WO2024018274A1

WO2024018274A1 - Fluid flow arrangement

Info

Publication number: WO2024018274A1
Application number: PCT/IB2022/061570
Authority: WO
Inventors: Hendrik Eduard GRUNDLINGH; Johannes Jacobus STRIJDOM
Original assignee: Airaqau (Pty) Ltd
Priority date: 2022-07-22
Filing date: 2022-11-30
Publication date: 2024-01-25

Abstract

A fluid flow arrangement (10) typically used in water distribution, flow regulation, and water saving applications. The arrangement comprises an internal chamber (12) which is provided in fluid flow communication with a first inlet (16) which is associated with a first fluid, and with a second inlet (18) which is associated with a second fluid. The internal chamber (12) furthermore has an outlet (20) from the internal chamber (12). The first inlet (16) is configured to direct a flow, stream or jet (130) of the first fluid through the internal chamber (12) in a direction towards the outlet (20). The configuration is furthermore such that the flow (130) of the first fluid remains substantially laminar for at least a predetermined distance (134) downstream of the first inlet (16). Typically, the substantially laminar flow of first fluid is at least partially surrounded or submerged by the second fluid.

Description

FLUID FLOW ARRANGEMENT

BACKGROUND TO THE INVENTION

This invention relates to a fluid flow arrangement. More particularly, the present invention relates to water flow arrangement, used during water distribution, for flow regulation, and for water saving applications.

Household water usage and wastage have, of late, become a major concern, with calls for the implementation of water saving strategies coming from various spheres. Some household areas, such as showers, are particularly uneconomical, with water flow rates of up to 25 litres per minute being the norm. Some known water saving systems simply reduce the water flow rate or closes off water flow during different stages of use. However, these systems often result in compromised experience, resulting in low levels of implementation. A need has been identified to reduce water usage by reducing a flow rate of water, whilst, at least substantially, replicating a user experience associated with a higher or “normal” flow rate of water.

Another function associated with the flow of water, relates to the aeration of water, or the introduction of substances to a flow of water. Aeration of water (such as during wastewater treatment) is associated with an introduction of oxygen into the water. Typically, water is aerated by large volumes of air pumped through the water. This is typically associated with high energy expenditure.

A venturi is a known flow arrangement used for introducing air, or other substances into a flow of fluid. A venturi comprises a constriction in a fluid flow path, which is associated with an increased flow velocity and decreased fluid pressure. An inlet provided directly into the constricted area (low pressure zone) facilitates suction of a substance into the stream of fluid.

Venturis are often associated with high flow velocities and energy expenditure associated with or caused by the constriction and resulting pressure differential.

A need has also been identified for an apparatus capable of efficiently introducing a substance into a flow of a fluid. It is believed that efficient introduction of a substance, such as air, other gases, water, or other liquids into a stream of fluid could improve various flow-related functions and applications.

It is accordingly an object of the invention to provide fluid flow arrangement that will, at least partially, address the above disadvantages of current flow arrangements.

It is also an object of the invention to provide a fluid flow arrangement which will be a useful alternative to existing arrangements, and which may provide improved efficiency, water saving, energy expenditure and the like. SUMMARY OF THE INVENTION

In accordance with a first aspect of the invention there is provided a fluid flow arrangement, comprising: an internal chamber; a first inlet into the internal chamber associated with a first fluid; a second inlet into the internal chamber associated with a second fluid; and an outlet from the internal chamber, wherein the first inlet is configured operatively to direct a flow of the first fluid through the internal chamber in a direction towards the outlet and wherein the arrangement is such that the flow of the first fluid is substantially laminar for at least a predetermined distance downstream of the first inlet.

The internal chamber comprises a combining or mixing chamber, which may comprise an enlarged chamber. An internal dimension (such as diameter) of the internal chamber may exceed an internal dimension (such as diameter) of the first inlet. At least for a portion along the predetermined distance, the flow of the first fluid may at least partially be surrounded by or submerged in the second fluid.

In some cases, the first inlet and the outlet may be substantially arranged in-line.

The first inlet and the outlet may both be provided in direct fluid flow communication with the internal chamber and may be spaced from each other by a first spacing distance. The spacing distance may have a length in a range of about a value of a diameter of the first inlet, to about double the value of the diameter of the first inlet. More particularly, the first spacing distance may define an unguided flow space. Operative interaction between the first and second fluids within the unguided flow space may cause the second fluid to flow through the second inlet and towards the outlet.

The first inlet may be configured for directing the flow of the first fluid into the internal chamber. At least a substantial portion of the first fluid flows from the internal chamber through the outlet.

A size of the first inlet may be smaller than a size of the outlet.

The first inlet may have relatively smooth or polished inner surfaces to facilitate substantially laminar flow of the first fluid for at least the predetermined distance downstream thereof.

The second opening may be situated above the first inlet and the outlet.

A ratio of diameters of the first inlet and outlet may be about 0.5:1 . A diameter of the first inlet may be in the range of 0.1 mm to 3000 mm. A diameter of the outlet may be in the range of 0.2 mm to 6000 mm. A diameter of the second inlet may be in the range of 0.2 mm to 1000 mm. A length of an outlet duct associated with the outlet may at least be double a value of a diameter of the first inlet.

Further according to the first aspect of the invention, the arrangement may comprise a first inlet duct having a first opening which defines the first inlet. The first opening may be situated within the internal chamber.

The first opening may be configured as a nozzle.

The first inlet duct may comprise a substantially cylindrical tube extending into the internal chamber, or alternatively, may comprise a converging or cone-shaped duct extending into the inlet chamber.

The arrangement may further comprise a partitioning arrangement provided in an outlet portion of the internal chamber, the partitioning arrangement configured as a backflow arrestor.

The arrangement may further comprise an outlet duct with an outlet opening defining the outlet, the outlet opening situated within the internal chamber. The outlet duct may have a predetermined diameter and length such that the predetermined distance for which the flow of the first fluid is substantially laminar terminates within, or towards an end of, the outlet duct. The outlet duct may have a relatively smooth or polished internal surface finish.

The second inlet may be provided with a flow regulator, such as a directional flow regulator, a valve, a one-way valve, or a vacuum breaker.

The internal chamber may be defined by a main body, manufactured from a plastics material, such as PVC, HDPE, or UHMWPE, or from a metal, such as steel, stainless steel, aluminium, or brass.

Further in accordance with the first aspect of the invention, and in accordance with a first use example, the arrangement may specifically be configured as a shower fitting and wherein:

- the first inlet is configured operatively to be provided in fluid flow communication with a shower feed pipe; and

- the outlet is configured operatively to be provided in fluid flow communication with a showerhead.

According to the first use example, the second inlet may be configured as an air intake. In use, water and air may be combined into an aerated mixture before being expelled through the showerhead. The first inlet may now be associated with a threaded pipe connection in the form of a socket or nipple, operatively to facilitate connection to the shower feed pipe.

The outlet may be associated with a threaded pipe connection in the form of a socket or nipple, operatively to facilitate connection to a distribution pipe or the showerhead.

The arrangement according to the first use example may be configured as part of a showerhead arrangement, and a main body of the arrangement may be configured for directly coupling to a showerhead. The main body may comprise a substantially spherical formation for receiving a showerhead in pivoting or swivelling fashion.

The first inlet may have a diameter in the range of about 2mm to about 4.5mm, while the second inlet may have a diameter in the range of about 1.5mm to about 3mm. The outlet may have a diameter in the range of about 3mm to about 6mm. The second inlet may be provided in fluid flow communication with the internal chamber in close proximity to the first inlet. A spacing distance between the first inlet and the outlet is in the range of about 25mm to about 30mm in length.

A main body of the arrangement may be integrally formed with a showerhead.

Further in accordance with the first aspect of the invention, and in accordance with a second use example, the arrangement may comprise a main body in the form of a vertically extending conduit with an open end facing upwards. The first inlet duct may extend through a sidewall of the conduit and into the internal cavity. An outlet duct may be arranged in-line with and across from the inlet pipe such that a spacing distance is defined between ends of the inlet and outlet ducts and wherein the outlet duct extends through the side wall of the main body.

The first inlet may operatively be provided in fluid flow communication with a return jet of a swimming pool. The conduit may be manufactured from a plastics material. The conduit may at least partially be submerged in a body of water, in use. At least a portion of the conduit, or an extension fitted thereto, may extend above a surface of the body of water in use. In cases where an extension is fitted to the conduit, same may comprise a flow regulator in the form of a strainer or agitator. The flow regulator may comprises one or more flaps, tabs or baffles provided for stirring water flowing into the second inlet, or for directing water flowing into the second inlet.

The second opening may be defined towards the upward facing open end. The second opening may operatively be provided in fluid flow communication with the body of water and an outside air environment or atmosphere, such that fluid entering the internal chamber may comprise a combination of water from the body of water, and air from the atmosphere.

A filter may be provided within the main body, or proximate the second inlet.

The first inlet may have a diameter of about 25 mm, the second inlet may have a diameter of about 110 mm and the outlet may have a diameter of about 50 mm. The first spacing distance may be about 25 mm and a length of the outlet duct may be between 105 mm and 200 mm.

In accordance with a second aspect of the invention, there is provided a shower installation, comprising:

- a feed pipe provided in communication with a water supply;

- a fluid flow arrangement according to the first aspect of the invention, wherein the feed pipe is connected to, and provided in flow communication with, a first inlet of the fluid flow arrangement; and - a shower head provided in fluid flow communication with an outlet of the fluid flow arrangement.

The shower installation may furthermore comprise a hot water source and a mixer. The hot water source may be of a geyser, heat pump, in-line water or ring-feed system. The feed pipe may further be connected to a source of cold water.

In accordance with a third aspect of the invention, there is provided a water circulation assembly of a body of water, comprising:

- a water outlet jet; and

- a fluid flow arrangement in accordance with the first aspect of the invention, wherein the water outlet jet is connected to, and provided in flow communication with, a first inlet of the fluid flow arrangement.

The water circulation assembly may further comprise a flow regulator, including at least one flow directing flap, tab or baffle which may extend relative to a second inlet of the fluid flow arrangement, and which operatively extend, at least partially, above a water level of the body of water.

The water circulation assembly may furthermore include a filter which is provided relative to the second inlet or within a main body of the fluid flow arrangement.

In accordance with a fourth aspect of the invention, there is provided a method of combining a first and second fluid, the method comprising the steps of:

- providing a fluid flow arrangement in accordance with the first aspect of the invention, the fluid flow arrangement comprising a first inlet, second inlet, an internal chamber and an outlet;

- providing a first stream of the first fluid through the first inlet and towards the outlet such that the first stream flows substantially laminarly for at least a predetermined distance downstream of the first inlet;

- providing a second fluid which, at least partially, surrounds or submerges the first stream thereby to interact with the first stream, causing the second fluid to be drawn into the internal chamber through the second inlet;

- causing the first and second fluids to combine within the internal chamber; and

- expelling the combined first and second fluids through the outlet.

The first fluid may typically comprise a liquid such as water and the second fluid may typically comprise a liquid such as water, a gas such as air, or a mixture thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

Figure 1 shows a schematic sectioned side view of a first example embodiment of a fluid flow arrangement in accordance with the invention; Figure 2 shows a schematic sectioned side view of a second example embodiment of a fluid flow arrangement in accordance with the invention;

Figure 3 shows a schematic sectioned side view of a third example embodiment of a fluid flow arrangement in accordance with the invention, in use, to show fluids operatively flowing through the arrangement;

Figure 4 shows a perspective view of a fluid flow arrangement in accordance with the invention, taking the form of a shower fitting;

Figure 5 shows a sectioned side view of a first example embodiment of the shower fitting of figure 4;

Figure 6 shows a sectioned side view of a second example embodiment of the shower fitting of figure 4;

Figure 7 shows a schematic side view of a shower, including the shower fitting of Figure 4;

Figures 8 and 9 show sectioned side views of further example embodiments of the shower fitting of figure 4;

Figure 10 shows a schematic side view of an alternative shower arrangement, including the shower fitting of Figure 4 and a water circulation arrangement;

Figures 11 and 12 show perspective views of further example embodiments of the shower fitting of figure 4;

Figure 13 shows a sectioned side view of the embodiment of the shower fitting of figure 11 ;

Figures 14 to 19 show various alternative example embodiments of the shower fitting of figure 4; Figure 20 shows a schematic sectioned view of an agricultural mixing apparatus, making use of the fluid flow arrangement according to the invention;

Figure 21 shows a perspective view of a fluid flow arrangement in accordance with the invention, taking the form of a swimming pool fitting;

Figure 22 shows a sectioned side view of the swimming pool fitting of Figure 21 ;

Figure 23 shows a perspective view of an assembly including the swimming pool fitting of Figure 21 and a flow regulator;

Figure 24 shows a side view of the assembly of Figure 23;

Figure 25 shows a sectioned side view of the assembly of Figure 23;

Figure 26 shows an exploded perspective view of the assembly of Figure 23;

Figure 27 shows a perspective view of the assembly of Figure 23, installed in a swimming pool, in use;

Figure 28 shows an exploded side view of an alternative embodiment of the swimming pool fitting of Figure 23;

Figure 29 shows an assembled side view of the swimming pool fitting of Figure 28; Figure 30 shows an assembled side view of the swimming pool fitting of Figure 28, including further hardware;

Figure 31 shows a side view of yet a further example embodiment of the swimming pool fitting of Figure 23; and

Figure 32 shows an assembly including the swimming pool fitting shown in Figure 31 .

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms "mounted", "connected", "engaged" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings and are thus intended to include direct connections between two members without any other members interposed therebetween and indirect connections between members in which one or more other members are interposed therebetween. Further, "connected" and "engaged" are not restricted to physical or mechanical connections or couplings. Additionally, the words "lower", "upper", "upward", "down" and "downward" designate directions in the drawings to which reference is made. The terminology includes the words specifically mentioned above, derivatives thereof, and words or similar import. It is noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the," and any singular use of any word, include plural referents unless expressly and unequivocally limited to one referent. As used herein, the term “include” and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items.

Referring to the drawings, in which like numerals indicate like features, a non-limiting example of a fluid flow arrangement (or simply “arrangement” for brevity) in accordance with the invention is generally indicated by reference numeral 10. It will be appreciated that the arrangement 10 may take the form of a fitting or an integral part of a larger apparatus or system. Even though various example embodiments and applications of the arrangement 10 are discussed herein, it will be appreciated that the arrangement 10 has further applications and its application is not limited to the examples provided. Reference is first made to figures 1 to 3 in which the arrangement 10 is shown schematically. Generally, the arrangement 10 comprises an internal chamber 12 which is defined by a main body 14. The arrangement comprises a first inlet 16 into the internal chamber 12, a second inlet 18 into the internal chamber 12, and an outlet 20 from the internal chamber.

The first inlet 16 is typically provided in fluid flow communication with a source of a first fluid (not shown in figures 1 to 3). The arrangement 10, and more particularly the first inlet 16, is configured to direct a jet, flow, or stream (indicated schematically by reference numeral 130 in figure 3) of the first fluid into and/or through the internal chamber 12, and in a direction of the outlet 20. The flow direction of the first fluid through the internal chamber 12 is shown by reference numeral 22 in figure 1 and 3.

The second inlet 18 is provided in fluid flow communication with a source of a second fluid. It will be appreciated, in some examples, that the first and second fluids may be of a similar nature and may even be from the same source. However, in some examples the first and second fluids may be from different sources or may be different fluids and from different sources. In the latter case, the internal chamber 12 may take the form of a combining or mixing chamber where the first and second fluids from the first inlet 16 and second inlet 18 combine (at least to a degree), before exiting the outlet 20. As is discussed below, such combining taking place within the internal chamber 12 is not necessarily associated with turbulence or thorough mixing resulting in a uniform composition of fluid flowing through the outlet. As discussed more fully below, to a large degree, the stream or jet of fluid from the first inlet remains substantially laminar for a predetermined length towards or even beyond the outlet (in other words, downstream from the first inlet). Furthermore, as will be discussed in more detail below, the second fluid is sucked or pulled into the internal chamber 12 through the second inlet 18, by reason of fluid dynamics and the shape, configuration, and relative dimensions of the internal chamber 12, the first inlet 16 and the outlet 20.

In some embodiments, the internal chamber 12 comprises an expanded or enlarged chamber, when compared to at least some of the sizes of the first inlet 16 and the outlet 20. Specifically, the inlet chamber has a cross-sectional dimension (typically, a diameter) which exceeds a cross-sectional dimension of the first inlet. In this regard, the internal chamber 12 can immediately be distinguished and differentiated from a throat portion of a venturi arrangement. It will also be appreciated that the second inlet is not located within such a throat portion which would typically be associated with a venturi arrangement.

The first inlet 16 and outlet 20 may typically be arranged in line, and in direct fluid flow communication with the internal chamber. However, in some cases, the outlet may be provided downstream of the first inlet and need not be provided strictly in line therewith. However, as discussed more fully below, fluid flow development of the jet or stream 130 of the first fluid dictates the shape, configuration and dimensions of the internal chamber 12, the outlet 20 and the like.

The first inlet 16 and the outlet 20 are spaced apart from each other by a spacing distance 24. Therefore, fluid flowing through the first inlet 16, flows freely through the internal chamber 12, at least along the spacing distance 24 before reaching the outlet 20. The arrangement of the internal chamber 12, the first inlet 16, the spacing distance 24 and the outlet is such that the stream of the first fluid flowing through the internal chamber 12 remains substantially laminar for at least a predetermined distance downstream of the first inlet or following introduction into the internal chamber 12. At least a substantial portion of the jet or stream of the first fluid flows towards and through the outlet 20.

Typically, the diameter or size of the first inlet 16 is smaller than the diameter or size of the outlet 20. The ratio of the sizes of the first inlet 16 and the outlet 20 is determined by, amongst others, the size of the spacing distance 24, flow velocities through the internal chamber, the type of the first fluid, and the like.

Typically, the ratio of the size of the first inlet to that of the outlet, is 0.5:1. The actual dimensions of the inlets and outlet are selected based on the specific application, the flow rates of fluids through the apparatus, the density and viscosity of the fluids, and the like. Typically, the diameter of the first inlet may be between 0.1 mm and 3000 mm. The diameter of the outlet may be between 0.2 mm and 6000 mm. The diameter of the second inlet may be between 0.2 mm and 1000 mm.

In some cases, especially when the second fluid is a gas, or more particularly, air, the second inlet 18 is situated towards a top or upper portion 26 of the internal chamber 12, and therefore higher than or above a level of the first inlet 16 and the outlet 20.

In some embodiments, the first inlet 16 is defined by a first inlet duct 28 which extends at least partially into the inlet chamber 12. A length of the first inlet duct 28 is shown by reference numeral 30. Again, the length 30 plays an important role in the fluid dynamics of the arrangement 10, and is selected based on among other things, the diameter or size of the first inlet 16, the diameter or size of the outlet 20, and the spacing distance 24.

The first inlet 16 may therefore take the form of a nozzle, a blow opening, or a blowhole formed at an end of the first inlet duct 28. Again, the particular characteristics of the nozzle, blow opening or blowhole will have an impact on the flow within the internal chamber 12. As shown in figure 1 , in some examples, the first inlet duct 28 takes the form of a cone-shaped duct which converges towards the first inlet 16. It will be appreciated that a first inlet duct 28 having a conical shape causes the stream or jet of the first fluid to accelerate before entering the internal chamber 12 through the first inlet 16. As shown in figure 2, on the other hand, the first inlet duct 28 may alternatively be a substantially cylindrical tube extending into the internal chamber 12.

As shown in figure 3, the first inlet 16 does not have to comprise a first inlet duct 28. Here, an inlet chamber 32 is defined towards an inlet side 34 of the main body 14 and separated from the internal chamber 12 by means of an inlet partition 36 which defines the first inlet 16.

In some cases, such as shown in figures 2 and 3, the outlet 20 may be defined by an outlet duct 38, which again may typically take the form of a substantially cylindrical duct or a conical duct (not shown) which diverges in the flow direction 22.

An outlet partition 40 may be provided towards an outlet portion 42 of the main body 14 and may separate the internal chamber 12 from an outlet chamber 44. The outlet partition 40 serves the purpose of a “backflow” arrestor, which is provided for at least substantially inhibiting fluid flow from the outlet chamber 44 back towards the internal chamber 12.

The second inlet 18 may be provided with a flow regulator 46 which may take various forms. For example, in some cases the flow regulator 46 takes the form of a one-way valve or a vacuum breaker. These may be provided to inhibit fluids from flowing from the internal chamber 12 towards and through the second inlet 18. This may typically occur when the arrangement 10 is implemented as part of a water reticulation system, and in cases when flow through the outlet 20 is inhibited. In other examples, such as when the arrangement 10 is provided as part of a swimming pool water circulation system, the flow regulator at 46 may take the form of a strainer and may be provided for agitating or stirring water entering through the second inlet 18. More is said about this below.

In use, the internal chamber 12 may at least partially be filled with the second fluid, and in some cases the first inlet 16 and the outlet 20 may be completely submerged by the second fluid within the internal chamber 12. In fact, at least during an initial portion 132 after the stream or jet 130 has entered the internal chamber, the first fluid flowing through the internal chamber 12 is largely, if not completely, surrounded by the second fluid in use. The first fluid therefore passes through the internal chamber 12 but does not fill the internal chamber completely.

Importantly, the configuration is such that the stream or jet 130 remains substantially laminar for a predetermined distance (shown schematically in figure 3 by numeral 134) following introduction into the internal chamber 12 through the first inlet 16. In some cases, such as the schematic embodiment of figure 1 , the predetermined distance 134 may be shorter than or equal to the spacing distance 24. In other cases, such as the example shown schematically in figure 3, the predetermined distance 134 exceeds the spacing distance 24. Typically, in such cases, an outlet duct 38 is provided and the length of the outlet duct 38 is such that the predetermined distance 134 terminates within the outlet duct 38 or towards or at an end 136 of the outlet duct 38. The diameter and length of the internal chamber 12 or of the outlet duct 38 (as the case may be depending on the configuration as discussed above) are important. For example, with reference to figure 3, within the laminar flow portion of the jet 130, the outlet duct serves as a guide or constriction to inhibit dispersion of the stream 130, thereby assisting in keeping the flow (and the flow upstream) laminar. However, if the length of the outlet duct 38 exceeds a critical length, internal friction between the outlet duct 38 and the stream 130 will cause the flow to become turbulent (this may, in turn, interfere with the development of the stream 130 in upstream portions, resulting in laminar flow in a portion which is shorter than the predetermined distance or length 134, or no laminar flow at all).

However, even in cases where an outlet duct is provided, the stream first passes through an enlarged portion (at 132) where the stream 130 interacts with the second fluid (which second fluid at this point, moves relatively slowly, compared to the stream 130). The laminar flow of the stream 130 which, as mentioned before, is substantially surrounded by the second fluid within the internal chamber 12, causes a suction which urges the second fluid in a flow direction with the stream 130 and therefore towards the outlet.

In cases where no such outlet duct 38 is required, the main body 14 towards the outlet 20 plays a similar role in the flow development of the stream 130 as discussed before with reference to the outlet duct 38.

It will be appreciated that the first inlet 16 (and inlet duct where relevant) plays an important role in creating a laminar flow of the stream 130 through the internal chamber 12.

The type of fluid provided as the first and second fluids may be determined by the specific application of the arrangement 10, and associated changes may be made to the dimensions and configurations of the arrangement 10. For example, in some cases the first fluid will be a liquid, such as water, and the second fluid will be a gas, such as air. In other cases, the second fluid may be a liquid as well, or a combination of a liquid and a gas (such as a mixture).

The main body 14 may be manufactured from a plastics material such as polyvinyl chloride (PVC), high density polyethylene (HDPE), or ultra-high molecular weight polyethylene (UHMWPE). Other suitable polymeric materials may also be used. Alternatively, the main body 14 may be manufactured from a metal, such as steel, stainless steel, aluminium, or brass. Again, the application and operating conditions (such as temperature, pressure, flow rate, type of fluids and the like) may determine the most suitable material.

Reference is now made to figures 4 to 19. Here, the arrangement 10 takes the form of a shower fitting 48. The shower fitting 48 is typically installed as part of a shower arrangement 50 which is shown in figure 7 and 10.

The first inlet 16, more particularly the first inlet duct 28, is now associated with threaded pipe connection, such as a threaded socket 52 of the known kind, with which the shower fitting 48 is fixed or attached to a feed pipe 54. The shower installation or arrangement 50 includes a connection to water mains 56, a hot water source 58 (such as a heat pump, geyser, in-line heater, ring feed system, and the like), hot water feed pipe 60, a cold-water feed pipe 62, a mixer 64, and a showerhead 66. The shower fitting 48 includes a further pipe connection, such as threaded nipple 68, which is associated with the outlet 20 or the outlet duct 38. The threaded nipple 68 facilitates connection of the shower fitting 48 to the showerhead 66.

It will be appreciated that the first fluid in this example is water (a mixture of hot and cold water, mixed by the mixer 64). The second fluid is air, and more particularly from the surroundings or atmosphere within the shower cubicle 70.

Because of the configuration of the shower fitting 48, in use, flow of water through the first inlet 16 and the internal chamber 12, and out of the outlet 20, causes suction which causes air to flow through the second inlet 18 into the internal chamber 12. The air sucked through the second inlet 18 mixes with water within the internal chamber 12, such that water flowing through the showerhead 66 comprises aerated water, being a mixture of water and air. A volumetric flow rate of the mixture flowing through the showerhead 66 is higher than a volumetric flow rate or feed rate of water through the feed pipe 54 (because of the addition of air in the mixture and the aeration thereof).

However, because of the aeration of the water before flowing through the showerhead 66, it is believed that a user experience of a person showering in the shower cubicle 70 would be similar or at least comparable to a user experience associated with a higher volumetric flow rate of unaerated water through a conventional showerhead 66 which is not provided in communication with the shower fitting 48. Therefore, providing the shower fitting 48 facilitates a similar or comparable user experience whilst using a reduced amount of water, when compared to conventional showers. It is believed that this could result in significant water savings. During a test where the shower fitting 48 was installed as part of the shower arrangement 50, it was found that a feed rate through the feed pipe 54 of below 5 L per minute was sufficient to provide a user with a shower experience comparable to that of conventional showers with significantly higher feed rates.

In some examples of the shower arrangement 50, it may be necessary to install a flow regulator 46 proximate the second inlet 18. Here, the flow regulator 46 will take the shape of a vacuum breaker typically used with geysers (this is typically shown in figures 8 and 9). The flow regulator is provided for preventing or at least inhibiting water flowing out of the second inlet 18 (therefore against a normal flow direction of fluids through the second inlet 18). This is particularly necessary, in cases where the shower fitting 48 is fitted upstream of the mixer 64 and water may not be allowed to flow out of the second inlet 18. Typically, the main body 14 of the shower fitting 48 is manufactured from a metal, such as brass, stainless steel or aluminium.

A diameter of the first inlet of the shower fitting ranges between 2 mm and 4.2 mm (typically about 2 mm), while a diameter of the outlet ranges between 2.5 mm and 8 mm (typically about 4 mm). A diameter of the second inlet is about 2 mm.

The embodiments of figures 8 and 9 have inlet ducts which are cone-shaped, and which converge towards the first inlet 16. The stream of water flowing through the first inlet 16 and into the internal chamber 12 is therefore projected in a direction towards the outlet 20.

It is foreseen that the arrangement 10 may be integrally formed with a showerhead 66 or provided as part of a showerhead assembly. For example, the embodiment shown in figures 11 and 13 comprises a shower fitting 48 which includes a substantially spherical head portion 94 to which a showerhead 66 is fitted in pivoting or swivelling fashion. This shower fitting 48 may therefore be fitted to a showerhead 66 to constitute a showerhead assembly (not shown) which is typically fitted directly to a feed pipe 54 of a shower 50. The arrangement 10 shown in figure 13 may typically have the following dimensions: diameter of first inlet 16: 3.3 mm (±0.3 mm) length of first inlet duct 28: 3 mm (±0.3 mm) spacing distance 24: 27 mm (±2 mm) diameter of second inlet 18: 2 mm (±0.3 mm) diameter of internal chamber 12: 4.5 mm (±0.5 mm) diameter of outlet 20: 4.5 mm (±0.5 mm) diameter of spherical head portion 94: 27.5 mm (±2 mm)

Figures 14 to 19 show further alternative embodiments of the shower fitting 48, which may either be installed as part of plumbing of a shower arrangement 50, or which may be incorporated into a showerhead arrangement. Like numerals refer to like features.

Figure 10 shows an alternative shower arrangement 50, which illustrates a further application of the arrangement 10, and more particularly, the shower fitting 48. The shower arrangement 50 here includes a water circulation arrangement 96 which comprises a diverter thermostat valve 98 fitted to a diverter conduit 100 which drains into a holding tank 102. The holding tank 102 has an outlet 104 which is connected to the second inlet 18 of the shower fitting 48, via a return conduit 106.

In use, before water flowing towards the diverter thermostat valve 98 reaches a predetermined temperature, the water is diverted by the valve 98 towards the holding tank 102 via the diverter conduit 100. At this point, no water flows towards the showerhead 66. Once a predetermined temperature is reached, the diverter thermostat valve 98 directs water towards the shower fitting 48 and eventually out of the showerhead 66. Since the second inlet 18 is connected to the holding tank 102, cold water (or rather, water below the predetermined temperature) is now sucked back into the stream of water flowing from the showerhead 66. In this way, water which would otherwise have gone to waste, is still used during showering, resulting in water savings. The operation of the shower fitting 48 therefore, in this application, facilitates the automatic reintroduction of water from the holding tank 102.

Reference is now made to figure 20 which shows an alternative application of the arrangement 10, which takes the form of a mixing unit 1 10, used as an irrigation or agricultural mixing unit. The mixing unit 1 10 includes a holding container 1 12 which is provided in flow communication with the second inlet 18. A regulating valve 1 14 is provided proximate the flow regulator 46 to enable close regulation of a flow rate from the holding container 112. In use, the holding container 1 12 typically contains a fertiliser mixture, which needs to be fed into a main flow or stream of water, such as irrigation water, at a predetermined rate. The use of the arrangement 10 facilitates the mixture from the holding container 1 12 to be fed into and mixed with water flowing through the inlet 16.

Reference is now made to figures 21 to 32. Here, the arrangement 10 takes the form of a swimming pool (or any pool, reservoir or pond) circulation assembly 72. The main body 14 now takes the form of a vertically extending conduit (which is closed at a bottom 74 and open at a top 76 thereof). The conduit is typically manufactured from a plastics material. The arrangement is typically such that the main body 14 is submerged below a water level 84 a swimming pool 78 in use. As shown in figure 27, the assembly 72 is installed in the pool 78, proximate a side wall 80. More particularly, the assembly is fitted to a return jet of the pool 78 by means of a pipe connection 82. Water flowing through the jet is conveyed along the pipe connection 82 towards the first inlet 16. A jet or stream of water therefore flows through the first inlet 16 and the internal chamber 12 and towards the outlet 20. The water is circulated back to the swimming pool 78 by the outlet 20.

The inlet duct 28 and outlet duct 38 may extend through the sidewall of the main body 14 and may be located substantially opposite one another.

The swimming pool circulating assembly 78 is typically provided with a flow regulator 46 in the form of a strainer 86. The strainer 86 is releasably attached to the top 76 of main body 14 and protrudes above the water level 84. The strainer 86 comprises a substantially cylindrical and open-ended main body 88 with a plurality of longitudinal slits or openings 90, each associated with an internal and external tab or baffle 92 provided for directing water entering through the openings 90. The tabs or baffles 92 may agitate the water to promote aeration of the water. Since the strainer extends above the water level 84, water and air is allowed to enter through the openings 90 such that the fluid flowing through the second inlet 18 may be a mixture of air and water. Again, because of the configuration of the swimming pool circulation assembly 72, in use, flow of water through the first inlet 16 and the internal chamber 12, and out of the outlet 20, causes suction which causes water and air to flow through the second inlet 18 into the internal chamber 12. The water and air sucked through the second inlet 18 combines with water within the internal chamber 12 such that water flowing through the outlet 20 comprises aerated water, being a mixture of water and air. In this configuration, a volumetric flow rate of the mixture flowing through the outlet 20 exceeds a volumetric flow rate or feed rate of water through the first inlet (because of the addition of water from the second inlet). The strainer may also create a whirlpool within the internal chamber, which may improve or facilitate water being sucked through the second inlet.

A diameter of the first inlet of the swimming pool circulation assembly is typically about 25 mm, while a diameter of the outlet is about 50 mm. A diameter of the second inlet is about 110 mm. The outlet duct may have a length of more than 50 mm, and in one example embodiment, it was found that an outlet duct having a length of between 105 mm and 195 mm yielded positive results. Particularly, a length of 195 mm was selected.

The second inlet may be provided with an internal filter housing 120 (typically shown in figures 30 to 32) which may furthermore be provided with a cloth filter (not shown) used for filtering particles or fragments from the water. In this way, plant matter and other particles typically floating on the surface of the pool may be collected and removed. The aeration of the water may also be useful in water treatment, and it is foreseen that an arrangement, substantially similar to the swimming pool circulation assembly 72 may be employed in sewage or waste-water treatment facilities.

In one example, a 1 .1 kW pump was used, which produced a water flow rate of 480 litres per minute. In this example, when the second inlet is provided with a filter, a flow rate (suction caused by the arrangement) of about 360 litres per minute (or approximately 75% of the flow rate generated by the pump) is induced through the first inlet. In cases where the second inlet is not provided with a filter (and therefore, in cases where a lower amount or degree of resistance or restriction is present in the arrangement), the flow rate (or suction) into the second inlet increases to a value between 75% and 100% of the flow rate of the pump.

As shown in figures 29 and 30, in some cases, the second inlet 18 may be provided with a one-way valve arrangement, which may take the form of a floating one-way valve. This may be provided to inhibit particles captured by the internal filter housing to flow back to the pool when flow of water through the arrangement 10 is terminated.

Furthermore, as shown in figure 32, in some cases, a filter unit 122 may be provided downstream of the second inlet 18.

It will be appreciated that the physical dimensions of, for example the first and second inlets and the outlet, may be adapted based on the fluids flowing through the arrangement 10. For example, if fluids with densities and/or viscosities different to that of water are supplied through the first inlet, flow rates of the fluid, supply pressures of the fluid, and/or diameters of the various inlets and outlets may be adapted accordingly.

The arrangement 10 have been found to operate at pressures and flow rates lower than those associated with the use of venturi arrangements. It is believed that this facilitates a wider scope of applications.

Internal surfaces of the arrangement 10, and particularly internal surfaces of the first inlet 16, the inlet duct (where relevant) the internal chamber 12, the outlet duct (where relevant) and the outlet 20 may be relatively smooth and/or polished, to facilitate flow development as discussed before.

It will be appreciated that the above description only provides a number of example embodiments of the invention and that there may be many variations without departing from the spirit and/or the scope of the invention. It is easily understood from the present application that the particular features of the present invention, as generally described and illustrated in the figures, can be arranged and designed according to a wide variety of different configurations. In this way, the description of the present invention and the related figures are not provided to limit the scope of the invention but simply represent selected embodiments.

The skilled person will understand that the technical characteristics of a given embodiment can in fact be combined with characteristics of another embodiment, unless otherwise expressed or it is evident that these characteristics are incompatible. Also, the technical characteristics described in a given embodiment can be isolated from the other characteristics of this embodiment unless otherwise expressed

Claims

1 . A fluid flow arrangement, comprising: an internal chamber; a first inlet into the internal chamber associated with a first fluid; a second inlet into the internal chamber associated with a second fluid; and an outlet from the internal chamber, wherein the first inlet is configured operatively to direct a flow of the first fluid through the internal chamber in a direction towards the outlet and wherein the arrangement is such that the flow of the first fluid is substantially laminar for at least a predetermined distance downstream of the first inlet.

2. The fluid flow arrangement according to claim 1 , wherein the internal chamber comprises a combining or mixing chamber.

3. The fluid flow arrangement according to claim 1 or claim 2, wherein the internal chamber comprises an enlarged chamber, wherein an internal dimension of the internal chamber exceeds an internal dimension of the first inlet and wherein, at least for a portion along the predetermined distance, the flow of the first fluid is at least partially surrounded by or submerged in the second fluid.

4. The fluid flow arrangement according to any one of the preceding claims, wherein the first inlet and the outlet are arranged in-line.

5. The fluid flow arrangement according to any one of the preceding claims, wherein the first inlet and the outlet are both provided in direct fluid flow communication with the internal chamber.

6. The fluid flow arrangement according to any one of the preceding claims, wherein the first inlet and the outlet are spaced from each other by a first spacing distance.

7. The fluid flow arrangement according to claim 6, wherein the spacing distance has a length in a range of about a value of a diameter of the first inlet, to about double the value of the diameter of the first inlet.

8. The fluid flow arrangement according to claim 6 or 7, wherein the first spacing distance defines an unguided flow space, and wherein operative interaction between the first and second fluids within the unguided flow space causes the second fluid to flow through the second inlet and towards the outlet.

9. The fluid flow arrangement according to any one of the preceding claims, wherein the first inlet is configured for directing the flow of the first fluid into the internal chamber, and such that at least a substantial portion of the first fluid flows from the internal chamber through the outlet. The fluid flow arrangement according to any one of the preceding claims, wherein a size of the first inlet is smaller than a size of the outlet. The fluid flow arrangement according to any one of the preceding claims, wherein the first inlet comprises a relatively smooth or polished inner surface to facilitate substantially laminar flow of the first fluid for at least the predetermined distance downstream thereof. The fluid flow arrangement according to any one of the preceding claims, wherein the second opening is situated above the first inlet and the outlet. The fluid flow arrangement according to any one of the preceding claims, wherein a ratio of diameters of the first inlet and outlet is about 0.5:1 . The fluid flow arrangement according to any one of the preceding claims, wherein a diameter of the first inlet is in the range of 0.1 mm to 3000 mm. The fluid flow arrangement according to any one of the preceding claims, wherein a diameter of the outlet is in the range of 0.2 mm to 6000 mm. The fluid flow arrangement according to any one of the preceding claims, wherein a diameter of the second inlet is in the range of 0.2 mm to 1000 mm. The fluid flow arrangement according to any one of the preceding claims, wherein a length of an outlet duct associated with the outlet is at least double a value of a diameter of the first inlet. The fluid flow arrangement according to any one of the preceding claims, further comprising a first inlet duct having a first opening which defines the first inlet, and wherein the first opening is situated within the internal chamber. The fluid flow arrangement according to claim 18, wherein the first opening is configured as a nozzle. The fluid flow arrangement according to claim 18 or 19, wherein the first inlet duct comprises a substantially cylindrical tube extending into the internal chamber. The fluid flow arrangement according to claim 18 or 19, wherein the first inlet duct comprises a converging or cone-shaped duct extending into the inlet chamber. The fluid flow arrangement according to any one of the preceding claims, further comprising a partitioning arrangement provided in an outlet portion of the internal chamber, the partitioning arrangement configured as a backflow arrestor. The fluid flow arrangement according to any one of the preceding claims, further comprising an outlet duct with an outlet opening defining the outlet, the outlet opening situated within the internal chamber, wherein the outlet duct has a predetermined diameter and length such that the predetermined distance for which the flow of the first fluid is substantially laminar terminates within, or towards an end of, the outlet duct. 24. The fluid flow arrangement according to claim 23, wherein the outlet duct has a relatively smooth or polished internal surface finish.

25. The fluid flow arrangement according to any one of the preceding claims, wherein the second inlet is provided with a flow regulator selected from the group comprising: i) a directional flow regulator; ii) a valve; iii) a one-way valve; and iv) a vacuum breaker.

26. The fluid flow arrangement according to any one of the preceding claims, wherein the internal chamber is defined by a main body, manufactured from a material selected from the group comprising plastics materials, including PVC, HDPE, and UHMWPE; and metals, including steel, stainless steel, aluminium, and brass.

27. The fluid flow arrangement according to any one of the preceding claims, configured as a shower fitting and wherein:

28. The fluid flow arrangement according to claim 27, wherein the second inlet is configured as an air intake, and wherein, in use, water and air are combined into an aerated mixture before being expelled through the showerhead.

29. The fluid flow arrangement according to claim 27 or 28, wherein the first inlet is associated with a threaded pipe connection in the form of a socket or nipple, operatively to facilitate connection to the shower feed pipe.

30. The fluid flow arrangement according to any one of claims 27 to 29, wherein the outlet is associated with a threaded pipe connection in the form of a socket or nipple, operatively to facilitate connection to a distribution pipe or the showerhead.

31 . The fluid flow arrangement according to any one of claims 27 to 29, configured as part of a showerhead arrangement.

32. The fluid flow arrangement according to claim 31 , wherein a main body of the arrangement is configured for directly coupling to a showerhead.

33. The fluid flow arrangement according to claim 32, wherein the main body comprises a substantially spherical formation for receiving a showerhead in pivoting or swivelling fashion.

34. The fluid flow arrangement according to claim 33, wherein the first inlet has a diameter in the range of about 2mm to about 4.5mm, wherein the second inlet has a diameter in the range of about 1.5mm to about 3mm, wherein the outlet has a diameter in the range of about 3mm to about 6mm, wherein the second inlet is provided in fluid flow communication with the internal chamber in close proximity to the first inlet, and wherein a spacing distance between the first inlet and the outlet is in the range of about 25mm to about 30mm in length.

35. The fluid flow arrangement according to claim 31 , wherein a main body of the arrangement is integrally formed with a showerhead.

36. The fluid flow arrangement according to any one of claims 1 to 26, comprising a main body in the form of a vertically extending conduit with an open end facing upwards.

37. The fluid flow arrangement according to claim 36, wherein a first inlet duct extends through a sidewall of the conduit and into the internal cavity.

38. The fluid flow arrangement according to claim 37, wherein an outlet duct is arranged in-line with and across from the inlet pipe such that a spacing distance is defined between ends of the inlet and outlet ducts and wherein the outlet duct extends through the side wall of the main body.

39. The fluid flow arrangement according to any one of claims 36 to 38, wherein the first inlet is operatively provided in fluid flow communication with a return jet of a swimming pool.

40. The fluid flow arrangement according to any one of claims 36 to 39, wherein the conduit is manufactured from a plastics material.

41 . The fluid flow arrangement according to any one of claims 36 to 40, wherein the conduit is at least partially submerged in a body of water, in use.

42. The fluid flow arrangement according to claim 41 , wherein at least a portion of the conduit, or an extension fitted thereto, extends above a surface of the body of water in use.

43. The fluid flow arrangement according to claim 42, wherein the extension fitted to the conduit comprises a flow regulator in the form of a strainer or agitator.

44. The fluid flow arrangement according to claim 43, wherein the flow regulator comprises one or more flaps, tabs or baffles provided for stirring water flowing into the second inlet, or for directing water flowing into the second inlet.

45. The fluid flow arrangement according to any one of claims 36 to 44, wherein the second opening is defined towards the upward facing open end, and wherein the second opening is operatively provided in fluid flow communication with the body of water and an outside air environment or atmosphere, such that fluid entering the internal chamber may comprise a combination of water from the body of water, and air from the atmosphere.

46. The fluid flow arrangement according to any one of claims 36 to 45, wherein a filter is provided within the main body, or proximate the second inlet.

47. The fluid flow arrangement according to any one of claims 36 to 46, wherein the first inlet has a diameter of about 25 mm, the second inlet has a diameter of about 110 mm and the outlet has a diameter of about 50 mm. 48. The fluid flow arrangement according to claim 38, wherein the first spacing distance is about 25 mm and wherein a length of the outlet duct is between 105 mm and 200 mm.

49. A shower installation, comprising: a feed pipe provided in communication with a water supply; a fluid flow arrangement according to any one of claims 27 to 35, wherein the feed pipe is connected to, and provided in flow communication with, a first inlet of the fluid flow arrangement; and a shower head provided in fluid flow communication with an outlet of the fluid flow arrangement.

50. A shower installation according to claim 49, further comprising a hot water source and a mixer.

51 . A shower installation according to claim 50, wherein the hot water source comprises one of a geyser, heat pump, in-line water heater and ring-feed system and wherein the feed pipe is further connected to a source of cold water.

52. A water circulation assembly of a body of water, comprising: a water outlet jet; and a fluid flow arrangement in accordance with any one of claims 36 to 48, wherein the water outlet jet is connected to, and provided in flow communication with, a first inlet of the fluid flow arrangement.

53. A water circulation assembly according to claim 52, further comprising a flow regulator, including at least one flow directing flap, tab or baffle which extends relative to a second inlet of the fluid flow arrangement, and which operatively extend, at least partially, above a water level of the body of water.

54. A water circulation assembly according to claim 53, further including a filter which is provided relative to the second inlet or within a main body of the fluid flow arrangement.

55. A method of combining a first and second fluid, the method comprising the steps of: providing a fluid flow arrangement in accordance with any one of claims 1 to 48, the fluid flow arrangement comprising a first inlet, second inlet, an internal chamber and an outlet; providing a first stream of the first fluid through the first inlet and towards the outlet such that the first stream flows substantially laminarly for at least a predetermined distance downstream of the first inlet; providing a second fluid which, at least partially, surrounds or submerges the first stream thereby to interact with the first stream, causing the second fluid to be drawn into the internal chamber through the second inlet; causing the first and second fluids to combine within the internal chamber; and expelling the combined first and second fluids through the outlet. The method according to claim 55, wherein the first fluid comprises water and the second fluid comprises one of water, air and a mixture comprising water and air.