Abstract:
Three flow paths within a single container are provided for the separation of contaminates, such as floating debris, heavy trash, lighter fluids and heavier fluids, from an effluent stream. A first flow path is provided for low flow conditions wherein the effluent stream pools in a first chamber within the container and the surface of the pooled fluid is drawn off, leaving heavy contaminates within the first chamber. The drawn fluid, with lighter and/or floating contaminates, enters a second chamber. The fluid is drawn from the second chamber below the surface level of the fluid, leaving the lighter and floating contaminates within the second chamber. In moderate flow conditions, a second flow path is established from the first chamber and out the container, bypassing the second chamber. Fluid for the second flow path is drawn from below the surface of the fluid in the first chamber to exclude light and floating contaminates. A third flow path is established when the first and second flow paths are insufficient to accommodate the effluent received by the container. The third flow path draws from the surface of the fluid in the first chamber and bypasses the second chamber in discharging from the container.

Description:
REFERENCE TO RELATED CASES 
     This application claims the benefits of U.S. Provisional applications Ser. No. 61/146,722 and 61/238,669 and 61/238,677. 
    
    
     BACKGROUND OF THE INVENTION 
     When it rains on a parking lot, a road, or other impervious surface, rain water will not permeate into the ground as it would if the surface were in its natural condition. The rain water will instead run off this surface often discharging directly into a stream or receiving body. Typically, some form of rain water collection and/or diversion is incorporated into the design of a paved surface of sufficient size to warrant storm water control. This results in an accumulation of the rain water prior to discharge into the watershed. 
     Because impervious surfaces typically have been paved for a purpose, they will have vehicles, activity and/or traffic on them, which will cause an accumulation of pollutants between rain events. The rain water runoff therefore will include a the accumulated pollutants as they are washed from the impervious surface during a rain storm. Treatment of rain water runoff is important to the preservation of watersheds. The pollutants are typically at their highest concentration in the rain water during the first portion of a storm, as most of the pollutants are typically washed off in the initial, and usually less intense, part of a storm. Consequently, the first runoff water is the most critical to treat. In an effort to minimize the impacts of pollutant contaminated runoff water, various systems have been developed to treat runoff water including removing the pollutants by separation and/or filtration. 
     Because precipitation occurs at variable rates, a system must be able to treat runoff during low rain flow as well as during high rain flow periods. The system must have the capacity to capture and treat polluted runoff while having the ability to properly handle large water flows which exceed the in line treatment capacity of a system, without release of pollutants or untreated contaminated water into the watershed during high rain flow events. Consequently, treating storm water creates additional difficulties because the system must be able to clean the water yet be able to pass very intense storms without flow slowdowns or backups that could cause flooding. 
     SUMMARY OF THE INVENTION 
     The apparatus described treats storm water through the diversion of pollutants and contaminated runoff. One embodiment of the invention diverts certain flow levels or volumes of storm water which are typically the most contaminated, so that this water can be treated further by filtration or other treatment means, as this water requires. 
     The present invention improves on the flow separator taught in U.S. Pat. Nos. 5,746,911 and 6,264,835, both of which are entitled “Apparatus for Separating a Light From a Heavy Fluid.” Similar in general operation to the separators of the above patents, the present invention provides for three potential flow paths for runoff water entering the separator device. The present invention provides differentiated treatment to runoff water dependent upon the rate of influent flow into the separator. The present invention, teaches a single structure with multiple chambers which can be retrofit into standard circular manhole structures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view of a first exemplary embodiment of the present invention with the cover removed to illustrate the internal components of the multiple flow paths of the present invention. 
         FIG. 2  is a cross sectional view of the embodiment of  FIG. 1 , taken along section line A-A of  FIG. 1 . 
         FIG. 3  is a cross sectional view of the embodiment of  FIG. 1 , taken along section line B-B of  FIG. 1 . 
         FIG. 4  is a cross sectional view of the embodiment of  FIG. 1 , taken along section line C-C of  FIG. 1 . 
         FIG. 5  is a perspective cut away view illustrating the internal configuration of the first embodiment of the present invention of  FIG. 1 . 
         FIG. 6  is a top view of a second exemplary embodiment of the present invention with the cover removed to illustrate the internal components of the multiple flow paths of the present invention. 
         FIG. 7  is a cross sectional view of the embodiment of  FIG. 6 , taken along section line A-A of  FIG. 6 . 
         FIG. 8  is a cross sectional view of the embodiment of  FIG. 6 , taken along section line B-B of  FIG. 6 . 
         FIG. 9  is a cross sectional view of the embodiment of  FIG. 6 , taken along section line C-C of  FIG. 6 . 
         FIG. 10  is a perspective cut away view illustrating the internal configuration of the second embodiment of the present invention of  FIG. 6 . 
         FIGS. 11 to 13  are flow diagrams illustrating standard low flow. 
         FIGS. 14 to 16  are flow diagrams illustrating moderate flow. 
         FIGS. 17 to 19  are flow diagrams illustrating high flow. 
         FIG. 20  illustrates the optional removable debris collection basket. 
     
    
    
     DETAILED DESCRIPTION 
     A first exemplary embodiment of the invention is illustrated in  FIGS. 1-5 . The flow separator is located within a cylindrical structure  10 , which can be an independent structure or an existing standard cylindrical ground water structure. The structure  10  includes a floor  11  and an interior wall  12 , which can be curved, as illustrated, or straight. The wall  12  divides the cylindrical structure  10  into two chambers, a primary chamber  15  and a storage/detainment chamber  16 . 
     At least one inlet  13  and one outlet  14  are provided for intake and discharge of runoff water. The structure can have multiple inlets which can be located in the side or the top of the structure, however all inlets must initially discharge into chamber  15  of the structure. The structure may also have multiple outlets if placed downstream of the separation structure. 
     A first conduit, surface flow conduit  17  connects primary chamber  15  with storage chamber  16 . Surface flow pipe  17  draws fluid from the surface of primary chamber  15  so that heavy contaminates are left behind to accumulate in primary chamber  15 , and discharges the fluid below the surface of the fluid in storage chamber  16 . Storage chamber  16  also includes a storage chamber outlet pipe  20  that draws from below the surface of the fluid in storage chamber  16  and discharges into outlet pipe  14 . Alternatively, storage chamber outlet pipe  20  can discharge directly to the exterior of structure  10  for combination with the outflow of outlet pipe  14  downstream of the discharge from structure  10 . Secondary flow conduit  18  connects primary chamber  15  with outlet pipe  14  and draws water from below the surface of the fluid in primary chamber  15 . Primary chamber  15  is further connected to outlet pipe  14  at a level above the intake and discharge of conduits  17  and  18 . Outlet pipe  14  opens into primary chamber  15  and is provided with a weir  21  which allows fluid to spill over from primary chamber  15  into outlet pipe  14  when the fluid level in chamber  15  reaches sufficient height. 
     As illustrated in  FIGS. 1 through 4 , during operation, runoff water enters the structure  10  through inlet pipe  13  and flows into primary chamber  15 . Primary chamber  15  will fill with runoff water up to the level of the opening into the top of surface flow pipe  17 . Once the water in chamber  15  exceeds the entry height of surface flow pipe  17 , water will enter and flow through surface flow pipe  17  into storage chamber  16 . Water can enter surface flow pipe  17  with or without the influence of a vortex generator  22  which may be included in chamber  15 , positioned adjacent the entrance to surface flow pipe  17 . Heavy contaminates remain behind in chamber  15 . 
     Storage chamber  16  will fill and retain water to the crest elevation of the storage chamber outlet pipe  20 . When the water in storage chamber  16  exceeds this level, the water will flow out outlet pipe  14 . 
     During normal operation, water will enter primary chamber  15  and fill to the crest of the surface flow pipe  17  where it will be induced to swirl and create a vortex if the vortex generator  22  is included. The surface water drawn into surface flow pipe  17  will include floating and light suspended contaminates. These contaminates will be concentrated and will flow through the surface flow pipe  17  into the storage chamber  16 . 
     Flow pipe  17  preferably discharges below the surface of the water contained in the storage chamber  16 , during normal operation. The light fluids and floating contaminates will rise to the surface of the fluid in chamber  16  and thus be separated from the below surface discharge from chamber  16  out pipe  20 . As more water enters chamber  16  from surface flow pipe  17 , water within chamber  16  is displaced and forced out storage chamber outlet pipe  20 . The input end of storage chamber outlet pipe  20  is sufficiently below the surface of the water in storage chamber  16  so as to avoid allowing floating particles, light contaminates or oils to be released from the storage chamber  16 . 
     Surface flow through surface flow pipe  17  and out chamber outlet pipe  20  will exist during all flow intensities of runoff water. During lower intensity flows, the flow of water through surface flow pipe  17  is the single flow path of the water. 
     During moderate flow rates, water continues to flow though surface flow pipe  17  and out outlet pipe  14  in the manner described above. However, in order to avoid inundation of storage chamber  16  and the possible resuspension of collected pollutants, a secondary flow will occur through the secondary flow pipe  18  when necessary and initiated by a runoff water of sufficient flow intensity. 
     The intake of secondary flow pipe  18  is located within primary chamber  15 , below the open end elevation of surface flow pipe  17 . Secondary flow pipe  18  discharges into outlet pipe  14  at a higher elevation than the storage chamber outlet pipe  20 . The differences in elevation enable the secondary flow pattern to occur only during moderate or severe events when the primary flow, through surface flow pipe  17  is insufficient to accommodate all of the runoff inflow into the structure  10 . 
     A third flow pattern will be established in extreme runoff events when the fluid in primary chamber  15  reaches an elevation above bypass weir  21 , thereby overflowing the weir  21  and flowing directly into outlet pipe  14 , bypassing the primary and secondary flow paths. This allows high volume flows to bypass through the system directly to the outlet  14  thereby preventing resuspension of already entrained heavy contaminates in primary chamber  15  or the flushing of floating or light fluid contaminates from chamber  16 . The primary and secondary flow patterns will continue although they may be of minimal effective flow due to potential back pressure dependant on the flow rate and hydraulic state of the components within container  10 . 
     Allowing high volume flow, which normally occurs sufficiently after the start of a rain event, to bypass the system will have a minimal effect on allowing contaminates to pass out of the container  10 , due to the continued entrainment of contaminates from the early, lower volume flow during which the majority of the accumulated contaminates are washed from the paved surfaces. 
     A second exemplary embodiment of the invention is illustrated in  FIGS. 6-19 . This embodiment is also illustrated as housed within a cylindrical container  10 . The cylinder  10  has a floor  11  and interior dividing walls  12  and  32 , creating three separate chambers, a primary chamber  15  and a storage chamber  16 , as in the previous embodiment, and an outlet chamber  33  having a raised floor  34 . Outlet chamber  33  functions similar to the interior portion of outlet conduit  14  of the previously illustrated embodiment. The container  10  also has at least one inlet  13  into primary chamber  15  and at least one outlet  14  from outlet chamber  33 . 
     The second embodiment also includes a low flow conduit  17  that has an inlet opening  30  in an upper surface at the first end of the conduit  17  situated within chamber  15 , for allowing surface water to flow from chamber  15  into the conduit  17 . Conduit  17  empties into chamber  16  through opening  31  in the interior dividing wall  12 . The discharge into chamber  16  is above the surface level of the fluid in chamber  16  during normal flow conditions. A subsurface control plate  35 , attached to the low flow conduit  17  and extending from the interior wall of container  10  to the dividing wall  12 , diverts water under conduit  17  for moderate flow conditions when the level of the water exceeds the lower entry edge of moderate/bypass flow opening  38  in dividing wall  12 . The surface water on the back side of conduit  17  is isolated from the surface water on the front side because conduit  17  and subsurface control plate  35  extend from the interior wall of the chamber  10  to the dividing wall  12 . By isolating the water surface and diverting flow below the subsurface control plate  35 , floating debris in chamber  15  will be prevented from reaching the back side of conduit  17  and therefore cannot flow out the lower portion of opening  38 . 
     A single opening  38  can function as the moderate and bypass flow opening  38  in the interior dividing wall  12 . Alternatively, the wall  12  can be provided with separate openings for moderate flow and for bypass flow, with the bypass flow opening located at a higher elevation than the moderate bypass flow opening. 
     Outlet chamber  33  can receive water via two entry points, storage pipe outflow tube  20  and the moderate/bypass flow opening  38  in dividing wall  12 . Storage chamber outflow tube  20  has an opening that is below the surface of the water in the storage chamber  16 , and an upper opening which empties into outlet chamber  33  through a hole in the floor  34  of chamber  33 . During low flow, pipe  20  will receive water from below the surface of chamber  16  and feed water out its upper end into outlet chamber  33 . Flow opening  38  has its lower edge above the level of the inlet opening  30  of conduit  17  and above the level of the discharge of pipe  20  into outlet chamber  33 . When the low flow path through conduit  17  is sufficient to convey all of the water entering chamber  15  out into chamber  16 , low flow conditions are maintained. When the inflow into chamber  15  exceeds the capacity of conduit  17 , the water level in chamber  15  will rise. Moderate flow through opening  38  will occur when the level of the water in primary chamber  15  rises sufficiently to exceed the level of the lower edge of opening  38 . 
     During low flow operation, as illustrated in  FIGS. 11 to 13 , water first enters primary chamber  15  from inflow pipe  13 . When the water level within chamber  15  reaches the inlet  30  of the low flow conduit  17 , the surface water will enter conduit  17  and flow into holding chamber  16 , leaving submerged debris to settle to the floor of primary chamber  15 . Floating debris will be transported with the water flow through conduit  17 , into storage chamber  16 . For the system to function without backwash, the chamber outlet pipe  14  must be lower than the inlet  30  of the low flow conduit  17 . 
     Water within primary chamber  15  will exit at the lowest point in that chamber as long as the low flow conduit  17  can maintain a flow rate sufficient to handle the inflow of water. As this water enters the low flow conduit  17  it passes through the interior dividing wall  12  into the storage chamber  16 . At this point the water may enter an optional trash basket  25 , as illustrated in  FIG. 20 , or simply enter the storage chamber  16 . Any debris, heavy or floating, which enters chamber  16  with the water, will be separated by floatation, settling, or capture in a basket  25  if used. As the water enters the storage chamber  16 , it displaces water from below the surface and pushes water thorough the outflow tube  20  to the outlet chamber  33  and out of the chamber  10  through the outlet pipe  14 . By drawing water from below the surface, outflow tube  20  will block the flow of floating debris out of chamber  16  into outlet chamber  33 , thus trapping floating debris in chamber  16 . 
     If the inlet water flow rate into chamber  15  increases, the system will move from low flow to moderate flow. During a moderate flow event, the low flow pattern will continue to operate, removing surface flow from the primary chamber and diverting it to the storage chamber. However as the water level in the primary chamber raises to a point that the water can now crest the lowest point of the moderate/bypass flow opening  38  in the interior dividing wall  12 , water from below the surface in the primary chamber  15  will flow below the subsurface control plate  35  into the opening  38  behind the low flow conduit  17 . This moderate flow level will be free of the surface flow that has the majority of the contaminants. These flow patterns will continue until the level of the water in the primary chamber  15  exceeds the top of low flow conduit  17 . Water will then be able to crest over conduit  17  and flow out opening  38  into outlet chamber  33 , including surface water. 
     Once conduit  17  has been crested, bypass flow of all surface flow occurs and treatment of floating debris essentially stops. The same volume of water will still flow through the storage chamber but the surface flow will bypass the separation of chamber  16  and go directly over the low flow conduit  17  and pass through the higher portion of the moderate/bypass opening  38  in dividing wall  12 . At this point in a storm event, the vast majority of debris has already washed off of the paved surface and has been collected in storage chamber  16 . 
     Splitting flows into chamber  16  prevents resuspension of collected pollutants and significantly limits the potential for the system to become occluded and cause a flow stoppage which would create a backup in the storm drain system. 
     In another exemplary embodiment, illustrated in  FIG. 20 , a basket  45  with an opening on its side to allow inflow, such that it can store the trash and debris collected for easy removal as it accumulates, is added to the flow path. The basket  25  has porous sides to allow the outflow of water while trapping debris, and is removable, as illustrated, so that the accumulated debris can be removed from the basket for disposal.