Abstract:
A filter and filter cleaning system wherein the filter is reusable after ultrasonic cleaning in a tank. The filter is disassembled, separating the filter element from the case. The filter element comprises a micromesh metallic filter core that traps contaminants within it during normal use. The micromesh core element is cleaned in a liquid bath while being exposed to ultrasonic vibrations that shake the contaminants from the mesh filter structure. The contaminants are washed from the mesh by the fluid bath as they are separated from the mesh structure. Once cleaned, the filter is reassembled and can be reused unlike typical paper care filters that must be discarded.

Description:
[0001]    This application claims priority from a provisional application, No. 62/291,105, filed Feb. 4, 2016. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention pertains to the field of filters and filter cleaning systems, and particularly to combustion engine filters that can be cleaned for reuse. 
       BACKGROUND OF THE INVENTION 
       [0003]    Caring for the environment has become a virtually universal goal for all industries and especially for those that regularly create a considerable quantity of waste products that challenge the environment. The present invention does its part to help ameliorate environmental concerns while offering industries, particularly those that operate fleet vehicle businesses, the opportunity to both lessen the environmental burden that their operations cause and save money. 
         [0004]    present invention combines a filter, most commonly though not exclusively a vehicular oil filter, having a micromesh metallic filter element with a cleaning apparatus that subjects the filter element to ultrasonic waves to clean it. Once cleaned, the filter element is reassembled into the filter casing to be reused rather than discarded, as is the present practice with ordinary paper-core oil filters. The invention simultaneously provides significant cost containment by making the filters reusable rather than disposable, and lessens the environmental impact of millions of discarded, contaminated filters. 
       SUMMARY OF THE INVENTION 
       [0005]    A reusable filter cleaning system that comprises in combination a reusable filter and an ultrasonic filter cleaning apparatus, the filter comprising a case and a removable, cleanable and reusable filter element, and the cleaning apparatus comprising a dual well fluid tank and an ultrasonic wave generator adjacent to one fluid well of said tank that generates ultrasonic wave energy into the said fluid well. The reusable filter element comprises a micromesh material that may be metallic. The metallic material may be stainless steel. 
         [0006]    The system further comprises a cleaning solvent in at least one well of the fluid tank. The ultrasonic wave generator produces dynamic frequency sweep ultrasonic energy waves. The ultrasonic generator comprises modular transducers. The system further comprises absorbent pads placed on the surface of the cleaning solvent for absorbing oil products suspended in the cleaning solvent. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    For purposes of illustrating the invention, the drawings show one or more forms in which the invention can be embodied. The invention is not, however, limited to the precise forms shown unless such limitation is expressly made in a claim. 
           [0008]      FIG. 1  is a functional block diagram of the system of the invention. 
           [0009]      FIG. 2  is a composite side elevation view and top plan view of a filter canister with its top removed. 
           [0010]      FIG. 3  is a composite of a side view and a top perspective view of a generalized representation of the micromesh filter element. 
           [0011]      FIG. 4 a    is a partial top detail view of a pleated micromesh filter element in place. 
           [0012]      FIG. 4 b    is a partial perspective view of a pleated micromesh filter element. 
           [0013]      FIG. 5 a    is a schematic view of the composite parts of a sintered metallic mesh filter material. 
           [0014]      FIG. 5 b    is an exploded view of a multilayer sintered metallic mesh filter material and a schematic view of the resulting filter material. 
           [0015]      FIG. 6  presents three schematic views of a sintered metallic mesh filter material. 
           [0016]      FIG. 7  is a perspective view of the ultrasonic cleaning tank. 
           [0017]      FIG. 8  is a perspective view of the ultrasonic cleaning tank and absorbent pads. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Herein described is a system providing a reusable filter together with an ultrasonic cleaning apparatus. The filter described herein as an example application is a vehicular oil filter, although this embodiment may not be the exclusive application of the reusable filter of the invention. The filter comprises a micromesh metallic filter element inside a canister rather than a paper, or other one-time use, filter element. The micromesh filter element entraps finer contaminant particles than paper filters typically remove from engine oil. 
         [0019]    The system also comprises a cleaning apparatus that provides for mounting the filter element in a cleaning solution wherein said filter is subjected to ultrasonic wave vibration. The ultrasonic exposure shakes contaminants loose from the filter mesh as the cleaning solution circulates within the apparatus. The ultrasonic waves create millions of tiny bubbles that implode as they circulate within the filter element, dislodging debris from even the smallest crevices in the mesh. The process is cavitation and the circulating solution carries away the debris that cavitation shakes loose from the filter element. This leaves the filter element clean and ready for reassembly into the canister to be reused in its entirety. 
         [0020]    This process of cleaning and reusing the filter is repeated at each oil change, eliminating the problem of disposal of millions of traditional paper element oil filters in the vehicular example. Because the micromesh filter core is accessible and removable it can be removed and cleaned as needed to extend the life of the filter for years. Reuse eliminates the necessity of disposing of used paper filters that normally are impregnated with up to 45 percent of their weight representing toxic used oil and heavy metal contaminants. 
         [0021]    Referring to  FIG. 1 , the system comprises a filter  10  that is a combination of a filter case  14  having a micromesh filter element  20  contained within it. Commonly the filter  10  comprises a cylindrical case  14  and a removable cap  12 . The filter  10  further comprises a sealing gasket  15  and an elastomer seat (not shown) at the bottom of the case  14 . A spring  13  is compressed between the cap  12  and the filter element  20  to hold the filter element  20  in place within the case  14 . The filter element  20  can be removed for cleanining by removing the cap  12 , spring  13  and gasket  15  and extracting the filter element  20 . 
         [0022]    The system further comprises a cleaning tank  30  that normally has two liquid wells that contain a cleaning fluid  16 . An ultrasonic generator  40  is affixed to the cleaning tank  30 . The ultrasonic generator  40  produces ultrasonic vibrations that pass into the cleaning fluid  16  to literally shake contaminating particulates from the filter element  20  that is submerged in the cleaning fluid  16 . 
         [0023]    Referring to  FIG. 2 , the filter  10  typically comprises a cylindrical case  14 , a gasket  15 , a spring  13  and a cap  12 . The cap  12  comprises a plurality of ports  18  that permit the entry and exit of the fluid, which in the described example is engine oil, that is cleaned by the micromesh filter element  20 . 
         [0024]      FIG. 3  illustrates two representations of the micromesh filter element  20 . The illustration on the left is a side elevation view of the normally (though not necessarily) cylindrical filter element  20  shown in the right view of  FIG. 3  in perspective. The micromesh material of the filter element may be a microns-thin stainless steel for long life and durability though other corrosion resistant metals may be employed. The stainless steel mesh has thousands of tiny micron apertures for fluid to circulate through the mesh, trapping contaminants in the mesh. Micron apertures of between 10 and 50 microns are generally employed. 
         [0025]    The actual configuration of the cylindrical micromesh filter element may be in the form of a pleated gathering of the mesh sheet material as illustrated in  FIGS. 4 a  and 4 b   . The micromesh material may start as a flat sheet of metal having thousands of micron-sized holes. The material is folded accordion style into a cylinder of overlapping segments.  FIG. 4 a    is a partial top view of the folded micromesh sheet  80  shaped to fit within a cylindrical filter casing.  FIG. 4 b    is a partial side elevation of the mieromesh sheet  90  illustrating the large number of micron apertures in the micromesh material folded into an accordion-type gathering within the filter. The thousands of micron apertures trap particulates in the mesh to keep the fluid, e.g., engine oil, as free of potentially damaging contaminants as possible. 
         [0026]    In some cases the filter element may further comprise a second component along with the pleated mesh. A porous sheet of metallic material resembling cloth may be incorporated into the filter element. Referring to  FIG. 5 , this material is a sintered mesh comprised of layered, flexible metallic sheet that acts much like a paper filter element.  FIG. 5 a    depicts as an example three sheets of fine screen mesh  505  having very small apertures.  FIG. 5 b    illustrates the assembly of these sheets  505  into a multilayered cloth-like material  507  by sintering them together.  FIG. 6  shows a sheet of the sintered mesh material  603  which can be formed into a crumpled mass  605  or rolled into a cylinder shape  607  for placement within a filter case. 
         [0027]    The fluid passes through the sintered mesh under pressure leaving contaminant particles trapped in the sintered mesh. Being metallic, the sintered mesh is also cleanable along with the pleated metallic mesh when subjected to ultrasonic vibration. The inclusion of a sintered mesh structure into the filter element with the pleated micromesh structure causes the fluid to pass through the filter in a “tortured path” intended to remove as many contaminant particles as possible in each journey through the filter. Together with the micromesh filter element  20 , this two-stage metallic filter is very effective in removing particulates from the circulating fluid, as in the example of vehicular oil. 
         [0028]    The filter material is micromesh metal rather than paper (as in most automobile oil filters) so that the filter may be removed, cleaned, and reused repeatedly. The cleaning apparatus is illustrated in  FIG. 7 . The cleaning apparatus comprises a fluid tank  100  with two fluid wells  102 ,  104 . The cleaning tank  104  contains a small amount of environmentally safe detergent to facilitate cleaning, and the second tank  102  contains water to facilitate a final rinse of the filter core. 
         [0029]    Attached to the side of one fluid well is an ultrasonic vibration generator  106 . The ultrasonic generator  106  creates ultrasonic vibrations that are transmitted into the cleaning fluid well  104  adjacent to the generator. A small rack (not shown) may be placed into the well  104  to support one or more filter elements in the cleaning solvent  109  during cleaning. 
         [0030]    The ultrasonic generator  106  comprises modular transducers  108  which are the elements that produce the ultrasonic sound waves within the ultrasonic generator  106 . These transducers  108  provide a dynamic frequency sweep that modulates the ultrasonic sound waves through a predetermined frequency range. This frequency modulation vibrates the filter element in a variable manner such that the entrapped contaminants, which might not be shaken loose at a single frequency, are exposed to a constantly changing frequency of vibration pattern. The modular transducers  108  are also removable and replaceable in the event that they fail or require maintenance. 
         [0031]    An example description of the cleaning process for a vehicular filter follows. A filter that has been in use for a prescribed period is removed from the engine. The filter is drained of used oil. The cap is removed from the filter case (see  FIG. 1 ) and the filter element (or “core”) is removed and again allowed to drain. Once the filter core is drained, the filter case and core are placed separately into the cleaning tank in the fluid well adjacent the ultrasonic generator. The cleaning tank fluid well contains a cleaning solvent that is typically warmed to approximately 170° F. before operation. 
         [0032]    The filter case and core should be cleaned by exposure to ultrasonic vibration for at least ten minutes. After cleaning, the filter core and case should be swirled in the cleaning solution in the second fluid well of the cleaning tank for a brief period to rinse off any loose particulates. The case and core are placed on a draining surface while the cleaning solution flows away. Once drained, the case and core should be exposed to forced air from the top down to blow residual moisture from the filter components. The filter components should be stored in a clean environment for about twenty-four hours before they are re-installed on an engine. The filter case, cap, and filter element are reassembled in the reverse order of their disassembly. The reusable filter with a metallic filter core has a functional period of over five years compared with the several months lifetime of a common paper filter. 
         [0033]    After several filters have been cleaned, the cleaning solvent  109  in both fluid wells  102 ,  104  of the tank  100  has used oil, particulates, and contaminants suspended in the solvent. Heavier particulates will settle to the bottom of the wells. Rather than replacing the solvent after each cleaning cycle, the oil products can be removed from the solvent by placing absorbent pads  120  onto the surface of the solvent  109  in each fluid well  102 ,  104  of the tank  100  as shown in  FIG. 8 . In a period of hours (typically overnight) the absorbent pads  120  soak up the oil products leaving the cleaning solvent ready for use again. 
         [0034]    Configurations of the invention that vary in some detail from the described embodiment are possible. Therefore, reference to the following claims is necessary to understand the scope and limits of the invention.