Filter press cloth replacement system

Abstract

The filter press (1) comprises a support structure (2) that defines a housing area (3) extending in a longitudinal direction, and an array of filter plates (7) housed in the housing area (3) and connected to the support structure (2) in a sliding manner along the longitudinal direction; each of said filter plates (7) comprising a wall (8) that has at least one filtering face (9), and at least one filter cloth (19) suitable to cover the filtering face (9); and a moving assembly (23) interposed between the wall (8) and the filter cloth (19) and configured to allow movement of the filter cloth (19) along a lateral direction, transverse to the longitudinal direction, between a filtering position, in which it is placed in front of the filtering face (9), and a removal position, in which it is placed next to the wall (8).

Description

[0001] FILTER PRESS CLOTH REPLACEMENT SYSTEM DESCRIPTION

[0002] The present invention relates to a filter press cloth replacement system , and in particular to a filter press comprising such system .

[0003] The filter press is a machine used in many fields to filter a suspension in order to separate the solid parts from the liquid parts.

[0004] Known filter presses comprise a load-bearing structure on which an array of filter plates is mounted.

[0005] Two types of filter presses are known: side beam filter presses and overhead beam filter presses.

[0006] In side beam filter presses, the load bearing structure comprises two side members placed at the sides of the array of filter plates.

[0007] Instead, in overhead beam filter presses, the loadbearing structure comprises an overhead beam on which the array of filter plates is fixed in a sliding manner. The overhead beam is arranged above the array of filter plates.

[0008] The present invention relates to overhead beam filter presses as they are free from lateral obstacles for replacing the filter cloth.

[0009] Operation of a filter press is known and comprises clamping the filter plates in a pack, using mechanical or hydraulic means, so as to form between two adjacent filter plates an inner chamber, which is divided into several spaces by the presence of a filter cloth.

[0010] The suspension to be filtered is pumped at high pressures into the chamber. The solid parts are retained by the filter cloths in a space, while the liquid parts pass through the filter cloth towards an outlet duct.

[0011] The filtering efficiency of a filter press decreases with use and wear of the filter cloths and therefore they must be replaced after a number of cycles.

[0012] The procedure for replacing a filter cloth is very complex and lengthy, especially in the filter presses of large size, used for example in the m ining industry.

[0013] Due to the complex mechanisms for coupling the filter cloth, skilled operators must position themselves between two filter plates to remove the filter cloth to be replaced, before mounting the new filter cloth. Moreover, the new filter cloth must be mounted as precisely as possible.

[0014] These lengthy and complicated operations inevitably require extended downtimes of the filter press, reducing productivity and increasing costs.

[0015] Added to this is the fact that replacement of the filter cloth must usually be performed by several operators simultaneously.

[0016] The object of the present invention is to provide a filter press in which the filter cloth can be replaced easily and rapidly.

[0017] Another object of the present invention is to provide a filter press in which the risks for an operator are m inim ised.

[0018] In accordance with the present invention, these and other objects are achieved by a filter press in accordance with claim 1 .

[0019] Further features of the invention are described in the dependent claims.

[0020] The advantages of this solution relative to the solutions of the prior art are various.

[0021] The features of the filter press allow the filter cloth to be replaced in a simple and rapid manner, reducing downtimes and inactivity of the filter press, thereby increasing productivity.

[0022] Moreover, the operations to replace the filter cloth are simplified, and operators can thus position themselves at the side of the filter press, reducing the risks of accidents and injuries.

[0023] Moreover, these operations can be carried out in safety also by a single operator, even on machines of large size, as the manual effort required is lim ited.

[0024] The features and the advantages of the present invention will be apparent from the following detailed description of a practical embodiment thereof, illustrated by way of non-lim iting example in the accompanying drawings, wherein:

[0025] Fig. 1 schematically shows a filter press in accordance with the present invention;

[0026] Fig. 2 shows a filter plate of the filter press of Fig. 1 in which the filter cloth is in filtering position;

[0027] Fig. 3 shows the filter plate of Fig. 2 in which the filter cloth is in removal position;

[0028] Fig. 4 shows a detail of the filter plate in accordance with the present invention;

[0029] Figs. 5a-5c, 6a and 6b show different versions of the guide element and of the supporting element of the filter press.

[0030] With reference to the accompanying figures, the reference number 1 indicates a filter press in accordance with the present invention. The filter press 1 is configured to receive and filter a suspension comprising solid parts dispersed in a liquid.

[0031] The filter press 1 comprises a support structure 2 that defines a housing area 3. The housing area 3 extends in a longitudinal direction. In use, the longitudinal direction is substantially horizontal.

[0032] The housing area 3 houses an array of filter plates 7 supported by the support structure 2.

[0033] The support structure 2 defines a lateral access 4 to the housing area 3, positioned next to the array of filter plates 7 to allow lateral removal of a filter cloth. The lateral access 4 is substantially a free space in which the support structure 2 is free from obstacles to allow an operator to laterally access the filter plates. There can be two lateral accesses 4, placed on the two sides of the array of filter plates 7.

[0034] The support structure 2 comprises a base frame 5 suitable to be fixed to or to rest on a bearing surface, such as the ground. The base frame 5 comprises two heads, opposite each other along the longitudinal direction, suitable to contain the array of filter plates.

[0035] Preferably, the base frame 5 comprises a platform arranged at the lateral access 4 to support an operator.

[0036] The filter press 1 is of the overhead beam type, i.e. , the support structure 2 comprises at least one overhead beam 6 extending along the longitudinal direction. The overhead beam 6 is positioned above the housing area 3. The overhead beam 6 is supported by the base frame 5.

[0037] In the present description and in the subsequent claims, the terms “upper” and “lower” refer to the conditions of normal use of the filter press 1 , as illustrated in Fig. 1 in which it is arranged resting on the ground.

[0038] The overhead beam 6 has a lower portion facing towards the housing area 3. This lower portion carries connection means to the filter plates 7. Preferably, the support structure 2 comprises a single overhead beam 6, which is positioned centrally above the housing area 3. However, it would also be possible for the support structure 2 to comprise a plurality of overhead beams.

[0039] As mentioned, the filter press 1 comprises an array of filter plates 7 suitable to be housed in the housing area 3. The filter plates 7 are arranged aligned along the longitudinal direction. In particular, the filter plates 7 are mounted on the support structure 2 vertically, i. e. , orthogonally to the longitudinal direction.

[0040] The filter plates 7 are connected to the support structure, in particular to the overhead beam 6, in a sliding manner along the longitudinal direction. Each filter plate 7 comprises respective carriages mounted on tracks arranged on the overhead beam 6. Each filter plate 7 can thus be moved away from / towards the others.

[0041] Sliding in the two directions, the filter plates 7 can be moved between an open configuration, in which they are spaced apart from one another, and a closed configuration, in which they are adjacent to one another (clamped in a pack).

[0042] In the closed configuration, two consecutive filter plates 7 form between them a chamber suitable to receive the suspension. Instead, in the open configuration the filter plates 7 are spaced apart to allow removal of the solid residues, and maintenance of the filter plates 7.

[0043] Movement of the filter plates 7 takes place through specific moving means mounted on the filter press 1 , which can be hydraulic or mechanical.

[0044] Introduction of the suspension into the chambers formed between two consecutive filter plates 7 takes place via a hydraulic feed line provided with an inlet duct and a pumping system .

[0045] Removal of the liquid parts after filtering instead takes place via a discharge line provided with an outlet duct.

[0046] Operation of the filter press 1 , and hence movement of the filter plates 7, introduction of the suspension and removal of the filtered liquids, is known in the state of the art, and therefore will not be described in detail.

[0047] Figs. 2 and 3 illustrate a filter plate 7. The filter plate 7 comprises a wall 8. This has a substantially flat structure, preferably rectangular in shape.

[0048] The wall 8 has at least one filtering face 9. The filtering face 9 is configured to produce, in closed configuration, with another filtering face 9, a chamber suitable to receive and contain the suspension. This cham ber is obtained by a depression 10 produced on the filtering face 9.

[0049] The filter plates 7 comprise a coupling system that allows, in closed configuration, sealing of the chamber.

[0050] The array of filter plates 7 comprises two end filter plates 7 and a plurality of central filter plates 7, included between the end plates. The end filter plates 7 comprise only one filtering face 9. The central filter plates 7 have a pair of filtering faces 9. These filtering faces 9 are opposite each other.

[0051] The wall 8 defines an upper perimeter portion 1 1 that delim its the filtering face at the top. The upper perimeter portion 1 1 is facing towards the overhead beam 6. In the present case, the wall 8 has a perimeter that delim its the depression 10. The perimeter has two lateral perimeter portions 12, opposite each other and arranged vertically, a lower perimeter portion 13 and the upper perimeter portion 1 1 , these last two extending horizontally between the two lateral perimeter portions 12.

[0052] The upper perimeter portion 1 1 is connected to the overhead beam 6. One of the lateral perimeter portions 12 is facing towards the lateral access 4.

[0053] The filtering face 9 has grooves that allow the filtered liquid to flow towards the perimeter portion, in particular the lower one 13.

[0054] The wall 8 comprises an inlet hole 14a configured to be connected to the inlet duct of the suspension to allow it to enter the chamber. The inlet hole 14a is produced close to the upper perimeter portion 1 1 . Moreover, the inlet hole 14a is in a substantially central position.

[0055] In use, the inlet holes 14a of the filter plates 7 are aligned with one another to produce a channel for passage of the suspension.

[0056] The wall 8 comprises at least one outlet hole 15a configured to be connected to an outlet duct of the filtered liquids.

[0057] In use, the outlet holes 15a of the filter plates 7 are aligned with each other to produce an outlet channel.

[0058] Preferably, the outlet hole 15a is arranged at the lower perimeter portion 13. However, it would also be possible for the outlet hole 15a to be produced at the lateral perimeter portion.

[0059] Preferably, the wall 8 comprises four outlet holes 15a. The four outlet holes 15a are arranged at the four vertices of the wall 8.

[0060] Each filter plate 7 comprises a supporting structure 16 connected to the upper perimeter portion 1 1 . The supporting structure 16 comprises at least one connection element 17 to the overhead beam 6. The supporting structure 16 comprises a crossbeam 18, to which the connecting element is connected, which extends parallel to the upper perimeter portion 1 1 . The crossbeam 18 is connected to the wall 8 by two lateral support rods fixed to the two lateral perimeter portions of the wall 8.

[0061] Each filter plate 7 comprises at least one filter cloth 19 which is suitable to cover the filtering face 9, as illustrated in Fig. 2. The filter cloth 19 is configured to be passed through by the liquid parts, while obstructing the passage of the solid parts.

[0062] The filter cloth 19 divides the chamber into at least two spaces. The liquid parts of the suspension, following high pressure pumping, pass through the filter cloth 19, passing between the two spaces.

[0063] The central filter plates 7 comprise two filter cloths 19 suitable to cover a respective filtering face 9. Therefore, inside the chamber there are two filter cloths 19, which divide it into a central space and two lateral spaces. The two lateral spaces are in fluid communication with the outlet hole 15a. The inlet duct introduces the suspension into the central space; the liquid parts, passing through the filter cloths 19, reach the lateral spaces; instead, the solid parts are retained in the central part, form ing a solid cake.

[0064] The filter cloth 19 is preferably made of at least one material selected from polypropylene, polyester, PBT, polyam ide, PTFE.

[0065] The filter cloth 19 has a shape sim ilar to the filtering face 9 to cover it. In the example illustrated, the filter cloth 19 is substantially rectangular. The filter cloth 19 defines an upper edge 20, in use facing towards the overhead beam 6. The upper edge 20 is intended to be arranged adjacent to the upper perimeter portion 1 1 of the wall 8. Moreover, the filter cloth 19 comprises two lateral edges and a lower edge.

[0066] The filter cloth 19 also comprises an inlet hole 14b configured to be connected to the inlet duct. In use, the inlet hole 14b of the filter cloth is aligned with that of the wall 8 to produce the channel for passage of the suspension. Therefore, its positioning is sim ilar to that of the inlet hole 14a of the wall 8.

[0067] The filter cloth 19 also comprises at least one outlet hole 15b configured to be connected to the outlet duct. In use, this outlet hole 15b is aligned with the outlet hole 15a of the wall 8.

[0068] In the example illustrated, the filter cloth 19 comprises four outlet holes 15b which are preferably produced at the four vertices.

[0069] Each filter plate 7 comprises sealed coupling means 21 configured to be interposed between the filter cloth 19 and the wall 8 to seal the passage produced by the inlet holes 14a, 14b. This arrangement allows the suspension introduced through the inlet duct to be sent towards the central space, preventing its entry into the lateral spaces.

[0070] The sealed coupling means 21 comprise a gasket 22 arranged around one of the inlet holes 14a, 14b, preferably that of the filter cloth 19, and configured to couple with the portion arranged around the other inlet hole 14a, 14b, preferably that of the wall 8.

[0071] The gasket 22 can couple simply by resting against the surface, thereby facilitating removal of the filter cloth. In fact, the seal is safely produced thanks to the pressurized clamping of the filter plates.

[0072] As illustrated in detail in Fig. 4, each filter plate 7 comprises a moving assembly 23 interposed between the wall 8 and the filter cloth 19.

[0073] The moving assembly 23 is configured to allow movement of the filter cloth 19 along a lateral direction, transverse to the longitudinal direction. In particular, the lateral direction is horizontal. Moreover, the lateral direction is perpendicular to the lateral perimeter portion of the wall 8, as well as being parallel to the filtering face 9. In practice, the lateral direction is facing from the housing area 3 towards the lateral access 4.

[0074] Movement of the filter cloth 19 is between a filtering position, in which it is placed in front of the filtering face 9, and a removal position, in which it is placed next to the wall 8.

[0075] In the filtering position, illustrated in Fig. 2, the filter cloth 19 covers the filtering face 9, thereby being able to position itself, in use, inside the chamber.

[0076] In the removal position, illustrated in Fig. 3, the filter cloth 19 is placed at the side of the wall 8 to be able to be removed, and replaced, by an operator. For this reason, in the removal position, the filter cloth 1 9 is arranged at the lateral access 4 described above.

[0077] The moving assembly 23 also acts as support for the filter cloth 19.

[0078] As illustrated in Fig. 4, the moving assembly 23 comprises a guide element 24 arranged at the upper perimeter portion 1 1 of the wall 8. The guide element 24 is configured to guide movement of the filter cloth 19 between the two positions described above.

[0079] The guide element 24 extends parallel to the lateral direction, i.e. , it extends between the two lateral perimeter portions 12.

[0080] The guide element 24 is fixed to the supporting structure 16. Preferably, the guide element 24 is fixed at one of its ends to the two support rods. The guide element 24 is also fixed to the crossbeam 18.

[0081] The guide element 24 is produced by means of a section bar, preferably metal.

[0082] In one version, the guide element 24 is fixed to the supporting structure 16, in particular to the crossbeam 18, in a movable manner along a vertical direction. Between the supporting structure 16 and the guide element 24 a spring element, which supports the guide element 24, is present. It is thus possible to move the guide element, for example by means of an adjustment screw, to adjust the position of the filter cloth mounted thereon and / or shake it to facilitate detachment of the solid residues.

[0083] The moving assembly 23 further comprises a supporting element 26 mounted at the upper edge 20 of the filter cloth 19. The supporting element 26 extends along substantially the whole of the upper edge 20 of the filter cloth 19; it therefore has a length substantially sim ilar to the width of the filter cloth 19.

[0084] The filter cloth 19 comprises a coupling portion 27 arranged at the upper edge 20, preferably above it. The supporting element 26 is fixed to the coupling portion 27. Fixing between the filter cloth 19 and the supporting element 26 can take place in one of the following ways: heat sealing, gluing, blocking by fixing means, pull-off closure (such as Velcro or Velcro together with pegs).

[0085] The coupling portion 27 has an inclined surface 28 suitable to move part of the filter cloth 19, the part having a filtering function, towards the filtering face 9. The inclined surface 28 is inclined, following the direction from the supporting element 26 to the upper edge 20, moving towards the filtering face 9. The supporting element 26 is configured to couple in a sliding manner with the guide element 24. The supporting element 26 is thus mounted sliding on the guide element 24 so that the filter cloth 19 can be moved between the two positions described above. This mounting is obtained by form-fit connection between the supporting element 26 and the guide element 24, which have shapes complementary to each other. In practice, one between the supporting element 26 and the guide element 24 defines a housing, while the other defines an insertion portion suitable to be inserted into the housing.

[0086] In an embodiment, illustrated in Figs. 6a and 6b, the guide element 24 defines a cavity, for example by means of a circular section thereof, into which the supporting element 26 is inserted, which thus has a shape complementary to the cavity.

[0087] In another embodiment, illustrated in Figs. 5a-5c, the housing is a sliding track, i.e. , at least one between the guide element 24 and the supporting element 26 defines a sliding track, preferably produced at an edge of the element. The insertion portion is an edge of the element, i.e. , the other one between the guide element 24 and the supporting element 26 defines an insertion edge into the sliding track. Preferably, the at least one between the guide element 24 and the supporting element 26 defines a pair of tracks, one produced at a lower edge and the other produced at an upper edge thereof. Consequently, the other between the guide element 24 and the supporting element 26 has a pair of insertion portions at an upper edge and at a lower edge thereof.

[0088] In one version, the guide element 24 comprises a tab 25 that is bent to produce the sliding track. Preferably, the guide element 24 comprises a lower tab 25 and an upper tab 25, to produce an upper sliding track and a lower sliding track. In practice, the guide element 24 is substantially omega shaped, as illustrated in Fig. 5a.

[0089] In this version, the supporting element 26 comprises a coupling edge 29 that is bent to define at least one part of a coupling groove 30 with the guide element 24. Preferably, the supporting element 26 comprises an upper coupling edge 29 and a lower coupling edge 29. In practice, the supporting element 26 is substantially “C” shaped.

[0090] Other versions in which the guide element 24 and the support element have different shapes are possible. In the example of Fig. 5b, the guide element 24 has a “C” shape and the tracks are produced close to the edges of the supporting element 26. In the example of Fig. 5c it is the supporting element 26 that is “C” shaped and the guide element 24 has a linear shape that is inserted into the supporting element. Preferably, sliding of the supporting element 26 along the guide element 24 is facilitated by the presence of wheels interposed between the two elements.

[0091] The supporting element 26 comprises at one end thereof a lim it stop to prevent movement of the filter cloth 19 beyond the filtering position.

[0092] Moreover, the supporting element 26 is configured so that, when in removal position, it can be separated from the guide element 24. For this reason, the ends of the supporting element have a through opening, communicating with the coupling groove 30, to allow insertion and removal of the guide element 24 into / from the coupling groove 30. Preferably, the supporting element is produced by means of a metal section bar.

[0093] In one embodiment, movement of the filter cloth 19 between the two positions is performed manually by an operator. For this reason, the moving assembly 23 comprises a gripping element, such as a hook or a handle, associated with the filter cloth 19 and configured to be grasped by an operator. A stick or other elongated element can be present, which can be coupled to the gripping element to make the gripping element easier to reach.

[0094] In one embodiment, movement of the filter cloth 19 takes place automatically. The moving assembly 23 thus comprises actuator means, not illustrated in the figures, operatively connected to the filter cloth 19 and configured to move the filter cloth 19 between the filtering position and the removal position. The actuator means comprise a motor, preferably electric, connected to the filter cloth 19 by means of a motion transm ission system . This system , when activated by the motor, is configured to generate a linear movement of the filter cloth 19 along the lateral direction.

[0095] Preferably, the moving assembly also comprises a control system operatively connected to the actuator means which, by means of a suitable interface, such as push buttons, allows the operator to activate the actuator means to move the filter cloth 19 between the two positions.

[0096] Operation of the invention is evident for the person skilled in the art from the description above and, in particular, is as follows. After having carried out several filtering cycles the filter cloths 19 require to be replaced. To carry out replacement, the filter plates 7 are taken to the open configuration; by means of the moving assembly, each filter cloth 19 is moved into the removal position so that the operator can replace it; subsequently, again by means of the moving assembly, the new filter cloth 19 mounted is moved into the filtering position.

[0097] The system thus conceived is susceptible to numerous modifications and variations, all falling within the scope of the inventive concept; moreover, all details can be replaced by technically equivalent elements.

Claims

CLAIMS1 . Overhead beam filter press (1 ), comprising: a support structure (2) defining a housing area (3) that extends in a longitudinal direction, said support structure (2) comprising an overhead beam (6) that extends along said longitudinal direction and is positioned above said housing area (3); and an array of filter plates (7) suitable to be housed in said housing area (3) and connected to said overhead beam (6) in a sliding manner along said longitudinal direction; wherein each of said filter plates (7) comprises a wall (8) having at least one filtering face (9), and at least one filter cloth (19) suitable to cover said filtering face (9); characterised by comprising a moving assembly (23) interposed between said wall (8) and said filter cloth (19) and configured to allow movement of said filter cloth (19) along a lateral direction, transverse to said longitudinal direction, between a filtering position, in which it is placed in front of said filtering face (9), and a removal position, in which it is placed next to said wall (8); said moving assembly (23) comprising:- a guide element (24) arranged at an upper perimeter portion (1 1 ) of said wall (8), and- a supporting element (26) mounted at an upper edgebeing configured to couple in a sliding manner with said guide element (24).

2. Filter press (1 ) in accordance with claim 1 , characterised in that said support structure (2) defines a lateral access (4) to said housing area (3), said lateral access (4) being positioned next to said array of filter plates (7), said filter cloth (19) in said removal position is arranged at said lateral access (4).

3. Filter press (1 ) in accordance with one of the preceding claims, characterised in that at least one between said guide element (24) and said supporting element (26) defines a sliding track; the other between said guide element (24) and said supporting element (26) defines an edge for insertion into said sliding track.

4. Filter press (1 ) in accordance with claim 3, characterised in that said at least one between said guide element (24) and said supporting element (26) defines a pair of tracks, one produced at a lower edge and the other produced at an upper edge thereof; said other between said guide element (24) and said supporting element (26) has a pair of insertion portions at an upper edge and at a lower edge thereof.

5. Filter press (1 ) in accordance with claim 3, characterised in that said supporting element (26) comprises a coupling edge (29) that is bent to define atleast one part of a coupling groove (30) with said guide element (24), said coupling groove (29) being suitable to couple with said sliding track.

6. Filter press (1 ) in accordance with one of the preceding claims, characterised in that said filter cloth (19) comprises a coupling portion (27) to which said supporting element (26) is fixed, said coupling portion (27) has an inclined surface (28) suitable to move a part of said filter cloth (19) towards said filtering face (9).

7. Filter press (1 ) in accordance with one of the preceding claims, characterised in that said supporting element (26) is configured so that, when in removal position, it can be separated from said guide element (24).

8. Filter press (1 ) in accordance with one of the preceding claims, characterised in that said moving assembly (23) comprises actuator means operatively connected to said filter cloth (19) and configured to move said filter cloth (19) between said filtering position and said removal position.

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