Patent Publication Number: US-2022226758-A1

Title: Filter for Treating a Fluid in a Piping of a Heating and/or Cooling System, in Particular of Domestic and/or Industrial Type

Description:
BACKGROUND OF THE INVENTION 
     1. The Field of the Invention 
     The present invention relates to a filter for treating a fluid in a piping of a heating and/or cooling system, in particular of domestic and/or industrial type, according to the preamble of claim  1 . 
     2. The Relevant Technology 
     In hydronic heating and/or cooling systems, it has become increasingly common to take all possible actions aimed at keeping the heat-transfer fluid as clean as possible (which is normally water, possibly with the addition of glycol or similar substances) and free from impurities that, especially in old systems, typically have a very high concentration of ferrous particles released from system components, particularly from pipes (typically made of iron) and radiators. 
     Such impurities are circulated by a pump included in the system; therefore, they tend to impair the proper and efficient operation of the control elements (e.g., valve components) and also of any heat exchangers included in the generators (e.g., boilers, refrigerators, heat pumps, and so on). 
     If such impurities are not removed, in the long run they can reduce the efficiency of the system and lead to damage to the components thereof, e.g., said control elements, exchangers and generators. 
     Moreover, such impurities may lead to perforation of the pipes due to corrosion; in fact, the accumulated impurities, in contact with the oxygen that is present in water, tend to oxidize those parts of the system where they deposit and may cause corrosion of such parts, resulting in a perforated pipe. 
     For these reasons, several techniques and method are known in the art for removing impurities from the fluid flowing in pipes of a water supply system, in particular a heating and/or cooling system. 
     In particular, it is known to use at least one filter associated with a pipe of the heating and/or cooling system, in particular said filter comprising at least one magnetic element trapping the ferrous impurities that may be present in the system. 
     Typically, said filter is associated with a pipe of the return circuit of the system for protecting the power generator (whether a heating power generator, e.g., a boiler, or a cooling power generator). 
     It is clear that the filters normally employed for heating and cooling system protection must be periodically maintained, in particular for the purpose of removing the residues of impurities that have accumulated after the heat-transfer fluid has flowed therethrough many times. 
     In this regard, it has been observed that the filters known in the art have some drawbacks, since in some cases such maintenance work is quite demanding because it requires that the heating and cooling system be completely drained of the liquid circulating therein. 
     In other cases, maintenance can be carried out by providing a first shut-off valve associated with the system and positioned upstream of the filter (so that it is possible to stop the flow of fluid towards the filter) and also a second shut-off valve associated with the system and positioned downstream of the filter, i.e., between the filter and the power generator (so that it is possible to stop the flow of fluid exiting the filter), the provision of said first and second shut-off valves making it possible to substantially isolate the filter from the rest of the system prior to removing the residues of impurities that have accumulated therein. 
     Nevertheless, also this solution has some drawbacks, in that associating the filter and the shut-off valves with the system is very difficult, and sometimes even impossible, because of the limited space normally left available in modern heating and cooling systems; it must be pointed out that this problem is particularly felt in apartments and houses where the power generator (boiler) is placed in suitable wall units that normally do not leave sufficient room for positioning a filter and the associated shut-off valves. 
     A further drawback is that the filters known in the art are not versatile and do not allow an installer to easily and readily use the same filter in association with different types of power generators and different installation configurations. 
     Document WO2018/207083A1 relates to a sludge separator for heating systems, which comprises a valve device (i.e., a fluid shut-off valve) combined with a filter device, which are structurally and functionally integrated together. 
     In particular, the sludge separator shown in document WO2018/207083A1 comprises a filter device having a cup-shaped body removably connected to a valve body having an inlet and an outlet for a heat-transfer fluid, an obstructor being provided in said valve body, fixed to a rod that can be manually actuated in order to close the inlet by means of said obstructor. 
     However, the sludge separator shown in document WO2018/207083A1 essentially still suffers from the same drawbacks as the devices known in the art. In fact, the mutual integration of a valve device and a filter device does not result in a device suitable for being optimally installed in the limited space available in modern heating and cooling systems. Moreover, said sludge separator does not allow an installer to easily and readily use the separator in association with different types of power generators and different installation configurations. 
     SUMMARY OF THE INVENTION 
     In this frame, it is the main object of the present invention to provide a filter for treating a fluid in a piping of a heating and/or cooling system, in particular of domestic and/or industrial type, which is so realized as to overcome the drawbacks of the prior art. 
     In particular, it is one object of the present invention to provide a filter for treating a fluid in a piping of a heating and/or cooling system, in particular of domestic and/or industrial type, which is so constructed that it can be easily subjected to maintenance work for removing the residues of impurities that have accumulated therein after the heat-transfer fluid has flowed therethrough many times. 
     It is another object of the present invention to provide a filter for treating a fluid in a piping of a heating and/or cooling system, in particular of domestic and/or industrial type, which is so constructed that it can be optimally installed in the limited space left available in modern heating and cooling systems. 
     It is a further object of the present invention to provide a filter for treating a fluid in a piping of a heating and/or cooling system, in particular of domestic and/or industrial type, which is so constructed as to be versatile and allow an installer to easily and readily use the filter in association with different types of power generators and different installation configurations. 
     Said objects are achieved by the present invention through a filter for treating a fluid in a piping of a heating and/or cooling system, in particular of domestic and/or industrial type, incorporating the features set out in the appended claims, which are an integral part of the present description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further objects, features and advantages of the present invention will become apparent from the following detailed description and from the annexed drawings, which are supplied by way of non-limiting explanatory example, wherein: 
         FIGS. 1 a  and 1 b    are perspective views of a filter for treating a fluid in a piping of a heating and/or cooling system, in particular of domestic and/or industrial type, according to the present invention; 
         FIGS. 2 a  and 2 b    are a side view and a longitudinal sectional side view, respectively, of the filter according to the present invention in a first operating condition; 
         FIGS. 3 a  and 3 b    are a side view and a longitudinal sectional side view, respectively, of the filter according to the present invention in a second operating condition; 
         FIG. 4  is an exploded view of some components of the filter according to the present invention; 
         FIG. 5 a    is a perspective view of a component of the filter according to the present invention,  FIG. 5 b    is a side view of the component of  FIG. 5 a   , and  FIG. 5 c    is a sectional view along line B-B of  FIG. 5   b.    
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the annexed drawings, reference numeral  1  designates as a whole a filter for treating a fluid in a piping of a heating and/or cooling system, in particular of domestic and/or industrial type, according to the present invention. 
     The filter  1  comprises a main body  2  internally comprising at least one chamber  10 . 
     The filter  1  then has a first mouth  11  and a second mouth  12 , respectively comprising a first duct C 1  and a second duct C 2  allowing the fluid to enter and/or exit said at least one chamber  10 . In particular, the first duct C 1  and the second duct C 2  are adapted to put said at least one chamber  10  of the filter  1  in communication with the other components (not shown in the annexed drawings) of the heating and/or cooling system, in particular with the pipes thereof. 
     The first mouth  11  has a first longitudinal axis X and the second mouth  12  has a second longitudinal axis Y, in particular the second mouth  12  being preferably positioned on the main body  2  in such a way that the second longitudinal axis Y is substantially perpendicular to the first longitudinal axis X of the first mouth  11 . 
     In a preferred embodiment, the main body  2  has a substantially cylindrical shape; in such an embodiment, the first mouth  11  is located on the side surface of the main body  2 , whereas the second mouth  12  is located at one end (or base) of the substantially cylindrical main body  2 . In this preferred embodiment, the second longitudinal axis Y of the second mouth  12  is substantially parallel to a longitudinal axis of the filter  1 ; it should be noted that in the annexed  FIGS. 2 b  and 3 b    said longitudinal axis of the filter  1  and the second longitudinal axis Y of the second mouth  12  coincide, and are therefore represented as a single straight line Y-Y. 
     Preferably, the first mouth  11  and the second mouth  12  are positioned on the main body  2  in such a way as to lie substantially in the same longitudinal plane, said longitudinal plane being parallel to a longitudinal axis of the filter  1 ; as previously explained, said longitudinal axis of the filter  1  is not shown in the annexed drawings because it substantially coincides with the second longitudinal axis Y of the second mouth  12  or is substantially parallel to said second longitudinal axis Y. 
     The filter  1  comprises also a filtering element  20  for treating the fluid, housed at least partially in said at least one chamber  10 , in particular said filtering element  20  comprising at least one magnetic element  21  adapted to intercept and trap the ferrous impurities that are present in the fluid to be treated. 
     In a preferred embodiment, and as shown in the annexed  FIGS. 2 b  and 3 b   , said at least one magnetic element  21  has a substantially rod-like shape. 
     The filter  1  comprises a closing element or plug  30  adapted to be coupled to the main body  2  in order to close said at least one chamber  10 . 
     In accordance with the present invention, the filter  1  comprises a shut-off element  40  housed in a portion of said at least one chamber  10  communicating with said first duct C 1  and second duct C 2 . 
     As particularly visible in  FIGS. 4 to 5   c , said shut-off element  40  has a substantially cylindrical or truncated conical shape and is provided with an outer wall  40 E, a first channel  41 , a second channel  42 , and a septum  43  adapted to divide said first and second channels  41 ,  42  from each other, said shut-off element  40  being adapted to rotate about a longitudinal axis of its own, which is substantially parallel to or coincides with the first longitudinal axis X of the first mouth  11 , so that it can be reversibly switched:
         from a first position (which may also be defined as “open” position, such position being shown, in particular, in  FIGS. 2 a  and 2 b   ), in which said shut-off element  40  is positioned in such a way as to allow the flow of fluid to enter the chamber  10  and/or exit the chamber  10  both via the communication of the first duct C 1  with said at least one chamber  10  through the first channel  41  and via the communication (which may also be defined as an at least partial alignment) of the second duct C 2  with said at least one chamber  10  through the second channel  42 ,   to a second position (which may also be defined as “closed” position, such position being shown, in particular, in  FIGS. 3 a  and 3 b   ), in which said shut-off element  40  is positioned in such a way as to prevent the flow of fluid from entering the chamber  10  and/or exiting the chamber  10 , said outer wall  40 E obstructing both the communication of the first duct C 1  with said at least one chamber  10  through the first channel  41  and the communication of the second duct C 2  with said at least one chamber  10  through the second channel  42 .       

     It must be pointed out that the term “reversibly” as used above refers to the fact that the shut-off element  40  can be rotated within the portion of said at least one chamber  10  that communicates with said first duct C 1  and said second duct C 2  for switching either from the first “open” position to the second “closed” position (as described) or from the second “closed” position to the first “open” position. 
     In a preferred embodiment, shown in particular in  FIGS. 5 a  to 5 c   , said substantially cylindrical or truncated conical shut-off element  40  comprises:
         a window  41 A formed on the outer wall  40 E;   an opening  41 B at one end of the cylindrical shut-off element  40 ,       

     wherein the window  41 A, the opening  41 B, the septum  43  and a part of the inner portion of the cylindrical shut-off element  40  form the first channel  41 . 
     In substance, in the embodiment of the first channel  41  shown in the annexed drawings, the fluid must follow a substantially L-shaped path, since it flows from the chamber  10  to the inner portion of the shut-off device through the window  41 A (or, vice versa, it flows from within the shut-off device  40  to the chamber  10  through the window  41 A) by following a direction that is substantially parallel to the second axis Y of the second mouth  12 , and then flows in the shut-off element  40  along a direction that is substantially parallel to the first axis X of the first mouth  11 . 
     Furthermore, in said preferred embodiment the substantially cylindrical or truncated conical shut-off element  40  comprises a first hole  42 A and a second hole  42 B formed on the outer wall  40 E in a manner such that they are substantially aligned with each other and form the second channel  42 , in particular in co-operation with the septum  43  and with a part of the inner portion of the shut-off element  40 . 
     In substance, in the embodiment of the second channel  42  shown in the annexed drawings, the fluid flow must follow a substantially straight path; in fact, it flows through the first hole  42 A, within the shut-off element  40  and through the second hole  42 B along a direction substantially parallel to the second axis Y of the second mouth  12 . 
     As a consequence, in the second “closed” position the shut-off element  40  is so positioned that the first channel  41  is oriented in such a way as to not put the first duct C 1  in communication with said at least one chamber  10 , in particular said window  41 A being so positioned as to not face, even partially, said at least one chamber  10 . 
     Meanwhile, when the shut-off element  40  is in the second “closed” position, the second channel  42  is misaligned with the second duct C 2 , in the sense that the first hole  42 A and the second hole  42 B of said second channel  42  do not face, even partially, the first duct C 1 . In particular, in said second “closed” position the outer wall  40 E of the shut-off element  40  directly obstructs and closes the second duct C 2  (as can be seen in  FIG. 3 b   ), in particular that part of said second duct C 2  which leads into the chamber  10 . 
     It should be noted that the shut-off element  40  is defined herein as an element having a cylindrical or truncated conical shape because it can be constructed, with equivalent results, as either:
         a solid (cylindrical or truncated conical) element, within which the first channel  41  and the second channel  42  are formed, so that the window  41 A, the opening  41 B, the first hole  42 A and the second hole  42 B are the end portions of the first channel  41  and of the second channel  42 ; or   a hollow (cylindrical or truncated conical) element (i.e., a tubular element), wherein the first channel  41  and the second channel  42  are obtained by forming the window  41 A, the first hole  42 A and the second hole  42 B in the outer wall  40 E of such tubular element (cylindrical or truncated conical in shape).       

     In both of such embodiments, the septum  43  is essentially a wall that permits dividing the path of the first channel  41  from that of the second channel  42 , in particular said septum  43  developing within the shut-off element  40  in a way mostly perpendicular to the longitudinal axis of said shut-off element  40 , i.e., substantially parallel to the second axis Y of the second mouth  12  when the shut-off element  40  is positioned inside the chamber  10 . 
     It must be pointed out, however, that the first channel  41  and the second channel  42  according to the present invention may also be constructed in different ways and/or shapes, other than those described and shown in the annexed drawings; merely by way of example, the first channel  41  and the second channel  42  may be formed during the moulding of the shut-off element  40  and/or in such a way as to have a more rounded profile than shown in the annexed drawings. 
     As can be seen in the annexed drawings, the shut-off element  40  has a shape that is substantially complementary to that of the inner portion of the main body  2  that houses it, in particular said shut-off element  40  being so designed as to have slightly smaller dimensions than the inner walls of the main body  2  adapted to receive it, i.e., than the walls of the main body  2  that delimit the chamber  10  and house said shut-off element  40 . 
     In substance, the outer wall  40 E of the shut-off element  40  is so realized that its shape substantially matches the shape of the inner wall of the main body  2  to which said outer wall  40 E is coupled, in particular said outer wall  40 E having a substantially cylindrical or truncated conical shape and a diameter and dimensions slightly smaller than those of the inner wall of the main body  2 ; such a conformation makes it possible, at the same time, to obtain the rotation of the shut-off element  40  about its longitudinal axis within the chamber  10  of the main body  2 , and also to provide an optimal hydraulic sealing between the outer wall  40 E and said first duct C 1  and second duct C 2  when the shut-off element  40  is in said second “closed” position. 
     Moreover, the shut-off element  40  is shown in the annexed drawings to be positioned in the chamber  10  in such a way that the longitudinal axis of the shut-off element  40  substantially coincides with the first longitudinal axis X of the first mouth  11 ; as a consequence, the longitudinal axis of the shut-off element  40  is not represented in the annexed drawings. It is however possible to position the shut-off element  40  in the chamber  10  in such a way that its longitudinal axis does not coincide perfectly with the first longitudinal axis X of the first mouth  11  or is offset relative thereto; in fact, for the purposes of the present invention, the shut-off element  40  must be positioned inside the chamber  10  in such a way that it can rotate about an axis of its own while at the same time allowing its the outer wall  40 E to obstruct, with optimal hydraulic tightness, the first duct C 1  and the second duct C 2  when the shut-off element  40  is in said second “closed” position. 
     The peculiar provisions of the shut-off element  40  according to the present invention make it possible to overcome the drawbacks of the filters known in the art for treating a fluid in a heating/cooling system, in particular of domestic and industrial type. 
     In fact, such provisions make it possible to provide a filter  1  designed to be easily subjected to maintenance work for removing the residues of impurities that have accumulated therein after the heat-transfer fluid has flowed therethrough many times. 
     In particular, such maintenance work can be carried out by turning the shut-off element  40  from the first “open” position to the second “closed” position, so as to prevent the flow of fluid from entering the chamber  10  and allow a user/operator to clean the filtering element  20  appropriately. When maintenance is complete, the filter  1  can be brought back into the normal working condition by turning the shut-off element  40  from the second “closed” position to the first “open” position. 
     It is therefore apparent that the provision of the shut-off element  40  allows the filter  1  of the present invention to be optimally installed in a system without requiring the use of any additional components, such as shut-off valves positioned upstream and downstream of the filter  1 ; as a result, the filter  1  according to the present invention is particularly suitable also for installation in the limited space available in modern heating and cooling systems. 
     In the annexed drawings one can see that the chamber  10  of the filter  1  according to the present invention is substantially divided into two portions, i.e., a first portion (communicating with the first duct C 1  and the second duct C 2 ) adapted to house the shut-off element  40 , and a second portion adapted to house the filtering element  20  for treating the fluid; in this context, the separation of said two portions may be more or less marked depending on the different possible embodiments of the filter  1  of the present invention, as regards both the internal conformation of the chamber  10  and the external conformation of the main body  2  and of the entire filter  1  according to the present invention. 
     It must be pointed out that the filter  1  may comprise at least one sealing element (not shown) to avoid any fluid leakage between the outer wall  40 E of the shut-off element  40  and the main body  2 . In a preferred embodiment, said at least one sealing element is made of rubber, and the outer wall  40 E is made of polymeric material, said components being mutually associated by co-moulding or another manufacturing technology, or by mechanical coupling between the rubber sealing element and the polymeric outer wall  40 E. It is however apparent that the outer wall  40 E and the sealing element may also be manufactured otherwise, and the coupling thereof may be effected in a different way (e.g., by mechanical assembly). 
     In accordance with the present invention, the shut-off element  40  is so constructed as to comprise actuating means  44 ,  45  (particularly visible in  FIGS. 2 a    to  4 ) that allow acting upon said shut-off element  40  in order to cause it to rotate about its longitudinal axis and switch from the first position to the second position, and vice versa. 
     In the embodiment shown in the annexed drawings, said actuating means comprise a pin  44  associated with a closing wall  41 C adapted to close an end of the shut-off element  40  opposite to that end of said shut-off element  40  which is provided with the opening  41 B. It should be noted that, as shown in  FIG. 4 , said closing wall  41 C is preferably made as one piece with said pin; it is however clear that the closing wall  41 C may also be manufactured otherwise, e.g., as one piece with the shut-off element  40  and coupled to the pin  44  by mutual fastening means. 
     The actuating means may then comprise a knob  45  adapted to be coupled to the pin  44  to facilitate rotating said pin  44  and the shut-off element  40 . 
     Preferably, said knob  45  has a substantially discoid shape and is provided with at least one raised portion  45 A that further facilitates the handling of the assembly consisting of the knob  45 , the pin  44  and the shut-off element  40 . 
     Furthermore, the raised portion  45 A is designed as an elongate protrusion formed on said knob  45  and substantially coinciding with the diameter of said discoid knob  45 . 
     Such a conformation of the raised portion  45 A facilitates the correct identification of the position of the shut-off element  40 . In fact, when the shut-off element  40  is in the first “open” position (as shown in  FIGS. 2 a  and 2 b   ), the knob  45  is preferably associated with the pin  44  in such a way that the raised portion  45 A is aligned with or parallel to the second axis Y of the second mouth  12 . 
     Conversely, when the shut-off element  40  is in the second “closed” position (as shown in  FIGS. 3 a  and 3 b   ), the knob  45  is preferably associated with the pin  44  in such a way that the raised portion  45 A is positioned substantially perpendicular to (or anyway incident on) the second axis Y of the second mouth  12 . 
     With particular reference to  FIG. 4 , it can be further noticed that the filter  1  comprises coupling means adapted to allow fixing the shut-off element  40  in said at least one chamber  10 . 
     In particular, said coupling means may comprise a cover  46  for closing the portion of said at least one chamber  10  that contains the shut-off element  40 , said cover  46  preferably having an aperture (not shown in  FIG. 4 ) for the passage of the actuating means  44 ,  45 , in particular for the passage of said pin  44 . 
     As shown in the annexed drawings, the knob  45  and the cover  46  are associated with the main body  2  on the side opposite to the first mouth  11 . 
     In accordance with a preferred embodiment, the first mouth  11  and the second mouth  12  are so constructed as to have substantially the same conformation. In particular, the first mouth  11  and the second mouth  12  are constructed in substantially the same manner in terms of dimensions and shape. In this context, the first mouth  11  and the second mouth  12  comprise similar connection means; for example, said connection means may consist of similar threads on the sides of said first mouth  11  and second mouth  12 , the term “sides” referring to that surface of the mouths  11 ,  12  which is opposite to the one which faces the first duct C 1  and the second duct C 2 , respectively. 
     The provisions of the present invention concerning the first and second mouths  11 ,  12  make it possible to considerably improve the potential of the filter  1  according to the present invention, since such provisions allow the filter  1  according to the present invention to be used without distinction in different configurations. 
     In fact, the filter  1  according to the present invention can be used indifferently in:
         a first configuration, wherein the first mouth  11  is associated with a duct for delivering the fluid to a power generator, and wherein the second mouth  12  is associated with a return duct of the heating and/or cooling system;   a second configuration, wherein the first mouth  11  is associated with a return duct of the heating and/or cooling system, and wherein the second mouth  12  is associated with a duct delivering the fluid to a power generator.       

     It should be noted that, since the filter  1  according to the present invention is generally installed under a power generator (or boiler), when said filter  1  is used:
         in the first configuration, it is mounted in such a way that (as shown in the annexed  FIGS. 1 b , 2 a , 2 b , 3 a  and 3 b   ) the first axis X of the first mouth  11  is substantially vertical and the second axis Y of the second mouth  12  is substantially horizontal;   in the second configuration, it is mounted in such a way that (as shown in the annexed  FIG. 1 a   ) the first axis X of the first mouth  11  is substantially horizontal and the second axis Y of the second mouth  12  is substantially vertical.       

     It must also be pointed out that the annexed drawings do not show the components belonging to the heating and/or cooling system, i.e., the delivery duct, the power generator and the return duct. 
     In a preferred embodiment, the filter  1  according to the present invention comprises a port  31  (also referred to as “multifunction” port) adapted to put the chamber  10  in communication with the environment outside the filter  1 . 
     For example, said port  31  may be associated with a pressure gauge, for measuring the pressure of the fluid in said chamber  10 , or with an air venting device. 
     Preferably, said “multifunction” port  31  is associated with the closing element or plug  30 . 
     In accordance with the present invention the filtering element  20  is coupled to the closing element  30 ; in this respect, the filtering element  20  and the closing element  30  comprise mutual coupling means (e.g., respective threads), which allow fixing the filtering element  20  to the closing element  30 . 
     In a preferred embodiment, the closing element  30  comprises a sheath  32  adapted to house the filtering element  20 . 
     In addition, the filtering element  20  preferably comprises a magnet cartridge  22  adapted to house said at least one magnetic element  21 , in particular said magnet cartridge  22  being in turn housed inside the sheath  32  of the closing element  30 . 
     As shown in  FIGS. 2 b , 3 b   , the magnet cartridge  22  and the sheath  32  develop in such a way as to allow positioning said at least one magnetic element  21  inside the chamber  10  of the filter  1 . 
     Preferably, said at least one magnetic element  21  has a substantially rod-like shape, and the main body  2  of the filter  1  has a substantially cylindrical or cup-like shape, said magnetic element extending within the chamber  10  substantially parallel to the longitudinal axis of the main body  2  of the filter  1  (which substantially coincides with the second axis Y of the second mouth  12 ); as a consequence, in this embodiment also the magnet cartridge  22  and the sheath  32  extend within the chamber  10  in a direction parallel to the second axis Y of the second mouth  12 . 
     The magnet cartridge  22  is extractable, since it can be separated from said sheath  32  and/or from said at least one magnetic element  21 ; also, the magnet cartridge  22  and the sheath  32  are preferably made of plastic material. Such provisions facilitate the removal of the ferrous residues captured by said at least one magnetic element  21 , which would otherwise be difficult to carry out because of the considerable intensity of the magnetic field generated by said at least one magnetic element  21 . 
     Preferably, the filter  1  according to the present invention comprises a second filtering element  25 , in particular of the mesh type, positioned in the chamber  10  for subjecting the fluid to be treated to a mechanical filtering, in particular for the purpose of trapping non-ferromagnetic impurities that may be present in said fluid to be treated; as a consequence, said second filtering element  25  permits subjecting the fluid to an additional filtering action so as to capture any non-ferromagnetic impurities that may have escaped the magnetic field exerted by the magnetic filtering element  20 . 
     In a preferred embodiment, said second filtering element  25  is so constructed as to have a substantially tubular shape and extend parallel to the second axis Y of the second mouth  12 . 
     Preferably, the second filtering element  25  is positioned in the chamber  10  in such a way as to enclose or contain the filtering element  20 ; moreover, the second filtering element  25  is preferably positioned in the chamber  10  in such a way as to enclose or contain the assembly consisting of the filtering element  20 , the magnet cartridge  22  and the sheath  32 . 
     Advantageously, the main body  2  comprises a wall  2 A (particularly visible in  FIG. 2 b   ), which extends in the chamber  10  parallel to the second axis Y of the second mouth  12 , so as to mate with a tract of the second filtering element  25  and allow it to be positioned correctly inside the chamber  10 . 
     In particular, also the wall  2 A has a substantially tubular shape, and its cross-section may be slightly greater (as shown in  FIG. 2 b   ) than that of the second filtering element  25 , so that said wall  2 A can be fitted over the initial tract of the second filtering element  25 . It is however clear that the wall  15  may alternatively be designed with a cross-section slightly smaller than that of the second filtering element  25 , so that it can be inserted into an initial tract of the second filtering element  25 . 
     Furthermore, the closing element  30  may be so shaped as to comprise a recess (not shown in the drawings), in particular having a substantially circular shape when viewed from the front (i.e., in a direction parallel to the axis A-A of the filter  1 ), which is adapted to receive an end portion of the second filtering element  25  and allow it to be positioned correctly inside the chamber  10 , in particular in co-operation with the wall  2 A. 
     Preferably, the filter  1  according to the present invention is provided with a third filtering element  26  comprising at least one additional magnetic element. 
     In particular, said third filtering element  26  of magnetic type is positioned inside the chamber  10  in a manner such as to be associated with or fixed to the inner wall of the main body  2 , i.e., that wall of the main body  2  which faces towards the chamber  10 ; as an alternative, said third filtering element  26  of magnetic type may be associated with the closing element  30 . 
     The provision of a filter  1  comprising a first filtering element  20  of magnetic type, a second filtering element  25  of mechanical type (mesh) and a third filtering element  26  of magnetic type ensures a complete filtration of the fluid flowing in the chamber  10 . 
     In this regard, it must be pointed out that the filtration of the fluid flow will occur in different ways (while still being optimal) depending on the configuration in which the filter  1  of the present invention is used, with the shut-off element  40  being always positioned in the first “open” position (which allows the flow of fluid to enter the chamber  10  and exit said chamber  10 ). 
     In fact, in the situation wherein the filter  1  according to the present invention is used in the configuration referred to herein as “first configuration” (i.e., that configuration—shown in the annexed  FIGS. 1 b , 2 a , 2 b , 3 a  and 3 b   —in which the first mouth  11  is associated with a duct for delivering the fluid to a power generator, and in which the second mouth  12  is associated with a return duct of the heating and/or cooling system), the fluid enters the chamber  10  through the second duct C 2 , undergoes a first (magnetic) filtration as it flows in proximity to the first filtering element  20 , undergoes a second (mechanical) filtration as it flows through the second mesh-type filtering element  25  (the direction of flow being from the inside to the outside), undergoes a third (magnetic) filtration as it flows in proximity to the third filtering element  26 , and then exits the chamber  10  through the first duct C 1 . 
     Whereas in the situation wherein the filter  1  according to the present invention is used in the configuration referred to herein as “second configuration” (i.e., that configuration—shown in the annexed  FIG. 1 a   —in which the first mouth  11  is associated with a return duct of the heating and/or cooling system, and wherein the second mouth  12  is associated with a duct for delivering the fluid to a power generator), the fluid enters the chamber  10  through the first duct C 1 , undergoes a first (magnetic) filtration as it flows in proximity to the third filtering element  26 , undergoes a second (mechanical) filtration as it flows through the second mesh-type filtering element  25  (the direction of flow being from the outside to the inside), undergoes a third (magnetic) filtration as it flows in proximity to the filtering element  20 , and then exits the chamber  10  through the second duct C 2 . 
     It is therefore apparent that, regardless of the mode in which said filter  1  is mounted (whether horizontally, in the “first configuration”, or vertically, in the “second configuration”), the flow of fluid will anyway be subjected to three filtering stages, i.e., a first filtering stage of magnetic type, a second filtering stage of mechanical type, and a third filtering stage, again of magnetic type. 
     In this frame, the provision of three filtering stages (magnetic/mechanical/magnetic) in accordance with the features of the filter  1  of the present invention ensures an optimal filtration of the fluid flow independently of the mode of installation and type of configuration (horizontal or vertical) of said filter  1 . 
     The features of the filter  1  according to the present invention, as well as the advantages thereof, are apparent from the above description. 
     In fact, the provisions of the present invention make it possible to realize the filter  1  in such a way as to ensure optimal removal of the impurities that are present in a fluid flowing in said water supply network, while at the same time facilitating the maintenance work necessary for removing the residues of impurities that have accumulated after the heat-transfer fluid has flowed therethrough many times. In particular, the filter  1  according to the present invention makes it possible to easily isolate the filter  1  from the heating and/or cooling system; in fact, it will be sufficient to operate the shut-off element  40  in order to isolate the filter  1  from the system and drain only the fluid that is contained in the chamber  10  in order to clean one or more of the filtering elements  20 ,  25 ,  26  that are present in said chamber  10 . As a consequence, it is apparent that the provisions of the present invention avoid the need for draining the whole system when maintenance in necessary for removing from the filtering elements the residues of impurities that have accumulated in the chamber  10  after the heat-transfer fluid has flowed therethrough many times. 
     It is therefore apparent that the provision of the shut-off element  40  allows the filter  1  of the present invention to be optimally installed in a system without requiring the use of any additional components, such as shut-off valves positioned upstream and downstream of the filter  1 ; as a result, the filter  1  according to the present invention is particularly suitable also for installation in the limited space available in modern heating and cooling systems. 
     Furthermore, the peculiar provisions of the filter  1  according to the present invention make it possible to provide a solution that considerably reduces the complexity and the costs incurred when installing its component in the system, since the filter  1  avoids the need for purchasing and installing any additional components, such as, for example, shut-off valves to be positioned upstream and downstream of the filter  1 . 
     In fact, the provisions of the present invention make it possible to realize said filter  1  in a manner such that it can be optimally installed in the limited space left available in modern heating and cooling systems. 
     Moreover, the provisions of the present invention make it possible to provide a filter  1  that turns out to be very versatile, in that such provisions will allow an installer to easily and readily use the filter  1  in association with different types of power generators and different installation configurations. 
     In this frame, it is apparent that the provision of three filtering stages (magnetic/mechanical/magnetic) in accordance with the features of the filter  1  of the present invention ensures an optimal filtration of the fluid flow independently of the mode of installation of said filter  1  (whether horizontal, in the “first configuration”, or vertical, in the “second configuration”). 
     The filter  1  for treating a fluid in a piping of a heating and/or cooling system, in particular of domestic and/or industrial type, described herein by way of example may be subject to many possible variations without however departing from the spirit of the inventive idea; it is also clear that in the practical implementation of the invention the illustrated details may have different shapes or be replaced with other technically equivalent elements.