Abstract:
A Multiple Parallel Layer Filter and Filtration Method is disclosed. Also disclosed is a device and method that provides superlative filtration in macro, micro and nano ranges for a variety of fluids. The device uses filtration elements that are relatively low cost, yet provide the significant advantage of being able to be flushed periodically to remove captured solids. The device further employs an arrangement of filter elements wherein the filtration axis of the filters is perpendicular to the flow axis of the collecting housing. Finally, the device and method further provides a way for adjusting filter to capture different sizes of solids, depending upon the particular user adjustment.

Description:
[0001]     This application is filed within one year of, and claims priority to Provisional Application Ser. No. 60/526,889, filed Dec. 4, 2003. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     This invention relates generally to fluid filtration systems and, more specifically, to a Multiple Parallel Layer Filter and Filtration Method  
         [0004]     2. Description of Related Art  
         [0005]     Filters of many designs and configurations have been used in many fields, and for filtering many fluids, including air, oil, water and many others. Whatever the type of conventional filter, it is normal that they be configured in different filtration sizes in order to obtain different results (and to be used with different fluid viscosities), ranging from nano- and micro- to macro-filtration. As filters begin to trap more and more material, they begin to clog and create a pressure drop as well as to block fluid flow. At some point, just about every type of filter element must be replaced due to this fouling.  
         [0006]     There is thus a widely held need to avoid this fouling problem because of the efficiency reductions of the system, as well as to avoid unnecessary replacement costs for new filters.  
         [0007]     What is needed, then, is a fluid filtration system and method in which the filtration size is adjustable in order to enable the user to vary the size of the suspended solids being trapped therein. Furthermore, a system that permits cleaning of the filter element(s) without the need for their replacement, is also needed.  
       SUMMARY OF THE INVENTION  
       [0008]     In light of the aforementioned problems associated with the prior systems and methods, it is an object of the present invention to provide a Multiple Parallel Layer Filter and Filtration Method. The device and method should provide superlative filtration in macro, micro and nano ranges for a variety of fluids. The device should use filtration elements that are relatively low cost, yet provide the significant advantage of being able to be flushed periodically to remove captured solids. The device should employ an arrangement of filter elements wherein the filtration axis of the filters is perpendicular to the flow axis of the collecting housing. The device and method should further provide a way for adjusting filter to capture different sizes of solids, depending upon the particular user adjustment.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, of which:  
         [0010]     FIG  1  is cutaway side view of the multiple layer parallel filter of the present invention;  
         [0011]      FIG. 2  is a perspective view of a filter stack of the filter of  FIG. 1 ;  
         [0012]      FIG. 3  is perspective view of the filtering assembly of the invention of  FIGS. 1 and 2 ; and  
         [0013]      FIGS. 4A and 4B  are graphs depicting the performance characteristics of a filter of the type of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]     The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventors of carrying out their invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide a Multiple Parallel Layer Filter and Filtration Method.  
         [0015]     The present invention can best be understood by initial consideration of  FIG. 1 .  FIG. 1  is cutaway side view of a preferred embodiment of the multiple layer parallel filter  10  of the present invention. The filter  10  is an assembly contained within a housing  12  is enclosed by a lid  14  attachable to its upper opening to form a recipient chamber  32  within it. The recipient chamber  32  is in fluid communication with an inlet port  16  and a refuse port  24 .  
         [0016]     The inlet port  16  allows fluid, such as water to flow through it into the recipient chamber  32  from an inlet duct  18  attached thereto. The inlet duct  18  is a source of non-filtered fluid expected to contained solid matter entrained within it. In a non-depicted version, the inlet duct  18  and inlet port  16  are located excentrically relative to the central axis of the housing  12 —such a shape creates a swirling effect for fluid entering the housing  12  which aids in the separation of particulates from the fluid via centrifugal force.  
         [0017]     The refuse port  24  allows the waste fluid effluent to exit the recipient chamber  32  and exit through a refuse duct  26 . Furthermore, the filter can be back-flushed periodically to remove captured solid matter from the filter media.  
         [0018]     Contained within the housing  12  is a novel filter assembly. The assembly is a stack of filter layers  34  that each have a hole in their middle, through which a collector housing  20  passes. A variety of materials may be employed for the layers  34 , but it has been demonstrated that “optical” precision filter elements (i.e. very high precision) demonstrate extremely suitable results. The filter layers  34  are held on the collector housing  20  by a compression plate  36 . The compression plate or bell  36  may be of a similar planar configuration to the filter layers  34 , although it may be slightly larger or smaller in diameter in order to avoid any centering issues. In the depicted version, however, the plate  36  actually has a concave bell shape that causes the upper rim of the plate  36  to be the point of contact between the plate  36  and the filter layers  34 —this design has been demonstrated as particularly successful because it creates an outer boundary filtration layer, with an inner core the causes less of a flow restriction. There may be a corresponding rim structure protruding from the lid  14 , to aid in creating this boundary layer of filtraton. The compression bell  36  is pressed against the stack of filter layers  34  by an adjustment device  38 , such as a conventional nut, bolt or screw. It should be apparent from the arrangement of the elements in the filter assembly that if the adjustment device  38  is tightened or loosened, it will squeeze or release squeezing force against the stack of filter layers  34 . By adding compression to the stack of layers  34  (by tightening the adjustment device  38 ), the filter stack height H(f) will be reduced and the gap between each layer  34  will be reduced. Conversely, if compression is reduced by loosening the adjustment device  38 , the filter stack height H(f) will increase due to the gap between each layer  34  increasing.  
         [0019]     s will be discussed more fully in connection with  FIGS. 2 and 3 , as fluid passes from the recipient chamber  32  and through the filter layers  34  (horizontally) from the outside of the stack of layers  34  and inward to the collector chamber  30 , the fluid will be filtered of the solid matter previously entrained in it, and it will exit the collector chamber  30  through the discharge port  20  and discharge duct  22 . Now turning to  FIG. 2 , we can continue to examine this novel invention.  
         [0020]      FIG. 2  is a perspective view of a filter stack  47  of the filter  10  of  FIG. 1 . The filter layers  34  are shown to be circular rings having an outer periphery  44  and an inner periphery  42  surrounding an inner aperture  40 . In other versions of the filter  10 , other shapes may be employed for the filter layers  34  (e.g. a square outer periphery and a circular inner periphery, etc.). Where the term “ring-shaped” is used herein, it is intended to describe a structure having an outer periphery and at least one centralized aperture—it is explicitly intended to limit the description to only circular structures.  
         [0021]     What is unique about this design is the filtration approach that this invention takes. The fluid flows inward from the outer periphery  44  towards the inner periphery  42  in a direction that is perpendicular  52  to the central axis  48  defined by the collector housing (see  FIG. 1 ). Once inside the collector housing (see  FIG. 1 ), the fluid (now filtered) will follow a parallel flow path  54  (relative to the central axis  48 ). This approach is very suitable for removing sand from water. The filter layers  34  may be made from a variety of materials and may exhibit a variety of stiffness or rigidity characteristics, depending upon the fluid being filtered and the expected solids that are wished to be removed.  
         [0022]     A very unique aspect of this invention is that the spacing  46  or gap between the layers  34  can be adjusted by tightening or loosening the compression plate or compression bell (see  FIG. 1 ). As the spacing  46  is decreased, smaller and smaller-sized solids will be captured as the fluid flows between the layers  34 . When the user desires to remove captured solids from the filter stack  47 , such as for routine maintenance, it is a simple matter to reduce the compression on the stack  47  by loosening the adjustment device (see  FIG. 1 ) so that the foreign bodies can be back-flushed out through the refuse port (see  FIG. 1 ). Turning, now to  FIG. 3 , we can review additional detail about other elements of the invention.  
         [0023]      FIG. 3  is perspective view of the filtering assembly  60  of the invention of  FIGS. 1 and 2 . The assembly  60  is a combination of the collector housing  28 , the filter layers  34 , the compression plate (or bell)  36  and the adjustment device  38 . The collector housing  28  is defined by an open top end  64  that connects the housing  28  to the discharge port  20 . The housing  28  has a bottom end  62  that has a threaded portion  66  adjacent to it (either external or internal threads). The bottom end  62  is sealed to prevent fluid flow into it. The inners apertures  40  are sized so that the filter layers  34  can be slipped over the collector housing  28 . The collector housing  28  further has a plurality of weep apertures  68  dispersed across its wall that allow filtered fluid to pass from the exterior of the collector housing  28  and into the collector chamber  30 . The apertures  68  can be slot-shaped as shown, or be other shapes, as desired.  
         [0024]     Here, the collector housing  28  and filter layers  34  are shown here to both have circular shapes; it should be understood neither of these elements are confined to these shapes—different shapes might be employed for a variety of applications.  
         [0025]     The stack of layers  34  is bounded on its bottom by a compression bell  36 ; there may be a fixed compression bell at the top of the stack of layers  34  as well. The filter layers  34  and plate  36  are held on the compression housing by an adjustment device  38  that is threadedly engaged with the threaded portion of the collector housing  28 . From this drawing it should be apparent that turning the adjustment device  38  will cause the device  38  to travel up and down the threaded portion  66  of the housing  28 , and will in turn increase or decrease the compression on the stack of filter layers  34 . Finally turning to  FIGS. 4A and 4B , we can understand the implications of this novel design.  
         [0026]      FIGS. 4A and 4B  are graphs depicting the performance characteristics of a filter of the type of the present invention.  FIG. 4A  represents that as filter stack height H(f) increases, the minimum size of the particles trapped in the filter will increase; as the height. H(f) is decreased, smaller particles will be trapped. Similarly, as shown in  FIG. 4B , as compressive force is increased on the filter stack, purity of the discharged (filtered) fluid will be increased as well.  
         [0027]     Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.