Filtration media pack with grooved sheet and facing sheet having protrusions - Patent Application 20070122997

Abstract

To provide a filtration media pack including a plurality of layers of filter media.SOLUTION: The media pack includes fluted sheets 100 and a facing sheet, with a plurality of flutes 106, 108 extending between the fluted sheets and the facing sheets. In an embodiment, at least one translucent protrusion 116 is provided, extending from at least any one of the fluted sheet or the facing sheet and the protrusion is substantially absent from the portions of single face media where the fluted sheet is not in contact with the facing sheet.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application was filed as a PCT international patent application on January 7, 2015, in the names of Donaldson Company, Inc., a U.S. corporation, as the applicant for all designated countries, and Scott M. Brown, a U.S. citizen, as the applicant and inventor for all designated countries, and claims priority to U.S. Provisional Patent Application No. 61 / 924,696, filed January 7, 2014, and U.S. Provisional Patent Application No. 62 / 077,891, filed November 10, 2014, the contents of which are incorporated herein by reference in their entireties.

[0002] The present invention relates to a filtration media pack that can be used to form a filter element. The present invention further relates to a filter element and a filtration media. [Background technology]

[0003] Fluid flows, such as airflows, often carry contaminants. In many instances, it is desirable to filter some or all of the contaminants from the fluid flow. For example, particulate contaminants may be carried by the airflow of an internal combustion engine for an automobile or power plant. In such systems, it is desirable to remove selected contaminants, such as particulate contaminants, from (or reduce the level of in) the airflow. Summary of the Invention [Problem to be solved by the invention]

[0004] A variety of fluid filter equipment has been developed to reduce contaminants, however, there is generally a need for continuous improvement. [Means for solving the problem]

[0005] The present disclosure focuses on a filtration media pack including multiple layers of media, including a channeled sheet and a facing sheet, as well as a filtration media pack, a filter element, and a filtration media. In some embodiments, a plurality of channel channels extend between the channeled sheet and the facing sheet, with a first portion of the channel channels closed to unfiltered air flowing into the first portion of the channel channels and a second portion of the channel channels closed to unfiltered air flowing out of the second portion of the channel channels. Air entering one side of the media pack and exiting the other side passes through the media to be filtered. In specific embodiments, the channeled sheet includes a plurality of protrusions, at least some of which contact the facing sheet. In other specific embodiments, the facing sheet includes a plurality of protrusions, at least some of which contact the channeled sheet. It will be understood that in some implementations, other portions of the channel channels are blocked so that the channel channels are closed at both ends of the channel or at a location within the channel (e.g., a midpoint from the end of the channel).

[0006] The filtration media pack can include protrusions having a height of, for example, 0.2 to 3 millimeters. In some embodiments, the protrusions have a height of 0.4 to 24 times the thickness of the media forming the channeled sheet. In one embodiment, the protrusions have a height of less than three times the thickness of the media forming the channeled sheet. In some implementations, the protrusions have a height of at least two times the thickness of the media forming the channeled sheet. Optionally, the protrusions are 10 to 90 percent of the height of the channels of the channeled sheet. Thus, the height of the protrusions can add, for example, 10 to 90 percent to the height of the channels excluding the protrusions. In some embodiments, the protrusions are less than 30 percent of the height of the channels of the channeled sheet. The protrusions can be, for example, at least 15 percent of the height of the channels of the channeled sheet. In exemplary implementations, the protrusions are 1 to 20 percent of the width of the channels of the channeled sheet. In specific embodiments, the protrusions are less than 10 percent of the width of the channels of the channeled sheet. The protrusions may, for example, be at least 5 percent of the width of the channels in the channeled sheet.

[0007] In some embodiments, the protrusions between the first side of the filtration media pack and the second side of the filtration media pack can be of equal height, while in other embodiments, they can be of different heights. The protrusions between the first side of the filtration media pack and the second side of the filtration media pack can be tapered in height relative to each other.

[0008] The filtration media pack can be used to filter fluids that are gaseous or liquid. A typical gaseous substance that can be filtered using the filtration media is air, while typical liquid substances that can be filtered using the filtration media include water, oil, fuel, and hydraulic fluids. The filtration media pack can be used to separate or remove at least a portion of a component from the fluid being filtered. The component can be a contaminant or other material targeted for removal or separation. Typical contaminants and target materials for removal include those characterized as solids, liquids, gases, or combinations thereof. Contaminants or target materials for removal can include particulate matter, non-particulate matter, or mixtures thereof. Target materials for removal can include chemical species that can be captured by the media. In some implementations, the media surface can remove contaminants without the fluid (liquid or gas) passing through the media, in which case the groove channels can be open rather than closed along their length. References to removal of components and contaminants should be understood to refer to complete removal or separation or partial removal or separation.

[0009] The protrusions can be formed, for example, by a roller or other device having raised portions and recesses corresponding to the groove channels and protrusions.

[0010] This Summary is an overview of some of the teachings of the present application and is not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details are set forth in the detailed description and appended claims. Other aspects will become apparent to those skilled in the art upon reading and understanding the following detailed description and viewing the drawings that form a part thereof, each of which is not to be taken in a limiting sense. The scope of the present invention is defined by the appended claims and their legal equivalents.

[0011] The invention can be more fully understood in connection with the following drawings. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of a sheet of fluted filtration media constructed and arranged in accordance with an embodiment of the present invention. [Figure 2] FIG. 1 is a perspective view of a sheet of fluted filtration media and a sheet of facer media constructed and arranged in accordance with an embodiment of the present invention. [Figure 3] FIG. 1 is a front view of a sheet of fluted filtration media and a sheet of facer media constructed and arranged in accordance with an embodiment of the present invention. [Figure 4] FIG. 1 is a front view of a plurality of sheets of fluted and facer media constructed and arranged in accordance with an embodiment of the present invention. [Figure 5] FIG. 1 is a front view of a sheet of fluted filtration media and a sheet of facer media constructed and arranged in accordance with an embodiment of the present invention. [Figure 6] FIG. 1 is a front view of a plurality of sheets of fluted and facer media constructed and arranged in accordance with an embodiment of the present invention. [Figure 7] 1 is an enlarged front view of a sheet of flute media and facer media constructed and arranged in accordance with an embodiment of the present invention, showing exemplary flute dimensions; [Figure 8] 1 is an enlarged perspective view of a sheet of flute media and facer media constructed and arranged in accordance with an embodiment of the present invention, showing exemplary protrusion dimensions on the flutes. [Figure 9] 1 is a perspective view of a sheet of fluted filtration media constructed and arranged in accordance with an embodiment of the present invention, illustrating variable spacing of protrusions on the fluted filtration media. [Figure 10] FIG. 10 is a front view of a sheet of fluted filtration media and a sheet of facer media constructed and arranged in accordance with the embodiment of the present invention shown in FIG. [Figure 11] FIG. 1 is a perspective view of a sheet of fluted filtration media constructed and arranged in accordance with an embodiment of the present invention. [Figure 12]FIG. 12 is a front view of a sheet of fluted filtration media and a sheet of facer media constructed and arranged in accordance with the embodiment of the present invention shown in FIG. [Figure 13] FIG. 1 is a perspective view of a sheet of fluted filtration media constructed and arranged in accordance with an embodiment of the present invention, showing a single protrusion on the fluted media sheet. [Figure 14] FIG. 14 is a front view of a sheet of fluted filtration media and a sheet of facer media constructed and arranged in accordance with the embodiment of the present invention shown in FIG. [Figure 15] FIG. 1 is a perspective view of a sheet of fluted filtration media constructed and arranged in accordance with an embodiment of the present invention. [Figure 16] FIG. 16 is a front view of a sheet of fluted filtration media and a sheet of facer media constructed and arranged in accordance with the embodiment of the present invention shown in FIG. 15. [Figure 17] FIG. 1 is a perspective view of a sheet of fluted filtration media and a sheet of facer media constructed and arranged in accordance with an embodiment of the present invention. [Figure 18] FIG. 1 is a perspective view of a filter element constructed and arranged in accordance with an embodiment of the present invention. [Figure 19] FIG. 2 is a graphical representation of the channel area to protrusion height ratio of a filtration media constructed and arranged in accordance with a first exemplary embodiment of the present invention. [Figure 20] FIG. 2 is a graphical representation of the lengths of corrugated and flat sheets of filtration media constructed and arranged in accordance with a first exemplary embodiment of the present invention. [Figure 21] FIG. 2 is a graphical representation of upstream and downstream protrusion heights for a filtration media constructed and arranged in accordance with a first exemplary embodiment of the present invention. [Figure 22] FIG. 10 is a graphical representation of the channel area to protrusion height ratio of a filtration media constructed and arranged in accordance with a second exemplary embodiment of the present invention. [Figure 23] FIG. 10 is a graphical representation of the lengths of corrugated and flat sheets of filtration media constructed and arranged in accordance with a second exemplary embodiment of the present invention. [Figure 24]FIG. 10 is a graphical representation of upstream and downstream protrusion heights for a filtration media constructed and arranged in accordance with a second exemplary embodiment of the present invention. [Figure 25] FIG. 10 is a graphical representation of the channel area to protrusion height ratio of a filtration media constructed and arranged in accordance with a third exemplary embodiment of the present invention. [Figure 26] FIG. 10 is a graphical representation of the lengths of corrugated and flat sheets of filtration media constructed and arranged in accordance with a third exemplary embodiment of the present invention. [Figure 27] FIG. 10 is a graphical representation of the channel area to protrusion height ratio of a filtration media constructed and arranged in accordance with a fourth exemplary embodiment of the present invention. [Figure 28] FIG. 10 is a graphical representation of the length of corrugated and flat sheets of filtration media constructed and arranged in accordance with a fourth exemplary embodiment of the present invention. [Figure 29] FIG. 10 is a graphical representation of upstream and downstream protrusion heights for a filtration media constructed and arranged in accordance with a fourth exemplary embodiment of the present invention. [Figure 30] FIG. 10 is a graphical representation of the channel area to protrusion height ratio of a filtration media constructed and arranged in accordance with a fifth exemplary embodiment of the present invention. [Figure 31] FIG. 10 is a graphical representation of the lengths of corrugated and flat sheets of filtration media constructed and arranged in accordance with a fifth exemplary embodiment of the present invention. [Figure 32] FIG. 10 is a graphical illustration of upstream and downstream protrusion heights for a filtration media constructed and arranged in accordance with a fifth exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] While the invention is susceptible to various modifications and alternative forms, specifics thereof have been shown by way of example and drawings and will hereinafter be described in detail. It is to be understood, however, that the invention is not limited to the particular embodiments described. On the contrary, it is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

[0014] The present disclosure focuses on a fluid filtration media pack, such as a gas or liquid filtration media pack, including multiple layers of media, including a channeled sheet and a facing sheet. The gas fluid to be filtered can be, for example, air. A plurality of channel passages extend between the channeled sheet and the facing sheet. In one implementation, a first portion of the channel passages is closed to unfiltered air flowing into the first portion of the channel passages, and a second portion of the channel passages is closed to unfiltered air flowing out of the second portion of the channel passages. Air entering the media pack and exiting the other side passes through the media, filtering the air. In a specific embodiment, the channeled sheet includes a plurality of protrusions, at least some of which contact the facing sheet. In another specific embodiment, the facing sheet includes a plurality of protrusions, at least some of which contact the channeled sheet.

[0015] In some embodiments, the repeating pattern of channel channels comprises at least one ridge extending along at least a portion of the channel length between adjacent peaks. The ridge can comprise a discontinuity in the channel curvature between adjacent peaks. Channel channels often also include a central peak. Often, protrusions are located on either side of this peak. In some embodiments, the protrusions are located on the peak itself. In either configuration, the protrusions are configured to reduce masking between the channeled sheet and the facing sheet. Masking can refer to areas of the filter media that restrict or reduce fluid flow, for example, due to blockage or contact. Masking refers to areas that cause two sheets of filter media to contact each other, reducing fluid flow through the sheet of filtration media and thereby reducing the amount of usable filter media.

[0016] Protrusions are generally small projections or other flares that extend above the surface of the media. In a typical embodiment, numerous protrusions are present on the grooved media. The protrusions can be, for example, circular, oval, elliptical, or polygonal when viewed from above the media surface. Typically, the protrusions have curved ends to minimize distortion of the media. Protrusions can vary in size and shape, and the upstream surface of the media often has protrusions of different shape, size, and / or number than the downstream surface. In fact, it is possible for only one side of the media, either the upstream or downstream side, to have protrusions.

[0017] Thus, in some embodiments, the channel includes peaks, and the channel is separated from the facing sheet by protrusions such that the peaks do not substantially contact the facing sheet along the entire length of the channel. In one aspect, a filtration media pack includes multiple layers of single-sided media including a channeled sheet, a facing sheet, and multiple channel extensions extending between the channeled sheet and the facing sheet. A first portion of the multiple channel extensions is closed to unfiltered air flowing into the first portion of the multiple channel extensions, and a second portion of the multiple channel extensions is closed to unfiltered air flowing out of the second portion of the multiple channel extensions, such that air entering from one of the first or second faces of the media pack and exiting from the other of the first or second faces of the media pack passes through the media to filter the fluid (e.g., air). At least one of the channel extensions includes at least one contact area, the contact area including at least one island extending from at least one of the facing sheet and the channeled sheet.

[0018] In one implementation, the filtration media pack includes multiple layers of single-sided media, each layer including a fluted sheet, a facing sheet, and a plurality of flutes extending between the fluted sheet and the facing sheet, the flutes having a flute length extending from the first face of the filtration media pack to the second face of the filtration media pack. A first portion of the flutes is closed to unfiltered air flowing into the first portion of the flutes, and a second portion of the flutes is closed to unfiltered air flowing out of the second portion of the flutes, such that air entering from one of the first face or the second face of the media pack and exiting from the other of the first face or the second face of the media pack passes through the media to be filtered. In such an implementation, the fluted sheet includes continuous inner peaks facing toward the facing sheet and continuous outer peaks facing away from the facing sheet. The repeating pattern of the flutes includes at least one ridge extending along at least a portion of the flute length between adjacent peaks. A plurality of protrusion islands extend from the groove channels to contact the facing sheet, with at least one of the protrusions being located between the ridges and peaks of the groove channels, and the protrusion islands extend over an area of ​​the media that is substantially free from the protrusions.

[0019] In some embodiments, the filtration media pack has multiple layers of single-sided media including a fluted sheet, a facing sheet, and a plurality of flutes extending between the fluted sheet and the facing sheet. A first portion of the plurality of flutes is closed to unfiltered air flowing into the first portion of the plurality of flutes, and a second portion of the plurality of flutes is closed to unfiltered air flowing out of the second portion of the plurality of flutes, such that air entering from one of the first face or the second face of the media pack and exiting from the other of the first face or the second face of the media pack passes through the media to be filtered. The fluted sheet further includes a plurality of protrusions, the protrusions being non-uniformly distributed along the fluted sheet.

[0020] The filtration media pack can include multiple layers of single-sided media including a fluted sheet, a facing sheet, and a plurality of flutes extending between the fluted sheet and the facing sheet. A first portion of the plurality of flutes is closed to unfiltered air flowing into the first portion of the plurality of flutes, and a second portion of the plurality of flutes is closed to unfiltered air flowing out of the second portion of the plurality of flutes, such that air entering from one of the first face or the second face of the media pack and exiting from the other of the first face or the second face of the media pack passes through the media to be filtered. The fluted sheet also includes a plurality of protrusions, the protrusions contacting the facing sheet. The protrusions are substantially absent from portions of the fluted sheet not contacting the facing sheet.

[0021] In some embodiments, a filtration media pack includes multiple layers of single-sided media including a fluted sheet, a facing sheet, and a plurality of flutes extending between the fluted sheet and the facing sheet. A first portion of the plurality of flutes is closed to unfiltered air flowing into the first portion of the plurality of flutes, and a second portion of the plurality of flutes is closed to unfiltered air flowing out of the second portion of the plurality of flutes, such that air entering from one of the first face or the second face of the media pack and exiting from the other of the first face or the second face of the media pack passes through the media to be filtered. The fluted sheet includes a plurality of protrusions, the protrusions covering only a portion of the fluted sheet.

[0022] The filtration media pack can include multiple layers of single-sided media including a fluted sheet, a facing sheet, and a plurality of flutes extending between the fluted sheet and the facing sheet. A first portion of the plurality of flutes is closed to unfiltered air flowing into the first portion of the plurality of flutes, and a second portion of the plurality of flutes is closed to unfiltered air flowing out of the second portion of the plurality of flutes, such that air entering from one of the first face or the second face of the media pack and exiting from the other of the first face or the second face of the media pack passes through the media to be filtered. The fluted sheet includes a plurality of protrusions extending from the remainder of the fluted sheet, the protrusions having a non-constant cross-section on the fluted sheet in all axes.

[0023] Referring now to the figures, Figure 1 shows a perspective view of a fluted sheet 100 of a filtration media. The fluted sheet 100 may include a first end 102 and a second end 104. The fluted sheet 100 may include one or more fluted channels 106, such as channels or peaks and valleys. The fluted channels 106 may extend from the first end 102 to the second end 104. The fluted sheet 100 may include a first fluted channel 106 on one side of the fluted sheet 100 and a second fluted channel 108 on the opposite side of the fluted sheet 100. The fluted channels 106, 108 may be asymmetric, such as when the first fluted channel 106 has a different shape or cross-sectional area than the second fluted channel 108.

[0024] When formed into a media pack or filter element, the first groove channel 106 can be closed to unfiltered air flowing into the second groove channel 108 so that the air in the second groove channel 108 is filtered. The groove channels can be tapered so that one end has a larger opening compared to the other end. In the embodiment of FIG. 1 , the groove channels are tapered so that the first groove channel 106 is larger than the second groove channel 108 at the first end 102 and the second groove channel 108 is larger than the first groove channel 106 at the second end 104. In some embodiments, the media includes tapered and non-tapered portions. For example, a first portion of the media can be tapered and a second portion can be non-tapered. In one exemplary embodiment, the upstream portion of the media is substantially untapered over the majority of the length of the groove channel, with only the downstream portion tapered. In some embodiments, at least half of the upstream length of the groove channel is untapered, while in other embodiments, at least three-quarters of the upstream length of the groove channel is untapered.

[0025] The channeled sheet 100 may include continuous peaks 112, 114 and a plurality of protrusions 116. The protrusions 116 may be disposed on the peaks 112, 114 or adjacent to the peaks so as to be slightly offset from their tips. The protrusions 116 may be discontinuous, such that there is a portion along the channel 106 between the first end 102 and the second end 104 that does not include the protrusions. The protrusions 116 may be arcuate, having a non-planar upper surface. The protrusions 116 may be of a constant height, size, or shape, or may be of varying heights, sizes, or shapes. The protrusions 116 may be tapered, such that the protrusions 116 closer to the first end 102 are higher or lower than the protrusions closer to the second end 104.

[0026] 2, a single-sided media 200 is shown that includes a fluted sheet 210 and a facing sheet 220. In one embodiment, the facing sheet 220 can be substantially flat. In one embodiment, the facing sheet 220 can include a first surface 222 and a second surface 224. The facing sheet 220 contacts a plurality of protrusions 216 on the fluted sheet 110, which limits contact between the fluted sheet 210 and the facing sheet 220, thereby reducing masking between the fluted sheet 210 and the second surface 224 of the facing sheet 220.

[0027] FIG. 3 shows a media 300 including a channeled sheet 310 and a facing sheet 320. The channeled sheet 310 can include one or more protrusions, such as protrusions 317 and 318. Protrusion 317 is disposed on one side of a peak 312, and protrusion 318 is disposed on the opposite side of the peak 312. In one embodiment, the peak 312 does not contact the facing sheet 320, such as to prevent masking. The channeled sheet 310 can include one or more ridges 326, as shown in FIG. 3. The ridges 326 can be discontinuities in the curve of the channeled sheet 310. In one embodiment, the ridges 326 can be inflection points where the channeled sheet 310 changes from convex downward to convex upward, or from convex upward to convex downward. In one embodiment, a first ridge 317 can be disposed between the ridge 326 and the channel peak 312. A second protrusion 318 can be disposed on the opposite side of the peak 312, between the peak 312 and a different ridge 326. The channeled sheet 310 can also include one or more additional protrusions 316, such as at the alternate peak-on-peak 314 shown in Figure 3. It will be appreciated that in some implementations, the protrusions 316, 317, 318 do not contact the facing sheet except when the element is under pressure, at which point distortion of the media causes contact.

[0028] FIG. 4 shows a front view of a media pack 400 showing multiple fluted sheets 410 and multiple facing sheets 420. The fluted sheets 410 and facing sheets 420 are shown stacked on top of each other in an alternating pattern. The fluted sheet 410 includes flutes 406 and 408. The flute 406 is shown to have a cross-sectional area significantly larger than that of the flute 408 in the embodiment shown. This larger cross-sectional area allows for a larger volume on one side of the media pack. In some embodiments, the side with the larger volume is the upstream side, which allows for a larger dust loading volume on the upstream side of the media. In the embodiment shown, the peak 412 does not contact the facing sheet 420. The adjacent peak 414 also does not contact the facing sheet 420 in this embodiment shown. The protrusions 416, 417, and 418 are the only portions of the fluted sheet 410 that significantly contact the facing sheet 420 in some embodiments.

[0029] This difference between the upstream and downstream volumes can be characterized as groove channel volume asymmetry (also referred to as media volume asymmetry). Media volume asymmetry occurs when one side of the media pack (either the upstream or downstream side) has a different volume than the other side of the media pack. Such asymmetry may be created by the way the groove channels are constructed, for example, by the groove channels having a tapered cross-sectional area. As used herein, the concept of media volume asymmetry generally measures the media volume ratio of a larger media volume defined by a groove channel peak to a smaller media volume defined by the opposite groove channel peak. In some, but not all, implementations, the larger media volume corresponds to the upstream open media volume and the smaller media volume corresponds to the downstream open media volume (the upstream volume can accumulate contaminants such as dust during use).

[0030] Media volume asymmetry is beneficial for a variety of reasons, including improved fluid flow and improved packing performance. In some implementations, media will exhibit media volume asymmetry of greater than 1%, greater than 3%, greater than 5%, or greater than 10%. Exemplary media structures exhibit media volume asymmetry of greater than 15%, greater than 20%, greater than 50%, greater than 75%, greater than 100%, greater than 150%, and greater than 200%. Suitable media volume asymmetry ranges include, for example, 1%-300%, 5%-200%, 50%-200%, 100%-200%, and 100%-150%. Tapered groove channels may incorporate media volume asymmetry to further improve filtration performance.

[0031] Media packs including tapered groove channels may also exhibit media cross-sectional area asymmetry, which is calculated based on the cross-section of the media at any given point. In tapered groove channels, the cross-sectional area asymmetry varies at the measurement location along the depth of the grooved media pack. It will be appreciated that cross-sectional area asymmetry may result in media volume asymmetry, but this is not always the case, as tapered media cross-sectional area can vary along the groove channel, which has the cumulative effect of equalizing the total volume of each side of the media. Also, a given cross-section of the media pack may exhibit a larger cross-sectional area on the upstream side of the media, but the continued tapering of the media may result in an overall media volume asymmetry that is larger downstream in terms of total media volume.

[0032] In some embodiments, the media pack will have a cross-sectional area asymmetry such that one side of the media has a cross-sectional area that is at least 1 percent greater than the other side of the same piece of media. Often, the difference in cross-sectional area across the media will be greater than 3%, greater than 5%, or greater than 10%. Exemplary media constructions exhibit media cross-sectional area asymmetries of greater than 15%, greater than 20%, greater than 50%, greater than 75%, greater than 100%, greater than 150%, and greater than 200%. Suitable ranges of media cross-sectional area asymmetry include, for example, 1%-300%, 5%-200%, 50%-200%, 100%-200%, and 100%-150%.

[0033] The difference in cross-sectional area is controlled by the design of the groove channel geometry. In many cases, the presence, number, and shape of ridges along the groove channel significantly affect the amount of cross-sectional area asymmetry. The taper of the groove channel generally changes the cross-sectional area asymmetry along the groove channel length. However, this is not necessarily true, such as when the groove channel height varies but the width remains constant, such that the cross-sectional area does not change. In such embodiments, it may be possible to make the total cross-sectional area constant by varying the relative position of the ridges along the groove channel (or otherwise by varying the distribution of media along the groove channel or by changing the groove channel radius).

[0034] The geometry of the groove channels, resulting in differences in cross-sectional area, can significantly affect the flow characteristics through the channels. Varying the relative cross-sectional areas of the groove channels results in changes in the cross-sectional areas of the upstream and downstream portions of the media pack in that area. If the cross-sectional area of ​​the upstream portion of the media pack increases, the downstream portion of the media pack will also decrease in cross-sectional area. The present invention allows for customization of media volume asymmetry and cross-sectional area asymmetry to improve filter performance.

[0035] Figure 5 shows a media pack 500 including a channeled sheet 510 and a facing sheet 520. Channeled sheet 510 can include one or more protrusions, such as protrusions 516 and 517. Protrusion 516 is disposed on one side of the channel, and protrusion 517 is disposed on the opposite side of the channel. Media pack 500 in Figure 5 also shows ridges 526 and 527 along channel 506.

[0036] FIG. 6 shows a front view of a media pack 600 having multiple channeled sheets 610 and multiple facing sheets 620. The channeled sheets 610 and facing sheets 620 are shown stacked on top of each other in an alternating pattern, with protrusions 616 and 617 contacting the facing sheet 620. Channels 606 and 608 are shown depicted in FIG. 6. The upstream ends of channel 606 or 608 are typically plugged (e.g., plugged by a bead seal, although it will be understood that in some implementations, the ends of the channel are not plugged or additional blockages occur at other locations along at least some of the channel), while the downstream ends of the other channel 606 or 608 are typically plugged near the downstream ends of the channel. Thus, for example, if the upstream end of channel 606 is plugged, the downstream end of channel 606 is typically open, while the upstream end of channel 608 is open and the downstream end of channel 608 is closed. It will be appreciated that in many cases the upstream channel flow path (which is blocked downstream) will have a larger volume than the downstream channel flow path.

[0037] 7, an enlarged front view of a sheet of channeled media 710 and facer media 720 constructed and arranged in accordance with an embodiment of the present invention is shown, along with exemplary channel dimensions. Channeled sheet 710 can include channel 706. Channeled sheet 710 includes a first channel 706 on one side of channeled sheet 710 and a second channel 708 on the opposite side of channeled sheet 710. Channel 706 in the illustrated embodiment has a width A measured from a first peak 716 to an adjacent peak 716. In an exemplary embodiment, width A is 0.75 to 0.125 inches, optionally 0.5 to 0.25 inches, and optionally 0.45 to 0.3 inches.

[0038] The protrusion 717 in the illustrated embodiment has a width B. In exemplary embodiments, width B is between 0.2 and 0.02 inches, optionally between 0.15 and 0.05 inches, and optionally between 0.1 and 0.075 inches. Width B can also be expressed as a multiple of the thickness F of the media-forming channeled sheet 710. In exemplary embodiments, width B is between 20 and 1 times the thickness F of the media-forming channeled sheet 710. In certain embodiments, the channeled width B of the protrusion is between 10 and 7 times the thickness F of the media-forming channeled sheet 710. In some embodiments, the protrusion 717 has a width, such as distance A' shown in FIG. 7, that extends along most or all of the channel width.

[0039] The groove channel 706 in the embodiment shown has a height C. In exemplary embodiments, height C is between 0.5 and 0.05 inches, optionally between 0.25 and 0.075 inches, and optionally between 0.15 and 0.1 inches.

[0040] The protrusions 717 in the illustrated embodiment have a height D. In exemplary embodiments, the height D is between 0.1 and 0.005 inches, optionally between 0.05 and 0.01 inches, and optionally between 0.025 and 0.015 inches. The height D can also be expressed as a multiple of the thickness of the media-forming grooved sheet 710. In exemplary embodiments, the height D is between 10 and 0.5 times the thickness of the media-forming grooved sheet 710. In some embodiments, the height D of the protrusions is between 2 and 1 times the thickness of the media-forming grooved sheet 710. The combined thickness E of the protrusions 717 and the facer sheet 720 is also shown in FIG. 7. In some embodiments, the combined thickness E is between 0.11 and 0.015 inches, or between 0.06 and 0.02 inches, or between 0.035 and 0.025 inches. The height of protrusion 716 can be the same or different than protrusion 717, and thus can be, for example, 0.1 to 0.005 inches, optionally 0.05 to 0.01 inches, and optionally 0.025 to 0.015 inches.

[0041] FIG. 8 is an enlarged perspective view of a sheet 810 of grooved media constructed and arranged in accordance with an embodiment of the present invention, showing the dimensions of an exemplary protrusion 872 on the media, and also showing a groove channel peak 812. The protrusion 817 is shown with an exemplary length G, height H, and width I. The protrusion height may refer to the distance between the top of the protrusion, shown as a line, and the flat portion of the filtration media. In one embodiment, the average height of the protrusion may be between 0.005 inches and 0.05 inches.

[0042] In one embodiment, the average height of the protrusions on the first surface can be less than or equal to 0.01 inches. In one embodiment, the average height of the protrusions on the first surface can be less than or equal to 0.05 inches. In one embodiment, the average height of the protrusions on the second surface can be 0.0275 inches. In one embodiment, the average upstream protrusion height can be at least 50% greater than the average downstream protrusion height. In one embodiment, the protrusions can have an average height of 0.017 inches. In one embodiment, the protrusions have an average height of 500 to 50 percent of the media thickness.

[0043] The projection size or projection width can vary depending on the application. The projections can vary in width from 0.2 inches to 0.02 inches. In one embodiment, the projections have an average width of 20,000 to 200 percent of the media thickness. In one embodiment, the projections can cover 20% to 1% of the surface area of ​​the filtration media.

[0044] FIG. 9 is a perspective view of a sheet of channeled filtration media constructed and arranged in accordance with an embodiment of the present invention, illustrating variable spacing of protrusions on the channeled filtration media. The channeled sheet 900 can include a first end 902 and a second end 904. The channeled sheet 900 can include one or more channel portions 906, such as channels or peaks and valleys. The channel portions 906 can extend from the first end 902 to the second end 904. The channeled sheet 900 can include a first channel portion 906 on one side of the channeled sheet 900 and a second channel portion 908 on the opposite side of the channeled sheet 900. The channel portions 906, 908 can be asymmetric, such as when the first channel portion 906 has a different shape than the second channel portion 908. The distances between the protrusions 916 are designated as distances D1, D2, and D3. In the illustrated embodiment, distance D1 is less than distance D2, which is less than distance D3. Thus, in this exemplary implementation, the distance between protrusions 916 increases further from first end 902. In other implementations, the distance between protrusions 916 can decrease further from first end 902.

[0045] Figure 10 is a front view of a sheet of channeled filtration media and a sheet of facer media 920 constructed and arranged in accordance with the embodiment of the invention shown in Figure 9. Facing sheet 920 can be substantially flat. Facing sheet 920 contacts a plurality of protrusions 916 on channeled sheet 900, which reduces masking between channeled sheet 910 and second surface 924 of facing sheet 920 by limiting contact between channeled sheet 910 and facing sheet 920.

[0046] FIG. 11 is a perspective view of a sheet of channeled filtration media constructed and arranged in accordance with an embodiment of the present invention, illustrating variable spacing of protrusions on the channeled filtration media. The channeled sheet 1100 can include a first end 1102 and a second end 1104. The channeled sheet 1100 can include one or more channel portions 1106, such as channels or peaks and valleys. The channel portions 1106 can extend from the first end 1102 to the second end 1104. The channeled sheet 1100 can include a first channel portion 1106 on one side of the channeled sheet 1100 and a second channel portion 1108 on the opposite side of the channeled sheet 1100. The channel portions 1106, 1108 can be asymmetric, such as when the first channel portion 1106 has a different shape than the second channel portion 1108. The channeled sheet 1100 of Figure 11 does not include ridges as shown in other embodiments, such as ridges 326 shown in Figure 3. Instead, the channeled sheet 110 includes a curved profile. Also, in the embodiment shown, the channel peaks include a row of protrusions 1116 and 1118 located at the peak of each channel 1106 and 1108.

[0047] Figure 12 is a front view of a sheet of channeled filtration media and a sheet of facer media 1100 constructed and arranged in accordance with the embodiment of the invention shown in Figure 11. The facing sheet 1120 can be substantially flat. In one embodiment, the facing sheet 1120 can include a first surface 1122 and a second surface 1124. The facing sheet 1120 contacts a plurality of protrusions 1116 on the channeled sheet 1100, which reduces masking between the channeled sheet 1110 and the second surface 1124 of the facing sheet 1120 by limiting contact between the channeled sheet 1110 and the facing sheet 1120.

[0048] 13 is a perspective view of a sheet of channeled filtration media constructed and arranged in accordance with an embodiment of the present invention, showing a single protrusion on a channeled media sheet 1300. The channeled sheet 1300 can include a first end 1302 and a second end 1304. The channeled sheet 1300 can include one or more channel flutes 1306, such as channels or peaks and valleys. The channel flutes 1306 can extend from the first end 1302 to the second end 1304. The channeled sheet 1300 can include a first channel 1306 on one side of the channeled sheet 1300 and a second channel 1308 on the opposite side of the channeled sheet 1300. The channel flutes 1306, 1308 can be asymmetric, such as when the first channel 1306 has a different shape than the second channel 1308.

[0049] Figure 14 is a front view of a sheet 1310 of channeled filtration media and a sheet 1320 of facer media constructed and arranged in accordance with the embodiment of the invention shown in Figure 13. The facing sheet 1320 can be generally flat. In one embodiment, the facing sheet 1320 can include a first surface 1322 and a second surface 1324. The facing sheet 1320 contacts a plurality of protrusions 1316 on the channeled sheet 1300, which reduces masking between the channeled sheet 1310 and the second surface 1324 of the facing sheet 1320 by limiting contact between the channeled sheet 1310 and the facing sheet 1320.

[0050] 15 is a perspective view of a sheet of channeled filtration media constructed and arranged in accordance with an embodiment of the present invention. The channeled sheet 1500 can include a first end 1502 and a second end 1504. The channeled sheet 1500 can include one or more channel flutes 1506, such as channels or peaks and valleys. The channel flutes 1506 can extend from the first end 1502 to the second end 1504. The channeled sheet 1500 can include a first channel 1506 on one side of the channeled sheet 1500 and a second channel 1508 on the opposite side of the channeled sheet 1500. The channel flutes 1506, 1508 can be asymmetric, such as when the first channel 1506 has a different shape than the second channel 1508.

[0051] Figure 16 is a front view of a sheet of channeled filtration media and a sheet of facer media constructed and arranged in accordance with the embodiment of the invention shown in Figure 15. The facing sheet 1520 can be generally flat. In one embodiment, the facing sheet 1520 can include a first surface 1522 and a second surface 1524. The facing sheet 1520 contacts the plurality of protrusions 1516 of the channeled sheet 1500, which reduces masking between the channeled sheet 1510 and the second surface 1524 of the facing sheet 1520 by limiting contact between the channeled sheet 1510 and the facing sheet 1520.

[0052] 17 is a perspective view of a sheet of channeled filtration media and a sheet of facer media 1700 constructed and arranged in accordance with an embodiment of the present invention, including a channeled sheet 1710 and a facing sheet 1720. The facing sheet 1720 can be substantially flat. The facing sheet 1720 includes a plurality of protrusions 1719, whereas the channeled sheet 1710 of the exemplary embodiment does not include protrusions. Thus, in this embodiment, the protrusions 1719 projecting downward toward the peaks of the channeled sheet 1710 reduce masking between the surfaces of the channeled sheet 1710 and the facing sheet 1720 by limiting contact between the two sheets.

[0053] FIG. 18 is a perspective view of a filter element 1800 constructed and arranged in accordance with an embodiment of the present invention. The filter element 1800 includes multiple sheets of filtration media. The filter element 1800 can include a filtration media pack. As described herein, the filtration media pack can include fluted media with protrusions. The filter element can include a housing, for example, to support or mount a single-sided media filter element. In an exemplary embodiment, the filter element 1800 has a depth of 2 to 20 inches; in other embodiments, the filter element 1800 has a depth of 2 to 16 inches; and in still other embodiments, the filter element has a depth of 2 to 12 inches. In some embodiments, the filter element 1800 has a depth of 6 to 20 inches; in other embodiments, the filter element 1800 has a depth of 6 to 16 inches; and in still other embodiments, the filter element 1800 has a depth of 6 to 12 inches. A suitable filter element 1800 depth is, for example, 6 to 10 inches. The construction of the present invention, having ridges separating the fluted sheet and the facing sheet, is particularly suitable for relatively deep filter elements.

[0054] In some implementations, the protrusions of the filtration media described herein can have a height at least equal to the thickness of the media. In other implementations, the protrusions have a height twice the thickness of the media. In other implementations, the protrusions have a height three times the thickness of the media. In other implementations, the protrusions have a height four times the thickness of the media. In other implementations, the protrusions have a height between two and five times the thickness of the media. In yet other implementations, the protrusions have a height between two and ten times the thickness of the media.

[0055] The protrusions can also be measured by their height relative to the channel height. The channel height is the distance from the facing sheet to the top of the channel. In some implementations, the protrusions are less than 90 percent of the channel height, or less than 75 percent of the channel height, or less than 50 percent of the channel height; in some implementations, the protrusions are at least 10 percent of the channel height, or at least 20 percent of the channel height, or at least 30 percent of the channel height. In some implementations, the protrusions are 10 to 90 percent of the channel height. In other implementations, the protrusions are 20 to 75 percent of the channel height, and in still other implementations, the protrusions are 25 to 50 percent of the channel height.

[0056] The protrusions can also be measured by their height relative to the width of the channel. The channel width is the distance between adjacent peaks on the same side of the channeled sheet. In some implementations, the protrusions are less than 40 percent of the channel width, or less than 30 percent of the channel width, or less than 25 percent of the channel width. In some implementations, the protrusions are at least 1 percent of the channel width, or at least 5 percent of the channel width, or at least 10 percent of the channel width. In some implementations, the protrusions are 1 to 40 percent of the channel width. In other implementations, the protrusions are 2 to 20 percent of the channel width, and in still other implementations, the protrusions are 3 to 10 percent of the channel width.

[0057] In some implementations, the protrusions are located at the peak or maximum height of the groove channel, while in other implementations, the protrusions are located on one or both sides of the groove channel peak. In some implementations, the groove channel peak has a sharp or small radius, while in other implementations, the peak has a gradual curve or is generally flat.

[0058] The protrusions can be of a generally uniform height or can vary. Individual protrusions can have varying heights along their length or width. Additionally, the height of the various protrusions can vary along the channel. Variations in protrusion height can facilitate the creation of media with tapered channel channels that vary in height along their length. In some cases, the protrusions become larger moving from the upstream to downstream side of the media pack. In other implementations, the protrusions are symmetrically aligned on either side of the channel axis.

[0059] Channeled media, including protrusions on the channel, can exhibit area or volume asymmetry. In the context of Z-media, area asymmetry generally refers to the asymmetry in the cross-sectional area of ​​the channel and can be exhibited by tapered channel shapes. For example, area asymmetry exists when the area of ​​a channel at one location along the channel length is different from the area of ​​the channel at another location along the channel length. Tapered channel shapes are area asymmetric because they decrease in size from a first location (e.g., end) of the media pack to a second location (e.g., end) of the media pack, or increase in size from a first location (e.g., end) of the media pack to a second location (e.g., end).

[0060] Volume asymmetry refers to the difference between the dirty and clean side spaces in a filtration media pack. Groove channel volume asymmetry refers to the volume difference within a filter element or filter cartridge between the upstream volume and the downstream volume. The upstream volume refers to the volume of media that receives unfiltered fluid (e.g., air), and the downstream volume refers to the volume of media that receives filtered fluid (e.g., air). Filter elements can be further characterized as having a dirty side and a clean side. Generally, the dirty side of a filter media refers to the volume of media that receives unfiltered fluid. The clean side refers to the volume of media that receives filtered fluid that passes through the filtration passages from the dirty side.

[0061] In some embodiments, the media has a dirty side or upstream volume that is larger than the clean side or downstream volume. It has been observed that when filtering air, particulates in the air accumulate on the dirty side, so that the capacity of the filtration media is determined by the volume of the dirty side. By providing a volume asymmetry, it is possible to increase the volume of media available to receive dirty air, thereby increasing media pack capacity.

[0062] Filtration media with channel volume asymmetry can be referred to as media packs with asymmetric volume structures. Desirably, media exhibiting volume asymmetry exhibits a volume asymmetry of about 10% or more, about 20% or more, 30% or more, and preferably about 50% or more. Exemplary ranges for channel volume asymmetry include about 30% to about 250%, and about 50% to about 200%. Generally, when it is desired to maximize media life, it may be desirable for the upstream volume to be larger than the downstream volume. Alternatively, there are situations in which it is desirable to minimize the upstream volume relative to the downstream volume. For example, in the case of safety elements, it is preferable to provide a safety element with a relatively small upstream volume to stop flow relatively quickly as an indication that the media is full and a rupture has occurred in the upstream filter element.

[0063] Filter element or filter cartridge configurations using z-filter media are sometimes referred to as "straight-through flow configurations" or variations thereof. Generally, what is meant in this context is that the serviceable filter element generally has an inlet end (or face) and an outlet end (or face) with flow entering and exiting the filter cartridge in approximately the same straight-through direction. The term "straight-through flow configuration" ignores, for purposes of this definition, the airflow of the media pack through the outermost wrap of facing media. In some instances, each inlet end and each outlet end is generally flat or planar, and the two are parallel to one another. However, variations from this, such as non-planar faces, may be used in some applications.

[0064] As used herein, the term "z-filter media construction" and variations thereof is meant to refer to any or all of: single-facer media having flute and facing media sheets and suitable closures to prevent airflow from one flow surface to another without filtering channels passing through the filtration media; and / or single-facer media that is convoluted, stacked, or otherwise constructed or formed into a three-dimensional network of flute channels; and / or filtration structures including single-facer media; and / or flute-channeled media that is constructed or formed (e.g., by folding or flute-forming) into a three-dimensional network of flute channels. Generally, it is preferable to provide suitable flute channel closure construction to prevent unfiltered air entering one side of the media from exiting the other side of the media as part of the filtered airflow exiting the media. In many constructions, the z-filtration media structure is configured to form a network of inlet and outlet groove channels, with the inlet groove channels being open adjacent the inlet face and closed adjacent the outlet face, and the outlet groove channels being closed adjacent the inlet face and open adjacent the outlet face.

[0065] Generally, filtration media are relatively flexible materials, usually nonwoven fibrous materials (cellulose fibers, synthetic fibers, or both), often containing resins therein and sometimes treated with additional substances. In some embodiments, the media fibers are primarily cellulose. The media generally can be processed or configured into various groove channels, such as corrugated patterns, without unacceptable media damage. The filter media can also be easily coiled or otherwise configured for use without unacceptable media damage. The media also typically can include a resin. During the corrugation process, the media can be heated to a temperature above the glass transition temperature of the resin. The resin is then cooled, and the resin helps maintain the shape of the groove channels.

[0066] Filtration media are provided as relatively flexible media comprising cellulose fibers, synthetic fibers, glass fibers, ceramic fibers, or combinations thereof, often containing resins therein and possibly treated with additional materials. An exemplary filtration medium can be characterized as a cellulose-based filtration medium that can tolerate strains of up to about 12% when wet and warm without splitting, but that is often found to break at lower strain rates (as low as 3% for some media) when dry and cold. In one embodiment, the filtration medium comprises cellulose. In one embodiment, the fibers forming the filtration medium can comprise at least 25% cellulose, at least 50% cellulose, or at least 75% cellulose. The filtration medium can be grooved to form a grooved filtration medium without unacceptable media degradation. Furthermore, the filtration medium is desirably of a nature that maintains its configuration during use. While some filtration media capable of strains greater than about 12% are available and can be used in accordance with the present invention, such media are typically more expensive due to the relatively high amount of synthetic fiber that must be incorporated.

[0067] During the dimpling process, an inelastic deformation is induced in the media, which prevents the media from returning to its original shape. However, when the forming displacement is released, the protrusion may be prone to partial springback, maintaining only a portion of the elongated and bent portion. The media may also contain a resin. During the dimpling process, the media can be heated to soften the resin. When the resin cools, it helps maintain the embossed shape.

[0068] In one embodiment, the filtration media may have a modulus of elasticity greater than 10,000 pounds per square inch. In one embodiment, the filtration media may have a modulus of elasticity less than 75,000 pounds per square inch.

[0069] For example, one or both sides of the filtration media can be fitted with fine fibrous materials according to U.S. Patent Nos. 6,955,775, 6,673,156, and 7,270,693, the contents of which are incorporated herein by reference in their entireties. Generally, fine fibers, which can be referred to as polymeric fine fibers (microfibers and nanofibers), can be provided in the media to improve filtration performance.

[0070] The fine fibers can be added at various stages of the manufacturing process. For example, in some implementations, the media includes the fine fibers before the protrusions are formed, while in other implementations, the fine fibers are added to the media as a layer or layers. The presence of fine fibers on the media allows for the provision of a media with reduced weight or thickness while achieving desired filtration characteristics. Thus, the incorporation of fine fibers on the media allows for improved filtration performance, the use of thinner media, or both. Exemplary materials that can be used to form the fine fibers include polyvinylidene chloride, polyvinyl alcohol polymers, polyurethanes, and copolymers including various nylons such as nylon 6, nylon 4,6, nylon 6,6, nylon 6,10, and copolymers thereof, polyvinyl chloride, PVDC, polystyrene, polyacrylonitrile, PMMA, PVDF, polyamide, and mixtures thereof.

[0071] Referring now to Figures 19-32, the relationship between various media and element properties is shown in schematic form for various exemplary embodiments of the present invention. In these structures, the x-axis represents the distance from the downstream end of the channel channel. Thus, point "0" represents the downstream end of the channel channel, and point "300" represents the vicinity of the upstream end of the channel channel. The upstream end of the channel channel is located at the face of the media pack where the fluid to be filtered enters the element, while the downstream end of the channel channel is located at the face of the media pack where the fluid to be filtered exits the element. Figures 19-21 present data for a first exemplary embodiment of the present invention. Figure 19 is a graphical representation of the channel area to peak height ratio of a filtration media constructed and deployed according to a first exemplary embodiment of the present invention. In this exemplary embodiment, the peak height ratio remains approximately constant, while the channel area ratio varies along a distance of approximately 300 mm, as the channel area is measured from the upstream portion of the element to the downstream portion of the element. Thus, the channel area ratio of the upstream cross section to the downstream cross section is greater at one end of the media pack than at the other end. In particular, the ratio of upstream to downstream cross-sectional area shows a distinct decrease near the end of the element (near where the fluid exits the element). Thus, the element exhibits a channel area asymmetry along most of its length, with the upstream cross-sectional area of ​​the element being larger than the downstream cross-sectional area of ​​the adjacent groove channel for most of the element's length, but this difference in cross-sectional area decreasing as the groove channel progresses to the end of the element where the fluid exits the element.

[0072] Figure 20 is a graphical illustration of the lengths of corrugated and flat sheets of filtration media constructed and arranged according to this first exemplary embodiment of the present invention. Figure 20 shows how the "D-length" of the media (such as the length indicated by the annotation "A" in Figure 7), which is the width of one groove channel of the media, remains approximately constant, while the length of the media along that groove channel (taken along a cross-section of the groove channel that is plane with respect to the groove channel length, and shown, for example, in Figure 7 as the length of the media along the groove channel corresponding to the groove channel width of "A"), is the "S-length," which shows only modest variations along the groove channel length. These modest variations in S-length are the result of changes in the media length along the groove channel as a result of the presence or absence of protrusions along each groove channel.

[0073] FIG. 21 is a graphical representation of the upstream and downstream projection heights of a filtration media constructed and arranged in accordance with a first exemplary embodiment of the present invention. FIG. 21 illustrates how, in this exemplary embodiment, the upstream projection height is smaller than the downstream projection height. Therefore, in some embodiments of the present invention, the downstream projection height is greater than the upstream projection height. The increased projection height of the downstream projections is beneficial in avoiding masking because, under load, the downstream projections are under increasing deformation pressure, resulting in a pressure differential between the upstream and downstream portions of the media pack. In the exemplary embodiment, the upstream and downstream projections vary in size relative to one another but are uniform along the element.

[0074] 22-24 illustrate element characteristics for a second exemplary construction, particularly for a media pack with air flowing from, for example, a cylindrical media pack. FIG. 22 is a graphical representation of the channel area to dimple height ratio of a filtration media constructed and deployed in accordance with a second exemplary embodiment of the present invention. As is apparent from FIG. 22, the dimple height ratio remains approximately constant along the length of the element in FIG. 22, while the upstream channel area relative to the downstream channel area increases along the element. This increase is somewhat variable, reflecting area changes caused by the media pack's protrusions and airflow. It will be understood that in some implementations, the channel area ratio will exhibit these variations, although the variations will be less than those shown in FIG. 22.

[0075] 23 is a graphical representation of the lengths of corrugated and flat sheets of filtration media constructed and arranged in accordance with a second exemplary embodiment of the present invention. It is apparent from FIG. 23 that the "D Length" of the media, which is the width of one channel of the media, is constant, while the length of the media along one channel, measured at the channel cross-section (perpendicular to the channel's longitudinal dimension), is "S Length," which shows modest variation along the channel length and variation from the asperity height.

[0076] 24 is a graphical representation of the upstream and downstream projection heights of a filtration media constructed and arranged in accordance with a second exemplary embodiment of the present invention. FIG. 24 illustrates how the upstream projection height is smaller than the downstream projection height. Thus, in the illustrated embodiment, the downstream projection height is greater than the upstream projection height. In the exemplary embodiment, the upstream and downstream projections vary in size relative to one another but are uniform along the element.

[0077] Figures 25 and 26 illustrate element characteristics of a third exemplary structure, particularly one in which the protrusions are tapered in height from one another. Figure 25 is a graphical representation of the channel area to protrusion height ratio of a filtration media constructed and arranged according to a third exemplary embodiment of the present invention. Figure 25 illustrates how the dimple height ratio decreases deeper into the element, and thus the size of the upstream dimples decreases relative to the downstream dimples along the length of the groove flow path (from the inlet face to the outlet face of the media pack, as viewed from right to left in Figure 25). Figure 26 is a graphical representation of how, in this exemplary embodiment, the upstream protrusion height decreases along the groove flow path, while the downstream protrusion height, measured from right to left in Figure 26, increases.

[0078] Figure 27 is a graphical representation of the channel area to protrusion height ratio for a filtration medium constructed and arranged in accordance with a fourth exemplary embodiment of the present invention, in which the upstream and downstream protrusions have various heights. Figure 28 is a graphical representation of the corrugated and flat sheet lengths for a filtration medium constructed and arranged in accordance with this fourth exemplary embodiment of the present invention. Figure 29 is a graphical representation of the upstream and downstream protrusion heights for a filtration medium constructed and arranged in accordance with this fourth exemplary embodiment of the present invention.

[0079] Figures 30-32 illustrate element characteristics for a fifth exemplary structure, specifically a media pack in which the protrusions have a "wave pattern," in which the dimples are largest at the upstream and downstream ends of the element and smallest in the center of the element. Figure 30 is a graphical representation of the channel area to protrusion height ratio for a filtration media constructed and arranged according to a fifth exemplary embodiment of the present invention, illustrating how, in this configuration, the ratio of dimple height remains constant, while the ratio of upstream to downstream channel area decreases near the downstream end of the element. In other words, the area asymmetry decreases near the downstream end of the element. Figure 31 is a graphical representation of the corrugated and flat sheet lengths for a filtration media constructed and arranged according to a fifth exemplary embodiment of the present invention. Figure 32 is a graphical representation of the upstream and downstream protrusion heights for a filtration media constructed and arranged according to a fifth exemplary embodiment of the present invention.

[0080] As used herein and in the appended claims, the singular forms "a," "an," and "the" include the plural referent unless the content clearly dictates otherwise. Thus, for example, reference to a composition containing a "compound" includes a mixture of two or more compounds. Also, the term "or" is generally used in its sense to include "and / or" unless the content clearly dictates otherwise.

[0081] Also, as used herein and in the appended claims, the term "configured" describes a system, apparatus, or other structure that is constructed or arranged to perform a particular task or adopt a particular configuration. The term "configured" can be used interchangeably with other similar terms such as arranged and configured, constructed and arranged, constructed, manufactured and arranged, etc.

[0082] The invention has been described with reference to various specific and preferred embodiments and techniques, but it should be understood that many variations and modifications can be made while remaining within the scope of the invention.

Claims

1. 1. A filtration media pack comprising: (a) a plurality of layers of single-sided media comprising a fluted sheet, a facing sheet, and a plurality of flutes extending between the fluted sheet and the facing sheet; (b) a first portion of the plurality of groove channels and a second portion of the plurality of groove channels, the first portion of the plurality of groove channels being closed with an occlusion to unfiltered air flowing into the first portion of the plurality of groove channels, and the second portion of the plurality of groove channels being closed with an occlusion to unfiltered air flowing out of the second portion of the plurality of groove channels, such that air entering from one of the first side or the second side of the filtration media pack and exiting from the other of the first side or the second side of the filtration media pack passes through the filtration media pack and is filtered; Equipped with a plurality of said channels comprising at least one contact area between said single-sided media and said fluted sheet, said contact area comprising at least one permeable protrusion extending from at least one of said facing sheet and said fluted sheet; the protrusions are absent from portions of the single-sided media where the fluted sheet does not contact the facing sheet; A filtration media pack wherein a plurality of said groove channels comprise peaks.

2. 10. The filtration media pack of claim 1, wherein the filtration media pack exhibits a media volume asymmetry of at least 10%.

3. 3. The filtration media pack of claim 1, wherein the fluted sheet comprises the permeable protrusions.

4. 4. The filtration media pack of claim 1, wherein the protrusions cover only a portion of the channeled sheet.

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