BACKGROUND OF INVENTION 1. Field of the Invention
This application relates to a fluid storage tank that can be assembled at a remote location where a supply of fluid, for example water, is needed.
An example of such a situation occurs where an oil or gas well treatment process such as fracturing is conducted at the well site. In such a situation either a large temporary water storage tank is assembled on site or a plurality of smaller portable water tanks are delivered to the site.
2. Description of Related Art
In the oil and gas industry, water storage has become an issue due to the large amount of barrels of water required to perform drilling operations. Cost of transporting a large number of tanks to location, and logistical problems of having enough space at the well site to accommodate their positioning has forced the oil and gas industry to find a solution. The solution that has developed is the use of a single mobile erecting tank. These tanks eliminate a large fleet of storage vessels and the cost of transporting them to location.
These large capacity tanks normally comprise 16 single panels that connect together side by side, forming in one embodiment a 122 ft. diameter tank with a height of 12 ft. After they are assembled a rubber sheet, plastic, or polypropylene sheet is positioned in the inside and the edges are laid over the top rail of the tank. These edges of the sheet are secured to the top rail by the use of c-clamps.
The suction lines are then hung over into the tank and the tank is then filled with water. As the tank is filled, water forces the sheet into the lower inside corners of the tank. This can allow the sheet to be pinched or protrude under the wall of the tank causing a leak or tear of the rubber sheet.
A drain sump is formed under the sheet so that most of the water can be evacuated from the tank.
An improved modular storage tank is disclosed in copending application Ser. No. 13/584,883 filed Aug. 14, 2012. However, the sheet that forms the bottom of the tank needs to extend up and over the sides of the tank which requires more material. Also it is still necessary to construct a sump in the ground to facilitate emptying of the tank.
BRIEF SUMMARY OF THE INVENTION
A fluid storage tank is formed by a plurality of arcuate wall support footings that provide structural support for a plurality of wall panel sections and also hold the floor sheet of the tank in sealing engagement with the wall panels without the need for the sheet to extend upwardly over the top of the wall panels. The footings also form a sump so that the water may be entirely withdrawn from the tank without the need for forming a sump ditch.
The footings may include a channel formed by a pair of curved rails or may include a single rail placed on the footing to engage the outer bottom portion of the wall panels.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 is a perspective view of a fluid tank according to an embodiment of the invention.
FIG. 2 is a top view of a support footing according to an embodiment of the invention.
FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2.
FIG. 4 is a cross-sectional view of a support fitting showing a wall portion fixed within the support footing.
FIG. 5 is a cross-sectional view of the vertical joint between adjacent wall sections.
FIG. 6 is an exploded view of the vertical wall joint between adjacent wall panels.
FIG. 7 is a cross-sectional view of a second embodiment of a support footing according to an embodiment of the invention.
FIG. 8 is a front view of a second embodiment of coupling structure for two adjacent panels according to the invention.
FIG. 9 is a top view of the coupling shown in FIG. 8.
FIG. 10 is a side view of a panel.
FIG. 11 is a perspective view of a coupling pin.
FIG. 12 is a top view of the support footing shown in FIG. 7.
FIG. 13 is a cross-sectional view of another embodiment of a support footing according to the invention.
FIG. 14 is a cross-sectional view of a vertical wall joint according to another embodiment of the invention.
FIG. 15 is a side view of the wall joint of FIG. 14.
FIG. 16 is a top view of the footing shown in FIG. 13.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, an embodiment of the instant invention is a storage tank 10 formed from a plurality of individual curved wall panel sections 9 connected to each other at 8. Wall panel sections 9 are supported by a plurality of footings 13 shown in greater detail in FIGS. 2 and 3. Wall panel sections 9 are placed on footings 13 in such a manner that wall joints 8 are located at approximately the mid-point of each footing 13.
As shown in FIGS. 2 and 3, each footing includes a bottom curved plate member 18, an angled plate 19, a top plate 11 and an end wall plate 26. Suitable supports 27 and 28 extend from top plate 11 and angled plate 9 to lower plate member 18 all of which are curved. Lower plate member 18 rests on the ground when the tank is constructed. A pair of curved rails 24 and 25 extends along the top plate 11 and are secured thereto by a suitable means such as by welding. Rails 24 and 25 may be solid or hollow, and may be square or rectangular in cross section for example. A channel 4 is formed between rails 24 and 25. A plurality of apertures 22 are formed in top plate 11 and a plurality of nuts 29 are fixed to the underside of top plate 11 in alignment with the apertures. A foundation for the tank is formed by positioning a plurality of the footings 13 in a circular array on the ground as shown in FIG. 1
Once the footings are arranged in a circular pattern, a circular floor sheet 42 having a diameter slightly larger than that of the tank is laid over the footings in the manner shown in FIG. 4. A pair of rubber gaskets 43 and 44 may be positioned underneath floor sheet 42 and over floor sheet 42 as shown in FIG. 4 to provide a water tight seal. Flexible sheet 42 may be made of rubber, for example.
After sheet 42 and gaskets 43 and 44 have been laid over rails 24 and 25, wall panels 9 are placed on footings 13. As shown in FIG. 4, wall panel sections 9 include a lower frame member 41 having a rectangular cross section and an upstanding wall portion 35. Frame member 41 is curved to the same extent that rails 25 and 26 are curved. Thus frame member 41 will fit in channel 4 between rails 24 and 25. The weight of wall panels 9 will slightly deform rubber gaskets 43 and 44 and bottom sheet 42 so as to form a tight seal. The channel 4 formed by rails 24 and 25 and top plate 11 provide lateral support for wall panel section 9. To provide further stability, a plurality of tie down clamps 37 are located on the support footings. Tie down clamps 37 include by way of example an L-shaped member having a first portion 36 that overlies bottom frame member 41 of the wall panel section and a second leg portion 39 that engages the top surface of the footing. The tie down clamp includes an aperture 38. A threaded bolt 31 extends through aperture 38 and aperture 22 in the footing. The threads on the bolt 31 engage threaded nut 32 so that the tie down clamps are secured to the footings and thus further hold wall panel section 9 in place.
As shown in FIG. 4, sloping wall portion 19 of the footing creates a natural sump area for facilitating complete draining of the tank. The clamps may include one or more strengthening flanges 34.
FIGS. 5 and 6 illustrates an embodiment of the joint structure between adjoining wall panels. A first wall panel 63 includes a metal strip 59 attached to the panel by a plurality of vertically spaced bolts and nuts 51 and 52. Metal strip includes a V-shaped portion 70. A second metal strip 60 is attached to wall panel 62 by a plurality of bolts 71 and nuts 72. Metal strip 60 has an angled portion 73 that abuts against V-portion 70 as shown in FIG. 5. A plurality of tabs 55 with an opening 56 extend outwardly from V-shaped portion 70 through slots 75 formed in section 73 of strip 60.
A reinforcement plate 58 having openings therein and rubber gasket 76 extend along both sides of joints 8 and are attached at either side to adjacent wall panels 62 and 63 as shown in FIG. 6. Pins 80 may be placed through holes 56 in tabs 55 thereby further securing the wall panels together. Additionally a rectangular reinforcing plate 57 can be fixed to angled portion 73 about each tab 55.
A second embodiment of a support footing 110 according to the invention is illustrated in FIG. 7. Each footing 110 includes a curved base plate 111 which may be about 24 inches wide. A plurality of footing 110 for example 16 are placed in a circle to form a support for the wall panels 9 shown in FIG. 1. A pair of curved rails 125 and 126 are fixedly secured to base plate 111 such as by welding. Rails 126 and 125 may be solid or hollow tubulars, and may be rectangular in cross section. As shown in FIG. 12, rails 126 and 125 are spaced apart so as to form a rectangularly shaped channel 199 sized to receive a lower frame member 141 of panel 9. Lower frame member 141 of panel 135 may have a rectangular cross section that fits within rectangular shaped channel 199. The support footing 110 also includes a plurality of L-shaped brackets 137 that include a horizontal section 136 and a vertical section 139. Vertical section rests on base plate 111 and horizontal portion 137 extends over lower frame member 141 of panel 135 as shown in FIG. 7. As in the embodiments of FIG. 1, a flexible tank floor sheet 142 and optionally a pair of rubber gaskets 144 and 145 over and below sheet 142 are first placed over rail members 125 and 126. Wall panels 9 are then placed on the support footings so that lower frame member 141 is positioned within channel 199. The weight of wall panels 9 will compress flooring sheet 142 and gaskets 144 and 145 to form a fluid tight seal, thus eliminating the need for the flexible floor sheet 142 to extend over the top of the wall panels.
Clamps 137 may then be installed to further secure the wall panels to the footings by means of threaded bolts 131 that extend through openings 138 in horizontal portion 136 and are threaded into threaded holes 140 provided in base plate 111.
FIGS. 8-11 illustrate a second embodiment of a coupling arrangement for adjacent wall panels according to the invention. FIG. 8 shows adjacent wall panels 9 and 7. A first wall panel 9 has a top frame member 121, a bottom frame member 124 and a side frame member 130 extending from top frame 121 to bottom frame member 124. All three frame members may be rectangular tubing. The same is true for adjacent wall panel 7 which is constructed in the same manner as wall panel 9. A first reinforcing plate 128 extends from bottom frame member 124 to top member 121 and one end of the wall panel. A second reinforcing plate 129 extends between bottom frame member 124 to top frame member 121 at a second end of the wall panel. Reinforcing plates 128 and 129 are fabricated from relatively stiff material such as steel. The plates include a plurality of apertures 126 and 127. As disclosed in copending application Ser. No. 13/584,882, filed on Aug. 14, 2012, the entire contents of which is hereby expressly incorporated herein by reference thereto, wall panels 9 and 8 may include a plurality of flexible reinforcing bands 123 which are connected at their ends to steel plates 128 and 129.
The coupling arrangement also includes a connector plate 152, which may be slightly curved to conform to the curvature of wall panels 9 and 7 which extends along and overlaps the ends of adjacent wall panels as shown in FIG. 9. Connector plate 152 has a plurality of apertures which align with apertures 126 and 127. Suitable bolts 156 and 157 are adapted to pass through the apertures in connector plate 152 and apertures 126 and 127 in reinforcing plates 128 and 129. Fasteners such as nuts can then be used to secure the connector plate 152 and reinforcing plates together or apertures 126 and 127 may be threaded. A strip 153 of gasket type material may be placed between connector plate 152 and reinforcing plates 128 and 129.
The holes in connector plate 152 and those in reinforcing plates 128 and 129 are aligned such that a gap 151 of approximately one half inch is maintained between adjacent panels 9 and 7.
The coupling assembly may further include a plurality of U-shaped members 170 fixedly secured such as by welding to the front vertically extending surfaces of side frame member 130 and 131. A plurality of locking pins 162 have a generally cylindrical core member 164. Four radially extending circular flanges 163 extending outwardly from core member 164 and form recesses 165 and 166 at either end of the locking pins. These recesses are sized to fit within the U-shaped channels of members 170 as shown in FIG. 9. This arrangement further presents lateral separation of the wall panels.
FIGS. 13-15 illustrate another embodiment of the invention. As in previous embodiments the storage tank includes a plurality of curved footing 260 that are positioned adjacent each other to form a circle. A plurality of wall panels 235 are placed on top of the footings to form a circular side wall of the storage tank.
Each footing 260 includes a ground engaging base 211. A single curved rail member 226 is fixed by welding for example to the base 261 at an outer portion of the base in a manner similar to that shown in FIG. 2 with respect to rail 24. The floor of the tank is formed by a ground engaging sheet of flexible material 242 that extends upwardly over base 211 and over rail member 226 as shown in FIG. 13. A first strip of flexible material 244 and a second strip of flexible material may be positioned below and on top of the rail 226 to protect floor member 242 from excessive wear. The base 211 of the footing extends a substantial distance toward the center of the tank from wall panel 235 to provide stability and support. It may extend for example up to five feet within the perimeter of the tank.
A plurality of clamps are used to secure the wall panels to the footings 260. Each clamp includes an L-shaped member including a vertical portion 239 and a horizontal portion 236. Horizontal portion 236 includes one or more apertures 238. Base 211 includes one or more threaded apertures 220 that are in alignment with apertures 238. A threaded bolt 231 having an enlarged head 232 is passed thru aperture 238 so that threads 251 of the bolt engage the threads of aperture 240. As the bolt is threaded down, enlarged head 252 of the threaded bolt 231 engages the top surface of horizontal portion 236 of the clamp. Horizontal portion 236 also extends over the top of a bottom frame member 241 of the wall panel 235 thereby clamping the sidewall panel to the footing. Clamps 237 may be the same radial length of the footings or may include a plurality of individual clamps that extend over only a radial portion of the footings.
FIGS. 14 and 15 illustrate another embodiment of a vertical coupling for the wall panels 235. As the wall panels 235 are positioned on top of the footings to form a circular sidewall, a gap 290 of approximately ¼ to ¾ inches for example is formed between the side edges 291 and 292 of adjacent wall panels. A vertically extending plate formed of steel or a similar material which may have a slight curvature to match the curvature of the sidewalls is positioned to overlay the gap 290 as shown in FIG. 14 and extends from the bottom to the top of the wall panels. A sealing member 271 of rubber or similar material may be placed between the metal strip 270 and the wall panels as shown in FIG. 14. Strips 270 are provided with a plurality of thread apertures 276. A plurality of bolts 272 having enlarged heads 273 that engage a washer member 274 are placed through gap 290 so that the threaded end of the bolt engages threaded apertures 276. As bolt 272 is tightened, enlarged head 274 forces washer 274 to engage the outer surfaces of adjacent sidewall panels 235 to thereby clamp the sidewall panels together. For added structural integrity, metal plate members 270 may be welded to the interior surface of sidewall panels 235 such by spot welds 298.
As shown in FIG. 15, a plurality of U-shaped member 281 may also be secured to the outer surfaces of adjacent sidewall panel members to receive locking pins 162 in the manner shown in FIGS. 9-11. This will further prevent the sidewall panels from separating from each other.
Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except to the extent that they are included in the accompanying claims.
Patent Application
20150114958
