DEVICE FOR THE MECHANICAL TREATMENT OF A LIQUID SUCH AS WATER

Description

technical field

[0001] The present invention relates to a device for the mechanical treatment of a fluid such as water, arranged to be placed on the path of a fluid circulating in a pipe of an installation, to restructure said fluid in order to avoid in particular the encrustation of limescale and / or the formation and deposition of sludge and / or the phenomena of corrosion, said device comprising a body with a longitudinal axis provided at its two ends with two fittings delimiting a fluid inlet orifice and a fluid outlet orifice, said fittings being arranged to mount said device in series in said pipe, said body comprising at least one channel extending between said inlet orifice and said outlet orifice for the passage of the fluid, and said device comprising at least one deflector arranged to transform a linear movement of the fluid entering said device into a vortex movement of the fluid exiting said device. Previous technique

[0002] For decades, various mechanical treatment devices have been known to treat moving fluids, such as water and aqueous solutions, in an environmentally friendly way—that is, without chemicals, energy input, consumables, or maintenance. These treatments improve the physicochemical properties of the fluids, regenerate and revitalize the water, and purify it to protect systems against limescale buildup, sludge formation and deposits, and other issues. This applies to both closed-loop heat transfer fluid circuits in heating and air conditioning systems and open-loop systems for domestic hot and drinking water. It is well known that these deposits lead to premature wear of the systems, increased energy consumption, reduced energy efficiency, and corrosion of the water network.

[0003] As an example, we can cite the devices described in the following publications: WO 81 / 02529 A1 which subjects the water circulating in a pipe to a magnetic field produced by permanent magnets arranged around said pipe to reduce limescale deposits in a heating circuit; EP 295 463 A2 which subjects the water circulating through a series treatment device in a pipe to a helical circular motion, combined with a magnetic field produced by permanent magnets in contact with the water to dissolve the salts contained in the water, in particular calcium carbonate, so that they remain longer in the dissolved phase, preventing their deposition and facilitating their removal; EP 1 810 952 A2 which subjects the water circulating to a helical circular motion through a double-walled housing, combined with high-quality spring water contained in the double wall to revitalize the water;US 2009 / 0321337 A1 which subjects water to pattern-forming crystals that revitalize the water; FR 2 989 678 A1 which subjects circulating water through a series treatment device in a conduit to a helical circular motion, combined with ultrapure water to permanently clarify water in closed heating systems, eliminate metallic and organic deposits and combat corrosion and abrasion.

[0004] We can also mention the devices described in the following publications: DE 20 2018 103659 U1 which subjects water to sinusoidal circulation and to a magnetic field produced by permanent magnets arranged outside, around the inlet and outlet orifices, to reduce limescale deposits in a heating circuit; DE 20 2008 009583 U1 which subjects water to helical circulation in an annular channel around a central body and to heat diffused by an energy source contained in said central body to oxygenate and purify drinking water.

[0005] Another device corresponding to the first embodiment which is not part of the present invention is presented on the following websites: https: / / drag-al.com.br / Eficalk.pdf and https: / / www.youtube.com / watch?v=CaJRktN8dZE.

[0006] These well-known treatment devices have the drawback of often being dedicated to a specific type of treatment and / or application, requiring the design of different devices to meet the needs of different treatment types and / or applications. Furthermore, some devices create pressure losses that are detrimental to the efficiency of a plant, are difficult to install, can be bulky and / or disrupt the environment, can release particles into the circulating water, etc. Presentation of the invention

[0007] The present invention aims to overcome these drawbacks by proposing a treatment device of simple design, reliable, food grade, durable, maintenance-free, consumable-free, modular so that it is versatile, i.e. easily adaptable or configurable according to the desired treatments and applications, generating negligible or even zero pressure losses, designed reversibly for easy installation, without risk of assembly error, ecological and environmentally friendly.

[0008] To this end, the invention relates to a device according to claim 1.

[0009] According to the invention, said device comprises a central tube extending along the longitudinal axis, and said at least one deflector comprises a mounting section assembled to said central tube, and a head provided with means for diverting the fluid and connected to said mounting section by a base.

[0010] According to the invention, the head of said at least one deflector is a flat head perpendicular to said longitudinal axis, and said fluid deflection means consist of radial blades inclined in the direction of the fluid from said inlet orifice to said outlet orifice.

[0011] In this second variant, the device may comprise two deflectors, each with blades, arranged in the same direction, opposite the inlet and outlet orifices respectively, such that the device is not reversible. Advantageously, the channels are regularly distributed around the central tube. They may comprise at least two sets of channels of different diameters, alternating with each other and regularly distributed around the central tube.

[0012] At least a portion of said channels forms a housing to receive at least one reactive element freely disposed in the path of said fluid circulating through said device, so that said at least one reactive element vibrates, strikes the walls of the channel which contains it, and transmits to the fluid mechanical sound waves which have the effect of destroying the sludge and / or limestone crystals present in the fluid.

[0013] The base of said deflectors may have a transverse dimension greater than the transverse dimension of said central tube and less than the internal transverse dimension of said body in order to partially close at least a part of said channels and form an axial stop for said at least one reactive element.

[0014] Said at least one reactive element may be chosen from the group of materials including ceramics, minerals, organic materials, glass, precious and / or semi-precious stones, or a combination of these materials, and may have a form chosen from the group including beads, granules, fragments, cylinders, these forms being solid or hollow, or a combination of these forms.

[0015] Said at least one or both deflectors may be hollow and include a cavity closed by a plug. In this case, they may also include at least one active element housed in said cavity, chosen from the group comprising mechanical wave emitters, magnetic field emitters, electromagnetic wave emitters, or a combination of these emitters, and arranged to transmit said waves to the fluid, having the effect of destroying the sludge and / or limestone crystals present in the fluid.

[0016] The central tube can be hollow and also form a housing to receive at least one active element.

[0017] The said device advantageously constitutes a modular device and the assembly of the plugs on the deflectors and / or the assembly of the deflectors on the central tube are demountable assemblies so as to be able to modify the contents of said cavities, of said central tube and / or of said channels according to the water treatment to be carried out. Brief description of the figures

[0018] The present invention and its advantages will become more apparent from the following description of an embodiment given by way of non-limiting example, with reference to the accompanying drawings, in which: there figure 1 is an exploded perspective view of a device according to a first embodiment which is not part of the present invention, the figure 2 is a top view of the device figure 1after assembly, the figure 3 is an exploded plan view of the device of the figure 1 , there figure 4 is a top view of the device figure 3 without the connector, the figure 5 is an axial cross-sectional view of the device of the figure 1 after assembly, the figure 6 is a top view of the device figure 5 without the connector or the deflector, the figure 7 is a perspective view of a device according to a second embodiment of the invention, without the fittings, the figure 8 is a top view of the device figure 7 , and the figure 9 is an axial cross-sectional view of the device of the figure 7 . Detailed description of the invention

[0019] In the illustrated embodiments, identical elements or parts bear the same reference numbers. Furthermore, terms with a relative meaning, such as vertical, horizontal, right, left, front, back, above, below, etc., must be interpreted under normal conditions of use of the invention, and as shown in the figures.

[0020] With reference to the figures, the treatment device 1, 100 according to the invention is designed to be installed in series in any type of plumbing, heating, air conditioning, and / or cooling system, whether open or closed circuit. It is specifically designed to be inserted into a pipe (not shown) belonging to said system, so as to allow the passage of a moving fluid, such as water with or without glycol, with or without additives such as corrosion inhibitors, pH regulators, and other chemicals, aqueous solutions, or other fluids. Its purpose is to act on the circulating fluid to agitate and restructure it in order to improve its physicochemical properties and / or prevent limescale deposits and / or the formation and deposition of sludge and / or corrosion.It constitutes a simple and versatile mechanical device as explained below thanks to a modular construction method which allows it to be easily configured and made compatible with the intended application.

[0021] To this end, the device 1, 100 according to the invention comprises a body 2 with longitudinal axis A, provided at its two ends with two fittings 3, 4, defining a fluid inlet 5 and a fluid outlet 6. The fittings 3, 4 and the inlet 5 and outlet 6 are preferably centered on the longitudinal axis A to create a straight device 1, 100 aligned with the axis of the pipeline. The fittings 3, 4 are assembled to said body 2, for example, by screwing. For this purpose, they comprise a mounting section 7 provided with a tapped internal bore 8 cooperating with a threaded external section 9 provided in the ends of said body 2. Of course, any other equivalent means of assembly may be suitable; the essential point is that said fittings 3, 4 are removable to access said body 2.The fittings 3 and 4 further comprise an end section 10 with a tapped internal bore 11 for attaching the device 1 to hydraulic fittings provided at the ends of a pipeline. The thread pitch of the tapped hole is, of course, adapted to the thread pitch of the hydraulic fittings, which are generally standardized country by country. Connection flanges may also be used in other cases. The end section 10 further comprises gripping means 12 for a tool, for example, a square shape, for tightening and loosening the fittings 3 and 4 on the corresponding hydraulic fittings of the pipeline. Any other shape of gripping means 12 may be suitable; the essential point is that it is adapted to the tool used for the hydraulic connection.The device 1, 100 has a generally cylindrical shape because it is designed to be compact and space-saving for easy in-line installation in a pipeline, regardless of the surrounding space available. Of course, any other shape may be suitable. It can be fitted with sealing means (not shown) placed between the contacting surfaces of said body 2 and said fitting ends 3, 4, and conventionally inside the hydraulic fittings, such as O-rings, annular seals, Teflon® tape, or similar.

[0022] The body 2 comprises a plurality of channels 13, 13' for the passage of the fluid through the device 1, 100. These channels 13, 13' are straight, parallel to the longitudinal axis A, and through-channels. They may comprise at least two sets of channels 13, 13', the channels 13 of the first set having a transverse dimension greater than that of the channels 13' of the second set. The number of different channel sets is not limited to two. It may vary depending on the transverse dimension of the body 2. In the example shown, the channels 13, 13' are cylindrical, and the transverse dimension corresponds to the diameter of said channels. However, any other channel shape may be suitable. They are distributed around the longitudinal axis A, preferably in a regular manner. To this end, the channels 13, 13' of the two sets are alternated to allow for a uniform distribution of said fluid through the device 1, 100.These channels 13, 13' are also adjacent, or even tangent to each other, to optimize the fluid passage volume relative to the volume of the body 2. Advantageously, the diameter of the channels 13, 13' and their number are determined by calculation so that the sum of these diameters is equal to or very close to the internal diameter of the pipe in order to minimize or even eliminate the pressure losses due to said device 1, 100. The internal diameter of the pipe can correspond to that of the fittings 3, 4.

[0023] At least some of these channels 13, 13' contain one or more reactive elements 15 that will interact with the circulating fluid to modify its molecular structure. These reactive elements 15 can be selected and adapted according to the intended application and the desired treatment, several examples of which are given in the available literature on this subject. In particular, they can be made from materials selected from the group including ceramics, minerals such as quartz, organic materials such as amber, glass, precious and / or semi-precious stones, or a combination of these materials. They can also be in one or more shapes selected from the group including beads, granules, fragments, cylinders, these shapes being either solid or hollow, or a combination thereof.

[0024] The device 1, 100 includes at least one deflector 16, 160 centered on the longitudinal axis A and positioned opposite the inlet orifice 6 to deflect the incoming fluid and instantaneously transform a linear motion of the fluid entering the device 1, 100 into a vortex motion of the fluid passing through and exiting said device 1, 100. The deflector 16, 160 is interposed between the inlet orifice 6 and the body 2, such that the plurality of channels 13, 13' is located downstream of the deflector 16, 160. The deflector 16, 160 is assembled to the body 2 by any suitable fastening means. In the illustrated examples, it is assembled by screwing it to a central tube 14, via a threaded mounting section 18 cooperating with a tapped internal bore 19 provided in the ends of the central tube 14.

[0025] In a first embodiment which is not part of the present invention, illustrated more particularly in the figures 1 to 6The device 1 includes a deflector 16 and preferably two deflectors 16, 17 arranged respectively opposite the inlet orifice 6 and the outlet orifice 7. They are mounted in opposition, back to back, centered on the longitudinal axis A.

[0026] The deflectors 16 and 17 each have a conical head 21 mounted on a section 18. The pointed apex of the conical head 21 of the deflectors 16 and 17 is directed respectively towards the inlet orifice 5 and the outlet orifice 6. The conical head 21 includes deflection means in the form of a spiral 22 which deflects and creates a vortex-like motion of the fluid entering the device 1. The spiral 22 is formed, in particular, by a groove extending from the apex 23 of the conical head 21, which coincides with the longitudinal axis A, towards the base 24 of the conical head 21.

[0027] In a second embodiment according to the invention, illustrated more particularly in the figures 7 to 9The device 1 comprises a deflector 160 and preferably two deflectors 160, 170, arranged respectively opposite the inlet orifice 6 and the outlet orifice 7. They are mounted in the same direction, centered on the longitudinal axis A. The deflectors 160, 170 each comprise a flat head 210 which surmounts a mounting section 18. The flat head 210 comprises deflection means in the form of blades 220 which extend radially in a plane perpendicular to the longitudinal axis A. The blades 220 are inclined in the direction of the fluid which passes through the device 100, i.e. from the inlet orifice 6 towards the outlet orifice 7, to deflect and create a vortex motion of the fluid entering said device 1 and exiting said device, in the manner of a Vortex. Thus, the 220 blades of the upstream deflector 160 are inclined towards the channels 13, 13', and the 220 blades of the downstream deflector 170 are inclined towards the outlet orifice 7.

[0028] The base 24, 240 of the deflectors 16, 17, 160, 170 has a transverse dimension greater than the transverse dimension of the central tube 14 and less than the internal transverse dimension of said body 2 in order to partially obstruct the channels 13, 13' which may contain reactive elements 15. Thus, the base 24, 240 of the deflectors 16, 17, 160, 170 forms an axial stop for the reactive elements 15 by holding them captive inside the channels 13, 13'. In the illustrated example, the deflectors 16, 17, 160, 170 have a circular cross-section, and the transverse dimensions correspond to diameters. Some channels 13 of the first set contain, as reactive elements 15, small ceramic cylinders that can move freely inside each channel 13 without coming out. Thus, the fluid circulating through device 1, 100 and animated by a swirling motion jostles and agitates the reactive elements 15.The reactive elements 15 are set in motion, collide with each other if there are several in the same channel 13, hit against the walls of the channels 13 which contain them, and cause the emission of mechanical sound waves which have the technical effect of destroying the sludge and / or the limestone crystals present in the fluid.

[0029] The deflectors 16, 17; 160, 170 are preferably hollow parts and each has a cavity 31 closed by a plug 32 ( Fig. 5 And 9They too can contain one or more active elements 20 which will act on the molecular structure of the fluid as it passes over said deflectors 16, 17, 160, 170. The plug 32 can be assembled to the deflector 16, 17, 160, 170 by any suitable fastening means, to seal the corresponding cavity 31, whether hermetically or not, such as by screwing. Depending on the application, the cavities 31 of the deflectors 16, 17, 160, 170, or even the central tube 14 if it is hollow, can remain empty or contain one or more active elements 20 which will act on the molecular structure of the fluid circulating through said device 1, 100.These active elements 20 can be selected from the group comprising mechanical wave emitters (sound, ultrasound, infrasound), such as battery-powered electronic micro-emitters, magnetic field emitters, such as permanent magnets, electromagnetic wave emitters, such as electromagnets, or a combination of these emitters. The cavities 31 of the deflectors 16, 17, 160, 170 can be sealed or not by the plugs 32. Similarly, the central tube 14 can also be sealed or not by the deflectors 16, 17, 160, 170.

[0030] The body 2 comprises a central section 25 surrounded by two end sections 26, 27, the central section 25 having a transverse dimension greater than that of the end sections 26, 27, delimiting between them two shoulders 28. The body 2 having a general cylindrical shape, the transverse dimensions correspond to diameters. The shoulders 28 serve as axial stops for the fittings 3, 4 when they are assembled to said body 2. The length of the end sections 26, 27 of the body 2 is less than the depth of the mounting sections 7 of the fittings 3, 4 to create two chambers 29, 30 respectively downstream of the inlet port 5 and upstream of the outlet port 6. The chamber 29 downstream of the inlet port 5 allows the distribution of the fluid entering the body 2, and the chamber 30 upstream of the outlet port 6 allows the collection of the fluid exiting said body 2.The inner diameter of the fittings 3, 4 corresponding to the inlet 5 and outlet 6 ports is less than the outer diameter of the end sections 26, 27 of the body 2.

[0031] The first embodiment of device 1 is symmetrical with respect to a transverse plane perpendicular to the longitudinal axis A. Thus, device 1 is perfectly reversible, its inlet 5 becoming the outlet and its outlet 6 becoming the inlet, depending on the direction in which it is connected to the pipeline. This reversibility greatly facilitates its installation. Of course, the device could be asymmetrical and therefore non-reversible if required. This is the case with the second embodiment of device 100, which is not reversible due to the shape of its deflectors 160, 170.

[0032] Furthermore, the choice of detachable assemblies for the deflectors 16, 17; 160, 170, their cap 32, and the fittings 3, 4 allows their contents to be modified, as well as, where applicable, those of the central tube 14, and all or part of the channels 13, 13', giving the device 1, 100 infinite modularity to meet all possible applications. By way of non-limiting examples, and depending on the application, the device 1, 100 may include reactive elements 15 in certain channels 13, 13', combined with the vortex to prevent the formation and deposition of sludge in closed circuits, or the device 1, 100 may include as an active element 20 one or more permanent magnets in the cavity 31 of the deflectors 16, 17; 160, 170, and where appropriate in the central tube 14, combined with reactive elements 15 and the vortex to prevent the formation and deposition of limescale in open circuits.

[0033] The manufacture of device 1, 100 of the invention can utilize different materials depending on the intended application and the nature of the fluid to be treated. The various components of said device 1, 100, and in particular the body 2 and the deflectors 16, 17, 160, 170, can each be made from a solid, machined block of metal, notably stainless steel, such as food-grade 316L steel. This material offers numerous known advantages, such as durability, temperature resistance, corrosion resistance, inertness, and non-release of fine particles, etc. However, this example is not limiting and extends to any material that can withstand the extreme temperatures of the fluid to be treated, such as molded or blown glass, synthetic and / or composite materials that can be molded, injected, or 3D printed, etc.In addition, the materials chosen may contain recycled materials and / or may be recyclable.

[0034] The implementation of device 1, 100 is particularly simple since it only requires connecting it via its fittings 3, 4 between two hydraulic connections of a pipeline of any type of installation: drinking water, sanitary water, heating, air conditioning, cooling, irrigation, etc. It requires no power supply, no external connection, no chemicals, no consumables, and no maintenance.

[0035] When connected, device 1, 100 is placed in series along the path of the fluid circulating in the installation and does not disrupt its flow in any way. The pressure losses it generates are negligible, or even zero. The fluid entering device 1, 100 along the longitudinal axis A strikes the deflector 16, 160 located at the inlet port 6 (see figures 2 And 9The spiral 22 of the deflector 16 or the inclined blades 220 of the deflector 160 deflects the fluid, transforming its linear axial motion into a vortex motion around the longitudinal axis A, forming a vortex in the direction of the spiral 22 or the inclined blades 220, for example, to the right. The fluid, driven by this vortex motion, enters the channels 13, 13' and flows freely through them. The channels 13, 13' create passage reductions of varying diameters, generating turbulence within the vortex fluid and a multitude of Venturi effects, accelerating the fluid velocity in each channel. As it passes through some of the channels 13, the fluid carries the reactive elements 15 with it.These reactive elements 15, under the influence of turbulence and fluid velocity, are disturbed, jostled, buffeted, begin to oscillate, vibrate, collide, and strike the walls of the channels 13, transmitting mechanical sound waves to the fluid passing through them. Simultaneously, the fluid is subjected to the active elements 20 through the deflectors 16, 17; 160, 170, and receives a magnetic field before exiting device 1, 100. Upon exiting device 1, 100, the fluid has undergone several physical phenomena similar to those occurring in the natural environment, which have the effect of oxygenating, regenerating, purifying, restructuring, and activating the fluid.

[0036] The vortex creates turbulence in the flow, recirculating the sludge. Stones or ceramics break up the sludge by emitting sound waves. Permanent magnets disrupt the calcium and magnesium carbonate that forms limescale. Combining all or some of these technical effects advantageously modifies the fluid's molecular structure to improve its physicochemical properties, reduces its surface tension to increase its availability and assimilation, transforms the crystalline structure of limescale into inert, non-scaling aragonite to eliminate limescale deposits, pulverizes rust particles and other sludge to remove fouling from circuits, and so on.The present invention is of course not limited to the examples of embodiment described but extends to any modification and variant obvious to a person skilled in the art without departing from the scope of the annexed claims.

Claims

1. Device (100) for mechanically treating a fluid such as water, arranged to be disposed in the path of a fluid circulating in a pipe of a facility, in order to restructure said fluid in order to avoid, in particular, the incrustation of limestone and / or the formation and deposition of sludge and / or corrosion phenomena, said device comprising a body (2) with a longitudinal axis (A) provided at its two ends with two connecting end pieces (3, 4) delimiting a fluid inlet orifice (5) and a fluid outlet orifice (6), said connecting end pieces (3, 4) being arranged to mount said device (100) in series in said pipe, said body (2) comprising at least one channel (13, 13') extending between said inlet orifice (5) and said outlet orifice (6) for the passage of the fluid through said device (100), and said device (100) comprising means arranged to transform a linear movement of the fluid entering said device into a swirling movement of the fluid leaving said device, said means arranged to transform a linear movement of the fluid entering said device into a swirling movement of the fluid leaving said device comprising a baffle (160, 170) centred on the longitudinal axis (A), arranged facing said inlet orifice (5), interposed between said inlet orifice (5) and said body (2) and provided with deflection means for deflecting and creating a swirling movement of said fluid entering said device in the manner of a vortex, said body (2) comprising a plurality of rectilinear channels (13, 13'), parallel to said longitudinal axis (A), bored-through, distributed around and downstream of said baffle (160, 170), the passage section of said plurality of said channels (13, 13') being equal to or very close to the passage section of said connecting end pieces (3, 4) corresponding to the passage section of said pipe so as to limit load losses, said device comprising a central tube (14) extending along the longitudinal axis (A), said baffle (160, 170) comprising a mounting section (18) assembled with said central tube (14) and a head (210) provided with said means for deflecting the fluid and connected to said mounting section (18) by a base (240), characterised in that the head of said baffle (160, 170) is a flat head (210) perpendicular to said longitudinal axis (A), in that said means for deflecting the fluid consist of radial blades (220) which are tilted in the direction of the fluid from said inlet orifice (6) towards said outlet orifice (6), and in that at least part of said channels (13, 13') forms a housing for receiving at least one reactive element (15) arranged freely in the path of said fluid circulating through said device (1), such that said at least one reactive element (15) vibrates, strikes the walls of the channel which contains it, and transmits to the fluid mechanical sound waves which have the effect of destroying the sludge and / or limestone crystals present in the fluid.

2. Device according to claim 1, characterised in that it comprises two baffles(160, 170) each comprising blades (220), disposed in the same direction, facing respectively said inlet orifice (5) and said outlet orifice (6) such that said device (1) is not reversible.

3. Device according to claim 1, characterised in that said channels (13, 13') are evenly distributed around said central tube (14).

4. Device according to claim 1, characterized in that said channels comprise at least two sets of channels (13, 13') with different diameters, alternating with each other and evenly distributed around said central tube (14).

5. Device according to claim 1, characterised in that the base (240) of said baffles(160, 170) has a transverse dimension greater than the transverse dimension of said central tube (14) and lower than the internal transverse dimension of said body (2) to partially block at least part of said channels (13, 13') and form an axial stop for said at least one reactive element (15).

6. Device according to claim 5, characterised in that said at least one reactive element (15) is selected from the group of materials comprising ceramics, minerals, organic materials, glass, precious and / or semi-precious stones, or a combination of these materials, and in that it has a shape selected from the group comprising beads, granules, fragments, cylinders, these shapes being solid or hollow, or a combination of these shapes.

7. Device according to any one of the preceding claims, characterised in that said baffle(s) (160, 170) are hollow and comprise a cavity (31) closed by a plug (32), and in that they comprise at least one active element (20) housed in said cavity (31), selected from the group comprising mechanical wave transmitters, magnetic field transmitters, electromagnetic wave transmitters, or a combination of these transmitters, and arranged to transmit to the fluid said waves having the effect of destroying the sludge and / or limestone crystals present in the fluid.

8. Device according to claim 7, characterised in that said central tube (14) is hollow and forms a housing for receiving at least one active element (20).

9. Device according to any one of the preceding claims, characterized in that it constitutes a modular device, and in that the assembly of the plugs (32) on the baffles (160, 170) and / or the assembly of the baffles (160, 170) on the central tube (14) are dismountable assemblies so as to be able to modify the content of said cavities (31), of said central tube (14) and / or of said channels (13, 13') according to the water treatment to be carried out.