METHOD AND TRANSDUCER FOR TREATING THE WATER IN A BASIN

Abstract: Method to treat the water in a basin, in particular to at least remove certain organisms from the water (4) of the basin (1) and to fight them, characterised in that it consists of producing vibrations (3) in the water (4), in particular vibrations (3) which suppress the organisms concerned by means of resonance.

Description: METHOD AND TRANSDUCER FOR TREATING THE WATER IN A BASIN The present invention concerns a method and a device to treat the water in a basin, in particular to at least remove certain organisms from the water of the basin and to fight them. By a basin is understood any pool in any shape whatsoever according to the invention, containing water, either of natural or artificial origin. In the first place are meant swimming pools, water collection basins, water tanks and ponds, but in a more general way it is not excluded to apply the invention in harbour docks and such. The invention is in the first place meant to prevent algal growth in the water, but in a more general way it is not excluded to apply the invention also to suppress other organisms, such as fungi and the like. In swimming pools for example, it is known that, due to the formation of algae, the water becomes less limpid and the bottom, the walls and the accessories which are found in the swimming pool, such as steps and ladders, are contaminated with a green layer of algae. This layer of algae is not only unaesthetic, it also forms a slippery layer which is dangerous for the users of the swimming pool, as they can slip on it. Moreover, the presence of such algae is little hygienic. In certain areas of the world, among others in South- Africa, depending on the climatic conditions, the formation of algae in swimming pools is a true plague. In this case, the algae are fought by putting an excess of chlorine in the water, which of course results in certain disadvantages, such as an unpleasant smell and health risks for the users of the swimming pool . In natural water basins such as ponds and the like, it is of course impossible to fight the algae with chlorine, and other, usually labour-intensive methods have to be applied. The invention aims a method and a device for treating the water of a basin, which make it possible to efficiently remove and/or fight at least certain organisms and/or contaminations. In particular, it aims a method and a device with which algae can be suppressed, without any chlorine having to be used to this end, and without any other chemicals having to be used to this aim. As far as the application in swimming pools is concerned, the aim is to at least exclude an excess of chlorine. To this end, the invention in the first place concerns a method, characterised in that it consists of producing vibrations in the water, in particular vibrations which suppress the organisms concerned. By applying vibrations according to the invention, the above-mentioned organisms, in particular the algae, can be destroyed in no time, and the growth of new algae can be easily prevented in a permanent manner. In new installations, the growth of algae is prevented from the beginning. It should be noted that the vibrations are easily transmitted in liquid, so that the entire mass of water can be easily covered, and it is possible to obtain a large efficiency with a relatively small capacity. According to a particularly important aspect of the invention, vibrations are used which damage the organisms or parts thereof by means of resonance effects created therein. In the case of algae, the algae die as the vacuoles in the alga cells are ripped apart and implode in the algae as a result of the resonance. De dead algae can then be easily removed from the water, for example in the case of a swimming pool by means of a pool vacuum cleaner or in any other way whatsoever. In particular, use is preferably made of vibrations in the ultrasonic range, preferably at least in the frequency range of 20 to 35 kHz. A very efficient suppressing method is obtained when vibrations having different frequencies are generated. According to the most preferred embodiment, the frequency will be periodically altered. By changing the range of the frequency, various frequencies get a chance to act, resonance vibrations are produced in all the aimed organisms, in particular in the algae, as a result of which they are killed. Preferably, different frequencies are applied in steps, so that at least every frequency concerned gets a chance to act for a specific length of time, as a result of which the organisms are subjected with great certainty for a certain length of time to the vibrations they resist the least. According to the most preferred embodiment, the applied vibrations will be interrupted, preferably periodically. This creates so to say a shock effect. Indeed, the inventor found that the organisms concerned, in particular the algae, can resist this even less. Preferably, the periodic lengths between the changes and/or interruption periods of the vibrations last at least 2 seconds . Use is preferably made of vibrations which consist of a square wave, or which approach a square wave. The square wave can hereby have a local deformation, preferably in the shape of a protruding lip in the waveform, better still a lip which connects to one or both flanks of the square wave, in particular in the shape of what is called an overshoot. A large quantity of harmonics are created by this lip, so that the range of frequencies with which the organisms are fought is considerably increased. According to a practical embodiment, use is made of a vibration source to generate the vibrations, consisting of a transducer. Such a transducer offers the advantage that it is small and can be made water-resistant, so that it can be mounted under water, and thus in direct contact with the water, which promotes an optimal efficiency. It is not excluded, however, to use other vibration sources, preferably however vibration sources that are fit to be placed under water. The invention also concerns a device to realise the above- described method, characterised in that it mainly consists of a vibration generator and at least one vibration source coupled thereto which is fit to produce vibrations in the water of a basin. Preferably, the vibration generator is provided with an electronic circuit which makes it possible to generate vibrations of the above-described frequencies and/or waveforms . This device is preferably built-in permanently in the basin, but it is not excluded to provide a mobile device which can for example be put in the basin daily for a couple of hours, for example during the night. It is clear that the invention also concerns basins, in particular swimming pools, which are equipped with such a device . The invention also concerns a transducer, in particular a transducer which is specially designed for realising the above-mentioned method and device, characterised in that this transducer contains at least one strip-shaped vibrating element which resonates when an electric signal is given having a frequency between 20 and 35 kHz. The intermediate frequency is preferably situated at about 27.5 kHz, and the vibrating element has a bandwidth of two times 7.5 kHz, on either side of the medium frequency respectively. Further, this transducer according to the invention is made water-tight, and there is preferably no air lock between the actual vibrating element and the water. Also in the case when another vibration source is applied, such an air lock is preferably avoided. In order to better explain the characteristics of the invention, the following preferred embodiments of the invention are described as an example only without being limitative in any way, with reference to the accompanying drawings, in which: figure 1 schematically represents a swimming pool which is equipped with a device according to the invention; figure 2 represents the part indicated by F2 in figure 1 as a section and to a larger scale; figure 3 represents a waveform of the vibrations which are preferably applied; figure 4 represents a schematic variant of the part which is indicated by arrow F4 in figure 1; figure 5 shows a variant of an application of the invention. Figure 1 represents a basin in the shape of a swimming pool 1 which is equipped with a device 2 according to the invention to generate vibrations 3 in the water 4 in correspondence with the above-mentioned method of the invention. The device 2 mainly consists of a vibration generator 5 and at least one vibration source 6 which is fit to generate the above-mentioned vibrations 3. The vibration generator 5 consists of a circuit which makes it possible to generate electric vibrations which are transformed in acoustic vibrations at the vibration source 6. It is clear that this vibration generator 5 preferably has an electronic nature and is built such that vibrations are produced having the characteristics mentioned in the introduction. On the basis of the information mentioned in the introduction regarding the nature and form of the vibrations, any professional will know how the electronic circuit is built. That is why the exact construction of such a circuit is not described in detail. Although, in principle, the vibration source 6 may be of any nature whatsoever, use is preferably made, as represented in figures 1 and 2, of an underwater transducer. Such a transducer offers the advantage that it is small and is ideally fit to generate the vibrations concerned in the water 4, and it can be mounted under water itself . As represented in figure 2, the transducer preferably contains a vibrating element 7, consisting of a laminated structure, in particular of ceramic material, which starts vibrating when an electric signal produced by the vibration generator 5 is transmitted to it . In the example represented in figure 2, the transducer has a tubular housing 8 made of plastic, for example PVC. In order to obtain an optimum effect, the vibrating element 7 is disconnected from said housing 8, by means of a structure made of foam plastic, preferably urethane, provided between this vibrating element 7 and the housing 8. The water-tight sealing of the whole, as well as the embedment of the connector 10, are obtained by means of an epoxy mass 11 and plastic sealings 12 and 13, preferably made of urethane. The transducer has a diameter in the order of magnitude of 5 cm and a length of about 13 cm. The vibration source 6, in this case the transducer, can be fixed to a support 14, such as an -shaped strut which is fixed to the wall 15 of the swimming pool 1, as represented in figure 1. The support 14 is preferably attached by means of a glued assembly so as not to undermine the watertightness of the wall 15. Preferably, the vibration source 6, and in particular the transducer, is mounted at a short distance under the normal water level 16. This offers the advantage that only a small volume of water will have to be drained from the swimming pool 1 in view of the mounting. Another advantage consists in that the transducer can be accessed as of the edge of the swimming pool 1, such that, if necessary, said transducer can be detached from the support 14 out of the water, for example when it needs to be replaced. Practically, the vibration source 6, in particular the transducer, is mounted at a distance D of about 30 cm under the water level 16. As represented in figures 1 and 2, the vibration source 6, i.e. the transducer, is directed with the main direction Z according to which the vibrations 3 are transmitted in the longitudinal direction of the swimming pool l. Thus, the distance to the opposite wall 17 is kept as long as possible, and the risk of waves being reflected which considerably attenuate the forward wave is minimised. Also, the main direction Z is preferably horizontal or practically horizontal . Further, a vibration source 6 is preferably used with an effective transmission angle A of at least 100 degrees, and better still 180 or almost 180 degrees, as indicated in figure 2. Thanks to the above-mentioned erection, in particular the horizontal positioning in combination with the large transmission angle A, one obtains that the vibration waves reflect against the bottom side of the water level 16, and that the signal is scattered, so that the creation of standing waves is excluded, or the risk thereof is minimal. The vibration generator 5 is preferably situated above the water and is connected to the vibration source 6 situated under the water via a cable 18. According to a variant which is not represented, it is not excluded, however, to build the vibration generator 5 and the vibration source 6 as a whole which is mounted under the water. According to yet another possibility, the vibration source 6 can be mounted in a recess in the wall of the swimming pool 1 instead of on a support 14, such that it does not hinder the users of the swimming pool 1. According to yet another variant, the vibration generator 5 and the vibration source 6 can be mounted in a housing 19 which has a shape as indicated by the dashed line in figure 1, such that the presence of the part situated above the water 4 automatically has for a result that the users of the swimming pool 1 cannot get into contact with the vibration source 6. The vibration generator 5 can be fed as such via a connection to the mains or such. The working of the device 2 can be easily derived from what precedes and mainly consists in that, when the vibration generator 5 is switched on, vibrations 3 as mentioned above are produced which fight the organisms concerned, in particular the algae. It is clear that the vibration generator 5 can be switched on either permanently, either regularly during a certain period, whereby it can be switched on either or not automatically in the latter case. Although the ultrasonic soun d h as no influence whatsoever on people, it is not exclu d ed to switch off the device 2 every time a user is in t h e swimming pool 1, for example by means of a sensor. For clarity's sake, figure 3 represents an embodiment of the waveform 20 which is preferably applied and which, as alrea d y explained in the introduction, consists of a square wave with a lip 21 in the shape of an overshoot. Figure 4 schematically represents another variant whereby the vibration source 6 is situated above the water, and the vibrations 3 are conducted in the water 4 by means of a conducting channel 22, whereby this conducting channel 22 is preferably also filled with water. It is clear that the invention can be used both in conventional swimming pools and in other types of swimming pools, such as bio swimming pools, by which are meant swimming pools in which grow plants. Especially for such bio swimming pools, the invention is particularly useful, as the use of chlorine is excluded because of the plants. It can also be used in ponds, lakes, harbour docks, storage reservoirs and the like. Figure 5 shows an example of such a bio swimming poo l 1 . In the known manner, it consists of at least two parts, a first part 23 in which are provided plants an d which functions as a water treatment basin, and a second part 2 4 respectively in which can be swum and which is usually deeper than the first part 23. On the bottom of the first part 23 is provided a layer of gravel 25, upon which can be formed a layer of bacteria. The water 4 is pumped round through the gravel in a manner which is not represented here, so that a purification effect is obtained with the help of the above-mentioned layer of bacteria. By equipping the bio swimming pool 1 with a device 2 according to the invention, it is possible to suppress the algae as mentioned above. It should be noted that not only algae on the walls of the parts 23 and 24 are suppressed, but also string algae which are easily formed in such bio swimming pools 1. It should be noted that the use of a vibration source 6, combined with the conventional elements of such a bio swimming pool, forms an ideal combination to keep said swimming pool 1 clean. Because of the large mass of water which is situated in the swimming pool 1, a good dissipation of the energy is obtained, such that algae which are very sensitive to the vibrations concerned are killed, whereas the less sensitive bacteria which clean the water together with the plants are preserved. Moreover, the invention makes it possible to search for optimal frequencies and bandwidths for the vibrations 3, so that certain organisms, by which are meant the algae in the first place, are efficiently suppressed, whereas other organisms are preserved. Preferably, the vibration source 6, and in particular the transducer, is provided in the first part 23. This offers the advantage that the algae, and especially the string algae which are formed where the plants are situated are optimally suppressed. Another advantage is that the vibration source 6 is more or less hidden behind the plants and is situated in the part where there is no swimming normally, so that the users of the swimming pool 1 are not hindered by i . Finally, it should be noted that even with a small capacity, for example of 15 Watts or less, the transducer already offers very good results and its use is also ecologically sound as far as energy consumption is concerned. Although the invention was explained in relation to the application in a swimming pool in the preceding detailed description, it is clear that it can also be applied in an identical manner in other basins. According to a variant of the embodiment which is not represented in the drawings, the vibration source can be fixed to a float, such that the whole can be simply placed in the water without any special supporting structures having to be provided. Preferably, the vibration source is fixed such under the float that the vibrating element is situated underneath the water surface. Such an embodiment with a float offers the advantage that it can be easily removed and can be used anywhere. Also in the case of the embodiment with a float, use will be preferably made of a transducer, but other forms of vibration sources are not excluded. The electronic unit which is required to generate the vibrations can be either or not attached to the float. Finally, it should be noted that the choice of the operating frequencies depends on the organisms to be fought, as the resonance effects in these organisms can vary. Naturally, these frequencies can be established by experiment . The invention is by no means limited to the above-described embodiments represented in the accompanying drawings; on the contrary, such a method and device for treating the water of a basin can be made in all sorts of variants while still remaining within the scope of the invention.

Claims: Claims . 1. Method to treat the water in a basin, in particular to at least remove certain organisms from the water (4) of the basin (1) and to fight them, characterised in that it consists of producing vibrations (3) in the water (4) , in particular vibrations (3) which suppress the organisms concerned. 2. Method according to claim 1, characterised in that vibrations (3) are applied which fight algae. 3. Method according to claim 1 or 2 , characterised in that use is at least made of vibrations (3) in the ultrasonic range, in particular vibrations which are selected such that the organisms are fought by means of resonance effects. 4. Method according to claim 3, characterised in that use is at least made of vibrations (3) in the frequency range of 20 to 35 kHz. 5. Method according to any of the preceding claims, characterised in that vibrations (3) having different frequencies are generated. 6. Method according to claim 5, characterised in that the frequency is periodically changed, preferably in steps. 7. Method according to any of the preceding claims, characterised in that vibrations (3) are applied which are interrupted, preferably periodically. 8. Method according to claim 6 or 7, characterised in that the periodic lengths between the changes and/or interruption periods of the vibrations (3) last at least 2 seconds . 9. Method according to any of the preceding claims, characterised in that use is made of vibrations (3) which consist of a square wave, or which approach a square wave. 10. Method according to claim 9, characterised in that the square wave is provided with a local deformation, preferably in the shape of a protruding lip (21) in the waveform (20) , better still a lip (21) which connects to one or both flanks of the square wave, in particular in the shape of what is called an overshoot. 11. Method according to any of the preceding claims, characterised in that use is made of a vibration source (6) to generate the vibrations (3) , consisting of a transducer. 12. Method according to any of the preceding claims, characterised in that use is made of a vibration source (6) which is provided under water or which is in direct contact with the water (4) of the basin (1) , and whereby any form of an air lock between the actual vibrating element and the water is preferably excluded. 13. Method according to any of the preceding claims, characterised in that use is made of a vibration source (6) whose main direction (Z) according to which the vibrations (3) are transmitted meet one or both of the following criteria: - that this main direction (Z) is directed according to or predominantly according to the longitudinal direction of the basin (1) ; that this main direction (Z) is horizontal or practically horizontal. 14. Method according to any of the preceding claims, characterised in that a vibration source (6) is applied with an effective transmission angle (A) of at least 100 degrees, and better still 180 or almost 180 degrees. 15. Device for realising the method according to any of the preceding claims, characterised in that it mainly consists of a vibration generator (5) and at least one vibration source (6) which is fit to produce vibrations (3) in the water (4) of a basin (1), in particular vibrations (3) of the nature as described in any of claims 1 to 10. 16. Device according to claim 15, characterised in that the vibration source (6) consists of an underwater transducer. 17. Device according to claim 16, characterised in that the transducer contains a vibrating element (7) , consisting of a laminated structure which is made to vibrate, in particular made of ceramic material . 18. Device according to claim 16 or 17, characterised in that the transducer has a tubular housing (8) and has a vibrating element (7) which is disconnected from said housing (8) , preferably by means of foam plastic. 19. Device according to any of claims 15 to 18, characterised in that it also contains a float, onto which the vibration source (6) is attached, such that the latter is situated underneath the water surface when the float floats on the water. 20. Basin, characterised in that it is equipped with a device (2) according to any of claims 15 to 19. 21. Basin according to claim 20, characterised in that it is a bio swimming pool (1) consisting of at least two parts, a first part (23) in which are provided plants and a second part (24) to swim in respectively, whereby the vibration source (6) is situated in the first part (23) . 22. Transducer, in particular for realising a method or a device according to any of claims 1 to 19, characterised in that this transducer has at least one strip-shaped vibrating element which resonates when an electric signal is given having a frequency between 20 and 35 kHz. 23. Transducer according to claim 22, characterised in that the intermediate frequency is situated at about 27.5 kHz, and in that the vibrating element has a bandwidth of at least two times 7.5 kHz, 7.5 kHz on either side of the medium frequency respectively. 24. Transducer according to claim 22 or 23, characterised in that it is made water-tight.

Inventors: THOMAS HILAIRE FERNAND ACHILLE, THOMAS, HILAIRE, FERNAND, ACHILLE
Applicants: THOMAS HILAIRE FERNAND ACHILLE, THOMAS, HILAIRE, FERNAND, ACHILLE
Application year: 1999
Main classification: C02F1
IPC codes: A61L2, C02F1