A backwash filtration system

Abstract

A system allowing a three-phase filtering and ensures selected return of a maximum volume of the backwash to the input line for feeding fluid back into the pool volume as required. The three-phase filtering can in one advantageous form include: 1. filtering through the top internal filter basket in the tank 2. Sediment separation by the unique base at the bottom of tank 3. return to the pool via the existing sand filter. This provides a substantial water saving.

Description

A BACKWASH FILTRATION SYSTEM Field of the Invention

[0001] The present invention relates to a backwash filtration system.

[0002] The invention has been developed primarily for use in / with a swimming pool with a sand filter requiring for a backwash filtration system and will be described hereinafter with reference to this application. However, it will be appreciated that the invention is not limited to this particular field of use. Background of the Invention

[0003] Water filtration systems, by their very nature, accumulate filtered material, such as water-borne solids, vegetation, insects, hair, and the like. To clean the filter medium, one can remove same from the filter body for cleaning and replacement, or the filtration mechanism may be reversed by backwashing water through the filter against the prevailing or normal direction of water flow to dislodge the filtered material. Such water- borne filtered material is generally disposed to waste or storm water. In a standard sized sand filter used for a domestic pool, a typical backwash volume of water is about 1,500 liters. This represents a substantial waste of clean pool water. The accumulative waste of useable, if not potable, water on a community scale represents a massive loss of precious water resources, particularly if one considers the enormous volumes of water used to backwash community pools, domestic pools and spas and commercial and industrial cooling plants.

[0004] Two types of swimming pool filtration systems use sand filters and cartridge filters.

[0005] Sand filters is the most popular filtration system and installed in approximately 75% of operating swimming pools. Pool water is forced through a tank filled with finely graded sand. Over time, impurities restrict the flow and the pressure gauge will indicate backwashing is required. Backwashing reverses the water flow and sends the unwanted waste down the drain.

[0006] Cartridge filter system uses a cartridge as the filter medium and doesn’t need to be connected to a sewer or waste line. Manual cleaning of the filter is required which consists of the removal of the cartridge and hosing it off using mains water.

[0007] It is a recommendation for responsible cleaning and general maintaining of swimming pools that filters be backwashed for three minutes each month.

[0008] In many cases, this recommendation requires approximately 400 litres per minute or 1200 litres in total of backwash water with its salt and chemicals to be discarded down the drain and into the sewerage system.

[0009] Cartridge filters with a flow rate of 25,000 litres per hour, the average cartridge filter will require cleaning once a month under normal operating conditions. Cleaning of the cartridge filter requires manual removal of the cartridge before soaking it in a bath of descaling solution e.g. in a plastic garbage bin holding approximately 100 litres. After sufficient soaking the filter is removed and all filter leaves are thoroughly hosed down with water using a high pressure spray nozzle with mains water. The hosing process may take 20 minutes for this single cartridge and with the average household garden tap releasing water at a rate of 45 litres per minute, 900 litres of water will be discarded plus the 100 litres of solution just to clean a single filter.

[0010] Therefore, a system is required with a novel backwash tank, which diverts foreign particles of backwashed water to a particular area of the tank enabling the tank water, minus impurities to be returned back into the pool.

[0011] It can be seen that known prior art backwash filtration systems have the problems of: a. Wastage of water, usually flushing away all the filter backwash water b. Difficulty of cleaning c. Complexity of cleaning the filters d. Not a combined filtering system e. Requiring substantial replacement water for replenishing pool

[0012] The present invention seeks to provide a backwash filtration system, which will overcome or substantially ameliorate at least one or more of the deficiencies of the prior art, or to at least provide an alternative.

[0013] It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country.Summary of the Invention

[0014] According to a first aspect of the present invention, there is provided a filtering tank for a backwash filtration system comprising a tank body having an upper opening leading to a main chamber, a filter for location in the upper opening and allowing ready selected removal therefrom and at least one input feed line extending along a top portion of the tank body from a lateral direction to the upper opening to allow feeding of fluid to be filtered by the filter and allow the filtered fluid to enter the main chamber. The filter can be removed, emptied and replaced without removing the input feed line.

[0015] The top portion of the tank body can include at least one strengthening rib. The at least one input feed line can extend within at least one strengthening rib. This at least one input feed line feeds to a filter chamber for holding the filter and receiving fluid from the at least one input feed line for entrapment of filtered material in the filter and removal.

[0016] Preferably the filter is a basket filter and receives fluid from the at least one input feed line feeding to the top of the basket filter without overhanging so as to allow the filter to be removed, emptied and replaced without removing the input feed line.

[0017] In one advantageous form, the upper opening is substantially central and the at least one strengthening rib each extends laterally from a substantially circumferential location to the central upper opening with the at least one input line extending from the circumferential location to the central upper opening through the at least one strengthening rib.

[0018] The at least one or more of the strengthening ribs can include a strengthening fold line.

[0019] Preferably the upper opening leading to a main chamber includes outlets smaller than the upper opening leading to a main chamber or the at least one input feed line to provide overflow outlets and / or to minimise glug feeding of the fluid to be filtered by the filter.

[0020] The top of the pod / tank can be adapted by shaping internally and externally to allow a fixed fitting to connect the pipework for the entering water to be fixed to the exterior of the tank which then connects to internal pipe work directing the water flow to the internal filter skimmer basket which sits in a purpose built holder.

[0021] In this form, the filter skimmer basket is situated in a top area of the tank / Pods while allowing ready removal without disconnection of pipework.

[0022] The invention also provides a backwash filtration system using a filtering tank according to any one of the preceding claims, the system including:a. Providing a first filtering system for connection to an input line for feeding fluid into a pool volume; b. Providing a second filtering system for taking fluid from the pool volume through the first filter system and forming a backwash and sending the backwash through a second filter, such as a sand filter, for providing a filtering of the accumulated detritus from the first filtering system; c. Providing the filtering tank with a concave base forming a third filtering system and a storage of the filtered fluid.

[0023] The system can allow the filtered fluid to have undergone a three-phase filtering and ensures selected return of a maximum volume of the backwash to the input line for feeding fluid back into the pool volume as required.

[0024] This three-phase filtering can in one advantageous form include: o Going through the top internal filter basket in the tank o Sediment separation by the unique base at the bottom of tank for sediment o And then return to the pool via the existing sand filter.

[0025] A backwash filtration system can include a filter and pump, said arrangement including a large water tank for receiving backwashed water having water-borne particles, wherein said tank is in communication with said filter and said pump; has a substantial height difference between the upper internal space and the lower internal space of said tank whereby said tank is adapted to permit water-borne particles to settle near the base of said tank over time to obtain a substantially clear water phase above the settled sediments; has a waste outlet near, in or on said base; has a recycling outlet above said waste outlet through which clear water from the clear water phase may be periodically released; and has an inlet above said recycling outlet, said inlet for receiving said backwashed water.

[0026] The tank can be adapted to permit water-borne sediments to settle in the lower 20% of its internal volume. Preferably said inlet is positioned above said lower 20% of said tank's internal volume.

[0027] The arrangement can further include at least one inline valve in the line communicating the filter to the tank that is controlled by a computer processor.

[0028] Also in one form the invention provides a water recycling tank using the novel filtering tank of the invention including a filter and pump, wherein said tankincludes: a. a tank body having an upper opening leading to a main chamber b. a filter for location in the upper opening and allowing ready selected removal therefrom c. At least one input feed line extending along a top portion of the tank body from a lateral direction to the upper opening to allow feeding of fluid to be filtered by the filter and allow the filtered fluid to enter the main chamber

[0029] In this way the filter can be removed, emptied and replaced without removing the input feed line. It is in communication with said filter and said pump; It uses a substantial height difference between the upper internal space and the lower internal space of said tank whereby said tank is adapted to permit water-borne particles to settle near the base of said tank over time to obtain a substantially clear water phase above the settled sediments; It includes a waste outlet near, in or on said base; and it is adapted top have a recycling outlet above said waste outlet and in communication with a water reservoir; and an inlet for receiving backwashed water from said water reservoir, said inlet located above said recycling outlet, and wherein said clear water phase can be periodically released through said recycling outlet to said water reservoir to replenish water level in said water reservoir.

[0030] Preferably the height of said tank is at least 1m.

[0031] The capacity of said tank can be at least 500 Litre and preferably 1800 Litre or 3000 Litre.

[0032] In one form the tank is substantially cylindrical. The tank base is internally concave to collect sediment towards the centre of said base and said waste outlet is located centrally in said base. The tank base is internally convex to disperse sediment towards the periphery of said lower internal space.

[0033] The water recycling tank can have said waste outlet located lowermost in the water recycling tank in a side wall of the water recycling tank. The recycling outlet is positioned above the settled sediment. The recycling outlet is the terminal end of a flexible hose that is weighted and / or floated to sit just under the upper water surface level in said tank.

[0034] It can be seen that the central dome in the base of the tank is there to divert the sediment to the perimeter of the tank / pod for easier cleaning once the sediment is needed to be removed.

[0035] The sediment water outlet or the cleaning valve is below the height of thedome to release the sediment once it has built up. Sediment build up can be determined by the water quality test valve (which is basically a tap) which is situated approx. the same height as the cleaning valve. This water can be tested to determine whether cleaning is required or not by taking a sample.

[0036] The cleaner return water outlet or the outlet valve which returns the water back to the pool is above the dome to ensure that the sediment that has settled is not drawn through this valve if cleaning hasn’t been performed when required.

[0037] The water recycling method of the invention in another form for a filtration system includes a filter, pump, and a settling tank according to any ones where the method comprises: a. directing water from a reservoir through said filter to perform a backwash; b. directing the backwashed water from said filter through a recycling inlet line to said tank; c. allowing water-borne sediments to settle on or near the base of the tank; d. directing water above said settled sediment from said tank through a recycling outlet line to said reservoir; and e. periodically exhausting said sediment-laden water near said base through a waste outlet.

[0038] The sediment-laden water can be reused for horticultural purposes.

[0039] A water recycling arrangement for a filtration system includes a filter and pump, said arrangement including a large water tank: in communication with said filter and said pump; that has a substantial height difference between the upper internal space and the lower internal space of said tank whereby said tank is adapted to permit water-borne particles to settle near the base of said tank over time to obtain a substantially clear water phase above the settled sediments; has a waste outlet near, in or on said base; has a recycling outlet above said waste outlet and in communication with a water reservoir; and has an inlet for receiving backwashed water from said water reservoir, said inlet located above said recycling outlet, wherein said clear water phase can be periodically released through said recycling outlet to said water reservoir to replenish the water level in said water reservoir.

[0040] Other aspects of the invention are also disclosed.Brief Description of the Drawings

[0041] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0042] Fig.1 is a diagrammatic top perspective view of a filtering tank for a backwash filtration system in accordance with a preferred embodiment of the present invention;

[0043] Fig.2 is cross sectional view of the filtering tank of Fig 1 showing the internal bottom structure

[0044] Fig 3 are various details of the top of the filtering tank for a backwash filtration system in accordance with a preferred embodiment of the present invention

[0045] Fig 4. are various details of the basket filter in the top of the filtering tank for a backwash filtration system in accordance with a preferred embodiment of the present invention

[0046] Fig 5 is a cross sectional detail of Fig 4 showing feed pipe along one modified flat rib such as shown in Fig 1

[0047] Fig 6 is a diagrammatic view of the connected system of backwash filtering using the filtering tank in accordance with an embodiment of the invention

[0048] Fig 7 is a diagrammatic view of the pod showing connection of outflow to inner base dome in accordance with an embodiment of the invention

[0049] Fig 8 is a diagrammatic view of the connected system of backwash filtering using two of the filtering tanks in accordance with an embodiment of the invention Description of Preferred Embodiments

[0050] It should be noted in the following description that like or the same reference numerals in different embodiments denote the same or similar features.

[0051] Referring to the drawings there is shown a filtering tank for a backwash filtration system

[0052] The System and Arrangement

[0053] The tank of the present invention may be provided in any suitable form and be comprised of a range of suitable materials. For example, the tank may be a standard cylindrical shape or may be shaped to better conform to its surrounds, particularly where space is at a premium. For example, the tank may be shaped to fit along a building wall profiled to minimise interruption to pedestrian traffic or other uses of the surroundingspace. The tank may be made from standard tank building materials, such as galvanised iron, stainless steel, polypropylene and the like. Blow moulded tank designs are becoming increasingly popular and enable the shaping of the tank to suit restricted or unusually shaped spaces.

[0054] The tank capacity will generally correspond to the capacity of the reservoir or the filter 26 itself. For example, a typical domestic pool containing 40,000 litres will require a settling tank having a capacity of 4,000 litres. A domestic spa having a capacity of 6,000 litres, will require a settling tank capacity of about 600 litres. Where the tank is relatively small in capacity (for example, 500-2,000 litres), advantageously the tank will be vertically elongate to give the water-borne solid materials sufficient distance along a so substantial vertical length to settle under the influence of gravity over time.

[0055] This settling process has the effect of achieving a separation of clean, reusable water comprising the 80-90% uppermost portion of the water in the tank on completion of the settlement process. The remaining lowermost 10-20% portion at the base of the tank may be composed of sediment and slime associated with the disposable product of filtered water. If left unaided, water-borne solid particles will tend to settle at the base 3 of a body of water whereby to achieve distinct clean water and sedimentary or colloidal Z phases over a period of about 2-3 months. Even very fine particles of silt will tend to o0 migrate to the base of the tank despite the presence of micro currents and movement occasioned by temperature variations across the length of the tank and bumps and vibrations that the tank may be exposed to, depending on its location.

[0056] Preferably, the recycling inlet is positioned to deliver back wash water into the tank at a height from between 25% and 95% of the height of the tank taken from its base. The lower the capacity of the pump to force water against pressure, the higher up the tank wall the recycling inlet should be. Therefore best results is returning through top of the tank 40. The reason for this is that as the tank fills with back lo1 wash water, the water pressure in the lower regions of the tank increases whereby further water, must be pressurised to be forced into the tank, once the water rises above the recycling inlet. Preferably, the recycling inlet is positioned upper most in the wall of the tank to minimise pressure resistance that might otherwise lead to back-flow pressure in the filter-tank line. Advantageously, a selectively directional valve in placed in line in the recycling inlet line to prevent backwash flowing back towards the filter from the tank.

[0057] The recycling outlet is preferably positioned just above the phase boundary of the sediment water zone near the base of the tank. This may ensure that, at the completion of the settling process, the water drawn through the recycling outlet is substantially for clean water to be returned through a recycled water return line to the reservoir optionally via the filter and / or the pump. To minimise turbulence at the base of the tank Whilst water is being drawn into the recycling outlet baffles in the base of the tank may be provided. Furthermore, the recycling outlet may extend into the tank by a recycling outlet and extending through the tank wall. The recycling outlet arm may include a flexible joint or portion close to the tank wall or may be composed substantially of a flexible material, such as rubber hose. By a combination of weights and / or floats, and taking into account the buoyancy of the recycling outlet arm, the recycling outlet may be adapted to be positioned just under the upper water surface in the tank to minimise turbulence at the base of the tank as water is drawn into the recycling outlet. In a 3o preferred form the recycling outlet is suspended by rigid arms just under the upper water surface, the upper ends of the rigid arms terminating in floats adapted to rest on the upper water surface. The recycling outlet may further include downwardly depending rigid arms adapted to space the outlet from the tank base to ensure that water from the sediment phase at the base is not drawn into the outlet and that only clean water is drawn into the outlet.

[0058] The waste outlet 44 is preferably located at or near the base 52 of the tank and below the upper surface of the phase boundary 49 between the sedimentary phase 47 and the clean water phase 48. The tank-waste line may be adapted to deliver the sediment water phase either to garden beds for recycling use or to sewer or other wastage channel for controlled disposal as waste.

[0059] With regard to use of the waste water as water for the garden, it is noted that chemicals used in the treatment of water will generally dissipate by evaporation or chemical breakdown over a period 2-3 months whereby there are no more than trace amounts of ON\ such chemicals in the sediment-containing water at the completion of the settling period. For example, chlorine gas will generally be given off into the atmosphere and salt in solution remains in generally low and non-harmful concentrations. In any case, care may be taken to deliver such waste water to selected plant types known to be salt in resistant or tolerant.

[0060] By the above described method, through each cycle between 80-90% of back wash water can be recycled by returning it to the reservoir and the remaining 10-20% ofsediment phase water can potentially be used to water gardens. Accordingly, the amount of replacement water required to top-up the reservoir over time can be substantially reduced leading to substantial savings in water use.

[0061] Referring to Figure 6, there is shown a water recycling and filter cleaning arrangement 11 comprising a pump 20, filter 30, and settling tank 40 so the pump 20 is a standard fixture for a typical domestic pool 15 having a usual capacity of between 20,000 and 40,000 litres.

[0062] The pump in one form can selectively direct water flow through one or more of four pipe lines: a pump-pool line, a pump-solar heating line, a pump-tank line and a pump- filter line. The pump-pool line is selectively opened and closed by the operation of a first valve, the pump-solar heating line is governed by a second valve and the pump-tank line is governed by a third valve. In turn, the first, second and third valves are governed by a control device, such as a simple computer processor typically used to control the operation of modem pool pumps. Alternatively, the selection of one line can be manually controlled by a lever-operated manual valve, commonly used in pool filters.

[0063] The pump-filter line communicates the pump 20 with the filter 30. The filter 30 is a standard sand filter, although other suitable filter types known in the art are within the scope of this invention. For example, activated carbon or charcoal filters as well as various synthetic filter media can also be cleaned by backwashing. The pump-filter line terminates at the filter 30. Extending between the filter 30 and the tank 40 is a pump-tank line made up of a first section and a second section. Extending between the pump-tank line and the pump-tank line is an intermediate line. The intermediate line includes an in- line valve. The second section of the filter tank line includes an inline back wash valve 22.

[0064] The tank 40 is a blow moulded polypropylene cylindrical body 42 which can include a transparent viewing window (for example, made of Perspex T31) insert in its or one of its vertical walls. The viewing window permits an operator to assess the water level 48, 49 at a quick glance.

[0065] The backwash filtration system uses water recycling and backwash arrangement and the filtering tank 40 by a. Providing a first filtering system fed through inlet line 32 by pump 20 to the sand filter 30 for filtering and by connection by a return line 33 for feeding first filtered fluid back into a pool volume;b. Providing a second filtering system for taking fluid from the pool volume 15 through the first filter system and by valves including backwash multichannel valve 22 forming a backwash and sending the backwash through a second filter, being a basket filter 66, for providing a filtering of the accumulated detritus from the first filtering system and returning filtered clean water 48 back through return line 38 back to the pool 15; c. Providing the filtering tank 40 with a concave base 53 forming a third filtering system for separating out sediments and allowing to exit waste outlet 44 and a storage of the filtered clean fluid 48 remains.

[0066] The system can allow the filtered fluid to have undergone a three phase filtering and ensures selected return of a maximum volume of the backwash to the input line for feeding fluid back into the pool volume as required. This three phase filtering can in one advantageous form include going through the top internal filter basket 66 in the tank, sediment separation by the unique base 53 at the bottom of tank for sediment and then return to the pool via the existing sand filter 30.

[0067] The tank 40 is covered with a lid 61 to limit evaporative loss and to reduce contamination from animal faeces and the ingress of decomposing vegetation, such as leaves. The lid 61 may be removable to allow inspections, repairs and maintenance operations to be performed internally in the tank. In this form, the filter skimmer basket is situated in a top area of the tank / Pods while allowing ready removal without disconnection of pipework.

[0068] At the base of the tank 40 the back washed water will contain a certain amount of sediment. After settling, this will be found in a lower-most sediment phase 47 in the lower most portion of the tank 40. The waste outlet 44 is placed in the base 52 of the tank 40. The base 52 is preferably marginally internally concave 53 and the waste outlet 44 is preferably located central to the base 52 whereby to most effectively drain the sediment phase through the waste outlet 44 periodically as will be described in detail below.

[0069] The recycled water return line 36 terminates in the tank 40 in a recycling outlet 43. The recycled water return line 36 extends through the vertical wall 50 through an appropriate water-tight annular seal. The internal length of the recycled water return line 36 may be flexible and may include floats to allow the recycling outlet 43 to rise and lower with the corresponding rising and lowering of the tank 40 water level 48, 49 to minimise the turbulence created near the base 52 by the drawing of water from the clean waterphase 48. The clean water phase 48 describes water found above the phase boundary 49 separating the sediment phase 47 from the clean water phase 48.

[0070] The tank 40 includes a recycling inlet 63 which is the terminal end of the second section of the filter-tank line 33. The recycling inlet 63 is positioned at the upper most in the vertical wall as the pump will provide sufficient positive pressure to ensure that back wash water can be forced into the tank 40 under pressure sufficient to fill the tank 40 to its capacity. In any case, unidirectional valve 34 will prevent backflow.

[0071] In Figure 6. the water level 48 varies between the high water level achieved when the tank is filled to capacity and the low water level achieved after the upper portion of water in the tank 40 is returned to the filter at the end of a settling period of between 2- 3 days. It will be noted that the low water level 47 is above the phase boundary 49 whereby only substantially clean water from the clean water phase 53 is recovered from the tank 40 for reuse in the pool 15.

[0072] The configuration of the arrangement 10 is shown with regard to the operation of valves achieves a back wash cleaning operation of the filter 30, water is drawn from the pool through the pump-pool lint 21 and through the pump 20 via the open valve 21 a. Note that the second and third valves are closed whereby water is directed into the pump- filter line, through the filter 30 to affect a back wash thereof. The water flow continues into the filter-tank line. The water is prevented from flowing into the intermediate line by the closed fourth valve, so that water is forced into the second section of the filter-tank line where the inline back wash valve permits the water to continue under force of the pump 20 into the tank 40 through the recycling inlet 63.

[0073] The back wash operation is continued until the water level in the tank reaches the top water level 48. The operator can monitor the rising water level 48 by viewing through the window. It will be appreciated that the viewing window may be substituted with any suitable functional equivalent, such as an external water level indicator tube in communication with the tank 40 through an aperture in the vertical wall 50 near the base 52, but above the phase boundary 49.

[0074] The back washed water residing in the tank 40 may be left to settle for 2-3 days so that sediments and other water-borne solids in the back washed water 53 migrate to the base 52 over time to form a sediment phase 47.

[0075] At the end of the settling period, an operator may activate the recycling procedure. The back wash procedure and the recycling procedure may be closing of thevalves. The pump 20 is used to draw clean water 48 from the tank 40 through the recycling outlet into the recycled water return line 38, through the pump 20 and returned to the pool 15 via the pump-pool line. This operation continues until the tank water level is lowered to the low water level 49. To ensure that water does not enter the lines - the minimum level that the clean water 48 can be reduced to is the lower level 49 just above the upper most portion of the recycling outlet 43. By this process, the back wash water is recovered as clean water 53 returned to the pool after the settling is period.

[0076] Finally, the remaining sediment phase 47 may be passively or actively drained from the tank 40 through the waste outlet 44, into the waste pipe 45 whereby it may be delivered into the garden for recycled horticultural use or otherwise disposed of down a sewer drain.

[0077] The Base

[0078] The backwash storage tank differs from existing water tanks because of the function of its unique base which is suitable for tanks of every size.

[0079] As its support the backwash storage tank has a flat outer base around the perimeter of the tank while the inner base of the tank projects up into the centre of the tank from the outside perimeter support Moving towards the centre of the tank from the outside perimeter support, the base projects up into the tank making the centre of the base of the tank its highest point and creating a concave sphere 53 which can vary in height 54.

[0080] The base section 52 of the water tank 40 therefore as depicted in the drawings and in particular which forms the centre circular extrusion that forms the concave radial sphere within the tank. The central dome in the tank is there to divert the sediment to the perimeter of the tank / pod for easier cleaning once the sediment is needed to be removed. The sediment water outlet or the cleaning valve is below the height of the dome to release the sediment once it has built up. Sediment build up can be determined by the water quality test valve (which is basically a tap) which is situated approx. the same height as the cleaning valve. This water can be tested to determine whether cleaning is required or not by taking a sample.The cleaner return water outlet or the outlet valve which returns the water back to the pool is above the dome to ensure that the sediment that has settled is not drawn through this valve if cleaning hasn’t been performed when required.

[0081] The top of the Tank

[0082] Views of the tank depict the flat outer base 1 around the perimeter of the tank providing the support for the tank and depict the inner base of the tank 2 projecting up into the tank making the centre of the base its highest point 3 which forms the centre circular extrusion that forms the concave radial sphere within the tank.

[0083] The filtering tank 40 for a backwash filtration system comprises a tank body 42 having an upper opening 65 in the lid 61 of the tank leading to a main internal chamber . A basket filter 66 for location in the upper opening 66 and allowing ready selected removal therefrom.

[0084] The lid includes ribs 62 radiating from the upper opening. At least one input feed line 68 extends within a modified rib 63 along a top portion of the tank body from a lateral direction to the upper opening 65 to allow feeding of fluid to be filtered by the basket filter 66 and allow the filtered fluid to enter the main chamber 43.

[0085] Because of location of the basket filter 66 below the opening 65 the filter can be removed, emptied and replaced without removing the input feed line 68.

[0086] The Method of Operation

[0087] A water recycling method for a filtration system that includes a filter, pump, and settling tank, said method comprising: (a) directing water from a reservoir through said filter to perform a backwash; (b) directing the backwashed water from said filter through a recycling inlet line to said tank; (c) allowing water-borne sediments to settle on or near the base of the tank; (d) directing water above said settled sediment from said tank through a recycling outlet line to said reservoir; and (e) periodically exhausting said sediment-laden water near said base through a waste outlet.

[0088] Referring to FIGS.6, 7 and 8 there is shown is a water recycling arrangement 10 comprising a pump 20, filter 30, and settling tank 40.

[0089] The tank 40 is provided in any suitable form and may be made from a range of suitable materials. For example, the tank 40 may be a standard cylindrical shape or may be shaped to better conform to its surroundings, particularly where space is at a premium. For example, the tank 40 may be shaped to fit along a building wall profiled to minimize interruption to pedestrian traffic or other uses of the surrounding space. The tank 40 is made from standard tank-forming materials, such as galvanized iron, and more preferably is made from a plastic material such as polycarbonate, polyethylene, polypropylene and the like. The tank 40 is preferably rota-molded to enable the shaping of the tank 40 to suit restricted or unusually shaped spaces. However, the tank 40 may be molded by other means, such as blow-molding.

[0090] The tank 40 capacity will generally be relative to the capacity of the reservoir and / or the filter 30. The reservoir shown in the drawings is a pool 60 As an example, where the pool 60 is a typical domestic pool containing 40,000 liters of water, the arrangement 10 will require a settling tank 40 having a capacity of 4,000 liters. Where the reservoir is a domestic spa having a capacity of 6,000 liters, the arrangement 10 will require a settling tank capacity of about 600 liters. Where the tank 40 is relatively small in capacity (for example, 500-2,000 liters), advantageously, the tank 40 will be vertically elongate to give water-borne solid materials sufficient distance along a substantial vertical length to settle under the influence of gravity over time.

[0091] This settling process has the effect of achieving a separation of clean, reusable water comprising the 80 to 90% uppermost portion of the water in the tank 40 on completion of the settlement process. The remaining lowermost 10 to 20% portion of the contents at the base 52 of the tank 40 may be composed of sediment and slime associated with the disposable product of water filtered by the arrangement 10. If left unaided, water-borne solid particles will tend to settle by the influence of gravity at the base 52 of the body of water in the tank 40 in order to achieve distinct clean water and sedimentary or colloidal phases over a period of about two to three days. Even very fine particles of silt will tend to migrate to the base 52 despite the presence of micro currents and movement occasioned by temperature variations across the length of the tank 40 and bumps and vibrations that the tank 40 may be exposed to, depending on its location.

[0092] The tank includes a recycling inlet 42 that is positioned to deliver backwash water into the tank 40 at an upper portion of the tank 40 and at least at a height from between 25 and 95% of the height of the tank 40 taken from its base 52. The lower the capacity of the pump 20 to force water against pressure, the higher up the tank 40 wall the recycling inlet 42 should be. The reason for this is that as the tank 40 fills with backwash water, the water pressure in the lower regions of the tank 40 increases, and further water must be pressurized to be forced into the tank 40 once the water rises above the recycling inlet 42. The recycling inlet 42 may be positioned uppermost in or through the wall 50 of the tank 40, and most preferably in or through the roof or lid 51 of the tank 40 (as shown in FIG. 4), to minimize pressure resistance that might otherwise lead to back-flow pressure in a filter-tank line 31, 33 joining the filter 30 to the tank 40. Advantageously, a selectively directional check valve 34 is placed in line in the recycling inlet line to prevent backwash flowing back towards the filter 30 from the tank 40.

[0093] The tank 40 has a recycling outlet 43 that is preferably positioned just above the phase boundary of the sediment / water zone 47 near the base 52 of the tank 40. This may ensure that, at the completion of the settling process, the water drawn through the recycling outlet 43 is substantially clean water to be returned through a recycled water return line 36 to the reservoir 60 optionally via the filter 30 and / or the pump 20. To minimize turbulence at the base 52 while water is being drawn into the recycling outlet 43, baffles (not shown) in the base 52 may be provided. Furthermore, the recycling outlet 43 may extend into the tank 40 by a recycling outlet arm 43a extending through the tank wall 50. The recycling outlet arm 43a may include a flexible joint or portion close to the tank wall 50 or may be composed substantially of a flexible material, such as rubber hose. By a combination of weights and / or floats and taking into account the buoyancy of the recycling outlet arm 43a, the recycling outlet 43 may be positioned just under the upper water surface 49 (see FIG. 3) in the tank 40 to minimize turbulence at the base 52 as water is drawn into the recycling outlet 43. However, in a preferred form, the recycling outlet 43 is in a fixed position located near the base 52 in the wall 50 just above the upper surface of the sediment phase 47. The recycling outlet 43 may further include downwardly depending rigid arms adapted to space the outlet 43 from the tank base 52 to ensure that water from the sediment phase 47 is not drawn into the outlet 43 and that only substantially clean water is drawn into the outlet 43.

[0094] The tank 40 has a waste outlet 44 that is preferably located at or near the base 52 and below the upper surface of the phase boundary between the sedimentary phase47 and the clean water phase 53. The arrangement includes a tank-waste line 45 that, for example, is adapted to deliver the sediment water phase 47, either to garden beds for recycled use or to a sewer drain or other wastage channel for controlled disposal as waste.

[0095] With reference to FIG.4, the tank 140 may include an internally convex base 152 having a centrally raised floor 152a similar in shape to the base of a wine bottle. In this arrangement, the waste outlet 144 may be located at the lower side edge of the tank 140 where the wall 150 and base 152 meet. Further details of this arrangement are described in more detail hereafter. The corollary of this arrangement is an arrangement in which the base 152 is internally concave and the waste outlet 144 is in such cases centrally located in the base 152 because the sediment 147 will tend to collect centrally on the internal surface of base 152.

[0096] With regard to use of the waste water as water for the garden, it is noted that chemicals used in the treatment of water in the tank 40, for example, where the reservoir 60 is a pool, will generally dissipate by evaporation or chemical breakdown over a period of two to three months. In such cases, it is believed that there are no more than trace amounts of such chemicals in the sediment-containing water 47 at the completion of a settling period. For example, chlorine gas will generally be given off into the atmosphere and salt in solution will remain in generally low and non-harmful concentrations. In any case, care may be taken to deliver such waste water 47 only to selected plant types that are known to be salt resistant or tolerant. However there is still requirement to be careful because there may be bacteria or pathogens.

[0097] By the above-described method, through each two-to three-day cycle, between 80 to 90% of backwash water can be recycled by returning it to the reservoir 60 and the remaining 10 to 20% of sediment phase water 47 can potentially be reused, for example, on plants and gardens as long as careful because there may be bacteria or pathogens. Accordingly, the amount of replacement water required to top-up the reservoir 60 over time can be substantially reduced leading to substantial savings in water use.

[0098] The preferred forms of the invention will now be described with greater particularity. In the first embodiment, the pump 20 shown in FIGS. 1 through 3 is a standard fixture for a typical domestic pool (not shown) having a usual capacity of between 20,000 and 40,000 liters. The pump can selectively direct water flow through one or more of four pipe lines: a pump-pool line 21, a pump-solar heating line 22, a pump-tank line 23 and a pump-filter line 24. The pump-pool line 21 is selectively opened and closed by the operation of the first valve 21a, the pump-solar heating line 22 is governed by a second valve 22a and the pump-tank line 23 is governed by a third valve 23a. In turn, the first, second and third valves 21a, 22a, 23a are governed by a control device, such as a simple computer processor typically used to control the operation of modern pool pumps. Alternatively, the selection of one line 21, 22, 23 can be manually controlled by a lever-operated manual valve, commonly used in pool filters.

[0099] The pump-filter line 24 communicates the pump 20 with the filter 30. The filter 30 is a standard sand filter, although other suitable filter types known in the art are within the scope of this invention. For example, activated carbon or charcoal filters as well as various synthetic filter media can also be cleaned by backwashing. The pump-filter line 24 terminates at the filter 30. Extending between the filter 30 and the tank 40 is a filter- tank line 31, 33 made up of a first section 31 and a second section 33. Extending between the filter-tank line 31, 33 and the pump-tank line 23 is an intermediate line 32. The intermediate line 32 includes an in-line intermediate valve 32a. The second section of the filter-tank line 33 includes an inline backwash valve 34. The section of pump-tank line 23 between the intermediate line 32 and the tank 40 may be described as a recycled water return line 36. The recycled water return line 36 includes an inline recycled water valve 35.

[0100] The tank 40 is preferably a rotary molded polypropylene hollow cylindrical body including a transparent viewing window 41 (for example, made of Perspex™) inserted in its, or one of its, vertical walls 50. Alternatively, the viewing window may be in the form of a sight tube spaced from the vertical wall 50. The viewing window 41 permits an operator to assess the water level 48, 49 at a quick glance. The tank 40, 140, 240 (referring to other embodiments of the invention) may be provided without a sight tube or glass where algal growth may present a problem. In this regard, where light is able to penetrate into the tank internal space, algal growth may be stimulated and this will generally be undesirable. However, where clean water 53 is to be frequently released from the tank 40 or the water 53 treated to prevent algal growth, a sight tube 41 may be desirable to enable easy assessment of the tank's 40 water level 48.

[0101] The tank 40 is covered with a lid 51 to limit evaporative loss and to reduce contamination from animal feces and the ingress of decomposing vegetation such as leaves. The lid 51 may be removable to allow inspections, repairs and maintenance operations to be performed internally in the tank 40.

[0102] At the base of the tank 40, the backwashed water will contain a certain amount of sediment. After settling, this will be found in a lowermost sediment phase 47 in the 10 to 20% lowermost portion of the tank 40. The waste outlet 44 is placed in the base 52 of the tank 40. The base 52 is preferably marginally internally concave and the waste outlet 44 is preferably located central to the base 52 to most effectively periodically drain the sediment phase 47 through the waste outlet 44 as will be described in detail below.

[0103] In FIG.6, the water level 48 represents the high water level achieved when the tank 40 is filled to capacity and the water level 49 represents the low water level achieved after the upper portion of water in the tank 40 is returned to the filter 30 / pump 20 / reservoir at the end of a settling period of between two to three days. It will be noted that the low water level 49 is above the phase boundary 54 whereby only substantially clean water from the clean water phase 53 is recovered from the tank 40 for reuse in the reservoir (not shown).

[0104] To achieve a backwash cleaning operation of the filter 30, water is drawn from the pool through the pump-pool line 21 and through the pump 20 via the open valve 21a. Note that the second and third valves 22a, 23a are closed whereby water is directed into the pump-filter line 24 through the filter 30 to affect a backwash thereof. The water flow continues into the filter-tank line 31. The water is prevented from flowing into the intermediate line 32 by the closed fourth valve 32a, so that water is forced into the second section of the filter-tank line 33 where the inline backwash valve 34 permits the water to continue under force of the pump 20 into the tank 40 through the recycling inlet 42. The backwash operation is continued until the water level in the tank reaches the top water level 48. The operator can monitor the rising water level 48 by viewing through the window 41. It will be appreciated that the viewing window 41 may be substituted with any suitable functional equivalent, such as an external water level indicator tube in communication with the tank 40 through an aperture in the vertical wall 50 near the base 52, but above the phase boundary 54.

[0105] The backwashed water residing in the tank 40 may be left to settle for two to three days so that sediments and other water-borne solids in the backwashed water 53 migrate to the base 52 over time to form a sediment phase 47.

[0106] At the end of the settling period, an operator may activate the recycling procedure. The backwash procedure and the recycling procedure may be advantageously controlled by a computer processor adapted to control the opening andclosing of the valves. The valves are open or closed whereby the pump 20 is used to draw clean water 48 from the tank 40 through the recycling outlet into the recycled water return line, through the pump 20 and returned to the pool 15 via the pump-pool line. This operation continues until the tank 40 water level is lowered to the low water level 49. To ensure that water does not enter the lines, the minimum level that the clean water 48 can be reduced to is the lower level 49 just above the uppermost portion of the recycling outlet 43. By this process, the backwash water is recovered as clean water returned to the pool after the settling period.

[0107] The remaining sediment phase 47 may be passively or actively drained from the tank 40 through the waste outlet 44, into the waste pipe 45 whereby it may be delivered into the garden for recycled horticultural use or otherwise disposed of down a storm water drain or otherwise disposed of, for example, where local regulations impose restrictions on how such waste may be disposed of.

[0108] A form of the backwash recycle system 110 uses an existing swimming pool filtration system, the system 110 comprising a pump 120, sand filter 130, and settling tank 140.

[0109] The tank 140 is similar to that shown in relation to the first embodiment and like features are indicated by like reference numerals plus 100. The base 152 is internally convex and includes a centrally raised internal floor forming a hemispherical-shaped mound 152a similar to a base of a wine bottle. As a consequence, during settlement, sediment 147 is dispersed from the center and pooled at the edges of the lower internal spaces of the tank 140 around the periphery of the base 152. At the base 152 there is located a drain portal 144 in the wall 150 from which extends a drain pipe 145. The drain portal 144 is preferably flush with the floor of the base 152 for more thorough drainage and has a poly threaded nipple 144a extending through the portal 144 and threadably connecting the tank 140 to the drain pipe 145. As a check valve, the drain portal further includes a nylon ball valve 144b. Sediment 147 tends to collect around the periphery of the base 152 and, on opening the waste outlet or drain portal 144, may be drained from the tank 140 as it follows the course of the annular channel 147a formed between the base 152, the mound 152a and the wall 150.

[0110] The recycling outlet 143 is connected to a backwash storage tank return line 136 that connects to a pump-pool line 121 using a PVC three-way ball valve 121a to control the junction of lines 121, 136.

[0111] The tank inlet 142 comprises a PVC (polyvinylchloride) valve socket 142a through which backwash water is pumped into the storage tank 140 via a second section of a filter tank line 133. A first section of the filter tank line 131 extends the filter tank line 131, 133 to the sand filter 130. At the junction between the first and second sections of the filter tank line 131, 133 is a PVC three-way ball valve 134 connecting the filter tank line 131, 133 to a waste outlet 145a, such as sewerage or storm water. The valves 121 and 134 may be controlled by computer programming operating a computer processor unit controlling the system 110, or may be manually manipulated by an operator.

[0112] Interposed between the filter 130 and the pump 120 is a pump filter line 124. A valve junction in the form of a three-way ball valve 121 a provides a junction between the return line 136 and a pump-pool line 121. The system is completed by a filter-pool line 125 terminating at the pool end in a pool return outlet 126.

[0113] To install the above-described arrangement 110, the following procedure may be followed: 1. Install the PVC three-way ball valve 121 a into an existing pool suction line 121 in front of an existing pool pump 120; 2. Install a PVC three-way ball valve 134 into the filter-tank line 131, 133; 3. Connect the filter-tank line to the top or roof 151 of the storage tank 140 and connect a PVC valve socket 142a to the tank inlet 142. The PVC valve socket 142a can be placed into either a threaded tank inlet 142 or a rubber or plastic bung may be used to secure the valve socket 142a in the tank inlet 142. 4. Connect the backwash storage tank return line 136, with appropriate fittings 161-166 to the three-way ball valve 121 a in the pump-pool line 121, noting that the arrangement of FIG.5 or that of FIG.6 for return line 137 should be used depending on whether the water outlet 143 is above or below the line of the filter 130; and 5. Connect the waste fittings 144a, 144b and 145 to the drain portal 144 of the tank 140.

[0114] During installation of the storage tank 140, the following should be noted: 1. The tank 140 site must be flat, level and smooth. Concrete, compacted sand or similar fill is ideal. Sand or fill must be boxed to prevent washing away. The prepared area requires that there be a centrally located mound of sand, not necessarily matching the indentation of the base 152 precisely, but ensuring that a certain amount of moundedsand is provided supporting the indentation of the tank base 152. It should be ensured that the outside perimeter of the tank 140 is also on a level surface.

[0115] With regard to operating instructions, the following procedures should be observed: 1. Ensure that all filters 130 and pumps 120 are switched off; 2. Open the three-way ball valve 134 ensuring that the line leading to the waste outlet 145a is closed. It should be noted that this three-way valve 134 may remain open for further water transfer to the tank 140. 3. Follow the backwash or waste procedures.

[0116] With regard to the operation of the return of clean water 153 to the swimming pool 60, the following operating procedures should be observed: 1. Ensure that the filter 130 and pump 120 are switched off. 2. Ensure that the ball valve 163 is open (refer to FIGS.5 and 6). 3. Open the three-way ball valve 121a to ensure that the return line 136, 137 is open and the pump-pool line 121 is closed. 4. Start the normal filtration cycle using the filter 130 so that clean water 153 will return from the tank 140 to the swimming pool 60 via the filter 130. 5. Once the required levels have been established in the pool 60 or the clean water 153 in the storage tank 140 has been exhausted, turn the filtration system 130 off. 6. Close the three-way ball valve 121 ensuring that the return line 136 is closed and the pump-pool line 121 is open. It is important that this step is carried out correctly and that the three way ball valve 121 a is closed properly as it is possible that water may be drawn from the tank 140 on the normal filtration cycle even if open slightly, and in cases where settlement of the water in the tank 140 is not yet completed, this may be undesirable.

[0117] A tank 240 that may be used in any one of the above-described embodiments. The tank 240 is rotary molded and all fittings are plastic as pool salt and chemicals will corrode components made, for example, of brass. The tank 240 includes an inlet 242 from the filter and an outlet 143 connecting the tank 240 back to the pool. The base 252 of the tank includes a centrally located waste outlet 144. As an option, the tank 240 may include an optional rain water inlet 243 located in the roof 250. The rain water inlet 243may be connected to storm water run off from a domestic dwelling. The tank 240 may include a sight glass 241 attached to the wall 252 of the tank 240. An overflow outlet 270 located uppermost in the tank 240 may be provided to connect the primary storage tank 240 to secondary storage tanks (not shown) or to waste. It should be noted that the clean water 253, even following settlement, will not normally be suitable for drinking, unless further treated.

[0118] Installation and Maintenance Backwash Pod Installation • Ensure Pod site is flat, level and smooth. Concrete, compacted sand or similar fill is ideal. • If using sand or fill, ensure it is boxed to prevent it from washing away • The special design of the Backwash Pod will require mounded sand in the centre of the prepared area. This mounded sand does not have to match the indentation of the Backwash Pod exactly, as long as there is a reasonable amount of mounding supporting the indentation of the Backwash Pod. • Ensure outside perimeter of Backwash Pod is on a level surface. All waste and overflow fittings are connected to appropriate outlets and it is recommended these fittings be connected to the existing sewer outlet as exposure of backwash water to the environment should be prevented. Installation Procedure Do not over tighten threads and ensure Teflon tape supplied is used on all threaded 40mm fittings and the 50mm 3 Way Valve). 50mm-40mm reducers accommodate existing 40mm systems. Installation Stage 1: Backwash Water Return (P1) • Install Three Way Ball Valve (Part A) into existing pool suction line in front of existing pool pump • Install Reducing Bush (Part B) to Three Way Ball Valve (Part A) if necessary to accommodate existing 40mm system to Part A • Install Poly Threaded Nipple (Part D) to 40mm threads in Backwash Pod foroutlet valve and cleaning valve • Install appropriate fittings for outlet valve and cleaning valve Part G (PVC rubber joiner) is to be used to connect outlet + cleaning valve to accommodate angle / bend • Install 40mm PVC pipe* (not supplied) connecting outlet valve and cleaning valve to three way Ball Valve (Part A) Reducing Bush (Part B) is used to connect 40mm PVC pipe to Three Way Ball Valve (Part A) Depending on Backwash Pod location a non-return valve may have to be installed in the Backwash Pod return line (P1) if the Backwash Pod is lower than the existing filtration system. This would be installed in the 40mm pvc pipe close to the outlet and cleaning valve to prevent water back now enabling the Backwash Pod return line to be primed at all times. Installation Stage 2: Backwash Water To Backwash Pod (Shown as P2 on Detailed System Diagram) • Install Three Way Ball Valve (Part A) into waste line • Install Reducing Bush (Part B) if necessary to Part A to accommodate existing 40mm systems • Install Valve Adaptor (Part C) into 40mm thread at the top of Backwash Pod (as shown figure 3) • Install 40mm PVC pipe* (not supplied) connecting Three Way Ball Valve (Part A) to Valve Adaptor (Part C) at the top of Backwash Pod - Reducing Bush (Part B) is required to connect 40mm PVC pipe to Three Way Ball Valve (Part A) It is recommended to use class 12 PVC pipe. All pipe work to be laid on or under ground level where possible. Selected 40mm PVC tees and 40mm PVC elbows are supplied in the Pod kit for pipe installation. More may be required for individual installation. This would be to the cost of the installer. Remaining Connections • Install brass Backwash Pod tap (Part F) to 20mm threaded poly Backwash Pod outlet for water quality test valve • Connect 90mm PVC cap (supplied) to inspection outlet• OVERFLOW TO BE CONNECTED TO APPROPRIATE OUTLET • Existing filtration system layout may need to be altered to accommodate appropriate Backwash fittings (e.g. existing pump moved). Maintenance • The quality of water should be inspected via the water quality test valve once every 12 months. • DO NOT BACKWASH SWIMMING POOL FOR A FOUR DAY PERIOD PRIOR TO MAKING THIS INSPECTION. • Open water quality test valve slightly allowing the Backwash Pod water to be dispersed into a clear glass or plastic container or similar for water quality inspection. • If inspection uncovers unsatisfactory results, cleaning of the Backwash Pod may be required. There are three options: Option 1 This option requires the removal of all water from the Backwash Pod into the swimming pool overfilling the pool until all water above outlet valve in the Backwash Pod has been returned to the pool. Remove top screw lid from top of Backwash Pod and also remove internal filter basket. Stir water around base perimeter of pod (sump) using a small broom with an extended handle or similar taking care not to damage inside of Backwash Pod. If sewer / waste outlet is not connected to mains sewerage system, appropriate disposal of wastewater for this option is required eliminating the release of the wastewater into the environment e.g., flexible hose dispersed to an appropriate outlet etc.. Refer to Detailed System Diagram for the following. 1. Ensure all filters and pumps are switched off and outlet valve is closed 2. Open three way ball valve ensuring line from Backwash Pod is open and line from swimming pool is closed. 3. Open cleaning valve4. Open three way ball valve ensuring line to Backwash Pod is closed and line leading to waste is open. 5. Select waste option on sand filter. 6. Start normal waste cycle. All foreign material from the base of the Backwash Pod will be directed to waste. 7. Once all foreign material has been dispersed turn off all filters and pumps. 8. Ensure cleaning valve is closed 9. Close three way ball valve ensuring line from Backwash Pod is closed and line from swimming pool is open. 10. Ensure 3 way ball valve is open to Backwash Pod and line to waste is closed. Follow the Backwash or Waste to Backwash Pod as explained. Water will return to the cleaned Backwash Pod via the Backwash Pod fill line (P2). Refit filter basket and screw top lid to top of Backwash Pod. Ensure sand filter and appropriate valves are returned for normal pool filtration. Dispose of excess water appropriately. Option 2 - Where available, the existing swimming pool vacuum line can be used to vacuum around the sump of the Backwash Pod, disposing of foreign material to waste. SEPTIC SYSTEM In situations of septic systems where swimming pool backwash water cannot enter these systems when flushing the Backwash Pod, the employment of an outside contractor who specializes in water tank cleaning will dispose of the backwash wastewater appropriately. Backwash Recyclers recommends this procedure at three year intervals. The above cleaning methods ensure all backwash waste is directed to appropriate outlets avoiding release into the environment. SWIMMING POOL EXCESS WATER OR WASTE REMOVAL eg. Excess water due to excessive rain periodsDO NOT direct of all unwanted excess pool water or waste through the Backwash Pod to waste. All unwanted pool water or waste is to be sent directly from pool to sewer / waste through Figure 2 which is positioned prior to Backwash Pod. If mains sewerage is not accessible, appropriate disposal of wastewater is required at all times. An excess water release valve is positioned before the Backwash Pod (Figure 2) for the excess water release. This is to be directed and dispersed to appropriate areas. Waste option is to be selected for this option. Under no circumstances is backwash to be selected for this purpose. Recommendations For Excess Water Use: Option 1 - Excess water can be used to Fill Backwash Pod to capacity for future use in pool. *If Backwash Pod is full DO NOT overflow Backwash Pod - dispose all unwanted excess pool water directly from pool to sewer / waste or appropriate outlet (as above). Option 2 - Backwash Pod rinse This option allows pool excess water to be used to rinse the Backwash Pod. This can be achieved by removing all stored Backwash Pod water straight to sewer. Refill Backwash Pod using excess pool water following operation instructions - Backwash water to Backwash Pod DO NOT OVERFLOW BACKWASH POD Operation Instructions - It is recommended that prior to normal backwashing procedure, water should be drawn from the Backwash Pod to “overfill” theswimming pool. This will enable normal backwashing procedures ( ushing allbackwash water to Backwash Pod) to drop the water level of the swimming pool until the required water levels have been re-established. BACKWASH POD RETURN TO SWIMMING POOL (SHOWN AS P1 ON DIAGRAM) 1. Ensure all filters and pumps are switched off 2. Ensure outlet valve (as shown fig 4) is open and cleaning valve is closed. 3. Open 3-way ball valve ensuring line from Backwash Pod is open and line from swimming pool is closed4. Start normal filtration cycle. Water will now be returning from the Backwash Pod to the swimming pool via the sand filter 5. Once required overfilled level in swimming pool has been established (approx 3 mins) turn filtration system off 6. Close 3-way ball valve (as shown fig 1 circled) ensuring line from Backwash Pod is closed and line from swimming pool is open and close outlet valve It is important step 6 is carried out correctly and the 3-way ball is completely closed. If both 3 way ball valve and outlet valve are even slightly open, water may be drawn from Backwash Pod on normal filtration cycle Benefits. Environmental • Conserves and stores water for future use. • The Bureau of Meteorology in partnership with the pool industry recommends that to maintain a functioning pool, water needs to be topped up to a required level. Using this system and with the aid of a pool blanket, pools would be totally self-reliant for water. • Salt and chemically treated water no longer need be drained into the • sewerage system. • Because the system’s tanks need not be ‘food standard’, they can be • manufactured from recycled material. • The unique design directs all dirt particles to particular areas to facilitate • easier cleaning. • The tank requires cleaning approximately every 3 years (according to • industry recommendations). • Rain water can be connected to tank. • Tank can be installed in a secluded area away from pool. • Is delivered in a kit with clear and hassle free instructions for easy • installation. • No manual running of hoses to pool as all connections are completed on installation.Economic • Alleviate the need to buy water that according to the government will be increased in price by enough to encourage people to use it more wisely. • Be cost effective because recycled water will be already chemically treated. • Be cost effective because the system is delivered in easy to install kit form at a cost less than the cost of many current non-recyclable systems. Social • Keep private sector swimming pools functional during even the most severe water restriction cycles and high temperatures for the community to maintain and enhance lifestyle. • Meet a need for social recreation associated with swimming pools as temperatures rise.

[0119] The current Swimming Pool and Spa Association recommendation for responsible cleaning and general maintaining of swimming pools is that they be backwashed for three minutes each month. In many cases, this recommendation requires approximately 400 litres per minute or 1200 litres in total of backwash water with its salt and chemicals to be discarded down the drain and into the sewerage system.

[0120] The present system and tank of the invention with its innovative base system is primarily a backwash minimization process that will recycle approximately 99% backwash water minus impurities. The unique innovative base that facilitates the process of backwash tank diverts foreign particles of backwash water to a particular area of the tank enabling the tank water, minus impurities, to be returned back to the pool. Swimming Pool Backwash Water Saving Test Results

[0121] Using the system of the invention connected to a sand filter on a 9 metre x 4.5 metre 61,000 litre concrete swimming pool with salt chlorinator (Pool Power RP23) and Sand filter (Hayward Super Pump SP2600 series) with approx.330 Liter per Minute flow rate the following results were achieved:This test shows that the total amount of water saved over a 12-month period in one swimming pool is 12,474 litres.Interpretation

[0122] Embodiments:

[0123] Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0124] Similarly it should be appreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description of Specific Embodiments are hereby expressly incorporated into this Detailed Description of Specific Embodiments, with each claim standing on its own as a separate embodiment of this invention.

[0125] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0126] Different Instances of Objects

[0127] As used herein, unless otherwise specified the use of the ordinal adjectives “first”, “second”, “third”, etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

[0128] Specific Details

[0129] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0130] Terminology

[0131] In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as "forward", "rearward", "radially", "peripherally", "upwardly", "downwardly", and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.

[0132] Orientational terms used in the specification and claims such as vertical, horizontal, top, bottom, upper and lower are to be interpreted as relational and are based on the premise that the component, item, article, apparatus, device or instrument will usually be considered in a particular orientation, typically with the lid uppermost.

[0133] Comprising and Including

[0134] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

[0135] Any one of the terms: including or which includes or that includes as used herein is also an open term that also means including at least the elements / features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising.

[0136] Scope of Invention

[0137] Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. For example, any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.

[0138] 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. Industrial Applicability

[0139] It is apparent from the above, that the arrangements described are applicable to the swimming pool industry and particularly users of filtering tanks and for backwash filtration cleaning industries.

Claims

Claims The claims defining the invention are as follows:

1. A filtering tank for a backwash filtration system comprising a. A tank body having an upper opening leading to a main chamber b. A filter for location in the upper opening and allowing ready selected removal therefrom c. At least one input feed line extending along a top portion of the tank body from a lateral direction to the upper opening to allow feeding of fluid to be filtered by the filter and allow the filtered fluid to enter the main chamber d. wherein the filter can be removed, emptied and replaced without removing the input feed line.

2. A filtering tank according to claim 1 wherein the top portion of the tank body includes at least one strengthening rib.

3. A filtering tank according to claim 2 wherein the at least one input feed line extends within at least one strengthening rib.

4. A filtering tank according to claim 1 wherein the at least one input feed line feeds to a filter chamber for holding the filter and receiving fluid from the at least one input feed line for entrapment of filtered material in the filter and removal.

5. A filtering tank according to claim 1 wherein the filter is a basket filter and receives fluid from the at least one input feed line feeding to the top of the basket filter without overhanging so as to allow the filter to be removed, emptied and replaced without removing the input feed line.

6. A filtering tank according to claim 1 wherein the upper opening is substantially central and the at least one strengthening rib each extends laterally from a substantially circumferential location to the central upper opening with the at least one input line extending from the circumferential location to the central upper opening through the at least one strengthening rib.

7. A filtering tank according to claim 1 wherein at least one or more of the strengthening ribs include a strengthening fold line.

8. A filtering tank according to claim 1 wherein the upper opening leading to a main chamber includes outlets smaller than the upper opening leading to a mainchamber or the at least one input feed line to provide overflow outlets and / or to minimise glug feeding of the fluid to be filtered by the filter.

9. A filtering tank according to claim 1 wherein the top of the pod / tank is adapted by shaping internally and externally to allow a fixed fitting to connect the pipework for the entering water to be fixed to the exterior of the tank which then connects to internal pipe work directing the water flow to the internal filter skimmer basket which sits in a purpose built holder.

10. A filtering tank according to claim 1 wherein the filter skimmer basket is situated in a top area of the tank / Pods while allowing ready removal without disconnection of pipework.

11. A filtering tank according to any one of the preceding claims forms a backwash storage tank having a base which is suitable for tanks of every size and including the features of: a. a flat outer base around the perimeter of the tank forming a support of the backwash storage tank; b. an inner base of the tank having upward projection up into the centre of the tank from the outside perimeter support; c. Moving towards the centre of the tank from the outside perimeter support, the base projects up into the tank making the centre of the base of the tank its highest point and creating a concave shape; wherein the base section of the water tank with the centre circular extrusion that forms the concave radial sphere within the tank diverts foreign particles of backwash water to a particular area of the tank enabling the tank water, minus impurities, to be returned back to the pool.

12. A backwash filtration system using a filtering tank according to any one of the preceding claims, the system including: a. Providing a first filtering system for connection to an input line for feeding fluid into a pool volume; b. Providing a second filtering system for taking fluid from the pool volume through the first filter system and forming a backwash and sending the backwash through a second filter, such as a sand filter, for providing a filtering of the accumulated detritus from the first filtering system;c. Providing the filtering tank forming a third filtering system and a storage of the filtered fluid; d. Wherein the filtered fluid has undergone a three phase filtering and ensures selected return of a maximum volume of the backwash to the input line for feeding fluid back into the pool volume as required.

13. A backwash filtration system according to claim 12 wherein the three-phase filtering includes: a. Going through the top internal filter basket in the tank b. Sediment separation by the unique base at the bottom of tank for sediment c. And then return to the pool via the existing sand filter.

14. A backwash filtration system according to claim 12 or 13 including a filter and pump, said arrangement including a large water tank for receiving backwashed water having water-borne particles, wherein said tank: a. is in communication with said filter and said pump; b. has a substantial height difference between the upper internal space and the lower internal space of said tank whereby said tank is adapted to permit water-borne particles to settle near the base of said tank over time to obtain a substantially clear water phase above the settled sediments; c. has a waste outlet near, in or on said base; d. has a recycling outlet above said waste outlet through which clear water from the clear water phase may be periodically released; and e. has an inlet above said recycling outlet, said inlet for receiving said backwashed water.

15. A backwash filtration system according to claim 12 or 13, wherein said tank is adapted to permit water-borne sediments to settle in the lower 20% of its internal volume.

16. A backwash filtration system according to claim 15, wherein said inlet is positioned above said lower 20% of said tank's internal volume.

17. A backwash filtration system according to claim 12 or 13, wherein said arrangement further includes at least one inline valve in the line communicating the filter to the tank that is controlled by a computer processor.

18. A water recycling tank using a filtering tank according to any one of claims 1 to 11 including a filter and pump, wherein said tank includes:a. a tank body having an upper opening leading to a main chamber b. a filter for location in the upper opening and allowing ready selected removal therefrom c. At least one input feed line extending along a top portion of the tank body from a lateral direction to the upper opening to allow feeding of fluid to be filtered by the filter and allow the filtered fluid to enter the main chamber d. wherein the filter can be removed, emptied and replaced without removing the input feed line. e. is in communication with said filter and said pump; f. a substantial height difference between the upper internal space and the lower internal space of said tank whereby said tank is adapted to permit water-borne particles to settle near the base of said tank over time to obtain a substantially clear water phase above the settled sediments; g. a waste outlet near, in or on said base; h. a recycling outlet above said waste outlet and in communication with a water reservoir; and i. an inlet for receiving backwashed water from said water reservoir, said inlet located above said recycling outlet, and wherein said clear water phase can be periodically released through said recycling outlet to said water reservoir to replenish water level in said water reservoir.

19. The water recycling tank of claim 18, wherein the height of said tank is at least 300 mm.

20. The water recycling tank of claim 18, wherein the capacity of said tank is at least 500 L.

21. The water recycling tank of claim 18, wherein said tank is substantially cylindrical.

22. The water recycling tank of claim 18, wherein said tank base is internally concave to collect sediment towards the centre of said base and said waste outlet is located centrally in said base.

23. The water recycling tank of claim 18, wherein said tank base is internally convex to disperse sediment towards the periphery of said lower internal space.

24. The water recycling tank of claim 18, wherein said waste outlet is located lowermost in the water recycling tank in a side wall of the water recycling tank.

25. The water recycling tank of claim 18, wherein said recycling outlet is positioned above the settled sediment.

26. The water recycling tank of claim 18, wherein said recycling outlet is the terminal end of a flexible hose that is weighted and / or floated to sit just under the upper water surface level in said tank.

27. A water recycling method for a filtration system that includes a filter, pump, and a settling tank according to any ones of claims 1 to 11, said method comprising: a. directing water from a reservoir through said filter to perform a backwash; b. directing the backwashed water from said filter through a recycling inlet line to said tank; c. allowing water-borne sediments to settle on or near the base of the tank; d. directing water above said settled sediment from said tank through a recycling outlet line to said reservoir; and e. periodically exhausting said sediment-laden water near said base through a waste outlet.

28. The method of claim 27, wherein said sediment-laden water is reused for horticultural purposes.

29. A water recycling arrangement for a filtration system including a filter and pump, said arrangement including a large water tank: a. in communication with said filter and said pump; b. that has a substantial height difference between the upper internal space and the lower internal space of said tank whereby said tank is adapted to permit water-borne particles to settle near the base of said tank over time to obtain a substantially clear water phase above the settled sediments; c. has a waste outlet near, in or on said base; d. has a recycling outlet above said waste outlet and in communication with a water reservoir; and e. has an inlet for receiving backwashed water from said water reservoir, said inlet located above said recycling outlet, wherein said clear water phase can be periodically released through said recycling outlet to said water reservoir to replenish the water level in said water reservoir.

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