AU2003100864A4 - A First Flush Diverter - Google Patents

Description

A FIRST FLUSH DIVERTER

FIELD

The present invention relates to a first flush diverter and in particular to a first flush diverter for use on existing rain water tanks.

BACKGROUND

Conservation and better management of water in a domestic or agricultural setting is important for the environment, especially in dry climates. Rain water storage may improve water management as rain water may be collected until it is needed at a later time.

Water storage is particularly important in remote or dry locations where large tanks may be used to catch water especially for domestic use. Water tanks have been commonly used to trap rainwater, especially making use of run off from roofs through a system of gutters and downpipes. Generally rain water tanks consist of a tank with an inlet at the top, commonly referred to as a strainer opening, for allowing water to enter the tank and a valved outlet at the base for controlling the removal of water from the tank. The head of the water creates the flow from the tank through a tap.

A problem with inherent collecting rain water from roofs has been the build up of debris between rainfalls collecting on the roof and being swept into the rain water. Thus, this "dirty" water is carried into the tank contaminating the water within the tank.

A solution has been known to attach a flush device to the down pipe to divert the first 15 to 20 litres from the roof, allowing the remainder of the water to enter the tank, provided there is sufficient rainfall. This solution is cumbersome and expensive as a plumber is required to cut into the existing pipes, install the device and re plumb the pipe work. Thus this system may be expensive to install.

Another solution has been to build a tank with an integral flush device.

Whilst this is a more efficient solution, it is expensive to replace a whole tank and leaves the consumer with a new problem of disposing of the old tank.

Still a further solution has been to divert the down pipe and manually flush the water in a down pour. This is inconvenient, particularly as this needs to be done during rainfall. Additionally damage may be caused to the walls of a house from run off water, especially if the downpipe suffers damage.

We have now produced a new device for flushing a first amount of water from rainwater tanks which substantially ameliorates the above problems or at least provides the consumer with a useful commercial choice.

STATEMENT OF INVENTION According to a first broad form of the invention, there is provided a first flush diverter comprising: a primary chamber; a secondary chamber; and a floating valve; wherein the first flush device is adapted to be received in a strainer opening of a rain water tank and retained in an upper portion of said rain water tank; and wherein the primary chamber is in fluid communication with a rain water supply; the primary chamber being disposed above the secondary chamber and having: an opening into the secondary chamber; and an outlet for allowing rain water to flow into the rainwater tank; the secondary chamber having a restricted flow outlet for releasing rain water wherein said secondary chamber outlet is disposed outside the rain water tank; the floating valve closing said opening when the secondary chamber is filled with rain water.

Rain water falls into the primary chamber, passes through the opening and enters the secondary chamber, during rain fall. The rainwater at the base of the secondary chamber flows through the lowermost outlet at a rate determined by the restricted flow. If the rainfall flowing into the secondary chamber is less than the flow rate out of the outlet, the secondary chamber will not fill. When the rainfall is in excess of the flow rate out of the secondary chamber outlet, the secondary chamber starts to fill and the floating valve starts to float with the rising level of the water.

When the floating valve reaches the opening, the opening is momentarily blocked and the primary chamber begins to fill. When the water in the primary chamber reaches the level of the outlet in the primary chamber, the water is diverted to flow into the rain water tank. The water level in the secondary chamber continues to empty at a rate governed by the flow restriction on the outlet. As the water leaves the secondary chamber, the floating valve sinks allowing more water to egress from the primary chamber into the secondary chamber thereby providing a continuous stream of water out of the rain water tank. Rain water may only enter the rain water tank if there is sufficient rainwater to fill the secondary chamber and the primary chamber, at least to the height of the outlet into the rain water tank.

The first flush diverter ensures the first 15 to 20 litres of rain water containing contaminants from the roof is diverted from the rain water tank. Thus, the second chamber is formed to hold at least that volume thereby ensuring the contaminated water is removed from the system through the restricted flow outlet.

The first flush diverter is adapted to be received in a strainer opening of a rain water tank and retained in an upper portion of said rain water tank. The outer diameter of the primary and secondary chambers may preferably be smaller than the diameter of a strainer opening to ensure that the device fits inside the strainer opening for installation. The device may preferably include a flange along the uppermost portion of the primary chamber said flange being wider than the strainer opening so that the device may support its own weight as the flange rests on top of the rain water tank. In this manner the device may be supported within the uppermost portion of the tank. The width of the flange and the material the device is formed from may be sufficient to ensure the device does not fall into the rain water tank.

The weight of the water within the device may hold it in place.

Additionally the weight of the device when empty should be suitable to keep the device weighted down. Alternatively the diverter may be fixed into place with fasteners such as screws or clamps. The form of the device may be adapted so that the supporting edge of the strainer of the rain water tank may rest on top of the flange straining the water before it enters the primary flush diverter device. This has the advantage of stopping large debris from entering the secondary chamber and keeping it collected in the strainer, which may be easily emptied.

The primary chamber is in fluid communication with a rain water supply, so that rainwater from the roof and gutters is collected in the downpipe and flows into the primary fluid chamber. The primary chamber is generally cylindrical, but could be formed into other shapes if required. The advantage of the cylindrical shape is that water pressure is evenly spread over the circumference of the cylinder.

Further by providing vertical walls the optimal volume is available for collecting rain water. A person skilled in the art would appreciate that other shapes could be substituted to serve the same purpose.

Locating the primary chamber above the secondary chamber takes advantages of gravity ensuring the water flows to the lowest point being the secondary chamber. The opening into the secondary chamber may have a reduced diameter so that it may be closed with the floating valve, while still maximising the volume of the primary chamber, by retaining the cylindrical shape.

In the primary chamber there may be provided an outlet for allowing rain water to flow into the rainwater tank. This outlet may be located below the strainer level to ensure the water does not back flow through the strainer. Once water reaches this level, the water will flow into the tank due to the water pressure flowing to the lowest point. As the water level in the primary chamber drops below this height, the water is restricted to flowing out through the outlet in the secondary chamber. Additionally as the water level in the tank rises above this level, water may seep into the device from the tank to flow out through the outlet in the secondary chamber. An overflow may be provided to allow excess water to run of to a storm water drain.

The secondary chamber may be conical in shape to maximise the volume available tapering outwards from the reduced diameter to the width of the primary chamber. Other shapes may be substituted, as would be understood by a person skilled in the art. The volume of the secondary chamber is at least the volume of the water required to be flushed from the rain water.

The secondary chamber may have a restricted flow outlet for releasing rain water wherein said secondary chamber outlet is in the form of a pipe that extends outside the rain water tank. The diameter of the restricted flow outlet restricts the flow rate of the water out of the secondary chamber and thereby out of the rain water tank. Being located at the lowest point in the device, the water tends to drain through this outlet. However, as the flow rate is restricted, if the secondary chamber is filled at a faster rate than the water tends to flow out of the outlet, the second chamber will tend to fill at a rate equivalent to the difference between the rate of the water flowing in and the rate of water flowing out. In this way water may fill the second chamber, force the valve block the opening and fill the first chamber until it spills into the tank while at the same time the water is draining from the second tank and the valve sinks reducing the level of water in the primary chamber.

The device may be made out of a suitable material such as plastic, aluminium or stainless steel, sufficient to resist the wet, corrosive environment without contaminating the water collected in the rain water tank. In particular, polyethylene may be the preferred material. The device may preferably be formed by rotational moulding of a plastics material. However, a person skilled in the art would appreciate that other methods of manufacture such as injection moulding may be employed to form the device.

The floating valve may be suitably formed, for example as a sphere, and manufactured from a material less dense than water so that it floats. The floating valve may be sufficiently large to close said opening when forced against it by the raised level of water in the secondary chamber forcing it upward. Other shapes could also be used as would be understood by a person skilled in the art, so long as they blocked the egress of water from the primary chamber to the secondary chamber as the secondary chamber filled with water. The material of the floating valve is sufficiently dense to allow the valve to float in the water. A suitable material may be polystyrene or an air filled plastic ball, sufficient to float. The floating valve may be hinged to the opening as a floating member or may be otherwise associated with the opening.

Preferably a retention ring will be used to hold the floating valve in place once the secondary chamber has been filled with water. Thus the retention ring will act as seat for the floating valve to ensure a tight fit to restrict flow. The retention ring is preferably a ring shape, being formed out of a flat sheet material such as polyethylene. The floating valve retained by the retention ring is preferably a sphere with a wider diameter than the inner diameter of the ring. The retention ring may include an outer diameter larger than the diameter of the opening to allow it to be attached thereto.

The retention ring may include holes so that the ring may be attached to the opening using stainless steel screws or similar. The holes may be laser cut to ensure that no stress raisers are formed in the holes. The inner ring hole may be laser cut to additionally reduce stress raisers.

Other means of attaching the ring may be employed such as welding, gluing or fixing the ring in place, as would be understood by a person skilled in the art.

A preferred embodiment of the Invention will now be described by way of example only, in reference to the drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG 1 shows a side view of the first flush diverter and a top view of the float and retention ring according to an embodiment of the invention; FIG 2 shows a side, top and bottom view of the first flush diverter according to an embodiment of the invention; FIG 3 shows a sketch of water entering and leaving the first flush diverter according to an embodiment of the invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG 1, the diverter comprises a primary chamber located above and opening 13 into a secondary chamber 20 to hold water that has entered from a rain water collection system. The primary chamber 10 may include a flange 11 along the uppermost portion said flange being wider than the strainer opening so that the device may support its own within the rain water tank. The primary chamber may include an outlet 12 so that water may spill from the primary tank into the rain water tank when the height of the outlet 12 is reached by the water level. The primary chamber opens into the secondary chamber through a opening 13.

Thus when water enters the primary chamber it may egress to the secondary chamber when the opening 13 is open. The secondary chamber 20 may include a restricted flow outlet 21 to limit the flow of water there through to a desired flow rate. A faster flow rate may be achieved by widening the diameter of the outlet, conversely slower flow rates may be achieved by narrowing the diameter of the outlet.

In the primary chamber 10, a retention ring 40 rests on the opening 13 to provide a suitable fit to act as a seat for the floating valve 30, when pushed against the retention ring 40. The retention ring may include an inner diameter 41 and outer diameter 42 such that the outer diameter is larger than the opening 13 and the inner diameter is smaller than the opening 13. Additionally a floating valve 30 floats within the secondary chamber 20 coming to rest against the retention ring 40 when the secondary chamber 20 is filled with water. The inner diameter 41 of the retention ring 40 is sufficiently smaller than the diameter of the floating valve 30 to provide a tight fit providing a seal sufficient to stop water seepage. The seal is broken when the water level in the secondary chamber 20 drops and the floating valve 30 sinks. The retention ring 40 may include at least one hole so that the retention ring may be affixed to the diverter at the opening 13.

FIG 2 shows the dimensions of the primary chamber 10 and secondary chamber 20 may be smaller than the flange 11 so that the chamber can fit within the strainer opening while the flange 11 rests on top of the rain water tank.

FIG 3 shows water running from the restricted flow outlet 21 in the secondary chamber 20 outside of the rain water tank. This drawing also shows the primary chamber 10 and secondary chamber 20 filled with water so that the floating valve 30 is fitted against the retention ring 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.

The term "comprise", or variations of the term such as "comprises" or "comprising", are used herein to denote the inclusion of a stated integer or stated integers but not to exclude any other integer or any other integers, unless in the context or usage an exclusive interpretation of the term is required.

Claims (4)

1. A first flush diverter comprising: a primary chamber; a secondary chamber; and a floating valve; wherein the first flush device is adapted to be received in a strainer opening of a rain water tank and retained in an upper portion of said rain water tank; and wherein the primary chamber is in fluid communication with a rain water supply; the primary chamber being disposed above the secondary chamber and having: an opening into the secondary chamber; and an outlet for allowing rain water to flow into the rainwater tank; the secondary chamber having a restricted flow outlet for releasing rain water wherein said secondary chamber outlet is disposed outside the rain water tank; the floating valve closing said opening when the secondary chamber is filled with rain water.

2. A first flush diverter according to claim 1 wherein a retention ring is located at the opening to provide a seat for the floating valve.

3. A first flush diverter according any of the preceding claims wherein the outside diameter of the primary and secondary chambers is smaller than the inner diameter of the strainer opening in the rain water tank.

4. A first flush diverter according any of the preceding claims wherein the volume of the secondary chamber is at least the volume of water desired to be flushed. A first flush diverter according to claim 1 wherein the floating valve is a buoyant sphere. DATED this 16th day of October 2003 By its Patent Attorneys CULLEN CO.