Enhancement of Fuel Water Separation Using Structural Embossing

Abstract

A filter medium, filter element, filter system, and method are provided. The filter medium provides improved filtering characteristics, including water separation efficiency. The filter medium may include one or more of increased surface roughness and / or embossing. The filter medium may be provided by pleated filter media.

Description

Technical Field

[0001] The present invention generally relates to filtration, and more specifically to, for example, agglomeration filtration systems for use in hydrocarbon fuel systems and their applications.

Background Art

[0002] Agglomeration filtration systems are often employed as a first stage in a filter / separator vessel for hydrocarbon fluids, such as fuels. Such systems filter to remove certain contaminants and agglomerate (bind together) highly dispersed and emulsified water particles into larger water droplets. These larger water droplets are then collected and removed from the system.

[0003] Various methodologies have been employed to achieve such agglomeration. For example, small droplets of water entrained in the fuel can adhere upon contact with the twisted yarns of a filter medium (e.g., glass fiber). The operating pressure within the system, and the flow of the fluid, push the droplets along these twisted yarns until the droplets reach the intersections of the twisted yarns where they combine, i.e., agglomerate into larger droplets.

[0004] Embossed patterns are often compression molded into the filter medium. These patterns often extend parallel to the flow direction, aligning the flow of the fluid parallel to the embossing and leading to a lower embossing contact area with the water droplets. For example, in a radial flow filter using a tube of filter medium having a vertical central axis, the elongated embossing typically has an elongated axis parallel to the radius of the tube of filter medium perpendicular to the central axis. This elongated axis is also in this case generally parallel to the flow of fluid from the upstream face of the filter medium block through the filter medium block to the downstream face of the filter medium block.

[0005] In use, the agglomerated water droplets flow along the filter medium, for example parallel to the central axis of the tube of the filter medium, into the water collection bowl. Unfortunately, this causes the water concentration to continuously increase as it moves from the top to the bottom of the filter medium tube, resulting in a high water concentration at the bottom of the element before the water droplets are collected within the water collection bowl. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] While the above-described system has been found to be satisfactory, there is still room for improvement. In fact, there is a constant desire to reduce the pressure drop across the filter element, and such pressure drop is typically driven by the filter medium used in the filter element. Therefore, there is a need in the art for a related filter medium that exhibits a reduced pressure differential while still providing the advantages of a filtration element and fuel water separation, i.e., water agglomeration. MEANS FOR SOLVING THE PROBLEM

[0007] This application provides not only such filter elements and related filter media, but also methods for forming them. This application provides improvements over the current state of the art.

[0008] In one embodiment, a pleated filter element is provided that includes a filter medium having pleated sides with structural embossing. The filter medium is pleated to provide a plurality of longitudinally extending adjacent opposing pleated sides of a selected depth and spacing, with an upstream filter surface and a downstream filter surface spaced apart between successive pleated sides. Adjacent pleated sides are connected by corresponding fold lines. Each of the successive pleated sides has a first side and a second side. A plurality of structural embossings are formed on at least one of the first and second sides on adjacent sides. The structural embossings have different geometries between adjacent structural embossings on the side, different angles of protrusions along at least one of the first and second sides relative to the longitudinal axis of the filter medium between adjacent embossings on the side, a configuration other than polygonal, a teardrop geometry, and / or first and second ends that define an embossing axis extending between the first and second ends and having at least one of the first and second ends where the embossing axis extends in an orientation non-parallel and non-perpendicular to the fold line connected to the corresponding pleated side.

[0009] In one example, a pleated filter element is provided that includes a pleated filter medium having a plurality of pleated sides and a plurality of structural embossings. The pleated filter medium has a first side that forms an upstream surface and a second side that forms a downstream surface. The pleated filter medium includes a plurality of pleated sides and a plurality of folds. A corresponding one of the plurality of folds connects adjacent pleated sides. A plurality of structural embossings are formed in at least one of the first and second sides of the pleated sides. Each structural embossing has a first end and a second end that define an embossing axis of the structural embossing. The embossing axis extends in an orientation non-parallel and non-perpendicular to the fold line connected to the corresponding pleated side.

[0010] In one example, the pleated filter medium forms a tube of the filter medium that defines a longitudinal central axis. The folds extend parallel to the longitudinal central axis. Each structural embossing is elongated along the embossing axis of the structural embossing.

[0011] In one example, a first structural embossing and a second structural embossing among a plurality of structural embossings are formed within a first pleated side among a plurality of pleated sides. The embossing axis of the first structural embossing extends at an angle different from the embossing axis of the second structural embossing.

[0012] In one example, the pleated filter medium has a gravity uppermost portion and a gravity lowermost portion. The gravity uppermost portion is vertically above the gravity lowermost portion (e.g., during use). The folds extend between the gravity uppermost portion and the gravity lowermost portion. The embossing axis of the first structural embossing is less aligned with gravity than the embossing axis of the second structural embossing. The first structural embossing is located closer to the gravity uppermost portion than the second structural embossing.

[0013] In one example, the pleated filter medium forms a block of the filter medium that defines an upstream face and a downstream face. The block of the filter medium has a flow direction in which fluid to be filtered flows from the upstream face to the downstream face. The flow direction is generally perpendicular to a plurality of folds.

[0014] In one example, the embossing axis is angled with respect to the folds such that as the embossing axis moves in the flow direction from the upstream face toward the downstream face, the embossing axis moves upward toward the gravity uppermost portion of the pleated filter medium.

[0015] In one example, a third structural embossing among a plurality of structural embossings is formed within a second pleat side among a plurality of pleat sides. A first fold among a plurality of folds is formed between the first pleat side and the second pleat side. A first end of the third structural embossing is axially positioned between a first end of the first structural embossing and a first end of the second structural embossing along the first fold. A first end of the second structural embossing is axially positioned between a first end and a second end of the third structural embossing.

[0016] In one example, the first, second, and third structural embossings form an orientation arranged to overlap when viewed in the direction of fluid flow in detail.

[0017] In one example, each of the plurality of structural embossings has a width generally perpendicular to the embossing axis. The width increases when moving from the first end to the second end.

[0018] In one example, the depth / height of the structural embossing increases when moving from the first end to the second end.

[0019] In one example, the first structural embossing and the second structural embossing form a protrusion on a first side of the pleated filter medium and a depression on a second side of the pleated filter medium. The third structural embossing forms a protrusion on a second side of the second pleat side and a depression on a first side of the second pleat side.

[0020] In one example, a filter medium is formed within a tube of a pleated filter medium that defines a central longitudinal axis. Each of the structural embossings forms a protrusion on one of a first side and a second side of a corresponding pleat side and a depression on the other of the first side and the second side of the corresponding pleat side. The width of the protrusion and the depth of the depression measured generally perpendicular to the corresponding axis of the structural embossing increase when moving radially away from the central longitudinal axis of the tube of the pleated filter medium along the embossing axis.

[0021] In one example, the width of the protrusions and the depth of the recesses, measured generally perpendicular to the corresponding axis of the structural embossing, increase as they move along the embossing axis radially away from the longitudinal axis of the center of the tube of the corrugated filter medium.

[0022] In one example, a corrugated filter medium is formed within the tube of the corrugated filter medium. The tube of the corrugated filter medium defines a central longitudinal axis. The tube of the corrugated filter medium is configured such that the fluid to be filtered flows radially through the tube of the corrugated filter medium when it is filtered. The separated water moves generally parallel (more parallel) to the central longitudinal axis. The tube of the corrugated filter medium has a gravity top and a gravity bottom. The gravity top is vertically above the gravity bottom. The central longitudinal axis and the folds extend between the gravity top and the gravity bottom. The embossing axis of the structural embossing is oriented along the longitudinal axis such that it moves towards the gravity bottom as it moves along the embossing axis. The embossing axis moves radially outwardly, away from the longitudinal axis. However, other embodiments may have the opposite orientation.

[0023] In one embodiment, a method of making a filter element as outlined above is provided. The method includes providing a filter medium, embossing the filter medium using a plurality of structural embossings, and folding the filter medium with a plurality of folds to form a plurality of corrugated sides.

[0024] In one embodiment, a method of filtering water from a fuel flow is provided. The method includes passing the fuel flow through the filter medium of the filter element as the fuel flows from an inlet of the filter element to an outlet of the filter element.

[0025] In one embodiment, as outlined above, a filtration system is provided that includes a filter head, a housing, and a filter element. The filter head has an inlet and an outlet. The housing defines a drainage receiving region. At least a portion of the filter element as described above is positioned within the housing vertically above the drainage receiving region and is fluidly placed between the inlet and the outlet.

[0026] In one embodiment, a method of making a filter medium is provided. The method includes providing a layer of filter medium having a surface with a predetermined roughness. The method includes contacting the surface of the medium with a device having a selected roughness to impart a roughness greater than the predetermined roughness to the surface of the medium.

[0027] The device may be a roller, a plate, a belt, or other structure for imparting an enhanced surface roughness. The device may also include a structure for forming a structural embossment.

[0028] In one embodiment, the method includes compressing the medium using the device. Thereby, an enhanced surface roughness or a structural embossment can be formed.

[0029] In one embodiment, the method includes pleating the medium after the medium has contacted the device.

[0030] In one embodiment, the method includes forming a structural embossment within the surface of the medium layer.

[0031] In one embodiment, the step of pleating the medium includes forming a fold line between adjacent pleat panels. The method includes forming a plurality of elongated structural embossments such that each of the plurality of structural embossments has a first end and a second end that define an embossment axis extending between the first end and the second end. The embossment axis extends in an orientation that is non - parallel and non - perpendicular to the fold line.

[0032] In one embodiment, a first structural embossing and a second structural embossing among a plurality of structural embossings are formed within a first pleated panel. The embossing axis of the first structural embossing extends at an angle different from the embossing axis of the second structural embossing with respect to the fold line.

[0033] In one embodiment, the filter element has a gravity topmost part and a gravity lowermost part. The gravity topmost part is vertically above the gravity lowermost part. The embossing axis of the first structural embossing is less aligned with gravity than the embossing axis of the second structural embossing.

[0034] In one embodiment, a third structural embossing among a plurality of structural embossings is formed within a second pleated panel. A fold line is formed between the first pleated panel and the second pleated panel. The first end of the third structural embossing is axially positioned along the fold line between the first end of the first structural embossing and the first end of the second structural embossing, and the first end of the second structural embossing is axially positioned between the first end and the second end of the third structural embossing.

[0035] In one embodiment, the plurality of structural embossings each have a width generally perpendicular to the structural embossing axis. The width increases when moving from the first end to the second end. In some embodiments, this is in a radially inward direction when forming the filter medium within the tube of the pleated filter medium. In other embodiments, this may simply be generally in the downstream direction, such as within a panel filter element, for example, from the upstream face to the downstream face of the filter medium pack.

[0036] In one embodiment, the first structural embossing and the second structural embossing form a protrusion on the first side of the layer of the filter medium and a recess on the second side of the filter medium. The third structural embossing forms a protrusion on the second side of the filter medium and a recess on the first side of the filter medium.

[0037] In one embodiment, the step of contacting a device having a selected roughness with the surface of the medium to impart a roughness greater than a predetermined roughness to the surface of the medium is performed on at least 80%, more preferably at least 90%, of the filter medium that does not include structural embossing.

[0038] In one embodiment, at least 95% of the surface of the filter medium was manipulated to include at least one of increased surface roughness, crease lines, and / or structural embossing.

[0039] In one embodiment, the roller or plate has a surface roughness of at least 35 μ, more preferably at least 190 μ.

[0040] In one embodiment, the enhanced surface roughness of the filter medium is 20 μ, more preferably at least 100 μ.

[0041] In one embodiment, the step of contacting a device having a selected roughness with the surface of the medium to impart a roughness greater than a predetermined roughness to the surface of the medium is performed without removing the material of the filter medium.

[0042] In one embodiment, the step of contacting a device having a selected roughness with the surface of the medium to impart a roughness greater than a predetermined roughness to the surface of the medium is performed by compressing the filter medium to form a greater roughness.

[0043] In one embodiment, the surface of the layer of filter medium is the upstream surface of the layer of filter medium that is the exposed surface.

[0044] In one embodiment, the layer of filter medium is a pre-laminated medium formed from a plurality of medium layers. The step of contacting a device having a selected roughness with the surface of the medium to impart a roughness greater than a predetermined roughness to the surface of the medium does not simultaneously secure a plurality of medium layers to form the layer of filter medium.

[0045] In certain embodiments, the filter medium is unwound from a roll of the filter medium in a stacked state before any surface roughness enhancement treatment is performed.

[0046] In one embodiment, the surface is then neither coated nor covered after the step of contacting the surface of the medium with a device having a selected roughness to impart a roughness greater than a predetermined roughness to the surface of the medium.

[0047] In one embodiment, the surface roughness of the filter medium layer has a contact angle measured using a goniometer with water between 130° and 140°, preferably 132°.

[0048] In one embodiment, a filter element is provided. The filter element includes a pleated filter medium pack formed from a layer of filtration medium. The layer of filtration medium forms a plurality of pleated panels formed by a plurality of fold lines. The filtration medium has an upstream surface and a downstream surface. The upstream surface is compressed to have a desired surface roughness.

[0049] In one embodiment, the surface roughness of the upstream surface is greater than the surface roughness of the downstream surface.

[0050] In one embodiment, the upstream surface of the layer of filtration medium is exposed such that the fluid to be filtered first contacts the upstream surface of the layer of filtration medium. Thus, the surface providing the desired roughness is not located between different layers of the filter medium. Further, the cracks or voids forming the surface roughness are not filled with other materials.

[0051] In one embodiment, the layer of filtration medium includes a structural embossing within the upstream surface of the medium layer.

[0052] In one embodiment, the plurality of structural embossings are elongated such that each of the plurality of structural embossings has a first end and a second end defining an embossing axis extending between the first end and the second end. The embossing axis extends in an orientation non-parallel and non-perpendicular to the fold lines.

[0053] In one embodiment, a first structural embossing and a second structural embossing among a plurality of structural embossings are formed within a first pleated panel. The embossing axis of the first structural embossing extends at an angle different from the embossing axis of the second structural embossing with respect to the fold line.

[0054] In one embodiment, the filter element has a gravity uppermost portion and a gravity lowermost portion, and the gravity uppermost portion is vertically above the gravity lowermost portion. The embossing axis of the first structural embossing is not aligned with gravity more than the embossing axis of the second structural embossing. The first structural embossing is vertically above the second structural embossing.

[0055] In one embodiment, a third structural embossing among a plurality of structural embossings is formed within a second pleated panel. A fold line is formed between the first pleated panel and the second pleated panel. The first end of the third structural embossing is axially positioned along the fold line between the first end of the first structural embossing and the first end of the second structural embossing, and the first end of the second structural embossing is axially positioned between the first end and the second end of the third structural embossing.

[0056] In one embodiment, a first, a second, and a third embossing are positioned between an upstream fold line and a downstream fold line (e.g., a radially outer fold line and a radially inner fold line within a cylindrical element).

[0057] In one embodiment, the first, the second, and the third embossings are positioned at the same location between the upstream fold line and the downstream fold line.

[0058] In one embodiment, the first, the second, and the third embossings are axially offset from each other along the fold line.

[0059] In one embodiment, the plurality of structural embossings each have a width generally perpendicular to the embossing axis. The width increases when moving from the first end to the second end. In a particular embodiment, this increase in width occurs when moving towards the downstream fold line (e.g., radially inwards within the cylindrical filter element or through the media pack when moving from the upstream face to the downstream face of the panel filter element).

[0060] In one embodiment, the first structural embossing and the second structural embossing form protrusions on the first side of the layer of filter media and depressions on the second side of the filter media. The third structural embossing forms protrusions on the second side of the filter media and recesses on the first side of the filter media.

[0061] In one embodiment, at least 80%, preferably at least 90%, of the filter media that does not include structural embossing has a surface roughness greater than the surface roughness of the structural embossing.

[0062] In one embodiment, at least 95% of the surface of the filter media is manipulated to include at least one of increased surface roughness, fold lines, and / or structural embossing.

[0063] In one embodiment, the surface roughness of the upstream surface is at least 116 μ equivalent to 120-grit sandpaper, more preferably at least 190 μ equivalent to 80-grit sandpaper, and even more preferably at least 425 μ equivalent to 40-grit sandpaper.

[0064] In one embodiment, the surface roughness of the upstream surface is at least equivalent to the surface roughness of 120-grit sandpaper, more preferably at least equivalent to the surface roughness of 80-grit sandpaper, and even more preferably at least equivalent to 40-grit sandpaper.

[0065] In one embodiment, the surface roughness of the upstream surface was manipulated such that it was at least 50% greater than in the unoperated state, more preferably at least 100% greater than in the unoperated state, and even more preferably at least 400% greater than in the unoperated state.

[0066] In one embodiment, the surface roughness of the upstream surface of the layer of filter medium was provided by compressing the upstream surface of the layer of filter medium, rather than by removing material from the upstream surface.

[0067] In one embodiment, the upstream surface of the layer of filter medium is an exposed surface, and the voids within the upstream surface that form the surface roughness are not filled with or coated by other materials. This necessarily does not involve the possibility that adjacent pleated panels will overlap when the filter medium is folded in pleats.

[0068] In one embodiment, the layer of filter medium is a pre-laminated medium formed from a plurality of media layers fixed to each other independently of the structure of the filter medium that provides the surface roughness of the upstream surface.

[0069] In one embodiment, the surface roughness of the filter medium layer has a contact angle measured using a goniometer with water between 130° and 140°, preferably at least 132°.

[0070] In certain embodiments, a method of filtering water from a fuel stream includes passing the fuel stream through the filter medium of a filter element according to any one of the embodiments outlined above when the fuel stream flows from an inlet of the filter element to an outlet of the filter element.

[0071] In certain embodiments, a filtration system is provided that includes a filter head having an inlet and an outlet, a housing that defines a drainage receiving region, and a filter element according to any one of the preceding embodiments. The filter element is positioned at least partially within the housing vertically above the drainage receiving region and is fluidically placed between the inlet and the outlet.

[0072] Other aspects, objects, and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

[0073] The accompanying drawings, which are incorporated herein and form a part of this specification, illustrate some aspects of the present invention and are useful in explaining the principles of the present invention together with the specification.

Brief Description of the Drawings

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[0075] The present invention will be described in connection with certain preferred embodiments, but it is not intended to limit the invention to those embodiments. On the contrary, all alternative forms, modifications, and equivalent forms are intended to be included within the spirit and scope of the invention as defined by the appended claims.

[0076] FIG. 1 incorporates the teachings of the present application and illustrates a simplified filter element 100. The filter element 100 includes a pleated filter medium block, specifically a pleated filter medium 102 (also referred to as a "filter medium") formed within a cylindrical tube. This embodiment illustrates the pleated filter medium 102 within a cylindrical tube, but other embodiments according to the present teachings can form the filter medium within a block of filter medium in the form of a flat panel.

[0077] The filter element 100 can be particularly beneficial when filtering water from a fluid flow such as a fuel flow. The filter element 100 can also filter specific substances from the fluid flow.

[0078] The contaminated fluid enters the filter element 100 through one or more inlets exemplified by arrow 104. The contaminated fluid flows from the upstream side / upstream surface (radially outside in the exemplified cylindrical tube of the filter medium) to the downstream side / downstream surface (radially inside in the exemplified cylindrical tube of the filter medium) through the filter medium 102 when the fluid flows through the filter medium 102. After passing through the filter medium 102, the cleaned fluid flows through one or more outlets exemplified by arrow 106.

[0079] The filter medium 102 is preferably configured to agglomerate water mixed in the unfiltered fluid such that the agglomerated water droplets 110 are separated from the fluid. The agglomerated water droplets 110 flow to the drain receiver 114 or other collection sites as exemplified by arrow 112. The flow of the water droplets 110 is generally parallel to gravity (exemplified by arrow 124).

[0080] FIG. 13 illustrates a filtration system 115 in which the filter element 100 can have a particular applicability. In this case, the drain receiver 114 is provided by a removable bowl 117 removably connected to the filter head 121. The filter head 121 provides the inlet 104 and the outlet 106.

[0081] The filter medium 102 is one or more layers of the filter medium, and by folding one or more layers of the filter medium, a pleated layer of the filter medium is formed having a plurality of folds 120 that define fold lines separating adjacent pleat panels 122. The folds 120 interconnect adjacent pairs of pleat panels 122 (also called pleat sides). In a preferred embodiment, the folds 120 are generally parallel to gravity exemplified by arrow 124 in FIG. 1.

[0082] Preferably, the water drain receiver 114 is at the lowermost end 130 of the filter medium 102, while the discharge port 106 is at the uppermost end 132, where "uppermost" and "lowermost" are defined with reference to gravity. In this way, gravity can be used to direct the aggregated water droplets 110 towards the water drain receiver 114 rather than the discharge port 106.

[0083] As pointed out, the filter medium 102 is preferably formed from a pleated medium in which the pleat folds 120 separate a plurality of pleat panels 122.

[0084] FIG. 2 is a top view of a pair of pleat panels 122A, 122B before folding along the fold line 120 provided by the cut line during fabrication in this embodiment. The fold 120 separates the pleat panel 122B from the pleat panel 122A, but also interconnects the two adjacent pleat panels 122A, 122B.

[0085] In a tubular filter element such as FIG. 1, the pleat folds 120 (which may be provided by the cut lines before folding) include radially outer pleat folds 120A and radially inner pleat folds 120B (for example, the radially outer pleat folds 120A may be referred to as upstream pleat folds, and the radially inner pleat folds 120B may be referred to as downstream pleat folds with a fluid flow from radially outer to radially inner as illustrated by the arrow 104 in FIG. 1). The pleat panels 122 generally extend radially between the outer pleat folds 120A and the inner pleat folds 120B (typically with a slight angle from completely radial). The outer pleat folds 120A can be considered to form the radially outer periphery or upstream surface of the filter medium tube (illustrated by the dotted line 119A), while the inner pleat folds 120B form the radially inner periphery or downstream surface of the filter medium tube (illustrated by the dotted line 119B).

[0086] In the panel filter element, the pleat fold 120A forms the upstream surface of the panel filter, while the pleat fold 120B forms the downstream surface of the panel filter element. The pleated panel 122 generally extends between the upstream and downstream surfaces.

[0087] Referring to FIG. 2, the filter medium also includes a plurality of structural embossments 140A, 140B. The structural embossment 140A is formed within the pleated panel 122A, while the structural embossment 140B is formed within the pleated panel 122B.

[0088] FIG. 2 illustrates the upstream surfaces 142 (see also FIG. 3) of two pleated panels 122A, 122B of the filter medium 102 before folding along the fold line 120. The upstream surface 142 is on the opposite side of the downstream surface 144. During operation, the dirty fluid first contacts the upstream surface 142 and then passes through the filter medium 102, and the cleaned fluid exits the filter medium 102 through the downstream surface 144.

[0089] The filter medium has a plurality of operations according to the embodiments of the present application. The first operation is to form pleat folds 120 that can be incisions or creases.

[0090] The second operation is to form the structural embossments 140A, 140B. Referring to FIGS. 2 and 3, in this embodiment, the embossment 140A is a concave embossment that forms a plurality of depressions in the upstream surface 142 of the filter medium 102 and a plurality of protrusions in the downstream surface 144 of the filter medium 102. The embossment 140B is a convex embossment that forms a plurality of protrusions in the upstream surface 142 and a plurality of depressions in the downstream surface 144.

[0091] This embodiment illustrates an embossing obtained by alternating the corrugated panel 122 that alternates between convex embossing and concave embossing. However, in some embodiments, all of the embossing can be convex, or all of the embossing can be concave. Further, in some embodiments, a single corrugated panel 122 can have both convex embossing and concave embossing.

[0092] Each of the embossings 140 includes a first end 146 and a second end 148. The embossing 140 extends longitudinally between the first end 146 and the second end 148 along the embossing axis 150.

[0093] In the exemplary embodiment of FIG. 2, the embossing tapers between the first end 146 and the second end 148. Specifically, the width W of the embossing 140 (illustrated by double arrows in FIG. 2) perpendicular to the embossing axis 150 increases when moving from the first end 146 towards the second end 148. Thereby, a teardrop shape is obtained. In other embodiments, the width can remain constant and need not increase when moving radially inwards.

[0094] At least a portion of each embossing 140 has a width W that is at least twice the thickness of the filter medium, preferably at least three times the thickness of the filter medium. In some embodiments, some or all of at least a portion of the embossing has a width W that is at least four times the thickness of the filter medium.

[0095] In some embodiments, the height H of the embossing 140 increases as it moves from one end to the other along the embossing axis 150. As illustrated in FIG. 3, the height H increases as it moves away from the fold 120 along the embossing axis 150. Although described with respect to the height H, the depth of the concave embossing can have a similar orientation. At least a portion of each embossing 140 has a height H that is at least twice the thickness of the filter medium, preferably at least three times the thickness of the filter medium. In some embodiments, at least a portion of some or all of the embossings have a height H that is at least four times the thickness of the filter medium.

[0096] In some embodiments, the pleated panel 122 is folded relative to each other at the fold 120 such that the second end 148 of the embossing 140 is positioned radially closer to the central axis 150 of the tube of the filter medium 102. In a flat panel filter, the embossing 140 generally becomes wider as it moves from the upstream face to the downstream face of the panel (e.g., in the direction of flow through the filter medium panel). However, in other embodiments, the orientation of the first end 146 and the second end 148 can be switched such that the second end 148 of the embossing 140 is positioned radially farther from the central axis 150 of the tube of the filter medium 102 than the first end 146.

[0097] This angled orientation helps to aggregate entrained water as the dirty fluid flows across the upstream face 142 of the filter medium 102, specifically across the embossing 140. The embossing also helps to maintain a spacing between adjacent pleated panels 122A and 122B when folded.

[0098] Referring to FIG. 2, in addition to tapering, in some embodiments, the embossing axis 150 extends in an orientation that is non - parallel and non - perpendicular to the fold 120 and gravity 124. Preferably, the non - parallel and non - perpendicular orientation creates a pattern arranged to overlap when viewed radially, thereby helping to reject more water droplets 110 from entering the medium.

[0099] FIG. 14 is a simplified illustration of a filter medium 102 that better exemplifies the pattern arranged to overlap.

[0100] In a preferred configuration, when transitioning from the uppermost end 132 towards the lowermost end 130, the orientation of the embossing axis 150 changes from one embossing 140 to the next embossing 140. Specifically, the orientation of the vertically - lower embossing 140 becomes steeper with respect to the radial direction the closer the corresponding embossing 140 is located to the lowermost end 130 and becomes closer to parallel due to the pleat fold 120 and gravity 124.

[0101] FIG. 14 further exemplifies that the angle of the embossing axis 150 varies from one embossing to the next. In this case, the embossing axes 150' of the two lower embossings 140A' and 140B' are steeper than the embossing axes 150 of the two upper embossings 140A and 140B. In particular, the embossings 140B, 140B' are shown in dashed lines as they are formed within a pleat panel hidden behind the pleat panel forming the embossings 140A, 140A'.

[0102] Furthermore, the embossings 140 in FIG. 14 are not teardrop - shaped but rather an alternative - shaped ellipse.

[0103] The steepness that increases when moving towards the lowermost part 130 enhances the effect of the embossing 140 in obstructing the progress of water. Thereby, the water droplets 110 are prevented from entering the corrugated area upstream of the filter medium, and as a result, the entire surface area for filtration can be utilized, and the performance of the lowermost area of the filter element 100 becomes better. This is particularly advantageous when the separated water droplets 110 move vertically downward towards the lowermost end 130 and the drain receiver 114. The increased performance of obstructing the progress of water helps offset the fact that due to the downward flow of water 112, the lowermost part of the filter element 100 has a high water concentration before collecting water at the drain receiver 114. Compared with the embossing axis 150, the increasing angle of the embossing axis 150' enhances the performance of the lower part of the filter medium 102 in obstructing the progress of water.

[0104] In a preferred embodiment, the embossing 140A of the corrugated panel 122A overlaps the embossing 140B of the corrugated panel 122A when viewed perpendicular to the fold 120. Thus, the first end of the embossing 140B is vertically positioned between the first ends of two adjacent embossings 140A. However, it is preferred that the first end of the embossing 140A is vertically positioned between the first end 146 and the second end 148 of the embossing 140B.

[0105] The angle of the embossing axis 150 with respect to the flow of fluid through the medium 102 (e.g., generally in the radial direction) prevents the coalesced water droplets from passing through by obstructing their re-introduction into the medium 102 and also assists in water separation using gravity.

[0106] As illustrated in FIG. 14, in one embodiment, the embossing axis 150 is angled with respect to the crease 120 and gravity such that it extends towards the top 132 when moving in the direction of fluid flow. This orientation radially moves the water droplets 110 outward (illustrated by arrow 111) as the droplets 110 move vertically downward due to gravity 124. This further facilitates the removal of water from the fluid being filtered. Referring to FIG. 13, the water droplets move outward towards the vertical walls of the bowl 117. However, the reverse orientation can be implemented.

[0107] Adjacent to the plurality of embossings 140A, 140B, 144, the filter medium 102 has a plurality of flat surface regions 160.

[0108] Preferably, the structural embossing 140A of one pleat panel 122A is axially offset from the structural embossing 140B of the adjacent pleat panel 122B along the crease 120 such that when the panels 122A, 122B are folded relative to each other at the crease 120, the embossing 140B is axially positioned between the embossings 140A along the crease 120. This enables the embossing 140B to cooperate and / or align with the flat surface regions 160 of the adjacent pleat panels 122A, 122B. This helps to maintain an appropriate spacing between the pleat panels 122A and 122B.

[0109] In a preferred embodiment, these surface regions 160 are manipulated to have an increased surface roughness. More specifically, the filter medium 102 is generally formed with a first surface roughness, and then the user manipulates the filter medium 102, specifically within these flat surface regions 160, to increase the surface roughness.

[0110] In one embodiment, the surface roughness of the upstream surface is at least 116 μ equivalent to the surface roughness of 120 - grid sandpaper, more preferably at least 190 μ equivalent to the surface roughness of 80 - grid sandpaper, and even more preferably at least 425 μ equivalent to 40 - grid sandpaper.

[0111] In one embodiment, the surface roughness 160 has a surface roughness of at least 116 μ, more preferably at least 425 μ, after the operation. Note that in some preferred embodiments, the embossing 140 has a height that is at least three times greater than the surface roughness.

[0112] In some embodiments, the surface roughness of the filter medium after the operation increases by at least 50%, more preferably by 100%, even more preferably by at least 400%.

[0113] In some embodiments, the surface roughness of the upstream surface 142 is greater than the surface roughness of the downstream surface 144. Although not always, typically only the surface roughness of the upstream surface 142 is manipulated because this upstream surface is the surface that the dirty fluid with entrained water first contacts. The surface roughness increases the surface energy of the upstream surface 142 and thus helps to enhance the water separation ability of the upstream surface 142.

[0114] In FIG. 2, the increased surface roughness is schematically illustrated by stippling on the surface of the filter medium 102. This roughness may be referred to as micro-roughness.

[0115] FIG. 4 illustrates a simplified filter medium processing system 200. The system typically includes a filter medium source 202 that is a roll of filter medium used to form the filter medium 102. The filter medium is unwound from the roll and then processed.

[0116] Downstream of the filter medium source 202 is a media operation station 204 that includes one or more media operation tools 205, 206 for performing surface operations on one or more surfaces and / or regions of the filter medium.

[0117] In certain implementations, media handling station 204 includes media handling tools that take the form of opposing compression rolls. In another implementation, a pair of opposing belts provides the media handling tools. In other implementations, the media handling tools are provided by a pair of linearly actuated stamping plates that move toward and away from each other along an axis generally perpendicular to the media flowing through media handling station 204.

[0118] In one implementation, media handling station 204 operates on only one side of the filter media, specifically the side of the filter media that becomes upstream surface 142 described above. In such an embodiment, media handling tools 205, 206 that cooperate with that side of the media manipulate the surface roughness of the corresponding surface of the filter media to increase the surface roughness as compared to the initial surface roughness of the filter media.

[0119] Preferably, media handling station 204 modifies the surface roughness without moving any or substantially any of the filter media, e.g., without polishing or laser etching the media. Rather, it is preferred to modify the surface roughness simply by compressing the filter media. Removal methods can, among other things, potentially leave debris on the filter media.

[0120] In one implementation, media handling tools 205, 206 that define the desired surface roughness are formed from a material that is more rigid than the other materials of media handling tools 205, 206. In some implementations, media handling tools 205, 206 may have a surface roughness profile laser etched into the surface of the tools.

[0121] In one embodiment, the same media handling tool 205 or 206 has both structural embossing formed therein and surface roughness features. In some embodiments, media handling tools 205, 206 provide only structural embossing with no surface roughness features.

[0122] In some embodiments, the media manipulation tools 205, 206 have a rigid member that provides a structural embossing profile formed therein, and the micro-roughness film adheres to the rigid member. The micro-roughness film surrounds the structural embossing.

[0123] In some implementations, the media manipulation station 204 has a two-step process for forming roughness and structural embossing using separate sets of tools that are successively aligned to perform one process first and then the other. Typically, the roughness process is performed first. Again, other systems may have only one of a variety of different media manipulation features.

[0124] In some implementations, the structural embossing does not operate on its surface to increase surface roughness, but rather operates only on the remaining portion of the pleated panel (the substantially planar portion of the filter media) to provide improved surface roughness.

[0125] In a preferred implementation, the media manipulation tools 205, 206 have both convex structural embossing features and concave structural embossing features that align to form a single structural embossing. For example, the protrusion of tool 205 aligns with the filter media and presses the filter media into a corresponding recess of cooperating tool 206 to form the embossing. However, preferably, while cooperating protrusion / recess features (e.g., cooperating convex and concave features) may be used to form the structural embossing, the surface roughness features are typically not formed using such a convex / concave arrangement. Rather, the surface roughness features are formed by simply one of the tools 205 or the other tool 206 without cooperating features between the tools 205 and 206 that cooperate to form the surface roughness.

[0126] In one implementation, the filter media is a laminate consisting of multiple layers of the filter media. This laminate is formed and the layers of this laminate are fixed to each other before passing through the media manipulation station 204.

[0127] Furthermore, it is preferable to enhance and increase the surface that had surface roughness, and it is preferable not to substantially coat these surfaces. This is particularly applicable because the surface roughness added to the filter medium is not used as a means for fixing separate layers together. In fact, the surface roughness should remain unobstructed by other materials so that improved water separation characteristics remain.

[0128] Downstream of the tools 205, 206, there is a folding machine 207 that folds the adjacent pleat panels 122 at the corresponding pleat folds 120.

[0129] FIG. 5 is a photograph of a filter medium 302 that has been operated to include folds 320 that define pleat panels 322A, 322B, structural embossments 340A, 340B, and a flat surface region 360 with enhanced roughness.

[0130] FIG. 6 is a photograph similar to FIG. 5. However, the filter medium did not include enhanced surface roughness surrounding the structural embossments.

[0131] FIG. 7 is a photograph of an unoperated sample of the filter medium used for the arrangement of FIGS. 5 and 6.

[0132] The applicants conducted various tests to compare the operating parameters of the filter media for all three arrangements of FIGS. 5 - 7. However, not all tests were conducted on samples without surface roughness.

[0133] FIGS. 8 and 9 compare the contact angles for the control filter medium of FIG. 7 and the modified filter medium of FIG. 5. The contact angle of water on the surface of the corresponding media was tested using a goniometer. It was confirmed that the samples with increased surface roughness had a larger contact angle. More specifically, the control sample had an average contact angle (average of two values) of 129° ± 0.8°, while the samples with increased surface roughness had an average contact angle (average of two values) of 135° ± 0.6°.

[0134] Figure 10 illustrates a comparison of flow rate limits and flow rates based on SAE J905. The fluid used was ultralow sulfur diesel (ULSD). As illustrated, the modified samples each had a lower pressure drop than the control samples at the same flow rate.

[0135] Figure 11 illustrates a comparison of moisture separation efficiency over time tested in accordance with SAE J1488. The test flow rate was 1 gpm. The flow was from the outside to the inside using a cylindrical filter element.

[0136] Figure 12 plots the pressure drop over time for three samples tested in accordance with SAE J1488. The test flow rate was 1 gpm. The flow was from the outside to the inside using a cylindrical filter element.

[0137] All references, including publications, patent applications, and patents cited herein, are hereby incorporated by reference in their entirety as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0138] In the context of describing the present invention (especially in the context of the following claims), the use of the terms "a", "an", and "the", and similar references, should be construed to cover both the singular and the plural, unless specifically stated otherwise herein or the context clearly dictates otherwise. The terms "comprising", "having", "including", and "containing" should be construed as non-limiting terms (i.e., meaning "including but not limited to") unless specifically stated otherwise. The recitation of values herein is merely intended to serve as a concise way of referring individually to each distinct value falling within the range, and each distinct value is hereby incorporated into the specification as if it were individually recited herein. Unless specifically stated otherwise herein or the context clearly dictates otherwise, all methods described herein can be performed in any suitable order. The use of any examples and all examples provided herein, or exemplary language (e.g., "such as"), is merely intended to better illuminate the present invention and does not impose a limitation on the scope of the present invention unless otherwise claimed. No language in this specification should be construed as indicating any non-claimed element as essential to the practice of the present invention.

[0139] This specification describes preferred embodiments of the invention and includes the best mode known to the inventors for carrying out the invention. Variations of these preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to adopt such variations as appropriate, and the invention is intended to be practiced in ways other than those specifically described herein. Accordingly, the invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, the invention includes any combination of the above-described elements in all possible variations of the invention, unless specifically stated otherwise herein or the context clearly dictates otherwise.

Claims

1. A pleated filter element having a first end located above the gravity direction and a second end located below the gravity direction in the gravity direction, To provide upstream and downstream filter surfaces at intervals, pleated, a filter medium having a plurality of longitudinally extending adjacent and opposing continuous pleated side surfaces of a selected depth and spacing between consecutive pleated side surfaces, wherein the adjacent pleated side surfaces are connected by corresponding fold lines Comprising Each of the continuous pleated side surfaces Has a first side and a second side, And a plurality of structural embossings formed in at least one of the first side and the second side on the adjacent side surfaces Have, the structural embossing Different angles of protrusions along at least one of the first side and the second side with respect to the longitudinal axis of the filter medium between adjacent embossings on the side surface Have, The orientation of the angle of the protrusion of the structural embossing disposed near the second end is closer to the gravity direction than the orientation of the angle of the protrusion of the structural embossing disposed near the first end, a pleated filter element.

2. A method of making the filter element according to claim 1, comprising: Providing a filter medium; Embossing the filter medium using a plurality of structural embossings; And folding the filter medium along a plurality of folds to form a plurality of pleated side surfaces A method comprising.

3. A method of filtering water from a fuel flow, comprising: Passing the fuel flow through the filter medium of the filter element when the fuel flows from an inlet of the filter element according to claim 1 to an outlet of the filter element A method comprising.

4. A filtration system, comprising: A filter head having an inlet and an outlet; A housing defining a drainage receiving area; The filter element according to claim 1, wherein at least a part is positioned vertically above the drainage receiving area inside the housing and is fluidly placed between the inlet and the outlet A filtration system comprising.

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