Technical field

The present invention relates generally to a rainwater harvesting system and device. It relates specifically to improvements made to a rainwater harvesting system and device including a rainwater drainage function, a debris cleansing function, a first flush function and a selectable time delay function to initiate clean rainwater collection for storage.

Background art

A prior art T-shaped first flush diverter device has been widely used in the rainwater harvesting systems. Such first flush diverter devices should be installed on each rainwater harvesting systems at various catchment areas. The total first flush volume on each system shall comply with the local authority’s stipulations as based on yearly rainfall density on different location and climates. For an example, local authorities often apply a simple formula of 10 square meters (roof area) to 5 litres (flush volume).

The prior art T-shaped first flush diverter device comprises a horizontal piping and a vertical downpipe carrying a floating ball inside. During a first flush situation, rainwater flows into the vertical downpipe and the floating ball rises to the top of the downpipe; the rainwater is next transferred horizontally through the horizontal piping connectable to a storage tank, while the first flush water is temporarily held in the downpipe. The vertical downpipe has a very small outlet at its bottom, that allows the first flush rainwater to escape slowly over time. After it has stopped raining, the first flush downpipe will eventually empty itself and be ready for the next first flush during the next rainfall. The bottom of the first flush downpipe can and should be removed from time to time to clean out any dirt or debris that is too large to escape through the small outlet.

Additionally, a prior art debris filter is often installed before or after the prior art first flush diverter device.

Summary of the invention

One object of the present invention is to incorporate a drainage function, a debris cleansing function and a first flush function to a rainwater harvesting system and device.

Another object is to incorporate a selectable time delay function to terminate the first flush function and to initiate clean rainwater collection for storage. Another object of the present invention is to avoid rainwater ponding in the rainwater harvesting system and device during no raining season.

Yet, another object of the present invention is that the improved rainwater harvesting system and device operates by mechanisms only, whereas no pump is being employed.

Still, another object of the present invention is to temporarily hold the first flush volume and drain off excess rainwater, without the need for any extra first flush storage tanks.

The above objects are achieved by various components of the present invention when they are disposed at four elevation positions therein a box-like container:-

Towards the topmost elevation position, there is a detachable diffuser plates chassis carrying diffuser plates, which is connectable to an external inlet pipe. In one instance, the external inlet pipe is connectable to roof catchment areas with the assistance of traditional gutters.

At a next lower elevation position, a fixed debris cleansing plate fitted with one or more numbers of supplemental shallow gutter connected to a verticular top-up tube leading to a first flush activator compartment below.

At next lower elevation position, there is disposed a rainwater diversion tray which is tiltable towards an external outlet pipe connectable to a clean rainwater storage tank.

At the bottom elevation position, a floating arm body compartment, a first flush activator compartment, and a drainage compartment, all adjacently disposed underneath the rainwater diversion tray.

The empty space therein the floating arm body compartment is in fluid communication with the first flush activator compartment via a communication hole.

A time delay wheel is employed to select and regulate the water flow rate between the two compartments, and different predetermined time delays can be selected.

A first flush drain hole is disposed on the bottom floor of the first flush activator compartment. The first flush activator compartment is disposed therein with a floating tube equipped with a seesaw lifting arm fitted to its bottom. The seesaw lifting arm is equipped with a drain cover to cover the drain hole:- When the floating tube moves downwards, the drain cover is clear off the first flush drain hole. Rainwater is allowed to be drained off freely.

When the floating tube moves upwards, the drain cover is urged to close the first flush drain hole.

The first flush activator compartment is disposed next to a drain compartment connectable to an external drain pipe.

Summarily, the proposed improvements are achieved by the present invention through the cooperation of relevant components.

Referring to Figure 1 , rainwater with any debris such as dry leaves and small objects from the catchment is first filtered by a domed grating as fixed inside the rain gutter and connected before a rainwater inlet pipe. Rainwater moves through a diffuser plates chassis carrying diffuser plates and next downwardly to the debris cleansing plate at next lower elevation. Eventually, excess rainwater with debris exits the system and device via the drain compartment leading to the drain pipe, and also the uncovered first flush drain hole of the first flush activator compartment.

Once rainwater becomes excessive as in a heavy rainfall, the floating tube inside the first flush activator compartment will rise and the drain cover will close off the drain hole. Rainwater continues to rise inside the first flush activator compartment. Any excess rainwater with debris exits the system and device via the drain compartment leading to the drain pipe.

Next, a time delay wheel, between the first flush activator compartment and the floating arm body compartment, provides a manipulative means to select a predetermined time delay to terminate this first flush function. Excess rainwater is allowed to move from the first flush activator compartment into the floating arm body compartment with a selected time delay.

As rainwater collects and rises, the floating arm body in the floating arm body compartment also rises. With the assistance from a pushing arm fitted to the floating arm body, the rainwater diversion tray is tilted towards the external outlet pipe. When this position is achieved, the first flush function is technically terminated and clean rainwater is collected into a storage tank for future re-cycle use.

Brief description of the drawings

In order that the present invention is more readily understood, the following description is given, by way of examples, of an improved rainwater harvesting system and device in accordance with the present invention. Reference will be made to the accompanying drawings, in which:

Figure 1 illustrates the installation of the present invention to a rainwater catchment roof.

Figure 2a shows various components of the present invention in four elevation positions when the present invention is not operating under a clean rainwater collection situation.

Figure 2b shows the present invention under a clean rainwater collection situation.

Figure 3a illustrates a bottom perspective view of a diffuser plates chassis carrying diffuser plates, connectable to an external inlet pipe and rainwater catchment area.

Figure 3b shows a top perspective view of the chassis shown in Figure 3a.

Figure 4a illustrates a top perspective view of a debris cleansing plate mechanism.

Figure 4b illustrates an underside view of the debris cleansing plate fitted with two shallow gutters and two top-up tubes.

Figure 5a illustrates a top perspective view of a rainwater diversion tray disposed above a floating arm body compartment which is in fluid communication with a first flush activator compartment.

Figure 5b illustrates an underside view of the rainwater diversion tray.

Figure 6a illustrates a top perspective view of a first flush activator compartment with a floating tube mechanism fitted with a seesaw lifting arm and a drain cover for its first flush drain hole on the ground floor of the first flush activator compartment. Figure 6b is a bottom perspective view of the first flush activator compartment shown in Figure 6a.

Figure 7a illustrates a top perspective view of a tiltable floating arm body inside a floating arm body compartment.

Figure 7b illustrates a bottom perspective view of the tiltable floating arm body shown in Figure 7a.

Figure 8a illustrates a perspective view of a time delay wheel.

Figure 8b illustrates a side view of the time delay wheel externally fitted to the wall of the floating arm body compartment partially shown.

Detailed description

As seen in Figures 2a and 2b, various components of the present invention are disposed in four elevation positions of a box-like container, when a clean rainwater collection situation is invoked.

Rainwater from roof catchment areas 13 are collected with the assistance of commonly known gutters 11. The design of the rainwater harvesting system and device depends on gravity feed of rainwater. At the topmost elevation position of the box-like container, an external inlet pipe 1 is horizontally disposed, leading into a mounted diffuser plates chassis 2 carrying diffuser plates 22, 23, 24.

Figures 3a and 3b illustrate how a debris cleansing function is achieved. The diffuser plates chassis 2 carrying diffuser plates 22, 23, 24, connectable to the external inlet pipe 1 and rainwater catchment area 13. The diffuser plates chassis 2 is substantially inverted U- shaped, with two side wall panels 21 and two open ends. The second diffuser plate 23 and the third diffuser plate 24 are flat. The top wall 25 is to be mounted onto the top ceiling of the box-like container. The bases of the two side wall panels 21 are slightly tugged-in and bent to hold each diffuser plate 22, 23, 24 firmly in proper inclined angles and fixed positions. In this present invention, it further comprises three detachable diffuser plates (first 22, second 23 and third 24) with perforated holes on these plates. The purpose of these diffuser plates are to reduce the rainwater impact pressure.

The first diffuser plate 22 is V-bent folded inwardly and faces the mouth of the inlet pipe 1. Either one of or both the second perforated diffuser plate 23 and the third perforated diffuser plate 24 can be omitted from the design of the rainwater harvesting system and device, if it is to collect rainwater from small catchment areas only.

Debris cleansing plate 3 Figures 4a and 4b illustrate a debris cleansing plate 3 at the next lower elevation position. The debris cleansing plate 3 is flanked between two side guides 31 with an exit end 35 which is slanting downwardly and leading to a rainwater diversion tray 4 at yet another lower elevation position. By design, the debris cleansing plate 3 carries perforated holes 34 or is made from others type of filter membrane. Depending on the cleanness requirements of the rainwater to be saved, the debris cleansing plate 3 serves to remove the debris carried by rainwater.

It is important to note that one or more numbers of half-round shallow gutter 32 connected to a vertical top-up tube 33 are further disposed beneath the debris cleansing plate 3. These components 32, 33 transfer a small volume of rainwater into a first flush activator compartment 5 which is disposed at the bottom of the box-like container.

By design, debris from rainwater as well as excess rainwater are carried on the surface of the debris cleansing plate 3 and eventually fall off into a drain compartment 71 below, connectable to a drain pipe 7 disposed on the bottom floor of the box-like container. On the other hand, the filtered rainwater from the debris cleansing plate 3 will be transferred onto a rainwater diversion tray 4 disposed on yet another elevation position, above the first flush activator compartment 5 on the bottom floor of the box-like container.

Rainwater diversion tray 4 A clean rainwater collection function is achieved after a debris cleansing and a first flush functions have been performed. A rainwater diversion tray 4 is the key component that physically terminates the first flush function of the present invention and initiates clean rainwater collection for storage. By design, as seen in Figure 5, the rainwater diversion tray 4 is movable and becomes operational when this rainwater diversion tray 4 is urged to tilt towards an external outlet pipe 8.

The rainwater diversion tray 4 is essentially an open top U-shaped chute channel with two side guide walls 41. One end is open 43 whereas the other outlet end is also open 44 and has a lower lipped extension.

It is important to note that a detachable latch mechanism 42 is disposed underneath the chute channel towards the outlet opening 81. In its natural disposition, the chute channel is oriented such that the open end is tilted downwardly.

Once this detachable latch mechanism 42 is installed, the rainwater diversion tray 4 becomes tiltable upwards or downwards, with the assistance of a pushing arm 64 fitted on top of a floating arm body 61 , when the diversion tray 4 has been raised.

First flush activator compartment 5

Figure 6 illustrates a first flush activator compartment 5 with a floating tube 53 mechanism fitted with a seesaw lifting arm 55 and a drain cover 56 for its first flush drain hole 51 on the bottom floor of the first flush activator compartment 5.

The floating tube 53 is disposed inside the box casing 54. The floating tube 53 is slidable mounted on a vertical wall section inside the first flush activator compartment 5.

The drain cover 56 is provided with a puncture 57 including a small hole or a groove. First flush rainwater temporarily retained will be continuously released and drained off.

Firstly, when there is no enough first flush rainwater in the first flush rainwater compartment 5, the floating tube 53 is resting and the drain hole 51 is uncovered. Rainwater will simply be discharged through the drain hole 51 .

Secondly, when there is sufficient first flush rainwater in the compartment 5, the floating tube 53 rises, with the drain hole 51 covered. This happens particularly when there is a heavy rainfall and the drain hole 51 is unable to discharge all the rainwater fast enough. Any excess rainwater will eventually overflow into the drain compartment 71 leading to a drain pipe 7. Flowever, no rainwater is yet to be collected and stored at this stage. It is important to note that the size of the drain hole 51 is predetermined by design in accordance for different catchment area 13 and local rainfall density. A larger size caters for bigger catchment area 13 and higher rainfall density.

The preferred drain hole 51 is made with a bigger possible diameter, so that it can be adapted with a reducer means for reducing the size if rainfall density is changed in future.

It is also important to note that a sloped cement block 52 is provided to ensure a smooth discharge of rainwater through the drain hole 51.

It is also important to note that a compartment cover 59 covering the first flush activator compartment 5 is perforated. This arrangement helps to reduce the rainwater pressure to cause any instability to the floating tube 53. Retained rainwater will eventually be drained.

Floating arm body compartment 6

As seen in Figures 2 and 7, the first flush activator compartment 5 is in fluid communication with an adjacent floating arm body compartment 6.

The floor of the floating arm body compartment 6 is at a higher elevation position than the floor of the first flush activator compartment 5.

Between the two compartments 5, 6, there is disposed a communication hole 66 which is regulated and manipulated by a specially designed circular time delay wheel 67. The floating arm body 61 is light and floatable. It maybe made with a built-in full size polystyrene cube inside for preventing water seepage/leakage which causes failure of the floating force. The floating arm body 61 is hinged 62 to a vertical wall section near the outlet pipe 8.

When first flush rainwater is slowly released into the floating arm body compartment 6 after the predetermined time delay, the floating arm body 61 will rise. A pushing arm 64 is disposed on its top side furthest from the hinge 62. The pushing arm 64 urges the rainwater diversion tray 4 to tilt towards the outlet pipe 8. This tilted position will technically terminate the first flush function and to initiate clean rainwater storage for recycle use.

When rainwater subsides, the water pressure will also subside and the floating arm body 61 will descend. Retained rainwater will be discharged through a deep valley groove 69 on a floor section nearest the communication hole 66 and eventually off the drain hole 51 . It is important to note that a sloped cement block 52 is employed in the first flush activator compartment 5 to provide a smooth discharge of rainwater ultimately towards the drain hole 51.

It is also important to note that a sloped cement block 691 is employed in the floating arm body compartment 6 to provide a smooth discharge of rainwater ultimately towards the drain hole 51 in the first flush activator compartment 5.

Selectable time delay function

The present invention also teaches how to implement a selectable time delay function to initiate clean rainwater collection.

Figure 8 illustrates a selectable time delay wheel 67 manipulating the rainwater flow rate through the fluid communication hole 66 between the first flush activator compartment 5 and the floating arm body compartment 6.

A first bolt and nut arrangement 63 is employed to pass through an axially central locking hole 671 of the selectable time delay wheel 67, so that the circular wheel 67 is mounted onto the outside wall of the floating arm body compartment 6.

In this embodiment as shown in Figure 8, another bolt and nut arrangement 65 is employed to pass through one selected indication screw hole from four indication screw holes 672a, 672b, 672c, 672d equi-distancedly provided on the imaginary larger circumference of the wheel 67. Diametrically opposite the four indication screw holes 672 on the wheel 67, there are provided correspondingly in pairs four flow rate controlling holes 673a, 673b, 673c, 673d. These controlling holes 673 are of different diameters and are calibrated for different time delays (to fill up the empty space inside the floating arm body compartment 6), and to urge the above mentioned rainwater diversion tray 4 upwards.

In other words, the larger diameter of the controlling hole 673 facilitates a faster rate of filling up and consequently the first flush volume will be lesser. A controlling hole 673 of smaller diameter prolongs the time delay duration and the first flush volume is increased.

Furthermore, all the controlling holes 673a, 673b, 673c, 673d are edge-to-edge in close contact with the fluid communication hole 66, so that rainwater can freely enter or drain out without any blockage. A water-tight medium 68 including a rubber ring seal or gasket can be placed between the wheel 67 and the outside wall of the floating arm body compartment 6.