Patent Abstract:
A water storage assembly is disclosed including a flexible bladder having a water storage cavity, a water inlet in fluid communication with said cavity, a water outlet in fluid communication with said cavity, and a rigid frame adapted to support said bladder wherein said bladder wherein said bladder is secured to said rigid frame and said bladder is adapted to expand and contract upon flow of said water into and out of said cavity.

Full Description:
FIELD OF THE INVENTION 
     The present invention relates to a water storage assembly and in particular to the storage of rainwater or grey water in a flexible bladder. 
     BACKGROUND OF THE INVENTION 
     Conservation of water has become a significant issue worldwide due to the reduction in rainfall, increase in population and salinity problems with existing water sources. These problems have increased the need to recycle and optimise use of existing water. For a household, the simplest way to reduce the quantity of mains water used is to collect rainwater in a tank. Water tanks capture rainwater at the point of use, for example, a dwelling, factory, school, building or the like. Unfortunately, due to an increased population and subsequent over development, adequate space in built-up areas to house water tanks is a significant problem. Further, with the growing focus on aesthetic looks of a dwelling or building, many people object to water tanks being visible. 
     The deficiencies of existing water tanks has led to the development of flexible water storage systems, such as that shown in WO 2004/053242. Flexible water storage systems are advantageous as they are more easily transportable when flat-packed than rigid tanks; relatively simple to construct on site; can be located in areas that are out of sight; in difficult access situations or where height restrictions exist (such as, under floors, decks or in walls) and complicated piping is generally not required. 
     However, the system of WO2004/053242 has been found to have practical installation and operation limitations. For example, the system uses a top fill method with a pivoting swing arm having o-rings as the method for sealing between the two arms. The o-rings have been found to leak after a period of time when the system is full. The swing arm also requires a significant space about it to operate correctly, thereby limiting the location in which the system can be installed and the potential capacity of the system as the fill potential fill height is limited by the presence of the filling mechanism. The o-rings have also been found to jam the swing arm mechanism in place thus preventing the system from filling to its full capacity. 
     Further, if a second reservoir is used, it is filled through a different inlet pipe from the primary reservoir. It is filled from the outlet pipe of the primary reservoir which in the case of WO2004/053242 is only a 32 millimeter pipe which restricts the flow. This has the potential to cause water to back up in the storm water downpipes because the primary reservoir is filling via a 90 mm pipe but only emptying to subsequent reservoirs via a 32 mm pipe. Still further, the system can not be installed by a home handyman. 
     Accordingly, there is a need to provide an efficient flexible water storage assembly to store rainwater or grey water which is easier to construct, install and operate is than existing systems, does not leak at junctions, will enable fixed pipe work to remain fixed without the risk of breaking from the weight or movement of the system, requires less maintenance and will fill several bladders more quickly and simultaneously and that can be filled via a 100 mm pipe or a 90 mm pipe. Further, there is a need for a flexible water storage assembly that can be installed by a home handyman. 
     OBJECT OF THE INVENTION 
     It is an object of the present invention to overcome or ameliorate one or more of the disadvantages of the prior art, or at least to provide a useful alternative. 
     SUMMARY OF THE INVENTION 
     The present invention provides a water storage assembly including: 
     a flexible bladder having a water storage cavity, said bladder being adapted to expand and contract upon flow of water into and out of said cavity, 
     one or more water inlets in fluid communication with said cavity, 
     one or more water outlets in fluid communication with said cavity, 
     a rigid frame adapted to support said bladder; and 
     one or more support slings having first and second ends, said first end being connected to said frame, and said second end being connected to said bladder, said sling being adapted to limit the movement of the bladder relative to the frame. 
     The water inlet and the water outlet are preferably mounted on a plate fixed relative to said frame. 
     The water inlet preferably includes an overflow adapted to direct water away from the bladder once the bladder is full. 
     The inlet is preferably positioned at approximately half of the vertical height of the bladder when full. 
     The water storage assembly preferably including a valve or number of valves adapted to isolate the flow of water through the bladder. 
     The water storage assembly preferably includes a plurality of said bladders. 
     The bladders are preferably connected to each other in parallel via the inlet pipes and the outlet pipes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A preferred form of the present invention will now be described by way of example only with reference to the accompanying drawings wherein: 
         FIG. 1  is a side elevational view of an assembly of an embodiment of the present invention, shown empty; 
         FIG. 2  is a side elevational view of  FIG. 1 , shown full; 
         FIG. 3  is front elevational view of an assembly of an embodiment of the present invention, shown empty; 
         FIG. 4  is a front elevational view of  FIG. 3 , shown full; and 
         FIG. 5  is a perspective view of a multiple bladder system of an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the accompanying drawings, there is schematically depicted a water storage assembly  1  including a flexible bladder  5  having an internal cavity  6  permitting the storage of water or other liquids. An inlet duct  10  is connected to the cavity  6  within the bladder  5 . The inlet duct  10  may be 90 mm or 100 mm in diameter or another suitable size. 
     The inlet duct  10  permits the flow of water under the force gravity into the bladder  5 . One or more outlet ducts  15  are connected to the cavity  6  and are operable to dispense water from the cavity  6  to a user. The inlet duct  10  includes an overflow outlet  20  at some point within the inlet pipe which is operable to direct water away from the m bladder  5  when the bladder  5  is full. The overflow outlet  20  is located above the level of the bladder  5 , corresponding to the intended maximum fill volume of the bladder  5 . The overflow  20  may be positioned close to the bladder  5  or in fact some distance away, provided that the invert of the overflow is set to the maximum fill height of the bladder  5 . 
     A valve  25  is located on either the inlet duct  10  or outlet duct  15  and is operable to isolate the flow of water through the bladder  5 . 
     A rigid support frame  30  supports the bladder  5 . The frame  30  is in the form of a rectangular prism having an internal volume adapted to contain approximately half of the bladder  5  when full. The frame  30  in a preferred form is made from steel bars and may include several members or sub frames that can easily be assembled in restricted areas such as beneath floors. 
     The inlet pipe  10  and the outlet pipe  15  are connected to a fixed plate  7  which is secured to the frame  30 . The plate  7  ensures that the location and angular orientation of the pipes  10 ,  15  does not change regardless of the position of the bladder  5  wall, or the amount of water contained therein. 
     The assembly  1  further includes one or more fabric slings  35 . All of the sides of the rigid frame  30  support the slings  35 . A first end of each fabric sling  35  is threaded in a loop around a portion of the frame  30 , and a second end of the sling  35  is connected to the bladder  5 . The sling  35  protects the bladder  5  from directly contacting the ground upon which the assembly  1  is located and provides protection from possible sharp objects that might harm the bladder. The sling  35  controls the expansion footprint of the bladder  5 , and also limits the movement of the bladder  5  relative to the frame, and hence influences the shape and internal volume of the bladder  5  during filling. The fabric sling  35  can be made from a geo-textile fabric or the like. The frame  30  and sling  35  secure the bladder  5  firmly in position, and keep the bladder  5  isolated relative to parts of the surrounding building, such as pylons or beams that could otherwise puncture or damage the bladder  5 . 
     The inlet duct  10  is connected to a rainwater or grey water collection system (not shown) or the like and utilises gravity, such that the water collection point is at a higher potential head (e.g. a gutter) relative to the inlet duct  10  of the bladder  5 . However, if necessary a pump  100  may be added to the assembly  1 . The assembly  1  may also be combined with other recycling devices utilising mains or grey water. 
     In the preferred form (and as best shown in  FIG. 5 ) the assembly  1  includes two or more bladders  5  connected in parallel. The bladders  5  connected in parallel would be connected to the same inlet duct  10  and outlet duct  15 . However, the bladders  5  may be connected in parallel, series or any other configuration. In this case, two or more valves  25  may be utilised. The assembly  1  may also include a breather fitting  40  or the like. All the inlets and outlets may have some form of vector protection to prevent the ingress of insects such as mosquitos. 
     The bladders  5  are designed to be able to sit on uneven surfaces and may be folded or rolled to allow access through restricted entry points such as house sub-floor or wall areas. The inlet duct  10  is preferably a large diameter rainwater delivery pipe made from PVC. The inlet duct  10  allows the bladders  5  to fill simultaneously and efficiently during heavy water flow rates. This is important to ensure the maximum amount of rainwater is captured quickly with minimal loss of rainwater in large downpours. 
     The outlet duct is preferably a 32 mm PVC pipe, and there are preferably two outlet pipes connected to each bladder  5 . This will enable both the connection of multiple bladders and a pump, or alternatively a float chamber to measure when the water level is low when a mains water controller is then used to switch from stored rainwater or grey water to mains water. 
     In use, assembly  1  is connected to a liquid collection system of a dwelling or other building such as a rainwater collection system. Water (or another liquid to be stored) is gravity fed into the inlet duct  10 , filling the cavity within the flexible bladder  5 . As the bladder  5  expands the pressure on the water flowing through the duct  10  increases and once the bladder  5  is full, water travelling within the inlet duct  10  is forced out of the overflow  20 . Advantageously, there are no moving parts in the overflow  20 , the water pressure generated by the increase in potential head simply activates the overflow  20  as required. When two or more bladders  5  are placed in parallel (such as in  FIG. 5 ) the water flowing by gravity from the rainwater collection system or the like flows through the inlet ducts  10  in parallel directly to the cavity within the bladders  5 . In this way, the flow is not be disrupted. 
     In the preferred form, the inlet duct  10  is manufactured of PVC piping or the like and is directly connected to the flexible expandable bladders  5  which will fill until the overflow  20  is reached. Alternatively flexible pipe might also be used. The overflow  20  can have a level which is adjustable by a user to enable the assembly  1  to be adapted for varying height restrictions when the assembly  1  is placed in a sub-floor installation. The overflow  20  would most likely direct the excess water to a stormwater dispersion pit or the like. The outlet  15  is preferably a threaded plastic pipe which delivers water to a pump  102 , simple dispersion system or the like. 
     The bladder  5  may be manufactured from two or more sheets of plastics material welded together to form a sealed unit or the like. It should also be noted that existing systems weld bladders together using a microwave process producing a non-continuous weld. The resultant bladder can leak due to weakness between the finish of one weld and the start of the next weld. The bladder is preferably fabricated using a “wedge” weld producing a continuous weld formed by passing the fabric edge over a heated wedge. One edge passes over the top and the other edge passes underneath. The edges are then compressed under a durable roller system or the like, producing a stronger weld than existing systems. 
     Though the assembly  1  has been discussed above in respect of a dwelling it should be understood that the assembly  1  can easily be used in any domestic, commercial or industrial application for water or any other liquid. The assembly  1  may also be used outside a dwelling and the fabric may be manufactured from a UV protected material or the like. Where the assembly  1  is installed outside a dwelling, and the critical function of the frame  30  may no longer be required to protect building structures from the expanding assembly  1 , a flexible reinforced fabric might be used without the inclusion of the frame  30  provided that the mounting plate  7  supporting the inlet  10  and the outlets  15  is still utilised to connect the pipe work to the flexible bladder  5 . The mounting plate  7  would also need to be suitably supported. As the assembly  1  can be significantly compact prior to use it can also be placed in hard to reach locations and expanded in situ. The assembly  1  advantageously fills more efficiently than existing systems, will not leak at junction points as all the pipe joins would be glued. The additional bladders  5  may fill more efficiently than existing systems. 
     The assembly  1  is very easy to install even by a home handyman and requires very little maintenance and repair due to the fact that it has no moving parts nor does the inlet pipe  10  need to set at a specific angle as it enters the bladder  5 . The assembly  1  on account of its simplicity is less likely to fail than existing systems, has far fewer parts and is easier to transport and much faster to install. Further, the inlet duct  10  and outlet duct  15  could be any type of pipe including flexible pipes. A flexible pipe requires less installation time and fewer plumbing parts as a flexible pipe can go around corners without the need for pipe elbows and other fittings. 
     Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Technology Classification (CPC): 8