Filter plate structure of a filter press device

Abstract

In a filter press device, the sealing performance is further enhanced, and leakage from the filter chamber is more reliably suppressed. [Solution] In the filter plate structure, the substrate portion has an annular first pressing portion that presses the contact portion around the space of the filter chamber when in contact, and the contact portion has an annular second pressing portion that presses the first pressing portion around the space of the filter chamber when in contact. Either the first pressing portion or the second pressing portion comprises an opposing portion that faces the other pressing portion and a recess that is recessed from the opposing portion. The other pressing portion is covered with a filter cloth. A convex portion is provided in the part of the filter cloth that faces the recess. Both the recess and the convex portion are arranged in an annular shape around the perimeter of the filter chamber when in contact. When in contact, the annular convex portion seals by directly or indirectly pressing the annular recess through another member.

Description

Technical Field

[0004] , , , ,

[0005] , , ,

[0001] This disclosure relates to the filter plate structure of a filter press device.

Background Art

[0002] In a conventionally provided filter press device, a plurality of filter plates are stacked and arranged, and muddy water is poured into the space formed between the filter plates, and the muddy water is squeezed between the filter plates to separate the solid content from the liquid content. As an example of the filter plate used in this type of filter press device, a technique such as Patent Document 1 has been proposed. The filter plate disclosed in Patent Document 1 is provided with frame-shaped convex portions on both the front and rear surfaces of the central portion of the substrate. In a state where a plurality of filter plates overlap, the recesses on the central side of adjacent filter plates face each other to form a filter chamber, and the frame-shaped convex portions of adjacent filter plates press against each other to seal the peripheral portion of the filter chamber.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the filter plate disclosed in Patent Document 1, a squeezing elastic body is covered on one of the adjacent filter plates, an annular recess is provided on the frame-shaped convex portion of the filter plate covered with the squeezing elastic body, and a sealing material made of a soft elastic body is accommodated inside the annular recess. When the filter plate is tightened, the space between the substrate and the peripheral portion of the squeezing elastic body is sealed via the sealing material made of a soft elastic body. However, since the filter plate disclosed in Patent Document 1 is configured such that the flat portions are in close contact with each other when the frame-shaped convex portions of adjacent filter plates press against each other, the sealing performance is not sufficient, and there is a risk that liquid or the like may leak from the peripheral portion when a strong internal pressure is applied by the solid-liquid mixture flowing into the filter chamber.

[0005] This disclosure provides a technology that can more easily realize a configuration that can further improve sealing performance and more reliably suppress leakage from the filter chamber, in order to solve at least one of the above-mentioned problems. [Means for solving the problem]

[0006] One of the disclosures is the filter plate structure of a filter press device. A filter plate having a plate-shaped substrate portion, A contact portion is positioned opposite the filter plate portion, and its relative position to the filter plate portion switches between a contact position in close contact with the filter plate portion and an open position away from the filter plate portion, filter cloth and Equipped with, A filter plate structure in a filter press device in which a filter chamber is formed by the filter plate portion and the contact portion when the contact portion is in the contact position, The substrate portion has an annular first pressing portion that presses the contact portion around the space of the filter chamber when in the contact state, The contact portion has an annular second pressing portion that presses the first pressing portion around the space of the filter chamber when in the contact state, Either the first pressing portion or the second pressing portion comprises an opposing portion facing the other pressing portion and a recess that is recessed from the opposing portion, The other pressing portion is covered by the filter cloth, In the aforementioned filter cloth, a protrusion is provided in the portion facing the recess. Both the recess and the protrusion are arranged in an annular shape around the filter chamber when in the state of close contact. When in the aforementioned tightly adhering state, the annular protrusion seals by directly or indirectly pressing against the annular recess via another member. [Effects of the Invention]

[0007] The technology described herein can further improve the sealing performance of a filter press apparatus and more reliably suppress leakage from the filter chamber. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view illustrating the filter plate structure of a filter press apparatus according to the first embodiment of the present invention. [Figure 2] This is an explanatory diagram illustrating a state in the filter plate structure shown in Figure 1 where one filter plate and another filter plate are in close contact and a solid-liquid mixture flows into the filter plate. [Figure 3] This is a front view of one of the filter plates in the filter plate structure shown in Figure 1. [Figure 4] This is a front view illustrating the state in which the filter cloth has been omitted from the filter plate in Figure 3. [Figure 5] Figure 3 is a rear view of the filter plate. [Figure 6] This is a rear view illustrating the state of the filter plate in Figure 5 with the filter cloth omitted. [Figure 7] This is an enlarged view showing a portion of the filter plate structure in Figure 1. [Figure 8] This is an enlarged view conceptually showing a portion of the filter plate structure in the state shown in Figure 2. [Figure 9] Figure 1 is a conceptual side view of a filter press apparatus having the filter plate structure shown in Figure 1. [Figure 10] This is an explanatory diagram showing an example of the configuration in Figure 2. [Figure 11] This is an explanatory diagram showing an example of the configuration in Figure 3. [Figure 12] This is an explanatory diagram showing an example of the configuration in Figure 4. [Figure 13] This is an explanatory diagram showing an example of the configuration in Figure 5. [Figure 14] This is an explanatory diagram showing an example of the configuration described in Figure 6. [Figure 15] This is an explanatory diagram showing a concrete example of a part of the filter press apparatus shown in Figure 9. [Figure 16] Figure 15 is a conceptual diagram illustrating the configuration of a part of the filter press apparatus as viewed from above. [Figure 17] Figure 15 is a conceptual diagram illustrating the configuration of a part of the filter press apparatus as seen from the front. [Figure 18] (A) is an explanatory diagram illustrating an example in which a cake falls while tilting when there is no regulating portion, and (B) is an explanatory diagram illustrating an example in which a cake falls while tilting when there is a regulating portion. [Figure 19] (A) is an explanatory diagram exemplifying a state of one set of adjacent filter plates as viewed from above in the first holding state, and (B) is an explanatory diagram exemplifying a state in which the filter plate set is separated to drop a cake. [Figure 20] It is a cross-sectional view schematically exemplifying a filter plate structure of a filter press apparatus according to a second embodiment of the present invention. [Figure 21] It is an explanatory diagram exemplifying a state in which a solid-liquid mixture flows in with the filter plate portion and the contact portion in contact with each other in the filter plate structure of the second embodiment. [Figure 22] It is a front view exemplifying a filter plate portion forming part of the filter plate structure of the second embodiment. [Figure 23] It is a front view exemplifying a state in which a filter cloth is omitted from the filter plate portion of FIG. 22. [Figure 24] It is a rear view of the filter plate portion of FIG. 22. [Figure 25] It is a rear view exemplifying a state in which a filter cloth is omitted from the filter plate portion of FIG. 22. [Figure 26] It is a front view exemplifying a frame body forming part of the filter plate structure of the second embodiment. [Figure 27] It is a rear view of the frame body of FIG. 27. [Figure 28] It is an explanatory diagram showing an example embodying a part of a filter press apparatus using the filter plate structure according to the second embodiment. <00001​​​​​​​​​This is an explanatory diagram illustrating the cleaning process of a filter press apparatus having a filter plate structure according to the second embodiment. [Figure 33] Figure 32 is an explanatory diagram illustrating the view from above of the filter plate and contact area during the cleaning process. [Figure 34] This is an explanatory diagram schematically showing a modified example 1 of the frame used in the filter plate structure of the second embodiment. [Figure 35] This is an explanatory diagram schematically showing a modified example 2 of the frame used in the filter plate structure of the second embodiment. [Figure 36] This is a schematic cross-sectional view illustrating the filter plate structure of a filter press apparatus according to a third embodiment of the present invention. [Figure 37] This is an explanatory diagram illustrating a state in which a solid-liquid mixture flows into the filter plate structure of the third embodiment while the filter plate portion and the contact portion are in close contact. [Figure 38] This is an explanatory diagram illustrating the state in the filter plate structure of the third embodiment when the filter plate portion and the contact portion are separated and the contact portion is inclined. [Modes for carrying out the invention]

[0009] [1] A filter plate having a plate-shaped substrate portion, A contact portion is positioned opposite the filter plate portion, and its relative position to the filter plate portion switches between a contact position in close contact with the filter plate portion and an open position away from the filter plate portion, filter cloth and Equipped with, A filter plate structure in a filter press device in which a filter chamber is formed by the filter plate portion and the contact portion when the contact portion is in the contact position, The substrate portion has an annular first pressing portion that presses the contact portion around the space of the filter chamber when in the contact state, The contact portion has an annular second pressing portion that presses the first pressing portion around the space of the filter chamber when in the contact state, Either the first pressing portion or the second pressing portion comprises an opposing portion facing the other pressing portion and a recess that is recessed from the opposing portion, The other pressing portion is covered by the filter cloth, In the aforementioned filter cloth, a protrusion is provided in the portion facing the recess. Both the recess and the protrusion are arranged in an annular shape around the filter chamber when in the state of close contact. When in the aforementioned tightly sealed state, the annular protrusion seals by directly or indirectly pressing against the annular recess via another member. Filter plate structure of a filter press device.

[0010] The filter plate structure of the filter press apparatus described in [1] above can further improve the sealing performance in the filter press apparatus and more reliably suppress leakage from the filter chamber.

[0011] <First Embodiment> The following describes a first embodiment of the filter plate structure and filter press apparatus according to the present invention, based on the drawings. These drawings are used to illustrate the technical features that the present invention may adopt. Unless otherwise specified, the structures of the apparatus described below are not intended to be the sole limiting factors, but are merely illustrative examples.

[0012] (Filter press device) First, let me explain the overview of the filter press apparatus 1. The filter plate structure 3 shown in Figure 1 is used, for example, in a single-type filter press device 1 as shown in Figure 9. The filter press device 1 shown in Figure 9 is a device that can dewater a solid-liquid mixture (for example, a slurry in which sludge, excavated soil, cement, etc. are mixed in water) and discharge a solidified object (cake) from the residue remaining after dewatering the solid-liquid mixture.

[0013] The filter press device 1 uses a filter plate structure 3 as shown in Figure 1, etc. This filter plate structure 3 is configured with filter plates 10 arranged in series, and each filter plate 10 has a plate-shaped base plate 11 with a perforated hole 16 formed in the center, over which a filter cloth 18 is stretched. The filter press device 1 shown in Figure 9 has an approach / separation device (detailed illustration omitted in Figure 9) that can move the multiple filter plates 10 constituting the filter plate structure 3 closer together and further apart from each other. When supplying a solid-liquid mixture, the adjacent filter plates 10 are stacked in close contact with each other (see Figures 2 and 8), and the solid-liquid mixture (for example, a slurry such as muddy water) is pressurized and injected into the perforated holes 16 of each filter plate 10 by a pump. The injected solid-liquid mixture accumulates in the filter chamber 40 shown in Figures 2 and 8, etc., under high internal pressure, and moisture is discharged through the minute gaps in the filter cloth 18. Then, between adjacent filter plates 10 (specifically, between the filter cloths 18 on adjacent filter plates 10), a solid substance (dewatered cake) is formed from the residue remaining after a large amount of water has been removed from the solid-liquid mixture supplied from the pump. In Figures 1 and 2, the details of the water flow path (details of the drainage channel 28) through the mesh of the filter cloth 18 into the interior of the filter plates 10 are omitted, but in reality, the water that flows into the interior of the filter plates 10 through the mesh of the filter cloth 18 is discharged to the outside (bottom) of the filter plates 10 through the drainage channel 28 inside the filter plates 10.

[0014] (Filter plate structure) Next, filter plate structure 3 will be described in detail. As shown in Figure 1, the filter plate structure 3 is composed of multiple filter plates 10. Each filter plate 10 has the same structure.

[0015] In the following description, a predetermined number of filter plates 10 arranged alternately will be referred to as filter plate sections 8, and a number of filter plates 10 arranged alternately between these filter plate sections 8 will be referred to as contact sections 9. In the filter plate structure 3, all filter plate sections 8 and all contact sections 9 have the same structure. Each contact section 9 is positioned opposite a filter plate section 8 and is configured to switch between a contacted position where it is in close contact with the filter plate section 8 and an open position where it is displaced from the filter plate section 8, and has an internal containment space. In the filter plate structure 3, when the contact section 9 is in the contacted position, a filter chamber is formed by the filter plate section 8 and the contact section 9.

[0016] Here, we will describe one of the components of the filter plate section 8 and the contact section 9 (the component of the filter plate 10). The filter plate 10 is a plate-shaped component that becomes either the filter plate section 8 or the contact section 9, and is mainly composed of a substrate section 11 and a filter cloth 18.

[0017] The substrate portion 11 has a plate-like shape overall and includes two central recesses 12 provided on both sides in the thickness direction, two pressing portions 14 provided on both sides in the thickness direction, and a hole portion 16.

[0018] The two central recesses 12 are both recesses in the thickness direction of the substrate portion 11, located in the center away from the periphery of the substrate portion 11. In Figure 1, etc., of the two central recesses 12 formed on each filter plate 10, the recess on one side (the side on which the annular protrusion 24 is formed) is referred to as one central recess 12A (or simply central recess 12A), and the recess on the other side (the side on which the annular recess 34 is formed) is referred to as the other central recess 12B (or simply central recess 12B). As shown in Figure 4, one central recess 12A has a rectangular outer diameter when viewed from the front, and as shown in Figure 6, the other central recess 12B has a rectangular outer diameter when viewed from the back.

[0019] In this configuration, one central recess 12A of the filter plate 10, which functions as the filter plate portion 8, functions as a recessed portion 8A, and the other central recess 12B of the filter plate 10, which functions as the filter plate portion 8, functions as a recessed portion 8B. The recessed portions 8A and 8B are formed on both outer surfaces (specifically, on both plate surfaces facing the two contact portions 9) of the substrate portion 11 that constitutes the filter plate portion 8, and constitute a part of the filter chamber 40, which will be described later. Furthermore, one central recess 12A of the filter plate 10, which functions as the contact portion 9, functions as a housing portion 9A, and the other central recess 12B of the filter plate 10, which functions as the contact portion 9, functions as a housing portion 9B. The housing portion 9A is configured in a concave shape, and when the contact portion 9 is in contact with the filter plate portion 8 on the side facing the housing portion 9A, it forms the filter chamber 40 together with the recessed portion 8B of the filter plate portion 8. The housing section 9B is configured in a concave shape, and when the contact section 9 is in close contact with the filter plate section 8 on the side opposite to the housing section 9B, it together with the recessed section 8A of the filter plate section 8 constitutes the filter chamber 40.

[0020] The pressing portion 14 is a part that is arranged in a ring shape surrounding the central recess 12. Of these, one pressing portion 14A of each filter plate 10 is a part that faces and presses against the other pressing portion 14B of the other filter plate 10. As shown in Figure 4, the pressing portion 14A on one side (the side on which the annular protrusion 24 is formed) is a rectangular frame when viewed from the front and is arranged in a square shape (specifically, a square shape) along the periphery of the filter plate 10. As shown in Figure 6, the pressing portion 14B on the other side (the side on which the annular recess 34 is formed) is a rectangular frame when viewed from the front and is arranged in a square shape (specifically, a square shape) along the periphery of the filter plate 10.

[0021] The pressing portion 14 provided on the filter plate 10, which functions as the filter plate portion 8, has one pressing portion 14A that functions as the first pressing portion 8C and the other pressing portion 14B that functions as the first pressing portion 8D. The first pressing portion 8C is positioned on the outer surface of one side in the thickness direction of the substrate portion 11 (the side of one contact portion 9) surrounding the recessed portion 8A, and when in contact, it functions to press the contact portion 9 opposite to the first pressing portion 8C. The first pressing portion 8D is positioned on the outer surface of one side in the thickness direction of the substrate portion 11 (the side of the other contact portion 9) surrounding the recessed portion 8B, and when in contact, it functions to press the contact portion 9 opposite to the first pressing portion 8D.

[0022] The pressing portion 14 provided on the filter plate 10, which functions as the contact portion 9, has one pressing portion 14A that functions as the second pressing portion 9C and the other pressing portion 14B that functions as the second pressing portion 9D. The second pressing portion 9C is positioned on the outer surface of one side in the thickness direction of the base portion 11 (the side of one filter plate portion 8) surrounding the housing portion 9A, and when in contact, it functions to press the first pressing portion 8D of the filter plate portion 8 that is opposite to the second pressing portion 9C. The second pressing portion 9D is positioned on the outer surface of one side in the thickness direction of the base portion 11 (the side of the other filter plate portion 8) surrounding the housing portion 9B, and when in contact, it functions to press the first pressing portion 8C of the filter plate portion 8 that is opposite to the second pressing portion 9D.

[0023] As shown in Figures 4 and 7, the pressing portion 14A on one side (the side on which the annular projection 24 is formed) has an opposing portion 22 arranged in an annular shape (specifically, in the shape of a square frame) around the central recess 12A, and an annular projection 24 arranged in an annular shape (specifically, in the shape of a square frame) around the central recess 12A and protruding from the surface of the opposing portion 22.

[0024] The annular projection 24 is made of an elastic material such as rubber or an elastomer other than rubber, and is fixed to the pressing part 14A by fitting into a groove formed in the opposing part 22 of the pressing part 14A (a groove formed to surround the central recess 12A). As shown in Figure 7, the annular projection 24 has a curved shape such that the outer shape of the cross section cut in a plane perpendicular to the direction in which the annular projection 24 extends is convex outwards. The annular projection 24 is also hollow, with a void 24A formed inside. The void 24A is formed outside the position of the opposing part 22 in the thickness direction of the filter plate 10 (farther away from the center in the thickness direction), and is configured to extend along the direction in which the annular projection 24 extends and to be arranged in a ring around the central recess 12.

[0025] As shown in Figures 6 and 7, the pressing portion 14B on the other side (the side on which the annular recess 34 is formed) has an opposing portion 32 arranged in an annular shape (specifically, in the shape of a rectangular frame) around the central recess 12B, and an annular recess 34 arranged in an annular shape (specifically, in the shape of a rectangular frame) around the central recess 12B and recessed from the surface of the opposing portion 32.

[0026] In this configuration, one opposing portion 22 of the filter plate 10, which functions as the filter plate portion 8, functions as the first opposing portion 8E, and the other opposing portion 32 of the filter plate 10, which functions as the filter plate portion 8, functions as the first opposing portion 8F. Each of the first opposing portions 8E and 8F is positioned around the recessed portions 8A and 8B, respectively, and when in contact, its surface faces the respective sides of the second pressing portions 9D and 9C. Similarly, one opposing portion 22 of the filter plate 10, which functions as the contact portion 9, functions as the second opposing portion 9E, and the other opposing portion 32 of the filter plate 10, which functions as the contact portion 9, functions as the second opposing portion 9F. Each of the second opposing portions 9E and 9F is positioned around the housing portions 9A and 9B, respectively, and when in contact, its surface faces the respective sides of the first pressing portions 8D and 8C.

[0027] As shown in Figure 1, in each filter plate 10, a hole 16 is formed so as to penetrate in the thickness direction between the central recess 12A on one side (the side on which the annular protrusion 24 is formed) and the central recess 12B on the other side (the side on which the annular recess 34 is formed). The hole 16 functions as a flow path that allows the solid-liquid mixture to flow in the thickness direction of the filter plate 10 so as to pass through the inside of the filter plate 10. The hole 16 of the filter plate 10, which functions as the filter plate portion 8, is configured to pass through the inside of the substrate portion 11 and becomes a flow path that leads to the recessed portions 8A and 8B. Similarly, the hole 16 of the filter plate 10, which functions as the contact portion 9, is configured to pass through the inside of the substrate portion 11 and becomes a flow path that leads to the housing portions 9A and 9B.

[0028] As shown in Figures 1 and 3, the filter cloth 18 is positioned to cover the area outside the hole 16 on one side in the thickness direction of the plate, and as shown in Figures 1 and 5, the filter cloth 18 is positioned to cover the area outside the hole 16 on the other side in the thickness direction of the plate. Note that in Figures 2 and 8, the two filter cloths 18 interposed between the opposing parts 22 and 32 and between the annular protrusion 24 and the annular recess 34 are omitted from the diagram. In Figures 1 to 8, the filter cloth 18 covering one side (the side on which the annular protrusion 24 is formed) is referred to as filter cloth 18A, and the filter cloth covering the other side (the side on which the annular recess 34 is formed) is referred to as filter cloth 18B.

[0029] As shown in Figure 3, the filter cloth 18A on one side (the side where the annular protrusion 24 is formed) is fixed to the annular plate portion 15A, which will be described later, and is distributed throughout the area outside the annular plate portion 15A, extending to the periphery of the substrate portion 11. As shown in Figure 5, the filter cloth 18B on the other side (the side where the annular recess 34 is formed) is fixed to the annular plate portion 15B, which will be described later, and is distributed throughout the area outside the annular plate portion 15B, extending to the periphery of the substrate portion 11. In Figures 1, 2, 7, and 8, the filter cloth 18 is conceptually shown by a dashed line, and in Figures 3 and 5, the filter cloth 18 is conceptually shown as a patterned area. In the examples of Figures 2 and 8, the filter cloth 18A and 18B also exist in the portion sandwiched between the pressing portions 14A and 14B, but the illustration (illustration by a dashed line) of the filter cloth 18A and 18B in this portion is omitted. In the example shown in Figure 1, the peripheral edges of the filter cloth 18A and the filter cloth 18B are connected in each filter plate 10, but the peripheral edges do not necessarily have to be connected. The filter cloth 18A only needs to be positioned to cover the inner surface of the central recess 12A in the area outside the hole 16, and the covering area of ​​the filter cloth 18A is not limited to the configurations shown in Figures 1 and 3.

[0030] In this configuration, the filter cloth 18 placed on the filter plate 10, which functions as a filter plate portion 8, is arranged to cover the inner surfaces of the recessed portions 8A and 8B and the surfaces of the first pressing portions 8C and 8D. One side of the filter cloth 18A is positioned across the recessed portion 8A and the first pressing portion 8C, while the other side of the filter cloth 18B is positioned across the recessed portion 8B and the first pressing portion 8D. The filter cloth 18 placed on the filter plate 10, which functions as a contact portion 9, is arranged to cover the inner surfaces of the housing portions 9A and 9B and the surfaces of the second pressing portions 9C and 9D. One side of the filter cloth 18A is positioned across the housing portion 9A and the second pressing portion 9C, while the other side of the filter cloth 18B is positioned across the housing portion 9B and the second pressing portion 9D.

[0031] In the above configuration, the annular protrusion 24 provided on the first pressing portion 8C functions as the first sealing portion 8G, is positioned around the recessed portion 8A, and protrudes from the surface of the first opposing portion 8E. The annular recess 34 provided on the first pressing portion 8D functions as the first sealing portion 8H, is positioned around the recessed portion 8B, and concaves from the surface of the first opposing portion 8F.

[0032] The annular projection 24 provided on the second pressing portion 9C functions as the second sealing portion 9G. The second sealing portion 9G is positioned around the housing portion 9A, protruding from the surface of the second opposing portion 9E, and pressing against the first sealing portion 8H when in close contact. The annular recess 34 provided on the second pressing portion 9D functions as the second sealing portion 9H. The second sealing portion 9H is positioned around the housing portion 9B, concave from the surface of the second opposing portion 9F, and pressing against the first sealing portion 8G when in close contact.

[0033] The filter plate structure 3 shown in Figure 1, etc., can be switched between a state in which adjacent filter plates 10 are spaced apart, as shown in Figures 1 and 7, and a state in which adjacent filter plates 10 are in close contact, as shown in Figures 2 and 8. The multiple filter plates 10 are aligned in the thickness direction as shown in Figure 1 by rails (not shown in Figure 1, etc.) (i.e., the thickness direction of each filter plate 10 is aligned in the same direction), and the position of the outer edge of each filter plate 10 (the position of the outer edge in a plane direction perpendicular to the thickness direction) is also aligned. By moving along the rails in this aligned state, adjacent filter plates 10 can move closer to and further apart from each other.

[0034] As shown in Figures 2 and 8, when multiple filter plates 10 are stacked so that one filter plate 10 is in close contact with another filter plate 10, the annular protrusion 24 of one filter plate 10 fits into the annular recess 34 of the other filter plate 10 and presses against the inner surface of the annular recess 34, creating a configuration in which the opposing portion 22 of one filter plate 10 and the opposing portion 32 of the other filter plate 10 press against each other. In the example of Figure 8, two filter cloths 18A and 18B that cover the two filter plates 10 are interposed between the opposing portion 22 of one filter plate 10 and the opposing portion 32 of the other filter plate 10, and in this state, the opposing portion 22 of one filter plate 10 and the opposing portion 32 of the other filter plate 10 press against each other. In other words, the opposing portion 22 of one filter plate 10 and the opposing portion 32 of the other filter plate 10 press against each other via the filter cloth 18A of one filter plate 10 and the filter cloth 18B of the other filter plate 10. Furthermore, two filter cloths 18A and 18B, each covering the two filter plates 10, are interposed between the annular protrusion 24 and the annular recess 34, and in this state (i.e., with the filter cloths 18A and 18B interposed between the outer surface of the annular protrusion 24 and the inner surface of the annular recess 34), the annular protrusion 24 and the annular recess 34 press against each other. That is, the annular protrusion 24 of one filter plate 10 presses against the inner surface of the annular recess 34 via the filter cloth 18A of one filter plate 10 and the filter cloth 18B of the other filter plate 10.

[0035] As shown in Figure 8, when adjacent filter plates 10 are stacked in close contact, and a solid-liquid mixture is injected through the holes 16 using the first injection device 60 (for example, a slurry supply device including a pump) shown in Figure 15, the injected solid-liquid mixture accumulates in the filter chamber 40 shown in Figures 2 and 8 (see also Figure 15) under high internal pressure, and moisture is discharged to the substrate portion 11 side (i.e., the back side of the filter cloth 18) through the minute gaps in the filter cloth 18. Then, a dewatered cake is formed between adjacent filter plates 10 (specifically, between the filter cloths of adjacent filter plates 10). The dewatered cake is an object from which a certain amount of moisture has been removed from the solid-liquid mixture 7 injected into the filter chamber 40, as shown in Figure 2.

[0036] In this configuration, each filter plate 10 is provided with a base plate portion 11. The base plate portion 11 is plate-shaped, and one of the two central recesses 12A and one of the two pressing portions 14A are formed on one side of the plate (the one side as described above), while the other central recess 12B and the other pressing portion 14B are formed on the other side of the plate (the other side as described above). A filter cloth 18A is provided so as to cover the inner wall of one central recess 12A, and a filter cloth 18B is provided so as to cover the inner wall of the other central recess 12B. On the back side of the filter cloth 18 in one central recess 12A and the other central recess 12B, drainage channels 28 (one drainage channel 28A and the other drainage channel 28B) leading to the outside of the filter plate 10 are provided.

[0037] In each of the central recesses 12A and 12B of the filter plate 10, a drain plate 13 (one drain plate 13A and the other drain plate 13B) is provided on the inner wall (inner surface) of the deepest part in the depth direction of each drain plate 13A and 13B, each equipped with a water passage that allows liquid to pass through in the direction of its plate thickness. The water passage of either drain plate 13A or 13B may be composed of numerous holes, or it may be composed of grooves or notches. The drain plates 13A and 13B are configured such that water can pass from the front side to the back side while supporting the filter cloth 18 on the front side, and may be configured such as having many through holes formed in a plate-like body, or they may be configured as a mesh. On the substrate portion 11, a plate-like body 11A is provided on the inside of each drain plate 13 in the thickness direction (thickness direction of the filter plate 10), with both sides in the thickness direction covered by each drain plate 13. As shown in Figures 1 and 4, one pressing portion 14A is a rectangular frame fixed along the periphery of the plate-like body 11A on one side of the plate-like body 11A. The other pressing portion 14B is a rectangular frame fixed along the periphery of the plate-like body 11A on the other side of the plate-like body 11A. One drain plate 13A is fixed with its periphery sandwiched between the inner edge of the frame that constitutes the plate-like body 11A and the pressing portion 14A. The other drain plate 13B is fixed with its periphery sandwiched between the inner edge of the frame that constitutes the plate-like body 11A and the pressing portion 14B.

[0038] Between each drain plate 13 (one drain plate 13A and the other drain plate 13B) and the plate-like body 11A, drainage channels 28A and 28B are formed, respectively, leading to the outside of the filter plate 10. Both drainage channels 28A and 28B are configured as water passages.

[0039] The drainage channels 28A formed on the back side of the filter cloth 18A in the central recess 12A are as shown in Figures 10 to 12, for example. In the example shown in Figures 10 to 12, multiple drainage channels 28A are formed in a groove shape on the lower end side (the lower vertical end side when installed) of one side of the base plate 11, and water can flow through each drainage channel 28A. One end (upper end) of each drainage channel 28A is located on the back side of the drainage plate 13A, and a part of the back surface of the drainage plate 13A faces the internal space of each drainage channel 28A. The other end (lower end) of each drainage channel 28A reaches the lower end of the filter plate 10, and the internal space of each drainage channel 28A is in communication with the space outside the filter plate 10. Furthermore, it is desirable that a space exists between the back surface of the drain plate 13A and the front surface of the plate-like body 11A, and that this space communicates with each drain channel 28A. With this configuration, moisture that flows into the back surface of the drain plate 13A can easily flow to the outside of the filter plate 10 through each drain channel 28A.

[0040] The drainage channels 28B formed on the back side of the filter cloth 18B in the central recess 12B are as shown in Figures 10, 13, and 14, for example. In the examples of Figures 10, 13, and 14, multiple drainage channels 28B are formed in a groove shape on the lower end side (the lower vertical end side when installed) of one side of the base plate 11, and water can flow through each drainage channel 28B. One end (upper end) of each drainage channel 28B is located on the back side of the drainage plate 13B, and a part of the back surface of the drainage plate 13B faces the internal space of each drainage channel 28B. The other end (lower end) of each drainage channel 28B reaches the lower end of the filter plate 10, and the internal space of each drainage channel 28B communicates with the space outside the filter plate 10. Furthermore, it is desirable that a space exists between the back surface of the drain plate 13B and the front surface of the plate-like body 11B, and that this space communicates with each drain channel 28B. With this configuration, moisture that flows into the back surface of the drain plate 13B can easily flow to the outside of the filter plate 10 through each drain channel 28B.

[0041] In the examples shown in Figures 10 to 15, a configuration is illustrated in which multiple drainage channels 28 are provided on the lower end side of the filter plate 10. However, any flow path that can discharge water that has flowed through the filter cloth 18 to the drainage plate 13 side to the outside of the filter plate 10 is acceptable.

[0042] As shown in Figures 1, 2, 3, and 5, the filter plate 10 has a pair of annular plate portions 15A and 15B fixed in one central recess 12A and the other central recess 12B of the substrate portion 11, respectively. The annular plate portions 15A and 15B have through-hole side projections 17A and 17B that protrude in the thickness direction of the filter plate 10. Multiple through-hole side projections 17A protrude from the annular plate portion 15A on one side, and these multiple through-hole side projections 17A are arranged around the hole portion 16, as shown in Figure 11. Similarly, multiple through-hole side projections 17B protrude from the annular plate portion 15B on the other side, and these multiple through-hole side projections 17B are arranged around the hole portion 16, as shown in Figure 13. The hole 16 is formed to communicate from one annular plate portion 15A to the other annular plate portion 15B of the pair of annular plate portions 15A and 15B. Specifically, the inside of the cylindrical portion connecting the pair of annular plate portions 15A and 15B is the hole 16. In this configuration, as shown in Figure 2, when one side of one filter plate 10 and the other side of the other filter plate 10 are placed on top of each other so as to press against each other, the through-hole side projection 17A on one side of the one filter plate 10 and the through-hole side projection 17B on the other side of the other filter plate 10 face each other. As shown in Figure 2, when the through-hole side projection 17A on one side of one filter plate 10 and the through-hole side projection 17B on the other side of the other filter plate 10 face each other, the distance between these through-hole side projections 17A and 17B (the distance between their tips) is smaller than the distance between the plates of the annular plate portions 15A and 15B, and may even be zero (i.e., the opposing through-hole side projections 17A and 17B may be in contact). Note that in the example shown in Figure 2, the filter cloth 18 is not interposed between the opposing through-hole side projections 17A and 17B.

[0043] Within one central recess 12A and the other central recess 12B, drain plate side projections 19 (one drain plate side projection 19A and the other drain plate side projection 19B) are formed, respectively, protruding in the thickness direction from the respective drain plate 13. One drain plate side projection 19A is fixed to at least one of the drain plate 13A or the plate-like body 11A, and is configured to protrude from the surface of the drain plate 13A in the thickness direction (the thickness direction of the filter plate 10). The drain plate side projection 19A has a tapered shape, becoming narrower as it approaches the tip in its protruding direction. In the example of Figure 4, a plurality of drain plate side projections 19A with such a configuration are arranged to surround the hole 16. The other drain plate side projection 19B is fixed to at least one of the drain plate 13B or the plate-like body 11A, and is configured to protrude from the surface of the drain plate 13B in the thickness direction (the thickness direction of the filter plate 10). The drain plate side projection 19B has a tapered shape, becoming narrower as it approaches the tip in its protruding direction. In the example in Figure 6, multiple drain plate side projections 19B with this configuration are arranged to surround the hole 16. When one side of one filter plate 10 and the other side of another filter plate 10 are placed on top of each other in a pressing manner, as shown in Figure 2, each drain plate side projection 19A on one side of the filter plate 10 and each drain plate side projection 19B on the other side of the other filter plate 10 face each other. When the drain plate side projection 19A on one side of the filter plate 10 and the drain plate side projection 19B on the other side of the other filter plate 10 face each other, as shown in Figure 2, the distance between these drain plate side projections 19A and 19B (the distance between their tips) is smaller than the distance between the opposing drain plates 13A and 3B. In the example shown in Figure 2, the filter cloths 18A and 18B are interposed between the opposing drain plate side protrusions 19A and 19B, and the filter cloths 18A and 18B are sandwiched between the opposing drain plate side protrusions 19A and 19B.

[0044] The filter press apparatus 1 shown in Figure 9 has such a filter plate structure 3. Specifically, as shown in Figures 15 and 16, the multiple filter plates 10 constituting the filter plate structure 3 are aligned in a predetermined position (i.e., a position in which the thickness direction of each filter plate 10 is in the same direction and the position of the outer edge of each filter plate 10 is aligned), and the multiple filter plates 10 can be moved along the guide rails 90 (guide rails 90A, 90B). Through this movement, adjacent filter plates 10 can move closer to and further apart from each other.

[0045] Although not shown in Figures 1 to 14, as shown in Figures 16 and 17, each filter plate 10 is provided with a pair of overhangs 41 and 42 that extend laterally from both the left and right sides of the base plate portion 11 of each filter plate 10. These pairs of overhangs 41 and 42 function as a pair of supported parts, and are supported while being placed on the guide rails 90A and 90B. As the pair of overhangs 41 and 42 move while being placed on the guide rails 90A and 90B, each filter plate 10 moves in a predetermined direction (the thickness direction of each filter plate 10) while maintaining a predetermined posture.

[0046] In addition to the filter plate structure 3 described above, the filter press apparatus 1 includes a holding device 50, a first injection device 60 (hereinafter also referred to as a slurry supply device), a second injection device 70 (hereinafter also referred to as an air supply device), a supply passage 62 for supplying the solid-liquid mixture 7, a supply passage 72 for supplying air, a first switching unit 81 for switching the opening and closing of the supply passage 62, a second switching unit 82 for switching the opening and closing of the supply passage 72, and so on. Although not shown in the figures, a control device (for example, an information processing device such as a computer) is also provided to control the operation (operating timing, control amount, etc.) of the holding device 50, the first injection device 60, the second injection device 70, the first switching unit 81, and the second switching unit 82.

[0047] The holding device 50 comprises a pair of guide rails 90 (guide rails 90A, 90B), a drive device 54, and fixed walls 51, 52, which are assembled integrally. The drive device 54 comprises an action part 54C that acts on the filter plates 10 at the end of the filter plate group 5 (the end on the fixed wall 52 side), a drive shaft 54B connected to the action part 54C, and a drive unit 54A that moves the drive shaft 54B in a predetermined direction (the direction that maintains the thickness of each filter plate 10 in the filter plate group 5). When the drive unit 54A moves the action part 54C toward the fixed wall 51 side via the drive shaft 54B, the multiple filter plates 10 are pressed toward the fixed wall 51 side while maintaining a predetermined posture, and as shown in Figures 15 and 16, adjacent filter plates in the filter plate group 5 come into contact with each other. On the other hand, the drive unit 54A moves the operating unit 54C toward the fixed wall 52 via the drive shaft 54B, causing adjacent filter plates in the filter plate group 5 to be spaced apart from each other. For example, if a spacing regulating unit (not shown) is provided to regulate the spacing so that the maximum distance between adjacent filter plates in a plurality of filter plates 10 is a predetermined distance, then when the operating unit 54C operates to move a filter plate 10 toward the fixed wall 52 while engaging with or holding the filter plate 10 at the end of the filter plate group 5 (the end on the fixed wall 52 side), each filter plate will move so that adjacent filter plates are spaced apart from each other. Note that the example shown here is merely one example, and the holding device may have other configurations as long as it can move the filter plates closer together and further apart while aligning the plurality of filter plates 10 in a predetermined position (i.e., a position in which the thickness direction of each filter plate 10 is in the same direction and the position of the outer peripheral edge of each filter plate 10 is aligned).

[0048] In this way, by moving the working part 54C toward the fixed wall 51, the holding device 50 can arrange multiple filter plates 10 in an overlapping state as shown in Figures 15 and 16, and hold them in a holding state (first holding state) where the annular protrusion 24 of one filter plate 10 enters into the annular recess 34 of the other filter plate 10 and presses against the inside of the annular recess 34, and the opposing part 22 of one filter plate 10 and the opposing part 32 of the other filter plate 10 press against each other (see Figures 2 and 8 for the specific state between adjacent filter plates).

[0049] The first injection device 60 is a transfer device that transfers a solid-liquid mixture from a solid-liquid mixture containment section (e.g., a slurry containment tank) (not shown) to the filter plate group 5. When the first switching section 81 is open and the supply passage 62 is in communication with the holes 16 at the end of the filter plate group 5, the solid-liquid mixture can be injected into the interior of the filter plate group 5 via the supply passage 62. Specifically, as shown in Figures 15 and 16, when the filter plate group 5, consisting of multiple filter plates 10, is held in a first holding state by the holding device 50, the first injection device 60 injects the solid-liquid mixture 7 into the interior of the multiple filter plates 10 from the holes 16 of the filter plates 10 at one end of the filter plate group 5. The first switching unit 81 is a device that switches between a first stop state, which stops the inflow and outflow of fluid at one end of the filter plate group 5, and a first release state, which releases the first stop state. It is composed of a known solenoid valve that switches the supply passage 62 (pipe) between an open state and a closed state, and the opening and closing of the first switching unit 81 is controlled by a control device (not shown).

[0050] The second injection device 70 is configured as a known air supply device capable of pressurizing air, and can inject air into the filter plate group 5 via the supply passage 72 when the second switching unit 82 is in an open state and the supply passage 72 is in communication with the hole 16 at the end of the filter plate group 5. Specifically, as shown in Figures 15 and 16, when the filter plate group 5, consisting of a plurality of filter plates 10, is held in a first holding state by the holding device 50, the second injection device 70 injects air into the plurality of filter plates 10 from the hole 16 at the other end of the filter plate group 5 opposite to one end. The second switching unit 82 is a device that switches between a second stop state, which stops the inflow and outflow of fluid at the other end of the filter plate group 5, and a second release state, which releases the second stop state, and is configured as a known solenoid valve that switches the supply passage 72 (pipe) between an open state and a closed state, and the opening and closing of the second switching unit 82 is controlled by a control device (not shown).

[0051] In the filter press apparatus 1, as shown in Figure 16, when the holding device 50 is holding in the first holding state, the second switching unit 82 is switched to the second stop state (the supply path 72 is blocked) and the first switching unit 81 is switched to the first release state (the supply path 62 is open), the first injection device 60 injects the solid-liquid mixture 7 into the filter plate group 5. Then, after the solid-liquid mixture 7 is injected by the first injection device 60, and the holding device 50 is held in the first holding state as shown in Figures 15 and 16, the first switching unit 81 is switched to the first stop state (the supply passage 62 is blocked) and the second switching unit 82 is switched to the second open state (the supply passage 72 is open). The second injection device 70 injects air into the filter plate group 5, causing the air to flow from the hole 16 side at the other end to the drainage passage 28 side of each filter plate 10, and the liquid (water) of the solid-liquid mixture 7 inside the filter plate group 5 is discharged to the outside of the filter plate group 5 via the drainage passage 28 along with the air. The operating timing and operating time of each device are controlled by a control device (not shown).

[0052] Furthermore, in this configuration, as shown in Figures 16 and 17, a pair of restricting parts 94 (restricting parts 94A and 94B) are arranged above each of the pair of guide rails 90A and 90B. The pair of guide rails 90A and 90B are each positioned opposite each other on both sides of each filter plate 10 and extend along the thickness direction. The pair of restricting parts 94A and 94B are each positioned opposite each other on both sides of each filter plate 10 at a position above the vertical center of each filter plate 10 and extend along the thickness direction. Specifically, recesses 41A and 42A are formed on the upper surfaces of a pair of protruding parts 41 and 42 formed on each filter plate 10, and the pair of restricting parts 94A and 94B are provided, respectively, positioned within these recesses 41A and 42A and supported by the recesses 41A and 42A.

[0053] (Example of effect) Next, we will illustrate the effects of this configuration. In the filter plate structure 3 described above, as shown in Figure 2, when one filter plate 10 and the other filter plate 10 are stacked on top of each other, the annular protrusion 24 of the first filter plate 10 enters into the annular recess 34 of the other filter plate 10 and presses against the inside of the annular recess 34, causing the opposing portion 22 of the first filter plate 10 and the opposing portion 32 of the other filter plate 10 to press against each other. With this configuration, when the two filter plates 10 are brought into close contact to form a filter chamber 40 (the inflow area of ​​the solid-liquid mixture formed by the central recess 12 of the first filter plate 10 and the central recess 12 of the other filter plate 10), a region that can ensure stronger adhesion can be arranged in a ring shape surrounding the part that makes up the filter chamber 40.

[0054] Specifically, in the first seal portion 8G and the second seal portion 9H, which press against each other when in close contact, one seal portion (first seal portion 8G) has a convex portion that protrudes toward the other seal portion (second seal portion 9H) when in close contact and is positioned to surround the filter chamber 40. The other seal portion (second seal portion 9H) has a concave portion that recesses toward the opposite side of the first seal portion (first seal portion 8G) when in close contact and is positioned to surround the filter chamber 40. When in close contact, the convex portion (first seal portion 8G) and the covering portion (filter cloth 18) covering the convex portion (first seal portion 8G) enter into the concave portion (second seal portion 9H) and press against the inner surface of the concave portion (second seal portion 9H). In other words, when in a tight seal, the filter cloth 18 is sandwiched between the convex portion (first sealing portion 8G) and the concave portion (second sealing portion 9H), and the convex portion (first sealing portion 8G) moves into the concave portion (second sealing portion 9H) while pressing against the inner surface of the concave portion (second sealing portion 9H).

[0055] Furthermore, in the first seal portion 8H and the second seal portion 9G, which press against each other when in close contact, one seal portion (second seal portion 9G) has a convex portion that protrudes toward the other seal portion (first seal portion 8H) when in close contact and is positioned to surround the filter chamber 40. The other seal portion (first seal portion 8H) has a concave portion that recesses toward the opposite side from the first seal portion (second seal portion 9G) when in close contact and is positioned to surround the filter chamber 40. When in close contact, the convex portion (second seal portion 9G) and the covering portion (filter cloth 18) covering the convex portion (second seal portion 9G) enter into the concave portion (first seal portion 8H) and press against the inner surface of the concave portion (first seal portion 8H). In other words, when in a tight seal, the filter cloth 18 is sandwiched between the convex portion (second sealing portion 9G) and the concave portion (first sealing portion 8H), and the convex portion (second sealing portion 9G) moves into the concave portion (first sealing portion 8H) while pressing against the inner surface of the concave portion (first sealing portion 8H).

[0056] As shown in Figure 1, each filter plate 10 is provided with a base plate portion 11. The base plate portion 11 is plate-shaped, and one of the two central recesses 12A and one of the two pressing portions 14A are formed on one side of the plate, while the other central recess 12B and the other pressing portion 14B are formed on the other side of the plate. A filter cloth 18A is provided to cover the inner wall of one central recess 12A, and a filter cloth 18B is provided to cover the inner wall of the other central recess 12B. A drainage channel 28 leading to the outside of the filter plate 10 is provided on the back side of the filter cloth 18 in both the central recess 12A and the other central recess 12B. Due to this configuration, as shown in Figure 2, when the filter plates 10 are stacked in a configuration where one side of one filter plate 10 and the other side of the other filter plate 10 are pressing against each other, a filter chamber 40 is formed between the central recess 12A of one of the filter plates 10 and the other central recess 12B of the other filter plate 10 (specifically, between the two filter cloths 18A and 18B that cover their inner walls). When slurry (mud, etc.) flows into the filter chamber 40 from the holes 16 under high pressure, the area on the peripheral side of the filter chamber 40 is sealed with increased airtightness, thus reliably preventing leakage or blowout of slurry from the peripheral side. With leakage from the peripheral side reliably suppressed in this way, the water in the slurry supplied into the filter chamber 40 is guided through the filter cloths 18A and 18B to the drainage channels 28A and 28B, while the solid matter in the slurry (particles that cannot pass through the filter cloths 18A and 18B) remains in the filter chamber 40, thus separating the water from the solid matter using the filter cloths 18A and 18B. The water in the slurry that has passed through the filter cloths 18A and 18B can be discharged to the outside of the filter plate 10 via the drainage channels 28A and 28B, and the solid matter that cannot pass through the filter cloths 18A and 18B remains in the area of ​​the filter chamber 40, forming a dewatered cake.

[0057] Furthermore, in the filter plate structure 3 shown in Figure 1, etc., since the annular protrusion 24 is made of an elastic material, when the annular protrusion 24 is inserted into the annular recess 34 and pressed, it can deform to match the shape of the area around the annular recess 34, thereby further improving the adhesion between the annular protrusion 24 and the annular recess 34.

[0058] Furthermore, in the filter plate structure 3, as shown in Figures 1 and 7, the annular protrusion 24 is hollow with a void 24A formed inside. The void 24A extends in the direction in which the annular protrusion 24 extends and is arranged in a ring around the central recess 12. This configuration makes the annular protrusion 24 more elastically deformable and further improves the adhesion between the annular protrusion 24 and the annular recess 34.

[0059] As shown in Figures 1, 2, 3, and 5, the filter plate 10 has a pair of annular plate portions 15A and 15B fixed in one central recess 12A and the other central recess 12B of the substrate portion 11, respectively. The annular plate portions 15A and 15B have through-hole side projections 17A and 17B that protrude in the thickness direction of the filter plate 10. A hole 16 is formed so as to communicate from the side of one annular plate portion 15A to the side of the other annular plate portion 15B, as shown in Figure 2. When one side of one filter plate 10 and the other side of the other filter plate 10 are stacked and pressed against each other, the through-hole side projection 17A on one side of the filter plate 10 and the through-hole side projection 17B on the other side of the other filter plate 10 are positioned close to each other and facing each other. With this configuration, even if one filter plate 10 attempts to bend and deform toward the other filter plate 10 due to, for example, the inflow of a solid-liquid mixture at high pressure, the through-hole side projections 17A and 17B come into contact with each other, suppressing the bending deformation. Therefore, it becomes easier to more effectively prevent situations in which the annular protrusion 24 of one filter plate 10 comes out of the annular recess 34 of the other filter plate 10 due to the large deformation of the filter plate 10. In particular, the vicinity of the hole 16 is a part where the displacement is large when the filter plate 10 bends and deforms, but with the above configuration, the displacement of this part can be restricted, so the effect of suppressing the bending deformation of the filter plate 10 becomes extremely high.

[0060] The through-hole side projection 17 has a tapered shape that becomes narrower as it approaches the tip, and the through-hole side projection 17A on one side of one filter plate 10 and the through-hole side projection 17B on the other side of the other filter plate 10 are configured so that their narrowest parts, the tips, face each other. With this configuration, it is possible to suppress the bending deformation of the filter plate 10 while suppressing the reduction in the volume of solid matter (cake) remaining in the filter chamber.

[0061] In each of the central recesses 12A and 12B of the filter plate 10, drainage plates 13 (one drainage plate 13A and the other drainage plate 13B) are provided on the inner wall portion at the deepest part in the depth direction, with multiple holes formed in the thickness direction. On the base portion 11, a plate-like body 11A is provided on the inside of each drainage plate 13 in the thickness direction (the thickness direction of the filter plate 10), and both sides in the thickness direction are covered by each drainage plate 13. Between each drainage plate 13 (one drainage plate 13A and the other drainage plate 13B) and the plate-like body 11A, drainage channels 28A and 28B leading to the outside of the filter plate 10 are formed, respectively. Furthermore, within one central recess 12A and the other central recess 12B, drain plate side projections 19 (one drain plate side projection 19A and the other drain plate side projection 19B) are formed, respectively, that protrude in the thickness direction from each drain plate 13. As shown in Figure 2, when one side of one filter plate 10 and the other side of the other filter plate 10 are stacked so as to press against each other, the drain plate side projection 19A on one side of the one filter plate 10 and the drain plate side projection 19B on the other side of the other filter plate 10 are configured to face each other. With this configuration, for example, even if one filter plate 10 tries to bend and deform toward the other filter plate 10 due to the inflow of a solid-liquid mixture at high pressure, the drain plate side projections 19 come into contact with each other, suppressing the bending deformation. Therefore, it becomes easier to more effectively prevent situations in which the annular protrusion 24 of one filter plate 10 comes off the annular recess 34 of the other filter plate 10 due to significant deformation of the filter plate 10.

[0062] The drain plate side projection 19 has a tapered shape that becomes narrower as it approaches the tip, and the drain plate side projection 19A on one side of one filter plate 10 and the drain plate side projection 19B on the other side of the other filter plate 10 are configured so that their narrowest parts, the tips, face each other. With this configuration, it is possible to suppress the bending deformation of the filter plate 10 while suppressing the reduction in the volume of solid matter (cake) remaining in the filter chamber. Moreover, if the tip is narrowed, the pressure received from the solid-liquid mixture is reduced at the relatively narrow tip side of the drain plate side projection 19, and a strong connection with the base side can be ensured at the relatively thicker base end side.

[0063] In the filter press apparatus 1, the holding device 50 can hold a plurality of filter plates 10 in a stacked state, with the annular protrusion 24 of one filter plate 10 fitting into the annular recess 34 of the other filter plate 10 and pressing against the annular recess 34, and the opposing portion 22 of one filter plate 10 and the opposing portion 32 of the other filter plate 10 pressing against each other. Furthermore, the second injection device 70 can inject a solid-liquid mixture 7 into the interior of the plurality of filter plates 10 from a hole 16 of a filter plate 10 at one end of the filter plate group 5 when the filter plate group 5 consisting of a plurality of filter plates 10 is held in the first holding state by the holding device 50, and can also inject air into the interior of the plurality of filter plates 10 from a hole 16 at the other end of the filter plate group 5 opposite to the one end when the filter plate group 5 is held in the first holding state. With this configuration, when the filter plate group 5 is held in the first holding state (when the annular protrusion 24 of one filter plate 10 fits into the annular recess 34 of the other filter plate 10 between adjacent filter plates, thereby enhancing the packing effect), it is possible to inject a solid-liquid mixture 7 to form a cake between the filter plates. In addition, when the filter plate group 5 is held in the first holding state, it is also possible to inject air to allow air to flow inside the filter plate group 5. If the annular protrusion 24 of one filter plate 10 fits into the annular recess 34 of the other filter plate 10 between adjacent filter plates, thereby enhancing the packing effect, it is possible to reliably prevent air from leaking from a predetermined position on the periphery of each filter plate 10 (the position where the packing effect described above is obtained) when air is allowed to flow inside the filter plate group 5.

[0064] The filter press apparatus 1 further includes a first switching unit 81 that switches between a first stop state, which stops the inflow and outflow of fluid at one end of the filter plate group 5, and a first release state, which releases the first stop state; and a second switching unit 82 that switches between a second stop state, which stops the inflow and outflow of fluid at the other end of the filter plate group 5, and a second release state, which releases the second stop state. Then, while the holding device 50 is holding in the first holding state, the second switching unit 82 switches to the second stop state and the first injection device 60 injects the solid-liquid mixture 7 into the filter plate group 5. After the injection of the solid-liquid mixture 7 by the first injection device 60, while the holding device 50 is holding in the first holding state, the first switching unit 81 switches to the first stop state and the second injection device 70 injects air into the filter plate group 5, causing the air to flow from the hole 16 side at the other end to the drainage channel 28 side of each filter plate 10, and the liquid of the solid-liquid mixture 7 present inside the filter plate group 5 is discharged to the outside of the filter plate group 5 via the drainage channel 28 along with the air.

[0065] With this configuration, not only is the solid-liquid mixture 7 drained from the drain channel by being injected at high pressure, but the forced drainage effect by passing air through the solid-liquid mixture 7 is also taken into account, making it possible to form a cake with a lower moisture content. However, when passing air through the solid-liquid mixture 7 in this way, it is necessary to supply air at extremely high pressure, so if the packing effect near the periphery between adjacent filter plates is weak, there is a risk that the solid-liquid mixture 7 will leak out from the periphery between adjacent filter plates along with the air. However, in this configuration, the feature that "the annular protrusion 24 of one filter plate 10 fits into the annular recess 34 of the other filter plate 10 between adjacent filter plates to enhance the packing effect" and the feature that "the liquid of the solid-liquid mixture 7 present inside the filter plate group 5 is discharged to the outside of the filter plate group 5 via the drain channel 28 along with the air" work synergistically, making it possible to form a cake with a lower moisture content while suppressing the leakage of air and solid-liquid mixture 7 from the periphery of the filter plates 10.

[0066] The filter press device 1 may include a pair of guide rails 90 that guide the movement direction of each filter plate 10 so that the movement direction of each filter plate 10 is in the thickness direction when the filter plates 10 are arranged in the thickness direction of each filter plate 10, and a pair of restricting parts 94 that are positioned above each of the pair of guide rails 90. The filter press device is configured such that each of the pair of guide rails 90 is positioned opposite to both sides of each filter plate 10 and extends along the thickness direction. The pair of restricting parts 94 is positioned opposite to both sides of each filter plate 10 at a position above the vertical center position of each filter plate 10 and extends along the thickness direction. In this way, if a pair of restricting parts 94 are arranged opposite each other on both sides of each filter plate 10, and each pair of restricting parts 94 is provided so as to extend in the thickness direction of each filter plate 10 (the direction of movement of each filter plate 10), and if these restricting parts 94 are provided at a position above the vertical center position of each filter plate 10, then when a discharge operation is performed to drop the cake 7A downwards by injecting a solid-liquid mixture 7 with multiple filter plates 10 in contact, and then changing from the state in Figure 19(A) to the state in Figure 19(B) to increase the distance between adjacent filter plates, even if the discharged cake tries to fall sideways while tilting as shown in Figure 18(B), the pair of restricting parts 94A and 94B can restrict the tilt and lateral movement of the cake, allowing it to fall downwards. If such restricting parts 94A and 94B are not present, there is a risk that the cake will fall onto the upper surface of the guide rail 90, as shown in Figure 18(A).

[0067] <Second Embodiment> Next, a second embodiment will be described with reference to the drawings. These drawings are used to illustrate the technical features that the present invention may adopt. Unless otherwise specified, the structures of the devices described below are not intended to be the sole limiting factors, but are merely illustrative examples.

[0068] The filter plate structure 203 of the second embodiment of the filter press apparatus shown in Figure 20 (hereinafter also referred to as filter plate structure 203) is a filter plate structure used in the double-type filter press apparatus 201 shown in Figure 28. As shown in Figure 28, the filter plate structure 203 includes an element group 205 which has a plurality of filter plate sections 208 and a filter plate section group 206 in which each filter plate section 208 is an element, and a frame group 207 which has a plurality of frame bodies (adhesion sections 209) and a frame body group 207 in which each frame body (adhesion section 209) is an element. In this element group 205, the elements that constitute the filter plate section group 206 (filter plate sections 208) and the elements that constitute the frame group 207 (adhesion sections 209) are arranged alternately.

[0069] As shown in Figure 28, each filter plate portion 208 constituting the filter plate group 206 has the same configuration as each filter plate portion 8 of the filter plate structure 3 of the first embodiment (Figures 1, 10, etc.), except for a few parts. Specifically, it has the configuration shown in Figure 20, and is the same configuration as the filter plate portion 8 shown in Figure 1, etc., except that an annular protrusion (first sealing portion 224B) is provided in place of the annular recess 34 in the filter plate portion 8 shown in Figure 1, etc. In other words, the substrate portion 211 has the same configuration as the substrate portion 11 shown in Figure 1, etc., except that an annular protrusion (first sealing portion 224B) is provided in place of the annular recess 34 in the filter plate portion 8. As shown in Figure 20, the filter cloth 218 has the same configuration as the filter cloth 18 of the filter plate portion 8 shown in Figure 1, etc. As shown in Figure 20, in the substrate portion 211, the plate-like body 211A has the same configuration as the plate-like body 11A of the filter plate portion 8 shown in Figure 1, etc. As shown in Figure 20, recessed portion 212A has the same structure as recessed portion 8A of the filter plate portion 8 shown in Figure 1, etc., and recessed portion 212B has the same structure as recessed portion 8B of the filter plate portion 8 shown in Figure 1, etc. As shown in Figure 20, first pressing portion 214A has the same structure as first pressing portion 8C of the filter plate portion 8 shown in Figure 1, etc., and first pressing portion 214B has the same structure as first pressing portion 8D of the filter plate portion 8 shown in Figure 1, etc. As shown in Figure 20, first opposing portion 222A has the same structure as first opposing portion 8E of the filter plate portion 8 shown in Figure 1, etc., and first opposing portion 222B has the same structure as first opposing portion 8F of the filter plate portion 8. As shown in Figure 20, the first seal portion 224A has the same structure as the annular projection 24 (first seal portion 8G) of the filter plate portion 8 shown in Figure 1, etc., and the first seal portion 224B has the same structure as the annular projection 24 of the filter plate portion 8 and the first seal portion 224A shown in Figure 1, etc. As shown in Figure 20, the drain plate side projections 219A and 219B each have the same structure as the drain plate side projections 19A and 19B of the filter plate portion 8 shown in Figure 1, etc. As shown in Figure 20, the annular plate portions 215A and 215B each have the same structure as the annular plate portions 15A and 15B of the filter plate portion 8 shown in Figure 1, etc. As shown in Figure 20, the through-hole side projections 217A and 217B each have the same structure as the through-hole side projections 17A and 17B of the filter plate portion 8 shown in Figure 1, etc. As shown in Figure 20, the hole 216 has the same structure as the hole 16 in the filter plate section 8 shown in Figure 1, etc.As shown in Figure 20, each of the drain plates 213A and 213B has the same structure as each of the drain plates 13A and 13B in the filter plate section 8 shown in Figure 1, etc. As shown in Figure 20, the drain channels 228A and 228B have the same configuration as each of the drain channels 28A and 28B in the filter plate section 8 shown in Figure 10, etc. The protruding sections 241 and 242 shown in Figure 22, etc. have the same configuration as the protruding sections 41 and 42 shown in Figure 17, etc., and in Figure 22, etc., the protruding sections 241 and 242 are shown in a simplified manner.

[0070] As shown in Figure 20, the filter plate structure 203 of the second embodiment comprises a filter plate portion 208 having a plate-shaped substrate portion 211, and a contact portion 209 which is positioned opposite the filter plate portion 208 and is configured as a frame-shaped portion of a different type from the filter plate portion 208, with a housing space configured inside. When the contact portion 209 is in a contacted position, the filter chamber 240 (Figures 21 and 28) is formed by the filter plate portion 208 and the contact portion 209. The contact portion 209 consists of a frame with a through-opening (housing portion 242), and is configured to switch between a contacted position (Figure 21) where it is in close contact with the filter plate portion 208 and an open position (Figure 20) where it is displaced from the filter plate portion 208.

[0071] As shown in Figures 20, 21, 23, and 25, the substrate portion 211 has recessed portions 212A and 212B, first pressing portions 214A and 214B, and a hole portion 216. Recessed portion 212A is a recess that constitutes part of the filter chamber 240 when in a tight-fitting state as shown in Figure 21, and is formed on the outer surface of the substrate portion 211 on the side facing the contact portion 209 (specifically, the side facing the contact portion 209 that recessed portion 212A faces). Recessed portion 212B is also a recess that constitutes part of the filter chamber 240 when in a tight-fitting state as shown in Figure 28, and is formed on the outer surface of the substrate portion 211 on the side facing the contact portion 209 (specifically, the side facing the contact portion 209 that recessed portion 212B faces). The first pressing portion 214A is a portion that surrounds the recessed portion 212A on the outer surface of the substrate portion 211 on the side facing the contact portion 209 (specifically, the side facing the recessed portion 209 that the recessed portion 212A faces). The first pressing portion 214A is a portion that surrounds the recessed portion 212B on the outer surface of the substrate portion 211 on the side facing the contact portion 209 (specifically, the side facing the recessed portion 209 that the recessed portion 212B faces). The hole portion 216 is a through hole formed in the thickness direction of the substrate portion 211 so as to penetrate the substrate portion 211, and is a portion that serves as a flow path that passes through the inside of the substrate portion 211 and continues to the recessed portions 212A and 212B.

[0072] As shown in Figure 23, the first pressing portion 214A comprises a first opposing portion 222A positioned around the recessed portion 212A, the surface of which faces the second pressing portion when in contact, and a first sealing portion 224A positioned around the recessed portion 212A, the surface of which protrudes from the surface of the first opposing portion 222A. The surface of the first opposing portion 222A is a flat surface along a planar direction perpendicular to the thickness direction of the substrate portion 211, and the first sealing portion 224A is configured to protrude from the surface of the first opposing portion 222A and is an annular and rib-shaped protrusion that surrounds the recessed portion 212A. The recessed portion 212A is a portion that is recessed in the thickness direction compared to the surface of the first opposing portion 222A.

[0073] As shown in Figure 25, the first pressing portion 214B comprises a first opposing portion 222B positioned around the recessed portion 212B, the surface of which faces the second pressing portion 244A when in contact, and a first sealing portion 224B positioned around the recessed portion 212B, the sealing portion 224B being convex from the surface of the first opposing portion 222B. The surface of the first opposing portion 222B is a flat surface along a planar direction perpendicular to the thickness direction of the substrate portion 211, and the first sealing portion 224B is configured to protrude from the surface of the first opposing portion 222B and is an annular and rib-shaped convex portion that surrounds the recessed portion 212B. The recessed portion 212B is a portion that is recessed in the thickness direction compared to the surface of the first opposing portion 222B.

[0074] Thus, the substrate portion 211 has recessed portions 212A, 212B and first pressing portions 214A, 214B formed on both sides in the thickness direction of the substrate portion, and the first opposing portions 222A, 222B and the first sealing portions 224A, 224B are arranged so as to surround the recessed portions 212A, 212B in each of the first pressing portions 214A, 214B.

[0075] The filter cloth 218 described above has the same configuration as the filter cloth 18 of the filter plate portion 8 shown in Figure 1, etc. Specifically, the filter cloth 218 has a filter cloth 218A which has the same configuration as the filter cloth 18A of the filter plate portion 8 shown in Figure 1, etc., and a filter cloth 218B which has the same configuration as the filter cloth 18B of the filter plate portion 8 shown in Figure 1, etc. As shown in Figure 22, the filter cloth 218A is configured to cover the substrate portion 211 so as to span the recessed portion 212A and the first sealing portion 224A, and as shown in Figure 24, the filter cloth 218B is configured to cover the substrate portion 211 so as to span the recessed portion 212B and the first sealing portion 224B. More specifically, it is positioned across the recessed portion 212A and the first pressing portion 214A so as to cover the entire outer region of the annular plate portion 215A in the recessed portion 212A and the entire first pressing portion 214A. Note that in Figure 21, the filter cloth 218 is omitted.

[0076] The contact portion 209 comprises a perforated housing portion 242 and second pressing portions 244A and 244B that press the first pressing portions 214B and 214A, respectively, when in contact, and is configured as a plate-shaped frame. The housing portion 242 is configured as an opening (perforation) that penetrates the thickness direction of the contact portion 209 (frame), and together with the recessed portions 212A and 212B, it constitutes the filter chamber 240 when in contact as shown in Figure 21.

[0077] As shown in Figure 26, the second pressing portion 244A is a portion arranged around the housing portion 242 on one side in the thickness direction of the contact portion 209, and is the portion that presses the first pressing portion 214B when in the contact state as shown in Figure 21. The second pressing portion 244A is arranged around the housing portion 242 and comprises a second opposing portion 252A whose surface faces the first pressing portion 214B when in the contact state as shown in Figure 21, and a second sealing portion 234A arranged around the housing portion 242, which is recessed from the surface of the second opposing portion 252A, and presses against the first sealing portion 224B when in the contact state. The surface of the second opposing portion 252A is a flat surface along a planar direction perpendicular to the thickness direction of the contact portion 209, and the second sealing portion 234A is configured to be recessed from the surface of the second opposing portion 252A and is an annular recess (annular groove portion) arranged in a groove shape to surround the housing portion 242.

[0078] As shown in Figure 27, the second pressing portion 244B is a portion arranged around the housing portion 242 on the other side in the thickness direction of the contact portion 209, and is the portion that presses the first pressing portion 214A when in the contact state as shown in Figure 21. The second pressing portion 244B is arranged around the housing portion 242 and comprises a second opposing portion 252B whose surface faces the first pressing portion 214A when in the contact state as shown in Figure 21, and a second sealing portion 234B arranged around the housing portion 242, which is recessed from the surface of the second opposing portion 252B and presses against the first sealing portion 224A when in the contact state. The surface of the second opposing portion 252B is a flat surface along a planar direction perpendicular to the thickness direction of the contact portion 209, and the second sealing portion 234B is configured to be recessed from the surface of the second opposing portion 252B and is an annular recess (annular groove portion) arranged in a groove shape to surround the housing portion 242.

[0079] Thus, the contact portion 209 (frame) has second pressing portions 244A and 244B formed on both sides in the thickness direction of itself, and in each of the second pressing portions 244A and 244B, the second opposing portions 252A and 252B and the second sealing portions 234A and 234B are arranged to surround the housing portion 242.

[0080] Furthermore, the contact section 209 is equipped with a plurality of support sections 260. The support sections 260 are configured in a linear or rod shape and are fixed at both ends in a manner that spans the opening area of ​​the housing section 242 (opening). The support sections 260 can be made of, for example, piano wire, wire, metal rod, etc.

[0081] Furthermore, the contact portion 209 is also provided with protruding portions 271 and 272 similar to those described above.

[0082] In the filter plate structure 203 configured in this way, the elements constituting the element group 205 can move closer together and further apart using the same apparatus as in the first embodiment. In adjacent pairs of elements in the element group 205 (i.e., adjacent pairs of filter plate portions 208 and contact portions 209), the first sealing portion is configured as a convex portion and the second sealing portion is configured as a concave portion. When the filter plate portion 8 and the contact portion 9 are in close contact, the convex portion of each pair of elements presses against the inner surface of the concave portion.

[0083] Specifically, in each "combination of elements" where the first pressing portion 214A and the second pressing portion 244B press against each other, the first sealing portion 224A is configured as a convex portion and the second sealing portion 234B is configured as a concave portion, and in the state of close contact, the first sealing portion 224A (convex portion) presses against the inner surface of the second sealing portion 234B (concave portion) in each "combination of elements". More specifically, in the state of close contact, with the filter cloth 218 sandwiched between the first sealing portion 224A (convex portion) and the second sealing portion 234B (concave portion), the first sealing portion 224A (convex portion) enters into the second sealing portion 234B (concave portion) and presses against the inner surface of the second sealing portion 234B (concave portion). Furthermore, in this "combination of elements," when in the aforementioned close contact state, the filter cloth 218 is interposed between the surface of the first opposing part 222A and the surface of the second opposing part 252B, and the first opposing part 222A presses against the second opposing part 252B with the filter cloth 218 in between.

[0084] Similarly, in each "set of elements" where the first pressing portion 214B and the second pressing portion 244A press against each other, the first sealing portion 224B is configured as a convex portion and the second sealing portion 234A is configured as a concave portion, and in the state of close contact, the first sealing portion 224B (convex portion) presses against the inner surface of the second sealing portion 234A (concave portion) in each "set of elements". More specifically, in the state of close contact, with the filter cloth 218 sandwiched between the first sealing portion 224B (convex portion) and the second sealing portion 234A (concave portion), the first sealing portion 224B (convex portion) enters into the second sealing portion 234A (concave portion) and presses against the inner surface of the second sealing portion 234A (concave portion). Furthermore, in this "combination of elements," when in the aforementioned close contact state, the filter cloth 218 is interposed between the surface of the first opposing part 222B and the surface of the second opposing part 252A, and the first opposing part 222B presses against the second opposing part 252A with the filter cloth 218 in between.

[0085] The holding device 50 shown in Figure 29 has the same configuration as the first embodiment and can hold the filter plate portion 208 and the adhesive portion 209 in an overlapping state in which the convex portion of the first seal portion and the second seal portion press against the inner surface of the recess. Specifically, in each "set of elements", the device holds multiple filter plate portions 208 and multiple adhesive portions 209 (frames) in an overlapping state in which multiple filter plate portions 208 and multiple adhesive portions 209 (frames) are overlapped in which the convex portion of the first seal portion and the second seal portion press against the inner surface of the recess.

[0086] The first injection device 60 (injection device) has the same configuration as the first embodiment, and as shown in Figures 28 and 29, when the holding device 50 holds the filter plate portion 208 and the contact portion 209 in an overlapping state, it injects the solid-liquid mixture 7 into the recessed portions 212A and 212B and the housing portion 242 through the hole portion 216. Specifically, when the holding device 50 holds multiple filter plate portions 208 and multiple contact portions 209 (frames) in an overlapping state, the first injection device 60 injects the solid-liquid mixture 7 into the recessed portions 212A and 212B and the housing portion 242 of each set of elements.

[0087] The holding device 50 functions as both an approaching and separating device, and can change the state between a state where the filter plate portion 208 and the contact portion 209 are separated, as shown in Figure 20, and a state where the filter plate portion 208 and the contact portion 209 are in contact, as shown in Figure 21. The holding device 50, functioning as a separating device, separates the filter plate portion 208 and the contact portion 209, as shown in Figure 20, after the first injection device 60 (injection device) has injected the solid-liquid mixture 7, as shown in Figure 28. Specifically, it separates the filter plate portions 208 adjacent to each contact portion 209 (frame) on both sides of each contact portion 209 (frame).

[0088] Furthermore, the holding device 50 functions as an example of a tilting device, and with the separating device separating the filter plate portion 208 and the contact portion 209 as shown in Figure 20, the contact portion 209 is tilted more than when it is in a contact state, as shown in Figures 30 and 31. This allows for good discharge of the cake. Note that the second seal portion is omitted in Figure 31.

[0089] As shown in Figure 32, the cleaning device 280 includes a water discharge unit 282 equipped with water outlets (multiple holes) for discharging cleaning water, a water supply device 284 for supplying cleaning water to the water outlets of the water discharge unit 282, and a moving device 286 for moving the water discharge unit 282.

[0090] When the holding device 50 (separation device) is in a separated state, separating any of the contact portion 209 (frame) from the filter plate portions 208 adjacent to both sides of the contact portion 209 (frame), the moving device 286 moves (moves up and down) the water discharge portion 282 between the separated filter plate portions 208 on both sides, as shown in Figure 32. Specifically, when the tilting device is in a predetermined tilted state with the contact portion 209 tilted as shown in Figure 32, the moving device 286 moves the water discharge portion 282 to a position where the cleaning water discharged from the water outlet passes through the housing portion 242 (opening) and hits the filter plate portion 208. More specifically, when the tilting device is tilting the contact portion 209, the moving device 286 moves at least a part of the water discharge portion 282 into the housing portion 242 (opening).

[0091] In this manner, the cleaning device 280 sprays cleaning water onto the separated filter plate sections 208 on both sides using a water discharge section located between the separated filter plate sections 208.

[0092] <Modification 1 of the second embodiment> As shown in Figure 34, the contact portion 209 (frame) may have one end fixed to the inner edge side of the housing portion 242 (opening) and the other end having an extension that extends linearly or rod-shaped toward the inside of the opening.

[0093] <Modification 2 of the second embodiment> As shown in Figure 35, the contact portion 209 (frame) may have an extension portion 262 at one end fixed to the inner edge side of the housing portion 242 (opening) and the other end extending linearly or rod-shaped toward the inside of the opening, and a mounting portion 260 similar to that of the second embodiment.

[0094] <Third Embodiment> Figures 36 to 38 illustrate the filter plate structure 303 of the third embodiment. The filter plate structure 303 of the third embodiment differs from the filter plate structure 203 of the second embodiment in that the filter plate portion 208 is changed to a filter plate portion 8 and the contact portion 209 is changed to a contact portion 309. The filter plate structure 303 is a filter plate structure used in a double-type filter press device. The filter press device having the filter plate structure 303 is the same as the filter press device 201 of the second embodiment, except that the filter plate structure 203 is changed to the filter plate structure 303.

[0095] The filter plate structure 303 comprises an element group having multiple filter plate sections 8, each of which is an element of the filter plate section 308, and a frame group having multiple contact sections 309 (frames), each of which is an element of the frame group. The element group is arranged with elements constituting the filter plate section group (filter plate sections 8) and elements constituting the frame group (contact sections 309) arranged alternately. Although only two elements of the filter plate section group are shown in Figures 36 to 38, in reality, many elements (filter plate sections 8) of the same structure are arranged. Similarly, although only one element (contact section 309) of the frame group is shown, in reality, many elements of the same structure are arranged.

[0096] Each filter plate portion 8 has the same structure as the filter plate portion 8 in the filter plate structure 3 of the first embodiment. Therefore, in the following description, for the filter plate portions 8 constituting the filter plate structure 303, parts that are the same as the filter plate portion 8 shown in Figure 1, etc., will be denoted by the same reference numerals as the filter plate portion 8 in Figure 1, and detailed explanations will be omitted.

[0097] The filter plate structure 303 comprises a filter plate portion 8 having a plate-shaped substrate portion 11, and a contact portion 309 positioned opposite the filter plate portion 8 and configured as a frame-shaped portion of a different type from the filter plate portion 8. The contact portion 309 is configured to switch between a contact position (Figure 37) where its relative position to the filter plate portion 8 is in close contact with the filter plate portion 8 and an open position (Figures 36 and 38) where it is displaced from the filter plate portion 8, and a housing space is formed inside. In this filter plate structure 303, as shown in Figure 37, when the contact portion 309 is in the contact position, the filter chamber 340 is formed by the filter plate portion 8 and the contact portion 309.

[0098] The filter plate portion 8 has the same configuration as the filter plate portion 8 of the first embodiment. The substrate portion 11 includes a central recess 12A (recess) and a pressing portion 14A (first pressing portion). The central recess 12A (recess) is formed on the outer surface of the substrate portion 11 on the side of the contact portion 309 so as to be recessed in the thickness direction of the substrate portion 11, and as shown in Figure 37, it constitutes a part of the filter chamber 340. The pressing portion 14A (first pressing portion) is arranged on the outer surface of the substrate portion 11 on the side of the contact portion 309 so as to surround the central recess 12A (recess), and as shown in Figure 37, it presses the contact portion 309 when in contact. The hole 16 is a through hole that passes through the inside of the substrate portion 11 and serves as a flow path leading to the central recess 12A (recess). Similarly, the substrate portion 11 includes a central recess 12B (recess) and a pressing portion 14B (first pressing portion). The central recess 12B (recess) is formed on the outer surface of the substrate portion 11 on the side facing the contact portion 309, recessed in the thickness direction of the substrate portion 11, and constitutes part of the filter chamber. The pressing portion 14B (first pressing portion) is positioned on the outer surface of the substrate portion 11 on the side facing the contact portion 309, surrounding the central recess 12B (recess), and presses the contact portion 309 when in contact. The hole 16 is a through hole that passes through the inside of the substrate portion 11 and serves as a flow path leading to the central recess 12A (recess).

[0099] The contact portion 309 consists of a frame having a through-hole, which is the housing portion 342. The housing portion 342 is perforated and, when in contact, forms the filter chamber 340 together with the central recesses 12A and 12B (recessed portions). Furthermore, the contact portion 309 has second pressing portions 344A and 344B. The second pressing portion 344A is positioned around the housing portion 342 and presses the pressing portion 14B (first pressing portion) when in contact as shown in Figure 37. The second pressing portion 344B is positioned around the housing portion 342 and presses the pressing portion 14A (first pressing portion) when in contact as shown in Figure 37.

[0100] The first pressing portion 14A comprises an opposing portion 22A (first opposing portion) positioned around the central recess 12A (recess) and whose surface faces the second pressing portion 344B when in close contact, and an annular projection 24 (first sealing portion) positioned around the central recess 12A (recess) and convex from the surface of the opposing portion 22A (first opposing portion). The first pressing portion 14B comprises an opposing portion 22B (first opposing portion) positioned around the central recess 12B (recess) and whose surface faces the second pressing portion 344A when in close contact, and an annular recess 34 (first sealing portion) positioned around the central recess 12B (recess) and concave from the surface of the opposing portion 22B (first opposing portion).

[0101] The second pressing portion 344A is arranged around the housing portion 342 and comprises a second opposing portion 352A whose surface faces the first pressing portion 14B when in close contact, and a second sealing portion 334A (annular protrusion) which is arranged around the housing portion 342, protrudes from the surface of the second opposing portion 352A, and presses against the annular recess 34 (first sealing portion) when in close contact. The second pressing portion 344B is arranged around the housing portion 342 and comprises a second opposing portion 352B whose surface faces the first pressing portion 14A when in close contact, and a second sealing portion 334B (annular recess) which is arranged around the housing portion 342, concave from the surface of the second opposing portion 352B, and presses against the annular protrusion 24 (first sealing portion) when in close contact.

[0102] In the configuration shown in Figures 36 to 38, the first and second sealing portions press against each other when in close contact. One sealing portion has a convex portion that protrudes toward the other sealing portion when in close contact and is positioned to surround the filter chamber, while the other sealing portion has a concave portion that recesses toward the opposite side of the first sealing portion when in close contact and is positioned to surround the filter chamber. When in close contact, the convex portion and the covering portion covering the convex portion enter into the concave portion and press against the inner surface of the concave portion.

[0103] For example, in the annular projection 24 (first seal portion) and the second seal portion 334B that press against each other when in close contact, the annular projection 24 (first seal portion), which is one of the seal portions, has a projection that, when in close contact, protrudes toward the other seal portion side (the second seal portion 334B side) and is positioned to surround the filter chamber 340. The other seal portion, the second seal portion 334B, has a recess that, when in close contact, is recessed toward the opposite side from the first seal portion (annular projection 24) and is positioned to surround the filter chamber 340. When in close contact, the annular projection 24 (first seal portion) and the covering portion (filter cloth 18) covering the annular projection 24 (first seal portion) enter into the recess (second seal portion 334B) and press against the inner surface of the recess (second seal portion 334B).

[0104] Furthermore, in the annular recess 34 (first seal portion) and the second seal portion 334A, which press against each other when in close contact, the second seal portion 334A, which is one of the seal portions, has a protrusion that, when in close contact, protrudes toward the other seal portion (towards the annular recess 34) and is positioned to surround the filter chamber 340. The annular recess 34 (first seal portion), which is the other seal portion, has a recess that, when in close contact, is recessed toward the opposite side from the first seal portion (second seal portion 334A) and is positioned to surround the filter chamber 340. When in close contact, the protrusion (second seal portion 334A) enters into the recess (the annular recess 34, which is the first seal portion) and presses against the inner surface of the recess (annular recess 34).

[0105] <Example of changes> The following configuration is also acceptable. The modified filter plate structure can also be configured to include a filter plate portion having a plate-shaped substrate portion, a contact portion positioned opposite the filter plate portion and whose relative position to the filter plate portion switches between a contact position in close contact with the filter plate portion and an open position away from the filter plate portion, and a filter cloth. This filter plate structure can also be configured such that a filter chamber is formed by the filter plate portion and the contact portion when the contact portion is in the contact position. In this filter plate structure as well, the substrate portion has an annular first pressing portion that presses the contact portion around the space of the filter chamber when in the contact state, and the contact portion has an annular second pressing portion that presses the first pressing portion around the space of the filter chamber when in the contact state. In this filter plate structure as well, either the first pressing portion or the second pressing portion has an opposing portion that faces the other pressing portion, and a recess that is recessed from the opposing portion.

[0106] In the modified filter plate structure, the other pressing portion is covered by a filter cloth. On the other hand, a protrusion is provided in the part of this filter cloth that faces the recess, and both the recess and the protrusion are arranged in an annular shape around the filter chamber when in close contact. When in close contact, the annular protrusion seals by directly or indirectly pressing against the annular recess through other members.

[0107] Specifically, this modification can be applied to any of the configurations of the first to third embodiments, or to any of the other embodiments described later, and more specifically, by modifying the filter plate portion or the contact portion that has the annular protrusion. For example, the pressing portion of the filter plate portion or the contact portion that has the annular protrusion can be modified so that the portion of the annular protrusion is a flat portion (a flat portion continuous with the surrounding portion) similar to the surrounding portion, and an annular protrusion having a protruding structure similar to the annular protrusion described above can be provided in the filter cloth covering this flat portion, in the portion facing the recess on the other side.

[0108] <Other Embodiments> This disclosure is not limited to the embodiments described above and in the drawings. For example, any combination of the features of the embodiments described above or below is possible as long as it does not contradict each other. Furthermore, any feature of the embodiments described above or below may be omitted unless explicitly stated as essential. In addition, the embodiments described above may be modified as follows.

[0109] In the first embodiment, an example was shown in which one annular projection 24 is provided on one side and one annular recess 34 is provided on the other side. However, two or more (for example, two) annular projections 24 may be provided in multiple layers on one side, and multiple (for example, two) annular recesses 34 corresponding to the annular projections 24 may be provided in multiple layers on the other side.

[0110] In the embodiment described above, the cross-section of the protruding portion of the annular projection 24 (the cross-section cut in a plane perpendicular to the direction in which the annular projection 24 extends) has a curved shape, but the cross-section may be trapezoidal, triangular, or any other shape. Similarly, the cross-section of the recessed portion of the annular recess 34 (the cross-section cut in a plane perpendicular to the direction in which the annular recess 34 extends) has a curved shape, but the cross-section may be trapezoidal, triangular, or any other shape.

[0111] In the embodiment described above, the annular protrusions 24 and annular recesses 34 were arranged in a rectangular frame shape around the central recess 12. However, as long as they are arranged around the recess, the annular protrusions 24 and annular recesses 34 may be circular (structures arranged in a circular shape along a planar direction perpendicular to the thickness direction of the filter plate), elliptical, or any other shape.

[0112] In the embodiment described above, an example was shown in which the pressing portion was arranged in a ring shape close to the recess, but the invention is not limited to such an example. For example, the pressing portion may be arranged in a ring shape outside the recess, at a distance from the recess.

[0113] In the embodiment described above, a filter plate 10 with a rectangular (square) outer edge shape was exemplified, but the outer edge shape of the filter plate may be circular, elliptical, or substantially rectangular, or any other shape. When the outer edge shape of the filter plate is circular, the first pressing portion may be configured as a circular frame along the periphery of the filter plate. The first pressing portion may also be located on the periphery side of the recessed portion, for example, slightly inward from the periphery of the filter plate. The recessed portion may be a recess in the thickness direction on the central side of the filter plate, and the outer edge shape is not limited to a rectangular shape, but may be circular, elliptical, substantially rectangular, or any other shape. The first pressing portion may be provided on the portion that is convex in the thickness direction on the periphery side of the filter plate, and the inner edge shape of the first pressing portion (inner edge shape of the frame) can be a variety of shapes such as circular, elliptical, or substantially rectangular. Similarly, the outer edge shape of the first pressing section (outer edge shape of the frame) can also be a variety of shapes, such as circular, elliptical, or roughly rectangular.

[0114] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is not limited to the embodiments disclosed herein, and is intended to include all modifications within the scope set forth in the claims or equivalents thereof. [Explanation of symbols]

[0115] 1,201,301… Filter press device 3,203,303…Filter plate structure of a filter press device 7…Solid-liquid mixture 8,208...filter plate section 8A, 8B, 212A, 212B... recessed area 8C, 8D, 214A, 214B… First pressing section 8E, 8F, 222A, 222B…1st opposing part 8G, 8H, 224A, 224B…First seal section 9,209… Close-up section 9A, 9B, 242… Storage Units 9C, 9D, 244A, 244B, 344A, 344B… Second pressing section 9E, 9F, 252A, 252B, 352A, 352B… Second Opposite Section 9G, 9H, 234A, 234B, 334A, 334B…Second Seat 11,211…Substrate part 16,216…holes 18,218… filter cloth

Claims

1. A filter plate having a plate-shaped substrate portion, A contact portion is positioned opposite the filter plate portion, and its relative position to the filter plate portion switches between a contact position in close contact with the filter plate portion and an open position away from the filter plate portion, filter cloth and Equipped with, A filter plate structure in a filter press device in which a filter chamber is formed by the filter plate portion and the contact portion when the contact portion is in the contact position, The substrate portion has an annular first pressing portion that presses the contact portion around the space of the filter chamber when in the contact state, The contact portion has an annular second pressing portion that presses the first pressing portion around the space of the filter chamber when in the contact state, Either the first pressing portion or the second pressing portion comprises an opposing portion facing the other pressing portion and a recess that is recessed from the opposing portion, The other pressing portion is covered by the filter cloth, In the aforementioned filter cloth, a protrusion is provided in the portion facing the recess. Both the recess and the protrusion are arranged in an annular shape around the filter chamber when in the state of close contact. When in the aforementioned tightly sealed state, the annular protrusion seals by directly or indirectly pressing against the annular recess via another member. Filter plate structure of a filter press device.

2. The portion of the other pressing portion that is covered by the convex portion is a flat portion. The filter plate structure of the filter press apparatus according to claim 1.

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