Abstract:
The present invention is directed to a method for filtering fluid, preferably effluent fluid in a septic system, by providing a staged, filtering array in an effluent flow path, the stages positioned in an orientation designed to maximize filtering capability in conjunction with predetermined aperture positions and dimensions.

Description:
CROSS-REFERENCE 
     This application claims the benefit of priority from U.S. Provisional Application Ser. No. 60/926,139 filed Apr. 25, 2007, and entitled “Multi-Level Filter Device”. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to filters used to separate suspended solids in a liquid solution. More specifically, the present invention is directed to methods and apparatuses for filtering septic tank effluent. 
     BACKGROUND 
     A number of different filtering devices are known for separating solid matter from water, such as, for example, waste water in septic tanks. Many of the known devices for removing waste water from septic tanks allow the solid materials to settle to the bottom of the tank and allow bacteria to react and digest the solid materials. The by-products of the reaction of the solid or semi-solid matter with the bacteria then pass through filtration to remove the remaining small particles, with the waste water being removed by overflow or by discharge pumps in to a drain field. Known filtration systems employ a filter cartridge having a stack of settling plates with a weir wall integral to the top side of the settling plate. Such known filters, however, only have one level of filtration or screening. Therefore, any solids smaller than the aperture either pass onto the drainfield or become trapped on the settling plate requiring more frequent servicing. Other known systems employ a filter that has a stack of inclined filter plates that have an integral weir wall extending from the settling plate. This design allows solids to side to slide back down the inclined surface before passing through the aperture. However, in these known designs smaller particles that pass through the aperture become trapped inside by the weir wall and again require frequent servicing. 
     SUMMARY OF THE INVENTION 
     The filter of the present invention solves the recognized problems in the field by, among other advantages, creating multiple apertures between any two settling plates. This is accomplished by making the weir wall as a separate component that is inserted between two inclined settling plates, thus allowing solid and semisolid masses larger in size than the apertures to settle on the inclined plates and then slough back into the septic tank. When solids build up and eventually block the aperture below the weir wall, the flow can continue through the filter by flowing through the aperture above the weir wall. In another embodiment of the present invention a third aperture can be formed into the weir wall itself. This can lead to double, or triple the time between servicing and cleaning of the filters. This saves the homeowner significant time and cost, while insuring that their drainfields are protected from excessive solids. 
     Separating the partition or weir wall from being a part of either the top or bottom surface of the settling plate, and creating a plurality of apertures in the weir wall allows for at least doubling the filter area. By adding in additional apertures into the weir wall itself, at discrete locations on the wall, even more filtration area in the same size cartridge is provided. The separation of the weir walls into completely separate, or discrete system components makes for less expensive production of multiple filter models with varying levels of filtration. Instead of having to produce molds for different filter plates, one only has to make different inserts. By creating multiple partition walls with progressively finer levels of filtration, the service interval required is greatly increased. This also allows for a greater level of filtration to be accomplished per filter with less servicing and/or down time required. Currently, to accomplish this, multiple filters must to be installed in series at great expense to the consumer. 
     In addition, in known field filtration systems, the alarms used for filters do not give a true indication of the capacity left in the filters, as the alarm switch for these filters can only be located on the unfiltered side of the filter. The present invention allows this alarm switch to be located on the downstream side of the first filter partition. Thus, the filter is protected from having “gross” solids attach to the switch and causing a false alarm situation. 
     In one embodiment, the present invention provides methods and apparatuses for filtering effluent comprising providing a filtering assembly, said assembly comprising at least one substantially planar component attached to at least one partition. The planar component and the partition are attached to create at least one aperture having a predetermined dimension, with the planar components positioned at an incline. A housing is dimensioned to receive the filtering assembly, with the housing comprising an inlet and an outlet and a means for positioning said assembly within said housing. An effluent flow is then provided to the assembly in the housing and flows through the assembly such that only the effluent having predetermined characteristics moves past the partitions and angled planar surfaces. 
     In a further one embodiment, the present invention provides methods and apparatuses for filtering effluent comprising providing a filtering assembly, said assembly comprising a first and second substantially planar component, said first and second planar components spaced apart by at least a first and second partitions, said partitions each comprising one or more apertures, said apertures bounded partially by a surface of the first or second planar components, with said planar components positioned at an incline, or angle. A housing is provided dimensioned to receive the filtering assembly, said housing comprising an inlet and an outlet and a means for positioning the filtering assembly within said housing. An effluent flow is provided to the assembly in the housing and is directed through the filtering assembly such that the only effluent having predetermined characteristics moves past the partitions and angled planar surfaces. Solid or semisolid material of a predetermined dimension is retained in the filtering assembly, while solids or semisolids having a dimension less than said predetermined dimension, and/or liquid effluent, is allowed to pass through the filtering assembly. In a preferred embodiment, a series of filter assemblies are maintained in the housing in a stacked orientation, and at least one partition further comprises an additional integral aperture, located at a distance from the apertures located about the perimeter of the partition. The integral apertures are preferably completely bounded by the partition. 
     According to a further embodiment of the present invention, the partitions have similar or varying dimensions from each other, or preferably comprise spacers extending from the edges thereof, such that the first partition, when in position with a planar component provides apertures having a first dimension, and the second partition when in position with a planar component provides apertures having a second dimension, such that the first and second aperture dimensions, etc., are not equal. In the most preferred embodiment, multiple partitions are oriented relative to a planar component to create a series of apertures of varying dimension such that the aperture dimensions progressively decrease in the direction of an effluent flow. 
     Further objects, advantages and embodiments of the invention will become evident from the reading of the following detailed description of the invention wherein reference is made to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective drawing of one embodiment of the present invention showing a multi-partition wall filter component. 
         FIG. 2  shows an exploded view of one embodiment of the present invention with two inclined plates with the multi-partition wall filter to be engaged therebetween. 
         FIG. 3  shows a perspective view of an assembled portion of the embodiment shown in  FIG. 2 . 
         FIG. 4  shows a perspective, partially exposed view of one embodiment of the present invention comprising a filter housing, or case. 
         FIG. 5  shows a partially exposed view of the housing of  FIG. 4  now comprising a plurality of inclined filter plates and a maintenance plate. 
         FIG. 6  shows a perspective view of one embodiment of the present invention showing a dual filter housing with a plurality of receiving zones. 
         FIG. 7  shows a perspective view of an embodiment of the present invention showing a dual housing with two filter cartridges in place. 
         FIG. 8  shows a side perspective view of the dual housing embodiment of  FIG. 7 , showing the maintenance plate impeding flow to the reserve filter cartridge. 
     
    
    
     DETAILED DESCRIPTION 
     According to one embodiment of the present invention, and with specific reference to the Figures, as shown in  FIG. 5 , a new and improved effluent filter  10  is shown for uses, such as, for example, in septic systems. The filter  10  preferably comprises a housing, or case  12  surrounding at least two, and typically a plurality of inclined settling plates  14  separated by a multi-partition wall assembly  16  (See  FIG. 1 ). 
     Referring now specifically to  FIGS. 1 and 2 , according to one embodiment of the invention, the multi-partition wall assembly  16  of one embodiment of the present invention is shown. The assembly consists of at least one filtering wall(s) or dams  66  connected by at least one spacing support  64 . The top  63  and bottom  65  edges of the multi-partition wall  66  comprises a plurality of connecting pins  78  with male end  80 . 
     As shown in  FIG. 2 , according to one embodiment of the present invention, the inclined settling plates  14  comprise a plurality of female receiving locations  82  designed and dimensioned to receive the male ends  80  of the multi-partition wall assembly  16  (See  FIG. 1 ), thus forming one assembled portion  18  (See  FIG. 3 ) of an embodiment of the present invention. The present invention further contemplates having fastening and spacing elements such, as, for example, the connecting pins  78  with the male end  80  as an integral part of the settling plate with the female receiving location being oriented as an integral part of the partition wall, or any combination thereof, as desired. 
     In one embodiment of the present invention, as shown in  FIGS. 2 and 3 , the connecting pins  78  also play an important structural role in the filtering action of the filter unit  10 . The dimension (e.g. height) of each connecting pin  78  assists in determining the distance between each multi-partition wall  66  and the adjacent inclined settling plate  14 , thus creating apertures. The connecting pins  78  must provide a sufficient distance between each multi-partition wall  66  and the adjacent inclined settling plate  14 , such that a series of gaps, or apertures  122 ,  124  and  126  are formed between at least the edge  65  of the filtering walls or dams  66  and the first or second surfaces  60  of an adjacent inclined settling plate  14 . Similarly, apertures  121 ,  123  and  125  are formed between at least the edge  65  of the filtering walls or dams  66  and the underside of an adjacent inclined settling plate  14   
     As shown in  FIG. 3 , the dimension of each gap, or apertures  122 ,  124  and  126  in the series of apertures changes, and preferably becomes progressively smaller, such that the level of filtration becomes greater as liquid passes through. The dimensions of each connecting pin  78 , therefore, also becomes smaller as liquid moves through each subsequent gap created above or below each partition wall. This produces a progressively smaller or “thinning” aperture dimension, such that wide substances such as, for example, toilet paper, etc. become trapped within the filter, while liquid is allowed to pass through. Additional apertures, or filter slots  128  may be added as desired into the partition wall  66  on the inlet side, as well as the outlet wall. These slots  128  would be substantially the same size (opening) as apertures  122  and  126  respectively, or could be differently sized. Preferably, at least one, substantially circular rod channel  76  is positioned on diametrically opposing sides of each inclined settling plate  14  for receiving rods of a positioning unit, such as, for example, a handle. An additional opening  102  is provided in each settling plate. The openings  102  in each settling plate are aligned. One purpose for such an opening  102  is to receive an optional alarm system (not shown, but known in the field), within the filter unit  18 . One such alarm system that can be incorporated into embodiments of the present invention is provided in U.S. Pat. No. 6,841,066, which is incorporated by reference as if made a part of the present specification. 
       FIG. 4  shows an embodiment of the present invention, where the filter housing, or case  12  comprises a first section  30  that holds the filter assembly  18 . The base of the case  12  shows that the first section  30  comprises an inclined lower shelf  32  upon which rests the filter cartridges  18 , along with a receptacle  34  into which the assembly rod seats, to assist in retaining the cartridges in place, as desired. The interior walls of the case  12  have a series of receiving members, or tracks  36  forming a channel  38  into which a maintenance plate  40  (See  FIG. 5 ) is inserted and “slid” into place, in order to block the flow of liquid from the second (unfiltered) section  42  of the case  12  to the section  30 . This allows the filter cartridge  18  to be removed and cleaned, serviced or replaced without allowing unfiltered liquids to exit the septic tank.  FIG. 5  shows the filter cartridges  18  in place in the case  12  with the maintenance plate  40  also in place. Not shown is a rod, upon which the sections of settling plates stack. The rod is then preferably capped at both ends, securing the plates tightly together. 
       FIG. 6  shows another embodiment of the present invention, where the filter case  12  comprises dual filter receiving zones  30  and an unfiltered flow channel  42  near the center of the case  12 .  FIG. 7  shows this case with two filter cartridges in place. 
       FIGS. 7 and 8  further show the dual filter case  31 , having two filter cartridges  18  in place. The maintenance plate  41  is in place, keeping a reserve cartridge from becoming soiled until needed to replace the cartridge  18  in the first filter zone. 
     The present invention, therefore, contemplates an improved filtration system having at least one partial partition wall placed substantially perpendicular to, and between, adjacent planar walls to form at least two filter apertures. Filter apertures are created between an area at the top edge of the weir wall and the bottom planar surface of one inclined plate. The second aperture is preferably created at an area between the bottom edge of the weir wall and the top planar surface of the adjoining inclined settling plate. The system preferably comprises substantially smooth surfaces that are preferably inclined at an angle of less than 90° relative to the planar floor  13  of the housing  12 , as shown by angle             in  FIG. 4 . However, the surfaces may be textured, if desired. As stated above, two or more partition walls may be present. In one embodiment, the aperture area of each progressive wall changes or remains constant, but preferably becomes smaller in size.
     Embodiments of the present invention further comprise a mounting means for mounting a high level alert device, or alarm system, preferably located in a filtered waste water side of the filter device. The mounting means may be integral with the filter device. Further, filter elements preferably have a closed bottom mounted in the filter housing and comprise a means for installing a maintenance plate to block the flow out of the tank during filter cleaning, maintenance or replacement. The inclined shelf or shelving on the bottom of the filter housing preferably has a receptacle to allow a handle, such as, for example, a rod to engage the unit and preferably lock into place. In addition, a receptacle is preferably located in the back of the filter housing for storing at least one maintenance plate and optionally a spare filter cartridge. 
     A central flow channel in the system is designed to encourage a well-developed laminar flow regime to optimize separation of solids and to maximize retention time within the filter system. By facilitating and/or creating a large flow area within the case itself prior to liquid entering the filter, the velocity of the flow is reduced thus allowing the opportunity for solids to settle back into the septic tank for further treatment. This too increases the service life of the filter. 
     While the apertures of varying dimension are shown in the FIGs. as occurring at the “top” and “bottom” of the partitions, it is contemplated herein that the apertures may occur on the sides of the partition also, to enhance filtering performance as desired, with or without the presence of connecting pins. 
     The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be construed in all respects as illustrative and not restrictive, the scope of the invention being indicated by the claims set forth below rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.