filter plate sub-frame

Abstract

A filter plate sub-frame (1) for a filter plate frame assembly having a filter plate frame and a filter plate sub-frame receivable therein. The filter plate sub-frame comprises separate peripheral segments (2a, 3a, 4a, 5a, 6a) attached to each other so as to form a continuous, substantially rectangular shaped peripheral area (1a) having side sides and end sides. The linear density of the side sides (2, 3) is lower than the linear density of the end sides (4, 5), the bending stiffness of the end sides (4, 5) is higher than the bending stiffness of the side sides (2, 3), either or both of the first end side (4) and the second end side (5) are provided with a stiffening strip (4b, 5b) for increasing the bending stiffness of the end side (4, 5). A support surface is provided on a first planar side (1c) of the peripheral segments forming the side sides (2, 3), the support surface being configured to support the filter plate sub-frame on a corresponding receiving surface of the associated filter plate frame.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a vertical filter press, such as a tower press, having filter plate frames for supporting filter plates and filter plate sub-frames receivable within the filter plate frames. More specifically, the present disclosure relates to such filter plate sub-frames. BACKGROUND

[0002] In conventional vertical filter presses, filter chambers are formed between adjacent stacked filter plates. Typically, the filter plates are supported on the equipment by filter plate frames which also laterally delimit the filter chambers between adjacent filter plates. That is, the filter plate frames must be arranged to have sufficient rigidity to both support the associated filter plates and to withstand the pressure differential exerted thereon during operation without undue deformation. As a result, such filter frames are relatively heavy and bulky which hinders the replacement of associated wear parts, such as seals and diaphragms, since the entire filter plate frame must be removed from the filter equipment to safely perform such replacement.

[0003] More recently, it has been found that the filter plate frame can be provided with a separate removable sub-frame to which many of the wear parts are attached. Since the filter plate frame still provides support and rigidity, the sub-frame can be provided with a relatively lighter construction which facilitates its removal and the replacement of wear parts. SUMMARY

[0004] It is an object of the present disclosure to provide a filter plate sub-frame which further facilitates the replacement of wear parts associated therewith.

[0005] The object of the present disclosure is achieved by a filter plate sub-frame.

[0006] The present disclosure is based on the idea of providing a sub-frame which is essentially rectangular in shape, the sub-frame having end sides which are structured to provide a bending stiffness which is higher than the bending stiffness of the flank sides, while the flank sides are structured to have a linear density which is less than the linear density of the end sides. To this end, either or both of the end sides are provided with a stiffening strip. Furthermore, the sub-frame is longitudinally slidably receivable within an associated filter plate frame along a support surface on a first planar side of the flank sides so as to be thereby supported within the frame.

[0007] An advantage of the sub-frame according to the present disclosure is that the stiffness of the sub-frame in a transverse direction to the longitudinal direction is increased while the overall weight of the sub-frame is reduced. This facilitates the replacement of wear parts associated with the sub-frame since, in general, a lighter overall weight makes the handling of the sub-frame easier. Furthermore, the increased stiffness in the transverse direction reduces the transverse cross-sectional deformation when the sub-frame is supported by the flank sides, thereby making it easier to withdraw and insert the sub-frame into the frame.

[0008] According to a first aspect of the present disclosure, a filter plate sub-frame for a filter plate frame assembly is provided. Such filter plate frame assembly has a filter plate frame and a filter plate sub-frame receivable therein.

[0009] The filter plate sub-frame comprises separate peripheral segments which are attached to each other so as to form a continuous peripheral area of the sub-frame. The peripheral area surrounds and delimits an open area of the sub-frame. In use, the open area of the sub-frame laterally delimits a filter chamber.

[0010] The peripheral area is of generally rectangular shape, having a first side and an opposite second side parallel to the first side. The sides extend in a longitudinal direction of the sub-frame. The peripheral area further has a first end side and an opposite second end side parallel to the first end side, the end sides being transverse to the sides.

[0011] In particular, the line density of the sides is lower than the line density of the end sides, and the bending stiffness of the end sides is higher than the bending stiffness of the sides. Furthermore, either or both of the first and second end sides are provided with a reinforcement strip for increasing the bending stiffness of said end side. Most suitably, the reinforcement strip is separate from the peripheral segments, but is detachably fixed thereto.

[0012] Furthermore, the sub-frame is configured to be slidably receivable within the filter plate frame along the longitudinal direction of the sub-frame. A support surface is provided on the first planar side of the peripheral segments forming the sides. The support surface is configured to support the filter plate sub-frame on a corresponding receiving surface of the associated filter plate frame along which the sub-frame is slid into the frame.

[0013] In embodiments according to the first aspect of the present disclosure, the support surface is arranged to have a dry kinetic friction coefficient with steel of no more than 0.3, as determined according to ASTM D1894. This can be achieved by selecting a suitable material and / or surface roughness for the support surface.

[0014] In another embodiment according to the first aspect of the present disclosure, the reinforcement strip extends to or beyond a corner between the end side and the side adjacent to the end side, the end side being associated with the reinforcement strip. That is, the reinforcement strip extends over the entire width of the sub-frame (i.e. in a direction transverse to the longitudinal direction), thereby ensuring that in use the reinforcement strip extends over the receiving surface of the associated filter frame.

[0015] In another embodiment according to the first aspect of the present disclosure, the material of the reinforcement strip is different from the material of the peripheral segments, the modulus of elasticity of the reinforcement strip being higher than the modulus of elasticity of the peripheral segments.

[0016] For example, this can be achieved by providing a reinforcement strip made of steel or a composite material, such as FRP, and by providing peripheral segments made of a plastic material.

[0017] In a further embodiment according to the first aspect of the present disclosure, each corner between adjacent end sides and edge sides is provided with the same corner peripheral section.

[0018] In a further embodiment according to the first aspect of the present disclosure, at least one of the peripheral sections is a feed section comprising one or more feed ports for feeding slurry to be filtered into the open area in use, such that the feed section is removably attached to an adjacent peripheral section.

[0019] This ensures that the feed section, which is prone to wear due to the abrasive slurry flowing through the feed ports, is individually replaceable without the need to replace the entire sub-frame.

[0020] Preferably, but not necessarily, the feed section is removable from the adjacent peripheral section in a direction away from the open area. This further facilitates replacement of the feed section, as it does not need to be disassembled inwardly towards the open area.

[0021] Preferably, but not necessarily, the feed section is provided at either or both of the first and second edge sides. This is a particularly advantageous location for the feed section, as the edge sides are supported along their length by the filter plate frame. This is also important, as the feed section is structurally less robust than the peripheral sections without feed ports.

[0022] Preferably, but not necessarily, the same feed section is provided at both the first and second edge sides.

[0023] In a further embodiment according to the first aspect of the present disclosure, a membrane groove is provided on the second planar side of the peripheral area, opposite the first planar side, for receiving and attaching a respective bead of a filter membrane. The membrane groove extends along the peripheral area and is formed on separate peripheral sections which are attached to each other so as to form a continuous annular groove.

[0024] For example, the membrane groove can have a cross-sectional profile with a bore opening towards the second planar side of the filter plate sub-frame, a bottom and a neck between the bore and the bottom. Furthermore, the lateral extension of the bottom can exceed the lateral extension of the neck. That is, in the cross-sectional profile of the membrane groove, the neck forms a narrowing waist relative to the bottom. This enables a relevant bead of a filter membrane having a corresponding cross-sectional profile to be shape-fittingly attached to the membrane groove.

[0025] Moreover, the lateral extension of the bottom can be defined as its maximum lateral extension (i.e. width), while the lateral extension of the neck can be defined as its minimum lateral extension (i.e. width). Then, the groove can suitably have an asymmetric cross-sectional profile with respect to a vertical axis of asymmetry passing through the lateral center point of the minimum width section of the neck. The vertical axis of asymmetry is perpendicular to the overall plane of the sub-frame, which is defined by the planarity of the open area. The minimum width section of the neck can be defined as a point of the cross-sectional profile of the groove at which the neck presents the minimum lateral extension. That is, the minimum width section is defined at the narrowest point of the neck, i.e. along the horizontal direction, transversal to the extension direction of the groove and parallel to the overall plane of the frame at the point having the minimum dimension of the neck.

[0026] Moreover, the bottom suitably extends laterally further away from the axis of asymmetry on the lateral outer side (facing away from the open area) than on the lateral inner side (facing towards the open area).

[0027] The above arrangement ensures that, when inserted in the septum groove, the respective crimp of the associated septum can better resist the torsion due to the weight of the septum itself.

[0028] In a further embodiment according to the first aspect of the present disclosure, a seal bar groove is provided on the first planar side of the peripheral area for receiving and attaching a respective seal bar for sealing a filter plate located underneath the sub-frame in use. The seal bar groove extends along the peripheral area and is formed on separate peripheral segments which are attached to each other so as to form a continuous annular groove.

[0029] Preferably, but not necessarily, the seal bar groove has a cross-sectional profile comprising a bottom and a neck between the bottom and the first planar side of the sub-frame. Moreover, the cross-sectional width of the neck can be smaller than the cross-sectional width of the bottom. That is, in the cross-sectional profile of the sub-frame, the neck of the seal bar groove is narrower than the bottom of the seal bar groove, as seen along the direction along which the groove extends at a given point.

[0030] Moreover, the cross-sectional profile of the seal bar groove can be asymmetric with respect to a vertical line extending perpendicularly to the first planar side through a lateral center point of the bottom of the seal bar groove, thereby defining a chamber side (on the open area side) and an outer side.

[0031] Preferably, but not necessarily, the chamber side of the bottom of the seal bar groove can present a greater curvature than the outer side of the bottom of the seal bar groove.

[0032] Preferably, but not necessarily, in the cross-sectional profile of the filter sub-frame, on the chamber side, the curvature of the bottom of the seal bar groove continuously extends to the neck. For example, the curvature of the bottom can transition into the neck with a continuous curvature.

[0033] Preferably, but not necessarily, in the cross-sectional profile of the subframe, on the outer side, the bottom of the sealing strip groove presents a linear profile that extends to the neck of the sealing strip groove.

[0034] In another embodiment according to the first aspect of this disclosure, a section seal is provided in a joint between adjacent peripheral sections. Most preferably, such a section seal is provided in each joint between adjacent peripheral sections.

[0035] Preferably, but not necessarily, this segment seal is disposed at a portion of the joint that overlaps with the diaphragm groove and the sealing strip groove, as described above, the segment seal being configured as a peg extending between the bottom of the diaphragm groove and the bottom of the sealing strip groove. Attached Figure Description

[0036] In the following, the present disclosure will be described in more detail with reference to the accompanying drawings, in which:

[0037] Figure 1 A schematic diagram of a filter plate subframe according to an embodiment of the present disclosure is shown in perspective.

[0038] Figure 2 It shows Figure 1 The filter plate subframe is shown in an exploded perspective view;

[0039] Figure 3 It shows Figure 1 The filter plate subframe is shown in a plan view;

[0040] Figure 4 It shows Figure 1 The filter plate subframe is shown in an exploded plan view;

[0041] Figure 5 It shows Figure 3 Detailed view of the circled area; and

[0042] Figure 6 It shows Figure 1 The filter plate subframe is shown in a side view.

[0043] List of reference numerals

[0044] 1. Filter plate subframe

[0045] 1a Outer area

[0046] 1b Open Area

[0047] 1c First Plane Side

[0048] 1d Second Plane Side

[0049] 2 First side

[0050] 2a Outer Section

[0051] 2a' Supply Section

[0052] 3 Second side

[0053] 3a Outer Section

[0054] 3a' Supply Section

[0055] 4 First end side

[0056] 4a Outer Section

[0057] 4b Reinforcing strip

[0058] 5 Second end side

[0059] 5a Outer Section

[0060] 5b Reinforcing Strip

[0061] 6. Corner

[0062] 6a Corner outer section

[0063] 7. Diaphragm Groove

[0064] 8-section seal Detailed Implementation

[0065] Figure 1 A perspective view of a filter plate subframe 1 according to an embodiment of the present disclosure is shown. The subframe 1 has a generally rectangular peripheral region 1a having a first side 2 and opposing second side 3, the first and second sides extending along the longitudinal direction of the subframe 1 and parallel to each other. The peripheral region 1a also includes a first end side 4 and opposing second end side 5, which are parallel to each other and laterally positioned relative to the sides 2 and 3. A corner 6 connects adjacent sides 2 and 3 and end sides 4 and 5 to each other. In particular, the peripheral region 1a defines and delineates an open region 1b therein.

[0066] Figure 2 The diagram more clearly illustrates how the peripheral region 1a comprises multiple peripheral segments forming the periphery of the subframe 1. Specifically, the first side 2 includes individual peripheral segments 2a attached to each other, one of which is a supply segment 2a'. Similarly, the second side 3 includes individual peripheral segments removably attached to each other, one of which is a supply segment 3a'. Although not shown, the supply segments 2a' and 3a' have one or more supply ports for supplying the slurry to be filtered to the open area during use. Specifically, the feed segments 2a' and 3a' are removable from adjacent peripheral segments 2a and 3a in a direction away from the open area. Furthermore, although not clearly visible from the drawings, the feed segments 2a' and 3a' are identical to each other.

[0067] The first end side 4 includes a single peripheral segment 4a, although alternatively the first end side 4 may be formed by multiple peripheral segments. Correspondingly, the second end side 5 also includes a single peripheral segment 5a, although alternatively the second end side 5 may be formed by multiple peripheral segments.

[0068] In the illustrated embodiment, sides 2 and 3 and end sides 4 and 5 are interconnected via corner 6. Specifically, corner 6 includes a corner segment 6a, which is removably attached to adjacent outer segments 2a, 3a, 4a, and 5a. It should be noted that, alternatively, sides 2 and 3 and end sides 4 and 5 can be configured to be directly connected to each other without separate corners. In the embodiment shown in the figures, corner segments 6a are identical to each other.

[0069] Both the first end side 4 and the second end side 5 are equipped with reinforcing strips 4b and 5b, which are removably attached to and extend over the outer perimeter sections 4a and 5a of the first end side 4 and the second end side. In the specifically illustrated embodiment, the reinforcing strips 4b and 5b are also removably attached to and extend over the relevant corner section 6a.

[0070] As mentioned earlier, the materials of reinforcing strips 4b and 5b are different from those of the outer sections 2a-6a, and the elastic modulus of reinforcing strips 4b and 5b is higher than that of the outer sections 2a-6a. For example, reinforcing strips 4b and 5b may be made of steel or composite materials, while the outer sections 2a-6a may be made of plastic materials.

[0071] Figure 3 The image shown is from the second planar side 1d of the outer region. Figure 1 Plan view of subframe 1. Figure 4 It also shows something similar to Figure 2 The decomposed structure is shown in a planar view observed from the second plane side 1d of the outer region.

[0072] Figure 5 It shows Figure 3 A detailed view of the circled portion between the lower left corner 6 and the first side 2 is shown. Specifically, the diaphragm groove 7 is used to receive the corresponding rolled edge of the filter membrane for attaching the diaphragm to the filter subframe 1. From Figures 1 to 5 As can be seen, the diaphragm groove 7 is disposed on the second planar side 1d and extends along the peripheral region 1b. In particular, the groove 7 is formed on the individual peripheral segments 2a-6a that are attached to each other, so as to form a continuous annular groove 7.

[0073] also, Figure 5 The seal 8 is shown in the joint between adjacent peripheral sections 2a and 6a.

[0074] Figure 6Again, the filter plate sub-frame 1 is shown in a side view. In particular, the first planar side 1c and the second planar side 1d of the peripheral region 1a are shown.

Claims

1. A filter plate sub-frame for a filter plate frame assembly having a filter plate frame and a filter plate sub-frame receivable therein, characterized in that the filter plate sub-frame comprising separate peripheral segments attached to each other so as to form a continuous peripheral area of the filter plate sub-frame, such that the peripheral area surrounds and bounds an open area of the filter plate sub-frame, wherein the peripheral area is rectangular in shape, having: a first side and a second side parallel and opposite to the first side, the first and second sides extending along a longitudinal direction of the filter plate sub-frame, and a first end side and a second end side parallel and opposite to the first end side, the first and second end sides being transverse to the first and second sides, wherein the linear density of the first and second sides is lower than the linear density of the first and second end sides, and the bending stiffness of the first and second end sides is higher than the bending stiffness of the first or second sides, wherein either or both of the first and second end sides are provided with a reinforcement strip for increasing the bending stiffness of the first and / or second end sides, wherein the filter plate sub-frame is configured to be slidably received within the filter plate frame along the longitudinal direction of the filter plate sub-frame, and wherein a support surface is provided on a first planar side of the peripheral segments forming the first and second sides, the support surface being configured to support the filter plate sub-frame on a corresponding receiving surface of the associated filter plate frame.

2. The filter plate subframe of claim 1, wherein, the support surface is arranged to have a dry dynamic friction coefficient with steel of no more than 0.

3.

3. The filter plate subframe of claim 1, wherein, the reinforcement strip extends to or beyond a corner between the first or second end side and the first or second side adjacent to the first or second end side, the first or second end side being associated with the reinforcement strip.

4. The filter plate subframe of the preceding claim 1, characterized in that, the material of the reinforcement strip is different from the material of the peripheral segments, the modulus of elasticity of the material of the reinforcement strip being higher than the modulus of elasticity of the peripheral segments.

5. The filter plate subframe of claim 4, wherein, the reinforcement strip is made of steel or a composite material, and wherein the peripheral segments are made of a plastic material.

6. The filter plate subframe according to any of the preceding claims 1 - 5, characterized in that, each corner between adjacent end sides and side sides is provided with a same corner peripheral segment.

7. The filter plate subframe according to any of the preceding claims 1 - 5, characterized in that, at least one of the peripheral segments is a feed segment comprising one or more feed ports for feeding slurry to be filtered into the open area when in use, and wherein the feed segment is removably attached to an adjacent peripheral segment.

8. The filter plate subframe of claim 7, wherein, the feed segment is removable from the adjacent peripheral segment in a direction away from the open area.

9. The filter plate subframe of claim 7, wherein, the feed segment is provided at either or both of the first and second sides.

10. The filter plate subframe of the preceding claim 7, characterized in that, the same feed segment is provided at both the first and second sides.

11. The filter plate subframe according to any of the preceding claims 1 - 5, characterized in that, a membrane groove is provided on a second planar side of the peripheral area opposite to the first planar side for receiving and attaching a corresponding rolled edge of a filter membrane, wherein the membrane groove extends along the peripheral area and is formed on a plurality of separate peripheral segments attached to each other so as to form a continuous annular groove.

12. The filter plate subframe of the preceding claim 11, characterized in that A seal bar groove is provided on a first planar side of the peripheral region for receiving and attaching a corresponding seal bar of the filter plate, wherein the seal bar groove extends along the peripheral region and is formed on a plurality of separate peripheral segments that are attached to each other so as to form a continuous annular groove.

13. The filter plate subframe of the preceding claim 12, characterized in that A segment seal is provided in the joint between adjacent peripheral segments.

14. The filter plate subframe of claim 13, wherein, The segment seal is provided at a portion of the joint that overlaps the septum groove and the seal bar groove, the segment seal being provided as a cylindrical plug that extends between the bottom of the septum groove and the bottom of the seal bar groove.

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