NZ529588A

NZ529588A - Rainwater harvesting

Info

Publication number: NZ529588A
Application number: NZ52958803A
Authority: NZ
Inventors: Hugh Barr Mcdonald; Mark Andrew Lance
Original assignee: Davey Products Pty
Priority date: 2002-11-20
Filing date: 2003-11-17
Publication date: 2004-06-25
Also published as: AU2003262296A1; AU2003262296B2

Abstract

A water supplementing system suitable for retrofitting to an existing mains water supply, said system including: means for detecting demand from a consumer; means for detecting presence of supplementing water; means for delivering said supplementing water to said consumer; means for actuating said means for delivering in response to detecting said demand for said presence of said supplementing water; and means for blocking said mains water supply when said means for delivering is actuated.

Description

529 5 8 8 Patent Form No. 5 NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION TITLE: RAINWATER HARVESTING ,NTE£^tCKML PROPERTY* OFFICE OF M.Z 1 7 NOV 2003 Received We Davey Products Pty. Ltd., an Australian company of 6 Lakeview Drive, Scoresby, Victoria, 3179, Australia, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: 4003q 2 RAINWATER HARVESTING INTELLECTUAL PROPERTY OFFICE OF N.Z. 17 FEB 2004 received The present invention relates to rainwater harvesting and in particular to a system suitable for automatically interfacing stored water including rainwater 5 to a mains water supply network.

Rainwater harvesting systems are known. One such system is disclosed in EP 1201834 by Bogemar S.L. The known system includes an auxiliary storage tank that is filled with water from a mains network. A float valve maintains water in the auxiliary tank between preset levels. A three way electric 10 valve is used to alternately establish a hydraulic connection between the inside of the auxiliary tank or a rainwater storage tank respectively and an inlet of a hydraulic pump. The hydraulic pump circulates water from the auxiliary tank or from the rainwater storage tank to a point of consumption.

One disadvantage of the prior art system is that a pump is required to 15 deliver water not only from the rainwater tank but also from the mains network. The pump therefore has to run whenever water is being consumed, including when the rainwater tank is empty. This makes the pump more liable to breakdown. A breakdown in the pump or an associated control system or a power out age means that water cannot be drawn either from the storage tank 20 or from the mains network.

The discussion of the background to the invention herein is included to explain the context of the invention. This is not to be taken as an admission that any of the material referred to was published, known or part of the common general knowledge in Australia as at the priority date of any of the claims. 25 An object of the present invention is to alleviate the disadvantages of the prior art or at the very least to provide consumers with a choice.

According to one aspect of the present invention there is provided a water supplementing system suitable for retrofitting to an existing mains water supply, said system including: means for detecting demand from a consumer; means for detecting presence of supplementing water; means for delivering said supplementing water to said consumer; means for actuating said means for delivering in response to detecting said demand and said presence of said supplementing water; and W:\marie\GABNODEL\RAINWATER HARVESTING(2).doc means for blocking said mains water supply when said means for delivering is actuated.

According to a further aspect of the present invention there is provided a method of retrofitting a water supplementing system to an existing mains water supply, said method including the steps of: providing means for detecting demand from a consumer; providing means for detecting presence of supplementing water; providing means for delivering said supplementing water to said consumer; providing means for actuating said means for delivering in response to detecting said demand and said presence of said supplementing water; and providing means for blocking said mains water supply when said means for delivering is actuated.

The means for detecting demand may include a flow sensor. The means for detecting supplementing water may include a water sensor. The water sensor may be provided by any means suitable for detecting presence of supplementing water and/or a low level of water in an associated water storage tank or the like. The supplementing water may be delivered from the water storage tank. The water sensor may include a pressure sensor, float level switch, string resistor network (for comparative resistance measurement) or the like. The pressure sensor may be provided by any suitable means and may be located within a flange associated with the storage tank. The float level sensor may be provided by any suitable means and may be associated with a switch for actuating a hydraulic pump.

The means for blocking may include a solenoid valve adapted to block the mains water supply when the means for delivering the supplementing water is actuated. Alternatively, the means for blocking may include a pressure reducing regulator adapted to provide an output pressure that is below a pressure head supplied by the means for delivering the supplementing water. An added benefit of a pressure reducing regulator is that it protects components against high pressure, reducing leaks and deformation of plastics and other sensitive components.

The means for delivering the supplementing water may include a hydraulic pump. The pump may be located inside the water storage tank such W:\marie\GABNODEL\RAINWATER HARVESTING(2).doc 4 that it is at least partly submerged when water is present in the tank or it may be located outside the tank such as in a cavity below the tank.

The means for actuating the means for delivering the supplementing water may include a relay. The means for delivering may be 5 actuated when presence of the supplementing water is detected (preventing loss of prime for the pump) and the means for detecting demand detects flow of water above a predetermined threshold. The blocking means may include a non-return valve in series with the pressure reducing regulator. The non-return valve may be located upstream or downstream relative to the pressure reducing 10 regulator. Preferably the non-return valve is located such that it may be inspected and checked regularly.

The control system may be arranged such that an air break is not introduced in the mains water supply when supplementing water is not being consumed.

The present invention may provide a system for interfacing stored water to a mains water supply in a manner which is relatively seamless from the point of view of a consumer. The system may be arranged such that it does not detract from the usual benefits associated with a conventional mains water supply network, at least when rainwater is not available or is not being used. 20 The system of the present invention may be arranged such that it may be easily overridden or switched off by the consumer to obtain water directly from the mains network.

The system of the present invention may provide an uninterrupted supply of water in the event of a failure of a pump or associated controller or in the 25 event of a power outage.

The system of the present invention may be arranged to minimize running of the pump, eg. at least when demand is relatively low or in the event of a slow leak. In those circumstances water demand may be supplied directly from the mains water supply network. This arrangement not only extends pump 30 life but also saves power.

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings wherein: FIG. 1 shows a diagram of a rainwater harvesting system according to one embodiment of the present invention; W:\marie\GABNODEL\RAINWATER HARVESTING(2).dOC FIG. 2 shows the system in FIG. 1 with a full tank and wherein water demand is above a predetermined threshold; FIG. 3 shows the system in FIG. 1 with a full tank and wherein water demand is below the predetermined threshold; FIG. 4 shows the system in FIG. 1 with an empty tank and wherein demand is being satisfied by the mains supply network; FIG. 5 shows a wiring diagram associated with the system shown in FIGs. 1 to 4; FIG. 6 shows a diagram of a rainwater system according to another 10 embodiment of the present invention; FIG. 7 shows a modification of the rainwater system shown in FIG. 6; and FIG. 8 shows a wiring diagram associated with the system shown in FIGs. 6 and 7; and FIG. 9 shows a cut away view of one embodiment of a rainwater harvesting system according to the present invention.

The rainwater harvesting system shown in FIG. 1 includes a storage tank 10 for rainwater. Tank 10 is adapted to store storm water collected from a catchment means such as a roof of a building (not shown) via downpipe 11. 20 Water is drawn from tank 10 via flange 12. Hydraulic pump 13 is in fluid communication with flange 12 via an inlet conduit 14. Hydraulic pump 13 also is in fluid communication with one terminal of T-section coupling 16 via outlet conduit 15. Outlet conduit 15 is connected to the one terminal of T-section coupling 16 via non-return valve 17. The mains supply network is connected to 25 another terminal of T-section coupling 16 via non-return valve 18 and normally open solenoid valve 19.

Consumer demand is sensed via flow sensor 20. Flow sensor 20 includes a preset threshold so that small leaks and the like do not cause unnecessary running of pump 13. Pump 13 is actuated via controller 21. 30 Controller 21 receives signals from flow sensor 20 and pressure sensor 22 located in flange 12. Flange 12 is positioned above base 23 of tank 10 to avoid drawing sediment and other debris which may find its way into tank 10. Pressure sensor 22 detects an acceptable head of water in tank 10 to avoid loss of prime in pump 13. Alternatively pressure sensor 22 may be positioned W:\marie\GABNODEL\RAINWATER HARVESTlNG<2}.doc 6 in a conduit upstream of pump 13 such as inlet conduit 14. Alternatively pressure sensor 22 may be replaced with a float level sensor/switch (not shown) located inside tank 10. The switch associated with the float level sensor may be adapted to actuate pump 13 when the quantity of water in tank 10 is 5 above a predetermined minimum level. In some embodiments pump 13 may be submersible and may also be located inside tank 10. The float level sensor/switch may be attached to or integrated with the submersible pump.

When pressure sensor 22 detects that there is sufficient water (ie. above a preset level) in tank 10 and flow sensor 20 detects demand for water from a 10 consumer above a preset threshold, controller 21 is arranged to close normally open solenoid valve 19 and to actuate pump 13. Closure of solenoid valve 19 causes water from the mains network to be cut off whilst actuation of pump 13 causes water to be drawn from tank 10 and pumped to the consumer via conduit 15, non-return valve 17 and T-section coupling 16.

FIG. 2 shows the system with sufficient water in tank 10 and wherein demand flow has been detected that is above a predetermined threshold, causing water to be drawn from tank 10 and supplied to the consumer in preference over the mains supply network.

FIG. 3 shows the system with sufficient water in tank 10 and wherein 20 demand flow has been detected that is below the predetermined threshold. Controller 21 has not actuated pump 13 and demand is supplied by the mains supply network avoiding unnecessary running of pump 13. One example of this includes a final stage of a toilet cistern filling cycle.

FIG. 4 shows the system with insufficient water in tank 10. Irrespective 25 of the level of demand flow, controller 21 will not actuate pump 13 because pressure sensor 22 has detected low pressure in flange 12. Demand is therefore supplied by the mains supply network.

Advantageously, in the event of a power outage or failure of pump 13, controller 21 or sensor 20 or 22, water is seamlessly available from the mains 30 supply network. Even when sufficient water is available from tank 10, the consumer may elect to override the rainwater harvesting system by disabling controller 21 via a suitable switch or the like (not shown).

FIG. 5 shows a wiring diagram associated with the rainwater harvesting system of FIGs. 1 to 4. The system includes a controller (relay) 21 actuated via W:\marie\GABNODEL\RAINWATER HARVESTING(2).doc 7 normally open flow switch 20 and normally open pressure switch 22 connected in series. When pressure switch 22 is closed denoting that water level in tank 10 is above a predetermined threshold and flow switch 22 is closed denoting that water demand or flow is above a predetermined threshold, power from the 5 AC mains is applied to controller (relay) 21 tripping it. When controller (relay) 21 is tripped it supplies power to normally open solenoid 19, causing it to close and block supply of water from the mains network. Controller (relay) 21 also supplies power to pump 13 causing it to run and to pump water from tank 10 to the consumer.

FIG. 6 shows a modification of the rainwater harvesting system in FIG. 1 wherein solenoid valve 19 is replaced with pressure reducing valve 24 upstream from T-section coupling 16. Operation of the modified system is similar to that described with reference to FIGs. 1 to 4 except that there is no solenoid valve 19 to block the flow of mains water when hydraulic pump 13 is actuated. 15 Instead blocking of mains water is performed by the series connection of pressure reducing valve 24 and non-return valve 18. Hydraulic pump 13 is arranged to supply an output pressure that is at least marginally greater than the output pressure associated with pressure reducing valve 24. This gives rise to pressure in T-section coupling 16 that is greater than the mains water 20 pressure downstream of pressure reducing valve 24, preventing flow of mains water whilst hydraulic pump 13 is actuated and is supplying adequate pressure to T-section coupling 16. Dispensing with solenoid valve 19 may provide an advantage in some installations because it may avoid undesirable water hammer which can occur when solenoid valve 19 is switched off rapidly. 25 FIG. 7 shows an alternative arrangement that is similar to FIG. 6 except that the positions of pressure reducing valve 24 and non-return valve 18 are interchanged.

FIG. 8 shows a wiring diagram associated with the rainwater harvesting system of FIGs. 6 and 7. The latter is identical to FIG. 5 except that solenoid 19 30 is dispensed with. Operation of the system is also similar to that described with reference to FIG. 5 except that when relay 21 is tripped, it supplies power to pump 13 only causing it to supply water under pressure to T-section coupling 16 that is sufficient to block supply of water from the mains network.

W:\marie\GABNODEL\RAINWATER HARVESTING(2).doc FIG. 9 shows a rainwater harvesting system according to one embodiment of the present invention enclosed in a housing 25. The pump 13 is separate from housing 25 and is connected thereto via water conduit 14. The system is similar to what is shown in the diagram of FIG. 6 and includes an inlet of pressure reducing valve 24 connected to the mains supply via non-return valve 18. The outlet of pressure reducing valve 24 is connected to one terminal of T-section coupling 16. Another terminal of T-section coupling 16 is connected to the consumer via flow sensor 20. The third terminal of T-section coupling 16 is connected to pump 13 (not shown) via conduit 14. The system includes a low voltage power supply (transformer) 26 for energizing the controller (not shown). An input from a float level switch mounted in an associated rainwater storage tank (not shown) is connected via conduit 27.

Finally, it is to be understood that various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the invention.

W:\marie\GABNODEL\RAINWATER HARVESTING(2).doc

Claims

9 THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A water supplementing system suitable for retrofitting to an existing mains water supply, said system including: 5 means for detecting demand from a consumer; means for detecting presence of supplementing water; means for delivering said supplementing water to said consumer; means for actuating said means for delivering in response to detecting said demand and said presence of said supplementing water; and 10 means for blocking said mains water supply when said means for delivering is actuated.

2. A system according to claim 1 wherein said means for detecting demand includes a flow sensor. 15

3. A system according to claim 1 or 2 wherein said means for detecting supplementing water includes a pressure sensor.

4. A system according to claim 1 or 2 where said means for detecting 20 supplementing water includes a float level switch. 25

5. A system according to any one of the preceding claims wherein said means for blocking includes a solenoid valve adapted to block said mains water supply when said means for delivering is actuated.

6. A system according to any one of claims 1 to 4 wherein said means for blocking includes a pressure reducing regulator adapted to provide an output pressure that is below a pressure head supplied by said means for delivering. 30

7. A system according to any one of the preceding claims wherein said means for delivering includes a hydraulic pump.

8. A system according to any one of the preceding claims wherein said means for actuating includes a relay. W:\marie\GABNODEL\RAINWATER HARVESTING(2).doc INTELLECTUAL PROPERTY OFFICE OF N.Z. 17 FEB 2004 received 10

9. A system according to any one of the preceding claims wherein said supplementing water is delivered from a rain water storage tank. 5

10. A method of retrofitting a water supplementing system to an existing mains water supply, said method including the steps of: providing means for detecting demand from a consumer; providing means for detecting presence of supplementing water; providing means for delivering said supplementing water to said 10 consumer; providing means for actuating said means for delivering in response to detecting said demand and said presence of said supplementing water; and providing means for blocking said mains water supply when said means for delivering is actuated. 15

11. A method according to claim 10 wherein said means for detecting demand includes a flow sensor.

12. A method according to claim 10 or 11 wherein said means for detecting 20 supplementing water includes a pressure sensor.

13. A method according to claim 10 or 11 where said means for detecting supplementing water includes a float level switch. 25

14. A method according to any one of claims 10 to 13 wherein said means for blocking includes a solenoid valve adapted to block said mains water supply during delivery of said supplementing water.

15. A method according to any one of claims 10 to 13 wherein said means 30 for blocking includes a regulator adapted to provide an output pressure that is below a pressure head supplied during delivery of said supplementing water.

16. A method according to any one of claims 10 to 15 wherein said means for delivering includes a hydraulic pump. W:\marie\GABNODEL\RAINWATER HARVESTING(2).doc INTELLECTUAL PROPERTY OFFICE OF N.Z. 17 FEB 2004 received 11

17. A method according to any one of claims 10 to 16 wherein said means for actuating includes a relay.

18. A method according to any one of claims 10 to 17 wherein said supplementing water is delivered from a rain water storage tank.

19. A system for supplementing a mains water supply substantially as herein described with reference to the accompanying drawings.

20. A method for supplementing a mains water supply substantially as herein described with reference to the accompanying drawings. END OF CLAIMS W:\maiie\GABNODEL\RAINWATER HARVEST!NG(2).doc INTELLECTUAL PROPERTY OFFICE OF N.Z. 17 FEB received 12 ABSTRACT A system is disclosed for supplementing a mains water supply with tank water such as rain water. The system includes means for detecting demand from a consumer, means for detecting presence of supplementing water, and means for delivering the supplementing water to the consumer. The system also includes means for actuating the means for delivering in response to detecting the demand and the presence of the supplementing water, and means for blocking the mains water supply when the means for delivering is actuated. A method of supplementing a mains water supply is also disclosed. INTELLECTUAL PROPERTY OFFICE OF NJ 1 7 NOV 2003 RECEIVED W:\marie\GABNODELARAINWATER HARVESTING (2).doc