Patent Description:
As is known, most of the filtering devices, including also the reverse osmosis filtering devices, usually comprise a container suitable to contain a filtering cartridge.

Further closure mechanisms for filter modules are known from <CIT>, <CIT>, <CIT>, <CIT>.

This container is generally formed by a cup-like body which comprises a tubular lateral wall, for example cylindrical, and a bottom plate that closes an axial end of said lateral wall.

The opposite axial end of the lateral wall defines the mouth of the cup-like body and is occluded by a closing system, which can be removed to allow the container to be opened, for example if it is necessary to replace the filtering cartridge.

Traditionally, the closing system consists of a cover which is screwed onto the mouth of the cup-like body, by interposition of one or more annular sealing gaskets, which have the function of preventing the outflow of the liquid being filtered.

This closing system, although very simple, has some long-standing drawbacks.

For example, in some applications, the cover tends to unscrew spontaneously due to the vibrations to which the filtering device is subjected, causing liquid leaks.

In other applications, on the contrary, the prolonged use of the filtering devices causes the annular sealing gaskets to adhere (stick) between the cover and the mouth of the cup-like body, making any unscrewing of the cover extremely difficult.

There are also filtering devices, including in particular those for reverse osmosis, where the container containing the filtering cartridge is subjected to a relatively high internal pressure.

This pressure acts against the walls of the cup-like body and the cover, which therefore tend to deform outwards.

In some cases this deformation is greater at the cover than at the mouth of the cup-like body, causing a loosening of the compression of the annular sealing gaskets which lose their effectiveness and cause the liquid outflow.

In light of the above, an object of the present invention is to solve the aforementioned drawbacks of the prior art, in the context of a simple, rational and relatively low-cost solution.

This and other purposes are achieved by the characteristics of the invention reported in independent claim <NUM>. The dependent claims outline preferred and/or particularly advantageous but not strictly necessary aspects of the invention.

In particular, an embodiment of the present invention makes available a container for filtering devices, comprising:.

Thanks to this solution, the sealing function and the support and contrasting function of the pressure forces are advantageously delegated to two separate components, respectively to the occlusion element and to the tightening element, allowing to eliminate the criticalities of traditional systems. In fact, while the annular sealing gaskets are carried by the occlusion element, which can be completely without threadings and can be sized to obtain the best seal under all operating conditions, the pressure is supported exclusively by the tightening member which, being without annular sealing gaskets, will always be easy to unscrew and remove when it is necessary to open the container.

In this regard, the ring nut of the fixing member can be, for example, a threaded ring nut which is screwed to the external of the lateral wall of the container but it is not excluded that, in other embodiments, the axial constraint can be made by means of a bayonet coupling or other.

According to an aspect of the invention, the lower portion of the occlusion element can be defined by a tubular wall which delimits an axial inner cavity open towards the bottom plate.

In this way, the internal pressure to which the container can be subjected during operation also acts on this tubular wall, pushing it from the inside towards the outside and, consequently, constantly tending to push the annular sealing gaskets against the inner surface of the lateral wall of the container.

In this regard, it is preferable that said tubular wall of the occlusion element is sized in such a way as to safely prevent the annular gaskets from losing contact with the lateral wall of the container, despite the expansions due to the internal pressure.

For example, it is envisaged that the tubular wall of the occlusion element may have a thickness less than the thickness of the lateral wall of the container, at least at the second axial end thereof.

According to the invention, the edge of the second axial end of the lateral wall of the container can be shaped so as to define a cam profile on which the abutment elements of the occlusion element can slide following a rotation of the latter around the axis thereof, said cam profile being suitable to transform said rotation into an axial displacement of the occlusion element with respect to the lateral wall.

In this way, the removal of the occlusion element is advantageously facilitated when it is necessary to open the container. In fact, even in the case in which the annular gaskets "stick" between the occlusion element and the lateral wall of the container, by rotating the occlusion element around the axis thereof, the abutment elements slide on the cam profile of the edge of the container, causing a roto-translation of the occlusion element which facilitates the detachment of the annular seals and causes a first axial extraction of the occlusion element with respect to the container.

In this regard, the upper portion of the occlusion element can have an axial cavity suitable to obtain a prismatic coupling with a manoeuvring key of the coupled type.

This solution has the advantage of allowing simpler actuation with rotation of the occlusion element with respect to the container, facilitating the manual removal thereof. Essentially for the same reason, the upper portion of the occlusion element can have one or more through slots having transverse axes with respect to the axis of the occlusion element itself, for example at the abutment elements.

These through slots can in fact accommodate any elongated tool, such as a screwdriver, by means of which it is possible to leverage to more easily rotate the occlusion element with respect to the lateral wall of the container.

According to another aspect of the present invention, the abutment surface of the tightening member can be defined by a bottom wall which occludes an axial end of the ring nut.

In this way, the tightening member essentially takes on the shape of a cover, which is simple and inexpensive to make, which is screwed onto the second end of the container. A preferred aspect of the present invention provides that the container can also comprise an anti-unscrewing system for the tightening member with respect to the lateral wall of the container.

Thanks to this solution it is advantageously possible to prevent the tightening member from unscrewing spontaneously, for example by effect of vibrations, causing accidental opening of the container.

For example, said anti-unscrewing system can comprise:.

In this way, after the tightening member has been screwed in, the second notch, pushed into engagement position by the spring, prevents any accidental unscrewing of the tightening member.

If it is necessary to open the container, it is then sufficient to manually displace the second notch into the disengagement position, in contrast to the action of the spring, and unscrew the tightening member.

Further features and advantages of the invention will be more apparent after reading the following description provided by way of non-limiting example, with the aid of the figures illustrated in the accompanying drawings.

The aforesaid figures describe two examples of a plant <NUM> for the treatment of water, which can be advantageously used both in the food sector, for example for the treatment of water intended for direct consumption or for the preparation of beverages or other foods, and in the technological field, for example for the treatment of water intended for washing plants (e.g. dishwashers, washing machines or other), and for applications that can be both for domestic and industrial use.

Both plants <NUM> schematically comprise an inlet duct <NUM> for the water to be treated, which can be connected for example with the water distribution network, an outlet duct <NUM> for the treated water, which can be connected with the utilities, and a discharge duct <NUM> for any reject water, which can be connected, for example, with a sewer disposal system.

According to an aspect of the present disclosure, the outlet duct <NUM> can be integrated into a more complex outlet module <NUM>, which comprises numerous other functions of the plant <NUM> in order to limit the connections with pipes and fittings.

The plant <NUM> also comprises a pumping group <NUM>, which is suitable to receive water coming from the inlet duct <NUM> and to feed it under pressure towards the outlet ducts <NUM> and discharge ducts <NUM>, after having made it pass through the treatment devices.

The inlet duct <NUM> can be provided with a main solenoid valve <NUM>, which is suitable to be controlled by an electronic control unit (not illustrated) to selectively allow or prevent the inflow of water towards the pumping group <NUM>.

The inlet duct <NUM> can also be provided with a bypass solenoid valve <NUM>, which is normally closed and can be controlled for its opening in order to place the inlet duct <NUM> in direct communication with the outlet duct <NUM>, regardless of the opening or closing state of the main solenoid valve <NUM>.

In particular, the bypass solenoid valve <NUM> can be controlled by the electronic control unit which also controls the main solenoid valve <NUM> or by a simple switch which allows the selective feeding of the electronic control unit or of the bypass solenoid valve <NUM>.

Between the pumping group <NUM> and the outlet ducts <NUM> and discharge ducts <NUM>, the plant <NUM> can comprise a first filtering device <NUM>, which is generally designed to retain the coarse particles and impurities that may be present in water and possibly to retain chlorine and/or other substances which may be present in water so as to eliminate or at least reduce the bacterial load.

The first filtering device <NUM> can be configured to perform a mechanical filtration and/or a filtration by adsorption of chemicals, for example by means of activated carbon. In addition or alternatively, the first filtering device <NUM> can contain resins which can also work by ion exchange, in order to advantageously replace some salts that are contained in the water with other salts. Depending on the type of resin chosen, said resins can operate in many different ways, for example but not exclusively by replacing carbonates with sodium chloride, in order to lower the hardness of water without reducing the fixed residue thereof.

The plant <NUM> can also comprise a second reverse osmosis filtering device <NUM>, which is suitable to receive the water filtered from the first filtering device <NUM> and is mainly designed to remove the salts that can be dissolved in the water.

As illustrated in the example of <FIG>, in some embodiments, the first filtering device <NUM> may be absent and may possibly be made in the form of a separate device (see <FIG>) which is positioned for example upstream of the plant <NUM>, i.e. which is suitable to receive the water to be filtered from the water network and which, after filtering it, feeds it to the inlet duct <NUM> of the plant <NUM> or to any other utility.

Starting from this general scheme, the various parts of the plant <NUM> are detailed below starting from the reverse osmosis filtering device <NUM>.

The reverse osmosis filtering device <NUM> comprises one or more modular elements <NUM>, substantially identical or in any case similar, which can be advantageously assembled together to vary the operative capacity of the reverse osmosis filtering device <NUM>, for example the hourly flow rate of filterable water, based on the specific needs and requirements of the utilities to which the plant <NUM> is intended.

As illustrated in <FIG>, each modular element <NUM> comprises a monolithic body <NUM>, which can be made of plastic, for example by means of the injection molding technique. In particular, the monolithic body <NUM> can be directly obtained as a single piece, or it can be obtained in several parts which are then inseparably joined together, for example by welding or gluing, thus forming a single piece.

The monolithic body <NUM> comprises (defines) a first container <NUM> and a second container <NUM>, each of which is substantially shaped like a vessel comprising a tubular-shaped lateral wall <NUM>, for example cylindrical, and a bottom plate <NUM>, for example with a rounded shape, which closes a first axial end of the lateral wall <NUM>.

The second and opposite axial end of each of said first and second container <NUM> and <NUM> is closed by a respective closing system <NUM> of the openable type, which will be described in detail below.

As clearly visible in <FIG>, the first and the second container <NUM> and <NUM> are preferably arranged so that the respective lateral walls <NUM> are arranged adjacent to each other and have respective mutually parallel central axes A and B.

Preferably, the lateral walls <NUM> of the first and of the second container <NUM> and <NUM> are not in mutual contact but are separated by a small interspace <NUM>.

Furthermore, the lateral walls <NUM> of the first and of the second container <NUM> and <NUM> preferably have the same length, i.e. the same longitudinal extension, and bring the respective bottom plates <NUM> substantially to the same axial level with respect to the central axes A and B.

In particular, the first and the second container <NUM> and <NUM> are intended to be installed in such a way that the central axes A and B of the corresponding lateral walls <NUM> are oriented vertically and that the bottom plates <NUM> are positioned at the bottom, each of them for closing the lower axial end of the corresponding lateral wall <NUM>.

Remaining on <FIG>, the first container <NUM> comprises an inlet <NUM> for the water to be filtered, a first outlet <NUM> for the filtered water and a second outlet <NUM> for the reject water. Preferably, the inlet <NUM> and the second outlet <NUM> are obtained in the lateral wall <NUM> of the first container <NUM>, for example both in the part facing towards the lateral wall <NUM> of the second container <NUM>.

In particular, the inlet <NUM> and the second outlet <NUM> can have mutually parallel axes, perpendicular to the central axes A and B of the lateral walls <NUM> of the first and of the second container <NUM> and <NUM>, and both lying in the same plane on which said central axes A and B lie.

The distance between the inlet <NUM> and the bottom plate <NUM> of the first container <NUM> is generally greater than the distance between said bottom plate <NUM> and the second outlet <NUM>.

However, both the inlet <NUM> and the second outlet <NUM> can be closer to the axial end of the lateral wall <NUM> in which the corresponding closing system <NUM> is placed than to the axial end in which the corresponding bottom plate <NUM> is placed.

The first outlet <NUM> can be obtained in the bottom plate <NUM> of the first container <NUM>, for example with axis coinciding with the central axis A of the lateral wall <NUM> of the first container <NUM> itself.

Inside the first container <NUM> an osmotic membrane filtering cartridge <NUM> can be accommodated, which is generally suitable to partition the internal volume of the first container <NUM> into three separate chambers, of which a first chamber <NUM> placed in communication with the inlet <NUM>, a second chamber <NUM> placed in communication with the first outlet <NUM>, and a third chamber <NUM> placed in communication with the second outlet <NUM>.

The osmotic membrane filtering cartridge <NUM> is known per se and generally comprises a central support tube <NUM>, which is internally hollow and has a perforated lateral wall.

The osmotic membrane filtering cartridge <NUM> further comprises one or more pockets, which are spirally wound around the central support tube <NUM> forming a sort of cylindrical coil <NUM>.

Each of said pockets is substantially formed by two sheets of osmotic membrane, which are at least slightly spaced apart from each other, defining a thin interspace.

In order to create the interspace between the pockets and inside them, a sort of mesh is used, called spacer or tricot.

The pockets are associated with the central support tube <NUM> so that the aforesaid interspaces are placed in communication with the holes obtained in the lateral wall of the central support tube <NUM>, isolating them from the surrounding environment.

The osmotic membrane filtering cartridge <NUM> can further comprise an annular gasket <NUM>, which can be coaxially associated externally to the cylindrical coil <NUM>.

The osmotic membrane filtering cartridge <NUM> is coaxially inserted inside the first container <NUM>, so that a terminal segment of the central support tube <NUM> is inserted, by interposition of suitable sealing gaskets, into the first outlet <NUM>.

In this way, the internal volume of the central support tube <NUM> practically defines the second chamber <NUM>.

The annular gasket <NUM>, on the other hand, is suitable for sealing between the outer surface of the cylindrical coil <NUM> and the inner surface of the lateral wall <NUM> of the first container <NUM>, preferably in a segment axially comprised between the inlet <NUM> and the second outlet <NUM>, partitioning the first chamber <NUM> from the third chamber <NUM>.

In this way, the water coming from the inlet <NUM> can flow freely outside the pockets of the osmotic membrane filtering cartridge <NUM> until it reaches the second outlet <NUM>.

However, by virtue of the fact that in the first container <NUM> there is a pressure level higher than the osmotic pressure, part of the water in transit is able to cross the osmotic membrane sheets and reach the interspace defined between them, and then flow through the internal cavity of the central support tube <NUM> towards the first outlet <NUM>.

Thanks to the reverse osmosis phenomenon, starting from a water at the inlet having a certain concentration of salts, the filtered water that outflows from the first outlet <NUM> will have a significantly lower concentration of salts than the reject water that reaches the second outlet <NUM>.

The second container <NUM> in turn comprises an inlet <NUM> for the water to be filtered, a first outlet <NUM> for the filtered water and a second outlet <NUM> for the reject water.

Preferably, the inlet <NUM> and the second outlet <NUM> are obtained in the lateral wall <NUM> of the second container <NUM>, for example both in the part facing towards the lateral wall <NUM> of the first container <NUM>.

The distance between the inlet <NUM> and the bottom plate <NUM> of the second container <NUM> is generally greater than the distance between said bottom plate <NUM> and the second outlet <NUM>.

However, while the second outlet <NUM> may be closer to the corresponding bottom plate <NUM> than to the corresponding closing system <NUM>, the inlet <NUM> may be closer to the corresponding closing system <NUM> than to the corresponding bottom plate <NUM>.

For example, with respect to the direction defined by the central axes A and B of the lateral walls <NUM> of the first and of the second container <NUM> and <NUM>, the inlet <NUM> of the second container <NUM> can be positioned between the inlet <NUM> and the second outlet <NUM> of the first container <NUM>, while the second outlet <NUM> of the second container <NUM> can be positioned between the second outlet <NUM> of the first container <NUM> and the bottom plates <NUM>.

Also in this case, the first outlet <NUM> can be obtained in the bottom plate <NUM> of the second container <NUM>, for example with axis coinciding with the axis B of the lateral wall <NUM> of the second container <NUM> itself.

Inside the second container <NUM>, a further osmotic membrane filtering cartridge <NUM> can be accommodated, which is generally suitable to partition the internal volume of the second container <NUM> into three separate chambers, of which a first chamber <NUM> placed in communication with the inlet <NUM>, a second chamber <NUM> placed in communication with the first outlet <NUM>, and a third chamber <NUM> placed in communication with the second outlet <NUM>.

The osmotic membrane filtering cartridge <NUM> is completely similar to the osmotic membrane filtering cartridge <NUM> described previously, of which it has the same characteristics.

The osmotic membrane filtering cartridge <NUM> is therefore coaxially inserted into the second container <NUM>, in such a way that a terminal segment of the central support tube <NUM> is inserted, by interposition of suitable sealing gaskets, into the first outlet <NUM>.

The annular gasket <NUM> is suitable for sealing between the outer surface of the cylindrical coil <NUM> and the inner surface of the lateral wall <NUM> of the second container <NUM>, preferably in a segment axially comprised between the inlet <NUM> and the second outlet <NUM>.

In this way, the water coming from the inlet <NUM> can flow freely externally to the pockets of the osmotic membrane filtering cartridge <NUM> until it reaches the second outlet <NUM> but, by virtue of the fact that a pressure level higher than the osmotic pressure reigns in the second container <NUM>, part of this water is able to cross the osmotic membrane sheets and reach the internal cavity of the central support tube <NUM> and then flow towards the first outlet <NUM>.

Also in this case, the reverse osmosis phenomenon ensures that starting from a water at the inlet having a certain concentration of salts, the filtered water that outflows from the first outlet <NUM> has a significantly lower concentration of said salts than the reject water reaching the second outlet <NUM>.

According to an important aspect of the modular element <NUM>, the monolithic body <NUM> also comprises a scavenging duct <NUM> which connects the second outlet <NUM> of the first container <NUM> with the inlet <NUM> of the second container <NUM>, so that the reject water exiting from the first container <NUM> becomes the water to be filtered in the second container <NUM>.

In other words, this solution entails that the first and the second container <NUM> and <NUM> are hydraulically connected between them in series, allowing the water coming from the inlet <NUM> of the first container <NUM> to be filtered in cascade by two osmotic membrane filtering cartridges <NUM> and <NUM>, thus producing two flows of filtered water through the first outlets <NUM> and <NUM> of the first and of the second container <NUM> and <NUM> and a single flow of reject water through the second outlet <NUM> of the second container <NUM>.

It is wished to observe here that, in order to ensure that a pressure higher than the osmotic pressure reigns inside the first container <NUM> and the second container <NUM>, the plant <NUM> generally comprises a flow restrictor, which is connected downstream of the second outlet <NUM> of the second container <NUM>, as will be described later.

Returning to the scavenging duct <NUM>, this duct can be obtained in a portion of the monolithic body <NUM> which extends into the interspace <NUM> between the first and the second container <NUM> and <NUM>, connecting the respective lateral walls <NUM>.

The scavenging duct <NUM> can be defined by a hole extending in a direction parallel to the central axes A and B of the lateral walls <NUM> and which can lead outwards at the closing systems <NUM>, where it can be occluded by a suitable plug <NUM>.

This hole can also be placed in communication with the inlet <NUM> of the first container <NUM>, which is however hydraulically separated from the scavenging duct <NUM> by a shutter insert <NUM> which is inserted into the hole, at a level comprised between the inlet <NUM> of the first container <NUM> and the inlet <NUM> of the second container <NUM>.

The monolithic body <NUM> of each modular element <NUM> can further comprise (define) a collection manifold <NUM>, which is placed in communication with both the first outlets <NUM> and <NUM> of the first and of the second container <NUM> and <NUM>, so as to collect the filtered water.

The collection manifold <NUM> can be directly joined to the bottom plates <NUM>, for example on the opposite side with respect to the lateral walls <NUM> of the first and of the second container <NUM> and <NUM>.

The collection manifold <NUM> can be shaped as a duct, for example a straight duct, the central axis C of which is oriented perpendicularly to the central axes A and B of the lateral walls <NUM> of the first and of the second container <NUM> and <NUM>, however lying preferably in the same plane on which said central axes A and B lie.

The collection manifold <NUM> is provided with an outlet mouth <NUM>, through which the filtered water can be conveyed towards the first outlet duct <NUM> of the plant <NUM>.

This outlet mouth <NUM> can have axis straight, for example coinciding with the central axis A of the lateral wall <NUM> of the first container <NUM>, facing on the opposite side with respect to the corresponding bottom plate <NUM>.

The collection manifold <NUM> can also be placed in direct communication with the first chamber <NUM> of the first container <NUM>, for example through a bypass opening <NUM> which can be obtained in the bottom plate <NUM> of the first container <NUM> and which can lead out at a first axial end of the collection manifold <NUM>.

In this way, part of the reject water (with a higher concentration of salts) present in the first container <NUM> can be mixed with the filtered water found in the collection manifold <NUM>, in order to adjust the effective salinity of the water that is supplied to utilities.

This expedient can be particularly useful when water is used in the preparation of beverages, for example to feed automatic coffee machines or the like, in order to ensure a correct flavour of the beverage.

For said mixing to be adjusted, the collection manifold <NUM> can be equipped with a valve <NUM>, for example a needle and manually operated valve, which is screwed to the end of the collection manifold <NUM> and which, based on the axial position thereof, is suitable for closing and/or adjusting the opening degree of the bypass opening <NUM>.

The opposite axial end of the collection manifold duct <NUM> can instead be simply closed by means of a plug <NUM>.

Switching now to <FIG>, it can be observed how the monolithic body <NUM> of each modular element <NUM> can comprise a first connection duct <NUM>, which is positioned in the interspace <NUM> comprised between the first and the second container <NUM> and <NUM> and is hydraulically placed in communication with the inlet <NUM> of the first container <NUM>.

In particular, said first connection duct <NUM> can have axis straight and orthogonal to the plane of lying which contains the central axes A and B of the first and of the second container <NUM> and <NUM>.

Furthermore, the first connection duct <NUM> can extend from both sides of the aforesaid lying plane, so as to have an intermediate segment placed in communication with the inlet <NUM> of the first container <NUM> and two opposite axial, open and free projecting ends.

For example, the first connection duct <NUM> can be obtained in the same portion of the monolithic body <NUM> in which the scavenging duct <NUM> is also obtained.

In particular, the first connection duct <NUM> can intersect the hole defining the scavenging duct <NUM> and be separated from the latter by the already mentioned shutter insert <NUM>.

As illustrated in <FIG>, the monolithic body <NUM> of each modular element <NUM> also comprises a second connection duct <NUM>, which is also positioned in the interspace <NUM> comprised between the first and the second container <NUM> and <NUM> but is hydraulically placed in communication with the second outlet <NUM> of the second container <NUM>.

This second connection duct <NUM> can also have axis straight and orthogonal to the plane of lying which contains the central axes A and B of the first and of the second container <NUM> and <NUM>.

Furthermore, the second connection duct <NUM> can also extend from both sides of the aforesaid lying plane, so as to have an intermediate segment placed in communication with the second outlet <NUM> of the second container <NUM> and two opposite axial open and free projecting ends.

For example, the second connection duct <NUM> can have substantially the same length as the first connection duct <NUM> and be perfectly aligned with the latter, along the direction defined by the central axes A and B of the first and of the second container <NUM> and <NUM>. As illustrated in <FIG>, the monolithic body <NUM> of each modular element <NUM> can finally also comprise a third connection duct <NUM>, which substantially intersects and is hydraulically placed in communication with the collection manifold <NUM>.

In particular, said third connection duct <NUM> can have axis straight and parallel to the axes of the first and of the second connection duct <NUM> and <NUM> but can be arranged offset with respect to the latter, for example positioned so as to intersect the central axis A of the lateral wall <NUM> of the first container <NUM>.

The third connection duct <NUM> can also extend from both sides of the lying plane which contains the central axes A and B of the first and of the second container <NUM> and <NUM>, so as to have an intermediate segment placed in communication with (which intersects) the collection manifold <NUM> and two opposite axial ends projecting from opposite sides of the collection manifold <NUM>, which are open and free.

In the embodiment illustrated in <FIG>, the reverse osmosis filtering device <NUM> comprises two of the modular elements <NUM> described above, which are connected between them so as to operate in parallel.

In particular, the two modular elements <NUM> are arranged so that the first connection duct <NUM>, the second connection duct <NUM> and the third connection duct <NUM> of each of them are coaxially aligned respectively with the first connection duct <NUM>, with the second connection duct <NUM> and with the third connection duct <NUM> of the other modular element <NUM>. As illustrated in <FIG>, the first connection ducts <NUM> of the two modular elements <NUM> can be hydraulically connected by means of a connecting sleeve <NUM>, preferably rigid and straight, the opposite ends of which can be inserted, preferably by interposition of annular sealing gaskets, on the free ends of the two first connection ducts <NUM> which are proximal to each other.

With regard to the distal ends of the first two connection ducts <NUM>, one of them can be occluded by a plug <NUM> while the other one can be connected so as to receive the water to be filtered.

In this way, the two first connection ducts <NUM> and the relative connecting sleeve <NUM> substantially define an inlet manifold which distributes the water to be filtered into the inlets <NUM> of the first containers <NUM> of both modular elements <NUM>.

Similarly (see <FIG>), the second connection ducts <NUM> of the two modular elements <NUM> can be hydraulically connected by means of a connecting sleeve <NUM>, preferably similar to the previous one, the opposite ends of which can be inserted, preferably by interposition of annular sealing gaskets, on the free ends of the two second connection ducts <NUM> which are proximal to each other.

The distal end of one of the second connection ducts <NUM> can be occluded by a plug <NUM>, while the distal end of the other connection duct <NUM> can be hydraulically connected directly to the discharge duct <NUM> of the plant <NUM>.

In this way, the two second connection ducts <NUM> and the relative connecting sleeve <NUM> substantially define a discharge manifold which collects the reject water coming from the second outlets <NUM> of the second containers <NUM> of both the modular elements <NUM> and conveys it towards the discharge duct <NUM>.

To ensure that a pressure higher than the osmotic pressure reigns inside the first and the second container <NUM> and <NUM> of each modular element <NUM>, the discharge duct <NUM> can contain the already mentioned flow restrictor <NUM>.

As illustrated in <FIG>, the flow restrictor <NUM> can be configured as a narrowing of the opening section of the discharge duct <NUM> and can optionally be of an adjustable type, i.e. it can allow a variation in the extent of such narrowing in order to suitably vary the pressure inside the first and the second container <NUM> and <NUM> of each modular element <NUM>.

Inside the discharge duct <NUM> there may also be a non-return valve <NUM>, which can be positioned downstream of the flow restrictor <NUM> with respect to the direction of exit of the reject water.

Said non-return valve <NUM> is oriented so as to allow the reject water to outflow towards the exit, while preventing instead the opposite path.

Referring now to <FIG>, it can be observed that also the third connection ducts <NUM> of the two modular elements <NUM> can be hydraulically connected by means of a connecting sleeve <NUM>, preferably similar to the previous ones, the opposite ends of which can be inserted, preferably by interposition of annular sealing gaskets, on the free ends of the two third connection ducts <NUM> which are proximal to each other.

Both distal ends of the two third connection ducts <NUM> can be singularly occluded by a plug <NUM>.

In this way, the two third connection ducts <NUM> and the relative connecting sleeve <NUM> place the collection manifolds <NUM> of both modular elements <NUM> in hydraulic communication, so as to convey all the filtered water towards the outlet duct <NUM> of the plant <NUM>. In particular, since the outlet duct <NUM> can be only one, it can be connected to the outlet mouth <NUM> of only one of the modular elements <NUM>, while the outlet mouth <NUM> of the other modular element <NUM> can be occluded with a plug.

It is wished to highlight that, in other embodiments, the connection between the modular elements <NUM> could take place without connecting sleeves <NUM> and/or <NUM> and/or <NUM>, for example by shaping the first connection ducts <NUM> and/or the second connection ducts <NUM> and/or the third connection ducts <NUM> so that they integrate themselves male/female couplings with relative seals, i.e. said male/female couplings are obtained as an integral part of the relative monolithic body <NUM>.

As illustrated in <FIG>, in order to facilitate the assembly of the modular elements <NUM>, the monolithic body <NUM> of each of them can comprise a plurality of positioning tangs <NUM> (see also <FIG> and <FIG>) deriving from the lateral walls <NUM> of the first and of the second container <NUM> and <NUM> with axes perpendicular to the plane on which the central axes A and B of said lateral walls <NUM> lie, as well as a plurality of positioning pins <NUM> also deriving from the lateral walls <NUM> of the first and of the second container <NUM> and <NUM>, each of which is coaxial to a corresponding positioning tang <NUM> but it is obtained on the opposite side with respect to the lying plane of the central axes A and B of the lateral walls <NUM>.

In this way, when the monolithic bodies <NUM> of two modular elements <NUM> are assembled together, the positioning pins <NUM> of one of said monolithic bodies <NUM> can be singularly aligned and coaxially coupled to the positioning tangs <NUM> of the other monolithic body <NUM>, ensuring perfect alignment also of the first, of the second and of the third connection ducts <NUM>, <NUM> and <NUM>.

To stably fix the modular elements <NUM> between them, each monolithic body <NUM> can further comprise one or more fixing bushings <NUM>, hollow inside, each of which can be positioned in the interspace <NUM> comprised between the lateral walls <NUM> of the first and of the second container <NUM> and <NUM>, where it can extend with axis orthogonal to the plane on which the central axes A and B of said lateral walls <NUM> lie.

For example, in the embodiment illustrated in the figures, the monolithic body <NUM> of the modular elements <NUM> comprises two fixing bushings <NUM> positioned between the first connection duct <NUM> and the second connection duct <NUM>.

When the monolithic bodies <NUM> of two modular elements <NUM> are assembled together, each fixing bushing <NUM> of one of said monolithic bodies <NUM> is coaxially aligned with a corresponding fixing bushing <NUM> of the other monolithic body <NUM>, as illustrated in <FIG>.

A cylindrical spacer <NUM> can optionally be interposed between a fixing bushing <NUM> of a modular element <NUM> and the corresponding fixing bushing <NUM> of the other modular element <NUM> and, inside their cavities, a threaded tie rod can be inserted which is fixed with a nut so as to keep the modular elements <NUM> axially locked.

Alternatively or in addition, the locking of the modular elements <NUM> can be obtained thanks to a shape coupling between them and a corresponding support structure.

In this regard (see <FIG>), the monolithic body <NUM> of each modular element <NUM> can comprise, for example, two fixing plates lying in the plane on which the central axes A and B of the first and of the second container <NUM> and <NUM> lie, of which a first fixing plate <NUM> deriving in a cantilever fashion from the lateral wall <NUM> of the first container <NUM>, on the opposite side with respect to the second container <NUM>, and a second fixing plate <NUM> deriving in a cantilever fashion from the lateral wall <NUM> of the second container <NUM>, on the opposite side with respect to the first container <NUM>.

Each of said fixing plates <NUM> and <NUM> can extend as a profile with a substantially constant section along a direction parallel to the central axes A and B of the first and of the second container <NUM> and <NUM>.

For example, the section of each of said fixing plates <NUM> and <NUM> can substantially have a T shape.

As illustrated in <FIG>, the support structure can be fixed for example inside a protective case that encloses the plant <NUM> and can comprise two flat walls <NUM> mutually parallel and facing each other, which are separated by a distance substantially equal to the distance between the fixing plates <NUM> and <NUM> of each modular element <NUM>.

Each of said flat walls <NUM> can have a plurality of slits <NUM> which extend parallel to each other, for example extending in a vertical direction.

Each slit <NUM> of a flat wall <NUM> can face a corresponding slit <NUM> of the flat wall <NUM>, opposite with respect to a direction orthogonal to the flat walls <NUM> themselves.

The distance between two consecutive slits <NUM> of the same flat wall <NUM> can be substantially equal to the distance that separates the fixing plates <NUM> and/or <NUM> of two modular elements <NUM> assembled together as previously described.

In this way, after having assembled the two modular elements <NUM>, they can be inserted into the space comprised between the two flat walls <NUM>, by inserting the fixing plates <NUM> and <NUM> of each modular element <NUM> into a pair of mutually opposite slits <NUM> of the two flat walls <NUM>, which thus lock the modular elements <NUM> in the assembly position with no the need for screws or bolts.

To better understand the operation of this embodiment, reference can be made to <FIG>, which shows the simplified hydraulic diagram of the reverse osmosis filtering device illustrated in <FIG>.

The water coming from the pumping group <NUM> is fed in parallel to the inlets <NUM> of the first containers <NUM> of both modular elements <NUM>.

The water crossing the osmotic membrane filtering cartridge <NUM> contained in each of said first containers <NUM> flows through the first outlets <NUM> directly into the collection manifold <NUM> towards the outlet duct <NUM>.

The reject water exiting from the second outlet <NUM> of each of the first containers <NUM> instead flows in the scavenging duct <NUM> towards the inlet <NUM> of the corresponding second container <NUM>.

The water crossing the osmotic filtering cartridge <NUM> contained in each of the second containers <NUM> also flows through the first outlets <NUM> in the collection manifold <NUM> towards the outlet duct <NUM>, while the reject water which finally outflows from the second outlets <NUM> flows through the flow restrictor <NUM> towards the discharge duct <NUM>.

In this way, the two modular elements <NUM> are hydraulically connected in parallel to each other, while the first and the second container <NUM> and <NUM> of each modular element are hydraulically connected in series.

Thanks to the connection in series, water can flow faster, making cross-flow filtration more efficient and therefore allowing less concentrate to be discarded.

By exploiting this modularity principle, other embodiments may provide that the reverse osmosis filtering device <NUM> comprises a greater number of modular elements <NUM>, assembled together in the same fashion illustrated previously.

Other embodiments, such as the one illustrated in <FIG>, can also provide that the reverse osmosis filtering device <NUM> comprises a single modular element <NUM>.

In this case, the modular element <NUM> is substantially similar to the one described above, the only difference being that the third connection duct <NUM> has both free ends occluded by a plug <NUM> (see <FIG>), that the first connection duct <NUM> has a free end suitable to be connected for receiving the water to be filtered and an opposite free end occluded by a plug <NUM> (see <FIG>), and that the second connection duct <NUM> has a free end occluded by a plug <NUM> and an opposite free end connected to the discharge duct <NUM>.

Also in this embodiment, the discharge duct <NUM> can be provided with the flow restrictor <NUM> and with the non-return valve <NUM>, as previously described with reference to <FIG>.

The simplified hydraulic scheme of this second embodiment is illustrated in <FIG>, in which it can be appreciated how the water coming from the pumping group <NUM> is fed to the inlet <NUM> of the first container <NUM> of the single modular element <NUM>.

The water crossing the osmotic membrane filtering cartridge <NUM> contained in the first container <NUM> flows through the first outlet <NUM> directly in the collection manifold <NUM> towards the outlet duct <NUM>, while the reject water exiting the second outlet <NUM> of the first container <NUM> flows in the scavenging duct <NUM> towards the inlet <NUM> of the second container <NUM>.

At this point, the water crossing the osmotic filtering cartridge <NUM> contained in the second container <NUM> also flows through the first outlet <NUM> in the collection manifold <NUM> towards the outlet duct <NUM>, while the last reject water that outflows from the second outlet <NUM> flows through the flow restrictor <NUM> towards the discharge duct <NUM>.

Also in this case, thanks to the connection in series, the water can flow faster, making the cross-flow filtration more efficient and therefore allowing less concentrate to be discarded. It is wished to point out here that the modular elements <NUM> used in the embodiments described above can all be identical to each other but could also be slightly different, while remaining conceptually very similar. For example, it is possible to provide versions in which one or more of the connection ducts, instead of being closed by plugs as described above, can have ends which are obtained already closed, for example in the molding step of the monolithic body <NUM>.

As previously mentioned, both the first and the second container <NUM> and <NUM> of each modular element <NUM> are closed, on the opposite side with respect to the bottom plate <NUM>, by a respective closing system <NUM>.

Said closing system <NUM>, which is the same for both containers <NUM> and <NUM>, is configured so as to allow selective opening of the container, for example to replace the corresponding osmotic membrane filtering cartridge <NUM> or <NUM>.

In the following, the closing system <NUM> will be described with reference to the first container <NUM> but the same considerations apply mutatis mutandis also to the closing system <NUM> of the second container <NUM>.

With particular reference to <FIG>, <FIG> and <FIG>, it can be observed that the closing system <NUM> comprises an occlusion element <NUM>, which is suitable to be coupled to the second end of the lateral wall <NUM> of the first container <NUM>, i.e. the one opposite the bottom plate <NUM>, preferably without any type of threaded connection.

Said occlusion element <NUM> has a cylindrical lower portion <NUM> suitable to be coaxially inserted into the second end of the lateral wall <NUM> of the first container <NUM>.

One or more annular seats <NUM> are coaxially obtained on the outer lateral surface of said cylindrical portion <NUM>, each of which is suitable to accommodate an annular gasket <NUM>. Although in the drawings the annular seats <NUM> have a substantially "C"-shaped cross section, i.e. with three closed sides and only one open side facing outwards, it is not excluded that in other embodiments the annular seats <NUM> may have a cross section with a substantially "L" shape, i.e. with two closed sides and two open sides facing outwards and in axial direction respectively.

The annular gaskets <NUM> are singularly designed to obtain a radial sealing between the outer lateral surface of the cylindrical portion <NUM> of the occlusion element <NUM> and the inner surface of the lateral wall <NUM> of the first container <NUM>.

In particular, it should be observed that the cylindrical portion <NUM> is internally hollow and is substantially defined by a tubular wall <NUM> having a first axial end closed by a transverse wall <NUM>, and a second and opposite open axial end, which faces the inside of the first container <NUM> towards the corresponding bottom plate <NUM>.

In this way, the transverse wall <NUM> occludes the internal volume of the first container <NUM> while the cavity delimited by the tubular wall <NUM> faces towards the bottom plate <NUM>.

Preferably, the tubular wall <NUM> has a thickness (in a radial direction with respect to the axis of the cylindrical portion <NUM>) which, at least in the area of mutual insertion, is smaller than the thickness of the lateral wall <NUM> of the first container <NUM> (in a radial direction with respect to the central axis A).

In this way, following the overpressure that reigns inside the first container <NUM> during the operation of the plant <NUM>, the tubular wall <NUM> of the occlusion element <NUM> tends to expand radially outwards, more than the lateral wall <NUM> of the first container <NUM>, resulting in the increase in the radial compression of the annular gaskets <NUM>, to the advantage of the seal.

The occlusion element <NUM> further comprises an upper portion <NUM>, which is suitable to remain external to the first container <NUM>, projecting axially beyond the open end of the lateral wall <NUM>, on the opposite side with respect to the bottom plate <NUM>.

Said upper portion <NUM> can be obtained as a single body with the lower cylindrical portion <NUM> and can also have a shape substantially cylindrical and coaxial with the cylindrical portion <NUM> itself.

From the lateral surface of the upper portion <NUM> one or more abutment elements <NUM> project radially in a cantilever fashion outwards, which are suitable to rest axially on the edge of the second axial end of the lateral wall <NUM> of the first container <NUM>, so as to limit the axial position of the cylindrical portion <NUM> in the insertion direction.

In the illustrated embodiment, the abutment elements <NUM> can be arranged angularly equidistant with respect to the axis of the lower cylindrical portion <NUM>.

According to an advantageous aspect of the present solution (see also <FIG>), the edge of the second axial end of the first container <NUM> is not perfectly flat, i.e. it does not lie in a single plane orthogonal to the central axis A of the lateral wall <NUM>, but it has circumferentially an alternation of depressions <NUM> and rises <NUM> that are mutually connected by means of inclined surfaces, in which the axial distance between the bottom of the depressions <NUM> and the bottom plate <NUM> is smaller than the axial distance between the bottom plate <NUM> and the top of the rises <NUM>.

For example, the edge of the second axial end of the first container <NUM> can comprise a number of depressions <NUM> (and therefore of rises <NUM>) equal to the number of abutment elements <NUM> of the occlusion element <NUM> and which can be distributed in the same way, for example angularly equidistant with respect to the central axis A of the lateral wall <NUM>. In this way, when the abutment elements <NUM> rest on the bottom of the depressions <NUM>, the cylindrical lower portion <NUM> of the occlusion element <NUM> is at the maximum insertion degree inside the first container <NUM>, in an operative position in which all annular gaskets <NUM> ensure an effective sealing.

If the occlusion element <NUM> is rotated around the central axis A of the first container <NUM>, starting from the aforesaid operative position, the abutment elements <NUM> slide on the inclined surfaces which connect the depressions <NUM> to the rises <NUM>, causing a progressive and contextual slipping off of the lower cylindrical portion <NUM>.

In other words, the shaped edge of the second axial end of the lateral wall <NUM> defines a cam profile on which the abutment elements <NUM> of the occlusion element <NUM> can slide, following a rotation of the latter around the central axis A, and which is suitable to transform said rotation into an axial displacement of the occlusion element <NUM> with respect to the lateral wall <NUM>.

This solution is advantageous because, during the operation of the reverse osmosis filtering device <NUM>, the annular gaskets <NUM> tend to adhere (stick) to the inner lateral surface of the lateral wall <NUM>, potentially making a purely axial extraction of the occlusion element <NUM> difficult.

Thanks to the cam system described above, the combined action of rotation and translation facilitates the detachment of the annular gaskets <NUM>, making it easier to remove the occlusion element <NUM>.

Furthermore, the release is less traumatic as it is progressive and always with coaxial movement, unlike a free and uncontrolled traction.

To facilitate the rotation of the occlusion element <NUM>, the upper portion <NUM> can comprise an axial cavity <NUM>, facing towards the outside of the first container <NUM>, which is suitable to obtain a prismatic coupling with a manoeuvring key <NUM> of the coupled type.

In the illustrated embodiment, the axial cavity <NUM> is made as a cylindrical cavity, from the inner surface of which one or more radial ribs <NUM> project.

The manoeuvring key <NUM> in turn comprises a cylindrical tang <NUM> suitable to be coaxially inserted, preferably to size, into the axial cavity <NUM>, which is provided with one or more slits <NUM> suitable to receive the radial ribs <NUM>, making in this way the manoeuvring key <NUM> integral in rotation with the occlusion element <NUM>.

However, it is not excluded that, in other embodiments, the prismatic coupling between the manoeuvring key <NUM> and the axial cavity <NUM> of the occlusion element <NUM> can be obtained with completely different shapes and/or methods.

Still with a view to facilitating the rotation of the occlusion element <NUM> during the removal step, for example if the manoeuvring key <NUM> was not available, the upper portion <NUM> of the occlusion element <NUM> can comprise one or more through slots <NUM> having axes oriented transversely (for example orthogonal) with respect to the axis of the cylindrical portion <NUM>.

Said through slots <NUM> can be obtained in the lateral wall that delimits the axial cavity <NUM>, for example at and above the abutment elements <NUM>, and can be diametrically aligned two by two, so that each pair of aligned through slots <NUM> substantially defines a single aperture which completely crosses the upper portion <NUM> of the occlusion element <NUM>.

In this way, the removal of the occlusion element <NUM> can be made by inserting any elongated tool, for example a screwdriver, into a pair of through slots <NUM>, and by using the lever provided by said tool, to rotate the occlusion element <NUM> and slide it on the cam profile.

It is wished to underline here that the latter tool, as well as the manoeuvring key <NUM> described above, are accessories which can be supplied and used to remove the occlusion element <NUM> but which are not part of the closing system <NUM>.

The closing system <NUM>, on the other hand, further comprises a tightening member <NUM>, the sole function of which is to axially lock the occlusion element <NUM> in the operative position in which the abutment elements <NUM> rest in the depressions <NUM>, supporting the axial pressure forces being unloaded on it.

This tightening member <NUM> comprises a ring nut <NUM>, for example with substantially cylindrical shape, which is suitable to surround the occlusion element <NUM> and to be coaxially screwed external to the second axial end of the lateral wall <NUM> of the first container <NUM>.

The tightening member <NUM> further comprises at least one abutment surface <NUM> suitable to rest on the upper portion <NUM> of the occlusion element <NUM>, when the same is in the operative position.

For example, the abutment surface <NUM> can be defined by a bottom wall <NUM> which for example completely occludes an axial end of the ring nut <NUM>, giving the tightening member <NUM> substantially the shape of a cover.

Since it only needs to provide an axial constraint against the slipping off of the occlusion element <NUM>, the tightening member <NUM> does not carry any type of gasket and does not have to be tightly screwed to the first container <NUM>.

Nevertheless, it is obviously preferable that the tightening member <NUM> cannot unscrew freely, for example following the vibrations caused by the operation of the plant.

For this reason, the closing system <NUM> can comprise an anti-unscrewing system which prevents the tightening member <NUM> from unscrewing with respect to the lateral wall <NUM> of the first container <NUM>.

This anti-unscrewing system can comprise a first notch <NUM> firmly fixed to the tightening member <NUM>, for example which projects axially in a cantilever fashion from the edge of the ring nut <NUM> on the opposite side with respect to the bottom wall <NUM> (see <FIG>).

In this way, by screwing and unscrewing the tightening member <NUM>, the first notch <NUM> is suitable to vary its own axial distance with respect to the second edge of the lateral wall <NUM> of the first container <NUM>, up to a maximum value that is reached when the tightening member <NUM> is completely screwed down.

The anti-unscrewing system can further comprise a second notch <NUM>, which is instead coupled to the lateral wall <NUM> of the first container <NUM>, so as to be able to move between an engagement position and a disengagement position.

In particular, the second notch <NUM> can be carried by a slider <NUM>, which is slidingly coupled to a guide <NUM> obtained in the lateral wall <NUM> of the first container <NUM>, for example aligned with the fixing plate <NUM> and between the latter and the second end of the lateral wall <NUM>.

The slider <NUM>, being coupled with this guide <NUM>, can be suitable to slide in a direction parallel to the central axis A of the lateral wall <NUM>, so that, when it is in the engagement position, the second notch <NUM> is closer to the second end of lateral wall <NUM> with respect to when it is in the disengagement position.

In particular, when it is in the engagement position, the second notch <NUM> is placed at a distance from the second end of the lateral wall <NUM> which is equal to or smaller than the distance reached by the first notch <NUM>, when the tightening member <NUM> is completely screwed down, while when it is in the disengagement position, the second notch <NUM> is placed at a distance from the second end of the lateral wall <NUM> which is greater than the distance reached by the first notch <NUM>.

In this way, by bringing the second tooth <NUM> into the disengagement position, it is advantageously possible to freely unscrew and screw again the tightening member <NUM>.

By instead bringing the second notch <NUM> into the engagement position, for example after the complete screwing of the tightening member <NUM>, the second notch <NUM> interferes with the first notch <NUM>, preventing accidental unscrewing of the tightening member <NUM>. A spring <NUM> (see <FIG>) can be interposed between the slider <NUM> and the relative guide <NUM>, so as to push and keep the second notch <NUM> normally in the engagement position.

It is wished to point out here that, although in the example illustrated the ring nut <NUM> is a threaded ring nut which is coaxially screwed to the external of the second axial end of the lateral wall <NUM> of the first container <NUM>, it is not excluded that, in other embodiments, the ring nut <NUM> can be axially constrained to the lateral wall <NUM> of the first container <NUM> by other means of mutual coupling, for example by means of a bayonet coupling or other.

As anticipated in the introduction, the plant <NUM> can comprise a pumping group <NUM>, which is suitable to receive the water coming from the inlet duct <NUM> and to feed it under pressure towards the reverse osmosis filtering device <NUM>, possibly after having made it transit through the mechanical separation filtering device <NUM>.

With particular reference to <FIG>, the pumping group <NUM> comprises a pump <NUM>, for example a vane pump, which is provided with an inlet <NUM> for low-pressure water and with an outlet <NUM> for high-pressure water, and a motor <NUM>, for example an electric motor, which is coupled to the pump <NUM> in order to drive it.

The pumping group <NUM> may further comprise a liquid cooling system for the motor <NUM>. This cooling system comprises a tubular manifold <NUM>, substantially shaped as a straight duct having a central axis D, which comprises an inlet terminal <NUM> and an outlet terminal <NUM>, positioned at a predetermined mutual distance, with respect to the direction defined by the axis central D of the tubular manifold <NUM>.

The cooling system further comprises a branch pipe <NUM>, which is wound as a coil around the motor <NUM> and has a first end <NUM> and a second opposite end <NUM>.

Both the first and the second end <NUM> and <NUM> of the branch pipe <NUM> are hydraulically connected to the tubular manifold <NUM>, in a portion comprised between the inlet terminal <NUM> and the outlet terminal <NUM>.

The first and the second end <NUM> and <NUM> of the branch pipe <NUM> are also positioned at a predetermined mutual distance, with respect to the direction defined by the axis D of the tubular manifold <NUM>.

For example, the first end <NUM> is placed at a distance from the inlet terminal <NUM> which is smaller than the distance between said inlet terminal <NUM> and the second end <NUM>, which can instead be closer to the outlet terminal <NUM>.

Preferably, the diameter of the branch pipe <NUM> is smaller than the diameter of the tubular manifold <NUM>, while the overall length thereof can be greater than the length Lc of the entire segment of the tubular manifold <NUM> which is comprised between the first and the second end <NUM> and <NUM> of branch pipe <NUM>.

In the embodiments illustrated in <FIG> and <FIG>, the inlet terminal <NUM> of the tubular manifold <NUM> is suitable to be connected with the inlet duct <NUM> of the plant <NUM>, for example through the main solenoid valve <NUM>, so as to be able to receive the water to be treated directly, for example the one coming from the water network.

The outlet terminal <NUM> of the tubular manifold <NUM> is instead connected to the inlet <NUM> of the pump <NUM>, the outlet <NUM> of which can be connected to the reverse osmosis filtering device <NUM>, possibly through the mechanical separation filtering device <NUM> (if any).

In this way, the tubular manifold <NUM> of the cooling system is hydraulically connected in series with the pump <NUM> and upstream of the latter with respect to the water direction. In other embodiments, while remaining hydraulically connected in series, the tubular manifold <NUM> of the cooling system could nevertheless be connected downstream of the pump <NUM> with respect to the water direction.

In this case, the inlet <NUM> of the pump <NUM> could be directly connected with the inlet duct <NUM> of the plant <NUM>, for example through the main solenoid valve <NUM>, while the outlet <NUM> of the pump <NUM> could be connected with the inlet terminal <NUM> of the tubular manifold <NUM>, the outlet terminal <NUM> of which could be connected to the reverse osmosis filtering device <NUM>, possibly through the mechanical separation filtering device <NUM> (if any).

In both cases, when the pump <NUM> is running and the main solenoid valve <NUM> is open, the tubular manifold <NUM> of the cooling system is traversed by the water that will be treated in the plant <NUM>.

In addition to further travelling along the tubular manifold <NUM>, from the inlet terminal <NUM> towards the outlet terminal <NUM>, part of this water is also diverted and flows inside the branch pipe <NUM>, placing itself in a heat exchange relationship with the motor <NUM>.

In this way, the water circulating in the branch pipe <NUM> subtracts part of the heat produced by the motor <NUM>, cooling it effectively, before joining again the portion of water that flows only in the tubular manifold <NUM> and continuing together towards the filtrating devices.

On the other hand, since not all the water traverses the branch pipe <NUM> but a substantial part thereof travels only along the tubular manifold <NUM>, from the inlet terminal <NUM> towards the outlet terminal <NUM>, this solution allows to keep pressure drops rather low. Naturally, to maximize the cooling of the motor <NUM> while minimizing the pressure drop, the various parts of the cooling system must be sized appropriately.

Purely by way of example, a rough sizing of the cooling system is shown, assuming to use a 360W motor <NUM> with <NUM>% efficiency and admitting an increase in temperature DT of the water in the branch pipe <NUM> equal to <NUM>.

To remove this heat (considering the specific heat of water and assuming pejoratively the total transfer of the heat to water), it can be calculated that the branch pipe <NUM> must be traversed by a water flow rate of at least <NUM> liters /minute.

To meet this requirement, the cooling system can be made using a tubular collector <NUM> having an intermediate segment length Lc =<NUM> and a pressure drop coefficient in turbulent flow Kc=<NUM> (experimental value based on the pipe used), and using a branch pipe <NUM> with overall length Ls=<NUM> and a pressure drop coefficient in turbulent flow Ks=<NUM> (experimental value based on the pipe used).

As proof of this, it can be considered that, in turbulent flow, the pressure drop P in a duct is proportional to the length L of the duct, to the pressure drop coefficient K and to the square of the flow rate Q.

Since the branch pipe <NUM> joins again the tubular manifold <NUM>, the pressure drop P of said two ducts must be the same, from which it follows that the following relationship must be satisfied: <MAT> where Qs is the flow rate along the branch pipe <NUM> while Qc is the flow rate along the intermediate segment of the tubular manifold <NUM>.

By inserting the previous values in this relationship, it is obtained that: <MAT>.

Considering that the pump <NUM> is able to produce a total flow rate equal to Qc+Qs=<NUM> liters/minute, it can be obtained that the flow rate along the intermediate segment of the tubular manifold <NUM> is equal to Qc=<NUM> liters/minute, while the flow rate along the branch pipe <NUM> is equal to Qs=<NUM> liters/minute, that is, well above the minimum of <NUM> liters/minute, required for cooling the motor <NUM> under the previous hypotheses.

In general terms, it can be stated that it is preferable that the tubular manifold <NUM> and the branch pipe <NUM> are sized so that the flow of water traversing the tubular manifold <NUM> is greater than the flow of water traversing the branch pipe <NUM>.

In particular, it is preferable that the sizing is such that the flow rate of water flowing along the tubular manifold <NUM> is equal to or greater than <NUM>% of the total water flow rate entering the cooling system and that only the remaining portion, equal or less than <NUM>%, flows along the branch pipe <NUM>.

In analytical terms, it is therefore preferable that the pressure drop coefficients Ks and Kc and the lengths Ls and Lc, respectively of the branch pipe <NUM> and of the tubular manifold <NUM>, are chosen so as to respect the following condition: <MAT>.

The mechanical separation filtering device <NUM> schematically includes a filtering group <NUM> and a fixed support element <NUM>, to which the filtering group <NUM> is preferably associated in a removable way, for example in order to allow the replacement thereof when necessary.

As anticipated in the introduction, the filtering device <NUM> can be inserted into the plant <NUM> or it can be obtained as a separate entity.

However, since the filtering device <NUM> has substantially the same characteristics in both cases, it will be described below with reference mainly to the case in which it is a separate entity, it being understood that the same considerations also apply in the case in which the filtering device <NUM> is integrated into the plant <NUM>, and vice versa.

As illustrated in <FIG>, the filtering group <NUM> comprises an external casing comprising a cup-like body <NUM> and a cover <NUM> suitable to close said cup-like body <NUM>.

The cup-like body <NUM> is generally provided with a lateral wall <NUM> with tubular shape, for example cylindrical, which has a predetermined central axis E, and a bottom plate <NUM> positioned so as to close a first axial end of said lateral wall <NUM>.

The second and opposite axial end of the lateral wall <NUM> is closed by the cover <NUM>, which can for example be screwed to the external to the lateral wall <NUM> preferably by interposition of at least one annular sealing gasket.

The cover <NUM> is provided with an inlet duct <NUM> for the water to be filtered and with an outlet duct <NUM> for the filtered water.

As illustrated in <FIG>, a filtering cartridge <NUM> is accommodated inside the cup-like body <NUM>, for example but not necessarily a filtering cartridge with a substantially tubular shape, which partitions the internal volume of the cup-like body <NUM> into a first chamber <NUM> , which is placed in communication with the inlet duct <NUM> (see <FIG>), and a second chamber <NUM>, which is placed in communication with the outlet duct <NUM>.

In this way, the water crossing the outer casing from the inlet duct <NUM> towards the outlet duct <NUM> is forced to cross the filtering cartridge <NUM>.

The filtering cartridge <NUM> generally comprises a filtering medium, which is suitable to be crossed by water in order to perform the intended filtration function.

This filtering medium can comprise a porous or perforated body, with meshes of suitable size, which allows to retain by mechanical action the coarse particles and/or other solid impurities that may be present inside water, in order to prevent them from reaching the reverse osmosis filtering device <NUM>, where they could damage the osmotic membrane filtering cartridges <NUM> and <NUM>.

Alternatively or in addition, the filtering medium of the filtering cartridge <NUM> can comprise activated carbon, for example in the form of flakes or granules, which, being crossed by water, may be able to absorb and/or retain chlorine and/or by chemical interaction and/or other unwanted chemicals that may be present in water.

Alternatively or in addition, the filtering medium of the filtering cartridge <NUM> can comprise resins, usually but not necessarily in the form of spheroidal granules, which can also work by ion exchange, in order to advantageously replace some salts that are contained in water with other salts. Depending on the type of resin chosen, said resins can operate in many different ways, for example but not exclusively by replacing carbonates with sodium chloride, in order to lower the hardness of water without reducing the fixed residue thereof.

In some embodiments, the filtering medium can simply be constituted by activated carbon, for example in the form of flakes or granules, or by resins, for example in the form of spheroidal granules, which are loaded directly into the cup-like body <NUM>.

Returning to the inlet and outlet ducts <NUM> and <NUM>, it can be observed in <FIG> that the inlet duct <NUM> comprises a connecting segment <NUM>, directly communicating with the first chamber <NUM> of the cup-like body <NUM>, which rises from the cover <NUM> with axis straight, parallel and preferably offset with respect to the central axis E of the lateral wall <NUM> (see also <FIG>).

The inlet duct <NUM> also comprises a terminal segment <NUM> deriving in a cantilever fashion from the connecting segment <NUM> and extending with axis F straight and orthogonal to the central axis E, so as to lead out to the outside of the cup-like body <NUM> for receiving the water to be filtered.

Similarly, it can be observed in <FIG> that the outlet duct <NUM> comprises a connecting segment <NUM>, directly communicating with the second chamber <NUM> of the cup-like body <NUM>, which rises from the cover <NUM> with axis straight, parallel and preferably coinciding with the central axis E of the lateral wall <NUM>.

The outlet duct <NUM> also comprises a terminal segment <NUM> deriving in a cantilever fashion from the connecting segment <NUM> and extending with axis G straight and orthogonal to the central axis E, so as to lead out to the outside of the cup-like body <NUM> for allowing the outflow of the filtered water.

As illustrated in <FIG>, the terminal segment <NUM> of the outlet duct <NUM> is arranged adjacent, oriented parallel to and facing in the same direction as the terminal segment <NUM> of the inlet duct <NUM>.

For example, the axes F and G of the terminal segments <NUM> and <NUM> can lie coplanar on a plane orthogonal to the axis E of the lateral wall <NUM> of the cup-like body <NUM>. Furthermore, the free ends of the terminal segments <NUM> and <NUM>, i.e. those afferent directly to the outside, can be placed at the same distance with respect to a plane orthogonal to the axes F and G and passing through the central axis E of the lateral wall <NUM>. As already mentioned, the filtering group <NUM> is suitable to be associated in a removable way with the corresponding fixed support element <NUM>, for example in order to be replaced when necessary.

In all the embodiments of the filtering device <NUM>, the support element <NUM> is provided with a first connection duct <NUM> and with a second connection duct <NUM>, each of which comprises a free terminal segment, indicated respectively with <NUM> and <NUM>.

As illustrated in <FIG>, the terminal segments <NUM> and <NUM> of the connection ducts <NUM> and <NUM> are mutually arranged adjacent, have parallel axes (for example horizontal) and are oriented in the same direction, substantially specular to the terminal segments <NUM> and <NUM> of the inlet and outlet ducts <NUM> and <NUM> of the filtering group <NUM>.

In this way, the terminal segment <NUM> of the inlet duct <NUM> of the filtering group <NUM> can be coaxially coupled with terminal segment <NUM> of the first connection duct <NUM> and, at the same time, the terminal segment <NUM> of the outlet duct <NUM> of the filtering group <NUM> can be coaxially coupled with the terminal segment <NUM> of the second connection duct <NUM>.

In particular, said coaxial couplings can take place by inserting the terminal segments <NUM> and <NUM> of the inlet <NUM> and outlet <NUM> duct of the filtering group <NUM> inside the corresponding terminal segments <NUM> and <NUM> of the first and of the second connection ducts <NUM> and <NUM>, as illustrated in <FIG>.

To ensure the sealing of said couplings, a respective annular sealing gasket <NUM> can be coaxially interposed between each terminal segment <NUM> and <NUM> of the first and of the second connection duct <NUM> and <NUM> and the corresponding terminal segment <NUM> and <NUM> of the inlet duct <NUM> and of the outlet duct <NUM> of the filtering group <NUM>.

Said annular gaskets <NUM> are preferably mounted coaxially inside the terminal segments <NUM> and <NUM> of the first and of the second connection duct <NUM> and <NUM>, where each of them can be axially locked by means of a respective ring nut <NUM> fixed to the end of the respective terminal segment <NUM> and <NUM>.

In this way, the two annular gaskets <NUM> remain constantly associated with the fixed support element <NUM>, while the filtering group <NUM>, which represents the replaceable part of the filtering device <NUM>, is advantageously simpler and therefore more economical.

The ring nut <NUM> can be a ring nut that can be inserted by pressure lock (clip) and which can possibly be removed by rotation, for example for maintenance interventions.

To facilitate the coupling and uncoupling of the filtering group <NUM> with respect to the support element <NUM>, the filtering device <NUM> can comprise a coupling and guide system suitable to constrain the filtering group <NUM> to the support element <NUM> in a configuration in which the axes F and G of the terminal segments <NUM> and <NUM> of the inlet duct <NUM> and of the outlet duct <NUM> of the filtering group <NUM> coincide respectively with the axis of the terminal segment <NUM> of the first connection duct <NUM> and with the axis of the terminal segment <NUM> of the second connection duct <NUM>.

By maintaining this configuration, the coupling and guide system also allows the filtering group <NUM> to slide with respect to the support element <NUM> along a sliding direction parallel to the axes F and G of said terminal segments <NUM> and <NUM> of the inlet duct <NUM> and of the outlet duct <NUM>, favouring the coupling and the uncoupling thereof.

As illustrated in <FIG>, said coupling and guide system may comprise for example a plate <NUM> fixed to the cover <NUM> of the filtering group <NUM> and having at least two lateral edges <NUM> oriented parallel to the axes F and G of the terminal segments <NUM> and <NUM> of the inlet duct <NUM> and of the outlet duct <NUM>.

The coupling and guide system can further comprise a pair of shelves <NUM> fixed to the support element <NUM> and extending parallel to the axes of the terminal segments <NUM> and <NUM> of the connection ducts <NUM> and <NUM>, which are suitable to receive, for rest, said lateral edges <NUM> of the plate <NUM> (see also <FIG>).

Thanks to the coupling between the plate <NUM> and the shelves <NUM>, the filtering group <NUM> can therefore be easily brought into an operating configuration, in which the terminal segments <NUM> and <NUM> of the inlet duct <NUM> and of the outlet duct <NUM> are coaxially coupled respectively with the terminal segment <NUM> of the first connection duct <NUM> and with the terminal segment <NUM> of the second connection duct <NUM>, as illustrated in <FIG>.

To selectively lock the filtering group <NUM> in this operating position, the filtering device <NUM> can comprise a suitable releasable locking system.

Said releasable locking system can comprise a tightening element <NUM> that can be slidably coupled to the support element <NUM> according to the same sliding direction as the filtering group <NUM>, after the latter has been brought into the operating position.

For example, the tightening element <NUM> can be shaped as a covering case, which is suitable to be inserted like a drawer on a box-like frame <NUM> which is fixed to the support element <NUM> and which is suitable to contain the terminal segments <NUM> and <NUM> of the connection ducts <NUM> and <NUM>, as well as the shelves <NUM>.

The box-like frame <NUM> can be shaped as a C-section profile and axis parallel to the axes of the terminal segments <NUM> and <NUM> of the connection ducts <NUM> and <NUM>, which has for example an upper flat wall <NUM>, which surmounts said terminal segments <NUM> and <NUM>, and two flat lateral walls <NUM>, which extend downwards from said upper wall <NUM> but on opposite sides of the terminal segments <NUM> and <NUM> themselves.

An axial end of said box-like frame <NUM> is open so as to allow the insertion of the filtering group <NUM>.

The tightening element <NUM> is inserted onto the box-like frame <NUM> and has a rear wall <NUM> suitable to close the open axial end of the box-like frame <NUM>, opposing the terminal segments <NUM> and <NUM> of the connection ducts <NUM> and <NUM>.

The tightening element <NUM> is also provided with one or more releasable snap-fitting members <NUM>, which are suitable to lock the tightening element <NUM> on the box-like frame <NUM> of the support element <NUM> in a predetermined stop position.

For example, said snap-fitting members <NUM> can be positioned on two lateral flanks of the tightening element <NUM>, which are suitable to cover the lateral walls <NUM> of the box-like frame <NUM>, and can be singularly configured to snap into a corresponding seat <NUM> obtained in said lateral walls <NUM>.

In particular, the hooking between the snap-fitting members <NUM> and the corresponding seats <NUM> can take place simply by pushing the tightening element <NUM> to make it slide on the box-like frame <NUM>, for example thanks to a suitable conformation of the aforesaid snap-fitting members <NUM> (for example with sawtooth shape) which allows them, following the aforesaid movement, to deform and then to snap into the relative seat <NUM>.

The tightening element <NUM> also has at least one abutment surface <NUM> which, when the filtering group <NUM> is in the operating position and the tightening element <NUM> is in the stop position, is suitable to stay in contact with a corresponding abutment surface of the filtering group <NUM> on the opposite side with respect to the terminal segments <NUM> and <NUM> of the connection ducts <NUM> and <NUM> with respect to the sliding direction, thus locking the filtering group <NUM> in the operating position.

As illustrated in <FIG> and <FIG>, in this embodiment, the abutment surface <NUM> is made available for example by a shelf <NUM> deriving from the inner surface of the rear wall <NUM> of the tightening element <NUM>, while the corresponding abutment surface is made available by one or more ribs which rise from the cover <NUM> of the filtering group <NUM> and which support the plate <NUM> (see also <FIG>).

Thanks to the solution described above, in order to remove the filtering group <NUM> it is then sufficient to release the snap-fitting members <NUM> and remove first the tightening element <NUM> and then the filtering group <NUM>.

For this purpose, a button <NUM> can be associated with each snap-fitting member <NUM>, which is suitable to be pressed to release the hooking produced by the snap-fitting member <NUM> itself.

In particular, the snap-fitting member <NUM> and the relative button <NUM> can be made as a single object.

It is wished to highlight that the buttons <NUM> must be pressed only when it is necessary to remove the tightening element <NUM> since, as previously anticipated, during the coupling step, the hooking between the snap-fitting members <NUM> and the corresponding seats <NUM> can take place simply by pushing the tightening element <NUM> to make it to slide on the box-like frame <NUM>.

If the filtering device <NUM> described above is located inside the plant <NUM>, as illustrated for example in <FIG>, the first connection duct <NUM> of the support element <NUM> can be stably connected with the outlet <NUM> of the pump <NUM>, while the second connection duct <NUM> can be stably connected with the first connection duct <NUM> of one of the modular elements <NUM> (see also <FIG>).

If, on the other hand, the filtering device <NUM> is separated, as illustrated for example in <FIG>, the first connection duct <NUM> of the support element <NUM> can be directly connected with the water network, while the second connection duct <NUM> can be connected with the inlet duct <NUM> of the plant <NUM> or, more generally, with any utility that must receive the water filtered by the filtering device <NUM>.

In this second case, it is further provided that, a non-return valve, indicated respectively with <NUM> and <NUM> (see <FIG> and <FIG>) can be inserted inside each terminal segment <NUM> and <NUM> of the connection ducts <NUM> and <NUM>.

Said non-return valves <NUM> and <NUM> have the function of automatically preventing the water from outflowing from the water network, when the filtering unit <NUM> is removed. Therefore, both non-return valves <NUM> and <NUM> are configured so as to be closed in the same direction, i.e. moving towards the end of the respective terminal segment <NUM> and <NUM>.

In this way, both non-return valves <NUM> and <NUM> prevent water from outflowing from the respective terminal segment <NUM> and <NUM>.

However, since the non-return valve <NUM> is placed on the first connection duct <NUM> (from which the water to be filtered comes from), when the filtering group <NUM> is repositioned it is necessary to reopen the non-return valve <NUM> in contrast to the action of water.

To do this, the terminal segment <NUM> of the first connection duct <NUM> can contain a presser element <NUM>, shaped for example as a sort of needle, which, following the insertion of the terminal segment <NUM> of the inlet duct <NUM>, is pushed by said terminal segment <NUM> and in turn pushes the non-return valve <NUM> into the opening position.

This presser element <NUM> is not present in the terminal segment <NUM> of the second connection duct <NUM>, since the non-return valve <NUM> opens automatically by effect of the exiting water flow.

With particular reference to <FIG> and <FIG>, the outlet module <NUM> first of all comprises the outlet duct <NUM>, which preferably extends rectilinearly along a predetermined central axis H.

At one axial end, the outlet duct <NUM> has a terminal segment <NUM>, which is suitable to be connected with one or more utilities of the treated water, for example but not necessarily through a manual or automatic delivery valve (not shown).

The outlet module <NUM> also comprises an inlet fitting <NUM>, which is suitable to receive the water filtered by the reverse osmosis filtering device <NUM> and to convey it towards the outlet duct <NUM>, preferably at the axial end opposite the terminal segment <NUM>.

As illustrated in <FIG>, the inlet fitting <NUM> can comprise a first segment <NUM> which defines a coupling sleeve suitable for being coaxially inserted, by interposition of suitable sealing rings, directly inside the outlet mouth <NUM> of one of the modular elements <NUM> of the reverse osmosis filtering device <NUM>.

The first segment <NUM> of the inlet fitting <NUM> can be axially locked to the outlet mouth <NUM> by means of a simple removable clip <NUM> which is inserted laterally on two opposed flanges obtained respectively around the first segment <NUM> of the inlet fitting <NUM> and around the outlet mouth <NUM> of the modular element <NUM>.

The inlet fitting <NUM> may further comprise a second segment <NUM>, which is suitable to hydraulically connect the first segment <NUM> with the outlet duct <NUM>.

This second segment <NUM> can be coaxial to the outlet duct <NUM> and can be orthogonal to the first segment <NUM>, giving the inlet fitting <NUM> substantially the shape of an elbow. Between the second segment <NUM> of the inlet fitting <NUM> and the outlet duct <NUM>, the outlet module <NUM> comprises a flow rate transducer <NUM>.

The flow rate transducer <NUM> generally comprises an outer casing suitable to contain an impeller <NUM>.

In detail, the outer casing of the flow rate transducer <NUM> can comprise a cylindrical tang <NUM>, which has a first axial end placed in hydraulic communication with the inlet fitting <NUM>.

For example, the cylindrical tang <NUM> can be coaxial to the second segment <NUM> of the inlet fitting <NUM> and can optionally be connected thereto by means of a truncoconical segment <NUM>.

The outer casing of the flow rate transducer <NUM> can also comprise a cover <NUM>, which is suitable to close the second and opposite axial end of the cylindrical tang <NUM> and is provided with at least one internal through aperture (not visible in the figures) suitable for placing in hydraulic communication the internal volume of the cylindrical tang <NUM> with the outlet duct <NUM>.

In particular, the cover <NUM> can comprise an annular tang <NUM> which, by interposition of suitable annular sealing gaskets, is inserted coaxially onto the cylindrical tang <NUM>.

The gaskets are preferably housed in corresponding annular seats <NUM> obtained on the outer surface of the cylindrical tang <NUM>.

According to one aspect of the invention, the cover <NUM>, with the eventual annular tang <NUM>, is part of a first monolithic body, globally indicated with <NUM>, which also comprises (defines) the outlet duct <NUM>.

Similarly, the cylindrical tang <NUM> is preferably part of a second monolithic body, globally indicated with <NUM>, which also comprises (defines) the inlet fitting <NUM>, including the first segment <NUM>, the second segment <NUM> and possibly the truncoconical segment <NUM>. Said first and second monolithic body <NUM> and <NUM> can be made of plastic material, for example by injection molding. In particular, each of said first and second monolithic body <NUM> and <NUM> can be directly obtained as a single piece, or it can be obtained in several parts which are then inseparably joined together, for example by welding or gluing, thus forming a single piece.

After the first and the second monolithic body <NUM> and <NUM> have been assembled together, by inserting the annular tang <NUM> onto the cylindrical tang <NUM>, they can be mutually fixed by any conventional system.

As illustrated in <FIG>, in the embodiment in question, this fixing is made possible by the fact that the second monolithic body <NUM> comprises a flat flange <NUM>, which is obtained between the truncoconical segment <NUM> and the cylindrical tang <NUM> and is suitable to face the cover <NUM> of the first monolithic body <NUM>.

The flat flange <NUM> comprises a plurality of through holes <NUM>, each of which is suitable to be aligned with a corresponding sleeve <NUM> deriving in a single body from the cover <NUM>.

In this way, the fixing between the first and the second monolithic body <NUM> and <NUM> can be obtained simply with the aid of a plurality of self-tapping screws (not shown), each of which can be inserted into a respective through hole <NUM> and screwed into the corresponding sleeve <NUM>.

Before the first and the second monolithic body <NUM> and <NUM> are joined together, a support disc <NUM> provided with a central hub <NUM> and with a plurality of through apertures for the free outflow of water can be coaxially accommodated inside the cylindrical tang <NUM>. The impeller <NUM>, which is free to rotate, by effect of the water in transit, around its own axis coinciding with the axis of the cylindrical tang <NUM> is also rotatably accommodated inside the cylindrical tang <NUM>.

For example, the impeller <NUM> can be rotatably coupled, by means of a central pin <NUM>, the opposite ends of which are respectively inserted in the central hub <NUM> of the support disc <NUM> and in a hole obtained centrally in the cover <NUM> (see <FIG>).

Although in the example illustrated the impeller <NUM> is positioned coaxially inside the cylindrical tang <NUM>, it is not excluded that, in other embodiments, the positioning of the impeller may be different.

The flow rate transducer <NUM> further comprises a system suitable for detecting the rotation speed of the impeller <NUM>.

Said detection system can comprise one or more reference elements <NUM> (see <FIG>) fixed in an eccentric position on the impeller <NUM> and a proximity sensor <NUM>, installed in a fixed position with respect to the impeller <NUM>, which is suitable to generate an electrical signal when each of said reference elements <NUM> passes close to the proximity sensor <NUM> itself.

For example, the reference elements <NUM> can be magnetic bodies and the proximity sensor <NUM> can be configured to react to the magnetic field generated by said magnetic bodies as they pass.

In the illustrated embodiment, the proximity sensor <NUM> can be installed in a cavity <NUM> of the first monolithic body <NUM>, which is made at the cover <NUM> so as to remain separated from the ducts in which the water flows, while the reference elements <NUM> can be positioned in order to be aligned with the proximity sensor <NUM> over a predetermined angular position of the impeller <NUM>.

The proximity sensor <NUM> can be electrically connected with an electronic processing unit (not illustrated) which, based on the rotation speed of the impeller <NUM>, is able to calculate the flow rate of water flowing from the inlet fitting <NUM> to the outlet duct <NUM>, for example in order to verify the correct operation of the plant <NUM>.

Downstream of the flow rate transducer <NUM> (with respect to the water direction), the outlet module <NUM> comprises at least one non-return valve <NUM> (see <FIG>), which is installed inside the outlet duct <NUM> so as to intercept all the water flowing inside it.

This non-return valve <NUM> is suitable to allow the passage of water flowing from the inlet fitting <NUM> towards the outlet duct <NUM>, preventing reverse flow.

In this way, when the utility connected to the outlet duct <NUM> stops requesting water, for example following the closure of the delivery valve, a water hammer is generated which automatically closes the non-return valve <NUM>, keeping an intermediate segment of the outlet duct <NUM> comprised between the terminal segment <NUM> and the non-return valve <NUM> itself under pressure.

When the utility requests water again, for example following the reopening of the delivery valve, the pressure in said intermediate segment of the outlet duct <NUM> drops rapidly, allowing the opening of the non-return valve <NUM> and therefore a new inflow of filtered water.

To make this operation safer, the outlet module <NUM> can comprise at least one further non-return valve <NUM>, which is completely similar to the previous one and is inserted inside the outlet duct <NUM>, upstream of the non-return valve. <NUM> with respect to the direction of the water outflow.

The outlet module <NUM> can comprise a locking element <NUM>, which is fixed to the outlet duct <NUM> at the terminal segment <NUM> and, protruding inside the outlet duct <NUM> itself without obstructing it, contacts the non-return valve <NUM> , locking it axially and preventing it from slipping off.

Returning to <FIG> and <FIG>, the first monolithic body <NUM> of the outlet module <NUM> can further comprise a secondary duct <NUM>, which derives from and is in hydraulic communication with the intermediate segment of the outlet duct <NUM> comprised between the non-return valve <NUM> and the terminal segment <NUM>.

Said secondary duct <NUM>, which can be straight and extend along an axis perpendicular to the axis H of the outlet duct <NUM>, therefore has an efferent axial end in the intermediate segment of the outlet duct <NUM> and an opposite free axial terminal end <NUM>.

In some embodiments, such as the one illustrated in <FIG>, the terminal end <NUM> of the secondary duct <NUM> can simply be closed with a plug.

In other embodiments, such as the one illustrated in <FIG>, the terminal end <NUM> of the secondary duct <NUM> can be connected with the inlet duct <NUM> of the plant <NUM>, by interposition of the bypass solenoid valve <NUM>.

In this way, if, for example, the plant <NUM> has a failure and the main solenoid valve <NUM> is kept constantly closed, the utilities can still be supplied with water (although it is not treated), simply by opening the bypass solenoid valve <NUM> which allows water coming from the water network to flow directly from the inlet duct <NUM> into the secondary duct <NUM> of the outlet module <NUM> and from there into the outlet duct <NUM> towards the utilities.

In this case, another non-return valve <NUM>, which is suitable to intercept all the water that flows inside the secondary duct <NUM>, can be interposed between the terminal end <NUM> of the secondary duct <NUM> and the bypass solenoid valve <NUM>.

In particular, said non-return valve <NUM> is suitable to allow the passage of water flowing from the bypass solenoid valve <NUM> towards the outlet duct <NUM>, preventing reverse flow. The first monolithic body <NUM> of the outlet module <NUM> can further comprise a connection port <NUM>, which is placed in hydraulic communication with the intermediate segment of the outlet duct <NUM> comprised between the non-return valve <NUM> and the terminal segment <NUM>.

In the illustrated embodiment, said connection port <NUM> derives laterally from the secondary duct <NUM>, for example from an intermediate segment of the secondary duct <NUM> comprised between the outlet duct <NUM> and the terminal end <NUM>.

The connection port <NUM>, which can extend with straight axis parallel to the central axis H of the outlet duct <NUM>, is suitable to be directly coupled with a pressure-sensitive device <NUM> (see <FIG> and <FIG>), so that the latter is suitable to detect the pressure that reigns in the intermediate segment of the outlet duct <NUM> comprised between the non-return valve <NUM> and the terminal segment <NUM>.

This pressure-sensitive device <NUM> is preferably a pressure switch which directly controls the pumping group <NUM> and possibly also the main solenoid valve <NUM>.

Alternatively, the pressure-sensitive device <NUM> can be a pressure transducer <NUM> which can be connected to the electronic control unit which controls the main solenoid valve <NUM> and the pumping group <NUM>.

In both cases, when the pressure-sensitive device <NUM> detects a pressure higher than a predetermined threshold value, indicative for example that the request for water by the utilities has been interrupted, the motor <NUM> of the pumping group <NUM> is automatically stopped and eventually the main solenoid valve <NUM> is also closed.

Conversely, when the pressure-sensitive device <NUM> detects that the pressure has dropped below the threshold value again, that is the utilities have been reopened and request water, the main solenoid valve <NUM> can be automatically opened and the motor <NUM> of the pumping group <NUM> is put back into operation.

The first monolithic body <NUM> of the outlet module <NUM> can further comprise a coupling port <NUM>, which derives from and is placed also in hydraulic communication with the intermediate segment of the outlet duct <NUM> comprised between the non-return valve <NUM> and the terminal segment <NUM>.

In the illustrated embodiment, said coupling port <NUM> can derive directly from the outlet duct <NUM>, for example extending with axis straight and coinciding with the axis of the secondary duct <NUM> but on the opposite side of the latter.

The coupling port <NUM> is suitable to be directly coupled with a conductivity transducer <NUM> (see <FIG>), so that the latter is suitable to detect the electrical conductivity of the water flowing along the intermediate segment of the outlet duct <NUM> comprised between the non-return valve <NUM> and the terminal segment <NUM>.

The conductivity transducer <NUM>, which is known per se and conventional, can be connected to the electronic control unit, so that the latter can, for example, control the operation and the efficiency of the plant <NUM>.

In fact, the electrical conductivity of water generally depends on the concentration of salts dissolved therein, so that this parameter can provide an indirect indication of the operation and of the filtering capacity of the reverse osmosis filtering device <NUM>.

Finally, the outlet module <NUM> can comprise a connecting duct <NUM>, which derives from and is also placed in hydraulic communication with the intermediate segment of the outlet duct <NUM> comprised between the non-return valve <NUM> and the terminal segment <NUM>.

This connecting duct <NUM> can extend with axis straight and orthogonal both to the central axis H of the outlet duct and to the axis of the secondary duct <NUM> but preferably incident with the latter into a common intersection point.

In the example of <FIG>, the connecting duct <NUM> is closed with a plug, however, in other embodiments, it is suitable to be hydraulically connected to an auxiliary device (not illustrated).

Said auxiliary device can be a tank, which is preferably positioned at a higher level than the outlet duct <NUM>.

This tank can effectively act as a buffer for storing the treated water, to allow a more immediate supply of the same when requested by the utilities.

In fact, as previously explained, when the utilities request water, for example through the opening of the respective delivery valve, the pressure in the outlet duct <NUM> decreases and, only following pressure decrease, the electronic control unit controls the actuation of the pumping group <NUM> and possibly the opening of the main solenoid valve <NUM>.

This procedure can therefore involve a certain delay between the instant in which the water is requested by the utilities and the instant in which the water is actually supplied.

The presence of a storage tank connected to the connecting duct <NUM> can mitigate this delay.

In fact, during normal operation of the plant <NUM>, the storage tank is filled with a part of the filtered water travelling towards the utilities connected to the outlet duct <NUM>.

When the request for water stops, this filtered water remains confined inside the storage tank.

When the delivery is reopened, the pressure drop in the outlet duct <NUM> causes the filtered water stored in the tank to flow immediately towards the utilities, waiting for the plant <NUM> to return to normal operation.

Claim 1:
A container (<NUM>) for filtering devices, comprising:
- a tubular lateral wall (<NUM>),
- a bottom plate (<NUM>) which closes a first axial end of said lateral wall (<NUM>), and
- a closing system (<NUM>) suitable to close - in an openable fashion - a second and opposite axial end of said lateral wall (<NUM>),
wherein said closing system (<NUM>) comprises:
- an occlusion element (<NUM>), which comprises a cylindrical lower portion (<NUM>) suitable to be coaxially inserted into the lateral wall (<NUM>), and an upper portion (<NUM>) from which one or more abutment elements (<NUM>) suitable to rest on the edge of the second axial end of the lateral wall (<NUM>) project,
- one or more annular seats (<NUM>) obtained coaxially on the outer lateral surface of the lower portion (<NUM>) of the occlusion element (<NUM>) and singularly suitable to receive an annular sealing gasket (<NUM>), and
- a tightening member (<NUM>) comprising a ring nut (<NUM>) suitable to surround the occlusion element (<NUM>) and to be axially constrained to the external of the lateral wall (<NUM>), at the second axial end thereof, and at least one abutment surface (<NUM>) suitable to rest on the upper portion (<NUM>) of the occlusion element (<NUM>), on the opposite side with respect to the bottom plate (<NUM>),
characterised in that the edge of the second axial end of the lateral wall (<NUM>) is shaped so as to define a cam profile on which the abutment elements (<NUM>) of the occlusion element (<NUM>) can slide following a rotation of the latter around the axis thereof, said cam profile being suitable to transform said rotation into an axial displacement of the occlusion element (<NUM>) with respect to the lateral wall (<NUM>).