Patent Publication Number: US-2020298164-A1

Title: Fume filter bank with panel filter

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 15/902,070, filed on Feb. 22, 2018, the disclosure of which is incorporated herein by reference. Patent application Ser. No. 15/902,070 claims the benefit of U.S. Provisional Patent Application Ser. No. 62/472,914, filed on Mar. 17, 2017, the disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     Embodiments of the present invention relate to filter banks for dust and fume extraction systems, and air filter cartridges for use in filter banks. 
     Description of Related Art 
     Filter banks are used to collect dust and fumes within a fume extraction system. Certain industrial processes, such as welding, hardfacing, or plasma cutting can generate fumes and dust. Fume extraction systems are employed to remove the fumes and dust entrained in the air around a work area. A fume extraction system can include individual suction inlets, commonly located on movable “arms” (e.g., repositionable branch ducts), that are tied to a common extraction duct. The extraction duct is connected to a filter bank (also referred to as a dust collector). Prior to discharging the removed air to another space or outdoors, the air passes through the filter bank and is cleaned. The filter bank is an enclosure containing air filters for cleaning the air of certain solid contaminants entrained in the air. Contaminated air enters the filter compartment and passes through the filters. The cleaned air can be ducted to an appropriate discharge location. 
     A conventional fume extraction filter bank is shown in  FIG. 1 . The filter bank has an outer enclosure  10  that forms a plenum for a contaminated airflow. The filters  12  within the enclosure  10  are cylindrical and are mounted horizontally or vertically within the enclosure. Contaminated air  14  is drawn or pushed through a pre-filter  16  and into the enclosure  10 . Air flows through the cylindrical filters  12  and into the interior of the filters. Cleaned air  16  then flows from the interior of the cylindrical filters  12  and out of an open end of the cylinder, and ultimately out of the enclosure  10 . The filter bank can include filter cleaning controls to monitor a pressure differential across the filters  12 , to determine when the filters themselves need to be cleaned or replaced. Pulsed air  18  can be directed into the interior central opening of the filters  12  to clean them. The pulsed air  14  “backwashes” the filter cartridge  12 , releasing dust collected on the surface of the filters. The dust can be collected at the bottom of the filter bank via a hopper and catch bin arrangement. 
     BRIEF SUMMARY OF THE INVENTION 
     The following summary presents a simplified summary in order to provide a basic understanding of some aspects of the devices, systems and/or methods discussed herein. This summary is not an extensive overview of the devices, systems and/or methods discussed herein. It is not intended to identify critical elements or to delineate the scope of such devices, systems and/or methods. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later. 
     In accordance with one aspect of the present invention, provided is a filter bank. The filter bank includes a filter enclosure. A first filter panel and a second filter panel are flexibly joined along respective proximal ends of the first filter panel and the second filter panel by a living hinge. A first sealing gasket extends along a distal end of the first filter panel and forms a first air seal within the filter enclosure. A second sealing gasket extends along a distal end of the second filter panel and forms a second air seal within the filter enclosure. A third sealing gasket extends along the living hinge. A pivoting sealing rail pivots within the filter enclosure to form a third air seal against said third sealing gasket extending along the living hinge. 
     The filter bank can further comprise a zigzag filter arrangement including the first filter panel, the second filter, a third filter panel, and a fourth filter panel, wherein the third filter panel and the fourth filter panel are joined by a second living hinge. The pivoting sealing rail can automatically pivot upward into a sealing position against said third sealing gasket due to insertion of the first filter panel and the second filter panel into the filter enclosure. Further, the pivoting sealing rail can be configured to raise the first filter panel to form the first air seal and raise the second filter panel to form the second air seal when pivoted upward into the sealing position. In other embodiments, the pivoting sealing rail is manually pivoted upward into a sealing position against said third sealing gasket, and the pivoting sealing rail is configured to raise the first filter panel to form the first air seal and raise the second filter panel to form the second air seal when pivoted upward into the sealing position. In certain embodiments, the filter bank further comprises a first sealing channel within the filter enclosure, and a second sealing channel within the filter enclosure, wherein the distal end of the first filter panel includes a first mounting flange vertically captured within the first sealing channel, and the distal end of the second filter panel includes a second mounting flange vertically captured within the second sealing channel. Further, the first mounting flange and the second mounting flange can be T-shaped, and the first sealing channel and the second sealing channel can be formed from C-channel. 
     In accordance with another aspect of the present invention, provided is a filter bank. The filter bank includes a filter enclosure. A first sealing channel is located within the filter enclosure. A second sealing channel is located within the filter enclosure. A first filter panel and a second filter panel are flexibly joined by a living hinge located between a proximal end of the first filter panel and a proximal end of the second filter panel. The first filter panel includes a first distal flanged end located within the first sealing channel, and the second filter panel includes a second distal flanged end located within the second sealing channel. A first sealing gasket extends along the first distal flanged end of the first filter panel and forms a first air seal within the first sealing channel. A second sealing gasket extends along the second distal flanged end of the second filter panel and forms a second air seal within the second sealing channel. A third sealing gasket extends along the living hinge and forms a third air seal within the filter enclosure. 
     The filter bank can further comprise a zigzag filter arrangement including the first filter panel, the second filter, a third filter panel, and a fourth filter panel, wherein the third filter panel and the fourth filter panel are joined by a second living hinge. The first distal flanged end of the first filter panel can be vertically captured within the first sealing channel, and the second distal flanged end of the second filter panel can be vertically captured within the second sealing channel. Further, the first distal flanged end of the first filter panel and the second distal flanged end of the second filter panel can be T-shaped, and the first sealing channel and the second sealing channel can be formed from C-channel. In certain embodiments, the filter bank further comprises a pivoting sealing rail, located beneath the living hinge, that pivots upward to form the third air seal against said third sealing gasket extending along the living hinge. Further, the pivoting sealing rail can automatically pivot upward into a sealing position against said third sealing gasket as the first distal flanged end of the first filter panel is inserted into the first sealing channel and the second distal flanged end of the second filter panel is inserted into the second sealing channel. Further still, the pivoting sealing rail can be configured to raise the first filter panel to form the first air seal and raise the second filter panel to form the second air seal when pivoted upward into the sealing position. In certain embodiments, the pivoting sealing rail can be manually pivoted upward into a sealing position against said third sealing gasket. 
     In accordance with another aspect of the present invention, provided is a filter bank. The filter bank includes a filter enclosure. A first sealing channel, a second sealing channel, a third sealing channel, and a fourth sealing channel are located within the filter enclosure. A first filter panel and a second filter panel are flexibly joined by a first living hinge located between a proximal end of the first filter panel and a proximal end of the second filter panel, wherein the first filter panel includes a first distal flanged end located within the first sealing channel, and the second filter panel includes a second distal flanged end located within the second sealing channel. A third filter panel and a fourth filter panel are flexibly joined by a second living hinge located between a proximal end of the third filter panel and a proximal end of the fourth filter panel, wherein the third filter panel includes a third distal flanged end located within the third sealing channel, and the fourth filter panel includes a fourth distal flanged end located within the fourth sealing channel. The first filter panel, the second filter panel, the third filter panel, and the fourth filter panel are arranged in a zigzag configuration and are respectively vertically captured by the first sealing channel, the second sealing channel, the third sealing channel, and the fourth sealing channel. A first sealing rail is movable within the filter enclosure between an unsealed position and a sealing position to form a first air seal against said the first living hinge. A second sealing rail is movable within the filter enclosure between an unsealed position to a sealing position to form a second air seal against the second living hinge. 
     The first sealing rail can be configured to lift the first filter panel and the second filter panel to form respective air seals with the first sealing channel and the second sealing channel, and the second sealing rail can be configured to lift the third filter panel and the fourth filter panel to form respective air seals with the third sealing channel and the fourth sealing channel. The first sealing rail can automatically pivot upward into the sealing position against the first living hinge due to insertion of the first filter panel and the second filter panel into the filter enclosure, and the second sealing rail can automatically pivot upward into a sealing position against the second living hinge due to insertion of the third filter panel and the fourth filter panel into the filter enclosure. In certain embodiments, the first distal flanged end, the second distal flanged end, the third distal flanged end, and the fourth distal flanged end are T-shaped, and the first sealing channel, the second sealing channel, the third sealing channel, and the fourth sealing channel are formed from C-channel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other aspects of the invention will become apparent to those skilled in the art to which the invention relates upon reading the following description with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a filter bank; 
         FIG. 2  is a perspective view of a filter bank; 
         FIG. 3  is a perspective view of filters; 
         FIG. 4  shows a perspective view of a filter sealing arrangement; 
         FIG. 5  shows a portion of a filter and a sealing channel for the filter; and 
         FIG. 6  shows a side view of a filter and bottom sealing rail for the filter. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates to filter banks or dust collectors for fume extraction systems. The present invention will now be described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. It is to be appreciated that the various drawings are not necessarily drawn to scale from one figure to another nor inside a given figure, and in particular that the size of the components are arbitrarily drawn for facilitating the understanding of the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It may be evident, however, that the present invention can be practiced without these specific details. Additionally, other embodiments of the invention are possible and the invention is capable of being practiced and carried out in ways other than as described. The terminology and phraseology used in describing the invention is employed for the purpose of promoting an understanding of the invention and should not be taken as limiting. 
     The filter bank discussed below employs generally flat filter panels rather than the cylindrical filter cartridges  12  shown in  FIG. 1 . Cylindrical filters can provide a high pressure drop across them during filtering, as compared to filter panels. A high pressure drop increases the power needed move air through the filters and reduces the efficiency of the fume extractor. Cylindrical filters also have a large volume and can be expensive to ship and require additional packaging material, as compared to filter panels. Filter panels can be shipped flat, whereas a cylindrical filter will include a large central void. A cylindrical filter filters air around its circumference. As can be seen in  FIG. 1 , the cylindrical filters  12  have upwardly-facing portions (e.g., between 11:00 and 1:00 positions around the circumference) that will collect dust. However, gravity does not assist in clearing such portions during pulsed air cleaning, which can result in dust falling back onto upwardly-facing portions of the cylindrical filter. The panel filters discussed below filter air through their downwardly-facing surfaces and, thus, gravity helps the filtered dust to fall away from the filters. Accordingly, panel filters can be less expensive to ship, more efficient to operate, and easier to clean than comparable cylindrical filters. 
     An example filter bank  20  employing panel filters  22  is shown in  FIG. 2 . The filter bank  20  has an outer filter enclosure  24 . The panel filters  22  are sealed within the filter enclosure  24 , such as by elastomeric gaskets on the filters, to divide the enclosure into contaminated and clean air handling portions. The filter bank  20  can include a pre-filter  26  in fluid communication with the contaminated air portions of the filter enclosure  24 . Contaminated air  14 , generated at a workstation such as a welding or plasma cutting station, is drawn or pushed through the pre-filter  26  and into the filter enclosure  24  by a blower or fan. The pre-filter  26  can include an air intake that is connected to ductwork for conveying contaminated air to the filter bank  20 . The filter bank  20  includes an air outlet  28  that may be attached to additional clean air ductwork for ventilating cleaned air  16  to a desired location. A blower or fan of the fume extraction system can be part of the filter bank  20  or located remotely from the filter bank. 
     The filter enclosure  24  can include a door (not shown) that provides access to the filters  22 . The door, or enclosure  24 , can include a gasket to seal the door against the enclosure when the door is closed. The enclosure  24  forms a lower hopper  30 . Dust and other contaminants are removed from the contaminated air by the panel filters  22  within the enclosure  24 . The dust can fall into the hopper  30  and be discharged to a receptacle  32 . The filter bank  20  can include legs  34  to raise the enclosure  24  above the ground, so that the receptacle  32  can be placed beneath the hopper  14 . 
     The filter bank  20  can include a local or remote control panel  36  having a user interface for controlling the operations of the filter bank and/or the fume extraction system. The control panel  36  can include indicators to inform a user that a filter requires cleaning or replacement (e.g., based on an increased pressure drop across a filter). The control panel  36  can also include controls for activating a filter cleaning system. The filter bank  20  can utilize blasts of compressed air to “backwash” the filters  22  and dislodge dust from the filter media. In certain embodiments, the filter bank  20  can include a compressed air tank for storing compressed air that is provided by an air compressor that is a part of the filter bank or located remote from the filter bank. Valves, such as solenoid valves for example, control the discharge of compressed air from the air tank to the filters in a series of pulses during a cleaning cycle. The filter enclosure  24  can include respective air nozzles aligned with the filters  22  to direct the air pulses in a reverse direction through the filters. 
     As can be seen in  FIG. 2 , the panel filters  22  form a zigzag filter arrangement within the filter enclosure  24 . An individual filter cartridge is formed from a number of generally flat filter panels (e.g., 2, 4, more than 4 panels, etc.)  FIG. 3  shows two filter cartridges  38 ,  40  each formed from two panel filters  22 , which are joined together along respective proximal ends  42  of the panels. The panels  22  of the filter cartridges  38 ,  40  can be square or rectangular, or other generally planar shapes if desired. The panels  22  of the filter cartridges  38 ,  40  can be hinged together, such as via a living hinge  44  formed by the filter material or some other flexible material (e.g., a paper strip, an elastomeric strip, foam gasket, etc.) located along adjacent edges of the panels. In  FIG. 3 , the living hinge  44  flexibly joins the individual filter panels  22  of each filter cartridge  38 ,  40  along the proximal ends  42  of the filter panels. When expanded or unfolded, the individual filter cartridges  38 ,  40  forming the zigzag pattern can have V-shapes, W-shapes, or other shapes as will be appreciated by one of ordinary skill in the art. 
     Individual filter cartridges  38 ,  40  can be shipped and stored in a flat state. If the filter cartridges  38 ,  40  have hinged panels  22 , the filter cartridges can be shipped and stored in a folded flat state in which the panel sections of the filter cartridge are adjacent one another. It is to be appreciated that the filter cartridges  38 ,  40  shown in  FIG. 3  will have a smaller volume when their panels  22  are folded together, as compared to an equivalent cylindrical filter. The filter cartridges  38 ,  40  can be kept in the folded state until installed in a filter bank, at which time they are unfolded along one or more hinges and expanded to increase the exposed surface area. 
     The generally flat panels  22  of the filter cartridges  38 ,  40  can have a lower pressure drop across them during filtering, as compared to an equivalent cylindrical filter. This is due to the greater open outlet area provided by the prism shapes of a zigzag filter configuration as compared to an equivalent cylindrical filter&#39;s open/exit area at one end of the cylinder. Thus, the filter cartridges discussed herein may be more efficient to operate than comparable cylindrical filters, and possibly shipped at less expense and stored more conveniently than comparable cylindrical filters. Moreover, pulsed air filter cleaning can be simplified using a zigzag configuration of filter panels. For example, with filter panels placed in a V or W shape, gravity helps filter contaminants to fall away from the filter media. 
     The filter media used in the filter cartridges  38 ,  40  can be any appropriate media for the intended application, such as cellulose, polyester, glass media, etc. The media can be pleated if desired to increase surface area. 
     The panels should be sealed within the filter bank enclosure along the edges of the panels, so that the contaminated airflow must pass through the filter media. Example sealing gaskets for sealing the filter panels  22  are shown in  FIGS. 3-6 . In certain embodiments, the distal ends  46  of the panels  22  can be flanged (e.g., T-shaped) to form distal flanged ends that are received in sealing channels  48  within the filter enclosure. Extending along the distal ends  46  of the panels  22  are one or more elastomeric sealing gaskets  50  for forming air seals within the filter enclosure. The panels  22  shown in the drawings include two sealing gaskets  50  on each distal flanged end  46 . However, the distal ends  46  can include a single sealing gasket or more than two gaskets if desired. The gaskets  50  are shown as being located on the top surface of the distal flanged ends  46  of the panels  22 . However, the gaskets could be located on other surfaces of the distal end, such as along the side or bottom surfaces of the flanged end. 
     The proximal ends  42  of the filter panels  22  can also include one or more sealing gaskets  52  extending along the living hinge  44 , for forming air seals within the filter enclosure. In certain embodiments, the living hinges  44  can have projections, such as one or more flexible flaps or wipers, that seal against the interior of the enclosure to provide the sealing gaskets. Opening or unfolding the filter panels can relax or unstretch the living hinge  44 , which can aid is sealing the hinge within the filter enclosure. 
     As noted above, the filter bank enclosure can include sealing channels  48 . The sealing channels  48  receive the distal flanged ends  46  of the filter panels  22 , and the sealing gaskets  50  seal against an interior surface of the channels. The sealing channels  48  can be formed from U or C-channel, for example, or have another appropriate shape. The sealing channels  48  can vertically capture the mounting flange of the distal ends  46  of the filter panels  22 , so that the filter panels can be hung from the channels. When installed, the filter panels  22  are slid into the sealing channels  48  (e.g., in a forward to rearward direction) and hang downward on their T-shaped flanges. The flanges on the distal ends  46  of the filter panels  22  could have various shapes suitable for being vertically captured within the sealing channels  48 , such as L-shaped or arrow shaped for example. 
     In certain embodiments, the living hinge  44  can seal directly against a lower surface of the filter enclosure. The filter enclosure could include a channel or other positioning structure, similar to the sealing channels discussed above, for properly positioning the proximal ends  42  of the filter panels  22  and creating an air seal against the sealing gaskets  52  that extend along the living hinge  44 . In the embodiments shown in the figures, the filter bank includes a sealing rail, such as a pivoting sealing rail  54 , that is located beneath the living hinge  44  and that pivots within the filter enclosure to form the air seal against the sealing gaskets  52  that extend along the living hinge  44 . The pivoting sealing rail  54  can allow the filter panels  22  to be pushed into the filter enclosure “loosely”, without the seals compressed during insertion (which could possibly damage the seals). The pivoting sealing rail  54  pivots upward into a sealing position to seal against the sealing gaskets  52  that extend along the living hinge  44 . The pivoting sealing rail  54  exerts an upward force on the filter cartridges. In certain embodiments, the pivoting sealing rail  54  also lifts the filter panels  22  so that their upper sealing gaskets  50  at the distal ends of the panels seal against the sealing channels  48 . The pivoting sealing rail  54  can pivot about a pivot member  56  as a result of the filter cartridge contacting the pivoting sealing rail, so as to automatically pivot upward into the sealing position against the sealing gaskets  52 . This will result in an automatic sealing of the filter within the filter enclosure due to insertion of the filter panels  22  into the filter enclosure. As the filter is inserted, it will contact a rear portion of the pivoting sealing rail  54 , causing it to pivot upward into the sealing position. Thus, as the distal flanged ends  46  of the filter panels  22  are inserted into the sealing channels  48 , the pivoting sealing rail  54  can automatically pivot upwards into the sealing position against the sealing gaskets  52  along the living hinge  44 . Alternatively, the pivoting sealing rail  54  can be moved manually upward into the sealing position, such as via a manually-operated lever, to seal the filter within the filter enclosure. The filter enclosure can include stops that limit the upward and downward rotation, or angle of travel, of the pivoting sealing rail  54 . The filter enclosure can also include a lock, such as a manually releasable locking tab, to hold the pivoting sealing rail  54  in the sealing position. In certain embodiments, the sealing rail does not pivot about a pivot member  56 , but translates upward and downward between the sealing position and an unsealed position. The filter enclosure can include a lifting mechanism, such as a lever or scissors-type lifting mechanism, to raise and lower the sealing rail. The upward and downward translation of the sealing rail could also include a forward-to-rearward or rearward-to-forward movement of the sealing rail, such as when moved by a pivoting lever for example. 
     The filter panels  22  are shown in the figures as being mounted within the filter enclosure  24  in a V shape, with the living hinge  44  located downward from the distal flanged ends  46 . However, the filter panels  22  could be mounted in other configurations, such as an inverted V in which the living hinge  44  is located higher within the filter enclosure  24  than the distal flanged ends  46  of the filter panels  22 . The filter panels  22  can include additional sealing gaskets if desired, such as along the front and rear faces of the panels, to seal against the filter enclosure door and rear wall for example. 
     It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.