FLOATING COVER FUEL STORAGE SYSTEM

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of United States Provisional Patent Application No. 60/868,052, filed November 30, 2006, the entire contents of which are hereby incorporated by reference herein.

BACKGROUND

[0002] Floating cover bulk water storage reservoirs are known for storing large quantities (e.g. millions of gallons) of water. Such reservoirs are often made by forming a recess in the ground and compacting the earth in the vicinity of the recess. Walls are provided around the perimeter of the recess. A liner made of polypropylene or high density polyethylene (HDPE) is positioned to overlie the recess and to line the walls. Alternatively, the recess and walls may be covered in asphalt. The liner is provided with at least one sump at the lowest portion of the reservoir for filling and extracting water from the reservoir. A tensioned floating cover including foam float assemblies and sand-filled ballast tubes is positioned to overlie the recess. The liner and the cover are joined together and securely fixed about the perimeter of the walls, thereby defining a variable volume storage space between the liner and the cover. When the reservoir is filled with water, the cover floats upon the water such that as the water level changes, the cover remains in intimate contact with the surface of the water. The foam float assemblies and ballast tubes cooperate to tension the cover and to maintain a substantially flat top surface of the cover.

SUMMARY

[0003] In one construction, the present invention provides a floating cover bulk fuel storage system including a recess, a first liner, a second liner, and a cover. The first and second liners overlie the recess. The cover is coupled to the first and second liners to define a variable- volume storage space for storing liquid fuel. The cover includes an aperture that communicates with at least one of an outlet assembly and an inlet assembly. The outlet assembly includes a coupling and a pump for removing fuel from the variable-volume storage space. The inlet assembly includes a coupling through which fuel is introduced into the variable-volume storage space.

[0004] In other constructions, the cover includes first and second apertures and the first aperture communicates with the outlet assembly and the second aperture communicates with the inlet assembly. The cover may also include a third opening that receives an access hatch that affords human access to the variable-volume storage space. The cover may further include additional apertures that receive vent assemblies. The system may include a draw-off sump positioned at a lower portion of the recess for collecting and removing water that accumulates within the variable-volume storage space, and a leak-detection sump. The leak-detection sump may include a leak detector positioned between the first and second liners for detecting liquid accumulation between the liners.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Fig. 1 is a perspective view of a floating cover fuel storage system with portions cut away.

[0006] Fig. 2 is top view of the fuel storage system of Fig. 1.

[0007] Fig. 3 is a section view taken along line F - F of Fig. 2.

[0008] Fig. 4 is top view of a sump flange of the fuel storage system of Fig. 1.

[0009] Fig. 5 is a section view taken along line C - C of Fig. 4.

[0010] Fig. 6 is a section view showing a liner seam for the fuel storage system of Fig. 1.

[0011] Fig. 7 is a section view of an anchor assembly for the fuel storage system of Fig. 1.

[0012] Fig. 8 is an enlarged view of the encircled portion of Fig. 3 showing an alternative construction of a system wall.

[0013] Fig. 9 is an enlarged view of the encircled portion of Fig. 3 showing another alternative construction of a system wall.

[0014] Fig. 10 is an enlarged view of a portion of Fig. 9 showing an anchor trench for use with the alternative constructions of the system sidewalls illustrated in Figs. 8 and 9.

[0015] Fig. 11 is a section view taken along line A - A of Fig. 2.

[0016] Fig. 12 is a section view taken along line D - D of Fig. 2.

[0017] Fig. 13 is a section view taken along line B - B of Fig. 2.

[0018] Fig. 14 is a section view taken along line C - C of Fig. 2.

[0019] Fig. 15 is a section view taken along line E - E of Fig. 2.

[0020] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

DETAILED DESCRIPTION

[0021] Fig. 1 illustrates a floating cover bulk fuel storage system 10. The system 10 includes a recess 14 defined by, for example, a base formed by the ground, and walls 18 surrounding the recess 14 to define a reservoir. The system 10 also includes an outer first liner 22, which overlies and is received by the recess 14, and which lines the inner surfaces of the walls 18. An inner second liner 26 overlies the first liner 22 and is in substantially continuous contact therewith. The first 22 and second liners 26 are coupled to the walls 18 and to one another, as discussed further below.

[0022] A cover assembly 30 is also coupled to the walls 18 and to at least the second liner 26. The cover assembly 30 includes a cover panel 32 that overlies the recess 14 and cooperates with the second liner 26 to define a variable volume storage space 34 that receives fuel 38. The cover assembly 30 also includes a tensioning system including floats 42 and ballast tubes 46. The ballast tubes 46 are positioned within rainwater collection troughs 47 that are defined by the cover panel 32. A central pump assembly 50 communicates with the rainwater collection troughs 47 and operates to remove fluids (e.g. rainwater) that collect on the upper surface of the

cover panel 32. The cover assembly 30 also includes at least one inlet assembly 52 for introducing fuel 38 into the storage space 34, and at least one outlet assembly 54 for removing fuel 38 from the storage space 34. In the illustrated construction, the first liner 22 and the cover panel 32 are formed of PETROGARD-VI™, a tripolymer material available from MPC Containment of Chicago, IL, and the second liner 26 is formed of 1940 PTFF, which is available from Seaman Corp. of Wooster, OH. Other materials suitable for prolonged contact with and containment of the type of fuel that is to be stored in the storage space 34 may also be used.

[0023] Referring also to Figs. 2 and 3, the recess 14 is formed by excavating and, in the illustrated construction, includes a slope of about 2 to 1. After excavation, the earthen material defining and surrounding the recess 14 may be compacted to provide a more consistent and stable surface upon which the system 10 may be constructed. A first draw-off sump 55 is provided at the bottom of the recess 14 to collect water which may accumulate within the storage space 34, and a second leak-detection sump 56 is provided at the bottom of the recess to detect fuel leakage between the first liner 22 and the second liner 26. Each sump 55, 56 is at least partially defined by a sump flange 57 (Figs. 4 and 5). Each sump flange 57 is positioned in the recess 14 and receives the first and second liners 22, 26.

[0024] The sump flange 57 for the draw-off sump 55 is provided with a fitting (not shown) for connection with a drainage pipe 58 such that water and other liquid contaminants, which tend to settle to the bottom of the space 34 due to their higher density relative to most liquid fuels, can be removed from the storage space 34 to reduce contamination of the fuel 38. The sump flange 57 for the leak-detection sump 56 is also provided with a fitting (not shown) for connection with a leak-detection system 59. The leak-detection system 59 includes a liquid sensor 60 positioned between the first liner 22 and the second liner 26 within the leak-detection sump 56. The leak detection system 59 also includes a conduit 61. The conduit 61 includes a liquid removal conduit for removing liquid from between the first and second liners 22, 26, and an electrical conduit for electrical activation of an alert system (e.g. illumination of a warning light) in response to detection of liquid between the liners 22, 26.

[0025] In the illustrated construction, the walls 18 are formed of concrete and are substantially T-shaped. The walls 18 each include a lower portion 62 that rests upon the ground

and is positioned substantially adjacent to an upper edge 66 of the recess 14. An upper portion 72 of each wall 18 extends substantially perpendicularly from the lower portion 62 and includes an inner surface 76, a top surface 80, and an outer surface 84. A berm 88 of compacted earth is formed against the outer surfaces 84 to support the walls 18.

[0026] Referring also to Fig. 6, the first and second liners 22, 26, and the cover panel 32 may be substantially continuous or may include a plurality of panels 92. If a plurality of panels 92 are used, the panels 92 are coupled to one another by overlapping the panels 92 with one another and applying a thermal weld 96 to the overlapping portions. Other known coupling methods that provide a suitable liquid-impervious seal can also be used.

[0027] With reference also to Fig. 7, the first and second liners 22, 26, and the cover panel 32 are coupled to the outer surfaces 84 of the walls 18 by a plurality of anchor assemblies 100. For clarity, the first and second liners 22, 26 and the cover panel 30 are illustrated as a single sheet of material in Fig. 7, and are designated by the single reference numeral 102.

[0028] Each anchor assembly 100 includes an anchor bolt 104, a gasket member 108, and a batten bar 112. The anchor bolt 104 is coupled to the wall 18 (e.g. by a concrete expansion anchor or epoxy) and extends substantially perpendicularly from the outer surface 84. The gasket member 108 and the liners and cover 102 define holes that receive the anchor bolts 104, and are clamped between the outer surface 84 of the wall 18 and the batten bar 112.

[0029] In the illustrated construction, the gasket member 108 may be a synthetic rubber strip that extends around the outer surfaces 84 of the walls. The liners and cover 102 extend over and along the top surfaces 80 of the walls 18, and extend downwardly along the outer surfaces 84 of the walls 18 to receive the anchor bolts 104 and engage the outer surface of the gasket member 108. The batten bar 112, which in the illustrated construction is a stainless steel plate defining holes that receive the anchor bolts 104, is positioned to overlie the liners and cover 102 and is clamped against the liners and cover 102, the gasket member 104, and the outer surface 84 of the wall 18 by washers 116 and nuts 120. A sealant 124 such as caulk can be applied to the interfaces of the outer surface 84, the gasket member 104, and the liners and cover 102 to further seal the storage space 34.

[0030] Referring also to Figs. 8-10, some constructions of the system 10 include walls 18a made of compacted earth in place of the concrete walls 18 discussed above. The earthen walls 18a may be substantially vertical, as illustrated in Fig. 8, or may include a slope (e.g. a 1 to 1 slope) as illustrated in Fig. 9. If earthen walls 18a are provided, an alternative anchor assembly 100a may also be provided (see Fig. 10). The anchor assembly 100a includes a trench 128 that extends around the perimeter of the system 10. The trench 128 is configured to receive the first and second liners 22, 26 and the cover panel 32 such that the liners 22, 26 and cover panel 32 follow a substantially serpentine path extending along the inner surfaces 76a and top surfaces 80a of the walls 18a and through the trench 128. When the liners 22, 26 and cover panel 32 are positioned in the trench 128, the trench 128 is filled with earthen material and that material and the surrounding earthen material is compacted, thereby securing the liners 22, 26 and the cover panel 32 within the trench 128, and also securing the liners 22, 26 and the cover panel 32 to one another.

[0031] Referring also to Fig. 11, the cover assembly 30 includes a drainage and tensioning system 136 that includes the floats 42, the ballast tubes 46, and the rainwater collection troughs 47. As illustrated in Fig. 2, for the illustrated substantially square cover assembly 30 the drainage and tensioning system 136 is substantially X-shaped, and includes two substantially linear portions that extend diagonally between corners of the cover assembly 30. Other shapes and configurations may also be used. For example, a rectangular cover assembly may include a drainage and tensioning system 136 arranged in a double- Y configuration. The drainage and tensioning system 136 is configured to maintain an appropriate amount of tension in the cover panel 32 in response to changes in the amount of fuel 38 in the storage space 34. The system 136 is also configured to collect fluid from the upper surface of the cover panel 32 and deliver such fluid to the central pump assembly 50, as discussed further below. The floats 42 and ballast tubes 46 are coupled to the panel by adhesives and/or by covering the floats 42 and ballast tubes 46 with sections of panel material 140 which are coupled or bonded to the cover panel 32. For example, the sections of panel material 140 can be joined to the cover panel 32 using thermal welds 96, as illustrated in Fig. 6.

[0032] Fig. 12 illustrates the pump assembly 50, which operates to remove fluid from the upper surface of the cover panel 32. The pump assembly 50 includes a pump basket 144, a pump

float 148 coupled to the cover panel 32, a ballast plate 152 positioned at the bottom of the pump basket 144, a submersible pump 154 positioned in the pump basket 144 and supported by the ballast plate 152, and a discharge pipe 156. In the illustrated construction, the pump basket 144 includes a substantially cylindrical portion 160, and a flange portion 164. The pump basket 144 is provided with apertures that communicate with the rainwater collection troughs 47 such that fluid (e.g. rainwater) flows freely into the pump basket 144 from the rainwater collection troughs 47. The flange portion 164 engages a lower surface of the cover panel 32, and the cylindrical portion 160 extends downwardly into the storage space 34. A central pump cover (not shown) fluidly isolates the central pump assembly 50 from the storage space 34 such that fluid collected from the upper surface of the cover panel 32 is not intermingled with fuel 38 stored in the storage space 34.

[0033] In the illustrated construction, the pump float 148 is substantially annular and is positioned on an upper surface of the cover panel 32 to substantially overlie the flange portion 164. Fasteners 168 extend through the flange portion 164 and the pump float 148 to couple the pump basket 144 and the pump float 148 to one another, and also to couple the pump float 148 and the pump basket 144 to the cover panel 32. A section of panel material 140 may also be provided to cover the pump float 148.

[0034] The ballast plate 152 is coupled to the bottom end of the pump basket 144 and the submersible pump 154 is coupled to the ballast plate 152. An aperture is provided in the cover panel 32 to accommodate the pump basket 144. One end of the discharge pipe 156 receives fluid from the submersible pump 154 inside the storage space 34, and an opposite end of the discharge pipe 156 is coupled to an outlet (e.g. a hose, as illustrated in Fig. 1) positioned outside of the storage space 34. A power cord 170 is also provided for supplying electrical power to the submersible pump 154. The submersible pump 154 may also include a float assembly that detects when fluid in the pump basket 144 is above or below a predetermined level to activate or deactivate, respectively, the submersible pump 154 during removal of fluid from the pump basket 144.

[0035] With reference also to Fig. 13, the inlet assembly 54 includes a coupling 172 suitable for engagement with a fuel hose 176 positioned outside the storage space 34, and a diffuser 180

positioned inside the storage space 34. The coupling 172 can be any suitable fuel coupling, including a standard fuel coupling, for receiving fuel from the fuel hose 176, which may be provided on, for example, a fuel truck. The coupling 172 is in fluid communication with the diffuser 180, which is constructed to divert the flow of incoming fuel 38 in a plurality of directions. In the illustrated construction, the diffuser 180 includes a frusto-conical portion 184 and a cylindrical portion 188 defining a plurality of apertures 192 such that the flow of incoming fuel is directed radially away from a central axis of the coupling 172.

[0036] The outlet assembly 54 is configured somewhat similarly to the inlet assembly 54 and includes a coupling 172 suitable for engagement with a fuel hose 176. The outlet assembly 54 may include a pipe or hose assembly extending into the storage space 34, and an inlet screen at an inlet end of the pipe or hose assembly that is submerged within the fuel 38. An outlet pump can be positioned within the storage space 34 for pumping fuel out of the outlet assembly 54, or the outlet pump may be positioned outside of the storage space for drawing fuel via suction through the pipe or hose assembly and through the outlet assembly 54.

[0037] With reference also to Fig. 14, the cover assembly 30 includes an access hatch 196. The access hatch 196 includes a cover 200 that can be opened and closed to provide access to the storage space 34. The access hatch 196 is coupled to the cover panel 32 and is at least partially supported by at least one float 204. In the illustrated construction there are 8 plank-like floats 204 positioned below the cover panel 32 (see Fig. X). A float wrap 208 couples the floats 204 to one another and to the access hatch 196, and also prevents fuel 38 from contacting the floats 204. Fasteners 212 extend through the access hatch 196, the cover panel 32, and the float wrap 208, thereby coupling the floats 204 and the access hatch 196 to the cover panel 32.

[0038] With reference also to Fig. 15, a plurality of vent assemblies 216 are provided in spaced relation to one another across the cover assembly 30. Each vent assembly 216 includes a substantially J-shaped vent pipe 220, a vent float 224, and a flange member 228 coupling the vent pipe 220 to the vent float 224 and the cover panel 32. The vent float 224 is positioned below the cover panel 32 and includes a vent channel 232 that communicates with the vent pipe 220 and the storage space 34. The vent assembly 216 extends through an aperture in the cover panel 32, and a section of panel material 140 is provided to overlie the aperture. A gasket 236

and a clamp 240 are provided to couple and seal the section of panel material 140 to the vent pipe 220.