Abstract:
A bag filter extender that comprises a quadrilateral tube is provided. The bag filter extender is configured to allow longer bag filter assemblies to be utilized in a holding frame.

Description:
BACKGROUND 
       [0001]    1. Field of the Disclosure 
         [0002]    Embodiments of the present disclosure generally relate to a bag filter extender. 
         [0003]    2. Description of the Related Art 
         [0004]    An air filtration system enhances air quality by removing impurities, such as dust, pollen, mold, and bacteria, from the air. The air filtration system has a holding frame for mounting a bag filter assembly. The bag filter assembly has a filter frame for supporting one or more filter bags comprised of a media configured to remove air impurities. As air flows into the bag filter assembly and through the filter bags, the air impurities are captured by the filter bag media. 
         [0005]    Since existing holding frames are permanently installed in a larger surrounding structure, such as an air duct of a building ventilation system, the bag filter assembly is designed to be easily removed from the holding frame when needed for replacement. Specifically, the filter frame of the bag filter assembly is releasably coupled to the holding frame. When installed, the filter frame of the bag filter assembly is coupled to the front end of the holding frame such that the filter bags extend through and out of the back end of the holding frame. 
         [0006]    Deeper bag filter assemblies have a larger surface area for filtering out air impurities, which increases the service life and reduces energy consumption. However, the depth or length of the bag filter assembly is limited to the space available behind the holding frame since the filter bags extend out of the back end of the holding frame. For example, the back end of the holding frame may be located close to a wall or a bend in an air duct, which can obstruct the filter bags extending out of the back end of the holding frame. Moving an existing, permanently installed holding frame so that a longer bag filter can be used is impractical and expensive. Thus, the efficiency of existing air filtration systems can be limited depending on the location of the holding frame. 
         [0007]    Therefore, there is a need for apparatus and methods for allowing use of longer bag filter assemblies with existing holding frames of air filtration systems. 
       SUMMARY 
       [0008]    A bag filter extender comprising a quadrilateral tube having a centerline extending from a first open end to a second open end, the quadrilateral tube having a width at the first open end within a range of about 293 mm to about 598 mm and a depth within a range of about 278 mm to about 328 mm. The quadrilateral tube comprising an inner shoulder formed at the first open end and an outer shoulder formed at the second open end, wherein the inner and outer shoulders are parallel to each other and perpendicular to the centerline of the quadrilateral tube, and wherein an outer perimeter of the inner shoulder is substantially equal to or less than a size of an outer perimeter of a holding frame. 
         [0009]    A method for reconfiguring a filtration system configured for use with a longer bag filter assembly comprising installing one open end of a bag filter extender in a holding frame, the bag filter extender having an opposite open end configured to accept a bag filter assembly. The method further comprising removing a first bag filter assembly from the holding frame, the first bag filter assembly having a filter media of a first length. The method further comprising installing a second bag filter assembly in the opposite open end of the bag filter extender, the second bag filter assembly bag filter assembly having a filter media of a second length that is greater than the first length of the filter media of the first bag filter assembly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    So that the manner in which the above recited features can be understood in detail, a more particular description of the embodiments briefly summarized above may be had by reference to the embodiments below, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments and are therefore not to be considered limiting of its scope, for the embodiments may admit to other equally effective embodiments. 
           [0011]      FIG. 1  illustrates a front perspective view of a bag filter extender, according to one embodiment disclosed herein. 
           [0012]      FIG. 2  illustrates a rear perspective view of the bag filter extender, according to one embodiment disclosed herein. 
           [0013]      FIG. 3  illustrates a front perspective exploded view of a bag filter assembly, the bag filter extender, and a holding frame, according to one embodiment disclosed herein. 
           [0014]      FIG. 4  illustrates a vertical sectional view of the bag filter assembly, the bag filter extender, and the holding frame, according to one embodiment disclosed herein. 
           [0015]      FIG. 5A  illustrates a side sectional view of the bag filter assembly, the bag filter extender, and the holding frame, according to one embodiment disclosed herein. 
           [0016]      FIG. 5B  illustrates an enlarged view of a portion of the side sectional view of the bag filter assembly, the bag filter extender, and the holding frame, according to one embodiment disclosed herein. 
           [0017]      FIG. 6  illustrates a horizontal sectional view the bag filter assembly, the bag filter extender, and the holding frame, according to one embodiment disclosed herein. 
           [0018]      FIG. 7A  illustrates a top sectional view of the bag filter assembly, the bag filter extender, and the holding frame, according to one embodiment disclosed herein. 
           [0019]      FIG. 7B  illustrates an enlarged view of a portion of the top sectional view of the bag filter assembly, the bag filter extender, and the holding frame, according to one embodiment disclosed herein. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]      FIGS. 1 and 2  illustrate front and rear perspective views, respectively, of a bag filter extender  100 , according to one embodiment disclosed herein. As illustrated, the extender  100  has four sides including an upper panel  10 A, a lower panel  10 B, a right side panel  20 A, and a left side panel  20 B. The upper and lower panels  10 A,  10 B have a width A within a range of about 293 mm to about 598 mm, and a depth C within a range of about 278 mm to about 328 mm. The right and left side panels  20 A,  20 B have a height B within a range of about 293 mm to about 598 mm, and substantially the same depth C. The width A and height B are selected to accommodate a bag filter assembly while engaging a holding frame, while not interfering with neighboring holding frames. 
         [0021]    The panels  10 A,  10 B,  20 A,  20 B are coupled together, such as by welded, riveted, and/or threaded connections, to form a substantially square or rectangular shaped tubular structure (e.g. a quadrilateral tube) with front (first) open end, a back (second) open end, and an open interior disposed between the front and back open ends into which a bag filter assembly can be inserted. The right and left side panels  20 A,  20 B have outer edge surfaces  21  that contact corresponding outer edge surfaces  22  of the top and bottom panels  10 A,  10 B, through which one or more rivets can be placed on the exterior of the extender  100  to connect the panels  10 A,  10 B,  20 A,  20 B together, thereby leaving a substantially flush open interior surface of the extender  100  through which a bag filter assembly can be inserted without obstruction. Alternatively, the panels  10 A,  10 B,  20 A,  20 B may be an integral single piece member. The panels  10 A,  10 B,  20 A,  20 B can be formed from materials such as galvanized steel, aluminum, wood product, glass-reinforced plastic, plastic, or any other material sufficient to structurally support a bag filter assembly. 
         [0022]    The front sides of the panels  10 A,  10 B,  20 A,  20 B form an inner shoulder  15  and an outer lip portion  16  circumscribing the inner shoulder  15  for supporting the front end of a bag filter assembly. The inner shoulder  15  has a width T 1  (referenced in  FIGS. 5B and 7B ) within a range of about 10 mm to about 15 mm. The inner shoulder  15  is substantially perpendicular to the centerline of the extender  100 , and is substantially equidistant from the top, bottom, right, and left sides of the extender  100 . 
         [0023]    The rear sides of the panels  10 A,  10 B,  20 A,  20 B form an outer shoulder  25  for inserting into a holding frame. The outer shoulder  25  has a width T 2  (referenced in  FIGS. 5B and 7B ) within a range of about 10 mm to about 15 mm. The outer shoulder  25  is substantially perpendicular to the centerline of the extender  100 , and is substantially equidistant from the top, bottom, right, and left sides of the extender  100 . The outer shoulder  25  and the inner shoulder  25  are substantially parallel to each other. The extender  100  is configured to couple a bag filter assembly to a holding frame as further illustrated in  FIG. 3 . 
         [0024]      FIG. 3  is a front perspective exploded view of an air filtration system comprising a bag filter assembly  200 , the bag filter extender  100 , and a holding frame  300 , according to one embodiment disclosed herein. The bag filter assembly  200  includes a filter frame  210  and a filter media  220  in the form of a plurality of individual filter bags with the open ends of the individual filter bags coupled to the filter frame  210 . The filter frame  210  also includes a plurality of openings  230  through which air can flow and be directed into the interior of the filter media  220 . Air impurities are captured by the filter media  220  to clean the air flowing through the bag filter assembly  200 . The filter media  220  may be formed out of glass, polymer fibers, and/or any other similar type of filtering media. The bag filter assembly  200  includes a width within a range of about 280 mm to about 600 mm, a height within a range of about 280 mm to about 900 mm, and a depth of about 280 mm to about 900 mm. The bag filter assembly  200  may alternatively have other sizes. 
         [0025]    The holding frame  300  has four sides including an upper panel  310 A, a lower panel  310 B, a right side panel  320 A, and a left side panel  320 B. The panels  310 A,  310 B,  320 A,  320 B are coupled together, such as by welded, riveted, and/or threaded connections, to form a substantially square or rectangular shaped tubular structure (e.g. a quadrilateral tube) with an open interior into which the extender  100  can be inserted. The panels  310 A,  310 B,  320 A,  320 B may alternatively be an integral single piece member. The panels  310 A,  310 B,  320 A,  320 B can be formed from materials such as galvanized steel, aluminum, wood product, glass-reinforced plastic, plastic, or any other material sufficient to structurally support the extender  100 . The rear sides of the panels  310 A,  310 B,  320 A,  320 B form an inner shoulder  325  for supporting the rear end of the extender  100 . The holding frame  300  also includes one or more attachment members  330 , such as spring clips, that are configured to securely attach the extender  100  to the holding frame  300 . 
         [0026]    The bag filter assembly  200  is inserted into the front end of the extender  100  such that the filter media  220  extends through the interior of the extender  100 . An outer shoulder  215  of the filter frame  210  contacts the inner shoulder  15  of the extender  100 , which prevents the bag filter assembly  200  from being inserted entirely through the extender  100 . Similarly, the extender  100  with the bag filter assembly  200  is inserted into the front end of the holding frame  300  such that the filter media  220  extends through the interior of the holding frame  300 . The outer shoulder  25  of the extender  100  contacts the inner shoulder  325  of the holding frame  300 , which prevents the extender  100  from being inserted entirely through the holding frame  300 . The extender  100  can be attached to the holding frame  300  using the attachment members  330 . Similar or different types of attachment members can be used to attach the bag filter assembly  200  to the extender  100 . 
         [0027]      FIG. 4  illustrates a vertical sectional view of the bag filter assembly  200 , the extender  100 , and the holding frame  300 , according to one embodiment disclosed herein. As illustrated, the inner shoulder  15  at the front ends of the top and bottom panels  10 A,  10 B may form part of a substantially L-shaped configuration. The outer shoulder  25  at the rear ends of the top and bottom panels  10 A,  10 B may form part of a substantially J-shaped configuration. The interior edge  17  of the inner shoulder  15  and the interior edge  27  of the outer shoulder  25  of the top and bottom panels  10 A,  10 B are formed by bending the top and bottom panels  10 A,  10 B so that the interior edges  17 ,  27  are curved and have no sharp edges to prevent damage, such as tearing, of the filter media  220  when inserted into the extender  100 . 
         [0028]      FIG. 5A  illustrates a side sectional view of the bag filter assembly  200  inserted into the extender  100  and the holding frame  300 , as well as the extender  100  inserted into the holding frame  300 , according to one embodiment disclosed herein. As illustrated, the filter media  220  extends a shortened distance X, such as about 12 inches, from the rear of the holding frame  300  by using the extender  100 . Normally, without the use of the extender  100 , the filter frame  210  is supported within the holding frame  300  such that the entire length Y, such as about  22  inches, of the filter media  220  extends out from the rear of the holding frame  300 . The extender  100  provides the advantage of using longer bag filter assemblies  200  (which have deeper filter bags with greater surface areas for filtering out air impurities, thereby increasing dust holding capacity for longer service life, as well as lowering pressure drop for lower energy consumption), while maintaining or even reducing the distance that the filter media  220  extends out from the rear end of the holding frame  300  when space behind the holding frame  300  is limited. 
         [0029]      FIG. 5B  illustrates an enlarged view of a portion of the side sectional view of the bag filter assembly  200 , the extender  100 , and the holding frame  300 , according to one embodiment disclosed herein. As illustrated, the outer shoulder  215  of the filter frame  210  is in contact with the inner shoulder  15  of the extender  100 . The outer lip portion  16  surrounds the filter frame  210 . The outer perimeter of the outer lip portion  16  is substantially equal to or less than the outer perimeter of the holding frame  300 . The inner shoulder  15  at the front end of the top panel  10 A may be part of a substantially L-shaped configuration. The interior edge  17  of the inner shoulder  15  has a curved bend to prevent damaging of the filter media  220  when being inserted into the extender  100 . As further illustrated in  FIG. 5B , the outer shoulder  25  of the extender  100  is in contact with the inner shoulder  325  of the holding frame  300 . The outer shoulder  25  at the rear end of the top panel  10 A may form part of a substantially J-shaped configuration. The interior edge  27  of the outer shoulder  25  has a curved bend to prevent damaging of the filter media  220  when being inserted into the extender  100 . 
         [0030]      FIG. 6  illustrates a horizontal sectional view of the bag filter assembly  200 , the extender  100 , and the holding frame  300 , according to one embodiment disclosed herein. As illustrated, the inner shoulder  15  at the front ends of the right and left side panels  20 A,  20 B may form part of a substantially L-shaped configuration. The outer shoulder  25  at the rear ends of the right and left side panels  20 A,  20 B also may form part of a substantially L-shaped configuration. The interior edge  17  of the inner shoulder  15  and the interior edge  27  of the outer shoulder  25  of the right and left side panels  20 A,  20 B are formed by bending the right and left side panels  20 A,  20 B so that the interior edges  17 ,  27  are curved and have no sharp edges to prevent damage, such as tearing, of the filter media  220  when inserted into the extender  100 . 
         [0031]      FIGS. 7A and 7B  illustrate a side sectional view of the bag filter assembly  200  inserted into the extender  100  and the holding frame  300 , as well as the extender  100  inserted into the holding frame  300 , according to one embodiment disclosed herein. As illustrated, the outer shoulder  215  of the filter frame  210  is in contact with the inner shoulder  15  of the extender  100 . The outer lip portion  16  surrounds the filter frame  210 . The outer lip portion  16  surrounds the filter frame  210 . The outer perimeter of the outer lip portion  16  is substantially equal to or less than the outer perimeter of the holding frame  300 . The inner shoulder  15  at the front end of the left side panel  20 B may form part of a substantially L-shaped configuration. The interior edge  17  of the inner shoulder  15  has a curved bend to prevent damaging of the filter media  220  when being inserted into the extender  100 . As further illustrated in  FIG. 7B , the outer shoulder  25  of the extender  100  is in contact with the inner shoulder  325  of the holding frame  300 . The outer shoulder  25  at the rear end of the left side panel  20 B may form part of a substantially L-shaped configuration. The interior edge  27  of the outer shoulder  25  has a curved bend to prevent damaging of the filter media  220  when being inserted into the extender  100 . 
         [0032]    In one embodiment, the holding frame  300  may be permanently installed in a larger surrounding structure (an air duct of a building ventilation system for example) such that the space available behind the holding frame  300  is limited. Longer bag filter assemblies have a larger surface area for filtering out air impurities, which increases dust holding capacity for longer service life, as well as lowers pressure drop for lower energy consumption. The length of the bag filter assembly  200 , however, is limited to the space available behind the holding frame  300 , since the bag filter assembly  200  is normally coupled directly to the holding frame  300  such that substantially the entire length of the filter media  220  extends out of the back end of the holding frame  300 . 
         [0033]    The extender  100  enables longer bag filter assemblies  200  to be used on existing holding frames  300  where space available behind the holding frame  300  is limited, without having to move the holding frame  300 . The extender  100  is coupled to the holding frame  300  and positions the front end of the bag filter assembly  200  at a location ahead of the holding frame  300  to maintain or reduce the length of the bag filter assembly  200  that extends out of the back end of the holding frame  300 . The extender  100  is easily coupled to and uncoupled from the holding frame  300  using the attachment members  330 , and the bag filter assembly  200  is easily coupled to and uncoupled from the extender  100  in a similar manner. 
         [0034]    While the foregoing is directed to certain embodiments, other and further embodiments may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.