Patent Description:
Many industries encounter particulate matter suspended in the atmosphere. In some industries, this particulate matter is a valuable product (for example, starch), and it would be beneficial if the suspended particulate matter could be recovered and reintroduced into the process. For other industries (for example, metal or wood working), it may be desirable to remove the particulate matter from the air in order to provide a clear working environment.

Some systems for cleaning an air or other gas streams laden with particulate matter include filter bags (sometimes referred to as socks) located in a housing. The filter bags are typically constructed of filter media, for example, fabric, pleated paper, etc. The gas stream contaminated with particulate matter is typically passed through the housing so that the particulate matter is captured and retained by one or more filter bags.

Air filter systems typically include a clean air chamber and a dirty air chamber. The two chambers are separated by a structure that is commonly referred to as a tubesheet. The tubesheet has a number of openings so that air can pass between the clean and dirty air chambers. The filter bags are positioned over the openings so that particulate-laden air (dirty air) introduced into the dirty air chamber must pass through a filter bag to move into the clean air chamber. The particulate matter in the dirty air collects on the filter bags as the air moves through the filter bags.

From the clean air chamber, the cleaned air is exhausted into the environment, or recirculated for other uses. See, for example, <CIT>), <CIT>), <CIT>), <CIT>), <CIT>), <CIT>), <CIT>), <CIT>), <CIT>), <CIT>), <CIT>), <CIT>), <CIT>), <CIT>), and <CIT>).

As the filter bags capture particulate matter, flow through the system is inhibited and periodic cleaning of the filter bags can be performed to increase air flow through the system. Cleaning can be accomplished by periodically pulsing a brief jet of pressurized air into the interior of the filter bag to reverse the air flow through the filter bag, causing the collected particulate matter to be driven off of the filter bag. The pressurized air may be directed into pulse collectors as described in, for example, <CIT>), <CIT>), <CIT>), <CIT>, <CIT>), <CIT>), and US Patent Application Publication <CIT>.

<CIT> discloses filter bags mounted on a tubesheet.

A filter bag according to the invention is disclosed in any one of appended claims <NUM>-<NUM>.

A filter bag assembly according to the invention is disclosed in any one of appended claims <NUM>-<NUM>.

A method of installing a filter bag on a filter bag support assembly is disclosed in appended claim <NUM>.

In one or more embodiments, the filter bags described herein have a closed end and a bag opening end spaced apart from each other along a bag axis. A sealing cuff extends around a perimeter of the bag opening, and a reference 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 changes when moving around the perimeter of the bag opening. Filter bags having a changing reference bag length as described herein have, as compared to conventional filter bags, an enlarged bag opening.

The enlarged bag openings of filter bags described herein may, in one or more embodiments, alternatively be characterized based on the length of the perimeter of the bag opening as compared to the length of the perimeter of the tubular body located between the bag opening and the closed end of the filter bag. The length of the perimeter of tubular body may be measured in the reference plane used to determine the reference bag length or any other plane (perpendicular to the bag axis) located between the closed end and the bag opening.

When filter bags with enlarged bag openings as described herein are advanced onto the cage of a filter bag support assembly as described herein, the enlarged bag openings provide advantages as compared to filter bags having smaller conventional bag openings.

One advantage of filter bags having enlarged bag openings over conventional filter bags is that the, as the enlarged bag opening is advanced over the cage of a flange assembly, the enlarged bag opening provides extra clearance between the bag opening and the cage (as compared to the smaller size of the tubular body between the bag opening and the closed end of the filter bag). The extra clearance at the enlarged bag opening can, for example, reduce friction between the bag opening and the cage as the bag opening is advanced over at least a portion of the cage. That reduced friction results in a corresponding decrease in the force required to advance the filter bag over the cage.

Although the entire filter bag could be enlarged to make installing the filter bag on a cage easier, an enlarged filter bag would result in filter bags that do not fit as tightly on the cages of bag support assemblies as described herein. That looser fit would be expected to decrease pulse cleaning performance and/or filter bag life.

In particular, pulse cleaning of the filter bags on bag support assemblies in filter systems as described herein can be improved by fitting the filter bags tightly on the cages of the bag support assemblies. The increased tautness of the tighter fitted filter media results in increases in the rapid acceleration associated with pulse cleaning of the filter bags (sometimes referred to as "bag snap"). The increased rapid outward acceleration may result in increased dislodgment of particulate matter collected on the filter bags, with the dislodged particulate matter falling into a hopper of the filter system under the force of gravity.

In addition to improving pulse cleaning performance, tighter fitting filter bag/cage combinations may also improve filter bag life by reducing filter bag wear caused by excessive movement between cages and looser fitting filter bags during pulse cleaning.

Yet another advantage that may be attributed to tighter fitting filter bag/cage combinations is that spacing between adjacent filter bags in the dirty air chamber of an air filter system may be reduced without causing corresponding reductions in pulse cleaning performance. That tighter spacing between adjacent filter bags can result in a corresponding reduction in the size of the air filter system as a whole. Smaller air filter systems that provide the same (or better) filtering capacity as larger air filter systems can be an important factor when available space in a facility is limited.

Still another advantage of filter bags having enlarged bag openings is that the proper orientation of the filter bags on the cages of flange assemblies can, in one or more embodiments, be guaranteed in those embodiments in which the filter bags are capable of being properly installed on the flange assemblies in only one orientation. Proper orientation of the filter bags on the filter bag support assemblies may be advantageous when, for example, the filter bags include a bag support feature proximate the closed end of the filter bags. In such embodiments, placement of the bag support feature on the top of the filter bag when mounted on a bag support assembly can be guaranteed because the filter bag will not fit properly on the bag support assembly when the bag support feature is on the bottom of the filter bag as mounted on the bag support assembly.

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 in which particulate matter must be removed from relatively large volumes of dirty air. As such, the filter bags and filter bag assemblies must be sized to handle those air volumes and the particulate matter associated with the volumes. Generally, the filter bags described herein may have a bag length measured from the bag opening to the closed end of the bag that is <NUM> meters or more, <NUM> meters or more, or even <NUM> meter or more. The associated bag height (measured transverse to the length of the bag) may be <NUM> meters or more, <NUM>. meters or more, <NUM> meters or more, or <NUM> meters or more.

In one or more embodiments, the filter bag assemblies include a flange assembly, a cage attached to the flange assembly, and a filter bag installed over the cage with an opening at the flange assembly. When installed in the dirty air chamber of a filter system, a seal between the flange assembly and the tubesheet defining the dirty air chamber is provided by applying a seal force on the end of the filter bag assembly located proximate the access panel on the side of the dirty air chamber opposite the tubesheet. That seal force is transmitted to the flange assembly through the cage.

Providing the seal force at the end of the filter bag assembly and transmitting that force through the cage to the flange assembly allows for removal and replacement of the filter bags (and the filter bag assemblies) through access ports on an access panel located across the dirty air chamber. As a result, the used filter bags (and the particulate matter collected on them) do not pass through, and potentially contaminate, the clean air chamber of the filter system.

Another potential advantage of providing and transmitting a seal 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, for example, pulse generators, etc. need not be removed or even partially disassembled to accommodate removal and replacement of filter bags.

In one or more embodiments of the filter systems described herein, the filter bags are supported in a dirty air chamber such that the filter bags and their supporting assemblies (for example, flange assemblies, cages, etc.) can be removed and replaced without passing through the clean air chamber of the filter system. That limits or prevents contamination of the clean air chamber by particulate matter dislodged during removal of used filter bags that is associated with removal of used filter bags through the clean air chamber.

Filter systems that include one or more of the various features and components described herein may offer one or more advantages such as, for example, improved energy efficiency, reduced noise generation, etc. by, in one or more embodiments, reduced pressure drops within the filter systems both during primary flow operation and pulse cleaning of the filter elements (where primary flow operation occurs when the filter system is removing particulate matter from a dirty air stream), reducing frictional losses in the filter systems (both during primary flow operation and pulse cleaning of the filter bags, improving particulate loading characteristics (thus potentially requiring fewer cleaning pulses), etc..

These advantages may, in one or more embodiments be synergistic, i.e., the energy efficiency, reduced noise, etc. may be improved by using two or more of the features and/or components together in the same filter systems.

As used herein and in 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 may include one or more of the components and equivalents thereof known to those skilled in the art. Further, the term "and/or" means one or all of the listed elements or a combination of any two or more of the listed elements.

It is noted that the term "comprises" and variations thereof do not have a limiting meaning where these terms appear in the accompanying description. Moreover, "a," "an," "the," "at least one," and "one or more" are used interchangeably herein.

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, a more complete understanding of the invention will become apparent and appreciated by reference to the following Description of Illustrative Embodiments and claims in view of the accompanying figures of the drawing.

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

<FIG> depict various views of one illustrative embodiment of a filter bag as described herein. In <FIG>, the filter bag <NUM> includes a bag opening <NUM> and a closed end <NUM>. A body <NUM> extends from the bag opening <NUM> to the closed end <NUM> along a bag axis <NUM> extending between the bag opening <NUM> and the closed end <NUM>.

The body <NUM> of the filter bag <NUM> can be described as a tubular body <NUM> extending between the bag opening <NUM> and the closed end <NUM>. In a side elevation view such as that of <FIG>, the filter bag <NUM> includes a top edge <NUM> extending from the bag opening <NUM>/seal <NUM> to the closed end <NUM> and a bottom edge <NUM> extending from the bag opening <NUM>/seal <NUM> to the closed end <NUM>.

The tubular bodies of filter bags described herein may take many different forms including, for example, an envelope-like shape, a triangular shape in which the tubular body includes two major sides that meet along a top edge and a bottom side connecting the bottom edges of the two major sides, a rectangular shape (also having, e.g., two major sides), etc..

In one or more embodiments, the bag axis <NUM> may be described as being coincident with a central axis of the tubular body <NUM>, where the central axis/bag axis <NUM> extends through center of the tubular body <NUM> such that the central axis/bag axis <NUM> contains the geometric centers of cross-sections of the tubular body <NUM> taken in planes oriented perpendicular to the central axis/bag axis <NUM>. In the depicted illustrative embodiment, the filter bag <NUM> includes a tubular body <NUM> in which the top edge <NUM> and the bottom edge <NUM> are aligned with (e.g., parallel to) each other.

A reference plane <NUM>' is also depicted in connection with illustrative filter bag <NUM> in <FIG>. The reference plane <NUM>' is oriented perpendicular to the bag axis <NUM>. In the depicted embodiment, the reference plane <NUM>' can also be described as being aligned with (e.g., parallel to) the closed end <NUM> of the filter bag <NUM> because, in the depicted embodiment, the closed end <NUM> is also oriented perpendicular to the bag axis <NUM>.

The body <NUM> of the filter bag <NUM> is primarily constructed of filter media configured to filter air or any other gas passing through the filter media forming the body <NUM> with particulate matter entrained in the air or other gas being captured within or on the filter media forming the body <NUM>. In general, the filter media may preferably be flexible enough such that the filter media is capable of being flexed during pulse cleaning as described herein with that flexing or movement of the filter media preferably resulting in removal of at least a portion of the particulate matter captured within or on the filter media forming the filter body <NUM>. The construction of such filter media is well known to those skilled in the art and may, for example, include woven materials, nonwoven materials, paper, etc. selected in view of the particulate matter to be collected, airflow requirements, strength requirements, etc. Suitable filter bags may be constructed of one or more layers of filter media, scrim, etc. that includes one or more of polyester, polypropylene, aramid, polyester/polytetrafluoroethylene material in both woven and/or nonwoven constructions, etc..

In one or more embodiments, the filter bags described herein may be distinguished from filter cartridges based on their response to compression forces directed between the filter bag opening the closed end of the filter bag, i.e., the end of the bag located opposite the bag opening. In the absence of any extraneous support (such as, for example, the internal cages described herein as part of the filter bag support assemblies and filter bag assemblies), filter bags described herein would, in one or more embodiments, deform under a compressive force of <NUM> Newtons (approx. <NUM> pound-force) directed along a line extending through the bag opening to the closed end of the filter bag (for example, along the bag axis <NUM> depicted in <FIG>). In addition to deforming, one or more embodiments of the filter bags used in the filter bag assemblies described herein, transmit essentially none of such a compressive force. A filter cartridge would, in contrast, not significantly deform and would transmit at least some, if not all, of such a compressive force. The flexibility that is the source of the inability of the filter bags used in the filter bag assemblies and filter systems described herein to transmit compressive forces is, however, at least in part the source of the filter bags' ability to rapidly accelerate (sometimes referred to as "snap") outward to remove particulate matter collected on the exterior of the filter media in response to a cleaning pulse.

With reference to <FIG>, the filter bag <NUM> depicted in <FIG> includes a sealing cuff <NUM> attached to the filter media forming the tubular shape of the body <NUM>. In one or more embodiments of the filter bags described herein, the sealing cuff <NUM> may extend around the entire perimeter of the bag opening <NUM> as seen in, for example, <FIG>.

In one or more embodiments, the sealing cuff <NUM> may be provided as a discrete component attached to the filter media forming the filter body <NUM> of the filter bag <NUM>. The sealing cuff may, in one or more embodiments, be provided as multiple layers of filter media combined through one or more of stitching, adhesives, thermal welding, chemical welding, etc. The sealing cuff may include a polymeric component, e.g., a flexible polymeric component. In one or more embodiments, the sealing cuff may be capable of taking the shape of the body <NUM> of the filter bag <NUM>. In one or more embodiments, the sealing cuff may be in the form of a compressible material, e.g., foam (closed cell, open cell, etc.), fabric, filter media, etc. to assist in forming a seal when clamped within a flange assembly of a filter system as described herein. In one or more embodiments, the sealing cuff may be formed of a resiliently compressible material capable of returning to its original shape (or nearly its original shape) after compression. In one or more other embodiments, the sealing cuffs may include one or more layers of material that exhibit increased resistance to abrasion and/or tearing. In yet other embodiments, the sealing cuffs use in filter bags as described herein may be formed of two or more components attached to the filter media through any suitable technique or combination of techniques.

Although the depicted illustrative embodiment of filter bag <NUM> includes a sealing cuff <NUM> positioned at the bag opening <NUM>, in one or more embodiments, the sealing cuff could be positioned proximally from the bag opening <NUM> as defined by the filter media forming the tubular body <NUM>. One advantage of providing a sealing cuff <NUM> located at the bag opening <NUM> is that compression of the sealing cuff <NUM> may be more readily obtained when such an arrangement of the sealing cuff <NUM> is provided. Compression of the sealing cuff <NUM> may be important in forming a proper seal to prevent unwanted passage of particulate matter when using filter bags as described herein.

One or more embodiments of filter bags having enlarged bag openings as described herein, such as depicted filter bag <NUM>, may have enlarged bag openings that can be described as being not perpendicular to the bag axis <NUM>. In a filter bag such as filter bag <NUM> in which the tubular body <NUM> terminates at a closed end <NUM> that, together with top edge <NUM> and bottom edge <NUM>, form a generally rectangular tubular body <NUM> between the bag opening <NUM>/sealing cuff <NUM> and the closed end <NUM>, the reference plane <NUM>' oriented perpendicular to the bag axis <NUM> may be aligned with (e.g., parallel to) the closed end <NUM> of the filter bag <NUM>. In such embodiments, the bag opening12/sealing cuff <NUM> can be described as not parallel to the reference plane <NUM>' and/or the bag axis <NUM>.

Although not required, the bag opening <NUM>/sealing cuff <NUM> of illustrative filter bag <NUM> may define a bag opening plane <NUM>', with the bag opening plane <NUM>' being oriented at an angle (e.g., canted) with respect to reference plane <NUM>'. The bag opening plane <NUM>' can also be described with reference to the bag axis <NUM>, i.e., the bag axis <NUM> is not normal to the bag opening plane <NUM>' defined by the bag opening <NUM>/sealing cuff <NUM> of filter bag <NUM>.

The filter bag <NUM> with its canted or non-perpendicular bag opening <NUM> is one example of an enlarged bag opening on a filter bag as described herein. Regardless of the specific form of the enlarged bag opening, another manner in which the filter bags having enlarged bag openings as described herein can be characterized is based on a reference bag length as measured along the bag axis <NUM>. In filter bags having enlarged bag openings as described herein, the reference bag length, e.g., the length (along the bag axis) between a reference plane and the bag opening (where the reference plane is oriented perpendicular to the bag axis) changes when moving around the perimeter of the bag opening. The reference planes used to characterize a filter bag in terms of reference bag length may be positioned at any location 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.

With reference to <FIG>, the reference bag length as measured along the bag axis <NUM> between the bag opening <NUM>/sealing cuff <NUM> and the reference plane <NUM>' along the top edge <NUM> of the filter bag <NUM> is shorter than the reference bag length along the bottom edge <NUM> of the filter bag <NUM>. The reference bag length can further be described as changing when moving around the perimeter of the bag opening <NUM>/sealing cuff <NUM>. For example, when moving along the perimeter of the bag opening <NUM> from the top edge <NUM> to the bottom edge <NUM>, the reference bag length (i.e., the distance between the reference plane <NUM>' and the bag opening <NUM>) increases. Conversely, when moving along the perimeter of the bag opening <NUM> from the bottom edge <NUM> towards the top edge <NUM>, the reference bag length (i.e., the distance between the reference plane <NUM>' and the bag opening <NUM>) decreases.

In the filter bag <NUM>, the reference bag length may be described as having a minimum bag length where the top edge <NUM> of the filter bag <NUM> meets the bag opening <NUM>/sealing cuff <NUM> and a maximum reference bag length where the top edge <NUM> of the filter bag <NUM> meets the bag opening <NUM>/sealing cuff <NUM>. In embodiments in which the bag opening <NUM>/sealing cuff define a bag opening plane <NUM>', the rate of change in the reference bag length when moving between top edge <NUM> and the bottom edge <NUM> can be described as being substantially linear. In addition, the distance between the location at which the top edge <NUM> meets the bag opening <NUM>/sealing cuff <NUM> and the location at which the bottom edge <NUM> meets the bag opening <NUM>/sealing cuff <NUM> are equal whether moving around the perimeter of the bag opening <NUM> clockwise or counterclockwise.

As described herein, one advantage of a filter bag such as filter bag <NUM> having a canted bag opening is that the size of the of the bag opening <NUM>/sealing cuff <NUM> as measured in bag opening plane <NUM>' is greater than the cross-sectional size of the filter bag <NUM> as measured in, e.g., reference plane <NUM>' that is perpendicular to the bag axis <NUM>. The enlarged bag opening/sealing cuff <NUM> can make installing the filter bag on a cage of a flange assembly as described herein easier (as discussed in connection with, e.g., <FIG>).

One way in which the size of the bag opening <NUM>/sealing cuff <NUM> as measured in bag opening plane <NUM>' and the cross-sectional size of the filter bag <NUM> in a perpendicular plane <NUM>' can be compared is based on the angle <NUM> formed between the bag opening plane <NUM>' containing the bag opening <NUM>/sealing cuff <NUM> and a reference plane <NUM>' that is perpendicular to the bag axis <NUM>. In one or more embodiments, the angle <NUM> may be <NUM> degrees or more, <NUM> degrees or more, <NUM> degrees or more, <NUM> degrees or more, <NUM> degrees or more, <NUM> degrees or more, or <NUM> degrees or more. At an upper end, the angle <NUM> may be <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, or <NUM> degrees or less.

Although increasing the size of the bag opening <NUM>/sealing cuff <NUM> by increasing angle <NUM> can make installation of the filter bag <NUM> easier, increasing angle <NUM> does also increase the overall length of the filter bag <NUM> as measured along the bottom edge <NUM> of the filter bag <NUM>. That increasing filter bag length would be expected to cause a corresponding increase in the size of a filter system in which filter bag <NUM> is installed. Because increases in the overall size of filter systems can be a concern, it may be preferred that the angle <NUM> be within a range of, for example, <NUM> degrees to <NUM> degrees, or, alternatively, <NUM> degrees to <NUM> degrees to provide a balance between easier installation and filter bag length while maintaining pulse cleaning performance and filter bag life.

Another way in which the size of the bag opening <NUM>/sealing cuff <NUM> as measured in bag opening plane <NUM>' and the cross-sectional size of the filter bag <NUM> in a reference plane <NUM>' can be compared is based on the length of the perimeter of the bag opening <NUM>/sealing cuff <NUM> as measured in bag opening plane <NUM>' and the length of the perimeter of the filter bag <NUM> measured in the reference plane <NUM>' located between the bag opening <NUM>/sealing cuff <NUM>. The difference in perimeter lengths is illustrated by <FIG>, with the perimeter length of the bag opening <NUM> as seen in <FIG> being larger than the perimeter length of the tubular body <NUM> of the filter bag <NUM> as seen in <FIG>. In the depicted illustrative embodiment of <FIG>, reference plane <NUM>' could be located anywhere between the junction of the top edge <NUM> of the tubular body <NUM> and the closed end <NUM> of the filter bag <NUM> with no real change in the size of the perimeter of the filter bag <NUM>.

Another optional feature of one or more embodiments of filter bags as described herein is the addition of a bag support connector <NUM> attached to the body <NUM> of the filter bag <NUM> proximate the closed end <NUM> of the body <NUM>. The bag support <NUM> may preferably be located outside of the interior volume <NUM> of the body <NUM> of the filter back <NUM>. In one or more embodiments, the bag support <NUM> may preferably include an aperture <NUM> configured to receive a hook or other structure configured to support the filter bag <NUM> at its closed end <NUM>. In one or more embodiments, the bag support connector <NUM> may be as simple as a loop of material attached to opposite sides of the body <NUM> of the filter bag <NUM>. Many variations are, of course possible as described elsewhere herein. For example, the bag support connector on the filter bag may be in the form of a hook while a chamber connector to which the hook attaches is in the form of a loop or aperture configured to receive the hook. In another alternative, a bag support may be in the form of a sling that may, for example wrap around the tubular body <NUM> of the filter bag <NUM>.

Although the illustrative embodiment of filter bag <NUM> as depicted in <FIG> is one example of a filter bag having an enlarged bag opening in which the bag opening <NUM>/sealing cuff <NUM> is located in a plane <NUM>', many alternative embodiments of filter bags having enlarged bag openings as compared to the size of the openings of the tubular bodies between the bag opening and the closed end of the filter bag. Only a few examples of the many potential filter bags are depicted in <FIG>.

In <FIG>, filter bag <NUM> includes a bag opening <NUM>/sealing cuff <NUM> and a closed end <NUM> located at opposite ends of a tubular body <NUM> along a bag axis <NUM>. The bag opening <NUM>/sealing cuff <NUM> have a rounded or arcuate shape over at least a portion of the bag opening <NUM>/sealing cuff <NUM> that, when flattened, provides an enlarged bag opening having a longer perimeter length as compared to the perimeter length of the tubular body <NUM> as measured in a reference plane <NUM>' oriented perpendicular to the bag axis <NUM> as described herein. In addition, the filter bag <NUM> provides another example of a filter bag in which the reference bag length measured between reference plane <NUM>' and the bag opening <NUM> changes when moving around the perimeter of the bag opening <NUM> as described herein. In this illustrative embodiment, the reference plane <NUM>' can be located at any location between the junctions of the bag opening <NUM>/sealing cuff <NUM> with either the top edge <NUM> or bottom edge <NUM> of the filter bag <NUM> and the closed end <NUM>. The depicted filter bag <NUM> also includes a closed end <NUM> that is not, itself, located in a plane, i.e., is rounded.

In <FIG>, filter bag <NUM> includes a bag opening <NUM>/sealing cuff <NUM> and a closed end <NUM> located at opposite ends of a tubular body <NUM> along a bag axis <NUM>. The bag opening <NUM>/sealing cuff <NUM> have a generally sinusoidal shape that, when flattened, provides an enlarged bag opening having a longer perimeter length as compared to the perimeter length of the tubular body <NUM> as measured in a reference plane <NUM>' oriented perpendicular to the bag axis <NUM> as described herein. In addition, the filter bag <NUM> provides another example of a filter bag in which the reference bag length measured between reference plane <NUM>' and the bag opening <NUM> changes when moving around the perimeter of the bag opening <NUM> as described herein. In this illustrative embodiment, the top edge <NUM> and the bottom edge <NUM> of depicted filter bag <NUM>, unlike edges <NUM>/<NUM> of filter bag <NUM> or edges <NUM>/<NUM> of filter bag <NUM>, are not aligned with the bag axis <NUM>.

Filter bag <NUM> of <FIG> includes a bag opening <NUM>/sealing cuff <NUM> and a closed end <NUM> located at opposite ends of a tubular body <NUM> along a bag axis <NUM>. The bag opening <NUM>/sealing cuff <NUM> have a V-shape that, when flattened, provides an enlarged bag opening having a longer perimeter length as compared to the perimeter length of the tubular body <NUM> as measured in a reference plane <NUM>' oriented perpendicular to the bag axis <NUM> as described herein. In addition, the filter bag <NUM> provides another example of a filter bag in which the reference bag length measured between reference plane <NUM>' and the bag opening <NUM> changes when moving around the perimeter of the bag opening <NUM> as described herein. In this illustrative embodiment, although bottom edge <NUM> of filter bag <NUM> is aligned with the bag axis <NUM>, the top edge <NUM> is not aligned with the bag axis.

The filter bag support assemblies described herein may be particularly well-suited for use with the filter bags described herein. With reference to <FIG>, one illustrative embodiment of a filter bag support assembly <NUM> is depicted, with the depicted filter bag support assembly <NUM> including a flange assembly that includes a base <NUM> and a clamp <NUM>. A cage <NUM> is attached to the base <NUM> and extends away from the base <NUM> through the clamp <NUM> along a cage axis <NUM>.

With reference to <FIG>, in the depicted illustrative embodiment, the base <NUM> includes a tubesheet panel <NUM> and a bag seal panel <NUM> separated from the tubesheet panel <NUM> by a passageway <NUM>. The bag seal panel <NUM> includes a bag seal surface <NUM> surrounding a base aperture <NUM> formed through the bag seal panel <NUM>. Air passing through the base aperture <NUM> formed through the bag seal panel <NUM> moves through passageway <NUM> towards tubesheet panel <NUM>, with tubesheet panel <NUM> including a tubesheet panel aperture <NUM> which allows air to pass through the tubesheet aperture <NUM> within pulse collector <NUM>. In the depicted embodiment, tubesheet panel aperture <NUM> is formed at the base of the pulse collector <NUM>. Although depicted as being located slightly inward from the tubesheet panel aperture <NUM>, in one or more embodiments, the base aperture <NUM> may preferably be at least as large as the tubesheet panel aperture <NUM> (although that is not required).

The tubesheet panel <NUM> of the base <NUM> of the flange assembly includes a tubesheet face <NUM> that is, in one or more embodiments, configured to seal against a dirty air chamber side of a tubesheet <NUM> (see <FIG>). In the depicted embodiment, a seal <NUM> is provided between the tubesheet face <NUM> of the tubesheet panel <NUM> and the tube sheet, with the seal <NUM> extending around the tubesheet aperture <NUM> in the tubesheet <NUM>. The pulse collector <NUM> of the depicted flange assembly extends from the tubesheet panel <NUM> of the base <NUM> through the tubesheet aperture <NUM>. The seal <NUM> prevents unwanted passage of air between the tubesheet <NUM> and the tubesheet face <NUM> of the tubesheet panel <NUM> of the base <NUM>.

With reference to <FIG>, the depicted illustrative embodiment of the bag support assembly also includes clamp <NUM> configured to act with the base <NUM> (in the depicted embodiment, against bag seal panel <NUM> of base <NUM>) to capture the sealing cuff of a filter bag as described herein. In particular, the base <NUM> includes a bag seal surface <NUM> (on bag seal panel <NUM> in the depicted embodiment) and the base <NUM> includes a clamp seal surface <NUM> facing the bag seal surface <NUM>. Together, the bag seal surfaced <NUM> on the base <NUM> and the clamp seal surface <NUM> on the clamp <NUM> are configured to form a seal with the sealing cuff of a filter bag mounted on the filter bag support assembly <NUM>.

The clamp <NUM> is depicted in <FIG> in a view taken along the cage axis <NUM> from the right side of the bag support assembly <NUM> as depicted in <FIG>. In <FIG>, the clamp seal surface <NUM> is depicted as surrounding a clamp aperture <NUM> formed through the clamp <NUM>. When assembled with the base <NUM>, the clamp aperture <NUM> is aligned with the base aperture <NUM> provided in bag seal panel <NUM> of base <NUM> allow air to pass through the clamp <NUM> into the base <NUM>, with the air passing through the base <NUM> and tubesheet aperture <NUM> and tubesheet <NUM> as described herein.

In the depicted illustrative embodiment of base <NUM> of the flange assembly, the passageway <NUM> is constructed of one or more materials that are impermeable to air such that air passing between the base aperture <NUM> in the bag seal panel <NUM> and the tubesheet panel aperture <NUM> in the tubesheet panel <NUM> of base <NUM> cannot pass out of the passageway <NUM> between the tubesheet panel <NUM> and the bag seal panel <NUM>.

The depicted embodiment of clamp <NUM> includes apertures <NUM> configured to receive fasteners (e.g., bolts, studs, etc.) that may be useful in securing the clamp <NUM> in position on base <NUM> form a seal with a sealing cuff of a filter bag as described herein. Many other structures and/or mechanisms for securing clamp <NUM> to base <NUM> could be used in place of such fasteners.

The flange assembly formed by the combination of the base <NUM> and clamp <NUM> can be described as defining a clean air outlet extending through the base <NUM> and the clamp <NUM> such that air (or any other gas) located within the interior volume of a filter bag installed on the filter bag support assembly passes into or out of the interior volume through the filter media of the filter bag or the clean air outlet. In particular, the clean air outlet in the depicted illustrative embodiment of filter bag support assembly <NUM> includes, moving from right to left in <FIG>, a tubesheet panel aperture <NUM> formed into the tubesheet panel <NUM> of base <NUM>, base aperture <NUM> formed in bag seal panel <NUM> of base <NUM>, and clamp aperture <NUM> formed in clamp <NUM>.

In the depicted illustrative embodiment of filter bag support assembly <NUM>, a cage <NUM> is attached to the base <NUM>, with the cage <NUM> extending away from the base <NUM> to support a filter bag as described herein. The cage <NUM> includes a first cage end attached to the base <NUM> of the flange assembly, with the cage <NUM> extending over a cage length to a second cage end <NUM> located distal from the base <NUM>. The cage <NUM> defines a cage axis <NUM> extending between the first cage end attached to the base <NUM> and the second cage end <NUM> located distal from the base <NUM>.

The depicted illustrative embodiment of cage <NUM> includes struts <NUM> extending away from the base <NUM> along the cage axis <NUM>, with struts <NUM> terminating at second end <NUM> located distal from the base <NUM>. The cage <NUM> as depicted in <FIG> also includes braces <NUM> extending between the struts <NUM> to provide additional support to a filter bag positioned on the cage <NUM>. Although not required, the struts <NUM> the depicted embodiment are aligned with the cage axis <NUM>. The depicted arrangements of struts <NUM> and braces <NUM> in cage <NUM> provide only one example of a cage that may be used to support a filter bag in connection with the filter bag support assemblies described herein.

Although the ends of struts <NUM> of cage <NUM> are depicted as terminating at the bag seal panel <NUM> of the base <NUM>, in one or more embodiments, the struts <NUM> may be attached to the base <NUM> at any location between tubesheet panel <NUM> and bag seal panel <NUM>. In those embodiments in which the struts <NUM> of cage <NUM> are attached to the bag seal panel <NUM>, the passageway <NUM> is sufficiently rigid to transfer forces applied to the second end <NUM> of the cage <NUM> the tubesheet panel <NUM> so that seal <NUM> prevents passage of air through the junction between the tubesheet face <NUM> of tubesheet panel <NUM> and the tubesheet <NUM> as described herein. In those embodiments in which the struts <NUM> extend to and are attached to the tubesheet panel <NUM> of base <NUM>, the struts <NUM> may pass through the base aperture <NUM> in the bag seal panel <NUM> to reach tubesheet panel <NUM>.

Another optional feature of one or more embodiments of a filter bag support assembly as described herein is depicted in <FIG> is a second cage end plane <NUM>' seen along its edge in <FIG>, with the second cage end plane <NUM>'being defined by the second cage end <NUM>. In one or more embodiments, the second cage end plane <NUM>' may preferably be parallel to the dirty air chamber surface of the tubesheet <NUM>.

In one or more embodiments of the filter bag support assemblies described herein, the clean air outlet defined within the flange assembly, that is, defined by the combination of the base aperture <NUM> and the clamp aperture <NUM>, may be elongated such that the clean air outlet defines a maximum height along a major axis and a maximum width less than the maximum height along a minor axis that is transverse to the major axis. In terms of <FIG>, the major axis would extend generally vertically from the narrow end of the base aperture <NUM> and clamp aperture <NUM> to the opposite end of the base aperture <NUM> and clamp aperture <NUM> (along the Y axis) while the minor axis would be generally transverse to that major axis (along the X axis). Both the major axis and the minor axis would be generally transverse to the cage axis <NUM>. In one or more embodiments, the maximum height of the clean air outlet as defined by the base apertures <NUM> and clamp aperture <NUM> may be greater than the maximum width by a factor of two or more, three or more, or four or more to provide an elongated clean air outlet as defined herein.

With reference to <FIG> which depicts a bag support assembly <NUM> configured to receive a filter bag having an enlarged (e.g., canted) bag opening as depicted in, e.g., <FIG>, the bag seal surface <NUM> on the bag seal panel <NUM> may be described as being oriented at an angle relative to the tubesheet face <NUM> of the tubesheet panel <NUM> of base <NUM> provide a transition between the enlarged (e.g., canted) bag opening of filter bag <NUM> and the tubesheet <NUM> of one embodiment of a filter system as described herein.

In one or more embodiments, the bag seal surface <NUM> may be described as defining a bag seal plane <NUM>' and the tubesheet face <NUM> of the tubesheet panel <NUM> may be described as defining a tubesheet plane <NUM>', with the edges of the bag seal plane <NUM>' and the tubesheet plane <NUM>' being depicted in <FIG>. Also depicted in <FIG> is angle <NUM>' between the bag seal plane <NUM>' and the tubesheet plane <NUM>'. In one or more embodiments, the angle <NUM>' between bag seal plane <NUM>' and tubesheet plane <NUM>' may be <NUM> degrees or more, <NUM> degrees or more, <NUM> degrees or more, <NUM> degrees or more, <NUM> degrees or more, <NUM> degrees or more, or <NUM> degrees or more. At an upper end, the angle <NUM>' between bag seal plane <NUM>' and tubesheet plane <NUM>' may be <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, or <NUM> degrees or less.

For reasons discussed above in connection with the illustrative embodiment of filter bag <NUM>, the angle <NUM>' formed between bag seal plane <NUM>' and tubesheet plane <NUM>' (which typically matches the angle <NUM> formed between plane <NUM>' and plane <NUM>' as depicted in <FIG> and discussed in connection there with), it may be preferred that the angle <NUM>' be within a range of, for example, <NUM> degrees to <NUM> degrees, or, alternatively, <NUM> degrees to <NUM> degrees.

Although the flange assembly formed by base <NUM> and clamp <NUM> of the depicted illustrative embodiment of filter bag support assembly <NUM> is configured to receive and retain a filter bag <NUM>, it will be understood that the base and clamp of one or more alternative embodiments of flange assemblies used in filter bag support assemblies as described herein may take different shapes that are complementary to the shape of a bag opening of a filter bag as described herein. For example, the base and clamp of one or more alternative embodiments of filter bag support assemblies as described herein may be shaped to receive and retain filter bags having bag openings/sealing cuffs as depicted in <FIG>.

Another optional feature that may be provided in connection with one or more embodiments of a filter bag support assembly as described herein is a guide aperture <NUM>. The guide aperture <NUM> may be located outside of the cage <NUM> attached to the base <NUM> as well as the clean air outlet as defined by the base aperture <NUM> and clamp aperture <NUM>. The guide aperture <NUM> is, in one or more embodiments, configured to receive a guide rail <NUM> attached to the tubesheet <NUM> when the clamp <NUM> is attached to the base <NUM> of the flange assembly (constituted by the base <NUM> and clamp <NUM>). When the guide aperture <NUM> is positioned on the guide rail <NUM>, the filter bag support assembly <NUM> can be described as being configured for advancement along the guide rail <NUM> towards the tubesheet <NUM> as described herein.

The guide aperture <NUM> may, in one or more embodiments, be formed in only one of the base <NUM> and the clamp <NUM>. In flange assemblies that have both a tubesheet panel <NUM> and a bag seal panel <NUM>, the guide aperture <NUM> could be provided in one or both of the tubesheet panel <NUM> and the bag seal panel <NUM>. In one or more alternative embodiments, the guide aperture <NUM> may be formed in the clamp <NUM> of a flange assembly formed by clamp <NUM> and base <NUM>.

The depicted embodiment of guide rail <NUM> also includes an optional bag connector <NUM> that may, in one or more embodiments, be configured to retain a bag support connection on a filter bag mounted on the filter bag support assembly <NUM> such as, e.g., connector <NUM> on filter bag <NUM> depicted in <FIG>.

<FIG> is a side elevation view of the filter bag support assembly of <FIG> (removed from the tubesheet) with one illustrative embodiment of a filter bag <NUM> as depicted in <FIG> partially advanced over the cage <NUM> extending from the base <NUM> of the flange assembly.

As seen in <FIG>, bag opening <NUM>/sealing cuff <NUM> of the filter bag <NUM> is oriented generally perpendicular to the bag axis <NUM>/cage axis <NUM> so that the enlarged bag opening <NUM>/sealing cuff <NUM> can be used to more easily advance the filter bag <NUM> over the cage <NUM>. In the depicted embodiment of filter bag <NUM>, a portion <NUM> of the bottom edge <NUM> of the filter bag <NUM> is folded or compressed to properly orient the back opening <NUM>/sealing cuff <NUM> as seen in <FIG>. As seen in <FIG>, the struts <NUM> of the cage <NUM> attached to the base <NUM> extend into the filter bag <NUM>.

In one or more embodiments, the distance between the junctions of the top edge <NUM> and bottom edge <NUM> of the filter bag <NUM> with the bag opening <NUM>/sealing cuff <NUM> when the bag opening <NUM>/sealing cuff <NUM> is oriented as depicted in <FIG> may be described as being greater than the distance between the top and bottom struts <NUM> of cage <NUM>. That arrangement provides, in one or more embodiments, the additional clearance to assist with advancement of the filter bag <NUM> over the cage <NUM> as described herein.

Also depicted in <FIG> is the clamp <NUM> which is also partially advanced over the filter bag <NUM> and the cage <NUM>. Although not previously described, <FIG> depicts that advancement of the clamp <NUM> over the filter bag <NUM> and cage <NUM> may also be performed with less interference between the filter bag <NUM> and the clamp aperture (see, e.g., clamp aperture <NUM> in <FIG>) by orienting the clamp <NUM> similar to the back opening <NUM>/sealing cuff <NUM> take advantage of the larger size of the clamp aperture in that orientation.

<FIG> depicts the filter bag support assembly and filter bag of <FIG> after advancement of the filter bag <NUM> to the base <NUM> of the flange assembly and further advancement of the clamp <NUM> towards the bag opening <NUM>/sealing cuff <NUM> of the filter bag <NUM>. As seen in <FIG>, the portion of the bag opening <NUM>/sealing cuff <NUM> approximate the bottom edge <NUM> of the filter bag <NUM> has been extended to place the bag opening <NUM>/sealing cuff <NUM> against the bag sealing surface <NUM> of bag seal panel <NUM> of base <NUM>. In addition, the clamp <NUM> has also been rotated to place the clamp sealing surface <NUM> on clamp <NUM> in its proper orientation so that the sealing cuff <NUM> on filter bag <NUM> can be retained between the clamp sealing surface <NUM> of clamp <NUM> and bag ceiling surface <NUM> of base <NUM>.

When fully advanced into contact with the sealing cuff <NUM> and attached to the base <NUM>, a seal is formed between the base <NUM> and the clamp <NUM> around the clean air outlet formed by the base aperture <NUM> and the clamp aperture <NUM>. In one or more embodiments, the sealing cuff <NUM> may be described as surrounding the clamp aperture <NUM> in the clamp <NUM> as well as the base aperture <NUM> in the base <NUM> (which, in the depicted illustrative embodiment, is located in bag sealing panel <NUM> as described herein).

With the seal formed by sealing cuff <NUM> between base <NUM> and clamp <NUM>, air (or any other gas) passing into or out of the interior volume of the filter bag must pass through the clean air outlet or the filter media forming the body <NUM> of the filter bag <NUM>. In one or more embodiments, the sealing cuff <NUM> is preferably compressed between the base plate and the clamp. As used herein, the term "compressed" means that the sealing cuff <NUM> has been at least partially deformed between the base <NUM> and the clamp <NUM>.

The filter bags, filter bag support assemblies, and filter bag assemblies described herein can all be used in any suitable filter system (sometimes referred to as a collector) to remove particulate matter from a gas stream (e.g., air) in which particulate matter is entrained. Although the filter systems, filter bag support assemblies, filter bag assemblies, and filter bags described below and depicted in, e.g., <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG> 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 could easily accommodate (or be configured to accommodate) filter bags having enlarged bag openings as described herein.

One illustrative embodiment of a filter system is depicted generally at <NUM> in <FIG> and is generally in the shape of a box and includes an upper wall panel <NUM>, and two pairs of opposite side wall panels <NUM> (one of which is visible in <FIG>). The filter system <NUM> includes a dirty air conduit <NUM> for receiving dirty or contaminated gas (e.g., air with particulate matter entrained therein) into the filter system <NUM>. A clean gas (e.g., air) conduit <NUM> (see, e.g., <FIG>) may be provided for removing clean or filtered air from the filter system <NUM>. The filter system <NUM> includes covers <NUM> closing access ports in the access panel <NUM> of the filter system <NUM>.

The filter system <NUM> may also include a hopper <NUM> to collect particulate matter separated from the dirty air stream as described herein. The hopper <NUM> may include sloped walls to facilitate collection of the particulate matter and may, in some embodiments, include a driven auger or other mechanism for removing the collected particulate matter.

The filter system of <FIG> is depicted in a side elevation in <FIG> and a top plan view in <FIG>. The filter system <NUM>, as seen in <FIG>, includes connectors <NUM> in fluid communication with pulse generators (not depicted in <FIG>) as part of a pulse-jet cleaning system, with the pulse generators configured to direct a pulse of air into the filter bags as described herein.

With reference to <FIG> and <FIG>, the depicted filter system <NUM> includes filter bag assemblies including filter bags <NUM> and flange assemblies <NUM> in a dirty air chamber <NUM> that is separated from a clean air chamber <NUM> by a tubesheet <NUM>. <FIG> is a cross-sectional view of the filter system <NUM> taken along line 15A-15A in <FIG> and shows the interior of the filter system <NUM> (with the filter bags <NUM> located therein being intact such that the support structure within the filter bags <NUM> is obscured from view). <FIG> is a cross-sectional view of the filter system <NUM> taken along line <NUM>-<NUM> in <FIG> (with the cross-sectional view depicting the interior volume of the filter bags <NUM> such that a portion of the support structure within the filter bags <NUM> is depicted). The filter bag assemblies are mounted on filter guides <NUM> located in the dirty air chamber <NUM>. In the depicted illustrative embodiment, the filter guides <NUM> extend across the dirty air chamber <NUM> from the tubesheet <NUM> to the access panel <NUM> of the filter system.

At the tubesheet end, each of the filter bag assemblies includes a flange assembly <NUM>. The flange assembly <NUM> includes an interior face <NUM> facing the dirty air chamber <NUM> and a tubesheet face that seals against the dirty air chamber side of the tubesheet <NUM>. Each of the flange assemblies <NUM> surrounds an aperture in the tubesheet <NUM> through which clean air can pass from the interior of a filter bag assembly into the clean air chamber and through which a pulse of air can pass into the interior of a filter bag during a pulse cleaning event.

Although the flange assemblies <NUM> on each of the filter bag assemblies are described in more detail herein, the flange assemblies <NUM> seen in <FIG> include a base <NUM> including the tubesheet face of the flange assembly <NUM> and a clamp <NUM> configured to attach to the base <NUM> on the interior face of the flange assembly <NUM>. In such an embodiment, the clean air outlet extends through the base <NUM> and the clamp <NUM>, with the bag opening of the filter bag <NUM> being retained between the clamp <NUM> and the base <NUM> on the interior face of the flange assembly <NUM>.

The illustrative embodiment of filter system <NUM> as depicted in <FIG> also includes pulse generators <NUM> located in the clean air chamber <NUM>. The pulse generators <NUM> are configured to deliver pulses of air into the interior volumes of the filter bags <NUM> to drive particulate matter that has accumulated on the filter bags <NUM> during use of the filter bags, with the dislodged particulate matter preferably falling into the hopper <NUM> located below the filter bags <NUM>. In one or more embodiments, the pulse generators <NUM> may be described as having elongated shapes that extend along pulse generator axes <NUM> as seen in, e.g., <FIG>. Pressurized air (or any other suitable gas) is delivered to the pulse generators through connectors <NUM> that, in the depicted embodiment, extend outside of the clean air chamber <NUM> for connection to a pulse cleaning system including one or more sources of pressurized gas (e.g., air), valves and a control system. Illustrative embodiments of pulse cleaning systems may be found in, e.g., <CIT>), <CIT>), <CIT>), <CIT>), <CIT>), and <CIT>).

Also depicted in connection with the illustrative embodiment of filter system <NUM> are pulse collectors <NUM> which, as will be described herein, may be attached to the flange assemblies <NUM> of the filter bag assemblies. In other embodiments, the pulse collectors <NUM> may be attached to the tubesheet <NUM>. Regardless of the structure to which they are attached, the pulse collectors <NUM> are configured to direct pulsed air emitted from the pulse generators <NUM> into the interior volumes of the filter bags <NUM> during the pulse cleaning process.

<FIG> are cross-sectional views taken along line 15B-15B in <FIG>, with <FIG> being taken when the filter system <NUM> is either not in use or is being used to filter dirty air entering the dirty air chamber <NUM> through inlet <NUM>. <FIG> depicts the filter bag <NUM> relative to the other structures of the filter bag assembly during a pulse cleaning event when pressurized air (or other gas) is delivered into the interior volume of the filter bag <NUM> as described herein.

<FIG> depicts a portion of the dirty air chamber side of the tubesheet <NUM> with flange assembly <NUM> located thereon. As discussed herein, the depicted illustrative embodiment of flange assembly <NUM> includes a base <NUM> and a clamp <NUM>, with the bag opening of the filter bag <NUM> being retained between the clamp <NUM> and the base <NUM> such that air can enter the interior volume of filter bag <NUM> only by passing through the filter media used to construct filter bag <NUM> or by passing through the clean air outlet <NUM> of the flange assembly <NUM>.

The filter bag assembly as seen in <FIG> includes a cage used to hold the depicted filter bag <NUM> in a triangular shape (with the cage being seen in the cross-sectional view of <FIG>). In the depicted illustrative embodiment, the cage includes a first cage end attached to the flange assembly <NUM>, with the cage extending away from the flange assembly <NUM> over a cage length along a cage axis <NUM> to a second cage end distal from the flange assembly <NUM>. In the depicted illustrative embodiment, the second cage is located proximate the access panel <NUM> of the filter system <NUM>.

In the depicted illustrative embodiment of the filter bag assembly, the cage includes a plurality of struts that extend away from the interior face of the flange assembly <NUM> towards the second cage end proximate the access panel <NUM> of the filter system <NUM>. The plurality of struts define a triangular shape such that, in each cross-section taken in a plane transverse to the cage axis <NUM> over a majority of the length of the cage, the plurality of struts define a triangle having a top vertex and a pair of bottom vertices opposite the top vertex.

In the depicted illustrative embodiment, the cage includes a top strut <NUM> and a pair of bottom struts <NUM> and <NUM>. The top strut <NUM> defines a top vertex of the triangles defined by the plurality of struts, while the pair of bottom struts <NUM> and <NUM> defined the bottom vertices of the triangles defined by the plurality of struts. The depicted illustrative embodiment of the cage also includes a series of braces <NUM> extending from the top strut <NUM> to each of the bottom struts <NUM> and <NUM> to provide additional support to the filter bag <NUM> at selected locations along the length of the cage.

When the cage is located in the filter bag <NUM>, the filter media of the filter bag <NUM> may be described as defining a pair of side surfaces <NUM> and a bottom surface <NUM>. Each of the side surfaces <NUM> includes a top edge proximate the top vertex (as defined by the top strut <NUM>) of each triangle defined by the plurality of struts. Moreover, each side surface <NUM> also includes a bottom edge distal from the top edge of the side surface <NUM>. With reference to <FIG>, the bottom edge of the right side surface <NUM> is defined by the right side bottom vertex (as defined by bottom strut <NUM>) of each triangle defined by the plurality of struts, while the bottom edge of the left side surface <NUM> is defined by the left side bottom vertex (as defined by bottom strut <NUM>) of each triangle defined by the plurality of struts.

Because the filter bags used in the filter bag assemblies of filter systems as described herein are made of generally flexible filter media, the top edges and bottom edges of the triangular-shaped filter bags may not be particularly distinct, i.e., the edges may not form a single line. It will, however, be understood that the edges may have a width around which the filter media extends when moving from the side surfaces <NUM> to the bottom surface <NUM> around the bottom struts <NUM> and <NUM> and/or when moving from one side surface <NUM> to the opposite side surface over the top strut <NUM>. Regardless of that lack of distinctiveness, the edges will be understood as conforming generally to the shape of the struts used to define the different vertices of the triangles.

The triangular shapes defined by the plurality of struts in the illustrative embodiment of the cage as seen in <FIG> are only one example of the triangular shapes that may be used in connection with filter bag assemblies and filter systems as described herein. In general, however, one or more embodiments of the filter bag assemblies described herein may be described as having a bottom surface <NUM> of filter media having a width measured between the bottom edges of the side surfaces <NUM> (as defined by the bottom struts <NUM> and <NUM>) that is less than a height of either of the side surfaces <NUM> as measured between their top edges and bottom edges (where the top edges are defined by the top strut <NUM> and the bottom edges are defined by the bottom struts <NUM> and <NUM>). In one or more embodiments, the width of the bottom surface <NUM> may be <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, or <NUM>% or less of the height of either side surface <NUM> of the pair of side surfaces. At a lower end, the width of the bottom surface may be <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more of the height of either side surface of the pair of side surfaces. The width and height as discussed herein are measured transverse to the cage axis <NUM>, i.e., as seen in, e.g., <FIG>.

Other features depicted in the cross-sectional views of <FIG> include filter guide <NUM> which, in the depicted illustrative embodiment, extends from the tubesheet <NUM> to the access panel <NUM> of the dirty air chamber <NUM>. In the depicted illustrative embodiment, the filter guide <NUM> defines a guide axis <NUM> passing through the tubesheet <NUM> and the access panel <NUM>. The depicted guide axis <NUM> is aligned with the cage axis <NUM> and, although, the two axes <NUM> and <NUM> may be parallel with each other, a perfectly parallel arrangement is not required.

Filter guide <NUM> includes an entry end <NUM> at which the guide aperture <NUM> on the flange assembly <NUM> can be threaded, guided, or otherwise directed onto the filter guide <NUM> so that the flange assembly <NUM> can be supported on the filter guide <NUM>. In one or more embodiments, the entry end <NUM> of the filter guide <NUM> may be located closer to the access panel <NUM> of the filter system than the tubesheet <NUM> against which the flange assembly <NUM> is forced as described herein.

Although the filter guide <NUM> extends from the tube sheet <NUM> to the access panel <NUM> in some of the depicted illustrative embodiments described herein, in one or more alternative embodiments, the filter guide <NUM> may only extend partially across the dirty air chamber such that, e.g., the filter guide <NUM> may terminate at a location short of the access panel <NUM> or even short of the tube sheet <NUM>. In one alternative embodiment, for example, the filter guide <NUM> may extend from the tubesheet <NUM> towards the access panel <NUM> but terminate short of the access panel <NUM>.

The filter guide <NUM> is located within a guide aperture <NUM> formed in the flange assembly <NUM>. The combination of the filter guide <NUM> and the guide aperture <NUM> formed in the flange assembly <NUM> provides support to the flange assembly <NUM> during insertion and removal of a filter bag assembly from the dirty air chamber <NUM> of the filter system <NUM>. In particular, it may be preferred that the filter guide <NUM> and guide aperture <NUM> allow for translational or sliding movement of the flange assembly <NUM> through an access port in the access panel <NUM> to the tubesheet <NUM>. Although the depicted filter guide <NUM> and guide aperture <NUM> in the flange assembly <NUM> have similar shapes, any suitable combination of shapes for both the filter guide and the guide aperture may be used.

Some alternative embodiments of filter guides and guide apertures are depicted in <FIG>. In <FIG>, the filter guide <NUM>' has a T-shaped profile and the guide aperture <NUM>' in flange assembly <NUM>' has a complementary shape configured to accept the filter guide <NUM>'. In <FIG>, the filter guide <NUM>" has an inverted T-shaped profile and the guide aperture <NUM>" in flange assembly <NUM>" has a complementary shape configured to accept the filter guide <NUM>". In <FIG>, the filter guide <NUM>‴ has a round profile and the guide aperture <NUM>‴ in flange assembly <NUM>‴ has a complementary shape configured to accept the filter guide <NUM>"'. Many other alternative shapes for filter guides and guide apertures could also be provided.

In addition to providing support to the flange assembly <NUM> in a vertical direction, the combination of filter guide <NUM> and guide aperture <NUM> may, in one or more embodiments, also serve to limit or prevent rotation of the flange assembly around the guide axis <NUM> so that proper alignment of the flange assembly <NUM> on the tubesheet <NUM> may be achieved. To limit or prevent such rotation, the filter guide <NUM> and guide aperture <NUM> on the flange assembly <NUM> may have a noncircular shapes, with the tri-lobed and T-shaped examples of the depicted illustrative embodiments providing examples of only some noncircular shapes that may limit or prevent rotation of the flange assembly <NUM> relative to the guide axis <NUM>.

In one or more embodiments, the filter guide <NUM> may include a dust cover to prevent accumulation of particulate matter on the filter guide <NUM> that could be dislodged during removal of the filter bag assembly (e.g., as the flange assembly <NUM> moves from the tubesheet <NUM> towards the access panel <NUM>).

Other features depicted in the cross-sectional views of <FIG> include the clean air outlet <NUM> provided in the flange assembly <NUM> which allows both clean air to exit the interior volume of the filter bags <NUM> and also allows for pulses of air or other gases 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 that extends from a top end (closest to the top strut <NUM>) and a bottom end (closest to the bottom struts <NUM> and <NUM>). The top end and the bottom end of the clean air outlet <NUM> may further be described as defining an outlet axis <NUM> that extends between the top and bottom ends of the clean air outlet <NUM>. In one or more embodiments, a projection of the outlet axis <NUM> along the cage axis <NUM> passes between the pair of bottom vertices of the triangles defined by the plurality of struts (where those bottom vertices are defined by the bottom struts <NUM> and <NUM>). Further, the projection of the outlet axis <NUM> passes through the top vertex (as defined by the top strut <NUM>) of the triangles defined by the plurality of struts.

Although not depicted in <FIG>, will be understood that tubesheet <NUM> includes a tubesheet aperture formed therethrough that is at least as large as the clean air outlet <NUM> provided in the flange assembly <NUM> such that the tubesheet aperture does not restrict airflow through the clean air outlet <NUM> into or out of the interior volume of the filter bag <NUM>. Furthermore, the tubesheet aperture may also be described as having a size that is smaller than the flange assembly <NUM> such that the flange assembly <NUM> can close or seal the tubesheet aperture such that air passing between the clean air chamber <NUM> and dirty air chamber <NUM> must pass through the clean air outlet <NUM> when the filter system <NUM> is operational.

The cross-sectional views of <FIG> also depicts the alignment between pulse generators <NUM> and the clean air outlet <NUM> of the flange assemblies <NUM> in the depicted illustrative embodiment of filter system <NUM>. In particular, the pulse generators <NUM> may be aligned with the clean air outlet <NUM>. Even more particularly, the pulse generator axis <NUM> may be aligned with the outlet axis <NUM> when viewed along the cage axis <NUM> as seen in <FIG>.

The views of <FIG> further depict the ports <NUM> of pulse generator <NUM>. In particular, the ports <NUM> face the clean air outlet <NUM> and the aperture in the tubesheet <NUM>. Air delivered through the ports <NUM> of the pulse generator <NUM> passes through those ports and into the clean air outlet <NUM> formed in flange assembly <NUM>.

When the filter bags used in filter systems as described herein have generally triangular shapes, various features may be incorporated into the ports <NUM> of the pulse generators <NUM> to facilitate the pulse cleaning process. For example, in one or more embodiments, the ports <NUM> closer to the bottom end of the clean air outlet <NUM> (i.e., closer to the bottom <NUM> of the filter bag <NUM>) may be larger in size than ports <NUM> located closer to the top end of the clean air outlet <NUM> (i.e., closer to the top edges of the sides <NUM> of the filter bag <NUM>). Alternatively, or in addition, the spacing between ports <NUM> may vary along the pulse generator axis <NUM>. For example, the spacing between the ports <NUM> located closer to the bottom end of the clean air outlet <NUM> may be smaller than the spacing between the ports <NUM> located closer to the top end of the clean air outlet <NUM>. Such variations in size and/or spacing of the ports <NUM> may facilitate the pulse cleaning process by providing more air and or higher pressures within the filter bag <NUM> proximate the bottom surface <NUM>.

A comparison of <FIG> illustrates the beneficial effects of the triangular-shaped filter bags described herein with respect to particular loading and pulse cleaning. In particular, as seen in <FIG> the triangular shaped filter bag <NUM> includes a bottom surface <NUM> that faces downwardly away from the dirty air inlet <NUM> into dirty air chamber <NUM> (see, e.g., <FIG>). Particulate matter introduced into the dirty air chamber <NUM> above the triangular filter bag <NUM> does not, therefore, impinge directly on or, under the force of gravity alone, collect on the bottom surface <NUM> of the filter bag <NUM>. This improves particulate loading performance of the filter bag <NUM> because only particulate matter entrained in dirty air that reaches the bottom surface <NUM> can be captured on the bottom surface <NUM>.

Improvements in pulse cleaning performance are also provided by the triangular-shaped filter bag <NUM> because particulate matter that does collect on the bottom surface <NUM> of the filter bag <NUM> is directed downwardly away from the bottom surface <NUM> during pulse cleaning. With reference to <FIG>, the bottom surface <NUM> of the filter bag <NUM> is forced outwardly/downwardly during pulse cleaning. By virtue of the nature of pulse cleaning, that outward/downward movement of the bottom surface <NUM> is a result of rapid acceleration which imparts a force to any dislodged particulate matter released from the bottom surface <NUM>, with the vector of that pulse cleaning force being generally aligned with the force of gravity to enhance movement of any dislodged particulate matter into a collection area such as, e.g., hopper <NUM> of filter system <NUM>.

In addition to the beneficial effects of the bottom surface <NUM> of the triangular-shaped filter bags <NUM> of filter systems as described herein, the side surfaces <NUM> of the filter bags <NUM> are also rapidly accelerated outward during pulse cleaning as seen in the changed positions of the sides <NUM> of filter bag <NUM> between <FIG>. As discussed herein, such movement of the sides <NUM> of the triangular-shaped filter bags <NUM> provides many of the same advantages in pulse cleaning performance associated with conventional envelope-shaped filter bags having vertical sides.

<FIG> is a simplified schematic diagram of components of the illustrative embodiment of filter system depicting one illustrative embodiment of a seal formed using a filter bag assembly in a filter system as described herein. In the depicted illustrative embodiment, the filter bag assembly includes a flange assembly <NUM>' and a cage <NUM>' attached to the flange assembly <NUM>'.

A filter bag <NUM>' is attached to the filter bag assembly, with bag opening <NUM>' being sealed against flange assembly <NUM>' and the cage <NUM>' located within the interior volume defined by the filter bag <NUM>'. For reference, clean air outlet <NUM>' extends along an outlet axis <NUM>' in a manner similar to the outlet axis <NUM> depicted in, e.g., <FIG>.

Cage <NUM>' defines a cage axis <NUM>' that extends through clean air outlet <NUM>' defined in flange assembly <NUM>'. Cage <NUM>' may also be described as including a first cage end attached to the flange assembly <NUM>' and a second cage end distal from the flange assembly <NUM>' along the cage axis <NUM>'. The second cage end of the cage <NUM>' may also be described as being proximate the second end <NUM>' of the filter bag <NUM>'.

Tubesheet <NUM>' includes aperture <NUM>' formed through the tubesheet <NUM>'. Clean air chamber <NUM>' and dirty air chamber <NUM>' are also indicated in <FIG>, with the two chambers being separated by the tubesheet <NUM>'. Flange assembly <NUM>' is positioned over the aperture <NUM>' in tubesheet <NUM>' such that air passing into and out of the interior volume of the filter bag <NUM>' from the clean air chamber <NUM>' passes through the aperture <NUM>' and the clean air outlet <NUM>' in the flange assembly <NUM>'.

<FIG> also depicts the access panel <NUM>' located opposite tubesheet <NUM>' across the dirty air chamber <NUM>'. Access port <NUM>' is provided in access panel <NUM>' to allow for removal and replacement of the filter bag assembly (including flange assembly <NUM>', filter bag <NUM>', and cage <NUM>' attached to flange assembly <NUM>' and located within the interior volume of the filter bag <NUM>'). Access port <NUM>' is closed by cover <NUM>' to seal the dirty air chamber <NUM>' during operation of the filter system.

Also depicted in <FIG> is a seal <NUM>' located between a tubesheet face of the flange assembly <NUM>' and the tubesheet <NUM>'. Seal <NUM>' is located around aperture <NUM>' in tubesheet <NUM>' as well as being located around clean air outlet <NUM>' in flange assembly <NUM>'. Seal <NUM>' ensures that air passing into the interior volume of the filter bag <NUM>' must pass either through the filter media forming filter bag <NUM>' (during, e.g., filtering) or the clean air outlet <NUM>' and aperture <NUM>' in tubesheet <NUM>. In other words, the seal <NUM>' between flange assembly <NUM>' and tubesheet <NUM>' prevents air (and preferably any particulate matter) from passing between the tubesheet face of the flange assembly <NUM>' and the tubesheet <NUM>' during operation of a filter system as described herein.

In one or more embodiments, seal <NUM>' may be formed by compression between the flange assembly <NUM>' and the tubesheet <NUM>'. In one or more embodiments, a seal actuator may be provided to apply a seal force on the cage <NUM>' of the filter bag assembly. In such embodiments, the seal force is preferably directed along the cage axis <NUM> towards the tubesheet <NUM>'. In one or more embodiments, the seal force may be described as being directed through the second end <NUM>' of the filter bag <NUM>' and further being transferred to the seal <NUM>' through the filter bag <NUM>', cage <NUM>', and flange assembly <NUM>'. In particular, the cover <NUM>', which functions as the seal actuator in the depicted illustrative embodiment, acts on the second (closed) end <NUM>' of the filter bag <NUM>' which, in turn, acts on the second cage end of the cage <NUM>', with the cage <NUM>' transferring that force to the flange assembly <NUM>' by virtue of its attachment to the flange assembly <NUM>'.

Seal <NUM>' may be constructed of any suitable material and/or structures. Although many seals may be formed by compression of one or more resilient and/or elastomeric materials (in, e.g., O-rings, gaskets, etc.), other seal constructions may also be used to form the required seal between the flange assembly and the tubesheet in filter systems as described herein when the flange assembly is subjected to a compression force (e.g., knife edge seals, radial seals, axial seals, etc.).

<FIG> is a perspective view of a portion of the tubesheet <NUM>, with the illustrative embodiment of a filter bag assembly including a filter bag <NUM> supported on the illustrative embodiment of filter guide <NUM>. As discussed herein, the filter bag assembly, including flange assembly <NUM> and filter bag <NUM> are supported on the filter guide <NUM>, with the flange assembly <NUM> forming a seal with the tubesheet <NUM>.

In one or more embodiments of the filter bags and filter systems described herein, a 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, with the bag support configured to prevent or limit sagging of the filter bag assembly at the second end of the filter bag due to, e.g., the weight of the cage located in 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 be provided on filter bag itself, as a part of the filter system, and/or include components provided as a part of the filter bag and as a part of the filter system.

The filter bag assembly depicted in <FIG> includes one illustrative embodiment of a bag support in the form of a bag support connector <NUM> attached to the filter bag <NUM> proximate the second (closed) end <NUM> of the filter bag <NUM> and a chamber connector <NUM> that is positioned in the dirty air chamber proximate the access panel <NUM> of the housing. In the depicted embodiment the chamber connector <NUM> is located on the filter guide <NUM> although such positioning is not required. The bag support connector <NUM> and the chamber connector <NUM> are configured to interlock with each other to support the second end of the filter bag <NUM> in the dirty air chamber (with the first end of the filter bag <NUM> being supported by the flange assembly <NUM> in cooperation with the filter guide <NUM> as described herein).

In the embodiment of a bag support as depicted in <FIG>, the bag support connector <NUM> is in the form of a loop while the chamber connector <NUM> is in the form of a hook, with the loop <NUM> connecting to the hook <NUM> to support the second end <NUM> of the filter bag <NUM>. Many variations are, of course possible. For example, the bag support connector <NUM> on the filter bag <NUM> may be in the form of a hook while the chamber connector <NUM> is in the form of a loop or aperture configured to receive the hook.

<FIG> depicts one alternative embodiment of a bag support that may be used to prevent or limit sagging of a filter bag assembly at the second end of the filter bag. In the depicted embodiment, the bag support includes the chamber connector <NUM> on filter guide <NUM> similar to that depicted in <FIG> which, in the depicted embodiment, is attached to access panel <NUM>" (with cover <NUM>" closing the access opening in the access panel <NUM>" as described herein). The embodiment of a bag support depicted in <FIG> includes a sling <NUM>" that may, for example wrap around the bag <NUM>", with the sling <NUM>" forming a loop that is configured to connect to the hook <NUM> on filter guide <NUM>. In one or more embodiments, the sling <NUM>" may be attached to the filter bag <NUM>" using one or more of, e.g., sewing, adhesives, etc. such that the sling <NUM>" is replaced with the filter bag <NUM>". Alternatively, the sling <NUM>" may be separate, e.g., unattached, to the filter bag <NUM>" such that the sling <NUM>" can be re-used with two or more different filter bags <NUM>".

<FIG> depicts yet another alternative embodiment of a bag support that may be used to prevent or limit sagging of a filter bag assembly at the second (closed) end of a filter bag. In the depicted embodiment, the bag support <NUM>"' is in the form of a surface provided proximate the bottom of the filter bag <NUM>‴ at the second end of the filter bag <NUM>"'. The bag support <NUM>"' may be attached to the access panel <NUM>"' and may be accessed through the opening in the access panel <NUM>"' that is closed by cover <NUM>"'. In one or more embodiments, the bag support <NUM>"' may be moved downward (away from the bag axis <NUM>) to assist with replacement of the filter bag <NUM>"'. Movement of the bag support <NUM>"' may include one or both of translational and rotational movement of the bag support <NUM>"'.

<FIG> is a perspective view of one illustrative embodiment of a portion of a access panel <NUM> including one illustrative embodiment of a cover <NUM> used to close a filter access port <NUM> formed in the access panel <NUM> through which filter bag assemblies including filter bags <NUM> can be removed from and inserted into the dirty air chamber of a filter system. The illustrative embodiment of cover <NUM> includes a latch <NUM> and catch <NUM> to secure the cover <NUM> in a closed position (see the covers <NUM> to the right of the open cover <NUM>). The covers <NUM> may be connected to the access panel <NUM> for rotation about a hinge axis <NUM> such that the covers <NUM> can be moved from a closed position to an open position in which filter bag assemblies can be inserted into or removed from the dirty air chamber through access port <NUM>.

Rotation of the cover <NUM> about hinge axis <NUM> moves the cover <NUM> to its closed position in which cover <NUM> covers filter access port <NUM>. When in the closed position, the cover <NUM> may, in addition to closing filter access port <NUM>, function as a seal actuator such that the cover <NUM> also acts on the second ends <NUM> of the filter bags <NUM> to force an attached flange assembly against a tubesheet to form a seal as described herein. The forces provided by the cover <NUM> acting as a seal actuator when closed may be described as acting along the cage axes <NUM>.

<FIG> is a perspective view of the access panel <NUM> of <FIG> including an alternative illustrative embodiment of a cover <NUM>' used to close a filter access port <NUM> formed in the access panel <NUM> through which filter bag assemblies including filter bags <NUM> can be removed from and inserted into the dirty air chamber of the filter system including access panel <NUM>. This illustrative embodiment of cover <NUM>' also includes a latch <NUM> and catch <NUM> to secure the cover <NUM>' in a closed position (see the cover <NUM>' to the right of the open cover <NUM>'). The covers <NUM>' may also be connected to the access panel <NUM> for rotation about a hinge axis <NUM> such that the covers <NUM>' can be moved from a closed position to an open position in which filter bag assemblies can be inserted into or removed from the dirty air chamber through access port <NUM>.

Rotation of the covers <NUM>' about hinge axis <NUM> moves the covers <NUM>' to their closed positions in which covers <NUM>' close filter access port <NUM>. When in the closed position, the covers <NUM>' may, in addition to closing filter access port <NUM>, function as seal actuators such that the covers <NUM>' also act on the second ends <NUM> of the filter bags <NUM> to force an attached flange assembly against a tubesheet to form a seal as described herein. The forces provided by the covers <NUM>' acting as seal actuators when closed may be described as acting along the cage axes <NUM>.

An additional feature depicted in covers <NUM>' are the embossments (cavities) <NUM> provided in covers <NUM>'. The embossments <NUM> may, in one or more embodiments, have shapes that are complementary to the shape of the ends <NUM> of the filter bags <NUM>. Such embossments may provide advantages such as, for example, additional stability to the filter bag assemblies proximate the access panel <NUM>, more uniform force distribution over the second ends <NUM> of the filter bags <NUM> and, therefore, over the cages located within the filter bags <NUM> in filter bag assemblies as described herein, verification of proper installation of the filter bag assemblies (such that, for example, the bottom surfaces of triangular filter bags are properly oriented in a dirty air chamber), etc. In embodiments that include such embossments, a bag support configured to support the second end of the filter bag (as discussed above in connection with, e.g., <FIG>) may be helpful in ensuring that the second ends <NUM> of the filter bags <NUM> are properly positioned as the covers <NUM>' are closed.

As discussed herein, the filter bags used in the filter bag assemblies of filter systems described herein are made of generally flexible filter media, the filter bags may not form particularly distinct triangles when viewed in cross-section. In general, however, the triangular-shaped filter bags and their associated cages can be described using the geometry of triangles with an understanding that the edges, sides, and vertices of such triangles will be generally approximated by the triangular cages and filter bags fitted thereon.

With that understanding, reference is made to <FIG> in which various triangular-shaped bag constructions that may be used in one or more embodiments of filter bag assemblies and filter systems using the filter bag assemblies as described herein.

The idealized triangular-shaped bag <NUM> depicted in <FIG> is, in many respects, similar to the triangular-shaped bag <NUM> discussed herein with respect to various embodiments of the filter bag assemblies and filter systems described above. The triangular-shaped bag <NUM> includes a top vertex <NUM> and a pair of bottom vertices <NUM> and <NUM>. A pair of side surfaces <NUM> extend between the top vertex <NUM> and each of the bottom vertices <NUM> and <NUM>. A bottom surface <NUM> extends between the bottom vertices <NUM> and <NUM>.

To further illustrate the difference between an idealized triangular-shaped defined by one or more embodiments of filter bags as described herein and the actual shapes taken by filter bags located on cages that provide the triangular shapes, the struts of a one illustrative embodiment of a cage are included in <FIG> along with cage axis <NUM> (which extends perpendicularly out of the paper on which <FIG> is located). In particular, top struts, bottom struts, and intermediate struts <NUM> are depicted inside filter bag <NUM> in <FIG>. It should be noted that two top struts <NUM> are provided. Such a construction may provide filter bag <NUM> with a small flat surface along its top edge. Regardless of the slight deviation from a perfect triangle, it can be seen that the side surfaces <NUM> and bottom surface <NUM> of the filter bag <NUM> take on a generally triangular shape as described herein.

The bottom surface <NUM> may be described as having a width wb extending between the bottom vertices <NUM> and <NUM>. The left side surface <NUM> may be described as having a height s1 measured between the top vertex <NUM> and bottom vertex <NUM>. The right side surface <NUM> may be described as having a height s2 measured between the top vertex <NUM> and bottom vertex <NUM>. As discussed herein the width of the bottom surface (wb) is preferably less than the height of either of the side surfaces (s1 or s2).

Although not required, the depicted triangular-shaped bag <NUM> forms a triangle that may be described as being an acute triangle and, optionally, an isosceles triangle (in which s1 = s2). In the case of an isosceles triangle, the axis <NUM> depicted in <FIG> may be described as being an altitude of the triangle formed by the filter bag <NUM>.

The triangular-shaped bag <NUM> may further be described with respect to the angle formed by the side surfaces <NUM>. In particular, the angle α (alpha) formed by side surfaces <NUM> at vertex <NUM> may be selected such that the width (wb) of the bottom surface <NUM> has a selected relationship with the heights of the side surfaces <NUM>. In one or more embodiments, the angle α (alpha) may be <NUM>° or less, <NUM>° or less, <NUM>° or less, <NUM>° or less, <NUM>° or less, <NUM>° or less, or <NUM>° or less. At a lower end, the angle α (alpha) may be, in one or more embodiments, <NUM>° or more, <NUM>° or more, <NUM>° or more, or <NUM>° or more.

<FIG> depicts one alternative triangular-shaped filter bag that may be used in one or more embodiments of a filter bag assembly and/or filter system as described herein. The triangular-shaped bag <NUM> includes a top vertex <NUM> and a pair of bottom vertices <NUM> and <NUM>. A pair of side surfaces <NUM> extend between the top vertex <NUM> and each of the bottom vertices <NUM> and <NUM>. A bottom surface <NUM> extends between the bottom vertices <NUM> and <NUM>. When mounted on a cage in a filter bag assembly as described herein, the cage axis would extend perpendicularly out of the paper on which <FIG> is located.

The triangular-shaped bag <NUM> may optionally be described with respect to the angle formed between the side surfaces <NUM> at vertex <NUM>. In particular, the angle α (alpha) formed by side surfaces <NUM> at vertex <NUM> may be selected such that the width (wb) of the bottom surface <NUM> has a selected relationship with the heights of the side surfaces <NUM>. In one or more embodiments, the angle α (alpha) may be <NUM>° or less, <NUM>° or less, <NUM>° or less, <NUM>° or less, <NUM>° or less, <NUM>° or less, or <NUM>° or less. At a lower end, the angle α (alpha) may be, in one or more embodiments, <NUM>° or more, <NUM>° or more, <NUM>° or more, or <NUM>° or more.

The depicted triangular-shaped bag <NUM> forms a triangle that may be described as being an obtuse triangle. The axis <NUM> depicted in <FIG> may be described as bisecting the angle α (alpha) and, as a result, the axis <NUM> also bisects the bottom surface <NUM>. In one or more embodiments of triangular-shaped filter bags as described herein, the axis passing through the top vertex and bisecting the angle formed at that vertex may preferably be oriented generally vertically within the dirty air chamber of a filter system. With respect to the embodiment of triangular-shaped filter bag <NUM>, axis <NUM> may be oriented vertically or, alternatively, the axis <NUM> may canted or angled with respect to a vertical axis.

Although the bottom surface <NUM> of the triangular-shaped filter bag <NUM> may not be oriented transverse to the vertical axis, particulate matter dislodged from the bottom surface <NUM> during pulse cleaning would have a vertical force component that, when added to the force applied by gravity, would preferentially move the dislodged particulate matter downward as described in connection with other illustrative embodiments of filter bags described herein.

<FIG> depicts a pair of triangular-shaped filter bags <NUM>. The triangular - shaped filter bag <NUM> on the right side of <FIG> has essentially the same shape as the filter bag <NUM> depicted in <FIG>. The triangular-shaped filter bag <NUM> on the left side of <FIG> is a mirror image of the filter bag <NUM> on the right side of <FIG>. Both the left and right side triangular-shaped filter bags <NUM> include vertically oriented surfaces <NUM> facing each other and aligned with a vertical axis V, while the outer side surfaces <NUM> of the triangular-shaped filter bags <NUM> face away from each other. One potential advantage of such an arrangement is that the triangular-shaped filter bags <NUM> may be spaced closer together (in a direction transverse to the vertical axis), thus increasing the surface area of filter media available within a given dirty air chamber volume while retaining the particulate loading and pulse cleaning advantages that may be associated with triangular-shaped filter bags as described herein.

<FIG> depicts another alternative triangular-shaped filter bag that may be used in one or more embodiments of a filter bag assembly and/or filter system as described herein. The triangular-shaped bag <NUM> includes a top vertex <NUM> and a pair of bottom vertices <NUM> and <NUM>. A pair of side surfaces <NUM> extend between the top vertex <NUM> and each of the bottom vertices <NUM> and <NUM>. A bottom surface <NUM> extends between the bottom vertices <NUM> and <NUM>. When mounted on a cage in a filter bag assembly as described herein, the cage axis would extend perpendicularly out of the paper on which <FIG> is located.

The depicted triangular-shaped bag <NUM> forms a triangle that may be described as being a right triangle. The axis <NUM> depicted in <FIG> may be described as bisecting the bottom surface <NUM>. In one or more embodiments of triangular-shaped filter bags as described herein, the axis passing through the top vertex and bisecting the bottom surface may be oriented generally vertically within the dirty air chamber of a filter system. With respect to the embodiment of triangular-shaped filter bag <NUM>, axis <NUM> may be oriented vertically or, alternatively, the right side surface <NUM> (forming a right angle with the bottom surface <NUM>) may be oriented vertically such that the bottom surface <NUM> is oriented generally horizontally to a vertical axis. As used herein, the phrase "generally horizontal" (and variations thereof) means that the component or components (e.g., a filter bag and/or filter bag assembly with cage) is/are arranged such that the component or components form an angle of <NUM> degrees or less, <NUM> degrees or less, <NUM> degrees or less, or <NUM> degrees or less off of a horizontal line (where gravitational force vectors define the vertical axis). For example, the cage axis or filter bag axis may define such an angle with a horizontal line if the filter bag and/or cage is canted with respect to perfectly horizontal line.

Even if the bottom surface <NUM> of the triangular-shaped filter bag <NUM> is not oriented transverse to the vertical axis (where, for example, the axis <NUM> is oriented vertically), particulate matter dislodged from the bottom surface <NUM> during pulse cleaning would have a vertical force component that, when added to the force applied by gravity, would preferentially move the dislodged particulate matter downward as described in connection with other illustrative embodiments of filter bags described herein.

<FIG> is a cross-sectional view of another illustrative embodiment of a filter bag assembly including an envelope-shaped filter bag <NUM> supported by a cage <NUM> on a flange assembly <NUM> as described herein. Although some illustrative embodiments of filter systems and filter bag assemblies described herein may advantageously use filter bags and cages that result in triangularly shaped filter bags, many of the advantages and benefits associated with filter bag assemblies that are compressed within a dirty air chamber as described herein are also available in connection with filter bags on filter bag assemblies having any selected shape.

In particular, <FIG> depicts one embodiment of a more conventional envelope -shaped filter bag assembly in which the opposite major sides of the filter bag <NUM> are generally parallel to each other in use (e.g., have an angle α (alpha) that is essentially <NUM>° (with reference to <FIG>)). The filter bag <NUM> is mounted on a cage constructed of struts <NUM> that define the envelope shape of the filter bag <NUM> mounted thereon.

The struts <NUM> are attached to a flange assembly <NUM> that includes a clean air outlet <NUM> as described in connection with other embodiments of flange assemblies of filter bag assemblies as described herein. The clean air outlet <NUM> is, in the depicted illustrative embodiment elongated along an outlet axis <NUM> as described in connection with other illustrative embodiments herein.

The struts <NUM> of the cage attached to the flange assembly <NUM> also extend away from that flange assembly <NUM> along a cage axis <NUM> to a distal end where they support a second end of the filter bag <NUM> as described in connection with other illustrative embodiments herein. Also depicted in <FIG> are a portion of the tubesheet <NUM> against which flange assembly <NUM> is forced to provide a seal, along with an aperture <NUM> in the tubesheet <NUM> through which air passes into or out of the clean air chamber located on the opposite side of the tubesheet <NUM>.

<NUM>-<NUM> depict one illustrative embodiment of a triangular filter bag that may be used in one or more embodiments of filter bag assemblies and filter systems as described herein. The triangular filter bag <NUM> includes an opening <NUM>, a closed end provided by a substantially triangular end cap <NUM>, and a body <NUM> extending from the opening <NUM> to the closed end along a bag axis <NUM> that extends between the opening <NUM> to the closed end of the filter bag <NUM>.

The body <NUM> of the triangular filter bag <NUM> is formed of filter media suitable for removing particulate matter from air in the application for which it is intended. In one or more embodiments, the body <NUM> may consist essentially of filter media with no other components provided. With reference to <FIG>, the body <NUM> may include seam edges <NUM> and <NUM> that are attached to each other to form a longitudinal seam <NUM>/<NUM> as seen in, e.g., <FIG>. When the seam edges <NUM>/<NUM> are attached to each other, the body may be described as taking a tubular shape that defines an interior volume between the opening <NUM> and the closed and defined by the triangular end cap <NUM>. In that tubular shape, the filter media of the body <NUM> also defines a closed end edge <NUM> located at the closed end of the filter bag <NUM> and an opening edge <NUM> located at the opening <NUM> of the filter bag <NUM>.

In one or more embodiments, the junction between the longitudinal seam <NUM>/<NUM> with the triangular end cap <NUM> may be located along one of the side edges <NUM> of the triangular end cap <NUM> between the bottom edge <NUM> and the apex <NUM> of the triangular end cap. In one or more alternative embodiments, a junction between a longitudinal seam and a triangular end cap of a filter bag as described herein may be located along the bottom edge <NUM> or the apex <NUM>. Further, although body <NUM> includes only one longitudinal seam <NUM>/<NUM>, one or more alternative embodiments of triangular filter bags as described herein may include two or more seams.

The triangular end cap of one or more embodiments of triangular filter bags as described herein may, with reference to the illustrative embodiment of triangular end cap <NUM>, include two side edges <NUM> that extend between a bottom edge <NUM> and an apex <NUM>. Described alternately, the side edges <NUM> of the triangular end cap <NUM> may be described as meeting at the apex <NUM> at a location distal from the bottom edge <NUM>.

To provide a filter bag capable of removing particulate matter from air, the filter media of the body <NUM> at the closed end edge <NUM> is sealed to the side edges <NUM>, bottom edge <NUM> and apex <NUM> of the triangular end cap <NUM> such that particulate matter is substantially prevented from passing through those junctions.

The triangular end cap <NUM> may, in one or more embodiments, define the generally triangular-shaped of the filter bag <NUM> along its length and will more definitely define the triangular-shape of the filter bag <NUM> proximate the triangular end cap <NUM>. With reference to <FIG>, the shape of the triangular end cap <NUM> can be described with reference to the included angle formed between the side edges <NUM> of the triangular end cap <NUM>. In particular, the bottom edge <NUM>, apex <NUM>, and side edges <NUM> of the triangular end cap <NUM> may, in one or more embodiments, be described as defining an included angle α (alpha) between the side edges <NUM> at the apex <NUM> of <NUM>° or less, <NUM>° or less, <NUM>° or less, <NUM>° or less, or <NUM>° or less. At a lower end, the angle α (alpha) may be, in one or more embodiments, <NUM>° or more, <NUM>° or more, <NUM>° or more, or <NUM>° or more.

The triangular end caps that may be used in one or more embodiments of triangular filter bags as described herein may alternatively be described with respect to the dimensions of the features of the triangular end cap. For example, the triangular end cap <NUM>, when projected onto a flat surface along the bag axis <NUM> may, in one or more embodiments, define a height (h) between the apex <NUM> and the bottom edge <NUM>. The projection of triangular end cap <NUM> may also define a width (w) across the bottom edge <NUM> between the side edges <NUM>. In one or more embodiments of triangular filter bags as described herein, the height (h) is greater than the width (w). More particularly, in one or more embodiments, the height (h) defined between the bottom edge and the apex of a triangular end cap may be <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, or <NUM> times or more 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 bottom edge and the apex of a triangular end cap may be, at an upper end, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, or <NUM> or less times the width (w) defined along the bottom edge between the sides of the triangular end. In one embodiment, the height (h) defined between the bottom edge and the apex of a triangular end cap may be <NUM> to <NUM> times the width (w) defined along the bottom edge between the sides of the triangular end. It should be noted that the height (h) is preferably measured along an end cap axis <NUM> that extends between the bottom edge <NUM> and the apex <NUM> and may, in one or more embodiments, be described as bisecting both the bottom edge <NUM> and the apex <NUM> and/or defining an axis of symmetry of the triangular end <NUM>. In one or more embodiments of filter bags including triangular end caps as described herein, the triangular end cap may be constructed of filter media, e.g., the same filter media used for the body <NUM> of the filter bag. In one or more alternative embodiments, the triangular end caps may be constructed of materials that are impermeable to air (unlike the filter media used for the body <NUM>). In one or more embodiments, the triangular end caps may be substantially rigid, self-supporting articles, while in other embodiments the triangle are end caps may be constructed of flexible materials that are not capable of self-support.

In one or more embodiments of filter bags including triangular end caps as described herein, the closed end edge <NUM> of the body <NUM> may be sealed to the side edges <NUM> of the triangular end cap <NUM> using any suitable technique or combination of techniques sufficient to provide structural integrity to that junction as well as limit/prevent passage of particulate matter through that junction. 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.

In one or more embodiments of filter bags including triangular end caps as described herein, the closed end edge <NUM> of the body <NUM> may be sealed to the bottom edge <NUM> of the triangular end cap <NUM> using any suitable technique or combination of techniques sufficient to provide structural integrity to that junction as well as limit/prevent passage of particulate matter through that junction. 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.

In one or more embodiments of filter bags including triangular end caps as described herein, the closed end edge <NUM> of the body <NUM> may be sealed to the apex <NUM> of the triangular end cap <NUM> using any suitable technique or combination of techniques sufficient to provide structural integrity to that junction as well as limit/prevent passage of particulate matter through that junction. 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.

With reference to FIGS. <NUM> and <NUM>, filter bag <NUM> also includes a sealing cuff <NUM> attached to the filter media of the body <NUM> proximate the open edge <NUM> of the body <NUM>. The cuff <NUM> may, in one or more embodiments, be used to seal the bag opening <NUM> in a flange assembly of a filter bag assembly as described herein.

Claim 1:
A filter bag (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>') comprising a tubular body (<NUM>; <NUM>; <NUM>; <NUM>) formed of filter media configured to remove particulate matter from air passing through the filter media, characterized in that the tubular body (<NUM>; <NUM>; <NUM>; <NUM>) extends from a closed end (<NUM>; <NUM>; <NUM>; <NUM>) to a bag opening (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>') along a bag axis (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>) coincident with a central axis of the tubular body (<NUM>; <NUM>; <NUM>; <NUM>), wherein a sealing cuff (<NUM>; <NUM>; <NUM>; <NUM>) extends around a perimeter of the bag opening (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>'), and wherein a reference bag length measured along the bag axis (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>) between a reference plane (<NUM>'; <NUM>'; <NUM>'; <NUM>') oriented perpendicular to the bag axis (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>) and the bag opening (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>') changes when moving around the perimeter of the bag opening (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>').