Abstract:
A fluid filter system including a cartridge filter housed in a tank having a standpipe extending from a bottom surface of the tank. The cartridge filter is positioned in the tank with the standpipe extending into an outlet tube in the filter. Fluids flow into the tank, through the filter, and out through the standpipe. The cartridge filter may include a seal in an upper portion of the filter for sealing the cartridge filter to the standpipe in a position that is above the contaminant laden fluids and debris that collect at the bottom of a tank during removal of a cartridge filter.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention is directed generally to fluid filters, and more particularly to fluid filters having replaceable filters.  
       BACKGROUND  
       [0002]     There exists numerous conventional fluid filters for removing contaminants, such as shown in U.S. Pat. Nos. 3,720,322 and 4,187,179. One particular style of fluid filter, such as those used in drinking water and pool cleaning systems, includes a generally cylindrical tank housing a removable cartridge filter, as shown in U.S. Pat. Nos. 4,561,979 and 5,316,677. The cartridge filter is formed from a filter media positioned between bottom and top plates. Fluids are filtered by passing the fluids into the tank, passing the fluids through the filter media, and expelling the filtered fluids through an outlet tube in the cartridge filter. Typically, the tanks include standpipes generally along longitudinal axes of the tanks. The standpipes prevent contaminant laden fluid from passing into the downstream portion of the systems containing the filtered fluids. Instead, the standpipes cause the contaminant laden fluids to collect in the filter media and surrounding space in the tanks.  
         [0003]     Typically, cartridge filters include seals in bottom portions of the filter to seal the cartridge filter to the standpipe. In this arrangement, the cartridge filter is sealed proximate to a bottom floor of the tank. After a filter system having this configuration is operated, the cartridge filter may be removed to be serviced, cleaned, or replaced by first removing a cover from the top of the tank. Typically, the cover is maintained in contact with the cartridge filter during operation to keep the filter sealed to the standpipe. Once the cover has been removed, the filter may be withdrawn. Withdrawing the cartridge filter leaves contaminant laden fluid together with all the debris filtered from fluid in the tank and in contact with the standpipe at the point where the cartridge filter is sealed to the standpipe. To insure that a seal is made between the outlet tube of the cartridge filter and the standpipe when the cartridge filter is reinstalled, the containment laden fluid and debris must be removed from the tank. In addition, the outer surface of the standpipe must be cleaned by a service personnel reaching into the tank and wiping the standpipe. Many times, accessing the lower portions of the standpipe can be very difficult and time consuming. Thus, a need exists for a fluid filter system having a more efficient system for replacing cartridge filters.  
       SUMMARY OF THE INVENTION  
       [0004]     This invention relates to a filter system for removing contaminants from a contaminant laden fluid and for reducing the amount of time necessary to perform cleaning operations to remove and replace a cartridge filter. The filter system includes a tank having an opening for receiving a cartridge, a cover attached to the tank to seal the opening, and a standpipe extending from a bottom surface of the tank towards the cover. The filter system also includes a cartridge filter configured to fit in the tank. The cartridge filter may include filter media between bottom and top surfaces of the filter and an outlet tube extending from the bottom surface toward the top surface. The cartridge filter may also include at least one seal positioned in the outlet tube in closer proximity to the top surface than to the bottom surface of the filter and in contact with the standpipe. The seal forms a seal between the outlet tube of the cartridge filter and the standpipe enabling filtered fluid to be passed through the standpipe and eventually out of the filter system without contacting the contaminant laden fluid.  
         [0005]     The seal positioned in the cartridge filter enables the cartridge filter to be attached to the standpipe and to form a seal with the standpipe proximate to the top of the tank. By sealing the standpipe to the cartridge filter above the bottom surface of the tank, the portion of the standpipe to which the seal contacts is not contacted by contaminant laden fluid when a cartridge filter is removed from the tank. Thus, this configuration advantageously eliminates the need to remove contaminated water contained in the tank once the cartridge filter has been removed and the need to clean the outside surface of the standpipe. In the rare event that the standpipe needs to be cleaned, the portion of the standpipe to which the seal in the cartridge filter contacts to form a seal is proximate to the top of the tank where it is easily accessible and does not require someone to reach into the bottom portions of the tank to clean the standpipe. These and other embodiments and advantages are described below. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     The accompanying drawings, which are incorporated in and form a part of the specification, illustrate embodiments of the presently disclosed invention and, together with the description, disclose the principles of the invention.  
         [0007]      FIG. 1  is an exploded perspective view of a filter system having aspects of this invention.  
         [0008]      FIG. 2  is an assembled front view of the filter system shown in  FIG. 1 .  
         [0009]      FIG. 3  is a cross-sectional view taken along section line  3 - 3  in  FIG. 1 .  
         [0010]      FIG. 4  is a detailed cross-sectional view of detail  4  shown in  FIG. 3 .  
         [0011]      FIG. 5  is a detailed cross-sectional view of detail  5  shown in  FIG. 3 .  
         [0012]      FIG. 6  is a partial cross-sectional view taken along section line  3 - 3  in  FIG. 1  with the cartridge filter removed.  
         [0013]      FIG. 7  is a perspective view of a standpipe assembly of the filter system.  
         [0014]      FIG. 8  is a cross-sectional view of a cartridge filter taken along section line  3 - 3  in  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]     As shown in  FIGS. 1-8 , this invention is directed to a filter system  10  having a cartridge filter  11  with an improved sealing mechanism  2  for sealing the cartridge filter  11  to a standpipe  39  of a standpipe assembly  35 . The sealing mechanism  2  may be located proximate to a cover  14  of the filter system  10  so that the portion of the standpipe  39  that contacts the seal assembly  2  is not in contact with contaminant laden fluid when the cartridge filter  11  is removed from the filter system  10 . The filter system  10  enables a cartridge filter  11  to be removed and reinstalled from the filter system  10  more easily and in less time than conventional cartridge filters.  
         [0016]     As shown in  FIG. 1 , the filter system  10  includes a generally hollow tank  12  having an opening  3  for receiving a cartridge filter  11 . A cover  14  may seal the opening  3 , and, as shown in  FIG. 2 , may be releasably attached to the tank  12  using any releasable mechanism, such as clamp band  13 . The cover  14  may include a flange  20  that forms a seal with opposing sealing flange  18  on the tank  12  and a seal  15 , which may be an o-ring seal, positioned between the flanges  18 ,  20 , as shown in  FIG. 4 . The cover  14  may include one or more ports  21 , as shown in  FIG. 1 , for use with condition detection devices, such as, but not limited to, a pressure relief valve, a pressure gauge, or other appropriate device. When the cover  14  is attached to the tank  12 , as shown in  FIG. 3 , the cover  14  need not contact the cartridge filter  11  to keep the cartridge filter  11  in place. Instead, the internal portions of the tank  12  are pressurized during operation, which keeps the cartridge filter  11  in place and the sealing mechanism  2  secure. A continuous gap may exist between a top surface  41  of the cartridge filter  11  and the cover  14 .  
         [0017]     As shown in  FIG. 1 , the tank  12  may include a base  16  and may also be generally cylindrical, or other appropriate shape. In at least one embodiment, the tank  12  may be supported and electrically grounded by legs  19 . The tank  12  may be divided into two regions, a cartridge receiving region  30 , and a ultraviolet (UV) treatment region  31 , as shown in  FIG. 6 . The UV treatment region  31  includes a UV lamp  22  for imparting UV light to fluids flowing through the filter system  10  to kill living organisms that may be found in the fluids, as shown in  FIG. 1 . The UV lamp  22  may be removably coupled to the tank  12  by inserting the UV lamp  22  through a coupling  26  and into a sleeve  25 , which may be a quartz sleeve, as shown in  FIG. 5 . The UV lamp  22  may be further held in position using a hex reducer bushing  24  and a UV adapter  23  to prevent the sleeve  25  from moving due to internal pressure in the tank  12 . The adapter  23  holds the sleeve  25  in place and enables the UV lamp  22  to be easily inserted into the sleeve  25 . The UV treatment region  31  may be strengthened with a rib  36 , and may include a baffle  37  for directing flow away from outlet port  40  to assure maximum residence time of fluid in the UV treatment region  31 , as shown in  FIG. 7 .  
         [0018]     The cartridge receiving region  30  includes at least one inlet  17  for receiving unprocessed fluids and may include a standpipe assembly with a standpipe  39 , otherwise referred to as an outlet tube  43 . A baffle  33 , as shown in  FIGS. 6 and 7 , may be positioned proximate to the inlet  17  for diverting the incoming fluid. The standpipe  39  may extend from a bottom surface  34  of the cartridge receiving region  30 , as shown in  FIG. 6 . In at least one embodiment, the standpipe  39  is positioned at the center of the cartridge receiving region  30  and extends generally along a longitudinal axis  50  of the tank  12  to a point in close proximity with the cover  14 . The standpipe  3  provides a fluid flow pathway between the cartridge receiving region  30  and the UV treatment region  31 . An outlet  40 , as shown in  FIGS. 3 and 6 , is located in the UV treatment region  31  enabling treated fluid to be expelled from the filter system  10 .  
         [0019]     As shown in  FIGS. 3 and 8 , the filter system  10  may also include a cartridge filter  11  configured to fit into the tank  12 . The cartridge filter  11  may include an outlet tube  43  adapted to be sealed to the standpipe  39  at a point proximate to the standpipe  39  using sealing mechanism  2 . The cartridge filter  11  may include a top  41 , a bottom  42 , and at least one layer of filter media  45  positioned between the top  41  and the bottom  42 . The filter media  45  may be attached to the top  41  and the bottom  42  with an adhesive (not shown), such as a potting adhesive. In at least one embodiment, the cartridge filter  11  may include three layers of filter media,  45 ,  46 , and  47  as shown in  FIG. 8 , positioned concentrically around the outlet tube  43  and forming a generally cylindrical filter. In at least one embodiment, the outlet tube  43  may be referred to as a central core and positioned along a longitudinal axis  51  of the cartridge filter  11 .  
         [0020]     A sealing mechanism  2  may be positioned in the cartridge filter  11  for sealing the central core to the standpipe  39 . The sealing mechanism  2  may be in closer proximity to the top  41  than to the bottom  42 , such as between a midpoint of the standpipe  39  and an open end of the standpipe  39  at the top of the tank  12 . In at least one embodiment, the sealing mechanism  2  may be positioned in close proximity to the top  41 , as shown in  FIG. 8 . The sealing mechanism  2  may include one or more seals  44 , such as, but not limited to, o-rings or other appropriate seals. In at least one embodiment, as shown in  FIGS. 3 and 8 , the sealing mechanism  2  may be formed from two o-rings  44 . The seals  44  may be positioned in one or more recesses in the side wall forming the outlet tube  43 . A fluid collection tube  49  may be positioned between the top  41  and the central core  43  for directing the flow of water into the central core  43 . In at least one embodiment, as shown in  FIG. 3 , the fluid collection tube  49  includes a plurality of holes  48  having cross-sectional areas that are larger than cross-sectional areas of the central core.  
         [0021]     During use, a cartridge filter  11  may be inserted through the opening  3  into the tank  12 . As the cartridge filter  11  is inserted into the tank  12 , the standpipe  39  may be directed to be inserted into the outlet tube  43 . The standpipe  39  contacts the sealing mechanism  2  and forms a seal between the standpipe  39  and the cartridge filter  11 . The cover  14  may then be installed by placing the cover  14  on the opening  3  in the tank  12 . As the cover  14  is installed, the cover  14  need not make contact with the cartridge filter  11  to keep the cartridge filter  11  in place during operation. The clamp band  13  may be installed around the cover  14  and tightened to secure the cover  14  to the tank  12 .  
         [0022]     Fluids having various contaminants may be circulated through the filter system  10  by first entering the inlet  17  and flowing through the filter media  45 . Contaminants are removed by the filter media  45  as the fluid flows through the filter media  45 . The fluids travel through the filter media  45  to the fluid collection tube  49 . The fluids pass through the openings in the fluid collection tube  49  and flow into standpipe  39 . The fluids then flow down through the standpipe  39  and may be discharged from the filter system  10  in some embodiments or, in other embodiments, may be expelled into the UV treatment region  31 . Fluids discharged into the UV treatment region  31  may be subjected to UV light to further sterilize remaining living organisms that may be contained in the fluid.  
         [0023]     After time, the cartridge filter  11  may need to be removed to be cleaned or replaced. The cartridge filter  11  may be removed by relieving the pressure on the filter system  10  and removing the cover  14 . Once, the cover  14  has been removed, the cartridge filter  11  may be pulled from the tank  12 . As the cartridge filter  11  is pulled from the tank  12 , the contaminant laden fluids collect in the bottom of the tank  12 ; however, the fluids are not in contact with the portion of the standpipe  39  to which the sealing mechanism  2  of the cartridge filter  11  contacts and forms a seal. Thus, the standpipe  39  need not be cleaned when a new cartridge filter  11  or a previously used cartridge filter  11  is inserted into the tank  12 . Rather, the cartridge filter  11  may be placed into the tank  12  and the sealing mechanism  2  may form a seal without requiring any maintenance be performed on the standpipe  39 . The cover  14  may be installed on the top of the tank  12  and the filter system  10  may be operated once again.  
         [0024]     The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of this invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of this invention.