A fluid channelling device for a modular cascade drainage system

Abstract

A system of modular units 502,504,506,508 attachable to create an inclined cascade drainage channel 500 on a slope, each unit (individually shown in Fig 1), having a floor 502a,504a,506a,508a (112) an

Description

TECHNICAL FIELD One or more embodiments in accordance with the present invention relate to drain units and drainage systems for channelling fluid down an incline. More specifically, the present invention relates to a modular fluid channelling device for a modular drainage system of the cascade type, providing means for controlling the flow capacity and velocity of the fluid being channelled. BACKGROUND Drain pipes are typically used to channel a body of water with the aid of gravity from higher ground to lower ground, for example, down an embankment. Conventional drain pipes are typically made out of concrete material and formed by connecting a series of fixed, shorter-length drain pipe sections to achieve the desired length. Each section may be U-shaped, which can deployed semi-embedded on the ground serving as an open drain system or tubular shaped, that is, a closed drain system suitable for burying underground. When installed, the drainage pipes are set at an incline to enable the body of water to flow in a downward direction influenced by the force of gravity. Typically, the flow capacity / velocity in such conventional drains are predetermined by the profile and dimensions of the drain pipes and the angle of incline when installed. There are generally no means of altering the flow velocity of the water of these drains. As the drain sections are generally made of concrete for durability and to keep cost down, they are heavy to transport and manoeuvre. Aspects and embodiments in accordance with the present invention have been devised with the foregoing in mind. SUMMARY OF THE INVENTION The appended claims may serve to summarize the disclosure. Viewed from a first aspect there is provided a fluid channelling device for forming a modular system used to channel fluid down an incline. The fluid channelling device comprises a floor and an upstanding wall portion extending upwardly when in use from the floor to form a temporary reservoir for the channelled fluid, a region of the upstanding wall having an uppermost edge portion providing a weir for the channelled fluid to exit from the temporary reservoir, wherein the weir is provided with a region of reduced height over which the fluid exits. A further region of the upstanding wall also have an uppermost edge portion over which channelled fluid enters the temporary reservoir. The fliud channeling device also comprise a lip portion extending downwardly when in use from the floor and in the region of the weir. Viewed from a second aspect there is provided a modular system for channelling fluid down an incline comprising two or more said interconnected fluid channelling devices. Advantageously, the fliud channeling device comprises a repeatable modular shape that is readily stackable to form a modular system of a desired length and incline for channelling fliud. Each device is of a weight that is suitable to be easily manhandled, and is designed to be easily interconnected to one another without a need to apply concrete or mortar to connect them together. BRIEF DESCRIPTION OF THE DRAWINGS One or more embodiments in accordance with the invention will now be described, by way of nonlimiting example only, and with reference to the accompanying drawings, in which: FIG. 1 dipicts a perspective view of an illustrative embodiment of the fluid channelling device. FIGs. 2A and 2B illustrates 3D computational fluid dynamics (CFD) model simulation showing results of the flow pattern for the two example embodiments. FIGs. 3A and 3B illustrates a 3D CFD model simulation set-up and associated results performed to determine how varying the height of the side wall height of the fluid channelling device affects the flow capacity of the device. FIG. 4 dipicts a perspective view of another illustrative embodiment of the fluid channelling device. FIG. 5 illustrates a perspective view of an embodiment showing a drainage system comprised of four fluid channelling devices 502, 504, 506, 508 of Fig. 1 interconnected together to form a modular cascade drainage system 500 FIG. 6 is a schematic illustration of how steel bolt 602a, 602,b, 604a, 604b may be configured to fasten several fluid channelling devices together to form a modular cascade drainage system. FIGs.7A and 7B illustrates yet another embodiment including an anchoring arrangement, for example, a U-bolt and pin system or such like. FIG.8 illustrates yet another embodiment that may channel fluid down an incline in an indirect manner, i.e. in one step of the cascade, the fluid may be redirected as necessary around a curved trough. DETAILED DESCRIPTION In the following description, for the purposes of non-limiting explanation only, numerous specific details are set forth to provide a thorough understanding of the present disclosure. In other instances, well-known structures and devices are shown in block diagram form to avoid unnecessarily obscuring the present disclosure. FIG. 1 shows a perspective view of a fluid channelling device 100 in accordance with one embodiment of the present invention. It should also be understood that the fluid may be water, chemically treated water, liquid chemicals, or any other liquid suitable for conduction by the fluid channelling device of the present invention. In the illustrative embodiment in Fig. 1, the fluid channelling device comprises a floor 112 that is substantially rectangular in shape. In use, the floor is positioned substantially planar with reference to the ground. Advantageously having a floor that is substantially planar with the ground (i.e. the floor is sloped at a zero-angle with respect to the ground) may simplify installation of the device and also minimizes or prevents over-topping (i.e. when the channelled fluid plunges and lands further away from the weir at the end of each cascade module), which can cause the flow of the channelled fluid to be less turbulent and at the same time increase flow capacity. Advantageously, by reducing or preventing over-topping of the channelled fluid, the manner in which the channelled fluid flows through the device 100 may be better regulated. In another embodiment, the floor may be sloped at an angle with respect to the ground. In other embodiments, the shape of the floor 112 may be square, circular or any other shape suitable for deployment. In order to evaluate the peak flow capacity achieved by the various embodiments, modelling of the flow capacity of different fluid channelling devices was performed based on 3D computational fluid dynamics (CFD) simulation models. In one analysis, the performance of a fluid channelling device 100 having a zero-degree gradient on each step of the cascade (i.e. floor being substantially planar with the ground) is compared to an identical device, but having a five-degree gradient on each step of the cascade (i.e. a sloped floor). The 3D CFD modelling results indicate that the fluid channelling device 100 with a zero-degree grade may yield a higher flow capacity compared to a cascade device with a five-degree grade / slope. The reason this occurs is that, in the latter cascade device, the water plunges and lands further away from the weir at the end of each cascade module, which may result in lower water levels over and immediately downstream of the weirs. Over-topping occurs in both embodiments. However, this effect is higher with the five-degree slope embodiment. This is shown in the 3D CFD model simulation results of the flow pattern for the two example embodiments in Figs. 2A and 2B. In the embodiment in Fig. 1, a side wall extends substantially upwardly from or close to the periphery edge of each side of the rectangular floor, thereby creating a temporary reservoir for housing fluid being channelled through the device. In one embodiment, the side walls 110a, 104a extend upwardly from the floor at an angle with respect to the floor such that the side walls lean away from the centre of the temporary reservoir. In another embodiment, the side walls 110a, 104a may extend upwardly substantially vertically. In yet another embodiment, a surface of the side walls 110a, 104a may have a curved profile. On a first side wall 106a of the device 100 in Fig. 1, there is a first uppermost edge portion 106 which provides a weir for channelled fluid collected within the temporary reservoir to overflow and exit the device. On the first uppermost edge portion that serves as the weir, there is a region of reduced height 116 over which some of the channelled fluid stored in the temporary reservoir exits. In the embodiment in Fig. 1, this region of reduced height 116 is substantially "V" shaped. In one or more embodiments, this region of reduced height 116 may be "U" shaped, rectangular or square shaped, or any suitable shape to allow the flow capacity / velocity of the channelled fluid to be controlled or regulated. The first side wall 106a may be of any suitable height necessary to create the temporary enclosure. By varying the dimensions of one or more of the side walls 110a, 104a, 106a, floor 112 and the profile of the region of reduced height, advantageously the flow capacity / velocity of the channelled fluid may be controlled and reduced as desired. For example, increasing the height of the side walls 110a, 104a, 106a has the effect of increasing the fluid flow capacity. 3D CFD modelling was also performed to determine how varying the height of the side wall height of the fluid channelling device 100 affects the flow capacity of the device. Simulation results in Figs. 3A and 3B indicate that there is a direct correlation between increasing the height of the side wall and an increase in the flow capacity of the device. Fig. 3B is a 3D CFD model with increased side wall height. An extended range of flows was modelled, and the water surface associated with each was recorded and plotted, as shown in Fig. 3A. The model assumed a uniform sidewall height. In the example, the height was set to contain a 118 litre per second flow rate, which is 85cm of side wall height above the base level. 118 litres per second is a function of the inflow water level and is not an intentional peak flow value. In the illustrative embodiment in Fig. 1, a second side wall 104a, 110a located perpendicular to and at or close to each end of the first side wall 106a has a right trapezoid shape. In the embodiment, the second side wall 104a, 110a having the longest side edge 404c, 410c abuts the side edge of a third side wall 102a. The second side wall has a second uppermost edge portion where the minimum height of the second uppermost portion is higher than the maximum height of the first uppermost edge with respect to the floor. In one or more embodiments, the second side wall 104a, 110a can be of any suitable shape and the second uppermost edge region could be of any suitable height. Advantageously, the choice of shape / height of the second side wall 104a, 110a helps to define the volume of the temporary reservoir. By controlling how much of the channelled fluid can be temporarily stored in the reservoir and when and how the fluid should exit the weir, the flow capacity / velocity of the channelled fluid can be controlled / reduced as desired. For example, the changing the volume of the temporary reservoir may change the amount of energy that can be extracted from the channelled fluid which may in turn alters the velocity of the fluid. In the embodiment in Fig. 1, a third side wall 102a directly opposing the first side wall 106a has a third uppermost edge portion 102. In this embodiment, an edge portion 102 extends in a perpendicular direction from the entire length of the third uppermost edge region in a direction away from the temporary reservoir, forming a lip portion 102b. The edge portion 102 may be of any suitable length. In one embodiment the third uppermost edge portion 102 does not comprise a lip portion 102b. In another embodiment, the edge portion does not extend from the entire length of the third uppermost edge region. In yet another embodiment, there may be two separate edge portions 102 extending from the third uppermost edge region. Advantageously, the edge portion 102 helps to prevent undermining. Undermining is a process where fluid at velocity begins to spin as a result of turbulence, if the lip was not present the fluid would erode the underlying soil, which would cause instability. In the embodiment in Fig. 1, a lip portion 108 extends downwardly from underneath the floor along the entire edge of the floor where the first side wall 106a is located. The purpose of the lip portion 108 is to allow adjustment of the horizontal positioning of the cascade devices and to prevent undermining. Undermining is an undesired effect where the channelled fluid overflows the fluid channelling device such that one or more flows develop outside of the intended fluid channelling path of the device. This can happen when the fluid flow volume and velocity to be channelled is unusually high and rapidly fill up and overflow the temporary reservoir. When this occurs, the overflowing fluid can seep into and erode the undersoil (bedding material) upon which the device sits thereby weakening its ability to structurally support the device. The lip portion 108 may serve to prevent undermining by shielding the soil (bedding material) providing structural support for the device from erosion when overflow occurs. During operation, the fluid being channelled should not come into direct contact with the underlying soil (bedding material) providing structural support to the modular cascade drain system at all times. In one or more embodiment 400 in Fig. 4, on a surface of the second side wall 404a, 410a facing away from the temporary reservoir, a fin 418a, 418b extends outwardly and substantially perpendicular to the surface. In embodiment 400, the fin 418a has a rectangular profile extending from a bottom edge of the second side wall to the second upper most edge. In this example embodiment, the second side wall comprises two fins 418a, 418b. In another embodiment, the second side wall 404a, 410a may comprise any suitable number of fins 418a, 418b extending from the surface of the second side wall facing away from the temporary reservoir. The fins may extend in any orientation and may have any suitable profile. The purpose of the fins 418a, 418b is to provide structural integrity for the side walls. The fins are optional features. Preferably larger embodiments where the side walls are larger may include fins for improved structural integrity. The fins 418a, 418b may be made of the same material as the sidewall or any suitable material. In one or more embodiments, matting for preventing erosion can be applied to an exterior surface of the fluid channelling device that comes into direct contact with the undersoil supporting the device when deployed. The matting prevents the undersoil from being eroded away thereby weakening the structural integrity of the device and can be made of any suitable material. Any suitable material may be used for the matting, including materials comprising bio-degradable and non-flammable materials. The fluid channelling device 100 in FIG. 1 is a singular device that may be interconnected with one or more identical devices to form a modular cascade drainage system of varying length. Fig. 5 illustrates a perspective view of an embodiment showing a drainage system comprised of four fluid channelling devices 502, 504, 506, 508 of Fig. 1 interconnected together to form a modular cascade drainage system 500. In the illustrative embodiment 500 in Fig 5, a first fluid channelling device 502 is located at the top of an incline, in this example, an embankment. The floor 502a of the first fluid channelling device 502 is substantially horizonal, that is, at 0% gradient with respect to the flat ground at the base of the embankment. The first fluid channelling device 502 is positioned such that a surface of the first side wall facing away from the temporary reservoir of the first fluid channelling device is pointing in a direction directly opposite to the incline. A second fluid channelling device 504 is positioned on the incline directly in front of the first fluid channelling device such that the floor 504a of the second fluid channelling device 504 is substantially horizontal with respect to the ground and at an altitude lower than the first fluid channelling device 502. In embodiment 500 in Fig. 5, the lip portion 502b of the first fluid channelling device 502 is arranged to extend into the temporary reservoir of the second fluid channelling device 504, such that the surface of the lip portion facing directly opposite to the incline (not shown in Fig. 5) is abutting or in close proximity to a surface of the third side wall of the second fluid channelling device 504 facing the direction of the incline. Following the above interconnection configuration, subsequent fluid channelling devices are added, extending downwards along the entire length the incline, thereby creating a continuous path to channel fluid from the top of the incline to the bottom of the incline in a controlled manner. In the embodiment in Fig. 5, during operation, fluid first enters the first fluid channelling device by flowing over the third uppermost edge region of the third side wall into the temporary reservoir of the first device. The level of fluid within the temporary reservoir begins rising. Once the fluid level reaches the height of the second uppermost edge region of the second side wall, further fluid entering the temporary reservoir causes fluid to overflow the second uppermost edge region, which acts as a weir. The fluid exiting the first fluid channelling device flows is directed into and begins filling up the temporary reservoir of the second fluid channelling device. The cascade or "stepped" design of the embodiment in Fig. 5 helps to dissipate energy in the channelled fluid by aerating the flow as it flows down the drainage system causing small particles in the water to be held in suspension. The weir effect created by the region of reduced height helps to reduce the flow's velocity and the build-up of silt. In the example embodiment in Fig. 5, the interconnected fluid channelling devices may be secured together to form the modular cascade drainage system 500 in several ways using fastening arrangements well known in the art. Such fastening arrangements may include, for example, a HDPE peg system, a steel bolt and pin assembly or such like. In an embodiment as shown in Fig. 6, the steel bolt 602a, 602,b, 604a, 604b may be configured to fasten the units together and also hold the pin assembly 602, 604 in place. The modular cascade drainage system example in Fig 2 may be anchored into the ground in a number of ways using anchoring arrangements that are well known in the art. Such an anchoring arrangement may include, for example, a U-bolt and pin system or such like as shown in Figs 7A and 7B. In an embodiment, the fluid channelling device may comprise of a composite material, for example G-Plast™ composite material. G-Plast™ is a composite material comprising glass reinforced fibre. Advantageously, by using G-Plast™ composite material, the fluid channelling device achieves good strength, weathering, abrasion and life expectancy characteristics. The flexibility of the G-Plast™ material enables the design and manufacture of lightweight but strong fluid channelling devices to specific dimensions. The fluid channelling device may also comprise of any suitable lightweight composite material such as glass fibre that can impart the above desired characteristics. The fluid channelling device in accordance with the present invention may be utilized to create a modular cascade drainage systems for use any suitable inclined surface such as an embankment, or the like to channel fluid in a controlled fashion. In one or more embodiments, the fluid channelling device may channel fluid down an incline in an indirect manner, i.e. in one step of the cascade, the fluid may be redirected as necessary around a curved trough as per feature 802 in embodiment 800 in Fig. 8. This feature is particularly useful for negotiating an embankment having an uneven or unusual contour or to go around existing obstacles e.g. trees, or existing structures. As used herein any reference to "one disclosure" or "a disclosure" means that a particular element, feature, structure, or characteristic described in connection with the disclosure is included in at least one disclosure. The appearances of the phrase "in one disclosure" or the phrase "in an disclosure" in various places in the specification are not necessarily all referring to the same disclosure. As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). In addition, use of the "a" or "an" are employed to describe elements and components of the disclosure. This is done merely for convenience and to give a general sense of the disclosure. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise. Various modifications may be made within the scope of the disclosure. The scope of the present disclosure includes any novel feature or combination of features disclosed therein either explicitly or implicitly or any generalisation thereof irrespective of whether or not it relates to the claimed subject matter or mitigates against any or all of the issues addressed by the present disclosure. The applicant hereby gives notice that new claims may be formulated to such features during prosecution of this application or of any such further application derived therefrom. In particular, with reference to the appended claims, features from dependent claims may be combined with those of the independent claims and features from respective independent claims may be combined in any appropriate manner and not merely in specific combinations enumerated in the claims.

Claims

1. A fluid channelling device for forming a modular system used to channel fluid down an incline, the fluid channelling device comprising:a floor and an upstanding wall portion extending upwardly when in use from the floor to form a temporary reservoir for the channelled fluid;a region of the upstanding wall having an uppermost edge portion providing a weir for the channelled fluid to exit from the temporary reservoir, wherein the weir is provided with a region of reduced height over which the fluid exits;a further region of the upstanding wall having an uppermost edge portion over which channelled fluid enters the temporary reservoir; anda lip portion extending downwardly when in use from the floor and in the region of the weir.

2. The fluid channelling device of claim 1, further configured such that an inwardly facing surface of the region of the upstanding wall having the uppermost edge portion is in a direction opposing an inwardly facing surface of the further region of the upstanding wall having the uppermost edge portion.

3. The fluid channelling device of any preceding claim, wherein the uppermost edge portion of the further region of the upstanding wall comprises a lip that extends in a direction away from the temporary reservoir of the fluid channelling device.

4. The fluid channelling device of any preceding claim, configurable to be interconnected with another fluid channelling device in a cascade arrangement, such that when attached, the temporary reservoir of the fluid channelling device is at an elevated position with respect to the temporary reservoir of the other fluid channelling device such that in use, fluid can be channelled from the uppermost edge portion of the region of upstanding wall of the fluid channelling device into the temporary reservoir of the other fluid channelling device.

5. The fluid channelling device of claim 4, wherein in the cascade arrangement, the lip portion of the fluid channelling device extends into the temporary reservoir of the other fluid channelling device.

6. The fluid channelling device of any preceding claim, wherein the device is formed of a composite material comprising glass fibre.

7. The fluid channelling device of any preceding claim, wherein the floor is rectangular in shape and the upstanding wall comprises a front wall a back wall and two parallel side walls, wherein each wall extending upwardly from or close to the edge of a side of the floor.

8. The fluid channelling device of any preceding claim, wherein the floor has a gradient of between 0 and 35% gradient.

9. The fluid channelling device of any preceding claim, wherein the region of reduced height has symmetrical geometry.

10. The fluid channelling device of claim 9, wherein the region of reduced height has a rectilinear shape.

11. The fluid channelling device of claim 10, wherein the region of reduced height has a "V" shaped profile.

12. The fluid channelling device of claim 10, wherein the region of reduced height has a "U" shaped profile.

13. The fluid channelling device of claim 10, wherein the region of reduced height has a "Y" shaped profile.

14. The fluid channelling device of claim 10, wherein the region of reduced height has a "V" shaped profile.

15. The fluid channelling device of claims 7 to 14 wherein when in use, each of the parallel sidewalls extends from the floor at an angle such that the side wall leans away from the centre of the floor.

16. The fluid channelling device of claim 15, wherein one of the parallel side walls further comprises means for securing the device onto the ground.

17. The fluid channelling device of claim 16, wherein the means for securing the device onto the ground is a securing a u-bolt installed on a surface of one of the parallel side walls facing away from the temporary reservoir to receive a pin.

18. The fluid channelling device of any claims 7 to 17, wherein a surface of the parallel side wall facing away from the temporary reservoir comprises a fin extending outwardly, wherein the fin is substantially perpendicular to the surface.

19. A modular system for channel fluid down an incline comprising two or more interconnected fluid channelling devices of claims 1 to 18.

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