Abstract:
A hydrocarbon capturing device includes a retainer that is inserted into the end of an outlet pipe in a storm sewer catch basin. The retainer includes a ring that expands under a bias against the inner surface of the outlet pipe and radially extending fingers mounted to the ring that prevent insertion of the ring into the pipe too far. Two hooks are mounted to the retainer near the upper side of the outlet pipe to fasten one end of a hydrophobic, hydrocarbon-absorbing fabric sheet to the retainer. The opposite end of the sheet extends into the passageway of the outlet pipe, thereby floating atop any water that flows through the pipe during and after a rainfall or snowfall.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates generally to storm water capturing systems, and more particularly to a device for removing hydrocarbons from storm water as it exits the catch basin of a storm water capturing system. 
     2. Description of the Related Art 
     Precipitation that falls on a surface that cannot absorb it must be directed to a reservoir or a waterway that carries the water away from the surface. This occurs commonly in paved parking lots and streets. Ordinarily the water is directed by gravity into catch basins, which are steel, cast iron, or pre-cast concrete receptacles buried in the ground. The catch basins&#39; openings are at the surface level and are covered by perforated metal covers, through which water can flow into the catch basins, and over which vehicles can drive. Underground pipes connect the catch basins together to direct storm water into a nearby river, stream, or reservoir. 
     Unfortunately, much of the storm water that washes into storm water systems carries foreign matter with it. This foreign matter can include naturally occurring materials such as soil, sand, branches and leaves. However, it often also includes refined chemicals such as automobile antifreeze, motor oil, fuel and other hydrocarbons that leak from automobiles. Additionally, the very pavement that makes up many road and parking lot surfaces includes hydrocarbons (in the form of asphalt) that leach into storm water. 
     Hydrocarbons, which float on water, become an environmental concern because they end up in water that is a potential source of drinking water and/or contains wildlife. It is therefore desirable to remove hydrocarbons that are carried by storm water. 
     Many people have attempted to address this environmental concern by constructing devices for removing hydrocarbons from storm water. U.S. Pat. No. 5,364,535 discloses a fabric that is mounted in a storm sewer catch basin beneath the perforated cover. The fabric absorbs oily pollutants but does not absorb water. However, hydrocarbons in the water coming in through the perforated cover will not be thoroughly removed because the water falls onto the top of the fabric material and prevents it from absorbing the hydrocarbons that float on top of the water. 
     It is also known conventionally to use filters at the opening of a catch basin. However, such filters often become blocked as larger objects, such as sticks and leaves, are filtered out and eventually obstruct the passage of water through the filter. Such obstruction can cause the storm sewer system to overflow, thereby defeating the purposes of both the storm sewer system and the hydrocarbon removal device. 
     Therefore, the need exists for a hydrocarbon removal apparatus that is reliable and does not block water flow. This apparatus should be easily accessed from the surface of the parking lot or roadway, and should remove substantially all of the hydrocarbons from storm water. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention is an improved storm water capturing system. In storm water capturing systems, water flowing across a surface of ground is captured and directed away from the surface of the ground into a catch basin. The catch basin is mounted with an upper lip beneath the surface of the ground. A catch basin sidewall extends from the upper lip downwardly to a floor beneath the upper lip. The sidewall and floor define a catch basin chamber. An outlet pipe extends through the catch basin sidewall into the catch basin chamber. Thus, the catch basin chamber is disposed in fluid communication with a passageway through the pipe defined by an inner pipe surface, which passageway removes water that flows into the catch basin chamber. 
     The improvement to the storm water capturing system described above includes a pair of sheet-retaining fasteners, such as hooks, mounted near an upper pipe edge. Furthermore, a hydrophobic, hydrocarbon-absorbing fabric sheet has a first end mounted to the sheet-retaining fasteners, and a second, opposite end extending downstream away from the catch basin chamber into the passageway through the outlet pipe. 
     An objective of the invention is that as water fills the catch basin chamber and begins to flow through the outlet pipe, the sheet in the outlet pipe floats on top of the flowing water. The water passes beneath the always floating sheet thereby allowing the sheet to absorb hydrocarbons floating on the water. 
     The direction of water flow maintains the sheet extending downstream from the sheet-retaining hooks away from the catch basin chamber into the outlet pipe. The orientation of the sheet, and the structure retaining it at only one end, prevent the invention from causing any overflow of the water falling into the catch basin. The sheet cannot become clogged with debris, but even if some debris becomes lodged in the sheet, the sheet does not block water flow, because water is not forced through it. The water&#39;s upper surface merely flows against the lower surface of the floating sheet. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is a side view in section illustrating the preferred embodiment of the present invention in its operable position. 
     FIG. 2 is an enlarged side view in section through the line  2 — 2  of FIG. 3 illustrating the preferred embodiment of the present invention in the outlet pipe of FIG.  1 . 
     FIG. 3 is an end view in section illustrating the preferred embodiment of the present invention. 
     FIG. 4 is a side view in section illustrating the corrugated pipe adapter. 
    
    
     In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the word connected or terms similar thereto are often used. They are not limited to direct connection but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art. 
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a conventional storm sewer catch basin  10  in its operable position buried underground with the ground surface  12  sloped toward the lip  14 . The ground surface is a conventional asphalt pavement, but could alternatively be gravel, concrete or some other conventional material. The catch basin sidewall  16  extends downwardly from the lip  14  to the floor  18 . A conventional perforated metal grate  20  covers the catch basin chamber  22  defined by the grate  20 , the sidewall  16  and the floor  18 , permitting vehicles driven across the surface  12  to pass over the catch basin. 
     An inlet pipe  24  and an outlet pipe  26  extend through opposite sides of the sidewall  16  into the catch basin chamber  22 . The invention also works with an alternative inlet and outlet pipe configuration in which a single pipe extends from one side of the catch basin chamber to the other, and the top of the pipe in the catch basin is cut out to permit water to enter the pipe. The side of the pipe directing water out of the catch basin is considered the outlet pipe in such a configuration. However, this pipe configuration is primarily found in older construction and is not common in newer sewer systems. 
     The passageway  27  through the outlet pipe  26  is defined by the outlet pipe&#39;s inner cylindrical surface  28 . The passageway  27  is in fluid communication with the catch basin chamber  22 . This means that fluids, such as liquids and gases, can flow between the catch basin chamber  22  and the passageway  27 . 
     The inlet pipe  24  is ordinarily connected to another catch basin for which its opposite end is an outlet pipe. There may be many other catch basins arranged in series with the catch basin  10 , or alternatively, there could be a hub-and-spokes configuration of catch basins and pipes in which several catch basins empty into one primary catch basin, which then directs the water elsewhere. Therefore, water flowing into an upstream catch basin is conveyed to the catch basin  10  by flowing from a distal end (not shown) of the pipe  24  to the end shown in FIG. 1 that empties into the catch basin  10 . 
     As is shown in FIG. 1 by the encircled region, and in FIG. 2, which is a more magnified view of the encircled region, the hydrocarbon removal structure is mounted in the outlet pipe  26 . The hydrocarbon removal structure includes, in the preferred embodiment, a retainer  30  that includes a ring  32 , shown in FIGS. 2 and 3. The ring  32  is preferably steel wire, rod or some other material including composites, such as fiberglass. 
     Referring to FIG. 3, the ring  32  has first and second ears  42  and  44 , and a bolt  46  extending from an aperture in one ear through an aperture in the other. An outwardly biased coil spring  48  extends between the ears  42  and  44  with the bolt  46  extending coaxially through the passageway of the spring  48 . The outwardly biased spring  48  exerts a force against the ears  42  and  44 , which is transmitted therethrough to the ends of the ring  32 , forcing the outer peripheral edge of the ring against the inner surface of the outlet pipe  26 . 
     Radially extending fingers  37 ,  38 ,  39  and  40  extend from the ring  32 . These fingers seat against the terminal end of the outlet pipe  26 , or the inner surface of the sidewall  16 , preventing the ring  32  from being forced into the passageway  27  beyond a predetermined point as shown near the outlet pipe end. It is preferred that the fingers be positioned sufficiently above the spring line or centerline of the outlet pipe in case the ring  32  is used with the alternative pipe configuration described above. 
     A pair of twisted hooks  34  and  36  extend from the ring  32  near the upper edge of the outlet pipe  26 . The hooks provide a fastening means for a sheet  50  to attach to the retainer  30  and prevent the sheet from becoming unfastened, for example in the event of a backflow. The sheet must absorb hydrocarbons but not water, and is preferably a hydrophobic meltblown polypropylene available from the New Pig Corporation, 1 Pork Avenue Tipton, Pa., 16684-0304. The sheet  50  has a pair of preferably flexible loops  54  and  56 , for example made of nylon rope, mounted through grommets attached to the end of the sheet through which the hooks  34  and  36  extend. The hooks retain the loops, and therefore the end of the sheet  50 , near the outlet pipe opening, and the opposite end of the sheet  50  extends freely downstream into the passageway  27 . 
     If the retainer  30  is desired to be positioned in a corrugated outlet pipe  26 ′ as shown in FIG. 4, an adapter  60  is required. This is because in some corrugated pipes the helical lands  62  and grooves between the lands  62  distort the retainer  30 . In all corrugated pipes, there is the difficulty of creating a retainer that fits at the predetermined distance from the end of the pipe and has the appropriate diameter for the pipe at that position. The adapter  60  is preferably made of rolled sheet metal that is bent into a circular shape to fit within the outlet pipe  26 ′ and, preferably, create an outward bias. 
     The outer surface of the adapter  60  seats against and spans across the lands  62 , providing an inner surface that the retainer  30  seats against without distortion. The adapter  60  preferably stays in place by its own spring force exerted against the inner surface of the corrugated pipe. However, the retainer  30  can maintain the adapter in place. The adapter fingers  64  and  66  and two other fingers (not shown), which are behind the retainer&#39;s fingers, prevent the adapter  60  from extending too far into the outlet pipe  62 ′. 
     Once the retainer  30  is in position at the end of the outlet pipe  26 , with or without the adapter  60 , the loops on the end of the sheet  50  are mounted to the hooks  34  and  36 . The downstream end of the sheet is folded under the upstream end and placed entirely in the passageway  27  of the outlet pipe  26 . When water fills the catch basin chamber  22  and begins to flow through the outlet pipe  26 , the flowing water causes the sheet to unfold and extends downstream into the passageway, aligning it with the outlet pipe  26 . Any hydrocarbons floating on top of the water flow against the underside of the sheet  50  that floats on top of the water, and are absorbed and/or adsorbed by the sheet  50 . Once the sheet is sufficiently saturated with hydrocarbons it is removed and cleaned or disposed of. The sheet is replaced with a clean sheet that is similar. 
     One could alternatively construct an outlet pipe with hooks mounted to it for retaining the sheet  50  rather than installing a separate retainer in the outlet pipe as with the preferred embodiment. One could alternatively place metal hooks in the cement of the catch basin when it is being cast rather than attaching them to the outlet pipe or the retainer. In principle, such hooks could be mounted anywhere near the outlet pipe opening so that the sheet could be attached and extended into the outlet pipe. 
     When water starts to flow, the sheet  50  must unfold completely. The sheet  50  must not impede the flow of water through the outlet pipe  26 . This is why it is important that the end of the sheet  50  mounts at the upper edge of the outlet pipe  26  and the opposite end of the sheet  50  extends freely into the passageway  27 , because it is undesirable for water to flow over the sheet  50 . The leading edge of the sheet  50  must stay above the surface of the water, because only then will hydrocarbons on the upper surface of the water be absorbed and/or adsorbed by the sheet  50 . 
     The sheet  50  must be long enough to extend from the upper edge of the outlet pipe to the bottom of the pipe and extend into the outlet pipe with approximately six feet of the sheet along the bottom surface of the pipe. This is to ensure that a sufficient, minimal length of sheet contacts the upper surface of water in the pipe to absorb hydrocarbons. Pipes can range in diameter from eight inches to eight feet, but most are in the lower end of the range. There is also a relationship between the length of time it takes to saturate the sheet with hydrocarbons and the surface area of the sheet  50 . When the pipe has a greater diameter, the width of the fabric increases, thereby increasing overall surface area. Therefore, it is preferred that the sheet  50  be substantially the width of the pipe&#39;s diameter and a length sufficient to permit about at least six feet of the sheet&#39;s length to contact the lower surface of the outlet pipe. It is, of course, possible that in some circumstances the sheet  50  will have a length greater than about six feet in contact with the pipe bottom, for example when it will be used where saturation will occur very rapidly otherwise. 
     It is possible that the outlet pipe  26  will fill with water under extremely heavy rain. Little or no hydrocarbons will be collected under such conditions because the sheet  50  is pressed against the top of the outlet pipe and the flow of water is too turbulent to permit all of the hydrocarbons to float to the top of the pipe. However, because most of the hydrocarbons are washed into the storm water at the beginning of a rain, and because it takes a significant amount of time for enough rain to wash into the storm sewer system to completely fill the outlet pipe, this will have little effect on the function of the invention. 
     When the sheet is saturated with hydrocarbons, it can be discarded or wrung out and reused many times. However, when sand or other grit get on the sheet it may reduce its useful life. Under ordinary conditions, the sheet should be checked after each rain. 
     It is most desirable to be able to remove and install the sheet  50  from the top opening of the catch basin  10 . There is ordinarily a space of 12 to 36 inches from the lip  14  to the outlet pipe  26 . Under such conditions a person could possibly reach down by hand and remove an old sheet and attach a new one. Alternatively, one could use a pole with a hook on the end to lower and raise the sheet from above the catch basin. By using the pole to attach the sheet, one can maintain the invention without worrying about enclosed space requirements established by governmental regulatory agencies. 
     The invention may be modified to permit it to be used in an exceptional situation. In this situation, a manhole opening into a catch basin or other storm sewer system may be smaller than the diameter of the outlet pipe to which a retainer is going to be attached. Thus, the ring of the retainer may be larger than the manhole opening through which the ring must be passed. Therefore, the ring is split in this situation to permit it to be collapsed so it can be taken down in two pieces and reassembled. In the preferred structure for such a situation, the ring is split and a sleeve is attached to a part of the ring. When the ring is to be reassembled within the manhole, one end of the ring is slipped into the sleeve. The force of the ring expanding against the inner wall of the outlet pipe holds the separate pieces of the ring together. 
     While certain preferred embodiments of the present invention have been disclosed in detail, it is to be understood that various modifications may be adopted without departing from the spirit of the invention or scope of the following claims.