WO2004088062A1

WO2004088062A1 - Flow generator

Info

Publication number: WO2004088062A1
Application number: PCT/NZ2004/000064
Authority: WO
Inventors: Craig Adam Harrison; Warren Roy AGNEW; Winston Duang WICKHAM
Original assignee: Siphonic Systems Limited
Priority date: 2003-04-04
Filing date: 2004-04-02
Publication date: 2004-10-14

Abstract

The invention consists in a flow generator, which comprises a hollow elongate member (2) defining an interior for flow of a fluid, and a restriction member (1) located within the interior such that air is excluded from the flow to produce full bore flow. In another aspect the invention consists in a flow generator device (1) comprising a ring shaped member being constructed such that insertion in a vertical discharge pipe (2), effects the flow to remove any air such that flow is maximised. In yet another aspect the invention consists in a tank outlet structure comprising a flow generator (1) which includes a ring shaped member being constructed such that insertion in the outlet structure (2), effects the flow to remove any air such that flow is maximised.

Description

FLOW GENERATOR

This invention relates to a flow generator for fluid discharge. The invention is directed particularly, but not solely, toward a fluid discharge from any storage means such as roofs and rainwater tanks.

BACKGROUND OF THE INVENTION

Vertical discharge pipes, for example, down-pipes or tank outlets, do not operate at full capacity due to air and friction. When the pipe is discharging a cone of air under atmospheric pressure forms within the outlet pipe at a point beginning at the end of the pie and extending up into the pipe. The discharging fluid is forced outside of the air column or cone so that while there might be the appearance of a full bore flow, the central section of the pipe at the end point is actually air.

If you have enough head or water above the top of the outlet discharge pipe or strong enough pump, full flow is possible. However this is not always practical or cost effective to do.

Existing conventional drainage systems also have problems with blockages. Often there is not enough normal flow in the system to remove blockages during rainfall or flow of the fluid. The use of full-bore or siphonic flow whereby the air in the flow is excluded causes a significant increase in flow rate such that any debris is drawn or washed away. However existing full-bore or siphonic flow systems comprise complicated and expensive inlet/outlet structures to achieve said flow. Existing systems also can require both maintenance and priming.

The phenomenon of sudden and torrential downpours is a design issue for homes and industries in many countries. Because of the reduced flow capacity due to air, in many situations a significant volume of rainwater is lost from the collection system, as it overflows the spouting and falls as waste or causes leaking in buildings.

The collection of rainwater is also a primary and important source of fresh rainwater for drinking. Therefore it can be extremely important to collect these often short but torrential rain bursts in some countries. It has become more important to do, so in countries where the rain bursts are occurring in the previously dry summer months and where the rainfall is lessened. At present no system can handle the collection of rainwater during torrential rain bursts without producing extremely large capacity rainwater collection components such as gutters, downpipes and supporting brackets etc. If large capacity downpipes and gutters are used, then this also impinges upon the structure and the aesthetic look of a building. It also means that you have to have a stronger and more robust supporting structure and there is also the fact that the system will only be used during very short periods of the life of the structure. So it would not be economically efficient to provide large structures for very short period collections that may or may not occur.

For storage tanks an adequate head must be developed to provide gravitational flow so that the discharge to remove fluid can be automatically initiated without expensive vacuum machinery.

It is the object of the present invention to provide an improved flow generator which will obviate or minimize the aforementioned problems in a simple yet effective manner and or which will at least provide the public with a useful choice.

STATEMENT OF INVENTION

Accordingly in a first aspect, the invention consists in a flow generator, the flow generator including a hollow elongate member defining an interior for flow of a fluid, and a restriction member wherein the restriction member is located within the interior such that air is excluded from the flow to produce full bore flow.

Preferably the hollow elongate member is fluidly connected to a volume of fluid thereby having a specific head with respect to discharge from the elongate member.

Preferably the restriction member comprises a ring shaped member.

Preferably the ring shaped member is provided with an adjustment means to enable insertion whereby the ring can be compressed during insertion and sprung back to its original shape afterwards.

Preferably the adjustment means includes a split in the ring shaped member.

Preferably the elongate member is a down-pipe or exit tube or pipe having an exit open end.

Preferably the ring is inserted at a specific distance from the bottom or exit point of the pipe. Preferably the ring is positioned at a minimum upwards distance of 1.5m for a 80mm diameter pipe, exit end of the pipe.

Preferably a specific head is required to achieve full bore flow.

Preferably the head required for a 80mm diameter pipe is 150mm.

Preferably the head can be measured as the height above the top of the discharge pipe from the height of water being discharged.

Preferably if a correct head is not achieved then the length of discharge pipe can be reduced.

Preferably the ring can be inserted at a specific distance from the bottom or exit point of the pipe.

Preferably the ring is positioned at a minimum upwards distance of 1.5m for a 80mm pipe exit end of the pipe.

Preferably the rings are layered to provide the full flow.

Preferably if an adequate length of discharge pipe is not possible then more than one ring shaped member is provided.

Accordingly in a second aspect the invention consists in a flow generator device comprising a ring shaped member being constructed such that insertion in a vertical discharge pipe, effects the flow to remove any air such that flow is maximised.

Preferably the discharge pipe is fluidly connected to a volume of fluid thereby having a specific head with respect to discharge from the discharge pipe.

Preferably the adjustment means includes a split in the ring shaped member.

Preferably a specific head is required to achieve full bore flow.

Preferably the head required for a 80mm diameter pipe is 150mm. Preferably the head can be measured as the height above the top of the discharge pipe from the height of water being discharged.

Preferably if a correct head is not achieved then the length of the discharge pipe can be altered to suit.

Preferably the rings are layered to provide the full flow.

Preferably a specific discharge pipe length is necessary to achieve full bore flow which is dependent on the discharge pipe diameter.

Preferably if a correct length of discharge pipe is not possible then more than one ring shaped member will be necessary.

Accordingly in a third aspect the invention consists in a tank outlet structure comprising a flow generator wherein the flow generator includes a ring shaped member being constructed such that insertion in the outlet structure, effects the flow to remove any air such that flow is maximised.

Preferably the outlet structure includes a vertical discharge pipe member.

Preferably the restriction member comprises a ring shaped member.

Preferably the elongate member is a down-pipe having an exit open end.

Preferably the adjustment means includes a split in the ring shaped member.

Preferably a specific head is required to achieve full bore flow.

Preferably if a .correct head is not achieved then the length of discharge pipe can be altered to suit. Preferably the rings are layered to provide the full flow.

Preferably the ring is inserted in the down-pipe at a specific distance from the exit end or outlet being dependent on the diameter of pipe.

Preferably the required distance for a 80mm diameter pipe is 150mm from the exit end.

Preferably if the correct length is not possible then more than one ring shaped member will be necessary.

DRAWING DESCRIPTION

Preferred forms of the invention will now be described with reference to the accompanying drawings.

Figure 1 shows a close up perspective view of the flow generator of the invention.

Figure 2 is a perspective view of the flow generator of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

For any storage tank before achieving a siphonic flow, i.e. during normal gravitational flow, the head of water that forms in the upper part of the tank forces the water through the pipe holes and out through a vertical discharge or outflow pipe. Siphonic flow or maximum flow may be required from any area or volume of fluid which is required to be discharged. Some examples are from roofs, tanks such as ground tanks or ship ballast holds. Where fluids are contained within a tank and are discharged by means of a siphon it is possible to increase the rate of discharge by some 300% through the generation of a siphonic or full-bore flow.

In the discharge from a tank where the internal siphon inlet pipe is inside of the tank and the outlet point is at a level below that of the fluid which is contained within the tank a standard gravitational flow through an 80mm pipe would be in the range of 4 litres per second. However an air cone can form at the base of the open outlet to further restrict the theoretical full bore flow which is possible. Therefore we need greater flows or water pressure to collapse the air cone. Also siphonic flows would also assist in this regard. Therefore a restriction e.g. a restrictor ring, placed near the outlet serves to break the formation of that air cone at the base of the vertical pipe and thus speed up the airflow. The restrictor ring causes greater flow to cause the cone of air to dissipate. Both the discharge volume and fluid velocity increase significantly during siphonic flow.

As shown in figures 1 and 2, a flow generator 1 is shown in use within a downpipe 2. The downpipe 2 can be any vertical discharge pipe. The downpipe 2 has a hollow interior 3 for the flow of a fluid there through in the direction shown. The siphonic flow generator can be installed in any pipe where a maximum flow of a fluid is required. In this case the downpipe can be part of the downpipe of any building such as a house or factory or the downflow can be part of an outlet structure of any storage tank facility.

The siphonic flow generator 1 is made up of a ring shaped member defining an interior a second interior portion 4 which enables the flow 4 to go there through. The ring shaped member has an adjustment means to facilitate insertion into any pipe or tube. For example this can be provided by at least one split 5 or at least a deformable portion, to enable the siphonic flow generator to be installed within downpipe 2. During installation the siphonic flow generator is simply installed by compressing the ring shaped member such that the split is closed thus reducing the diameter of the ring shaped member to enable it to be push and slide fitted within the interior 3 of a downpipe 2.

The following measurements apply to a standard 80mm diameter pipe but can equally be amended to fit other diameter pipes. Obtaining full flow is dependent on the head of water above the discharge pipe and length of discharge pipe. Obtaining full flow is more dependent on the length of discharge pipe. If the head is not adequate then the length of discharge can be altered to compensate. However a more common and difficult problem is getting enough length from a discharge pipe especially if it is already in place. To solve this we can add layers of the rings until the best or maximum flow is produced.

The flow generator 1 is ideally situated 1500mm from the H-head of the downpipe 2 to enable full-bore flow or maximum siphonic flow to be possible or to be triggered. If this head distance is not able to be provided, then a further flow generator will be necessary. To commence a standard gravitational siphon flow without the use of vacuum it is necessary for there to be a head of water in the system. If a restrictor ring is place within the outflow pipe at a point at least 1.5 metres below the full water level for an 80mm pipe then a siphonic flow is induced in the discharge. If the thickness of the restrictor ring is increased the siphonic flow is induced with a lesser head required but the discharge volume is lessened.

The head can be measured as the height from the top of the discharge pipe to the top of the water level within the tank or any other suitable measurement for example, it may be measured from an outlet valve to the top of the outlet pipe.

The device is able to be used on any discharge pipe from any storage of a fluid. The storage may from a tank, a water tank, a roof, a ships tanks etc. Other features are possible such as providing grooves or slots on the ring to assist in flow or rounding or sloping the edges.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and application of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be limiting.

Throughout the description and claims of this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps.

The siphonic flow generator and system have at least the following advantages:

1. Simple installation.

2. Modest production costs.

3. Maximum fluid flows .

4. Easy to manufacture.

5. Makes tank flow discharge efficient.

Claims

1. A flow generator, the flow generator including a hollow elongate member defining an interior for flow of a fluid, and a restriction member wherein the restriction member is located within the interior such that air is excluded from the flow to produce full bore flow.

2. The flow generator as claimed in claim 1 wherein the hollow elongate member is fluidly connected to a volume of fluid thereby having a specific head with respect to discharge from the elongate member.

3. The flow generator as claimed in claim 2 wherein the restriction member comprises a ring shaped member.

4. The flow generator as claimed in claim 3 wherein the ring shaped member is provided with an adjustment means to enable insertion whereby the ring can be compressed during insertion and sprung back to its original shape afterwards.

5. The flow generator as claimed in claim 4 wherein the adjustment means includes a split in the ring shaped member.

6. The flow generator as claimed in claim 5 wherein the elongate member is a down- pipe or exit tube or pipe having an exit open end.

7. The flow generator as claimed in claim 6 wherein the ring is inserted at a specific distance from the bottom or exit point of the pipe.

8. The flow generator as claimed in claim 7 wherein the ring is positioned at a minimum upwards distance of 1.5m for a 80mm diameter pipe, exit end of the pipe.

9. The flow generator as claimed in claim 8 wherein the specific head is required to achieve full bore flow.

10. The flow generator as claimed in claim 9 wherein the head required for a 80mm diameter pipe is 150mm.

11. The flow generator as claimed in claim 10 wherein the head can be measured as the height above the top of the discharge pipe from the height of water being discharged.

12. The flow generator as claimed in claim 11 wherein if a correct head is not achieved then the length of discharge pipe can be reduced.

13. The flow generator as claimed in claim 12 wherein the ring can be inserted at a specific distance from the bottom or exit point of the pipe.

14. The flow generator as claimed in claim 13 wherein the ring is positioned at a minimum upwards distance of 1.5m for a 80mm pipe exit end of the pipe.

15. The flow generator as claimed in claim 14 wherein the rings are layered to provide the full flow.

16. The flow generator as claimed in claim 15 wherein if an adequate length of discharge pipe is not possible then more than one ring shaped member is provided.

17. A flow generator device wherein the generator comprises a ring shaped member being constructed such that insertion in a vertical discharge pipe, effects the flow to remove any air such that flow is maximised.

18. A flow generator device as claimed in claim 17 wherein the discharge pipe is fluidly connected to a volume of fluid thereby having a specific head with respect to discharge from the discharge pipe.

19. A flow generator device as claimed in claim 18 wherein the ring shaped member is provided with an adjustment means to enable insertion whereby the ring can be compressed during insertion and sprung back to its original shape afterwards.

20. A flow generator device as claimed in claim 19 wherein the adjustment means includes a split in the ring shaped member.

21. A flow generator device as claimed in claim 20 wherein the a specific head is required to achieve full bore flow.

22. A flow generator device as claimed in claim 21 wherein the head required for a 80mm diameter pipe is 150mm.

23. A flow generator device as claimed in claim 22 wherein the head can be measured as the height above the top of the discharge pipe from the height of water being discharged.

24. A flow generator device as claimed in claim 23 wherein if a correct head is not achieved then the length of the discharge pipe can be altered to suit.

25. A flow generator device as claimed in claim 24 wherein the rings are layered to provide the full flow.

26. A flow generator device as claimed in claim 25 wherein a specific discharge pipe length is necessary to achieve full bore flow which is dependent on the discharge pipe diameter.

27. A flow generator device as claimed in claim 26 wherein if a correct length of discharge pipe is not possible then more than one ring shaped member will be necessary.

28. A tank outlet structure wherein the outlet structure comprises a flow generator wherein the flow generator includes a ring shaped member being constructed such that insertion in the outlet structure, effects the flow to remove any air such that flow is maximised.

29. A tank outlet structure as claimed in claim 28 wherein the outlet structure includes a vertical discharge pipe member.

30. A tank outlet structure as claimed in claim 29 wherein the restriction member comprises a ring shaped member.

31. A tank outlet structure as claimed in claim 30 wherein the ring shaped member is provided with an adjustment means to enable insertion whereby the ring can be compressed during insertion and sprung back to its original shape afterwards.

32. A tank outlet structure as claimed in claim 31 wherein the elongate member is a down-pipe having an exit open end.

33. A tank outlet structure as claimed in claim 32 wherein the adjustment means includes a split in the ring shaped member.

34. A tank outlet structure as claimed in claim 33 wherein a specific head is required to achieve full bore flow.

35. A tank outlet structure as claimed in claim 34 wherein the head can be measured as the height above the top of the discharge pipe from the height of water being discharged.

36. A tank outlet structure as claimed in claim 35 wherein if a correct head is not achieved then the length of discharge pipe can be altered to suit.

37. A tank outlet structure as claimed in claim 36 wherein the rings are layered to provide the full flow.

38. A tank outlet structure as claimed in claim 37 wherein the ring is inserted in the down-pipe at a specific distance from the exit end or outlet being dependent on the diameter of pipe.

39. A tank outlet structure as claimed in claim 38 wherein the required distance for a 80mm diameter pipe is 150mm from the exit end.

40. A tank outlet structure as claimed in claim 39 wherein the correct length is not possible then more than one ring shaped member will be necessary.