Abstract:
A filtration system for use in a turbine flow path is provided. The filtration system includes a cartridge filter and an attachment portion coupled to the cartridge filter, the attachment portion configured to couple the cartridge filter to a tube sheet, such that the tube sheet is secured within an annular cavity defined between a first flange and a second flange extending from the attachment portion.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The field of the invention relates generally to filter assemblies for use in baghouses, and more particularly, to baghouses in industrial filtration applications. 
         [0002]    Fabric filters are commonly used to remove particulate matter from an air stream in an industrial air filtration system. For example, such filters are often used in known baghouses. At least some known baghouses include a housing that has an inlet that receives dirty, particulate-containing air, and an outlet through which clean air is discharged from the baghouse. In such baghouses, often the interior of the housing is divided, by a tube sheet, into a dirty air or upstream plenum, and a clean air or downstream plenum. Air flows through the inlet into the dirty air plenum, through the filters, and into the clean air plenum before clean air is discharged through the outlet of the clean air plenum. Known tube sheets are formed with a plurality of apertures that couple the dirty air plenum in flow communication with the clean air plenum through the filters. More specifically, in known tube sheets, each of the filter elements is mounted about a respective aperture such that at least a portion of the filter element extends through the assorted aperture. 
         [0003]    More specifically, in such baghouses, to clean dirty air, a plurality of tubular fabric filters, referred to as cartridge filters may be used. Such cartridge filters are typically mounted in a vertical or horizontal orientation within the baghouse, such that streams of a dust-laden gas to be filtered are passed through the filters prior to the gas entering the clean air plenum. 
         [0004]    Although such baghouses are commonly used, because of the different designs, manufacturing tolerances and variations, known tube sheets may be unintentionally formed with multiple-sized apertures. Because of the variation in the size of the apertures, dust leakage around the filters is possible. Moreover, depending on the aperture size there is only one sized filter to fit tube sheet apertures. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0005]    In one aspect, a filtration system for use in a turbine flow path is provided. The filtration system includes a cartridge filter and an attachment portion coupled to the cartridge filter, the attachment portion configured to couple the cartridge filter to a tube sheet, such that the tube sheet is secured within an annular cavity defined between a first flange and a second flange extending from the attachment portion. 
         [0006]    In another aspect, an attachment portion for use with a cartridge filter. The attachment portion includes a first flange extending radially outward and configured to securely couple against a first side of a tube sheet and a second flange extending radially outward and configured to securely couple against a second side of a tube sheet, the second flange spaced from the first flange such that an annular cavity is defined therebetween, the cavity sized to receive the tube sheet therein. 
         [0007]    In another aspect, method for assembling a filtration system for use with a turbine assembly is provided. The method includes providing a cartridge filter, coupling an attachment portion to the cartridge filter, wherein the attachment portion includes a cavity that is defined between a first flange and a second flange that is spaced a distance from the first flange, and coupling the attachment portion to a tube sheet within the turbine assembly, such that the tube sheet is secured in the cavity between the first and second flanges. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a schematic illustration of an exemplary filtration system that may be used with the turbine engine assembly shown in  FIG. 1 . 
           [0009]      FIG. 2  is a schematic illustration of an exemplary filter assembly that may be used with the filtration system shown in  FIG. 1 . 
           [0010]      FIG. 3  is a schematic illustration of an alternative filter assembly that may be used with the filtration system shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0011]      FIG. 1  is a schematic illustration of an exemplary filtration system  41  that is contained in air plenum or baghouse  40 .  FIGS. 2 and 3  are enlarged cross-sectional views of exemplary filter assemblies  46  that may be used with filtration system  41 . In the exemplary embodiment, baghouse  40  includes a housing  42  that includes an inlet  44  and an outlet  48  that is downstream from inlet  44 . A tube sheet  54  that extends across baghouse  40  divides baghouse  40  into a dirty air plenum  50  and a clean air plenum  52 . As used herein, the terms “dirty air” and/or “dirty gas” are defined as particulate-containing air and/or gas, and the terms “clean air” and/or “clean air” are defined as air and/or gas that has had substantially all particulate matter removed therefrom. 
         [0012]    In the exemplary embodiment, tube sheet  54  is fabricated from a heat-resistive material, such as sheet metal, and includes at least a portion that is substantially planar. The planar portion of tube sheet  54  includes a plurality of apertures  56  defined therein. In the exemplary embodiment, tube sheet  54  is positioned against the inner walls of the outer periphery of baghouse  40  such that apertures  56  are the only locations within baghouse  40  that couple the dirty air plenum  50  and the clean air plenum together in flow communication. In the exemplary embodiment, apertures  56  are substantially evenly spaced across tube sheet  54 . Alternatively, apertures  56  can have any spacing and/or orientation that allows baghouse  40  to function as described herein. 
         [0013]    Each filter assembly  46  is coupled to tube sheet  54  such that each assembly is adjacent to a respective aperture  56 . More specifically, each filter assembly  46  is coupled against tube sheet  54  such that each assembly  46  extends at least partially through a respective aperture  56 . As such, in the exemplary embodiment, each filter assembly  46  is positioned against both a dirty air side  57  and a clean air side  58  of tube sheet  54  as described in more detail below. Moreover, when fully assembled, dirty gas plenum  50  is substantially isolated from clean gas plenum  52  other than being coupled in flow communication via apertures  56 . Although, filter assemblies  46  are illustrated as being vertically oriented, it should be noted that tube sheet  54  and filter assemblies  46  can be mounted in any relative orientation that enables baghouse  40  to function as described herein. 
         [0014]    In the exemplary embodiment, each filter assembly  46  includes an attachment portion  100  that is coupled to a cartridge filter  110 . More specifically, in the exemplary embodiment, each cartridge filter  110  at least substantially circumscribes attachment portion  100 . In one embodiment, cartridge filter  110  is potted in attachment portion  100  Cartridge filters  110  may be constructed of any material that enables a desired level of filtering to be satisfied based on the operating conditions of baghouse  40 . For example, filter  110  may be fabricated from materials such as, but not limited to polyester, polypropylene, aramid, acrylic, fiberglass, and ePTFE. 
         [0015]    Each attachment portion  100  includes a plurality of tube sheet flanges  104  that extend outward from attachment portion base  106 . In the exemplary embodiment, flanges  104  are oriented such that a cavity  108  is defined between flanges  104 . Cavity  108 , as described in more detail below, is sized and shaped to receive tube sheet  54  therein. Tube sheet flanges  104  each include a substantially planar surface  114  and a substantially tapered surface  112 . Tapered surface  112  facilitates attachment portion  100  being inserted into tube sheet  54 . Attachment portion  100  may be fabricated from materials that are substantially impervious to air and fluid, such as, but not limited to epoxy, silicone, and urethane, etc. 
         [0016]    In the exemplary embodiment, attachment portion  100  is bonded to filter  110  via a molding process in which filter  110  is securely coupled to attachment portion  100 . In such an embodiment, as attachment portion  100  cures, filter  110  is chemically bonded to attachment portion  100 . In an alternative embodiment, cartridge filter  110  is securely coupled to attachment portion  100  via a welding process, such as a sonic welding process. In another embodiment, cartridge filter  110  is securely coupled to attachment portion  100  via an adhesive process. Alternatively, any other bonding technique can be used to securely couple cartridge filter  110  to attachment portion  100 . 
         [0017]    Referring specifically to  FIG. 2 , in the exemplary embodiment, attachment portion base  106  is fabricated with a concave cross-sectional profile that extends from cartridge filter  110 . In such an embodiment, each tube sheet flange  104  has a different diameter than the other tube sheet flanges  104 . In the exemplary embodiment, the diameter of each tube sheet flange  104  progressively decreases in size from the cartridge filter  110  outward towards portion base  106 . Fabricating attachment portion  100  to include tube sheet flanges  104  that decrease in diameter enables filter assembly  46  to be pushed upward into tube sheet  54  until a desired fit is achieved. 
         [0018]    Referring specifically to  FIG. 3 , in the exemplary embodiment, attachment portion base  106  is fabricated with a convex cross-sectional profile that extends from cartridge filter  110 . In such an embodiment, each tube sheet flange  104  has a different diameter than the other tube sheet flanges  104 . In the exemplary embodiment, the diameter of each tube sheet flange  104  progressively increases in size from the cartridge filter  110  outward towards portion base  106 . Fabricating attachment portion  100  to include tube sheet flanges  104  that progressively increase in diameter enables filter assembly  46  to be pulled upward into tube sheet  54  until a desired fit is achieved. 
         [0019]    In the exemplary embodiment, filter  110  is formed with a tubular orientation that has a substantially circular cross-sectional profile to be perpendicular to central axis A. Alternatively, filter media  110  may be formed in any shape or configuration that enables assemblies  46  to function as described herein. Filter media  110  may include any filter that enables assemblies  46  to function as described herein such as a bag filter. Filter assemblies  46  may be fabricated in any form from any filter media that enables filter assembly  41  to function as described herein, including but not limited to, circle, ellipse, and polygons, etc. Moreover, filter assemblies  46  may be formed with any desired length L that enables desired filtering requirements of baghouse  40  to be satisfied. 
         [0020]    When filter assembly  46  is inserted into tube sheet  54 , tapered surface  112  of flange  104  facilitates attachment portion  100  being inserted into tube sheet  54  in a snap-fit configuration. In the exemplary embodiment, tube sheet  54  is seated in cavity  108  such that an outer periphery of each aperture  56  is in sealing contact with attachment portion  100 . Moreover, when tube sheet  54  is seated in cavity  108  tube sheet flange surfaces  110  and  112  are each coupled against tube sheet  54  in a friction fit such that sealing contact is made between flange surface  114  and tube sheet  54 , and between flange surface  112  and tube sheet  54 . In the exemplary embodiment, flanges  104  facilitate attachment portion  100  self-centering filter assembly  46  within tube sheet  54 . 
         [0021]    During operation, particulate-laden gas flow D enters inlet  44 , and clean gas flow C is discharged through outlet  48  towards turbine engine inlet  30  (shown in  FIG. 1 ). More specifically, particulate-laden flow D is filtered by assemblies  46  positioned within baghouse  40  and clean flow C exits through baghouse outlet  48 . Dirty gas plenum  50  is substantially sealed from clean gas plenum  52  with filter assembly  46  such that flow communication therebetween is substantially prevented between dirty gas plenum  50  and clean gas plenum  52  except through assemblies  46 . Tube sheet flanges  104  and  106  supports filter assembly  46  as the filter assembly  46  is suspended from tube sheet  54  as flow moves through filter assembly  46  during operation of baghouse  40 . 
         [0022]    The above described methods and systems provide a cost-effective filter assembly that can accommodate the aperture size variations found in baghouse tube sheets. The above described filter assemblies provide effective sealing of varying sized apertures within tube sheets, such that dust leakage around the filters is substantially prevented regardless of the size of the tube sheet apertures. The use of the above described filter assemblies also decreases the need to reject an entire set of cartridge filters that may be improperly sized to fit tube sheet apertures. 
         [0023]    Exemplary embodiments of filter assembly for a baghouse or gas turbine inlet filtration system are described above in detail. The methods and systems are not limited to the specific embodiments described herein, but rather, components of systems and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein. For example, the methods may also be used in combination with other filtration systems and methods, and are not limited to practice with only the turbine systems and methods as described herein. Rather, the exemplary embodiment can be implemented and utilized in connection with many other filtration or sealing applications such as but not limited to cement kilns, cement transfer stations, asphalt plants, foundries, lime kilns, coal fired power plant baghouses, fly ash handling, bin vents, wood processing dust collectors, spray driers, aluminum ore processing, steel mills, and food processing plants. 
         [0024]    Although specific features of various embodiments of the invention may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the invention, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.