OA21391A

OA21391A - A filter plate assembly for a horizontal plate and frame - type filter, such as a tower press, a filter plate and a vat liner.

Info

Publication number: OA21391A
Application number: OA1202200431
Authority: OA
Inventors: Ismo JUVONEN; Mirva MUSTAKANGAS; Janne KAIPAINEN; Teemu ELORANTA; Mika ILLI; Kari Vanttinen
Original assignee: Metso Outotec Finland Oy
Filing date: 2020-06-03
Publication date: 2024-06-05

Abstract

The present disclosure concerns a filter plate assembly (1) which is resistant to both wear and deformation caused by creeping, while facilitating maintenance thereof. The disclosure is based on the idea of providing a filtrate vat (4) formed on, and integral with the filter plate (2), in addition to a separate, replaceable vat liner (5). In this way, a rigid structure of the filtrate vat (4) capable of resisting deformation may be achieved, while the vat liner (5) separates the filtrate from the filtrate vat (4) and the associated filter plate (2), providing wear resistance and facilitating maintenance. The present disclosure further concerns the filter plate (2) and the filtrate vat (5).

Description

A FILTER PLATE ASSEMBLY FOR A HORIZONTAL PLATE AND FRAME -TYPE FILTER, SUCH AS A TOWER PRESS, A FILTER PLATE AND A VAT LINER

FIELD OF THE DISCLOSURE

The présent disclosure relates to horizontal plate and trame- type filters, such as tower presses, and more particularly to a filter plate assembly for such a filter. The présent disclosure further concerns a filter plate and a vat liner for such a filter plate assembly.

BACKGROUND OF THE DISCLOSURE

Conventionally in horizontal filter plate and frame -type filters, such as tower presses, a filtrate is collected to a filtrate vat from a filter chamber formed above the vat. As the filtrate typically contains small solid particles, the filtrate flow (and a possible drying air flow) is abrasive over numerous repeated filtration cycles. To this end, the filtrate vat has conventionally been provided as a separate, replaceable component, made of a material able to sufficiently withstand wear caused by the abrasive flow. In known arrangements, the filtrate vat has been provided as component forming a réceptacle for receiving the filtrate and has been placed on top of a substantially fiat filter plate. When the filtrate vat has worn excessively, it is replaced.

However, it has been noticed, that such a wear résistant separate filtrate vat is prone to creeping under as it is repetitively compressed over numerous filtration cycles. Moreover, it has not been generally considered that changing the material of the filtrate vat so as to better resist deformation due to creeping would resuit in unsatisfactory wear-resistance characteristics.

It has also been noted that conventional, separate filtrate vats hâve faced issues related to contamination from the slurry to be filtered and other process fluids. Particularly, slurry that has reached the interface between the filter plate and the filtrate vat may travel underneath the filtrate vat due to the capillary effect and the répétitive compression of the filtration cycles. Such impurities cause a bulge on the otherwise fiat filter plate, thereby leading to prématuré wear of the filtrate vat and even breakage thereof. Moreover, slurry or other process fluid contamination may seize fasteners used to attach the filtrate vat to the filter plate, thereby hindering the maintenance of the associated filter, such as replacement of the filtrate vat.

BRIEF DESCRIPTION OF THE DISCLOSURE

An object of the présent disclosure is to provide a filter plate assembly, a filter plate and a vat liner, which are résistant to both wear and deformation caused by creeping, while facilitating maintenance.

The object of the disclosure is achieved by the filter plate assembly, the filter plate and the vat liner which are characterized by what is stated in the independent claims. The preferred embodiments of the disclosure are disclosed in the dépendent claims.

The disclosure is based on the idea of providing the filtrate vat formed on, and intégral with the filter plate, in addition to a separate, replaceable vat liner. In this way, a rigid structure of the filtrate vat capable of resisting deformation may be achieved, while the vat liner séparâtes the filtrate from the filtrate vat and the associated filter plate, providing wear résistance and facilitating maintenance.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the disclosure will be described in greater detail by means of preferred embodiments with référencé to the accompanying drawings, in which

Fig. 1 illustrâtes a plan view of a filter plate assembly according to an embodiment of the présent invention;

Fig. 2 illustrâtes a cross-sectional eut view along the eut line illustrated in Fig. 1;

Fig. 3 illustrâtes a filter plate assembly similar to that of Fig.1, without outlet pièces, and equipped with a filtrate vat, as seen as an exploded perspective view;

Fig. 4 illustrâtes the filter plate assembly of Fig. 3 as seen as a plan view;

Fig. 5 illustrâtes the filter plate assembly of Fig. 3 as an exploded cross section eut view along the dashed line illustrated in Fig. 4;

Fig. 6 illustrâtes the filter plate assembly of Fig. 3 as a cross section eut view along the dashed line illustrated in Fig. 4;

Fig. 7 illustrâtes the filter plate assembly of Fig. 1, as seen as a semi-exploded perspective view;

Fig. 8 illustrâtes a detailed view of the outlet piece of Fig. 7;

Fig. 9 illustrâtes the situation of Fig. 8 in a non-exploded view;

Fig. 10 illustrâtes the filter plate assembly of Fig. 7 as a plan view;

Fig. 11 illustrâtes an exploded partial cross-sectional eut view of the filter plate assembly of Fig 7, along the dashed line illustrated in Fig. 10, and

Fig. 12 illustrâtes the situation of Fig. 11 in a non-exploded view.

DETAILED DESCRIPTION OF THE DISCLOSURE

According to a first aspect of the présent disclosure, a filter plate assembly 1 for a horizontal plate and frame -type filter, such as a tower press, is provided.

The filter plate assembly comprises a filter plate 2 having a rigid plate-like body. The filter plate 2 has a frame side 2a and a vat side 2b. The frame side 2a is intended to face towards a plate frame 9, on which the filter plate is supported, when in use, whereas the vat side 2b refers to the side of the filter plate 2, on which a filtrate vat 4 is formed, and is intended to face towards a filter chamber formed by the filter plate assembly 1 together with an adjacent filter plate assembly above. When in use, a filter plate assembly 1 is separated from an adjacent filter plate assembly above, with which a closed filter chamber is formed, with a filter medium (typically a filter cloth), such that slurry is fed into the filter chamber of the filter plate assembly 1 above, and filtrate separated from the slurry by the cloth is received in the filtrate vat 4 of the filter plate assembly 1 below.

The filter plate 2 comprises, on the vat side 2b, a border 3 having at least an inner latéral wall 3a and an upper surface 3b. The border 3 is elevated for a distance at least from a portion of the filter plate 2 delimited within the border 3. Particularly, the border 3 is formed intégral with the filter plate 2.

Particularly, a filtrate vat 4 is formed by the filter plate 2, such that the inner latéral wall 3a of the border forms a latéral wall of the filtrate vat 4, and a portion of the filter plate delimited by the border 3 forms a bottom of the filtrate vat 4. That is, a réceptacle for receiving filtrate is formed by the shape of the filter plate 2 itself.

For example, the filter plate 2 may be provided in accordance with the third aspect of the présent disclosure.

The filter plate assembly 1 further comprises a vat liner 5 having a sheet-like body. The vat liner 5 is nested within the filtrate vat 4 such that the vat liner 5 extends onto the upper surface 3b of the border 3, so that the filter plate 2 is separated from filtrate within the filtrate vat 4 by the vat liner 5, when in use. That is, the vat liner 5 extends along latéral inner wall 3a of the border 3.

For example, the vat liner 5 may be provided in accordance with the third aspect of the présent disclosure.

In this way, the filter plate 2 may be constructed so as to provide a rigid structure forming the shape of the filtrate vat 4 being able to resist deformation due to creeping, while the vat liner 5 shield the filtrate vat 4 from wear caused by abrasion, as discussed earlier. Furthermore, as the vat liner 5 is much lighter, as compared to a conventional separate filtrate vat, maintenance is facilitated as manipulating the vat liner 5 is easier and the whole filter plate does not ned to be removed from the associated filter apparatus.

Preferably, but not necessarily, the vat liner 5 also extends over the upper surface 3b of the border 3.

Most suitably, the filter plate 2 is of a more rigid material, and able to better resist creeping than the vat liner 5, whereas the vat liner 5 is of a more wear résistant material than the filter plate 2.

Examples of such materials of the filter plate 2 include, but are not limited to, metals, such as steel, FRP (fibre-reinforce plastics) materials, such as reinforced composite materials with a thermoset or thermoplastic matrix, and thermoset materials. Correspondingly, examples of such materials of the vat liner 5 include, but are not limited to, wear résistant polymers, such as thermoplastics including thermoplastic vulcanizates and thermoplastics elastomers, PUR and rubber.

It should be noted that a plate frame 9 for supporting the filter plate 2 may be included in the filter plate assembly 1. Alternative^, the filter frame 9 may be provided as a separate component or assembly attachable to the filter plate assembly 1.

In an embodiment according to the first aspect of the présent disclosure, the border 3 has an outer latéral wall 3c, and the vat liner 5 additionally extends onto the latéral outer wall 3c.

In this kind of arrangement, slurry or other process fluids are less likely to travel between the vat liner 5 and the filter plate 5 ail the way to the filtrate vat 4 or even the upper surface 3b of the border 3, where contamination may cause excess wear or even breakage under répétitive compression, as discussed above. This facilitâtes maintenance as the maintenance intervals can be extended.

Furthermore, a more rigid structure of the vat liner 5 itself is achieved, which facilitâtes maintenance, as the vat liner 5 deforms less during installation and is easier to be seated in the filtrate vat 4.

Most suitably, but not necessarily, the vat liner 5 extends over the outer latéral wall 3c of the border 3. This further improves the benefits mentioned above, as slurry or other process fluids must travel even further to reach areas where contamination may cause issues.

For example, a trough 5c may be formed on the vat liner 5, the through 5c running along the perimeter thereof of the vat liner 5. Moreover, the border 3 is then nested within the trough 5c, and an inside of the trough 5c is hollow and the border 3 is solid. This kind of structure further allows the border formed 3 by the filter plate 2 to be load bearing against the forces required to close a filter chamber (i.e. adjacent filter plate assemblies being pressed against each other), while the vat liner 5 merely acts as a covering or coating separating the filtrate from the filter plate 2. Additionally, the border 3 being seated in the trough further secures the vat liner to the filter plate 2.

Furthermore, the trough 5c of the vat liner 4 together with the border 3 acts as a guide rail during installation of the vat liner 5, thereby facilitating maintenance.

In an embodiment according to the first aspect of the présent disclosure, a gap 3d is provided on the border 3, such that an outlet opening extending laterally through the border 3 is formed, thereby providing a fluid drainage route from the filtrate vat 4.

As the drainage route from the filtrate vat 4 runs laterally, maintenance is facilitated, as the drainage rout is easily accessible, as compared to a structure in which the drainage route runs vertically through the filter plate.

Preferably, but not necessarily, the vat liner 5 is formed so as to extend into the outlet opening, and to cover the border 3 adjacent to the outlet opening, such that the filter plate 2 is separated from filtrate within the outlet opening by the vat liner 5, when in use. This further helps prevent contamination of filtrate running through the outlet opening from travelling under the vat liner 5.

Preferably, but not necessarily, on the vat side 2b of the filter plate 2, a recessed portion 2c of the filter plate situated at the outlet opening is recessed with respect the bottom of the filtrate vat 4. Moreover, the vat liner 5 is spaced apart from the filter plate 2 at the recessed portion 2c in a direction transverse to the general planarity of the filter plate 2.

In this kind of structure, the vat liner 5 forms an overhang at the outlet opening, thereby preventing filtrate contamination from travelling under the vat liner 5, between the vat liner 5 and the filter plate 2.

Preferably, but not necessarily, the filter plate assembly 1 further comprises a removably fixed outlet piece 6 at least partly nested within the outlet opening. Moreover, the outlet piece 6 is being arranged such that the fluid drainage route runs therethrough.

This facilitâtes maintenance, as the outlet piece 6 can be replaced separately - the outlet piece is commonly subjected to most wear due abrasion of the filtrate and/or drying air flow.

Suitably, also the outlet piece 6 is of a creeping-resistant material, as creeping is particularly prominent at the outlet piece due to the physical discontinuity in the physical structure of the filter plate 2. Examples of such materials of the filter plate 2 include, but are not limited to, metals, such as steel, FRP (fibre-reinforce plastics) materials, such as reinforced composite materials with a thermoset or thermoplastic matrix, and thermoset materials.

The outlet piece may suitably be coated with a wear-resistant material to protect it from prématuré wear caused by the filtrate or drying air flow. Examples of such materials include, but are not limited to, wear résistant polymers, such as thermoplastics including thermoplastic vulcanizates and thermoplastics elastomers, PUR and rubber.

Furthermore, using separate outlet pièces 6 enables using differently constructed outlet pièces for different types of filtrâtes, depending on the application. For example, the outlet piece can be shaped so as to optimize the flow characteristics thereof for a certain kind of filtrate.

More preferably, the vat liner 5 extends into the outlet piece 6. This ensures, that the vat liner 5 can be sealed against outlet piece 6 and minimizes risk of contamination from filtrate, slurry, or other process liquids between the vat liner 5 and the filter plate 2. Moreover, the one or more outlet pièces 6 can be used to secure the vat liner 5 in place, such that no other separate fasteners are required. This facilitâtes maintenance, as the fasteners or fixing éléments securing the filtrate vat 5 are situated only in wearing parts (i.e., the outlet piece 6) which will be replaced along with the filtrate vast 5.

More preferably, the outlet piece 6 comprises a base 7 and a lid 8. The base 7 is at least partly nested within the recessed portion 2c of the filter plate 2, between the filter plate 2 and the vat liner 5. The lid 8, in turn, is provided on an opposite side of the vat liner 5 with respect to the base.

The base 7 is removably fixed to the remaining filter plate assembly 1, for example to either or both of the filter plate 2 and the plate frame 9 supporting the filter plate, whereas the lid 8 is a removably fixed to the base 7, such that the vat liner 5 is clamped between the base 7 and the lid 8. In this way, the filtrate drainage route is formed between the vat liner 5 and the lid 8, while a sealed attachment between the outlet piece 6 and the vat liner 5 is achieved, thereby reducing filtrate contamination form travelling under between the vat liner 5 and the filter plate 2.

Most preferably, the base 7 of the outlet piece 6 comprises a recessed seat 7a into which a gap portion 5d of the vat liner 5, corresponding to a gap 3d of the border 3, is seated.

' 7

Furthermore, the lid 8 comprises a plurality of spaced apart ribs 8a projecting towards the recessed seat 7a, such that the vat liner 5 is clamped between the recessed seat 7a and the ribs 8a, and is sealed against the recessed seat 7a. The lid 8 extends over the gap 3d and seals against the border portion 5b of the liner 5 at a position corresponding to the upper surface 3b of the border 3. Such an arrangement ensures a secure and sealed attachment between the vat liner 5 and the outlet piece 6.

For example, the base 7 may further comprises a recessed chute 7b as a continuation of the recessed seat 7a for conducting filtrate out of the outlet piece 6.

Preferably, but not necessarily, the filter plate 2 is of a generally rectangular shape having a first flank side 2d and a second flank side 2e parallel to the first flank side 2d, and a first end side 2f and a second end side 2g parallel to the first end side 2f. Moreover, the first and second end sides 2f, 2g extend in a direction transverse to a direction in which the first and second flank sides 2d, 2e extend, and the first and second flank sides 2d, 2e hâve a length greater than that of the first and second end sides 2f, 2g.

In such a case, one or more gaps 3d of the border 3 are formed on either or both of the first flank side 2d and the second flank side 2e.

The first and second flank sides 2d, 2e are considered preferred positions for the gaps 3d, as this provides easiest access for maintenance (e.g. replacing outlet pièces 6).

More preferably, one or more gaps 3d of the border 3 are formed in a corner région between a flank side 2d, 2e and an end side 2f, 2g. The corner régions are considered particularly preferred positions for the gaps 3d, as this additionally provides most secure attachment of the filtrate vat 5, when it is attached to the filter plate 2 using outlet pièces 6.

More preferably, the filter plate comprises one or more latéral indentation portion 2i provided on either or both of the first flank side 2d and the second flank side 2e. Such latéral indentation portions 2i are arranged to circumvent suspension éléments and/or support éléments of a filter plate frame 9 on which the filter plate 2 is supported.

Such an arrangement facilitâtes maintenance by allowing the filter plate 2 to be removed from a plate frame 9 on which it is supported without removing the plate frame 9 from the filter apparatus.

The filter plate 2 may additionally comprise one or more latéral widening portions 2j provided on either or both of the first flank side 2d and the second flank side 2e. The latéral widening 2j portions are arranged between latéral indentation portions 2i adjacent to the widening portion 2j. Moreover, the latéral widening portions 2j are arranged to laterally overhang a filter plate trame 9 supporting the filter plate 2.

Such an arrangement further facilitâtes maintenance by allowing the filter plate 2 to be lifted at the latéral widening portions 2j.

In an embodiment according to the first aspect of the présent disclosure, the filter plate 2 comprises a plurality of attachment holes 2h running along the periphery of the filter plate 2 and extending therethrough. The attachment holes 2h are situated on an outer side of the border 3 with respect to the filtrate vat 4, such that the attachment holes 2h are not in contact with filtrate within the filtrate vat, when in use.

Such an arrangement facilitâtes maintenance, as the attachment holes, through which the filter plate 2 is attached to the plate frame 9 are less like to be contaminated form slurry, filtrate ort other process fluids. Consequently, any fasteners used for attaching the filter plate to the plate frame are less likely to seize.

It should be noted that the first aspect of the présent disclosure encompasses any combination of two or more embodiments, or variants thereof, in accordance with the above.

According to a second aspect of the présent disclosure, a filter plate 2 for a filter plate assembly 1 of a horizontal plate and frame -type filter, such as a tower press, is provided.

The filter plate 2 has a rigid plate-like body with a frame side 2a and a vat side 2b. The frame side 2a is intended to face towards a plate frame 9, on which the filter plate is supported, when in use, whereas the vat side 2b refers to the side of the filter plate 2 on which the filtrate vat 4 is formed, and is intended to face towards a filter chamber formed by the filter plate assembly together with an adjacent filter plate assembly above.

The filter plate 2 comprises, on the chamber 2b side, a border 3 having at least an inner latéral wall 3a and an upper surface 3b. The border 3 is elevated for a distance at least from a portion of the filter plate 2 delimited within the border 3. Moreover, the border 3 is an intégral part of the filter plate 2.

Preferably, but not necessarily, the filter plate 2 may hâve a vat area of between 1,5 m²9 m². More preferably, but not necessarily, the filter plate 2 may hâve a vat area of between 2,5 m² - 7 m². Most preferably, but not necessarily, the filter plate 2 may hâve a vat area of between 2,5 m² - 7 m². In the context of this disclosure, the vat area is defined as the area of the portion of the filter plate 2 delimited by the border 3, i.e. the bottom of the filtrate vat.

Preferably, but not necessarily, the border, particularly the upper surface 3b thereof, may be elevated for a distance of at least 10 mm from the portion of the filter plate 2 delimited within the border. Preferably, but not necessarily, the border, particularly the upper surface 3b thereof, may be elevated for a distance of no more than 40 mm from the portion of the filter plate 2 delimited within the border. For example, the border, particularly the upper surface 3b thereof, may be elevated for a distance of 15-20 mm from the portion of the filter plate 2 delimited within the border.

Preferably but not necessarily, the border 3 has a width of at least 15 mm. Preferably, but not necessarily, the border has a width of no more than 200 mm. For example, the width of the border may be between 75 mm - 100 mm. In the context of this disclosure, the width of the border 3 refers to a transverse dimension thereof parallel with the planar bottom 5a. Also, it should be noted, that the border may hâve different widths at different parts of the filter plate.

Preferably, but not necessarily, the filter plate 2 may hâve an average material thickness of between 8 mm - 30 mm at the portion thereof delimited by the border 3.

In this way, the filter plate 2 may be constructed so as to provide a rigid structure forming the shape of the filtrate vat 4 being able to resist deformation due to creeping.

Most suitably, the filter plate 2 is of a rigid material able to resist creeping. Examples of such materials of the filter plate 2 include, but are not limited to, metals, such as steel, FRP (fibre-reinforce plastics) materials, such as reinforced composite materials with a thermoset or thermoplastic matrix, and thermoset materials.

In an embodiment according to the second aspect of the présent disclosure, the border 3 has an outer latéral wall 3c. In other words, the border 3 is also elevated with respect to an area of the filter plate 2 surrounding the border 3.

In an embodiment according to the second aspect of the présent disclosure, a gap 3d is provided on the border 3, such that an outlet opening extending laterally through the border 3 is formed, thereby providing a fluid drainage route from the filtrate vat 4.

Preferably, but not necessarily, the one or more gaps 3d hâve a length of between 150 mm - 300 mm in the longitudinal direction of an associated side 2d, 2e, 2f, 2g on which the gap 3d is situated.

Preferably, but not necessarily, the gap 3d has a height corresponding to that of the border 3.

Preferably, but not necessarily, the length of the first and second flank sides 2d, 2e is between 1,5-3 times of that of the first and second end sides 2f, 2g, respectively

More preferably, one or more gaps 3d of the border 3 are formed in a corner région between a flank side 2d, 2e and an end side 2f, 2g.

More preferably, the filter plate comprises one or more latéral indentation portions 2i provided on either or both of the first flank side 2d and the second flank side 2e. Such latéral indentation portions 2i are arranged to circumvent suspension éléments and/or support éléments of a filter plate frame 9 on which the filter plate 2 is supported.

The filter plate 2 may additionally comprise one or more latéral widening portions 2j provided on either or both of the first flank side 2d and the second flank side 2e. The latéral widening 2j portions are arranged between latéral indentation portions 2i adjacent to the widening portion 2j. Moreover, the latéral widening portions 2j are arranged to laterally overhang a filter plate frame 9 supporting the filter plate 2.

In an embodiment according to the second aspect of the présent disclosure, the filter plate 2 comprises a plurality of attachment holes 2h running along the periphery of the filter plate 2 and extending therethrough. The attachment holes 2h are situated on an outer side of the border 3 with respect to the filtrate vat 4, such that the attachment holes 2h are not in contact with filtrate within the filtrate vat, when in use.

It should be noted that the second aspect of the présent disclosure encompasses any combination of two or more embodiments, or variants thereof, in accordance with the above.

According to a third aspect of the présent disclosure, a vat liner 5 for a filter plate assembly 1 of a horizontal plate and frame -type filter, such as a tower press, is provided.

The vat liner 5 has a sheet -like body comprising a planar bottom portion 5a, and a border portion 5b. The border portion further comprises an inner latéral wall portion extending vertically from the planar bottom portion 5a, and an upper surface portion extending outwardly from the inner latéral wall portion in direction transverse thereto. That is, the upper surface portion is elevated from the planar bottom portion 5a.

Preferably, but not necessarily, the vat liner 5 may hâve a bottom area of between 1,5 m²- 9 m². More preferably, but not necessarily, the vat liner 5 2 may hâve a bottom area of between 2,5 m² - 7 m². Most preferably, but not necessarily, the vat liner 5 may hâve a bottom area of between 2,5 m² - 7 m². In the context of this disclosure, the bottom area is defined as the area of bottom surface (i.e. the surface intended to sit against the filtrate vat 4) of the vat liner 5 corresponding to the bottom portion 5b.

Preferably, but not necessarily, the upper surface portion of the border portion 5b is parallel with the planar bottom portion 5a.

Preferably, but not necessarily, the upper surface of the border portion 5b is elevated at a height of between 10mm - 40 mm from the planar bottom portion 5b. For example, the upper surface of the border portion 5b may be elevated at a height of 15mm from the planar bottom portion 5b.

Preferably but not necessarily, the border portion 5b has a width of at least 15mm. Preferably but not necessarily, the border portion 5b has a width of no more than 200mm. For example, the border portion 5b may hâve a width of between 75mm 100mm. In the context of this disclosure, the width of the border portion 5b refers to a transverse dimension thereof parallel with the planar bottom 5a.

Preferably, but not necessarily, the vat liner 5 may hâve, at the bottom portion 5a thereof, a material thickness of between 1mm - 10mm, more preferably, but not necessarily, of between 2-5 mm. Preferably, but not necessarily, the vat liner 5 may hâve, at the border portion 5b thereof, a material thickness of between 1mm - 10mm, more preferably, but not necessarily, of between 2-5 mm.

In an embodiment according to the third aspect of the présent disclosure, the border portion 5b further comprises an outer latéral wall portion extending from the upper surface portion. The outer latéral wall portion extends vertically with respect to the planar bottom portion 5a. In such an arrangement, a hollow trough 5c is formed on the vat liner 5 by the border portion 5b, running along the perimeter thereof.

In this kind of arrangement, when the vat liner 5 is nested in a corresponding filtrate vat 4, slurry or other process fluids are less likely to travel between the vat liner 5 and the filter plate 5 ail the way to the filtrate vat 4 or even the upper surface 3b of the border 3, where contamination may cause excess wear or even breakage under répétitive compression, as discussed above.

In an embodiment according to the third aspect of the présent disclosure, a gap portion 5d is formed on the border portion 5b, exhibiting a gap extending laterally through the border portion 5b. Moreover, the planar bottom portion 5a extends into the gap portion.

In this arrangement, a fluid drainage route from the planar bottom portion 5a is formed laterally through the border portion 5b.

Preferably, but not necessarily, the one or more gap portions 5d hâve a length of between 150 mm - 300 mm in the longitudinal direction of an associated side portion 5e5h on which the gap 5d is situated

Preferably, but not necessarily, if a hollow trough 5c is formed on the vat liner 5, the trough 5c is closed towards the gap portion (5d).

In an embodiment according to the third aspect of the présent disclosure, the vat liner 5 is of a generally rectangular shape having a first flank side portion 5e and a second flank side portion 5f parallel to the first flank side portion 5e, and a first end side 5g portion and a second end side portion 5h parallel to the first end side portion 5g.

The first and second end side portions 5g, 5h extend in a direction transverse to a direction in which the first and second flank side portions 5e, 5f extend. Moreover, the first and second flank side portions 5e, 5f hâve a length greater than that of the first and second end side portions 5g, 5h.

In such a configuration, one or more gap portions 5d of the border portion 5b are suitably formed on either or both of the first flank side portion 5e and the second flank side portion 5f.

When a new vat liner is installed during maintenance, the vat liner 5 is inserted in place between adjacent filter plates either end side portion 5g, 5h first due to the structure of the associated filter press. In other words, the vat liner 5 is handled and manipulated from the first and second flank portions 5e, 5f. Providing the gap portions 5d at either or both of the first and second flank portions 5e, 5f (instead of the end side portions 5g, 5h) ensures that an unbroken stiffened structure (i.e., trough 5c) is achieved at the end side portions 5g, 5h, thereby improving the vat liners 5 ability to resist deformation during installation, and thereby facilitating maintenance.

Preferably, the length of the first and second flank side portions 5e, 5f is 1,5-3 times that of the first and second end side portions 5g, 5h.

Preferably, but not necessarily, one or more gap 5d portions of the border 5b portion are formed in a corner région between a flank side portion and an end side portion.

It should be noted that the third aspect of the présent disclosure encompasses any combination of two or more embodiments, or variants thereof, in accordance with the above.

Fig. 1 illustrâtes a plan view of a filter plate assembly according to an embodiment of the présent invention. Particularly, Fig. 1 shows the filter plate assembly 1 as seen from the vat side 2b. The filter plate assembly has a filter plate 2 and a vat liner 5 placed on top the filter plate 2. The filter plate 2 is of a rectangular shape having a first flank side 2d, a second flank side 2e, a first end side 2f and a second end side 2g.

Outlet pièces 6 are placed at the first and second flarik sides 2d, 2e at the corner régions between flank side 2d, 2e and the end sides 2f, 2g, where gaps 3d of the border 3 and the gap portions 5d of the vat liner 5 (covered by the outlet piece 6) are exhibited.

A filtrate vat 4 is formed in the central are of the filter plate 2, delimited by the border, and is covered by the vat liner 5

The flank sides 2d, 2e hâve indented portions 2i, which are laterally recessed with respect to adjacent portions of the filter plate, and widening portions 2j, which extend laterally further with respect to their adjacent portions. The widening portions 2j are provided between indented portion 2i, although other configurations are foreseeable. Attachment holes 2h can be seen extending around the periphery of the filter plate 2.

Fig. 2 illustrâtes a cross-sectional eut view along the eut line illustrated in Fig. 1 (i.e., running across the second flank side 2e). Fig. 2 illustrâtes the filter plate 2 being supported on a plate frame 9. Moreover Fig. 2 better illustrâtes the border 3 of the filter plate 2 having an inner latéral wall 3a, top surface 2b and an outer latéral wall 3c. The vat liner is seated on the filter plate such that the border portion 5b receives the border 3 and the bottom portion 5a is seated in the area are delimited by the border (i.e. the filtrate vat 4)

Fig. 3 illustrâtes a filter plate assembly 1 similar to that of Fig.1, without outlet pièces 6, and equipped with a filtrate vat 4, as seen as an exploded perspective view. Fig. 3 also illustrâtes how a grid 10 is to be received in the filtrate vat covered by the vat liner 5. As the Fig. 3 is shown as an exploded view, the border 3 of the filter plate 2 is revealed along with the gaps 3d, and the recessed portion 2c situated at the gaps 3d.

Fig. 4 illustrâtes the filter plate assembly of Fig. 3 as a plan view seen from the vat side 2b. Fig. 4 shows a dashed line, along which the cross-sectional eut views of Fig. 5 and Fig. 6 are seen.

Fig. 5 illustrâtes the filter plate assembly of Fig. 3 as an exploded cross-sectional eut view along the dashed line illustrated in Fig. 4, whereas Fig. 6 is illustrated in a nonexploded view. These drawings clearly illustrate how the shape of the filtrate vat 4 is formed by the by the filter plate 2 and the border thereof, whereas the vat liner 5 merely acts as a lining following the shape of the actual filtrate vat 4. Moreover, these drawings illustrate how the vat liner 5 is tightly seated together with the filtrate vat 4 and the border 3, and how a grid 10 may be received in the filtrate vat 4, above the vat liner 5.

Fig. 7 illustrâtes the filter plate assembly of Fig. 1, as seen as a semi-exploded perspective view. Particularly, the vat liner 5 and the encircled outlet piece 6 haven illustrated in a displaced, unassembled configuration. Fig. 7 illustrated the vat liner 5, from which the first flank side portion 5e, the second flank side portion 5f, the first end side portion 5a and the second end side portion can be identified forming a generally rectangular shape of the vat liner 5. Furthermore, the border portion 5b of the filtrate vat (and particularly the chute 5c formed thereunder) is closed towards the gap 3d.

Fig. 8 shows a detailed view of the outlet piece encircled in Fig. 7. Particularly, Fig. 8 illustrâtes how the outlet piece is arranged with respect to the filter plate 2, and the vat liner 5.

The base 7 of the outlet piece 6 is received in a seated manner in the recessed portion 2b of the outlet at the gap 3d of the border. Particularly, the base 7 is situated between the filter plate 2 and the vat liner 5, such that the vat liner 5 extends onto the base 7. Fig. 8 also illustrâtes attachment members (i.e. screws, although other attachment member may be envisaged) with which the base 7 is attached to the filter plate 2. Furthermore, the Fig. 8 shows the base having a recessed seat 7a against which the vat liner 5 is placed, and the recessed chute 7b extending from the recessed seat, slightly elevated therefrom such that the vat liner 5 extends up to the recessed chute 7b.

The lid 8 of the outlet piece is situated partially above the vat liner 5 and is attachable to the base 7, such that the vat liner 5 résides between the base 7 and the lid 8, and is clamped therebetween in a sealed manner. It should be noted that the attachment between the lid 8 and the base 7 is situated on a portion of the outlet piece 6 onto which the vat liner 5 does not extend to, thereby separating the point of attachment between the lid 8 and the base 7 from any filtrate running through the drainage route. Fig. 8 also illustrâtes attachment members (i.e. screws, although other attachment member may be envisaged) with which the lid 8 is attached to the base 7.

Fig. 9 illustrâtes a detailed view of the outlet piece shown in Fig. 8 in an assembled configuration. It can also be seen from Fig. 9 that the lid 8 extends and seals against the border portion 5b of the vat liner 5, when attached to the base 7.

Fig. 10 is a plan view of the filter plate assembly 1 of Fig. 7, as seen from the vat side 2b.

Fig. 11, illustrâtes an exploded eut view of the outlet piece denoted with the number 6 along the dashed lined shown in Fig. 10, whereas Fig. 12 illustrâtes the same in a nonexploded configuration. Particularly Fig. 11 and Fig. 12 further illustrating how the base 7 and lid 8 of the outlet piece 6 is arranged with respect to the filter plate 2 and the vat liner 5. Particularly the recessed seat 7a of the base 7 can be seen to be flush with the filtrate vat 4 and that the vat liner extends over the recessed seat 7a. Furthermore, the ribs 8a of the lid can be seen to press against the vat liner 5, thereby securely clamping it in place and sealed against the recessed seat. Furthermore, the base 7 can be attached to the plate frame 9 through the filter plate 2.

LIST OF REFERENCE NUMERALS

The invention is not limited to the embodiment/s illustrated in the drawings. Accordingly, it should be understood that where features mentioned in the appended daims are followed by reference signs, such signs are included solely for the purpose of enhancing the intelligibility of the daims and are in no way limiting on the scope of the daims.

filter plate assembly filter plate

2a frame side

2b vat side

2c recessed portion

2d first flank side

2e second flank side

2f first end side

2g second end side

2h attachment holes

2i indented portion

2j widening portion border

3a inner latéral wall

3b upper surface

3c outer latéral wall

3d gap filtrate vat vat liner

5a bottom portion

5b border portion

5c trough

5d gap portion

5e first flank side portion

5f second flank side portion

5g first end side portion

5h second end side portion outlet piece base

7a

7b

8a recessed seat recessed chute lid ri b filter plate frame filtrate vat

Claims

1. A filter plate assembly (1) for a horizontal plate and frame -type filter, comprising a filter plate (2) having a rigid plate-like body with a frame side (2a) and a vat side (2b), wherein the filter plate (2) comprises, on the vat side (2b), a border (3) having at least an inner latéral wall (3a) and an upper surface (3b), the border (3) being elevated for a distance at least from a portion of the filter plate (2) delimited within the border (3), and characterized in that the border (3) is an intégral part of the filter plate, wherein a filtrate vat (4) is formed by the filter plate, such that the inner latéral wall (3a) of the border forms a latéral wall of the filtrate vat (4), and a portion of the filter plate delimited by the border forms a bottom of the filtrate vat (4), and wherein the filter plate assembly further comprises a vat liner (5) having a sheet-like body, the vat liner (5) being nested within the filtrate vat (4) such that the vat liner (5) extends onto the upper surface (3b) of the border (3), such that the filter plate (2) is separated from filtrate within the filtrate vat (4) by the vat liner (5), when in use.

2. The filter plate assembly (1) according to Claim 1, characterized in that the border (3) has an outer latéral wall (3c), and wherein the vat liner (5) extends onto the latéral outer wall (3c).

3. The filter plate assembly according to Claim 2, characterized in that a trough (5c) is formed on the vat liner (5), running along a perimeter thereof, wherein the border (3) is nested within the trough (5c), and wherein an inside of the trough (5c) is hollow and the border (3) is solid.

4. The filter plate assembly (1) according to any of the preceding Claims 1-3, characterized in that a gap (3d) is provided on the border (3), such that an outlet opening extending laterally through the border (3) is formed, thereby providing a fluid drainage route from the filtrate vat (4).

5. The filter plate assembly (1) according to Claim 4, wherein the vat liner (5) is formed so as to extend into the outlet opening, and to cover the border (3) adjacent to the outlet opening, such that the filter plate (2) is separated from filtrate within the outlet opening by the vat liner (5), when in use.

6. The filter plate assembly (1) according to Claim 4 or 5, characterized in that, on the vat side (2b) of the filter plate (2), a recessed portion (2c) of the filter plate situated at the outlet opening is recessed with respect the bottom of the filtrate vat (4), and wherein the vat liner (5) is spaced apart from the filter plate (2) at the recessed portion (2c) in a direction transverse to the general planarity of the filter plate (2).

7. The filter plate assembly according to any of the preceding Claims 4-6, characterized by further comprising a removably fixed outlet piece (6) at least partly nested within the outlet opening, wherein the outlet piece (6) being arranged such that the fluid drainage route runs therethrough.

8. The filter plate assembly according to Claim 7, wherein the vat liner (5) extends into the outlet piece (6).

9. The filter plate assembly according to Claim 7 or 8, characterized in that the outlet piece (6) comprises

- a base (7) at least partly nested within the recessed portion (2c) of the filter plate (2), between the filter plate (2) and the vat liner (5), and

- a lid (8) on an opposite side of the vat liner with respect to the base, wherein the base (7) is removably fixed to the remaining filter plate assembly (1), and wherein the lid (8) is a removably fixed to the base (7) such that the vat liner (5) is clamped between the base (7) and the lid (8) and a sealed attachment between the outlet piece (6) and the vat liner (5) is formed, and wherein the filtrate drainage route is formed between the vat liner (5) and the lid (8).

10. The filter plate assembly according to Claim 9, characterized in that the base (7) of the outlet piece (6) comprises a recessed seat (7a) into which a gap portion (5d) of the vat liner (5), corresponding to a gap (3d) of the border (3), is seated, wherein the lid (8) comprises a plurality of spaced apart ribs (8a) projecting towards the recessed seat (7a), such that the vat liner (5) is clamped between the recessed seat (7a) and the ribs (8a), and is sealed against the recessed seat (7a), and wherein the lid (8) extends over the gap (4) and seals against the border portion (5b) of the liner at a position corresponding to the upper surface (3b) of the border (3).

11. The filter plate assembly (1) according to Claim 10, characterized in that the base (7) comprises a recessed chute (7b) as a continuation of the recessed seat (7a) for conducting filtrate out of the outlet piece (6).

12. The filter plate assembly (1) according to any of the preceding Claims 4-11, characterized in that the filter plate (2) is of a generally rectangular shape having a first flank side (2d) and a second flank side (2e) parallel to the first flank side (2d), and a first end side (2f) and a second end side (2g) parallel to the first end side (2f), wherein the first and second end sides (2f, 2g) extend in a direction transverse to a direction in which the first and second flank sides (2d, 2e) extend, wherein the first and second flank sides (2d, 2e) hâve a length greater than that of the first and second end sides (2f, 2g), and wherein one or more gaps (3d) of the border (3) are formed on either or both of the first flank side (2d) and the second flank side (2e).

13. The filter plate assembly (1) according to Claim 12, characterized in that a gap (3d) of the border (3) is formed in a corner région between a flank side (2d, 2e) and an end side (2f, 2g).

14. The filter plate assembly according to any of the preceding Claims 12 or 13, characterized in that the filter plate comprises one or more latéral indentation portion (2i) provided on either or both of the first flank side (2d) and the second flank side (2e), wherein the latéral indentation portion (2i) is arranged to circumvent suspension éléments and/or support éléments of a filter plate frame (9) on which the filter plate (2) is supported.

15. The filter plate assembly (1) according to Claim 14, characterized in that the filter plate (2) comprises one or more latéral widening portions (2j) provided on either or both of the first flank side (2d) and the second flank side (2e), wherein the latéral widening (2j) portions are arranged between latéral indentation portions (2i) adjacent to the widening portion (2j), wherein the latéral widening portions (2j) are arranged to laterally overhang a filter plate frame (9) supporting the filter plate (2).

16. The filter plate assembly according to any of the preceding Claims 1-15, characterized in that the filter plate comprises a plurality of attachment holes (2h) running along a periphery of the filter plate (2) and extending therethrough, wherein the attachment holes (2h) are situated on an outer side of the border (3) with respect to the filtrate vat (4), such that the attachment holes (2h) are not in contact with filtrate within the filtrate vat, when in use

17. A vat liner (5) for a filter plate assembly (1) of a horizontal plate and frame -type filter, such as a tower press, the vat liner (5) having a sheet -like body, comprising a planar bottom portion (5a), and a border portion (5b), further comprising:

- an inner latéral wall portion extending vertically from the planar bottom portion (5a), and

- an upper surface portion extending outwardly from the latéral wall portion in direction transverse thereto.

18. The vat liner (5) according to Claim 17, characterized by the border portion (5b) further comprising an outer latéral wall portion extending from the upper surface portion, · wherein the outer latéral wall portion extends vertically with respect to the planar bottom portion (5a), and wherein a hollow trough (5c) is formed on the vat liner (5), running along the perimeter thereof.

19. The vat liner (5) according to Claim 17 or 18, characterized in that a gap portion (5d) is formed on the border portion (5b), exhibiting a gap extending laterally through the border portion (5b), and wherein the planar bottom portion (5a) extends into the gap portion.

20. The vat liner according to Claim 19, characterized in that the hollow through (5c) is closed towards the gap portion (5d). ’ ~

21. The vat liner (5) according to any of the preceding Claims 17-20, characterized in that the vat liner (5) is of a generally rectangular shape having a first flank side portion (5e) and a second flank side portion (5f) parallel to the first flank side portion (5e), and a first end side (5g) portion and a second end side portion (5h) parallel to the first end side portion (5g), wherein the first and second end side portions (5g, 5h) extend in a direction transverse to a direction in which the first and second flank side portions (5e, 5f) 5 extend, wherein the first and second flank side portions (5e, 5f) hâve a length greater than that of the first and second end side portions (5g, 5h), and wherein one or more gap portions (5d) of the border portion (5b) are formed on either or both of the first flank side portion (5e) and the second flank side portion (5f).

10 22. The vat liner (5) according to Claim 21, characterized in that one or more gap (5d) portions of the border (5b) portion are formed in a corner région between a flank side portion and an end side portion.