing techniques, either prior to or simultaneous with corrugation.
• the meshes (the term “mesh” also includes “screen”) prevent opposing surfaces of the filter medium from coming into contact with one another and enables fluid to evenly flow to or from substantially all portions of the surface of the filter medium when the pleats are in the laid-over state. Thus, virtually the entire surface area of the filter medium may be effectively used for filtration.
• a variety of meshes are suitable for use in aspects of the invention.
• the meshes can be made of any materials having suitable edgewise flow characteristics, i.e., suitable resistance to fluid flow through the layer in a direction parallel to its surface.
• the edgewise flow resistance of the drainage meshes is preferably low enough that the pressure drop in the drainage layer is less than the pressure drop across the filter medium, thereby providing an even distribution of fluid along the surface of the filter medium.
• a filter 3100 will be equipped with end caps 850 (only one of which is shown in Fig. 3) at one or both ends of the filter element 3000.
• the end caps 850 can be either blind (closed) or open end caps, and the material of which they are formed and their shape can be selected in accordance with the filtering conditions and the materials of the members to which the end caps are to be joined.
• the end caps 850 are attached to the filter element 3000, but they may also be attached to the inner core 800 or the outer cage 900. Conventional techniques can be used to attach the end caps to the filter element.
• an insert in the form of a strip of material having a good affinity for the end cap material can be corrugated into the ends of the filter element 3000 to improve the seal between both ends of the filter element 3000 and the end caps 850.
• a strip of another fluoropolymer such as a fluorinated ethylene-propylene (FEP) resm, can be corrugated into the ends of the filter element as the insert.
• FEP fluorinated ethylene-propylene
• the insert need only be wide enough to bond the filter medium to the end cap, and therefore, it might extends for only a portion of the axial length of the filter element 3000.
• a typical width for the insert is approximately 0.5 inches.
• aspects of the filter device and filter are suitable for outside-in flow in which a fluid to be filtered flows from an outer periphery (e.g., the outer cage) through the filter element into the hollow center (e.g., the inner core), or it can be used for inside-out flow in which fluid flows from the hollow center (e.g., the inner core) through the filter element to the outer periphery (e.g., the outer cage).
• the filter element 3000 illustrated in Figure 3 can be manufactured by a variety of techniques, for example, as described in U.S. Patent 5,543,047.
• the filter composite is first corrugated to form a corrugated sheet, cut to a suitable length or suitable number of pleats, and then formed into a cylindrical shape. The lengthwise edges of the corrugated sheet are then sealed to each other by conventional means to form a cylindrical filter element. The pleats of the filter element are then laid over as the filter element 3000 is inserted into a cage 900. After the filter element has been fit into the cage 900, a core 800 is inserted into the hollow center of the filter element 10, and then end caps are attached to the ends of the filter element to form a completed filter.
• the filter comprising the filter element is disposed in a housing comprising at least one inlet and at least one outlet and defining at least one fluid flow path between the inlet and the outlet, wherein the filter is across the fluid flow path, to provide a filter device.
• the filter device is sterilizable. Any housing of suitable shape and providing at least one inlet and at least one outlet may be employed.
• the housing can be fabricated from any suitable rigid impervious material, including any impervious thermoplastic material, which is compatible with the fluid being processed.
• the housing can be fabricated from a metal, such as stainless steel, or from a polymer.
• the housing is a polymer, in some aspects, a transparent or translucent polymer, such as an acrylic, polypropylene, polystyrene, or a poly carbonated resin.
• This example demonstrates an improvement in permeability of a test filter device containing a filter element according to an aspect of the invention compared to test filter devices including a commercial available filter element that has laid-over longitudinal pleats (as generally descnbed in U.S. Patent 5,543,047).
• the filter element a high-density polyethylene (HDPE) membrane
• HDPE high-density polyethylene
• the filter element is pleated (with upstream and downstream meshes) using a Rabofsky PM600 corrugator such that the first and second bridge heights are 1 inch (wherein the width of the gap is .85 inches) the (I)H1 heights are 0.6 inches, the (I)H2 heights are 0.4 inches, and the (O)H1 heights are 0.3 inches (see, Figs. 1, 2A and 2B).
• the pore size is 15 nm.
• the commercially available filter element (HDPE membrane) has longitudinal pleat heights of 1 inch.
• the filter element according to an aspect of the invention and the commercially available filter element have the same perforated inner cores and outer cages, and the same gap width of .85 inches.
• Each filter element has an open end cap at one end and a closed end cap at the other end, and are placed in a test housing arranged for outside-in flow.
• the test device with the filter element according to an aspect of the invention has the same pressure drop but at a lower membrane area than the test device with the commercially available filter element.
• the permeability (flow per unit area per unit pressure drop) of the filter elements according to an aspect of the invention show an enhancement of up to 20%.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Physics & Mathematics (AREA)
• Geometry (AREA)
• Filtering Materials (AREA)
• Separation Using Semi-Permeable Membranes (AREA)
• Filtration Of Liquid (AREA)
• Filtering Of Dispersed Particles In Gases (AREA)

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• 2023
  • 2023-07-20 TW TW112127073A patent/TWI873730B/zh active
  • 2023-08-02 JP JP2025505576A patent/JP2025525132A/ja active Pending
  • 2023-08-02 KR KR1020257003419A patent/KR20250027834A/ko active Pending
  • 2023-08-02 CN CN202380061339.XA patent/CN119768217A/zh active Pending
  • 2023-08-02 EP EP23850702.4A patent/EP4565348A1/de active Pending
  • 2023-08-02 WO PCT/US2023/029265 patent/WO2024030464A1/en not_active Ceased

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