Abstract:
An inline backwash, flushing filter assembly comprising a header assembly, a rotatable valve assembly, and a filter element assembly disposed within a filter housing assembly. In operation, the controller moves the turn knob of the rotatable valve assembly a one-quarter turn which results in the reversal of fluid flow through the assembly to periodically back flush the filter utilizing fluid from the system inlet. Debris removed from the filter element during the backwash process are immediately discharged from the system through a drain port. Simultaneously, the hydraulic shearing mechanism of the backwash process dislodges and drains debris which may have accumulated on the screen and at the bottom of the lower filter assembly during normal filter operations. The controller then returns the filter assembly to filtration operation by a reverse one-quarter turn of the turn knob of the rotatable valve assembly.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/728,479, filed on Dec. 5, 2003, the disclosure of which is incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   1. Technical Field 
   The present invention relates to an apparatus and method for improving the cleaning operation of an inline filter and, more specifically, for the backwash and flushing of the filter element and filter assembly without taking the filter assembly offline for a prolonged period and does not require any special tools or skills to operate. 
   2. Description of Related Art 
   Filters are commonly used to remove particulates and undesired solids from a fluid medium. A common filtration process involves passing a fluid through a filter medium. Solids are retained on the filter medium, while the fluid passes through the filter medium and continues down stream. However, as solids begin to accumulate on the filter media, the differential pressure across the filter medium increases and consequentially the fluid flow rate decreases. Likewise, the solids retained on the filter may slough due to gravitational force and begin to form a sediment which collects at the lower end of the filter assembly which further decreases the efficiency of the filtration system. 
   In order to return the filter and the system to peak operating efficiency, the solids which are retained by the filter must be removed from the filter, along with the sedimentation located at the bottom of the filter assembly. A common method of filter particulate removal is known as “backwashing” wherein the filter is taken offline, and the flow of fluid through the filter element reversed. The principal of hydrodynamic shear removes the accumulated solids from the filter media. These solids which have now become suspended in the backwash fluid are then directed to a waste drain. Depending on the location of the waste drain port located on the filter assembly, the sediments which have collected at the bottom of the filter assembly either remain or inhibit the flow of the backwash waste water. As such, the lower filter assembly usually requires manual cleaning by the operator, which increases the time the filter system is offline and out of operation. Once the filter media and filter assembly are cleaned, the filter system is then placed back into operation until the next backwashing is desired or required. 
   Unfortunately, most filtration backwash systems require the filter to be taken offline and placed out of service while the backwash operation is performed. This is due, in part, to the consistent design of filtration systems wherein the filter assembly does not provide an efficient mechanism for removing sedimentary solids which have accumulated at the bottom of the filter assembly. Moreover, most prior art backwash systems require a secondary piping system dedicated solely to the backwashing process whereby backwash water is introduced and circulated in the opposite direction of normal, operational fluid flow for purposes of removing the accumulated solids on the filter media. 
   In view of the drawbacks which exist in the prior art, a need exists for an improved filter backwash apparatus that provides the ability to backwash the filter media without requiring that the filter be taken offline for an extended period of time. Similarly, a need exists in the art for an improved filter backwash apparatus which can provide a quick, efficient flushing mechanism to remove sedimentary solids which have accumulated in the filter assembly. 
   Accordingly, it is an object of this invention to provide a back washable filter assembly which does not require the cessation of filter operations for an extended period of time during the backwashing process. It is further an object of this invention to provide a back washable filter system that does not require a secondary piping system dedicated to backwashing operations. It is further an object of this invention to provide a back washable filter assembly that incorporates an efficient flushing mechanism which results in the removal of solids from the filter media and the removal of sedimentary solids which have collected at the bottom of the filter assembly. It is further an object of this invention to perform these multiple functions in a single, one-quarter turn movement to initiate the backwash process, and to return to normal filter operations in a reverse single, one-quarter turn movement. It is a further object of this invention to provide a backwash, flushing filter with a unique flat seal around the inlet and outlet ports to minimize fluid “blow-by” during filter and backwash operations. It is further an object of this invention to provide a unique application of a dual tab-lock and sealing mechanism allowing for the operation and backwash operation of the filter unit disclosed herein without leakage between moving components. It is a further object of this invention to incorporate a unique mechanism for retaining a gasket seal located near the backwash fluid drain port which retains the seal in place during the fluid turbulence generated during backwash operations. It is a further object of this invention to incorporate a unique filter assembly design that utilizes a slot design to capture accumulated solids by reducing fluid turbulence and yet provide for effective backwash operations. Further objects of this invention will be apparent to persons knowledgeable with devices of this general type upon reading the following description and examining the accompanying drawings. 
   SUMMARY OF THE INVENTION 
   In accordance with the foregoing objects, the present invention—a self-cleaning, backwash flushing filter system—generally comprises a system inlet; a filter assembly, a backwash drain pipe and a filtered fluid outlet in selective fluid communication with the system inlet. 
   The preferred embodiment of the present backwash flushing filter assembly invention comprises a header assembly, a rotatable valve assembly, a filter element assembly, and a filter housing assembly. In a single operation, the controller moves the turn knob on the rotatable valve assembly a one-quarter turn to reverse the flow of fluid through the filter assembly, including the filter element assembly. Any debris removed from the filter element media during the backwash process are immediately discharged from the system through the drain port located in the bottom portion of the filter housing. The hydraulic shearing mechanism of the backwash fluid breaks up and dislodges any debris which have accumulated on the filter media and at the bottom of the filter assembly during normal filter operation, which are then removed from the filter assembly through the backwash drain port. The controller then returns the filter assembly operation to filtration operation by a reverse one-quarter turn of the turn knob, which again reverses the fluid flow through the filter assembly and normal filtration operation commences once again. 
   Many other features, objects and advantages of the present invention will be apparent to those of ordinary skill in the relevant arts, especially in light of the foregoing discussions and the following drawings, exemplary detailed description and appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings wherein: 
       FIG. 1  is a perspective view of the backwash flushing filter assembly embodying the invention disclosed herein; 
       FIG. 2  is a fragmentary view of the components of the backwash flushing filter assembly embodying the invention disclosed herein; 
       FIG. 3  is a profile cross-sectional view of the backwash flushing filter assembly shown in the assembled mode; 
       FIG. 4A  is a top cross-sectional view of the rotatable valve assembly shown in standard filter operation mode; 
       FIG. 4B  is a profile cross-sectional view of the backwash flushing filter in standard filter operation; 
       FIG. 4C  is a top cross-sectional view of the rotatable valve assembly shown in filter backwash operation mode; 
       FIG. 4D  is a profile cross-sectional view of the backwash flushing filter in filter backwash operation mode; 
       FIG. 5  is a perspective view of a backwash flushing filter assembly in accordance with another embodiment of the invention disclosed herein; and 
       FIG. 6  is a profile cross-sectional view of the backwash flushing filter assembly of  FIG. 5  shown in the assembled mode. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The preferred embodiment of the invention disclosed herein as shown in  FIGS. 1–4D  is a backwash flushing filter assembly  10  whereby switching from filtration mode to backwash flushing mode is performed by a one-quarter turn of the rotatable valve assembly and vice versa as discussed in further detail below. 
     FIG. 1  depicts the assembled backwash flushing filter assembly  10  with connection points to a fluid source pipe  12 , filtered fluid outlet pipe  14 , and backwash drain pipe  16 . The filter assembly  10  is preferably constructed so that the filter assembly  10  can be readily accessed to permit visual component inspection, filter media removal and replacement, if necessary. The filter assembly  10  can be constructed in a variety of sizes to accommodate both standard and custom filter element sizes and uses as known in the art. 
   Turning now to  FIG. 2 , the backwash flushing filter assembly  10  is shown in exploded view. Filter assembly  10  is comprised of a header assembly  20 , a rotatable valve assembly  30 , a filter element assembly  40 , and a filter housing assembly  50 . In further detail, the header assembly  20  is comprised of a cylinder cap  21  and cylinder base  22  which includes threaded connector means within the interior circumference of cylinder base  22 . A fluid inlet connect  23  is formed as part of cylinder cap  21  and provides for the inflow of fluid into the backwash flushing filter assembly  10 . The filtered fluid outlet connect  24  is formed as part of cylinder cap  21  and is oriented, in the preferred embodiment, opposite of fluid inlet connect  23 , although other configurations may be utilized depending on the application. Filter fluid outlet connect  24  provides an outlet for fluid that has been filtered by the filter assembly  10 . Set clip  25  is removably inserted into and through the cylinder cap  21  via a preformed slot in cylinder cap  21  as shown. In this embodiment, set clip  25  is utilized to retain the rotatable valve assembly  30 , described in detail below, within the header assembly  20  during filter and backwash operations. An alternative embodiment of the present invention may include one or more independent pins which are inserted through preformed holes in the cylinder cap  21  as the retention mechanism for the rotatable valve assembly  30 . Likewise, additional means for securing the rotatable valve assembly within the header assembly may include threaded screw-type connections, tongue-in-groove connections and locking tabs in various orientations to accomplish the retention objective and allowing for the insertion and removal of the rotatable valve assembly  30  from the header assembly  20 . 
   The rotatable valve assembly  30  includes a turn knob  31 , two seal gaskets  32 , a backwash fluid inlet port  33 , a filtered fluid outlet port  34 , a top filter coupler  35 , and a turn guide slot  36  which is preformed into the rotatable valve assembly  30  below the turn knob  31  as shown in  FIG. 2 . Rotatable valve assembly  30  includes an interior chamber  38  which during filter operations receives filtered fluid from the filter element assembly  40  and allows for the passage of filtered fluid to the fluid filter outlet port  34 . During backwash mode, backwash fluid is delivered into the interior chamber  38  of the rotatable valve assembly  30  via backwash fluid inlet port  33  which then flows in the reverse direction down through the filter element assembly  40  and results in the backwashing of same. Seal gaskets  32  minimize fluid “blowby” when the filter assembly  10  is switched from filter operation to backwash operations and vice versa and also maintains segregation of the unfiltered inlet fluid, filtered fluid and backwash fluid during filter and backwash operations. 
   Filter element assembly  40  is comprised of a filter stalk  41 , filter ports  42 , filter media or mesh  43 , lower filter coupler  44  with a threaded gasket stem  45 , a gasket seal  46 , and gasket cap  47 . In the disclosed embodiment, filter stalk  41  is a cylindrical pipe having first and second open ends. The first or lower open end is sealably connected to lower filter coupler  44 , while the second or upper open end is sealably connected to the interior cavity of the rotatable valve assembly  30  via the top filter coupler  35  and releasably locked into place by locking tabs or pin  37 . Gasket seal  46  is releasably connected to lower filter coupler  44  by placement around gasket stem  45  and retained by screwing on gasket cap  47  via the threaded exterior of gasket stem  45 . Alternative embodiments of the filter element assembly may include a barb gasket stem, instead of a threaded gasket stem, which allows the user to simply slip gasket seal  44  over the barbed end of the gasket stem which thereby retains the gasket seal  44  in a secured position. Additional connection means for retaining gasket seal  44  to gasket stem  45  maybe employed as required by the particular application or operating environment. Filter element assembly  40  is thereby releasably secureable within filter housing assembly  50 . The lower filter coupler  44  may also include preformed slots or surface indentations which act to minimize fluid turbulence during filter operation mode, thereby aiding in the capture and sedimentation of accumulated solids at the bottom end of the filter assembly  50 . 
   Filter housing assembly  50  is comprised of a filter housing  51 , a header/filter body threaded connect  52 , a backwash drain port connect  53 , and a backwash fluid drain port  54 . Filter housing assembly  50  is cylindrical in shape and, in the embodiment shown, is composed of a filter housing  51  with an open upper end and a lower end with a reduced diameter in appropriate relation to the diameter and length of filter element assembly  40 . The lower end of filter housing assembly  50  includes a threaded backwash drain connect  53  and open backwash drain port  54  as depicted in  FIG. 2 . 
     FIG. 3  shows an assembled version of the backwash flushing filter assembly  10 . In the preferred embodiment, the rotatable valve assembly  30  is slidably disposed within the header assembly  20 . Filter element assembly  40  is releasably attached to the rotatable valve assembly via locking tab  37 . The filter housing assembly  50  is releasably secured to the header assembly  20  via threaded connects  52 . After assembly in this manner, the filter assembly  10  is ready for placement in an operational environment. 
   A plurality of pipes may be connected to the filter assembly  10  for introducing fluids into and removing fluids from the filter assembly  10 . In the present embodiment, a fluid source pipe  12  and a filter fluid outlet pipe  14  are connected to the filter assembly  10 , via fluid inlet connect  23  and fluid outlet connect  24 , respectively, so as to communicate with the interior of the header assembly  20 , rotatable valve assembly  30 , filter element assembly  40 , and filter housing assembly  50 . The fluid source pipe  12  is used to introduce an unfiltered inlet fluid to be filtered into the header assembly  20  and filter housing assembly  50  from an un-illustrated source, the filtered fluid outlet pipe  14  transports filtered fluid downstream, and the backwash drain pipe  16  is used to remove unwanted debris suspended in the backwash fluid from the filter element assembly  40  and filter housing assembly  50  via backwash drain port  54 . 
   Turning to  FIG. 4A , a cross-sectional top view of the rotatable valve assembly  30  is shown in the filtration mode position. In this view, regular filter operation is ongoing and the backwash fluid inlet port  33  is shown in the closed position and filter fluid outlet port  34  is shown in the open position. As shown in  FIG. 4B , inflow fluid to be filtered enters the filter assembly  10  through fluid inlet connect  23  and circulates into the filter housing assembly  50  and contacts the filter element assembly  40 . As the inflow fluid continues to circulate, suspended solids within the inflow fluid contact filter media  43 . At this point, solids of a predetermined size are prevented from passing through filter media  43  while the newly filtered fluid then passes into and up through the filter stalk  41  via filter ports  42  due to the pressure differential between the incoming fluid from fluid source pipe  12  which is under a greater pressure than the fluid pressure present in the filtered fluid outlet pipe  14 . Due to the hydraulic differential, the filtered fluid then moves into the interior cavity  38  of the rotatable valve assembly  30  and exits the interior cavity  38  via filter fluid outlet port  34  and into filter fluid outlet pipe  14 . As the filtration process continues, suspended solid matter will begin to accumulate on filter media  43  and begin to form a sediment deposit at the bottom of the filter housing assembly  50  between the filter element assembly  40  and the filter housing filter housing  51 . In turn, this causes the efficiency of the filtering process to decline to a point at which the controller initiates the filter backwash operation. 
   Turning to  FIG. 4C , a cross-sectional top view of the rotatable valve assembly  30  is shown in the backwash mode position. In order to initiate backwashing operations, the rotatable valve assembly  30  is turned a one-quarter turn by manipulation of the turn knob  31 . This causes the filter fluid outlet port  34  to be placed in the closed position and the backwash fluid inlet port  33  to be in the open position, which then results in connection with fluid inlet connect  23  which is in communication with fluid source pipe  12 . Fluid is introduced via fluid source pipe  12  into the interior chamber  38  of the rotatable valve assembly  30  and proceeds down into the interior of the filter stalk  41 . At the same time, due to the inclined slot  36  into which the set clip  25  is positioned, by turning turn knob  31  a one-quarter turn, the rotatable valve assembly  30  and filter element assembly  40  proceeds to move axially within the header assembly  20  and filter housing assembly  50 , which results in the filter element assembly  40  being disconnected from sealed contact with the filter housing  51  via gasket seal  46  which results in the creation of a pressure differential between the fluid source pipe  12  and the backwash drain port  54 . As a result, backwash fluid flows from the interior of filter stalk  41  via filter ports  42  and back through filter media  43 . This reversal of fluid flow results in a hydraulic shearing mechanism by which suspended solids  60  are washed away from the filter media  43  and exit filter element assembly  40  via backwash drain port  54 . Likewise, the reversal of fluid flow through the filter element assembly  40  creates a “flushing” action which erodes and removes, via backwash drain port  54 , any sedimentary build up that has collected at the bottom of the filter housing assembly  50  between the filter element assembly  40  and the filter housing filter housing  51 . During the backwashing cycle, the gasket seal  46  is securely held in place around the gasket stem  45  by gasket cap  47  thereby preventing the gasket seal  46  from becoming dislodged and blocking the backwash drain port  54  during backwash operations by the fluid turbulence generated during backwash operations. 
   After the backwash operation is complete, the controller turns turn knob  31  a reverse one-quarter turn. This results in the filter fluid outlet port  34  returning to the open position and the backwash fluid inlet port  33  to be placed in the closed position. Fluid to be filtered once again enters the filter assembly  10  through fluid inlet connect  23 , circulates into the filter housing assembly  50  and contacts the filter element assembly  40  as previously discussed. At the same time, due to the inclined slot  36  into which the set clip  25  is positioned, by turning turn knob  31  a reverse one-quarter turn, the rotatable valve assembly  30  and filter element assembly  40  move axially in the reverse direction and enter into sealed contact with the filter housing  51  via gasket seal  46  which results in the creation of a pressure differential between the fluid source pipe  12  and the filtered fluid outlet pipe  14 . The fluid then contacts the filter media  43  resulting in the removal of suspended solids and the filtered fluid then moves into the interior volume of the filter stalk  41 , then into the interior chamber  38  of the rotatable valve assembly  30  and exits the rotatable valve assembly  30  via the filtered fluid outlet port  34 . 
   An additional feature of the invention disclosed herein allows for the simple and quick removal and replacement of the filter media  43 , without the need to remove the entire filter assembly  10  from the piping system. To change the filter media  43  or filter stalk  41 , the user may simply shut off fluid communication to the filter assembly  10 , pull set clip  25  out of the header assembly  20  and remove the rotatable valve assembly  30  and filter element assembly  40  from the filter housing assembly  50 . The user can then remove, reinstall and/or change the filter media or an entire filter stalk as the need arises. The user then reassembles the filter assembly  10  in the reverse order of the steps outlined above, reinitiates fluid communication with the filter assembly  10  and resumes filter operations. 
     FIG. 5  is a perspective view of a backwash flushing filter assembly in accordance with another embodiment of the invention disclosed herein.  FIG. 6  is a profile cross-sectional view of the backwash flushing filter assembly of  FIG. 5  shown in the assembled mode. Like the filter assembly  10  shown in  FIGS. 1 and 2 , the filter assembly  110  shown in  FIGS. 5 and 6  comprises a header assembly  120 , a rotatable valve assembly  130 , a filter element assembly  140 , and a filter housing assembly  150 . A fluid source pipe  112  directs fluid into a cylinder cap  121  of the header assembly  120 , thereby providing an inflow of fluid into the backwash flushing filter assembly  10 . A filtered fluid outlet pipe  114  of the cylinder cap  121  is oriented, in a preferred embodiment, opposite of the fluid source pipe  112 , although other configurations may be utilized depending on the application. The filtered fluid outlet pipe  114  provides an outlet for fluid that has been filtered by the filter assembly  110 . Rather than using a set clip  25  to retain the rotatable valve assembly  30  as shown in  FIG. 3 , an alternative embodiment of the present invention, as shown in  FIG. 5 , may include one or more independent pins  125  which are inserted through pin guides  160  in the cylinder cap  121  as the retention mechanism for the rotatable valve assembly  130 . Likewise, additional means for securing the rotatable valve assembly within the header assembly may include threaded screw-type connections, tongue-in-groove connections and locking tabs in various orientations to accomplish the retention objective and allowing for the insertion and removal of the rotatable valve assembly from the header assembly. 
   Returning to  FIGS. 5 and 6 , each pin guide  160  has a longitudinal bore  136  to accommodate a set pin  125 . If desired, the longitudinal bore  136  can be threaded to help retain a threaded set pin  125 . Each longitudinal bore  136  within the respective pin guide  160  opens briefly into the interior of the header assembly  120  such that when set pins  125  are inserted into the pin guides  160 , the pins also pass through turn-guide slots of the rotatable valve assembly  130 , thereby securing the rotatable valve assembly  130  in place. The rotatable valve assembly  130  can be rotated by turning the turn knob  131 , and the valve assembly  130  will still remain secured by the set pins  125 , which pass through portions of the turn-guide slots. The spiral configuration of the turn-guide slots, however, enables the rotatable valve assembly  130  and the attached filter element assembly  140  to rise or descend as it is turned, which in turn opens and closes a backwash fluid drain port. The rotatable valve assembly  130  and filter element assembly  140  can be detached from the filter housing assembly by removing the set pins  125  from the pin guides  160 . 
   The backwashing filter apparatus and method disclosed herein are subject to application and modification by those of ordinary skill in the art. Although the present invention has been described in terms of an exemplary embodiment, it is not limited to these embodiments and modifications. Alternative embodiments, modifications, and equivalents, which would still be encompassed by the invention, may be made by those of ordinary skill in the art, in light of the foregoing teachings. Therefore, the following claims are intended to cover any alternative embodiments, modifications, or equivalents which may be included within the spirit and scope of the invention defined by the claims.