Filtration apparatus and method of use of a filtration apparatus

Abstract

The present invention relates to a filtration apparatus, in particular for separating the liquid fraction from the solid fraction of a mixture, more specifically for separating the solid suspension from the liquid that makes up the waste water, comprising: a containment tank 4 configured to contain the waste water to be filtered, a filtering assembly configured to separate the liquid fraction from the solid fraction, a support assembly 6 configured to support and maintain in position said filtering assembly, and wherein said support assembly 6 is composed of a plurality of components held together by stable and reversible association means 11, 21, 23, 32, 34. The present invention also relates to a method of using a filtration apparatus.

Description

[0001] FILTRATION APPARATUS AND METHOD OF USE OF A FILTRATION APPARATUS

[0002] DESCRIPTION

[0003] FIELD OF INVENTION

[0004] The present invention relates to a filtration apparatus and a method of using a filtration apparatus, in particular a method for maintaining a filtration apparatus. STATE OF THE ART

[0005] Filtering devices are known for separating the solid fraction from the liquid fraction of wastewater. These well-known filter devices comprise a filter membrane, generally made of a non-woven fabric or membrane, which is supported by a drum composed of a series of consecutive support discs. In known systems, these discs consist of a welded skeleton on which the filter sectors are positioned.

[0006] Furthermore, in known devices the different discs are joined by joints, making them substantially inseparable, in order to make the device more stable.

[0007] However, this solution is not entirely satisfactory because, when the filter needs to be replaced, which is generally every 5 or 6 years, it is necessary to apply considerable force to remove the filter segments, with the risk of damaging the structure. This operation, in addition to being delicate and complex due to the friction caused by the considerable size of the filter segments, often causes wear or even damage to the machine's structure, which must therefore be replaced, at least partially.

[0008] The state of the art also includes document GB 2 103 101 which relates to a pressure filtering apparatus in which there is a cartridge filter that can be removed from the support tap.

[0009] The state of the art also includes US 2,891 ,673 which relates to a pressure filtering apparatus in which there is a cartridge filter that can be removed from the support tap.

[0010] PURPOSES OF THE INVENTION

[0011] The purpose of the present invention is to propose a filtration apparatus and a method of using a filtration apparatus that allow the drawbacks of the prior art to be overcome.

[0012] Another aim of the invention is to propose a device that is simpler to build and maintain than solutions according to the known art.

[0013] Another aim of the invention is to propose an apparatus that can be used to treat large volumes of mixtures.

[0014] Another aim of the invention is to propose an apparatus that is economical to manufacture.

[0015] A further aim of the invention is to propose a modular apparatus.

[0016] Another aim of the invention is to propose a method that allows for the simplification of maintenance operations.

[0017] Another aim of the invention is to propose an apparatus and a method that allow to reduce the risks of damaging the filter element during maintenance operations.

[0018] It is also the aim of the invention to propose a method that allows only a part of the apparatus to be replaced.

[0019] All these purposes, and others which will clearly result from the description, are achieved by means of a filtration apparatus having the characteristics described in claim 1 and a method of using a filtration apparatus according to claim 10.

[0020] Other structural and functional characteristics of the present innovation and the related advantages with respect to the known art will become even clearer and more evident from an examination of the following description, referring to an exemplary and preferred, but not limiting, embodiment of the apparatus and method which are the object of the present invention.

[0021] OBJECT

[0022] The specific object of the present invention is therefore a filtration apparatus, in particular for separating the liquid fraction from the solid fraction of a mixture, more specifically for separating the solid suspension from the liquid that makes up the waste water, comprising: a containment tank configured to contain the waste water to be filtered, a filtration assembly 7 configured to separate the liquid fraction from the solid fraction, a support assembly configured to support and maintain in position said filtration assembly 7, an outlet pipe), and characterised in that said outlet pipe is an outlet device configured to be inserted at least partially into said outlet pipe.

[0023] Also according to the invention, said output device may comprise a telescopic tubular portion.

[0024] Still according to the invention, said outlet device may comprise a sealing lip.

[0025] Advantageously, according to the invention, said outlet pipe can comprise a sealing gasket whose internal diameter substantially corresponds to the external diameter of said tubular portion.

[0026] Furthermore, according to the invention, said sealing lip may have an upwardly flared profile.

[0027] Preferably according to the invention, said outlet pipe may have a closing valve or gate at and / or near the outlet from said containment tank.

[0028] Advantageously according to the invention, said apparatus may comprise at least one, and preferably a plurality of backwash tubes configured to spray a fluid in order to descale said filter assembly 7.

[0029] Also in accordance with the invention, said at least one backwash tube may comprise a stiffening device configured to prevent twisting of said backwash tube.

[0030] Still according to the invention, said stiffening device may comprise a stiffening rod removably associated with at least one, and preferably a pair of fastening elements welded to said backwash tube.

[0031] A further object of the present invention is a method for using an apparatus according to one or more of the preceding claims, characterised in that when said support assembly must be removed from said containment tank, said outlet device is removed from said pipe when said containment tank still contains said mixture to be filtered.

[0032] BRIEF DESCRIPTION OF THE FIGURES

[0033] The present invention will now be described, by way of example and not by way of limitation, according to some of its preferred embodiments, and with the aid of the attached figures, in which:

[0034] Figure 1 shows a perspective view of an apparatus according to the invention without the filter assembly 7 for clarity,

[0035] Figure 2 shows a perspective view of the support assembly of an apparatus according to the invention,

[0036] Figure 3a shows a perspective view of a support disk of an apparatus according to the invention in a partially disassembled condition,

[0037] Figure 3b shows a perspective view of a support disk of an apparatus according to the invention with the filter elements mounted.

[0038] Figure 4a shows a perspective view of a portion of a support disk of an apparatus according to the invention,

[0039] Figure 4b shows it in lateral view

[0040] Figure 5 shows a perspective view of a connecting element of an apparatus according to the invention,

[0041] Figure 6 shows a perspective view of a closing element of an apparatus according to the invention,

[0042] Figure 7 shows a perspective view of a closing plate of an apparatus according to the invention,

[0043] Figure 8 shows a perspective view of a backwash tube of an apparatus according to the invention,

[0044] Figure 9 shows a perspective view of a lock bar,

[0045] Figure 10 shows a perspective view of an outlet device of an apparatus according to the invention and a pipe.

[0046] DETAILED DESCRIPTION OF THE INVENTION

[0047] As is clearly shown in the figures, the present invention relates to a filtration apparatus, generally indicated by the number 1 .

[0048] In particular, apparatus 1 can be configured to separate a mixture, preferably comprising a solid suspension in a liquid, by removing a solid particulate from a liquid. For example, said mixture may include wastewater, with its suspended particulates.

[0049] The apparatus 1 according to the invention may be that described in patent application WO 2020 / 098997, the contents of which are hereby incorporated in their entirety by reference.

[0050] In the following, the Z-axis is used to indicate the main development axis of the apparatus 1 , i.e., the axis around which the filters can be configured to rotate, as will be clear later. Furthermore, the (r, 9) plane is defined as the plane perpendicular to the Z-axis, and which has its intersection with the same axis as its origin, r is the radial coordinate, which represents the distance of a point from the origin, while 0 is the angular coordinate, which indicates the direction along which the indicated point is located, in a traditional cylindrical coordinate system. In particular, as is clearly shown in the figures, the filtering apparatus 1 according to the invention is of the axial type, i.e., the filtered liquid is located downstream in the axial direction with respect to the liquid to be filtered. Therefore, the concentration gradient can be negative along the Z-coordinate, and essentially zero along the r- and 0-coordinates.

[0051] The apparatus 1 may comprise a support structure 2 configured to support and / or move the further components of the apparatus 1 , as will be clear later.

[0052] Advantageously, said support structure 2 can comprise at least one containment tank 4 configured to contain, at least partially, the mixture to be filtered.

[0053] In particular, the tank can be significantly larger than the filtration assembly 7, for example, 10 to 1000 times larger. For example, the tank can have a volume of several hundred cubic meters.

[0054] Preferably, the tank may feature and / or be connected to an inlet pipe configured to transport the fluid to be filtered into the tank itself, through an inlet mouth positioned in a substantially opposite position to that in which the filtering assembly 7 is positioned.

[0055] Furthermore, the support structure 2 comprises a support assembly 6, configured to support and move the filters and / or filter assemblies of the apparatus, as will be clear later.

[0056] The support assembly can therefore be conveniently configured to support and hold in place the filters and / or the filter assembly 7 that make up the apparatus. Preferably, the filters and / or the filter assembly 7 can be associated with the filter assembly 7 in a stable and reversible manner by means of association means, for example screws and bolts and corresponding through holes, threaded or not, or interlocking means, or snap- fit, or form-fitting means. Conveniently, in this way, when it is necessary to remove the filters and / or the filter assembly 7 in order to clean it without having to remove the entire apparatus, as will be clear later. Advantageously, the support assembly 6 can be positioned, at least partially, inside the environment defined by said containment tank 4, and, in particular, it can be rotatably associated with at least one, and preferably with at least two perimeter walls of the containment tank 4. Suitably, the support assembly can be operated in rotation, and consequently allow the rotation of the filtering assembly 7. In particular, the apparatus 1 is a filtering apparatus with rotating discs.

[0057] The support assembly 6 can therefore comprise a plurality of support disks 8, each configured to support a corresponding filter assembly 7. Advantageously, the support disks 8 can be aligned along the Z direction. Therefore, each support disk 8 can be configured to develop mainly on a plane substantially parallel to the plane (r, 0). Clearly, the support disk 8 can have the shape of a disk or, in an embodiment represented in fig. 1 -6, it can have the shape of a polygon, preferably regular, which substantially approximates that of a disk.

[0058] Advantageously, each disc can be independent and separate - i.e. not directly connected - from the other supporting discs 8, with the exception of the motor means.

[0059] Furthermore, each support disk 8 can conveniently comprise a central component 12 to which a plurality of different radial elements 10 are associated.

[0060] The central component 12 may have a substantially annular shape. Preferably, the central component 10 may be rigidly associated with a motor 15 configured to impart a rotary motion to the different support disks 8. Advantageously, the central component 12 may be made in a single body, or in a plurality of welded elements.

[0061] Advantageously, the central component 12 can have a central opening 13 configured to allow the passage of a delivery pipe 51 , as will be clear later.

[0062] Suitably, as mentioned, each support disk 8 can comprise a plurality of radial elements 10.

[0063] Each radial element 10 may have a substantially elongated shape, and preferably can be positioned along a corresponding direction 0. Advantageously, the different radial elements 10 can be oriented along a plurality of directions spaced in a substantially equi-angled manner - i.e., two consecutive elements forming an angle 0 that is always substantially equal.

[0064] Advantageously, each radial element 10 can be associated by means of suitable first association means 11 , in a stable and reversible manner to the central component 12. For example, the first association means may comprise screws and bolts and corresponding through holes, threaded or not, or interlocking means, or snap- fit means, or shape-fit means. Alternatively, they may comprise interlocking means and / or shape-fit means. It is therefore possible to remove each support component 10 from the central component 12 by disengaging said association means, for example by disengaging the support components 10, or by unscrewing the screws. In particular, it is possible to remove the radial elements 10 without breaking or irreparably damaging the support disk 8 or in any case the apparatus 1 .

[0065] Each radial element 10 may comprise a pair of elongated elements 14, 16 configured to be associated with said central component 12 at a first end 14', 16'. Preferably said elongated elements 14, 16 may be joined by a transverse element 18, so as to form a substantially U-shaped or square U-shaped structure.

[0066] Advantageously, the apparatus 1 according to the invention further comprises at least one connecting element 20.

[0067] At the opposite end 14", 16", each elongated element 14, 16 and / or each connecting element 20 may provide corresponding second connecting means 21 configured to allow the connection of a connecting element 20. The connecting element 20 is made as a single piece with respect to the second connecting means

[0068] 21. In other embodiments, said second connecting means 21 may be welded. The second connecting means 21 may also comprise screws and bolts and corresponding through holes, threaded or not. Alternatively, they may comprise interlocking means and / or form-fitting means. Advantageously, it is therefore possible to simply and reversibly separate the connecting element 20 from the elongated elements 14, 16.

[0069] Each support component 10 may comprise at least one closure component

[0070] 22, and preferably at least one pair of closure elements 22, 22' configured to define the outer perimeter of the support disk 8. Preferably said connection element 20 or said closure component 22 may in turn comprise third association means 23 configured to allow the association of said closure elements 22, 22' with said connection element 20. In one embodiment said third association means may be defined, solely or in addition, on said closure elements 22, 22'.

[0071] Similarly to the connecting element 20, the closing component is also made of one piece with respect to the third connecting means 23. In other embodiments, said third connecting means 23 can be welded.

[0072] Furthermore, the second 21 and third 23 association means are adapted to lock said locking rod in position.

[0073] The third connecting means 23 may also comprise screws and bolts and corresponding through holes, whether threaded or not. Alternatively, they may comprise interlocking and / or form-fitting means. Advantageously, it is therefore possible to simply and reversibly separate the connecting element 20 from the closing elements 22, 22'.

[0074] Furthermore, each radial element 10 may comprise at least one, and preferably a pair of circumferential portions 24, 24', preferably positioned at the second end 14", 16" of the longitudinal elements. Advantageously, said circumferential portions 24, 24' may be solidly associated with the longitudinal elements 14, 16' or with the transverse element 18. Preferably, each circumferential portion 24, 24' may define a seat 25 for the insertion of a closing plate 26. Advantageously, each circumferential element 24, 24' may have a substantially "skeleton" shape, and therefore may comprise two pairs of opposite sides that define a central opening.

[0075] The closing plate 26 and / or the connecting element 20 may have suitable fourth connecting means 32 configured to allow stable and reversible mutual connection. For example, the fourth connecting means 32 may include screws and bolts and corresponding threaded or non-threaded through holes. Alternatively, they may include interlocking means and / or form -fitting couplings. Advantageously, it is therefore possible to simply and reversibly separate the connecting element 20 from the closing plate 26.

[0076] Furthermore, each circumferential portion 24, 24' may advantageously comprise corresponding fifth connecting means 34 configured to permit the connection between two adjacent circumferential portions 24, 24'. For example, the fifth connecting means 34 may comprise screws and bolts and corresponding threaded or non-threaded through holes. Alternatively, they may comprise interlocking and / or form-fitting means. Advantageously, therefore, it is possible to simply and reversibly separate two adjacent radial elements 10.

[0077] Furthermore, the support assembly may comprise a pair of connecting elements 36, configured to connect to the support structure 2, for example by means of a flange 38. The connecting elements 36 may be rigidly associated with the support assembly 6, and in particular with a head / tail support disk 8. Preferably, therefore, the connecting elements 36 may be set in motion by suitable movement means, for example the motor 15.

[0078] In particular, furthermore, the apparatus 1 comprises at least one filter assembly 7 (not shown), and preferably a plurality of filter assemblies configured to separate the solid suspension of the mixture from the liquid fraction.

[0079] In particular, each filter assembly 7 can be made of fabric or non-woven fabric. Preferably, it can be substantially flexible and deformable.

[0080] Therefore, each filter assembly 7 can conveniently have a first face facing the liquid to be filtered, and a second face facing the filtered liquid. Conveniently, each face is substantially flat.

[0081] Suitably, each filter assembly 7 may comprise a plurality of filter elements 7', preferably with a substantially trapezoidal and / or triangular shape, each held in position between two spoke elements 10.

[0082] In a preferred embodiment, each filter assembly 7 may have a substantially circular shape, or a regular polygon. Advantageously, each filter element may have the shape of a circular sector, or a triangular one, so that a juxtaposition of a plurality of filter elements constitutes a filter assembly 7.

[0083] Each filter element can be permeable to liquids; for this purpose, it can be made of polymeric materials, such as polyester (PE), polyethylene (PET), polyethylene terephthalate (PTFE), or polyamides. Filter elements can preferably have pore sizes between 2 and 40 pm, and more preferably between 15 and 25 pm.

[0084] Each filter element is held in place between an elongated member 14 or 16 and a locking bar 27 (see Figure 9). The latter includes a folded closure flap 271 , adapted to be locked in place by a connecting member 20 or closure component 22.

[0085] In particular, therefore, the filtering apparatus defines a plurality of substantially discoid-shaped regions, in which regions 50 external to the filtering assembly 7, in which the mixture to be filtered is located, alternate with regions 52 internal to the filtering assembly 7, i.e., in which the filtered liquid is located. Therefore, the internal regions are given by the union of all the spaces internal to the elongated elements 14, 16. Essentially, therefore, the external regions are given by the union of all the spaces external to the elongated elements 14, 16.

[0086] In correspondence with the regions 50 the solid particulate matter tends to accumulate on the filter assembly 7, risking clogging the filter assembly 7, thus limiting the filtering capacity of the apparatus 1 .

[0087] In order to prevent this possibility, a plurality of backwash tubes 53 are provided, preferably one for each region 50 into which the apparatus 1 is divided, configured to spray a cleaning fluid, for example water, onto the filter assembly 7 in order to remove encrustations through a plurality of appropriately directed nozzles. Advantageously, said backwash tubes 53 can all be fed through a single delivery tube 51 configured to slide substantially along the axis of the filter assembly 7, passing inside the holes present at the center of the connecting elements 36.

[0088] In order to limit the risk of deformation of the backwash tubes 53 caused by the force exerted by the rotating mixture, each backwash tube 53 may comprise a stiffening device 54. In particular, the stiffening device may comprise a stiffening rod 55, which preferably has a longitudinal development substantially corresponding to that of the backwash tube 53. Preferably, the stiffening rod 55 may be fixed to the backwash tube 53 by means of at least one, and preferably at least a pair of fastening elements 56. Advantageously, the at least one fastening element 56 may be firmly fixed to the backwash tube 53, preferably it may be welded. Preferably, furthermore, the stiffening rod 55 may be associated with the fastening elements 56 in a reversible manner.

[0089] The apparatus 1 provides for an advantageous removal phase of a filter assembly 7. This removal phase involves the dismantling of the components 10, 25, 20, 22 of the support disk 8 by disengaging the first 11 , second 21 , third 23, fourth 32 and / or fifth 34 support means.

[0090] In detail, the connecting element 20 and, if applicable, the closing component 22, the closing plate 26 from its respective seat 25, the radial elements 10, and the locking bar 27, which ensure the stable positioning of the filter during the operation, are removed.

[0091] In this way it is possible to replace the filter, which is placed on the elongated elements 14 or 16, before arranging the locking bar 27 and fixing it by means of the closing flap 271 , with the connecting element 20.

[0092] Subsequently, still in the phase of reinstallation of the filter assembly 7 on said support assembly 6, the components 10, 25, 20, 22 of the support disk 8 are reassembled by re-engaging the first 11 , second 21 , third 23, fourth 32 and / or fifth 34 support means.

[0093] The apparatus 1 may comprise an outlet for the filtered liquid, through which the liquid is conveyed from the containment tank 4 towards a discharge pipe 60 (see figure 10). In particular, therefore, the liquid outlet may comprise an outlet device 62, of a substantially tubular shape.

[0094] The inlet of the filtered liquid into the discharge pipe 60 can be conveniently regulated by at least one weir 61 configured to regulate the flow rate entering the outlet pipe. In particular, at least one weir can have a substantially polygonal inlet cross-section, for example quadrangular, in which a recess 6T, also polygonal, is formed. Conveniently, in this way it is possible to increase the flow rate downstream of the weir itself.

[0095] The device 62 may comprise a substantially tubular portion 63 within which it is configured to pass the filtered mixture. The substantially tubular portion 63 may be telescopic. Preferably, the outlet device 62 provides, at one end 62', a fitting 64 configured to ensure a watertight joint with the containment tank 4. At the opposite end, i.e. the one configured to be inserted inside the pipe 60, the outlet device 62 comprises a sealing lip 66, the function of which will be better described below.

[0096] Said sealing lip 66 may have an asymmetrical profile, in particular it may have a profile that flares upwards, that is, narrower in the part that will be inserted first into the pipe 60, and wider in the part that will be inserted last. Advantageously, the diameter of the sealing lip 66 in the widest part can substantially correspond to the internal diameter of the pipe 60, so that when said sealing lip 66 is inside the pipe itself, it can create a substantially watertight seal.

[0097] Advantageously, the first sealing gasket 66 can be made of a substantially elastic material, so that it can be elastically deformed during the insertion / removal operations in the pipe 60, and then return substantially to its original shape and / or volume when it is in position inside the pipe 60.

[0098] Pipe 60 includes a sealing gasket 68, which preferably has a smaller internal diameter than pipe 60.

[0099] In particular, the sealing device 62 is configured to be inserted inside the pipe 60 so as to allow the sealing lip 66 to pass beyond the sealing gasket 68. This passage is made easier by the flared shape of the sealing lip 66, and by the fact that the sealing gasket 68 is made of an elastic material which allows it to shrink in order to pass inside the sealing lip 66. Subsequently, once it has passed the sealing lip 66, the sealing gasket 68 is positioned on the upper portion of the sealing lip 66 itself, sealing the sealing device 62 and the pipe 60.

[0100] The pipe 60 can then run outside the containment tank 4, and, at the outlet, and preferably just downstream of its exit from the containment tank 4, it can be blocked by a suitable valve or gate.

[0101] Advantageously, the present invention also relates to a method for the maintenance of the apparatus 1 , and in particular a method for its maintenance.

[0102] The method may include a preliminary phase of emptying the containment tank 4. Alternatively, the method may include a phase of isolating the containment tank, by closing the valve or gate located in correspondence with the pipe 60. Subsequently, a phase of separation of the support assembly 6 from the containment tank 4 may be provided. During this phase, the sealing lip 66 slides inside the pipe 60, until it passes the sealing gasket 68, possibly deforming it, until the outlet device 62 completely emerges from the pipe 60. In particular, during this phase, the pipe 60 may fill with unfiltered mixture, but, since the gate is positioned just downstream of the pipe outlet from the containment tank, this volume is small and / or negligible. During this phase, the filter assembly 7 may still be associated with the support assembly 6. Subsequently, a disassembly phase of the support assembly may be envisaged by disengaging the first 11 , second 21 , third 23, fourth 32, and fifth 34 connection means, i.e. , by disengaging the different components, or by unscrewing screws and bolts. During this phase, the support assembly 6 may be separated from the filter assembly 7. Subsequently, once maintenance has been completed, the support assembly may be reassembled, thanks to the reversibility of the first 11 , second 21 , third 23, fourth 32, and fifth 34 connection means, together with the filter assembly 7. As can be seen, the presented solution is based on a disc filter structure which, in its final assembly configuration, is made up of longitudinal crosspieces which radially support central rings which are disconnected from each other and free to perform slight axial gaps.

[0103] From what has been said it is clear that the apparatus 1 and the method according to the invention are advantageous, indeed, optimal, since they allow for the reduction and simplification of maintenance operations on the apparatus itself, decreasing downtimes and improving overall efficiency.

Claims

CLAIMS1 . Filtration apparatus (1 ) for filtering large quantities of mixture, in particular to separate the liquid fraction from the solid fraction of a mixture, more particularly to separate the solid suspension from the liquid composing the waste water, comprising: a containment tank (4) configured to contain the waste water to be filtered, a filter assembly 7 configured to separate the liquid fraction from the solid fraction, a support assembly (6) configured to support and maintain in position said filter assembly 7, and comprising a plurality of components held together by stable and reversible association means (11 , 21 , 23, 32, 34) configured to maintain said filter assembly (7) associated with said support assembly.

2. Apparatus according to claim 1 characterised in that said support assembly comprises at least one support disk (8) and preferably a plurality of support disks (8) separate and distinct from each other and configured to support said filter assembly (7).

3. Apparatus according to any of the preceding claims characterised in that each disc comprises a central component (12) of substantially annular shape.

4. Apparatus according to any of the preceding claims characterised in that each support disk (8) comprises a plurality of radial elements (10) which depart radially from said central element (12) and are associated with said central element (12) at a first end (14' 16') by means of first stable and reversible association means (11 ).

5. Apparatus according to any of the preceding claims characterised in that said radial elements (10) comprise, at a second end (14", 16") at least one, and preferably a pair of circumferential portions (24, 24').

6. Apparatus according to any of the preceding claims characterised in that said circumferential portions (24, 24') are configured to be associated, by means of suitable stable and reversible fifth association means (34), with a circumferential portion (24', 24) of an adjacent radial element (10).

7. Apparatus according to any of the preceding claims characterised in that each circumferential portion (24, 24') defines a seat (25) for the insertion of a closing plate (25).

8. Apparatus according to any of the preceding claims characterised in that said support discs comprise a connecting element (20) configured to be associated by means of second stable and reversible association means (21 ) to said spoke element (10), and by means of fourth stable and reversible association means (32) to said closing plate.

9. Apparatus according to any of the preceding claims characterised in that said support disk (8) comprises at least one closing element (22) configured to be associated in a stable and reversible manner with said connecting element (20) by means of third stable and reversible association means (23).

10. Apparatus according to any of the preceding claims characterised in that it comprises an outlet pipe (60) and that said outlet pipe (60) is an outlet device (62) configured to be inserted at least partially into said outlet pipe (60).11 . Apparatus according to any of the preceding claims characterised in that said output device (62) comprises a telescopic tubular portion (63).

12. Apparatus according to any of the preceding claims characterised in that said output device (62) comprises a sealing lip (66).

13. Apparatus according to any of the preceding claims characterised in that said outlet pipe (60) comprises a sealing gasket (68) whose internal diameter substantially corresponds to the external diameter of said tubular portion (63).

14. Apparatus according to any of the preceding claims characterised in that said sealing lip (66) has an upwardly flared profile.

15. Apparatus according to any of the preceding claims characterised in that said outlet pipe (60) has a closing valve or gate at and / or in proximity to the outlet from said containment tank (4).

16. Apparatus according to any of the preceding claims characterised in that it comprises at least one, and preferably a plurality of backwash tubes (53) configured to spray a fluid in order to descale said filter assembly (7).

17. Apparatus according to any preceding claim characterized in that said at least one backwash tube (53) comprises a stiffening device (54) configured to prevent twisting of said backwash tube (53).

18. Apparatus according to any of the preceding claims characterised in that said stiffening device (54) comprises a stiffening rod (55) removably associated with at least one, and preferably a pair of fastening elements (56) welded to said backwash tube (53).

19. Method for using an apparatus according to one or more of the preceding claims comprising a step of removing said filter assembly (7) from said support assembly (6), and characterized from the fact that said phase of removal of said filter assembly (7) involves dismantling the components (10, 25, 20, 22, 27) of said support disk (8) by disengaging said first (11 ), second (21 ), third (23), fourth (32) and / or fifth (34) support means, and a phase of reinstallation of said filter assembly 7 on said supportassembly (6), and the subsequent removal of the filter membrane from the support assembly, from the fact that said removal phase of said filter assembly 7 involves reassembling the components (10, 25, 20, 22, 27) of said support disk (8) by re- engaging said first (11 ), second (21 ), third (23), fourth (32) and / or fifth (34) support means.

20. Method for using an apparatus according to one or more of claims 1 - 18 characterised in that when said support assembly (6) is to be removed from said containment tank (4), said outlet device (62) is withdrawn from said pipe (60) when said containment tank still contains said mixture to be filtered.

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