Abstract:
A water collection structure comprises within it first and second sub-chambers and at least one water collection chamber. The first sub-chamber is at least partially bounded by a wall and has extending from it a water input guide configured and arranged to direct water toward a portion of the wall of the first sub-chamber. The second sub-chamber is open to the first sub-chamber and configured to accept a filter. The second sub-chamber is open to a conduit configured for the carriage of water from the second sub-chamber to an output port of the water collection tank. In use a filter disposed in the second sub-chamber preferentially filters water from the first sub-chamber such filtered water being deflected by the wall of the second sub-chamber to fall into the water collection chamber while the debris laden waste water falls out the lower part of the filter into the conduit.

Description:
TECHNICAL FIELD 
     The present invention relates to water collection and, in particular, to a water collection structure that employs a filter within the water collection structure. 
     BACKGROUND OF THE INVENTION 
     Rainfall is intermittent and variable. Sometimes rainfall variations are regular with the seasons. In other instances, rainfall fluctuates over longer periods of time. The variability of rainfall has forced man to develop systems to collect water when available to provide water when rain is scarce. 
     In a more contemporary perspective, water supplies, particularly in the Southwestern United States have come under particular pressure arising from increasing populations and what appears to be increasing rainfall variability. 
     In response to rainfall variability, the collection of rain has been undertaken for centuries. Cisterns were used in the classic era to hold rainwater collected from roofs and more recently, rain collection receptacles such as rain barrels have been located in suburban neighborhoods. These are found with increasing frequency throughout the Southwestern United States to supplement local supplies at reasonable cost. 
     The water collected from rainfall, either through especially constructed collection systems or from structures such as roofs, for example, will typically include unwanted material washed into the collection systems and receptacles. Without some sort of filtration or selection system, vegetative matter such as leaves and twigs along with animal waste such as bird droppings, will frequently wash into the storage receptacles of water collection systems. 
     Consequently, a variety of filtration systems have been developed to inhibit the collection of unwanted material and waste in rain collection systems. Such systems have used a variety of techniques such as direct filtration through mesh or fiber screens while other systems have used cyclonic or circulatory action to assist the passage of higher quality water through filters while leaving the more debris laden water for differential collection. 
     In each case, however, the filtering system has added complexity and unsightly apparatus to filtration systems. This is of particular concern in residential installations where rain barrels are increasing in use. Most available filtration systems add visible plumbing and unsightly complexity to what should preferably be utilitarian and unobtrusive installations whether devised to enhance the water supply for residential water users while lowering the load on the neighborhood or city supply facilities or providing water supplies in locations far removed from established supplies. 
     What is needed therefore is a filtration system devised to remove substantial amounts of unwanted debris and residue from rain water before collection for later use while minimizing the visibility of the filtration apparatus. 
     SUMMARY OF THE INVENTION 
     A water collection structure includes first and second sub-chambers and at least one water collection chamber. A water inlet and the first sub-chamber are configured to impart rotational motion to inlet water. A second sub-chamber exhibits an opening to the first sub chamber. An open-ended filter is disposed into the opening of the second sub-chamber. The filter has an at least partially water-permeable wall that inhibits passage of debris from circulating water passing to the second sub-chamber from the first sub-chamber. The water to which rotational motion has been imparted preferentially passes through the permeable walls of the filter and is deflected by the wall of the second sub chamber to descend to the rain collection chamber. Debris-laden water and the debris that do not pass through the permeable wall of the filter pass through the lower open end of the filter into a conduit that carries the debris and associated waste water to an exit port of the water collection tank. In a preferred embodiment, the wall of the second sub-chamber acts as a deflection wall and deflects the water passed through the filter toward the outer perimeter of the conduit which is smooth to provide for the water a capillary path into the water collection chamber thus inhibiting eddy currents that could otherwise result from the water passing through the filter falling directly into the collection chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts a cutaway view of a water collection structure in accordance with a preferred embodiment of the present invention. 
         FIG. 2  is an enlarged perspective cutaway view of the upper part of the embodiment of the rain collection structure shown in  FIG. 1 . 
         FIG. 3  depicts the area shown in  FIG. 2  showing the disposition of a filter within the rain collection structure embodiment. 
         FIG. 4  depicts the area of the embodiment shown in  FIG. 2  but with a filter placed in the structure and exemplified water flow represented by arrows. 
         FIG. 5  is an enlarged depiction of a portion of the water collection structure embodiment with a filter in place that is shown in  FIG. 4 . 
         FIG. 6  depicts the path of an exemplified conduit and its path exiting a water collection structure in accordance with a preferred embodiment. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIG. 1  is a cross-sectional depiction a water collection structure  10  in accordance with a preferred embodiment. As those of skill will readily recognize, structure  10  may be called in the art a “tank” or “barrel” depending on its capacity. For purposes of this exposition, however, it should be understood that the term “tank” may, from time to time, be employed without any implication that a size limitation is imposed by use of that shorthand term for water collection structure  10 . 
     Water collection structure (“tank”)  10  has outer wall  12  with optional inspection ports  12   p . Although shown as a cylindrical structure, tank  10  may take on a variety of shapes prismatic, squared, spherical and/or various cylindrical configurations. Tank  10  comprises a water retention chamber  14 , first sub-chamber  16  with wall  18  and a second sub-chamber  20  with wall  22  and conduit  24 . Optional accessory chamber  25  is shown at the floor of tank  10 . Conduit  24  is shown having an exit portion  24 E concealed in chamber  25  but as those of skill will recognize after appreciating this disclosure, conduit  24  can take a variety of paths and be comprised of a variety of portions or sections. Preferably, first sub-chamber  16  and second sub-chamber  20  and conduit  24  along particularly its upper length, are aligned along an imaginary axis shown with dotted A line through tank  10 . They need not be so aligned but such alignment is preferred. 
     Water collection structure  10  is typically comprised from structurally sound plastic but it may be configured from a variety of materials with or without a supporting frame as determined to be appropriate for the capacity of water to be held and the available fabrication methods. As those of skill will recognize after appreciating this disclosure, the elements of water collection structure  10  may be fabricated in individual elements or sub-structures or in some cases all at once or other ways convenient for whatever fabrication process is employed. One preferred mode of fabrication employs the process of roto-molding allowing the fabrication of complex functional configurations at reasonable expense. Other more complex modes of mold-based fabrication may also be employed as those of skill will recognize. 
       FIG. 2  is an enlarged cutaway perspective of the upper part of water collection structure  10 . First sub-chamber  16  shown within tank  10  is depicted as being cylindrical in configuration. First sub-chamber  16  may, however, take on a variety of configurations such as, for example, a bowl or other container having any of a variety of linear or non linear walled shapes. Thus, as should be apparent, depicted floor  26  is not required for first sub-chamber  16 . Water inlet guide  28  guides water into first sub-chamber  16  and is configured so as to impart to entering water a rotational motion that preferably persists about sub-chamber  16 . That motion is encouraged by the configuration of first sub-chamber  16  having, for example, a wall  18  configured to exhibit an arcuate shape such as is shown in  FIGS. 1 and 2 . The orientation of water inlet guide  28  relative to the axis A of first sub-chamber  16  preferably assists in imparting rotational motion to entering water. 
     Second sub-chamber  20  has open ends  30 A and  30 B and wall  22 . As shown in  FIGS. 1 and 2 , second sub-chamber  20  is disposed beneath first sub-chamber  16  and preferably along coincident axis A. Second sub-chamber  20  is disposed so as to present open end  30 A to first sub-chamber  16  to allow the passage of water from first sub-chamber  16  to second sub-chamber  18 . The rotational motion imparted to the water tends to persist and particularly if aligned about common axis A allowing water rotating about first sub-chamber  16  to be induced to fall by gravity into second sub-chamber  20  while still retaining at least a part of its rotational motion. Various combinations of water inlet guide configurations in cooperation with the configuration of first and second sub-chambers  16  and  20  respectively can be devised to manage the degree of rotational motion imparted to entering water. Further, if the upstream collection system that provides water to tank  10  collects a large volumetric flow of water added velocity may be imparted to the water flow, thus encouraging increased velocity in water entering tank  10  and, therefore, enhanced circulatory action by the combination of water inlet guide  28  and first sub-structure  16  of tank  10 . 
     Second sub-chamber  20  includes wall  22  which operates as a deflector to water emerging from the sides of a filter inserted into second sub-chamber  20  of tank  10  as will be later explained and shown with reference to later  FIGS. 4 and 5 . Conduit  24  is disposed to receive water flow from second sub-chamber  20  and has outer wall  32  which in some preferred embodiments is smooth. In the depicted embodiment, the outer diameter D c  of conduit  24  is less than the inner diameter D s  of second sub-chamber  20 . 
     Second sub-chamber  20  is shown as being connected to conduit  24  by tangs  34  but those of skill will recognize that a variety of modes may be employed to dispose conduit  24  in relation to second sub-chamber  20  depending on the various modes of fabrication chosen for water collection structure  10 . With continuing reference to  FIG. 2 , slots  36  are visible between second sub-chamber  20  and conduit  24  at the perimeter of opening  30 B of second sub-chamber  20 . 
       FIG. 3  depicts the disposition of filter  40  into second sub-chamber  20 . Filter  40  has an outer diameter D f  which is smaller than inner diameter D s  of second sub-chamber  20 . Filter  40  is preferably cylindrical in configuration although it could partake of other shapes, and it has open ends F 1  and F 2 . Filter  40  is bounded by filter material  42  disposed about its circumference. Filter material  42  is preferably a two stage metallic screen constructed from corrosion resistant metallic material but at those of skill will recognize after appreciating this disclosure, filter material  42  made by comprised of a variety of materials including certain plastics and synthetic or natural materials in addition to metallic material and may have any number of layers. 
       FIG. 4  is an enlarged depiction of the upper part of water collection structure  10  with filter  40  disposed in place into second sub-chamber  20 .  FIG. 4  depicts a gasket  21  between filter  40  and second sub-chamber  20 . Gasket  21  may be part of filter  40  or a part of water collection structure  10  or a separate piece but it is to inhibit the passage of water so that it falls down opening F 1  of filter  40  when water collection structure  10  is in operation. Gasket  21  may be comprised of any material that provides a water inhibiting seal.  FIG. 4  includes various arrows to depict the flow of water when tank  10  is in use collecting water. As shown in  FIG. 4  by arrow  44 , water enters water input guide  28  to enter first sub-chamber  16 . From its angle of attack, the entering water tends to circulate about first sub-chamber  16  as shown further in its path by arrow  46  that represents the circulatory or cyclonic water flow in a preferred embodiment. 
     As the water circulates, it tends by the force of gravity to coincidentally fall toward second sub-chamber  20  whose opening  30 A (shown in earlier  FIG. 2 ) is now filled by filter  40  and gasket  21 . Consequently, flows through opening F 1  of filter  40  into the interior of filter  40  while its persisting circulatory motion impels the water against the inside of filter material  42  of filter  40 . As the water tends toward the inner side of filter material  42  (e.g., a screen), at least a portion the water is filtered by filter  40  and continues out of the filter (as shown by arrows  47  in subsequent  FIG. 5 ) outward from the central axis A toward wall  22  of second sub-chamber  20 . 
     Wall  22  acts as a deflector to the filtered water emergent from filter  40  tending to cause that water to fall by gravity between filter  40  and deflection wall  22  through gaps  36  (shown in earlier  FIG. 2 ) as shown by flow arrows  48  in  FIGS. 4 and 5 . As those of skill will appreciate after understanding this disclosure, if conduit  24  has an appropriate outer wall  32  of smooth aspect, the water flow  48  will, at least in part, tend to follow the outer wall  32  as it descends into water accumulation chamber  14 . Thus, disturbance of the already accumulated water in chamber  14  tends to minimized as water is added to the accumulation. 
     If water flow  46  into filter  40  is laden with debris, filter  40  inhibits passage of such debris laden water out through filter material  42  and that waste water tends to fall out the lower opening F 2  of filter  40  which is open to conduit  24  down into the inner path of conduit  24  as depicted by flow arrow  50 . 
       FIG. 5  is an enlarged depiction showing in greater magnification the exemplar flows of water in tank  10  as collection is underway. 
       FIG. 6  is an enlarged depiction of the passage of conduit  24  toward exit port  52  of tank  10  in a preferred embodiment. As shown, exit portion  24 E of conduit  24  is substantially concealed by accessory box  25  but as those of skill will recognize, box  25  can be dispensed with and conduit  24  merely brought to exit port  52  directly without concealment or a special exit portion such as  24 E. Water flow  50  depicted in earlier  FIG. 4  passes down conduit  24  and flows out exit port  52 . Exit port  52  may be fabricated by use of spin weld techniques to provide a sound structural fitting for subsequent connection of hoses or other water management devices on the outside of tank  10 . Exit port  52  may be threaded or fitted with any of a variety of fittings appropriate for the subsequent management of the waste water flow from conduit  24 . As those of skill will recognize, the inclusion of accessory box  25  can allow additional control devices for pumps or lights or other accessories within the footprint of tank  10  thus further enhancing the visual simplicity and utility provided by the consolidated (i.e. when used with internal filter) structure provided by tank  10 .