WO2024119203A1 - Flow system for generating a counterflow - Google Patents

Abstract

The invention relates to a flow system (1) comprising a swimming pool (2) and at least one flow device (3) for generating a counterflow (4) for a subject (5) in the pool (2), wherein the flow device (3) comprises the following: at least one flow drive (6) which is driven by at least one motor (7) of the flow device (3), and at least one drive channel (8) in which a pressure difference between at least one drive channel inlet (9) and at least one drive channel outlet (10) can be generated by the flow drive (6), wherein the drive channel inlet (9) and drive channel outlet (10) are arranged below a water line (11) of the pool (2), and wherein the drive channel outlet (10) is oriented to output the counterflow (4) along a counterflow direction (12), wherein the flow device (3), or a combination (Z) of at least two flow devices (3), comprises at least one bypass channel (13) having a bypass channel inlet (14) and a bypass channel outlet (15), wherein the at least one bypass channel (13) is at least partially spaced apart from a drive channel outer edge (16), and wherein the bypass channel outlet (15) is oriented substantially along the counterflow direction (12).

Description

Flow system for generating a counterflow

The invention relates to a flow system comprising a water basin and at least one flow device for generating a countercurrent for a subject in the water basin, wherein the flow device comprises: at least one flow drive which is driven by at least one motor of the flow device, and at least one drive channel in which, by means of the flow drive, a pressure difference can be generated between at least one drive channel inlet and at least one drive channel outlet, wherein the drive channel inlet and drive channel outlet are arranged below a water line of the water basin, and wherein the drive channel outlet is aligned to output the countercurrent along a countercurrent direction.

The purpose of the flow system or a countercurrent system is to create the possibility of keeping a subject, which is usually a human being who is performing swimming movements, in place in a water basin or swimming pool by providing a countercurrent. By applying a defined volume flow at a defined flow speed in the water, the subject can be kept in a fixed or constant, consistent position in relation to the water basin without reaching the edge of the water basin.

Countercurrent systems according to the state of the art generally comprise a single flow outlet or drive channel outlet from which a countercurrent is emitted in the direction of the swimmer. In some countercurrent systems, a deflection element is also used to obtain a directed countercurrent. A significant disadvantage of known countercurrent systems is that, despite the use of deflection elements or an adapted shape of the outlet, the actual movement cross-section or movement space of a swimming user is not flowed against in an insufficiently homogeneous manner. Known countercurrent systems also take up a lot of space when used in a water pool or emit a weak countercurrent.

A desirable homogeneous or homogenized countercurrent is generally understood to mean that the flow in the area of the subject has little turbulence, eddies and disturbances, and that there are no asymmetrical flow profiles. Pulsations can also disrupt movement in the water. This desirable homogenized counterflow is generally not achieved in known counterflow systems. This is because when a counterflow or flow is generated by a propeller, as is the case in most cases, the counterflow is inherently subjected to swirl and an uneven speed profile. Likewise, diverting a flow using a bend in the counterflow can impose swirl-affected or inhomogeneous flow structures, which on the one hand are associated with higher dissipation and thus losses of the kinetic energy of the counterflow, and on the other hand can disrupt or make impossible a subject's smooth movement.

Some of the countercurrent systems from the state of the art recognize these problems, but supply the movement space or reference space of a subject with a very inhomogeneous countercurrent. In addition, deflection elements or bends cause large losses of kinetic energy of the flow and pressure losses due to narrowing or widening of the flow cross-section, or the flow through rectifier openings and the associated increased friction or flow deflection. This consequently requires stronger flow drives, which usually take up more space.

Another problem that arises with known counter-current systems is product safety. One of the most common causes of death for small children is drowning in pools, also caused by counter-current systems that have structurally-related hazards. For this reason, strict guidelines generally apply in public pools with regard to counter-current systems.

Dangers, and thus product safety deficiencies, arise primarily from high negative pressures or suction pressures at the drive channel inlet of countercurrent systems. Suction, especially of children and frail people, increases the risk of them drowning.

Another factor in product safety is that in many well-known systems a propeller is used as a flow drive to provide the countercurrent. Long hair in particular poses a risk, as many countercurrent systems often have to be made very small due to the space limitations in a water basin, which makes it easier for hair to get caught in the propeller. The greatest danger here is again possible drowning due to hair becoming caught or trapped in the propeller.

Another source of danger is getting trapped under or behind a counter-current system.

A countercurrent system of the prior art is disclosed in EP3653275A1. The countercurrent system is designed with a propeller coupled to a motor, to which a channel is connected, through which the water is directed into a water basin. The outlet nozzle can be designed such that the cross-section of the opening is oval-shaped.

Another example of a known countercurrent system having a rectifier or outlet diffuser is disclosed in US4665572A. This rectifier is intended to provide a layered countercurrent flow, with lamellar structures or deflection elements being formed in the outlet of the flow in order to divide and straighten the countercurrent flow.

DE2401040A1 discloses a countercurrent system for swimming pools, where the water outlet nozzle has an adapted cross-section, which is intended to provide a swimmer with a more favorable cross-sectional shape of the water flow with the same intensity, while requiring little effort. However, the problems and disadvantages described above are not sufficiently recognized in this countercurrent system either.

In light of the prior art, the object of the invention can be seen as providing a solution to the above-mentioned disadvantages of known countercurrent systems. The primary aim is to demonstrate a more compact solution for providing a homogenized countercurrent for a subject in a water basin compared to the prior art, without increasing the required drive power.

According to the invention, the present object is achieved in that a flow device of the flow system, or a combination of at least two flow devices, comprises at least one bypass channel with a bypass channel inlet and a bypass channel outlet, wherein the at least one bypass channel is at least partially spaced from a drive channel edge, and wherein the bypass channel outlet is aligned substantially along the counterflow direction. The at least one bypass channel offers two essential advantages that contribute to solving the problem at hand.

Firstly, additional water is entrained through the bypass channel with the flow generated by the drive channel, so that the resulting counterflow provides an increased volume flow with the same drive power compared to a flow device without the bypass channel according to the invention. This makes it possible to compact the motor and/or the flow drive of the flow device according to the invention, which in total makes it possible to provide a smaller and cheaper flow device. A more compact flow device is also easier to transport and set up, and also takes up less space in a water basin, which means that there is more room for a subject to move.

Secondly, the at least one bypass channel provides a further inlet for entrained water, which supplies the countercurrent or the free jet or free jets from the drive channel with additional water. This results in a cross section around the subject being subjected to a countercurrent over a large area. If no bypass channel were formed, in the case of a single free jet emerging from the drive channel, the circumference at which the free jet can entrain surrounding water would be limited to the outer circumference of the free jet. In the case of several free jets emerging distributed over the exit cross section of the drive channel, these free jets would contract into a single free jet due to the insufficient amount of water between the free jets. In both cases, this results in the cross section in which the countercurrent has an approximately homogeneous speed distribution not encompassing the entire movement space of the subject. In the case of a swimming person, this results in an unnatural swimming sensation, since the cross section of the countercurrent around the swimming person does not have a sufficiently homogeneous speed distribution.

A free jet is a flow that is emitted into the free environment without wall boundaries via the outlet opening of the drive channel. The outgoing counterflow has a higher momentum than the water in the water basin and therefore also different speeds. A shear layer is formed between them, through which surrounding water is sucked in and entrained. The bypass channels represent gaps in the outlet opening, so that the circumference over which a shear layer can form increases, while at the same time allowing sufficient water to flow through the bypass channels to be entrained. This has a beneficial effect on the volume flow of the counterflow and the homogeneity of its velocity distribution.

Further secondary advantages which can be provided by the at least one bypass channel when suitably dimensioned are given below.

The advantage can be obtained that the volume flow of water flowing through the bypass channel flows into the core area of the counterflow from the drive channel outlet, which in turn leads to an equalization or homogenization of the counterflow, since the flow in the core area does not move forward unhindered by the external fluid and therefore does not move forward. The core area of the flow is to be understood as that, due to wall friction effects and the formation of boundary layers on walls, there will always be a flow at the outlet of the drive channel which has areas that flow more slowly than others. The core area is the area which is not influenced by wall boundary layers, etc. The cross-section of the core area of a free jet decreases with increasing distance from the outlet opening as a result of the expanding shear layer at the edge of the free jet. Since the at least one bypass channel is arranged at a distance from the drive channel outer edge, and water is drawn from this, the cross-section of the unbraked core area is already reduced at the outlet opening. This results in homogenization, whereby at the same time the flow drive has to impart less energy to the flow in order to provide a counterflow of sufficient speed and sufficient cross-section.

A further effect that can reduce the required drive power of the motor is that the backflow, which inevitably forms in the water basin due to the deflection of the counterflow at the water basin rear wall, is partly absorbed by at least one bypass channel inlet, in order to then be added to the counterflow with its remaining undissipated and deflected flow velocity in order to be directed again to the swimmer.

In known countercurrent systems, however, the countercurrent and subsequently the diverted return current are diffused in an uncontrolled manner at the front wall of the water basin, where the flow device is usually positioned, or are deflected in such a way that they cannot be mixed into the flow of the drive channel in a directed manner by means of bypass channels. Preferably, the bypass channel inlet is arranged behind the bypass channel outlet, pointing against the counterflow direction, and the bypass channel inlet and bypass channel outlet are formed essentially straight with respect to their centers. This provides the advantage that a return flow which is deflected by the front wall of the water basin can be absorbed particularly efficiently by the at least one bypass channel inlet. The straightness of the bypass channel leads to a particularly directed and conditioned counterflow, whereby the lack of bends and other deformations or deflections means that the bypass channels can flow through and the core area of the flow can be filled with particularly little loss.

The term "center" refers to the center point that is equally spaced from the edges of the respective bypass channel inlet and outlet. The word "straight" refers to the geometric shape of the connecting line, or center line, of the respective center points.

In one embodiment, the flow drive and the motor can be located outside a frontal plane projection of the bypass channel outlet, with the bypass channel inlet being arranged at a distance from the water basin. This provides the advantage that the bypass channels are free of deflections, whereby water can be entrained from the front wall of the water basin with particularly little loss.

Preferably, the drive channel outer edge has the cross-sectional shape of a shell of frontal flat projections of the subject, below the waterline. This makes it possible to provide a countercurrent that is adapted to the subject, since only the relevant cross-section around the subject is subjected to a countercurrent. Adapted countercurrent can be understood to mean that, for example, the torso of a swimmer, which represents the greatest resistance to the countercurrent when swimming on its stomach, is particularly exposed to the flow. If the countercurrent only flows against this area, firstly, less engine power or drive power needs to be applied, since less water needs to be accelerated around the swimmer. Secondly, this creates more space for the return flow, which inevitably has an inverse flow velocity to the countercurrent, whereby flowing past one another always entails losses.

However, the primary meaning of adapted countercurrent is to mean the largest possible cross-section of the countercurrent around the subject, so that a natural swimming movement or a large-area flow around the subject is provided. In one embodiment of the invention, the drive channel outlet can have a perforated plate with at least two holes through which the counterflow exits, whereby the holes can be dimensioned and arranged in such a way that a counterflow that is as homogeneous as possible or a flow speed that is the same in each case can be provided from the holes. This provides the advantage that an even more homogeneous counterflow can be provided for a swimmer or a subject being flowed around. It should be noted that the holes can also output the counterflow at an angle.

In a further embodiment, the drive channel has a bend, wherein the bend continuously transfers the cross section of the drive channel inlet to the cross section of the drive channel outlet. The bend provides the advantage that the internal flow of the flow device is diverted and undergoes a certain preconditioning in the process, so that a more homogeneous counterflow can be provided for the subject being flowed around. For this purpose, the interior of the bend can be equipped with deflection plates, baffles, guide vanes, perforated plates or other elements for flow guidance and flow homogenization.

Furthermore, the manifold can have several flow channels, whereby the flow channels are individually connected to the holes in the perforated plate. This has the advantage that the internal flow of the flow device is directed specifically to each hole in order to obtain a particularly defined flow velocity from each hole. The flow channels are not limited to round cross-sections, but can also be oval or rectangular cross-sections, for example. Some of the holes can be designed as bypass channels.

If, in addition, a length and a diameter profile and a flow channel curvature of the flow channels are dependent on their relative position to the flow drive and drive channel outlet, and are designed in such a way that an equal flow velocity emerges from the holes and/or a countercurrent is maintained for an adapted swimming feeling, the advantage is also obtained that how the countercurrent impacts on a subject can be defined particularly precisely.

The key to achieving the right swimming experience is to specifically manipulate the exit speeds. This may mean that the exit speed needs to be higher in the edge zone of the current. In one embodiment, a housing can surround the flow drive and the drive channel inlet at a distance, the housing being adjustable in length to reach a bottom of the water basin. On the one hand, this provides the advantage that elements of the flow system that pose a potential danger can be shielded from a user or swimmer. On the other hand, the length adjustability can prevent a swimmer or a swimming subject from remaining under the flow device.

In a further embodiment, the housing can have a boundary surface with perforations, the perforations being dimensioned such that a single perforation has an opening area of less than 1 cm ² , preferably less than 0.5 cm ² . The perforations can also have an opening diameter of less than 8 mm, or greater than 25 mm. When arranged over a large area and in full, these perforations prevent local flow peaks from forming, where high suction pressures can occur, which can consequently lead to a swimmer or subject being sucked in. By keeping the perforations small, product safety is increased.

Advantageous and non-limiting embodiments of the invention are explained in more detail below with reference to the figures.

Fig. 1 shows a flow device of a flow system in perspective.

Fig. 2 shows the flow device from Fig. 1 in frontal view.

Fig. 3 shows a section of the perforated plate of the flow device of Fig. 1 and Fig. 2 in detail.

Fig. 4 shows a special embodiment of a manifold.

Fig. 5 shows a flow system with a flow device in a water basin. Fig. 6 shows a frontal view of a swimmer in a freestyle swimming movement, a contour of a drive channel outer edge and a contour of the cross-section of the countercurrent flow.

Fig. 7 shows a frontal view of a person in a walking or running movement, a contour of a drive channel outer edge and a contour of the cross-section of the counterflow.

Fig. 8 shows a frontal view of a horse in a walking or running movement, a contour of a drive channel outer edge and a contour of the cross-section of the countercurrent flow. Fig. 9 shows a frontal view of a dog in a swimming motion, a contour of a drive channel outer edge and a contour of the cross-section of the countercurrent.

Fig. 10 shows an embodiment of the flow device with housing.

Fig. 11 shows an embodiment of a flow system in which the flow device is flush with a water basin front wall. Fig. 12 shows an embodiment of a flow system in which a drive channel 8 extends into a water basin.

Fig. 13 shows an embodiment of a flow system in which a drive channel runs outside the water basin, wherein a drive channel inlet draws water in the region of a side wall of the water basin.

Fig. 14 shows a special embodiment of a flow device, wherein ten bypass channels are arranged in a funnel-shaped drive channel outlet. Fig. 15 shows a special embodiment of a flow device, wherein eight drive channel outlets are penetrated by a grid-shaped bypass channel.

Fig. 16 shows a special embodiment of a flow device, wherein the drive channel is X-shaped.

Fig. 17 shows a special embodiment of a flow device, in which a flow device with two drive channels is shown.

Fig. 18 shows a sectional view of the flow device of Fig. 10 in a water basin.

Fig. 19 shows the flow device of Fig. 1 and a complete flow in a water basin out of the drive channels and bypass channels.

Fig.20 shows the flow system from Fig.19 in a top view.

Fig. 1 shows a flow device 3 comprising a flow drive 6, which is driven by at least one motor 7 of the flow device 3, and a drive channel 8, in which a pressure difference between at least one drive channel inlet 9 and at least one drive channel outlet 10 can be generated by the flow drive 6, wherein the drive channel inlet 9 and drive channel outlet 10 are arranged below a water line 11 of the water basin 2, and wherein the drive channel outlet 10 is aligned to output the counterflow 4 along a counterflow direction 12. The flow device 3 has three bypass channels 13, wherein each bypass channel 13 comprises a bypass channel inlet 14 and a bypass channel outlet 15, wherein each bypass channel 13 is spaced from a drive channel outer edge 16. the bypass channel outlets 15 are aligned along the counterflow direction 12. In the embodiment of Fig. 1, the bypass channels 13 penetrate the drive channel 8. It should be noted that the bypass channels 13 can also be openly connected to the drive channel outer edge 16. The flow device described in Fig. 1 is shown in Fig. 19 in the context of a flow system with a water basin and subject 5. Fig. 20 shows the flow system of Fig. 19 in a top view.

In this case, suction directions 24 of the bypass channels 13 and suction directions 25 of the drive channel 8 are shown, whereby the flow direction 27 of the drive channel 8 and the flow direction 26 of the bypass channels 13 are also shown.

The flow drive 6 can also be understood to mean several propellers, or pump wheels, impellers, or other working machines, both flow machines and displacement machines. The flow drive 6 can be driven by a single motor 7, or by several which are connected to one another with a gear or another machine element. It should be noted that the flow drive 6 and the motor 7 do not necessarily have to be arranged within the water basin 2. For example, one or more motors 7 could also be accommodated outside the water basin 2. Likewise, the flow drive 6 can also be located outside the water basin 2, since only the drive channel inlet 9, drive channel outlet 10 and the at least one bypass channel 13 have to be below the water line 11 in order to be able to draw water in from the water basin 2 and expel it again.

The motor 7 of the flow device 3 can also be an internal combustion engine, turbine motor, or even an electric motor. Preferably, a DC electric motor with 24 volts on a standard 230 volt connection is used. The counterflow that can be generated by such an electric motor can reach, for example, 1.45 meters per second.

In the embodiment shown in Fig. 1, the flow drive 6 is a propeller that is arranged inside the drive channel 8. The flow drive 6 is set in rotation by a motor 7 in order to achieve the necessary pressure difference to impose a flow speed on the water in the water basin 2. The motor 7 is connected to the flow drive 6 by a drive shaft. The motor 7 is cooled on its outer wall by the water flowing past in order to enable continuous operation. The flow drive 6 is spaced so far from the drive channel inlet 9 and drive channel outlet 10 that even long hair of a swimmer 5 cannot be wound up in order to ensure the greatest possible Product! safety. Long hair can be defined as hair with a length of 40, 50, or 60 cm or even longer.

As shown in Fig. 10, the drive channel 8, its drive channel inlet 9, and the flow drive 6 can be surrounded by a housing 20 at a distance. The drive channel inlet 9 is arranged at a distance from the underside of the housing so that water can flow unhindered into the drive channel inlet 9. The length of the housing 20 is adjustable so that it can contact the bottom of the water basin 2 in the operating position to prevent a swimmer 5 from remaining under the flow device 3 and getting stuck. Preferably, the adjustable length of the housing 20 can be adapted to a water basin depth of 1.2 to 1.6 meters, but lengths of 2 or 3 meters are also possible. The flow device 3 described in Fig. 10 is shown in Fig. 18 in the context of a flow system 1 with water basin 2 and subject 5.

The housing 20 of the flow device 3 from Fig. 10 is designed with perforations over a large area over its boundary surface, with the exception of reinforcing ribs, which give the housing 20 a high resistance to external influences. Firstly, these perforations serve as a sieve or filter to catch disruptive bodies from the water in order to keep the flow drive 6 and the motor 7, as well as the drive channels 8 and bypass channels 13 clear. Secondly, the fine-meshed perforations offer protection for the swimmer or the swimming subject 5, so that he or she cannot contact the flow drive 6 with any part of his or her body. Preferably, the minimum distance that can be reached from a body part of the swimmer or the swimming subject 5 on a minimal path to the flow drive 6 is at least 40 centimeters long. The perforations are designed in such a way that even a child cannot put his or her fingers through the perforation. Preferably, the perforations have a diameter of no more than 3 or 8 millimeters and the flow velocity at the housing 20 is preferably less than 0.3 or less than 0.5 meters per second. The size of the perforations and their number and distribution can also be determined according to the bath hygiene law. According to this law, the force on standard hairs attracted must not exceed 25 Newtons.

The perforations can be hole-shaped or grid-like. The size, position and distribution of the individual perforations can depend on the flow drive 6 and its surrounding flow profile in order to compensate for local flow peaks and to achieve a homogeneous suction across the entire perforated interface. For example, there can be smaller holes towards the drive channel inlet 9, which are filled with become larger with a greater distance from the drive channel inlet 9. The boundary surface of the housing 20 can also be designed with folds which increase its surface area and thus reduce flow losses.

It should be noted that the part of the housing 20 that touches the ground can be designed with weight elements, such as sand or lead balls, which can be placed in a deformable membrane. This makes it possible to compensate for unevenness or gaps on the bottom of a water basin 2 and also prevent the flow device 3 from floating. In addition, the flow device 3 is given increased stability in the operating position due to the removable weight. Installation in a water basin 2 is also made easier because the weight elements can only be added when the flow device 3 is placed in the water basin 2.

The flow drive 6 and the motor 7 of the flow device 3 of Fig. 1 are arranged along a vertical axis in order to take up as little area of the water basin 2 as possible. In order to output the counterflow 4 in the desired counterflow direction 12, a bend 19 is provided in the drive channel 8, whereby the bend 19 continuously transfers the cross section of the drive channel inlet 9 to the cross section of the drive channel outlet 10. The bend 19 can specifically redirect the internal flow of the flow device 3 using guide plates, bends, deflection plates, internal rectifiers, W-shaped collectors, or Y-shaped collectors. Fig. 14 shows a flow device 3 without a bend.

The bypass channel inlets 14 are arranged behind the respective bypass channel outlet 15 pointing against the counterflow direction 12, the respective bypass channel inlet 14 and respective bypass channel outlet 15 being essentially straight in relation to their centers 17. In Fig. 2, in which the flow device 3 from Fig. 1 is shown in frontal view, it is clear how this feature is represented. The three bypass channels 13 are free of bends in frontal view and the bypass channel inlets 14 and bypass channel outlets 15 are arranged one behind the other. It should also be understood that the bypass channels 13 can also be arranged at an angle to the counterflow direction 12. The bypass channel inlets 14 can be designed with curves or bevels for low-loss inflow.

It should be noted that the surfaces of the bypass channel inlets 14 and the bypass channel outlets 15 can have different shapes and sizes. For example, the bypass channel outlet 14 could be designed to be smaller than the bypass channel inlet 15 in order to create a nozzle effect in which the flow velocity through the bypass channel 13 increases towards the smaller area.

In addition, the flow drive 6 and the motor 7 are located outside a frontal plane projection of the bypass channel outlet 15. In other words, there are no bulky elements in the path of the flow through the bypass channel 13, which could negatively influence the flow through necessary deflections, redirections or constrictions. It should be noted that the motor 7 could, for example, be located above the bypass channels 13 or outside the water basin 2, and only a thin drive shaft could lead through the frontal plane projection to the flow drive 6. It is not absolutely necessary for a flow drive 6 and a motor 7 to be located outside a frontal plane projection of the bypass channel outlets 15. An example of this is the flow device 3 in Fig. 14.

Frontal plane projection can be understood to mean that in the frontal view of the flow device 3, as shown in Fig. 2, no other elements are cut in the projection of the bypass channel outlets 15.

Another feature that the flow device 3 can have is a perforated plate 18 provided in the drive channel outlet 10. The perforated plate 18 is designed with at least two holes through which the counterflow 4 exits, the holes being dimensioned and arranged in such a way that a counterflow 4 that is as homogeneous as possible is provided. Fig. 3 shows a section of the perforated plate 18 of the flow device 3 of Fig. 1 and Fig. 2 in detail. It can be seen that holes near the bypass channels 13 are designed with a smaller diameter in order to accelerate the exit speed from these by means of the nozzle effect in order to draw a particularly large amount of water from the bypass channels 13 with appropriate dimensioning of the remaining elements of the flow device 3. It should be noted that the perforated plate 18 can be designed like a grid or net. The holes in the perforated plate 18 can also be covered with a net or grid. Furthermore, it should be noted that the holes can also be conical.

It can also be seen in Fig. 3 that the holes can protrude from a plane, connected by rounded portions. Individual holes can protrude from this plane by different distances in order to encourage the drawing of water from the bypass channels 13. Preferably, the roundings are formed not only on the outside of the holes, but also on the inside. This has the advantage that fewer losses occur when the flow is diverted into the holes. It should also be noted that the holes can also end smoothly with the perforated plate 18, or the plane mentioned. The perforated plate 18 can also be curved out of the plane in order to further homogenize the counterflow 4.

The holes in the perforated plate 18 can also emit their respective flow at an angle in order to provide an adapted cross-sectional shape of the counterflow 4. Adjustment devices, for example in the form of ball valve-like inlets, could also be provided in the holes in order to change the angle mentioned or to reduce or close individual holes. The protruding holes can therefore also be designed as nozzles or diffusers in order to further homogenize the counterflow 4 and/or to adapt the cross-section of the counterflow 4.

It should also be noted that the perforated plate 18 itself can already have a curvature or can be deformed at an angle. In one embodiment of the perforated plate, a surface of the perforated plate in which the holes are arranged can be curved in order to specifically direct the water flow or the counterflow. This makes it possible to achieve a larger cross-section in the relevant flow area or in the cross-section of the counterflow 23 of the applying subject 5. The drive channel outlet can also be designed from several curved surfaces that are inclined outwards, with the secondary flow channels 13 being aligned essentially along the flow direction.

It should be noted that the holes in the perforated plate 18 can also be designed with closure elements, whereby the closure elements can change the diameter of the holes or close them reversibly. In order to adapt the cross section of the counterflow 4 to different float sizes and also the distances between the float 5 and the flow device 3.

In Fig. 4, a special embodiment of a bend 19 of a flow device 3 is shown in section. Several flow channels 21 are provided, wherein the flow channels 21 are each individually connected to the holes of the perforated plate 18. Particularly preferred are a length and a diameter profile and a flow channel curvature of the flow channels 21, depending on their relative position to the flow drive 6 and drive channel outlet 10, so that an equal flow velocity emerges from the holes. A particular advantage of this embodiment is that the flow channels 21 have a longer distance for dissipating the swirling flow, which is imposed by the bend 19 or by the flow drive 6. In addition, by dividing the flow into several flow channels 21, the imposed swirl is partitioned early on and weakened via the flow channel wall and internal fluid friction. The flow channels 21 are guided in such a way that they are not in collision with the bypass flow channels 13.

Now referring to Fig. 5, in which an entire flow system 1 is shown, wherein the flow device 3 from Figs. 1 and 2 is arranged in a water basin 2. It should be made clear that the cross section 23 of the countercurrent 4 in the area of the subject 5, which in the case of Fig. 5 is a swimmer 5 who swims at a distance from the flow device 3, widens from the drive outlet 10 towards the swimmer 5. The drive channel outlet 10 therefore does not have to be the same size as the swimmer 5, but it is preferred that the drive channel outlet 10 has the cross-sectional shape of a transversely flat projection of a swimmer 5, below the waterline 11 in a prone swimming position, with arms crossed in front of the body. By the time the countercurrent 4 has reached the swimmer 5, it has expanded to such an extent that all common swimming movements, such as breaststroke, butterfly and crawl, can be reliably and precisely supplied with current without supplying more current than necessary. The crawl movement with the outlet shape described above is shown in Fig. 6.

It should also be mentioned that the cross-sectional shape of the drive channel outlet 10 or the drive channel outer edge 16 can also be shaped as a round hole, oval or slot. Likewise, the size, number, orientation and cross-sectional shape of the bypass channels 13 in relation to the geometric design of the at least one drive channel outlet 10 can determine how far the counterflow 4 expands to the float 5 and which cross-section of the counterflow 4 actually reaches the float 5. Thus, by drawing water through the bypass channels 13, even a round cross-section of the drive channel outlet can be converted into a non-round cross-section of the counterflow 4, with suitable distribution. It should be noted that the boundary condition of the water surface or water line 11 also has an influence on the shape of the cross-section of the counterflow 23. Fig. 6 shows the drive channel outer edge 16 as a dashed line and the cross section of the countercurrent 23 as a solid line. The same applies to Fig. 7, Fig. 8, and Fig. 9, whereby the respective drive channel outer edge 16 and thus the cross section of the countercurrent 23 are each adapted to the subject 5. In concrete terms, the respective subject 5 is a walking person 5 in Fig. 7, a swimming or walking horse 5 in Fig. 8, and a swimming dog 5 in Fig. 9.

Fig. 11 shows an embodiment of a flow system 1 in which the flow device 3 is flat or flush with a water basin front wall. It can also be understood that the water basin 2 has a water-conducting niche or recess in which the flow device 3 is placed.

Fig. 12 shows a further embodiment of a flow system 1 in which a drive channel 8 extends into a water basin 2. It should be noted that the drive channel 8 can also be arranged at any location in the water basin 2.

Fig. 13 shows yet another embodiment of a flow system 1 in which the drive channel 8 runs outside the water basin 2, wherein a drive channel inlet 9 draws water in the region of a side wall of the water basin 2.

Fig. 14 shows a further embodiment of a flow device 3, wherein ten bypass channels 13 are arranged in a funnel-shaped drive channel outlet 10. It can be seen that the flow drive and motor 9 are arranged one behind the other in a frontal plane projection.

Fig. 15 shows a further embodiment of a flow device 3, wherein eight drive channel outlets 10 are penetrated by a grid-shaped bypass channel 13. It should be noted that the bypass channel 13 is connected to an imaginary drive channel outer edge 16 (shown in dashed lines), wherein the bypass channel 13 is still at least partially spaced from the imaginary drive channel outer edge 16.

In Fig. 16, a further embodiment of a flow device 3 is shown, wherein the drive channel outlet 10 is X-shaped and has four notch-like bypass channels 13, which are at least partially spaced from an imaginary drive channel outer edge 16 (shown in dashed lines). Fig. 17 shows a further embodiment of a flow device 3, wherein the flow device 3 is shown with two drive channels 8. The two drive channels 8 are penetrated in the middle by a secondary flow channel 13. It should be noted that in order to obtain the embodiment of Fig. 17, two separate flow devices 3 can also be combined in a combination Z. Similarly, for example, any number of flow devices 3 of Fig. 16 can be arranged next to one another in order to obtain a flow system 1 which can output a counterflow 4 from an entire wall of a water basin 2.

It should also be noted that the flow drive can also be designed from several counter-rotating propellers, or as a propeller with a guide device in order to impart a reduced swirl to the counterflow.

Likewise, at least one bypass channel can be provided with rounding radii in order to achieve a more favorable inflow or outflow of water from it. The drive channel inlet and/or the drive channel outlet can also be provided with rounding radii.

Another way to provide a swirl-free flow is to use two opposing drive channels that converge in a Y-shape or T-shape, each with a flow drive. The swirl is emitted in opposite directions and at the same magnitude by each flow drive, in order to produce a swirl-free flow.

It is also conceivable to provide adjustable deflection elements or closure elements on the drive channel and/or bypass channel. This would allow two divided countercurrents to be efficiently provided for two swimmers or swimming subjects in the same water basin at the same time. The adjustable closure elements could be used to provide a strong and a weak countercurrent for the respective swimmers or swimming subjects. It would also be conceivable to direct the countercurrent to the edge of the water basin in order to obtain a ring-shaped flow without changing the installation angle of the flow device.

It should also be mentioned that the flow system can firstly be provided as a built-in system, whereby the flow device is integrally installed in the water basin. Secondly, the flow system can also be provided in such a way that the flow device consists of is designed to be removable from the water basin, whereby it can be designed to be suspended from the edge of the water basin.

Finally, it should be noted that in one embodiment, the drive channel outer edge can have the cross-sectional shape of the combinatorial shell of transversely planar projections of a swimmer in a breaststroke, butterfly stroke and front crawl stroke below the waterline. This provides a particularly efficient counterflow from the drive channel outlet, since only the most relevant cross-section around a swimmer is subjected to a counterflow.

Claims

Patent claims: 1. Flow system (1) comprising a water basin (2) and at least one flow device (3) for generating a countercurrent (4) for a subject (5) in the water basin (2), wherein the flow device (3) comprises: at least one flow drive (6) which is driven by at least one motor (7) of the flow device (3), and at least one drive channel (8) in which, by means of the flow drive (6), a pressure difference between at least one drive channel inlet (9) and at least one drive channel outlet (10) can be generated, wherein the drive channel inlet (9) and drive channel outlet (10) are arranged below a water line (11) of the water basin (2), and wherein the drive channel outlet (10) is aligned to output the countercurrent (4) along a countercurrent direction (12), characterized in that the flow device (3), or a combination (Z) of at least two flow devices (3), has at least one bypass channel (13) with at least one bypass channel inlet (14) and a bypass channel outlet (15), wherein the at least one bypass channel (13) is at least partially spaced from a drive channel outer edge (16), and wherein the bypass channel outlet (15) is aligned substantially along the counterflow direction (12). 2. Flow system (1) according to claim 1, characterized in that the bypass channel inlet (14), pointing against the counterflow direction (12), is arranged behind the bypass channel outlet (15) and the bypass channel inlet (14) and bypass channel outlet (15) are formed substantially rectilinearly with respect to their centers (17). 3. Flow system (1) according to one of the preceding claims, characterized in that the flow drive (6) and the motor (7) are located outside a frontal plane projection of the bypass channel outlet (15) and that the bypass channel inlet (14) is arranged at a distance from the water basin (2). 4. Flow system (1) according to one of the preceding claims, characterized in that the drive channel outlet outer edge (16) has the cross-sectional shape of an envelope of frontal plane projections of the subject (5), below the waterline (11). 5. Flow system (1) according to one of the preceding claims, characterized in that the drive channel outlet (10) has a perforated plate (18) with at least two holes through which the counterflow (4) exits, wherein the holes are dimensioned and arranged such that a counterflow (4) that is as homogeneous as possible or a flow velocity that is always the same is provided from the holes. 6. Flow system (1) according to one of the preceding claims, characterized in that the drive channel (8) has a bend (19), wherein the bend (19) continuously transfers the cross section of the drive channel inlet (9) to the cross section of the drive channel outlet (10). 7. Flow system (1) according to one of the preceding claims, characterized in that a housing (20) surrounds the flow drive (6) and the drive channel inlet (9) at a distance, wherein the housing (20) is adjustable in length in order to reach a bottom of the water basin (2). 8. Flow system (1) according to claim 7, characterized in that the housing (20) has an interface with perforations, wherein the perforations are dimensioned such that a single perforation has an opening area of less than 1 cm ² , preferably less than 0.5 cm ² , or has an opening diameter of less than 8 mm, or greater than 25 mm. 9. Flow system (1) according to claims 5 and 6, characterized in that the manifold (19) has a plurality of flow channels (21), wherein the flow channels (21) are individually connected to the holes of the perforated plate (18). 10. Flow system (1) according to claim 9, characterized in that a length and a diameter profile and a flow channel curvature of the flow channels (21) are dependent on their relative position to the flow drive (6) and drive channel outlet (10) so that an equal flow velocity emerges from the holes and/or a counterflow is maintained for an adapted swimming feeling.