Patent Description:
Filter systems often use replaceable filter elements that are replaced when damaged or have reached the end of their serviceable life (e.g. when they have become full of particulates removed from the fluid being filtered). Portions of the filter systems, such as portions of the filter system to which the filter elements are mounted or mounting mechanisms for securing the filter elements within the filter system, are often reusable components.

Filter systems such as air intake systems will often have a mounting arrangement where a threaded shaft extends through an end of a filter element. An attachment member such as a nut or threaded handle will attach to the end of the threaded shaft and secure the filter element to the mounting arrangement.

One such system where this type of filter mounting arrangement is often employed is in air intakes for gas turbines. Here, a plurality of filter elements are mounted to a mounting arrangement in the form of a tube sheet. A mounting yoke will extend from the tube sheet and will include the threaded shaft for each of the filter elements that are mounted to the tube sheet. One intake system can have hundreds of individual filter elements.

Due to maintenance costs and the cost of downtime or periods of reduced operational output, it is valuable to limit the amount of time required to remove the old filter element and then mount the new filter element.

It is also desirable to make sure that the amount of load applied to the filter element by the attachment member is within a desired range. If the load is too big or too little, the seal between the filter element and the mounting arrangement (e.g. tube sheet) may be compromised and result in fluid leaks or premature damage to the seal allowing dirty fluid to bypass the filter element.

Additionally, the filter elements are often mounted in a cantilevered orientation with the tube sheet in a vertical orientation. Due to gravity, the cantilevered orientation can generate uneven forces on sealing elements because the sealing forces are not parallel to gravity. Instead, vertically lower portions of a seal may often have higher forces applied thereto than upper portions of the seal. This can require overloading the lower portions of the seal to get sufficient loading of vertically upper portions of the seal or under loading the upper portions of the seal when trying to obtain appropriate sealing forces for the lower portions of the seal, or a combination of both.

Also, because of how the filter elements are mounted and how closely they are positioned, it is often impossible to see the seal with the mounting arrangement to visually inspect the degree to which the seal has or seals have been compressed. This problem can be exacerbated in systems where multiple filter element sections are stacked axially relative to one another with seal members therebetween to form one larger filter element.

Further yet, it can be useful to prevent unauthorized filter elements to be used in a filter system to avoid inferior or inadequate filter elements from being employed.

In addition, due to the number of filter elements that are often employed, the filter elements are often packed close together limiting the flow space between adjacent filter elements. The applicants have determined that as filter elements are packed more tightly and closer together, the limited space therebetween can inhibit air flow upstream of the system which may increase pressure drop across the system. The applicants have determined that reducing flow disturbance and flow separation can reduce flow restriction and turbulence around and through the filter elements, and thus reducepressure loss. This can allow for any one of or any combination of smaller filter elements, fewer filter elements, more tight packing of the filter elements, or improved pressure performance of the overall system. Reduced flow separation from the upstream surface of the filter element can also improve the full usage of all filter media of the filter elements.

The present disclosure relates to improvements over the current state of the art that can provide one or more of the following: reduced maintenance time and/or improved repeatability in applying a desired seal loading to the filter element and associated seals and/or alternative filter element spacing and/or size and design. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.

The following documents may provide technical background to the present disclosure: <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; and <CIT>.

New filter elements, filter mounting systems, filter systems, methods of servicing filter systems, and methods of mounting filter elements are provided herein.

A filter element including a tube of filter media and a seal member is provided, as defined in appended claim <NUM>. The tube of filter media extends axially between a first end and a second end. The tube of filter media defines a central cavity. The tube of filter media is frustoconical increasing in radial dimension when moving along a central axis from the second end towards the first end. The tube of filter media extends at a first angle relative to the central axis. The filter media of the tube of filter media has a radially inner most edge at the first end. The seal member is attached to a first end of the tube of filter media. The seal member has a radially inward facing tapered inner surface. The tapered inner surface extends at a second angle relative to the central axis. The first angle is more parallel to the central axis than the second angle.

In one example, the first and second angles are less than <NUM> degrees.

In one example, an axially outermost extent of the tapered inner surface of the seal member that is spaced axially the furthest from the first end of the tube of filter media is positioned radially outward of the inner most edge at the first end.

In one example, the cross-sectional shape of the tube of filter media and the first seal member is generally polygonal. The polygonal shape of the seal member defines a plurality of straight sides interconnected by a plurality of corner region. The second angle is measured in a portion of the polygonal shape of the seal member defined by a straight side.

In one example, the corner portions of the radially inward facing surface of the seal member extend at a third angle relative to the central axis. The third angle is more parallel to the central axis than the second angle.

In an example, a filter system including a tube sheet and a filter element is provided. The tube sheet defines a flow aperture therethrough. The filter element is mounted to the tube sheet. The filter element includes a tube of filter media defining a central cavity. The tube of filter media extends between first and second ends along a central axis. The first end is adjacent the tube sheet. The filter element includes a first seal member attached to the first end of the tube of filter media. The first seal member is annular and defines a flow opening in fluid communication with the central cavity. The first seal member includes a radially inward facing surface. The radially inward facing surface is tapered at a first angle relative to the central axis of the tube of filter media such that the radially inward facing surface is spaced further from the central axis when moving axially away from the tube of filter media.

In one example, the tube of filter media is frustoconical and is tapered relative to the central axis at a second angle such that an outer periphery of the tube of filter media increases in radial dimension when moving from the second end towards the first end. The second angle is more parallel to the central axis than the first angle.

In one example, the first end of the tube of filter media defines an inner edge. The inner edge is spaced radially inward of a periphery of the flow aperture through the tube sheet.

In one example, the tube of filter media has a plurality of first sides and the flow aperture through the tube sheet has a plurality of second sides. The first and second sides have a same number of sides. Corresponding ones of the first and second sides are parallel. The inner edge of the tube of filter media extends along, at least, the plurality of first sides. The periphery of the flow aperture through the tube sheet extends along, at least in part, the plurality of second sides.

In one example, the radially inward facing surface has a first surface edge spaced axially from the tube of filter media. The first surface edge is spaced radially between the inner edge of the tube of filter media and the periphery of the flow aperture.

In one example, the radially inward facing surface has a second surface edge. The second surface edge being closer to the second end of the tube of filter media than the first surface edge. The second surface edge is spaced radially inward of the first surface edge.

In one example, the first seal member has an axially facing abutment shoulder that faces away from the tube of filter media. The first surface edge is formed at the intersection of the axially facing abutment shoulder and the radially inward facing surface.

In one example, the axially facing abutment shoulder abuts the tube sheet when the filter element is mounted to the tube sheet.

On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.

<FIG> partially illustrates a filtration system <NUM> according to a first example of the disclosure. The filtration system <NUM> finds particular use in high volume air filtration systems, such as in a filter house that may form the intake for a gas turbine engine. The system includes a plurality of filter elements <NUM> mounted to a mounting arrangement illustrated in the form of a tube sheet <NUM>. Mounting yokes <NUM> (one illustrated in full detail in <FIG>) are attached to or proximate the tube sheet <NUM> to secure the filter element <NUM> to the tube sheet <NUM>. Attachment members, illustrated in the form of threaded handles <NUM>, secure filter elements <NUM> to corresponding mounting yokes <NUM>.

While only two filter elements <NUM> are illustrated, these systems will typically have many if not hundreds of filter elements <NUM>. As such, minor improvements associated with each filter element can provide significant advantages for the overall system (e.g. improved filtration, reduced pressure drop, improved sealing or improved maintenance efficiency).

In general, the filter elements <NUM> are tubular defining internal cavities. When mounted, internal cavities <NUM> defined by the filter elements <NUM> are in fluid communication with flow apertures <NUM> extending through the tube sheet <NUM>. A tube sheet seal <NUM> of the filter element <NUM> seals the internal cavity of the filter element <NUM> to the tube sheet to prevent fluid bypass between the filter element <NUM> and the tube sheet <NUM>.

In the illustrated example, each filter element <NUM> includes a pair of filter element sections <NUM>, <NUM> in a stacked orientation. Each filter element section <NUM>, <NUM> includes a section of filter media <NUM>, <NUM> through which dirty fluid will flow to remove particulates and/or other impurities entrained in the fluid to be filtered. In this example, the sections of filter media <NUM>, <NUM> form tubes of filter media that are generally triangular in cross-section. The tubes are also generally frusto-conical such that they narrow in dimension when moving from the second end <NUM> toward the first end <NUM>, e.g. away from the tube sheet <NUM>.

In other embodiments, the tubes need not be frusto-conical and could have a constant cross-section their entire length. Further, in other embodiments, the filter element <NUM> could be formed from a single section. Further, other cross-sectional shapes are contemplated.

The filter element sections <NUM>, <NUM> are formed from a plurality of separate filter media panels combined to form a generally triangular cross-section when viewed in a plane orthogonal to a central axis of the filter element sections <NUM>, <NUM> and the frusto-conical tube. <FIG> is a cross-sectional illustration through filter element sections <NUM>. As illustrated, the filter element section <NUM> includes three separate panel sections <NUM> that are interconnected to one another. The panel sections <NUM> are generally flat panels that have a trapezoidal outer periphery. The trapezoidal outer periphery may be viewed in <FIG>. Typically, the trapezoidal outer periphery is an isosceles trapezoid with the parallel sides being generally parallel to the tube sheet and proximate corresponding seal members.

With reference to <FIG> and <FIG>, each panel section <NUM> includes a filter media panel <NUM> and a filter media panel support member that includes inner and outer mesh supports <NUM>, <NUM>. A clip in the form u-shaped connector <NUM> secures wing portions of adjacent panel sections <NUM> to one another.

With reference to <FIG> and <FIG>, the inner and outer mesh supports <NUM>, <NUM> are interfolded with one another as well as a portion <NUM> of the pleated filter media to secure the portions of a panel section <NUM> together into a single unit. The interfolding of the filter media in the wing portions also provides improved sealing between the adjacent panel sections <NUM>.

In the illustrated example, the interfolded portions of a panel section <NUM> form the wing portions of each panel section <NUM>. It is these wing portions of adjacent panel sections <NUM> that are then clipped or secured together using clip <NUM> to form the tubular filter element <NUM>.

<FIG> is partial illustration of two exploded panel sections <NUM> and <FIG> illustrates two panel sections <NUM> after final assembly.

The inner and outer mesh supports <NUM>, <NUM> wrap around to protect and support the filter media panel <NUM>. Each side (e.g. wing portion) of each panel section <NUM> is a mirror image of one another so only one side (e.g. wing portion) need be described.

In this example, the inner mesh support <NUM> includes a main panel <NUM> and a connection region <NUM> that includes an intermediate section <NUM>, a bend <NUM> and an end section <NUM>. The intermediate section <NUM> extends at an angle to main panel <NUM> and end section <NUM> folds back over the intermediate section <NUM> by way of bend <NUM>. This forms a receiving slot <NUM> between the intermediate section <NUM> and the end section <NUM>.

The outer mesh support <NUM> has a main panel <NUM>, an intermediate side section <NUM> and an end section <NUM>. The intermediate side section <NUM> extends adjacent a side of the filter media panel towards the inner mesh support <NUM>. The end section <NUM> extends outward from the side of the filter media and relative to the main panel <NUM> of the inner mesh support <NUM> at an angle. The end section <NUM> forms a connection region of the outer mesh support <NUM>.

When assembled, the connection region of the outer mesh support <NUM> cooperates with the connection region <NUM> of the inner mesh support <NUM> to secure the inner and outer mesh supports <NUM>, <NUM> to one another. The end section <NUM> of the outer mesh support <NUM> is received in the receiving slot <NUM> of the inner mesh support <NUM>.

Main panel <NUM> is proximate an inner surface <NUM> of filter media panel <NUM> and main panel <NUM> is proximate an outer surface <NUM> of filter media panel <NUM>. The main panels <NUM>, <NUM> and inner and outer surfaces <NUM>, <NUM> of the filter media <NUM> are generally parallel.

The intermediate side section <NUM> of the outer mesh support <NUM> is proximate a side surface <NUM> that extends between the inner and outer surfaces <NUM>, <NUM> of the filter media panel <NUM>, typically, but not necessarily, in perpendicular fashion. The side surface <NUM> and intermediate side section <NUM> are generally parallel to one another.

When assembled, intermediate section <NUM>, end section <NUM> and end section <NUM> are generally parallel to one another. The end section <NUM> and end section <NUM> generally extend at a same angle relative to main panel <NUM> and inner surface <NUM>.

With reference to <FIG>, a first section <NUM> of the end portion <NUM> of the filter media panel <NUM> is captured between intermediate section <NUM> and end section <NUM> while a second section <NUM> of the end portion <NUM> is captured between end section <NUM> and end section <NUM>.

Once each panel section <NUM> is formed, adjacent panel sections <NUM> are interconnected. To do this, the intermediate sections <NUM> of the inner mesh support <NUM> of each adjacent panel section <NUM> are positioned adjacent one another and the u-shaped connector <NUM> is installed to secure the folded over regions of the panel sections <NUM> to one another. The u-shaped connector may be crimped and plastically deformed to secure the components to one another.

In some embodiments, a sealing material may be provided between the adjacent wing portions and particularly between intermediate sections <NUM>. The sealing material may be in the form of an adhesive. For example, hot melt or urethane, such as foamed urethane may be employed. Further yet, sealing material may be applied between the filter media and the inner and outer mesh supports <NUM>, <NUM>, such as between the wing portions of the panel sections <NUM> and the end portions <NUM> of the filter media. The addition of the seal material prevents or reduces leak paths.

The overlapping portions of the panel sections <NUM> as well as u-shaped connector provide axial rigidity to the corresponding filter element section <NUM>, <NUM>. The positioning of the connector <NUM> as well as portions of the mesh supports <NUM>, <NUM> provide a high stiffness-to-weight ratio, which prevents the need for standalone structural members to accommodate the axial compression forces required for mounting and/or sealing to the tube sheet <NUM>.

Once the panel section sections <NUM> are interconnected, various seals or other components forming the ends of the filter element sections <NUM>, <NUM> may be attached or molded thereto.

In some embodiments, the mesh supports <NUM>, <NUM> are formed from steel mesh. The u-shaped connector <NUM> may be formed from extruded metal and particularly extruded steel.

Further, other cross-sectional shapes are contemplated such as circular, rectangle, etc. Some particular benefits may be provided for some shapes that are not provided for other shapes. In <FIG>, a filter element <NUM> is provided with filter element sections <NUM>, <NUM> having circular cross-sectional shapes. The first filter element section <NUM> has a constant outer diameter from one end to the other while the second filter element section <NUM> has a frusto-conical configuration.

With reference to <FIG> and <FIG>, a mating seal arrangement <NUM> is provided between the stacked filter element sections <NUM>, <NUM> to prevent fluid bypass. While not required, in some examples, clocking features are provided to properly angularly orient the stacked filter element sections <NUM>, <NUM> and/or prevent relative angular motion therebetween. In this example, the clocking features are incorporated into the shape and profile of the mating components of the mating seal arrangement <NUM>.

Further yet, in other embodiments, the stacked filter element sections may be clocked directly to the tube sheet <NUM>. For example, mating projections and recesses provided by the filter element section <NUM> and/or the tube sheet <NUM> could be provided. Further, non-circular shapes of the filter element could be used in conjunction with projections or recesses formed in the tube sheet <NUM> for clocking purposes. A separate clocking adaptor could be attached to the tube sheet <NUM> or the mounting yoke <NUM> for clocking of the filter element sections <NUM>, <NUM>. It is contemplated that round filter element sections <NUM>, <NUM> could be clocked as well. In such an instance, the clocking features could be provided on the axial ends or project radially outward from the associated seals or endcaps (if provided).

Further, the triangular shape of the mounting yoke <NUM> also clocks the filter elements <NUM> relative to the tube sheet <NUM> and mounting yoke <NUM> in the illustrated example.

While this example illustrates stacked filter element sections <NUM>, <NUM>, other filter elements may incorporate only a single section or more than two sections.

The filter elements <NUM> extend longitudinally between first and second ends <NUM>, <NUM>. One end is provided by each of the filter element sections <NUM>, <NUM> in this example.

With reference to <FIG> and <FIG>, at the first end <NUM>, an end plate <NUM> is provided. The end plate <NUM> includes an end plate aperture <NUM> (also referred to herein as a "mounting aperture"). A threaded shank <NUM> of the mounting yoke <NUM> operably extends through the end plate <NUM> and particularly end plate aperture <NUM> when the filter element <NUM> is mounted.

The end plate <NUM> in this example is reusable and is not permanently attached to the filter element <NUM> (e.g. permanently attached to either filter element section <NUM> or <NUM>). In other words, either filter element <NUM> or the end plate <NUM> is not damaged when the two components are separated. Instead, an end plate seal <NUM> is provided by first filter element section <NUM> and cooperates with the end plate <NUM> so that the end plate <NUM> is removably sealed to the first filter element section <NUM> when the filter element <NUM> is mounted.

With reference to <FIG> and <FIG>, in other embodiments, the end plate <NUM> may be permanently attached to the filter media of the filter element <NUM>. For example, the end plate <NUM> could be permanently attached to the filter media of first filter element section <NUM> and the end plate can form an end cap for that end of the first filter element section <NUM>.

With reference to <FIG> and the embodiment therein, the end plate <NUM> is formed from a plurality of components. The end plate <NUM> includes an outer shell <NUM> and an inner plate <NUM>. The inner plate <NUM> is partially embedded in the outer shell <NUM>. The outer shell <NUM> may be molded to the inner plate <NUM>. The inner plate <NUM> optionally includes through holes (see e.g. <FIG>) to allow material of the outer shell <NUM> to pass therethrough during molding of the outer shell <NUM> to the inner plate <NUM> and improve engagement therebetween. In some instances, the outer shell is a urethane and is molded in a molten state. In some embodiments, the end plate <NUM> is a single piece continuous component.

In an example, the inner plate <NUM> is formed from metal, such as stamped metal while the outer shell <NUM> is formed from plastic or rubber. In one example, the outer shell may be formed from polyurethane. However, in other arrangements, the outer shell <NUM> or inner plate <NUM> may be formed from plastics. Further yet, in some arrangements, the outer shell <NUM> is entirely eliminated and only the inner plate <NUM> is provided.

In some examples, the end plate seal <NUM> could be formed by the outer shell <NUM> or the end plate. In further examples, the end plate seal <NUM> may be entirely independent of the end plate <NUM> or the filter element <NUM>.

In this example, the inner plate <NUM> provides increased rigidity to the end plate <NUM> and allows for transmitting axial loading provided by the handle <NUM> to the filter element sections <NUM>, <NUM> to press the tube sheet seal <NUM> against a sealing surface of the tube sheet <NUM> surrounding flow aperture <NUM>. This force can also compress other axial seals within the arrangement.

Clocking features between the end plate <NUM> and the first filter element section <NUM> are provided. In this example, the clocking features are provided by a mating groove <NUM> and projection <NUM> provided by end plate <NUM> (e.g. outer shell <NUM>) and end plate seal <NUM> (see also <FIG> for these features). These components could be flipped in other embodiments. Further, other clocking features could be provided such as a plurality of separate projections and recesses that can be provided either or both of the mating components. Further yet, the general shape of the filter element (e.g. the triangular periphery in this example) could be used to clock the components relative to one another.

With reference to <FIG> and <FIG>, the seal between the end plate <NUM> and the end plate seal <NUM> is described in more detail. The projection <NUM> of end plate <NUM> provides a first sealing rib <NUM> that projects axially from a body of the end plate that provides outward facing surface <NUM>. The first sealing rib <NUM> is generally annular and forms a gasket. Notably, something that is annular need not be circular and could have other peripheral shapes. In this example, the first sealing rib <NUM> is generally triangular. The first sealing rib <NUM> is spaced radially inward from outer edge <NUM> and radially outward from inner edge <NUM>. The inner edge <NUM> is where the surface <NUM> meets an inner portion if inner plate <NUM>. As such, there is a portion of surface <NUM> radially outward of sealing rib <NUM> and radially inward of sealing rib <NUM>.

Again, the sealing rib <NUM>, in this embodiment, is annular and triangular in shape and thus has three sides illustrated as generally straight sections <NUM> with adjacent straight sections <NUM> interconnected by a corresponding corner portion <NUM>.

The straight sections <NUM> have a thickness T1 that is generally greater than a thickness T2 of the corner portions <NUM>.

As illustrated in <FIG>, the inner plate <NUM> has outward extending flange portions <NUM> that extend generally along each side of the triangular periphery of the inner plate <NUM> and end plate <NUM>. In this example, the flange portions <NUM> extend axially into the first sealing rib <NUM> and outward beyond outward facing surface <NUM>. This allows the inner plate <NUM> and particularly the flange portions <NUM> to provide increased rigidity to the first sealing rib <NUM>.

In this embodiment, the end plate seal <NUM> is molded to the filter media of first filter element section <NUM>. The end plate seal <NUM> has cooperating structure that cooperates with the first sealing rib <NUM> and the outward facing surface <NUM> of the end plate <NUM>.

With principle reference to <FIG>, the end plate seal <NUM> has a second sealing rib <NUM> that is annular and triangular in shape when viewed in a plane generally orthogonal to a central axis of the filter element section. The triangular shape has straight sections <NUM> interconnected by corner portions <NUM>. The annular configuration of second sealing rib <NUM> forms a gasket. The shape and size of the second sealing rib <NUM> coordinates with the shape and size of the first sealing rib <NUM> to provide a primary seal interface between the first and second sealing ribs <NUM>, <NUM> when in an installed state.

With reference to <FIG> and <FIG>, a pair of shoulders <NUM>, <NUM> straddle the second sealing rib <NUM>. Shoulder <NUM> is radially outward of the second sealing rib <NUM> while shoulder <NUM> is radially inward of second sealing rib <NUM>. The shoulders <NUM>, <NUM> extend axially outward, e.g. away from the filter media of the first filter element section <NUM>, farther than the second sealing rib <NUM>. This forms groove <NUM> identified above in the outward facing end of the end plate seal <NUM>.

In this example, the second sealing rib <NUM> is fully recessed relative to shoulders <NUM>, <NUM>. The groove <NUM>, in this example, is annular.

Thus, in this example, the end plate seal <NUM> may be considered a female component while the end plate <NUM> may be considered male component. Again, this arrangement can be reversed in other examples.

The first and second shoulders <NUM>, <NUM> are radially spaced from the second sealing rib <NUM> such that channels <NUM>, <NUM> are formed therebetween. Channels <NUM>, <NUM> are annular and have a triangular shape. Preferably, the adjacent walls of the shoulders <NUM>, <NUM> and the second sealing rib <NUM> are tapered relative to one another such that the channels <NUM>, <NUM> get wider when moving axially away from the filter media of the first filter element section <NUM>.

In this example, with reference to <FIG>, the straight sections <NUM> have a thickness T3 that is greater than thickness T4 of the corner regions <NUM>. Further, in some, but not all, embodiments, the thickness T1 of rib <NUM> in the straight portions <NUM> is greater than corresponding thickness T3 while thickness T2 of corner portions <NUM> is greater than corresponding thickness T4. The smaller thickness T4 in the corner regions <NUM> relative to thickness T3 allows reduced localized axial clamping force to sufficiently compress the sealing rib <NUM> in the corner regions <NUM> and prevent dirty fluid bypass.

When assembled, such as illustrated in <FIG>, a primary seal that is axially oriented is formed between the first and second sealing ribs <NUM>, <NUM>. The outer shoulders <NUM>, <NUM> will axially abut the outer and inner portions of outward facing surface <NUM> and provide a gasket stop as well as provide secondary sealing functionality. The abutment of shoulders <NUM>, <NUM> with outward facing surface <NUM> also provides increased stability at the interface between the end plate <NUM> and end plate seal <NUM>.

In one example, the first sealing rib <NUM> extends axially from the outward facing surface <NUM> a greater distance than the second sealing rib <NUM> is recessed inward relative to the shoulders <NUM>, <NUM>. This allows the sealing ribs <NUM>, <NUM> to axially engage prior to the shoulders <NUM>, <NUM> engaging surface <NUM>. Thus, during assembly, one or both of the sealing ribs <NUM>, <NUM> will axially compress prior to engagement between the shoulders <NUM>, <NUM> and surface <NUM>. As such, when the user is tightening the end plate <NUM> against the first filter element section <NUM>, significant tactile feedback will occur once the end plate <NUM> is fully seated against the first filter element section <NUM> and particularly against the end plate seal <NUM>.

The triangular shape of the sealing rib <NUM> and groove <NUM> clock the end plate <NUM> to the end plate seal <NUM> to clock the end plate <NUM> to the filter element section <NUM>.

With reference to <FIG> and <FIG>, the configuration of the mating seal arrangement <NUM> between the first and second filter element sections <NUM>, <NUM>, is the same configuration as between the end plate <NUM> and the end plate seal <NUM>. The seal arrangement <NUM> includes a first seal member <NUM> that mates with a second seal member <NUM>.

The first seal member <NUM> is provided by the first filter element section <NUM> and the second seal member <NUM> is provided by the second filter element section <NUM>. The first seal member <NUM> has the same mating structures as those provided by end plate <NUM> discussed previously. More particularly, first seal member <NUM> includes sealing rib <NUM> and adjacent surfaces <NUM>, <NUM>.

However, unlike the end plate <NUM>, which is generally impermeable because it closes off the end of the filter element <NUM> by closing off the end of filter element section <NUM>, the first seal member <NUM> is annular and has opening <NUM> to permit fluid flow between the interior cavities formed by filter element section <NUM> and filter element section <NUM>.

The second seal member <NUM> is substantially the same as end plate seal <NUM> except it may be dimension differently due to the frusto-conical configuration of filter element <NUM>. The second seal member <NUM> includes seal rib <NUM>, shoulders <NUM>, <NUM> and recess <NUM> that forms an annular groove.

This seal arrangement <NUM> and the cooperating axially abuting ribs, shoulders and surfaces provides improved stability as noted above between the end plate <NUM> and end plate seal <NUM>.

It is noted that while the first seal member <NUM> is illustrated as being the male component and the second seal member <NUM> is illustrated as being the female component, these configurations could be reversed.

The mating relationship between the first and second seal members <NUM>, <NUM> clocks the filter element sections <NUM>, <NUM> to one another.

The male components, e.g. end plate <NUM> and first seal member <NUM>, are typically formed from a more rigid material than the female components, e.g. end plate gasket <NUM> and second seal member <NUM>. This allows for more predictable deformation of the components of the seal arrangements. More particularly, the less rigid sealing ribs of the female components will compress first/prior to the more rigid sealing ribs of the male components. In some embodiments, the sealing ribs of the female components are configured to compress about one-half of their axial height when the cooperating components are properly axially engaged with one another after assembly. This better ensures that a predetermined amount of axial compression is applied to the sealing rib of the female component.

Tactile feedback can be provided to the operator because once the sealing ribs properly compress, the shoulders will then abut the cooperating surfaces of the other component providing an increase in resistance to further compression of the seal arrangement. The shoulders will thus operate as a gasket stop informing the user of when appropriate pressure has been reached and/or inhibit over compression of the seal ribs.

At the end of the second filter element section <NUM> opposite second seal member <NUM> is tube sheet seal <NUM>. The tube sheet seal <NUM> includes a sealing rib <NUM> that is straddled by shoulders <NUM>, <NUM>. The sealing rib <NUM> is separated from shoulders <NUM>, <NUM> by channels <NUM>, <NUM>. Again, similar to seal ribs <NUM>, <NUM> above, when appropriate amount of axial compression is applied to tube sheet seal <NUM>, seal rib <NUM> will be sufficiently compressed and the shoulders <NUM>, <NUM> will abut tube sheet <NUM> and act as a gasket stop inhibiting further compression, e.g. over compression, of the seal rib <NUM>.

Unlike the other sealing ribs <NUM>, <NUM>, sealing rib <NUM> projects axially outward beyond the end of should <NUM>, <NUM>. This is because the cooperating seal surface of the tube sheet <NUM> is generally flat (see e.g. <FIG>).

However, it is contemplated that the sealing rib <NUM> could be recessed and the tube sheet <NUM> could provide a corresponding axial projection. This could also further facilitate clocking of the filter element <NUM> and particularly tube sheet seal <NUM> to the tube sheet <NUM>.

As illustrated in <FIG> and <FIG>, the radially inward facing surface <NUM> of the tube sheet seal <NUM> is tapered radially inward when moving axially away from the tube sheet <NUM>. Notably, the angle α1 of surface <NUM> from an axis <NUM> orthogonal to the tube sheet <NUM> is typically greater than angle α2 of the angular relationship of the sides of the filter element section <NUM> to axis <NUM>. Angle α2 corresponds to the angle of the inner surface of the panel section <NUM> (e.g. the inner surface of the inner mesh support or the inner surface of the filter media) relative to axis <NUM>. Axis <NUM> is typically parallel to a central axis of the filter element <NUM>.

In the illustrated example, the tube sheet seal <NUM> and the flow apertures <NUM> are configured such that inner edge <NUM> of the end <NUM> of the filter media panel <NUM> closest the tube sheet <NUM> is spaced radially inward of the corresponding side of the aperture <NUM> illustrated by space R1 in <FIG>. This applies for all three sides of the filter element <NUM>. As illustrated in <FIG>, the dimension D1 of the aperture <NUM> is thus greater than dimension D2 formed between opposed inner edges <NUM> of the end <NUM> of the filter media panels <NUM>.

The inclusion of tapered surface <NUM> provides a fairing at the outlet from the interior cavity of the filter element <NUM>. This arrangement provides some static pressure recovery. The different angles and particularly more tapered magnitude of angle α1 improves the recovery of static pressure. In a preferred example angle α1 will be at least <NUM> degrees but less than <NUM> degrees. This tapered arrangement allows the flow exiting the filter element <NUM> to diffuse before reaching the tube sheet aperture <NUM>. This also reduces the extent of any wake in the air flow exiting the filter element and tube sheet <NUM>. This provides an associated reduction in total pressure loss across the filter element <NUM>.

This results in a filter element with a lower pressure loss for a given airflow, or higher air flow for a given pressure drop. This can provide benefits including, but not limited to, use of fewer filter elements, higher efficiency media which can provide longer life to downstream components, higher output by downstream components (such as turbines) or longer filter life by allowing for a larger degree of pressure drop due to increased amount of loading of impurities filter from the air flowing through the filter media.

By reducing the pressure losses associated with the system, air flow through the filter system can be increased, thus allowing for a reduced number of filter elements <NUM> required for a given air flow rate.

The inner surface <NUM> of the tube sheet seal <NUM> within the corner region has an angle α3 (see <FIG>) that is more parallel to axis <NUM> than angle α1. This angle α3 is configured to promote a snug fit engagement of the corner regions of the inner surface <NUM> with the legs <NUM> of the yoke <NUM>. This promotes proper alignment (i.e. clocking) of the filter element section <NUM> relative to aperture <NUM>. In some embodiments, the corner regions form sweeps or pockets that receive and wrap around the legs of the yoke <NUM> when mounted.

With reference to <FIG> and <FIG>, the tube sheet seal <NUM> includes pockets <NUM> for receiving the yoke bolts <NUM> in each corner. In this example, the pockets <NUM> receive the heads of yoke bolts <NUM>. By capturing the heads of the yoke bolts <NUM> within the pockets <NUM>, the tube sheet seal <NUM> inhibits back driving of the yoke bolts <NUM> in use.

In <FIG> and <FIG> the tapered region (e.g. surface <NUM>) is provided by the tube sheet seal <NUM> that is integrally formed with the rest of the filter element section <NUM>, e.g. molded directly to or adhesively secured directly the panel sections <NUM>.

With reference to <FIG>, in alternative embodiments, a tapered outlet adapter <NUM> could be provided.

The outlet adapter <NUM> has a tube sheet end <NUM> that is substantially identical to the outlet end of the tube sheet seal <NUM> described previously. As such, the tube sheet end <NUM> may include a sealing rib one or more shoulders that act as a gasket stop as well as pockets for receiving yoke bolts <NUM>. Further yet, the adapter <NUM> may have tapered inner surface <NUM>. However, in this example, the adaptor is a separate component from the rest of filter element <NUM>. This adaptor may be reusable with other filter element sections.

A filter element end <NUM> of the adaptor <NUM> would be configured similar to second gasket <NUM> described previously and would be configured to mate with a seal of a corresponding filter element/filter element section that is similar to first seal member <NUM> provided by the filter element/filter element section.

In other examples, the streamlined fairing, e.g. tapered surface <NUM>, could be provided by a component that forms part of the tube sheet <NUM>. For example, the adaptor <NUM> could be incorporated into or permanently secured to the tube sheet <NUM>.

The adaptor <NUM> may be molded, pressed metal, <NUM>-d printed, a polymer molding or co-molding with a metal insert.

When the adapter <NUM> is a separate component, the corners of the adaptor <NUM> may be configured similar to corner regions of the tube sheet seal <NUM> and provide a snug fit arrangement with legs <NUM> of the filter mounting yoke <NUM>.

For pleated filter media, media permeability, overall media area, pleat size and spacing all influence the pressure loss across the media pack and hence the relative distribution of pressure losses between the media pack and filter framework. For the same filter element topology, but different media packs, different adapters/fairings may be supplied or attached to the filter element, with varying lengths, inlet or outlet areas, depending on whether lower cost, lower pressure loss, or increased media area are desired. For example, a cartridge filter with a deeper media pack and an adapter would have the same outlet aperture, and therefore, similar outlet pressure loss, as a filter with a shallower media pack, and could utilize the same mounting arrangement inside the filter system.

While the adaptor is shown in use with a triangularly shaped filter element, the adaptor concept is equally applicable to filters of different shapes, such as, without limitation, round or square cross-section filter elements.

In addition to the outlet end of the filter elements <NUM> having pressure reduction features, e.g. the tapered inner surfaces of either the seal member <NUM> that cooperates with the tube sheet <NUM> or the adapter <NUM>, the end plate <NUM> includes pressure reduction features. Again, reduced pressure loss for the air flowing the system can provide one or more of the benefits mentioned above as it relates to air flow through the system.

As filter elements <NUM> are positioned closer together to reduce the size of the filter house, increase the number of filter elements in a filter house, or a combination of both, the filter framework and components of the system can disrupt the air flow approaching the filtration media creating drag and leading to increased pressure loss.

As such, an end face of the end plate <NUM> includes fairing features on the radial outer most periphery to help reduce disturbance to the incident airflow at the upstream end of the filter element <NUM>, e.g. the end spaced away from tube sheet <NUM>. Flow separation from this peripheral edge is reduced or eliminated and flow entering the passage between two adjacent filters will have a lower, more uniform velocity. This reduces drag as well as allows the air flow to more effectively use and pass through the filter media proximate the end plate <NUM> rather than flowing around the end plate <NUM> and then first coming into contact with the filter media at a location spaced away from the end plate <NUM> and closer to the tube sheet <NUM>. This increases the amount of useable surface area of the filter element <NUM> thereby reducing pressure drop across the filter element <NUM> as well as the service life of the filter element <NUM>.

With reference to FGS. <NUM> and <NUM>, in one example, the fairing of the end plate <NUM> is a curved profile incorporated into the outer periphery of the end plate <NUM> such as illustrated proximate arrows <NUM>. In the illustrated example, the curved profile <NUM> is provided by a half round but could take other shapes such as quarter round curved profile. In this example, the radially outer portion of the half round may be the only functional portion of the half round profile. The curved profile need not have a constant radius of curvature. Further, it could be different than <NUM> degree (half round) or <NUM> degree (quarter round) profiles as mentioned above.

In a preferred example, the radius of curvature R2 of the curved profile <NUM> is at least <NUM>% of the shortest distance between the edge of the end plate and its centroid, more preferably at least <NUM>% of this distance. The larger the radius of curvature R2 the reduced amount of disturbance that occurs to the airflow as it flows around the curved profile <NUM> of the end plate <NUM> by providing a smaller rate of change in the flow direction.

The centroid may or may not go through the center of the mounting aperture through the end plate.

The curved profile <NUM> preferably extends radially outward to the upper most outer edge <NUM> of the panel section <NUM> and radially inward as illustrated by radial dimension R3 at least <NUM>% of the shortest distance between the edge of the end plate <NUM> and its centroid, more preferably at least <NUM>% of this distance.

The radius of curvature R2 of the curved profile <NUM> is also preferably at least <NUM>% and ideally <NUM>% of the distance between the outermost edge of end plate <NUM> and the parallel edge of end plate on the next adjacent filter.

Preferably, the curved profile <NUM> is also at least a quarter round such that the curved surface extends at least <NUM> degrees if it has a constant radius of curvature.

In some examples, the axial height H1 of the curved profile <NUM> is at least <NUM>% of thickness T5, more preferably at least <NUM>% of thickness T5.

The curved profile <NUM> can be provided by a removable/reusable end plate <NUM> such as the end plate <NUM> illustrated in <FIG>, or could be formed by an end plate that is permanently attached to the filter element <NUM> such as by way of being adhesively secured or molded to the rest of the filter element <NUM>. In the illustrated example, the curved profile <NUM> and associate fairings provided thereby are formed by the outer shell <NUM> of the end plate <NUM>.

The curved profile could be provided by a fabricated component, a pressed metal part, a <NUM>-d printed part, a polymer molded part, a component co-molded with a metal insert.

The inlet fairings may have cut-outs, or recesses to facilitate mounting and securing of the filter in a holding frame or to yoke <NUM>. Where fairings are separate components that are reusable, they may include seals or gaskets on mating surfaces.

With reference to <FIG>, a compression member <NUM>, illustrated in the form of a washer, is interposed between the handle <NUM> and the end plate <NUM>. In this example, the compression member <NUM> is also interposed between the end plate <NUM> (particularly the inner plate <NUM>) and the threaded shank <NUM> of the mounting yoke <NUM>.

The compression member <NUM>, of this example, provides a first function of sealing the end plate <NUM> to the threaded shank <NUM> of the mounting yoke <NUM> to prevent dirty fluid bypass through the end plate aperture <NUM>. More particularly, the compression member <NUM> includes a seal region <NUM>, which may be referred to or provided as a separate seal. With additional reference to <FIG>, the seal region <NUM> is a helical wiper seal on an inner diameter of a bore <NUM> also referred to as a compression member aperture through the compression member <NUM>. The helical wiper seal is sized and configured to mate with the external threads <NUM> of the threaded shank <NUM>. Thus, the seal region <NUM> is generally a threaded structure with several threads that mate with and are similar to the threads <NUM> of threaded shank <NUM>.

In one example, the helical wiper seal (e.g. threads of the compression member <NUM>) may be sized smaller than normal mating threads that would otherwise mate with threads <NUM> to promote improved sealing between the seal region <NUM> and threaded shank <NUM>. In one example, the helical wiper seal is sized to engage with the minor diameter of the threads of the threaded shank <NUM> but have an increased major diameter, thereby increasing compliance and allowing them to bend and not shear when the threaded shank <NUM> is passed through the inner diameter of bore <NUM>.

In other examples, the inner diameter of the seal region <NUM> may be sized such that it simply deforms into threads <NUM> to effectuate the seal with shank <NUM>.

In addition to sealing to threaded shank <NUM>, the compression member <NUM> seals with the end plate <NUM>. In this embodiment, the seal provided therebetween may be both an axial seal of the compression member <NUM> being pressed against an outer surface <NUM> of inner plate <NUM> as well as a radial seal between the portion of inner plate <NUM> forming end plate aperture <NUM> and an alignment projection <NUM> (see e.g. <FIG> and <FIG>) of the compression member <NUM> that extends through end plate aperture <NUM>.

In addition to the sealing function, axial load to secure the filter elements <NUM> to the tube sheet <NUM> with good sealing engagement between tube sheet seal <NUM> and tube sheet <NUM> is transmitted from the handle <NUM> to the end plate <NUM> through the compression member <NUM>.

In one example, the compression member <NUM> is configured to provide torque identification and/or limiting that either or both of identifies when sufficient load is applied to the filter element <NUM> from handle <NUM> or/and prevents over loading the filter element <NUM> by over torqueing handle <NUM>.

More particularly, the compression member <NUM> includes a compression region <NUM>. The handle <NUM> and particularly an axial pressure region <NUM> thereof presses on the compression region <NUM> when the handle is rotated to tighten the handle <NUM> against the filter element <NUM>.

In one example, a desired amount of axial load is used to press the tube sheet seal <NUM> against the corresponding sealing surface of the tube sheet <NUM> (see e.g. <FIG>). Over tightening of the handle <NUM> can over compress tube sheet seal <NUM> leading to potential failure of the tube sheet seal <NUM> or other components of the filter element <NUM>. Under tightening can provide improper seating of the filter element and allow leak paths.

However, as the tube sheet seal <NUM> may not be visible when mounting the filter element due to the size of the filter elements <NUM> and the arrangement of the filter elements <NUM> on tube sheet <NUM>, the compression member <NUM> can provide a cue as to when the desired load is being applied by handle <NUM>. Other cues are outlined below.

The compression region <NUM> is configured to compress once the desired load is applied by the handle <NUM> to the compression member <NUM>. Thus, the user may be able to visually see the compression of the compression member <NUM>, such as in the compression region <NUM>, and determine that sufficient axial load is being applied.

In one example, the tube sheet seal <NUM> is has a first minimum axial load required to provide a desired seal with the tube sheet <NUM>. The compression region <NUM> begins to compress under a second minimum axial load that is greater than the first minimum axial load. As such, the compression region <NUM> will not begin to compress, at least in a significant manner (e.g. less than <NUM>%), until sufficient loading has been applied to the tube sheet seal <NUM>. As such, if the user has not seen evidence of compression of the compression member <NUM>, such as at the compression region <NUM>, the user would know that insufficient force is being applied to the filter element and particularly to tube sheet seal <NUM>.

In one example, the tube sheet seal <NUM> is configured (e.g. size, shape, material properties, etc.) such that it will deform at loading less than the second minimum axial load such that it will deform prior to the compression region <NUM> deforming due to loading provided by handle <NUM>.

In some examples, the tube sheet seal <NUM> is formed from a material that is softer than the material used to form the compression member <NUM> and particularly the compression region <NUM>, thereof. For example, the durometer of the compression region <NUM> may be greater than the durometer of the tube sheet seal <NUM>.

In the illustrated example, first and second washer members <NUM>, <NUM> are attached to the compression member <NUM>. The first washer member <NUM> is positioned radially inward of the second washer member <NUM>. In this example, the first and second washer members <NUM>, <NUM> are discrete members formed from separate bodies of material such that the two components are not formed into a single continuous piece of material. The washer members <NUM>, <NUM> could be formed from metal, such as steel or aluminum or from a plastic that is preferably more rigid than the material of the compression member <NUM>.

The first washer member <NUM> is aligned with the compression region <NUM>. As such, the first washer member <NUM> and compression region <NUM> have a similar radial spacing from the central axis <NUM> of the bore <NUM>. This central axis <NUM> is also coincident with the central axis of threaded shank <NUM>.

The handle <NUM>, and particularly, axial pressure region <NUM> axially presses against and angularly slides on the outer face <NUM> of the first washer member <NUM> when the handle <NUM> is being tightened to secure the filter element <NUM> against the tube sheet <NUM> so as to apply loading to the compression region <NUM> and the compression member <NUM>.

The transition from <FIG> illustrates the compression of compression region <NUM> as the handle <NUM> is rotated to tighten the filter element <NUM>. As illustrated in <FIG>, the compression member <NUM> and the compression region <NUM> are in an undeformed state with the handle axially pressing against the outer face <NUM> of the first washer member <NUM>.

As the user rotates the handle <NUM> to tighten the assembly, the compression member <NUM> and compression region <NUM> thereof compress and deform. This is illustrated in <FIG>. Notably, during this process, the first washer member <NUM> becomes axially displaced relative to the second washer member <NUM>. This provides an initial visual identification that the desired amount of axial load is being approached. Further, in some embodiments, the compression region <NUM> is configured such that at the onset of axial displacement of the compression region, torque feedback to the installer should also increase.

The second washer member <NUM> functions to prevent over tightening the handle <NUM> to prevent overloading the filter element <NUM> and particularly any of the seals therein and more particularly the tube sheet seal <NUM>.

The second washer member <NUM> defines a plurality of first angular catches <NUM>. These angular catches <NUM> are radially offset from the center of the end plate aperture <NUM> (e.g. offset from axis <NUM>). These angular catches <NUM> define abutments that will engage and inhibit rotational motion of handle <NUM> once sufficient loading has been applied.

The handle <NUM> includes a plurality of second angular catches <NUM> that will angularly abut the first angular catches <NUM> to prevent continued angular rotation of handle <NUM>. The second angular catches <NUM> are axially offset from the axial pressure region <NUM> of the handle <NUM>. Thus, when the handle <NUM> initially abuts the top surface <NUM> of the first washer member <NUM> as illustrated in <FIG>, the second angular catches <NUM> are axially offset from the first angular catches <NUM> such that the catches <NUM>, <NUM> will not abut or inhibit angular rotation of the handle <NUM>.

Other axial offset orientations are contemplated. For example, washer members <NUM>, <NUM> could be axially offset rather than axial pressure region <NUM> and second angular catches <NUM>. Alternatively both the washer members <NUM>, <NUM> and the axial pressure region <NUM> and second angular catches <NUM> could be axially offset.

As the load increases due to increased tightening of handle <NUM>, the compression region <NUM> compresses independent of or at a greater rate than the portion of compression member <NUM> proximate the second washer member <NUM>. As such, the axial spacing/offset between the first angular catches <NUM> and the second angular catches <NUM> reduces as the load increases. Once a desired amount of load is present, the compression region <NUM> will be sufficiently compressed that the first and second angular catches <NUM>, <NUM> can abut when angularly aligned. In this condition, continued rotation will be inhibited.

With reference to simplified <FIG>, the compression member <NUM> can have geometry changes, such as in the form of a groove <NUM>, between the compression region <NUM> and region <NUM> (a radially outer region in this example) that supports second washer member <NUM> to help separate the compression of compression region <NUM> from acting on the second washer member <NUM>.

The groove <NUM> isolates compression region <NUM> from region <NUM> to prevent or reduce shear forces between the compression region <NUM> and region <NUM>, which could cause undesirable compression of region <NUM> and axial displacement of second washer member <NUM>. Alternatively, this could cause the second outer washer member <NUM> to disconnect (e.g. peal) from the compression member <NUM>. <FIG>, shows compression region <NUM> in an uncompressed state and <FIG> shows the compression region <NUM> in a compressed state.

Notably, the desired amount of load may occur when the second angular catches <NUM> are angularly offset from the first angular catches, such as located angularly between adjacent first angular catches <NUM>. In this situation, the user will rotate the handle <NUM> while the bottom of the angular catches <NUM> slides on the top surface <NUM> of the second washer member <NUM> until the first and second angular catches <NUM>, <NUM> abut. In this instance, when properly aligned, the projections <NUM> that define the second angular catches <NUM>, <NUM> will drop into the lobes <NUM> or recesses formed in the second washer member <NUM> that form the first angular catches <NUM>. This action allows the opposed catches <NUM>, <NUM> to abut and inhibit further rotation allowing for continued tightening of handle <NUM>. <FIG> is a cross-sectional illustration through the second washer member <NUM> and the handle <NUM> when sufficient loading has occurred to allow the first and second angular catches <NUM>, <NUM> to abut and to allow projections <NUM> to drop into lobes <NUM>.

During this process as the bottom of the catches <NUM> slide on the top surface <NUM> of the second washer member <NUM>, there will be increasing torque feedback to the installer. During the remaining rotation of handle <NUM> relative to compression member <NUM>, the compression region will continue to compress. Once the angular catches <NUM> drop into lobes <NUM>, some of the compression will release and result in both pronounced feedback to the installer and increased axial engagement between the catches <NUM>, <NUM>.

When the handle <NUM> drops into the lobes <NUM>, this may also provide tactile feedback to the operator that the proper loading of the handle <NUM> against the filter element has been reached.

It is noted that in this embodiment, the compression member <NUM> and particularly portion <NUM> has a triangular cross-section that corresponds to a triangular cross-section of the end plate <NUM> so that the compression member <NUM> and attached second washer member <NUM> are angularly clocked to the end plate <NUM>.

With reference to <FIG>, the faces of projections <NUM> opposite the second angular catches <NUM> may provide a tapered surface <NUM> to assist in axially lifting the projections <NUM> out of lobes <NUM> when loosening handle <NUM>. The angle α of the tapered <NUM> shall be such that premature loosening of the handle <NUM> is prevented, such as by way of vibrations, but sufficient enough to allow for a user to avoid needing a tool to loosen handle <NUM>.

Here, the load applied by handle <NUM> will be slightly greater than the minimum desired load. In this example, by using three first angular catches <NUM> and three second angular catches <NUM>, each of which are evenly angularly spaced apart (e.g. spaced apart <NUM> degrees), the amount of over-tightening after the desired load is reached will be held at an acceptable minimum.

The action of the projections <NUM> dropping into the lobes <NUM> of the second washer provides a further cue that the handle <NUM> has applied an appropriate level of loading.

Notably, <FIG> illustrates a handle <NUM> with only two levers <NUM>.

With additional reference to <FIG> and <FIG>, the coupler <NUM> of this design has an oval cross-sectional shape. The compression member <NUM> and particularly the second washer member <NUM> has an opening <NUM> that has a corresponding oval shape. When the desired load is applied to sufficiently compress the compression region <NUM> and the corresponding oval shapes are aligned, the coupler <NUM> is permitted to drop into the oval opening defined by the second washer member <NUM> and provide the visual and tactile cue that the handle <NUM> is properly tightened.

In other examples, the filter element <NUM> may include one or more identifiers thereon that determines when the desired load is applied. For example, as illustrated in <FIG>, the end plate <NUM> and particularly the outer shell thereof <NUM> includes identifiers in the form of triangles provided on an outer surface of outer shell <NUM>. As illustrated in <FIG>, the levers of the handle <NUM> are aligned with the triangles that provide a quick and easy visual cue that the handle <NUM> has been properly tightened.

Further yet, the non-circular shape of the filter element or components thereof, e.g. the end plate <NUM>, can provide the visual cue. It is clear in <FIG>, for the mounted filter element <NUM>, that each lever of the handle extends towards a corner of the triangular shape of the filter element <NUM>. This again, provides a visual cue for quick and easy inspection to determine if the desired load has been reached.

In addition to and/or in opposite to determining when a desired load has been reached, these visual cues may at a minimum may illustrate if the handle <NUM> has been moved from its desired orientation. For example, if it is known that the handle <NUM> was originally tightened to the desired load, if the handle <NUM> is not in the proper orientation relative to the visual identifier/cue, an operator would quickly know to check the securement of the particular filter element <NUM>/handle <NUM>.

In this example, the rotation limiting feature provided by the second washer member <NUM> could be provided by the first end plate <NUM> or other components of the filter element <NUM>.

In this example, the second washer member <NUM> is angularly fixed to the compression member <NUM>, the compression member <NUM> is angularly fixed to the first end plate <NUM>, the first end plate <NUM> is angularly fixed to the filter element sections <NUM>, <NUM> which are angularly fixed to the mounting yoke <NUM>. Thus, over rotation of the handle <NUM> cannot occur by rotation of the filter element <NUM> allowing for over loading of the sealing elements in the system.

As noted above, the compression member <NUM> and the first angular catches <NUM>, in this example, are removable and reusable. In other embodiments, the compression member <NUM> and/or the first angular catches <NUM> are permanently attached to the end plate <NUM> and/or the rest of the filter element <NUM>. The end plate <NUM> may be a permanent component of the filter element <NUM> or a reusable component.

Further, the angular catches could be provided by other shaped structures and could be reversed such that the projections could be provided by the filter element and the lobes or recesses could be provided by the handle. Other shapes such as apertures and pins could be used.

In addition to the features above, the handle <NUM> is configured for quick attachment and release from the threaded shank <NUM> of the mounting yoke <NUM>. The handle <NUM> includes a plurality of levers <NUM> attached to a coupler <NUM>. In this example, the handle <NUM> is a single unitary body with the levers <NUM> and coupler <NUM> formed from a continuous piece of material.

In some arrangements the lever(s) <NUM> and coupler <NUM> are separate components that rotationally engage one another. In such an arrangement, once the levers <NUM> has been used to tighten the coupler <NUM> to secure the filter element sections to the yoke <NUM>, the levers <NUM> can be used to secure additional couplers <NUM> to other yokes <NUM> for securing other filter element sections. Thus, a single lever component is required for use with multiple couplers <NUM> of the overall system.

<FIG> and <FIG> illustrates a coupler <NUM> that does not include the lever for securing the filter element <NUM>. In other words, the coupler and levers are not a single continuous component). In this example, coupler <NUM> has an outer periphery configured to be engaged by a tool for imparting torque to the coupler <NUM>. In this example, the outer periphery of coupler <NUM> is similar to a hexagonal nut. As such, the lever has not been illustrated but a lever configured to rotationally engage the coupler <NUM> would be provided.

In this example, the coupler <NUM> has the oval outer periphery and the compression member <NUM> has the oval cavity that cooperates with the oval periphery of the coupler as discussed above with the example of <FIG>.

Returning to the prior examples, the coupler <NUM> defines an internally threaded bore <NUM> that extends axially through the body <NUM> of the coupler <NUM>. The threads <NUM> of the threaded bore define a threaded bore axis <NUM>. This axis is generally orthogonal to axial pressure region <NUM> that applies pressure to the compression member <NUM> when securing the filter element <NUM> to the tube sheet <NUM>. When the handle <NUM> is being tightened on the threaded shank <NUM>, the threaded bore axis <NUM> is coincident with the axis <NUM>. This is illustrated in <FIG> and <FIG>.

In this example, a clearance bore <NUM> intersects the internally threaded bore <NUM>. The clearance bore <NUM> defines a clearance bore axis <NUM> that extends at a non-parallel angle to the threaded bore axis <NUM>. The clearance bore <NUM> is sized and configured that when the clearance bore axis <NUM> is aligned with axis <NUM>, the threads <NUM> of the threaded bore <NUM> do not engage threads <NUM> of shank <NUM>. This is illustrated in <FIG>. In this orientation, the handle can be slid axially along the threaded shank <NUM> with limited to no resistance and without requiring the user to rotate handle <NUM> about axis <NUM>, as represented by arrow <NUM>. This prevents the user from having to perform the conventional run-down of the nut on the threaded shank <NUM>, which can be time consuming.

In some examples, the angle between axis <NUM> and axis <NUM> is between <NUM> and <NUM> degrees and preferably between <NUM> and <NUM> degrees.

Thus, prior to tightening or after sufficient loosening of handle <NUM>, the user can quickly mount or remove handle <NUM>.

When mounting the handle <NUM>, the user would align the clearance bore <NUM> with the threaded shank <NUM> and slide handle <NUM> along shank <NUM> until it abuts first washer member <NUM> as illustrated in <FIG>. Once in this position, the user would manipulate the handle <NUM> to pivot the handle <NUM> such that the threaded shank <NUM> is aligned with the threaded bore <NUM> and the threads <NUM> engage threads <NUM> as illustrated in <FIG>. Thereafter, the user can rotate the handle <NUM> about axis <NUM> to tighten the handle <NUM> against the filter element <NUM>. Notably, when the handle <NUM> is tight against the filter element, the axial pressure region <NUM> engages the top surface <NUM> of the first washer member <NUM> and prevents pivoting back to the orientation where the clearance bore <NUM> aligns with the threaded shank <NUM> (e.g. axis <NUM> aligns with axis <NUM>). Only after the user has rotated the handle <NUM> to loosen the handle <NUM> can the handle be pivoted to the orientation of <FIG> and the handle quickly slid off of shank <NUM>.

In a preferred arrangement, the lead angle of threads <NUM> and <NUM> cause the handle <NUM> to move axially along the threaded shank <NUM> quickly such that limited angular rotation of handle <NUM> is required to tighten handle <NUM> against the filter element <NUM>. This reduces the likelihood of the handle <NUM> pivoting back to the orientation of <FIG> prior to sufficient force acting between axial pressure region <NUM> and the compression member <NUM> to maintain the handle <NUM> in the orientation of <FIG>. In an example, only <NUM> turns of the handle <NUM> are required to reach the desired axial load on the filter element <NUM>.

However, in some embodiments, knurling or texturing can be provided to surface <NUM> to further prevent back driving handle <NUM> or prevent pivoting to the orientation in <FIG>.

In one example, this results in approximately <NUM> of travel of the handle <NUM> along shank <NUM>.

This same thread pattern would be used with the helical wiper seal discussed above.

Further, a proprietary thread pitch could be provided.

In one example, the thread of the threaded shank <NUM> is m12 x <NUM>, <NUM> lead with <NUM> degree lead angle. The thread is based on an ISO <NUM> vee thread profile. The external thread minor diameter is <NUM>. The external thread major diameter is <NUM>. The internal thread minor diameter is <NUM> and the internal thread major diameter is <NUM> of the handle <NUM>, nut <NUM> discussed below, and the helical wiper seal discussed above. The thread of the thread shank <NUM> can be a bespoke thread to assist with fast compression of the filter gaskets. A proprietary thread can further promote mounting of a correct filter element to the system. However, the use of standard thread configurations is also contemplated.

The over tighten features and the quick mount/release features of the arrangement discussed above may be used together or independent from one another.

With reference to <FIG> and <FIG>, in the illustrated example, the threaded shank <NUM> is provided by a carriage bolt <NUM> mounted to a yoke in the form of tripod <NUM>. The tripod <NUM> is attached to the tube sheet <NUM> and the carriage bolt <NUM> is mounted to a free end of the tripod <NUM>. In other embodiments, the threaded shank could be a rod directly attached to the tube sheet. By using a carriage bolt <NUM>, the carriage bolt <NUM> can be clocked relative to the tripod <NUM> such that the carriage bolt <NUM> will not rotate when the user attempts to tighten the handle <NUM>.

In some examples, a proprietary nut <NUM> can be used to secure carriage bolt <NUM> to tripod <NUM>. The proprietary nut <NUM> will have an outer peripheral surface that requires a keyed tool to fasten the nut <NUM> to carriage bolt <NUM>. Once the nut is torqued to <NUM>, the only way it can be removed is destructively. This prevents a third party from using a different handle having a different thread pitch as compared to the proprietary thread pitch used with shank <NUM> discussed above.

While the system above is described with the quick mount coupler <NUM>, other systems could incorporate other benefits of the examples while simply using a special nut that does not incorporate the clearance bore of the coupler discussed above.

It is contemplated that in some examples, the coupler, lever or the entire handle could be permanently attached to the filter. For instance, the coupler could be captured by the end plate <NUM> such that it could rotate relative to the end plate, but it could not be removed from the end plate <NUM>.

<FIG> is an alternative illustration of system <NUM> and illustrates more filter elements <NUM>. In <FIG>, the system <NUM> has the filter elements <NUM> in a cantilevered orientation with respect to tube sheet <NUM>. Tube sheet <NUM> is oriented substantially vertical and parallel to gravity, which is illustrated as arrow <NUM>. When the yoke of the system <NUM> is centered through an end plate <NUM> associated with a corresponding filter element <NUM>, the force profile on the filter element <NUM> due to the cantilevered orientation can present sealing issues for the filter element <NUM> against the outer face of the tube sheet <NUM>. The triangular cross-sectional shape of the filter elements <NUM> and orientation as illustrate could further exacerbate the sealing issues as sealing pressure at the vertically lower portion of the triangular seal could be different than the sealing pressure at the vertically upper portion of the triangular seal. This is due to gravitational forces that are not parallel to the clamping forces for securing the filter elements <NUM> against the tube sheet <NUM>.

<FIG> illustrates an end view of a portion of a further system <NUM> that attempts to compensate for the sealing pressure imbalance and provide more uniform sealing pressure to the various seals within the system and particularly to tube sheet seal <NUM> of the filter elements <NUM>. While only two filter elements are provided, this system <NUM> can incorporate any number of elements and as many, fewer than or more than system <NUM>. To compensate for the forces provided by gravity, the mounting yoke <NUM> is configured such that the shank <NUM> of the mounting yoke <NUM> is off-center from center of the end plate <NUM> securing the filter element <NUM> to the tube sheet <NUM>.

In addition, the shank <NUM> is off-center from the central axis of the filter element <NUM>.

With additional reference to <FIG> and <FIG>, an alternative mounting yoke <NUM> is illustrated with the filter element <NUM> and end plate <NUM> removed. The shank <NUM> is moved toward the upper most corner 727A of the tube sheet aperture <NUM> along an axis 725A that generally extends through the center <NUM> of tube sheet aperture <NUM> and the upper most corner 727A of tube sheet aperture <NUM>. In some examples, the axis 725A bisects corner 727A and passes through center <NUM>. In doing so, the shank <NUM> is moved both vertically upward and horizontally relative to center <NUM>. In this example, the shank <NUM> is moved towards the vertically oriented side 729A of tube sheet aperture <NUM>.

In this example, the mounting yoke <NUM> includes three legs 785A, 785B, 785C. The shank <NUM> is moved horizontally away from the mounting location 731B of leg 785B and horizontally towards the mounting locations 731A, 731C of legs 785A and 785C. Further, the shank <NUM> is moved vertically upward toward the mounting location 731A of leg 785A and vertically away from the mounting locations 731B and 731C of legs 785B and 785C.

Notably, center <NUM> is typically co-axial about an axis perpendicular to the tube sheet <NUM> with a center of a circle defined by the mounting locations 731A, 731B, 731C of the legs 785A, 785B, 785C. As such, center <NUM> may be used to the center of either arrangement.

When the user mounts the filter element <NUM> to the mounting yoke <NUM>, the upper most leg 785A becomes a tension leg, the bottom most leg 785C is a compression leg and the vertically intermediate leg 785B is a neutral leg. Leg 785A is considered a tension leg because it acts in tension during service prior to the filter element <NUM> being tightened against the tube sheet <NUM> while the filter element rests vertically on the mounting yoke <NUM> due to gravity. The lower most leg 785C is considered the compression leg because during service, prior to tightening the filter element <NUM> against the tube sheet, this leg is loaded in compression due to gravity. The intermediate leg 785B is referred to as a neutral leg because it generally provides lateral stability to the tension leg 785A and the compression leg 785C.

This off-center arrangement of the mounting shank <NUM> and associated configuration of the legs 785A, 785B, 785C redistributes the non-uniform gasket compression forces applied to tube sheet seal <NUM> and moves some of the loading that would otherwise be applied proximate the bottom most corner 727C (e.g. proximate mounting location 731C) due to the cantilevered configuration (e.g. associated with gravitational forces) upwards towards the upper most corner 727A (e.g. proximate mounting location 731A).

In this example, each leg 785A, 785B, 785C has its own profile to effectuate the load redistribution and off-center location of the mounting shank <NUM>. However, the legs are generally designed so that they mate with the inner corners of the tube sheet seal <NUM> to provide clocking and proper seating of the filter element <NUM> as described previously with relation to mounting yoke <NUM>. Thus, each leg 785A, 785B, 785C, when begining at the end opposite the mounting shank <NUM> begins with a generally straight section 733A, 733B, 733C.

Leg 785A has bend 735A that is planar with a plan orthogonal to the tube sheet <NUM> and that includes axis 725A. This bend 735A allows the straight section 733A of leg 785A to extend outward from the tube sheet <NUM> at a more horizontal orientation (i.e. more perpendicular to tube sheet <NUM>) than if leg 785A is straight between flattened tip <NUM> and the tube sheet <NUM>. The horizontal orientation of leg 785A improves stability and also, when using multiple filter element sections, assists in guiding and positioning subsequently mounted filter element sections when assembling the full filter element.

Leg 785B is a more complex shape and has a first bend 735B, a second bend 735C and a third bend 735D. First bend 735B has a smaller radius that second and third bends 735C, 735D. First bend 735B is planar in that it is within a plane defined by axis 725B that is orthogonal to tube sheet <NUM>. The second and third bends 735C, 735D are non-planar and bend out of the plane defined by axis 725B that is orthogonal to tube sheet <NUM>. These non-planar bends 735C, 735D can be best viewed in <FIG>. In general, the non-planar bends 735C, 735D in leg 785B compensate for the vertical shift of the mounting shank <NUM>.

Leg 785C is generally a mirror of leg 785B and has first bend 735E, second bend 735F and third bend <NUM>. First bend 735E is planar in that it is within a plane defined by axis 725C that is orthogonal to tube sheet <NUM>. The second and third bends 735F, <NUM> are non-planar and bend out of the plane defined by axis 725C that is orthogonal to tube sheet <NUM>. These non-planar bends 735F, <NUM> can be best viewed in <FIG>.

Preferably, the flattened tip <NUM> of leg 785A is the outermost tip and terminates over the other leg tips to maximize rigidity of the mounting yoke <NUM> and to better accommodate gravitational loads. Preferably, all flattened tips are generally parallel to one another as well as parallel to tube sheet <NUM> and the mounting shank <NUM> extends perpendicularly relative to the flattened tips as well as to the tube sheet <NUM>.

Further, with reference to <FIG>, the lengths of straight section 733A of leg 785A is longer than the straight sections 733B, 733C. In preferred embodiments, the lengths of all of the straight sections 733A, 733B, 733C are such that they extend into the outer most filter element section, e.g. filter element section <NUM>, so that they can mate with the inner most end of the section and provide proper clocking and location of the filter element section by engaging the corners of any seal components thereof. However, this is not required in all examples.

<FIG> illustrates a corresponding end plate <NUM> and <FIG> illustrates an inner plate <NUM> of the end plate <NUM>. These <FIG> and <FIG> illustrate that in addition to the mounting shank <NUM> of the mounting yoke <NUM> being offset towards the mounting location 733A of leg 785A, endplate aperture <NUM> is similarly offset towards the corresponding corner 745A of the end plate <NUM> and the inner plate <NUM> of end plate <NUM> along axis 725A. Axis 725A is generally perpendicular to the side opposite corner 745A and generally bisects corner 745A.

In one example, the end plate <NUM> is reusable and the filter element <NUM> is the same as used in system <NUM>. Here, the end plate <NUM> allows for the use of the same filter element <NUM> with either arrangement. In other embodiments, the end plate <NUM> may be formed as an integral component with the rest of the filter element or with one filter element section if the filter element is formed from a plurality of sections.

In a preferred example, the straight sections 733A, 733B, 733C and the tubesheet seal <NUM> are configured such that the inner periphery of the tube sheet seal <NUM> and particularly the corners of the tube sheet seal <NUM> are formed to mate with the straight sections 733A, 733B, 733C of legs 785A, 785B, 785C. Again, this is done to improve stability of the fit and helps enter the fitler about the tube sheet aperture <NUM>.

By redistributing the loading to provide more uniform sealing pressure all portions of the tube sheet seal <NUM> that the legs 785A, 785B, 785C compress simultaneously and more uniform and similarly all portions of the tube sheet seal <NUM> that engage tube sheet <NUM> compress simultaneously and more uniformly. This uniform compression of the tube sheet seal <NUM> reduces the torque required to achieve full tube sheet seal <NUM> compression. This also reduces or otherwise prevents over compression of some portions of the tube sheet seal <NUM>, under compression of portions of the tube sheet seal <NUM>, or a combination of both over and under compression of portions of the tube sheet seal <NUM>.

The offset location of the mounting shank <NUM> causes the tension within the legs 785A, 785B, 785C generated when tightening a filter element <NUM> against the tube sheet <NUM> to be non-uniform. Instead, a larger portion of the tension acts through the uppermost leg 785A. This is due, in part, to the straighter profile of leg 785A. Combined with this arrangement, the reacting forces through the end plate <NUM> are transmitted along the axis of the filter element <NUM> but are shifted upward toward upper portions of the tube sheet seal <NUM> (and other seals). This redistribution of loads through the filter element <NUM> results in more uniform compression of all seals.

The term "at least one of A and B" shall be understood to mean "only A, only B or both A and B.

Claim 1:
A filter element (<NUM>) comprising:
a tube of filter media (<NUM>, <NUM>) extending axially between a first end (<NUM>) and a second end (<NUM>) and defining a central cavity (<NUM>), the tube of filter media (<NUM>, <NUM>) being frustoconical increasing in radial dimension when moving along a central axis from the second end (<NUM>) towards the first end (<NUM>), the tube of filter media (<NUM>, <NUM>) extending at a first angle relative to the central axis, the filter media of the tube of filter media (<NUM>) having a radially inner most edge at the first end (<NUM>);
a seal member (<NUM>) attached to a first end (<NUM>) of the tube of filter media, the seal member (<NUM>) having a radially inward facing tapered inner surface (<NUM>), the tapered inner surface (<NUM>) extending at a second angle relative to the central axis; and
the first angle being more parallel to the central axis than the second angle.