AU2006203290A1 - Grey water tank - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE

SPECIFICATION

STANDARD

PATENT

Invention Title: Grey water tank The following statement is a full description of this invention, including the best method of performing it known to us: 005110009 2 Grey water tank Field of the invention The present invention has application to the field of grey water reuse. More particularly, the present invention relates to a device for preventing overflow of grey water from a grey water surge tank.

Background of the invention In areas of water shortages and increases in potable water demands and the desire to reuse water waste for environmental reasons including reducing loading on water treatment plants, domestic grey water waste has been identified as a suitable water source in which to reduce demands upon water supply sources and waste water treatment plants.

Grey water is classified as domestic waste water excluding toilet waste, and which may include wastewater generated from hand basins, kitchens, baths, showers and laundries. Grey water typically contains pollutants such as microorganisms, chemical waste, biological waste, lint and other suspended particulate matter. These pollutants are often particularly harmful for to humans, animals and the environment.

The amount of grey water generated by a domestic dwelling is typically of the order of of the total waste water generated, and for an average domestic dwelling this represents some 350 litres per day. This volume of waste water is seen as providing a suitable amount of water for typical outdoor water requirements in domestic dwellings such as hosing of hard surfaces, washing of vehicles and irrigation and watering of gardens. Depending upon the application to which reused grey water is to be applied, varying levels of treatment including filtration and disinfection may be required.

Due to the high level of suspended solids with grey water, filtration is typically required as suspended solids are known to clog conduits and irrigation and hosing devices. For above ground application, in particular when an aerosol of grey water is created, a high level of disinfection is required after filtration for health reasons and the level of 005110009 3 disinfection required is typically determined by governing bodies. For below ground applications such as sub-terrain irrigation, disinfection is not required as they grey water S does not come into contact with human, animal or insect life, however filtration of suspended solids is still required.

Due to non-regular loading of waste grey water, a surge tank is typically provided for receiving the waste grey water from a dwelling such as bathroom and laundry waste until the water is to be used. A filter element or system is typically provided to filter particular matter from the water prior to the water entering the surge tank. However, in the event that the filter is not routinely cleaned or in the event that an unexpected 0 amount of solids is present within the waste water, the filter may unexpectedly clog and the grey water may be trapped in the supply network or spilling to the environment thus posing serious occupational health and safety risks. Furthermore, in the event that excessive volumes of grey water are delivered to the surge tank or water already located within the tank is unused and the capacity of the tank is exceeded, again the water may back up the supply network or overflow from the tank into the environment again posing serious health risks.

It is an object of the present invention to provide a grey water tank with overflow protection capability, apparatus for a grey water tank to provide overflow protection and/or to provide the public with a useful alternative overflow protection apparatus for a ?0 liquid storage tank.

Summary of the invention According to a first aspect of the present invention, there is provided an inlet and overflow arrangement for a grey water surge tank, the arrangement including a well formed in or securable to an upper portion of a surge tank and including a recessed surface, an inlet including an inlet port, and a backup inlet extending through the recessed surface, wherein excess water received at the inlet is directed to the backup inlet via the well, the backup inlet being connected to a waste conduit.

Preferably, the inlet has a volume that provides a buffer before excess water is produced at the inlet port. The volume may be provided by a filter for filtering water received at the inlet before passing it to the surge tank.

005110009 4 Preferably, the inlet and overflow arrangement further includes an overflow port positioned within the tank body and connected to an overflow conduit that directs grey S water received by the overflow port to the waste conduit.

Preferably, the waste conduit extends away from the backup inlet substantially vertically and exits the surge tank at a lower portion of the surge tank.

Preferably, the inlet occupies an area of approximately between 40% and 50% of the area of the well.

According to a second aspect of the present invention, there is provided a grey water surge tank including a tank body, a well including a recessed surface located inwardly of 0 an upper portion of the tank body, an inlet including an inlet port extending through the recessed surface, an outlet port for grey water extending through a lower portion of the tank body, and a backup inlet extending through the recessed surface and connecting to a waste conduit, wherein excess water received at the inlet port is directed to the waste conduit via the well and the backup inlet.

Preferably, the grey water surge tank further includes a filter member for trapping particulate matter in grey water received by the inlet port and for passing filtered grey water into the tank body. The filter member has a volume, allowing the rate of water received at the inlet port to exceed the rate of water delivered by the inlet port to the tank body for a period of time before excess water results.

Preferably, the grey water surge tank further includes an overflow port positioned to receive grey water from the tank body when the amount of grey water in the tank body exceeds a predetermined level, the overflow port connected to an overflow conduit that directs grey water received by the overflow port out of the tank body. The overflow port may be positioned proximate the inlet. The overflow conduit may be connected to the waste conduit so that grey water received by the overflow port is directed to the waste conduit. The overflow port and overflow conduit may be located entirely within the tank body.

Preferably, the waste conduit extends from the backup inlet through the surge tank and exits the surge tank at a lower portion of the surge tank.

005110009 Preferably, the waste conduit extends away from the backup inlet substantially vertically. The waste conduit may extend substantially below the tank body.

Preferably, the inlet occupies approximately between 40% and 50% of the well.

Preferably, the grey water surge tank further includes a purge line and a valve for opening and closing the purge line, wherein when the purge line is open a flow path is created from a lower portion of the surge tank to the waste conduit. The outlet port may be connected to an outlet conduit and the purge line may extend between the outlet conduit and the waste conduit.

According to a third aspect of the present invention, there is provided a grey water 0 surge tank system including a surge tank including a tank body for receiving waste grey water, a well defined by a recessed surface extending inwardly from an upper portion of the tank body, an inlet port extending through the recessed surface, the inlet port adapted to seat a filter member for trapping particulate matter from grey water entering the tank body through the inlet port, an outlet port extending through a lower portion the wall of the tank body for providing filtered grey water to a reticulation system, a backup inlet extending through the recessed surface, and a waste conduit in fluid communication with the backup inlet and being adapted to be connected to a waste system, wherein upon at least partial restriction of flow of water through the filter member and into the tank body, excess water is directed to waste via the backup inlet and the waste conduit.

According to a fourth aspect of the present invention, there is provided an inlet and overflow arrangement for a grey water surge tank substantially as herein described with reference to the accompanying drawings.

According to a fifth aspect of the present invention, there is provided a grey water surge tank substantially as herein described with reference to the accompanying drawings.

According to a sixth aspect of the present invention, there is provided an inlet and overflow arrangement substantially as herein described with reference to the accompanying drawings when used with or forming part of a grey water surge tank or another liquid storage tank.

005110009 6 Further aspects of the present invention, which should be considered in all its novel aspects, will become apparent from the following description, given by way of example only and with reference to the accompanying drawings.

Brief description of the drawings Figure 1 shows a perspective view of an embodiment of a grey water surge tank system according to the present invention.

Figure 2 shows a side view of the embodiment of the grey water surge tank system as depicted in Figure 1.

Figure 3 shows a sectional view of the embodiment of the grey water surge tank system 0 as depicted in Figure 2.

Figure 4 shows an enlargement of the area 4 shown in Figure 3.

Detailed description of the embodiments The following description refers to preferred embodiments of a grey water surge tank system according to the present invention. To facilitate an understanding of the invention, reference is made in the description of the accompanying drawings whereby the present invention is illustrated in a preferred embodiment. It will be understood that although described with reference to particular applications, the invention may be used for other or alternative applications without departing from the spirit and scope of the invention as defined in the appended claims.

Referring to Figures 1 and 2, there is shown a preferred embodiment of a grey water surge tank 10 according to the present invention. The surge tank 10 includes a tank body 12, which is adapted to hold grey water piror to use for applications such as irrigation and watering of plants. The tank body 12 in the present embodiment has a volume of about 200 litres so as to be able to receive domestic grey water waste, for example from a washing machine and/or a shower or bath. Grey water is introduced into the tank body 12 via inlet conduit 13 in the direction as depicted by arrow A. The surge tank 10 has a well 20 defined by a recessed surface 22, which extends inwardly from an upper portion of the outer surface of the tank body 12. An inlet port 24 extends 005110009 7 through the recessed surface 22 to allow water to enter the tank body 12 from inlet conduit 13. A filter member 30 is disposed within the inlet port 24, the filter member S capturing lint and particulate matter present within the grey water as the water passes into the tank body 12.

Referring now to Figures 3 and 4, grey water 40 within the tank body 12 exists the tank body 12 through an outlet port 14 and travels through an outlet conduit 16 for applications such as irrigation or watering of plants in the direction as denoted by arrow C. Although not depicted within the drawings, those skilled in the art will appreciate that a control valve may be provided downstream so as to allow for controlled use of the 0 grey water 40 when required. Furthermore, a pump device (not shown) may be provided should the water be required under pressure or at heights greater than that of the tank body 12.

The filter member 30 has a lint basket 32 having a plurality of apertures 34 extending through the link basket 32, and a fine lint bag 36 surrounding the lint basket 32. The filter member 30 is retained within the inlet port 24 via a collar portion 38.

As grey water passes from the inlet conduit 13 and into the filter member 30, waste particulates such as clothing link, hair and other particulars are trapped within the lint basket by the apertures 34, or finer particulate matter which passes through the apertures 34 is captured by the lint bag 36, which is a fine material mesh formed into a bag that fits around the filter member 30. With continued delivery of grey water into the tank body 12, the filter member 30 becomes progressively clogged and restricts flow of water into the tank body 12. In the event that water is supplied form the inlet conduit 13 at a rate greater than which can pass through the filter member 30, the excess water backups form the filter member 30 into the well 20 and is delivered to waste in the direction as denoted by arrow B, for example, a sewer system, via a backup inlet 26 and a waste conduit 18. As such, in the event that the filter member 30 cannot pass the a portion or any of the water delivered to the inlet port 24 from the inlet conduit 13, excess water, is directed unfiltered to the waste conduit 28. The waste conduit 28 may be connected to a suitable waste, for example a sewage system. Therefore, particulate matter is prevented from being introduced into the tank body 13 even during overflow conditions.

005110009 8 In the present embodiment, the waste conduit 18 extends through the tank body 12 and exits through the base of the tank body 12. A suitable seal (not shown) is provided about the waste conduit 18 at the intersection with the tank body 12. However, the waste conduit 18 in alternate embodiments may direct the excess grey water from the filter member 30 to waste in other manners. For example the waste conduit 18 may exit through a side portion or an end portion of the tank body 12 whilst still allowing excess grey water to be safely directed to waste.

As is shown in Figure 3, the outlet port 14 is the lowest point of the tank body 12 in the IND present embodiment. This allows the tank body 12 to be fully purged of filtered grey 0 0 10 water 40 at any time by opening tank purge valve 19 and directing the water 40 to waste conduit 18 via tank purge conduit 11, which extends between the outlet 16 and the waste conduit 18.

When grey water is delivered to the tank body 12 at a rate greater than which the filtered grey water is removed form the tank body 12 via outlet conduit 16 (and/or tank purge conduit 11), the water level within the tank body 12 rises. When it reaches a predetermined height defined by the height of an overflow port 17, excess filtered grey water is delivered to waste via the overflow port 17, which is in fluid communication with an overflow conduit 15. The overflow conduit 15 directs the excess filtered grey water into the waste conduit 18. Thus the filtered grey water in the event of excessive volume _0 being delivered to the tank body 12 is safely diverted to waste.

As is shown in Figures 3 and 4, in the present embodiment the inlet conduit 13 delivers unfiltered grey water to the filter member 30 at a height greater than that of overflow port 17. Again, although overflow port 17 is connected to the waste conduit 18 via an overflow conduit 15 inside the tank body 12, the overflow port 17 may be connected to waste in other manners without departing from the scope of the invention.

In the present embodiment, the well 20 has a depth of about 45 mm and a diameter of about 200 mm. The inlet port 24 has a diameter of about 132 mm and the backup inlet 26 has a diameter of about 25 mm. The inlet conduit 13, filter member 30, inlet port 24 and backup inlet 26 are suitably sized such that when the filter member 30 becomes at least partly impervious to the grey water, the grey water is directed to waste without 005110009 9 O flowing out of the well 20, and hence contamination of the surrounding area of the surge tank 10 by grey water waste is prevented. The filter member 30 is sized so as to allow ease of flow of typical grey water waste flow rates from domestic applications such as bathroom and laundry waste. It will be understood that in other applications with alternate flow rates form the inlet conduit 13 the features of the invention may be suitably sized such that overflow of waste grey water from the well is also prevented.

Furthermore, although the well in the present embodiment is depicted as a rebated circular surface 22, the well 20 may take other forms such as a concave recess within the surge tank body 12. Alternatively, the well may be provided in a form which is not IN 10 integrally formed with the tank body 13, but rather as a separate unit which is adapted to be engaged with existing surge tanks, which do not include this feature of the present invention. This separate unit may extend proud of the tank body 12 whilst still providing a well 20 with a recessed surface, the recessed surface being recessed relative to the walls of the well, which may or may not be below an upper surface of the tank body 12.

Integral units may also stand proud of the tank body 12.

The surge tank may be formed from a polymeric material such as polyethylene and may have a capacity in the range of from about 130 litres to about 250 litres, more preferably about 190 litres. The surge tank may be generally cylindrical in shape having a diameter in the range of from about 400 mm to about 500 mm, more preferably about 450 mm, and a horizontal length in the range of from about 800 mm to about 1300 mm, more preferably about 1300 mm.

Domestic grey water waste has been identified as being suitable in many instances for irrigation and watering of plants, in particular for sub-terrain irrigation via dripping outlets. The present invention, when coupled to a sub-terrain irrigation system, prevents waste particulate including lint and hair form being delivered to the site where irrigation occurs. This prevents clogging of sprinkling devices and watering devices thus providing a more reliable system for irrigation of plants. various government bodies have varying regulations in regard to the use of waste grey water for irrigation in domestic residences. The present invention, although depicted in a preferred embodiment above, may be adapted to suit particular requirements, including for example any relevant statutory requirements and health and safety guidelines.

005110009 I Grey water has been identified as a suitable source of irrigation water for plants in C domestic environments. Grey water, although suitable for sub-terrain irrigation, poses p significant health risks due to the biological waste suspended within the water. Various

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health and safety guidelines exist which specify the manner in which grey water may be used for irrigation in domestic environments. For example, many governing organisations have health requirements which stipulate that grey water must not be 0 stored for more than 24 hours and must be completely used within this time. In this case the valve 19 may be automatically opened periodically by a controller with a suitable timer (not shown). Some governing bodies do not allow surface distribution of grey water, and forbid grey water emittance at depths of less than 100 mm below the surface N of the ground. This avoids run-off of grey water and prevents pollution to adjacent areas.

It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evidence from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

Claims (23)

1. An inlet and overflow arrangement for a grey water surge tank, the arrangement including a well formed in or securable to an upper portion of a surge tank and including a recessed surface, an inlet including an inlet port, and a backup inlet extending through the recessed surface, wherein excess water received at the inlet is directed to the backup inlet via the well, the backup inlet being connected to a waste conduit.

2. The inlet and overflow arrangement of claim 1, wherein the inlet has a volume that provides a buffer before excess water is produced at the inlet port.

3. The inlet and overflow arrangement of claim 2, wherein the volume is provided by a filter for filtering water received at the inlet before passing it to the surge tank.

4. The inlet and overflow arrangement of any one of claims 1 to 3 further including an overflow port positioned within the tank body and connected to an overflow conduit that directs grey water received by the overflow port to the waste conduit.

5. The grey water surge tank of any one of claims 1 to 4, wherein the waste conduit extends away from the backup inlet substantially vertically and exits the surge tank at a lower portion of the surge tank.

6. The grey water surge tank of any one of claims 1 to 5, wherein the inlet occupies an area of approximately between 40% and 50% of the area of the well.

7. A grey water surge tank including a tank body, a well including a recessed surface located inwardly of an upper portion of the tank body, an inlet including an inlet port extending through the recessed surface, an outlet port for grey water extending through a lower portion of the tank body, and a backup inlet extending through the recessed surface and connecting to a waste conduit, wherein excess water received at the inlet port is directed to the waste conduit via the well and the backup inlet. 005110009 12

8. The grey water surge tank of claim 7, further including a filter member for (trapping particulate matter in grey water received by the inlet port and for passing filtered grey water into the tank body.

9. The grey water surge tank of claim 8, wherein the filter member has a volume, allowing the rate of water received at the inlet port to exceed the rate of water Sdelivered by the inlet port to the tank body for a period of time before excess N water results. IN

10. The grey water surge tank of any one of claims 7 to 9 further including an Ooverflow port positioned to receive grey water from the tank body when the amount of grey water in the tank body exceeds a predetermined level, the overflow port connected to an overflow conduit that directs grey water received by the overflow port out of the tank body.

11. The grey water surge tank of claim 10, wherein the overflow port is positioned proximate the inlet.

12. The grey water surge tank of claim 10 or claim 11, wherein the overflow conduit is connected to the waste conduit so that grey water received by the overflow port is directed to the waste conduit.

13. The grey water surge tank of claim 12, wherein the overflow port and overflow conduit are located entirely within the tank body.

14. The grey water surge tank of any one of claims 7 to 13, wherein the waste conduit extends from the backup inlet through the surge tank and exits the surge tank at a lower portion of the surge tank.

The grey water surge tank of any one of claims 7 to 13, wherein the waste conduit extends away from the backup inlet substantially vertically.

16. The grey water surge tank of claim 14, wherein the waste conduit extends substantially below the tank body. 005110009 13

17. The grey water surge tank of any one of claims 7 to 16, wherein the inlet occupies approximately between 40% and 50% of the well.

18. The grey water surge tank of any one of claims 7 to 17, further including a purge line and a valve for opening and closing the purge line, wherein when the purge line is open a flow path is created from a lower portion of the surge tank to the waste conduit.

19. The grey water surge tank of claim 18, wherein the outlet port is connected to an outlet conduit and the purge line extends between the outlet conduit and the waste conduit.

20. A grey water surge tank system including a surge tank including a tank body for receiving waste grey water, a well defined by a recessed surface extending inwardly from an upper portion of the tank body, an inlet port extending through the recessed surface, the inlet port adapted to seat a filter member for trapping particulate matter from grey water entering the tank body through the inlet port, an outlet port extending through a lower portion the wall of the tank body for providing filtered grey water to a reticulation system, a backup inlet extending through the recessed surface, and a waste conduit in fluid communication with the backup inlet and being adapted to be connected to a waste system, wherein upon at least partial restriction of flow of water through the filter member and into the tank body, excess water is directed to waste via the backup inlet and the waste conduit.

21. An inlet and overflow arrangement for a grey water surge tank substantially as herein described with reference to the accompanying drawings.

22. A grey water surge tank substantially as herein described with reference to the accompanying drawings.

23. An inlet and overflow arrangement substantially as herein described with reference to the accompanying drawings when used with or forming part of a grey water surge tank or another liquid storage tank.