Particle separator filter having an axially extending flow surface - Patents.com

Abstract

A two-stage separator system includes a housing extending between a first end and a second end. The housing defines a housing inlet, a separator outlet toward the second end, and a filtration outlet on the first end. The filter assembly includes a first sheet of filter media bonded to a second sheet of filter media defining a plurality of axially extending longitudinal flutes therebetween. The filter assembly defines an inlet flow face and an outlet flow face. The filter assembly is disposed within the housing and bonded to the housing about the filtration outlet such that the outlet flow face is in fluid communication with the filtration outlet. The inlet flow face of the filter assembly has an axial flow face length.

Description

[Technical field]

[0001] This application claims priority to U.S. Provisional Patent Application No. 62 / 824,812, filed March 27, 2019, which is incorporated herein by reference.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to particle separators and, more particularly, to particle separators having an axially extending flow face. Summary of the Invention [Means for solving the problem]

[0003] Some embodiments of the present technology relate to a two-stage separator system. A housing extends between a first end and a second end and defines a housing inlet, a separator outlet towards the second end, and a filtration outlet on the first end. A filter assembly is disposed within the housing. The filter assembly has a first sheet of filter media bonded to a second sheet of filter media that mutually define a plurality of axially extending flutes, the filter assembly defining an inlet flow face and an outlet flow face. The filter assembly is bonded to the housing about the filtration outlet such that the outlet flow face is in fluid communication with the filtration outlet. The inlet flow face has an axial flow face length.

[0004] In some such embodiments, a radial distance is defined between the inlet flow face and the housing, the radial distance increasing from the first end to the second end for at least a portion of the axial flow face length. Additionally or alternatively, the filter assembly has an outer radial barrier surface that extends axially from the filtration outlet beyond the housing inlet. Additionally or alternatively, the filter assembly has an outer radial barrier surface that has an axial length from the outlet flow face that is equal to or greater than the axial distance from the filtration outlet to the distal end of the housing inlet.

[0005] Additionally or alternatively, the housing inlet defines an airflow path tangential to the outer radial barrier surface of the filter assembly. Additionally or alternatively, at least a portion of the outer radial barrier surface is defined by a first sheet of filter media. Additionally or alternatively, the inlet flow surface defines a taper from the first end toward the second end for at least a portion of the axial flow face length. Additionally or alternatively, the taper increases from the first end toward the second end for at least a portion of the axial flow face length. Additionally or alternatively, the taper changes continuously along the axial flow face length from the first end toward the second end. Additionally or alternatively, the taper increases continuously along the axial flow face length from the first end toward the second end. Additionally or alternatively, the first sheet of filter media is a facing sheet and the second sheet of filter media is a fluted sheet. Additionally or alternatively, the first sheet of filter media and the second sheet of filter media define a spiral configuration about an axially extending z-axis.

[0006] Additionally or alternatively, the system includes a rod extending through a center of the filter assembly, the rod having a proximal end positioned toward the outlet flow surface and a distal end positioned toward the inlet flow surface, the system including a rod receiving portion defined by the second end of the housing, the rod receiving portion configured to receive the distal end of the rod. Additionally or alternatively, the distal end of the rod defines a handle. Additionally or alternatively, the filter assembly has a circular cross section. Additionally or alternatively, the filter assembly includes a plurality of first sheets of filter media and a plurality of second sheets of filter media in an alternating stacked configuration, and a radial sleeve disposed around the stacked first sheets of filter media and the second sheets of filter media. Additionally or alternatively, a housing inlet is defined toward the first end of the housing.

[0007] The above summary is not intended to describe each embodiment or every implementation. Rather, illustrative embodiments will become more fully understood by reference to the following detailed description of exemplary embodiments and claims, taken in conjunction with the accompanying drawings in which:

[0008] The present technology will be more fully understood and appreciated in consideration of the following detailed description of various embodiments in conjunction with the accompanying drawings, in which: [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a side view of an exemplary two-stage separator system consistent with the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view of a housing of an exemplary separator system consistent with FIG. 1. [Diagram 3] FIG. 1 is a perspective view of an exemplary filter assembly consistent with the technology disclosed herein. [Figure 4A] FIG. 2 is a perspective view of another exemplary filter assembly consistent with the technology disclosed herein. [Figure 4B] FIG. 4B is a detailed view A' of FIG. 4A. [Diagram 5] 1 is a side cross-sectional view of another exemplary filter assembly consistent with the technology disclosed herein; [Figure 6A] 1 is an exemplary filter media consistent with certain embodiments. [Figure 6B] 1 is another exemplary filter media consistent with certain embodiments. [Figure 6C] 1 is yet another exemplary filter media consistent with certain embodiments. [Figure 6D] 1 is an exemplary filter media consistent with certain embodiments. [Figure 7] FIG. 2 is a perspective view of another exemplary filter assembly consistent with the technology disclosed herein. [Figure 8] 1 illustrates a cross-sectional view of an exemplary filter assembly consistent with the technology disclosed herein. [Figure 9A] FIG. 2 is a perspective view of another exemplary filter assembly consistent with the technology disclosed herein. [Figure 9B] FIG. 6b is a front view of the first face of the filter assembly of FIG. 6a. [Figure 10] 1 is a perspective view of yet another exemplary filter assembly consistent with the technology disclosed herein; FIG. [Figure 11] 1 is a perspective view of yet another exemplary filter assembly consistent with the technology disclosed herein; FIG. [Figure 12] 1 is a perspective view of yet another exemplary filter assembly consistent with the technology disclosed herein; FIG. [Figure 13] 1 is a perspective view of yet another exemplary filter assembly consistent with the technology disclosed herein; FIG. [Figure 14A] FIG. 2 is a side view of another exemplary filter assembly consistent with the technology disclosed herein. [Figure 14B] FIG. 14B is a front view of the filter media consistent with FIG. 14A. [Figure 15A] 1 is a cross-sectional view of another exemplary filter assembly consistent with the technology disclosed herein. [Figure 15B] FIG. 15B is a front view of the filter media consistent with FIG. 15A. [Figure 16A] 1 is a cross-sectional view of another exemplary filter assembly consistent with the technology disclosed herein. [Figure 16B] FIG. 16B is a front view of the filter media consistent with FIG. 16A. [Figure 17A] FIG. 2 is a perspective view of another exemplary filter assembly consistent with the technology disclosed herein. [Figure 17B] FIG. 17B is a front view of the filter media consistent with FIG. 17A. [Figure 18] 1 is a cross-sectional side view of a filter assembly consistent with the technology disclosed herein. [Figure 19] FIG. 2 is another cross-sectional side view of a filter assembly consistent with the technology disclosed herein. [Figure 20]FIG. 2 is another cross-sectional side view of a filter assembly consistent with the technology disclosed herein. [Figure 21] FIG. 2 is a cross-sectional view of a filter media consistent with various embodiments. [Figure 22] 1 is a schematic diagram of a front flow surface of an exemplary filter assembly consistent with the technology disclosed herein. [Diagram 23] 1 is a cross-sectional schematic view of a filter assembly consistent with the technology disclosed herein. [Figure 24] FIG. 2 is a cross-sectional view of another exemplary two-stage separator system consistent with some embodiments. [Figure 25a] FIG. 3 shows a schematic diagram of a first exemplary cross section associated with FIG. 2. [Figure 25b] FIG. 14b shows a schematic diagram of a second exemplary cross section associated with FIG. 14a. [Figure 26a] 14a-14c show a first exemplary cross-sectional schematic diagram associated with a system incorporating a filter assembly similar to that shown in FIG. 14a. [Figure 26b] 14b shows a second exemplary cross-sectional schematic diagram associated with a system incorporating a filter assembly similar to that shown in FIG. 14a. [Figure 27a] 1 illustrates a schematic diagram of a first exemplary cross section associated with another exemplary system consistent with some embodiments. [Figure 27b] 27b shows a schematic diagram of a second exemplary cross section associated with the exemplary system of FIG. 27a. [Figure 28] FIG. 1 is a cross-sectional view of yet another exemplary two-stage separator system consistent with certain embodiments. [Figure 29] FIG. 1 is a cross-sectional view of an exemplary standard two-stage separator system consistent with the previous art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The figures are shown primarily for clarity and, as a result, are not necessarily drawn to scale. Additionally, various structures / components, including but not limited to fasteners, electrical components (wires, cables, etc.), etc., may be shown diagrammatically or removed in part or in whole from the figures to better illustrate aspects of the illustrated embodiment, or the inclusion of such structures / components is not necessary for an understanding of the various exemplary embodiments described herein. However, the absence of illustration / description of such structures / components in a particular figure should not be construed as limiting the scope of the various embodiments in any way.

[0011] 1 is a side view of an exemplary two-stage separator system 1900 consistent with the present disclosure. Separator system 1900 has a housing 1910 that houses a filter assembly 1950 disposed therein. Filter assembly 1950 can be generally consistent with the filter assemblies described herein consistently in FIGS.

[0012] The housing 1910 generally extends between a first end 1912 and a second end 1914. The housing 1910 defines an interior space 1916. In various embodiments, the housing 1910 extends in an axial direction defined by a central axis z. The housing 1910 defines a housing inlet 1920, a separator outlet 1930 towards the second end 1914, and a filtration outlet 1940 on the first end 1912. A filter assembly 1950 is positioned within the interior space 1916. The housing 1910 is configured to receive an unfiltered fluid, such as air, through the housing inlet 1920, allow for discharge of separated particulates through the separator outlet 1930, and allow filtered air to exit through the filtration outlet 1940. This function is described in more detail below.

[0013] In various embodiments, the housing 1910 has a main portion 1960 and a removably coupled access cover 1970. The main portion 1960 can define a first end 1912 of the housing 1910, and the access cover 1970 can define a second end 1914 of the housing 1910. The main portion 1960 and the access cover 1970 are removably coupled for removal and installation of the filter assembly 1950 through the second end 1962 of the main portion 1960. The access cover 1970 surrounds the second end 1962 of the main portion 1960 of the housing 1910.

[0014] The main portion 1960 and the access cover 1970 are removably coupled at mating features 1980 defined therein. In this example, the access cover 1970 defines a latch 1982 and the second end 1962 of the main portion 1960 defines a latch receiver 1984, although other configurations are certainly contemplated. For example, the main portion 1960 and the access cover 1970 could define a mating threaded connection, a bayonet connection, or the like.

[0015] The housing inlet 1920 can be defined by a tubular structure 1922 (not necessarily of circular cross section) extending outwardly from the housing 1910. The housing inlet 1920 is defined by a main portion 1960 of the housing 1910. In various embodiments, including the one shown, the housing inlet 1920 is a tangential inlet, meaning that airflow through the housing inlet 1920 is directed tangentially to the filter assembly 1950. In other words, in some embodiments, the housing inlet is not generally directed toward the central axis z of the housing 1910. However, housing inlets 1920 having alternative configurations can also be used. In some embodiments as shown, the housing inlet 1920 is defined toward the first end 1912 of the housing 1910.

[0016] In this example, the housing inlet 1920 is in fluid communication with an internal flow guide 1924 that is configured to receive fluid flowing into the housing 1910 from the housing inlet 1920 and direct the fluid in a spiral flow path around the interior space 1916 of the housing 1910. The flow guide 1924 can be a ramp, deflector, wall, channel, or other structure extending from the housing inlet 1920 that defines a portion of the spiral flow path in the interior space 1916 of the housing 1910. Some embodiments may not have a flow guide 1924. In some other embodiments, the flow guide can be defined by a filter assembly 1950, which is described in more detail below.

[0017] The separator outlet 1930 is generally defined by an ejector tube 1932 extending outwardly from the housing 1910. The ejector tube 1932 is defined by an access cover 1970 of the housing 1910. The ejector tube 1932 allows for the ejection of at least a portion of the particulate contaminants from the unfiltered fluid during operation. In some embodiments, the ejector tube 1932 has an evacuator valve arrangement 1934 for selectively evacuating collected particulate contaminants.

[0018] The filtered outlet 1940 is defined by an outlet tube 1942 that extends outwardly from the housing 1910. The filtered outlet 1940 is defined by a main portion 1960 of the housing 1910. In this example, the filtered outlet 1940 extends axially away from the housing on a first end of the housing 1910.

[0019] In an exemplary embodiment consistent with FIG. 1 , air enters the system 1900 through a housing inlet 1920 in a direction tangential to the filter assembly 1950. The housing inlet 1920 directs the airflow into an internal flow guide 1924, which directs the airflow along a helical path around the filter assembly 1950 toward the second end 1914 of the housing 1910. Such airflow can separate at least a portion of the relatively large particles in the air, which can have sufficient momentum to proceed to the second end 1914 of the housing 1910. The particles can travel to an ejector tube 1932 and can be exhausted through a separator outlet 1930 via an evacuator valve arrangement 1934.

[0020] The remainder of the particulates in the air that are not exhausted through the separator outlet 1930 are directed by the vacuum force through the filter assembly 1950. The air is filtered by the filter assembly 1950 and exits the housing 1910 through a filtered outlet 1940 in an outlet tube 1942 on the first end 1912 of the housing 1910. The filtered air can then be directed to an associated external system.

[0021] 2 is a first exemplary cross-sectional view consistent with the separator system 1900 of FIG. 1. The system 1900 can have the same components, structures, and possible modifications as described above. In general, a housing 1910 extends between a first end 1912 and a second end 1914 and defines a housing inlet 1920 toward the first end 1912. The housing 1910 defines a separator outlet 1930 toward the second end 1914 and a filtration outlet 1940 on the first end 1912.

[0022] Filter assembly 1950 is disposed within housing 1910 and is generally configured to filter air within housing 1910. Filter assembly 1950 has an inlet flow face 1952, an outlet flow face 1954, and a filter media 1956 extending in an axial direction z. Filter media 1956 extends between inlet flow face 1952 and outlet flow face 1954. A "flow face," as defined herein, is a side of the filter assembly configured to allow fluid to enter and exit the filter assembly.

[0023] The inlet flow face 1952 is configured to receive unfiltered air from within the housing 1910. The outlet flow face 1954 is configured to expel air that has been filtered by the filter media 1956. The inlet flow face 1952 and the outlet flow face 1954 are defined at opposite axial ends of the filter assembly 1950. In various embodiments, the filter assembly 1950 is configured to restrict fluid from axially entering the filter assembly 1950. In various embodiments, the filter assembly 1950 is configured to restrict fluid from axially exiting the filter assembly 1950. In some embodiments, the outlet flow face is planar, while in other embodiments, the outlet flow face is non-planar, as described below with respect to FIGS. 3-20.

[0024] The filter assembly 1950 is coupled to the housing 1910 about the filtration outlet 1940 such that the outlet flow face 1954 is in fluid communication with the filtration outlet 1940. In various embodiments, the filter media 1956 surrounding the outlet flow face 1954 is coupled to the housing 1910 about the filtration outlet 1940. In this example, the filter assembly 1950 has a potting feature 1953 that is a radial potting sleeve configured to receive a first end of the filter media 1956 about the outlet flow face 1954. The first end of the filter media 1956 can be coupled to the potting feature 1953 using an adhesive, a gasket, a compression fit, and / or through additional or alternative structures. The potting feature 1953 and the first end of the filter media 1956 are configured to form a seal about the outlet flow face 1954. In various embodiments, the potting feature can be adhesively sealed to the first end of the filter media 1956.

[0025] The potting feature 1953 is generally configured to form a sealed connection between the outlet flow surface 1954 of the filter media 1956 and the filtration outlet 1940 of the housing 1910. In particular, the potting feature 1953 and the housing 1910 are configured to form a sealed connection that separates the outlet flow surface 1954 and the filtration outlet 1940 from the remainder of the interior space 1916 of the housing 1910. The potting feature 1953 can be substantially impermeable to air flow therethrough. The potting feature 1953 can be impermeable to air flow therethrough.

[0026] In this example, the housing 1910 has a potting feature 1953 and a filter receiver 1926 configured to receive a first end 1951 of the filter media. In some embodiments, a radial seal can be disposed radially between an outer radial surface 1955 of the potting feature 1953 in the filter receiver 1926 and an inner radial surface 1927 of the housing 1910. In some embodiments, an annular axial seal can be disposed between an annular surface 1957 defined by the potting feature 1953 in the filter receiver 1926 and a mating surface of the housing 1910. In some alternative examples, the potting feature and the filter receiver of the housing can define a mating structure that receives a radial seal between an inner radial surface of the potting feature in the filter receiver and an outer radial surface of the housing.

[0027] The filter assembly 1950 has an outer radial barrier surface 1958 between the inlet flow face 1952 and the outlet flow face 1954. In some embodiments, the outer radial barrier surface 1958 can be configured to direct airflow tangentially around the filter assembly 1950. In some such embodiments, the housing inlet 1920 defines an airflow path that is tangential to the outer radial barrier surface 1958 of the filter assembly 1950.

[0028] The outer radial barrier surface 1958 is generally configured to impede airflow through the outer radial barrier surface 1958 and into the filter assembly 1950. In some embodiments, at least a portion of the outer radial barrier surface 1958 is defined by a filter media 1956 that is a sheet of filter media. In some embodiments, the outer radial barrier surface 1958 is defined by a separate sleeve disposed around the filter media 1956. The sleeve can be constructed from a material that has a higher resistance to airflow therethrough as compared to the inlet flow surface 1952 of the filter assembly 1950, which can impede airflow through the sleeve and thus promote a helical airflow around the filter assembly toward the second end 1914 of the housing 1910. Such a configuration can improve the efficiency of the separator. In some embodiments, the sleeve is constructed from a cellulosic material, and in some embodiments, the sleeve is constructed from a polymeric material.

[0029] The outer radial barrier surface 1958 has an axially extending length L surface The outer radial barrier surface 1958 can extend from the outlet flow surface 1954 toward the inlet flow surface 1952. In an example, the outer radial barrier surface 1958 is defined in part by the potting feature 1953. Thus, the length L of the outer radial barrier surface 1958 surface extends axially from the potting feature 1953 to the inlet flow surface 1952. In some embodiments, the length L of the outer radial barrier surface 1958 surface is greater than or equal to the axial distance D from the filtration outlet 1940 to the distal end of the housing inlet 1920. The "distal end of the housing inlet" is the portion of the housing inlet 1920 that is axially furthest from the filtration outlet 1940. In some embodiments, the outer radial barrier surface 1958 extends axially from the filtration outlet 1940 beyond the housing inlet 1920. Such a configuration promotes a helical airflow around the filter assembly 1950 towards the second end 1914 of the housing 1910.

[0030] In some embodiments, the outer radial barrier surface 1958 can define a flow guide configured to receive fluid flowing into the housing 1910 from the housing inlet 1920 and direct the fluid in a spiral flow path around the interior space 1916 of the housing 1910. The flow guide can be a ramp, deflector, wall, channel, or other structure that extends at least partially around the outer radial barrier surface 1958.

[0031] The inlet flow face 1952 of the filter assembly 1950 has a flow face length L inlet In some embodiments, the inlet flow face 1952 has an axial flow face length L from the first end 1912 toward the second end 1914 of the housing 1910. inlet Such a taper can assist in promoting helical airflow around the filter assembly 1950 toward the second end 1914 of the housing 1910 and inhibiting the settling of contaminants across the inlet flow face 1952. The inlet flow face 1952 defines an axial flow face length L inlet In some embodiments, for example in the example shown in FIG. 2, the taper defines a taper of at least a portion of the axial flow surface length L inlet 19, where the general shape defined by the inlet flow surface 1952 is a rounded cone. The taper of the inlet flow surface 1952 increases from the first end 1912 toward the second end 1914 by an axial flow surface length L inlet Indeed, in this example, the taper of the inlet flow face 1952 varies continuously along the axial flow face length L from the first end 1912 to the second end 1914. inlet increases continuously along

[0032] Radial distance R 1、2 is generally defined between the inlet flow surface 1952 and the housing 1910 relative to the central axis z. In various embodiments, the radial distance R 1、2is the first radial distance R 1 and a second radial distance R 2 As shown by the axial flow surface length L inlet 19 increases from the first end 1912 to the second end 1914 of the housing 1910 for at least a portion of the first radial distance R 1 is the second radial distance R 2 is measured from a point on the inlet flow surface 1952 that is axially aligned with the point on the inlet flow surface 1952 at which the first radial distance R 1 and a second radial distance R 2 are parallel and axially aligned. The axial flow surface length L inlet along the radial distance R 1、2 Increasing the axial length of the filter assembly 1950 may help promote helical airflow around the filter assembly 1950 toward the second end 1914 of the housing 1910. However, other configurations are certainly contemplated.

[0033] In this example, the housing 1910 maintains a relatively constant distance from the central axis z. However, in some embodiments, the housing 1910 may define a taper. In such embodiments, the housing 1910, and in particular the interior space 1916 of the housing 1910, may taper from the first end 1912 to the second end 1914, or from the second end 1914 to the first end 1912, along at least a portion of its axial length. However, the radial distance between the inlet flow face 1952 and the housing 1910 may increase along at least a portion of the axial length of the inlet flow face 1952 from the first end 1912 to the second end 1914 of the housing 1910.

[0034] The annulus defined between the inlet flow face 1952 and the housing 1910 in a cross section perpendicular to the z-axis has an increasing area along at least a portion of the axial length of the inlet flow face 1952 from the first end 1912 to the second end 1914 of the housing 1910. Figures 25a and 25b show simplified schematic diagrams of such an exemplary cross section, where Figure 25a shows the R 1 FIG. 25b is a cross section at R in FIG. 2 25a and 25b depict the cross-sectional shape of the inlet flow face 1952 as having a smooth circular shape for simplicity, in various embodiments, the flute profile forms the periphery of the inlet flow face 1952. For example, the series of peaks and valleys that define the media flute profile are arranged about the central axis z to define a generally circular shape.

[0035] In FIG. 25a, a ring A is defined between the outer peripheral edge of the inlet flow surface 1952 and the housing 1910. 1 The area of ​​ring A is 2 where A is the area of ​​the 1 is a first position P along the axial length of the inlet flow surface 1952. 1 Located in A 2 is a second position P along the axial length of the inlet flow surface 1952. 2 An "annulus" is defined herein as a shape, such as a ring, defined between an inner boundary and an outer boundary, where the inner boundary and the outer boundary are not necessarily circular, not necessarily concentric, and not necessarily the same shape. Figures 25a and 25b show an inlet flow face 1952 at a first position P along the axial length of the inlet flow face 1952. 1 and the second position P 2 , a radial distance R defined between the inlet flow surface 1952 and the housing 1910 with respect to the central axis z. 1、2 Also shown is the second radial distance R 2 is the first radial distance R 1 Greater than.

[0036] As noted above, in this example, the general shape defined by the inlet flow surface 1952 forms a rounded regular cone. "Regular" means that the cone is generally symmetric about the z-axis. The cone is not necessarily perfectly symmetric about the z-axis. In some other embodiments, the inlet flow surface can have alternative configurations, some of which are described below with reference to other figures described herein. For example, the general shape defined by the inlet flow surface can be irregular, in other words, asymmetric about the z-axis. Figures 14A, 26a, and 26b, discussed in detail below, provide one such example in which the flow surface forms the general shape of a rounded oblique cone.

[0037] In various embodiments, the filter assembly 1950 is positioned in the center of the housing 1910 such that the z-axis extends through the center of the filter assembly 1950. In the example shown here, the filter media 1956 is at least a first sheet of filter media and a second sheet of filter media in a spiral configuration about the z-axis, which is described in more detail below with reference to FIG. 3. In some other embodiments, the filter assembly is eccentric within the housing such that the z-axis does not extend through the center of the filter assembly. FIGS. 27a and 27b show cross sections perpendicular to the central axis z associated with an example in which the filter assembly 1950′ is eccentrically positioned within the housing 1910. Otherwise, the exemplary filter assembly 1950′ can be consistent with the filter assembly of FIG. 2, except that the filter assembly 1950′ has a central axis Z that extends axially through the filter assembly 1950′ that is different from the central axis z of the housing 1910.

[0038] Similar to FIGS. 25a and 25b discussed above, in FIG. 27a, annulus A is defined between inlet flow surface 1952′ and housing 1910. 1 The area of ​​ring A is 2 The area of ​​A is smaller than that of 1 is a first position P along the axial length of the inlet flow surface 1952′. 1 Located in A2 is a second position P along the axial length of the inlet flow surface 1952′. 2 Furthermore, at a first position P along the axial length of the inlet flow surface 1952′ 1 and the second position P 2 , a radial distance R defined between the inlet flow surface 1952′ and the housing 1910 with respect to the central axis z. 1、2 The second radial distance R 2 is the first radial distance R 1 The first radial distance R 1 and a second radial distance R 2 are axially aligned and parallel.

[0039] Returning to the example of FIGS. 1-2, the filter assembly 1950 has a rod 1990 around which the filter media 1956 is wound. Thus, the rod 1990 extends through at least a portion of the center of the filter assembly 1950. In some embodiments, the rod 1990 extends through the entire filter assembly 1950. The rod 1990 can be a single component or can be constructed from multiple components that may or may not be bonded together. In some embodiments, the rod 1990 does not extend through the entire filter assembly 1950, while in other embodiments, the rod 1990 extends through the entire filter assembly 1950. In one example, the rod 1990 has a tubular extension with a plug disposed at each end. In such an embodiment, the plugs can form a handle, which is described in more detail below.

[0040] A rod receiver 1992 defined by the second end 1914 of the housing 1910 is configured to receive a distal end 1994 of the rod 1990. The rod 1990 can have a proximal end positioned towards the outlet flow face 1954 (not visible here). In some embodiments, the proximal end of the rod 1990 is positioned between the inlet flow face 1952 and the outlet flow face 1954. The distal end of the rod 1990 is positioned towards the inlet flow face 1952. In such embodiments, the rod receiver 1992 is a positioning feature that helps maintain the positioning of the inlet flow face 1952 of the filter assembly 1950 relative to the second end 1914 of the housing 1910. Specifically here, the rod receiver 1992 is a centering feature that helps maintain the centering of the filter assembly 1950 relative to the second end 1914 of the housing 1910. In some embodiments, the distal end 1994 of the rod 1990 defines a handle that can be manually grasped by a user to aid in the removal and installation of the filter assembly 1950 relative to the housing 1910 .

[0041] In various embodiments, the rod can be omitted from the system. In some other embodiments, instead of defining the rod receiver shown in FIG. 2, the second end of the housing can define a rod structure extending axially toward the first end of the housing. The inlet flow face of the filter assembly can be configured to receive the rod structure to position the inlet flow face of the filter assembly relative to the second end of the housing. For example, the rod receiver can be coupled to the inlet flow face of the filter assembly. In some such embodiments, the rod receiver can define a handle structure that a user can grasp, such as one or more radial protrusions extending from the rod receiver. Other features can also be implemented to fix the position of the inlet flow face of the filter assembly relative to the second end of the housing.

[0042] In some embodiments, the housing 1910 can have a positioning feature that directly receives a distal end of the inlet flow face 1952. For example, the second end 1914 of the housing 1910 can define an annular protrusion that extends circumferentially about a central axis of the filter assembly 1950. The annular protrusion can be configured to surround the distal end of the inlet flow face 1952. In some embodiments, the annular protrusion can be configured to frictionally engage the distal end of the inlet flow face 1952. In various embodiments, the annular protrusion as a positioning feature is omitted from the separator system 1900.

[0043] FIG. 3 illustrates an exemplary filter assembly consistent with the system illustrated in FIGS. 1-2. The filter assembly 1 is constructed from a filter media 10 defining a first flow face 20, a second flow face 30, and a plurality of flutes 40 extending axially from the first flow face 20 to the second flow face 30. In this example, the first flow face is defined on a first end 12 of the filter assembly 1, and the second flow face 30 is defined on an opposite second end 14 of the filter assembly 1. The first end 12 and the second end 14 are opposite axial ends of the filter assembly 1. Consistent with FIG. 2 above, the first flow face 20 can be an inlet flow face, and the second flow face 30 can be an outlet flow face. As discussed above, the first flow face 20 defines an axial flow face length L. As discussed above, the first flow face 20 defines a taper over at least a portion of the axial flow face length.

[0044] The filter media 10 is a plurality of sheets of filter media, specifically a first sheet of filter media 50 and a second sheet of filter media 60. The second sheet of filter media 60 is adjacent to the first sheet of filter media 50. The first sheet of filter media 50 and the second sheet of filter media 60 mutually define a plurality of flutes 40. The filter media 10 defines a spiral configuration about the Z axis. Thus, each of the first sheet of filter media 50 and the second sheet of filter media 60 defines a spiral configuration about the Z axis. Thus, the plurality of flutes 40 are also in a spiral configuration about the Z axis.

[0045] The first sheet of filter media 50 and the second sheet of filter media 60 are generally elongated such that the first sheet of filter media 50 and the second sheet of filter media 60 can be spiraled about an axially extending Z-axis to form a filter assembly. In this example, the first sheet of filter media 50 and the second sheet of filter media 60 are contiguous, meaning that the first sheet of filter media 50 and the second sheet of filter media 60 are part of a single cohesive sheet of filter media. The first sheet of filter media 50 and the second sheet of filter media 60 are separated by a fold 70. The fold 70 defines the second flow surface 30 of the filter assembly. The first sheet of filter media 50 defines a first edge 52 and the second sheet of filter media 60 defines a second edge 62. The first edge 52 and the second edge 62 mutually define the first flow surface 20 of the filter assembly 1. The “edge” of a media sheet is defined herein as the outer limit of the media sheet and is distinct from the fold 70 .

[0046] In some alternative embodiments, described in more detail below, the first sheet of filter media 50 and the second sheet of filter media 60 are separate sheets, in which case the second flow face is defined by the respective edges of the sheets of filter media. Additionally, in various embodiments, the first sheet of filter media can be unfluted and can be characterized as a facing sheet of filter media that abuts a fluted second sheet of filter media to form a unitary facer media.

[0047] In examples consistent with the present embodiment, both the first sheet of filter media 50 and the second sheet of filter media 60 are each fluted. As used herein, the term "fluted" is synonymous with the term "corrugated" and describes a series of alternating elongated ridges / peaks and elongated grooves / valleys. The term "fluted" is used herein to describe elongated channels mutually defined by adjacent portions of media. In this embodiment, the flutes are parallel, but in some other embodiments, the flutes are not parallel.

[0048] The filter assembly 1 is generally constructed to define a fluid pathway 16 between a first flow face 20 and a second flow face 30 through the filter media 10 such that fluid is filtered by the filter media 10. In particular, a plurality of flutes 40 define a fluid pathway 16 (1) into the filter assembly 1 and then to the filter media 10 ("entrance flutes"), or (2) out of the filter assembly 1 ("exit flutes") from the filter media 10. Each of the figures provided in this application shows a particular direction of fluid pathway through the depicted filter assembly for clarity, although it will be understood that the fluid pathway may be in the opposite direction in various examples.

[0049] Each of the plurality of flutes 40 defines a flute opening 42 and a flute closure 70. The flute opening 42 forms the extreme end of the fluid path 16 along the flute and accommodates fluid flow to or from the filter assembly 1. The flute closure 70 blocks fluid flow along the flute, thereby defining a portion of the fluid path 16 through the filter media 10. In this example, the plurality of inlet flutes define the flute openings 42 at the first flow face 20. The flute closure 70 can be defined near the second flow face 30 in some embodiments. In some embodiments, including the embodiment shown, the flute closure 70 is adjacent to the second flow face 30. More specifically, the flute closure 70 can abut the second flow face 30. Although the flute closure 70 can have a variety of different configurations, in this embodiment, the flute closure 70 is defined by a fold 70, which defines the second flow face 30. In some other embodiments, a flute closure can be defined between the first flow surface 20 and the second flow surface.

[0050] In this embodiment, the volume defined between the outer surface 56 of the first sheet of filter media and the outer surface 66 of the second sheet of filter media defines an exit path for the fluid pathway 16 that is not necessarily characterized by being defined by a plurality of flutes. The term "outer surface" is defined as the surfaces of the first sheet of filter media and the second sheet of filter media that face away from one another when the filter media 10 is disposed as a flat sheet (when not coiled). The exit path extends from the obstruction 72 to an opening defined at the second end 14 of the filter assembly 1 between the coiled folds 70.

[0051] The obstructions 72 may be disposed within the convolutions and outside of the plurality of flutes 40 such that fluid passing through the first and second flow faces 20, 30 of the filter assembly 1 must first pass through the filter media 10. Additional obstructions may be disposed around the periphery of the filter assembly 1, in any other gaps in the filter media such as the central opening of the filter assembly 1, to block fluid flow therethrough. The obstructions may be formed by placing an adhesive, such as an adhesive bead, in the appropriate location.

[0052] Each of the plurality of flutes 40 defines a flute distance between the first flow surface 20 and the second flow surface 30. The "flute distance" as defined herein is the distance between a first end of a particular flute on the first flow surface of the filter assembly and a second end of a particular flute on the second flow surface of the filter assembly. In this embodiment, each of the plurality of flutes 40 is straight, and thus the length of the flute is equal to the "flute distance" as defined herein. However, in some alternative embodiments, such as those in which the flutes are curved or otherwise do not form a single straight line, the "flute distance" is not equal to the length of the flute. Furthermore, in embodiments in which the ends of the flutes are not spaced apart by a fixed distance, the "flute distance" is defined to be the maximum distance between the ends of the flutes.

[0053] In this embodiment, a first flute 44 of the plurality of flutes 40 is spaced apart from the first flow surface 20 by a first flute distance D 1 and a second flute 46 of the plurality of flutes 40 defines a second flute distance D between the first flow surface 20 and the second flow surface 30. 2 In some examples, the first flute distance D 1 is the second flute distance D as shown herein 2 In some other examples, the first flute distance D 1 is the second flute distance D 2 In one embodiment, the first flute distance D 1 and the second longitudinal groove distance D 2In some embodiments, the first flute distance D 1 is the second flute distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 and differs by 3mm~20mm, 10mm~20mm, or 15mm~25mm.

[0054] In some embodiments, the third flute 48 of the plurality of flutes 40 is spaced apart from the first flow surface 20 by a third flute distance D between the first flow surface 20 and the second flow surface 30. 3 Define the third flute distance D 3 is generally the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 The third flute distance D differs from both by more than 2 mm. 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 In this example, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 In some other examples, the third flute distance D 3 As will be understood, the first flute distance D 1 and the second longitudinal groove distance D 2 and the first longitudinal groove distance D 1 and the second longitudinal groove distance D 2 is smaller than the other.

[0055] The difference in flute distance between the first flow surface 20 of the filter assembly 1 and the second flow surface 30 of the filter assembly 1 is also evidenced by the shape of the flow surfaces relative to one another. In various embodiments, at least one of the first flow surface 20 and the second flow surface 30 is non-planar. In various embodiments, at least one of the first flow surface 20 and the second flow surface 30 is substantially planar. A "planar" flow surface, as defined herein, means that the surface of the media defining the flow surface forms an imaginary plane within a 2 mm margin of error.

[0056] In some examples consistent with this particular embodiment, the first flow surface 20 is non-planar and the second flow surface 30 is planar. In some other examples consistent with this particular embodiment, the first flow surface 20 is non-planar and the second flow surface 30 is non-planar. Here, the first flow surface 20 defines a spiral about an axially extending Z-axis. The second flow surface 30 is not visible in this view, but it will be understood that the second flow surface 30 can be non-planar or planar. For example, in some embodiments, the second flow surface 30 can be concave and extend inwardly relative to the filter assembly, similar to the flow surface shown in FIG. 18.

[0057] It will be appreciated that in some alternative embodiments, the first flow surface 20 can be planar and the second flow surface 30 can be non-planar. In some embodiments, at least one flute of the plurality of flutes 40 defines a flute opening that is non-planar, where "non-planar" means that the flute opening does not define a plane within 2 mm tolerance.

[0058] In examples consistent with this embodiment, the obstruction 72 is disposed adjacent to the second edge 62 of the second sheet of filter media 60 along the length of the second sheet of filter media 60. Because the second edge 62 of the second sheet of filter media 60 is non-planar, the obstruction 72 is also non-planar. In some embodiments in which the filter surface is non-planar, the obstruction disposed adjacent to the filter surface is also non-planar. However, in other embodiments in which the filter surface is non-planar, such as the embodiment shown in FIG. 4A, the obstruction disposed adjacent to the filter surface is planar.

[0059] 4A illustrates another exemplary filter assembly 100 consistent with the technology disclosed herein. The filter assembly 100 is constructed from a filter media 110 defining a first flow face 120, a second flow face 130, and a plurality of longitudinal grooves 140 extending from the first flow face 120 to the second flow face 130. In this example, the first flow face 120 is defined on a first end 102 of the filter assembly 100, and the second flow face 130 is defined on an opposing second end 104 of the filter assembly 100. The first flow face 120 has a first axial flow face length L 1 The second flow surface 130 defines a second axial flow surface length L 2 In this example, the first flow surface 120 does not define a taper.

[0060] The filter media 110 is a plurality of sheets of filter media, specifically a first sheet of filter media 150 and a second sheet of filter media 160. The second sheet of filter media 160 is adjacent to the first sheet of filter media 150. The first sheet of filter media 150 and the second sheet of filter media 160 mutually define a plurality of flutes 140. The filter media 110 defines a spiral configuration about the Z axis. Thus, each of the first sheet of filter media 150 and the second sheet of filter media 160 defines a spiral configuration about the Z axis. Thus, the plurality of flutes 140 are also in a spiral configuration about the Z axis. Although the end 101 of the filter media 110 is shown in cross section extending outward from the spiral to show components that would not otherwise be visible, generally, substantially the entire length of the filter media 110 is in a spiral configuration. In this example, the plurality of flutes 140 are substantially parallel.

[0061] The first sheet of filter media 150 and the second sheet of filter media 160 are generally elongated. In this example, the first sheet of filter media 150 and the second sheet of filter media 160 are discontinuous, meaning that the first sheet of filter media 150 and the second sheet of filter media 160 are separate sheets of filter media. In examples consistent with the present embodiment, the first sheet of filter media 150 is a fluted sheet and the second sheet of filter media 160 is a facing sheet, where a "facing sheet" is generally defined as a planar, non-fluted sheet.

[0062] The first sheet of filter media 150 defines a first edge 152 and a second edge 154 opposite the first edge 152. The first edge 152 defines a first flow face 120 and the second edge 154 defines a second flow face 130. The first sheet of filter media 150 has a first width W defined by the perpendicular distance from the first edge 152, or first flow face 120, to the second edge 154, or second flow face 130. 1 and a first width W 1is generally constant along the first sheet of filter media 150. Similarly, the second sheet of filter media 160 defines a third edge 162 and a fourth edge 164 opposite the third edge 162. The third edge 162 defines the first flow face 120 and the fourth edge 164 defines the second flow face 130. The second sheet of filter media 160 has a second width W defined by the perpendicular distance from the third edge 162, or first flow face 120, to the fourth edge 164, or second flow face 130. 2 and the width is generally constant along the second sheet of filter media 160. In this embodiment, the first width W 1 is the second width W 2 and differs by more than 2 mm.

[0063] The filter assembly 100 is generally constructed to define a fluid path 116 between a first flow surface 120 and a second flow surface 130 through the filter media 110 such that fluid is filtered by the filter media 110. Each of the plurality of flutes 140 defines a flute opening 142, which can be seen more clearly in FIG. 4b and as a detailed view of FIG. 4a. Each of the plurality of flutes 140 defines a flute closure 170, which can be seen in FIG. 4a because a portion of the first sheet 150 of filter media has been cut away for clarity. In this example, the flute opening 142 is defined at the first flow surface 120 and the flute closure 170 is defined near the second flow surface 130. In some embodiments, including the embodiment shown, the flute closure 170 is adjacent to the second flow surface 130. More specifically, the flute closure 170 can abut the second flow surface 130. Although flute closure 170 can have a variety of different configurations, in this embodiment flute closure 170 is a physical barrier, such as an adhesive bead, disposed near the second flow surface between first sheet of filter media 150 and second sheet of filter media 160.

[0064] The obstructions 172 may be disposed within the convolutions and outside of the plurality of flutes 140 such that fluid passing through the first flow face 120 and the second flow face 130 of the filter assembly 100 must first pass through the filter media 110. Additional obstructions may be disposed around the periphery of the filter assembly 100, in the central opening of the filter assembly 100, or in any other gap in the filter media to block fluid flow therethrough. The obstructions may be formed by placing an adhesive, such as an adhesive bead or other barrier in the appropriate location.

[0065] In various embodiments, including the embodiment shown, at least one of the first flow surface 120 and the second flow surface 130 is non-planar. In examples consistent with this particular embodiment, the first flow surface 120 is non-planar and the second flow surface 130 is non-planar. In particular, the first edge 152 and the third edge 162 (notably visible in FIG. 4b) that define the first flow surface 120 are non-planar, even though the first edge 152 is planar and the third edge 162 is planar. The second edge 154 and the fourth edge 164 that define the second flow surface 130 are similarly non-planar, even though the second edge 154 is planar and the fourth edge 164 is planar. In this embodiment, flute closure 170 is disposed adjacent to fourth edge 164 of second sheet of filter media 160 such that flute closure 170 is generally planar, although in some alternative examples flute closure 170 is non-planar. Similarly, obstruction 172 is disposed adjacent to third edge 162 of second sheet of filter media 160 such that obstruction 172 is also planar, although in some alternative examples obstruction 172 is non-planar.

[0066] In various embodiments, at least one flute of the plurality of flutes defines an opening that is non-planar, such as first flute 144 (FIG. 4b) in this exemplary embodiment. In particular, in this embodiment, all of the plurality of flutes 140 define a non-planar opening with first edge 152 and third edge 162 defining one flute opening and second edge 154 and fourth edge 164 defining the other flute opening.

[0067] 5 illustrates a side cross-sectional view of yet another exemplary filter assembly 200 consistent with the technology disclosed herein. The filter assembly 200 is constructed from a filter media 210 having a first elongated edge 212 defining a first flow face 220, a second elongated edge 214 defining a second flow face 230, and a plurality of flutes 240 extending from the first flow face 220 to the second flow face 230. In this example, the first flow face 220 is defined on a first end 202 of the filter assembly 200 and the second flow face 230 is defined on an opposing second end 204 of the filter assembly 200. The first flow face 220 has an axial flow face length L. The first flow face 220 also defines a taper from the first end 202 toward the second end 204 for at least a portion of the axial flow face length. In this example, the taper is relatively constant from the first end 202 to the second end 204 for at least a portion of the axial flow face length.

[0068] Similar to the embodiment shown in Figures 3-4b, the filter assembly 200 is generally constructed to define a fluid path 218 between a first flow surface 220 and a second flow surface 230 through the filter media 210 such that fluid is filtered by the filter media 210. Thus, in this example, each of the plurality of flutes 240 defines a flute opening and a flute closure. Also similar to the embodiment shown in Figures 3-4b, the filter assembly 200 is constructed from the filter media 210 in a spiral configuration about a Z-axis. An exemplary filter media 210 configuration consistent with Figure 5 and other embodiments disclosed herein is described in further detail below with reference to Figures 6a-6d.

[0069] 5, each of the plurality of flutes 240 defines a flute distance between the first flow surface 220 and the second flow surface 230. In this embodiment, a first flute 244 of the plurality of flutes 240 defines a first flute distance D between the first flow surface 220 and the second flow surface 230. 1 and a second flute 246 of the plurality of flutes 240 defines a second flute distance D between the first flow surface 220 and the second flow surface 230. 2 In this embodiment, the first flute distance D 1 is the second flute distance D 2 In other embodiments, the first flute distance D 1 is the second flute distance D 2 In various embodiments, the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 and differs by 3mm~20mm, 10mm~20mm, or 15mm~25mm.

[0070] In some embodiments, the third flute 248 of the plurality of flutes 240 is spaced apart from the first flow surface 220 by a third flute distance D 3 In this embodiment, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 The third flute distance D is greater than the third flute distance D. 3 is generally the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2The third flute distance D differs from both by more than 2 mm. 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 may differ from one or both of the above to the same extent.

[0071] In various embodiments, at least one of the first flow surface 220 and the second flow surface 230 is planar. In examples consistent with this particular embodiment, the first flow surface 220 is planar, the second flow surface 230 is planar, and the first flow surface 220 is non-parallel to the second flow surface 230. In some embodiments, one or both of the first flow surface and the second flow surface can be non-planar. For example, one or both of the first flow surface and the second flow surface can be cut to be a three-dimensional surface.

[0072] The filter assembly 200 of FIG. 5 can be constructed from various configurations of filter media 210, examples of which are depicted and described in connection with FIGS. 6a-6d and generally described later in this document. Referring initially to FIG. 6a, the exemplary filter media 210 is a plurality of sheets of filter media, specifically a first sheet of filter media 250 and a second sheet of filter media 260. The second sheet of filter media 260 is adjacent to the first sheet of filter media 250. The first sheet of filter media 250 and the second sheet of filter media 260 mutually define a plurality of flutes 240. Here, although shown in an unrolled arrangement consistent with FIG. 5, the filter media 210 is arranged in a spiral configuration about a Z-axis (FIG. 5). Thus, each of the first sheet of filter media 250 and the second sheet of filter media 260 are arranged to define a spiral configuration about the Z-axis. Thus, the plurality of flutes 240 are also in a spiral configuration about the Z axis. In this example, the plurality of flutes 240 are generally parallel. In an example consistent with the embodiment of FIG. 6a, the first sheet of filter media 250 is a fluted sheet and the second sheet of filter media 260 is a fluted sheet.

[0073] The first sheet of filter media 250 and the second sheet of filter media 260 are generally elongated. In this example, the first sheet of filter media 250 and the second sheet of filter media 260 are contiguous and separated by a fold 270. The fold 270 defines the second flow face 230 and the second elongated edge 214 of the filter assembly 200 shown in FIG. 5. The first sheet of filter media 250 defines a first edge 252 and the second sheet of filter media 260 defines a second edge 262. The first edge 252 and the second edge 262 are configured to mutually define the first flow face 220, and thus the first elongated edge 212, of the filter assembly 200 (FIG. 3).

[0074] In the example filter media 210, flute openings 242 (visible in FIG. 6a) of a plurality of flutes 240 are defined at the first flow surface 220 (visible in FIG. 5) and flute closures 270 (visible in FIG. 6a) are defined near the second flow surface 230 (visible in FIG. 5). In some embodiments, including the embodiment shown, flute closures 270 are adjacent to the second flow surface 230 (FIG. 5). More specifically, flute closures 270 can abut the second flow surface 230. Although flute closures 270 can have a variety of different configurations, in the embodiment of FIG. 6a, flute closures 270 are folds 270 between the first sheet of filter media 250 and the second sheet of filter media 260.

[0075] The obstruction 272 may be disposed outside of the plurality of flutes 240 such that fluid passing through the first flow face 220 and the second flow face 230 (FIG. 5) of the filter assembly 200 must first pass through the filter media 210. The obstruction may be disposed near the first elongated edge 212 of the filter media 210 during construction of the filter assembly 200 of FIG. 5. As described, additional obstructions may be disposed in any other gaps in the filter media 210, such as around the periphery of the filter assembly 200, at the central opening of the filter assembly 200, to block fluid flow therethrough. The obstructions may be formed by placing an adhesive, such as an adhesive bead, in the appropriate location.

[0076] As previously mentioned, to construct the filter assembly 200 of FIG. 5, the filter media 210 of FIG. 6a is rolled around the Z-axis and the obstruction 272 is disposed in contact with the filter media 210 in the appropriate location to induce the desired fluid flow through the media. In various embodiments, after the filter media 210 is rolled into a cylindrical shape, the filter media 210 is cut to form the desired shape of the first flow face 220. In the embodiment shown in FIG. 5, the first flow face 220 can be cut with a cutting tool to form a plane that is non-parallel to the second flow face 230. In examples consistent with this embodiment, the second flow face 230 is generally not cut due to the presence of the folds 270 that form obstructions that direct the fluid flow. In some examples, the filter media 210 can be cut using laser cutting, and in other examples, the filter media 210 can be cut using a sharp blade, such as a saw or knife blade. In such an embodiment, the obstruction 272 can be disposed in contact with the filter media 210 in a location that is not cut and removed.

[0077] In some alternative embodiments, the first elongated edge 212 of the filter media 210 is cut after the filter media 210 is rolled and before it is rolled to form the intended shape of the associated flow surface.

[0078] 6b illustrates another filter media 210 consistent with the embodiment illustrated in FIG. 5, before the filter media has been rolled and cut. Filter media 210 includes multiple sheets of filter media, specifically, a first sheet of filter media 257 and a second sheet of filter media 267. Second sheet of filter media 267 is adjacent to first sheet of filter media 257. First sheet of filter media 257 and second sheet of filter media 267 mutually define a plurality of flutes 240 illustrated in FIG.

[0079] The first sheet of filter media 257 and the second sheet of filter media 267 are generally elongated. In this example, the first sheet of filter media 257 and the second sheet of filter media 267 are discontinuous. The first sheet of filter media 257 defines a first edge 254 and the second sheet of filter media 267 defines a second edge 264. The first edge 254 and the second edge 264 are configured to mutually define the first flow face 220 of the filter assembly 200, and thus the first elongated edge 212 (FIG. 5). The first sheet of filter media 257 defines a third edge 256 and the second sheet of filter media 267 defines a fourth edge 266. Third edge 256 and fourth edge 266 are configured to mutually define second flow face 230 of filter assembly 200, and thus second elongated edge 214 (FIG. 3).

[0080] For construction of the filter assembly 200 of FIG. 5, the filter media 210 is arranged in a spiral configuration about the Z-axis (FIG. 5). Thus, each of the first sheet of filter media 257 and the second sheet of filter media 267 are arranged to define a spiral configuration about the Z-axis. Thus, the plurality of flutes 240 are also in a spiral configuration about the Z-axis. In this example, the plurality of flutes 240 are generally parallel. In an example consistent with the embodiment of FIG. 6b, the first sheet of filter media 257 is a fluted sheet and the second sheet of filter media 267 is also a fluted sheet.

[0081] In this example filter media 210, flute opening 245 (visible in FIG. 6b) is defined at first flow surface 220 (visible in FIG. 5) and flute closure 275 (visible in cutaway in FIG. 6b) is defined near second flow surface 230 (visible in FIG. 5). In some embodiments, including the embodiment shown in FIG. 6b, flute closure 275 is adjacent second flow surface 230 (FIG. 5). More specifically, flute closure 275 can abut second flow surface 230. Although flute closure 275 can have a variety of different configurations, in the embodiment of FIG. 6b, flute closure 275 is a physical blockage, such as an adhesive bead, disposed between first sheet of filter media 257 and second sheet of filter media 267.

[0082] The obstruction 273 may be disposed outside of the plurality of flutes 240 such that fluid passing through the first flow face 220 and the second flow face 230 ( FIG. 5 ) of the filter assembly 200 must first pass through the filter media 210. The obstruction may be disposed near the first elongated edge 212 of the filter media 210 during construction of the filter assembly 200 of FIG. 5. As described, additional obstructions may be disposed in any other gaps in the filter media 210, such as around the periphery of the filter assembly 200, at the central opening of the filter assembly 200, etc. to block fluid flow therethrough.

[0083] The filter media 210 of FIG. 6b can be cut and formed into filter assemblies 200 similar to the filter media described in FIG. 6a above.

[0084] 6C illustrates yet another filter media 210 consistent with the embodiment illustrated in FIG. 5, before the filter media has been rolled and cut. Filter media 210 includes multiple sheets of filter media, specifically, a first sheet of filter media 251 and a second sheet of filter media 261. Second sheet of filter media 261 is adjacent to first sheet of filter media 251. First sheet of filter media 251 and second sheet of filter media 261 mutually define a plurality of flutes 240.

[0085] The first sheet of filter media 251 and the second sheet of filter media 261 are generally elongated. In this example, the first sheet of filter media 251 and the second sheet of filter media 261 are discontinuous. The first sheet of filter media 251 defines a first edge 253 and the second sheet of filter media 261 defines a second edge 263. The first edge 253 and the second edge 263 are configured to mutually define the first flow face 220 of the filter assembly 200, and thus the first elongated edge 212 (FIG. 5). The first sheet of filter media 251 defines a third edge 255 and the second sheet of filter media 261 defines a fourth edge 265. Third edge 255 and fourth edge 265 are configured to mutually define second flow face 230, and thus second elongated edge 214, of filter assembly 200 (FIG. 5).

[0086] For construction of the filter assembly 200 of FIG. 5, the filter media 210 is arranged in a spiral configuration about the Z-axis (FIG. 5). Thus, each of the first sheet of filter media 251 and the second sheet of filter media 261 are arranged to define a spiral configuration about the Z-axis. Thus, the plurality of flutes 240 are also in a spiral configuration about the Z-axis. In this example, the plurality of flutes 240 are generally parallel. In an example consistent with the embodiment of FIG. 6c, the first sheet of filter media 251 is a fluted sheet and the second sheet of filter media 261 is a facing sheet.

[0087] In this example filter media 210, flute opening 243 (visible in FIG. 6c) is defined at first flow surface 220 (visible in FIG. 5) and flute closure 271 (visible in cutaway in FIG. 6b) is defined near second flow surface 230 (visible in FIG. 5). In some embodiments, including the embodiment shown in FIG. 6c, flute closure 271 is adjacent second flow surface 230 (FIG. 5). More specifically, flute closure 271 can abut second flow surface 230. Although flute closure 271 can have a variety of different configurations, in the embodiment of FIG. 6c, flute closure 271 is a physical blockage, such as an adhesive bead, disposed between first sheet of filter media 251 and second sheet of filter media 261.

[0088] The obstruction 273 may be disposed outside of the plurality of flutes 240 such that fluid passing through the first flow face 220 and the second flow face 230 ( FIG. 5 ) of the filter assembly 200 must first pass through the filter media 210. The obstruction may be disposed near the first elongated edge 212 of the filter media 210 during construction of the filter assembly 200 of FIG. 5. As described, additional obstructions may be disposed in any other gaps in the filter media 210, such as around the periphery of the filter assembly 200, at the central opening of the filter assembly 200, etc. to block fluid flow therethrough.

[0089] The filter media 210 of FIG. 6c can be cut and formed into filter assemblies 200 similar to the filter media described in FIG. 6a above.

[0090] FIG. 6d is a front view of a relatively larger elongated segment of filter media 210 than that shown in FIGS. 4a-4c, providing an understanding of the general overall shape of filter media 210 in an unrolled configuration. FIG. 6d can generally correspond to the media shown in each of FIGS. 6a-6c. FIG. 6d shows that filter media 210 has a first elongated edge 280, a second elongated edge 282, a first edge 284, and a second edge 286. First elongated edge 280 corresponds to the first edge of the first sheet of filter media and the second edge of the second sheet of filter media in FIGS. 6a-6c above. Thus, first elongated edge 280 also defines the first flow face 220 (FIG. 5) of the filter assembly. Second elongated edge 282 can correspond to fold 270 between the first sheet of filter media and the second sheet of filter media in FIG. 6a, or the third edge of the first sheet of filter media and the fourth edge of the second sheet of filter media in FIGS. 6a-6c.

[0091] First elongated edge 280 generally forms a sinusoidal pattern of increasing or decreasing frequency over the length of filter media 210. Second elongated edge 282 extends generally linearly. Similarly, first edge 284 and second edge 286 extend linearly and are each perpendicular to second elongated edge 282. In this example, filter media 210 does not form a trapezoidal shape due to the wavy pattern of at least first elongated edge 280.

[0092] Experimental Data An exemplary configuration generally consistent with the technology disclosed herein was tested in an exemplary separator system and compared to a standard two-stage separator system consistent with previous technology. A cross-sectional view of a standard two-stage separator 2100 is shown in FIG. 29. The separator 2100 incorporates a pleated tubular filter media 2156 having an inlet formed by an outer cylindrical boundary 2152 of the filter assembly and an outlet 2154 defined in a central opening 2158 of the tubular filter media. Retention elements 2126 on each end of the separator housing 2110 sealably receive a first end 2151 and a second end 2153 of the filter assembly 2150 to direct airflow through the filter media 2156.

[0093] Three new designs generally consistent with the present technology were tested against the standard design. The filter assemblies and separator housings tested were similarly dimensioned. The three filter assemblies consistent with the present disclosure were not tubular filter elements with radial inlets as in the standard design. Rather, each of the new filter elements was an axial flow filter with an inlet flow face having an axial length (as disclosed herein), and some of the internal seals and support structures for the standard design were not necessary for the new design. Each of the tested filter assemblies consistent with the present disclosure was constructed from a filter media with a single facer media structure, such as that shown and described with respect to FIG. 6C above, that is spiraled around a central axis.

[0094] The first new design (referred to in the tables below as "New No. 1") was a filter assembly generally consistent with that described with respect to FIG. 2. The filter assembly was mounted in a separator housing consistent with that shown and described with respect to FIG. 29 above, with a retaining element on each end of the separator housing that received the first and second ends (inlet flow faces) of the filter assembly. However, there was no seal between the retaining element and the inlet flow faces of the filter assembly. For the second design (referred to in the tables below as "New No. 2"), the filter assembly was the same as the first design, but the retaining element on the second end of the separator housing (that received the inlet flow face of the filter assembly in the first new design, and the second end of the filter element in the standard design) was removed from the separator housing.

[0095] The third novel design (referred to as "New No. 3" in the table below) was a filter assembly generally consistent with that described with respect to FIG. 2. The filter assembly 2250 was mounted in a separator housing 2210 generally consistent with that shown in FIG. 28. The retaining element consistent with that discussed above with respect to FIG. 29 was omitted. However, the housing 2210 has a centering feature 2290 extending axially from the second end 2214 of the housing 2210 toward the first end 2212 of the housing 2210. The centering feature 2290 engages the distal end of the inlet flow face 2252 to maintain the positioning of the distal end of the inlet flow face 2252. Furthermore, the access cover 2270 of the housing 2210 was tapered inwardly toward the central axis z. The inlet and outlet of the separator housing 2210 were enlarged compared to the other tested systems.

[0096] The initial pressure drop (dP), the dust on the element after the test ("element gain"), the total dust fed into the system, and the separation efficiency were measured. The air flow rate for each test was set at 4.94 cubic meters per minute. Table 1 below shows the results.

[0097] [Table 1]

[0098] The data shows that new designs #1 and #2 have a higher initial pressure drop than the standard design but increased separation efficiency of the system, which can contribute to longer filter life. New design #3 has a lower initial pressure drop than the standard design but a higher separation efficiency. New design #3 has 12% more dust on the element compared to the standard design and 26% more total dust fed into the system versus the standard design tested.

[0099] FIG. 7 illustrates another exemplary filter assembly 300 consistent with the technology disclosed herein. The filter assembly 300 is a panel filter assembly. The filter assembly 300 is constructed from a filter media 310 defining a first flow surface 320, a second flow surface 330, and a plurality of flutes 340 extending from the first flow surface 320 to the second flow surface 330. In this example of FIG. 7, the first flow surface 320 is defined on a first end 302 of the filter assembly 300, and the second flow surface 330 is defined on an opposite second end 304 of the filter assembly 300. In this example of FIG. 7, the first flow surface 320 is non-planar and the second flow surface 330 is generally planar, although in some other embodiments, each of the first flow surface 320 and the second flow surface 330 may be non-planar. The first flow surface 320 has a flow surface length L in the Z direction. In this example, the first flow face 320 does not define a taper from the first end towards the second end for at least a portion of the axial flow face length.

[0100] The filter media 310 is a plurality of sheets of filter media. In particular, the plurality of sheets of filter media includes alternating fluted sheets 352 of filter media and alternating facing sheets 354 of filter media. The plurality of sheets of filter media are in a laminated configuration. Each of the plurality of sheets of filter media is discontinuous. Each sheet of filter media has a first edge 312 that defines a first flow surface 320 of the filter assembly 300. In this embodiment, each sheet of filter media has a second edge 314 that defines a second flow surface 330 of the filter assembly 300. The plurality of sheets of filter media cumulatively define a plurality of flutes 340. Each of the plurality of flutes 340 defines a flute opening 342 and a flute closure 370, where a portion of the facing sheet 354 has been cut away from the fluted sheet 352 to allow the exemplary flute closure 370 to be seen. Each of the plurality of flutes 340 defines a flute distance that extends from the first flow surface 320 to the second flow surface 330. In this example, the plurality of flutes 340 are generally parallel. The plurality of flutes 340 may be upstream flutes or downstream flutes.

[0101] The plurality of flutes 340 defined by the plurality of sheets of filter media are arranged in a regularly alternating pattern of flute layers. The first flute layers 350 regularly alternate with the second flute layers 360. The first flute layers 350 each have a first layer distance L between the first flow surface 320 and the second flow surface 330. 1 Each of the second layers has a second layer distance L between the first flow surface 320 and the second flow surface 330. 2 In this example, the first layer distance L 1 is the second layer distance L 2 In another example, the first layer distance L 1 is the second layer distance L 2 Larger than the first layer distance L 1 and the second layer distance L 2 Typically, the first layer distance L differs by more than 2 mm. 1 is the second layer distance L 2 In some embodiments, the first layer L1 is the second layer distance L 2 In some embodiments, the first layer distance L 1 is the second layer distance L 2 In some such embodiments, the first layer distance L 1 is the second layer distance L 2 differs by at least 14 mm.

[0102] Each flute in the first fluted layer 350 is defined by a fluted sheet 352 and an adjacent facing sheet 354. Similarly, each of the second layers 360 is defined by a fluted sheet 362 and an adjacent facing sheet 364. In the example of FIG. 7, each fluted sheet and facing sheet of each fluted layer defines a substantially equal distance between the first flow surface 320 and the second flow surface 330. However, in some embodiments, each fluted sheet and facing sheet of at least one fluted layer defines a distance that differs by more than 2 mm. Also, in the embodiment of FIG. 7, each fluted layer defines a substantially constant distance between the first flow surface 320 and the second flow surface 330 in the depth direction d (represented by an arrow in FIG. 7). This means that the distance defined by each fluted layer between the first flow surface 320 and the second flow surface 330 is equal to the flute distance between the first flow surface 320 and the second flow surface 330 of each flute in the fluted layer. However, in some embodiments, the distance defined between the first flow surface and the second flow surface for one or more sheets of filter media may vary in depth, in which case the flute distance between the first flow surface and the second flow surface may be used to characterize the fluted layer.

[0103] 7, the multiple sheets of filter media further define a third fluted layer 380 that regularly alternates with the first fluted layer 350 and the second fluted layer 360. Each third fluted layer 380 has a third layer distance L between the first flow surface 320 and the second flow surface 330. 3 In this embodiment, the third layer distance L 3is the first layer distance L 1 Larger, third layer distance L 3 is the second layer distance L 2 3. The third layer distance L is smaller than the third layer distance L, but as explained, other relative relationships are possible. 3 is the first layer distance L 1 and the second layer distance L 2 and differs by more than 2 mm.

[0104] Furthermore, in the present example of FIG. 7, the multiple sheets of filter media define a regularly alternating pattern of fourth fluted layers 390, each fourth fluted layer having a fourth layer distance L between the first flow surface 320 and the second flow surface 330. 4 The fourth layer distance L is defined as 4 is the first layer distance L 1 , the second layer distance L 2 , and the third layer distance L 3 4. Fourth layer distance L 4 is the first layer distance L 1 , the second layer distance L 2 , and the third layer distance L 3 and differs by more than 2 mm. Similar to the first fluted layer 350 and the second fluted layer 360, the third fluted layer 380 and the fourth fluted layer 390 each have a fluted sheet 382, ​​392 and a facing sheet (not visible). In alternative embodiments, additional or fewer fluted layers can be incorporated into a filter assembly consistent with the present technology. In this example (and the example discussed with reference to FIG. 9a below), each regularly alternating layer defines a different distance between the first flow surface 320 and the second flow surface 330, although in some examples, two or more regularly alternating layers can define the same distance between the first flow surface and the second flow surface.

[0105] In various embodiments, a filter assembly having layers and flow faces generally consistent with the above description of FIG. 7 can be incorporated into a two-stage separator system when modified to define a central axis and an outer radial barrier surface between a first and second flow face. FIG. 8 shows a schematic cross-sectional view of such a filter assembly 300a, where the cross-section is perpendicular to the axial direction between the first and second flow faces. The filter assembly 300a has a central axis Z extending axially between the flow faces, and an outer radial barrier surface 359 extending about the central axis Z between a first flow face, such as an inlet flow face, and a second flow face, such as an outlet flow face (not shown here, but similar to that shown in FIG. 3). At least one of the flow faces (which can be configured to form an inlet flow face in the separator system) has an axial flow face length L (which can be the same as the flow face length in FIG. 7).

[0106] To achieve a configuration consistent with Figure 8, in some examples, the sides extending between the first and second flow faces of the panel filter assembly 300 consistent with Figure 7 can be cut using a laser cut or sharp edges to form a circular cross section. To promote helical air flow around the filter element toward the second end of the separator housing (as described above with respect to Figure 2), a sleeve can define the outer radial barrier surface 359 of the filter assembly 300a. The sleeve can be consistent with the sleeve discussed above with respect to Figure 2.

[0107] The examples shown and described below in connection with Figures 9A-13 also depict panel filter assemblies. Similar to the discussion above for Figure 8, each of these panel filter assemblies can be configured for incorporation into a two-stage separator system by (1) configuring the sides of the panels between the flow faces to form a circular cross-sectional shape having a central axis, and (2) incorporating (for example) a sleeve to define an outer radial barrier surface extending between the inlet and outlet flow faces. In such embodiments, at least one flow face has an axial length.

[0108] 9a shows a perspective view and FIG. 9b shows a front view of another exemplary filter assembly 400 at a first flow face 420 of the exemplary filter assembly 400 consistent with the technology disclosed herein. The filter assembly 400 is a panel filter assembly. The filter assembly 400 is constructed from a filter media 410 defining a first flow face 420, a second flow face 430, and a plurality of flutes 440 extending axially from the first flow face 420 to the second flow face 430. The first flow face 420 is defined on a first end 402 of the filter assembly 400, and the second flow face 430 is defined on an opposite second end 404 of the filter assembly 400. 8, both the first flow surface 420 and the second flow surface 430 are non-planar, but in some other embodiments, only one of the first flow surface 420 and the second flow surface 430 is non-planar and the other of the first flow surface 420 and the second flow surface 430 is planar. A1 , L A2 Neither first flow face 420 nor second flow face 430 defines a taper along at least a portion of their respective axial flow face lengths.

[0109] The filter media 410 is a plurality of sheets of filter media. In particular, the plurality of sheets of filter media comprises fluted sheets of filter media. The plurality of sheets of filter media are in a stacked configuration. The plurality of sheets of filter media are continuous with respect to one another. Each sheet of filter media has a first fold 412 that defines a first flow surface 420 of the filter assembly 400. In this embodiment, each sheet of filter media has a second fold 414 that defines a second flow surface 430 of the filter assembly 400. The plurality of sheets of filter media 410 cumulatively define a plurality of flutes 440. Each of the plurality of flutes 440 defines a flute opening 442 and a flute closure 470, the flute closure 470 being defined between a pair of the first folds 412 of the first flow surface 420 and a pair of the second folds 414 of the second flow surface 430. In some alternative embodiments, the flute closure can be defined by a single fold line separating adjacent sheets of filter media. In this example, the flutes 440 are generally parallel. The flutes 440 can be upstream flutes or downstream flutes.

[0110] The multiple sheets of filter media define a regularly alternating pattern of first fluted layers 450 and second fluted layers 460. Each first fluted layer 450 has a first layer distance L between the first flow surface 420 and the second flow surface 430. 1 Each of the second flute layers 460 has a second layer distance L between the first flow surface 420 and the second flow surface 430. 2 The second layer distance L 2 In this example, the first layer distance L 1 Although smaller, in some embodiments, the second layer distance L 2 is the first layer distance L 1 Larger than the first layer distance L 1 and the second layer distance L 2 Typically, the first layer distance L differs by more than 2 mm. 1 is the second layer distance L 2 In some embodiments, the first layer L 1 is the second layer distance L2 In some embodiments, the first layer distance L 1 is the second layer distance L 2 In some such embodiments, the first layer distance L 1 is the second layer distance L 2 is at least 14 mm different.

[0111] Each of the first fluted layers 450 is defined by a first fluted sheet 452 and an adjacent second fluted sheet 454. Similarly, each of the second fluted layers 460 is defined by a third fluted sheet 462 and an adjacent fourth fluted sheet 464. As with the embodiment described above with respect to FIG. 7, in the present embodiment of FIG. 9a, each fluted layer defines a substantially constant distance between the first flow surface 420 and the second flow surface 430 in the depth direction d2. This means that the distance defined by each fluted layer is equal to the flute distance between the first flow surface 420 and the second flow surface 430 of each flute in the fluted layer. However, in some embodiments, the distance defined by one or more sheets of filter media between the first flow surface 420 and the second flow surface 430 may vary in the depth direction d2.

[0112] Similar to the previous example shown in FIG. 7, additional alternating flute layers can be incorporated into a filter assembly consistent with the technology disclosed herein.

[0113] FIG. 10 shows a perspective view of yet another exemplary filter assembly 700 consistent with the technology disclosed herein. The filter assembly 700 is a panel filter constructed from multiple sheets of filter media 710 in a stacked configuration that cumulatively defines a first plurality of flutes 740, a first flow face 720, and a second flow face 730 opposite the first flow face relative to the filter assembly 700. The multiple stacked sheets of filter media 710 are alternating fluted sheets of filter media and facing sheets of filter media. The multiple stacked sheets of filter media 710 are discontinuous. In various embodiments, at least one of the first flow face 720 and the second flow face 730 is non-planar. In this example, the first flow face 720 defines a flow face length L. The first flow face 720 defines a taper for at least a portion of the axial flow face length L. The taper increases for at least a portion of the axial flow face length, and the taper varies continuously along the axial flow face length.

[0114] Each of the first plurality of flutes 740 defines a flute opening 742 at the first flow surface 720 and a flute closure 744 near the second flow surface 730. In some embodiments, at least one flute 745 of the plurality of flutes 740 defines a flute opening 742 that is non-planar. Each of the first plurality of flutes 740 defines a flute distance from the first flow surface 720 to the second flow surface 730. Each sheet of filter media 710 can be characterized as having a width extending in a direction parallel to the x-axis and a length extending in a direction parallel to the z-axis. The multiple sheets of filter media 710 are stacked in a direction parallel to the y-axis.

[0115] In some embodiments, the filter assembly 700 includes at least a first sheet of filter media 750 and a second sheet of filter media 760 that mutually define a first flow face 720, a second flow face 730, and a portion of the first plurality of flutes 740. In this example, the first sheet of filter media 750 is a fluted sheet and the second sheet of filter media 760 is a facing sheet. The first flutes 741 of the first plurality of flutes 740 are spaced apart by a first flute distance d1 and a second flute 743 of the first plurality of flutes 740 defines a second flute distance d 2 In this example, the first flute distance d 1 is the second flute distance d 2 Although larger, in some other examples, the first flute distance d 1 is the second flute distance d 2 First flute distance d 1 and the second longitudinal groove distance d 2 In some embodiments, the first flute distance d 1 and the second longitudinal groove distance d 2 In some embodiments, the first flute distance d 1 and the second longitudinal groove distance d 2 In some embodiments, the first flute distance d 1 and the second longitudinal groove distance d 2 In some embodiments, the first flute distance d 1 and the second longitudinal groove distance d 2 differ by at least 15 mm.

[0116] The filter assembly 700 also includes a third sheet of filter media 770, where the third sheet of filter media and the second sheet of filter media 760 mutually define a second plurality of flutes 780, a first flow face 720, and a second flow face 730. Each of the second plurality of flutes 780 extends from the first flow face 720 to the second flow face 730. Each of the second plurality of flutes 780 defines a flute opening (not visible in this view) at the second flow face 730 and a flute closure near the first flow face 720. The flute closure may be an obstruction disposed between the second sheet of filter media 760 and the third sheet of filter media 770 near the first flow face 720. The second plurality of flutes 780 defines a third flute distance d between the first flow face 720 and the second flow face 730. 3 In this example, the third flute distance d 3 is the first flute distance d1 and the second longitudinal groove distance d 2 Although larger, alternating relative relationships between the flute distances are contemplated, as above. First flute distance d 1 is the third flute distance d 3 In some embodiments, the first flute distance d 1 , second flute distance d 2 , and the third flute distance d 3 Each of the first flute distances d differs by more than 2 mm. 1 is the second flute distance d 2 and the third longitudinal groove distance d 3 and the amounts and ranges set forth herein above.

[0117] 10, the second flute 743 is adjacent to the first flute 741 in the x-axis direction, while in some other embodiments the second flute 743 is not adjacent to the first flute 741. In some embodiments the third flute 747 is positioned in the y-axis direction relative to the first flute 741, while in other embodiments the third flute 747 is not positioned in the y-axis direction relative to the first flute 741. In some alternative embodiments the third flute 747 can be a flute of the first plurality of flutes 740.

[0118] In this example, the first flow surface 720 is non-planar and the second flow surface 730 is planar. In alternative exemplary embodiments, both the first flow surface and the second flow surface are non-planar. In some embodiments, the first flow surface and the second flow surface are planar and non-parallel to one another. In various embodiments, the plurality of flutes 740 are parallel, while in some embodiments, the plurality of flutes 740 are non-parallel.

[0119] Similar to the embodiment shown in Figures 3-4b, the filter assembly 700 is generally constructed to define a fluid pathway 718 between a first flow surface 720 and a second flow surface 730 through the filter media 710 such that fluid is filtered by the filter media 710.

[0120] In various embodiments, at least one of the first flow surface 720 and the second flow surface 730 is planar. In an example consistent with the particular embodiment of FIG. 10, the first flow surface 720 is planar, the second flow surface 730 is planar, and the first flow surface 720 is non-parallel to the second flow surface 730. In alternative embodiments, one or both of the first flow surface and the second flow surface can be non-planar. For example, one or both of the first flow surface and the second flow surface can be cut to be a three-dimensional surface.

[0121] FIG. 11 illustrates a perspective view of yet another exemplary filter assembly 800 consistent with the technology disclosed herein. The filter assembly 800 is a panel filter constructed from multiple sheets of filter media 810 in a stacked configuration defining a first plurality of flutes 840, a first flow face 820, and a second flow face 830 opposite the first flow face relative to the filter assembly 800. The multiple stacked sheets of filter media 810 are fluted sheets of filter media. The multiple stacked sheets of filter media 810 are discontinuous. In various embodiments, at least one of the first flow face 820 and the second flow face 830 is non-planar, and in this embodiment, both the first flow face 820 and the second flow face 830 are non-planar. Each of the first flow face 820 and the second flow face 830 has an axial flow face length (see, e.g., L). Each of the first flow face 820 and the second flow face 830 defines an axial taper.

[0122] The multiple sheets of filter media 810 cumulatively define multiple flutes 840. Each of the first multiple flutes 840 defines a flute opening 842 at the first flow surface 820 and a flute closure (not shown) near the second flow surface 830, where the flute closure is similar to that shown in at least FIGS. 4a and 6b above. In some embodiments, at least one flute 845 of the multiple flutes 840 defines a flute opening 842 that is non-planar. Each of the first multiple flutes 840 defines a flute distance from the first flow surface 820 to the second flow surface 830. Each sheet of filter media 810 can be characterized as having a width extending in a direction parallel to the x-axis and a length extending in a direction parallel to the z-axis. The multiple sheets of filter media 810 are stacked in a direction parallel to the y-axis.

[0123] In some embodiments, filter assembly 800 includes at least a first sheet of filter media 850 and a second sheet of filter media 860 that mutually define a first flow face 820, a second flow face 830, and a portion of a first plurality of flutes 840. In this example, first sheet of filter media 850 and second sheet of filter media 860 are both fluted sheets. A first flute 841 of a portion of first plurality of flutes 840 is spaced apart by a first flute distance d 1 and a second flute 843 of the first plurality of flutes 840 defines a second flute distance d 2 In this example, the first flute distance d 1 is the second flute distance d 2 Although larger, in some other embodiments, the first flute distance d 1 is the second flute distance d 2 First flute distance d 1 and the second longitudinal groove distance d 2 can vary by more than 2 mm and further vary in the amounts and ranges set forth above.

[0124] The filter assembly 800 also includes a third sheet of filter media 870, where the third sheet of filter media and the second sheet of filter media 860 mutually define a second plurality of flutes 880, a first flow face 820, and a second flow face 830. Each of the second plurality of flutes 880 extends from the first flow face 820 to the second flow face 830. Each of the second plurality of flutes 880 defines a flute opening (not visible in this view) at the second flow face 830 and a flute closure near the first flow face 820. The flute closure may be an obstruction disposed between the second sheet of filter media 860 and the third sheet of filter media 870 near the first flow face 820.

[0125] The second plurality of flutes 880 are spaced apart by a third flute distance d between the first flow surface 820 and the second flow surface 830. 3 In this example, the third flute distance d 3 is the first flute distance d1 and the second flute distance d 2 Although larger, alternating relative relationships between the flute distances are contemplated. First flute distance d 1 is the third flute distance d 3 In some embodiments, the first flute distance d 1 , second flute distance d 2 , and the third flute distance d 3 Each of the first flute distances d differs by more than 2 mm. 1 is the second flute distance d 2 and the third longitudinal groove distance d 3 and the amounts and ranges set forth herein above.

[0126] In this example, the second flute 843 is adjacent to the first flute 841 in the x-axis direction, but in some other embodiments, the second flute 843 is not adjacent to the first flute 841. In some embodiments, the third flute 847 is positioned in the y-axis direction relative to the first flute 841, but in other embodiments, the third flute 847 is not positioned in the y-axis direction relative to the first flute 841. In some alternative embodiments, the third flute 847 can be a flute of the first plurality of flutes 840.

[0127] In this example, first flow surface 820 is non-planar and second flow surface 830 is non-planar. In particular, first flow surface 820 is concave relative to filter assembly 800. Similarly, second flow surface 830 is concave relative to the filter assembly. In alternative examples, the first and second flow surfaces are both planar and non-parallel to one another. In some embodiments, first plurality of flutes 840 are parallel, while in some embodiments, first plurality of flutes 840 are non-parallel.

[0128] Similar to the above embodiments, the filter assembly 800 is generally constructed to define a fluid pathway 818 between a first flow surface 820 and a second flow surface 830 through the filter media 810 such that fluid is filtered by the filter media 810.

[0129] The exemplary filter assembly described and depicted in Figures 9 and 10 can be constructed by a variety of different approaches. In at least one embodiment, the flute plug is placed between adjacent sheets of filter media in the appropriate location, and the sheets of filter media are stacked. The stacked media is then cut with a cutting tool (an example of which was discussed above with respect to Figure 5) to form the first and / or second flow faces into the desired configuration. In an alternative embodiment, the edges of the sheets of filter media corresponding to the flow faces are cut into the desired configuration, and then the cut sheets of media are stacked to form the filter assembly. The flute plug can be placed on the sheets of filter media before or after the sheets of filter media are cut.

[0130] 12 illustrates a perspective view of yet another exemplary filter assembly 900 consistent with the technology disclosed herein. The filter assembly 900 is a panel filter constructed from multiple sheets of filter media 910 in a stacked configuration that defines a first plurality of flutes 940, a first flow face 920 of the filter assembly 900, and a second flow face 930 opposite the first flow face 920 relative to the filter assembly 900. The multiple sheets of filter media 910 are fluted sheets of filter media. In various embodiments, at least one of the first flow face 920 and the second flow face 930 is non-planar, and in this embodiment, the first flow face 920 is non-planar and the second flow face 930 is planar. The first flow face 920 has an axial flow face length L extending in the axial direction Z. The first flow face 920 defines a taper along at least a portion of the axial flow face length.

[0131] The multiple sheets of filter media 910 are continuous with respect to one another. Each sheet of filter media has a first fold 912 that defines a first flow face 920 of the filter assembly 900. Each sheet of filter media 910 has a second fold 914 (only a small portion of which is visible) that defines a second flow face 930 of the filter assembly 900. Each of the first multiple flutes 940 defines a flute opening 942 at the first flow face 920 and a flute closure 916 near the second flow face 930. The flute closure 916 is defined by the filter media on the second flow face 930, with the filter media extending between adjacent second folds 914 on the second flow face 930.

[0132] In some embodiments, at least one flute 945 of the plurality of flutes 940 defines a flute opening 942 that is non-planar. Each of the first plurality of flutes 940 defines a flute distance from the first flow surface 920 to the second flow surface 930. Each sheet of filter media 910 can be characterized as having a width extending in a direction parallel to the x-axis and a length extending in a direction parallel to the z-axis. The multiple sheets of filter media 910 are stacked in a direction parallel to the y-axis.

[0133] In some embodiments, the filter assembly 900 includes at least a first sheet of filter media 950 and a second sheet of filter media 960 that mutually define a first flow face 920, a second flow face 930, and a portion of the first plurality of flutes 940. In this example, the first sheet of filter media 950 and the second sheet of filter media 960 are both fluted sheets. A first flute 941 of the portion of the first plurality of flutes 940 is spaced apart by a first flute distance d 1 and a second flute 943 of the first plurality of flutes 940 defines a second flute distance d 2 In this example, the first flute distance d 1 is the second flute distance d 2 Although smaller, in some other examples, the first flute distance d 1 is the second flute distance d 2 First flute distance d 1and the second longitudinal groove distance d 2 can vary by more than 2 mm and further vary in the amounts and ranges set forth above.

[0134] The filter assembly 900 also includes a third sheet of filter media 970, where the third sheet of filter media and the second sheet of filter media 960 mutually define a second plurality of flutes 980, a first flow face 920, and a second flow face 930. Each of the second plurality of flutes 980 extends from the first flow face 920 to the second flow face 930. Each of the second plurality of flutes 980 defines a flute opening (not visible in this view) at the second flow face 930 and a flute closure 916 near the first flow face 920. The flute closure may be an obstruction disposed between the second sheet of filter media 960 and the third sheet of filter media 970 near the first flow face 920. In this embodiment, the flute closure 916 is a portion of the filter media defined by one or more folds 912, similar to that described with respect to Figures 9a and 9b. The second plurality of flutes 980 are spaced apart by a third flute distance d between the first flow surface 920 and the second flow surface 930. 3 In this example, the third flute distance d 3 is the first flute distance d 1 and the second longitudinal groove distance d 2 Although larger, alternating relative relationships between the flute distances are contemplated. First flute distance d 1 is the third flute distance d 3 In some embodiments, the first flute distance d 1 , second flute distance d 2 , and the third flute distance d 3 Each of the first flute distances d differs by more than 2 mm. 1 is the second flute distance d 2 and the third longitudinal groove distance d 3 and the amounts and ranges set forth herein above.

[0135] 12, the second flute 943 is adjacent to the first flute 941 in the x-axis direction, while in some other embodiments the second flute 943 is not adjacent to the first flute 941. In some embodiments the third flute 981 is positioned in the y-axis direction relative to the first flute 941, while in other embodiments the third flute 981 is not positioned in the y-axis direction relative to the first flute 941. In some alternative embodiments the third flute 981 can be a flute of the first plurality of flutes 940.

[0136] 12, the first flow surface 920 is non-planar and the second flow surface 930 is planar. In alternative exemplary embodiments, the first flow surface and the second flow surface are both planar and non-parallel to one another. In some embodiments, the first plurality of flutes 940 are parallel, while in some alternative embodiments, the first plurality of flutes 940 are non-parallel. Also, in this embodiment, the filter media is pleated, while in some other embodiments, the media is not pleated.

[0137] Similar to the above embodiments, the filter assembly 900 is generally constructed to define a fluid pathway 918 between a first flow surface 920 and a second flow surface 930 through the filter media 910 such that fluid is filtered by the filter media 910.

[0138] 13 shows a perspective view of yet another exemplary filter assembly 1000 consistent with the technology disclosed herein. The filter assembly 1000 is a panel filter constructed from multiple sheets of filter media 1010 in a stacked configuration that defines a first plurality of flutes 1040, a first flow face 1020 of the filter assembly 1000, and a second flow face 1030 opposite the first flow face 1020 relative to the filter assembly 1000. The multiple sheets of filter media 1010 are fluted sheets of filter media. In this embodiment, the first flow face 1020 is planar, the second flow face 1030 is planar, and the first flow face 1020 is non-parallel to the second flow face 1030. The first flow face 1020 has a flow face length L. The first flow face 1020 defines a taper along at least a portion of the axial flow face length.

[0139] The multiple sheets of filter media 1010 are continuous with respect to one another. Each sheet of filter media has a first fold 1012 that defines a first flow face 1020 of the filter assembly 1000. Each sheet of filter media 1010 has a second fold 1014 (only a small portion of which is visible) that defines a second flow face 1030 of the filter assembly 1000. Each of the first multiple flutes 1040 defines a flute opening 1042 at the first flow face 1020 and a flute closure 1016 near the second flow face 1030. The flute closure 1016 is defined by the filter media on the second flow face 1030, where the filter media extends between adjacent second folds 1014 on the second flow face 1030. The flute closure 1016 may be similar to that described in the discussion of Figures 9a and 9b.

[0140] Each of the first plurality of flutes 1040 defines a flute distance from the first flow surface 1020 to the second flow surface 1030. Each sheet of filter media 1010 can be characterized as having a width extending in a direction parallel to the x-axis and a length extending in a direction parallel to the z-axis. The multiple sheets of filter media 1010 are stacked in a direction parallel to the y-axis.

[0141] In some embodiments, the filter assembly 1000 includes at least a first sheet of filter media 1050 and a second sheet of filter media 1060 that mutually define a first flow face 1020, a second flow face 1030, and a portion of the first plurality of flutes 1040. In this example, the first sheet of filter media 1050 and the second sheet of filter media 1060 are both fluted sheets. A first flute 1041 of the portion of the first plurality of flutes 1040 is spaced apart by a first flute distance d 1 and a second flute 1043 of the first plurality of flutes 1040 defines a second flute distance d 2 In this example, the first flute distance d 1 is the second flute distance d 2 In some other embodiments, the first flute distance d 1 is the second flute distance d 2 First flute distance d 1 and the second longitudinal groove distance d 2 can vary by more than 2 mm and further vary in the amounts and ranges set forth above.

[0142] The filter assembly 1000 also includes a third sheet of filter media 1070, where the third sheet of filter media and the second sheet of filter media 1060 mutually define a second plurality of flutes 1080, a first flow face 1020, and a second flow face 1030. Each of the second plurality of flutes 1080 extends from the first flow face 1020 to the second flow face 1030. Each of the second plurality of flutes 1080 defines a flute opening (not visible in this view) at the second flow face 1030 and a flute closure 1016 near the first flow face 1020. The flute closure may be an obstruction disposed between the second sheet of filter media 1060 and the third sheet of filter media 1070 near the first flow face 1020. In this embodiment, the flute closure 1016 is a portion of the filter media defined by one or more folds 1012 .

[0143] The second plurality of flutes 1080 are spaced apart by a third flute distance d between the first flow surface 1020 and the second flow surface 1030. 3 In this example, the third flute distance d 3 is the first flute distance d 1 and the second longitudinal groove distance d 2 Although smaller, in some embodiments, the third flute distance d 3 is the first flute distance d 1 and the second longitudinal groove distance d 2 The first flute distance d is greater than one or both of the first flute distance d 1 is the third flute distance d 3 In some embodiments, the first flute distance d 1 , second flute distance d 2 , and the third flute distance d 3 Each of the first flute distances d differs by more than 2 mm. 1 is the second flute distance d 2 and the third longitudinal groove distance d 3 and the amounts and ranges set forth herein above.

[0144] 13, the second flute 1043 is adjacent to the first flute 1041 in the x-axis direction, while in some other embodiments the second flute 1043 is not adjacent to the first flute 1041. In some embodiments the third flute 1081 is positioned in the y-axis direction relative to the first flute 1041, while in other embodiments the third flute 1081 is not positioned in the y-axis direction relative to the first flute 1041. In some alternative embodiments the third flute 1081 can be a flute of the first plurality of flutes 1040.

[0145] In some embodiments, the first plurality of flutes 1040 are parallel, while in some embodiments, the first plurality of flutes 1040 are non-parallel. Also, in this embodiment, the filter media is pleated, while in some other embodiments, the pleated media is not pleated and an obstruction is positioned between the sheets of filter media to seal the ends of the flutes.

[0146] Similar to the above embodiments, the filter assembly 1000 is generally constructed to define a fluid pathway 1018 between a first flow surface 1020 and a second flow surface 1030 through the filter media 1010 such that fluid is filtered by the filter media 1010.

[0147] 14A illustrates one exemplary filter assembly consistent with the technology disclosed herein. The filter assembly 500 is constructed from a filter media 510 defining a first flow face 520, a second flow face 530, and a plurality of flutes 540 extending in a vertical direction Z from the first flow face 520 to the second flow face 530. In this example, the first flow face 520 is defined on a first end 502 of the filter assembly 500, and the second flow face 530 is defined on an opposing second end 504 of the filter assembly 500. The first flow face 520 has an axial flow face length L and defines a taper along at least a portion of the axial flow face length.

[0148] The filter media 510 is a plurality of sheets of filter media, specifically a first sheet of filter media 512 and a second sheet of filter media 514. The second sheet of filter media 514, which shows a portion of the filter media 510 in a flat, unrolled arrangement, can be seen in FIG. 14B to distinguish it from the spirally wound filter media 510 of the filter assembly 500 corresponding to FIG. 14A. FIG. 14B is a front view of the second sheet of filter media 514. The second sheet of filter media 514 is adjacent to the first sheet of filter media 512. The first sheet of filter media 512 and the second sheet of filter media 514 mutually define a plurality of flutes 540. The filter media 510 defines a spiral configuration about the Z-axis. Thus, each of the first sheet of filter media 512 and the second sheet of filter media 514 defines a spiral configuration about the Z-axis. Thus, the plurality of flutes 540 are also in a spiral configuration about the Z axis.

[0149] In this example, the first sheet of filter media 512 and the second sheet of filter media 514 are spiraled around the rod 585. Thus, the rod 585 extends through the center of the filter assembly 500. The rod 585 has a proximal end positioned toward the second flow face 530 and a distal end positioned toward the first flow face 520, which may be the outlet flow face and which may be the inlet flow face 520. The rod 585 defines a handle 586 at its distal end configured to be grasped by a user during installation and removal of the filter assembly 500 in a two-stage separator system (see FIGS. 1 and 2). In such an embodiment, the separator system may define a centering feature configured to receive the handle 586, as described above with respect to FIG. 2. In some embodiments, the handle may be omitted from the filter element. In some embodiments, both the handle and the rod are omitted from the filter element.

[0150] As can be seen in FIG. 14B, the filter media 510 (specifically the first sheet of filter media 512 and the second sheet of filter media 514) are generally elongated such that the first sheet of filter media 512 and the second sheet of filter media 514 can be spiraled about a Z-axis to form a filter assembly. In this example, the first sheet of filter media 512 and the second sheet of filter media 514 are discontinuous. The first sheet of filter media 512 defines a first edge 511 and a second edge 513 (FIG. 14A). The second sheet of filter media 514 defines a third edge 515 and a fourth edge 517 (FIG. 14B). The first edge 511 and the third edge 515 mutually define a first flow face 520 of the filter assembly 500. The second edge 513 and the fourth edge 517 mutually define a second flow face 530 of the filter assembly 500. The first edge 511 and the third edge 515 each individually form an undulating or corrugated line. The second edge 513 and the fourth edge 517 each individually form a straight line. An example filter media 510 consistent with this embodiment has four edges. The shape of the filter media 510 is generally non-rectangular and non-trapezoidal due to the undulating / corrugated edges. In particular, the first edge 511 and the third edge 515 mutually define a plurality of concave and convex shapes.

[0151] In examples consistent with this embodiment, a first sheet of filter media 512 is fluted and a second sheet of filter media 514 is the facing sheet. In this embodiment, the flutes are parallel, but in some other embodiments, the flutes are non-parallel.

[0152] The filter assembly 500 is generally constructed to define a fluid pathway 506 between a first flow face 520 and a second flow face 530 through the filter media 510 such that fluid is filtered by the filter media 510. In particular, the plurality of flutes 540 define either inlet flutes or outlet flutes, similar to those described in FIG.

[0153] Each of the plurality of flutes 540 defines a flute opening 542 and a flute closure (not visible). The flute opening 542 forms the extreme end of the fluid path 506 along the flute and accommodates fluid flow to or from the filter assembly 500. The flute closure blocks fluid flow along the flute, thereby defining a portion of the fluid path 506 through the filter media 510. So, for example, the plurality of inlet flutes can define flute openings 542 at the first flow face 520, and a flute closure is defined across the plurality of inlet flutes near the second flow face 530. In some embodiments, the flute closure is adjacent the second flow face 530. More specifically, the flute closure can abut the second flow face 530. The flute closure can be similar to the flute closure discussed above.

[0154] In this embodiment, the volume defined between an outer surface 516 of a first sheet of filter media 512 (FIG. 14A) and an outer surface 518 of a second sheet of filter media 514 (FIG. 14B) defines a fluid pathway 506 that is not necessarily characterized by being defined by a plurality of flutes when the filter media is coiled (FIG. 14A).

[0155] The obstructions may be disposed within the convolutions and outside of the plurality of flutes 540 such that fluid passing through the first and second flow faces 520, 530 of the filter assembly 500 must first pass through the filter media 510. Additional obstructions may also be disposed around the periphery of the filter assembly 500, in any other gaps in the filter media, such as in the central opening of the filter assembly 500, to block fluid flow therethrough. The obstructions may be formed by placing an adhesive, such as an adhesive bead, in the appropriate location.

[0156] Each of the plurality of flutes 540 defines a flute distance between the first flow surface 520 and the second flow surface 530. In this embodiment, a first flute 544 of the plurality of flutes 540 defines a first flute distance D between the first flow surface 520 and the second flow surface 530. 1and a second flute 546 of the plurality of flutes 540 defines a second flute distance D between the first flow surface 520 and the second flow surface 530. 2 In some embodiments, the first flute distance D 1 is the second flute distance D as shown herein 2 In some other embodiments, the first flute distance D 1 is the second flute distance D 2 In one embodiment, the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 and 3mm~520mm, 510mm~520mm, or 15mm~25mm.

[0157] In some embodiments, the third flute 548 of the plurality of flutes 540 is spaced apart from the first flow surface 520 by a third flute distance D 3 Define the third flute distance D 3 is generally the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 The third flute distance D differs from both by more than 2 mm. 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 In this example, the third flute distance D 3 is the first flute distance D 1 Larger, second flute distance D 2 Less than.

[0158] The difference in flute distance between the first flow surface 520 of the filter assembly 500 and the second flow surface 530 of the filter assembly 500 is also evidenced by the shape of the flow surfaces relative to one another. In various embodiments, at least one of the first flow surface 520 and the second flow surface 530 is non-planar. In various embodiments, at least one of the first flow surface 520 and the second flow surface 530 is generally planar. In examples consistent with this particular embodiment, the first flow surface 520 is non-planar and the second flow surface 530 is planar. Furthermore, in this particular embodiment, the first flow surface 520 is configured such that the first flow surface 520 protrudes outward from the filter assembly in the axial direction Z. The shape of the first flow surface 520 is generally asymmetric with respect to the Z axis.

[0159] 26a and 26b show an exemplary cross section of an exemplary filter assembly 500 mounted in a housing similar to housing 1910 shown in FIGS. 1-2, where the cross section is perpendicular to a z-axis centered through housing 1910 and filter assembly 500. Filter assembly 500 has a first flow face 520 that does not mirror a flute profile. FIG. 26a shows a first position P along the axial length of first flow face 520. 1 26b is a first cross-section taken at a second location P along the axial length of the first flow surface 520. 2 26a is a second cross-section taken at 100° C. The annulus defined between first flow surface 520 and housing 1910 in a cross-section perpendicular to the z-axis has an increasing area A along at least a portion of the length of first flow surface 520 from the first side to the second side of housing 1910. In particular, the annulus defined between first flow surface 520 and housing 1910 in FIG. 26a is a second cross-section taken at 100° C. 1 Ring A in 1 The area of ​​the 2 Ring A in 2 is smaller than the area of

[0160] Furthermore, at a first position P along the axial length of the inlet flow surface 520 1 and the second position P 2A radial distance R defined between the first flow surface 520 and the housing 1910 with respect to the central axis z at 1、2 The second radial distance R 2 is the first radial distance R 1 is greater than the first radial distance R 1 and a second radial distance R 2 are axially aligned and parallel.

[0161] It will be appreciated that in some alternative embodiments, first flow surface 520 can be planar and second flow surface 530 can be non-planar. In some embodiments, at least one flute of plurality of flutes 540 defines a flute opening that is non-planar.

[0162] In an example consistent with the present embodiment, obstruction 549 is disposed along the length of second sheet of media 514 adjacent fourth edge 517 of second sheet of media 514. When filter media 510 is in a spiral configuration, fourth edge 517 of second sheet of media 514 is generally planar. Here, when filter media 510 is in a spiral configuration, obstruction 549 is also generally planar.

[0163] 15A illustrates an example filter assembly 550 consistent with the technology disclosed herein, and FIG. 15B illustrates a front view of a corresponding filter media 560 in an unwrapped or planar arrangement. The filter assembly 550 is constructed from a filter media 560 defining a first flow face 570, a second flow face 580, and a plurality of flutes 590 extending from the first flow face 570 to the second flow face 580. In this example, the first flow face 570 is defined on a first end 552 of the filter assembly 550, and the second flow face 580 is defined on an opposing second end 554 of the filter assembly 550. The first flow face 570 has an axial flow face length L, and the first flow face 570 defines a taper along at least a portion of the axial flow face length L.

[0164] The filter media 560 is a plurality of sheets of filter media, specifically a first sheet of filter media 562 and a second sheet of filter media 564. The second sheet of filter media 564, which is a portion of the filter media 560 in a flat, unrolled arrangement, can be seen in FIG. 15B to distinguish it from the spirally wound filter media 560 forming the filter assembly 550 corresponding to FIG. 15A. FIG. 15B is a front view of the second sheet of filter media 564. The second sheet of filter media 564 is adjacent to the first sheet of filter media 562. The first sheet of filter media 562 and the second sheet of filter media 564 mutually define a plurality of flutes 590. The filter media 562 can have a variety of configurations, some examples of which are described in connection with FIGS. 6a-6d and below. In this embodiment, the plurality of flutes are parallel, but in some other embodiments, the plurality of flutes are not parallel.

[0165] Filter media 560 defines a spiral configuration about the Z-axis. Thus, first sheet of filter media 562 and second sheet of filter media 564 each define a spiral configuration about the Z-axis. Thus, the plurality of flutes 590 are also in a spiral configuration about the Z-axis.

[0166] As can be seen in FIG. 15B, the filter media 560 (specifically, the first sheet of filter media 562 and the second sheet of filter media 564) are generally elongated such that the first sheet of filter media 562 and the second sheet of filter media 564 can be spiraled about a Z-axis to form a filter assembly. In this example, the first sheet of filter media 562 and the second sheet of filter media 564 can be continuous or discontinuous. In embodiments where the sheets are discontinuous, the first sheet of filter media 562 defines a first edge 561 and a second edge 563 (FIG. 15A), and the second sheet of filter media 564 defines a third edge 565 and a fourth edge 567 (FIG. 15B). The first edge 561 and the third edge 565 mutually define a first flow face 570 of the filter assembly 550. Second edge 563 and fourth edge 567 mutually define second flow face 580 of filter assembly 550. Second edge 593 and fourth edge 567 each individually form a straight line that defines an edge of filter media 564.

[0167] First edge 561 and third edge 565 together and individually form a stepped line. The stepped line has a horizontal segment 572 joined by a vertical segment 574. The shape of filter media 564 is generally non-rectangular and non-trapezoidal based on the stepped edges.

[0168] Filter assembly 550 is generally constructed to define a fluid pathway 556 between a first flow face 570 and a second flow face 580 through filter media 560 such that fluid is filtered by filter media 560. In particular, a plurality of flutes 590 define either inlet flutes or outlet flutes, similar to those described above.

[0169] Each of the plurality of flutes 590 defines a flute opening 592 and a flute closure (not visible). The flute opening 592 forms the extreme end of the fluid path 556 along the flute and accommodates fluid flow to or from the filter assembly 550. The flute closure blocks fluid flow along the flute, thereby defining a portion of the fluid path 556 through the filter media 560. So, for example, the plurality of inlet flutes can define flute openings 592 at the first flow face 570, and a flute closure is defined across the plurality of inlet flutes near the second flow face 580. In some embodiments, the flute closure is adjacent the second flow face 580. More specifically, the flute closure can abut the second flow face 580. The flute closure can be similar to the flute closure discussed above.

[0170] In this embodiment, the volume defined between an outer surface 566 of a first sheet of filter media 562 (FIG. 15A) and an outer surface 568 of a second sheet of filter media 564 (FIG. 15B) defines a fluid pathway 556 that is not necessarily characterized by being defined by a plurality of longitudinal grooves when the filter media is coiled (FIG. 15A).

[0171] The obstructions may be disposed within the convolutions and outside of the plurality of flutes 590 such that fluid passing through the first flow face 570 and the second flow face 580 of the filter assembly 550 must first pass through the filter media 560. Additional obstructions may be disposed around the periphery of the filter assembly 550, in any other gaps in the filter media, such as in the central opening of the filter assembly 550, to block fluid flow therethrough. The obstructions may be formed by placing an adhesive, such as an adhesive bead, in the appropriate location.

[0172] Each of the plurality of flutes 590 defines a flute distance between the first flow surface 570 and the second flow surface 580. In this embodiment, a first flute 594 of the plurality of flutes 590 defines a first flute distance D between the first flow surface 570 and the second flow surface 580. 1and a second flute 596 of the plurality of flutes 590 defines a second flute distance D between the first flow surface 570 and the second flow surface 580. 2 In some embodiments, the first flute distance D 1 is the second flute distance D as shown herein 2 In some other embodiments, the first flute distance D 1 is the second flute distance D 2 In one embodiment, the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 and 3mm~570mm, 560mm~570mm, or 15mm~25mm.

[0173] In some embodiments, the third flute 598 of the plurality of flutes 590 is spaced apart from the first flow surface 570 by a third flute distance D 3 Define the third flute distance D 3 is generally the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 The third flute distance D differs from both by more than 2 mm. 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 In this example, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 In some other examples, the third flute distance D 3As will be understood, the first flute distance D 1 and the second longitudinal groove distance D 2 and the first longitudinal groove distance D 1 and the second longitudinal groove distance D 2 is smaller than the other.

[0174] The difference in flute distance between the first flow surface 570 of the filter assembly 550 and the second flow surface 580 of the filter assembly 550 is also evidenced by the shape of the flow surfaces relative to one another. In various embodiments, at least one of the first flow surface 570 and the second flow surface 580 is non-planar. In various embodiments, at least one of the first flow surface 570 and the second flow surface 580 is generally planar. In examples consistent with this particular embodiment, the first flow surface 570 is non-planar and the second flow surface 580 is planar. Furthermore, in this particular embodiment, the first flow surface 570 has a stepped configuration in which the first flow surface 570 defines a plurality of planes 576. Each plane can be offset in the axial direction Z from the other planes that form the first flow surface 570. The general shape of the first flow surface 520 can be radially symmetrical about the Z axis, although in some embodiments, the general shape of the first flow surface is asymmetrical about the Z axis.

[0175] It will be appreciated that in some alternative embodiments, first flow surface 570 can be planar and second flow surface 580 can be non-planar. In some embodiments, at least one flute of plurality of flutes 590 defines a flute opening that is non-planar.

[0176] In an example consistent with the present embodiment, obstruction 599 is disposed along the length of second sheet of media 564 adjacent fourth edge 567 of second sheet of media 564. Because fourth edge 567 of second sheet of media 564 is generally planar when filter media 560 is in a spiral configuration, obstruction 599 is also generally planar when filter media 560 is in a spiral configuration.

[0177] As with the previous two examples, Figure 16A illustrates one exemplary filter assembly 1800 consistent with the technology disclosed herein, where the filter assembly 1800 is a spiral wound filter media 1810, and Figure 16B illustrates a front view of the filter media 1810 in an unwound configuration. The filter assembly 1800 is constructed from a filter media 1810 defining a first flow face 1820, a second flow face 1830, and a plurality of flutes 1840 extending from the first flow face 1820 to the second flow face 1830. In this example, the first flow face 1820 is defined on a first end 1802 of the filter assembly 1800, and the second flow face 1830 is defined on an opposing second end 1804 of the filter assembly 1800. The first flow face 1820 has an axial flow face length L, and the first flow face 1820 defines a taper along at least a portion of the axial flow face length L. In this example, the taper of the first flow face 1820 increases along at least a portion of the axial flow face length L.

[0178] The filter media 1810 is a plurality of sheets of filter media, specifically a first sheet of filter media 1812 and a second sheet of filter media 1814. The second sheet of filter media 1814, which is a portion of the filter media 1810 in a planar, unrolled arrangement, can be seen in FIG. 16B. FIG. 16B is a front view of the second sheet of filter media 1814. The second sheet of filter media 1814 is adjacent to the first sheet of filter media 1812. The first sheet of filter media 1812 and the second sheet of filter media 1814 mutually define a plurality of flutes 1840. The filter media 1810 can have a variety of configurations, some examples of which are described in connection with FIGS. 6a-6d and below.

[0179] The filter media 1810 defines a spiral configuration about the Z-axis. Thus, each of the first sheet of filter media 1812 and the second sheet of filter media 1814 defines a spiral configuration about the Z-axis. Thus, the plurality of flutes 1840 are also in a spiral configuration about the Z-axis. In this embodiment, the plurality of flutes are parallel, however, in some other embodiments, the plurality of flutes are non-parallel.

[0180] As can be seen in FIG. 16B, the filter media 1810 (particularly the first sheet of filter media 1812 and the second sheet of filter media 1814) are generally elongated such that the first sheet of filter media 1812 and the second sheet of filter media 1814 can be spiraled about the Z-axis to form the filter assembly. In this example, the first sheet of filter media 1812 and the second sheet of filter media 1814 can be discontinuous. In such an embodiment, the first sheet of filter media 1812 defines a first edge 1811 and a second edge 1813 (FIG. 16A), and the second sheet of filter media 1814 defines a third edge 1815 and a fourth edge 1817 (FIG. 16B). The first edge 1811 and the third edge 1815 mutually define a first flow face 1820 of the filter assembly 1800. The second edge 1813 and the fourth edge 1817 together define a second flow face 1830 of the filter assembly 1800. The first edge 1811 and the third edge 1815 together and individually form a curve having a convex portion and a concave portion. The second edge 1813 and the fourth edge 1817 together and individually form a straight portion.

[0181] Example filter media 1810 consistent with the present embodiment has four edges, a first elongated edge 1805 (corresponding to first edge 1811 and third edge 1815), a second elongated edge 1807 (corresponding to second edge 1813 and fourth edge 1817), a first edge 1808, and a second edge 1809. The shape of filter media 1810 is generally non-rectangular and non-trapezoidal based on the curve defined by at least first elongated edge 1805.

[0182] The filter assembly 1800 is generally constructed to define a fluid pathway 1806 between a first flow face 1820 and a second flow face 1830 through the filter media 1810 such that fluid is filtered by the filter media 1810. In particular, the plurality of flutes 1840 define either inlet flutes or outlet flutes, similar to those described in FIG.

[0183] Each of the plurality of flutes 1840 defines a flute opening 1842 and a flute closure (not visible). The flute opening 1842 forms the extreme end of the fluid path 1806 along the flute and accommodates fluid flow to or from the filter assembly 1800. The flute closure blocks fluid flow along the flute, thereby defining a portion of the fluid path 1806 through the filter media 1810. So, for example, the plurality of inlet flutes can define flute openings 1842 at the first flow face 1820, and a flute closure is defined across the plurality of inlet flutes near the second flow face 1830. In some embodiments, the flute closure is adjacent the second flow face 1830. More specifically, the flute closure can abut the second flow face 1830. The flute closure can be similar to the flute closure discussed above.

[0184] In this embodiment, the volume defined between an outer surface 1816 of a first sheet of filter media 1812 (FIG. 16A) and an outer surface 1818 of a second sheet of filter media 1814 (FIG. 16B) defines a fluid pathway 1806 that is not necessarily characterized by being defined by a plurality of longitudinal grooves when the filter media is coiled (FIG. 16A).

[0185] The obstructions may be disposed within the convolutions and outside of the plurality of flutes 1840 such that fluid passing through the first flow face 1820 and the second flow face 1830 of the filter assembly 1800 must first pass through the filter media 1810. Additional obstructions may be disposed around the periphery of the filter assembly 1800, in any other gaps in the filter media, such as in the central opening of the filter assembly 1800, to block fluid flow therethrough. The obstructions may be formed by placing an adhesive, such as an adhesive bead, in the appropriate location.

[0186] Each of the plurality of flutes 1840 defines a flute distance between the first flow surface 1820 and the second flow surface 1830. In this embodiment, a first flute 1844 of the plurality of flutes 1840 defines a first flute distance D between the first flow surface 1820 and the second flow surface 1830. 1 and a second flute 1846 of the plurality of flutes 1840 defines a second flute distance D between the first flow surface 1820 and the second flow surface 1830. 2 In some embodiments, the first flute distance D 1 is the second flute distance D as shown herein 2 In some other embodiments, the first flute distance D 1 is the second flute distance D 2 In one embodiment, the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 and differs by 3mm~1020mm, 1010mm~1020mm, or 15mm~25mm.

[0187] In some embodiments, the third flute 1848 of the plurality of flutes 1840 is spaced apart from the first flow surface 1820 by a third flute distance D between the first flow surface 1820 and the second flow surface 1830.3 Define the third flute distance D 3 is generally the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 The third flute distance D differs from both by more than 2 mm. 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 In this example, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 In some other examples, as will be appreciated, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 and the first longitudinal groove distance D 1 and the second longitudinal groove distance D 2 is smaller than the other.

[0188] The difference in flute distance between the first flow surface 1820 of the filter assembly 1800 and the second flow surface 1830 of the filter assembly 1800 is also evidenced by the shape of the flow surfaces relative to one another. In various embodiments, at least one of the first flow surface 1820 and the second flow surface 1830 is non-planar. In various embodiments, at least one of the first flow surface 1820 and the second flow surface 1830 is generally planar. In examples consistent with this particular embodiment, the first flow surface 1820 is non-planar and the second flow surface 1830 is planar. Furthermore, in this particular embodiment, the first flow surface 1820 is configured such that the first flow surface 1820 projects outward from the filter assembly in the axial direction Z. The general shape of the first flow surface 1820 can be considered radially symmetrical about the Z axis.

[0189] It will be appreciated that in some alternative embodiments, the first flow surface 1820 can be planar and the second flow surface 1830 can be non-planar. In some embodiments, at least one flute of the plurality of flutes 1840 defines a flute opening that is non-planar.

[0190] In examples consistent with the present embodiment, the obstruction 1849 is disposed along the length of the second sheet of media 1814 adjacent to a fourth edge 1817 of the second sheet of media 1814. Because the fourth edge 1817 of the second sheet of media 1814 is generally planar when the filter media 1810 is in a spiral configuration, the obstruction 1849 is also generally planar when the filter media 1810 is in a spiral configuration.

[0191] 17A illustrates yet another exemplary filter assembly 1100 consistent with the technology disclosed herein, where the filter assembly 1100 is a spiral wound filter media 1110, and FIG. 17B illustrates a front view of the filter media 1110 in an unwound configuration. The filter assembly 1100 is constructed from a filter media 1110 defining a first flow face 1120, a second flow face 1130, and a plurality of flutes 1140 extending from the first flow face 1120 to the second flow face 1130. In this example, the first flow face 1120 is defined on a first end 1102 of the filter assembly 1100, and the second flow face 1130 is defined on an opposing second end 1104 of the filter assembly 1100. The first flow face 1110 has an axial flow face length L. In this example, the first flow surface 1120 does not define a taper along at least a portion of the axial flow surface length L.

[0192] The filter media 1110 is a plurality of sheets of filter media, specifically a first sheet of filter media 1112 and a second sheet of filter media 1114. The second sheet of filter media 1114, which is part of the filter media 1110 in a planar arrangement, can be seen in FIG. 17B. FIG. 17B is a front view of the second sheet of filter media 1114. The second sheet of filter media 1114 is adjacent to the first sheet of filter media 1112. The first sheet of filter media 1112 and the second sheet of filter media 1114 mutually define a plurality of flutes 1140. The filter media 1110 can have a variety of configurations, some examples of which are described in connection with FIGS. 6a-6d and below.

[0193] It should be noted that the entirety of the longitudinal grooves defined in this design embodiment have been omitted from FIG. 17A to simplify the drawing and provide clarity with respect to the relatively complex shape of the first flow surface 1120.

[0194] The filter media 1110 defines a spiral configuration about the Z-axis. Thus, the first sheet of filter media 1112 and the second sheet of filter media 1114 each define a spiral configuration about the Z-axis. Thus, the plurality of flutes 1140 are also in a spiral configuration about the Z-axis. In this embodiment, the plurality of flutes are parallel, but in some other embodiments, the plurality of flutes are non-parallel.

[0195] As can be seen in FIG. 17B, the filter media 1110 (particularly the first sheet of filter media 1112 and the second sheet of filter media 1114) are generally elongated such that the first sheet of filter media 1112 and the second sheet of filter media 1114 can be spiraled about a Z-axis to form a filter assembly. In this example, the first sheet of filter media 1112 and the second sheet of filter media 1114 can be continuous or discontinuous. In embodiments where the sheets are discontinuous, the first sheet of filter media 1112 defines a first edge 1111 and a second edge 1113 (FIG. 17A), and the second sheet of filter media 1114 defines a third edge 1115 and a fourth edge 1117 (FIG. 17B). The first edge 1111 and the third edge 1115 mutually define a first flow face 1120 of the filter assembly 1100. The second edge 1113 and the fourth edge 1117 mutually define a second flow face 1130 of the filter assembly 1100. The first edge 1111 and the third edge 1115 each individually form a sinusoidal pattern having a constant frequency over the length of the filter media 1110. The second edge 1113 and the fourth edge 1117 each individually form a straight line.

[0196] Example filter media 1110 consistent with the present embodiment has four edges, a first elongated edge 1105 (corresponding to first edge 1111 and third edge 1115), a second elongated edge 1107 (corresponding to second edge 1113 and fourth edge 1117), a first end edge 1108, and a second end edge 1109. The shape of the filter media 1110 is generally non-rectangular and non-trapezoidal based on the corrugated pattern defined by at least the first elongated edge, defining a plurality of convex and concave portions.

[0197] The filter assembly 1100 is generally constructed to define a fluid pathway 1106 between a first flow face 1120 and a second flow face 1130 through the filter media 1110 such that fluid is filtered by the filter media 1110. In particular, the plurality of flutes 1140 define either inlet flutes or outlet flutes, similar to those described in FIG.

[0198] Each of the plurality of flutes 1140 defines a flute opening 1142 and a flute closure (not visible). The flute opening 1142 forms the extreme end of the fluid path 1106 along the flute and accommodates fluid flow to or from the filter assembly 1100. The flute closure blocks fluid flow along the flute, thereby defining a portion of the fluid path 1106 through the filter media 1110. So, for example, the plurality of inlet flutes can define flute openings 1142 at the first flow face 1120, and a flute closure is defined across the plurality of inlet flutes near the second flow face 1130. In some embodiments, the flute closure is adjacent the second flow face 1130. More specifically, the flute closure can abut the second flow face 1130. The flute closure can be similar to the flute closure discussed above.

[0199] In this embodiment, the volume defined between the outer surface 1116 of the first sheet of filter media 1112 (FIG. 17A) and the outer surface 1118 of the second sheet of filter media 1114 (FIG. 17B) defines a fluid pathway 1106 that is not necessarily characterized by being defined by a plurality of longitudinal grooves when the filter media is coiled (FIG. 17A).

[0200] The obstructions may be disposed within the convolutions and outside of the plurality of flutes 1140, such that fluid passing through the first flow face 1120 and the second flow face 1130 of the filter assembly 1100 must first pass through the filter media 1110. Additional obstructions may be disposed around the periphery of the filter assembly 1100, in any other gaps in the filter media, such as in the central opening of the filter assembly 1100, to block fluid flow therethrough. The obstructions may be formed by placing an adhesive, such as an adhesive bead, in the appropriate location.

[0201] Each of the plurality of flutes 1140 defines a flute distance between the first flow surface 1120 and the second flow surface 1130. In this embodiment, a first flute 1144 of the plurality of flutes 1140 defines a first flute distance D between the first flow surface 1120 and the second flow surface 1130. 1 and a second flute 1146 of the plurality of flutes 1140 defines a second flute distance D between the first flow surface 1120 and the second flow surface 1130. 2 In some embodiments, the first flute distance D 1 is the second flute distance D as shown herein 2 In some other embodiments, the first flute distance D 1 is the second flute distance D 2 In one embodiment, the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 and differs by 3mm~20mm, 10mm~20mm, or 15mm~25mm.

[0202] In some embodiments, the third flute 1148 of the plurality of flutes 1140 is spaced apart from the first flow surface 1120 by a third flute distance D 3 Define the third flute distance D 3 is generally the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 The third flute distance D differs from both by more than 2 mm. 3 is the first flute distance D 1 and the second longitudinal groove distance D 2In this example, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 In some other examples, the third flute distance D 3 As will be understood, the first flute distance D 1 and the second longitudinal groove distance D 2 and the first longitudinal groove distance D 1 and the second longitudinal groove distance D 2 is smaller than the other.

[0203] The difference in flute distance between the first flow surface 1120 of the filter assembly 1100 and the second flow surface 1130 of the filter assembly 1100 is also evidenced by the shape of the flow surfaces relative to one another. In various embodiments, at least one of the first flow surface 1120 and the second flow surface 1130 is non-planar. In various embodiments, at least one of the first flow surface 1120 and the second flow surface 1130 is generally planar. In an example consistent with this particular embodiment, the first flow surface 1120 is non-planar and the second flow surface 1130 is planar. Furthermore, in this particular embodiment, the first flow surface 1120 is configured such that the first elongated edge of the filter media 1110 undulates circumferentially about the Z-axis.

[0204] It will be appreciated that in some alternative embodiments, the first flow surface 1120 can be planar and the second flow surface 1130 can be non-planar. In some embodiments, at least one flute of the plurality of flutes 1140 defines a flute opening that is non-planar.

[0205] In an example consistent with the present embodiment, the obstruction 1149 is disposed along the length of the second sheet of filter media 1114 adjacent to a fourth edge 1117 of the second sheet of filter media 1114. Because the fourth edge 1117 of the second sheet of filter media 1114 is generally planar when the filter media 1110 is in a spiral configuration, the obstruction 1149 is also generally planar when the filter media 1110 is in a spiral configuration.

[0206] 18 illustrates a side cross-sectional view of yet another exemplary filter assembly 1200 consistent with the technology disclosed herein. The filter assembly 1200 is constructed from a filter media 1210 having a first elongated edge 1212 defining a first flow face 1220, a second elongated edge 1214 defining a second flow face 1230, and a plurality of flutes 1240 extending from the first flow face 1220 to the second flow face 1230. In this example, the first flow face 1220 is defined on a first end 1202 of the filter assembly 1200 and the second flow face 1230 is defined on an opposing second end 1204 of the filter assembly 1200. The first flow face 1220 has a first axial flow face length L 1 and the second flow surface 1230 has a second axial flow surface length L 2 Each of the first flow face 1220 and the second flow face 1230 defines a taper along the respective axial flow face length.

[0207] As with other embodiments described herein, the filter assembly 1200 is generally constructed to define a fluid path 1218 between a first flow surface 1220 and a second flow surface 1230 through the filter media 1210 such that fluid is filtered by the filter media 1210. In this example, each of the plurality of flutes 1240 defines a flute opening and a flute closing, as described with respect to the previous figures. Also, as with some other embodiments, the filter assembly 1200 is constructed from the filter media 1210 in a spiral configuration about a Z-axis. The first sheet of filter media 1250 and the second sheet of filter media 1260 mutually define the plurality of flutes 1240. The filter media 1210 has a first sheet of filter media 1250 that is fluted and a second sheet of filter media 1260 that is a facing sheet adjacent to the first sheet of filter media 1250. The filter assembly 1200 of FIG. 18 can be constructed from a variety of configurations of filter media 1210, examples of which are described in connection with FIGS. 6a-6d and below.

[0208] The first sheet of filter media 1250 and the second sheet of filter media 1260 are generally elongated. In this example, the first sheet of filter media 1250 and the second sheet of filter media 1260 are discontinuous. The first sheet of filter media 1250 defines a first edge 1253 and the second sheet of filter media 1260 defines a second edge 1263. The first edge 1253 and the second edge 1263 are configured to mutually define the first flow face 1220 of the filter assembly 1200, and thus the first elongated edge 1212. The first sheet of filter media 1250 defines a third edge 1255 and the second sheet of filter media 1260 defines a fourth edge 1265. The third edge 1255 and the fourth edge 1265 are configured to mutually define the second flow face 1230 of the filter assembly 1200 , and thus the second elongated edge 1214 .

[0209] Each of the first sheet of filter media 1250 and the second sheet of filter media 1260 are arranged to define a spiral configuration about the Z axis. Thus, the plurality of flutes 1240 are also in a spiral configuration about the Z axis. In this example, the plurality of flutes 1240 are generally parallel.

[0210] Each of the plurality of flutes 1240 defines a flute distance between the first flow surface 1220 and the second flow surface 1230. In this embodiment, a first flute 1244 of the plurality of flutes 1240 defines a first flute distance D between the first flow surface 1220 and the second flow surface 1230. 1 and a second flute 1246 of the plurality of flutes 1240 defines a second flute distance D between the first flow surface 1220 and the second flow surface 1230. 2 In this embodiment, the first flute distance D 1 is the second flute distance D 2 In other embodiments, the first flute distance D 1 is the second flute distance D 2 In various embodiments, the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 and differs by 3mm~20mm, 10mm~20mm, or 15mm~25mm.

[0211] In some embodiments, the third flute 1248 of the plurality of flutes 1240 is spaced apart from the first flow surface 1220 by a third flute distance D 3 In this embodiment, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 The third flute distance D is greater than the third flute distance D. 3is generally the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 The third flute distance D differs from both by more than 2 mm. 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 may differ from one or both of the above to the same extent.

[0212] In an example consistent with this particular embodiment, the first flow surface 1220 is non-planar and the second flow surface 1230 is non-planar. One or both of the first and second flow surfaces can be cut to be three-dimensional surfaces. In this example, at least one of the first and second flow surfaces 1220 and 1230 is concave, thus defining a cavity that flares inwardly relative to the filter assembly 1200. In this example, the first and second flow surfaces 1220 and 1230 each define a recess and are each concave. In some other embodiments, one of the first and second flow surfaces 1220 and 1230 is concave relative to the filter assembly and the other of the first and second flow surfaces 1220 and 1230 is planar or convex. In this example, the general shape of the first and second flow surfaces 1220 and 1230 is symmetrical about the Z axis. In some other embodiments, the first flow surface 1220 and the second flow surface 1230 are asymmetric with respect to the Z axis. In some embodiments, the first flow surface 1220 and the second flow surface 1230 have similar shapes, while in other embodiments, the first flow surface 1220 and the second flow surface 1230 have different shapes.

[0213] 19 illustrates a side cross-sectional view of yet another exemplary filter assembly 1300 consistent with the technology disclosed herein. The filter assembly 1300 is constructed from a filter media 1310 having a first elongated edge 1312 defining a first flow face 1320, a second elongated edge 1314 defining a second flow face 1330, and a plurality of longitudinal grooves 1340 extending from the first flow face 1320 to the second flow face 1330. In this example, the first flow face 1320 is defined on a first end 1302 of the filter assembly 1300 and the second flow face 1330 is defined on an opposing second end 1304 of the filter assembly 1300. The first flow face 1320 has a first axial flow face length L 1 and the second flow surface 1330 has a second axial flow surface length L 2 Each of the first flow face 1320 and the second flow face 1330 defines a taper along the respective axial flow face length.

[0214] As with other embodiments described herein, the filter assembly 1300 is generally constructed to define a fluid path 1318 between a first flow surface 1320 and a second flow surface 1330 through the filter media 1310 such that fluid is filtered by the filter media 1310. Thus, each of the plurality of flutes 1340 defines a flute opening and a flute closure, as described with respect to the previous figures. Also, as with some other embodiments, the filter assembly 1300 is constructed from the filter media 1310 in a spiral configuration about a Z-axis. The filter media 1310 has a first sheet of filter media that is fluted and a second sheet of filter media adjacent to the first sheet of filter media (not discernible here from this figure). The first sheet of filter media and the second sheet of filter media mutually define a plurality of flutes. The filter assembly 1300 of FIG. 19 can be constructed from a variety of alternative configurations of filter media 1310, examples of which are described in connection with FIGS. 6a-6d and below.

[0215] The first sheet of filter media and the second sheet of filter media are each arranged to define a spiral configuration about the Z axis. Thus, the plurality of flutes are also in a spiral configuration about the Z axis. In this example, the plurality of flutes 1340 are generally parallel.

[0216] Each of the plurality of flutes 1340 defines a flute distance between the first flow surface 1320 and the second flow surface 1330. In this embodiment, a first flute 1344 of the plurality of flutes 1340 defines a first flute distance D between the first flow surface 1320 and the second flow surface 1330. 1 and a second flute 1346 of the plurality of flutes 1340 defines a second flute distance D between the first flow surface 1320 and the second flow surface 1330. 2 In this embodiment, the first flute distance D 1 is the second flute distance D 2 In other embodiments, the first flute distance D 1 is the second flute distance D 2 In various embodiments, the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 and differs by 3mm~20mm, 10mm~20mm, or 15mm~25mm.

[0217] In some embodiments, the third flute 1348 of the plurality of flutes 1340 is spaced apart from the first flow surface 1320 by a third flute distance D 3 In this embodiment, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 The third flute distance D is greater than the third flute distance D. 3is generally the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 The third flute distance D differs from both by more than 2 mm. 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 may differ from one or both of the above to the same extent.

[0218] In various embodiments, at least one of the first flow surface 1320 and the second flow surface 1330 is planar. In an example consistent with this particular embodiment, the first flow surface 1320 is planar, the second flow surface 1330 is planar, and the first flow surface 1320 is non-parallel and non-perpendicular to the second flow surface 1330. Unlike the example of Figure 5, here the flow surfaces are not each perpendicular to the flutes.

[0219] 20 illustrates a side cross-sectional view of yet another exemplary filter assembly 1400 consistent with the technology disclosed herein. The filter assembly 1400 is constructed from a filter media 1410 having a first elongated edge 1412 defining a first flow face 1420, a second elongated edge 1414 defining a second flow face 1430, and a plurality of longitudinal grooves 1440 extending from the first flow face 1420 to the second flow face 1430. In this example, the first flow face 1420 is defined on a first end 1402 of the filter assembly 1400 and the second flow face 1430 is defined on an opposing second end 1404 of the filter assembly 1400. The first flow face 1420 has a first axial flow face length L 1 and the second flow surface 1430 has a second axial flow surface length L 2 Each of the first flow face 1420 and the second flow face 1430 defines a taper along its respective axial flow face length.

[0220] As with other embodiments described herein, the filter assembly 1400 is generally constructed to define a fluid path 1418 between a first flow surface 1420 and a second flow surface 1430 through the filter media 1410 such that fluid is filtered by the filter media 1410. Thus, each of the plurality of flutes 1440 defines a flute opening and a flute closing, as described with respect to the previous figures. Also, as with some other embodiments, the filter assembly 1400 is constructed from the filter media 1410 in a spiral configuration about a Z-axis. The filter media 1410 has a first sheet of filter media that is fluted and a second sheet of filter media adjacent to the first sheet of filter media (not discernible in this view). The first sheet of filter media and the second sheet of filter media can conform to the examples described in connection with Figures 6a-6d, examples of which are also described below.

[0221] Each of the first sheet of filter media and the second sheet of filter media are arranged to define a spiral configuration about the Z axis. Thus, the plurality of flutes 1440 are also in a spiral configuration about the Z axis. In this example, the plurality of flutes 1440 are generally parallel.

[0222] Each of the plurality of flutes 1440 defines a flute distance between the first flow surface 1420 and the second flow surface 1430. In this embodiment, a first flute 1444 of the plurality of flutes 1440 defines a first flute distance D between the first flow surface 1420 and the second flow surface 1430. 1 and a second flute 1446 of the plurality of flutes 1440 defines a second flute distance D between the first flow surface 1420 and the second flow surface 1430. 2 In this embodiment, the first flute distance D 1 is the second flute distance D 2 In other embodiments, the first flute distance D 1 is the second flute distance D 2 In various embodiments, the first flute distance D 1 and the second longitudinal groove distance D 2In some embodiments, the first flute distance D 1 is the second flute distance D 2 In some embodiments, the first flute distance D 1 is the second flute distance D 2 and differs by 3mm~20mm, 10mm~20mm, or 15mm~25mm.

[0223] In some embodiments, the third flute 1448 of the plurality of flutes 1440 is spaced apart from the first flow surface 1420 by a third flute distance D between the first flow surface 1420 and the second flow surface 1430. 3 In this embodiment, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 The third flute distance D is greater than the third flute distance D. 3 is generally the first flute distance D 1 and the second longitudinal groove distance D 2 In some embodiments, the third flute distance D 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 The third flute distance D differs from both by more than 2 mm. 3 is the first flute distance D 1 and the second longitudinal groove distance D 2 may differ from one or both of the above to the same extent.

[0224] In an example consistent with this particular embodiment, the first flow surface 1420 is non-planar and the second flow surface 1430 is non-planar. One or both of the first and second flow surfaces can be cut to be three-dimensional surfaces. In this example, at least one of the first flow surface 1420 and the second flow surface 1430 protrudes relative to the filter assembly 1400. In this example, the first flow surface 1420 and the second flow surface 1430 each protrude axially outward (in the Z direction) from the filter assembly 1400. In some alternative embodiments, at least one of the first flow surface 1420 and the second flow surface 1430 protrudes outward and the other of the first flow surface 1420 and the second flow surface 1430 is concave or planar.

[0225] Further media configuration The filter assemblies described herein can be constructed from filter media having a variety of different configurations, including those already shown herein. Various embodiments, including any exemplary filter assemblies disclosed herein, can incorporate a filter media constructed from a fluted sheet and a facing sheet adjacent to the fluted sheet, where a plurality of flutes extending between the fluted sheet and the facing sheet are defined. In some of these embodiments, the fluted sheet defines a plurality of protrusions that contact the facing sheet. Exemplary filter media are described, for example, in U.S. Patent No. 9,623,362, which is incorporated herein by reference.

[0226] Also, in some of those embodiments, the fluted sheet defines a ridge along at least a portion of the length of a portion of the flutes, where the ridge is a line of intersection between different slopes of the media that form a particular flute. Also, in some of those embodiments, at least a portion of the flutes can define a sharp flute peak, meaning that the flute peak is not curved. Also, in some of those embodiments, at least a portion of the flutes can be tapered from a first flow surface of the media assembly to a second flow surface of the media assembly. The above flute configurations, as well as other flute configurations such as those disclosed in U.S. Pat. Nos. 7,959,702 and 8,545,589, each of which is incorporated herein by reference, are certainly contemplated. In some embodiments, the flutes do not extend from the first flow surface of the filter media to the second flow surface, for example, a portion of the flute tapers to a point between the first and second flow surfaces of the filter media.

[0227] Filter assemblies constructed from fluted media consistent with the technology disclosed herein can incorporate different types of filter media arranged in parallel or series, where "different types of filter media" is used to mean that the filter media are constructed from different materials or have flutes that exhibit differences in flute shape, flute size, flute height, flute width, flute length, flute cross section, and / or filter media. Such configurations are described in WO 2008 / 111923 and U.S. Ser. No. 62 / 683,542, which are incorporated herein by reference.

[0228] In some embodiments where the filter media is constructed from a fluted sheet and a facing sheet that mutually define a plurality of flutes, the plurality of flutes has at least a first group of flutes and a second group of flutes, the first group of flutes and the second group of flutes exhibiting differences in flute shape, flute size, flute height, flute width, flute length, flute cross-section, and / or filter media.

[0229] 21 illustrates a cross-sectional view of an exemplary filter media 1500 consistent with various embodiments. A first sheet of filter media 1502 and a second sheet of filter media 1504 mutually define a plurality of flutes 1506. The filter assembly 1500 has two types of flutes, first flutes 1510 and second flutes 1520. The first flutes 1510 and second flutes 1520 are arranged in parallel flow. The filter media 1500 can be used to form a spiral wound filter assembly (as described) or the filter media 1500 can be stacked with similar or different filter media to form a panel filter assembly consistent with embodiments herein. In the exemplary two flute structure shown herein, the first flutes and second flutes can be selected such that the first plurality of flutes comprises 20-50 percent of the volume of the filter assembly, e.g., 20, 30, 40, or 50 percent of the volume of the filter assembly, and the second plurality of flutes comprises 20-50 percent of the volume of the pack, e.g., 20, 30, 40, or 50 percent of the volume of the filter assembly.

[0230] In an exemplary configuration having two types of flutes, the first and second flutes can be selected such that the first plurality of flutes occupies between 20 and 50 percent of the media surface area of ​​the filter assembly, e.g., 20, 30, 40, or 50 percent of the media surface area of ​​the filter assembly, and the second plurality of flutes occupies between 20 and 50 percent of the media surface area of ​​the filter assembly, e.g., 20, 30, 40, or 50 percent of the media surface area of ​​the filter assembly.

[0231] In an exemplary configuration having two types of flutes, the first and second flutes can be selected such that the first plurality of flutes occupies between 20 and 50 percent of the inlet surface of the filter assembly, e.g., 20, 30, 40, or 50 percent of the inlet surface of the filter assembly, and the second plurality of flutes occupies between 20 and 50 percent of the inlet surface of the filter assembly, e.g., 20, 30, 40, or 50 percent of the inlet surface of the filter assembly.

[0232] Although FIG. 21 shows two different types of flutes, other embodiments can have additional different types of flutes incorporated into the filter media.

[0233] A filter assembly having a stacked configuration as described herein can be constructed from multiple different types of filter media. FIG. 22 is a front schematic view of an exemplary filter assembly 1600 showing a stacked configuration with two types of filter media. The two types of filter media are a first media 1610 and a second media 1620. The filter media are arranged parallel to the fluid flow. The media are shown in a stacked configuration with separate media types rather than a mixture of the two types of filter media. In this exemplary embodiment, the ratio of filter media 1610 to 820 to 830 is about 4:3 based on the filter assembly inlet (or outlet) area.

[0234] In some embodiments, the first media (having the first plurality of flutes) defines 10-90 percent of the inlet surface area of ​​the media assembly, e.g., 10, 20, 30, 40, 50, 60, 70, 80, or 90 percent of the inlet surface area of ​​the filter assembly, and the second filter assembly (having the second plurality of flutes) defines 90-10 percent of the inlet surface area of ​​the media assembly, e.g., 90, 80, 70, 60, 50, 40, 30, 20, or 10 percent of the inlet surface area of ​​the media assembly. Alternatively, the first plurality of flutes occupies 20-40 percent of the inlet surface area of ​​the media assembly, and the second plurality of flutes occupies 60-80 percent of the inlet surface area of ​​the media assembly. In other embodiments, the first plurality of flutes occupies 40-60 percent of the inlet surface area of ​​the media assembly, and the second plurality of flutes occupies 60-40 percent of the inlet surface area of ​​the media assembly. In yet another embodiment, the first plurality of flutes occupies between 60 and 90 percent of the inlet face of the media assembly, and the second plurality of flutes occupies between 40 and 10 percent of the inlet face of the media assembly.

[0235] A media assembly having a spirally wound media arrangement consistent with the present disclosure can also be constructed from multiple types of filter media arranged in series. FIG. 23 is a schematic cross-sectional view of an exemplary filter assembly 1700 showing a winding configuration with two types of filter media 1710 and 1720. The media is wound with a first media 1710 on the inside and a second media 1720 on the outside. The first media 1710 and the second media 1720 are spliced ​​together. Although flutes are not shown here, it should be understood that each of the first media and the second media is generally a fluted media. The first media 1710 and the second media 1720 can have ratios and parameters consistent with those described above with reference to FIG. 22.

[0236] Figure 24 is a cross-sectional view of a two-stage separator system 2000 consistent with Figure 1. Unlike Figure 2, this cross-section is taken through the filter assembly as well as the separator housing so that an alternative filter assembly configuration can be seen. The separator system 2000 has a housing 2010 that houses a filter assembly 2050 disposed therein. The filter assembly 2050 can be generally consistent with the filter assemblies described herein above.

[0237] The housing 2010 extends between a first end 2012 and a second end 2014. The housing 2010 defines an interior space 2016. In various embodiments, the housing 2010 extends in an axial direction defined by a central axis z. The housing 2010 defines a housing inlet 2020, a separator outlet 2030 towards the second end 2014, and a filtration outlet 2040 on the first end 2012. In this example, the housing inlet 2020 is defined towards the first end 2012. A filter assembly 2050 is positioned within the interior space 2016. The housing 2010 is configured to receive unfiltered fluid, such as air, through the housing inlet 2020, allow for discharge of separated particulates through the separator outlet 2030, and allow filtered air to exit through the filtration outlet 2040. This functionality is similar to that described above for Figures 1 and 2.

[0238] The housing 2010 has a main portion 2060 and a removably coupled access cover 2070. The main portion 2060 can define a first end 2012 of the housing 2010, and the access cover 2070 can define a second end 2014 of the housing 2010. The main portion 2060 and the access cover 2070 are removably coupled as described above with respect to Figures 1 and 2. The access cover 2070 surrounds the second end 2062 of the main portion 2060 of the housing 2010.

[0239] The particular configurations of the housing inlet 2020, separator outlet 2030, and filtration outlet 2040 can be similar to those described above with respect to FIGS.

[0240] The filter assembly 2050 is disposed within the housing 2010 and is generally configured to filter air within the housing 2010. The filter assembly 2050 has an inlet flow face 2052, an outlet flow face 2054, and a filter media 2056 extending axially between the inlet flow face 2052 and the outlet flow face 2054. Although not visible in this view, the filter media 2056 defines a number of axially extending flutes. The flutes may extend axially between the inlet flow face 2052 and the outlet flow face 2054. The filter assembly 2050 has each flow face 2052, 2054 having an axial length L. 1 , L 2 18 in that the inlet flow face 2052 and the outlet flow face 2054 each have a concave shape and extend inwardly relative to the filter assembly 2050.

[0241] The filter assembly 2050 is coupled to the housing 2010 about the filtration outlet 2040 such that the outlet flow surface 2054 is in fluid communication with the filtration outlet 2040. In various embodiments, the filter media 2056 surrounding the outlet flow surface 2054 is coupled to the housing 2010 about the filtration outlet 2040. In this example, the filter assembly 2050 has a potting feature 2026 that is a radial potting sleeve configured to receive a first end of the filter media 2056. The first end 2051 of the filter assembly 2050 can be coupled to the housing 2010 using adhesives, gaskets, compression fits, and / or through additional or alternative structures.

[0242] The filter assembly 2050 has an outer radial barrier surface 2058 between the inlet flow face 2052 and the outlet flow face 2054. In some embodiments, the outer radial barrier surface 2058 can be configured to direct airflow tangentially around the filter assembly 2050. The outer radial barrier surface 2058 can have a configuration consistent with the description above with respect to FIG. 2. The outer radial barrier surface 2058 has an axially extending length Lsurface 20, which is equal to or greater than the axial distance D from the filtration outlet 2040 to the distal end of the housing inlet 2020. In some embodiments, the outer radial barrier surface 2058 extends axially from the filtration outlet 2040 beyond the housing inlet 2020. Such a configuration promotes a helical air flow around the filter assembly 2050 towards the second end 2014 of the housing 2010.

[0243] The inlet flow face 2052 of the filter assembly 2050 has a flow face length L 1 Unlike the example of FIG. 2, here the inlet flow face 2052 has an axial flow face length L inlet The inlet flow surface 2052 defines at least a portion of a taper of an axial flow surface length L inlet In some embodiments, the taper defines at least a portion of the axial flow surface length L inlet 2. The taper of the inlet flow face 2052 increases from the second end 2014 toward the first end 2012 for at least a portion of the axial flow face length L inlet Indeed, in this example, the taper of the inlet flow face 2052 varies continuously along the axial flow face length L from the second end 2014 towards the first end 2012. inlet increases continuously along

[0244] Radial distance R 1、2 is generally defined between the inlet flow surface 2052 and the housing 2010. In various embodiments, the radial distance R 1、2 is the first radial distance R 1 and a second radial distance R 2 As shown by the axial flow surface length L inlet2, the housing 2010 is not shown as tapered here, although in some examples the housing can define a taper along at least a portion of the axial length of the housing 2010.

[0245] In the embodiment shown, the filter media 2056 is at least a first sheet of filter media and a second sheet of filter media in a spiral configuration about the z-axis, similar to the filter assembly described above with respect to FIG.

[0246] Description of an exemplary embodiment of a two-stage separator system of the present technology Embodiment 1. A method for manufacturing a separator comprising the steps of: providing a separator inlet port at said first end and a separator outlet port at said second end; and disposing said separator inlet port at said first end and a separator outlet port at said second end. a filter assembly having a first sheet of filter media bonded to a second sheet of filter media, the first sheet of filter media mutually defining a plurality of axially extending flutes; Equipped with the filter assembly defines an inlet flow face and an outlet flow face; the filter assembly is disposed within the housing and coupled to the housing about the filtration outlet such that the outlet flow surface is in fluid communication with the filtration outlet; the inlet flow face having an axial flow face length; Two-stage separator system.

[0247] Embodiment 2. A radial distance is defined between the inlet flow surface and the housing; the radial distance increases from the first end to the second end along at least a portion of the axial flow face length. A system according to any one of claims 1 and 3 to 17.

[0248] Embodiment 3. The filter assembly has an outer radial barrier surface extending axially from the filtration outlet beyond the housing inlet. A system described in any one of embodiments 1 to 2 and 4 to 17.

[0249] Embodiment 4. The filter assembly has an outer radial barrier surface having an axial length from the outlet flow surface toward the inlet flow surface that is equal to or greater than the axial distance from the filtration outlet to the distal end of the housing inlet. A system described in any one of embodiments 1 to 3 and 5 to 17.

[0250] Embodiment 5. The housing inlet defines an airflow path tangential to an outer radial barrier surface of the filter assembly. A system described in any one of embodiments 1 to 4 and 6 to 17.

[0251] Embodiment 6. At least a portion of the outer radial barrier surface is defined by a first sheet of filter media. A system described in any one of embodiments 1 to 5 and 7 to 17.

[0252] Embodiment 7. The inlet flow face defines a taper from the first end toward the second end along at least a portion of the axial flow face length. A system described in any one of embodiments 1 to 6 and 8 to 17.

[0253] Embodiment 8. The taper increases from the first end to the second end along at least a portion of the axial flow face length. A system described in any one of embodiments 1 to 7 and 9 to 17.

[0254] Embodiment 9. The taper varies continuously along the axial flow face length from the first end toward the second end. A system described in any one of embodiments 1 to 8 and 10 to 17.

[0255] Embodiment 10. The taper increases continuously along the axial flow face length from the first end toward the second end. A system described in any one of embodiments 1 to 9 and 11 to 17.

[0256] Embodiment 11. The first sheet of filter media is a facing sheet; the second sheet of filter media is a fluted sheet; A system described in any one of embodiments 1 to 10 and 12 to 17.

[0257] Embodiment 12. The first sheet of filter media and the second sheet of filter media define a spiral configuration about a z-axis extending in the axial direction. A system described in any one of embodiments 1 to 11 and 13 to 17.

[0258] Embodiment 13. A filter assembly comprising: a rod extending through a center of the filter assembly, the rod having a proximal end positioned toward the outlet flow surface and a distal end positioned toward the inlet flow surface; a rod receiving portion defined by the second end of the housing, the rod receiving portion configured to receive a distal end of the rod; Further comprising: A system described in any one of embodiments 1 to 12 and 14 to 17.

[0259] Embodiment 14. The distal end of the rod defines a handle. A system described in any one of embodiments 1 to 13 and 15 to 17.

[0260] Embodiment 15. The filter assembly has a circular cross-section. A system described in any one of embodiments 1 to 14 and 16 to 17.

[0261] Embodiment 16. The filter assembly, a plurality of first sheets of filter media and a plurality of second sheets of filter media in an alternating stacked configuration; a radial sleeve disposed about the stacked first sheet of filter media and the stacked second sheet of filter media; Equipped with A system described in any one of embodiments 1 to 15 and 17.

[0262] EMBODIMENT 17 Embodiment 17. The housing inlet is defined toward the first end of the housing. A system described in any one of embodiments 1 to 16.

[0263] Description of an exemplary filter assembly embodiment for use in the two-stage separator system of the present technology Any of the following exemplary filter assemblies may be incorporated into a two-stage separator system as described herein.

[0264] Embodiment 1. A filter assembly comprising a first sheet of filter media and a second sheet of filter media mutually defining a first plurality of flutes, a first flow face on a first end of the filter assembly, and a second flow face on an opposing second end of the filter assembly; each of the first plurality of flutes defines a distance from the first flow surface to the second flow surface; each of the first plurality of flutes defines a flute opening at the first flow surface and a flute closure adjacent the second flow surface; a first flute of the first plurality of flutes defines a first flute distance; a second flute of the first plurality of flutes defining a second flute distance; the first flute distance and the second flute distance differ by more than 2 mm; Filter assembly.

[0265] Embodiment 2. The first sheet of filter media and the second sheet of filter media are discontinuous. The filter assembly according to any one of embodiments 1 and 3 to 17.

[0266] Embodiment 3. The first sheet of filter media and the second sheet of filter media are contiguous and separated by a fold. The filter assembly according to any one of embodiments 1 to 2 and 4 to 17.

[0267] Embodiment 4. The flute closure is adjacent to the second flow surface. The filter assembly according to any one of embodiments 1 to 3 and 5 to 17.

[0268] Embodiment 5. The filter further comprises a third sheet of filter media. the third sheet of filter media and the second sheet of filter media mutually define a second plurality of flutes, the first flow surface, and the second flow surface; each of the second plurality of flutes extends from the first flow surface to the second flow surface; each of the second plurality of flutes defines a flute opening at the second flow surface and a flute closure adjacent the first flow surface; The filter assembly according to any one of embodiments 1 to 4 and 6 to 17.

[0269] Embodiment 6. The second plurality of flutes comprises a third flute defining a third flute distance from the first flow surface to the second flow surface; the third flute distance differs from the first flute distance and the second flute distance by more than 2 mm; The filter assembly according to any one of embodiments 1 to 5 and 7 to 17.

[0270] Embodiment 7. The first plurality of flutes comprises a third flute defining a third flute distance; the third flute distance differs from the first flute distance and the second flute distance by more than 2 mm; The filter assembly according to any one of embodiments 1 to 6 and 8 to 17.

[0271] Embodiment 8. The first flute distance differs from the second flute distance by at least 5 mm. The filter assembly according to any one of embodiments 1 to 7 and 9 to 17.

[0272] Embodiment 9. The first flute distance differs from the second flute distance by 3 mm to 20 mm. The filter assembly according to any one of embodiments 1 to 8 and 10 to 17.

[0273] Embodiment 10. The first flute distance differs from the second flute distance by at least 8 mm. The filter assembly according to any one of embodiments 1 to 9 and 11 to 17.

[0274] Embodiment 11. The first flute distance differs from the second flute distance by at least 15 mm. The filter assembly according to any one of embodiments 1 to 10 and 12 to 17.

[0275] Embodiment 12. The first flow surface and the second flow surface are non-parallel. The filter assembly according to any one of embodiments 1 to 11 and 13 to 17.

[0276] Embodiment 13. At least one of the first flow surface and the second flow surface is non-planar. The filter assembly according to any one of embodiments 1 to 12 and 14 to 17.

[0277] Embodiment 14. At least one of the first flow surface and the second flow surface is concave. The filter assembly according to any one of embodiments 1 to 13 and 15 to 17.

[0278] Embodiment 15. At least one of the first flow surface and the second flow surface is planar. The filter assembly according to any one of embodiments 1 to 14 and 16 to 17.

[0279] Embodiment 16. The first flow surface and the second flow surface are both non-planar. The filter assembly according to any one of embodiments 1 to 15 and 17.

[0280] Embodiment 17. The first sheet is a fluted sheet of filter media; the second sheet being a facing sheet of filter media; The filter assembly according to any one of embodiments 1 to 16 and 18.

[0281] Embodiment 18. The first sheet and the second sheet are both fluted sheets of filter media. The filter assembly according to any one of the first to seventeenth embodiments.

[0282] Embodiment 19. A filter medium defining a spiral configuration about a z-axis, the filter media defines a first flow surface, a second flow surface, and a plurality of flutes extending from the first flow surface to the second flow surface; each of the plurality of flutes defines a flute opening and a flute closing portion; the plurality of flutes comprising first flutes defining a first flute distance between the first flow surface and the second flow surface and second flutes defining a second flute distance between the first flow surface and the second flow surface; the first flute distance differs from the second flute distance by more than 2 mm; Filter assembly.

[0283] Embodiment 20. The second flow surface is non-parallel to the first flow surface. The filter assembly according to any one of embodiments 19 and 21 to 32.

[0284] Embodiment 21. The first flow surface is non-planar; the second flow surface is planar; The filter assembly according to any one of embodiments 19 to 20 and 22 to 32.

[0285] Embodiment 22. The first flow surface is non-planar. the second flow surface is non-planar; The filter assembly according to any one of embodiments 19 to 21 and 23 to 32.

[0286] Embodiment 23. One of the first flow surface and the second flow surface is concave. The filter assembly according to any one of embodiments 19 to 22 and 24 to 32.

[0287] Embodiment 24. A filter comprising a first sheet of filter media and a second sheet of filter media adjacent to the first sheet of filter media; the first sheet and the second sheet define a spiral configuration about the z-axis; the first sheet and the second sheet mutually define the plurality of flutes; The filter assembly according to any one of embodiments 19 to 23 and 25 to 32.

[0288] Embodiment 25. The first sheet and the second sheet are discontinuous. The filter assembly according to any one of embodiments 19 to 24 and 26 to 32.

[0289] Embodiment 26. The first sheet and the second sheet are contiguous and separated by a fold that defines the second flow surface. The filter assembly according to any one of embodiments 19 to 25 and 27 to 32.

[0290] Embodiment 27. A filter according to embodiment 27, wherein the first sheet of filter media has a first width defined by the first flow surface and the second flow surface; the second sheet of filter media has a second width defined by the first flow surface and the second flow surface; the first width differs from the second width by more than 2 mm; The filter assembly according to any one of embodiments 19 to 26 and 28 to 32.

[0291] Embodiment 28. The first sheet of filter media is a fluted sheet; the second sheet of filter media is a facing sheet; The filter assembly according to any one of embodiments 19 to 27 and 29 to 32.

[0292] Embodiment 29. The first flute distance differs from the second flute distance by at least 5 mm. The filter assembly according to any one of embodiments 19 to 28 and 32.

[0293] Embodiment 30. The first flute distance differs from the second flute distance by 3 mm to 20 mm. The filter assembly according to any one of embodiments 19 to 29 and 31 to 32.

[0294] Embodiment 31. The first flute distance differs from the second flute distance by at least 8 mm. The filter assembly according to any one of embodiments 19 to 30 and 32.

[0295] Embodiment 32. The first flute distance differs from the second flute distance by at least 15 mm. 32. The filter assembly according to any one of embodiments 19 to 31.

[0296] Embodiment 33. A filter medium comprising a plurality of sheets of filter media in a laminated configuration mutually defining a first flow surface, a second flow surface, and a plurality of flutes extending from the first flow surface to the second flow surface; the plurality of sheets of filter media defining a regularly alternating pattern of first fluted layers and second fluted layers; each of the first layers defines a first layer distance between the first flow surface and the second flow surface; each of the second layers defines a second layer distance between the first flow surface and the second flow surface; The first layer distance and the second layer distance differ by more than 2 mm; Panel filter assembly.

[0297] Embodiment 34. Each of the plurality of flutes defines a flute opening and a flute closing portion. The panel filter assembly according to any one of embodiments 33 and 35 to 48.

[0298] Embodiment 35. Each of the first and second layers is defined by a fluted sheet and an adjacent facing sheet. The panel filter assembly according to any one of embodiments 33 to 34 and 36 to 48.

[0299] Embodiment 36. Each fluted sheet and facing sheet of each fluted layer defines a substantially equal distance between the first flow surface and the second flow surface. The panel filter assembly according to any one of embodiments 33 to 35 and 37 to 48.

[0300] Embodiment 37. Each fluted sheet and facing sheet of at least one fluted layer defines a distance between the first flow surface and the second flow surface that differs by more than 2 mm. The panel filter assembly according to any one of embodiments 33 to 36 and 38 to 48.

[0301] Embodiment 38. Each of the first layer and the second layer is defined by two adjacent fluted sheets of filter media. The panel filter assembly according to any one of embodiments 33 to 37 and 39 to 48.

[0302] Embodiment 39. The plurality of sheets of filter media are discontinuous. The panel filter assembly according to any one of embodiments 33 to 38 and 40 to 48.

[0303] Embodiment 40. The sheets of the filter media are contiguous and separated by a first set of folds that define the first flow surface and a second set of folds that define the second flow surface. The panel filter assembly according to any one of embodiments 33 to 39 and 41 to 48.

[0304] Embodiment 41. The plurality of sheets of filter media further defines a regularly alternating pattern of a third flute layer; each third flute layer having a third layer distance between the first flow surface and the second flow surface; The third layer distance differs from the first layer distance and the second layer distance by more than 2 mm. The panel filter assembly according to any one of embodiments 33 to 40 and 42 to 48.

[0305] Embodiment 42. The plurality of sheets of filter media further defines a regularly alternating pattern of fourth flute layers; each fourth flute layer has a fourth layer distance between the first flow surface and the second flow surface; the fourth layer distance differs from the first layer distance, the second layer distance, and the third layer distance by more than 2 mm; The panel filter assembly according to any one of embodiments 33 to 41 and 43 to 48.

[0306] Embodiment 43. The second flow surface is planar. The panel filter assembly according to any one of embodiments 33 to 42 and 44 to 48.

[0307] Embodiment 44. The first flow surface and the second flow surface are non-planar. The panel filter assembly according to any one of embodiments 33 to 43 and 45 to 48.

[0308] Embodiment 45. The first layer distance differs from the second layer distance by at least 5 mm. The panel filter assembly according to any one of embodiments 33 to 44 and 46 to 48.

[0309] Embodiment 46. The first layer distance is different from the second layer distance by 3 mm to 20 mm. The panel filter assembly according to any one of embodiments 33 to 45 and 47 to 48.

[0310] Embodiment 47. The first layer distance differs from the second layer distance by at least 8 mm. The panel filter assembly according to any one of embodiments 33 to 46 and 48.

[0311] Embodiment 48. The first layer distance differs from the second layer distance by at least 14 mm. The panel filter assembly according to any one of embodiments 33 to 47.

[0312] Embodiment 49. A filter comprising a first sheet of filter media and a second sheet of filter media mutually defining a first plurality of flutes, a first flow surface, and a second flow surface; each of the first plurality of flutes extends from the first flow surface to the second flow surface; each of the first plurality of flutes defines a flute opening at the first flow surface and a flute closure adjacent the second flow surface; At least one of the first flow surface and the second flow surface is concave. Filter assembly.

[0313] Embodiment 50. The first sheet is a fluted sheet of filter media and the second sheet is a facing sheet of filter media. A filter assembly according to any one of embodiments 49 and 51 to 62.

[0314] Embodiment 51. The first sheet and the second sheet are both fluted sheets of filter media. The filter assembly according to any one of embodiments 49 to 50 and 52 to 62.

[0315] Embodiment 52. The flute closure is adjacent to the second flow surface. The filter assembly according to any one of embodiments 49 to 51 and 53 to 62.

[0316] Embodiment 53. The filter further comprises a third sheet of filter media. the third sheet of filter media and the second sheet of filter media mutually define a second plurality of flutes, the first flow surface, and the second flow surface; each of the second plurality of flutes extends from the first flow surface to the second flow surface; each of the second plurality of flutes defines a flute opening at the second flow surface and a flute closure adjacent the first flow surface; The filter assembly according to any one of embodiments 49 to 52 and 54 to 62.

[0317] Embodiment 54. The first plurality of flutes has first flutes defining a first flute distance between the first flow surface and the second flow surface and second flutes defining a second flute distance between the first flow surface and the second flow surface; the second plurality of flutes includes a third flute defining a third flute distance between the first flow surface and the second flow surface; each of the first flute distance, the second flute distance, and the third flute distance differ by more than 2 mm; The filter assembly according to any one of embodiments 49 to 53 and 55 to 62.

[0318] Embodiment 55. The filter assembly is a panel filter. The filter assembly according to any one of embodiments 49 to 54 and 56 to 62.

[0319] Embodiment 56. The first sheet of filter media and the second sheet of filter media define a spiral configuration about a z-axis. The filter assembly according to any one of embodiments 49 to 55 and 57 to 62.

[0320] Embodiment 57. The first sheet of filter media and the second sheet of filter media are contiguous and separated by a fold that defines the second flow surface. A filter assembly according to any one of embodiments 49 to 56 and 58 to 62.

[0321] Embodiment 58. A first flute of the first plurality of flutes defines a first flute distance between the first flow surface and the second flow surface; a second flute of the first plurality of flutes defines a second flute distance between the first flow surface and the second flow surface; the first flute distance differs from the second flute distance by more than 2 mm; A filter assembly according to any one of embodiments 49 to 57 and 59 to 62.

[0322] Embodiment 59. The first flow surface and the second flow surface are both non-planar. The filter assembly according to any one of embodiments 49 to 58 and 60 to 62.

[0323] Embodiment 60. The first sheet and the second sheet are discontinuous. The filter assembly according to any one of embodiments 49 to 59 and 61 to 62.

[0324] Embodiment 61. The first flow surface is opposite the second flow surface with respect to the filter assembly. A filter assembly according to any one of embodiments 49 to 60 and 62.

[0325] Embodiment 62. The flutes are parallel. A filter assembly according to any one of embodiments 49 to 61.

[0326] Embodiment 63. A filter medium comprising a plurality of stacked sheets of filter media, each having a width extending in a direction parallel to the x-axis and a length extending in a direction parallel to the z-axis; A plurality of sheets of the filter media are stacked in a direction parallel to the y-axis; the plurality of sheets of filter media defining a plurality of flutes, a first flow surface, and a second flow surface; each of the plurality of flutes defines a flute opening at the first flow surface and a flute closure adjacent the second flow surface; a first flute of the plurality of flutes defines a first flute distance between the first flow surface and the second flow surface; a second flute of the plurality of flutes defines a second flute distance between the first flow surface and the second flow surface; a third flute of the plurality of flutes defines a third flute distance between the first flow surface and the second flow surface; the second groove is adjacent to the first groove in the x-axis direction; the third flute is positioned in a y-axis direction relative to the first flute; the first flute distance differs from the second flute distance by more than 2 mm; the first flute distance differs from the third flute distance by more than 2 mm; Panel filter assembly.

[0327]

[0046] Embodiment 64. The plurality of laminated sheets of the filter media are discontinuous. The panel filter assembly according to any one of embodiments 63 and 65 to 76.

[0328] Embodiment 65. The plurality of laminated sheets of the filter media are continuous and separated by folds. The panel filter assembly according to any one of embodiments 63 to 64 and 66 to 76.

[0329] Embodiment 66. The first flute distance, the second flute distance, and the third flute distance differ by more than 2 mm. The panel filter assembly according to any one of embodiments 63 to 65 and 67 to 76.

[0330] Embodiment 67. At least one of the first flow surface and the second flow surface is non-planar. The panel filter assembly according to any one of embodiments 63 to 66 and 68 to 76.

[0331] Embodiment 68. At least one of the first flow surface and the second flow surface is concave. The panel filter assembly according to any one of embodiments 63 to 67 and 69 to 76.

[0332] Embodiment 69. The first flow surface and the second flow surface are both non-planar. The panel filter assembly according to any one of embodiments 63 to 68 and 70 to 76.

[0333] Embodiment 70. The first flow surface and the second flow surface are non-parallel. The panel filter assembly according to any one of embodiments 63 to 69 and 71 to 76.

[0334] Embodiment 71. The first flute distance differs from the second flute distance and the third flute distance by at least 5 mm. The panel filter assembly according to any one of embodiments 63 to 70 and 72 to 76.

[0335] Embodiment 72. The first flute distance differs from the second flute distance and the third flute distance by 3 mm to 20 mm. The panel filter assembly according to any one of embodiments 63 to 71 and 73 to 76.

[0336] Embodiment 73. The first flute distance differs from the second flute distance and the third flute distance by at least 8 mm. A panel filter assembly according to any one of embodiments 63 to 72 and 74 to 76.

[0337] Embodiment 74. The first flute distance differs from the second flute distance and the third flute distance by at least 15 mm. The panel filter assembly according to any one of embodiments 63 to 73 and 75 to 76.

[0338] Embodiment 75. The plurality of stacked sheets of filter media comprises alternating fluted sheets of filter media and facing sheets of filter media. The panel filter assembly according to any one of embodiments 63 to 74 and 76.

[0339] Embodiment 76. Each of the plurality of laminated sheets of filter media is a fluted sheet of filter media. 76. A panel filter assembly according to any one of embodiments 63 to 75.

[0340] Embodiment 77. A filter medium defining a plurality of flutes, a first edge defining a first flow surface, and a second flow surface opposite the first flow surface relative to the filter assembly; each of the plurality of flutes defines a flute opening at the first flow surface and a flute closure adjacent the second flow surface; the plurality of flutes includes at least one flute defining a flute opening that is non-planar; Filter assembly.

[0341] Embodiment 78. The filter media comprises a plurality of sheets of filter media in a laminated configuration. A filter assembly according to any one of embodiments 77 and 79 to 90.

[0342] Embodiment 79. The plurality of sheets of filter media comprises alternating fluted sheets of filter media and facing sheets of filter media. A filter assembly according to any one of embodiments 77 to 78 and 80 to 90.

[0343] Embodiment 80. The plurality of sheets of filter media are fluted sheets of filter media. A filter assembly according to any one of embodiments 77 to 79 and 81 to 90.

[0344] Embodiment 81. The filter media comprises a first sheet of filter media and a second sheet of filter media in a spiral configuration about a z-axis. A filter assembly according to any one of embodiments 77 to 80 and 82 to 90.

[0345] Embodiment 82. The first sheet of filter media is a fluted sheet; the second sheet of filter media is a facing sheet; A filter assembly according to any one of embodiments 77 to 81 and 83 to 90.

[0346] Embodiment 83. The filter assembly is a panel filter. A filter assembly according to any one of embodiments 77 to 82 and 84 to 90.

[0347] Embodiment 84. The first flute of the plurality of flutes defines a first flute distance between the first flow surface and the second flow surface; the second flute of the plurality of flutes defines a second flute distance between the first flow surface and the second flow surface; the first flute distance differs from the second flute distance by more than 2 mm; A filter assembly according to any one of embodiments 77 to 83 and 85 to 90.

[0348] Embodiment 85. The first flute distance differs from the second flute distance by at least 5 mm. A filter assembly according to any one of embodiments 77 to 84 and 86 to 90.

[0349] Embodiment 86. The first flute distance differs from the second flute distance by 3 mm to 20 mm. A filter assembly according to any one of embodiments 77 to 85 and 87 to 90.

[0350] Embodiment 87. The first flute distance differs from the second flute distance by at least 8 mm. A filter assembly described in any one of embodiments 77 to 86 and 88 to 90.

[0351] Embodiment 88. The first flute distance differs from the second flute distance by at least 15 mm. A filter assembly according to any one of embodiments 77 to 87 and 89 to 90.

[0352] Embodiment 89. The first flow surface and the second flow surface are both non-planar. A filter assembly described in any one of embodiments 77 to 88 and 90.

[0353] Embodiment 90. The flute closure is adjacent to the second flow surface. A filter assembly described in any one of embodiments 77 to 89.

[0354] Embodiment 91. A filter comprising a first sheet of filter media and a second sheet of filter media mutually defining a first plurality of flutes, a first flow surface, and a second flow surface; each of the first plurality of flutes extends from the first flow surface to the second flow surface; each of the first plurality of flutes defines a flute opening at the first flow surface and a flute closure adjacent the second flow surface; the first flow surface and the second flow surface are planar; the first flow surface is non-parallel to the second flow surface; Filter assembly.

[0355] Embodiment 92. The first sheet is a fluted sheet of filter media; the second sheet being a facing sheet of filter media; A filter assembly described in any one of embodiments 91 and 93 to 103.

[0356] Embodiment 93. The first sheet and the second sheet are both fluted sheets of filter media. A filter assembly described in any one of embodiments 91 to 92 and 94 to 103.

[0357] Embodiment 94. The flute closure is adjacent to the second flow surface. A filter assembly according to any one of embodiments 91 to 93 and 95 to 103.

[0358] Embodiment 95. The filter further comprises a third sheet of filter media. the third sheet of filter media and the second sheet of filter media mutually define the second plurality of flutes, the first flow surface, and the second flow surface; each of the second plurality of flutes extends from the first flow surface to the second flow surface; each of the second plurality of flutes defines a flute opening at the second flow surface and a flute closure adjacent the first flow surface; A filter assembly according to any one of embodiments 91 to 94 and 96 to 103.

[0359] Embodiment 96. The first plurality of flutes has a first flute defining a first flute distance between the first flow surface and the second flow surface and a second flute defining a second flute distance between the first flow surface and the second flow surface; the second plurality of flutes includes a third flute defining a third flute distance between the first flow surface and the second flow surface; each of the first flute distance, the second flute distance, and the third flute distance differ by more than 2 mm; A filter assembly according to any one of embodiments 91 to 95 and 97 to 103.

[0360] Embodiment 97. The filter assembly is a panel filter. A filter assembly described in any one of embodiments 91 to 96 and 98 to 103.

[0361] Embodiment 98. The first sheet of filter media and the second sheet of filter media define a spiral configuration about a z-axis. A filter assembly described in any one of embodiments 91 to 97 and 99 to 103.

[0362] Embodiment 99. A first flute of the first plurality of flutes defines a first flute distance between the first flow surface and the second flow surface; a second flute of the first plurality of flutes defines a second flute distance between the first flow surface and the second flow surface; the first flute distance differs from the second flute distance by more than 2 mm; A filter assembly according to any one of embodiments 91 to 98 and 100 to 103.

[0363] Embodiment 100. The first sheet and the second sheet are discontinuous. A filter assembly according to any one of embodiments 91 to 99 and 101 to 103.

[0364] Embodiment 101. The first sheet and the second sheet are contiguous and separated by a fold line. A filter assembly according to any one of embodiments 91 to 100 and 102 to 103.

[0365] Embodiment 102. The first flow surface is opposite the second flow surface with respect to the filter assembly. A filter assembly described in any one of embodiments 91 to 101 and 103.

[0366] Embodiment 103. The first plurality of flutes are parallel. A filter assembly described in any one of embodiments 91 to 102.

[0367] It should also be noted that, as used in this specification and the appended claims, the term "configured" describes a system, apparatus, or other structure that is constructed to perform a particular operation or adopt a particular structure. The term "configured" can be used interchangeably with similar terms such as "disposed," "built," "manufactured," etc.

[0368] All publications and patent applications in this specification are indicative of the level of skill of those skilled in the art to which this technology belongs. All publications and patent applications are incorporated herein by reference to the same extent as if each individual publication or patent application was specifically and individually indicated by reference. In the event of a conflict between the disclosure of this application and the disclosure of any document incorporated herein by reference, the disclosure of this application shall control.

[0369] This application is intended to cover any adaptations or variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not limiting, and that the claims are not limited to the illustrative embodiments set forth herein.

Claims

1. a housing extending between a first end and a second end, the housing defining a housing inlet, a separator outlet towards the second end, and a filtration outlet on the first end; a filter assembly having a first sheet of filter media bonded to a second sheet of filter media that mutually define a plurality of axially extending flutes, the filter assembly defining an inlet flow face and an outlet flow face; a rod extending through a center of the filter assembly, the rod having a proximal end positioned toward the outlet flow surface and a distal end positioned toward the inlet flow surface; Equipped with the filter assembly is disposed within the housing and coupled to the housing about the filtration outlet such that the outlet flow surface is in fluid communication with the filtration outlet; the inlet flow face having an axial flow face length; the distal end of the rod being a handle; Two-stage separator system.

2. a radial distance is defined between the inlet flow surface and the housing; the radial distance increases from the first end to the second end along at least a portion of the axial flow face length. The system of claim 1 .

3. the filter assembly having an outer radial barrier surface extending axially from the filtration outlet beyond the housing inlet; A system according to any one of claims 1 to 2.

4. the filter assembly having an outer radial barrier surface having an axial length from the outlet flow surface toward the inlet flow surface that is equal to or greater than the axial distance from the filtration outlet to the distal end of the housing inlet. A system according to any one of claims 1 to 3.

5. the housing inlet defines an airflow path tangential to the outer radial barrier surface of the filter assembly; A system according to any one of claims 3 and 4.

6. at least a portion of the outer radial barrier surface is defined by the first sheet of filter media; A system according to any one of claims 3 to 5.

7. the inlet flow face defines a taper from the first end toward the second end along at least a portion of the axial flow face length. A system according to any one of claims 1 to 6.

8. the taper increases from the first end to the second end along at least a portion of the axial flow face length. The system of claim 7.

9. the taper varies continuously along the axial flow face length from the first end toward the second end. A system according to any one of claims 7 to 8.

10. the taper increases continuously along the axial flow face length from the first end toward the second end. A system according to any one of claims 7 to 9.

11. a first sheet of the filter media is a facing sheet; the second sheet of filter media is a fluted sheet; A system according to any one of claims 1 to 10.

12. the first sheet of filter media and the second sheet of filter media define a spiral configuration about a z-axis extending in the axial direction. A system according to any one of claims 1 to 11.

13. and further comprising a rod receiving portion defined by the second end of the housing, the rod receiving portion configured to receive the distal end of the rod. A system according to any one of claims 1 to 12.

14. the filter assembly having a circular cross-section; A system according to any one of claims 1 to 13.

15. The filter assembly comprises: a plurality of first sheets of filter media and a plurality of second sheets of filter media in an alternating stacked configuration; a radial sleeve disposed about the stacked first sheet of filter media and the stacked second sheet of filter media; and Equipped with A system according to any one of claims 1 to 14.

16. the housing inlet is defined toward the first end of the housing; A system according to any one of claims 1 to 15.

Images