Oval tubular filter cartridges and filtration systems using the same

Abstract

The present application relates to oval tubular filter cartridges and filtration systems using these oval tubular filter cartridges. Filter cartridges including tubular filter media having oval cross-sections and filtration systems using these oval tubular filter cartridges are described herein. The inner perimeters of the oval cross-sections of one or more of these filter cartridges may be asymmetric, i.e., the inner perimeters of the cross-sections of the tubular filter media in these filter cartridges may not have straight lines around which the inner perimeters are symmetrical. The inner perimeters of the oval cross-sections of the tubular filter media in one or more of these filter cartridges may have only one line of symmetry.

Description

[0001] The present application is a divisional application of an application filed on March 14, 2014, with application number 201480013334.0 and invention name “Oval tubular filter cartridges and filtration systems using these oval tubular filter cartridges”.

[0002] Related Applications

[0003] This application claims the benefit under 35 USC §119 of U.S. Provisional Patent Application No. 61 / 789,385, filed on March 15, 2013, entitled "OVATE TUBULAR FILTER CARTRIDGES AND FILTER SYSTEMS USING THE SAME," which is incorporated herein by reference in its entirety.

[0004] Described herein are filter cartridges that include tubular filter media having an oval cross-section, and filtration systems that use these oval tubular filter cartridges. Background Art

[0005] In many different industries, particulate matter is suspended in air or other airflows, and in many cases, it is necessary to remove particulate matter from the airflow. A system for cleaning an airflow filled with particulate matter includes an air filtration system having a filter element located in a housing. The filter element may be in the form of a suitable fabric or pleated paper bag or a sock-like cover. The airflow contaminated with particles is usually passed through the housing so that the particles are captured and trapped by the filter element. In some systems, cleaning is achieved by periodically pulsing a short burst of compressed air to the interior of the filter element to reverse the air flow flowing through the filter element, causing the collected pollutants to be collected. For example, examples of these air filtration systems are disclosed in U.S. Patents 4,218,227 (published by Frey) and 4,395,269 (published by Schuler).

[0006] In a general design, an air filtration system has a clean air chamber and a dirty air chamber. The two chambers are separated by a metal plate, commonly called a tube sheet. The tube sheet has a plurality of openings on which filter elements are located. Air filled with particles is introduced into the dirty air chamber, and the particles are collected on the filter elements as the air passes from the dirty air chamber through the openings in the tube sheet into the clean air chamber. The cleaned air is exhausted from the clean air chamber into the environment, or recirculated for other uses. For example, U.S. Pat. No. 4,424,070 to Robinson, U.S. Pat. No. 4,436,536 to Robinson, U.S. Pat. No. 4,443,237 to Ulvestad, U.S. Pat. No. 4,445,915 to Robinson, U.S. Pat. No. 5,207,812 to Tronto et al., U.S. Pat. No. 4,954,255 to Muller et al., U.S. Pat. No. 5,222,488 to Forsgren, U.S. Pat. No. 5,211,846 to Kott et al., U.S. Pat. No. 5,730,766 to Clements, U.S. Pat. No. 4,661,131 to Howeth, U.S. Pat. No. 6,488,746 to Kosmider et al., and U.S. Pat. No. 8,128,724 to Mills et al. disclose examples of various filter element designs. Summary of the invention

[0007] Filter cartridges including tubular filter media having such oval cross-sections, and filtration systems using such oval tubular filter cartridges are described herein.

[0008] In one or more embodiments, the filter cartridges having filter media shaped or formed as described herein with an oval cross-section can exhibit a higher particle loading capacity because more of the filter media faces downward rather than upward when the filter cartridges are in at least one orientation. In one or more embodiments, the filter media facing downward can be less susceptible to particle loading during use than the filter media facing upward. The higher particle loading capacity of the filter cartridge can provide advantages of lower pulse cleaning requirements in terms of, for example, fewer pulses required, less pulse energy required per pulse, etc.

[0009] Although the shape is described as oval or ovoid, in one or more embodiments, the cross-sections of the tubular filter media within the filter cartridges described herein may have one or more flat edges, i.e., the oval or ovoid cross-sections may not be true ovals that include only curves. Instead, the cross-sectional shapes of one or more embodiments of the tubular filter cartridges may be only partially in true oval form.

[0010] In one or more embodiments, the inner perimeters of the oval cross-sections of the filter cartridges described herein may be asymmetric, i.e., where asymmetric means that there is no straight line about which the inner perimeters of the cross-sections of the tubular filter media of the filter cartridges are symmetric. In one or more alternative embodiments, the inner perimeters of the oval cross-sections of the tubular filter media within the filter cartridges may have only one line of symmetry. In one or more alternative embodiments, the single line of symmetry may be described as extending through a top and a bottom of the tubular filter media.

[0011] As described herein, an inscribed circle may also provide another way to characterize the inner circumferences of the cross-sections of the tubular filter media within the filter cartridges described herein. In one or more embodiments, limiting the maximum radial clearance between an inscribed circle and the inner circumference of the filter cartridges described herein may provide pulse cleaning improvements of a filter cartridge having the following characteristics (having the following improvements including, for example, lower pulse energy required per pulse, etc.).

[0012] In a first aspect, one or more embodiments of the filter cartridges described herein include: tubular filter media defining an interior surface facing an interior volume of the filter cartridge and an exterior surface facing away from the interior volume, wherein the tubular filter media defines a tubular filter media length measured along a tube axis extending from a first end to a second end of the tubular filter media; a filter cartridge housing including a first end cap at the first end of the tubular filter media and a second end cap at the second end of the tubular filter media; wherein, in a cross-section taken transverse to the tube axis at any position along a majority of the length of the tubular filter media, the interior surface of the tubular filter media defines an inner perimeter; wherein the cross-section includes a maximum height ( Hmax), wherein the vertex and the base point are located on the inner perimeter and a maximum height axis, the maximum height axis extending across the cross section at a certain position and in a certain orientation such that the vertex and the base point are the points on the inner perimeter that are farthest away from each other along any straight line extending across the cross section; wherein the cross section includes a maximum width (Wmax) measured between a first point and a second point located on the inner perimeter and on a maximum width axis, wherein the maximum width axis is positioned along a straight line perpendicular to the maximum height axis, and wherein the maximum width axis intersects the maximum height axis at a bottom axis intersection point, wherein at the bottom axis intersection point, the first point and the second point are farthest away from each other on any straight line perpendicular to the maximum height axis; wherein the bottom axis intersection point does not bisect the maximum height of the cross section as measured between the vertex and the base point.

[0013] In one or more embodiments of the filter cartridges described herein, the cross section includes a bottom segment height measured along the maximum height axis from the bottom point to the bottom axis intersection, and wherein the bottom segment height is less than or equal to 0.4 times the maximum height measured along the maximum height axis from the apex to the bottom point. In one or more embodiments, the bottom segment height is greater than 0.1 times the maximum height.

[0014] In one or more embodiments of the filter cartridge described herein, the inner perimeter of the cross-section includes a bottom perimeter segment including the bottom point, wherein the bottom perimeter segment includes a bottom perimeter segment length measured from the first point to the second point along the inner perimeter; wherein the inner perimeter of the cross-section includes a top perimeter segment including the vertex, wherein the top perimeter segment extends from a first end to a second end, wherein the first end is located on the inner perimeter between the first point and the vertex, and the second end is located on the inner perimeter between the second point and the vertex, wherein the first end of the top perimeter segment and the second end is the point where a top perimeter segment line intersects the inner perimeter, and wherein the top perimeter segment includes a top perimeter segment length measured along the inner perimeter from the first end to the second end; wherein the top perimeter segment line is a straight line perpendicular to the maximum height axis and intersecting with the maximum height axis at a top axis intersection point, wherein the cross section includes a top portion height measured along the maximum height axis from the top axis intersection point to the vertex on the inner perimeter; wherein the top segment height is equal to the bottom segment height; and wherein the bottom perimeter segment length is greater than the top perimeter segment length. In one or more embodiments, the bottom perimeter segment length is 1.2 times or more greater than the top perimeter segment length. In one or more embodiments, the bottom perimeter segment length is 2 times or more greater than the top perimeter segment length.

[0015] In one or more embodiments of the filter cartridge described herein, the inner perimeter of the cross-section includes a bottom perimeter segment containing the bottom point and extending from the first point to the second point, wherein the entire bottom perimeter segment curves continuously from the first point to the second point.

[0016] In one or more embodiments of the filter cartridge described herein, between the first point and the second point, no segment of the inner perimeter lies in a straight line for a distance greater than 1 centimeter.

[0017] In one or more embodiments of the filter cartridges described herein, the maximum height axis is not on a line of symmetry of the inner perimeter of the cross-section.

[0018] In one or more embodiments of the filter cartridge described herein, the inner perimeter of the cross-section defines only one line of symmetry.

[0019] In one or more embodiments of the filter cartridge described herein, the inner perimeter of the cross-section defines only one line of symmetry, and wherein the maximum height axis coincides with the line of symmetry.

[0020] In one or more embodiments of the filter cartridges described herein, the inner perimeter of the cross-section is asymmetric.

[0021] In a second aspect, one or more embodiments of the filter cartridge described herein may include: a tubular filter medium defining an interior surface facing an interior volume of the filter cartridge and an exterior surface facing away from the interior volume, wherein the tubular filter medium defines a tubular filter medium length measured along a tube axis extending from a first end to a second end of the tubular filter medium; a filter cartridge housing comprising a first end cap at the first end of the tubular filter medium and a second end cap at the second end of the tubular filter medium; wherein, in a cross-section taken transverse to the tube axis at any position along a majority of the length of the tubular filter medium, the interior surface of the tubular filter medium defines an inner perimeter having an oval shape; wherein the oval shape of the inner perimeter of the cross-section is asymmetric.

[0022] In one or more embodiments of the filter cartridge described herein, the cross-section includes a maximum height (Hmax) measured between a vertex and a bottom point, wherein the vertex and the bottom point are located on the inner perimeter and a maximum height axis, the maximum height axis passing through the cross-section at a position and in a direction such that the vertex and the bottom point are the points farthest from each other along any straight line traversing the cross-section; wherein the cross-section includes a maximum width (Wmax) measured between a first point and a second point located on the inner perimeter and on a maximum width axis, wherein the maximum width axis is positioned along a straight line perpendicular to the maximum height axis, and wherein the maximum width axis intersects the maximum height axis at a bottom axis intersection point, wherein at the bottom axis intersection point, the first point and the second point are farthest from each other on any straight line perpendicular to the maximum height axis; and wherein the bottom axis intersection point does not bisect the maximum height of the cross-section as measured between the vertex and the bottom point.

[0023] In one or more embodiments of the filter cartridges described herein, the cross section includes a bottom segment height measured along the maximum height axis from the bottom point to the bottom axis intersection, and wherein the bottom segment height is less than or equal to 0.4 times the maximum height measured along the maximum height axis from the apex to the bottom point. In one or more embodiments, the bottom segment height is greater than 0.1 times the maximum height.

[0024] In one or more embodiments of the filter cartridge described herein, the inner perimeter of the cross-section includes a bottom perimeter segment containing the bottom point, wherein the bottom perimeter segment includes a bottom perimeter segment length measured from the first point to the second point along the inner perimeter; wherein the inner perimeter of the cross-section includes a top perimeter segment containing the apex, wherein the top perimeter segment extends from a first end to a second end, wherein the first end is located on the inner perimeter between the first point and the apex, and the second end is located on the inner perimeter between the second point and the apex, wherein the first end of the top perimeter segment is located between the second point and the apex, and wherein the first end of the top perimeter segment is located between the first point and the apex. The first end and the second end are the points where a top perimeter segment line intersects the inner perimeter, and wherein the top perimeter segment includes a top perimeter segment length measured along the inner perimeter from the first end to the second end; wherein the top perimeter segment line is a straight line perpendicular to the maximum height axis and intersecting the maximum height axis at a top axis intersection point, wherein the cross section includes a top segment height measured along the maximum height axis from the top axis intersection point to the vertex on the inner perimeter; wherein the top segment height is equal to the bottom segment height; and wherein the bottom perimeter segment length is greater than the top perimeter segment length. In one or more embodiments, the bottom perimeter segment length is 1.2 times or more greater than the top perimeter segment length. In one or more embodiments, the bottom perimeter segment length is 2 times or more greater than the top perimeter segment length.

[0025] In one or more embodiments of the filter cartridge described herein, the inner perimeter of the cross-section includes a bottom perimeter segment containing the bottom point and extending from the first point to the second point, wherein the entire bottom perimeter segment curves continuously from the first point to the second point.

[0026] In one or more embodiments of the filter cartridge described herein, between the first point and the second point, no segment of the inner perimeter lies in a straight line for a distance greater than 1 centimeter.

[0027] In a third aspect, one or more embodiments of the filter cartridge described herein include: a tubular filter medium defining an interior surface facing an interior volume of the filter cartridge and an exterior surface facing away from the interior volume, wherein the tubular filter medium defines a tubular filter medium length measured along a tubular axis extending from a first end to a second end of the tubular filter medium; a filter cartridge housing including a first end cap at the first end of the tubular filter medium and a second end cap at the second end of the tubular filter medium; wherein, in a cross-section taken transverse to the tubular axis at any position along a majority of the length of the tubular filter medium, the The interior surface of the tubular filter media defines an inner perimeter; wherein the cross section includes a maximum height (Hmax) measured between a vertex and a base point, wherein the vertex and the base point are located on the inner perimeter and a maximum height axis, the maximum height axis extending across the cross section at a location and in an orientation such that the vertex and the base point are the points on the inner perimeter that are farthest from each other along any straight line extending across the cross section; wherein the cross section includes a maximum width (Wmax) measured between a first point and a second point located on the inner perimeter and on a maximum width axis, wherein the maximum width axis is located along a line perpendicular to the maximum height axis, and wherein the maximum width wherein the cross section comprises a bottom segment height measured along the maximum height axis from the bottom point to the bottom axis intersection point; wherein the inner perimeter of the cross section comprises a bottom perimeter segment containing the bottom point, wherein the bottom perimeter segment comprises a bottom perimeter segment length measured along the inner perimeter from the first point to the second point; wherein the inner perimeter of the cross section comprises a top perimeter segment containing the vertex, wherein the top perimeter segment extends from a first end to a second end, wherein the first end is located on the inner perimeter at the intersection of the first point and the second point. The top perimeter segment is located between the second point and the vertex, and the second end is located on the inner perimeter between the second point and the vertex, wherein the first end and the second end of the top perimeter segment are the points where the top perimeter segment line intersects the inner perimeter, and wherein the top perimeter segment includes a top perimeter segment length measured along the inner perimeter from the first end to the second end; wherein the top perimeter segment line is a straight line perpendicular to the maximum height axis and intersecting the maximum height axis at a top axis intersection point, wherein the cross-section includes a top portion height measured along the maximum height axis from the top axis intersection point to the vertex on the inner perimeter; wherein the top segment height is equal to the bottom segment height; and wherein the bottom perimeter segment length is greater than the top perimeter segment length.

[0028] In one or more embodiments of the filter cartridges described herein, the bottom perimeter segment length is 1.2 or more times greater than the top perimeter segment length.

[0029] In one or more embodiments of the filter cartridges described herein, the bottom perimeter segment length is 2 or more times greater than the top perimeter segment length.

[0030] In one or more embodiments of the filter cartridges described herein, the bottom section height is greater than zero.

[0031] In one or more embodiments of the filter cartridges described herein, the bottom section height is greater than or equal to 0.1 times the maximum height.

[0032] In one or more embodiments of the filter cartridges described herein, the bottom segment height is less than or equal to 0.4 times the maximum height measured along the maximum height axis from the apex to the bottom point.

[0033] In one or more embodiments of the filter cartridge described herein, the inner perimeter of the cross-section includes describing a bottom perimeter segment containing the bottom point and extending from the first point to the second point, wherein the entire bottom perimeter segment curves continuously from the first point to the second point.

[0034] In one or more embodiments of the filter cartridge described herein, between the first point and the second point, no segment of the inner perimeter lies in a straight line for a distance greater than 1 centimeter.

[0035] In one or more embodiments of the filter cartridges described herein, the maximum height axis is not on a line of symmetry of the inner perimeter of the cross-section.

[0036] In one or more embodiments of the filter cartridge described herein, the inner perimeter of the cross-section defines only one line of symmetry.

[0037] In one or more embodiments of the filter cartridge described herein, the inner perimeter of the cross-section defines only one line of symmetry, and wherein the maximum height axis coincides with the line of symmetry.

[0038] In one or more embodiments of the filter cartridges described herein, the inner perimeter of the cross-section is asymmetric.

[0039] In one or more embodiments of the filter cartridge described herein, an inscribed circle located within the inner perimeter of the cross-section occupies less than all of an inner area defined by the inner perimeter and occupies 60% or more of the inner area defined by the inner perimeter. In one or more embodiments, the inscribed circle located within the inner perimeter of the cross-section occupies 70% or more of the inner area defined by the inner perimeter. In one or more embodiments, the inscribed circle located within the inner perimeter of the cross-section occupies 80% or more of the inner area defined by the inner perimeter.

[0040] In one or more embodiments of the filter cartridge described herein, wherein an inscribed circle within the inner perimeter of the cross-section defines a maximum radial clearance between the circle and the inner perimeter, the maximum radial clearance being 0.5 or less times the diameter of the inscribed circle, wherein the maximum radial clearance is measured along a radial line extending through the center of the inscribed circle. In one or more embodiments, the maximum radial clearance is 0.25 or less times the diameter of the inscribed circle.

[0041] In one or more embodiments of the filter cartridge described herein, the first end cap includes an end cap inner perimeter, and one of the alignment mechanisms includes a notch, the notch including a notch opening facing the interior volume, wherein the notch extends from the notch opening toward the end cap inner perimeter. In one or more embodiments, the alignment mechanism includes two or more notches, wherein each of the two or more notches includes a notch opening facing the interior volume, and wherein each of the two or more notches extends from the notch opening toward the end cap inner perimeter. In one or more embodiments, the second end cap includes an alignment mechanism having one or more notches, wherein each of the two or more notches of the second end cap includes a notch opening facing the interior volume, and wherein each of the one or more notches of the second end cap extends from the notch opening toward the end cap inner perimeter.

[0042] In one or more embodiments of the filter cartridges described herein, the cross section is taken transverse to the tube axis at any location along 10% or more, optionally 25% or more, and optionally 50% or more of the length of the tubular filter media.

[0043] In one or more embodiments of the filter cartridges described herein, the tubular filter media includes pleats extending between the interior surface and the exterior surface.

[0044] - As used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to "a" or "the" component may include one or more of the components and equivalents thereof known to those skilled in the art. In addition, the term "and / or" means one or all of the listed elements or any combination of two or more of the listed elements.

[0045] -It should be noted that the term "includes" and its variants do not have a limiting meaning where these terms appear in the accompanying description. In addition, "a", "an", "the", "at least one" and "one or more" are used interchangeably herein.

[0046] The above summary is not intended to describe every embodiment or every implementation of the filter cartridges and filtration systems using the filter cartridges described herein. Instead, a more complete understanding of the present invention will be apparent and appreciated from the following description with reference to the illustrated embodiments and claims in light of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a perspective view of an illustrative embodiment of a filter cartridge described herein.

[0048] Figure 2 yes Figure 1 A perspective view of the filter media in the filter cartridge.

[0049] Figure 3 is Figure 2 The image is taken in plane 3. Figure 2 A cross-sectional view of the filter media.

[0050] Figure 4 It is intercepted in plane 3 Figure 2 Another cross-sectional view of the filter medium, with the inscribed circle located within the inner circumference.

[0051] Figure 5 is a cross-sectional view of the filter media of an alternative embodiment of the filter cartridge described herein.

[0052] Figure 6 is a cross-sectional view of the filter media of another alternative embodiment of the filter cartridge described herein.

[0053] Figure 7 is a side elevation view of one illustrative embodiment of a yoke and venturi in which the filter cartridges described herein may be installed within a filtration system.

[0054] Detailed description of the embodiment

[0055] In the following description of illustrated embodiments, reference is made to the accompanying drawings and specific embodiments which form a part hereof and in which are shown by way of illustration. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.

[0056] The filter cartridges described herein are fluid filters, i.e., the filter cartridges described herein filter or remove particles from a fluid. In one or more embodiments, the filter cartridges described herein are gas filters for removing particles from a gas stream. In many cases, the gas being filtered is air, but many other gas streams can be filtered using the filter cartridges described herein.

[0057] exist Figure 1 and 2 An illustrative embodiment of an oval filter cartridge described herein is shown in a perspective view of FIG. The filter cartridge includes a filter medium 10 having an end cap 20 located on each of the first end 12 and the second end 14 of the filter medium 10.

[0058] In one or more embodiments, the end cap 20 on the first end 12 of the filter media 10 may have an opening that allows access to the interior volume of the filter cartridge. In one or more embodiments, the end cap 20 on the opposite end of the filter media 10 may be closed so that the end cap prevents access to the interior volume of the filter cartridge and so that gas (e.g., air) that enters the interior volume of the filter cartridge through the end cap 20 on the first end 12 of the filter media 10 must flow out through the filter media in the filter cartridge. In one or more alternative embodiments, both end caps 20 may be open to allow access to the interior volume of the filter cartridge.

[0059] In one or more embodiments, a gasket 22 may be provided on the end cap 20 to seal the filter cartridge over an opening in, for example, a tube sheet, venturi, or other structure through which gas is delivered to the interior volume of the filter cartridge.

[0060] The tubular axis 11 passes through the tubular filter cartridge and extends between the first end 12 and the second end 14. The filter medium 10 has a length L between its first end 12 and its second end 14. Figure 2 The filter medium 10 of the filter cartridge described herein defines an outer surface 16 and an inner surface 18 positioned about the tubular axis 11. The inner surface 18 faces the inner volume of the filter cartridge 10, and the outer surface 16 faces away from the inner volume.

[0061] Although not shown in the illustrated embodiments of the filter cartridge, in one or more embodiments of the filter cartridge described herein, an outer liner may be provided on the outer surface of the filter media, and / or an inner liner may be provided on the inner surface of the filter media to provide, for example, protection, support, etc. to the filter media. Examples of some liners that can be used with the filter cartridges described herein can be found in, for example, U.S. Pat. No. 6,488,746 (published by Kosmider et al.), U.S. Pat. No. 8,128,724 (published by Mills et al.), etc. In one or more embodiments, one or both of the liners may be sufficiently flexible to accommodate the oval cross-sectional shape of the tubular filter cartridge described herein. In one or more alternative embodiments, one or both of the liners may be formed into the oval cross-sectional shapes described herein and maintain those shapes in the absence of any external forces acting on the liners.

[0062] Figure 3 and 4 An illustrative embodiment of an oval cross-section formed by the tubular filter media 10 within the filter cartridge is shown, the cross-section being taken transverse to the tube axis 11. For example, Figure 2 The plane 3 shown in FIG. Figure 3 and 4 , wherein plane 3 is oriented orthogonal to the tube axis 11. In one or more embodiments, a cross section of the tubular filter medium described herein may be taken at any location along the length L of the filter cartridge containing the filter medium 10. In one or more alternative embodiments, the cross section of the tubular filter medium 10 described herein may exist at any location along 10% or more of the length L of the filter medium. In other words, there may be a partial length L of the tubular filter medium whose cross section does not exhibit the features described herein. In one or more alternative embodiments, a cross section of the tubular filter medium described herein may exist at any location along 25% or more of the length L of the filter medium. In one or more alternative embodiments, the cross section of the tubular filter medium described herein may exist at any location along 50% or more of the length L of the filter medium.

[0063] In one or more embodiments, the tubular filter media 10 may have the same shape along the entire length L, although this is not required in all embodiments (ie, in one or more embodiments, the cross-sectional shape of the tubular filter media 30 may vary over the length L).

[0064] like Figure 3 and 4As shown in the oval cross-section shown in , the tubular filter media 10 defines an inner perimeter corresponding to the interior surface 18 of the filter media 10. Since the inner perimeter of the cross-section essentially coincides with the interior surface 18 of the filter media 10, the identifier 18 may also be used herein to refer to the inner perimeter of the cross-section. The filter media disposed in the filter cartridge can take a variety of different forms, but in one or more embodiments, the filter media 10 can include pleats 19 having inner folds located along the inner perimeter represented by the interior surface 18 and outer folds located along the outer perimeter of the filter media 10. In one or more embodiments, the folds in the pleats 19 will generally be located along the surface of the inner liner, following and / or defining the shape of the inner perimeter and the interior surface 18 of the filter cartridge described herein.

[0065] Although the cross-sections of the tubular filter media in the filter cartridges described herein are discussed using terms such as upper, lower, top, and bottom, those terms are merely used to provide a frame of reference for describing the shapes and / or features of the cross-sections. Specifically, it should be understood that the filter cartridges described herein may be used in any orientation in a filtration system. For example, in one or more embodiments, when the filter cartridges are installed in a filtration system, the surface identified as the "bottom" of the filter media or filter cartridge may be present on the top surface of the filter cartridge (relative to the direction of gravity).

[0066] In one or more embodiments, the oval cross-section of the filter media 10 has a maximum height 33 (Hmax) measured along a maximum height axis 30 between an apex 31 and a base 32. The apex 31 and the base 32 are located on the inner perimeter 18 of the cross-section of the filter media 10, and in one or more embodiments are the points on the inner perimeter 18 that are farthest from each other along any straight line extending across the cross-section. In some cases, the inner perimeter 18 may have two or more maximum height axes, each of which intersects the inner perimeter 18 at two points equally spaced from each other along two or more different straight lines extending across the inner perimeter 18 of the cross-section. In such cases, any one of the maximum height axes may be used to characterize the features of the oval cross-section described herein.

[0067] The inner perimeter 18 of the oval cross-section of the filter media 10 described herein also has a maximum width 43 (Wmax) measured between a first point 41 and a second point 42 on the inner perimeter 18. The first point 41 and the second point 42 are located on a maximum width axis 40 that is positioned along a line perpendicular to the maximum height axis 30. The maximum width axis 40 intersects the maximum height axis 30 at a bottom axis intersection point 44, where the first point 41 and the second point 42 at which the maximum width axis 40 intersects the inner perimeter 18 are spaced farthest from each other on any line perpendicular to the maximum height axis 30.

[0068] Due to the oval or ovoid shape of the cross-section of the filter media 10 , in one or more embodiments, the bottom axis intersection point 44 does not bisect the maximum height of the cross-section measured along the maximum height axis 30 between the apex 31 and the bottom point 32 .

[0069] In one or more embodiments of the tubular filter media described herein, for example, Figure 3 , the oval cross-section may define a bottom segment height 34 (Hwmax) measured along the maximum height axis 30 from the bottom point 32 to the bottom axis intersection 44. In one or more embodiments, the bottom segment height 34 may be less than or equal to 0.4 times the maximum height (Hmax) measured along the maximum height axis 30 from the apex 31 to the bottom point 32. In one or more embodiments, the bottom segment height 34 is greater than zero. In one or more embodiments, the bottom segment height 34 is greater than or equal to 0.1 times the maximum height measured along the maximum height axis 30 from the apex 31 to the bottom point 32.

[0070] Another way to characterize the oval cross-section of the tubular filter media of the filter cartridges described herein is with respect to the length of the inner perimeter at both the top and the bottom of the filter media of the filter cartridges. For example, the inner perimeter 18 of the cross-section of the filter media of the filter cartridges described herein may define a bottom perimeter segment that contains the bottom point 32, and the bottom perimeter segment extends from the first point 41 where the maximum width axis 40 intersects the inner perimeter 18 to the second point 42. The bottom perimeter segment, i.e., the portion of the inner perimeter 18 from the first point 41 to the second point 42 (and including the bottom point 32), has a bottom perimeter segment length measured along the inner perimeter 18 from the first point 41 to the second point 42.

[0071] The inner perimeter 18 of the oval cross-section of the filter media 10 of the filter cartridge described herein may also define a top perimeter segment that includes the apex 31 at which the maximum height axis 30 intersects the inner perimeter 18. The top perimeter segment extends from a first end 46 on the inner perimeter 18 to a second end 47, the first end 46 being located between the first point 41 on the inner perimeter 18 and the apex 31, and the second end 47 being located between the second point 42 on the inner perimeter 18 and the apex 31. The first end 46 and the second end 47 of the top perimeter segment are the points at which the top perimeter segment line 45 intersects the inner perimeter 18. The top perimeter segment line 45 is a straight line that is perpendicular to the maximum height axis 30 and intersects the maximum height axis 30 at a top axis intersection point 49. The top axis intersection point 49 is located between the first point 31 and the second point 32 at which the maximum height axis 30 intersects the inner perimeter 18 within the inner perimeter 18. The top axis intersection point 49 defines a top segment height 35 measured along the maximum height axis 30 from the top axis intersection point 49 to the apex 31 on the inner perimeter 18 .

[0072] In one or more embodiments, the top section height 35, for example Figure 3 In the illustrated embodiment shown in , the distance from the top axis intersection point 49 to the vertex 31 is equal to the bottom segment height 34 in the oval cross-section of the filter media in the filter cartridge described herein. In one or more embodiments, the bottom perimeter segment length measured along the inner perimeter 18 between points 41 and 42 (and including the bottom point 32) is greater than the top perimeter segment length measured along the inner perimeter 18 between the first end 46 and the second end 47 (and including the vertex 31). In one or more embodiments, the bottom perimeter segment length is 1.2 times or more greater than the top perimeter segment length. In one or more alternative embodiments, the bottom perimeter segment length is 2 times or more greater than the top perimeter segment length.

[0073] In one or more embodiments of the filter media 10 within the filter cartridge described herein, the bottom perimeter segment of the inner perimeter 18 between the first point 41 and the second point 42 may be continuously curved from the first point 41 to the second point 42. As used herein, "continuously curved" means that the inner perimeter 18 does not include a straight line portion between the first point 41 and the second point 42, although the curvature of the inner perimeter 18 may not be uniform along the entire length of the bottom perimeter segment. In one or more alternative embodiments, the bottom perimeter segment of the inner perimeter 18 may include one or more limited portions that form a straight line, however, no portion of the bottom perimeter segment of the inner perimeter 18 is located on a straight line for a distance greater than 1 cm.

[0074] One or more embodiments of the filter media 10 in the filter cartridges described herein may also include a filter element composed of, for example, Figure 3 and4 The inner perimeter 18 of the cross section shown in FIG. 1 defines a line of symmetry. Specifically, in one or more embodiments, filter cartridges having the oval shapes described herein may define only a single line of symmetry. Figure 3 and 4 In the illustrated embodiment shown in , the inner perimeter 18 of the cross section of the filter media 10 defines a single line of symmetry that coincides with the maximum height axis 30. However, this relationship between the line of symmetry and the maximum height axis may not necessarily be required in all embodiments described herein.

[0075] In one or more embodiments of the filter cartridge described herein, an inscribed circle 50 may be provided within the inner perimeter 18 of the oval cross-section of the filter medium 10, wherein the inscribed circles described herein are the largest inscribed circles that can be located within the inner perimeter 18 of the cross-section of the filter medium 10. Since the shape of the inner perimeter 18 is not circular, the area occupied by the inscribed circle 50 is less than the total area within the inner perimeter 18. Figure 4 As shown in , the inscribed circle 40 does not occupy areas 52 , 54 , and 56 within the inner perimeter 18 of the filter media 10 .

[0076] In one or more embodiments, the inscribed circle 50 located within the inner perimeter 18 may occupy 60% or more of the inner area defined by the inner perimeter 18. In one or more alternative embodiments, the inscribed circle 50 may occupy 70% or more of the inner area defined by the inner perimeter 18. In one or more additional alternative embodiments, the inscribed circle 50 may occupy 80% or more of the inner area defined by the inner perimeter 18. Figure 4 In the illustrative embodiment shown in , the inscribed circle 50 occupies greater than 80% of the inner area defined by the inner perimeter 18 .

[0077] As described herein, the use of these inscribed circles can also provide another way to characterize the inner perimeter of the cross-section of the tubular filter media within the filter cartridges described herein. Figure 4 In the illustrative embodiment shown in FIG, the inscribed circle 50 located within the inner perimeter 18 may be described as defining a maximum radial gap between the inscribed circle 50 and the inner perimeter 18. Figure 4, the maximum radial clearance may be measured between points 58 and 59 located along an axis 57 passing through the center 51 of the inscribed circle 50. In one or more embodiments, the maximum radial clearance measured between points 58 and 59 may be 0.5 times or less of the diameter of the inscribed circle 50. In one or more alternative embodiments, the maximum radial clearance between the inscribed circle and the inner circumference of the cross-section of the filter media in which the inscribed circle is located may be 0.25 times or less of the diameter of the inscribed circle. In one or more embodiments, limiting the maximum radial clearance between the inscribed circle and the inner circumference may provide improvements in pulse cleaning of filter cartridges having such features. Additionally, although not discussed below with respect to Figure 5 and 6 The other alternative illustrative embodiments described describe this feature, but this feature can be determined with respect to any tubular filter media used in the filter cartridges described herein, and in one or more embodiments, it can be controlled to the above-mentioned ratio.

[0078] exist Figure 5 Another illustrative embodiment of an oval cross-section of a filter media 110 that may be used in the tubular filter cartridges described herein is shown in FIG. Figure 3 and 4 The cross-sections of the filter media 10 shown in FIG. Figure 5 The oval cross-section of the filter media 110 shown in FIG. 1 has an inner perimeter 118 that does not define a line of symmetry, ie, the inner perimeter 118 of the filter media 110 is asymmetric.

[0079] In one or more embodiments, the oval cross-section of the filter media 110 has a maximum height 133 (Hmax) measured along a maximum height axis 130 between an apex 131 and a base 132. The apex 131 and the base 132 are located on the inner perimeter 118 of the cross-section of the filter media 110, and in one or more embodiments are the points that are furthest from each other along any straight line extending through the inner perimeter 118 of the cross-section.

[0080] The inner perimeter 118 of the oval cross-section of the filter media 110 described herein also has a maximum width 143 (Wmax) measured between a first point 141 and a second point 142 on the inner perimeter 118. The first point 141 and the second point 142 are located on a maximum width axis 140 positioned along a line perpendicular to the maximum height axis 130. The maximum width axis 140 intersects the maximum height axis 130 at a bottom axis intersection point 144, where the first point 141 and the second point 142 at which the maximum width axis 140 intersects the inner perimeter 118 are spaced farthest from each other on any line perpendicular to the maximum height axis 130 between the apex 131 and the bottom point 132.

[0081] Due to the oval or ovoid shape of the cross-section of the filter media 110 , in one or more embodiments, the bottom axis intersection point 144 does not bisect the maximum height 130 of the cross-section as measured between the apex 131 and bottom point 132 .

[0082] In one or more embodiments of the tubular filter media described herein, for example, Figure 5 , the oval cross-section may define a bottom segment height 134 (Hwmax) measured along the maximum height axis 130 from the bottom point 132 to the bottom axis intersection 144. In one or more embodiments, the bottom segment height 134 may be less than or equal to 0.4 times the maximum height (Hmax) measured along the maximum height axis 130 from the apex 131 to the bottom point 132. In one or more embodiments, the bottom segment height 134 is greater than 0. In one or more embodiments, the bottom segment height 134 is greater than or equal to 0.1 times the maximum height measured along the maximum height axis 130 from the apex 131 to the bottom point 132.

[0083] Another way in which the cross-sections of the tubular filter media of the filter cartridges described herein may be characterized is with respect to the length of the inner perimeter at both the top and bottom of the filter media of the filter cartridge. For example, the inner perimeter 118 of the cross-section of the filter media 110 described herein may define a bottom perimeter segment that includes the bottom point 132 and extends from the first point 141 where the maximum width axis 140 intersects the inner perimeter 118 to the second point 142. The bottom perimeter segment, i.e., the portion of the inner perimeter 118 from the first point 141 to the second point 142 (and including the bottom point 132), has a bottom perimeter segment length measured along the inner perimeter 118 from the first point 141 to the second point 142.

[0084] The inner perimeter 118 of the cross-section of the filter media 110 of the filter cartridge described herein may also define a top perimeter segment that includes the apex 131 at which the maximum height axis 130 intersects the inner perimeter 118. The top perimeter segment extends from a first end 146 on the inner perimeter 118, the first end 146 being located between the first point 141 on the inner perimeter 118 and the apex 131, and the second end 147 being located between the second point 142 on the inner perimeter 118 and the apex 131. The first end 146 and the second end 147 of the top perimeter segment are points at which a top perimeter segment line 145 intersects the inner perimeter 118 on opposite sides of the maximum height axis 130. The top perimeter segment line 145 is a straight line that is perpendicular to the maximum height line 130 and intersects the maximum height axis 130 at a top axis intersection point 149. The top axis intersection point 149 is located between the maximum height axis 130 within the inner perimeter 118 and the first point 131 and the second point 132 at which the inner perimeter 118 intersects. The top axis intersection point 149 defines a top segment height 135 measured along the maximum height axis 130 from the top axis intersection point 149 to the vertex 131 on the inner perimeter 118.

[0085] In one or more embodiments, the top section height 135, for example Figure 5 In the illustrated embodiment shown in , the distance from the top axis intersection point 149 to the vertex 131 is equal to the bottom segment height 134 in these cross-sections of the filter media in the filter cartridge described herein. In one or more embodiments, the bottom perimeter segment length measured between points 141 and 142 (and including the bottom point 132) along the inner perimeter 118 is greater than the top perimeter segment length measured between the first end 146 and the second end 147 (and including the vertex 131) along the inner perimeter 118. In one or more embodiments, the bottom perimeter segment length is 1.2 times or more greater than the top perimeter segment length. In one or more alternative embodiments, the bottom perimeter segment length is 2 times or more greater than the top perimeter segment length.

[0086] In one or more embodiments of the filter media 110 within the filter cartridge described herein, the bottom perimeter segment of the inner perimeter 118 between the first point 141 and the second point 142 may curve continuously from the first point 141 to the second point 142. In one or more alternative embodiments, the bottom perimeter segment of the inner perimeter 118 may include one or more limited portions that form a straight line, however, no portion of the bottom perimeter segment of the inner perimeter 118 is located on a straight line at a distance greater than 1 centimeter.

[0087] exist Figure 6Still another illustrative embodiment of a tubular filter medium 210 having an oval cross-section that may be used in the filter cartridges described herein is shown in FIG. Figure 3 and 4 The cross section of the filter medium 10 shown in FIG. Figure 5 The cross-section of the filter media 110 shown in FIG. Figure 6 The cross section of the filter media 210 shown in FIG. 2 has an inner perimeter 218 that includes a flat or straight portion. However, for the purposes of the filter cartridge described herein, the cross section of the filter media 210 is formed to be oval in that the cross section has a base that is wider than the top.

[0088] In one or more embodiments, the cross section of the filter media 210 has a maximum height 233 (Hmax) measured along a maximum height axis 230 between a vertex 231 and a base 232. The vertex 231 and the base 232 are located on the inner perimeter 218 of the cross section of the filter media 210 and, in one or more embodiments, are the points that are furthest from each other along any straight line extending across the inner perimeter 218 of the cross section.

[0089] The inner perimeter 218 of the cross-section of the filter media 210 described herein also has a maximum width 243 (Wmax) measured between a first point 241 and a second point 242 on the inner perimeter 218. The first point 241 and the second point 242 are located on a maximum width axis 240 that is positioned along a line perpendicular to the maximum height axis 230. The maximum width axis 240 intersects the maximum height axis 230 at a bottom axis intersection point 244, where the first point 241 and the second point 242 at which the maximum width axis 240 intersects the inner perimeter 218 are spaced farthest from one another on any line perpendicular to the maximum height axis 230 between the apex 231 and the bottom point 232.

[0090] Due to the oval or ovoid shape of the cross-section of the filter media 210 , in one or more embodiments, the bottom axis intersection point 244 does not bisect the maximum height 230 of the cross-section as measured between the apex 231 and bottom point 232 .

[0091] In one or more embodiments of the tubular filter media described herein, for example, Figure 6, the cross section may define a bottom segment height 234 (Hwmax) measured along the maximum height axis 230 from the bottom point 232 to the bottom axis intersection 244. In one or more embodiments, the bottom segment height 234 may be less than or equal to 0.4 times the maximum height measured along the maximum height axis 230 from the vertex 231 to the bottom point 232. In one or more embodiments, the bottom segment height is greater than zero. In one or more embodiments, the bottom segment height 234 may be greater than or equal to 0.1 times the maximum height measured along the maximum height axis 230 from the vertex 231 to the bottom point 232.

[0092] Another way to characterize the cross-section of the tubular filter media of the filter cartridge described herein is with respect to the length of the inner perimeter at both the top and bottom of the filter media of the filter cartridge. For example, the inner perimeter 218 of the cross-section of the filter media 210 described herein may define a bottom perimeter segment that includes the bottom point 232 and extends from the first point 241 where the maximum width axis 240 intersects the inner perimeter 218 to the second point 242. The bottom perimeter segment, i.e., the portion of the inner perimeter 218 from the first point 241 to the second point 242 (and including the bottom point 232), has a bottom perimeter segment length measured along the inner perimeter 218 from the first point 241 to the second point 242.

[0093] The inner perimeter 218 of the cross-section of the filter media 210 of the filter cartridge described herein may also define a top perimeter segment that includes the vertex 231 at which the maximum height axis 230 intersects the inner perimeter 218. The top perimeter segment extends from a first end 246 on the inner perimeter 218 to a second end 247, the first end 246 being located between the first point 241 on the inner perimeter 218 and the vertex 231, and the second end 247 being located between the second point 242 on the inner perimeter 218 and the vertex 231. The first end 246 and the second end 247 of the top perimeter segment are points at which a top perimeter segment line 245 intersects the inner perimeter 218 on opposite sides of the maximum height axis 230. The top perimeter segment line 245 is a straight line that is perpendicular to the maximum height axis 230 and intersects the maximum height axis 230 at a top axis intersection point 249. The top axis intersection point 249 is located between the maximum height axis 230 and the first point 231 and the second point 232 at which the inner perimeter 218 intersects within the inner perimeter 218. The top axis intersection point 249 defines a top segment height 235 measured along the maximum height axis 230 from the top axis intersection point 249 to the vertex 231 on the inner perimeter 218.

[0094] In one or more embodiments, the top section height 235, for example Figure 6In the illustrated embodiment shown in the figure, the distance from the top axis intersection point 249 to the vertex 231 is equal to the bottom segment height 234 in the cross section of the filter media in the filter cartridge described herein. In one or more embodiments, the bottom perimeter segment length measured between points 241 and 242 (and including the bottom point 232) along the inner perimeter 218 is greater than the top perimeter segment length measured between the first end 246 and the second end 247 (and including the vertex 231) along the inner perimeter 218. In one or more embodiments, the bottom perimeter segment length may be 1.2 times or more larger than the top perimeter segment length. In one or more alternative embodiments, the bottom perimeter segment length may be 2 times or more larger than the top perimeter segment length. This relationship between the bottom perimeter segment length and the top perimeter segment length can be a more descriptive way of describing the filter media 210 facing upward than facing downward.

[0095] In one or more embodiments of the filter media 210 within the filter cartridge described herein, the bottom perimeter segment of the inner perimeter 218 between the first point 241 and the second point 242 may curve continuously from the first point 241 to the second point 242. In one or more alternative embodiments, the bottom perimeter segment of the inner perimeter 218 may include one or more limited portions that form a straight line, however, no portion of the bottom perimeter segment of the inner perimeter 218 is located on a straight line at a distance greater than 1 centimeter.

[0096] The filter medium 210 is another illustrative example of a cross-section having an inner perimeter 218 that includes a line of symmetry. Specifically, the inner perimeter 218 defines at most a single line of symmetry. Figure 6 In the illustrative embodiment shown in , the single line of symmetry coincides with the maximum height axis 230. However, this relationship may not necessarily be required in all embodiments described herein.

[0097] Although only combined Figures 1 to 6 While three different oval cross-sectional shapes of filter media 10, 110, and 210 within a filter cartridge are discussed, the description of the various features of those oval cross-sectional shapes is applicable to an infinite number of different oval shapes that can be used to form filter media for use in the tubular filter cartridges described herein. Therefore, the specific embodiments disclosed herein should be viewed as merely illustrative in nature.

[0098] refer to Figure 1 and 7In one or more embodiments of the filter cartridges described herein, the end caps 20 on the filter cartridges may include an alignment mechanism in the form of, for example, an optional tab 24 in which a notch 26 is located. The notches 26 may be sized to receive the upper and lower members 52 and 54 of a yoke 50 on which the filter cartridge may be mounted in a filtration system. In one or more embodiments, each notch 26 may be described as having an opening facing the interior volume of the filter cartridges, the notch 26 extending toward the inner perimeter 28 of the end cap 20. Although in the illustrated embodiment, each notch 26 is formed in a single tab 24, in one or more alternative embodiments, the notch 26 may be formed between two members protruding from the inner perimeter 28 of the end cap 20, wherein the two members forming the notch 26 are not the same structural members.

[0099] Examples of some potentially suitable filtration systems that may include a yoke on which a filter cartridge is mounted and in which the filter cartridges described herein may be used may be described, for example, in the following references, such as U.S. Pat. No. 3,942,962 (issued by Duyckinck), U.S. Pat. No. 4,218,227 (issued by Frey), U.S. Pat. No. 5,562,746 (issued by Raether), U.S. Pat. No. 6,090,173 (issued by Johnson et al.), U.S. Pat. No. 6,902,592 (issued by Green et al.), and U.S. Pat. No. 7,641,708 (issued by Kosmider et al.); and, for example, U.S. Provisional Patent Application No. 61 / 648,492 (filed on May 17, 2012, entitled: AIR FILTER ASSEMBLY HAVING VENTURI ELEMENTS WITH EXTENDED PULSE OUTLET PULSE OUTLETS) and U.S. Provisional Patent Application No. 61 / 648,494 (filed on May 17, 2012 and entitled: FILTER ASSEMBLY WITH DIRTY AIR CHAMBER VENTURIELEMENTS).

[0100] exist Figure 7 An illustrative embodiment of a yoke 50 having upper and lower members 52 and 54 is shown in FIG. The upper and lower members 52 and 54 are structurally connected to each other by an intermediate member 56. Figure 7 In the illustrated embodiment, the intermediate member 56 may be a continuous member, providing structural support to the upper and lower members 52 and 54 and increasing the rigidity of the yoke 50. Figure 7Also shown is a venturi 60 that can be used to move gas into and out of the interior volume of the filter cartridge on the yoke 50. The venturi 60 can have a filter cartridge face 62 relative to which the end cap (e.g., end cap 20) of the filter cartridge can be positioned, and a tube sheet face 64 configured for attachment to an orifice in a tube sheet as described in the various patent documents described herein.

[0101] The yoke 50 is shown partially inserted into Figure 1 Although only the filter cartridge in Figure 1 In the nearest end cap 20, but in one or more embodiments, Figure 1 The end caps 20 on both ends of the filter cartridge may include tabs 24 having notches 26 formed therein. In one or more embodiments, the use of two tabs 24 in conjunction with a yoke 50 having two members 52 and 54 may be beneficial in preventing or at least limiting rotation of the filter cartridge about its tubular axis 11 when installed on the yoke 50 in a filtration system.

[0102] While one or more embodiments of the tubular filter media disposed within the filter cartridges described herein may be in the form of pleated filter media, in one or more alternative embodiments, the tubular filter media may or may not be pleated. Additionally, while the filter media used in the filter cartridges described herein may be used to filter particulate matter from an airflow, in one or more embodiments, the filter media may be further capable of removing other materials from an airflow, such as chemical contaminants, etc.

[0103] The filter cartridges described herein can be used in a variety of filtration systems. For example, the filter cartridges can be used in filtration systems similar to those described in, for example, U.S. Pat. No. 3,942,962 (Duyckinck), U.S. Pat. No. 4,218,227 (Frey), U.S. Pat. No. 4,424,070 (Robinson), U.S. Pat. No. 4,436,536 (Robinson), U.S. Pat. No. 4,395,269 (Schuler), U.S. Pat. No. 4,443,237 (Ulvestad), U.S. Pat. No. 4,445,915 (Robinson), U.S. Pat. No. 4,661,131 (Howeth), U.S. Patent 5,207,812 (issued by Tronto et al.), U.S. Patent 4,954,255 (issued by Muller et al.), U.S. Patent 5,222,488 (issued by Forsgren), U.S. Patent 5,211,846 (issued by Kott et al.), U.S. Patent 5,730,766 (issued by Clements), U.S. Patent 6,090,173 (issued by Johnson et al.), U.S. Patent 6,488,746 (issued by Kosmider et al.), U.S. Patent 6,902,592 (issued by Green et al.) and U.S. Patent 7,641,708 (issued by Kosmider et al.). Still further, the filter cartridges described herein may be used in filtration systems similar to those described in the following references, such as U.S. Provisional Patent Application No. 61 / 648,492 (filed on May 17, 2012, entitled: AIR FILTER ASSEMBLY HAVING VENTURI ELEMENTS WITH EXTENDED PULSE OUTLETS) and U.S. Provisional Patent Application No. 61 / 648,494 (filed on May 17, 2012, entitled: FILTER ASSEMBLY WITH DIRTY AIR CHAMBER VENTURI ELEMENTS).

[0104] The complete disclosures of the patents, patent documents, and publications identified herein are incorporated herein by reference as if each were individually incorporated. To the extent there is a conflict or inconsistency between the disclosure in this document and any so incorporated document, this document will control.

[0105] The illustrative embodiments of the filter cartridges and filtration systems including these filter cartridges discussed herein include some possible variations that have been described. Those skilled in the art will appreciate these and other changes and modifications in the present invention without departing from the scope of the present invention, and it should be understood that the present invention is not limited to the illustrative embodiments set forth herein. Therefore, the present invention is limited only to the claims provided below and their equivalents. It should also be understood that the present invention may also be appropriately practiced in the absence of any element that is not specifically disclosed as being necessary herein.

Claims

1. A filter cartridge, comprising: a tubular filter media defining an inner surface facing the interior space of the filter cartridge and an outer surface facing away from the interior space, wherein the tubular filter media defines a tubular filter media length measured along a tube axis extending from a first end of the tubular filter media to a second end of the tubular filter media; and a first end cap at a first end of the tubular filter media and a second end cap at a second end of the tubular filter media, wherein the first end cap includes an end cap inner perimeter and an alignment mechanism including two or more notches, each notch including a notch opening inwardly from the end cap inner perimeter facing the interior space, and wherein each notch is configured to receive a yoke member extending through the tubular filter media; wherein the inner surface of the tubular filter media defines an inner perimeter having an oval shape in a cross-section taken transverse to the tube axis at any location along a majority portion of the length of the tubular filter media; The inner circumference of the oval cross section is asymmetrical. 2 . The filter cartridge of claim 1 , wherein each notch is formed in a single tab. 3 . The filter cartridge of claim 1 , wherein each of the two or more notches extends outwardly from a notch opening toward an inner perimeter of the end cap.

4. The filter cartridge of claim 1, wherein each recess is formed between two members protruding from an inner perimeter of the end cap, and wherein the two members forming the recess are not the same structural member.

5. The filter cartridge of claim 1 , wherein the second end cap comprises an alignment mechanism comprising one or more notches, wherein each of the one or more notches of the second end cap comprises a notch opening facing the interior space, and wherein each of the one or more notches of the second end cap extends from the notch opening toward an inner perimeter of the end cap.

6. The filter cartridge of claim 1, wherein the cross section is taken transverse to the axis of the tube at any location along 10% or more of the length of the tubular filter media.

7. The filter cartridge of claim 1, wherein the tubular filter media includes pleats extending between an inner surface and an outer surface.

8. The filter cartridge of claim 1, wherein the outer surface of the filter cartridge matches the shape of the inner perimeter of the filter cartridge in cross-section.

9. A filter cartridge according to any one of claims 1 to 8, wherein the maximum radial clearance between the inscribed circle defined by the inscribed circle within the inner circumference of the cross-section and the inner circumference is 0.5 times or less of the diameter of the inscribed circle to enhance pulse cleaning of the filter cartridge; wherein the maximum radial clearance is measured along a radial line extending through the center of the inscribed circle.

10. The filter cartridge according to claim 9, wherein the maximum radial gap is 0.25 times or less the diameter of the inscribed circle.

11. The filter cartridge of any one of claims 1-8, wherein an inscribed circle within the inner perimeter of the cross section occupies less than all of the inner area defined by the inner perimeter and occupies 60% or more of the inner area defined by the inner perimeter.

12. The filter cartridge according to any one of claims 1 to 8, wherein an inscribed circle located within the inner perimeter of the cross-section occupies 70% or more of an inner area defined by the inner perimeter.

13. The filter cartridge according to any one of claims 1 to 8, wherein an inscribed circle located within the inner perimeter of the cross-section occupies 80% or more of an inner area defined by the inner perimeter.

14. A filter cartridge end cap for a tubular filter media of a filter cartridge, the filter cartridge end cap being configured to be located at a first end of the tubular filter media and comprising: an end cap inner perimeter, the end cap inner perimeter defining an end cap opening, the end cap opening being configured to be located adjacent the first end of the tubular filter media and to allow access to an interior space of the tubular filter media through the end cap; and An alignment mechanism includes two or more notches, each notch including a notch opening facing inward from an inner perimeter of the end cap, wherein each notch extends outwardly toward the inner perimeter of the end cap from each respective notch opening, and wherein each notch is configured to receive a member of the yoke extending through the tubular filter media when the end cap is advanced along the yoke.

15. The filter cartridge end cap of claim 14, wherein the end cap opening comprises an oval opening.

16. The filter cartridge end cap of claim 14, wherein the notch is formed in the single tab.

17. The filter cartridge end cap of claim 14, wherein each recess is formed between two members protruding from an inner perimeter of the end cap, and wherein the two members forming the recess are not the same structural member.

18. The filter cartridge end cap of any one of claims 14-17, wherein the end cap opening defined by the end cap inner perimeter is asymmetrical.

19. The filter cartridge end cap of any one of claims 14-17, wherein the end cap opening includes a maximum height (Hmax) measured between an apex and a base point, wherein the apex and the base point are located on an inner perimeter and a maximum height axis, the maximum height axis being at a location and extending across the end cap opening in a direction such that the apex and the base point are points on the inner perimeter of the end cap that are furthest from each other along any straight line extending across the end cap opening; wherein the end cap opening includes a maximum width (Wmax) measured between a first point and a second point located on the inner perimeter and on a maximum width axis, wherein the maximum width axis is located along a line perpendicular to the maximum height axis, and wherein the maximum width axis intersects the maximum height axis at a base axis intersection point, wherein the first point and the second point are farthest from each other on any line perpendicular to the maximum height axis; The bottom axis intersection point does not bisect the maximum height of the end cap opening measured between the top point and the bottom point.

20. The filter cartridge end cap of claim 19, wherein the cross section includes a bottom segment height (Hwmax) measured along the maximum height axis from the bottom point to the bottom axis intersection point, and wherein the bottom segment height (Hwmax) is less than or equal to 0.4 times the maximum height measured along the maximum height axis from the apex to the bottom point; The bottom section height (Hwmax) is greater than or equal to 0.1 times the maximum height.

21. The filter cartridge end cap of claim 19, wherein the inner perimeter of the cross-section includes a bottom perimeter segment including a bottom point, wherein the bottom perimeter segment includes a length of the bottom perimeter segment measured along the inner perimeter from a first point to a second point; wherein the inner perimeter of the end cap includes a top perimeter segment including an apex, wherein the top perimeter segment extends from a first end to a second end, wherein the first end is located on the inner perimeter between the first point and the apex, and the second end is located on the inner perimeter between the second point and the apex, wherein the first end and the second end of the top perimeter segment are points where a top perimeter segment line intersects the inner perimeter, and wherein the top perimeter segment includes a top perimeter segment length measured along the inner perimeter from the first end to the second end; wherein the top perimeter segment line is a line perpendicular to the maximum height axis and intersecting the maximum height axis at a top axis intersection point, and wherein the end cap opening includes a top segment height measured along the maximum height axis from the top axis intersection point to a vertex on the inner perimeter; The top segment height is equal to the bottom segment height (Hwmax); and wherein the bottom perimeter segment length is greater than the top perimeter segment length; The length of the bottom perimeter segment is 1.2 times or more greater than the length of the top perimeter segment.

22. The filter cartridge end cap of claim 19, wherein the inner perimeter of the end cap includes a bottom perimeter segment having a bottom point and extending from a first point to a second point, wherein the entire bottom perimeter segment curves continuously from the first point to the second point.

23. The filter cartridge end cap of claim 19, wherein the inner perimeter of the end cap defines only one line of symmetry, and wherein the axis of maximum height coincides with the line of symmetry.

24. The filter cartridge end cap of any one of claims 14-17, wherein the inscribed circle located within the inner perimeter of the end cap occupies less than all of the end cap opening defined by the inner perimeter of the end cap and occupies 60% or more of the end cap opening defined by the inner perimeter of the end cap; or wherein an inscribed circle located within the inner perimeter of the end cap occupies 70% or more of the end cap opening defined by the inner perimeter of the end cap; Or wherein an inscribed circle located within the inner perimeter of the end cap occupies 80% or more of the end cap opening defined by the inner perimeter of the end cap.

25. The filter cartridge end cap of any one of claims 14-17, wherein a maximum radial clearance between an inscribed circle defined by an inscribed circle within the inner perimeter of the end cap and the inner perimeter of the end cap is 0.5 times or less the diameter of the inscribed circle, wherein the maximum radial clearance is measured along a radial line extending through the center of the inscribed circle; Or wherein the maximum radial clearance is 0.25 times the diameter of the inscribed circle or less.

26. The filter cartridge of claim 1, wherein the two or more recesses are asymmetrically disposed around an inner perimeter of the end cap.

27. The filter cartridge end cap of claim 14, wherein the two or more recesses are asymmetrically disposed around an inner perimeter of the end cap.

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