Filter grid that can be placed in the filtrate tank of a filter press

Abstract

The filter grid (1) includes a plate-shaped grid body (2) having a first surface (2a) and an opposite second surface (2b). The grid body (2) further includes a plurality of openings (4) extending between the first surface (2a) and the second surface (2b) and passing through the grid body (2) to provide fluid communication between the first surface (2a) and the second surface (2b). Each of the plurality of openings (4) defines an opening area and an opening circumference such that the ratio of the opening area in square millimeters to the opening circumference in millimeters is greater than 1.3, and the plurality of openings (4) occupy at least 35% of the total area of ​​the first surface (2a). A filtrate tank assembly, a filter plate assembly, and a filter press are also disclosed.

Description

Disclosure Fields

[0001] The present disclosure relates to a filter press, and more particularly to a filter grid that serves to support a filter medium away from a filtrate tank. The present disclosure further relates to a filtrate tank assembly, a filter plate assembly, and a filter press that include such a filter grid.

[0002] Filter grids are used in filter presses, where a filter chamber is formed between adjacent filter plates such that a filter medium is disposed between the plates. A slurry is fed into the filter chamber, allowing liquid filtrate to flow through the filter element into a filtrate tank formed on the side of the filter element opposite the filter chamber. To prevent the filter element from deforming and entering the filtrate tank and blocking the filtrate flow therein, a filter grid is often provided in the filtrate tank. Typically, such a filtrate grid is a perforated plate having a flat surface on one side for supporting the filter element and a number of projections on the opposite side. The projections support the remaining part of the grid away from the bottom of the filtrate tank, thereby allowing filtrate to flow between the filtrate grid itself and the bottom of the filtrate tank.

[0003] Generally speaking, it is desirable for the openings in the grid to be relatively small, as this provides better support for the filter element; i.e., openings that are too large provide insufficient support for the filter element, which will tend to deform into such openings under filtration pressure, resulting in excessive wear of the filter element. At the same time, the grid should have a sufficiently large open area (i.e., occupied by openings) to allow sufficient filtrate flow therethrough. Typically, this is addressed by providing a sufficiently large number of openings.

[0004] Another consideration is the mechanical strength of the grid, which should be sufficient to withstand repeated compression cycles without undue permanent deformation.

[0005] Conventional grids leave room for improvement with respect to achieving a satisfactory balance between filtrate flow and support and mechanical strength of the filter element.

[0006] It is an object of the present disclosure to provide a filter grid that provides sufficient support for the filter element while improving filtrate flowability. It is a further object of the present disclosure to provide a filtrate tank assembly, a filter plate assembly, and a filter press incorporating such a filter grid.

[0007] The object of the present disclosure is achieved by a filter grid, a filtrate tank assembly, a filter plate assembly and a filter press, which are characterized by what is stated in the independent claims. Preferred embodiments of the present disclosure are disclosed in the dependent claims.

[0008] The present disclosure is based on the realization that in addition to the area that the openings occupy relative to the total area of ​​the grid (i.e., the open area ratio of the grid), the area of ​​a single opening also plays an important role in the filtrate flow capacity of the grid.

[0009] That is, relatively small openings provide good support for the filter element, and a sufficiently large number of such openings can provide a relatively large open area ratio for the grid, but relatively small openings reduce the flow capacity of the grid.

[0010] This is believed to be a result of the smaller apertures having a longer perimeter relative to the aperture size compared to the larger area apertures, which creates flow resistance for filtrate flow through the aperture, and therefore flow resistance is smaller for apertures having a larger open area.

[0011] The objectives of the present disclosure are therefore achieved with a filter grid having a plurality of openings for use in allowing filtrate to pass through the grid, where each of the plurality of openings has a sufficiently large ratio of open area to the circumference of the opening, and where the area occupied by the plurality of openings is sufficiently large compared to the total area of ​​the grid supporting the filter elements, as described in more detail below.

[0012] An advantage of the present disclosure is that it provides a filter grid with improved flow characteristics while maintaining adequate support for the filter element.

[0013] According to a first aspect of the present disclosure, there is provided a filter grid accommodated within a filtrate vessel of a filter press, the filter grid comprising a plate-shaped grid body including a first surface and an opposing second surface.

[0014] The first face defines a generally planar first surface that supports a filter element (such as a filter fabric) in use. The second face includes a plurality of spaced apart convex nubs that support another portion of the grid away from an associated filtrate reservoir. The grid body further includes a plurality of apertures extending between the first and second faces that provide fluid communication between the first and second faces through the grid body.

[0015] The plurality of openings allows filtrate received across the filter element supported by the filter grid to flow through the filter grid and onto the filtrate reservoir, while the convex nubs provide a flow path for said filtrate between the filter grid and the filtrate reservoir.

[0016] In particular, each of the plurality of apertures defines an aperture area and aperture circumference such that the ratio of aperture area in square millimeters to aperture circumference in millimeters is greater than 1.3, thereby ensuring that the individual apertures are sized such that flow resistance caused by friction between the periphery of such aperture and the flowing filtrate does not unduly restrict filtrate flow in typical filtration applications.

[0017] Additionally, the plurality of openings occupies at least 35% of the total area of ​​the first face, again ensuring that the amount of openings is sufficient to allow sufficient filtrate flow across the grid in typical filtration applications.

[0018] Advantageously, the ratio of aperture area in square millimetres to aperture circumference in millimetres exceeds 1.4, more preferably exceeds 1.5, most preferably exceeds 1.6.

[0019] Advantageously, the plurality of apertures occupies at least 36% of the total area of ​​the first face, more preferably at least 37% of the total area of ​​the first face.

[0020] Advantageously, each of the plurality of openings has an opening area of ​​40 square millimeters or less, more preferably 39 square millimeters or less, and most preferably 38 square millimeters or less. It has been found that such an opening area is sufficient to support the filter elements placed on the filter grid in typical filtration applications. For example, an opening area of ​​37 square millimeters is considered to be beneficial, although an opening area as small as 27 square millimeters is considered to be suitable. Advantageously, the opening area is defined by the height of the first surface.

[0021] In one embodiment of the first aspect of the invention, each of the plurality of apertures is hexagonal in shape, most preferably regular hexagonal in shape. In the description of the present disclosure, the shape of an aperture refers to its cross-sectional shape, unless otherwise stated. It has been found that such a hexagonal shape provides a particularly advantageous ratio of aperture area to aperture circumference for a given aperture size, while maintaining a sufficiently rigid mechanical structure of the filter grid.

[0022] Preferably, but not necessarily, the plurality of openings is arranged on the first surface in a honeycomb arrangement, i.e., the plurality of openings includes a plurality of first rows and a plurality of second rows, both of which extend in the longitudinal direction. Most preferably, the openings in the same row are equally spaced from each other. The first rows are preferably spaced from the second rows in a direction transverse to their longitudinal direction. Furthermore, the first rows are arranged parallel to the second rows and alternate with each other. In other words, the first and second rows alternate with each other in a direction transverse to the longitudinal direction of these rows. Furthermore, the openings in the first row are staggered in the longitudinal direction of the first and second rows with respect to the openings in the second row. That is, the longitudinal position of the openings in the first row is different from the longitudinal position of the openings in the second row.

[0023] Such an arrangement allows for a greater number of openings to be provided while still maintaining sufficient rigidity of the grid body.

[0024] Preferably, but not necessarily, the openings in the first row overlap the openings in the second row in a direction transverse to the longitudinal directions of the first and second rows.

[0025] Such an arrangement allows for a greater number of openings to be provided whilst still maintaining sufficient rigidity of the grid body.

[0026] More preferably, but not necessarily, the openings in the first row are further spaced apart from the openings in the second row in the longitudinal direction of the first and second rows.

[0027] Such an arrangement allows for more openings to be provided whilst still maintaining improved stiffness of the grid body.

[0028] Preferably, but not necessarily, each of the plurality of openings has an inscribed circle diameter of at least 5 mm, and more preferably, each of the plurality of openings has an inscribed circle diameter of at least 6 mm. For hexagonal shaped openings, the inscribed circle diameter corresponds to the distance between the parallel opposing sides of the hexagon. Such diameters have been found to provide flow characteristics suitable for typical filtration applications. For example, inscribed circle diameters of 6.5 mm or 5.6 mm are considered to be particularly advantageous.

[0029] Preferably, but not necessarily, the minimum distance between adjacent openings is between 2 mm and 6 mm, more preferably between 3 mm and 5 mm, and most preferably between 3.5 mm and 4.5 mm. It has been found that such dimensions provide sufficient material strength between adjacent openings to provide the required mechanical rigidity for a grid body suitable for typical filtration applications. For example, a distance of 3 mm or 4 mm is considered particularly advantageous. For regular hexagonal openings, the minimum distance corresponds to the distance between the opposing parallel sides of adjacent openings.

[0030] Additionally, the openings may be tapered such that their open area decreases towards the second surface. Alternatively, the openings may be tapered such that their open area increases towards the second surface. If the openings are tapered, it is preferred that the difference in open area at either end of the opening is 5% or less. Additionally, the edge between the opening and the first surface may be R-chamfered or C-chamfered. Of course, such R-chamfering may alternatively or additionally be applied to the edge between the opening and the second surface.

[0031] In one embodiment of the first aspect of the present invention, the non-peripheral humps of the plurality of convex humps are provided on the second surface between three immediately adjacent openings, and the term non-peripheral humps is used in the present disclosure to describe humps that are not the outermost in the pattern formed by the plurality of humps provided on the grid.

[0032] It has been found that providing the grid with non-circumferential nodules in the areas of the second surface between three adjacent openings provides sufficient rigidity for typical filtration applications without interfering with filtrate flow through the openings.

[0033] Preferably, but not necessarily, the three openings are equally spaced circumferentially from one another about the nub surrounded by the three openings, thereby maximizing the size of the nub that can be incorporated into the area between the openings adjacent the nub.

[0034] Preferably, but not necessarily, the projected portion of such a non-peripheral hump on the second surface coincides with the projected portion of an opening adjacent to such a non-peripheral hump. In other words, the projected portion of such a non-peripheral hump on the second surface may be in contact with the projected portion of an opening adjacent to said hump, preferably adjacent to each other. Alternatively, the projected portion of such a non-peripheral hump on the second surface may overlap with the projected portion of an opening adjacent to such a non-peripheral hump. In other words, the projected portion of such a non-peripheral hump on the second surface may extend into the projected portion of an opening adjacent to the hump.

[0035] In one embodiment of the first aspect of the present invention, the convex hump has a circular cross-sectional shape. Preferably, such a circular hump has a maximum cross-sectional diameter between 3 mm and 7 mm, more preferably between 4 mm and 6 mm, and most preferably between 4.5 mm and 5.5 mm. Suitably, the convex hump may be tapered such that the diameter increases towards the second surface of the grid body.

[0036] It should be noted that the first aspect of the present disclosure encompasses any combination of two or more of the embodiments or variations thereof, as described above.

[0037] According to a second aspect of the present disclosure, a filtrate tank assembly is provided.

[0038] Such a tank assembly includes a tank body including a filtrate surface defining a reservoir, thereby forming a filtrate tank for receiving filtrate. The tank body further includes a plate surface configured to be supported on a filter plate. Moreover, the filtrate surface and the plate surface are on opposite sides of the tank body.

[0039] In particular, the tank assembly comprises a filter grid according to the first aspect of the present disclosure housed within the filtrate tank.

[0040] According to a third aspect of the present disclosure, a filter plate assembly is provided.

[0041] Such a filter plate assembly comprises a filter plate, the filter plate including a reservoir surface, the reservoir surface having a filtrate reservoir disposed thereon, the filtrate reservoir configured to receive filtrate, the filter plate further including a chamber surface forming at least a portion of a filter chamber, the filter chamber may be defined by two adjacent filter plates.

[0042] In particular, the filter plate assembly further comprises a filter grid according to the first aspect of the present disclosure housed within the filtrate reservoir.

[0043] Preferably, but not necessarily, the filter plate assembly further comprises a filtrate tank assembly according to the second aspect of the present disclosure disposed on the tank surface of the filter plate.

[0044] According to a fourth aspect of the present disclosure, there is provided a filter press comprising a plurality of filter plates arranged such that at least a filter chamber is defined between adjacent filter plates.

[0045] The filter press further comprises a filter media (such as a filter fabric) disposed between adjacent filter plates such that the filter media partially defines a filter chamber and separates the slurry to be filtered into a solid cake and a liquid filtrate.

[0046] The filter press further comprises a filtrate reservoir for containing filtrate, the filtrate reservoir being disposed on a side of the filter element facing the filter chamber, in particular the filtrate reservoir being disposed to contain, in use, liquid filtrate separated by the filter element from the slurry provided to the filter chamber.

[0047] In particular, the filter press further comprises a filter grid received within the filtrate vessel for supporting the filter element thereon according to the first aspect of the present disclosure.

[0048] Preferably, but not necessarily, the filter press further comprises a filtrate tank assembly according to the second aspect of the present disclosure.

[0049] Preferably, but not necessarily, the filter press further comprises a filter plate assembly according to the third aspect of the present disclosure. [Brief description of the drawings]

[0050] Hereinafter, the present disclosure will be described in more detail by way of preferred embodiments with reference to the accompanying drawings. [Figure 1] 1 shows a schematic cross-sectional view of a filter grid according to an embodiment of the present disclosure, viewed from the side; [Diagram 2] 2A and 2B show schematic detailed views of a filter grid according to an embodiment of the present disclosure from its first side; [Diagram 3] 1A and 1B are schematic cross-sectional views of a filtrate tank assembly according to one embodiment of the present disclosure, as viewed from the side; [Figure 4] 1A and 1B are schematic cross-sectional views of a filter plate assembly according to one embodiment of the present disclosure, as viewed from the side; [Diagram 5] FIG. 1 shows a schematic cross-sectional view of a filter press according to one embodiment of the present disclosure, as viewed from the side. Detailed Description of the Disclosure

[0051] 1 shows a schematic cross-sectional view of a filter grid 1 according to one embodiment of the present disclosure, as viewed from the side. The filter grid 1 comprises a plate-like grid body 2 having a first face 2a and a second face 2b. The first face 2a is generally flat and has convex humps 3 extending from the second face 2b. A plurality of openings 4 extend between the first face 2a and the second face 2b, thereby providing flow paths for filtrate to pass through the grid body 2.

[0052] 2 shows a schematic detailed view of a filter grid 1 according to an embodiment of the present disclosure from its first face 2a. The grid body 2 has a number of openings 4 extending from its first face 2a to its second face 2b.

[0053] The openings 4 are of the shape of regular hexagons arranged in a staggered honeycomb arrangement. In the arrangement of FIG. 2, the openings 2 are arranged in a first row 4a and a second row 4b parallel to each other, both rows having a plurality of openings 4 spaced apart along the longitudinal direction of the row. In the arrangement of FIG. 2, the openings 4 in the same row are equally spaced apart from each other. The first row 4a is spaced apart from the second row 4b. Moreover, the first row 4a and the second row 4b are arranged alternately with each other, i.e., in a direction transverse to the longitudinal direction of the aforementioned rows 4a, 4b, the first row 4a is followed by the second row 4b, then the second row 4b is followed again by the first row 4b, and so on.

[0054] The first row 4a of openings is offset from the openings in the second row 4b in the longitudinal direction of the first and second rows 4a, 4b. Meanwhile, the longitudinal positions of the openings 4 in the first row 4a are aligned with the longitudinal positions of the openings in the following first row 4a. Similarly, the longitudinal positions of the openings 4 in the second row 4b are aligned with the longitudinal positions of the openings 4 in the following second row 4b.

[0055] In the arrangement of Figure 2, the openings 4 of the first row 4a overlap with the openings of the second row 4b in a direction transverse to the longitudinal direction of the first and second rows 4a, 4b, in other words the openings 4 of the second row 4b lie partially within the area between longitudinally consecutive openings 4 of the adjacent first row and vice versa.

[0056] Furthermore, the openings 4 of the first row 4a do not overlap with the openings 4 of the second row 4b in the longitudinal direction of the first and second rows 4a, 4b, in other words, the openings 4 of the second row 4b do not lie in the areas between the transversely adjacent openings 4 of the first row surrounding the second row 4b, and vice versa.

[0057] The humps 3 protruding from the second face 2b of the grid body 2 are not visible from the first face 2a of the grid body 2, but their positions relative to the openings are indicated by dashed circles. The humps 3 are provided on the second face 2b in the areas between adjacent openings 4. More specifically, the non-peripheral humps 3' (i.e., the humps that are not located on the periphery of the pattern formed by the humps 3) are located between three openings 4' immediately adjacent to each other. It is not necessary to provide a hump 3' in all the spaces bounded by three adjacent openings 4'. Such openings 4' that bound the non-peripheral humps 3' are equally spaced apart from each other in the circumferential direction around the respective humps 3'. Moreover, the projections of such non-peripheral humps 3' on the second face 2b coincide with the projections of the openings 4' adjacent to such non-peripheral humps 3'. That is, on the second surface 2b, the non-circumferential hump portions 3' extend into adjacent openings 4' and may slightly overlap each other.

[0058] FIG. 3 shows a schematic cross-sectional view of a filtrate tank assembly 5 according to one embodiment of the present disclosure, as viewed from the side. The tank assembly 5 comprises a tank body 6 having a filtrate surface 6a and a plate surface 6b. The filtrate surface 6a defines a receiving portion forming a filtrate tank 6'. In the embodiment of FIG. 3, the filtrate tank 6' is formed by a recessed area in the center of the filtrate surface 6a, which is surrounded by an edge portion that is raised relative to the recessed area. The plate surface 6b of the tank body 6 is then adapted to be supported by a filter plate in use. In the arrangement of FIG. 3, the plate surface 6b of the tank body 6 is flat. Furthermore, the filtrate tank assembly 5 also comprises a filter grid 1 that is received in the filtrate tank 6'. Although not shown in the accompanying drawings, the tank body 6 may of course comprise a drainage channel that leads the filtrate from the tank 6' to be received elsewhere.

[0059] 4 shows a schematic cross-sectional view of a filter plate assembly 7 according to one embodiment of the present disclosure, as viewed from the side. The filter plate assembly 7 comprises a filter plate 8 having a tank surface 8a, on which a filtrate tank 6' is disposed. In the arrangement of FIG. 4, the filtrate tank 6' is provided essentially as the filtrate tank assembly 5 of FIG. 3, although the filtrate tank 6' may alternatively be provided in other ways, for example as an integral part of the filter plate 8.

[0060] The filter plate assembly 7 further comprises a filter grid 1 housed within the filtrate tank 6'. Opposite the tank side 8a, the filter plate 8 defines a chamber side 8 which is arranged to define, in use, at least a part of a filter chamber 9. In the arrangement of Figure 4 this is achieved by providing a recessed area in the chamber side 8b. Although not shown in Figure 4, the filter plate may of course be provided with feed channels for introducing slurry into the filter chamber 9.

[0061] Figure 5 shows a schematic cross-sectional view of a filter press 10 according to one embodiment of the present disclosure, as viewed from the side. In particular, the filter press 10 includes adjacent filter plates 10 stacked one on top of the other. In the arrangement of Figure 5, the filter plates 8 are provided essentially as the filter plate assembly 7 of Figure 4. Although only two filter plates 8 are illustrated in Figure 5, it should be understood that a greater number of filter plates 8 may be provided in the filter press.

[0062] A filter element 11 (e.g., a filter cloth) is disposed between adjacent filter plates 8, so that a filter chamber 9 is defined between the filter element 11 and the filter plate 8 whose chamber surface 8b faces the filter element 11. Furthermore, the filter plate 8 whose chamber surface 8a faces the filter element 11 has a grid 1 accommodated in the filtrate tank 6' such that the filter element 11 is supported by the filter grid 1.

[0063] In use, slurry is fed under pressure into filter chamber 9 so that the liquid component of the slurry (i.e., filtrate) passes through filter element 11 to be received in filtrate tank 6' from where it can be further discharged. Grid 1 supports filter element 11 and prevents it from deforming into filtrate tank 6' which could both damage filter element 11 and impede the flow of filtrate into filtrate tank 6'. Openings 4 in grid 1 allow filtrate to pass through grid 1 into filtrate tank 6', whilst nubs in the grid allow filtrate to flow out below the grid into tank 6'.

[0064] According to a first specific embodiment of the present disclosure, a grid 1 having a geometry similar to that shown in FIG. 2 may be provided with openings 4 each having a regular hexagonal cross-sectional shape with an inscribed circle diameter of 6.5 mm. The openings 4 are arranged in a honeycomb array to fill the first face 2a of the grid 1 such that the distance between the parallel sides of adjacent openings is 4 mm. As a result, the openings 4 occupy 37.5% of the area of ​​the first face 2a of the grid, with each opening having an area of ​​36.6 square millimeters. This arrangement results in a ratio of opening area in square millimeters to opening circumference in millimeters of 1.63, allowing for a maximum hump diameter of 5 mm.

[0065] According to a second specific embodiment of the present disclosure, a grid 1 similar to that of the first specific embodiment 2 may be provided, except that the distance between the parallel sides of adjacent openings is 3 mm, such that a plurality of openings 4, each having an opening area of ​​36.6 square millimeters, occupies 45.9% of the area of ​​the first face 2a of the grid. This arrangement results in a ratio of opening area in square millimeters to opening circumference in millimeters of 1.63, allowing for a maximum hump diameter of 4 mm.

[0066] According to a third specific embodiment of the present disclosure, a grid 1 having a geometry similar to that shown in FIG. 2 may be provided with openings 4 each having a regular hexagonal cross-sectional shape with an inscribed circle radius of 5.6 mm. The openings 4 are arranged in a honeycomb array to fill the first face 2a of the grid 1 such that the distance between the parallel sides of adjacent openings is 3 mm. As a result, the openings 4 occupy 41.25% of the area of ​​the first face 2a of the grid, each having an opening area of ​​27.2 square millimeters. This arrangement results in a ratio of opening area in square millimeters to opening circumference in millimeters of 1.4, allowing a maximum hump diameter of 3.5 mm. LIST OF REFERENCE NUMBERS

[0067] 1. Filter Grid 2 Grid Body 2a First side of grid body 2b Second side of grid body 3. Convex lump 3' Non-peripheral hump 4 aperture 4' Opening surrounding non-peripheral hump 4a First row of apertures 4b Second row of openings 5 Filtrate tank assembly 6 Filtrate tank body 6' Filtrate tank 6a Filtrate level in the tank body 6b Plate surface of tank body 7 Filter plate assembly 8 Filter plate 8a Filter plate tank surface 8b Chamber surface of filter plate 9 Filter Chamber 10. Filter Press 11 Filter Media

Claims

1. a plate-shaped grid body having a first surface and an opposite second surface, the grid body being capable of being housed within a filtrate tank of a filter press; the first face defines a generally planar first surface that supports the filter element in use; the second surface includes a plurality of spaced apart convex nubs for supporting the remaining portion of the grid away from the associated filtrate reservoir; the grid body further having a plurality of openings extending between the first surface and the second surface thereby providing fluid communication between the first surface and the second surface through the grid body; each of the plurality of apertures defines an aperture area and an aperture circumference such that a ratio of aperture area in square millimeters to aperture circumference in millimeters is greater than 1.3; A filter grid, wherein the plurality of openings occupy at least 35% of the total area of ​​the first face.

2. 2. The filter grid of claim 1, wherein each of said plurality of openings is hexagonal in shape.

3. 3. The filter grid of claim 2, wherein the plurality of openings are arranged in a honeycomb array on the first surface and include a plurality of first rows and a plurality of second rows, both of which extend in the longitudinal direction; the first rows are parallel to the second rows and alternate with each other; 10. A filter grid, wherein the openings in a first row are offset relative to the openings in a second row in a staggered manner along the longitudinal direction of the first and second rows.

4. A filter grid as described in claim 3, characterized in that the openings of the first row overlap with the openings of the second row in a direction transverse to the longitudinal direction of the first and second rows.

5. A filter grid as described in claim 4, characterized in that the openings in the first row do not overlap with the openings in the second row in the longitudinal direction of the first and second rows.

6. 6. The filter grid according to claim 2, wherein each of the plurality of openings has an inscribed circle with a diameter of at least 5 mm, and more preferably, each of the plurality of openings has an inscribed circle with a diameter of at least 6 mm.

7. A filter grid as described in any one of claims 1 to 5, characterized in that the ratio of the opening area in square millimeters to the opening circumference in millimeters exceeds 1.4, more preferably exceeds 1.5, and most preferably exceeds 1.

6.

8. 6. A filter grid according to claim 1, wherein the plurality of openings occupy at least 36% of the total area of ​​the first face, more preferably at least 37% of the total area of ​​the first face.

9. A filter grid according to any one of claims 1 to 5, wherein each of the plurality of openings has an opening area of ​​40 mm 2 or less, more preferably 39 mm 2 or less, and most preferably 38 mm 2 or less. 。

10. A filter grid as described in any one of claims 1 to 5, characterized in that the minimum distance between adjacent openings is between 2 mm and 6 mm, more preferably between 3 mm and 5 mm, and most preferably between 3.5 mm and 4.5 mm.

11. A filter grid as described in any one of claims 1 to 5, characterized in that non-peripheral nodule portions among the plurality of convex nodule portions are provided on the second surface between three openings immediately adjacent to each other.

12. 12. The filter grid according to claim 11, wherein the three openings are equally spaced apart from one another in the circumferential direction about a hump surrounded by the three openings.

13. 12. The filter grid of claim 11, wherein a projection of the non-peripheral nodule on the second surface coincides with a projection of an opening adjacent the non-peripheral nodule.

14. A filter grid as described in any one of claims 1 to 5, characterized in that the convex bump-like portion has a circular cross-sectional shape with a maximum diameter preferably between 3 mm and 7 mm, more preferably between 4 mm and 6 mm, and most preferably between 4.5 mm and 5.5 mm.

15. a filtrate surface defining a receiving portion and thereby forming a filtrate reservoir for receiving the filtrate; and - a plate surface adapted to be supported on a filter plate A filtrate tank assembly comprising a tank body including:

6. A filtrate tank assembly, further comprising a filter grid according to claim 1 housed within the filtrate tank.

16. a reservoir surface on which a filtrate reservoir is arranged, the filtrate reservoir being adapted to receive filtrate; and a chamber surface forming at least part of the filter chamber; A filter plate assembly comprising a filter plate including:

6. A filter plate assembly, further comprising a filter grid according to claim 1, housed in the filtrate tank.

17. a plurality of filter plates each having at least one filter chamber formed between adjacent filter plates; a filter medium disposed between the adjacent filter plates and partially defining the filter chamber, the filter medium separating the slurry to be filtered into a solid cake and a liquid filtrate; a filtrate tank disposed on a side of the filter element opposite the filter chamber and configured to contain filtrate; In a filter press comprising: The filter press further comprises a filter grid according to any one of claims 1 to 5 housed within the filtrate tank, on which the filter element is supported.

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