Patent Document

FIELD OF THE INVENTION 
     The present invention relates to the field of wastewater management. More particularly the present invention relates to a low cost and effective apparatus for controlling and reducing the flow of pollutants and solids into an outlet of a catch basin. 
     BACKGROUND OF THE INVENTION 
     Stormwater runoff is characterized by the United States Environmental Protection Agency as one of the greatest remaining sources of water pollution in America. Thus, efforts to implement stormwater quality improvement regulations are accelerating across the United States, compelling municipalities and land developers to maximize the usefulness and effectiveness of stormwater infrastructure as never before. 
     In urban, suburban, and commercial settings polluted stormwater, also referred to wastewater, is often collected in a catch basin, also referred to as a wastewater basin. In its simplest form, a catch basin functions to intercept surface water flows in order to prevent the accumulation of stormwater in an area where flooding could impede traffic or pedestrians, cause property damage, or otherwise present a nuisance. Stormwater collects in the catch basins, and flows through a network of pipes, sewers, and additional catch basins to an outlet point such as a lake, stream, river, ocean, unpopulated area, or similar location where the wastewater may be dispersed without the threat of flood or property damage. However, catch basins are also often the entry point of pollutants from diffuse sources found in stormwater runoff. For example stormwater runoff may contain pollutants such as hydrocarbons (also referred to as “oil”), bacteria, sediment, trash, organic material such as leaves, grass clippings, particulate, soil, detergents, coolants, grease, fertilizer, paint, and feces. As a result, polluted wastewater is often discharged untreated, directly into lakes, streams, and oceans. 
     As discussed in U.S. Pat. No. 6,126,817 to Duran et al., which is hereby incorporated by reference, many types of equipment and processes have been suggested in the past for reducing the level of pollutants in wastewater. Many of these systems are based on the principle of differential specific gravity separation. The liquid mixture, which usually is wastewater, flows slowly through an elongated path in a liquid-retaining structure, such as, for example, a catch basin. The matter to be collected is usually oil and floatable debris, both of which accumulate on the surface of the wastewater because they have a specific gravity lower than that of water. Alternatively, as the wastewater flows through the catch basin solids carried by the wastewater accumulate on the bottom of the basin. These solids sink to the bottom of the catch basin because they have a specific gravity greater than water. 
     U.S. Pat. No. 6,126,817 discloses an outlet hood (or “hood”) for use in a catch basin to reduce the flow of oil and other pollutants into an outlet, also referred to as an outlet pipe, in the catch basin. The hood is useful for capturing trash and floatables, and modest levels of free oils, and sediment. The hood is sealably mounted to the wall of a catch basin over the outlet pipe in the wall of the catch basin. The hood is mounted such that the bottom of the hood extends below the lowest level of the outlet. As wastewater collects in the catch basin heavier pollutants sink and collect on the bottom of the catch basin in the sump, the area below the outlet. Other pollutants having a specific gravity less than water, such floatables and oil, float on the surface of the wastewater. 
     The bottom of the hood prevents pollutants with a specific gravity lower than water from entering the outlet pipe since the bottom of the hood extends below the static water level of the wastewater that accumulates in the catch basin. As the wastewater level rises in the catch basin, water flows underneath the bottom of the hood, which is below the surface of the water, and into the outlet pipe. Pollutants with a specific gravity lower than water, however, remain on the surface of the wastewater. The wall of the hood acts as a barrier and prevents the oil and other floatables from flowing into the outlet pipe. Periodically, the catch basin is cleaned to remove oil and other floatables that have accumulated therein, as well as sediment that has accumulated in the bottom of the catch basin. In this way the hood provides an inexpensive means of reducing the level of pollution in wastewater. 
     It is known to manufacture an outlet hood by casting or molding a continuous hood from cast iron or fiberglass. The molded hood can be, at least partially, sealably mounted to the wall of a catch basin over an outlet pipe. In some catch basins the outlet pipe protrudes from the wall of the catch basin some distance. The length of the protrusion from the wall varies in each catch basin. Therefore, it is preferred that a single hood can be used in catch basins having varying outlet pipe configurations. 
     In reference to  FIG. 1 , a known outlet hood  10  is shown. The hood  10  is installed to the wall  20  of a catch basin over an outlet pipe  30  in the wall  20  of the catch basin. The outlet pipe  30  is shown with hidden lines and its distal end appears to protrude slightly from the wall  20  of the catch basin. 
     The bottom  12  of the hood  10 , shown in  FIG. 1 , is open. The top  18  and sides  15 ,  16  of the hood  10  are sealably mounted to the wall  20  of the catch basin. The front of the hood bulges outwardly from the wall  20  of the catch basin. The installed hood  10  forms a hood compartment defined by the wall  20  of the catch basin and the hood  10 . Wastewater that accumulates in the catch basin flows under the bottom barrier  12  of the hood  10  and into the hood compartment where it is drawn into the outlet pipe  30 . The static water level in the catch basin, i.e. the water level in the catch basin when the net flow fluid through the basin is zero, is defined by the bottom level of the outlet pipe  32 . After the hood is installed the surface of the wastewater consists of two distinct areas: (1) the area of the surface wastewater inside the hood compartment, and (2) the area of the surface wastewater outside the hood compartment. 
     The front and sides  15 ,  16  of the hood  10  comprise a hood wall  14  that is curved in the horizontal axis and extends along a vertical axis. In known hood  10  designs the curvature of the hood wall  14  is substantially constant. For example, in a cross section plane defined by the static water level in the catch basin the hood wall  14  is substantially a semicircle with a constant radius. This curved shaped extends along the vertical axis of the hood. Both ends of the semicircle  15 ,  16  are sealably mounted to the flat catch basin wall  20  thereby defining the distinct area of the surface wastewater inside the hood compartment. 
     The upper portion or top  17  of the hood  10  comprises a semispherical closure as shown in  FIG. 1 . In known hoods the semispherical closure, or dome  17 , has a constant radius equal to that of the curved hood wall  14 . The ends of the semispherical dome  17  are sealably mounted to the wall  20  of the catch basin. The dome  17  may include a vent hole or vent pipe, or, as shown in  FIG. 1 , may be completely sealed. It is preferred that the semispherical dome  17  is sealably mounted to the wall  20  to prevent oil, pollutants, and other floatables that accumulate on the surface of the wastewater from flowing over a top of the hood wall  14  and into the outlet pipe  30 , especially during high flow events, when the level of the wastewater rises in the catch basin. 
     The hood wall  14  is semicircular in the cross section plane defined by the static water level  32  in the catch basin. This constant curvature allows the hood  10  to fit over an outlet pipe  30  that protrudes from the wall  20  of the catch basin, while at the same time provides clearance for wastewater to flow under the bottom  12  of the hood  10  and into the outlet  30 . 
     A disadvantage of known hoods is that they do not efficiently facilitate precipitation of particulate suspended in the wastewater flowing through the catch basin. 
     Another disadvantage of known hoods is that they do not increase the distance of the flow path of wastewater flowing through the catch basin system, thereby facilitating precipitation of particulate suspended in the wastewater flowing through the catch basin. The ability of solids to stay suspended in wastewater is a function of the energy in the flow path and the settling velocity of the solid particles. Assuming the characteristics of the particles are constant, the goal is to remove as much energy in the flow path as is feasible, thus allowing for particles to settle and flow to continue as required by a given drainage structure (e.g. stopping flow altogether is optimal in terms of settling, but not in terms of a structure still functioning as a drainage facility). The longer the flow path, the more energy that is dissipated over that path and the more solids that will settle out of the wastewater. 
     Another disadvantage of known hoods is that they do not create multiple flow paths in a laminar fashion to increase the flow path of more rapidly accumulate on the surface of the wastewater outside the hood compartment. With less surface area outside the hood compartment, oil and other pollutants that accumulate on the surface of the water and are more susceptible to being drawn under the hood and into the outlet pipe, especially as the level of pollutants increases, before they can be emptied from the catch basin by service personnel. 
     Another disadvantage of known hoods is that their ability to prevent oil and other pollutants from flowing under the bottom of the hood and into the outlet pipe decreases as the ratio of the area of the surface water inside the hood compartment to the area of the surface water outside the hood compartment increases. This problem commonly occurs in catch basins having circular cross section in the horizontal plane. 
     Another disadvantage of known hoods and hood shapes is that they do not prevent ice from forming on the surface of the wastewater outside the hood compartment and proximate to the bottom of the hood. 
     Another disadvantage of known hoods is that they are susceptible to structure failure in high flow conditions, especially when used in catch basins having a circular cross section. In catch basins having relatively small cross sections water enters at higher velocities. This high rate of flow exerts direct pressure on the hood. Known hoods are susceptible failure under these conditions because they the side of the hood wall are not perpendicular with the circular wall of the catch basin. 
     Another disadvantage of known hoods is they are not provided with an apparatus that prevents floatables and other debris inadvertently drawn under the bottom barrier of hood from entering the outlet. wastewater flowing through the catch basin and increase the settling ability of the drainage structure. 
     Another disadvantage of known hoods is that they do not induce a hydraulic wedge in wastewater that flows into the catch basin, thereby inducing two laminar counter-cyclic eddies, both creating a longer flow path than in known outlet hoods. As wastewater is directed toward the known hood in the catch basin the known hood does not efficiently increase the length of the flow path of the wastewater flowing through the system. 
     Another disadvantage of known hoods is that they do not induce an increased laminar flow path in wastewater that enters the basin and flows toward the circular front wall of the hood. 
     Another disadvantage of known hoods is that they are difficult to install in circular catch basins (circular in the horizontal plane), especially in catch basins having a relatively small diameter, because there is insufficient space for personnel to sealably mount the hood to the wall of the catch basin due to the curvature of the front of the hood and the curvature of the catch basin wall. 
     Another disadvantage of known hoods is that they cannot be used in a catch basin having a relatively small cross sectional area and relatively large outlet pipe. 
     Another disadvantage of known hoods is that their ability to prevent oil and debris from flowing under the bottom of the hood and into the outlet pipe decreases with a larger hood compartment (i.e. hood wall having a larger constant radius). A larger hood compartment occupies a greater area of the water surface in the catch basin. This in turn reduces the area on the water surface outside the hood compartment causing oil and pollutants to 
     Another disadvantage of known hoods is that they are increasingly difficult to mold from fiberglass or form from metal or plastic as the size of the hood increases. As the dimensions of the hood increase the molding produces a less consistent shape, thereby increasing production costs, and limiting the strength of the outlet hood. 
     What is desired therefore is an apparatus for reducing the flow of pollutants such as hydrocarbons, sediment, soil, trash, and floatables into the outlet of a catch basin. Another desire is such an apparatus that can be used in a catch basin that has a circular cross section, and a relatively small diameter. Another desire is an apparatus that extends along an axis, and has a wall shaped to partially sealingly fit around the outlet of an interior wall of a catch basin so as to define at least a partially sealable compartment therewith that is open to the outlet and extends below the outlet so that waste materials floating on said water mixture outside of the compartment are prevented from entering said outlet, wherein the wall forms a prow in a cross section plane being defined by a static water level in said catch basin. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide an apparatus for retaining and/or absorbing pollutants in wastewater that flows through a catch basin. 
     It is another object of the present invention to provide a hood, and more specifically a novel hood wall, that efficiently facilitates the precipitation of particulates suspended in the wastewater flowing through the catch basin. 
     It is another object of the present invention to provide a hood, and more specifically a novel hood wall that creates multiple flow paths in a laminar fashion to increase the flow path of wastewater flowing through the catch basin and increase the settling ability of the drainage structure. 
     It is another object of the present invention to provide a hood, and more specifically a novel hood wall, that creates a hydraulic wedge in wastewater flowing through the catch basin, thereby inducing two laminar counter-cyclic eddies, both creating a longer flow path than just than in known outlet hoods. 
     It is another object of the present invention to provide a hood that induces an increased laminar flow path in wastewater that enters the basin and flows toward the circular front wall of the hood. 
     It is another object of the present invention to provide a hood, and more specifically a novel hood wall, that induces longer dual eddy flow paths in the wastewater that flows through the catch basin. 
     It is another object of the present invention to provide a hood, and more specifically a novel hood wall, that is easy to install in a circular catch basin. More specifically, it is an object of the present invention to provide a wedge shaped, or prow shaped front hood wall. Although this design reduces the area of the hood compartment, it provides additional area on either side for unobstructed access to the side flanges of the hood for sealably mounting to the curved wall of a catch basin having a circular cross section. 
     It is another object of the present invention to provide a hood, and more specifically a novel hood wall, that can be used in a catch basin having a rectangular cross section with a relatively small plan area and a relatively large outlet pipe. 
     It is another object of the present invention to provide a hood, and more specifically a novel hood wall, that can be installed over varying sized outlet pipes, both in diameter and/or length of protrusion from the catch basin wall. 
     It is another object of the present invention to provide a hood, and more specifically a novel hood wall, that prevents oil and debris from flowing under the bottom of the hood and into the outlet pipe. More specifically, the novel hood wall has a prow, i.e. wedge shape. With this novel shape the hood compartment occupies a lesser area of the water surface in the catch basin compared to a known hood having a curved front wall sized to fit over a similar sized outlet pipe. 
     It is another object of the present invention to provide a hood, and more specifically a hood having a wedge shaped front wall, wherein the hood wall splits flow in the catch basin thereby reducing the formation of ice in the wastewater. 
     It is another object of the present invention to provide a hood, and more specifically a hood having a wedge shaped front wall, wherein the hood wall acts to break up ice that flows into the catch basin through an inlet in the catch basin. 
     It is another object of the present invention to provide a hood, and more specifically a hood having a wedge shaped wall, wherein the hood can be manufactured in multiple separate molds, thereby reducing production and shipping costs, especially for larger sized hoods. 
     It is another object of the present invention to provide a screen apparatus mounted under and around the bottom of hood, wherein the apparatus prevents floatables and other debris inadvertently drawn under the bottom barrier of hood from entering the outlet. 
     It is another object of the present invention to provide a hood, and more specifically a hood having a wedge shaped wall, wherein a plurality hoods are securely stackable, thereby reducing shipping and storage costs. 
     It is yet another object of the present invention to provide a single apparatus that comprises a catch basin and a hood mounted therein, wherein the hood is mounted in the catch basin prior to the catch basin being installed into the ground. 
     These and other objects of the present invention are achieved through an apparatus comprising a hood, wherein a front wall of the hood is formed in the shape of a prow that extends along an axis, thereby overcoming the problems of the prior art. More particularly, these and other objects of the present invention are achieved via an apparatus that extends along an axis, and has a wall shaped to partially sealingly fit around the outlet of an interior wall of catch basin so as to define at least a partially sealable compartment therewith that is open to the outlet and extends below the outlet so that waste materials floating on said water mixture outside of the compartment are prevented from entering said outlet, wherein the hood wall substantially forms a prow in a cross section plane being defined by a static waterline in said catch basin. 
     The invention and its particular features and advantages will become more apparent from the following detailed description considered with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the invention are explained in more detail in the description which follows and are represented in the drawings, in which: 
         FIG. 1A  is a orthogonal view of a catch basin wall, wherein a known hood design having a front wall in the horizontal plane with a constant radius is sealably mounted to the wall of a catch basin over an outlet. 
         FIG. 1B  is an orthogonal view of one embodiment of the novel hood wherein front wall of the hood forms a prow that extends along a vertical axis. 
         FIG. 2  is a front view of the hood shown in  FIG. 1B . 
         FIG. 3  is a side view of the hood shown in  FIG. 1B . 
         FIG. 4  is a top view of the hood shown in  FIG. 1B . 
         FIG. 5  is a top view of the hood shown in  FIG. 1B  wherein the hood is rotated 90 degrees counter clockwise about its vertical axis. 
         FIG. 6  is a side view of the hood shown in  FIG. 1B  wherein the hood is sealably mounted to the wall of a catch basin. 
         FIG. 7  is a top view of the hood shown in  FIG. 6  showing a cut away view in a horizontal plane parallel to the static water level in the catch basin. 
         FIG. 8  is a top view of the hood shown in  FIG. 6  showing a cut away view in a horizontal plane parallel to the static water level in the catch basin.  FIG. 8  further discloses, with hidden lines, the outline of the front wall of a known hood, wherein the curvature of the known hood wall is constant. 
         FIG. 9  is a front view of a screen apparatus mounted around the bottom of hood. 
         FIG. 10  is a side view of the screen apparatus shown in  FIG. 9 . 
         FIG. 11  is a top view of the screen apparatus shown in  FIG. 9 . 
         FIG. 12  is a front view of one embodiment of the present invention. 
         FIG. 13  is a side view of the hood shown in  FIG. 12 . 
         FIG. 14  is a top view of the hood shown in  FIG. 12 . 
         FIG. 15  is a front view of one embodiment of the present invention. 
         FIG. 16  is a side view of the hood shown in  FIG. 14 . 
         FIG. 17  is a top view of the hood shown in  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views. 
       FIGS. 1B ,  2 ,  3 ,  4 , and  5  illustrate a novel hood  100  wherein the hood wall  114  forms a prow  120  or a wedge  120  that extends along an axis. The hood in  FIGS. 1B ,  2 ,  3 ,  4 , and  5   100  comprises a hood wall  114 , and hood top  144 . The hood wall  114  and the hood top  144  come together to form a continuous hood  100 . The perimeter of the hood  100  has a flange  150 . The flange  150  provides a surface to sealably mount the hood  100  to the catch basin wall  210 . The hood  100  includes a vent  160  to equalize air pressure in hood compartment  102  with the ambient air in the catch basin  200  outside the hood compartment  104 . The hood top  144  further includes an access port  162  for accessing the hood compartment  102  after installation. It should be understood that some embodiments of the present invention do not include a vent or vent pipe  160 , and in some embodiments the air in the hood compartment  102  is not in communication with the ambient air in the catch basin  200  outside the hood compartment  104 . In other embodiments the hood  100  comprises a hood wall  114 , and does not include a hood top  144 . For example, the hood  100  is open at its top. 
     The hood  100  disclosed in  FIG. 1B  is designed to be sealably mounted to the interior wall  210  of a catch basin  200  having a circular cross section in a horizontal plane. In other embodiments of the present invention the hood  100  is designed to be sealably mounted to the interior wall  210  in a catch basin  200  having a square or rectangular cross section in the horizontal plane. For example against a flat wall. 
     In reference to  FIG. 1B , the hood  100  comprises a hood wall  114 . The hood wall  114  extends along a substantially vertical axis. The bottom  112  of the hood wall  114  defines a barrier that prevents oil and other floatables from entering the outlet  220  (note that outlet and outlet pipe are used interchangeably) when the hood  100  is mounted to the catch basin wall  210  and the bottom  112  extends below the lowest point  222  of the outlet  220 . In some embodiments, as shown in  FIG. 1B  the bottom  112  of the hood wall  114  includes a splitter  152  that extends along a least a portion of the bottom  112  of hood wall  114 . The splitter  152  extends outward from the hood  100  in the horizontal plane. The splitter  152  provides an efficient barrier to prevent floatables from being drawn under the bottom  112  of the hood  100  by the flow of wastewater  240 . For example, if wastewater  240  flows down a surface of the hood wall  114 , the splitter  152  interrupts the flow and forces it to circulate around the horizontal splitter  152  at the bottom  112  of the hood wall  114  before it can flow into the hood compartment  102  and outlet pipe  220 . This obstruction  152  creates vortices or eddies in the wastewater  240  that jettisons floatables and other pollutants from the wastewater  240  current, to the surface of the wastewater  240  outside the hood compartment  140 . 
     In reference to  FIGS. 12-14  another embodiment of the inventive hood  500  is shown wherein the front wall comprises a plurality of splitters. The hood comprises two sections, a top section  510  and a bottom section  520 . Each section  510 ,  520  is formed in a separate mold, as discussed below. The hood  500  is similar in shape to that discussed in the above paragraph. The hood  500  further includes a second splitter  554  that extends along at least a portion of the hood wall at juncture  530  of the top section  510  and bottom section  520 . The second splitter  554  provides an efficient barrier to prevent floatables from being drawn under the bottom of the hood by the flow of wastewater  240 . The second splitter  554  works in combination with the first splitter  552  to increase the efficiency of the present invention. It should be understood that in some embodiments of the present invention there are additional splitters on the front wall of the hood. 
     In further reference to  FIG. 1B , the hood wall  114  further comprises a left side  115  and right side  116 . A flange  150  extends along a least a portion of the perimeter of the left side  115  and right side  116 . The flange  150  provides a surface to sealably mount the hood  100  to the wall  210  of the catch basin  200 . The flange  150  may include one or more holes  164 , as shown in the FIGS. for sealably mounting the hood  100  to the wall  210 . It should be understood that any system may be used to sealably mount the hood  100  to the wall  210  of a catch basin  200 . For example, cement, sealant, external fixtures, or bolts may be used to sealably mount the hood  100  to the wall  210  of the catch basin  200 . 
     In further reference to  FIG. 1B  the hood wall  114  forms a prow  120  in the horizontal plane defined by the static water level  222  in the catch basin  200 . Again, the static water level is the lowest point of the outlet pipe  222 . In other words, the hood wall  114  forms a wedge in the horizontal plane, when the hood  100  is mounted to the wall  210 . In some embodiments the prow  120  extends along a vertical axis. In reference to  FIG. 1B  the prow  120  extends between a bottom  124  and a top  122 . In the disclosed embodiment the bottom  124  of the prow  120  is below the static water level  222 , and the top  122  of the prow  120  is above the static waterline  222 . In the embodiment shown the bottom  124  of the prow  120  extends to the bottom  112  of the hood wall  114 , and the top  122  of the prow  120  extends to the top  118  of the hood wall  114 . 
     In some embodiments of the present invention the prow  120  comprises a single point. For example, the hood wall  114  has a pyramid shape, wherein the point of the pyramid projects into catch basin  200  in the horizontal plane. In other embodiments of the present invention the prow  120  extends along an axis that is not parallel with the vertical axis of the catch basin  200 . For example, in some embodiments the prow  120  extends along an axis and all points of the prow  120  along the axis are equidistant to a vertical wall  210  of the catch basin  200 . In other embodiments the prow  120  extends along an axis and the distance between the interior wall  210  and each point along the prow  120  axis varies. 
     Referring to  FIGS. 1B and 5 , and  7  the prow  120  is formed in the center of hood wall  114  as measured along its horizontal axis. The hood wall  114  has a left panel  126  and a right panel  128 . Each hood wall  114  panel  126  and  128  is a substantially flat plate that extends along the vertical axis. The left panel  126  and the right panel  128  meet along at the centerline of the hood wall  112  forming the wedge or prow  120 . In other embodiments the left and right panels  126 ,  128  bulge outward, and in yet other embodiments the left and rights panels  126 ,  128  bulge inward, or have any other shape known in the art. 
     In reference to  FIGS. 5 and 7  the intersection of the left panel  126  and the right panel  128  forms an angle beta opposite the interior wall  210 , wherein beta is less than 180 degrees. In some embodiments, like that shown in  FIG. 5 , there is an arc transition or fillet  129  at the juncture of the left panel  126  and the right panel  128  in the cross section defined by the static water level  222 . In some embodiments the fillet  129  extends along the entire prow  120 . In some embodiments the transition between the left panel  126  and right panel  128  is not arc, but rather a linear transition, for example an intersection between two planes. 
     In reference to the embodiment disclosed in  FIG. 1B  the hood  100  further comprises a hood top  144 . In other embodiments the hood  100  does not include a hood top  144 , but rather comprises a hood wall  114  wherein either side  115 ,  116  of the hood wall  114  is sealably mounted to the interior wall  210  of the catch basin  200  and the top of the hood  100  is open to the ambient air in the catch basin  200 . In some embodiments the hood wall  114  and the hood top  144  are formed from a single mold. In other embodiments the hood wall  114  and hood top  144  are formed from two or more molds. In the embodiment shown in  FIG. 1B  the bottom  148  of the hood top  144  has the same contour as the top  118  of the hood wall  114  along the horizontal axis. In the embodiment disclosed in  FIG. 1B  the hood wall  114  and hood top  144  are joined together along this contour to form the hood  100 . In some embodiments the hood top  144  further includes the flange  150  around its perimeter. The flange  150  provides a surface to sealably mount the hood  100  to the interior wall  210 . In the disclosed embodiment the hood top  144  further includes a vent  160  and an access port  162 . 
     In other embodiments the hood is formed from a top section  510  and a bottom section  520  wherein the top section  510  and the bottom section  520  may be formed in different molds. For example, in reference to  FIGS. 12-14 , and  FIGS. 15-17 , two embodiments of the present hood is shown wherein the hood is formed from a top section and a bottom section. It should be understood that hood comprising multiple section, the juncture between the sections is not necessarily coextensive with the juncture hood wall, and the hood top. For example, in references to  FIGS. 12-14 , the hood wall comprises at least a portion of the bottom section  520 , and the top section  510 . 
     When the hood  100  is mounted to the interior wall  210  a hood compartment  102  is defined inside the hood  100 . The hood compartment is defined by the interior wall  210 , the static water level  222 , the hood wall  114 , and the hood top  144 . To the extent the hood  100  does not include a hood top  144 , an imaginary horizontal plane that intersects with the top  118  of the hood wall  114  defines the top of the hood compartment  102 . The hood top  144  forms a cover over the hood compartment  102  thereby preventing wastewater from flowing over the hood wall  114  and into the hood compartment  102 . It should be understood that in the embodiments that do not include a hood top  144 , rising wastewater in the catch basin will reach a level when it flows over the top  118  of the hood wall  114  and into the hood compartment  102 , thereby bypassing the bottom  112  barrier of the hood wall  114 . 
     In reference to  FIGS. 2-7  the prow  120  is in the center of the hood wall  114  between the left side  115  and right side  116  of the hood wall  114 . In some embodiments the prow  120  is not centered in the horizontal plane between the left side  115  and right side  115  of the hood wall  114 . For example the prow  120  is justified toward the left or right side of the hood wall  114 . This configuration also disrupts the flow of wastewater  240  as it enters the catch basin  200  and flows around the outside of the hood wall  114 , thereby overcoming problems over the prior art. 
     In reference to  FIG. 4  a top view of one embodiment of the hood  100  is shown. The prow  120  extends out from the catch basin wall  210  in the horizontal plane, similar to the bow of ship. In further reference to  FIG. 2-5  the prow  120  is the portion of the hood that extends furthest from the catch basin wall  210 , with the exception of the splitter  152  at the bottom  112  of the hood wall  114 . As wastewater  240  flows into the catch basin  200  and into the hood wall  114 , the prow  120  creates a bi-lateral flow path in the wastewater that is forced to flow to either the left  115  or right side  116  of the hood wall  114 . The increased length of flow decreases energy, thereby increasing the precipitation or particulate suspended in the wastewater  240 . After the particulate is precipitated from the wastewater flow  240  it sinks to the bottom of the catch basin  200 , also referred to as the sump  228 , for later collection. 
     In reference to  FIG. 7  a top cross section view of a circular catch basin  200  is shown wherein one embodiment of the inventive hood  100  is sealably mounted to the curved interior wall  210  of the catch basin  200 . The circular catch basin  200  has an outlet pipe  220 , represented by dash lines. The hood  100  is mounted to the interior wall  210  of the catch basin  200  over the outlet pipe  220 . In addition the circular catch basin  200  includes a first inlet pipe  230  and a second inlet pipe  232 . The first inlet pipe  230 , shown with dashed lines, is directly opposite the outlet pipe  220  in the catch basin  200 . The second inlet pipe  232 , also shown with dashed lines, is perpendicular to the first inlet pipe  232  and the outlet pipe  220 . It should be understood that there are many possible configurations for the inlet and outlet flow of a catch basin  200 . 
     In reference to  FIG. 6 , a vertical cross section of the circular catch basin  200  of  FIG. 7  is shown. In this catch basin  200 , the first inlet pipe  230  enters catch basin  200  at the same vertical level as the outlet pipe  220 . In some embodiments the first inlet pipe  230  and/or the second inlet pipe  232  are above the outlet pipe  220  thereby preventing wastewater from backing up in the inlet pipes  230  and  232 . The prow  120  extends toward the middle of the catch basin in the horizontal plane as shown in  FIGS. 6 and 7 . In some embodiments it is preferred that the prow extends to a center point of the catch basin in a cross section plane defined by the static waterline. This is preferred because it provides sufficient room inside the hood compartment to allow the hood to accommodate different size outlets, while also providing sufficient room outside the hood compartment for pollutants to collect on the surface of the wastewater. The prow  120  further extends along a vertical axis from the top of the hood wall  118  to the bottom of the hood wall  112 . The bottom of the hood wall  112  is substantially below that static water level  222  in the catch basin  200 . In the embodiment shown in  FIG. 6  the splitter extends along the entire length of the bottom  112  of the hood wall  114 . 
     As wastewater  240  enters the catch basin  200  from the inlet pipe  230  substantially opposite the hood wall  114  it flows directly toward the prow  120  of the hood  100 . The prow  120  forms a hydraulic wedge in the wastewater  240  around the prow  120 . In some embodiments the first inlet pipe  230  is substantially above the hood  100 , and wastewater falls onto the prow  120 , thereby driving the hydraulic wedge deeper into the wastewater  240  collected in the catch basin  200 . The hydraulic wedge induces additional precipitation of particulate as discussed above. Moreover, the prow  120  induces a flow in the wastewater around the bottom  112  of the hood wall  114 . As discussed above, this flow jettisons floatables and causes the precipitation of certain particulate. In addition, the flow reduces ice formation in around the bottom  112  of the hood wall  114 . This is advantageous because ice that forms in and around the bottom  112  of the hood wall  114  may prevent the hood  100  from functioning properly by restricting the flow of wastewater  240 . The increased bi-lateral flow makes it more difficult for ice to form. 
     In further reference to  FIGS. 6 and 7 , the prow  120  prevents ice blocks that flow into the catch basin  200  from damaging the hood  100  and/or the catch basin structure. During colder months and in colder climates it is common for large ice flows and ice blocks to form in wastewater systems. Typically the ice will increase in size throughout the winter. As the temperature increases in the spring the ice will inevitably melt, and flow down the system and into a catch basin  200 . Ice flow poses a significant risk to infrastructure, especially in wastewater systems with substantial elevation change. For example, in a system with a large elevation change, the ice flow could fall or slide into a catch basin under the force of gravity at a high rate of speed and collide with the hood. The momentum of the ice flow could dismount the hood  100 , crack the hood  100 , or block the flow of wastewater  240  in the catch basin  200 . 
     In the case of a massive destructive ice flow, the prow  120  acts as an ice breaker. As the ice flows into the catch basin  100  it collides with the prow  120  and is spilt apart. The prow  120  further protects the hood  100  and catch basin  200  from damage, and prevents ice from clogging the catch basin  100 . The shape of the hood wall  114  increases the structural strength of hood  100  and allows it to withstand increased forces and collisions with ice flows. The increased strength is especially applicable in circular catch basins, wherein the sides  114 ,  116  of the hood wall  114  are substantially perpendicular to the catch basin wall  210 , as shown in  FIGS. 7 and 8 . 
     In reference to  FIG. 8 , a horizontal cross section of a hood  100  mounted to the wall  210  of circular catch basin  200  is shown. The dashed line  14  in  FIG. 8  represents the outline of a prior art hood wall  14 . As is evident from  FIG. 8 , the prior art hood wall  14  extends much further into the horizontal plane of the catch basin  200 . In reference to the left  115  and right  116  sides of the novel hood wall  114 , the angle between the interior wall  210  of the catch basin  200  and the outer side of the hood wall  115 ,  116  is substantially ninety degrees. This configuration provides room to access the flange  150  and sealably mount the hood  100  to the interior wall  210  of a circular catch basin  200 . In addition, as discussed above, this perpendicular configuration increases the strength of the hood  100 , and the integrity of its seal. 
     However, in reference to the outline of the prior art hood wall  14  the angle between the interior wall  210  of the catch basin  200  and the outer side of the hood wall  15 ,  16  is substantially less than ninety degrees. This configuration does not provide sufficient space to sealably mount the hood wall  14  to the interior catch basin wall  210 . The prow  120  of the inventive hood wall  114  combined with the left and right panels  126 ,  128  provides additional space between the sides  115 ,  116  of the hood wall  114  and the interior catch basin wall  210 . 
       FIG. 8  further illustrates that with the novel hood  100  the ratio of the area of the surface water inside the hood compartment  102  to the area of the surface water outside the hood compartment  104  is substantially less than the known hood  10 . The prow  120  hood  100  results in a hood compartment  102  having a smaller area as measured at the static water level. This in turn results in much larger surface area outside the hood compartment  104 . This effect is especially true in catch basins having a circular cross section as shown in  FIG. 8 . The increased area outside of the hood compartment  104  provides additional area relative to the diameter of the catch basin  200  for oil and other floatables to collect. In addition, the increased area greatly improves flow characteristics in and around the bottom  112  of the hood  100 . In addition, the increased area outside the hood compartment  104  is better adapted to allow ice flow to pass through the catch basin, and to allow at least some ice formation in the catch basin  200  without substantially degrading the ability of the hood  100  to prevent pollutants from flowing into the outlet  220 . Finally the additional space outside the hood compartment allows personnel to more easily enter the catch basin for maintenance. 
     In some embodiments of the present invention, the inventive hood  100  is preinstalled in a catch basin  200  before that catch basin  200  is installed in the ground and integrated into a wastewater collection system. For example, in some embodiments the catch basin  200  has a circular cross section. The catch basin  200  may comprise a plastic, PVC, or any other known material that can be used to manufacture a catch basin off site. The catch basin further includes openings in its interior walls for joining outlet and inlet pipes to the catch basin  200  once it is installed. In addition, a hood  100  is preinstalled in the catch basin  200 . The combination catch basin  200  and hood  100  is shipped to the work site, where the combination is installed into an existing wastewater collection system. This configuration significantly reduces installation costs. 
     In reference to  FIGS. 9-11 , a novel screen apparatus  500  is shown for use with a hood  300  installed to the wall  410  of a catch basin  400 . In some embodiments the screen  500  is used as standalone apparatus in a catch basin  400 . In other embodiments the screen  500  is used in combination with the novel hood  100  having a prow  120  in its front wall  114 , or in combination with a known hood  10 . The screen  500  is adapted to be installed to the catch basin wall  410  so that a least a portion of the wastewater  440  flowing through the catch basin  400  and into the outlet  430  passes through the screen apparatus  500 , thereby preventing floatables from entering the outlet pipe  420 . 
     In reference to  FIG. 9  the screen comprises a screen wall  514  that extends along an axis. The screen wall  514  has a left side  515  and a right side  516 . In reference to the embodiment shown in  FIG. 11 , the screen wall  514  has a curved shaped in a horizontal cross section. The left side  515  and right side  516  are adapted to be fixed to the interior wall  410  of the catch basin  400 . For example, in some embodiments the left side  515  and the right side  516 , include a flange that extends along at least a portion of the side and provides a surface to mount the screen  500  to the wall  410 . 
     In some embodiments the top of the screen wall  514  is above the bottom  312  of the hood wall  314  when the screen  500  is installed to the wall of the catch basin. For example, in the embodiments disclosed in  FIGS. 9-10  the top of the screen wall  514  extends above the bottom of the hood  312 . The bottom  512  of the screen wall  514  extends below the bottom  412  of the hood wall  314 . In some embodiments the distance that the screen wall  514  extends above the hood bottom  312  is approximately five times the distance the screen wall  514  extends below the hood bottom  312 . 
     In reference to  FIG. 9 , the screen wall  514  comprises a mesh or a screen that allows wastewater  440  to freely pass through, but prevents larger size floatables from passing through, for example cans, paper, and other floatables. In some embodiments the screen wall  514  may comprise a mesh having ¼ inch openings. In other embodiments, the screen wall  514  may comprises a mesh having 2 inch openings. In yet other embodiments the screen wall  514  may comprise one or more sheets of metal, wherein the sheet metal includes a plurality of perforations thereby allowing wastewater  440  to flow through. In some embodiments the screen  500  is manufactured from plastic, being rigid or flexible. In further embodiments, the perimeter of the screen apparatus  500 , or a least a portion thereof, is reinforced to increase the strength of the structure, especially as it is subject to great forces as the flow rate increases in the catch basin  400 . 
     Referring to  FIG. 11 , the disclosed screen  500  does not include a bottom or a top, rather it is open, thereby allowing wastewater and some non-floatable pollutants to pass through. For example, wastewater  440  flows under the bottom  512  of the screen wall  514 . In some embodiments the screen apparatus  500  includes a screen bottom. In reference to  FIG. 11 , the screen apparatus  500  further does not include a screen top. This facilitates installation in and around the hood  300 , and also serves to release excess wastewater  440  in the case where the screen becomes clogged and wastewater  440  collects in the catch basin  400 . As the wastewater  440  rises above the highest level of the screen it flows over the screen wall  514 . It should be understood that in some embodiments the screen  500  may include a bottom, and or a top. It should be further understood that in some embodiments the screen  500  may have varying mesh size, designed to filter pollutants commonly found at a particular location. 
     It should be understood that the foregoing is illustrative and not limiting, and that obvious modifications may be made by those skilled in the art without departing from the spirit of the invention. Accordingly, reference should be made primarily to the accompanying claims, rather than the foregoing specification, to determine the scope of the invention.

Technology Category: 7