Abstract:
An environmentally secure weather containment system for at least one chemical container comprising a primary container significantly nested within and sealingly mated with a secondary container, the primary tank having an exposed portion, the secondary container providing a housing for at least one pump and at least one port for at least one a power line or signal line above a 110% containment level.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is related to, and claims priority to, Provisional Application Ser. No. 61/070,802 filed Mar. 26, 2008 entitled Secure Weather Containment System—Enviro Tank, inventor Kirk D. Claborn. 
    
    
     FIELD OF THE INVENTION 
     The invention lies in the field of secure weather containment systems for chemical tanks of approximately 25 to 500 gallon capacity, and is especially applicable for unmanned sites. 
     BACKGROUND OF THE INVENTION 
     In current practice 25 to 500 gallon chemical tanks with a pump are frequently staged at industrial sites and utilized to pump chemicals upon need. Frequently the sites are unmanned. As indicated in the “prior art” of  FIGS. 1A-1D , such chemical tanks are typically supported on legs over a pan. A pump for the chemicals, as shown in the  FIG. 1A , is typically located above the pan and under the tank. Gravity can at least assist the feed for the chemicals to the pump which can be electrically powered or gas powered. 
     The pan is provided so that any spill, as well as run-off rain that picks up chemicals leaking from orifices of the tank or pump, will be collected in the pan. Rain water is of particular concern in these circumstances as the rain that washes over the tank frequently becomes contaminated with leaking chemical. E.g. fittings installed not only on the tank but also around the pump and power lines and supply lines and gauge lines can leak at their seals. 
     Environmental issues are arising with these chemical tanks handled in accordance with the current practices. The issue is made more pressing when the tanks are located near urban areas and particularly when the tanks are unmanned. As mentioned above, a containment tank has fittings, such as for a chemical supply line and a sensor line, and chemicals can leak at these fittings over time. The pump can also leak chemicals at its seals. Rain washes the chemicals down into the pan, and although the potentially chemically laden rainwater that collects in the pan is in theory to be disposed of using proper procedures, unfortunately a drain in the pan may sometimes simply be pulled and the collected rainwater, contaminated or not, drained into the ground. Further, birds, animals and livestock may drink the contaminated water collected in the pan and become ill. 
     In particular in the oil and gas industry, and especially in regard to unmanned chemical tanks located near urban areas by such industry, the EPA is requiring tighter controls over the chemical tanks. Thus, it is desirable to improve the containment system for primary chemical tanks, in particular for tanks utilized for supporting pumping applications on pipelines, well heads, refineries and pulp and paper facilities. Most of these locations dictate unmanned operations, where an improved secondary containment system would be valuable to properly prevent all chemical spills and contamination. 
     One system developed in response to the animal problem mentioned above is illustrated in  FIG. 1D . This system provides a porous lid (not clearly visible) over the pan. Chemically laden rain water drains through holes provided in the porous lid such that animals, livestock and birds cannot drink through the porous lid. A second alternate system proposes to minimize rainwater mixing with chemicals leaking from tank and pump seals by covering the tanks and pump with a tarp. Farm and industrial operations are known to utilize double walled tanks to contain primary tank leakage and spillage, but those systems do not address the problems of the contamination of rain water by leaks from a pumping mechanism. In sum, none of the prior art systems are totally satisfactory. 
     U.S. Pat. No. 6,149,026 to Manson teaches a secondary containment tank for enclosing a primary tank, and the inventor offers a remark about a possible provision for enclosing a pump. However, the containment system of Manson makes no provision for the treatment of power and chemical lines in and out of the system, especially as required by a pump, and the structure of the Manson system is unnecessarily expensive vis-à-vis the instant invention. The structure of the secondary and primary vessels of Manson are independent. Each Manson vessel provides self-sufficient, independent support. And the primary vessel has no portion exposed, for maintenance and convenience. 
     By contrast, the mating and nesting structure of the instant invention provides economies of construction cost and space while containing all leaks and spills from the primary container and the pump. (As “nesting” is used herein, two structures that “nest” when mated together exhibit enhanced structural strength, in excess of either structure alone.) The instant invention is comprised of at least one primary tank (preferably constructed essentially of one piece of plastic and designed to hold fluids such as petroleum products, chemicals or water solvents,) which primary tank sealingly mates with and nests within a secondary containment tank, preferably also constructed essentially of one piece of plastic, with a primary tank portion exposed. The nested construction permits economies of structure, space and cost, not possible with free-standing primary and secondary tanks. Provision is made for containing a pump, including utilizing a gravity feed. 
     A portion of the primary tank is exposed, preferably a primary tank lid portion. The secondary tank of the instant invention is preferably constructed to provide, in conjunction with portions of one or more primary tanks themselves, at least 110% chemical containment in the case of a primary tank rupture, as well as a containment housing for at least one pump. Fittings for lines are provided in and out of the secondary container above its 10% fluid containment level, to avoid issues of chemical leak at the secondary tank fittings and seals and thus the possible contamination of rainwater thereby. 
     The primary tank receives structural support and economy of space by significantly nesting within the secondary tank. In a preferred embodiment the secondary tank sealingly secures to and under a top portion of at least one primary tank. This construction permits the top or tops of the primary tank(s) to be accessible. The secondary tank is further designed to house the pumping mechanism(s), thus eliminating the risk of the contamination of rainwater by pump fittings, and preferably provides an access lid, sealingly mated to primary tank and/or the secondary tank portion. 
     The system of the instant invention significantly encloses at least one primary tank and pumping mechanism within a nested secondary container, protecting the surrounding environment from contamination by rainwater washing over chemicals leaking from fittings associated with either the primary tank or the associated pump as well as from spillage from a primary tank rupture. Preferably a portion of the primary tank(s) are exposed. A preferably unitary secondary tank component, together with primary tank portions, provides at least 110% containment for the primary tank fluids. Secondary tank fittings or openings are located above the 110% containment level of the primary tank liquid. In preferred embodiments rain water is inhibited from entering the secondary containment area by weather tight sealing between the secondary and primary tank(s) and the access lid. 
     The containment system of the instant invention is particularly useful to hold liquid for pumping applications in pipelines, well heads, refineries and pump and paper facilities. These locations are largely unmanned, and secondary containment is important to prevent chemical contamination of the environment, especially when the facilities closely interface with urban environments. Economies of material and cost and space arise with the nesting structure construction. 
     SUMMARY OF THE INVENTION 
     The invention includes a system and method for environmental containment for the chemical content of approximately 25 to 500 gallon chemical tanks and associated pumps. The system includes at least one primary tank substantially nested within a secondary tank, the secondary tank and primary tank sealingly mating against penetration by weather, with a portion of the primary tank exposed, preferably a lid portion. The secondary tank is sized to accommodate at least one pump and structured and sized in conjunction with the primary tank(s) to contain at least 110% of the primary tank(s) capacity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A better understanding of the present invention can be obtained when the following detailed description of the preferred embodiments are considered in conjunction with the following drawings, in which: 
         FIGS. 1A-1D  illustrate prior art systems for protecting against chemical contamination from chemical tanks stationed at sites. 
         FIG. 2  illustrates a preferred embodiment of the containment system of the instant invention, in perspective and in exploded view. 
         FIG. 3  illustrates the containment system above including in particular the primary tank, the secondary tank and a nesting structure. 
         FIG. 4  illustrates in greater detail the primary unit of the secondary tank, above. 
         FIG. 5  illustrates in greater detail the primary tank above, designed to nest within the secondary tank. 
         FIG. 6  illustrates a detachable lid as a portion of the secondary tank and containment system, above. 
         FIG. 7  illustrates a preferred embodiment of a nipple through which chemical is fed from the primary tank to the pump. 
         FIG. 8  illustrates a preferred embodiment of a latch for securing latching the lid to the secondary tank and the primary tank, above. 
         FIG. 9  illustrates a preferred embodiment of a primary tank cap, permitting access to the primary tank from the outside of the containment system. 
         FIG. 10  illustrates a gauge for indicating fluid level in the primary tank, the gauge visible through the top of the primary tank and containment system above. 
         FIG. 11  illustrates a vent for exhausting fumes from the secondary tank, above. 
         FIG. 12  illustrates a secondary container designed to house two primary containers and two pumps. 
     
    
    
     The drawings are primarily illustrative. It would be understood that structure may have been simplified and details omitted in order to convey certain aspects of the invention. Scale may be sacrificed to clarity. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1A-1D  illustrate prior art systems for protecting against chemical contamination from chemical tanks stored at sites and have been discussed above under Background of the Invention. These figures illustrate the pan system, with or without the porous lid, as discussed above. 
       FIGS. 2-12  illustrate preferred embodiments of the instant invention. As illustrated in  FIG. 2 , the containment system  001  is comprised of several main parts, illustrated more particularly in the exploded view. System  001  illustrates the several parts assembled. The assembled view also illustrates a louvered and screened side vent  007 . The exploded view illustrates fluid level indicator  008  that inserts into primary tank  002 , latch  006  for attaching the secondary container access lid  004 , secondary container weather proof access lid  004 , pump motor P/M which rests inside secondary container  003 , primary tank nipple assembly  009  which fits into a lower side wall of primary container  002 , primary tank vented cap  005  which fits securely on a top opening of the primary tank, primary tank (or container)  002 , with primary tank lid portion  010  and secondary tank (or container)  003 . Preferably primary container  002  is constructed of plastic in one piece, including tank body and lid, both designed to substantially nest within, and to sealingly mate with, secondary container  003 , also preferably constructed of plastic in one piece. 
     Features of containment system  001  include an EPA friendly closed container  002  having an externally visible float level indicator and externally accessible cap. The secondary container  003  has built-in structural ribs and lift handles  017  for convenience. Edges of the secondary container are structured for weather tight seals. Grommetted access holes ( FIG. 4 ) above the 110% content level are provided for lines into and out of the secondary container, such as for exhaust, power and supply. A louvered side screen ventilator  007  is provided to vent the secondary container. 
       FIGS. 3  (A-E) offer further perspective, plan and cut-away views of the preferred embodiment of the secure weather containment system  001 .  FIG. 3A  illustrates how a top portion  012  of a float gauge assembly  008  protrudes through and is anchored onto an exposed top or lid portion  010  of a primary tank  002 .  FIG. 3E , in a cut-away portion of  FIG. 3A , illustrates where nipple  009  is attached to a lower body wall of interior primary tank  002 . In the preferred embodiment illustrated in  FIGS. 3A-E , a 110% containment level will fall below the level of the grommets  014  of  FIG. 3E . The secondary container  003  provides, in combination with primary container  002 , 110% containment of the fluid contained within primary container(s)  002 . Economies of scale, size, cost and construction are achieved by providing a sealingly mating, nested construction of primary container  002  to and with secondary container  003 . Structural strengths of the nested assembly exceeds the structural strength of either container above. It is further preferable that a unitary secondary containment element provide, together with the primary tank, 110% containment.  FIG. 3E  also illustrates three grommet access holes  014 , located above a 110% containment level of the secondary tank, and the use of four latches  006 , also  FIG. 3D , to securely affix access lid  004 , also  FIG. 3B , to portions of both secondary container  003  and primary container  002 . The location of vented cap  005 , on a top portion of primary tank  002  and exposed to the environment is also indicated in  FIGS. 3A and 3B . In the interactive design between the secondary container, the primary container and the access lid, external rain drip ledges and all-around internal interlocking rain grooves are designed to completely seal the primary container, secondary container and interlocking access lid from penetration by the weather, when mated and latched in place.  FIG. 3D  illustrates placement of a louvered and secured side vent  007  on the secondary container  003 .  FIG. 3C  also illustrates a female threaded cap  005  sealing against the primary container interior against weather elements.  FIG. 3A  also illustrates a male groove  015  mating with a female external rain drip ledge  016 . 
       FIG. 4  illustrates in more detail features of the secondary container  003  preferably made of plastic. The structure of the side of the secondary tank preferably provides strengthening ribs and lifting handles  017 . The secondary tank contains a rain drip ledge  018  around its upper periphery. Again, a location for three access holes, for grommets,  014  is indicated on an upper side wall of the secondary tank, above a 110% containment level. The external rain drip ledge  018  and interlocking rain grooves  019  are designed to assist completely sealing the primary container, the secondary container and interlocking lid from penetration by weather elements. 
       FIG. 5  further illustrates a preferred embodiment of the construction of a primary tank  002  designed and structured to sealingly mate with, and substantially nest within, a secondary container  003 . Preferably the primary tank or container, including lid portion  010 , is constructed of one piece out of plastic. The primary tank is shown with a cylindrical tank section topped with a square top portion, all constructed of one piece, the top having reinforcing top ribs and opening  013  for a float gauge and a threaded opening  011  for access cap  005 . Three sides of the tank lid provide for sealingly mating with upper periphery portions of the secondary container. A fourth side of the primary tank lid provides for sealingly mating with the access lid  004 . The primary tank preferably contains a three inch opening on top for attaching a float level indicator and an opening for attaching a 7-inch vented cap, female threaded. Edges of the primary tank top lid, designed for mating with the access lid, contain a female rain drip bevel along the entire front edge. Again, an external rain drip bevel and three internal interlocking rain grooves are designed to completely seal the primary container, secondary container and interlocking access lid from weather elements. 
       FIG. 6  illustrates a preferred embodiment of a third primary element of the system, an interlocking access lid  004 . The interlocking lid contains grooves for interlocking with portions of the secondary container as well as a special groove  015  for interlocking with the edge of the primary container top. 
     The nipple  009  illustrated in  FIG. 7  provides sealed access to the chemicals stored in the primary tank, provided for fluid communication with the pump motor P/M. In preferred embodiments the pump motor is contained within the secondary container, at one side of the primary tank. Preferably the pump motor utilizes a gravity feed for the chemicals, receiving chemicals from the primary tank through the nipple in a lower portion of the primary tank wall. 
       FIG. 8  illustrates a preferred embodiment of a latch  006  used to help secure mating attachment between the interlocking access lid, the primary tank and the secondary tank. Preferably four such latches would be utilized. 
       FIG. 9  illustrates a preferred embodiment of a vented cap  005  for the primary tank, accessible to the outside. 
       FIG. 10  illustrates a preferred embodiment of a float gauge  008  for utilization inside of the primary tank and for visualization of a portion of the float gauge outside of the primary tank and the containment system. 
       FIG. 11  illustrates a preferred embodiment of a louvered vent  007  for an upper side wall portion of the secondary container in order to exhaust unwanted vapors that might collect around the pump and between the primary and secondary container. Preferably the vent is also screened. The vent is located above the 110% containment level. 
       FIG. 12  illustrates an embodiment of a secondary container  023  designed to house two primary containers  002 . Secondary container  023  is similar in most respects with secondary container  003 , except that secondary container  023  provides for the nesting of two primary tanks  002  with lid portions  010  exposed, as illustrated in  FIG. 12 . Two access lids are provided, an access lid  024  analogous to access to lid  004 , the access lid  024  being on top of secondary container  023 . An additional access door  034  is provided recessed into the side of the secondary container  023 . Access door  034  is anticipated to be hinged to the side of secondary container  023  and closed with suitable latches. 
     The lid portions  010  of primary containers  002  could be domed shaped for enhanced water and snow runoff. Access lid  024  on the double-sized secondary container  023  should seal with primary container lid portions  010  in an analogous manner as in the single primary tank secondary container. The weather type rain guard on secondary container  023  should be analogous to the weather type rain guard on secondary container  003 . In the double secondary container  023 , spaces are provided to position a single pump to run both primary tanks or to position two pumps each to run one primary tank or both pumps to pump chemicals from both tanks. 
     In operation primary tank  002  is placed within secondary container  003 . Primary tank lid  010  sealingly mates with upper edges of secondary container  003 . Primary tank  002  contains within it float gage  008 . A vented cap  005  sealingly mates with an opening in lid  010 . Weatherproof lid  004  is latched by means of latches  006  to sealingly mate against portions of secondary container  003  and primary container  002 . Pump motor P/M has been placed inside secondary container  003 . Lines connect pump motor PM with a nipple at the bottom of primary container  002 . Grommet access holes  014  provide access for data, power, fluid lines and the like through secondary container  003  above the 110% containment line. With such means the pump can be operated in accordance with power and control signals and status of the pump in the tanks can be monitored through information lines. The level of fluid in the primary tank can also be visually monitored from the exterior through the float gauge  008  with the portion  012  extending through the top lid  010  of primary container  002 . 
     The foregoing description of preferred embodiments of the invention is presented for purposes of illustration and description, and is not intended to be exhaustive or to limit the invention to the precise form or embodiment disclosed. The description was selected to best explain the principles of the invention and their practical application to enable others skilled in the art to best utilize the invention in various embodiments. Various modifications as are best suited to the particular use are contemplated. It is intended that the scope of the invention is not to be limited by the specification, but to be defined by the claims set forth below. Since the foregoing disclosure and description of the invention are illustrative and explanatory thereof, various changes in the size, shape, and materials, as well as in the details of the illustrated device may be made without departing from the spirit of the invention. The invention is claimed using terminology that depends upon a historic presumption that recitation of a single element covers one or more, and recitation of two elements covers two or more, and the like. Also, the drawings and illustration herein have not necessarily been produced to scale.