AU750508B2 - Sustainable water supply system for urban buildings - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Actual Inventor: Address for Service: Invention Title: RODNEY GEORGE WADE RODNEY GEORGE WADE CULLEN CO., Patent Trade Mark Attorneys, 239 George Street, Brisbane, Qld. 4000, Australia.

SUSTAINABLE WATER SUPPLY SYSTEM FOR URBAN BUILDINGS Details of Associated Provisional Application: No. PQ3401 filed 13 October 1999 The following statement is a full description of this invention, including the best method of performing it known to me: SUSTAINABLE WATER SUPPLY SYSTEM FOR URBAN BUILDINGS BACKGROUND OF THE INVENTION This invention relates to a sustainable water supply system for urban buildings and is particularly concerned with utilizing rainwater collected from the roof of a building as the preferred main source of water but also enabling the draw-down of town water to supplement the rainwater during dry periods or during periods of over utilisation of the collected rainwater.

As towns and cities grow, water usage places an ever increasing burden on the water supply authorities to provide new water catchment areas and treatment stations.

Such catchment areas are becoming more and more scarce 15 and the necessary infrastructure establishment costs are extremely high. The supply of town water to individual buildings has been addressed in some instances by water usage restrictions, by metering the water and placing increasingly higher water rates on the usage, and/or by requiring plumbing fittings such as cisterns to use 0 06.minimal water during flushing. None of these "solutions" is particularly desirable or necessarily effective in cutting down water usage.

0 g..o 0 00 25 It is an anomaly in all of this that in many towns and cities, the problems of insufficient town water is not due to a lack of precipitation. The quantity of rainwater falling on a building can be very high yet advantage is not made of that water and it wastefully drains away to rivers and seas.

OBJECT OF THE INVENTION It is therefore an object of the invention to provide a water conservation system which makes use of the rainwater falling on a roof so that this can be used as the prime source of water for the building, and wherein that supply is supplemented with the normal town water supply. In this way, town water usage is significantly reduced and the water supply authorities do not need to be concerned with providing additional water supplies.

SUMMARY OF THE INVENTION According to one aspect of the present invention there is provided a water reticulation system for an urban building, said system comprising a water storage tank connected to a town water supply and to a rainwater supply, valve means to regulate the supply of town water to the tank when the water level within the tank falls below a first predetermined level and rises to a second predetermined level, and means to deliver water from the storage tank to the building, wherein the town water supply is isolated from the building with a first shut-off valve and a non-return valve.

According to another aspect of the present invention there is provided a water storage tank for use in the aforementioned water reticulation system, said tank having a rainwater inlet and a town water inlet, valve means to regulate the supply of town water through its inlet when the water within the tank falls below a first predetermined level, overflow means to enable e excess water within the tank to escape, and water outlet means including a standard constant water pressure pump fitted with a non-return valve.

The valve means which regulates the supply of town water through the associated inlet suitably comprises a dual float valve which opens to admit the town water when the level of the water within the tank drops down to a first predetermined level between about 150 and 450 mm and shuts off automatically when the water level reaches a second predetermined level of between about 300 and 600 mm. However, the levels can be varied to suit any particular application.

A particularly preferred operating range is from 300 mm at the lower water level and 450 mm at the upper water level.

Such a system enables the building to operate on free rainwater collected from the roof and delivered via the rainwater inlet of the tank, until the level of water in the tank drops down to the first predetermined .oo.o: o. level due to excess usage over supply. At that point, and in the absence of sufficient further rainwater, the 009e system then automatically draws from the town water supply, a small quantity of water, until such time as the rainwater supply meets demand. This small quantity of water is the amount contained between the first and 000( second predetermined levels in the tank. By careful .0.0 selection of the tank size and setting the appropriate 0 levels of operation within the tank, town water usage can be kept to an absolute minimum.

The water supply system will typically 00 25 incorporate conventional accessories for treating the rainwater prior to it flowing into the storage tank.

Such accessories will include debris and vermin excluders as well as dirt removers and purifiers.

The overflow means which outlets from the top of the tank, preferably has a portion which extends down to the bottom of the tank so that when excess water flows from the tank, any fine sediment on the bottom of the tank is sucked away from the normal water delivery region of the tank which is located here.

The means to deliver the water to the building from the tank may be simply a feed pipe when the system relies upon gravity feed. However, in most instances the delivery means will comprise a standard constant water pressure pump system which is fitted with a non-return valve on the discharge line. This pump system can be solar powered to further enhance the conservation aspect of the system.

Should it become necessary to restore the town water supply to the building, it is simply a matter of turning the shut-off valve back on. This can be done either manually or by using a standard solenoid controlled valve switched from within the building or from some other suitable location.

15 As an alternative arrangement, the water 0:0..

requirements for the building could be adjusted to suit the occupant's preferences. Thus, for instance, if it is required that the prime source of water be town water, 00 then this can be accommodated by appropriate valve control. If a combination of town water and rainwater is 000 required, for instance for different outlets so that the 0 drinking water and personal washing water is always town water, then this can also be incorporated into the reticulation system design.

The sustainable water supply system can be adapted for use with either domestic or commercial buildings as an excellent water conservation system that comes at a once only cost and is effective, efficient and automatic in use.

The system can be made entirely vector proof and the water contained within the storage tank can be protected from contamination from the roof by the use of such devices as the water diverter/flush device which is the subject of my Australian Patent No. 692835.

The system not only conserves water but it also ensures a water supply to the building if the town water supply is disrupted for any reason.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic cross-sectional view of a water supply system according to the invention, and Figure 2 is a schematic representation of the water supply system juxtaposed with respect to a domestic building.

DESCRIPTION OF PREFERRED EMBODIMENT A preferred embodiment of the invention will now be described with reference to the accompanying 15 drawings, in both of which like reference numerals refer to like parts.

Referring firstly to Figure 1, the water *reticulation system comprises a water storage tank having a rain water inlet 11 and a town water inlet 12.

A water outlet 13 to the building is located in the *bottom region of the tank sidewall and an overflow 14 extends through the top side wall of the tank.

S* 25 The water inlet 11 has an associated rainwater diverter 15 which removes sediment from the rainwater before it enters the tank. One such suitable rainwater diverter is the subject of my aforementioned Australian Patent No. 692835. The rainwater diverter 15 can have an interposed screening arrangement 16 comprising one or more screens which captures debris and vermin, and prevents small insects such as mosquitoes from entering the system. The interposed arrangement can be the "leaffree gutter and downpipe rainhead" which is the subject of my Australian Patent No. 629139.

A dual float valve 18 is connected to the town water inlet 12 to regulate the flow of town water between a first predetermined level and a second predetermined level "B" The water outlet 13 has an associated electric pump 19 fitted with a non-return valve and constant pressure valve, to supply water at the required rate and pressure to the building by way of line 20. The electric pump 19 is preferably solar powered.

The overflow 14 includes a pipe 14a which extends to the bottom region of the water tank to a position adjacent the water outlet 13. This enables fine sediment in this region to be sucked out of the tank when excess water flows from the tank; that is, when level "C" 15 is reached. The overflow will also include a siphon o breaker to ensure that water below level is not drawn out.

Referring to Figure 2, the water supply system shown in Figure 1 is illustrated with respect to a typical domestic building 21. Mains pressure town water supply is represented by box 22. An existing water line 23 connects the town water supply 22 to the building 21 by way of feeder lines 25, 26, 27, 28, 29 to water usage areas such as garden taps 30, 31, the kitchen 32, the bathroom 33 and the toilet 34. An additional water line 24 connects the existing water line 23 to inlet 12 of the storage tank 10 and a non-return valve 35 is provided to ensure there is no back flow to the mains water supply 22. Shut-off valves #1 and #2 are provided to control the mains water supply to the building. These operate either manually or by solenoid control.

In operation, rainwater falling on the building's roof is captured by the roof guttering 17 and passes by way of the screening arrangement 16 into the diverter 15. Clean rain water passes out of the diverter through the inlet 11 into the storage tank 10 and fills the tank. Excess rainwater flows out through the overflow 14 by way of pipe 14a.

Water is drawn from the storage tank 10 as and when required by the pump 19 which automatically starts pumping when a reduction in water pressure in the building water supply line 20 is sensed, as occurs when a tap is turned on in the building.

In the absence of further rain and the continued depletion of water within the storage tank the level of the water eventually falls to level At this point the dual action valve 18 automatically opens 15 and admits mains pressure town water into the tank by way •co :of inlet 12 and water line 24.

When the level of water in the tank reaches .".level the dual action valve 18 automatically closes 20 to prevent further mains pressure town water being added.

This ensures that there is no unnecessary quantity of **water added to the storage tank from the mains pressure town water supply in case it begins to rain again and free rainwater can be taken advantage of.

The system doubles as an emergency water supply and/or the primary water supply by the turn of a valve or the flick of a switch to control shut-off valve #1.

In this manner an assured sustainable water supply system is provided for urban buildings.

Whilst the above has been given by way of illustrative example of the invention, many modifications and variations may be made thereto by persons skilled in the art without departing from the broad scope and ambit of the invention as herein set forth.

Claims (12)

1. A water reticulation system for an urban building comprising a water storage tank connected to a town water supply and to a rainwater supply, valve means to regulate the supply of town water to the tank when the water level within the tank falls below a first predetermined level and rises to a second predetermined level, and means to deliver water from the tank to the building, wherein the town water supply is isolated from the building with a first shut-off valve and a non-return valve.

2. A water reticulation system as claimed in claim 1, wherein the town water supply is connected to the storage tank by way of a second shut-off valve. *sees:

3. A water reticulation system as claimed in claim 1 or claim 2, wherein the valve means comprises a dual 20 float valve which opens to admit town water into the water storage tank when the level of the water within the tank drops down to the first predetermined level and shuts off automatically when the level of the water in the tank reaches the second predetermined level.

4. A water reticulation system as claimed in claim 3, wherein the first predetermined level is between 150 and 450mm from the bottom of the tank. S 30

5. A water reticulation system as claimed in claim 3 or claim 4 wherein the second predetermined level is between 300 and 600mm from the bottom of the tank, but at least 150mm above the first predetermined level.

6. A water reticulation system as claimed in any of the preceding claims and including overflow means in the STI~Ntorage tank to enable excess water flowing into the tank the rainwater supply to escape from the tank.

7. A water reticulation system as claimed in any one of the preceding claims, wherein the means to deliver water from the water storage tank to the building comprises a standard constant water pressure pump fitted with a non-return valve.

8. A water storage tank for use in the aforementioned water reticulation system, said tank having a rainwater inlet and a town water inlet, valve means to regulate the supply of town water through its inlet when the water within the tank falls below a first predetermined level and rises to a second predetermined level, overflow means to enable excess water within the tank to escape, and water outlet means including a standard constant water pressure pump fitted with a non- return valve.

9. A water storage tank as claimed in claim 8 and 20 including overflow means to enable excess water flowing into the tank from the rainwater supply to escape from the tank. A water storage tank as claimed in claim 8, wherein the valve means comprises a dual float valve which opens to admit town water when the level of the water within the tank drops down to a first predetermined level and shuts off automatically when the level of water in the tank reaches the second predetermined level.

S.

11. A water reticulation system for an urban building substantially as herein described with reference to the accompanying drawings.

12. A water storage tank substantially as herein described with reference to Figure 1 of the accompanying S ,drawings. 11 DATED this 23 rdDay of May 2002 Rodney George Wade By his Patent Attorneys CULLEN &CO .4 0