Enlarged aperture filter bag, support assembly and filter bag assembly

Abstract

Described herein are filter bags, filter bag support assemblies, and filter bag assemblies that may be used in air filter systems to remove particulate matter from air or other gases. Methods of using the air filter systems and methods of assembling the filter bag assemblies are also described.

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Described herein are filter bags, filter bag support assemblies, filter bag assemblies and filter systems, and corresponding methods. [Background technology]

[0002] Many industries encounter particulate matter suspended in the air. In some industries, this particulate matter is a valuable product (e.g., starch) and it would be beneficial if the suspended particulate matter could be recovered and reintroduced into the process. For other industries (e.g., metal or wood processing), it may be desirable to remove particulate matter from the air to provide a cleaner working environment.

[0003] Some systems for purifying air or other gas streams filled with particulate matter include filter bags (sometimes called socks) disposed within a housing. The filter bags are typically constructed from a filter media, such as fabric, pleated paper, etc. The gas stream contaminated with particulate matter is typically passed through the housing such that the particulate matter is captured and retained in the filter bag or bags.

[0004] An air filter system typically includes a clean air chamber and a dirty air chamber. The two chambers are separated by a structure commonly called a tube sheet. The tube sheet has a number of openings to allow air to pass between the clean air chamber and the dirty air chamber. A filter bag is positioned over the openings so that particle-filled air (dirty air) introduced into the dirty air chamber must pass through the filter bag to move to the clean air chamber. Particulate matter from the dirty air collects on the filter bag as the air moves through the filter bag.

[0005] From the clean air chamber, the clean air is exhausted to the environment or recirculated for other uses. See, for example, U.S. Pat. No. 3,942,962 (Duyckinck), U.S. Pat. No. 4,218,227 (Frey), U.S. Pat. No. 4,424,070 (Robinson), U.S. Pat. No. 4,436,536 (Robinson), U.S. Pat. No. 4,443,237 (Ulvestad), U.S. Pat. No. 4,445,915 (Robinson), U.S. Pat. No. 4,661,131 (Howeth), U.S. Pat. No. 5,207,812 (Robinson), U.S. Pat. See, for example, U.S. Pat. No. 4,954,255 (Muller et al.), U.S. Pat. No. 5,222,488 (Forsgren), U.S. Pat. No. 5,211,846 (Kott et al.), U.S. Pat. No. 5,730,766 (Clements), U.S. Pat. No. 6,090,173 (Johnson et al.), U.S. Pat. No. 6,902,592 (Green et al.), and U.S. Pat. No. 7,641,708 (Kosmider et al.).

[0006] When the filter bag traps particulate matter, flow through the system is impeded and periodic cleaning of the filter bag can be performed to increase airflow through the system. Cleaning can be accomplished by periodically pulsing short jets of pressurized air into the interior of the filter bag to reverse the airflow through the filter bag, blowing the collected particulate matter out of the filter bag. The pressurized air can be directed to a pulse collector, such as those described in U.S. Pat. No. 3,942,962 (Duyckinck), U.S. Pat. No. 4,218,227 (Frey), U.S. Pat. No. 6,090,173 (Johnson et al.), U.S. Pat. No. 4,395,269, U.S. Pat. No. 6,902,592 (Green et al.), U.S. Pat. No. 7,641,708 (Kosmider et al.) and U.S. Patent Publication No. 2006 / 0112667 A1. Summary of the Invention [Means for solving the problem]

[0007] Described herein are filter bags, filter bag support assemblies, and filter bag assemblies that may be used in air filter systems to remove particulate matter from air or other gases. Methods of using the air filter systems and methods of assembling the filter bag assemblies are also described.

[0008] In one or more embodiments, the filter bags described herein have a closed end and a bag open end spaced apart from one another along a bag axis. The sealing cuff extends around the periphery of the bag opening, and a nominal bag length measured along the bag axis between the sealing cuff and a reference plane oriented perpendicular to the bag axis between the closed end and the bag opening varies when moving around the periphery of the bag opening. Filter bags with varying nominal bag lengths as described herein have an enlarged bag opening compared to conventional filter bags.

[0009] The enlarged bag opening of the filter bags described herein, in one or more embodiments, may instead be characterized based on the peripheral length of the bag opening compared to the peripheral length of the tubular body located between the bag opening and the closed end of the filter bag. The peripheral length of the tubular body may be measured at the reference plane used to determine the nominal bag length or any other plane (perpendicular to the bag axis) located between the closed end and the bag opening.

[0010] When a filter bag having an enlarged bag opening as described herein is advanced onto a cage of a filter bag support assembly as described herein, the enlarged bag opening provides an advantage compared to a filter bag having a smaller conventional bag opening.

[0011] One advantage of a filter bag having an enlarged bag opening over a conventional filter bag is that the enlarged bag opening provides additional clearance between the bag opening and the cage (compared to a smaller sized tubular body between the bag opening and the closed end of the filter bag) when the enlarged bag opening is advanced over the cage of the flange assembly. The additional clearance of the enlarged bag opening can, for example, reduce friction between the bag opening and the cage when the bag opening is advanced over at least a portion of the cage. That reduction in friction results in a corresponding reduction in the force required to advance the filter bag over the cage.

[0012] While the entire filter bag could be enlarged to make it easier to mount the filter bag on the cage, the enlarged filter bag would result in a filter bag that does not fit as tightly on the cage of the bag support assembly as described herein, and that loose fit would be expected to reduce pulse cleaning performance and / or filter bag life.

[0013] In particular, pulse cleaning of the filter bag on the bag support assembly of the filter system described herein can be improved by tightly fitting the filter bag on the cage of the bag support assembly. The increased tightness of the more tightly fitted filter media results in increased sudden acceleration associated with pulse cleaning of the filter bag (sometimes referred to as "bag snap"). The increased outward sudden acceleration can result in increased removal of particulate matter collected on the filter bag, which falls under gravity into the hopper of the filter system.

[0014] In addition to improving pulse cleaning performance, a more closely fitted filter bag / cage combination may also improve filter bag life by reducing wear on the filter bag caused by excessive movement between the cage and a more loosely fitted filter bag during pulse cleaning.

[0015] Yet another advantage that can result from a closer fitting filter bag / cage combination is that the spacing between adjacent filter bags in the contaminated air chamber of the air filter system can be reduced without causing a corresponding decrease in pulse purification performance. That closer spacing between adjacent filter bags can result in a corresponding reduction in the size of the air filter system as a whole. A smaller air filter system that provides the same (or better) filtering capacity as a larger air filter system can be an important factor when available space in a facility is limited.

[0016] Yet another advantage of a filter bag having an enlarged bag opening is that in one or more embodiments, proper orientation of the filter bag on the cage of the flange assembly may be ensured in those embodiments where the filter bag can be properly mounted on the flange assembly in only one orientation. Proper orientation of the filter bag on the filter bag support assembly may be advantageous, for example, when the filter bag includes a bag support mechanism proximate the closed end of the filter bag. In such an embodiment, it may be ensured that the bag support mechanism is located at the top of the filter bag when mounted on the bag support assembly, because the filter bag would not fit properly on the bag support assembly if the bag support mechanism was at the bottom of the filter bag when mounted on the bag support assembly.

[0017] The filter bags, filter bag support assemblies and filter bag assemblies described herein may be particularly useful in filter systems designed for use in industrial air filter applications where particulate matter must be removed from relatively large volumes of polluted air. Thus, the filter bags and filter bag assemblies must be sized to handle those air volumes and the particulate matter associated with those volumes. In general, the filter bags described herein may have a bag length, measured from the bag opening to the closed end of the bag, that is 0.3 meters or more, 0.5 meters or more, or even 1 meter or more. The associated bag height (measured transversely to the bag length) may be 0.2 meters or more, 0.3 meters or more, 0.4 meters or more, or 0.5 meters or more.

[0018] In one or more embodiments, the filter bag assembly includes a flange assembly, a cage attached to the flange assembly, and a filter bag mounted on the cage having an opening in the flange assembly. When mounted to a dirty air chamber of a filter system, a seal between the flange assembly and the tubesheet that defines the dirty air chamber is provided by applying a sealing force on an end of the filter bag assembly that is located adjacent the access panel on a side of the dirty air chamber opposite the tubesheet. The sealing force is transmitted through the cage to the flange assembly.

[0019] By providing a sealing force to the ends of the filter bag assembly and transmitting that force through the cage to the flange assembly, removal and replacement of the filter bag (and filter bag assembly) is possible through an access port on an access panel located across the dirty air chamber. As a result, used filter bags (and particulate matter collected thereon) do not pass through and potentially contaminate the clean air chamber of the filter system.

[0020] Another potential advantage of providing a sealing force at the end of the filter bag assembly and transmitting that force through the cage to the flange assembly is that other components, such as the pulse generator, do not need to be removed or even partially disassembled to accommodate removal and replacement of the filter bag.

[0021] In one or more embodiments of the filter systems described herein, the filter bags are supported within the dirty air chamber such that the filter bags and their support assemblies (e.g., flange assemblies, cages, etc.) can be removed and replaced without passing through the clean air chamber of the filter system, which limits or prevents contamination of the clean air chamber by particulate matter removed during removal of the used filter bags associated with removal of the used filter bags through the clean air chamber.

[0022] A filter system including one or more of the various features and components described herein may provide one or more advantages, such as improved energy efficiency, reduced noise generation, etc., due to reduced pressure drop within the filter system during both primary flow operation and pulse cleaning of the filter element (where primary flow operation occurs when the filter system is removing particulate matter from the contaminated air stream), reduced friction losses in the filter system during both primary flow operation and pulse cleaning of the filter bag, improved particle loading characteristics (and thus potentially fewer cleaning pulses required), etc., in one or more embodiments.

[0023] These benefits may be synergistic in one or more embodiments, i.e., energy efficiency, noise reduction, etc. may be improved by using two or more features and / or components together in the same filter system.

[0024] In a first aspect, one or more embodiments of the filter bag described herein include a tubular body formed from a filter medium configured to remove particulate matter from air passing through the filter medium, the tubular body extending from the closed end to a bag opening along a bag axis coincident with a central axis of the tubular body, the sealing cuff extending around a periphery of the bag opening, and a reference bag length measured along the bag axis between a reference plane oriented perpendicular to the bag axis and the bag opening changes when moving around the periphery of the bag opening.

[0025] In a second aspect, one or more embodiments of a filter bag support assembly described herein include a flange assembly including an inner surface and a tubesheet surface, the flange assembly including a clean air outlet extending through the flange assembly, and a cage including a first cage end attached to the flange assembly, the cage extending away from the inner surface of the flange assembly a cage length from a base to a distal second cage end, the cage defining a cage axis extending between the first cage end and the second cage end, the flange assembly including a base and a clamp configured to attach to the base on the inner surface of the flange assembly, the clean air outlet being configured to extend through a base opening formed in the base. and a clamp opening formed in the clamp, the base including a bag seal surface surrounding the base opening, the bag seal surface facing the clamp, the clamp including a clamp seal surface surrounding the clamp opening, the clamp seal surface facing the bag seal surface when the clamp is attached to the base, the base including a tubesheet face facing away from the second end of the cage, the tubesheet face including a tubesheet face opening defining a portion of the clean air outlet, the tubesheet face including a tubesheet seal surface surrounding the tubesheet face opening, and a distance between the bag seal surface and the tubesheet seal surface in a direction aligned with the cage axis changes when moving around the periphery of the base opening.

[0026] In a third aspect, one or more embodiments of the filter bag support assembly described herein include a flange assembly including an inner surface and a tubesheet surface, the flange assembly including a clean air outlet extending through the flange assembly; and a cage including a first cage end attached to the flange assembly, the cage extending away from the inner surface of the flange assembly a cage length from a base to a distal second cage end, the cage defining a cage axis extending between the first cage end and the second cage end, the flange assembly including a base and a clamp configured to attach to the base on the inner surface of the flange assembly, the clean air outlet being defined by a base opening formed in the base and a clamp opening formed in the clamp, the base including a bag sealing surface surrounding the base opening, the bag sealing surface facing the clamp, the clamp including a clamp sealing surface surrounding the clamp opening, the clamp sealing surface facing the bag sealing surface when the clamp is attached to the base, the bag sealing surface and the clamp sealing surface defining a bag sealing plane when the clamp is attached to the base, and the cage axis is not perpendicular to the bag sealing plane.

[0027] In a fourth aspect, one or more embodiments of the filter bag assembly described herein include a filter bag assembly including a flange assembly including an inner surface and a tubesheet surface, the flange assembly including a clean air outlet extending through the flange assembly; a cage including a first cage end attached to the flange assembly, the cage extending away from the inner surface of the flange assembly a cage length from a base to a distal second cage end, the cage defining a cage axis extending between the first cage end and the second cage end; and a filter bag including a tubular body formed from a filter media configured to remove particulate matter from air passing through the filter media, the tubular body extending from the closed end to a bag opening along a bag axis coincident with a central axis of the tubular body, the cage being received within the tubular body of the filter bag, the sealing cuff extending around a periphery of the bag opening. and a bag, the flange assembly including a base and a clamp configured to attach to the base on an inner surface of the flange assembly, the clean air outlet being defined by a base opening formed in the base and a clamp opening formed in the clamp, the base including a bag sealing surface surrounding the base opening, and the clamp including a clamp sealing surface surrounding the clamp opening, the sealing cuff being disposed between the bag sealing surface and the clamp sealing surface when the clamp is attached to the base, the base including a tubesheet surface facing away from the second end of the cage, the tubesheet surface including a tubesheet face opening defining a portion of the clean air outlet, the tubesheet surface including a tubesheet seal surface surrounding the tubesheet face opening, and a distance between the bag sealing surface and the tubesheet seal surface in a direction aligned with the cage axis changes when moving around a periphery of the base opening.

[0028] In a fifth aspect, one or more embodiments of the filter bag described herein include a tubular body formed from a filter medium configured to remove particulate matter from air passing through the filter medium, the tubular body extending from the closed end to the bag opening along a bag axis coincident with a central axis of the tubular body, the sealing cuff extending around a periphery of the bag opening, and a bag opening periphery length measured around the periphery of the bag opening is greater than a body periphery length measured in a reference plane oriented perpendicular to the bag axis at a location between the bag opening and the closed end.

[0029] In a sixth aspect, one or more embodiments of the air filter system described herein include a housing including a tube sheet separating an interior volume of the housing into a clean air chamber and a dirty air chamber, a dirty air inlet configured to direct dirty air into the dirty air chamber and a clean air outlet configured to remove clean air from the clean air chamber, and a filter bag as described herein, wherein the filter bag is disposed within the dirty air chamber.

[0030] In a seventh aspect, one or more embodiments of the air filter system described herein includes a housing including a tube sheet separating an interior volume of the housing into a clean air chamber and a dirty air chamber, a dirty air inlet configured to direct dirty air into the dirty air chamber and a clean air outlet configured to remove clean air from the clean air chamber, and a filter bag assembly described herein, wherein the filter bag assembly is disposed within the dirty air chamber.

[0031] In an eighth aspect, one or more embodiments of a method for removing particulate matter from polluted air using the air filtration system described herein include feeding polluted air into a polluted air chamber through a polluted air inlet and removing clean air from the clean air chamber through a clean air outlet.

[0032] In a ninth aspect, one or more embodiments of a method of mounting a filter bag on a filter bag support assembly to provide a filter bag assembly as described herein include positioning the filter bag such that the filter bag opening is larger than a cage of the filter bag support assembly; advancing the filter bag opening on the cage toward a base of the filter bag support assembly; advancing a clamp of a flange assembly of the filter bag support assembly over the filter bag such that a tubular body of the filter bag extends through the clamp opening of the clamp; and attaching the clamp to the base such that a sealing cuff on the filter bag forms a seal around the clamp opening and a base opening of the base such that air entering or exiting the filter bag must pass through the base opening or the filter media forming the filter bag.

[0033] Also described herein is the use of any of the filter systems, filter bag assemblies and filter bags described herein for removing particulate matter from contaminated air (or any other gas).

[0034] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a" or "the" component can include one or more of the component and equivalents thereof known to those of ordinary skill in the art. Additionally, the term "and / or" means one or all of the listed elements or a combination of any two or more of the listed elements.

[0035] It should be noted that the terms "comprises" and variations thereof do not have a limiting meaning when these terms appear in the accompanying description. Additionally, "a," "an," "the," "at least one," and "one or more" are used interchangeably herein.

[0036] The above summary is not intended to describe each embodiment or every implementation of the filter bags, filter bag support assemblies, filter bag assemblies, filter systems and methods described herein. Rather, the present invention will become more fully understood by reference to the following description of exemplary embodiments and claims, taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0037] [Figure 1] FIG. 2 is a side view of one exemplary embodiment of a filter bag having an enlarged bag opening as described herein. [Diagram 2] 2 is a view of the bag opening of the filter bag of FIG. 1 taken along a viewing axis perpendicular to plane 20' of FIG. 1. [Figure 3A] 3A is a cross-sectional view of the filter bag of FIG. 1 taken along line 3A-3A of FIG. 1. [Figure 3B] 3B is a cross-sectional view of the filter bag of FIG. 2 taken along line 3B-3B of FIG. 2. [Figure 4] 1A-1C are side views of several alternative exemplary embodiments of filter bags having enlarged bag openings as described herein. [Diagram 5] 1A-1C are side views of several alternative exemplary embodiments of filter bags having enlarged bag openings as described herein. [Figure 6] 1A-1C are side views of several alternative exemplary embodiments of filter bags having enlarged bag openings as described herein. [Figure 7] FIG. 1 is a side view of one exemplary embodiment of a filter bag support assembly described herein including a base having a cage extending therefrom and a clamp positioned for advancement on the cage, the filter bag support assembly being mounted within a tubesheet opening of a tubesheet of an air filter system. [Figure 8] 8 is an end view of the base of the filter bag support assembly of FIG. 7 taken along the cage axis 51 referenced in FIG. 7. [Figure 9] 8 is a view of the clamp of the filter bag support assembly of FIG. 7 removed from the cage, as viewed along the cage axis 51 referenced in FIG. 7. FIG. [Figure 10] FIG. 8 is a side view of the filter bag support assembly of FIG. 7 (removed from the tubesheet) with one exemplary embodiment of a filter bag partially advanced onto a cage extending from the base of the flange assembly. [Figure 11] 11 is a side view of the filter bag support assembly and filter bag of FIG. 10 after advancement of the filter bag to the base of the flange assembly and further advancement of the clamp towards the sealing cuff of the filter bag. [Figure 12] FIG. 1 is a perspective view of one exemplary embodiment of a filter system described herein. [Figure 13] FIG. 13 is a side view of the filter system shown in FIG. 12. [Figure 14] FIG. 14 is a top view of the filter system shown in FIGS. 12 and 13. [Figure 15A] 15A is a cross-sectional view of the filter system of FIGS. 12-14 taken along line 15A-15A in FIG. 14. [Figure 15B] 15B is a cross-sectional view of the filter system of FIG. 14 taken along line 15B-15B of FIG. 15A when the system is not in operation. [Figure 15C] 15B is a cross-sectional view of the filter system of FIG. 14 taken along line 15B-15B of FIG. 14 during a pulsed cleaning event. [Figure 15D] 1 illustrates several alternative embodiments of filter guides and corresponding guide openings that may be provided in one or more embodiments of the filter systems described herein. [Figure 15E] 1 illustrates several alternative embodiments of filter guides and corresponding guide openings that may be provided in one or more embodiments of the filter systems described herein. [Figure 15F]1 illustrates several alternative embodiments of filter guides and corresponding guide openings that may be provided in one or more embodiments of the filter systems described herein. [Figure 15G] 15G is a cross-sectional view of the filter system of FIGS. 12-14 taken along line 15G-15G in FIG. 14. [Figure 16] FIG. 2 is a schematic diagram of the components of one exemplary embodiment of the filter system described herein, illustrating the seal formed using the filter bag assembly described herein. [Figure 17A] FIG. 2 is a perspective view of a portion of a tube sheet in which one exemplary embodiment of a filter bag assembly is supported over one exemplary embodiment of a filter guide described herein. [Figure 17B] 1 illustrates one alternative embodiment of a bag support that may be provided in one of the many embodiments of the filter systems and filter bags described herein. [Figure 17C] 1 illustrates another alternative embodiment of a bag support that may be provided in one of the many embodiments of the filter systems and filter bags described herein. [Figure 18A] FIG. 1 is a perspective view of one exemplary embodiment of a portion of an access panel including one exemplary embodiment of a cover used to close an access port through which a filter bag assembly of a filter system is threaded during removal and replacement. [Figure 18B] FIG. 13 is a perspective view of a portion of an access panel and an alternative exemplary embodiment of a cover used to close an access port, the cover including embossments shaped to complement a filter bag assembly. [Figure 19] 1 is a diagram of an exemplary embodiment of a triangle formed by an exemplary embodiment of a filter bag used in a filter system described herein. FIG. [Figure 20] 1A is a diagram of one exemplary embodiment of a triangle formed by another exemplary embodiment of a filter bag used in the filter system described herein. FIG. [Figure 21] FIG. 21 shows one illustrative example of a possible arrangement of pairs of filter bags as shown in FIG. 20. [Figure 22] 11A-11C are diagrams of one exemplary embodiment of a triangle formed by another exemplary embodiment of a filter bag used in the air filter system described herein. [Diagram 23] FIG. 2 is a cross-sectional view of another exemplary embodiment of a filter bag assembly including an envelope-like filter bag supported by a cage on a flange assembly described herein. [Figure 24] FIG. 2 is a perspective view of one exemplary embodiment of a triangular filter bag that may be used in one or more embodiments of the filter bag assembly in the air filter system described herein. [Diagram 25] 25 illustrates components that may be used to construct the exemplary embodiment of the triangular filter bag shown in FIG. 24. [Figure 26] FIG. 26 is a schematic diagram illustrating the relationship between the features of the exemplary embodiment of the triangular end cap shown in FIGS. 24-25. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] In the following description of exemplary embodiments, reference is made to the accompanying drawings which form a part hereof, and in which specific embodiments are shown by way of illustration, It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.

[0039] 1-3 show various views of one exemplary embodiment of a filter bag described herein. In FIG. 1, filter bag 10 includes a bag opening 12 and a closed end 14. A body 16 extends from the bag opening 12 to the closed end 14 along a bag axis 11 that extends between the bag opening 12 and the closed end 14.

[0040] The body 16 of the filter bag 10 may be described as a tubular body 16 extending between the bag opening 12 and the closed end 14. In a side view, such as in FIG. 1, the filter bag 10 includes a top edge 13 that extends from the bag opening 12 / seal 20 to the closed end 14 and a bottom edge 15 that extends from the bag opening 12 / seal 20 to the closed end 14.

[0041] The tubular body of the filter bags described herein can take many different forms including, for example, an envelope-like shape, a triangular shape in which the tubular body includes two major faces that meet along a top edge and a base face that connects the bottom edges of the two major faces, a rectangular shape (also having, for example, two major faces), etc.

[0042] In one or more embodiments, the bag axis 11 may be described as coinciding with the central axis of the tubular body 16, with the central axis / bag axis 11 extending through the center of the tubular body 16 such that the central axis / bag axis 11 includes the geometric center of a cross-section of the tubular body 16 taken in a plane oriented perpendicular to the central axis / bag axis 11. In the exemplary embodiment shown, the filter bag 10 includes a tubular body 16 whose top edge 13 and bottom edge 15 are aligned (e.g., parallel) to one another.

[0043] A datum plane 14' is similarly shown in relation to the exemplary filter bag 10 of Figure 1. The datum plane 14' is oriented perpendicular to the bag axis 11. In the embodiment shown, the datum plane 14' may also be described as being aligned (e.g., parallel) with the closed end 14 of the filter bag 10 because, in the embodiment shown, the closed end 14 is also oriented perpendicular to the bag axis 11.

[0044] The body 16 of the filter bag 10 is constructed primarily from a filter medium configured to filter air or any other gas passing through the filter medium forming the body 16, with particulate matter entrained in the air or other gas being trapped in or on the filter medium forming the body 16. In general, the filter medium may preferably be sufficiently flexible to allow the filter medium to flex during pulse cleaning as described herein, and preferably such flexing or movement of the filter medium removes at least a portion of the particulate matter trapped in or on the filter medium forming the filter body 16. The construction of such filter media is well known to those skilled in the art and may include, for example, woven fabrics, nonwoven materials, papers, etc., selected with consideration of the particulate matter to be collected, airflow requirements, strength requirements, etc. Suitable filter bags may be constructed from one or more layers of filter media, scrims, etc., including one or more of polyester, polypropylene, aramid, polyester / polytetrafluoroethylene materials, etc., in both woven and / or nonwoven constructions.

[0045] In one or more embodiments, the filter bags described herein can be distinguished from filter cartridges based on their response to a compressive force directed between the filter bag opening and the closed end of the filter bag, i.e., the end of the bag located opposite the bag opening. In the absence of any external support (such as, for example, the filter bag support assembly and the internal cage described herein as part of the filter bag assembly), the filter bags described herein, in one or more embodiments, deform under a compressive force of 5 Newtons (about 1.1 pounds-force) directed along a line extending through the bag opening to the closed end of the filter bag (for example, along the bag axis 11 shown in FIG. 1). In addition to deformation, one or more embodiments of the filter bags used in the filter bag assemblies described herein essentially do not transmit any of such compressive forces. In contrast, the filter cartridge does not deform significantly and transmits at least some, but not all, of such compressive forces. However, the flexibility that accounts for the inability of the filter bags used in the filter bag assemblies and filter systems described herein to transmit compressive forces is at least partially the source of the filter bags' ability to rapidly accelerate outward (sometimes referred to as "snap") in response to a cleaning pulse to dislodge particulate matter that has collected on the outside of the filter media.

[0046] 1-3, the filter bag 10 shown in FIG. 1 includes a sealing cuff 20 attached to the filter media that forms the tubular shape of the body 16. In one or more embodiments of the filter bags described herein, the sealing cuff 20 may extend around the entire periphery of the bag opening 12, as seen, for example, in FIG.

[0047] In one or more embodiments, the sealing cuff 20 may be provided as a discrete component attached to the filter media forming the filter body 16 of the filter bag 10. The sealing cuff may be provided in one or more embodiments as multiple layers of filter media held together by one or more of stitching, adhesives, heat welding, chemical welding, and the like. The sealing cuff may include a polymeric component, such as a flexible polymeric component. In one or more embodiments, the sealing cuff may be capable of assuming the shape of the body 16 of the filter bag 10. In one or more embodiments, the sealing cuff may be in the form of a compressible material, such as a foam (closed cell, open cell, etc.), fabric, filter media, etc., to aid in the formation of a seal when clamped into a flange assembly of a filter system described herein. In one or more embodiments, the sealing cuff may be formed from a resiliently compressible material capable of returning to its original shape (or approximately its original shape) after compression. In one or more other embodiments, the sealing cuff may include one or more layers of material that exhibit increased resistance to abrasion and / or tearing. In yet other embodiments, the sealing cuffs used in the filter bags described herein may be formed from two or more components that are attached to the filter media by any suitable technique or combination of techniques.

[0048] Although the illustrated exemplary embodiment of the filter bag 10 includes a sealing cuff 20 positioned at the bag opening 12, in one or more embodiments, the sealing cuff may be positioned proximally from the bag opening 12 defined by the filter media forming the tubular body 16. One advantage of providing a sealing cuff 20 disposed at the bag opening 12 is that compression of the sealing cuff 20 may be more easily obtained when such an arrangement of the sealing cuff 20 is provided. When using the filter bags described herein, compression of the sealing cuff 20 may be important to the formation of a proper seal that prevents unwanted passage of particulate matter.

[0049] One or more embodiments of the filter bags having an enlarged bag opening described herein, such as filter bag 10 shown, may have an enlarged bag opening that may be described as not being perpendicular to the bag axis 11. In a filter bag such as filter bag 10 in which tubular body 16 terminates at closed end 14, forming, together with top edge 13 and bottom edge 15, a generally rectangular tubular body 16 between bag opening 12 / sealing cuff 20 and closed end 14, a reference plane 14' oriented perpendicular to bag axis 11 may be aligned (e.g., parallel) with closed end 14 of filter bag 10. In such an embodiment, bag opening 12 / sealing cuff 20 may be described as not being parallel to reference plane 14' and / or bag axis 11.

[0050] Although not required, the bag opening 12 / sealing cuff 20 of the exemplary filter bag 10 may define a bag opening plane 20' that is angled (e.g., inclined) relative to the reference plane 14'. The bag opening plane 20' may also be described with respect to the bag axis 11, i.e., the bag axis 11 is not perpendicular to the bag opening plane 20' defined by the bag opening 12 / sealing cuff 20 of the filter bag 10.

[0051] The filter bag 10 with its angled or non-vertical bag opening 12 is one example of an enlarged bag opening on the filter bag described herein. Regardless of the specific form of the enlarged bag opening, another way in which the filter bag with the enlarged bag opening described herein can be characterized is based on a reference bag length measured along the bag axis 11. In the filter bag with the enlarged bag opening described herein, the reference bag length, e.g., the length (along the bag axis) between a reference plane and the bag opening (when the reference plane is oriented perpendicular to the bag axis), changes when moving around the periphery of the bag opening. The reference plane used to characterize the filter bag in terms of the reference bag length can be located anywhere along the bag axis between the closed end and the bag opening. Any such reference plane should not intersect either the bag opening or the closed end of the filter bag.

[0052] 1 , the reference bag length measured along the bag axis 11 between the bag opening 12 / sealing cuff 20 and the reference plane 14′ along the top edge 13 of the filter bag 10 is less than the reference bag length along the bottom edge 15 of the filter bag 10. The reference bag length may be further described as changing when moving around the circumference of the bag opening 12 / sealing cuff 20. For example, when moving around the circumference of the bag opening 12 from the top edge 13 to the bottom edge 15, the reference bag length (i.e., the distance between the reference plane 14′ and the bag opening 12) increases. Conversely, when moving around the circumference of the bag opening 12 from the bottom edge 15 toward the top edge 13, the reference bag length (i.e., the distance between the reference plane 14′ and the bag opening 12) decreases.

[0053] In filter bag 10, the nominal bag length may be described as having a minimum bag length where top edge 13 of filter bag 10 meets bag opening 12 / sealing cuff 20 and a maximum nominal bag length where top edge 13 of filter bag 10 meets bag opening 12 / sealing cuff 20. In embodiments where bag opening 12 / sealing cuff defines bag opening plane 20', the rate of change of nominal bag length when moving between top edge 13 and bottom edge 15 may be described as substantially linear. Furthermore, the distance between the location where top edge 13 meets bag opening 12 / sealing cuff 20 and the location where bottom edge 15 meets bag opening 12 / sealing cuff 20 is equal regardless of whether moving clockwise or counterclockwise around the circumference of bag opening 12.

[0054] One advantage of a filter bag, such as filter bag 10, having an angled bag opening as described herein is that the size of the bag opening 12 / sealing cuff 20, as measured at the bag opening plane 20', is greater than the cross-sectional size of the filter bag 10, as measured at a reference plane 14' that is perpendicular to the bag axis 11, for example. The enlarged bag opening / sealing cuff 20 can make it easier to mount the filter bag onto a cage of a flange assembly as described herein (e.g., as discussed in connection with FIG. 5).

[0055] One way in which the size of the bag opening 12 / sealing cuff 20 measured at the bag opening plane 20' can be compared to the cross-sectional size of the filter bag 10 in the perpendicular plane 14' is based on the angle 22 formed between the bag opening plane 20' containing the bag opening 12 / sealing cuff 20 and a reference plane 14' that is perpendicular to the bag axis 11. In one or more embodiments, the angle 22 can be 15 degrees or more, 20 degrees or more, 25 degrees or more, 30 degrees or more, 35 degrees or more, 40 degrees or more, or 45 degrees or more. At the upper limit, the angle 22 can be 60 degrees or less, 55 degrees or less, 50 degrees or less, 45 degrees or less, 40 degrees or less, 35 degrees or less, 30 degrees or less, 25 degrees or less, or 20 degrees or less.

[0056] Increasing the size of the bag opening 12 / sealing cuff 20 by increasing angle 22 may make installation of filter bag 10 easier, but increasing angle 22 also increases the overall length of filter bag 10 as measured along bottom edge 15 of filter bag 10. That increase in filter bag length is expected to cause a corresponding increase in the size of the filter system in which filter bag 10 is installed. Because an increase in the overall size of the filter system may be a concern, it may be preferred that angle 22 be within the range of, for example, 15 degrees to 45 degrees, or alternatively 20 degrees to 40 degrees, to provide a balance between easier installation and filter bag length while maintaining pulse cleaning performance and filter bag life.

[0057] Another way in which the size of the bag opening 12 / sealing cuff 20 measured at the bag opening plane 20' and the cross-sectional size of the filter bag 10 at the reference plane 14' can be compared is based on the peripheral length of the bag opening 12 / sealing cuff 20 measured at the bag opening plane 20' and the peripheral length of the filter bag 10 measured at the reference plane 14' located between the bag opening 12 / sealing cuff 20. The difference in peripheral length is illustrated by Figures 2 and 3A, where the peripheral length of the bag opening 12 referenced in Figure 2 is greater than the peripheral length of the tubular body 16 of the filter bag 10 referenced in Figure 3A. In the illustrated exemplary embodiment of Figure 1, the reference plane 14' could be located anywhere between the junction of the top edge 13 of the tubular body 16 and the closed end 14 of the filter bag 10, with no actual change in the peripheral size of the filter bag 10.

[0058] Another optional feature of one or more embodiments of the filter bag described herein is the addition of a bag support connector 40 attached to the body 16 of the filter bag 10 proximal to the closed end 14 of the body 16. The bag support 40 may preferably be located outside the interior volume 13 of the body 16 of the filter bag 10. In one or more embodiments, the bag support 40 may preferably include an opening 42 configured to receive a hook or other structure configured to support the filter bag 10 at its closed end 14. In one or more embodiments, the bag support connector 40 may be as simple as a loop of material attached to both sides of the body 16 of the filter bag 10. Of course, many variations are possible, as described elsewhere herein. For example, the bag support connector on the filter bag may be in the form of a hook, while the chamber connector to which the hook attaches is in the form of a loop or opening configured to receive the hook. In another alternative, the bag support may be in the form of a sling that can be wrapped around the tubular body 16 of the filter bag 10, for example.

[0059] Although the exemplary embodiment of filter bag 10 shown in Figures 1-3 is one example of a filter bag having an enlarged bag opening in which the bag opening 12 / sealing cuff 20 is disposed in a plane 20', many alternative embodiments of filter bags have a bag opening that is enlarged relative to the size of the opening in the tubular body between the bag opening and the closed end of the filter bag. Just a few examples of the many possible filter bags are shown in Figures 4-6.

[0060] 4, filter bag 110 includes a bag opening 112 / sealing cuff 120 and a closed end 114 disposed at an opposite end of tubular body 116 along bag axis 111. Bag opening 112 / sealing cuff 120 has a rounded or arcuate shape over at least a portion of bag opening 112 / sealing cuff 120 that, when flattened, provides an enlarged bag opening having a longer perimeter length as compared to the perimeter length of tubular body 116 measured at a reference plane 114' oriented perpendicular to bag axis 111 as described herein. Additionally, filter bag 110 provides another example of a filter bag in which a reference bag length measured between reference plane 114' and bag opening 112 changes as one moves around the circumference of bag opening 112 as described herein. In this exemplary embodiment, the reference surface 114' may be located anywhere between the juncture of the bag opening 112 / sealing cuff 120 with either the top edge 113 or bottom edge 115 of the filter bag 110 and the closed end 114. The filter bag 110 shown also includes a closed end 114 that is not, itself, laid out in a plane, i.e., is rounded.

[0061] 5, filter bag 210 includes a bag opening 212 / sealing cuff 220 and a closed end 214 disposed at an opposite end of tubular body 216 along bag axis 211. Bag opening 212 / sealing cuff 220 has a generally sinusoidal shape that, when flattened, provides an enlarged bag opening having a longer perimeter length as compared to the perimeter length of tubular body 216 measured at a reference plane 214' oriented perpendicular to bag axis 211 as described herein. Additionally, filter bag 210 provides another example of a filter bag in which the reference bag length measured between reference plane 214' and bag opening 212 changes as one moves around the perimeter of bag opening 212 as described herein. In this exemplary embodiment, top edge 213 and bottom edge 215 of filter bag 210 shown are not aligned with bag axis 211 as are edges 13 / 15 of filter bag 10 or edges 113 / 115 of filter bag 110.

[0062] The filter bag 310 of FIG. 6 includes a bag opening 312 / sealing cuff 320 and a closed end 314 disposed at an opposite end of the tubular body 316 along the bag axis 311. The bag opening 312 / sealing cuff 320 has a V-shape that, when flattened, provides an enlarged bag opening with a longer perimeter length compared to the perimeter length of the tubular body 316 measured at a reference plane 314' oriented perpendicular to the bag axis 311 described herein. Additionally, the filter bag 310 provides another example of a filter bag in which the reference bag length measured between the reference plane 314' and the bag opening 312 changes as one moves around the circumference of the bag opening 312 described herein. In this exemplary embodiment, the bottom edge 315 of the filter bag 310 is aligned with the bag axis 311, while the top edge 313 is not aligned with the bag axis.

[0063] Filter Bag Support Assembly The filter bag support assemblies described herein may be particularly suitable for use with the filter bags described herein. With reference to Figures 7-11, one exemplary embodiment of a filter bag support assembly 50 is shown, the filter bag support assembly 50 shown includes a flange assembly including a base 60 and a clamp 80. A cage 70 is attached to the base 60 and extends away from the base 60 through the clamp 80 along a cage axis 51.

[0064] 7-8, in the exemplary embodiment shown, the base 60 includes a tubesheet panel 62 and a bag seal panel 64 separated from the tubesheet panel 62 by a flow passage 66. The bag seal panel 64 includes a bag seal surface 65 that surrounds a base opening 67 formed through the bag seal panel 64. Air passing through the base opening 67 formed through the bag seal panel 64 travels through the flow passage 66 towards the tubesheet panel 62, which includes a tubesheet panel opening 69 that allows air to pass through the tubesheet opening 32 within the pulse collector 68. In the embodiment shown, the tubesheet panel opening 69 is formed in the base of the pulse collector 68. While shown to be located slightly inboard from the tubesheet panel opening 69, in one or more embodiments the base opening 67 can preferably (but need not be) at least as large as the tubesheet panel opening 69.

[0065] A tubesheet panel 62 of the base 60 of the flange assembly includes a tubesheet face 63 and, in one or more embodiments, is configured to seal against the contaminated air chamber side of the tubesheet 30 (see FIG. 7 ). In the embodiment shown, a seal 34 is provided between the tubesheet face 63 of the tubesheet panel 62 and the tubesheet, with the seal 34 extending around the tubesheet opening 32 of the tubesheet 30. A pulse collector 68 of the shown flange assembly extends from the tubesheet panel 62 of the base 60 through the tubesheet opening 32. The seal 34 prevents unwanted passage of air between the tubesheet 30 and the tubesheet face 63 of the tubesheet panel 62 of the base 60.

[0066] 7 , the illustrated exemplary embodiment of the bag support assembly also includes a clamp 80 configured to act with the base 60 (and in the embodiment shown, against the bag seal panel 64 of the base 60) to capture a sealing cuff of a filter bag as described herein. In particular, the base 60 includes a bag sealing surface 65 (in the embodiment shown, on the bag seal panel 64) and the base 80 includes a clamp seal surface 85 facing the bag sealing surface 65. The bag sealing surface 65 on the base 60 and the clamp seal surface 85 on the clamp 80 are configured together to form a seal with the sealing cuff of a filter bag mounted on the filter bag support assembly 50.

[0067] Clamp 80 is shown in Figure 9 in a view along cage axis 51 from the right side of bag support assembly 50 as shown in Figure 7. In Figure 9, clamp seal surface 85 is shown surrounding clamp opening 87 formed through clamp 80. When combined with base 60, clamp opening 87 aligns with base opening 67 provided in bag seal panel 64 of base 62, allowing air to pass through clamp 80 to base 60, where it passes through base 60 and tubesheet opening 32 and tubesheet 30 as described herein.

[0068] In the illustrated exemplary embodiment of the base 60 of the flange assembly, the flow passage 66 is constructed from one or more materials that are impermeable to air such that air passing between the base opening 67 of the bag seal panel 64 and the tubesheet panel opening 69 of the tubesheet panel 62 of the base 60 cannot exit the flow passage 66 between the tubesheet panel 62 and the bag seal panel 64.

[0069] The illustrated embodiment of clamp 80 includes openings 84 configured to receive fasteners (e.g., bolts, tacks, etc.) that may be useful for securing clamp 80 in place on base 62 and forming a seal with the sealing cuff of a filter bag described herein. Many other structures and / or mechanisms for securing clamp 80 to base 60 in place of such fasteners may be used.

[0070] The flange assembly formed by the combination of the base 60 and the clamp 80 may be described as defining a clean air outlet extending through the base 60 and the clamp 80 such that air (or any other gas) disposed within the interior volume of a filter bag mounted on the filter bag support assembly may enter or exit the interior volume through the filter media or clean air outlet of the filter bag. In particular, the clean air outlet of the illustrated exemplary embodiment of the filter bag support assembly 50 includes, from right to left in FIG. 7 , a tubesheet panel opening 69 formed in the tubesheet panel 62 of the base 60, a base opening 67 formed in the bag seal panel 64 of the base 60, and a clamp opening 87 formed in the clamp 80.

[0071] In the illustrated exemplary embodiment of the filter bag support assembly 50, a cage 70 is attached to the base 60, and the cage 70 extends away from the base 60 to support a filter bag as described herein. The cage 70 includes a first cage end that is attached to the base 60 of the flange assembly, and the cage 70 extends a cage length from the base 60 to a second cage end 72 that is distally disposed. The cage 70 defines a cage axis 51 that extends between the first cage end that is attached to the base 60 and the second cage end 72 that is distally disposed from the base 60.

[0072] The shown exemplary embodiment of cage 70 includes struts 74 that extend away from base 60 along cage axis 51, with struts 74 terminating at second ends 72 disposed distally from base 60. Cage 70 shown in FIG. 7 also includes braces 73 extending between struts 74 to provide additional support to a filter bag positioned on cage 70. Although not required, struts 74 in the shown embodiment are aligned with cage axis 51. The shown arrangement of struts 74 and braces 73 in cage 70 provides only one example of a cage that may be used to support a filter bag in association with the filter bag support assemblies described herein.

[0073] Although the ends of the struts 74 of the cage 70 are shown as terminating at the bag seal panel 64 of the base 60, in one or more embodiments, the struts 74 may be attached to the base 60 at any location between the tubesheet panel 62 and the bag seal panel 64. In those embodiments in which the struts 74 of the cage 70 are attached to the bag seal panel 64, the flow passages 66 are sufficiently rigid to transfer forces applied to the second end 72 of the cage 72 to the tubesheet panel 62 such that the seal 34 prevents the passage of air through the joint between the tubesheet face 63 of the tubesheet panel 62 and the tubesheet 30 as described herein. In those embodiments in which the struts 74 are attached to and extend to the tubesheet panel 62 of the base 60, the struts 74 may pass through the base openings 65 of the bag seal panel 64 to reach the tubesheet panel 62.

[0074] Another optional feature of one or more embodiments of the filter bag support assembly described herein is a second cage end plane 72', shown in and referenced along the edge of FIG. 7, where the second cage end plane 72' is defined by the second cage end 72. In one or more embodiments, the second cage end plane 72' may preferably be parallel to the dirty air chamber surface of the tubesheet 30.

[0075] In one or more embodiments of the filter bag support assemblies described herein, the clean air outlet defined in the flange assembly, i.e., defined by the combination of the base opening 64 and the clamp opening 84, may be elongated such that the clean air outlet defines a maximum height along a major axis and a maximum width that is less than the maximum height along a minor axis that is transverse to the major axis. With reference to Figures 8-9, the major axis will generally extend vertically (along the Y axis) from the narrow end of the base opening 67 and the clamp opening 87 to the opposite end of the base opening 67 and the clamp opening 87, while the minor axis will be generally transverse to the major axis (along the X axis). Both the major and minor axes will be generally transverse to the cage axis 51. In one or more embodiments, the maximum height of the clean air outlet defined by the base opening 64 and the clamp opening 84 may be two or more times, three or more times, or four or more times greater than the maximum width to provide an elongated clean air outlet as defined herein.

[0076] For example, with respect to FIG. 7 , which illustrates a bag support assembly 50 configured to accept a filter bag having an enlarged (e.g., angled) bag opening as shown in FIG. 1 , the bag seal surface 65 on the bag seal panel 64 may be described as being oriented at an angle relative to the tubesheet surface 63 of the tubesheet panel 62 of the base 62, providing a transition between the enlarged (e.g., angled) bag opening of the filter bag 10 and the tubesheet 30 of one embodiment of the filter system described herein.

[0077] In one or more embodiments, the bag seal surface 65 may be described as defining a bag seal plane 65' and the tubesheet surface 63 of the tubesheet panel 62 may be described as defining a tubesheet plane 62', with the edges of the bag seal plane 65' and the tubesheet plane 62' being shown in FIG. 7. The angle 22' between the bag seal plane 65' and the tubesheet plane 62' is also shown in FIG. 11. In one or more embodiments, the angle 22' between the bag seal plane 65' and the tubesheet plane 62' may be 15 degrees or more, 20 degrees or more, 25 degrees or more, 30 degrees or more, 35 degrees or more, 40 degrees or more, or 45 degrees or more. At the upper limit, the angle 22' between the bag seal plane 65' and the tubesheet plane 62' may be 60 degrees or less, 55 degrees or less, 50 degrees or less, 45 degrees or less, 40 degrees or less, 35 degrees or less, 30 degrees or less, 25 degrees or less, or 20 degrees or less.

[0078] For reasons discussed above in connection with the exemplary embodiment of filter bag 10, angle 22' formed between bag seal plane 65' and tubesheet plane 62' (which generally corresponds to and is discussed in connection with angle 22 formed between plane 20' and plane 14' shown in FIG. 1 ), it may be preferred that angle 22' be within a range of, for example, 15 degrees to 45 degrees, or alternatively, 20 degrees to 40 degrees.

[0079] Although the flange assembly formed by the base 60 and clamp 80 of the illustrated exemplary embodiment of the filter bag support assembly 50 is configured to receive and hold the filter bag 10, it will be understood that the base and clamp of one or more alternative embodiments of the flange assemblies used in the filter bag support assemblies described herein may take on a different shape that is complementary to the shape of the bag opening of the filter bags described herein. For example, the base and clamp of one or more alternative embodiments of the filter bag support assemblies described herein may be shaped to receive and hold a filter bag having the bag opening / sealing cuff shown in FIGS. 4-6.

[0080] Another optional feature that may be provided in connection with one or more embodiments of the filter bag support assembly described herein is a guide opening 90. The guide opening 90 may be located outside of the cage 70 attached to the base 60 and the clean air outlet defined by the base opening 67 and the clamp opening 87. The guide opening 90, in one or more embodiments, is configured to receive a guide rail 92 that is attached to the tube sheet 30 when the clamp 80 is attached to the base 60 of the flange assembly (comprised of the base 60 and the clamp 80). When the guide opening 90 is positioned on the guide rail 92, the filter bag support assembly 50 may be described as configured for advancement along the guide rail 92 toward the tube sheet 30 as described herein.

[0081] The guide opening 90 may, in one or more embodiments, be formed in only one of the base 60 and the clamp 80. In a flange assembly having a tubesheet panel 62 and a bag seal panel 64, the guide opening 90 may be provided in one or both of the tubesheet panel 62 and the bag seal panel 64. In one or more alternative embodiments, the guide opening 90 may be formed in the clamp 80 of the flange assembly formed by the clamp 80 and the base 60.

[0082] The depicted embodiment of guide rail 92 also includes an optional bag connector 94, which in one or more embodiments may be configured to hold a bag support connection on a filter bag mounted on filter bag support assembly 50, such as connector 40 on filter bag 10 shown in FIGS. 1-2.

[0083] Filter Bag Assembly FIG. 10 is a side view of the filter bag support assembly of FIG. 7 (removed from the tubesheet) with one exemplary embodiment of the filter bag 10 shown in FIGS. 1-3 partially advanced onto a cage 70 extending from the base 60 of the flange assembly.

[0084] 10, the bag opening 12 / sealing cuff 20 of the filter bag 10 is oriented generally perpendicular to the bag axis 11 / cage axis 51 so that the enlarged bag opening 12 / sealing cuff 20 can be used to more easily advance the filter bag 10 over the cage 70. In the illustrated embodiment of the filter bag 10, a portion 17 of the bottom edge 15 of the filter bag 10 is folded or compressed to properly orient the bag opening 12 / sealing cuff 20 as referenced in FIG. 10. As referenced in FIG. 10, the struts 74 of the cage 70, which are attached to the base 60, extend into the filter bag 10.

[0085] In one or more embodiments, the distance between the junctures of the top and bottom edges 13, 15 of the filter bag 10 with the bag opening 12 / sealing cuff 20 when the bag opening 12 / sealing cuff 20 is oriented as shown in Figure 10 may be described as being greater than the distance between the top and bottom struts 74, 74 of the cage 70. That arrangement, in one or more embodiments, provides additional clearance to aid in the advancement of the filter bag 10 over the cage 70, as described herein.

[0086] Clamp 80 is also shown in Figure 10 being partially advanced onto filter bag 10 and cage 70. Although not previously mentioned, Figure 10 illustrates that advancement of clamp 80 onto filter bag 10 and cage 70 can be performed without interference between filter bag 10 and the clamp opening (see, e.g., clamp opening 87 in Figure 9) by orienting clamp 80 similarly to bag opening 12 / sealing cuff 22 to take advantage of the larger size clamp opening in that orientation.

[0087] 11 illustrates the filter bag support assembly and filter bag of FIG. 10 after advancement of the filter bag 10 onto the base 60 of the flange assembly and further advancement of the clamp 80 towards the bag opening 12 / sealing cuff 20 of the filter bag 10. As seen in FIG. 11, the portion of the bag opening 12 / sealing cuff 20 near the bottom edge 15 of the filter bag 10 has been extended to position the bag opening 12 / sealing cuff 20 against the bag sealing surface 65 of the bag seal panel 64 of the base 60. Additionally, the clamp 80 has been rotated to position the clamp sealing surface 85 on the clamp 80 in its proper orientation such that the sealing cuff 20 on the filter bag 10 can be held between the clamp sealing surface 85 of the clamp 80 and the bag ceiling surface 65 of the base 60.

[0088] When fully advanced into contact with the sealing cuff 20 and attached to the base 60, a seal is formed between the base 60 and the clamp 80 around the clean air outlet formed by the base opening 67 and the clamp opening 87. In one or more embodiments, the sealing cuff 20 may be described as surrounding the clamp opening 87 of the clamp 80 as well as the base opening 67 of the base 60 (which in the exemplary embodiment shown is disposed in the bag seal panel 64 described herein).

[0089] Due to the seal formed by the sealing cuff 20 between the base 60 and the clamp 80, air (or any other gas) entering or exiting the interior volume of the filter bag must pass through the clean air outlet or the filter media forming the body 16 of the filter bag 10. In one or more embodiments, the sealing cuff 20 is preferably compressed between the base plate and the clamp. As used herein, the term "compressed" means that the sealing cuff 20 is at least partially deformed between the base 60 and the clamp 80.

[0090] Filter System The filter bags, filter bag support assemblies, and filter bag assemblies described herein can all be used in any suitable filter system (sometimes called a collector) to remove particulate matter from a particulate-laden gas stream (e.g., air). Although the filter systems, filter bag support assemblies, filter bag assemblies, and filter bags described below and shown, for example, in Figures 12-14, 15A, 15G, 16, 17A, 24, and 25 do not themselves include enlarged bag openings or features designed to accommodate filter bags having enlarged bag openings as described herein, it will be understood that the filter systems, filter bag support assemblies, and filter bag assemblies can simply accommodate (or be configured to accommodate) filter bags having enlarged bag openings as described herein.

[0091] One exemplary embodiment of a filter system is generally shown at 410 in FIG. 12 and is generally box shaped and includes a top wall panel 416 and two pairs of side wall panels 417 (one of which can be seen in FIG. 12). The filter system 410 includes a dirty air tube 411 for receiving dirty or contaminated gas (e.g., air that has particulate matter entrained therein) into the filter system 410. A clean gas (e.g., air) tube 413 (see, e.g., FIG. 14) may be provided for removing clean or filtered air from the filter system 410. The filter system 410 includes a cover 470 that closes an access port in an access panel 419 of the filter system 410.

[0092] The filter system 410 may also include a hopper 418 to collect particulate matter that is separated from the contaminated airflow as described herein. The hopper 418 may include sloping walls to facilitate collection of the particulate matter, and in some embodiments may include a driven auger or other mechanism for removing the collected particulate matter.

[0093] The filter system of Figure 12 is shown in side view in Figure 13 and in plan view in Figure 14. As part of a pulse jet cleaning system, filter system 410, as can be seen in Figures 13 and 14, includes a connector 486 in fluid communication with a pulse generator (not shown in Figures 12-14) configured to direct pulses of air to a filter bag as described herein.

[0094] 15A and 15G, the filter system 410 shown includes a filter bag assembly including a filter bag 440 and a flange assembly 430 in a dirty air chamber 424 separated from a clean air chamber 422 by a tube sheet 420. FIG. 15A is a cross-sectional view of the filter system 410 taken along line 15A-15A of FIG. 14, showing the interior of the filter system 410 (the filter bag 440 disposed therein is in its entirety, so that the support structure within the filter bag 440 is not visible from the view). FIG. 15G is a cross-sectional view of the filter system 410 taken along line 15G-15G of FIG. 14 (the cross-sectional view shows the interior volume of the filter bag 440 such that a portion of the support structure within the filter bag 440 is shown). The filter bag assembly is mounted on a filter guide 460 that is disposed within the dirty air chamber 424. In the exemplary embodiment shown, the filter guide 460 extends across the dirty air chamber 424 from the tube sheet 420 of the filter system to an access panel 419.

[0095] At the tubesheet ends, each of the filter bag assemblies includes a flange assembly 430. The flange assemblies 430 include an inner surface 435 that faces the dirty air chamber 424 and a tubesheet face that seals against the dirty air chamber side of the tubesheet 420. Each of the flange assemblies 430 surrounds an opening in the tubesheet 420 through which clean air can pass from the interior of the filter bag assembly to the clean air chamber and through which pulses of air can pass to the interior of the filter bag during a pulse cleaning event.

[0096] 15A , the flange assembly 430 includes a base 432 that includes a tubesheet surface of the flange assembly 430, and a clamp 434 that is configured to attach to the base 432 on an inner surface of the flange assembly 430. In such an embodiment, the clean air outlet extends through the base 432 and the clamp 434, and the bag opening of the filter bag 440 is held between the clamp 434 and the base 432 on the inner surface of the flange assembly 430.

[0097] The exemplary embodiment of the filter system 410 shown in FIG. 15A also includes a pulse generator 480 disposed in the clean air chamber 422. The pulse generator 480 is configured to send a pulse of air into the interior volume of the filter bag 440 to drive particulate matter accumulated on the filter bag 440 during use of the filter bag, with the removed particulate matter preferably falling into a hopper 418 disposed below the filter bag 440. In one or more embodiments, the pulse generator 480 may be described as having an elongated shape extending along a pulse generator axis 481, as seen, for example, in FIG. 15A. Pressurized air (or any other suitable gas) is delivered to the pulse generator through a connector 486 that extends outside the clean air chamber 422 for connection to a pulse purification system that, in the embodiment shown, includes one or more pressurized gas (e.g., air) sources, valves, and a control system. Exemplary embodiments of pulse purification systems can be found, for example, in U.S. Pat. No. 4,218,227 (Frey), U.S. Pat. No. 5,562,746 (Raether), U.S. Pat. No. 6,090,173 (Johnson et al.), U.S. Pat. No. 6,902,592 (Green et al.), U.S. Pat. No. 7,641,708 (Kosmider et al.), and U.S. Pat. No. 8,075,648 (Raether).

[0098] A pulse collector 484 is also shown in connection with the exemplary embodiment of the filter system 410, and the pulse collector 484 may be attached to the flange assembly 430 of the filter bag assembly, as described herein. In other embodiments, the pulse collector 484 may be attached to the tube sheet 420. Regardless of the structure to which they are attached, the pulse collectors 484 are configured to direct pulsed air emitted from the pulse generator 480 into the interior volume of the filter bag 440 during the pulse cleaning process.

[0099] Figures 15B and 15C are cross-sectional views taken along line 15B-15B in Figure 15A, with Figure 15B being taken when filter system 410 is not in use or is being used to filter contaminated air entering contaminated air chamber 424 through inlet 411. Figure 15C shows filter bag 440 relative to other configurations of filter bag assemblies described herein when pressurized air (or other gas) is directed into the interior volume of filter bag 440 during a pulse cleaning event.

[0100] 15B shows a portion of the dirty air chamber side of tube sheet 420 with flange assembly 430 disposed thereon. As discussed herein, the illustrated exemplary embodiment of flange assembly 430 includes a base 432 and a clamp 434, and a bag opening of filter bag 440 is held between clamp 434 and base 432 such that air can only enter the interior volume of filter bag 440 through the filter media used to construct filter bag 440 or through clean air outlet 436 of flange assembly 430.

[0101] 15B and 15C includes a cage that is used to hold the filter bag 440 in a triangular shape (the cage is shown in cross section in FIG. 15G). In the exemplary embodiment shown, the cage includes a first cage end that is attached to the flange assembly 430 and the cage extends away from the flange assembly 430 a cage length along a cage axis 451 to a second cage end distal from the flange assembly 430. In the exemplary embodiment shown, the second cage is disposed proximal to the access panel 419 of the filter system 410.

[0102] In the illustrated exemplary embodiment of the filter bag assembly, the cage includes a plurality of struts that extend away from the inner surface of the flange assembly 430 toward a second cage end proximate the access panel 419 of the filter system 410. The plurality of struts define a triangular shape such that in each cross-section taken in a plane transverse to the cage axis 451 over the majority of the length of the cage, the plurality of struts define a triangle having a top apex and a pair of bottom apexes opposite the top apex.

[0103] In the exemplary embodiment shown, the cage includes a top strut 452 and a pair of bottom struts 454 and 456. The top strut 452 defines the top apex of a triangle defined by the multiple struts, while the pair of bottom struts 454 and 456 defined the bottom apex of a triangle defined by the multiple struts. The exemplary embodiment shown of the cage also includes a series of braces 453 extending from the top strut 452 to each of the bottom struts 454 and 456 to provide additional support to the filter bag 440 at selected locations along the length of the cage.

[0104] When the cage is placed within the filter bag 440, the filter media of the filter bag 440 may be described as defining a pair of sides 442 and a bottom side 444. Each of the sides 442 includes a top edge proximate to the top apex (defined by top strut 452) of each triangle defined by the plurality of struts. Additionally, each side 442 also includes a bottom edge distal to the top edge of the side 442. With reference to FIG. 15B , the bottom edge of the right side 442 is defined by the right bottom apex (defined by bottom strut 454) of each triangle defined by the plurality of struts, while the bottom edge of the left side 442 is defined by the left bottom apex (defined by bottom strut 456) of each triangle defined by the plurality of struts.

[0105] Because the filter bags used in the filter bag assemblies of the filter systems described herein are generally made from flexible filter media, the top and bottom edges of the triangular shaped filter bag may not be particularly distinct, i.e., the edges may not form a single line. However, it will be understood that the edges may have a width that the filter media extends to when moving from side 442 to bottom side 444 around bottom struts 454 and 456 and / or from one side 442 to the opposite side over top strut 452. Regardless of that lack of distinctness, it will be understood that the edges generally conform to the shapes of the struts used to define the different vertices of the triangle.

[0106] 15B and 15C are just a few examples of triangular shapes that may be used in connection with the filter bag assemblies and filter systems described herein. In general, however, one or more embodiments of the filter bag assemblies described herein may be described as having a bottom surface 444 of the filter media having a width measured between the bottom edges of the sides 442 (defined by bottom struts 454 and 456) that is less than the height of either of the sides 442 measured between their top and bottom edges (where the top edge is defined by top strut 452 and the bottom edge is defined by bottom struts 454 and 456). In one or more embodiments, the width of the bottom surface 444 may be 50% or less, 40% or less, 30% or less, 20% or less, 15% or less, 12% or less, 10% or less, 8% or less, or 5% or less of the height of either side 42 of the pair of sides. At the lower limit, the width of the base may be 4% or more, 5% or more, 6% or more, 8% or more, 10% or more, 12% or more, 15% or more of the height of either side of the pair of sides. Widths and heights discussed herein are measured transversely to the cage axis 451, i.e., as seen for example in FIG. 15B.

[0107] 15B and 15C includes a filter guide 460 which, in the exemplary embodiment shown, extends from the tube sheet 420 to the access panel 419 of the dirty air chamber 424. In the exemplary embodiment shown, the filter guide 460 defines a guide axis 461 which passes through the tube sheet 420 and the access panel 419. The guide axis 461 is shown aligned with the cage axis 451, and although the two axes 451 and 461 can be parallel to one another, a perfectly parallel arrangement is not required.

[0108] Filter guide 460 includes an inlet end 463 at which guide opening 462 on flange assembly 430 can be threaded, guided, or otherwise oriented into filter guide 460 so that flange assembly 430 can be supported on filter guide 460. In one or more embodiments, inlet end 463 of filter guide 460 can be located closer to a filter system access panel 419 than a tubesheet 420 against which flange assembly 430 presses, as described herein.

[0109] In some of the illustrated exemplary embodiments described herein, filter guide 460 extends from tube sheet 420 to access panel 419, however, in one or more alternative embodiments, filter guide 460 may extend only partially across the contaminated air chamber, such that, for example, filter guide 460 may terminate at a location away from access panel 419 or even away from tube sheet 420. In one alternative embodiment, for example, filter guide 460 may extend from tube sheet 420 toward access panel 419, but terminate away from access panel 419.

[0110] The filter guide 460 is disposed within a guide opening 462 formed in the flange assembly 430. The combination of the filter guide 460 and the guide opening 462 formed in the flange assembly 430 provides support to the flange assembly 430 during insertion and removal of the filter bag assembly from the dirty air chamber 424 of the filter system 410. In particular, it may be preferred that the filter guide 460 and guide opening 462 allow for translational or sliding movement of the flange assembly 430 through the access port in the access panel 419 to the tubesheet 420. The illustrated filter guide 460 and guide opening 462 of the flange assembly 430 have similar shapes, however, any suitable combination of shapes for both the filter guide and guide opening may be used.

[0111] Several alternative embodiments of filter guides and guide openings are shown in Figures 15D-15F. In Figure 15D, filter guide 460' has a T-shaped profile and guide opening 462' of flange assembly 430' has a complementary shape configured to receive filter guide 460'. In Figure 15E, filter guide 460'' has an inverted T-shaped profile and guide opening 462'' of flange assembly 430'' has a complementary shape configured to receive filter guide 460''. In Figure 15F, filter guide 460''' has a circular profile and guide opening 462'''' of flange assembly 430'''' has a complementary shape configured to receive filter guide 460''. Many other alternative shapes for filter guides and guide openings may be provided as well.

[0112] In addition to providing vertical support to the flange assembly 430, the combination of filter guide 460 and guide opening 462, in one or more embodiments, may also function to limit or prevent rotation of the flange assembly about guide axis 461 so that proper placement of the flange assembly 430 on the tubesheet 420 may be achieved. To limit or prevent such rotation, filter guide 460 and guide opening 462 on flange assembly 430 may have a non-circular shape, with the trilobe and T-shaped examples of the exemplary embodiment shown providing examples of only some of the non-circular shapes that may limit or prevent rotation of the flange assembly 430 relative to guide axis 461.

[0113] In one or more embodiments, the filter guide 460 may include a dust cover that may be dislodged during removal of the filter bag assembly to prevent the accumulation of particulate matter on the filter guide 460 (e.g., as the flange assembly 430 moves away from the tubesheet 420 toward the access panel 419).

[0114] Other features shown in the cross-sectional views of Figures 15B and 15C include a clean air outlet 436 provided in the flange assembly 430, which allows clean air to both exit the interior volume of the filter bag 440 and also pulses of air or other gas to enter the interior volume during a pulse cleaning process. In one or more embodiments, the clean air outlet may be described as having an elongated shape extending from a top end (closest to the top strut 452) and a bottom end (closest to the bottom struts 454 and 456). The top and bottom ends of the clean air outlet 436 may be further described as defining an outlet axis 431 that extends between the top and bottom ends of the clean air outlet 436. In one or more embodiments, the projection of the outlet axis 431 along the cage axis 451 passes between a pair of bottom apexes of a triangle defined by the struts (where those bottom apexes are defined by the bottom struts 454 and 456). Additionally, the projection of the outlet axis 431 passes through the top apex (defined by top strut 452) of the triangle defined by the struts.

[0115] 15B and 15C, it will be understood that the tubesheet 420 includes a tubesheet opening formed therethrough that is at least as large as the clean air outlet 436 provided in the flange assembly 430 such that the tubesheet opening does not restrict air flow through the clean air outlet 436 to or from the interior volume of the filter bag 440. Additionally, the tubesheet opening may also be described as having a smaller size than the flange assembly 430 such that when the filter system 410 is in use, the flange assembly 430 can close or seal the tubesheet opening such that air passing between the clean air chamber 422 and the dirty air chamber 424 must pass through the clean air outlet 436.

[0116] The cross-sectional views of Figures 15B and 15C also illustrate the placement of the pulse generator 480 and the clean air outlet 436 of the flange assembly 430 in the illustrated exemplary embodiment of the filter system 410. In particular, the pulse generator 480 may be aligned with the clean air outlet 436. Even more particularly, the pulse generator axis 481 may be aligned with the outlet axis 431 when viewed along the cage axis 451 referenced in Figures 15B and 15C.

[0117] 15B and 15C further show ports 482 of the pulse generator 480. In particular, ports 482 face the clean air outlet 436 and the opening in the tubesheet 420. Air routed through ports 482 of the pulse generator 480 passes through those ports to the clean air outlet 436 formed in the flange assembly 430.

[0118] When the filter bags used in the filter systems described herein have a generally triangular shape, various features may be incorporated into the ports 482 of the pulse generator 480 to facilitate the pulse cleaning process. For example, in one or more embodiments, the ports 482 closer to the bottom end of the clean air outlet 436 (i.e., closer to the bottom 444 of the filter bag 440) may be larger in size than the ports 482 located closer to the top end of the clean air outlet 436 (i.e., closer to the top edge of the side 442 of the filter bag 440). Alternatively or in addition, the spacing between the ports 482 may vary along the pulse generator axis 481. For example, the spacing between the ports 482 located closer to the bottom end of the clean air outlet 436 may be smaller than the spacing between the ports 482 located closer to the top end of the clean air outlet 436. Such variations in size and / or spacing of the ports 482 may facilitate the pulse cleaning process by providing more air and / or higher pressure within the filter bag 440 proximate the bottom surface 444.

[0119] A comparison of Figures 15B and 15C illustrates the beneficial effect of the triangular shaped filter bag described herein on specific loading and pulse cleaning. In particular, as can be seen in Figure 15B, the triangular shaped filter bag 440 includes a bottom surface 444 that faces downward, away from the dirty air inlet 411 to the dirty air chamber 424 (see, for example, Figure 15A). Thus, particulate matter introduced into the dirty air chamber 424 above the triangular filter bag 440 does not directly touch the bottom surface 444 of the filter bag 440 or collect on the bottom surface 444 of the filter bag 440 under gravity alone. This improves the particle loading performance of the filter bag 440, since only particulate matter entrained in the dirty air that reaches the bottom surface 444 can be captured on the bottom surface 444.

[0120] Improved pulse cleaning performance is also provided by the triangular shaped filter bag 440 because particulate matter that collects on the bottom surface 444 of the filter bag 440 is directed downwardly away from the bottom surface 444 during pulse cleaning. Referring to FIG. 15C, the bottom surface 444 of the filter bag 440 is pushed outward / downward during pulse cleaning. Due to the nature of pulse cleaning, that outward / downward movement of the bottom surface 444 is the result of a sudden acceleration that imparts a force to any removed particulate matter released from the bottom surface 444, and that pulse cleaning force vector is approximately aligned with gravity to enhance the movement of any removed particulate matter to a collection area, such as, for example, the hopper 418 of the filter system 410.

[0121] In addition to the beneficial effect of the bottom surface 444 of the triangular shaped filter bag 440 of the filter systems described herein, the side surface 442 of the filter bag 440 is also rapidly accelerated outward during pulse cleaning, as can be seen in the changed position of the side surface 442 of the filter bag 440 between Figures 15B and 15C. As discussed herein, such movement of the side surface 442 of the triangular shaped filter bag 440 provides many of the same advantages in pulse cleaning performance associated with conventional envelope-like filter bags having vertical sides.

[0122] 16 is a simplified schematic diagram of components of an exemplary embodiment of a filter system illustrating one exemplary embodiment of a seal formed using a filter bag assembly in the filter systems described herein. In the exemplary embodiment shown, the filter bag assembly includes a flange assembly 430' and a cage 450' attached to the flange assembly 430'.

[0123] The filter bag 440' is attached to the filter bag assembly, the bag opening 441' is sealed against the flange assembly 430', and the cage 450' is disposed within an interior volume defined by the filter bag 440'. For reference, the clean air outlet 436' extends along an outlet axis 431' in a manner similar to the outlet axis 431 shown in Figures 15A-15C, for example.

[0124] The cage 450' defines a cage axis 451' that extends through the clean air outlet 436' defined in the flange assembly 430'. The cage 450' may also be described as including a first cage end attached to the flange assembly 430' and a second cage end distal from the flange assembly 430' along the cage axis 451'. The second cage end of the cage 450' may also be described as proximate the second end 443' of the filter bag 440'.

[0125] Tube sheet 420' includes an opening 426' formed therethrough. A clean air chamber 422' and a dirty air chamber 424' are also shown in FIG. 16, with the two chambers separated by tube sheet 420'. A flange assembly 430' is positioned over opening 426' in tube sheet 420' such that air entering and exiting the interior volume of filter bag 440' from clean air chamber 422' passes through opening 426' in flange assembly 430' and clean air outlet 436'.

[0126] 16 also shows an access panel 419' disposed on the opposite side of the tube sheet 420' spanning the dirty air chamber 424'. An access port 474' is provided in the access panel 419' to allow for removal and replacement of the filter bag assembly (including the flange assembly 430', the filter bag 440', and the cage 450' attached to the flange assembly 430' and disposed within the interior volume of the filter bag 440'). The access port 474' is closed by a cover 470' to seal the dirty air chamber 424' during operation of the filter system.

[0127] Also shown in FIG. 16 is a seal 438' disposed between the tubesheet face of the flange assembly 430' and the tubesheet 420'. The seal 438' is disposed around the opening 426' of the tubesheet 420' and around the clean air outlet 436' of the flange assembly 430'. The seal 438' ensures that air entering the interior volume of the filter bag 440' must pass through the filter media (e.g., during filtration) forming the filter bag 440' or the clean air outlet 436' and the opening 426' of the tubesheet 420. In other words, the seal 438' between the flange assembly 430' and the tubesheet 420' prevents air (and preferably any particulate matter) from passing between the tubesheet face of the flange assembly 430' and the tubesheet 420' during operation of the filter system described herein.

[0128] In one or more embodiments, the seal 438' may be formed by compression between the flange assembly 430' and the tube sheet 420'. In one or more embodiments, a seal actuator may be provided to apply a sealing force on the cage 450' of the filter bag assembly. In such embodiments, the sealing force is preferably directed along the cage axis 451 toward the tube sheet 420'. In one or more embodiments, the sealing force may be described as being directed through the second end 443' of the filter bag 440' and transmitted through the filter bag 440', the cage 450', and the flange assembly 430' to the seal 438'. In particular, the cover 470', which functions as the seal actuator in the illustrated exemplary embodiment, acts on the second (closed) end 443' of the filter bag 440' which in turn acts on the second cage end of the cage 450', which transmits the force to the flange assembly 430' by its attachment to the flange assembly 430'.

[0129] The seal 438' may be constructed from any suitable material and / or structure. While many seals may be formed by compression of one or more resilient and / or elastomeric materials (e.g., O-rings, gaskets, etc.), other seal configurations may also be used to form the necessary seal between the flange assemblies and tubesheets in the filter systems described herein when the flange assemblies are subjected to compressive forces (e.g., knife edge seals, radial seals, axial seals, etc.).

[0130] 17A is a perspective view of a portion of tube sheet 420 and an exemplary embodiment of a filter bag assembly including a filter bag 440 supported on an exemplary embodiment of a filter guide 460. As discussed herein, the filter bag assembly including a flange assembly 430 and a filter bag 440 is supported on filter guide 460, with flange assembly 430 forming a seal with tube sheet 420.

[0131] In one or more embodiments of the filter bags and filter systems described herein, the bag support may be provided proximate the second end of the filter bag, i.e., the closed end of the filter bag distal from the flange assembly, and the bag support is configured to prevent or limit sagging of the filter bag assembly at the second end of the filter bag, for example, due to the weight of a cage disposed on the filter bag. In one or more embodiments of the filter bags, filter bag assemblies and / or filter systems described herein, the bag support may itself be provided on the filter bag as part of the filter system, and / or may include a component provided as part of the filter bag and as part of the filter system.

[0132] 17A includes one exemplary embodiment of a bag support in the form of a bag support connector 446 attached to the filter bag 440 proximate the second (closed) end 443 of the filter bag 440 and a chamber connector 464 positioned in the dirty air chamber proximate the housing access panel 419. In the embodiment shown, the chamber connector 464 is disposed on the filter guide 460, although such positioning is not required. The bag support connector 446 and the chamber connector 464 are configured to mate with each other to support the second end of the filter bag 440 in the dirty air chamber (the first end of the filter bag 440 is supported by the flange assembly 430 along with the filter guide 460 described herein).

[0133] 17A, the bag support connector 446 is in the form of a loop while the chamber connector 464 is in the form of a hook, and the loop 446 connects to the hook 464 to support the second end 443 of the filter bag 440. Of course, many variations are possible. For example, the bag support connector 446 on the filter bag 440 can be in the form of a hook while the chamber connector 464 is in the form of a loop or an opening configured to receive the hook.

[0134] FIG. 17B illustrates one alternative embodiment of a bag support that may be used to prevent or limit sagging of the filter bag assembly at the second end of the filter bag. In the illustrated embodiment, the bag support includes a chamber connector 464 on the filter guide 460, similar to that shown in FIG. 17A, which in the illustrated embodiment is attached to the access panel 419″ (a cover 470″ closes the access opening of the access panel 419″ described herein). The embodiment of the bag support shown in FIG. 17B includes a sling 447″ that may be wrapped, for example, around the bag 440″, the sling 447″ forming a loop configured to connect to a hook 464 on the filter guide 460. In one or more embodiments, the sling 447″ may be attached to the filter bag 440″ using, for example, one or more of sutures, adhesives, etc., such that the sling 447″ may be replaced along with the filter bag 440″. Alternatively, the sling 447'' may be separate, eg, unattached, to the filter bag 440'', such that the sling 447'' may be reused with two or more different filter bags 440''.

[0135] 17C illustrates yet another alternative embodiment of a bag support that may be used to prevent or limit sagging of the filter bag assembly at the second (closed) end of the filter bag. In the illustrated embodiment, the bag support 446''' is in the form of a surface disposed adjacent the bottom of the filter bag 440''' at the second end of the filter bag 440'''. The bag support 446''' may be attached to the access panel 419'''' and may be accessed through an opening in the access panel 419'''' that is closed by a cover 470'''. In one or more embodiments, the bag support 446''' may be moved downward (away from the bag axis 451) to aid in replacement of the filter bag 440'''. The movement of the bag support 446''' may include one or both of translational and rotational movement of the bag support 446'''.

[0136] 18A is a perspective view of one exemplary embodiment of a portion of the access panel 419 including one exemplary embodiment of a cover 570 used to close a filter access port 574 formed in the access panel 19 through which a filter bag assembly including a filter bag 540 can be removed from and inserted into the dirty air chamber of the filter system. The exemplary embodiment of the cover 570 includes a latch 572 and a catch 573 to secure the cover 570 in a closed position (see cover 570 to the right of open cover 570). The cover 570 can be connected to the access panel 19 for rotation about a hinge axis 571 such that the cover 570 can be moved from a closed position to an open position through which a filter bag assembly can be inserted or removed from the dirty air chamber through the access port 574.

[0137] Rotation of cover 570 about hinge axis 571 moves cover 570 to its closed position where it covers filter access port 574. When in the closed position, cover 570 can function as a seal actuator such that, in addition to closing filter access port 574, cover 570 also acts on second end 543 of filter bag 540 to press an attached flange assembly against a tube sheet to form a seal as described herein. The force provided by cover 571 acting as a seal actuator when closed can be described as acting along cage axis 551.

[0138] 18B is a perspective view of the access panel 19 of FIG. 18A including an alternative exemplary embodiment of a cover 570′ used to close a filter access port 574 formed in the access panel 19 through which a filter bag assembly including a filter bag 540 can be removed from and inserted into a dirty air chamber of a filter system including the access panel 19. This exemplary embodiment of the cover 570′ also includes a latch 572 and a catch 573 to secure the cover 570′ in a closed position (see cover 570′ to the right of the open cover 570′). The cover 570′ can be connected to the access panel 19 for rotation about a hinge axis 571 such that the cover 570′ can be moved from a closed position to an open position through which a filter bag assembly can be inserted into or removed from a dirty air chamber through the access port 574.

[0139] Rotation of covers 570' about hinge axis 571 moves covers 570' to their closed positions that close filter access ports 574. When in the closed position, covers 570' can function as a seal actuator such that, in addition to closing filter access ports 574, cover 570' also acts on second end 543 of filter bag 540 to press an attached flange assembly against a tube sheet to form a seal as described herein. The force provided by cover 570' acting as a seal actuator when closed can be described as acting along cage axis 551.

[0140] An additional feature shown on cover 570' is an embossment (indentation) 576 provided on cover 570'. Embossment 576 may have a shape that is complementary to the shape of end 543 of filter bag 540 in one or more embodiments. Such an embossment may provide benefits such as, for example, additional stability to the filter bag assembly proximate access panel 19, more uniform force distribution on second end 543 of filter bag 540 and thus on a cage disposed within filter bag 540 of a filter bag assembly described herein, verification of proper installation of the filter bag assembly (e.g., such that the bottom surface of the triangular filter bag is properly oriented in the contaminated air chamber), etc. In embodiments including such an embossment, a bag support configured to support the second end of the filter bag (e.g., as discussed above in connection with FIGS. 17A-17C) may be beneficial in ensuring that second end 543 of filter bag 540 is properly positioned when cover 570' is closed.

[0141] As discussed herein, the filter bags used in the filter bag assemblies of the filter systems described herein are generally made from flexible filter media, and the filter bags may not form a particularly well-defined triangle when viewed in cross section. In general, however, triangular shaped filter bags and their associated cages can be described using triangular geometry with the understanding that the edges, sides and apexes of such triangles are generally approximated by the triangular cages and filter bags mounted thereon.

[0142] With that understanding, reference is made to Figures 23-26, which illustrate various triangular bag configurations that may be used in one or more embodiments of the filter bag assemblies and filter systems using the filter bag assemblies described herein.

[0143] 19 is similar in many respects to the triangular bag 440 discussed herein with respect to the various embodiments of the filter bag assemblies and filter systems described above. The triangular bag 540 includes a top apex 545 and a pair of bottom apexes 546 and 547. A pair of sides 542 extend between the top apex 545 and each of the bottom apexes 546 and 547. A bottom side 544 extends between the bottom apexes 546 and 547.

[0144] To further illustrate the difference between the advantageous triangular shape defined by one or more embodiments of the filter bags described herein and the actual shape assumed by a filter bag disposed on a cage that provides the triangular shape, the struts of one exemplary embodiment of the cage are included in FIG. 19 along with a cage axis 551 (extending perpendicularly from the paper on which FIG. 19 is placed). In particular, top struts, bottom struts and middle struts 574 are shown on the inside of filter bag 540 in FIG. 19. Note that there are two top struts 574. Such a configuration may provide filter bag 540 with a small flat surface along its top edge. Regardless of slight deviations from a perfect triangle, it can be seen that side 542 and bottom 544 of filter bag 540 assume the approximate triangular shape described herein.

[0145] The bottom side 544 may be described as having a width wb extending between bottom apexes 546 and 547. The left side 542 may be described as having a height s1 measured between the top apex 545 and the bottom apex 547. The right side 542 may be described as having a height s2 measured between the top apex 545 and the bottom apex 546. As discussed herein, the width of the bottom side (wb) is preferably less than the height of either of the side sides (s1 or s2).

[0146] Although not required, the triangular bag 540 shown forms a triangle that may be described as an acute triangle and optionally an isosceles triangle (where s1=s2). In the case of an isosceles triangle, the axis 501 shown in FIG. 19 may be described as the height of the triangle formed by the filter bag 540.

[0147] The triangular bag 540 may be further described with respect to the angle formed by the sides 542. In particular, the angle α (alpha) formed by the sides 542 at the apex 545 may be selected such that the width (wb) of the base 544 has a selected relationship to the height of the sides 542. In one or more embodiments, the angle α (alpha) may be 45° or less, 30° or less, 20° or less, 15° or less, 12° or less, 10° or less, or 5° or less. At the lower limit, the angle α (alpha) may be 2° or more, 3° or more, 4° or more, or 5° or more in one or more embodiments.

[0148] 20 illustrates an alternative triangular shaped filter bag that may be used in one or more embodiments of the filter bag assemblies and / or filter systems described herein. Triangular shaped bag 640 includes a top apex 645 and a pair of bottom apexes 646 and 647. A pair of sides 642 extend between top apex 645 and each of bottom apexes 646 and 647. A bottom side 644 extends between bottom apexes 646 and 647. When installed on a cage of a filter bag assembly described herein, the cage axis extends vertically out of the paper on which FIG. 20 is placed.

[0149] The bottom side 644 may be described as having a width wb extending between bottom vertices 646 and 647. The left side 642 may be described as having a height s1 measured between the top vertex 645 and the bottom vertex 647. The right side 642 may be described as having a height s2 measured between the top vertex 645 and the bottom vertex 646. As discussed herein, the width of the bottom side (wb) is preferably less than the height of either of the side surfaces (s1 or s2).

[0150] Triangular bag 640 may optionally be described in terms of an angle formed between sides 642 at apex 645. In particular, angle α (alpha) formed by sides 642 at apex 645 may be selected such that width (wb) of base 644 has a selected relationship with height of sides 642. In one or more embodiments, angle α (alpha) may be 45° or less, 30° or less, 20° or less, 15° or less, 12° or less, 10° or less, or 5° or less. At the lower limit, angle α (alpha) may be 2° or more, 3° or more, 4° or more, or 5° or more in one or more embodiments.

[0151] The triangular bag 640 shown forms a triangle that may be described as an obtuse triangle. The axis 601 shown in FIG. 20 may be described as bisecting the angle α (alpha), and as a result, the axis 601 also bisects the base 644. In one or more embodiments of the triangular filter bag described herein, the axis passing through the top apex and bisecting the angle formed at that apex may preferably be oriented approximately vertically within the contaminated air chamber of the filter system. For the embodiment of the triangular filter bag 640, the axis 601 may be oriented vertically, or alternatively, the axis 601 may be tilted or angled relative to a vertical axis.

[0152] Although the bottom surface 644 of the triangular shaped filter bag 640 may not be oriented transverse to the vertical axis, during pulse cleaning, particulate matter removed from the bottom surface 644, when subjected to a force acting by gravity, will have a vertical force component that preferentially moves the removed particulate matter downward as described in connection with other exemplary embodiments of the filter bag described herein.

[0153] FIG. 21 shows a pair of triangular shaped filter bags 640. The triangular shaped filter bag 640 on the right side of FIG. 21 has essentially the same shape as the filter bag 640 shown in FIG. 20. The triangular shaped filter bag 640 on the left side of FIG. 21 is a mirror image of the filter bag 640 on the right side of FIG. 21. Both the left and right triangular shaped filter bags 640 face each other and include vertical faces 642 aligned with the vertical axis V, while the outer faces 643 of the triangular shaped filter bags 640 face away from each other. One potential advantage of such an arrangement is that the triangular shaped filter bags 640 are spaced closer together (transverse to the vertical axis), thereby increasing the surface area of ​​the filter media available within a given contaminated air chamber volume, while retaining the particle loading and pulse cleaning advantages that may be associated with the triangular shaped filter bags described herein.

[0154] 22 illustrates another alternative triangular shaped filter bag that may be used in one or more embodiments of the filter bag assemblies and / or filter systems described herein. Triangular shaped bag 740 includes a top apex 745 and a pair of bottom apexes 746 and 747. A pair of sides 742 extend between top apex 745 and each of bottom apexes 746 and 747. A bottom side 744 extends between bottom apexes 746 and 747. When installed onto a cage of a filter bag assembly described herein, the cage axis extends vertically out of the paper on which FIG. 22 is placed.

[0155] The bottom side 744 may be described as having a width wb extending between bottom apexes 746 and 747. The left side 742 may be described as having a height s1 measured between the top apex 745 and the bottom apex 747. The right side 742 may be described as having a height s2 measured between the top apex 745 and the bottom apex 746. As discussed herein, the width of the bottom side (wb) is preferably less than the height of either of the side sides (s1 or s2).

[0156] Triangular-shaped bag 740 may optionally be described in terms of an angle formed between sides 742 at apex 745. In particular, angle α (alpha) formed by sides 742 at apex 745 may be selected such that width (wb) of base 744 has a selected relationship with height of sides 742. In one or more embodiments, angle α (alpha) may be 45° or less, 30° or less, 20° or less, 15° or less, 12° or less, 10° or less, or 5° or less. At the lower limit, angle α (alpha) may be 2° or more, 3° or more, 4° or more, or 5° or more in one or more embodiments.

[0157] The triangular bag 740 shown forms a triangle that may be described as a right-angled triangle. The axis 701 shown in FIG. 22 may be described as bisecting the bottom surface 744. In one or more embodiments of the triangular filter bags described herein, the axis passing through the top apex and bisecting the bottom surface may be oriented substantially vertically in the contaminated air chamber of the filter system. For the embodiment of the triangular filter bag 740, the axis 701 may be oriented vertically, or alternatively, the right side surface 742 (forming a right angle with the bottom surface 744) may be oriented vertically such that the bottom surface 744 is oriented substantially horizontally with respect to the vertical axis. As used herein, the phrase "substantially horizontal" (and variations thereof) means that the components (e.g., filter bags and / or filter bag assemblies having cages) are positioned such that the components form an angle of 45 degrees or less, 30 degrees or less, 20 degrees or less, or 15 degrees or less from the horizontal (when the gravity vector defines the vertical axis). For example, the cage axis or filter bag axis may define an angle with the horizontal if the filter bag and / or cage is tilted relative to a perfectly horizontal line.

[0158] If the bottom surface 744 of the triangular shaped filter bag 740 is not oriented transverse to the vertical axis (e.g., when axis 701 is oriented vertically), then during pulse cleaning, particulate matter removed from the bottom surface 744, when added to the force acting by gravity, will have a vertical force component that preferentially moves the removed particulate matter downward as described in connection with other exemplary embodiments of the filter bag described herein.

[0159] 23 is a cross-sectional view of another exemplary embodiment of a filter bag assembly including an envelope-like filter bag 840 supported by a cage 850 on a flange assembly 830 as described herein. Some exemplary embodiments of the filter systems and filter bag assemblies described herein may advantageously use filter bags and cages that result in triangular shaped filter bags, although many of the advantages and benefits associated with the filter bag assemblies pressurized in the contaminated air chamber described herein are also available in connection with filter bags on filter bag assemblies having any selected shape.

[0160] In particular, Figure 23 illustrates one embodiment of a more general envelope-like filter bag assembly, in which opposing major faces of a filter bag 840 are generally parallel to one another in use (e.g., have an angle α (alpha) that is essentially 0° (with respect to Figures 23-26)). The filter bag 840 is mounted on a cage constructed from struts 850 that define the envelope shape of the filter bag 840 mounted thereon.

[0161] The struts 850 are attached to a flange assembly 830 that includes a clean air outlet 836 as described in connection with other embodiments of the flange assemblies of the filter bag assemblies described herein. The clean air outlet 836, in the exemplary embodiment shown, extends along an outlet axis 831 as described in connection with other exemplary embodiments herein.

[0162] Cage struts 850 attached to the flange assembly 830 also extend away from the flange assembly 830 along a cage axis 851 to a distal end, the struts 850 supporting a second end of a filter bag 840 as described in connection with other exemplary embodiments herein. The portion of the tube sheet 820 against which the flange assembly 830 presses to provide a seal is also shown in FIG. 23 along with openings 826 in the tube sheet 820 through which air enters or exits a clean air chamber located on the opposite side of the tube sheet 820.

[0163] 28-30 illustrate one exemplary embodiment of a triangular filter bag that may be used in one or more embodiments of the filter bag assemblies and filter systems described herein. The triangular filter bag 940 includes an opening 943, a closed end provided by a substantially triangular end cap 990, and a body 980 extending from the opening 943 to the closed end along a bag axis 941 that extends between the opening 943 and the closed end of the filter bag 940.

[0164] The body 980 of the triangular filter bag 940 is formed from a filter media suitable for removing particulate matter from the air in its intended application. In one or more embodiments, the body 980 may consist essentially of the filter media, with no other components provided. With reference to FIG. 25, the body 980 may include seam edges 982 and 983 that are attached to one another to form a longitudinal seam 982 / 983, for example, as referenced in FIG. 24. When the seam edges 982 / 983 are attached to one another, the body may be described as assuming a tubular shape that defines an interior volume between the opening 943 and the closed end defined by the triangular end cap 990. In that tubular shape, the filter media of the body 980 also defines a closed end edge 984 that is disposed at the closed end of the filter bag 940, and an opening edge 985 that is disposed at the opening 943 of the filter bag 940.

[0165] In one or more embodiments, the joint between the longitudinal seam 982 / 983 and the triangular end cap 990 may be located along one of the side edges 992 of the triangular end cap 990, between the bottom edge 994 and the apex 995 of the triangular end cap. In one or more alternative embodiments, the joint between the longitudinal seam and the triangular end cap of the filter bags described herein may be located along the bottom edge 994 or the apex 995. Additionally, while the body 980 includes only one longitudinal seam 982 / 983, one or more alternative embodiments of the triangular filter bags described herein may include two or more seams.

[0166] A triangular end cap of one or more embodiments of the triangular filter bags described herein, for an exemplary embodiment of a triangular end cap 990, may include two side edges 992 that extend between a bottom edge 994 and an apex 995. Stated alternatively, the side edges 992 of the triangular end cap 990 may be described as meeting at the apex 995 at a location distal to the bottom edge 994.

[0167] To provide a filter bag capable of removing particulate matter from the air, the filter media of the body 980 at the closed end edge 984 is sealed to the side edges 992, bottom edge 994 and apex 995 of the triangular end cap 990 to substantially prevent particulate matter from passing through their junction.

[0168] The triangular end cap 990, in one or more embodiments, may define the generally triangular shape of the filter bag 940 along its length, and more clearly define the triangular shape of the filter bag 940 proximate the triangular end cap 990. With reference to FIG. 26, the shape of the triangular end cap 990 may be described in terms of an included angle formed between side edges 992 of the triangular end cap 990. In particular, the base edge 994, apex 995 and side edges 992 of the triangular end cap 990 may be described as defining an included angle α (alpha) between the side edges 992 at the apex 995 that is, in one or more embodiments, 20° or less, 15° or less, 12° or less, 10° or less, or 5° or less. At the lower limit, the angle α (alpha) may be, in one or more embodiments, 2° or more, 3° or more, 4° or more, or 5° or more.

[0169] A triangular end cap that may be used in one or more embodiments of the triangular filter bags described herein may alternatively be described in terms of the size of the features of the triangular end cap. For example, the triangular end cap 990, when projected onto a flat surface along the bag axis 941, may in one or more embodiments define a height (h) between the apex 995 and the bottom edge 994. The projection of the triangular end cap 990 may also define a width (w) across the bottom edge 994 between the side edges 992. In one or more embodiments of the triangular filter bags described herein, the height (h) is greater than the width (w). More specifically, in one or more embodiments, the height (h) defined between the bottom edge and the apex of the triangular end cap may be 4 times or more, 6 times or more, 8 times or more, 10 times or more, 12 times or more, or 15 times or more than the width (w) defined along the bottom edge between the sides of the triangular end. In one or more embodiments, the height (h) defined between the base edge and the apex of the triangular end cap may be, at an upper limit, 20 times or less, 15 times or less, 12 times or less, 10 times or less, 8 times or less, or 6 times or less than the width (w) defined along the base edge between the sides of the triangular end. In one embodiment, the height (h) defined between the base edge and the apex of the triangular end cap may be 7 to 8 times the width (w) defined along the base edge between the sides of the triangular end. It is noted that the height (h) is preferably measured along an end cap axis 991 extending between the base edge 994 and the apex 995, and in one or more embodiments may be described as bisecting the base edge 994 and the apex 995 and / or defining an axis of symmetry for the triangular end 990. In one or more embodiments of the filter bags including the triangular end caps described herein, the triangular end caps may be constructed from a filter media, such as the same filter media used for the body 980 of the filter bag. In one or more alternative embodiments, the triangular end caps may be constructed from a material that is impermeable to air (different than the filter media used for the body 980). In one or more embodiments, the triangular end caps may be substantially rigid, self-supporting articles, while in other embodiments, the triangular end caps may be constructed from a flexible material that is not self-supporting.

[0170] In one or more embodiments of the filter bags including the triangular end caps described herein, the closed end edge 984 of the body 980 may be sealed to the side edge 992 of the triangular end cap 990 using any suitable technique or combination of techniques sufficient to provide structural integrity to the joint and limit / prevent the passage of particulate matter through the joint. In one or more embodiments, the closed end edge may be sealed to the side edge using one or more of a sewn seam, a stitched seam, an adhesive seam, a chemically welded seam, and a thermally welded seam.

[0171] In one or more embodiments of the filter bags including the triangular end caps described herein, the closed end edge 984 of the body 980 may be sealed to the bottom edge 994 of the triangular end cap 990 using any suitable technique or combination of techniques sufficient to provide structural integrity to the joint and limit / prevent the passage of particulate matter through the joint. In one or more embodiments, the closed end edge may be sealed to the side edge using one or more of a sewn seam, a stitched seam, an adhesive seam, a chemically welded seam, and a thermally welded seam.

[0172] In one or more embodiments of the filter bags including the triangular end caps described herein, the closed end edge 984 of the body 980 may be sealed to the apex 995 of the triangular end cap 990 using any suitable technique or combination of techniques sufficient to provide structural integrity to the joint and limit / prevent the passage of particulate matter through the joint. In one or more embodiments, the closed end edge may be sealed to the side edges using one or more of a sewn seam, a stitched seam, an adhesive seam, a chemically welded seam, and a thermally welded seam.

[0173] 28 and 29 , the filter bag 940 also includes a sealing cuff 649 attached to the filter media of the body 980 proximate the open edge 985 of the body 980. The cuff 949, in one or more embodiments, may be used to seal the bag opening 943 in a flange assembly of the filter bag assemblies described herein.

[0174] Exemplary Aspects The following are exemplary aspects of the filter bags, filter bag support assemblies, filter bag assemblies, air filter systems and methods described herein.

[0175] In independent aspect A1, a filter bag as described herein includes a tubular body formed from a filter medium configured to remove particulate matter from air passing through the filter medium, the tubular body extending from the closed end to a bag opening along a bag axis coinciding with a central axis of the tubular body, the sealing cuff extending around a periphery of the bag opening, and a reference bag length measured along the bag axis between a reference plane oriented perpendicular to the bag axis and the bag opening changes when moving around the periphery of the bag opening.

[0176] In embodiment A2 according to embodiment A1, the reference bag length includes a minimum reference bag length at a first location on the periphery of the bag opening and a maximum reference bag length at a second location on the periphery of the bag opening.

[0177] In embodiment A3 according to embodiment A2, the rate of change of the reference bag length between the first position and the second position is substantially linear.

[0178] In embodiment A4 according to embodiment A2 or A3, the distance between the first position and the second position is equal when moving clockwise and counterclockwise along the circumference of the bag opening from the first position to the second position.

[0179] In aspect A5 according to any one of aspects A2 to A4, a periphery of the bag opening defines a bag opening plane, and the bag opening plane defines an angle with a reference plane, the angle defined between the bag opening plane and the reference plane being 15 degrees or more, 20 degrees or more, 25 degrees or more, 30 degrees or more, 35 degrees or more, 40 degrees or more, or 45 degrees or more; optionally, the angle defined between the bag opening plane and the reference plane being 60 degrees or less, 55 degrees or less, 50 degrees or less, 45 degrees or less, 40 degrees or less, 35 degrees or less, 30 degrees or less, 25 degrees or less, or 20 degrees or less; further, optionally, the angle defined between the bag opening plane and the reference plane is within a range of 15 degrees to 45 degrees, or alternatively 20 degrees to 40 degrees.

[0180] In embodiment A6 according to any one of embodiments A1 to A5, the reference bag length varies continuously over at least a majority of the circumference of the bag opening.

[0181] In embodiment A7 according to any one of embodiments A1 to A5, the reference bag length varies continuously over the entire circumference of the bag opening.

[0182] In embodiment A8 according to any one of embodiments A1 to A7, the bag opening perimeter length measured around the perimeter of the bag opening is greater than the body perimeter length measured at a reference plane oriented perpendicular to the bag axis at a position between the bag opening and the closed end.

[0183] In embodiment A9 according to any one of embodiments A1-A8, the filter bag includes a bag support connector attached to the body near the closed end of the body, the bag support being disposed outside the interior volume of the body.

[0184] In embodiment A10 according to embodiment A9, the bag support connector includes an opening configured to receive the hook.

[0185] In independent aspect B1, the filter bag support assembly includes a flange assembly including an inner surface and a tubesheet surface, the flange assembly including a clean air outlet extending through the flange assembly, and a cage including a first cage end attached to the flange assembly, the cage extending away from the inner surface of the flange assembly a cage length from a base to a distal second cage end, the cage defining a cage axis extending between the first cage end and the second cage end, the flange assembly including a base and a clamp configured to attach to the base on the inner surface of the flange assembly, the clean air outlet being formed in a base opening formed in the base and the clamp. the base includes a bag seal surface surrounding the base opening, the bag seal surface facing the clamp, the clamp including a clamp seal surface surrounding the clamp opening, the clamp seal surface facing the bag seal surface when the clamp is attached to the base, the base includes a tubesheet face facing away from the second end of the cage, the tubesheet face including a tubesheet face opening defining a portion of the clean air outlet, the tubesheet face including a tubesheet seal surface surrounding the tubesheet face opening, and a distance between the bag seal surface and the tubesheet seal surface in a direction aligned with the cage axis changes when moving around the periphery of the base opening.

[0186] In embodiment B2 according to embodiment B1, the tubesheet seal surface defines a tubesheet seal plane and the cage axis is approximately perpendicular to the tubesheet seal plane.

[0187] In embodiment B3 according to embodiment B1 or B2, the second cage end defines a second cage end plane that is substantially perpendicular to the cage axis.

[0188] In embodiment B4 according to any one of embodiments B1-B3, the cage includes a plurality of struts attached to the base.

[0189] In embodiment B5 according to embodiment B4, the plurality of struts are attached to the base between the base opening and the bag sealing surface.

[0190] In embodiment B6 according to embodiment B4, the plurality of struts are attached to the base between the tubesheet face opening and the tubesheet seal face.

[0191] In embodiment B7 according to any one of embodiments B4-B6, the plurality of struts attached to the base are aligned with the cage axis between the first cage end and the second cage end.

[0192] In aspect B8 according to any one of aspects B1-B7, the base opening and the clamp opening are each elongated such that they each define a major axis and a minor axis oriented perpendicular to the major axis, the major axis being greater than the minor axis, and optionally the major axis being at least two times, at least three times, or at least four times larger than the minor axis.

[0193] In embodiment B9 according to embodiment B8, the cage includes a first strut attached to the base proximate a first end of the base opening on the longitudinal axis and a second strut attached to the base proximate a second end of the base opening on the longitudinal axis, the first strut including a first strut length between the base and the second cage end that is greater than a second strut length between the base and the second cage end.

[0194] In embodiment B10 according to any one of embodiments B1-B9, the distance between the bag sealing surface and the tubesheet sealing surface in a direction aligned with the cage axis varies continuously when moving around the periphery of the base opening.

[0195] In aspect B11 according to any one of aspects B1 to B10, the filter bag support assembly includes a guide opening in the flange assembly, the guide opening being positioned outside the cage and the clean air outlet, the guide opening being configured to receive a guide rail when the clamp is attached to the base, and the flange assembly being configured for advancement along the guide rail received in the guide opening when the clamp is attached to the base.

[0196] In embodiment B12 according to embodiment B11, when the clean air outlet is elongated such that it defines a maximum height along the major axis and a maximum width along a minor axis transverse to the major axis that is smaller than the maximum height, the guide opening is disposed along the major axis.

[0197] In embodiment B13 according to embodiment B11 or B12, the guide opening is formed in only one of the base and the clamp of the flange assembly.

[0198] In embodiment B14 according to any one of embodiments B11 to B13, the guide opening is formed in a clamp of the flange assembly.

[0199] In independent embodiment C1, the filter bag support assembly includes a flange assembly including an inner surface and a tubesheet surface, the flange assembly including a clean air outlet extending through the flange assembly, and a cage including a first cage end attached to the flange assembly, the cage extending away from the inner surface of the flange assembly a cage length from a base to a distal second cage end and defining a cage axis extending between the first cage end and the second cage end, the flange assembly including a base and a clamp configured to attach to the base on the inner surface of the flange assembly, the clean air outlet being defined by a base opening formed in the base and a clamp opening formed in the clamp, the base including a bag sealing surface surrounding the base opening, the bag sealing surface facing the clamp, the clamp including a clamp sealing surface surrounding the clamp opening, the clamp sealing surface facing the bag sealing surface when the clamp is attached to the base, the bag sealing surface and the clamp sealing surface defining a bag sealing plane when the clamp is attached to the base, and the cage axis is not perpendicular to the bag sealing plane.

[0200] In embodiment C2 according to embodiment C1, the cage axis forms an angle with the bag seal plane of 85 degrees or less, 80 degrees or less, 75 degrees or less, or 70 degrees or less, and optionally the angle is 50 degrees or more, 55 degrees or more, 60 degrees or more, 65 degrees or more, 70 degrees or more, 75 degrees or more, 80 degrees or more, or 85 degrees or more.

[0201] In embodiment C3 according to embodiment C1 or C2, the second cage end defines a second cage end plane that is approximately perpendicular to the cage axis.

[0202] In embodiment C4 according to any one of embodiments C1-C3, the cage includes a plurality of struts attached to the base, the plurality of struts being attached to the base between the base opening and the bag sealing surface.

[0203] In embodiment C5 according to embodiment C4, the plurality of struts attached to the base are aligned with the cage axis between the first cage end and the second cage end.

[0204] In aspect C6 according to any one of aspects C1 to C5, the base opening and the clamp opening are each elongated such that they each define a major axis and a minor axis oriented perpendicular to the major axis, the major axis being greater than the minor axis, and optionally the major axis being at least two times, three times, or four times greater than the minor axis.

[0205] In embodiment C7 according to embodiment C6, the cage includes a first strut attached to the base proximate a first end of the base opening on the long axis and a second strut attached to the base proximate a second end of the base opening on the long axis, the first strut including a first strut length between the base and the second cage end that is greater than a second strut length between the base and the second cage end.

[0206] In embodiment C8 according to any one of embodiments C1 to C7, the base includes a tubesheet face facing away from the second end of the cage, the tubesheet face including a tubesheet face opening defining a portion of the clean air outlet, the tubesheet face including a tubesheet seal face surrounding the tubesheet face opening, the tubesheet seal face defining a tubesheet seal plane, and the cage axis is oriented approximately perpendicular to the tubesheet plane.

[0207] In embodiment C9 according to embodiment C8, the tubesheet seal plane forms an angle with the bag seal plane of 30 degrees or less, 25 degrees or less, 20 degrees or less, 15 degrees or less, 10 degrees or less, or 5 degrees or less, and optionally, the angle formed between the tubesheet seal plane and the bag seal plane is 5 degrees or more, 10 degrees or more, 15 degrees or more, 20 degrees or more, or 25 degrees or more.

[0208] In embodiment C10 according to any one of embodiments C1 to C7, the base includes a tubesheet face facing away from the second end of the cage, the tubesheet face including a tubesheet face opening defining a portion of the clean air outlet, the tubesheet face including a tubesheet seal face surrounding the tubesheet face opening, and a distance between the bag seal face and the tubesheet seal face in a direction aligned with the cage axis changes when moving around the periphery of the base opening.

[0209] In embodiment C11 according to embodiment C10, the distance between the bag sealing surface and the tubesheet sealing surface in a direction aligned with the cage axis varies continuously when moving around the periphery of the base opening.

[0210] In aspect C12 according to any one of aspects C1 to C11, the filter bag support assembly includes a guide opening in the flange assembly, the guide opening being positioned outside the cage and the clean air outlet, the guide opening being configured to receive a guide rail when the clamp is attached to the base, and the flange assembly being configured for advancement along the guide rail received in the guide opening when the clamp is attached to the base.

[0211] In embodiment C13 according to embodiment C12, when the clean air outlet is elongated such that it defines a maximum height along the major axis and a maximum width along a minor axis transverse to the major axis that is smaller than the maximum height, the guide opening is arranged along the major axis.

[0212] In embodiment C14 according to embodiment C12 or C13, the guide opening is formed in only one of the base and the clamp of the flange assembly.

[0213] In embodiment C15 according to any one of embodiments C12-C14, the guide opening is formed in a clamp of the flange assembly.

[0214] In independent aspect D1, a filter bag assembly includes a flange assembly including an inner surface and a tube sheet surface, the flange assembly including a clean air outlet extending through the flange assembly, a cage including a first cage end attached to the flange assembly, the cage extending away from the inner surface of the flange assembly a cage length from a base to a distal second cage end, the cage defining a cage axis extending between the first cage end and the second cage end, and a filter bag including a tubular body formed from a filter media configured to remove particulate matter from air passing through the filter media, the tubular body extending from the closed end to a bag opening along a bag axis coincident with a central axis of the tubular body, the cage being received within the tubular body of the filter bag, the sealing cuff extending around a periphery of the bag opening, the filter bag including a tubular body formed from a filter media configured to remove particulate matter from air passing through the filter media, the tubular body extending from the closed end to a bag opening along a bag axis coincident with a central axis of the tubular body, the cage being received within the tubular body of the filter bag, the sealing cuff extending around a periphery of the bag opening, the cage assembly includes a base and a clamp configured to attach to the base on an inner surface of the flange assembly, the clean air outlet being defined by a base opening formed in the base and a clamp opening formed in the clamp, the base including a bag seal surface surrounding the base opening, and the clamp including a clamp seal surface surrounding the clamp opening, the sealing cuff being disposed between the bag seal surface and the clamp seal surface when the clamp is attached to the base, the base including a tubesheet surface facing away from the second end of the cage, the tubesheet surface including a tubesheet face opening defining a portion of the clean air outlet, the tubesheet surface including a tubesheet seal surface surrounding the tubesheet face opening, and a distance between the bag seal surface and the tubesheet seal surface in a direction aligned with the cage axis changes when moving around a periphery of the base opening.

[0215] In embodiment D2 according to embodiment D1, the tubesheet seal surface defines a tubesheet seal plane and the cage axis is approximately perpendicular to the tubesheet seal plane.

[0216] In embodiment D3 according to embodiment D1 or D2, the second cage end defines a second cage end plane that is approximately perpendicular to the cage axis.

[0217] In embodiment D4 according to any one of embodiments D1-D3, the cage includes a plurality of struts attached to the base.

[0218] In embodiment D5 according to embodiment D4, the plurality of struts are attached to the base between the base opening and the bag sealing surface.

[0219] In embodiment D6 according to embodiment D4, the plurality of struts are attached to the base between the tubesheet face opening and the tubesheet seal face.

[0220] In embodiment D7 according to any one of embodiments D4-D6, the plurality of struts attached to the base are aligned with the cage axis between the first cage end and the second cage end.

[0221] In embodiment D8 according to any one of embodiments D1 to D7, the base opening and the clamp opening are each elongated such that they each define a major axis and a minor axis oriented perpendicular to the major axis, the major axis being greater than the minor axis, and optionally the major axis being at least two times, at least three times, or at least four times larger than the minor axis.

[0222] In embodiment D9 according to embodiment D8, the cage includes a first strut attached to the base proximate a first end of the base opening on the long axis and a second strut attached to the base proximate a second end of the base opening on the long axis, the first strut including a first strut length between the base and the second cage end that is greater than a second strut length between the base and the second cage end.

[0223] In embodiment D10 according to any one of embodiments D1-D9, the distance between the bag sealing surface and the tubesheet sealing surface in a direction aligned with the cage axis varies continuously when moving around the periphery of the base opening.

[0224] In aspect D11 according to any one of aspects D1 to D10, the filter bag support assembly includes a guide opening in the flange assembly, the guide opening being positioned outside the cage and the clean air outlet, the guide opening being configured to receive a guide rail when the clamp is attached to the base, and the flange assembly being configured for advancement along the guide rail received in the guide opening when the clamp is attached to the base.

[0225] In embodiment D12 according to embodiment D11, when the clean air outlet is elongated such that it defines a maximum height along the major axis and a maximum width along a minor axis transverse to the major axis that is smaller than the maximum height, the guide opening is arranged along the major axis.

[0226] In embodiment D13 according to embodiment D11 or D12, the guide opening is formed in only one of the base and the clamp of the flange assembly.

[0227] In embodiment D14 according to any one of embodiments D11 to D13, the guide opening is formed in a clamp of the flange assembly.

[0228] In embodiment D15 according to any one of embodiments D1 to D14, for the filter bag, a reference bag length measured along the bag axis between a reference plane oriented perpendicular to the bag axis and the bag opening changes when moving around the circumference of the bag opening, and optionally, the bag axis is aligned with the cage axis.

[0229] In independent aspect E1, the filter bag includes a tubular body formed from a filter medium configured to remove particulate matter from air passing through the filter medium, the tubular body extending from the closed end to the bag opening along a bag axis coinciding with a central axis of the tubular body, the sealing cuff extending around a periphery of the bag opening, and a bag opening periphery length measured around the periphery of the bag opening is greater than a body periphery length measured in a reference plane oriented perpendicular to the bag axis at a position between the bag opening and the closed end.

[0230] In aspect E2 according to aspect E1, a periphery of the bag opening defines a bag opening plane, and the bag opening plane defines an angle with a reference plane, the angle defined between the bag opening plane and the reference plane being 15 degrees or more, 20 degrees or more, 25 degrees or more, 30 degrees or more, 35 degrees or more, 40 degrees or more, or 45 degrees or more, optionally the angle defined between the bag opening plane and the reference plane being 60 degrees or less, 55 degrees or less, 50 degrees or less, 45 degrees or less, 40 degrees or less, 35 degrees or less, 30 degrees or less, 25 degrees or less, or 20 degrees or less, further optionally the angle defined between the bag opening plane and the reference plane is in the range of 15 degrees to 45 degrees, or alternatively 20 degrees to 40 degrees.

[0231] In aspect E3 according to any one of aspects D1-D2, the reference bag length measured along the bag axis between a reference plane oriented perpendicular to the bag axis and the bag opening changes when moving around the circumference of the bag opening.

[0232] In embodiment E4 according to embodiment E3, the reference bag length includes a minimum reference bag length at a first location on the periphery of the bag opening and a maximum reference bag length at a second location on the periphery of the bag opening.

[0233] In embodiment E5 according to embodiment E4, the rate of change of the reference bag length between the first position and the second position is substantially linear.

[0234] In embodiment E6 according to embodiment E4 or E5, the distance between the first position and the second position is equal when moving clockwise and counterclockwise along the circumference of the bag opening from the first position to the second position.

[0235] In embodiment E7 according to any one of embodiments E3 to E6, the nominal bag length varies continuously over at least a majority of the circumference of the bag opening.

[0236] In embodiment E8 according to any one of embodiments E3 to E7, the nominal bag length varies continuously around the entire circumference of the bag opening.

[0237] In embodiment E9 according to any one of embodiments E1-E8, the filter bag includes a bag support connector attached to the body near the closed end of the body, the bag support being positioned outside the interior volume of the body.

[0238] In embodiment E10 according to embodiment E9, the bag support connector includes an opening configured to receive the hook.

[0239] In independent embodiment F1, an air filter system includes a housing including a tube sheet separating an interior volume of the housing into a clean air chamber and a dirty air chamber, a dirty air inlet configured to direct dirty air into the dirty air chamber and a clean air outlet configured to remove clean air from the clean air chamber, and a filter bag according to any one of embodiments A1-A10 or any one of embodiments E1-E10, wherein the filter bag is disposed within the dirty air chamber.

[0240] In independent embodiment G1, an air filter system includes a housing including a tube sheet separating an interior volume of the housing into a clean air chamber and a dirty air chamber, a dirty air inlet configured to direct dirty air into the dirty air chamber, and a clean air outlet configured to remove clean air from the clean air chamber, and a filter bag assembly described in any one of embodiments D1 to D15, wherein the filter bag assembly is positioned within the dirty air chamber.

[0241] In independent aspect H1, a method of removing particulate matter from polluted air using an air filter system described in aspect F1 or G1 includes feeding polluted air into a polluted air chamber through a polluted air inlet and removing clean air from the clean air chamber through a clean air outlet.

[0242] In independent embodiment I1, to provide a filter bag assembly according to any one of embodiments D1-D15, a method of mounting a filter bag on a filter bag support assembly includes positioning the filter bag such that the filter bag opening is larger than a cage of the filter bag support assembly, advancing the filter bag opening on the cage towards a base of the filter bag support assembly, advancing a clamp of a flange assembly of the filter bag support assembly over the filter bag such that a tubular body of the filter bag extends through the clamp opening of the clamp, and attaching the clamp to the base such that a sealing cuff on the filter bag forms a seal around the clamp opening and a base opening of the base such that air entering or exiting the filter bag must pass through the base opening or the filter media forming the filter bag.

[0243] The complete disclosures of the patents, patent documents, and publications identified herein are incorporated by reference in their entirety as if each were individually incorporated. To the extent of any inconsistency or contradiction between this specification and the disclosure of any such incorporated document, this specification will control.

[0244] Exemplary embodiments of filter bags, filter bag support assemblies, filter bag assemblies and filter systems and methods of using and / or assembling the same are discussed herein, and several possible variations are described. These and other variations and modifications of the present invention will be apparent to those skilled in the art without departing from the scope of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Accordingly, the present invention is limited only by the claims presented below and their equivalents. It should also be understood that the present invention may be suitably practiced in the absence of any element not specifically disclosed herein as necessary.

Claims

1. A filter bag including a tubular body formed from a filter medium configured to remove particulate matter from air passing through the filter medium, the tubular body extending from a closed end to a bag opening along a bag axis coincident with a central axis of the tubular body, a sealing cuff extending around a periphery of the bag opening, and a reference bag length measured along the bag axis between a reference plane oriented perpendicular to the bag axis and the bag opening changes when moving around the periphery of the bag opening.

2. 2. The filter bag of claim 1, wherein the reference bag length comprises a minimum reference bag length at a first location on the periphery of the bag opening and a maximum reference bag length at a second location on the periphery of the bag opening.

3. The filter bag of claim 2 , wherein the rate of change of the reference bag length between the first position and the second position is substantially linear.

4. 4. The filter bag of claim 2 or 3, wherein the distance between the first position and the second position is equal when moving clockwise and counterclockwise along the circumference of the bag opening from the first position to the second position.

5. 5. The filter bag of claim 2, wherein the periphery of the bag opening defines a bag opening plane and the bag opening plane defines an angle with the reference plane, the angle defined between the bag opening plane and the reference plane being 15 degrees or more, 20 degrees or more, 25 degrees or more, 30 degrees or more, 35 degrees or more, 40 degrees or more or 45 degrees or more, optionally the angle defined between the bag opening plane and the reference plane being 60 degrees or less, 55 degrees or less, 50 degrees or less, 45 degrees or less, 40 degrees or less, 35 degrees or less, 30 degrees or less, 25 degrees or less or 20 degrees or less, further optionally the angle defined between the bag opening plane and the reference plane is in the range of 15 degrees to 45 degrees or alternatively 20 degrees to 40 degrees.

6. The filter bag of any one of claims 1 to 5, wherein the nominal bag length varies continuously over at least the majority of the circumference of the bag opening.

7. 7. The filter bag of claim 1, wherein a bag opening perimeter measured around the perimeter of the bag opening is greater than a body perimeter measured in a reference plane oriented perpendicular to the bag axis at a position between the bag opening and the closed end.

8. 8. The filter bag of claim 1, further comprising a bag support connector attached to the body near the closed end of the body, the bag support being positioned outside an interior volume of the body.

9. 1. A filter bag assembly comprising: a flange assembly including an inner surface and a tubesheet surface, the flange assembly including a clean air outlet extending through the flange assembly; a cage including a first cage end attached to the flange assembly, the cage extending away from the inner surface of the flange assembly a cage length from a base to a distal second cage end, the cage defining a cage axis extending between the first cage end and the second cage end; a filter bag including a tubular body formed from a filter medium configured to remove particulate matter from air passing through the filter medium, the tubular body extending from a closed end to a bag opening along a bag axis coincident with a central axis of the tubular body, the cage being contained within the tubular body of the filter bag, and a sealing cuff extending around a periphery of the bag opening; Including, the flange assembly includes a base and a clamp configured to attach to the base on the inner surface of the flange assembly; the clean air outlet is defined by a base opening formed in the base and a clamp opening formed in the clamp; the base includes a bag sealing surface surrounding the base opening, and the clamp includes a clamp sealing surface surrounding the clamp opening, the sealing cuff being disposed between the bag sealing surface and the clamp sealing surface when the clamp is attached to the base; the base includes a tubesheet face facing away from the second end of the cage, the tubesheet face including a tubesheet face opening defining a portion of the clean air outlet, the tubesheet face including a tubesheet seal face surrounding the tubesheet face opening, and a distance between the bag seal face and the tubesheet seal face in a direction aligned with the cage axis varies when moving around a periphery of the base opening.

10. 10. A method of mounting a filter bag on a filter bag support assembly to provide the filter bag assembly of claim 9, comprising the steps of: positioning the filter bag such that a bag opening of the filter is larger than a cage of the filter bag support assembly; advancing the filter bag opening over the cage toward a base of the filter bag support assembly; advancing a clamp of a flange assembly of the filter bag support assembly over the filter bag, a tubular body of the filter bag extending through a clamp opening of the clamp; attaching the clamp to the base, wherein a sealing cuff on the filter bag forms a seal around the clamp opening and the base opening of the base such that air entering or exiting the filter bag must pass through the base opening or the filter media forming the filter bag; The method includes:

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