AU2018101308A4 - Self-contained water treatment apparatus - Google Patents

Abstract

The present invention relates generally to means for treating water collected from environmental sources, such as rainwater. In particular, but not exclusively, the present invention may be embodied in the form of a self-contained water filtration apparatus. One embodiment of the invention provides a self-contained water treatment apparatus comprising: a first walled structure having a fluid inlet and a first fluid outlet; a second walled structure inferior to the first walled structure , the second walled structure having a second fluid outlet; and a fluid treatment means in fluid communication with the first and second walled structures, wherein the first walled structure, the second walled structure and the fluid treatment means are arranged such that a fluid in the first walled structure flows under gravity via the fluid treatment means into the second chamber. FIRST COVER HOUSING C H A M B I RIF IR S T INLET OUTLET (TO DRAIN) CONTAMINANT BACKWASHING CHAMBER SLANTED SECOND FILTER OUTLET (TO TANK)

Description

SELF-CONTAINED WATER TREATMENT APPARATUS

FIELD OF THE INVENTION

[001]. The present invention relates generally to means for treating water collected from environmental sources, such as rainwater. In particular, but not exclusively, the present invention may be embodied in the form of a self-contained water filtration apparatus.

BACKGROUND TO THE INVENTION

[002]. Freshwater scarcity is increasing and is being driven by growing freshwater use and the depletion of usable freshwater resources. Due to the increasing scarcity and valué of freshwater there is a need to make efficient use of all sources of water including water that would otherwise be lost into the ground such as rainwater.

[003]. Means for rainwater harvesting are known which involve capturing, storing and using at least a portion of the captured rainwater that falls upon an area. There are three main ways that rainwater may be harvested which involve capturing rainwater tfom roofs, roads or green spaces and storing the captured rainwater in a storage tank.

[004], Harvested rainwater typically contains contaminants such as dirt particles, sediment and other debris including plant material (such as leaves, twigs, and seeds), and inseets. A problem arises in that these contaminants may contribute to blockage of conduits. A further problem arises where a contaminant enters a water storage tank, and in which case the material may decay leading to spoilage of stored water or otherwise lead to microbial growth.

[005]. Harvested rainwater may be used for non-potable applications such as watering gardens, washing a car or plumbing applications such as flushing toilets. Harvested water can also be used in potable applications but the harvested rainwater must be treated prior to use in potable applications. Even in some non-potable applications such as plumbing applications it is desirable to treat the harvested rainwater prior to use to remo ve the larger pieces of dirt, particles, sediment and debris to prevent blockages as mentioned above.

[006]. The prior art pro vi des many examples of filtration means configured to remo ve insoluble contaminants from harvested rainwater. One approach to improve the quality of harvested rainwater is by the use of a “gutter guard”. A gutter guard is essentially a coarse filter used to cover a gutter (typically a roof gutter) to prevent the entry of debris such as leaves, twigs and larger seeds and therefore into the rainwater flowing into the gutter. However, gutter guards still allow relatively small pieces of contaminant such as plant buds, seed pods, evergreen needles and insects to enter the gutter and therefore contamínate rainwater flowing in the gutter. Gutter guards also require periodic cleaning to prevent debris accumulating on top and blocking the entry of water to the underlying gutter. Maintaining gutter guards may be difficult or even dangerous given the need for a worker to scale a ladder to gain access.

[007]. Another approach to improving the quality of harvested rainwater includes a first flush diverter which diverts the portion of water that initially flows upon the commencement of rainfall away from the rainwater harvesting system. The first portion of water typically contains high levels of contaminants (e.g. sediments that have accumulated on a roof) which would spoil any collected water. Subsequent portions of water are cleaner, and therefore suitable for collection and reuse.

[008]. To work effectively first flush diverters must be sized correctly and properly installed. Whilst a first flush diverter is effective in diverting the first flow of water away from the rainwater harvesting system the diverter cannot wholly prevent water borne contaminants from entering the harvesting system. For example, rainwater harvested during a heavy rainfall may contain significant amounts of debris even after the first flush due to the accumulation of debris that has not been washed away by previous drizzle or light rain. Furthermore, first flush diverters have moving parts and require significant maintenance. If not correctly maintained a first flush diverter may actually worsen the problem the first flush diverter aims to solve. For example, maintaining a first flow divert involves ensuring the outlet remains clear of any debris together with periodic cleaning which involves disassembling the first flow diverter before removing any debris that has accumulated within the first flow diverter together with cleaning the flow control valve and filter screen. First flush diverters may also be vulnerable to physical impacts and treeze-cracking.

[009]. Outside of the field of rainwater harvesting, means for retaining and/or treating liquids on a large scale are known in industrial and public infrastructure applications.

[010]. For example, waste water may be treated by various processes configured to remove contaminants or convert contaminants to a non-toxic form. Given the complex engineering considerations of such sizeable Systems, the systems are typically very expensive to fabrícate, transport, assemble, install, test and valídate. Typically, sepárate components of a storage and/or treatment system are sourced and then transported to the installation site. For example, pumps, tanks, filters, controllers, conduits, valves, sensors, and the like are all transported as sepárate ítems to an installation site. Once delivered to the site, a team of workers assemble the components of a protocol set by the system designers. In many cases, errors are made in the assembly with remedial action required at some later point in time. In all, the assembly of the system components into a system is labour intensive and dependent on the expertise of the workers involved. Typically, the system designer will prefer that its own workers will assemble the system given their better knowledge and skills. However, this requires the added expense of transporting workers to the installation site.

[011]. Once assembled, the system must be tested and validated to ensure that all components opérate as required within the system as designed. The testing and validation must be performed to a very high level given the possibility that a poorly installed system may not opérate correctly and release toxic agents into the environment. This is not a trivial process and requires significant expertise and also the generation of accurate documentation evidencing the validation. Again, the system designer will prefer that its own personnel take charge of any work in relation to testing and validation this adding further to the overall expense to the installation.

[012], Once assembled, tested and validated systems for the treatment of liquids involve maintenance. For example, a water treatment system using a filter may require periodic inspection of the filter and manual cleaning of the filter to remove any dirt particles, sediment or debris that has been caught in the filter or altematively replacement of the filter. In some prior art arrangements, access to the filter may require some disassembly of the system.

[013]. It is an aspect of the present invention to overeóme or alleviate a problem of the prior art by providing a filter apparatus for filtering untreated rainwater and/or a rainwater harvesting system that is an improvement in terms of one or more of efficient filtration of harvested rainwater, ease of inspecting, ease of maintaining, durability, the potential for corrosión, economy, weight, ease of transport, ease of assembly, ease of installation, and ease of testing or validation. It is a further aspect to provide an altemative to prior art means.

[014], The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each provisional claim of this application.

SUMMARY OF THE INVENTION

[015]. In a first aspect, but not necessarily the broadest aspect, the present invention provides a self-contained water treatment apparatus comprising: a first walled structure having a fluid inlet and a first fluid outlet; a second walled structure inferior to the first chamber, the second walled structure having a second fluid outlet; and a fluid treatment means in fluid communication with the first and second chambers, wherein the first chamber, the second walled structure and the fluid treatment means are arranged such that a fluid in the first walled structure flows under gravity via the fluid treatment means into the second chamber.

[016]. In one embodiment of the first aspect, the first chamber, the fluid inlet, the first fluid outlet, the second walled structure the fluid treatment means, and the second fluid outlet are arranged such that a fluid carrying an insoluble contaminant enters the first walled structure via the fluid inlet, the insoluble contaminant is retained in the first walled structure by the fluid treatment means, the insoluble contaminant being moved toward the first fluid outlet to at least some extent by movement of the fluid carrying the insoluble contaminant, the insoluble contaminant exiting the self-contained water treatment apparatus via the first fluid outlet.

[017]. In one embodiment of the first aspect, the fluid treatment means comprises a filter having a plurality of spaces, the spaces configured and/or dimensioned so as to prevent the passage of an insoluble contaminant whilst allowing fluid flow therethrough.

[018]. In one embodiment of the first aspect, the areas bordering each of the plurality of spaces are substantially planar, and optionally substantially mutually co-planar.

[019]. In one embodiment of the first aspect, the substantially planar bordering areas provide at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95% of the total surface area of the filter which presents to an incoming insoluble contaminant.

[020]. In one embodiment of the first aspect, the substantially planar bordering areas presents a smooth surface to an insoluble contaminant retained by the filter thereby allowing the insoluble contaminant to travel across the filter and toward the first fluid outlet.

[021 ]. In one embodiment of the first aspect, each of the plurality of spaces is a slot.

[022], In one embodiment of the first aspect, the slots are each highly elongate, having a length to width ratio of at least about 10:1,20:1,30:1,40:1,50:1,60:1,70:1,80:1,90:1, or 100:1.

[023]. In one embodiment of the first aspect, the slots each have a width of at least about 0.01 mm, 0.05 mm, 0.1 mm, 0.2 mm, 0.5 mm, 0.4 mm, 0.5 mm. 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm or 2.0 mm.

[024], In one embodiment of the first aspect, the slots are mutually parallel.

[025]. In one embodiment of the first aspect, the surface of the filter which presents to an incoming insoluble contaminant has the appearance of a píate comprising a plurality of mutually parallel slots disposed therein.

[026]. In one embodiment of the first aspect, the water treatment means is a filter, optionally in the form of a slotted wedge panel.

[027]. In one embodiment of the first aspect, the water treatment means has an axis, and the water treatment means is mounted such that its axis is slanted at an angle of at least about 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees or 10 degrees to the horizontal when the apparatus is installed so as to facilítate the movement of fluid and/or contaminant toward the first outlet.

[028]. In one embodiment of the first aspect, the water treatment means has an axis, and the water treatment means is mounted such that its axis is slanted toward the first fluid outlet.

[029]. In one embodiment of the first aspect, the water treatment means is fabricated from a corrosión resistant metallic material or a polymeric material, or a combination thereof.

[030]. In one embodiment of the first aspect, the first walled structure has an access port configured to allow access to the fluid treatment means so as to facilítate inspection and/or maintenance and/or replacement thereof.

[031 ]. In one embodiment of the first aspect, the access port is fitted with an access cover.

[032], In one embodiment of the first aspect, the access port is an opening in the self-contained water treatment apparatus superior to the water treatment means.

[033]. In one embodiment of the first aspect, the lowest portion of the first fluid outlet is inferior to the lowest portion of the fluid inlet.

[034], In one embodiment of the first aspect, the fluid inlet and the first fluid outlet are generally opposing.

[035]. In one embodiment of the first aspect, the second fluid outlet is generally opposed but inferior to the fluid inlet.

[036]. In one embodiment of the first aspect, the second fluid outlet is generally unopposed and inferior to the first fluid outlet.

[037]. The self-contained water treatment apparatus comprises fluid channelling means configured to channel an insoluble contaminant and/or a fluid towards the first fluid outlet.

[038]. In one embodiment ofthe first aspect, the fluid channelling means comprises abase flow surface extending from a position inferior and proximal to the fluid inlet to a position inferior and proximal to the first fluid outlet.

[039]. In one embodiment ofthe first aspect, the base flow surface comprises an aperture configured to receive the fluid treatment means.

[040]. In one embodiment of the first aspect, the base flow surface is slanted toward the first fluid outlet at an angle of at least about 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees or 10 degrees lfom the horizontal when the apparatus is installed so as to facilítate the movement of fluid and/or contaminant toward the first outlet.

[041], In one embodiment of the first aspect, the flow channelling means comprises one or more vertical flow surfaces adjacent to and angled toward the first fluid outlet such that an insoluble contaminant that is carried by a fluid flowing from the fluid inlet is directed toward the first fluid outlet.

[042], In one embodiment of the first aspect, the self-contained water treatment apparatus comprises paired vertical flow surfaces straddling and angled towards the first fluid outlet such that an insoluble contaminant that is carried by a fluid flowing from the fluid inlet is directed toward the first fluid outlet.

[043]. In one embodiment of the first aspect, each of the vertical flow surface(s) is/are a píate extending across a comer of the first chamber, the comer being adj acent the first fluid outlet, the píate configured such that an insoluble contaminant that is carried by a fluid flowing from the fluid inlet is channelled away from the comer and toward the first fluid outlet.

[044], In one embodiment of the first aspect, the self-contained water treatment apparatus comprises an in situ fluid treatment means cleaning means configured to remove an insoluble contaminant bound to the fluid treatment means.

[045]. In one embodiment of the first aspect, the in situ fluid treatment means cleaning means is a backwash system configured to pass a cleansing fluid from the second walled structure and through the fluid treatment means to the first chamber.

[046]. In one embodiment of the first aspect, the fluid inlet and/or the first fluid outlet and/or the second fluid outlet is/are each configured to form a substantially watertight connection with a conduit external to the apparatus.

[047]. In one embodiment of the first aspect, the fluid inlet and/or the first fluid outlet and/or the second fluid outlet has/have an extensión comprising a flexible sealing means configured to fit a conduit external to the apparatus so as to form a substantially watertight connection there with.

BRIEF DESCRIPTION OF THE FIGURES

[048]. FIG. 1 illusfiates in a highly diagrammatical manner a generalized form of the self-contained water treatment apparatus of the present invention.

[049]. FIG. 2 illusfiates an isometric view of a system for rainwater harvesting and a self-contained water treatment apparatus of the present invention.

[050]. FIG. 3A illusfiates an isometric view of a highly preferred self-contained water treatment apparatus suitable for installation above ground of the present invention.

[051]. FIG. 3B illusfiates an isometric view of the self-contained water treatment apparatus shown in FIG. 2A, taken at an altemative view.

[052], FIG. 3 C illusfiates diagrammatically a sectional representation ofthe self-contained water treatment apparatus shown in FIG 3 A. The diagram is of the section taken through the line marked A-A in FIG. 3D.

[053]. Fig 3D illusfiates diagrammatically and in plan view the self-contained water treatment apparatus shown in FIG 3 A.

[054], FIG. 4A illustrates an isometric view of a preferred self-contained water treatment apparatus suitable for installation underground of the present invention.

[055]. FIG. 4B illustrates diagrammatically a side view of the self-contained water treatment apparatus shown in FIG 4A.

[056]. FIG. 4C illustrates diagrammatically a sectional representation ofthe self-contained water treatment apparatus shown in FIG 4A. The diagram is of the section taken through the line marked E-E in FIG. 4D.

[057]. FIG. 4D illustrates diagrammatically and in plan view the self-contained water treatment apparatus shown in FIG 4A.

[058]. FIG. 5 illustrates a perspective view of the of a self-contained water treatment apparatus installed in the system shown at FIG. 2 showing the components ofthe apparatus in greater detail. .

[059]. FIG 6A illustrates an isometric view of a highly preferred self-contained water treatment apparatus suitable for installation above ground of the present invention.

[060]. FIG. 6B illustrates an isometric view of the self-contained water treatment apparatus shown in FIG. 5A, taken at an altemative view.

[061 ]. FIG. 6C illustrates diagrammatically a sectional representation ofthe self-contained water treatment apparatus shown in FIG 6A. The diagram is of the section taken through the line marked A-A in FIG. 6D.

[062], Fig 6D illustrates diagrammatically and in plan view the self-contained water treatment apparatus shown in FIG 6A.

[063]. FIG 7A illustrates an isometric view of a highly preferred self-contained water treatment apparatus suitable for installation above ground of the present invention.

[064], FIG. 7B illusfiates diagrammatically a sectional representation ofthe self-contained water treatment apparatus shown in FIG 7A. The diagram is of the section taken through the line marked A-A in FIG. 7C.

[065]. Fig 7C illusfiates diagrammatically and in plan view the self-contained water treatment apparatus shown in FIG 7A.

[066]. FIG. 8 illusfiates a perspective isometric view of a preferred self-contained water treatment apparatus suitable for installation underground of the present invention.

[067]. FIG. 9. Illusfiates a perspective isometric view of a portion of a preferred stainless Steel slotted wedge wire (vee-wire) screen panel of the present invention in operation.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS THEREOF

[068]. After considering this description it will be apparent to one skilled in the art how the invention is implemented in various altemative embodiments and altemative applications. However, although various embodiments of the present invention will be described herein, it is understood that these embodiments are presented by way of example only, and not limitation. As such, this description of various altemative embodiments should not be construed to limit the scope or breadth of the present invention. Furthermore, statements of advantages or other aspects apply to specific exemplary embodiments, and not necessarily to all embodiments covered by the claims.

[069]. Throughout the description andthe claims ofthis specification the word "comprise" and variations of the word, such as "comprising" and "comprises" is not intended to exelude other additives, components, integers or steps.

[070]. Reference throughout this specification to “one embodiment” or “an embodiment” 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.

[071]. The present invention is predicated at least in part on Applicant’s discovery that advantage is provided where rainwater collected from a roof, for example, is directed to a self-contained apparatus capable of removing insoluble contaminants (such as plant material) from the water using a filter, and where the filter is exposed to a cross-flow of water on the reteníate side. This discovery may be embodied in a first aspect of the invention which provides a self-contained water treatment apparatus comprising: a first walled structure having a fluid inlet and a first fluid outlet; a second walled structure inferior to the first chamber, the second walled structure having a second fluid outlet; and a fluid treatment means in fluid communication with the first and second chambers, wherein the first chamber, the second walled structure and the fluid treatment means are arranged such that a fluid in the first walled structure flows under gravity via the fluid treatment means into the walled structure .

[072], As used herein to describe the present apparatus, the term “walled structure” ineludes a structure that is capable of directed retaining a fluid toward the fluid treatment means and/or retaining a fluid for at least some time on or about the fluid treatment means. A wall of the walled structure may function at least in part by deflecting water flowing from the fluid inlet toward the fluid treatment means and/or inhibit fluid flowing away from the water treatment means. A walled structure may comprise any number of walls, including 1,2, 3,4, 5,6, 7, 8, 9 or 10 walls. A wall may be angled in any way, and in some embodiments may be generally vertical (when the apparatus is installed), or may be generally perpendicular to a floor of the walled structure or a plañe or an axis of the fluid treatment means. It is not necessary for a wall of the walled structure to be planar, with curved and even irregular geometries being useful in some applications of the invention.

[073]. A walled structure may have a floor, or a partial floor. In some cases the fluid treatment means may form the floor or part of the floor of the walled structure.

[074], Insome embodiments ofthe invention a wall structure is a chamber. As used herein to describe the present apparatus, the term “chamber” refers to a partially or completely enclosed space of the apparatus that is capable of containing a fluid for at least some time. In the context ofthe present invention, a chamber may not have a continuous wall, floor or ceiling, and in some cases may have no ceiling at all. Typically, however, where a chamber has no ceiling or an incomplete ceiling a removable cover of some type is provided to prevent entry of debris or animáis. The cover may be continuous or non-continuous (such as a grating). In some embodiments, a cover may be considered to be a component of a chamber, although in other embodiments a chamber may be defined without any reference to a cover.

[075]. As used herein to describe the present apparatus, the terms “inlet” and “outlet” refer to points of entry or exit (respectively) of fluid to or from the apparatus. An inlet or outlet may be a simple aperture in a wall, ceiling or floor of a walled structure, but in some embodiments may further comprise an associated conduit extending outwardly from the apparatus (for connection to extemal conduits) or inwardly into a walled structure of the apparatus.

[076]. The fluid treatment means will be a size exclusión filter in many embodiments, such filter typically having a reteníate side (i.e. the side facing the incoming rainwater which enters the apparatus via the fluid inlet) and a permeate side (i.e. the side facing the second walled structure across which treated rainwater exits the filter). Water is retained about the reteníate side by the walls of the first walled structure.

[077]. In some embodiments, the apparatus is generally configured such that input rainwater is generally directed (for example, by orientation of the fluid inlet) generally across the reteníate face of the filter. The cross-flow of water is distinct to the normal mode of “dead-end” filtration where incoming water falls generally perpendicular to the reteníate face of a filter. The cross-flow of water acts to inhibit the build-up of contaminants on the reteníate side, with the water sweeping contaminants across the face of the reteníate side and out of the apparatus via the drain outlet (the first outlet). Thus, a proportion of the water entering the apparatus is used to carry contaminant to and into the drain outlet, this leading to some loss of water from the system. The majority of water however is retained in the apparatus, and after passing through the filter collects in a walled structure below (the second chamber) and is subsequently conveyed out ofthe apparatus via a second outlet to a storage tank for later use.

[078]. By virtue of the cross-flow function of the water, the retentante side of the filter is maintained relatively clean. Even where a contaminant becomes lodged in a space of the filter, the cross-flow of water may act to free the contaminant and push it toward the drain (first) outlet ofthe apparatus.

[079]. Even where contaminant build-up occurs, the contaminant tends to deposit toward one end of the filter (i.e. the end nearest the drain outlet) thereby leaving the remainder of the filter relatively free to pass incoming rain water. Higher water pressures at the end of the filter closest to the fluid inlet generally unsure that at least some of the reteníate surface stays clear of debris and is therefore free to pass incoming water for collection in the walled structure below.

[080]. The filter is selected so as to exelude (by size) at least some of the expected contaminants. While almost all contaminants will be removed where a very fine filter is used, this approach will decrease the rate of water flow through the filter and into the walled structure below. As a result, an unnecessarily large amount of the incoming rain water will flow across the reteníate side of the filter and most of the water will remain unfiltered and lost to the drain outlet.

[081 ]. A balance is therefore sought in the ability of a filter to remove contaminants, while also permitting sufficient water cross-flow to inhibit build-up on the contaminant side and furthermore ensuring that a reasonable proportion of the incoming water is filtered and conveyed to the storage tank.

[082], In that regard, consideration may be had to the expected flow rates on incoming rain water in so far as a higher flow rate may díctate the need for a coarser filter so as to maximize the volume of water passing through the filter. A necessary trade-off in that approach may be that smaller contaminants are not retained by the filter.

[083]. The fineness or coarseness of a filter relates for the ability of the filter to prevent passage of an insoluble contaminant. A fine filter may have very small spaces (such as pores, voids, channels, slots and the like) which are sized so as to not admit small and large insoluble contaminants. A fine filter will also resist the passage of water to some extent. By comparison, a coarse filter may have larger spaces so as to admit smaller contaminants (which pass through the filter) but exelude larger contaminates which remain on the réntate side of the filter. A coarse filter provides much less resistance to the passage of water which is positive, so long as sufficient water is maintained on the reteníate side of the filter to sweep away contaminant build up.

[084], In light of the above, the skilled person having the benefit of the present specification will be able by routine experimentation only select a filter of appropriate coarseness or fineness for a given application.

[085]. Other filter parameters may be considered, including the ability ofthe reteníate face of the filter to facilítate the movement of contaminants being across the reteníate face and toward the drain outlet. A reteníate face that tends to snare contaminants is to be generally avoided given that contaminants will resist being swept to the drain outlet by the rainwater cross-flow and instead clog the filter. A reteníate face that is substantially planar and fabricated lfom a smooth material (such as a polished metal) will better allow for contaminants to be swept parallel to the reteníate face and toward the drain outlet.

[086]. A particularly usefbl type of filter in this regará is a slotted wedge wire screen filter (also known as profile wire, V-wire and Tri-wire). These filters typically fabricated from Steel and have slots (in the realm of 0.5 mm wide) while are regularly spaced. The width of the space dictates the ability of the filter to pass or not pass contaminants and water. A slot which is relatively wide will not remo ve small contaminants but will easily pass water. A slot which is relatively narrow will remo ve small contaminants but will resist the passage of water.

[087]. Slotted wedge wire screen filters may provide advantage because of the relatively large planar surface area on the reteníate side. The majority of the retenate face which presents to the incoming rainwater is smooth metal, with the spaced slots making up a relative minority of the reteníate face area. Thus, a contaminant that is excluded from entering the slots on the basis of size may be easily pushed across or tumbled over the smooth metal of reteníate side of the filter by the rainwater in which it is carried without becoming snared. By contrast, a less preferred type of filter would be a woven wire filter which presents an undulating surface to a contaminant, with the contaminant being much more like to become snared on the reteníate face thereby contributing to filter blockage and build up.

[088]. Further advantage may be gained where the filter is slanted downwardly from the rainwater inlet to the drain outlet such that the incoming water carrying suspended contaminants runs downhill under gravity to some extent toward the drain outlet of the apparatus. The slant generally assists with cross-flow across the reteníate side face of the filter, thereby minimising snaring and build-up of contaminants. As will be appreciated, such slanting requires the rainwater inlet to be disposed slightly higher than the drain outlet.

[089]. Reference is made to FIG. 1 showing a generalised embodiment of the present invention detailing the flow of water and contaminants therethrough. The direction of water flow of water is indicated by the dashed arrows. Rainwater (collected from a nearly roof, for example) enters the apparatus via the inlet and carries with it a range of contaminants. Both water and contaminants contact the reteníate (upper) face of the filter with the majority of water passing through the filter into the second chamber, before exiting via the second outlet (to tank). A proportion of the water continúes to sweep across the reteníate face of the filter, carrying with it contaminant that is too large to enter the spaces of the filter. As the water flows from left to right (as drawn), most continúes to pass through the filter and into the second chamber.

[090]. The contaminants are moved from left to right (as drawn) mainly by the movement of water across the filter, but also assisted by gravity given the slant of the filter downwardly toward the first outlet (to drain). A relatively small proportion of water travels through the first outlet, with that water being used to move contaminant out of the apparatus and to drain.

[091]. The net results ofthe general scheme shown in FIG. 1 is (i) a relatively large volume of clean water exiting the second outlet (i) a relatively small volume of contaminated water exiting the first outlet, and (iii) the reteníate face of the filter being maintained free of contaminant build up.

[092], The embodiment of FIG. 1 pro vides for an access port having a cover. The access port allows direct access to the filter means allowing for ready inspection of the filter and for easy maintenance or replacement. By contrast, with large scale water treatment apparatus it is often difficult to inspect or access filters. As previously mentioned, first flush diverters require significant maintenance and ifnot correctly maintained may actually worsen the problem the first flush diverter aims to solve. The filter means in a first flush diverter cannot generally be inspected or cleaned without disassembling the device.

[093]. The self-contained nature of the present apparatus is of distinct advantage in commercial applications. The apparatus may be provided as fully fimctioning and validated unit having set specifications that may be simply supplied and fitted to [094], In addition or altemative ly to the direct maintenance of the filter described above, an in situ backwashing system may be included in or added to the present apparatus. The function of the backwashing system is the removal of contaminants that have become lodged in the filter means. Typically, the backwashing system reverses the fluid flow through the filter so as to dislodge contaminates from the filter. For example, (and staying with FIG. 1) a backwashing port is provided on the second chamber, the port being connected to mains water supply. During backwashing mains water is forced into the second chamber and up through the filter in the reverse direction (i.e. from permeate side to reteníate side) thereby dislodging any contaminants caught in the filter. The flow rate of water may be sufficiently high such that water flows in the reverse direction through the filter even though the second outlet remains open. Where sufficiently high flow rates of backwashing mains water are not achievable, a valve (not shown) may be provided and actuated so as to cióse the second outlet. Contaminant material dislodged during backwashing remains on the reteníate side of the filter and is flushed to drain via the first oulet.

[095]. To provide for more concentrated cleaning, the mains water of the backwashing system may fed through a ring manifold and forced out ofjets against the permeate side of the filter.

[096]. Tuming now to FIG. 2 there is shown an isometric view (part cutaway) of a system for rainwater harvesting using a self-contained water treatment apparatus of a preferred embodiment of the invention.

[097]. A system for rainwater harvesting 10 ineludes a self-contained water treatment apparatus having a fluid inlet conduit 12, a first fluid outlet conduit 14 and second fluid outlet conduit 16 which are in fluid communication respectively with the fluid inlet (not shown), the first fluid outlet (not shown) and the second fluid outlet (not shown). The second fluid outlet conduit 16 is connected via a fluid conduit 18 to a liquid storage vessel 20. The self-contained water treatment apparatus ineludes an access opening in the top which is shown covered.

[098]. In operation, untreated rainwater water is directed from a rainwater capture means (not shown) via a fluid conduit (not shown) into the fluid inlet conduit 12 of the self-contained water treatment apparatus before being directed to the fluid inlet of the self-contained water treatment apparatus. The untreated water is directed from the fluid inlet of the self-contained water treatment apparatus into the first chamber 22 of the self-contained water treatment apparatus and flows under gravity through a fluid treatment means 24 into the second chamber 26 of the self-contained water treatment apparatus. The filtered rainwater flows from second chamber of the self-contained water treatment apparatus into the second fluid outlet conduit 16 of the self-contained water treatment apparatus. The filtered rainwater then flows into the fluid conduit 18 which directs the filtered rainwater into the liquid storage vessel 20.

[099]. FIG. 3A, FIG. 3B, FIG. 3C and FIG. 3D show a self-contained water treatment apparatus suitable for installation above ground of a preferred embodiment of the invention. The self-contained water treatment apparatus has a body 28 that is a rectangular box having a rectangular access opening 30 in the top of the body. Preferably, the body is manufactured from stainless Steel. The access opening 30 may optionally may be covered by a cover (not shown) suitable for pressurizing the interior of the body. The body has a fluid inlet 32 in one side wall, a first fluid outlet 34 in the opposite side wall and a second fluid outlet 36 in the same wall as the first fluid outlet. The self-contained water treatment apparatus includes flow channeling means to urge contaminants and/or bypass fluid flow towards the first fluid outlet in the form of flow plates. The flow plates comprise a base flow píate 38 and vertical flow plates 40 (which may be integrally formed) that are fitted to the interior of the body. The base flow píate 38 is adapted to have a filter píate 42 mounted to it in a parallel position to the base flow píate. The base flow píate extends across the interior of the body in a downwards direction from the interior of the side wall containing the fluid inlet at a position immediately below the fluid inlet 32 to the interior of the opposite side wall at a position immediately below the first fluid outlet 34. The base flow píate 38 is at an angle of approximately 2 degrees to the horizontal. The vertical flow plates are angled from the edges of the first fluid outlet to the adjacent side walls. The body and the flow plates define a first chamber 44 and a second chamber 46 inferior to the first chamber. The first chamber 44 has the fluid inlet 32 in one side wall and the first fluid outlet 34 in the opposite side wall. The second chamber 46 has the second fluid outlet 36 in the same side wall of the body having the first fluid outlet and is positioned directly below the first fluid outlet. Preferably the bottom of the second fluid outlet is approximately 300mm below the bottom of the first fluid outlet Preferably the fluid inlet conduit and first outlet conduit are HDPE pipe having a diameter of 250 mm. Preferably the second fluid outlet conduit is preferably HDPE pipe having a diameter of 200 mm. Preferably the filter píate is a stainless Steel slotted wedge wire (vee-wire) screen panel. Preferably the body and the flow píate are manufactured from stainless Steel. Preferably the base flow píate and vertical flow plates are integrally formed from a single piece of stainless Steel.

[100] . The self-contained water treatment apparatus can have a relatively low height profile because the filter píate is cióse to horizontal, the fluid inlet and the first fluid outlet are proximal to filter píate and the second fluid outlet is positioned a relatively small distance below the filter píate. A relatively low height profile may be advantageous where the self-contained water treatment apparatus is installed underground or suspended from a ceiling where it desirable to allow sufficient clearance above the self-contained water treatment apparatus to use the access opening.

[101] . In operation, untreated rainwater water is directed from a rainwater capture means (not shown) via a fluid conduit (not shown) into the fluid inlet. The untreated water enters the first chamber and is directed by the flow plates across a filter píate. The untreated water flows under gravity through the filter píate into the second chamber before filtered rainwater exits the second fluid outlet for transport into a storage vessel. Contaminants in the untreated water such as dirt particles, sediment or debris having a size larger than the width of the voids in the filter píate are unable to pass through the filter píate and are urged towards the first fluid outlet together with bypass flows because of the shape of the first chamber and the filter píate used. The first fluid outlet is connected to a fluid conduit (not shown) that directs contaminants filtered from the rainwater and bypass flows to the storm water system.

[102] , FIG. 4A, FIG. 4B FIG 4C and FIG. 4D show a self-contained water treatment apparatus suitable for underground installation.

[103] . The self-contained water treatment apparatus has a body 48 of a generally barrel shape with an access opening in the top that can be covered by a removable cover 50. The body has a fluid inlet conduit 52 extending radially from one side wall and a first fluid outlet conduit 54 extending radially from the opposite side wall. The fluid inlet conduit 52 and the first fluid outlet conduit 54 are substantially parallel. The body also has a second fluid outlet conduit 56 that extends radially from a side wall and is substantially perpendicular to both the fluid inlet conduit and the first fluid outlet conduit. It will be appreciated that the second fluid outlet conduit 56 may extend at a non-perpendicular angle as require for a given installation. The fluid inlet conduit, first fluid outlet conduit and second fluid outlet conduit are respectively in fluid communication with the fluid inlet 58, first fluid outlet 60 and second fluid outlet 62.

[104] , The self-contained water treatment apparatus ineludes flow channeling means to channel contaminants and/or bypass fluid flow towards the first fluid outlet in the form of a flow píate 61. The flow píate 61 is adapted to have a filter píate 63 mounted to it in a parallel position to the base flow píate. The flow píate 61 extends across the interior of the body in a downwards direction from the interior of the side wall containing the fluid inlet at a position immediately below the fluid inlet 84 to the interior of the opposite side wall at a position immediately below the first fluid outlet 86.

[105] . The body ineludes a central body section 64 that is an upright cylindrical shape. The central body section 64 is connected at the top to an upper tapering body section 66 that is frustoconical in shape and connected at the bottom to a lower tapering body section 68 that is also frustoconical in shape. The upper tapering section is connected to a top body section 70, the top body section being a vertical square tubular section having a square access opening (not shown) at the top. The top body section 70 is adapted to receive the cover 50 to cover the square aperture. The lower tapering section 68 is connected to the body base 72 which is generally circular in shape. The fluid inlet conduit 52 and first outlet conduit 54 are preferably HDPE pipe having a diameter of 225 mm. The second fluid outlet conduit 56 is preferably HDPE pipe having a diameter of 150 mm. The body is preferably manufactured lfom polyethylene. The cover 50 is preferably a square 600mm x 600mm Class B pedestrian cover including drainage holes. Preferably the flow píate is manufactured from stainless Steel.

[106] . In operation, untreated rainwater water is directed from a rainwater capture means (not shown) via a fluid conduit (not shown) into the fluid inlet conduit and through the fluid inlet of the self-contained water treatment apparatus. The untreated water is directed from the inlet into the first chamber and flows under gravity through a filter píate into the second chamber. The filtered rainwater exits the second fluid outlet and is directed into the second fluid outlet conduit before being directed into a fluid conduit (not shown) for transport into a storage vessel. Contaminants in the untreated water such as dirt particles, sediment or debris having a size larger than the width of the voids in the filter píate are unable to pass through the filter píate and are urged towards the first fluid outlet together with bypass flows because of the shape of the first chamber and the filter píate used. The first fluid outlet is connected to a fluid conduit (not shown) that directs contaminants filtered from the rainwater and bypass flows to the storm water system.

Although not shown, the present apparatus may comprise a means for blocking the entry of fluid into a storage tank, or diverting fluid away from the tank when the tank is filled to a predetermined level. A practical implementation of such diversionary means may be a diverter on the second outlet which actúate (via mechanical, electrical or pneumatic means, for example) when the storage tank is approaching a full level so as to send water to a drain (via the second outlet, or indeed another outlet). A blocking means may be embodied in the form of a valve which actuates when the storage tank is near full so as to prevent further watering entering the tank, and causing water to flow to drain via the first outlet or another outlet.

[107] . FIG. 5 shows an isometric view (part cutaway) of a self-contained water treatment apparatus suitable for underground installation of an altemative embodiment of the invention. The self-contained water treatment apparatus has a housing 74 having a housing opening 76 covered by a housing cover 78. The housing 74 is adapted to accommodate a body 80. The body 80 is a rectangular box having a rectangular access opening 82 in the top of the body. Preferably, the body is manufactured from stainless Steel. The access opening 80 may optionally may be covered by a cover (not shown) suitable for pressurizing the interior of the body. The body has a fluid inlet 84 in one side wall, a first fluid outlet 86 in the opposite side wall and a second fluid outlet 88 in the same wall as the first fluid outlet. A fluid inlet conduit 90, first fluid outlet conduit 92 and second fluid outlet conduit 94 are respectively received by and in fluid communication with the fluid inlet 84, first fluid outlet 86 and second fluid outlet 88. The housing 74 has apertures to receive the fluid inlet conduit 90, first fluid outlet conduit 92 and second fluid outlet conduit 94. The self-contained water treatment apparatus includes flow channeling means to urge contaminants and/or bypass fluid flow towards the first fluid outlet in the form of a base flow píate 96. The base flow píate 96 is adapted to have a filter píate 98 mounted to it in a parallel position to the base flow píate. The base flow píate 96 extends across the interior of the body in a downwards direction from the interior ofthe side wall containing the fluid inlet at a position immediately below the fluid inlet 84 to the interior of the opposite side wall at a position immediately below the first fluid outlet 86. The base flow píate 96 is at an angle of approximately 2 degrees to the horizontal. The body and the base flow píate 96 define a first chamber 100 and a second chamber 102 inferior to the first chamber. The first chamber 100 has the fluid inlet 84 in one side wall and the first fluid outlet 86 in the opposite side wall. The second chamber 102 has the second fluid outlet 88 in the same side wall of the body having the first fluid outlet and is positioned directly below the first fluid outlet. Preferably the fluid inlet conduit and first outlet conduit are HDPE pipe having a diameter of 250 mm. Preferably the housing is manufactured from concrete. Preferably the second fluid outlet conduit is preferably HDPE pipe having a diameter of 200 mm. Preferably the filter píate is a stainless Steel slotted wedge wire (vee-wire) screen panel. Preferably the body and flow plates are manufactured from stainless Steel. Preferably the bottom of the second fluid outlet is approximately 300mm below the bottom of the first fluid outlet.

[108] . FIG. 6A, FIG. 6B FIG. 6C and FIG. 6D show a preferred self-contained water treatment apparatus of the present invention. This embodiment of the water treatment apparatus has essentially the same features as the embodiment illustrated in FIGS. 3 A, 3B, 3C and 3D but has different proportions.

[109] . FIG. 7A, FIG. 7B and FIG 7C show a preferred self-contained water treatment apparatus of the present invention. This embodiment of the water treatment apparatus has essentially the same features as the embodiment illustrated in FIGS. 3A, 3B, 3C and 3D but has different proportions.

[110] . FIG. 8 shows a perspective isometric view of the preferred self-contained water treatment apparatus of the present invention illustrated in FIGS. 3A, 3B, 3C and 3D suspended lfom the ceiling of a basement. Due to low height profile of the self-contained water treatment apparatus it can be suspended lfom a ceiling with sufficient clearance above to use the access opening to inspect, maintain or replace the filter means.

[111] , FIG. 9. Illustrates a perspective isometric view of a portion of a preferred stainless

Steel slotted wedge wire (vee-wire) screen panel of the present invention in operation. Slotted wedge wire screens are particularly suited to water treatment applications as this type of filter accumulates less debris than many other types of filter plates. One reason for the reduced accumulation of debris is that wedge wire screens have a fíat and smooth upper surface which promotes flow of any contaminants too large to fit through the wedge wire screen across the wedge wire screen. Any contaminant that passes into a slot of the screen is highly unlikely to lodge in the space below the slot because of the geometry of the space. More particularly, the space (being flanked by two wedges) widens according to distance lfom the slot such that any contaminant that is sufficiently small as to pass through the slot is unlikely to contact the wedge faces flanking the space as it travels downwardly and toward the permeate side. The geometry of the space also facilitates backwashing in so far as reverse water flow (i.e. ffom the permeate side to the reteníate side) is concentrated toward the slot thereby increasing the probability that any contaminant lodged in the slot is ejected upwardly and out of the slot.

[112] , Preferably, the wedge wire screen is manufactured lfom stainless Steel and has a slot width of approximately 0.5 mm (500 microns) which is an effective size for treating harvested rainwater.

[113] . The stainless Steel intemal components of the self-contained water treatment apparatus can be easily removed and cleaned.

[114] , Those skilled in the art will appreciate that the invention described herein is susceptible to further variations and modifications other than those specifically described. It is understood that the invention comprises all such variations and modifications which fall within the spirit and scope of the present invention.

[115] . While the invention has been disclosed in connection with the preferred embodiments shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art.

[116] . Accordingly, the spirit and scope of the present invention is not to be limited by the foregoing examples, but is to be understood in the broadest sense allowable by law.

Claims (5)

CLAIMS:

1. A self-contained water treatment apparatus comprising: a first walled structure having a fluid inlet and a first fluid outlet; a second walled structure inferior to the first walled structure , the second walled structure having a second fluid outlet; and a fluid treatment means in fluid communication with the first and second walled structures, wherein the first walled structure, the second walled structure and the fluid treatment means are arranged such that a fluid in the first walled structure flows under gravity via the fluid treatment means into the second chamber.

2. The self-contained water treatment apparatus of claim 1, wherein the first walled structure, the fluid inlet, the first fluid outlet, the second walled structure, the fluid treatment means, and the second fluid outlet are arranged such that a fluid carrying an insoluble contaminant enters the first walled structure via the fluid inlet, and the insoluble contaminant is retained in the first walled structure by the fluid treatment means, the insoluble contaminant being moved toward the first fluid outlet to at least some extent by movement of the fluid carrying the insoluble contaminant, the insoluble contaminant exiting the self-contained water treatment apparatus via the first fluid outlet.

3. The self-contained water treatment apparatus of claim 1 or claim 2, wherein the fluid treatment means comprises a filter having a plurality of spaces, the spaces configured and/or dimensioned so as to prevent the passage of an insoluble contaminant whilst allowing fluid flow therethrough, and wherein the areas bordering each of the plurality of spaces are substantially planar, and optionally substantially mutually co-planar.

4. The self-contained water treatment apparatus of any one of claims 1 to 3, wherein the water treatment means is a filter, optionally in the form of a slotted wedge panel.

5. The self-contained water treatment apparatus of any one of claim 1 to 4, wherein the water treatment means has an axis, and the water treatment means is mounted such that its axis is slanted at an angle of at least about 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees or 10 degrees to the horizontal when the apparatus is installed so as to facilítate the movement of fluid and/or contaminant toward the first outlet. DATED: September 6, 2018 CHURCHILL ATTORNEYS Attomeys for AKS INDUSTRIES AUSTRALIA PTY LTD ACN 151 483 984 191 Station Street CORIO VIC 3214