Abstract:
A method and corresponding apparatus employ purified water to backflush a filtration device. Purified water includes water having a total dissolved solids reading less than that of the water being filtered. Examples of purified water may include water treated using reverse osmosis, steam distillation, or deionization processes, and the like. In the simplest form, the purified water is used to rinse or backflush a filter or filter cartridge. Further extensions include valves to switch from a primary flowpath used for normal operations to a secondary flowpath used to conduct backflushing routines. Backflushing routines may be initiated on demand or through an automated routine that repeats the process on a regular basis.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a method and apparatus for backflushing a water filter and, more particularly, but not by way of limitation, to backflushing the water filter with pure water.  
           [0003]    2. Description of the Related Art  
           [0004]    Water of sufficient quality for human consumption has always been a concern, especially in newly developing countries, and there is a growing concern even in industrialized countries. Water quality issues range from merely reducing water hardness or removing high concentrations of minerals to the dire one of removing contaminants, such as biological or harmful chemicals.  
           [0005]    Water quality issues may be addressed through water treatment equipment that employ various methods for purifying water, some in conjunction with others, to obtain a desired grade or level of water quality. Example water treatment methods include reverse osmosis, deionization and steam generation. Water treatment equipment employing these methods typically require a filter in line prior thereto to remove particles up to a preselected size range.  
           [0006]    Unfortunately, filters typically have a limited life and are treated as consumables. Filters commonly used in the marketplace contain a filter cartridge that is replaceable. Therein, a service agent or maintenance person must remove and replace the filter cartridge on a scheduled basis. When new, the filter cartridges allow water to pass freely, with minimal pressure buildup. As the filtering process continues, the flow through the filter is reduced due to clogging, calcification and compaction due to continued pressure. Problems with servicing of filters include varying levels of clogging associated with different types of water, as well as varying levels of service available in different areas. In remote or less populated areas, access to service agents is limited. Consequently, the use of filters in a water delivery system can be cost prohibitive and inefficient.  
         SUMMARY OF THE INVENTION  
         [0007]    In accordance with the present invention, a method and corresponding apparatus employ purified water to backflush a filtration device. Purified water includes water having a total dissolved solids reading less than that of the water being filtered, preferably at least fifty percent less. In the simplest form, purified water is used to rinse or backflush a filter or filter cartridge. Further embodiments include a pressurized flow and a submersing tank to backflush or submerge a filter .  
           [0008]    An alternative embodiment includes a primary or filtered flowpath used during normal operations and a secondary flowpath used for backflushing routines, wherein purified water is the source water used for backflushing the filter. Switching a set of valves substantially simultaneously provides the two separate and distinct flowpaths. The use of the secondary flowpath allows purified water to enter the primary flowpath, and move backwards through the filter. The water is then purged from the filtered flowpath to remove concentrations of solids that have been displaced from the filter by the backflushing routine. Switching of the valves may be accomplished manually or a controller may be added to the system to provide the capability of automatically backflushing the filter on a scheduled basis.  
           [0009]    It is therefore an object of the present invention to utilize purified water as a cleansing media.  
           [0010]    It is a further object of the present invention to provide an apparatus for cleansing a filter using purified water.  
           [0011]    It is still further an object of the present invention to provide an apparatus for backflushing a filter in a filtered flowpath using purified water.  
           [0012]    It is still yet further an object of the present invention to provide an apparatus for automatically backflushing a filter in a filtered flowpath on a scheduled basis. It is still yet further an object of the present invention to provide a method of automatically backflushing a filter in a filtered flowpath on a scheduled basis.  
           [0013]    Still other objects, features, and advantages of the present invention will become evident to those of ordinary skill in the art in light of the following. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 illustrates a method of cleansing a filter cartridge.  
         [0015]    [0015]FIG. 2 illustrates a method of cleansing a filter cartridge using a pressurized flow.  
         [0016]    [0016]FIG. 3 illustrates a primary flowpath according to the preferred embodiment.  
         [0017]    [0017]FIG. 4 illustrates a secondary flowpath for a filter backflush unit according to the preferred embodiment.  
         [0018]    [0018]FIG. 5 is a method flowchart for using the filter backflush unit according to the preferred embodiment.  
         [0019]    [0019]FIG. 6 illustrates a self-flushing filter backflush unit according to the preferred embodiment.  
         [0020]    [0020]FIG. 7 provides a method flowchart for using the self-flushing backflush unit according to the preferred embodiment. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]    As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. It is further to be understood that the figures are not necessarily to scale, and some features may be exaggerated to show details of particular components or steps.  
         [0022]    The invention at hand is a method and apparatus for backflushing a filtration device with purified water. Purified water includes water having a lower total dissolved solids reading than the water being filtered, preferably with a total dissolved solids reading fifty percent lower than that of the water being filtered, more preferably with a total dissolved solids reading eighty percent lower than that of the water being filtered, and still more preferably with a total dissolved solids reading ninety five percent lower than that of the water being filtered. Those skilled in the art will recognize that purified water may be produced using any suitable purification process, such as reverse osmosis, steam distillation or deionization. Backflushing of a filtration device allows the backflush media to lift compacted particles. Water with a low total dissolved solids reading is essentially unsaturated and able to dissolve particles attached to the filter medium. The particles are then removed from the filter medium through the use of a second flowpath terminating in a sanitary drain or other disposal. Various embodiments of the invention may be employed to extend the life of filters, unclog clogged filters or keep new filters from clogging. Backflushing of a filter may be accomplished manually or through an embodiment of this invention that automatically backflushes a filter on a scheduled basis.  
         [0023]    In the simplest form, a filter  101  or a filter cartridge  118  may be removed from a filtered flowpath for cleansing with purified water. Cleansing may take place in various embodiments ranging from submerging the filter cartridge  118  in a container or sink to backflushing the filter cartridge  118  with a hose or a pressure flow system as shown in FIGS. 1 and 2, or a combination of both. Submerging the filter cartridge  118  in purified water dissolves the filtered components clinging to a filter medium  130 . In the pressurized flow system, purified water is forced backwards and forwards through the filter cartridge  118 , therein dissolving and dislodging particles from the filter medium  130 . The pressurized flow further allows the dissolved particles to be transported away from the filter medium  130 , therein removing the high concentration of particles from the filtered flowpath.  
         [0024]    Alternatively, the filter medium  130  may be cleansed in place with a backflush unit  100 . The backflush unit  100  includes a primary flowpath  150  and a secondary flowpath  160 . As shown in FIG. 3, the primary or filtered flowpath  150  includes a filter  101 , a fluid source  106 , an inlet pipe  110 , an outlet pipe  111  and an end-use device  107 . The filter  101  includes the filter medium  130  disposed therein, an inlet end  114  and an outlet end  115 , wherein fluids are filtered as they pass through the filter  101  from the inlet end  114 , through the filter medium  130  in the filter cartridge  118  to the outlet end  15 . The inlet end  114  of the filter  101  is coupled to the inlet pipe  110 , which is coupled to the fluid source  106 . The outlet end  115  is coupled to an outlet pipe  111 , which in turn is coupled to the end-use device  107 . Therein, water moves from the fluid source  106  through inlet pipe  110 , through the filter  101 , and through outlet pipe  111  to the end-use device  107  in the primary flowpath  150  for consumption or use.  
         [0025]    The secondary flowpath  160  may be created from the primary flowpath  150  with the addition of a first tee  128  in the inlet pipe  110  between the inlet valve  102  and the inlet end  114  of the filter  101 , a second tee  129  in the outlet pipe  111  near the outlet end  115  of the filter  101  and an inlet valve  102  between the first tee  128  and the fluid source  106  as shown in FIG. 4. A first port  131  and a second port  132  of the first tee  128 , therein connect to an inlet pipe  110   a  or  110   b , respectively, while a third port  133  of the first tee  128  connects to a first port  141  of a drain valve  104 . A second port  142  of the drain valve  104  connects to an inlet end  144  of a drain pipe  113 . An outlet end  145  of the drain pipe  113  is connected to a suitable sanitary disposal or storage device.  
         [0026]    The second tee  129  includes a first port  146 , a second port  147  and a third port  148 . The first port  146  and the second port  147  connect to an outlet pipe  111   a  or  111   b , respectively, and the third port  148  connects to a first port  152  of a flush valve  103 . The flush valve  103  further includes a second port  153  connectable to a first end  121  of a flush inlet pipe  112 . A second end  122  of the flush inlet pipe  112  is attached to a flush source  108 .  
         [0027]    The inlet valve  102  includes a first port  135  and a second port  136 . The first port  135  is coupled to an inlet pipe  110   c , which is attached to the fluid source  106 . The second port  136  of the inlet valve  102  is connected to the inlet pipe  110   b  which further connects to the first port  131  of the first tee  128 . Having an on and an off position, the inlet valve  102  provides the ability to stop the flow of fluid from the fluid source  106 .  
         [0028]    The secondary flowpath  160 , used for backflushing and cleansing the filter medium  130  in the filter  101 , does not impact the primary flowpath  150  when the inlet valve  102  is in an open position, and the flush valve  103  and the drain valve  104  are in a closed position. In a backflushing or cleansing mode, the inlet valve  102  is in a closed position, and the flush valve  103  and the drain valve  104  are in an open position. Therein, the secondary flowpath  160  allows purified water to flow from the flush source  108  through the flush inlet pipe  112 , through the flush valve  103  and into the second tee  129  to gain entrance to the primary flowpath  150 . The secondary flowpath  160  continues from the second tee  129 , through the outlet pipe  111   a , in the outlet end  115  of the filter  101 , backwards through the filter medium  130 , out the inlet end  114  of the filter  101 , through the inlet pipe  110   a , through the first tee  128 , through the first port  141  of the drain valve  104 , through the drain valve  104  and the drain pipe  113  to a suitable disposal. Switching of the positions of the inlet valve  102 , the flush valve  103  and the drain valve  104 , substantially simultaneously, therein provides either the primary flowpath  150  or the secondary flowpath  160  for use.  
         [0029]    The flush media stored in the flush source  108  in this preferred embodiment is purified water. While this embodiment has been shown to include a flush source  108 , it should be clearly evident to one skilled in the art that the flush source  108  containing flush media could be permanently installed or temporarily installed at the flush inlet pipe  112 . Still another embodiment could include pouring flush media into the flush inlet pipe  112  as required for cleaning or cleansing of the filter cartridge  118  in the filter  101 .  
         [0030]    In operation, the backflush unit  100  must be changed from a non-flush state to a flush mode to execute a backflush routine. The process of going from the non-flush state to the flush mode is shown in the method flowchart of FIG. 5. The process commences with step  10 , wherein the inlet valve  102  is closed to shut off the flow of fluid from the fluid source  106 , and the flush valve  103  and the drain valve  104  are opened to utilize the secondary flowpath  160 . As shown in step  20 , the process continues with purified water flowing from the flush source  108 , through the flush source pipe  112 , through the flush valve  103  and into the second tee  129 , therein gaining entrance to the primary or filtered flowpath  150 . The purified water then flows through the first port  146  of the second tee  129 , through the outlet pipe  11   a , into the outlet end  115  of the filter  101 , backwards through the filter  101 , out the inlet end  114 , through the source inlet pipe  110   a , through the second port of the first tee  128 , through the third port of the first tee  128 , through the drain valve  104  and through the outlet pipe  113  for disposal. Upon completion of a prescribed backflushing time, one to two minutes in this preferred embodiment, the process moves to step  30 , wherein the inlet valve  102 , the flush valve  103  and the drain valve  104  are switched back to the primary or filtered flowpaths,  150  to stop the backflushing operation and allow fluid to again flow from the fluid source  106  to the end-use device  107 . Switching of the valves in steps  10  and  30  may be accomplished manually.  
         [0031]    The flowing of purified water backwards through the filter  101  dissolves, unclogs and removes particles embedded in the filter medium  130 . The removal of particles and calcified filtered debris from the filter medium  130  increases the efficiency and life span of the filter  101 . Execution of a backflush routine on a regularly scheduled basis unclogs clogged portions of the filter medium  130  and ensures the filter medium  130  will not become clogged.  
         [0032]    In another embodiment, a backflush unit  200  is identical to the aforementioned backflush unit  100  shown in FIG. 4, however, the addition of components allows the backflush unit  200  to execute a backflush routine on a prescribed interval. As such, similar components are marked with like numerals. As shown in FIG. 6, the backflush unit  200  further includes a controller  220 , a plurality of electrically actuated valves  202 ,  203  and  204 , a wire harness  221 ,  222  and  223  for each respective valve, and a power source (not shown). Hydraulically, the backflush unit  200  operates identically to the backflush unit  100 , with water flowing from the source  106  to the end-use device  107  under normal operation in the primary flowpath  150 . In the backflush mode, the secondary flowpath  160  allows flush media to move from the flush source  108 , through the flush valve  203 , through the outlet pipe  111   a , backwards through the filter  101 , through the inlet pipe  110   a , through the drain valve  204  and through the drain pipe  113  to a proper disposal.  
         [0033]    The method steps for using the backflush unit  200  are show in FIG. 7. The process commences with a start command as shown in step  40 . In step  45 , the controller  220  is in a wait state. The process then moves to step  50 , wherein the controller  220  checks for timer activation. If the timer has not been activated in step  50 , the controller  220  returns to step  45 . If the timer has been activated in step  50 , the controller  220  moves to step  60 , wherein the controller  220  sends signals to switch the flowpaths, wherein the inlet valve  202  is closed, and the flush valve  203  and the drain valve  204  are opened to move the system flow from the primary flowpath  150  to the secondary flowpath  160 .  
         [0034]    After changing to the secondary flowpath  160 , purified water flows from the flush source  108 , through the flush source pipe  112 , through the flush valve  203 , through the outlet pipe  111   a , backwards through the filter  101 , through the inlet pipe  110   a , through the drain valve  204 , and through the drain pipe  113  to a proper disposal as shown in step  65 . After the flush has been activated for a predetermined interval, one to two minutes in this preferred embodiment, the controller  220  moves to step  70 , wherein the controller  220  switches the system to the primary flowpath  150  to allow water to flow from the water source  106  to the end-use device  107 . The process then moves to step  75 , wherein the controller  220  checks for a stop signal. If a stop signal has not been noted, the process returns to step  45 , wherein the controller  220  waits for activation of the timer. The controller  220  will continue to activate and deactivate the flush mode on a predetermined interval, approximately every six hours in this preferred embodiment. If a stop signal has been noted, the process will move to step  80 , where it will end.  
         [0035]    Controller  220 , in this preferred embodiment includes a microcontroller, associated hardware and software, timer mechanisms, and the like. Further extensions of this embodiment include programmable software routines for customization of backflushing subroutines in a water treatment system. While this invention has been shown with three valves, it should be clearly evident to one skilled in the art that the number of valves and flow lines may be adjusted to accommodate various types of water systems and components. Power requirements for this invention may include the unit operating with antintegral power source, a separate power source or the backflush unit  100  may be slaved off of an existing power supply in an associated water treatment system component.  
         [0036]    Although the present invention has been described in terms of the foregoing preferred embodiment, such description has been for exemplary purposes only and, as will be apparent to those of ordinary skill in the art, many alternatives, equivalents, and variations of varying degrees will fall within the scope of the present invention. That scope, accordingly, is not to be limited in any respect by the foregoing detailed description; rather, it is defined only by the claims that follow.