Filter plate type filter

Abstract

The invention provides a filter plate type filter which can more effectively inhibit leakage of filtered stock solution and filtrate penetrating through a filtering material and is high in convenience. The filter plate type filter is provided with a plurality of filter plates (an upper filter plate (2a) and a lower filter plate (2b)) which are arranged with a filter material (1) therebetween; a filter chamber (C) formed between the plurality of filter plates (an upper filter plate (2a) and a lower filter plate (2b)); a stock solution introduction path (3) that introduces the stock solution (L1) to be filtered into the filtration chamber (C); a pressure sealing means (4) for applying a sealing pressure to the filter material (1) so as to suppress the leakage of the filtered stock solution and filtrate in the filter chamber (C) to the outside of the filter chamber (C); and a control means (5) for automatically controlling the sealing pressure in accordance with variations in the pressure in the filter chamber (C).

Description

Technical Field

[0001] The present invention relates to preventing leakage of a raw liquid to be filtered (hereinafter referred to as "raw liquid") and a filtrate in a plate filter. Background Art

[0002] Conventionally, there is a plate-type filter in which a plurality of filter plates that are freely openable and closable are pressed and closely contacted with each other via filter media to form a filter chamber, and filtering is performed inside the filter chamber (see, for example, Patent Document 1).

[0003] A multi-stage horizontal plate filter having the above-described structure can automatically and repeatedly perform filtering treatment, and is also called the Schneider method.

[0004] There is also an invention of a pressure filtration device that compresses and filters a concentrate by the pressure of compressed air in a filtration chamber formed by making the lower surface of an upper filter frame closely contact with the upper surface of a frame of a filter plate below via a filter cloth (for example, see Patent Document 2).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2012-24712

[0008] Patent Document 2: Japanese Patent Application No. 2696666 Summary of the invention

[0009] Problems to be solved by the invention

[0010] The plate filter as described above forms a filter chamber by pressing a plurality of filter plates together with filter media interposed therebetween. Therefore, in terms of structure, a gap extending from the inside of the filter chamber to the outside of the filter chamber may be generated on the contact surface between the filter media and the filter plates.

[0011] In this way, the raw liquid supplied to the filter chamber may leak out of the filter chamber through the above-mentioned gap due to its supply pressure.

[0012] Furthermore, the filtrate that has passed through the filter medium may leak out from the filter chamber to the outside of the filter medium through the inside of the filter medium due to the capillary phenomenon generated in the filter medium.

[0013] In order to prevent the above situation, for example, Patent Document 2 discloses a method of fixing a pair of seals to seal the opposing portions where the filter plates and filter frames are in contact with each other via the filter cloths.

[0014] However, when plate-type filtration is actually performed, the pressure in the filter chamber constantly fluctuates, and therefore it is difficult to sufficiently suppress leakage of the raw liquid and the filtrate from the filter chamber using a common sealing method such as a seal.

[0015] The present invention has been made in view of the above-mentioned problems, and the technical problem to be solved is to provide a plate filter which can more effectively suppress leakage of raw liquid and filtrate from the filter chamber and has high convenience.

[0016] Solutions for solving problems

[0017] In order to solve the above-mentioned technical problems, the present invention is a filter plate type filter, which makes a plurality of filter plates that are freely opened and closed be pressed against each other and tightly connected via filter materials to form a filter chamber, and filtering is performed inside the filter chamber, wherein the filter plate type filter comprises: a plurality of filter plates, which are arranged via the filter materials; a filter chamber, which is formed between the filter plates; a raw liquid inlet path, which introduces the raw liquid including the solid components to be filtered into the filter chamber; a pressurized sealing unit, which applies sealing pressure to the filter material, thereby suppressing the raw liquid and filtrate in the filter chamber from leaking out of the filter chamber; and a control unit, which automatically controls the sealing pressure according to the change of the pressure outside the filter chamber.

[0018] In a preferred embodiment of the present invention, the pressure sealing unit applies sealing pressure to the filter material by supplying a sealing fluid to the filter material.

[0019] In a preferred embodiment of the present invention, the pressure sealing unit applies the sealing pressure to the filter material by supplying the sealing fluid to the filter material from a plurality of different directions.

[0020] In a preferred embodiment of the present invention, the pressure sealing unit includes a pressure sealing portion body formed of an elastic body, and the sealing pressure is applied to the filter medium by supplying a sealing fluid to deform the pressure sealing portion body.

[0021] In a preferred embodiment of the present invention, the control unit automatically controls the sealing pressure to suppress leakage of the filtered raw liquid and the filtrate out of the filter chamber.

[0022] In a preferred embodiment of the present invention, the control unit automatically controls the sealing pressure to suppress the sealing fluid supplied to the filter medium from invading the filter chamber.

[0023] In a preferred embodiment of the present invention, the control unit controls the sealing pressure in such a manner that the pressure difference between the internal pressure of the filter chamber and the sealing pressure is maintained at a predetermined pressure difference value.

[0024] In a preferred embodiment of the present invention, the pressurizing sealing unit has a first pressure sensing unit for sensing a first pressure in the raw liquid introduction path, and the control unit controls the sealing pressure based on the pressure in the filter chamber estimated from the first pressure in the raw liquid introduction path.

[0025] In a preferred embodiment of the present invention, the pressurized sealing unit has a fluid supply path for supplying sealing fluid to the filter material and a second pressure sensing unit for sensing a second pressure in the fluid supply path, and the control unit controls the sealing pressure based on the pressure in the filter chamber estimated according to the first pressure in the raw liquid inlet path sensed by the first pressure sensing unit and the second pressure in the fluid supply path sensed by the second pressure sensing unit.

[0026] In a preferred embodiment of the present invention, the filter plate filter comprises a plurality of filter chambers, the raw liquid inlet passage comprises branch inlet passages for respectively introducing the raw liquid into the plurality of filter chambers, the first pressure sensing unit senses a first pressure in the raw liquid inlet passage upstream of a branch point of the branch inlet passage, and the control unit controls the sealing pressure based on the pressure in the filter chamber estimated from the first pressure in the raw liquid inlet passage.

[0027] In a preferred embodiment of the present invention, the pressurized sealing unit has a fluid supply path for supplying sealing fluid to the filter material and a second pressure sensing unit for sensing a second pressure in the fluid supply path, the fluid supply path includes branch supply paths for supplying sealing fluid to a plurality of filter materials respectively arranged in a plurality of filter chambers, the second pressure sensing unit senses the pressure in the fluid supply path upstream of a branch point of the branch supply path, and the control unit controls the sealing pressure based on the first pressure in the stock liquid inlet path and the second pressure in the fluid supply path.

[0028] In a preferred aspect of the present invention, the control unit controls the sealing pressure so as to maintain a pressure difference between a first pressure in the raw liquid introduction path and a second pressure in the fluid supply path at a predetermined pressure difference value.

[0029] In addition, the present invention is a filtering method, which is a filtering method performed using a filter plate filter, wherein the filter plate filter includes a plurality of filter plates arranged with filter media interposed therebetween and filter chambers formed between the filter plates, wherein the filtering method comprises:

[0030] a pressure sealing step of applying sealing pressure to the filter medium; and a pressure control step of automatically controlling the sealing pressure to prevent the raw liquid and filtrate including the filtered solid components introduced into the filter chamber from leaking out of the filter chamber.

[0031] In a preferred embodiment of the present invention, in the pressure sealing step, the sealing pressure is applied to the filter medium by supplying a sealing fluid to the filter medium.

[0032] In a preferred embodiment of the present invention, in the pressure sealing step, the sealing pressure is applied to the filter medium by supplying the sealing fluid to the filter medium from a plurality of different directions.

[0033] In a preferred embodiment of the present invention, in the pressure sealing step, the sealing pressure is applied to the filter medium by supplying a sealing fluid to deform an elastic body.

[0034] In a preferred embodiment of the present invention, in the pressure control step, the sealing pressure is automatically controlled to suppress leakage of the raw liquid and the filtrate to the outside of the filter chamber.

[0035] In a preferred embodiment of the present invention, in the pressure control step, the sealing pressure is automatically controlled so as to suppress the sealing fluid supplied to the filter medium from intruding into the filter chamber.

[0036] Effects of the Invention

[0037] According to the present invention, it is possible to provide a plate filter which can effectively suppress leakage of raw liquid and filtrate from a filter chamber and has high convenience. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a figure which shows the plate filter which concerns on one Embodiment of this invention.

[0039] Figure 2 It is a diagram showing the flow and pressure of the fluid inside the plate filter according to one embodiment of the present invention.

[0040] Figure 3 This is a cross-sectional view of the plate filter taken along the line AA′ according to one embodiment of the present invention.

[0041] Figure 4 It is a cross-sectional view of a plate filter taken along line AA' according to another embodiment of the present invention.

[0042] Figure 5 It is a cross-sectional view of a plate filter according to another embodiment of the present invention.

[0043] Figure 6 It is a cross-sectional view of a plate filter according to another embodiment of the present invention.

[0044] Figure 7 It is a diagram showing the flow and pressure of the fluid inside the plate filter according to another embodiment of the present invention.

[0045] Figure 8 It is a cross-sectional view of a plate filter according to another embodiment of the present invention.

[0046] Fig. 9 This is a perspective view showing an example of the overall structure of a horizontal plate filter.

[0047] Fig.10It is a cross-sectional view of a plate filter taken along line AA' according to another embodiment of the present invention.

[0048] Fig.11 It is a cross-sectional view of a plate filter taken along line AA' according to another embodiment of the present invention. DETAILED DESCRIPTION

[0049] Below, use Figures 1 to 9 A plate filter according to an embodiment of the present invention will be described.

[0050] Fig. 9 This is a perspective view showing an example of the overall structure of a horizontal plate filter.

[0051] Fig. 9 The horizontal filter plate filter 9 shown as an example includes an upper filter plate 92a, multiple intermediate filter plates 92b, 92b, 92b and a lower filter plate 92c, and these upper filter plate 92a, multiple intermediate filter plates 92b, 92b, 92b and lower filter plate 92c are stacked in the upper and lower directions by inserting guide rods (not shown) serving as guide members for upward and downward movement.

[0052] Furthermore, hollow filter chambers (filter chambers) (not shown) are formed between the upper filter plate 92a and the middle filter plate 92b, between the middle filter plates 92b and the middle filter plates 92b, and between the middle filter plate 92b and the lower filter plate 92c.

[0053] The upper filter plate 92a has the function of receiving the original liquid containing the filtered solid components, the lower filter plate 92c has the function of recovering the filtered liquid (filtrate), and the middle filter plates 92b, 92b, 92b have these two functions respectively. These are collectively referred to as the filter plate stack 92.

[0054] Furthermore, a filter medium holder fr is disposed in a space adjacent to the filter plate stack 92, and a plurality of filter medium rollers 91A, 91B, 91C, and 91D are rotatably disposed.

[0055] The filter materials 91a, 91b, 91c, and 91d are wound into rolls on the filter material rollers 91A, 91B, 91C, and 91D, forming a supply device that supplies the filter materials 91a, 91b, 91c, and 91d from one side to the other on the upper surface of each filter plate (middle filter plates 92b, 92b, 92b, and lower filter plate 92c).

[0056] Furthermore, a filter material extractor (Extractor) fe is arranged in a space adjacent to the filter plate stack 92 .

[0057] When the filter medium is replaced, the filter medium 91a, 91b, 91c, 91d is pulled out from the upper surface of each filter plate (middle filter plates 92b, 92b, 92b, lower filter plate 92c) by the discharge roller device er and discharged to the outside of the machine.

[0058] Next, the operation of the horizontal plate filter 9 will be described.

[0059] First, the stacked filter plates (upper filter plate 92a, middle filter plates 92b, 92b, 92b, lower filter plate 92c) are pressed by the pressure jack pj above to make each filter chamber in a sealed state. The stock solution is supplied to the filter materials 91a, 91b, 91c, 91d of each filter chamber in a sealed state through the stock solution introduction path 93 to start the filtration process.

[0060] When the filtration process progresses and the filtration resistance of the filter media 91a, 91b, 91c, and 91d gradually increases and filtration becomes difficult, the supply of the raw liquid is stopped and the pressurized state by the pressurizing jack pj is released.

[0061] Then, the upper filter plate 92a and multiple intermediate filter plates 92b, 92b, 92b are pulled upward to form gaps between the upper filter plate 92a and the intermediate filter plate 92b, between the intermediate filter plates 92b and the intermediate filter plates 92b, and between the intermediate filter plate 92b and the lower filter plate 92c, thereby releasing the fastened state of the filter materials 91a, 91b, 91c, and 91d.

[0062] At this time, the filter material extractor fe moves the filter materials 91a, 91b, 91c, and 91d released from the fastened state, thereby replacing the filter materials 91a, 91b, 91c, and 91d arranged between the upper filter plate 92a and the middle filter plate 92b, between the middle filter plate 92b and the middle filter plate 92b, and between the middle filter plate 92b and the lower filter plate 92c from the used part to the unused part.

[0063] It should be noted that the horizontal plate filter 9 aims to reduce the installation area, sets the filtration area of ​​each section to an appropriate size, and is constructed into multiple sections to increase the overall filtration area to achieve the required filtration capacity, but the basic structure and effect are the same in a single section.

[0064] <Implementation method 1>

[0065] Figure 1 2 is a cross-sectional view showing the structure of a plate filter X1 according to one embodiment of the present invention. Figure 1 As shown, the plate filter X1 includes a filter material 1, a plurality of filter plates (an upper filter plate 2a and a lower filter plate 2b), a filter chamber C, a raw liquid introduction path 3, a pressurized sealing unit 4, and a control unit 5. It should be noted that the filter chamber C is formed by assembling the upper filter plate 2a and the lower filter plate 2b with the filter material 1 interposed therebetween.

[0066] The filter medium 1 is sandwiched between a plurality of filter plates (an upper filter plate 2 a and a lower filter plate 2 b ) so that the inside and outside of the filter chamber C communicate with each other.

[0067] The upper filter plate 2 a and the lower filter plate 2 b form a filter chamber C with the filter medium 1 interposed therebetween.

[0068] The raw liquid introduction path 3 leads from the upper filter plate 2a to the filter chamber C. It should be noted that the piping of the raw liquid introduction path 3 and the upper filter plate 2a are as follows. Figure 1 Connect as shown in the enlarged diagram in the dialog box. The same applies to the connection of other pipes and filter plates.

[0069] The pressurizing and sealing unit 4 includes a first pressure sensing unit 41 , a second pressure sensing unit 42 , a fluid supply path 43 , and a pressure regulating unit 44 .

[0070] The first pressure sensing unit 41 is preferably a pressure sensor or the like, and is provided in the stock solution introduction path 3 as described later to sense the first pressure P1 in the stock solution introduction path 3 .

[0071] The second pressure sensing unit 42 is preferably a pressure sensor or the like, and is provided in the fluid supply path 43 as described later to sense a second pressure P2 in a supply path main body 431 (described later) of the fluid supply path 43 .

[0072] The fluid supply path 43 includes a supply path main body 431 and a seal flow path (pressing path) 432 .

[0073] The seal flow path (pressing path) 432 is formed to surround the filter chamber C (the details will be described later).

[0074] The pressure regulating unit 44 preferably uses a regulating valve or the like that regulates the flow rate of the fluid flowing into the fluid supply path 43 , and can regulate the second pressure P2 in the fluid supply path 43 as described later.

[0075] The control unit 5 is connected to the first pressure sensing unit 41, the second pressure sensing unit 42 and the pressure regulating unit 44 at least through a wired or wireless signal transmission unit. The control unit 5 receives pressure sensing signals from the first pressure sensing unit 41 and the second pressure sensing unit 42, and based on the signals, sends signals to the pressure regulating unit 44 to automatically control the pressure regulating unit 44.

[0076] Figure 3 yes Figure 1 The sectional view of the plate filter X1 taken along the line A-A' is shown. Figure 1 As shown, the sealing flow path (pressing path) 432 is formed on the lower surface of the upper filter plate 2a in a manner connected to the filter material 1 when the filter material 1 is sandwiched between multiple filter plates (upper filter plate 2a, lower filter plate 2b), and as shown in FIG. Figure 3 As shown, it is formed to surround the filter chamber C.

[0077] That is, the sealing fluid supplied through the supply path main body 431 passes through the sealing flow path (pressing path) 432 of the fluid supply path 43 and spreads over the portion of the filter medium 1 located at the periphery of the filter chamber C, resulting in a sealing pressure being applied to this portion of the filter medium 1.

[0078] It should be noted that in Figure 3 In the embodiment, the supply path main body 431 is set as one, but the present invention is not limited to this. Figure 4 As shown, an additional second supply path body 431 (2) may be provided from a direction different from the first supply path body 431 (1) so that the sealing fluid SF is uniformly distributed in the sealing flow path (pressing path) 432. That is, the pressurizing sealing unit 4 can apply sealing pressure to the filter material uniformly by supplying the sealing fluid SF to the filter material from a plurality of different directions.

[0079] It should be noted that the additional supply path body 431 may include one or more (or more than two) solutions.

[0080] For example, in addition to providing an additional supply path main body 431 Figure 4 In addition to the above-mentioned embodiment, two or three additional supply path bodies 431 may be provided. Fig.10 , Fig.11 The scheme shown.

[0081] In this case, it is preferable that the plurality of supply path main bodies 431 are provided at equal intervals along the outer circumference of the sealing flow path (pressing path) 432 so as to uniformly supply the sealing fluid SF.

[0082] Hereinafter, in embodiments 1 to 4 described in this specification, unless otherwise specified, the upper filter plate 2a and the intermediate filter plates 2b-1, 2b-2, and 2b-3 are provided with the same fluid supply path 43 as described above (in the case of the intermediate filter plates 2b-1, 2b-2, and 2b-3, they are branch supply paths 431a, 431b, 431c, and 431d), which are described in advance.

[0083] Figure 2 It is a cross-sectional view showing the flow of a fluid in a plate filter X1 according to one embodiment of the present invention.

[0084] In addition, let the raw liquid be L1, the filtrate be L2, and the sealing fluid be SF, and the flow of each fluid is indicated by the corresponding arrows.

[0085] like Figure 2 As shown, the raw liquid L1 is introduced into the filter chamber C through the raw liquid introduction path 3, and passes through the filter medium 1 to be filtered.

[0086] The filtrate L2 obtained by the filtration is discharged to the outside of the filter chamber C through the discharge path 3b.

[0087] The sealing fluid SF is a fluid supplied to the sealing flow path (pressing path) 432 through the supply path main body 431. By supplying the sealing fluid SF to the sealing flow path (pressing path) 432, the sealing portion of the filter material 1 is flattened, and the tiny gaps (leakage path of the stock solution L1) generated on the surface where the filter material 1 contacts the upper filter plate 2a, the inside of the filter material 1 (leakage path of the filtrate L2), and the tiny gaps (leakage path of the filtrate L2) generated on the surface where the filter material 1 contacts the lower filter plate 2b are blocked, thereby suppressing the leakage of the stock solution L1 and the filtrate L2.

[0088] It should be noted that, as the sealing fluid SF, for example, nitrogen is preferably used, but compressed air or other inert gases may also be used. In addition, the supply source of the sealing fluid SF is assumed to be a sealing gas supply unit such as a gas cylinder, for example.

[0089] Through the flow of each of the above-mentioned fluids, pressure is applied to each of the inside of the stock solution introduction path 3, the supply path body 431, the filter chamber C, and the sealed flow path (pressing path) 432. In this specification, the pressure applied to the inside of the stock solution introduction path 3 is defined as the first pressure P1, the pressure applied to the inside of the supply path body 431 is defined as the second pressure P2, the pressure applied to the inside of the filter chamber C is defined as the filter chamber internal pressure P3, and the pressure applied to the inside of the sealed flow path (pressing path) 432 is defined as the sealing pressure P4.

[0090] The object of the present invention is to prevent the original liquid and the filtrate from leaking out of the filter chamber C by achieving a balance between the pressure P3 in the filter chamber and the sealing pressure P4.

[0091] Therefore, it is ideal to directly measure the filter chamber pressure P3 and the sealing pressure P4, but the filter chamber pressure P3 and the sealing pressure P4 are difficult to measure in terms of position. Therefore, the first pressure P1 and the second pressure P2, which are easier to measure, are measured, and the relationship between the filter chamber pressure P3 and the sealing pressure P4 is estimated based on them.

[0092] Specifically, the control unit 5 estimates the filter chamber internal pressure P3 of the filter chamber C based on the first pressure P1 sensed by the first pressure sensing unit 41 .

[0093] It should be noted that “estimation” herein includes directly regarding the sensed first pressure P1 as the filter chamber internal pressure P3 of the filter chamber C, and calculating the filter chamber internal pressure P3 of the filter chamber C by performing a predetermined operation process on the sensed first pressure P1.

[0094] Next, the control unit 5 automatically operates the pressure regulating unit 44 based on the estimated filter chamber pressure P3 of the filter chamber C and the second pressure P2 in the fluid supply path 43 sensed by the second pressure sensing unit 42. It should be noted that the second pressure P2 can also be regarded as the same value as the sealing pressure P4 in the structure of the present embodiment, and the sealing pressure P4 can also be calculated by performing a predetermined operation process on the second pressure P2.

[0095] The control unit 5 continuously monitors the second pressure P2 via the second pressure sensing unit 42 and continuously adjusts the operation amount of the pressure regulating unit 44 so that the pressure difference between the pressure P3 in the filter chamber and the second pressure P2 is a specified pressure difference value.

[0096] As a result, the balance between the filter chamber pressure P3 estimated from the first pressure P1 in the stock liquid introduction path 3 and the sealing pressure P4 estimated from the second pressure P2 in the fluid supply path 43 is automatically adjusted. Through this adjustment, the leakage of the stock liquid L1 through the gap generated at the contact surface between the filter material 1 and the upper filter plate 2a and the leakage of the filtrate L2 passing through the inside of the filter material 1 due to the capillary phenomenon can be more effectively suppressed.

[0097] It should be noted that the control unit 5 may be any type of control unit as long as it is a control panel for industrial equipment, a computer device, or the like that can realize the above-mentioned functions.

[0098] <Implementation method 2>

[0099] Figure 5 It is a cross-sectional view of a plate filter X2 according to another embodiment of the present invention.

[0100] like Figure 5 As shown, the plate filter X2 includes: a plurality of filter materials 1a, 1b, 1c, 1d; a plurality of filter plates (upper filter plate 2a, middle filter plates 2b-1, 2b-2, 2b-3, lower filter plate 2b; a plurality of filter chambers C1, C2, C3, C4; a raw liquid introduction path 3; a pressurized sealing unit 4; and a control unit 5. In the following, descriptions that overlap with the description of the plate filter X1 are appropriately omitted, and only the characteristic parts of the plate filter X2 are described.

[0101] The raw liquid introduction path 3 has branch introduction paths 31a, 31b, 31c, and 31d leading from the upper filter plate 2a, the middle filter plates 2b-1, 2b-2, and 2b-3 to the filter chambers C1, C2, C3, and C4, and can introduce the raw liquid L1 into the filter chambers C1, C2, C3, and C4.

[0102] In this specification, the pressure applied to the inside of each filter chamber C1, C2, C3, and C4 by the raw liquid L1 is defined as filter chamber internal pressure P3a, P3b, P3c, and P3d, respectively.

[0103] The fluid supply path 43 includes branch supply paths 431a, 431b, 431c, 431d and sealed flow paths (pressing paths) 432a, 432b, 432c, 432d leading from the upper filter plate 2a, the middle filter plates 2b-1, 2b-2, 2b-3 to the filter chambers C1, C2, C3, C4.

[0104] In this specification, the pressure applied to the inside of each sealing flow path (pressing path) 432a, 432b, 432c, 432d by the sealing fluid SF is defined as sealing pressure P4a, P4b, P4c, P4d, respectively.

[0105] Sealing fluid SF is supplied to the sealing flow paths (pressing paths) 432a, 432b, 432c, 432d through branch supply paths 431a, 431b, 431c, 431d, respectively, whereby the sealing parts of the multiple filter materials 1a, 1b, 1c, 1d are flattened by the sealing pressures P4a, P4b, P4c, P4d, and the leakage paths of the original liquid L1 and the filtrate L2 are blocked, thereby suppressing the leakage of the original liquid and the filtrate.

[0106] The first pressure sensing unit 41 preferably uses a pressure sensor or the like, which can sense the first pressure P1 in the raw liquid introduction path 3 upstream of the branch point B1 of the branch introduction paths 31a, 31b, 31c, and 31d, and send a pressure sensing signal to the control unit 5.

[0107] The second pressure sensing unit 42 preferably uses a pressure sensor or the like, which can sense the second pressure P2 in the fluid supply path 43 upstream of the branch point B2 of the branch supply paths 431a, 431b, 431c, and 431d, and send a pressure sensing signal to the control unit 5.

[0108] The control unit 5 controls the sealing pressures P4a, P4b, P4c, and P4d based on the first pressure P1 in the raw liquid introduction path 3 sensed by the first pressure sensing unit 41 and the second pressure P2 in the fluid supply path 43 sensed by the second pressure sensing unit 42.

[0109] Here, in the structure of the present embodiment, the first pressure P1 in the raw liquid inlet path 3 sensed by the first pressure sensing unit 41 can be estimated as the internal pressures P3a, P3b, P3c, P3d of each of the multiple filter chambers C1, C2, C3, C4, and the second pressure P2 in the fluid supply path 43 sensed by the second pressure sensing unit 42 can be estimated as the internal pressures of each of the multiple branch supply paths 431a, 431b, 431c, 431d (i.e., the sealing pressures P4a, P4b, P4c, P4d).

[0110] Therefore, the sealing pressures P4a, P4b, P4c, and P4d are controlled based on the first pressure P1 in the raw liquid inlet path 3 sensed by the first pressure sensing unit 41 and the second pressure P2 in the fluid supply path 43 sensed by the second pressure sensing unit 42. The sealing pressures P4a, P4b, P4c, and P4d are controlled based on the filter chamber internal pressures P3a, P3b, P3c, and P3d and the sealing pressures P4a, P4b, P4c, and P4d. As a result, as a whole, the filter machine can minimize the leakage of filtrate through the filter material 1 caused by capillary phenomenon and the excessive supply of sealing fluid that may occur in each filter chamber.

[0111] In addition, by maintaining the pressure difference between the first pressure P1 in the raw liquid inlet path 3 sensed by the first pressure sensing unit 41 and the second pressure P2 in the fluid supply path 43 sensed by the second pressure sensing unit 42 at a specified pressure difference value, the following control can be performed more robustly: the leakage of filtrate through the filter material 1 and the excessive supply of sealing fluid caused by capillary phenomenon that may occur in each filter chamber are minimized.

[0112] Therefore, the first pressure sensing unit 41 senses the first pressure P1 in the raw liquid inlet path 3 upstream of the branch point B1, and the second pressure sensing unit 42 senses the second pressure P2 in the fluid supply path 43 upstream of the branch point B2. Therefore, there is no need to respectively set a sensor in each of the multiple filter chambers C1, C2, C3, C4 and each of the multiple branch supply paths 431a, 431b, 431c, 431d, and the leakage of raw liquid and filtrate in each part / excessive supply of sealing fluid can also be minimized in terms of structure.

[0113] <Implementation method 3>

[0114] Figure 6 It is a cross-sectional view of a plate filter X3 according to another embodiment of the present invention.

[0115] like Figure 6 As shown, the plate filter X3 includes a filter medium 1, a plurality of filter plates (an upper filter plate 2a and a lower filter plate 2b), a filter chamber C, a raw liquid introduction path 3, a pressurizing sealing unit 4, and a control unit 5. Hereinafter, descriptions that overlap with the description of the plate filter X1 are appropriately omitted, and only the characteristic parts of the plate filter X3 are described.

[0116] The pressurizing seal unit 4 has a pressurizing seal body 45 formed of an elastic body, and the end of the pressurizing seal body 45 is fixed in the sealing flow path (pressing path) 432 of the upper filter plate 2a. Alternatively, as the pressurizing seal body 45, a pressurizing seal body formed of an elastic material into a tubular shape can be used.

[0117] That is, Figure 7As shown, the sealing fluid SF supplied from the fluid supply path 43 causes the elastically deformed pressurized sealing portion body 45 to bend downward in the figure, thereby applying a sealing pressure P4 to the portion in contact with the filter material 1 to flatten the filter material 1 for sealing.

[0118] That is, the pressurizing seal unit 4 can supply the sealing fluid SF to the pressurizing seal main body 45 to deform the pressurizing seal main body 45 , thereby applying the sealing pressure to the filter medium 1 .

[0119] In the present embodiment, the sealing fluid SF does not contact the raw liquid L1 and the filtrate L2 , and therefore, as the sealing fluid SF, liquids such as pressurized oil may be used in addition to gases such as nitrogen, compressed air, and inert gas.

[0120] Here, the control unit 5 controls the sealing pressure P4 based on the first pressure P1 in the raw liquid introduction path 3 sensed by the first pressure sensing unit 41 and the second pressure P2 in the fluid supply path 43 sensed by the second pressure sensing unit 42 .

[0121] Specifically, the control unit 5 controls the sealing pressure P4 so as to maintain the pressure difference between the first pressure P1 in the raw liquid introduction path 3 sensed by the first pressure sensing unit 41 and the second pressure P2 in the fluid supply path 43 sensed by the second pressure sensing unit 42 at a predetermined pressure difference value.

[0122] In this way, the balance between the filter chamber pressure P3 estimated based on the first pressure P1 in the raw liquid inlet path 3 and the sealing pressure P4 estimated based on the second pressure P2 in the fluid supply path 43 can be automatically adjusted, and leakage of raw liquid and filtrate from the filter chamber C can be suppressed more effectively and accurately.

[0123] It should be noted that the configuration of the third embodiment described above can also be combined with the second embodiment to provide the filter chamber C in multiple stages.

[0124] <Implementation method 4>

[0125] Figure 8 (a) Figure 8 (b) is a cross-sectional view of a plate filter X4 according to another embodiment of the present invention.

[0126] like Figure 8 (a) Figure 8 As shown in (b), the plate filter X4 includes a filter material 1, a plurality of filter plates (an upper filter plate 2a and a lower filter plate 2b), a filter chamber C, a raw liquid introduction path 3, a pressurized sealing unit 4, and a control unit 5. Hereinafter, descriptions that overlap with the description of the plate filter X1 are appropriately omitted, and only the characteristic parts of the plate filter X4 are described.

[0127] The control unit 5 has a raw liquid chamber 51 connected to the raw liquid introduction path 3, a fluid chamber 52 connected to the fluid supply path 43, and a pressure transmission unit 53. The raw liquid chamber 51 and the fluid chamber 52 are separated and connected in the middle by the pressure transmission unit 53 formed by an elastic body.

[0128] That is, the raw liquid L1 and the sealing fluid SF do not flow or mix between the raw liquid chamber 51 and the fluid chamber 52 , but the first pressure P1 in the raw liquid introduction path 3 and the second pressure P2 in the fluid supply path 43 are transmitted to each other.

[0129] like Figure 8 As shown in (a), when the first pressure P1 in the raw liquid introduction path 3 and further the pressure P3 in the filter chamber is greater than the second pressure P2 in the fluid supply path 43 and further greater than the sealing pressure P4, the pressure transmission unit 53 is deformed toward the fluid chamber 52 side.

[0130] Thus, the volume of the space on the sealing fluid SF side including the fluid chamber 52 and the fluid supply path 43 decreases. Therefore, if the fluid flow rate is constant, the second pressure P2 in the fluid supply path 43 increases accordingly, and the sealing pressure P4 increases accordingly.

[0131] like Figure 8 As shown in (b), when the first pressure P1 in the raw liquid introduction path 3 and further the pressure P3 in the filter chamber is lower than the second pressure P2 in the fluid supply path 43 and further lower than the sealing pressure P4, the pressure transmission unit 53 is deformed toward the raw liquid chamber 51 side.

[0132] Thus, the volume of the space on the sealed fluid side including the fluid chamber 52 and the fluid supply path 43 expands. Therefore, if the fluid flow rate is constant, the second pressure P2 in the fluid supply path 43 decreases accordingly, and the sealing pressure P4 decreases accordingly.

[0133] Therefore, even the control unit 5 of the above-described structure can automatically control the second pressure P2 in the fluid supply path 43 and further automatically control the sealing pressure P4 based on the change of the first pressure P1 in the raw liquid introduction path 3 and further based on the change of the pressure P3 in the filter chamber.

[0134] It should be noted that by setting a pressure reducing valve RV in the raw liquid inlet path 3 connected to the upper filter plate 2a on the downstream side of the branch point B3, or setting a pressure boosting pump BP in the fluid supply path 43 connected to the upper filter plate 2a on the downstream side of the branch point B4, a fixed pressure difference can be generated between the filter chamber internal pressure P3 and the sealing pressure P4.

[0135] The configuration of the fourth embodiment described above can also be combined with the second embodiment to provide a multi-stage filter chamber C. In this case, it is preferred that the branch point B3 be located upstream of the branch point B1 and the branch point B4 be located upstream of the branch point B2.

[0136] According to the plate filter X1~X4 of embodiments 1~4 of the present invention, the control unit 5 automatically controls the sealing pressure P4 (or P4a, P4b, P4c, P4d) according to the changes in the pressure P3 (or P3a, P3b, P3c, P3d) in the filter chamber to suppress the leakage of the original liquid L1 and the filtrate L2 in the filter chamber C (or C1, C2, C3, C4) to the outside of the filter chamber C (or C1, C2, C3, C4), thereby more effectively suppressing the leakage of the original liquid L1 and the filtrate L2.

[0137] According to the plate filter X1 to X4 of embodiments 1 to 4 of the present invention, the pressurized sealing unit 4 applies a sealing pressure P4 (or P4a, P4b, P4c, P4d) to the filter material 1 (or 1a, 1b, 1c, 1d) by supplying a sealing fluid SF to the filter material 1 (or 1a, 1b, 1c, 1d). Therefore, the leakage path of the original liquid L1 or the filtrate L2 at the contact part between the filter material 1 (or 1a, 1b, 1c, 1d) and each filter plate and the leakage path of the filtrate L2 inside the filter material 1 (or 1a, 1b, 1c, 1d) are sealed by the sealing fluid SF, which can more effectively suppress the leakage of the original liquid L1 and the filtrate L2.

[0138] According to the plate filter X1~X4 of embodiments 1~4 of the present invention, the pressurized sealing unit 4 applies sealing pressure P4 (or P4a, P4b, P4c, P4d) to the filter material 1 (or 1a, 1b, 1c, 1d) by supplying sealing fluid SF to the filter material 1 (or 1a, 1b, 1c, 1d) from multiple different directions. Therefore, the sealing pressure P4 (or P4a, P4b, P4c, P4d) is applied to the filter material 1 (or 1a, 1b, 1c, 1d) without deviation, which can more effectively suppress the leakage of the original liquid L1 and the filtrate L2.

[0139] According to the plate filter X1 to X4 of embodiments 1 to 4 of the present invention, the control unit 5 automatically controls the sealing pressure P4 (or P4a, P4b, P4c, P4d) to inhibit the leakage of the raw liquid L1 and the filtrate L2 out of the filter chamber C (or C1, C2, C3, C4). Therefore, it can not only inhibit the leakage of the raw liquid L1 and the filtrate L2, but also inhibit the excessive supply of the sealing fluid SF.

[0140] According to the plate filter X1~X4 of embodiments 1~4 of the present invention, the control unit automatically controls the sealing pressure P4 (or P4a, P4b, P4c, P4d) to inhibit the sealing fluid SF supplied to the filter material 1 (or 1a, 1b, 1c, 1d) from invading the filter chamber C (or C1, C2, C3, C4). Therefore, it can not only prevent the leakage of the original liquid L1 and the filtrate L2, but also prevent the reduction in filtration accuracy and the reduction in the quality of the filter caused by the invasion of the sealing fluid SF into the filter chamber C (or C1, C2, C3, C4).

[0141] According to the plate filter X1 to X4 of embodiments 1 to 4 of the present invention, the control unit 5 controls the sealing pressure P4 (or P4a, P4b, P4c, P4d) in such a manner that the pressure difference between the inner pressure P3 (or P3a, P3b, P3c, P3d) of the filter chamber and the sealing pressure P4 (or P4a, P4b, P4c, P4d) is maintained at a specified pressure difference value, thereby enabling robust control even for larger pressure changes.

[0142] According to the plate filter X1 to X4 of embodiments 1 to 4 of the present invention, the control unit controls the sealing pressure P4 (or P4a, P4b, P4c, P4d) based on the pressure P3 (or P3a, P3b, P3c, P3d) in the filter chamber estimated according to the first pressure P1 in the raw liquid inlet path 3. Therefore, there is no need to set a sensing unit in the filter chamber C (or C1, C2, C3, C4), which can simplify the structure of each filter plate.

[0143] According to the plate filter X1~X4 of embodiments 1~4 of the present invention, the control unit controls the sealing pressure P4 (or P4a, P4b, P4c, P4d) based on the pressure P3 (or P3a, P3b, P3c, P3d) in the filter chamber estimated according to the first pressure P1 in the raw liquid inlet path 3 sensed by the first pressure sensing unit 41 and the second pressure P2 in the fluid supply path 43 sensed by the second pressure sensing unit 42. Therefore, the first pressure P1 and the second pressure P2 can be used to perform higher-precision sealing pressure control, further improving the leakage suppression effect.

[0144] According to the method of using the plate filter X1~X4 of embodiments 1~4 of the present invention, in the pressure control process, the sealing pressure P4 (or P4a, P4b, P4c, P4d) is automatically controlled according to the change of the pressure P3 (or P3a, P3b, P3c, P3d) in the filter chamber to suppress the leakage of the filtered raw liquid and the filtrate to the outside of the filter chamber C (or C1, C2, C3, C4), thereby more effectively suppressing the leakage of the raw liquid L1 and the filtrate L2.

[0145] According to the method of using the filter plate filter X1~X4 of embodiments 1~4 of the present invention, in the pressurized sealing process, the sealing pressure P4 (or P4a, P4b, P4c, P4d) is applied to the filter material 1 (or 1a, 1b, 1c, 1d) by supplying the sealing fluid SF to the filter material 1 (or 1a, 1b, 1c, 1d). Therefore, the leakage path of the original liquid L1 or the filtrate L2 at the contact part of the filter material 1 (or 1a, 1b, 1c, 1d) and each filter plate and the leakage path of the filtrate L2 inside the filter material 1 (or 1a, 1b, 1c, 1d) are sealed by the sealing fluid SF, which can more effectively suppress the leakage of the original liquid L1 and the filtrate L2.

[0146] According to the method of using the plate filter X1~X4 of embodiments 1~4 of the present invention, in the pressurized sealing process, the sealing pressure P4 (or P4a, P4b, P4c, P4d) is applied to the filter material 1 (or 1a, 1b, 1c, 1d) by supplying the sealing fluid SF to the filter material 1 (or 1a, 1b, 1c, 1d) from multiple different directions. Therefore, the sealing pressure P4 (or P4a, P4b, P4c, P4d) is applied to the filter material 1 (or 1a, 1b, 1c, 1d) without deviation, which can more effectively suppress the leakage of the original liquid L1 and the filtrate L2.

[0147] According to the method of using the plate filter X1~X4 of embodiments 1~4 of the present invention, in the pressure control process, the sealing pressure P4 (or P4a, P4b, P4c, P4d) is automatically controlled to suppress the leakage of the filtered raw liquid L1 and the filtrate L2 to the outside of the filter chamber C (or C1, C2, C3, C4), thereby not only suppressing the leakage of the raw liquid L1 and the filtrate L2, but also suppressing the excessive supply of the sealing fluid SF.

[0148] According to the method of using the plate filter X1~X4 of embodiments 1~4 of the present invention, in the pressure control process, the sealing pressure P4 (or P4a, P4b, P4c, P4d) is automatically controlled to inhibit the sealing fluid supplied to the filter material 1 (or 1a, 1b, 1c, 1d) from invading the filter chamber C (or C1, C2, C3, C4). Therefore, not only the leakage of the original liquid L1 and the filtrate L2 can be prevented, but also the reduction in filtration accuracy and filtration quality caused by the invasion of the sealing fluid SF into the filter chamber C (or C1, C2, C3, C4) can be prevented.

[0149] According to the plate filter X2 of embodiment 2 of the present invention, the first pressure sensing unit 41 senses the first pressure P1 in the raw liquid inlet path 3 upstream of the branch point B1 of the branch inlet paths 31a, 31b, 31c, and 31d. Therefore, not only is the processing capacity of the device improved by providing multiple filter chambers, but the number of required sensing units is also small, thereby simplifying the structure.

[0150] According to the plate filter X2 of embodiment 2 of the present invention, the second pressure sensing unit 42 senses the second pressure P2 in the fluid supply path upstream of the branch point B2 of the branch supply paths 431a, 431b, 431c, and 431d. Therefore, not only is the processing capacity of the device improved by providing multiple filter chambers, but the number of sensing units required is also small, thereby simplifying the structure.

[0151] In addition, the sealing pressures P4a, P4b, P4c, and P4d are controlled based on the first pressure P1 in the raw liquid inlet path 3 upstream of the branch point B1 of 31a, 31b, 31c, and 31d and the second pressure P2 in the fluid supply path 43 upstream of the branch point B2 of 431a, 431b, 431c, and 431d. As a result, the filter as a whole can minimize the leakage of the raw liquid L1 and the filtrate L2 that may occur in each filter chamber and the excessive supply of the sealing fluid SF.

[0152] According to the plate filter X2 of embodiment 2 of the present invention, the control unit controls the sealing pressures P4a, P4b, P4c, and P4d in such a manner that the pressure difference between the first pressure P1 in the raw liquid inlet path 3 and the second pressure P2 in the fluid supply path 43 is maintained at a specified pressure difference value, thereby being able to robustly perform the following sealing pressure control: minimizing the leakage of the raw liquid L1 and the filtrate L2 that may occur in each filter chamber and the excessive supply of the sealing fluid SF.

[0153] According to the plate filter X3 of embodiment 3 of the present invention, the pressurized sealing unit 4 has a pressurized sealing portion main body 45 formed by an elastomer, and the pressurized sealing portion main body 45 is deformed by supplying a sealing fluid SF to apply a sealing pressure P4 to the filter material 1, so that the sealing fluid SF is not in contact with the raw liquid L1 and the filtrate L2. As the sealing fluid SF, in addition to gases such as nitrogen, compressed air, and inert gas, liquids such as pressurized oil can also be used.

[0154] According to the method of using the plate filter X3 of embodiment 3 of the present invention, a sealing pressure P4 is applied to the filter material 1 by supplying a sealing fluid SF to deform the elastomer, so that the sealing fluid SF does not contact the raw liquid L1 and the filtrate L2. As the sealing fluid SF, in addition to gases such as nitrogen, compressed air, and inert gas, liquids such as pressurized oil can also be used.

[0155] Embodiments 1 to 4 of the present invention have been described above, but the configurations and functions shown in the above-mentioned embodiments are merely examples, and various changes can be made based on design requirements and the like.

[0156] Description of Reference Numerals

[0157] 1, 1a, 1b, 1c, 1d: filter material;

[0158] 2a: upper filter plate;

[0159] 2b-1, 2b-2, 2b-3: middle filter plates;

[0160] 2b: Lower filter plate;

[0161] 3: stock solution introduction route;

[0162] 31a, 31b, 31c, 31d: branch introduction path;

[0163] 4: Pressurized sealing unit;

[0164] 41: a first pressure sensing unit;

[0165] 42: second pressure sensing unit;

[0166] 43: fluid supply path;

[0167] 431a, 431b, 431c, 431d: branch supply paths;

[0168] 44: pressure regulating unit;

[0169] 5: Control unit;

[0170] 9: Horizontal plate filter;

[0171] C, C1, C2, C3, C4: filter chamber.

Claims

1. A plate filter, wherein a plurality of filter plates which are freely opened and closed are pressed and closely contacted with each other via filter materials to form a filter chamber, and filtering is performed inside the filter chamber, wherein: The plate filter has: A plurality of filter plates are arranged across the filter material; A filter chamber formed between the filter plates; A raw liquid introduction path, for introducing the raw liquid to be filtered into the filter chamber; A pressurized sealing unit, which applies sealing pressure to the filter material to inhibit the filtered raw liquid and the filtrate from leaking out of the filter chamber to the outside of the filter chamber; as well as The control unit automatically controls the sealing pressure according to the change of the pressure in the filter chamber.

2. The plate filter according to claim 1, wherein: The pressure sealing unit applies the sealing pressure to the filter medium by supplying a sealing fluid to the filter medium.

3. The plate filter according to claim 2, wherein: The pressure sealing unit applies the sealing pressure to the filter medium by supplying the sealing fluid to the filter medium from a plurality of different directions.

4. The plate filter according to claim 1, wherein: The pressurizing seal unit has a pressurizing seal main body formed of an elastic body. The sealing pressure is applied to the filter medium by supplying a sealing fluid to elastically deform the pressurizing seal portion body.

5. The plate filter according to any one of claims 2 to 4, wherein: The control unit automatically controls the sealing pressure to suppress the filtered raw liquid and the filtrate from leaking out of the filter chamber.

6. The plate filter according to any one of claims 2 to 4, wherein: The control unit automatically controls the sealing pressure to suppress the sealing fluid supplied to the filter medium from intruding into the filter chamber.

7. The plate filter according to claim 1, wherein: The control unit controls the sealing pressure so that the pressure difference between the internal pressure of the filter chamber and the sealing pressure is maintained at a predetermined pressure difference value.

8. The plate filter according to claim 1, wherein: The pressurizing and sealing unit includes a first pressure sensing unit that senses a first pressure in the raw liquid introduction path. The control unit controls the sealing pressure based on the pressure in the filter chamber estimated from the first pressure in the raw liquid introduction path.

9. The plate filter according to claim 8, wherein: The pressurizing and sealing unit includes a fluid supply path for supplying a sealing fluid to the filter material and a second pressure sensing unit for sensing a second pressure in the fluid supply path. The control unit controls the sealing pressure based on the pressure in the filter chamber estimated from the first pressure in the raw liquid introduction path sensed by the first pressure sensing unit and the second pressure in the fluid supply path sensed by the second pressure sensing unit.

10. The plate filter according to claim 8, wherein: The plate filter has a plurality of filter chambers. The raw liquid introduction path has branch introduction paths for introducing the raw liquid to be filtered into the plurality of filter chambers respectively. The first pressure sensing unit senses a first pressure in the stock solution introduction path on the upstream side of the branch point of the branch introduction path. The control unit controls the sealing pressure based on the pressure in the filter chamber estimated from the first pressure in the raw liquid introduction path.

11. The plate filter according to claim 10, wherein: The pressurizing and sealing unit includes a fluid supply path for supplying a sealing fluid to the filter material and a second pressure sensing unit for sensing a second pressure in the fluid supply path. The fluid supply path includes a branch supply path for supplying a sealing fluid to the plurality of filter materials respectively arranged in the plurality of filter chambers. The second pressure sensing unit senses a second pressure in the fluid supply path upstream of a branch point of the branch supply path. The control unit controls the sealing pressure based on a first pressure in the raw liquid introduction path and a second pressure in the fluid supply path.

12. The plate filter according to claim 9 or 11, wherein: The control unit controls the sealing pressure so that the differential pressure between the first pressure in the raw liquid introduction path and the second pressure in the fluid supply path is maintained at a predetermined differential pressure value.

13. A filtering method, which is a filtering method performed using a plate filter, the plate filter comprising a plurality of filter plates arranged with filter media interposed therebetween and filter chambers formed between the filter plates, wherein: The filtering method comprises: a pressurized sealing step of applying sealing pressure to the filter medium; and a pressure control step of automatically controlling the sealing pressure to inhibit the filtered raw liquid and the filtrate from leaking out of the filter chamber to the outside of the filter chamber.

14. The filtering method according to claim 13, wherein: In the pressure sealing step, the sealing pressure is applied to the filter medium by supplying a sealing fluid to the filter medium.

15. The filtering method according to claim 14, wherein: In the pressure sealing step, the sealing pressure is applied to the filter medium by supplying the sealing fluid to the filter medium from a plurality of different directions.

16. The filtering method according to claim 13, wherein: In the pressure sealing step, the sealing pressure is applied to the filter medium by supplying a sealing fluid to elastically deform an elastic body.

17. The filtering method according to any one of claims 14 to 16, wherein: In the pressure control step, the sealing pressure is automatically controlled to suppress the filtered raw liquid and the filtrate from leaking out of the filter chamber.

18. The filtering method according to any one of claims 14 to 16, wherein: In the pressure control step, the sealing pressure is automatically controlled so as to suppress the sealing fluid supplied to the filter medium from intruding into the filter chamber.

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