Filter, processing device, and processing method

Abstract

Provided are: a filter which has excellent solid-liquid separation performance, can inhibit problematic clogging of the filter medium, and has excellent wear resistance; a processing device; and a processing method. The filter is for removing solid matter from a liquid to be filtered containing solid matter, and comprises a filter medium and a surface treatment layer provided to the filter medium. The surface treatment layer has a higher hardness than the filter medium. The filter has an opening size less than 30 μm and has a thickness of 0.5-30 mm.

Description

Filter body, treatment device and treatment method

[0001] The present invention relates to a filter body, a treatment device, and a treatment method for removing solids from a liquid to be filtered that contains solids, and more particularly to a filter body having a filtering material provided with a surface treatment layer, a treatment device, and a treatment method.

[0002] Conventionally, solids have been removed from a liquid to be filtered by solid-liquid separation using a filter or the like. There are various types of liquid to be filtered. For example, the liquid to be filtered includes river water, lake water, and seawater, which contain solid matter such as living organisms or sand particles. Other examples of liquid to be filtered include grinding fluid, which contains sludge such as grinding chips and abrasive grains as solid matter, and cutting oil, which contains solid matter such as machining chips generated by machining using a milling machine or lathe.

[0003] For example, Patent Document 1 describes a filter body equipped with a filtering material that captures and removes organisms in water taken in as ballast water, the filtering material being formed of a fluororesin-coated filter with a mesh size of 30 to 120 μm and a fluororesin coating thickness of 0.005 to 20 μm. Patent Document 1 also describes that the filtering material is a wire-wound filter in which a metal wire is wound in a coil shape around a plurality of supporting struts, allowing raw water to pass through gaps between adjacent windings of the wire.

[0004] Patent Document 2 also describes a filter body used in a solid-liquid separator that removes liquid from a solid-liquid mixed fluid containing a large amount of impurities and separates it from solids. The filter body is a thin-walled cylindrical filter material made of a hard porous body with a porosity of 50 to 90%, with network-like continuous pores in which the weight ratio of polyvinyl acetal resin and phenolic resin is 1 / 40 to 1 / 2; a perforated cylindrical reinforcing member that is detachable from the inner periphery of the filter material and whose outer periphery is in contact with the inner periphery of the filter material when attached; and sealing members provided at both ends of the filter material to which the reinforcing member is attached.

[0005] Alternatively, development can be performed by washing out the uncured resin and other components of the unexposed areas of a flexographic printing plate precursor after imagewise exposure in an aqueous developer or by using a brush or the like while applying an aqueous developer. The developer described above is also called a washout solution. The uncured resin and other components remain dispersed in the aqueous developer after development. Solids such as the dispersed uncured resin are removed from the developer in which the uncured resin and other components remain dispersed.

[0006] Japanese Patent Application Laid-Open No. 2014-166611

[0007] The filter material in Patent Document 1 is formed of a filter coated with a fluororesin. The fluororesin coating is insufficient in hardness and has low abrasion resistance. Therefore, when the solid matter in the liquid to be filtered is hard, such as glass or ceramics, the fluororesin coating may peel off, resulting in insufficient abrasion resistance. Insufficient abrasion resistance also shortens the life of the filter material. Patent Document 2 also uses a thin-walled, cylindrical filter material made of a hard porous material with interconnected pores. When this filter material becomes clogged with solid matter in the liquid to be filtered after repeated filtration, the accumulated solid matter is removed by physical contact, such as by pressing a blade against the surface of the filter material. However, in Patent Document 2, the filter material is made of a polyvinyl acetal resin and a phenolic resin, which is insufficiently hard, wears the filter material due to contact with the blade, and has insufficient abrasion resistance. Insufficient abrasion resistance also shortens the life of the filter material. As such, currently, there is no filter material that has excellent solid-liquid separation performance, can suppress clogging, and also has excellent abrasion resistance. An object of the present invention is to provide a filter body, a treatment device and a treatment method which have excellent solid-liquid separation performance, can suppress clogging of the filter material and are also excellent in abrasion resistance.

[0008] To achieve the above-mentioned object, invention [1] is a filter body for removing solids from a liquid to be filtered that contains solids, the filter body having a filtering material and a surface treatment layer provided on the filtering material, the hardness of the surface treatment layer being equal to or greater than the hardness of the filtering material, the mesh size of the filter body being less than 30 μm, and the thickness of the filter body being 0.5 to 30 mm. invention [2] is the filter body according to invention [1], in which the thickness of the surface treatment layer is 0.005 μm or more and less than 15 μm. invention [3] is the filter body according to invention [1] or [2], in which the surface of the filter body is lyophobic. invention [4] is the filter body according to any one of inventions [1] to [3], in which the solids in the liquid to be filtered are solids in a developer for a water-developable flexographic printing plate precursor. invention [5] is the filter body according to any one of inventions [1] to [4], in which the filter body is made of metal.

[0009] Invention [6] is a treatment device for removing solids from a solid-containing liquid to be filtered, the treatment device comprising a filtration material and a surface treatment layer provided on the filtration material, the hardness of the surface treatment layer being equal to or greater than the hardness of the filtration material, the mesh size of the filter body being less than 30 μm, and the thickness of the filter body being 0.5 to 30 mm. Invention [7] is a treatment device according to Invention [6], which has a backwash function for removing filtered material adhering to the surface of the filter body from the filter body by removing solids with the filter body. Invention [8] is a treatment device according to Invention [6] or [7], which has a removal unit for removing filtered material adhering to the surface of the filter body by removing solids with the filter body. Invention [9] is a treatment device according to Invention [8], in which the removal unit has a scraper, and filtered material adhering to the surface of the filter body is removed by the scraper. Invention

[10] is a method for treating a liquid to be filtered using a filter body that removes solids from the liquid to be filtered containing solids, the filter body having a filtering material and a surface treatment layer provided on the filtering material, the hardness of the surface treatment layer being equal to or greater than the hardness of the filtering material, the mesh size of the filter body being less than 30 μm, and the thickness of the filter body being 0.5 to 30 mm.

[0010] According to the present invention, it is possible to provide a filter body, a treatment device and a treatment method which have excellent solid-liquid separation performance, can suppress clogging of the filter material and have excellent abrasion resistance.

[0011] FIG. 1 is a schematic perspective view showing a first example of a filter body according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing an enlarged view of a portion of the first example of the filter body according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a first example of a filter material for the filter body according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing a second example of a filter material for the filter body according to an embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing a third example of a filter material for the filter body according to an embodiment of the present invention. FIG. 6 is a schematic perspective view showing a second example of a filter material for the filter body according to an embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing a third example of a filter material for the filter body according to an embodiment of the present invention. FIG. 8 is a schematic cross-sectional view showing a second example of a filter material for the filter body according to an embodiment of the present invention.

[0012] The filter body, processing device, and processing method of the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings. Note that the drawings described below are merely illustrative for explaining the present invention, and the present invention is not limited to the drawings shown below. In the following, the range of values ​​indicated by "to" includes the values ​​written on both sides. For example, when ε is a value ε α ~Number ε β That is, the range of ε is the number ε α and the number ε β The range includes ε α ≦ε≦ε β Furthermore, unless otherwise specified, angles such as "perpendicular," orthogonal, and parallel include the range of error generally accepted in the relevant technical field. Furthermore, unless otherwise specified, lengths, temperatures, pressures, concentrations, and the like include the range of error generally accepted in the relevant technical field.

[0013] [Filter Body] FIG. 1 is a schematic perspective view showing a first example of a filter body according to an embodiment of the present invention. FIG. 2 is a schematic view showing an enlarged portion of the first example of the filter body according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a first example of a filtering material of a filter body according to an embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2, but shows a reduced number of filtering components 15. The filter body 10 shown in FIG. 1 removes solids from a liquid to be filtered (not shown) that contains solids. The filter body 10 has a filtering material 12 (see FIG. 3) and a surface treatment layer 14 (see FIG. 3) provided on the filtering material 12. The filtering material 12 provided with the surface treatment layer 14 is referred to as a filtering component 15.

[0014] The filter material 12 constitutes the outer shape of the filter body 10. The filter body 10 shown in Fig. 1 is, for example, a hollow cylindrical shape. The filter body 10 is oriented in the direction C of extension of the central axis C. Ｌ The filter body 12 has the same structure as the filter body 10, except that the surface treatment layer 14 is not formed.

[0015] When the filter body 10 is cylindrical, for example, the filtering component 15 is made of a wire material, and the filtering component 15 is wound to form a cylindrical shape. Ｒ The filter body 10 having the configuration shown in Fig. 1, which is formed by winding a wire as described above, is also called a wire-wound filter. The filter material 12 has a triangular cross-sectional shape as shown in Figs. 2 and 3. The filter material 12 is arranged so that one side of the triangle cross-sectional shape is the surface 10a of the filter body 10. A surface treatment layer 14 is provided on the entire surface of the filter material 12. The surface treatment layer 14 has a uniform thickness d, for example.

[0016] The surface treatment layer 14 is not limited to being provided on the entire surface of the filtration material 12 and having a uniform thickness d, but may be provided partially on the entire surface of the filtration material 12. In this case, for example, the surface treatment layer 14 is preferably provided on the surface 10a side of the filter body 10 and in the gaps 16 from the viewpoint of suppressing wear of the filtration material 12 and adjusting the mesh size. When the surface treatment layer 14 is formed of a plating layer or the like, the thickness d is uniform, but unevenness in thickness due to manufacturing errors or the like is acceptable. The filtration component 15 also has a triangular cross-sectional shape. The outer shape of the cross-sectional shape of the filtration material 12 and the outer shape of the cross-sectional shape of the filtration component 15 are similar to each other. As shown in FIG. 2, the filtration component 15 has a triangular cross-section in the extension direction C of the central axis C (see FIG. 1). Ｌ The filter components 15 are arranged with a gap 16 between them. Ｌ The length at this point is the mesh size δ (see FIGS. 2 and 3). To determine the mesh size δ, first, an image of the surface 10a of the filter body 10 is obtained using a digital microscope, and 10 points corresponding to the gaps 16 between adjacent filtration components 15 are randomly selected. The lengths of the 10 points on the image corresponding to the selected gaps 16 are measured. The average value of the lengths of the 10 measured points is taken as the mesh size δ.

[0017] The filter body 10 receives a liquid to be filtered (not shown) from the surface 10a and passes it through the interior 10b. During this process, solids (not shown) contained in the liquid to be filtered are removed, and a filtrate Sr (see FIG. 3 ) adheres to the surface 10a of the filter body 10. The liquid to be filtered that has passed through the interior 10b of the filter body 10 becomes a filtrate (not shown) from which the solids have been removed. The filtrate is then removed to the outside of the filter body 10. In the filter body 10, the filtration media 12 and the filtration components 15 are arranged such that one side of a triangle faces the surface 10a of the filter body 10, as shown in FIGS. 2 and 3 . This configuration narrows the gaps 16 formed on the surface 10a of the filter body 10 by lining up the sides of adjacent triangles. The slopes of the adjacent triangles are inclined away from each other from the surface 10a toward the interior 10b of the filter body 10, and the interior 10b of the filter body 10 is wider. Therefore, when the liquid to be filtered passes from the surface 10a to the interior 10b of the filter body 10, the solids are captured in the gaps 16, making it possible to remove the solids from the liquid to be filtered. On the other hand, since the filter body 10 narrows from the interior 10b toward the surface 10a, when backwashing is performed, the pressure of the fluid flowing from the interior 10b side of the filter body 10 into the gaps 16 increases, making it possible to efficiently remove the filtered material Sr (see FIG. 3) adhering to the gaps 16. Furthermore, by arranging the filtration components 15 so that one side of the triangle is on the surface 10a of the filter body 10, as shown in FIGS. 2 and 3, the surface 10a of the filter body 10 can be made flat with few irregularities.

[0018] FIG. 4 is a schematic cross-sectional view showing a second example of a filter element of a filter body according to an embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing a third example of a filter element of a filter body according to an embodiment of the present invention. The cross sections shown in FIGS. 4 and 5 correspond to the cross section taken along line A-A in FIG. 2. The number of filtration components 15 is also reduced in FIGS. 4 and 5. Note that in FIGS. 4 and 5, the same components as in FIG. 3 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. The filtration component 15 shown in FIG. 3 has a triangular cross-sectional shape, but the cross-sectional shape is not limited to a triangle. For example, the filtration component 15, i.e., the filtration material 12, may have a rectangular cross-sectional shape as shown in FIG. 4. A surface treatment layer 14 is provided on the entire surface of the filtration material 12 having a rectangular cross-sectional shape. The surface treatment layer 14 has a uniform thickness d, for example.

[0019] The filtration component 15 shown in FIG. 4 is arranged so that one side of the rectangle is the surface 10a of the filter body 10. By arranging the filtration component 15 so that one side of the rectangle is the surface 10a of the filter body 10, the surface 10a of the filter body 10 can be made flat with few irregularities. The filtration component 15 shown in FIG. 4 is arranged so that one side of the rectangle is the surface 10a of the filter body 10, but this is not limited thereto. For example, the filtration component 15 may be arranged so that one of its four corners is the surface 10a of the filter body 10. In this case, the cross-sectional shape of the filtration component 15 is a rhombus. Examples of the quadrilateral cross-sectional shape of the filtration component 15 include a square, a rectangle, a rhombus, and a parallelogram. Furthermore, the cross-sectional shape of the filtration component 15 may be a polygon other than the triangle and rectangle described above, such as a pentagon, a hexagon, or an octagon.

[0020] The filtration component 15, i.e., the filtration material 12, may have a circular cross-sectional shape, for example, as shown in Fig. 5. A surface treatment layer 14 is provided on the entire surface of the filtration material 12 having a circular cross-sectional shape. The surface treatment layer 14 has a uniform thickness d, for example. In Figs. 4 and 5, the opening δ is also determined by the distance δ between the adjacent surface treatment layers 14 in the extension direction C of the central axis C of the gap 16. ＬIn the configuration of the filtration components 15 having a circular cross section shown in FIG. 5 , the gaps 16 between adjacent filtration components 15 curve away from each other from the gap 16 toward the surface 10a of the filter body 10. Furthermore, the curved surfaces curve away from each other from the gap 16 toward the interior 10b, and face each other. Therefore, the gaps 16 are the narrowest, and the surface 10a side of the filter body 10 and the interior 10b side of the filter body 10 are both wider than the gaps 16 in the arrangement direction of the filtration components 15. As a result, when the liquid to be filtered passes from the surface 10a of the filter body 10 to the interior 10b, solids are captured in the gaps 16, allowing the solids to be removed from the liquid to be filtered. Meanwhile, because the filter body 10 narrows from the interior 10b toward the surface 10a, during backwashing, the pressure of the fluid flowing from the interior 10b side of the filter body 10 into the gaps 16 increases, allowing the filtered material Sr (see FIG. 3 ) adhering to the gaps 16 to be efficiently removed.

[0021] The cross-sectional shapes of the filtration component 15 and the filtration medium 12 shown in Fig. 5 are not limited to circular shapes, but may be elliptical, for example. Elliptical shapes include shapes known as super ellipses. A super ellipse is a shape that satisfies the following conditions in Equation (1): 0 < a, b, 1.00 < p (except when p = 2), and 1.00 < q (except when q = 2).

[0022]

[0023] As the configuration of the filtration component 15, i.e., the filtration material 12, the configurations shown in Figures 3 to 5 are preferred from the viewpoint of the strength of the filter body 10. Among Figures 3 to 5, the configuration shown in Figure 3, which has a triangular cross section, is more preferred because it has a high backwashing effect.

[0024] Fig. 6 is a schematic perspective view showing a second example of a filter body according to an embodiment of the present invention. In Fig. 6, the same components as those in the filter body 10 shown in Fig. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. In the filter body 10d shown in Fig. 6, the filtration component 15, i.e., the filtration material 12, is arranged in the direction C of extension of the central axis C. Ｌ1 , except that the filter body 10d is arranged parallel to the filter body 10 shown in Fig. 1 . The filter body 10d is configured with filtration components 15 having a triangular cross-sectional shape as shown in Figs. 2 and 3 described above, similar to the filter body 10 shown in Fig. 1 . The filter body 10d can also be configured with filtration components 15 having a square cross-sectional shape as shown in Fig. 4 described above, or filtration components 15 having a circular cross-sectional shape as shown in Fig. 5 . The filtration components 15 having a triangular cross-sectional shape are also called wedge wires.

[0025] FIG. 7 is a schematic diagram showing an enlarged portion of a third example of a filter body according to an embodiment of the present invention. FIG. 8 is a schematic diagram showing an enlarged portion of a fourth example of a filter body according to an embodiment of the present invention. FIG. 9 is a schematic diagram showing an enlarged portion of a fifth example of a filter body according to an embodiment of the present invention. FIGS. 7 to 9 show enlarged views of the configuration of a filtration component 15 constituting the filter body. Note that in FIGS. 7 to 9, the same components as those in FIG. 3 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. The filtration component 15 shown in FIGS. 7 to 9 can be configured as the filtration component 15 having a triangular cross-sectional shape shown in FIGS. 2 and 3, the filtration component 15 having a rectangular surface shape shown in FIG. 4, or the filtration component 15 having a circular cross-sectional shape shown in FIG. 5.

[0026] The direction x and the direction y shown in Fig. 7 are orthogonal to each other. As shown in Fig. 7, a mesh is formed by the filtration components 15. In the example shown in Fig. 7, a plurality of filtration components 15 extending in the direction x are arranged along the direction y at intervals δ ２ A plurality of filtering elements 15 extending in the direction y are arranged at intervals δ along the direction x. １ The filtration components 15 extending in the direction y are arranged at different positions from the filtration components 15 adjacent in the direction x. The filtration components 15 extending in the direction y are arranged alternately along the direction x, above and below the filtration components 15 extending in the direction x. Note that the spacing δ １ and interval δ ２The smaller of these is the mesh size δ. In the example shown in Figure 7, the filtration components 15 are configured to extend in the orthogonal directions x and y, and are arranged orthogonally, but this is not limiting. For example, the filtration components 15 may be arranged to intersect at any angle other than orthogonal.

[0027] As shown in FIG. 8 , a mesh is formed from a filtration component 18 having a plurality of holes 18 a formed therein. FIG. 8 shows a configuration similar to that of a so-called punched metal member. The opening shape of the holes 18 a is circular in FIG. 8 , but is not limited thereto. It may be elliptical, including the super ellipse described above, or polygonal, such as a triangle, square, pentagon, hexagon, or octagon, as described above. When the opening shape of the holes 18 a is rectangular, the configuration shown in FIG. 9 is obtained. In FIG. 9 , a mesh is formed from a filtration component 19 having a plurality of holes 19 a formed therein. The filtration component 18 and the filtration component 19 have the same configuration as the filtration component 15 having a rectangular cross-sectional shape described above, and the surface treatment layer 14 (see FIG. 4 ) is formed on the entire surface of the filtration material 12 (see FIG. 4 ). In the configuration shown in FIG. 8 , when the opening shape of the holes 18 a is circular, the diameter of the holes 18 a is the mesh size δ. In the configuration shown in FIG. 9 , the length of the short side of the rectangular holes 19 a is the mesh size δ. In the configuration shown in Fig. 9, the opening shape of the holes 19a is rectangular, but this is not limited thereto and the opening shape may be square. When the opening shape of the holes is square, the length of one side is the mesh size δ. As described above, examples of the configuration of the filter body include the configurations shown in Figs. 1, 6, and 7 to 9. Of these, a wire-wound filter such as the filter body 10 shown in Fig. 1 is preferred from the viewpoint of strength.

[0028] As described above, the filter body 10 removes solids from the liquid to be filtered, which contains solids. The filter body 10 may have a porous structure. Compared to a wire-wound filter, a porous structure has poor backwashing efficiency, and if clogging occurs, the entire filter body must be replaced or cleaned. Furthermore, in the case of a porous structure, forming a surface treatment layer with a uniform thickness requires the formation of a diamond-like carbon (DLC) or the like by ion implantation, which makes the formation of the surface treatment layer complicated. For this reason, the above-mentioned wire-wound filter is preferable to the porous structure for the filter body 10. In FIGS. 1 and 6 , the filter body 10 has an external shape that is cylindrical, but this is not limited thereto. The filter body 10 can have an external shape depending on the application, etc. The filter body 10 may have a flat shape, and the external shape of the flat shape may be circular, elliptical, or polygonal. Furthermore, the backwashing method for the filter body may be an air method using gas, or a method in which filtrate obtained by removing solids from the liquid to be filtered is passed through the filter body. The mesh size δ of the filter body 10 is appropriately set depending on the size of the solid matter to be separated, but is less than 30 μm. The mesh size δ of the filter body 10 is preferably less than 2 μm. The lower limit of the mesh size δ of the filter body 10 is 0.1 μm.

[0029] The thickness of the filter body 10 is 0.5 to 30 mm. If the thickness of the filter body is 0.5 to 30 mm, a decrease in flow rate due to pressure loss caused by a longer flow path is suppressed, and clogging due to backwashing is easily eliminated. As a result, backwashing efficiency is increased and the filter body is less susceptible to clogging. If the thickness of the filter body 10 exceeds 30 mm, a decrease in flow rate due to pressure loss occurs, making it difficult to eliminate clogging due to backwashing, and as a result, backwashing efficiency is reduced. Furthermore, if the thickness of the filter body 10 is less than 0.5 mm, the strength of the filter body 10 is insufficient and the filter body 10 may be deformed under filtration pressure.

[0030] Here, backwashing refers to supplying a fluid, such as gas or liquid, to the interior 10b of the filter body 10, allowing the fluid to flow from the interior 10b of the filter body 10 into the gaps 16, thereby removing filtered material adhering to the surface 10a of the filter body 10, i.e., the gaps 16. Backwashing efficiency is determined based on the degree to which the pressure on the filter body's pressure gauge (hereinafter referred to as the filter body pressure) approaches 0 MPa or the amount of filtrate inflow. For example, when the filter body becomes clogged and the filter body pressure reaches 0.3 MPa, backwashing begins with water or air. If the filter body pressure returns from 0.3 MPa to 0.01 MPa after backwashing, backwashing efficiency is considered high. Conversely, if the filter body pressure does not return to a value close to 0, such as from 0.3 MPa to 0.25 MPa, backwashing efficiency is considered low. Furthermore, in terms of the amount of filtrate inflow, backwashing efficiency is considered high when the efficiency (percentage percentage) at which the filtrate inflow returns to the flow rate before clogging of the filter body is high.

[0031] The pressure on the pressure gauge of the filter body (pressure of the filter body) is the pressure difference between the inside and outside of the filter body. The thickness of the filter body 10 is the length D of the filtration components 15 shown in Figures 3 to 5. The length D of the filtration components 15 is the length in a direction perpendicular to the arrangement direction of the filtration components 15. In the configuration of the filter body 10 shown in Figure 1, the arrangement direction of the filtration components 15 is the extension direction C of the central axis C (see Figure 1). Ｌ The direction is parallel to the direction of the filter element 15 (see FIG. 1). The length D of the filter element 15 is measured by using a vernier caliper or a micrometer.

[0032] The surface 10a of the filter body 10 is preferably lyophobic. If the surface of the filter body is lyophobic, the liquid to be filtered will have difficulty passing through the gaps 16 of the filter body 10, and the filter body will allow only smaller solids of various sizes to pass through, thereby increasing the efficiency of removing solids from the liquid to be filtered. The lyophobicity of the surface 10a of the filter body 10 is determined by the contact angle of the surface 10a of the filter body 10 with the liquid to be filtered. The contact angle is measured using the θ / 2 method. The larger the contact angle with the liquid to be filtered, the more lyophobic the surface 10a is, and a contact angle of 75° or greater is considered lyophobic. The lyophobicity of the surface 10a of the filter body 10 can be controlled, for example, by the material of the surface treatment layer 14. When lyophobic, the lyophobicity is referred to as hydrophobicity when it comes to water.

[0033] The filtering material 12 and the surface treatment layer 14 that constitute the filter body 10 will be described below. (Filter Material) The filtering material is made of metal, resin, or ceramic. Metals include alloys, and examples of metals that can be used include stainless steel (SUS), general structural rolled steel (SS material), brass, copper and aluminum, and aluminum alloys. In the case of metals, stainless steel is most preferably used. Examples of resins that can be used include polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and phenolic resin. The filtering material 12 can also be formed from notched wire or wedge wire.

[0034] (Surface Treatment Layer) The surface treatment layer has a hardness equal to or greater than the hardness of the filtration medium 12 and is provided on the entire surface of the filtration medium 12. The surface treatment layer 14 can suppress wear of the filtration medium 12, i.e., the filter body 10. Here, when the filtration medium 12 and the surface treatment layer 14 are made of metal or ceramic, the hardness is determined by Vickers hardness. The hardness of the filtration medium 12 and the hardness of the surface treatment layer 14 can be compared using Vickers hardness. The Vickers hardness is measured by the Vickers hardness test (JIS (Japanese Industrial Standards) Z2244:2009). When the filtration medium 12 is made of resin and the surface treatment layer 14 is made of metal or ceramic, the hardness of the resin and the metal or ceramic cannot be compared using the same scale, such as Vickers hardness. Therefore, when the filtering material 12 is made of resin and the surface treatment layer 14 is made of metal or ceramics, the hardness of the surface treatment layer 14 is set to be equal to or greater than the hardness of the filtering material 12 made of resin.

[0035] The method for forming the surface treatment layer 14 is not particularly limited and may be a wet process or a dry process. In wet processes, electroless nickel plating, hard chrome plating, or copper plating can be used. The surface of the filter body can also be made hydrophobic by using plating containing PTFE (polytetrafluoroethylene), such as fluorine. For example, PTFE-containing Ni plating is used. In this case, the surface treatment layer 14 is composed of an electroless nickel plating layer, a hard chrome plating layer, a copper plating layer, or a PTFE-containing Ni plating layer. Note that electroless nickel plating is preferred from the viewpoint of film thickness accuracy and film uniformity. When using electroless nickel plating, if the filter material 12 is made of stainless steel, the degreasing process, electrolytic degreasing process, pickling process, and plating process are performed in this order. To improve adhesion to the filter material, it is preferable to perform an electrical pretreatment, strike treatment (electrolytic nickel plating), before electroless nickel plating. When the filtering material 12 is made of aluminum, the electroless nickel plating is performed in the following order: degreasing, etching, desmutting, zincating, and plating. When the filtering material 12 is made of copper, plastic (resin), or ceramic, it is preferable to adsorb palladium before plating.

[0036] The dry process is a process performed in a vacuum. In the dry process, DLC (diamond-like carbon), TiN, or CrN can be used. In this case, the surface treatment layer 14 is composed of a DLC layer, a TiN layer, or a CrN layer. Note that DLC is preferable from the viewpoints of film thickness accuracy, film uniformity, and control of lyophobicity. Typical DLC treatment methods include PVD (physical vapor deposition), CVD (chemical vapor deposition), ionization deposition, and ion implantation. From the viewpoint of adhesion to the base material, PVD or ion implantation is preferable. When the filter material 12 is composed of resin, the DLC layer can be formed using ion implantation, a dry process.

[0037] Alternatively, the surface treatment layer 14 can be formed by coating the filtering material 12 with metal particles or ceramic particles. When the filtering material 12 is aluminum, its surface can be modified by electrolytic treatment using an acid or alkaline solution, and a ceramic coating such as alumina can be formed as the surface treatment layer 14. The processing time for the electrolytic treatment described above can control the mesh size by expanding the filtering material 12. The surface treatment layer 14 is formed after the filtering material 12 is molded into the external shape of the filter body 10. In this case, the surface treatment layer 14 is formed, for example, as an electroless nickel plating layer or a DLC layer, while the filtering material 12 is molded into the external shape of the filter body 10. The filtering material 12 molded into the external shape of the filter body 10 is immersed in a plating solution to form an electroless plating layer as the surface treatment layer 14.

[0038] The thickness d of the surface treatment layer 14 is preferably 0.005 μm or more and less than 15 μm, and is preferably set to a film thickness such that the mesh size δ does not become zero. The mesh size δ can be controlled by the thickness d of the surface treatment layer 14. If the thickness d of the surface treatment layer 14 is 0.005 μm or more and less than 15 μm, peeling of the surface treatment layer is suppressed, and furthermore, the occurrence of defects such as pinholes is also suppressed, which is preferable. The thickness d of the surface treatment layer 14 is more preferably 1 μm to 10 μm, since it allows for accurate film formation. Regarding the thickness d of the surface treatment layer 14, first, the length d of the part corresponding to the diameter of the filtration medium 12 (see FIG. 3) before the surface treatment layer 14 is formed is calculated. １ Next, after the surface treatment layer 14 is formed, the length d of the part corresponding to the diameter of the filtering component 15 (see FIG. 3) is measured. ２ The thickness d of the surface treatment layer 14 is measured using a vernier caliper or a micrometer. ２ -d １ ) / 2. Using this formula, the thickness d of the surface treatment layer 14 is calculated. When the length D of the filtration component 15 is used, the thickness d of the surface treatment layer 14 is calculated by the following formula: d=(D-d １ ) / 2. １ is the length of the portion of the filtration medium 12 corresponding to the length D of the filtration component 15.

[0039] In solid-liquid separation, metal filters manufactured using a wire-wound filter method are used as filters that do not consume filter material and have good backwashing efficiency. However, the manufacturing limit for wire-wound metal filters is 2 μm. Therefore, they cannot filter solids with particle sizes less than 2 μm. In contrast, the above-mentioned filters can have a mesh size δ of less than 2 μm by adjusting the thickness d (see FIG. 3) of the surface treatment layer 14. On the other hand, porous filters manufactured using a metal sintering method or resin porous filters can have a mesh size of less than 2 μm. However, the above-mentioned porous filters and resin porous filters have poor backwashing efficiency, and when clogging occurs, the entire filter body must be replaced or cleaned. In contrast, the above-mentioned filters can have an opening of less than 2 μm and also have good backwashing efficiency. As such, the filters have excellent solid-liquid separation performance, can suppress clogging of the filter material, and have excellent wear resistance. Clogging is evaluated by filtering a predetermined amount of liquid to be filtered and measuring the amount of filtrate obtained in a set time, for example, 30 minutes, i.e., the throughput. When the gaps in the filter body are clogged with filtered material, the amount of liquid to be filtered flowing into the interior of the filter body from its surface decreases, and the amount of filtrate obtained also decreases. Therefore, clogging can be evaluated by measuring the amount of filtrate obtained by filtering the liquid to be filtered within a set time for a set amount of liquid to be filtered. Since the amount of filtrate flowing in decreases as the pressure of the filter body increases, clogging can also be evaluated using the pressure of the filter body.

[0040] <First Example of Processing Apparatus> The processing apparatus will be described below. Fig. 10 is a schematic diagram showing a first example of a processing apparatus according to an embodiment of the present invention. In Fig. 10, the symbol G １ indicates the flow of liquid during filtration, and symbol G ２indicates the flow of fluid during backwashing. The treatment device 20 removes solids from a liquid to be filtered containing solids and includes the cylindrical filter body 10 shown in FIG. 1. In the treatment device 20, the filter body 10 removes solids from the liquid to be filtered. The treatment device 20 can also be configured to include the cylindrical filter body 10d shown in FIG. 6. In the treatment device 20 shown in FIG. 10, the same components as those in FIGS. 1 to 9 are designated by the same reference numerals and detailed descriptions thereof are omitted. The treatment device 20 includes a container 22 in which the filter body 10 is housed. The liquid to be filtered is filtered in the interior 22a of the container 22, and solids are separated from the liquid to be filtered, thereby obtaining a filtrate. The container 22 includes a cylindrical container body 23, a first housing 24a provided at one longitudinal end 23a of the container body 23, and a second housing 24b provided at the other longitudinal end 23b of the container body 23. The interior of the container body 23 is the interior 22a of the container 22. A pipe 25 is connected to the peripheral surface 23c of the container body 23. A tank 26 is provided at the end of the pipe 25. The tank 26 is a storage tank for the liquid to be filtered. A pump 27 is provided in the pipe 25 between the container body 23 and the tank 26.

[0041] A pipe 28 is connected to the first housing 24a. A recovery tank 29 is provided at the end of the pipe 28. The recovery tank 29 is a storage tank for the filtrate. A first switching valve 30 is provided between the first housing 24a and the recovery tank 29.

[0042] The supply unit 33 can also supply filtrate or gas to the interior 10b of the filter body 10 to perform backwashing from the interior 10b to the surface 10a of the filter body 10. A pipe 31 is connected to the first switching valve 30. A supply unit 33 is provided at the end of the pipe 31. The supply unit 33 supplies filtrate or gas to the filter body 10 during backwashing. In the case of gas, for example, the supply unit 33 has a gas cylinder (not shown) used for backwashing and a regulator (not shown) for adjusting the flow rate of the gas. The supply unit 33 may have a compressor. The pipe 31 and the supply unit 33 constitute a backwashing unit that performs the backwashing function.

[0043] A pipe 36 is connected to the second housing 24b. An on-off valve 37 is provided on the pipe 36. A container 38 is disposed below an end 36a of the pipe 36. The container 38 stores waste matter discharged from the inside of the container body 23 during backwashing.

[0044] <First Example of Treatment Method> A first example of the treatment method will be described using the treatment device 20. The first example of the treatment method is a treatment method for removing solids from a liquid to be filtered that contains solids, using the above-mentioned filter body 10. In the first example of the treatment method, the liquid to be filtered in the tank 26 of the treatment device 20 is pumped and supplied into the container body 23 by the pump 27. As a result, the inside of the container body 23 is filled with the liquid to be filtered, and the filter body 10 becomes entirely immersed in the liquid to be filtered.

[0045] Next, the first switching valve 30 is opened to the collection tank 29 and closed to the supply unit 33. The liquid to be filtered is sent by the pump 27 and filtered, and the filtrate is stored in the collection tank 29. At this time, the liquid to be filtered supplied to the surface 10a of the filter body 10 passes through the gaps 16 (see FIG. 2) with a mesh size δ and is sent to the interior 10b of the filter body 10. The liquid to be filtered supplied to the surface 10a of the filter body 10 passes through the interior 10b of the filter body 10 and is filtered, and solids (not shown) are removed from the liquid to be filtered, resulting in a filtrate. The solids adhere to the surface 10a of the filter body 10 as filtrate Sr (see FIG. 3), for example, in the form of a layer (filtration process). The filtrate in the collection tank 29 is reused or discarded as waste. In this way, the filtered liquid to be filtered, i.e., the filtrate, is discharged to the outside of the filter body 10. As described above, the process of sending the liquid to be filtered to the interior 22a of the container 22, removing solid matter from the liquid to be filtered, and filtering the liquid to be filtered is called liquid-feed filtration.

[0046] In the treatment method using the treatment device 20, backwashing is performed, for example, as follows. First, in the treatment device 20, the first switching valve 30 is opened relative to the piping 31 and closed relative to the recovery tank 29. The filtrate or gas used for backwashing is supplied from the supply unit 33 through the piping 31 to the interior 10b of the filter body 10. Then, the filtered material adhering to the surface 10a of the filter body 10 is removed. At this time, the on-off valve 37 is opened, and the removed filtered material is discharged from the interior 22a of the container 22 through the piping 36 and into the container 38.

[0047] Furthermore, backwashing can be performed using filtrate instead of gas, which is used for backwashing. In this case, the liquid to be filtered may or may not be present in the interior 22a of the container 22. The treatment device 20 and the treatment method using the treatment device 20 use the filter body 10, which provides excellent solid-liquid separation performance, prevents clogging of the filter material, and is also excellent in wear resistance.

[0048] <Second Example of Processing Apparatus> Fig. 11 is a schematic diagram showing a second example of a processing apparatus according to an embodiment of the present invention. Fig. 12 is a schematic plan view showing a second example of a processing apparatus according to an embodiment of the present invention. In Figs. 11 and 12, the same components as those in Figs. 1 to 10 are given the same reference numerals, and detailed description thereof will be omitted. In Fig. 11, the reference numeral G １ indicates the flow of liquid during filtration, and symbol G ２ indicates the flow of fluid during backwashing. The treatment device 40 removes solids from a liquid to be filtered that contains solids, and includes the cylindrical filter body 10 shown in FIG.

[0049] The treatment device 40 includes the filter body 10, a storage tank 42, a pressure reducing unit 44, a driving unit 46, a scraper 48, and a control unit 50. Each unit of the treatment device 40 is controlled by the control unit 50.

[0050] The filter body 10 has a hollow cylindrical structure with both ends 10c (see FIG. 12) open in the extension direction of the central axis C (see FIG. 12). As shown in FIG. 12, one end 10c of the filter body 10 is closed by a side plate 51a, and the other end 10c is closed by a side plate 51b. The interior 10b of the filter body 10 is sealed by the side plates 51a and 51b. A hollow rotating shaft 52 communicating with the interior 10b of the filter body 10 is provided in the side plate 51a. A pipe 53 is connected to the hollow rotating shaft 52. The drive unit 46 is connected to the side plate 51b via a rotating shaft 54. The rotating shaft 54 ​​and the hollow rotating shaft 52 are each provided with a bearing, not shown. The filter body 10 can rotate, for example, in a direction Dr (see FIG. 11 ) around a central axis C by means of the hollow rotary shaft 52 and the rotary shaft 54, and the hollow rotary shaft 52 and the rotary shaft 54 ​​are each supported by bearings. The filter body 10 may be provided with a cylindrical frame (not shown) in the interior 10b. Providing a cylindrical frame increases the rigidity of the filter body 10. The configuration of the filter body 10 is as described above.

[0051] As described below, the pressure in the interior 10b of the filter body 10 is reduced by the pressure reducing unit 44, and the liquid to be filtered supplied to the surface 10a of the filter body 10 passes through the gaps 16 with a mesh size δ (see FIG. 2 ) and enters the interior 10b of the filter body 10. At this time, solid matter in the liquid to be filtered is captured on the surface 10a of the filter body 10, and the solid matter is removed from the liquid to be filtered. As a result, a filtrate from which the solid matter has been removed is obtained and accumulates in the interior 10b of the filter body 10. Furthermore, during filtration, the solid matter captured on the surface 10a of the filter body 10 adheres, for example, in the form of a layer, as filtrate Sr. The filtrate Sr is composed of solid matter. The filtrate described above is the liquid to be filtered from which the solid matter has been removed.

[0052] As shown in Fig. 11 , the storage tank 42 stores the liquid to be filtered in its interior 42a, and supplies the liquid to be filtered to the surface 10a of the filter body 10. As shown in Fig. 12 , the storage tank 42 is longer than the length of the filter body 10 in the extension direction of the central axis C. Also, as shown in Fig. 11 , the storage tank 42 is provided so as to cover a portion of the entire circumference of the surface 10a of the filter body 10. As shown in Fig. 12 , the storage tank 42 is disposed with a gap 43 provided between the storage tank 42 and the surface 10a of the filter body 10. The liquid to be filtered is supplied into the gap 43. As shown in Fig. 11 , the filter body 10 is disposed so that a portion of the entire circumference of the surface 10a extends into the storage tank 42, and a portion of the filter body 10 is immersed in the liquid to be filtered.

[0053] A pipe 25 is connected to the storage tank 42, and the liquid to be filtered is supplied from the tank 26 to the storage tank 42 through the pipe 25. As a result, a portion of the filter body 10 is immersed in the liquid to be filtered. At this time, for example, a pump 27 is provided on the pipe 25 to supply the liquid to be filtered to a gap 43 between the tank 26 and the storage tank 42. Note that if the liquid to be filtered can be supplied to the gap 43 by utilizing the pressure difference due to the difference in height between the tank 26 and the storage tank 42, the pump 27 is not necessarily required. A pipe 36 is connected to the bottom surface 42c of the storage tank 42, as in the treatment device 20 described above. An open / close valve 37 is provided on the pipe 36. A container 38 is disposed below an end 36a of the pipe 36. The container 38 stores the waste discharged from the storage tank 42 during backwashing.

[0054] Furthermore, a pipe 53 is connected to a hollow rotating shaft 52 of a side plate 51a provided at the end 10c of the filter body 10, and a pressure reducing unit 44 is provided on this pipe 53. Because the pipe 53 communicates with the interior 10b of the filter body 10, the pressure reducing unit 44 can be used to reduce the pressure in the interior 10b of the filter body 10. A first switching valve 30 is provided between the pressure reducing unit 44 and the side plate 51a. A supply unit 33 is provided to the first switching valve 30 via a pipe 55. A pipe 28 is provided to the pressure reducing unit 44. A recovery tank 29 is provided at the end of the pipe 28. Filtrate is supplied from the pressure reducing unit 44 to the recovery tank 29 through the pipe 28.

[0055] The pressure reducing unit 44 reduces the pressure inside the interior 10b of the filter body 10, and passes the liquid to be filtered, which has been supplied to the surface 10a of the filter body 10, through the gaps 16 (see FIG. 2 ) with a mesh size δ of the filter body 10 into the interior 10b, thereby removing solids from the liquid to be filtered using the filter body 10 to obtain filtrate. The filtrate accumulates in the interior 10b of the filter body 10. The pressure reducing unit 44 reduces the pressure inside the interior 10b of the filter body 10, thereby discharging the filtrate accumulated in the interior 10b of the filter body 10 to the outside of the filter body 10 and storing it in the recovery tank 29. The process of reducing the pressure inside the interior 10b of the filter body 10, taking the liquid to be filtered into the interior 10b of the filter body 10, removing solids from the liquid to be filtered, and filtering the liquid to be filtered is called vacuum filtration or reduced-pressure filtration.

[0056] A vacuum pump, for example, is used as the pressure reducing unit 44. Due to the pressure difference between the outside and the inside 10b of the filter body 10 generated by the pressure reducing unit 44, the liquid to be filtered supplied to the surface 10a of the filter body 10 is taken into the inside 10b of the filter body 10 and filtered under reduced pressure. When the surface 10a of the filter body 10 is not in contact with the liquid to be filtered, the pressure difference causes the moisture in the filtered material Sr to be taken into the inside 10b, thereby reducing the moisture content of the filtered material Sr attached to the surface 10a of the filter body 10. This reduces the moisture content of the separated solid matter.

[0057] Here, the pressure inside the interior 10b of the filter body 10 when the pressure reducing section 44 is decompressed is expressed as the pressure difference from the pressure outside the filter body 10, i.e., atmospheric pressure. Therefore, the pressure inside the interior 10b of the filter body 10 when the pressure reducing section 44 is decompressed can be obtained by measuring the pressure inside the interior 10b of the filter body 10 using, for example, a pressure gauge or a pressure sensor. The pressure of the vacuum pump when decompressed corresponds to the pressure inside the interior 10b of the filter body 10.

[0058] As shown in FIG. 12 , the drive unit 46 rotates the filter body 10 around the central axis C of the filter body 10, for example, in a direction Dr (see FIG. 11 ). A rotation shaft 54 ​​is connected to the side plate 51 b, and the drive unit 46 is connected to the rotation shaft 54. The rotation, direction, and rotation speed of the filter body 10 by the drive unit 46 are controlled by the control unit 50. Note that, although the drive unit 46 is directly connected to the rotation shaft 54 ​​in the illustrated embodiment, this is not limiting. For example, a motor may be used for the drive unit 46, a pulley may be provided on the rotation shaft 54, and the pulley may be connected to a drive wheel of the motor's reducer by a belt. In this case, the rotational force of the motor may be transmitted to the pulley via a belt to rotate the rotation shaft 54, thereby rotating the filter body 10. Here, if the rotation speed of the filter body 10 is slow, the time during one rotation during which the surface 10a of the filter body 10 is in contact with the liquid to be filtered becomes longer, and a large amount of filtered material adheres to the liquid to be filtered, blocking the gaps 16 of the mesh size δ (see FIG. 2 ), reducing the amount of liquid to be filtered that is drawn into the interior 10b of the filter body 10, which tends to slow down the filtration rate. However, the time during which the surface 10a of the filter body 10 is not in contact with the liquid to be filtered also becomes longer, which lengthens the time required for the dehydration step described below, and therefore tends to lower the moisture content of the filtered material Sr.

[0059] On the other hand, if the rotation speed of the filter body 10 is fast, the time during which the surface 10a of the filter body 10 is in contact with the liquid to be filtered is shortened, less filtered material adheres to the liquid to be filtered, and the clogging of the gaps 16 (see FIG. 2 ) of the mesh size δ is suppressed, which tends to increase the filtration rate. However, the time during which the surface 10a of the filter body 10 is in contact with the liquid to be filtered is shortened, which tends to shorten the time for the dehydration process described below and increase the water content of the filtered material. Furthermore, if the rotation speed of the filter body 10 is too fast, the removal efficiency of the filtered material Sr on the surface 10a of the filter body 10 is reduced. When filtered material remains on the surface 10a of the filter body 10, the clogged gaps 16 (see FIG. 2 ) are formed, making it difficult for the liquid to be filtered to be taken into the interior 10b of the filter body 10, and the filtration rate tends to be slower.

[0060] If the rotation speed of the filter body 10 is 2.5 to 7.5 rpm (revolutions per minute), the surface 10a of the filter body 10 is in contact with the liquid to be filtered for an appropriate period of time per rotation, which reduces the amount of filtrate adhering to the liquid to be filtered and suppresses clogging of the gaps 16 (see FIG. 2) of the mesh size δ. Furthermore, the filtrate Sr on the surface 10a of the filter body 10 can be appropriately removed, suppressing a decrease in the filtration rate. For this reason, it is preferable that the rotation speed of the filter body 10 be 2.5 to 7.5 rpm. The filtration rate is the amount of filtrate discharged per unit time. Therefore, the filtration rate can be obtained by measuring the flow rate of filtrate discharged from the filter body 10, i.e., the flow rate of filtrate in the piping 53 or the flow rate of filtrate in the pressure reducing section 44.

[0061] The filter body 10 includes a removal unit (not shown) that removes the filtered material Sr adhering to the surface 10a of the filter body 10 due to the removal of solid matter by the filter body 10. The removal unit, for example, removes the filtered material Sr adhering to the surface 10a of the filter body 10 while the filter body 10 is rotated by the drive unit 46. An example of the removal unit is a scraper 48. Note that the removal unit is not particularly limited to the scraper 48. The configuration of the scraper 48 is not particularly limited as long as it can remove the solid matter, i.e., the filtered material Sr, adhering to the surface 10a of the filter body 10. The scraper 48 is, for example, a flat plate made of PTFE. The end 48c of the scraper 48 is a side portion extending in the extension direction of the central axis C of the filter body 10. The end 48c of the scraper 48 is pressed against the surface 10a of the filter body 10. For this reason, if the surface 10a of the filter body 10 has low hardness, it is prone to wear.

[0062] A container 60 is disposed below the scraper 48. The container 60 collects the filtered material Sr. The filtered material Sr from the filter body 10 removed by the scraper 48 slides over the surface 48a of the scraper 48 and is stored in the interior 60a of the container 60. The scraper 48 is disposed so that the surface 48a forms a larger angle with the surface 10a of the filter body 10 than the back surface 48b. This allows the removed filtered material Sr to be more reliably stored in the container 60. In addition, a spring or the like may be provided as a scraping pressure adjustment unit to adjust the scraping pressure of the scraper 48.

[0063] When the filtered matter Sr adhering to the surface 10a of the filter body 10 is sufficiently scraped off, the amount of filtered matter Sr adhering to the surface 10a of the filter body 10 is small, and the liquid to be filtered is supplied to the surface 10a of the filter body 10 in a state in which blockage of the gaps 16, i.e., clogging, is suppressed. In this case, when the pressure inside 10b of the filter body 10 is reduced, the liquid to be filtered is more easily taken into the inside 10b of the filter body 10. In other words, the amount of liquid to be filtered increases. This increases the filtration rate.

[0064] The scraping pressure of the scraper 48 is set within a range, including an upper limit, depending on the strength of the surface 10a of the filter body 10, so that the surface treatment layer 14 is not damaged, such as peeled off. If the scraping pressure is appropriate, the filtered material Sr adhering to the surface 10a of the filter body 10 can be sufficiently scraped off without damaging the surface treatment layer 14, such as peeling off, and the filtration rate increases. The scraping pressure is measured using a commercially available pressure measurement film. A specific example of a pressure measurement film is the pressure measurement film Prescale (product name) manufactured by Fujifilm Corporation. The prescale is set on the surface 10a of the filter body 10, and the scraper 48 is brought into contact with the prescale for five seconds. The pressure calculated from the prescale after the scraper 48 has been in contact for five seconds is the scraping pressure. The scraping pressure is the pressure at the center of the scraper 48 in the extension direction of the central axis C of the filter body 10.

[0065] In the treatment device 40, the position where the liquid to be filtered in the gap 43 contacts the surface 10a of the filter body 10 on a plane (not shown) perpendicular to the central axis C of the filter body 10 shown in FIG. 11 is defined as D. １ , D ２ The position where the scraper 48 contacts the surface 10a of the filter body 10 is defined as D ３ In this case, when the filter body 10 is rotated in the direction Dr, the position D １ ~Position D ２ Section R １ The filtration step is carried out at position D. ２ ~Position D ３ Section R ２ The dehydration step is carried out at position D ３ ~Position D １ Section R ３ The removal process is carried out at position D. １ ~Position D ２ Section R １ At position D, the filter body 10 is immersed in the liquid to be filtered. １ ~Position D ２ Section R １ (filtration process), position D ２ ~Position D ３ Section R ２ (Dehydration process), position D ３ ~Position D １ Section R ３ The rate of the (removal step) is not particularly limited, but is determined appropriately depending on, for example, the filtration rate. １ ~Position D ２ Section R １ (filtration process), position D ２ ~Position D ３ Section R ２ (Dehydration process), position D ３ ~Position D １ Section R ３ The ratio of (removal step) is, for example, R １ :R ２ :R ３= 3:5:1. In the treatment device 40, the filter body 10 is rotated in the direction Dr, and the filtration process, dehydration process, and removal process are performed in this order, repeatedly for each rotation of the filter body 10. The filtration process, dehydration process, and removal process are performed with the interior 10b of the filter body 10 under reduced pressure.

[0066] The filtration process is a process in which the liquid to be filtered supplied to the surface 10a of the filter body 10 is filtered through the interior 10b of the filter body 10 as described above, removing solids from the liquid to obtain filtrate. In the filtration process, solids adhere to the surface 10a of the filter body 10 as filtrate Sr. The dehydration process is a process in which the pressure difference between the exterior and interior 10b of the filter body 10 is used to take the moisture from the filtrate Sr adhered to the surface 10a of the filter body 10 into the interior 10b, thereby further removing moisture from the filtrate Sr. The dehydration process reduces the moisture content of the filtrate Sr. If the dehydration process is insufficient, for example, due to a high rotation speed of the filter body 10, the moisture content of the filtrate Sr will increase. The removal process is a process in which the filtrate Sr adhered to the surface 10a of the filter body 10 is removed using, for example, a scraper 48 while the filter body 10 is rotating. The removed filtrate Sr is stored in the interior 60a of the container 60. The supply section 33 can also supply filtrate or gas to the interior 10b of the filter body 10 to perform backwashing from the interior 10b of the filter body 10 to the surface 10a.

[0067] 1. The processing device 40 can also use the filter body 10d shown in FIG. 6 instead of the filter body 10 shown in FIG. 1. The filter body 10 shown in FIG. 1 has a filtration component 15 arranged in a circumferential direction C. Ｒ 4, the extension direction of the end 48c of the scraper 48 is perpendicular to the arrangement direction of the filtration components 15. On the other hand, in the filter body 10d shown in Fig. 6 described above, the extension direction of the end 48c of the scraper 48 is parallel to the arrangement direction of the filtration components 15. Therefore, a filter body 10 in which the arrangement direction of the filtration components 15 is perpendicular to the extension direction of the end 48c of the scraper 48 is preferable because it has less resistance to the scraper 48 and suppresses wear of the surface treatment layer 14 of the filter body 10.

[0068] <Second Example of Treatment Method> A second example of the treatment method will be described using a treatment device 40. The second example of the treatment method is a treatment method for removing solids from a liquid to be filtered that contains solids using the above-mentioned filter body 10. The second example of the treatment method will be described using an example of a method for removing solids using a developer fatigue liquid that contains solids generated by removing unexposed areas of a flexographic printing plate precursor after imagewise exposure through development using a washout liquid as the liquid to be filtered. In the treatment method, first, the liquid to be filtered in the tank 26 is supplied to the storage tank 42 by the pump 27. As a result, a portion of the entire circumference of the surface 10a of the hollow cylindrical filter body 10 is immersed in the liquid to be filtered, and the liquid to be filtered is supplied to the surface 10a of the filter body 10.

[0069] Next, the pressure inside 10b of the filter body 10 is reduced by the pressure reducing unit 44. At this time, the liquid to be filtered supplied to the surface 10a of the filter body 10 is sucked into the interior 10b of the filter body 10 through the gaps 16 of opening δ (see FIG. 2). The liquid to be filtered supplied to the surface 10a of the filter body 10 is passed through the interior 10b of the filter body 10 and filtered, solids (not shown) are removed from the liquid to be filtered, and filtrate is obtained. The solids adhere to the surface 10a of the filter body 10 as filtrate Sr, for example, in the form of a layer (filtration process). The filtrate accumulates in the interior 10b of the filter body 10. The filtration process is also performed when the filter body 10 is rotated and reaches position D shown in FIG. 11 as described above. １ ~Position D ２ Section R １ It will be carried out in.

[0070] Next, the filtrate in the interior 10b of the filter body 10 is discharged to the outside of the filter body 10 (discharge step). In the discharge step, the pressure inside the interior 10b of the filter body 10 is reduced by the pressure reducing unit 44, and the filtrate in the interior 10b of the filter body 10 is sent to the pipe 53. The filtrate is then sent to the pipe 28 via the pressure reducing unit 44 and stored in the recovery tank 29. The filtrate in the recovery tank 29 is then reused or discarded as waste. In this way, the filtered liquid to be filtered, i.e., the filtrate, is discharged to the outside of the filter body 10.

[0071] Furthermore, following the filtration step, a dehydration step is carried out in which, while the filter body 10 is rotating, the moisture in the filtered material Sr adhering to the surface 10a of the filter body 10 is taken into the interior 10b of the filter body 10 by utilizing the pressure difference between the exterior and interior 10b of the filter body 10, thereby further removing moisture from the filtered material Sr. ２ ~Position D ３ Section R ２ Furthermore, the removal step is carried out immediately after the dehydration step, in which the filtered matter Sr adhering to the surface 10a of the filter body 10 is removed while the filter body 10 is rotating. ３ ~Position D １ Section R ３ In the removal step of the filtrate Sr, it is preferable to remove the filtrate Sr adhering to the surface 10a of the filter body 10 using, for example, a scraper 48. As described above, the scraper 48 is set to a scraping pressure that can sufficiently scrape off the filtrate Sr adhering to the surface 10a of the filter body 10 and increase the filtration rate. Furthermore, the rotation speed of the filter body 10 is preferably 2.5 to 7.5 rpm, since this allows the filtrate Sr on the surface 10a of the filter body 10 to be appropriately removed and a decrease in the filtration rate can be suppressed.

[0072] Furthermore, by reducing the pressure inside the filter body 10 as described above, after the liquid to be filtered is supplied to the surface 10a of the filter body 10, the area of ​​the surface 10a of the filter body 10 that has left the storage tank 42 due to the rotation of the filter body 10 is also absorbed by the reduced pressure inside the filter body 10. This reduces the moisture content of the solid filtered material Sr. The filtered material Sr is then removed from the surface 10a of the filter body 10 with a scraper 48 and stored inside the container 60a. The filtered material Sr is disposed of as waste, but because its moisture content has been reduced by the dehydration process, the amount of waste is reduced and incineration does not require much energy. When incinerated, the moisture content of the filtered material Sr is preferably 50% or less, more preferably 25% or less. The moisture content of the filtered material Sr is determined by flaking the filtered material Sr and drying it at 95°C for 16 hours. The weight of the filtered material before drying and the weight of the filtered material after drying are measured using a balance, and the value calculated using the following formula is the moisture content of the filtered material: Moisture content of filtered material = {((weight of filtered material before drying) - (weight of filtered material after drying)) / (weight of filtered material before drying)} x 100 (%). Note that, since the treatment device 40 and the treatment method using the treatment device 40 use the filter body 10, they have excellent solid-liquid separation performance, can suppress clogging of the filter material, and are also excellent in abrasion resistance.

[0073] In a treatment method using the treatment device 40, backwashing is performed, for example, as follows. During backwashing, for example, the interior 42a of the storage tank 42 may or may not contain a liquid to be filtered. First, in the treatment device 40, the first switching valve 30 is opened relative to the piping 55 and closed relative to the pressure reducing unit 44. The filtrate or gas used for backwashing is supplied from the supply unit 33 through the piping 53 to the interior 10b of the filter body 10. Then, the filtered material adhering to the surface 10a of the filter body 10 is removed. At this time, the on-off valve 37 is opened, and the removed filtered material is discharged from the interior 42a of the storage tank 42 through the piping 36 and into the container 38.

[0074] Furthermore, backwashing can be performed using filtrate instead of gas, which is used for backwashing. In this case, the liquid to be filtered may or may not be present in the interior 42a of the storage tank 42. The pumps, valves, piping, tanks, and containers that make up the treatment device 20 and treatment device 40 described above may be any of those known in the art.

[0075] <Liquid to be Filtrated> The liquid to be filtrated will now be described. There are no particular limitations on the liquid to be filtrated, as long as it contains solid matter to be removed.

[0076] (Flexographic Printing Plate Precursor) A flexographic printing plate precursor forms a flexographic printing plate used in flexographic printing, and its configuration is not particularly limited. A flexographic printing plate precursor is thin, having a thickness of about several millimeters, and is flexible. Having flexibility means that a flexographic printing plate precursor returns to its original state after a force is applied to it and the force is removed. The size of the flexographic printing plate precursor is, for example, 800 mm × 1200 mm or 1050 mm × 1500 mm. The flexographic printing plate precursor can be developed with, for example, an aqueous washout solution containing water as the main component, and is called a water-developable flexographic printing plate precursor. In this case, the washout solution is an aqueous washout solution. As the flexographic printing plate precursor, a known flexographic printing plate precursor that can be developed with an aqueous washout solution can be used, and the flexographic printing plate precursor may be a flexographic printing plate material that is compatible with CTP (Computer To Plate) and has a black layer applied to its surface.

[0077] The washout liquid will be described below. A washout liquid appropriate for the flexographic printing plate precursor is used. <Washout Liquid> A water-based washout liquid is used. The water-based washout liquid may be a liquid consisting of water alone, or may be an aqueous solution containing 50% by mass or more of water and having a water-soluble compound added thereto. Examples of the water-soluble compound include surfactants, acids, and alkalis.

[0078] Examples of surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants, and among these, anionic surfactants are preferred. Specific examples of the anionic surfactant include aliphatic carboxylates such as sodium laurate and sodium oleate; higher alcohol sulfates such as sodium lauryl sulfate, sodium cetyl sulfate and sodium oleyl sulfate; polyoxyethylene alkyl ether sulfates such as sodium polyoxyethylene lauryl ether sulfate; polyoxyethylene alkyl allyl ether sulfates such as sodium polyoxyethylene octylphenyl ether sulfate and sodium polyoxyethylene nonylphenyl ether sulfate; alkyl sulfonates such as alkyl diphenyl ether disulfonates, sodium dodecyl sulfonate and sodium dialkyl sulfosuccinate; alkyl allyl sulfonates such as alkyl disulfonates, sodium dodecyl benzene sulfonate, sodium dibutyl naphthalene sulfonate and sodium triisopropyl naphthalene sulfonate; higher alcohol phosphates such as disodium lauryl phosphate monoester and sodium lauryl phosphate diester; and polyoxyethylene alkyl ether phosphates such as disodium polyoxyethylene lauryl ether phosphate monoester and sodium polyoxyethylene lauryl ether phosphate diester. These may be used alone or in combination of two or more. Although sodium salts have been given as specific examples, the present invention is not limited to sodium salts, and calcium salts, ammonium salts, etc. may also provide similar effects.

[0079] Specific examples of nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether or polyoxyethylene lauryl ether, polyoxyethylene alkyl phenyl ethers such as polyoxyethylene nonylphenyl ether or polyoxyethylene octylphenyl ether, polyoxyethylene polyoxypropylene glycols, mono- and diesters of fatty acids and polyethylene glycol such as polyethylene glycol monostearate, polyethylene glycol monooleate, or polyethylene glycol dilaurate, esters of fatty acids and sorbitan such as sorbitan monolaurate or sorbitan monooleate, and polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate, or polyoxyethylene sorbitan trilaurate. Examples of the ester include esters of ethylene glycol adducts and fatty acids, esters of sorbitol and fatty acids such as sorbitol monopalmitate or sorbitol dilaurate, esters of polyoxyethylene adducts of sorbitol and fatty acids such as polyoxyethylene sorbitol monostearate or polyoxyethylene sorbitol dioleate, esters of pentaerythritol and fatty acids such as pentaerythritol monostearate, esters of glycerol and fatty acids such as glycerol monolaurate, fatty acid alkanolamides such as lauric acid diethanolamide or lauric acid monoethanolamide, amine oxides such as lauryldimethylamine oxide, fatty acid alkanolamines such as stearyldiethanolamine, polyoxyethylene alkylamines, triethanolamine fatty acid esters, and alkaline salt compounds such as phosphates, carbonates, silicates, etc. These may be used alone or in combination of two or more.

[0080] Specific examples of cationic surfactants include primary, secondary, and tertiary amine salts such as monostearyl ammonium chloride, distearyl ammonium chloride, and tristearyl ammonium chloride, quaternary ammonium salts such as stearyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, and stearyl dimethyl benzyl ammonium chloride, alkyl pyridinium salts such as N-cetyl pyridinium chloride and N-stearyl pyridinium chloride, N,N-dialkyl morpholinium salts, fatty acid amide salts of polyethylene polyamines, acetate salts of urea compounds of amides of aminoethyl ethanolamine and stearic acid, and 2-alkyl-1-hydroxyethyl imidazolinium chloride. These may be used alone or in combination of two or more.

[0081] Specific examples of amphoteric surfactants include amino acid surfactants such as laurylamine sodium propionate, carboxybetaine surfactants such as lauryl dimethyl betaine or lauryl dihydroxyethyl betaine, sulfobetaine surfactants such as stearyl dimethyl sulfoethylene ammonium betaine, imidazolinium betaine surfactants, lecithin, etc. These surfactants may be used alone or in combination of two or more.

[0082] Specific examples of acids include inorganic or organic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, acetic acid, oxalic acid, succinic acid, citric acid, malic acid, maleic acid, and paratoluenesulfonic acid. Specific examples of alkalis include lithium hydroxide, sodium hydroxide, magnesium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide, sodium carbonate, sodium hydrogencarbonate, and calcium carbonate.

[0083] <Developer fatigue liquid> As described above, the developer fatigue liquid is a washout liquid containing solids generated by removing the unexposed areas of the flexographic printing plate precursor after imagewise exposure, and refers to the washout liquid after development. The washout liquid after development is the liquid to be filtered. In addition, in a washout liquid containing solids, "containing solids" refers to a state in which the solids are dissolved or dispersed. When the liquid to be filtered is the developer fatigue liquid, the solids in the liquid to be filtered are solids in the developer of the flexographic printing plate precursor. The developer fatigue liquid is not particularly limited as long as it is a washout liquid containing solids generated by removing the unexposed areas of the flexographic printing plate precursor by development using the above-mentioned washout liquid, i.e., a washout liquid containing an uncured resin. However, the developer fatigue liquid may also include a developer fatigue liquid containing a conventionally known photosensitive resin composition for forming a general photosensitive resin layer. The uncured resin removed by development may be a photosensitive resin contained in the photosensitive resin composition. Furthermore, since the target to be treated is preferably a developer fatigue liquid obtained when development is performed using the LAM (Laser Ablation Masking) method, the uncured resin removed by development is preferably a photosensitive resin contained in a photosensitive resin composition. Furthermore, examples of such photosensitive resin compositions include compositions containing, in addition to the photosensitive resin, for example, a polymerization initiator, a polymerizable compound, a polymerization inhibitor, a plasticizer, etc., and therefore the developer fatigue liquid may contain, in addition to the uncured resin, a polymerization initiator, a polymerizable compound, a polymerization inhibitor, a plasticizer, etc. Note that when the flexographic printing plate precursor is a water-developable flexographic printing plate precursor, the solid matter in the liquid to be filtered is a solid matter in the developer of the water-developable flexographic printing plate precursor.

[0084] The liquid to be filtered is not particularly limited to the washout liquid after development described above. In addition to the washout liquid after development described above, other examples of the liquid to be filtered include river water, lake water, or seawater containing living organisms or sand particles. Other examples of the liquid to be filtered include grinding fluids containing sludge such as grinding chips and abrasive grains, or cutting oils containing machining chips generated by machining using a milling machine or lathe. Another example of the liquid to be filtered is grinding fluids containing grinding chips generated when grinding glass or plastic lenses. Grinding chips include glass and plastic that make up the lens, and abrasive grains generated during grinding. Another example of the liquid to be filtered is electrical discharge machining fluid used in electrical discharge machining. Electrical discharge machining fluids contain solid matter such as electrode wear powder and dust generated by electrical discharge machining.

[0085] The present invention is basically configured as described above. Although the filter body, processing device, and processing method of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various improvements and modifications may be made without departing from the spirit and scope of the present invention.

[0086] The features of the present invention are explained in more detail below with reference to examples. The materials, reagents, amounts and ratios of substances, and procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples below. In these examples, the removability of solid matter after filtration, clogging of the coating material, and wear of the filter material were evaluated for Examples 1 to 9 and Comparative Examples 1 to 3. The results of the removability of solid matter after filtration, clogging of the coating material, and wear of the filter material are shown in Table 1 below. The removability of solid matter after filtration, clogging of the filter material, and wear of the filter material are explained below. In these examples, the developer fatigue solution described below was used as the filtered liquid.

[0087] <Removability of solid matter after filtration> The removal rate of solid matter in the fatigued developer solution was confirmed when 40 L of the fatigued developer solution was sent to the treatment device. The removal rate of solid matter in the fatigued developer solution was evaluated according to the following evaluation criteria. The removal rate of solid matter was calculated using (1 - (solid matter concentration after filtration / solid matter concentration before filtration)) x 100 (%). The solid matter concentration was measured using a heat-drying moisture meter from A&D Co., Ltd. Evaluation criteria 1: Solid matter removal rate is 0 to 20% (unusable level) 2: Solid matter removal rate is more than 20% and not more than 40% 3: Solid matter removal rate is more than 40% and not more than 60% 4: Solid matter removal rate is more than 60% and not more than 80% 5: Solid matter removal rate is more than 80%

[0088] <Clogging of filter material> The developer fatigue solution was sent to the processing device, and the processing flow rate after 30 minutes was confirmed. The processing flow rate after 30 minutes was evaluated according to the following evaluation criteria. The processing flow rate after 30 minutes was calculated using the following formula: ((weight of developer fatigue solution tank before processing - weight after 30 minutes) / 30) x 60 (kg (L) / h) Evaluation criteria 1: Processing flow rate is 20 L / h or less (unusable level) 2: Processing flow rate is more than 20 L / h and not more than 40 L / h 3: Processing flow rate is more than 40 L / h and not more than 60 L / h 4: Processing flow rate is more than 60 L / h and not more than 80 L / h 5: Processing flow rate is more than 80 L / h

[0089] <Wear of filter material> The outer diameter of the filter body was measured before and after pumping 40 L of developer fatigue solution. The lifespan of one filter material was calculated from the amount of change in the outer diameter of the filter body before and after pumping 40 L of developer fatigue solution. The lifespan of one filter material was evaluated according to the following evaluation criteria. The outer diameter of the filter body was measured using a vernier caliper to determine the amount of change in the outer diameter of the filter body before and after pumping 40 L of developer fatigue solution. The lifespan relative to the amount of change in the outer diameter of the filter body was set in advance, and the lifespan of one filter material was calculated from the above-mentioned amount of deformation. Evaluation criteria 1: Lifespan of 1 week or less 2: Lifespan of more than 1 week and 1 month or less 3: Lifespan of more than 1 month and 3 months or less 4: Lifespan of more than 3 months and 6 months or less 5: Lifespan of more than 6 months

[0090] <Hardness of Filtering Material and Surface Treatment Layer> In Examples 1 to 9 and Comparative Examples 1 to 3, phenolic resin, aluminum 1050, SUS304, electroless Ni plating, PTFE-containing Ni plating, and DLC were used for the filtering material and surface treatment layer. It is difficult to evaluate the hardness of these materials using the same scale. For this reason, the hardness of the phenolic resin was set to "1" among the above materials. Of the above materials, the hardness of materials other than phenolic resin was evaluated according to the following criteria based on the known Vickers hardness of each material. Criteria 1: Very soft 2: Soft 3: Normal 4: Hard 5: Very hard

[0091] <Contact Angle> The contact angle was measured under the following measurement conditions. Test pieces were prepared by subjecting the surface of a stainless steel plate to various surface treatments. A contact angle meter DMS-401 (manufactured by Kyowa Interface Science Co., Ltd.) was used to measure the static contact angle by dropping a droplet of the liquid to be filtered onto each test piece. Then, analysis software FAMAS (manufactured by Kyowa Interface Science Co., Ltd.) was used to measure the contact angle by the θ / 2 method. The mesh size was measured as follows. The surface of the filter was photographed using a digital microscope (Keyence Corporation) VHX-1000. The photographed image was analyzed to measure the mesh size.

[0092] The devices and liquid to be filtered used in Examples 1 to 9 and Comparative Examples 1 to 3 are shown below. <Treatment device> Fujiloy manufactured by Fuji Filter Industrial Co., Ltd. PC separator manufactured by AION Co., Ltd. <Liquid to be filtered> Solid concentration: 2.5% by mass <Treatment volume> 40 liters

[0093] <Preparation of solution to be filtered> (Imaging machine) CDI Spark 4835 Inline (manufactured by ESKO) (Exposure machine) Ultraviolet exposure machine Concept 302 ECDLF (product name) (manufactured by Glunz & Jensen) (Developing machine) SB-926 (manufactured by GS TR Corporation) (Flexographic printing plate precursor) FLENEX FW-L2 (manufactured by Fujifilm Graphic Solutions Co., Ltd.) (Developer) Aqueous solution (concentration: 0.5% by mass) of Finish Power & Pure Powder SP (manufactured by Reckitt Benckiser Japan KK) The above-mentioned flexographic printing plate precursor was subjected to back exposure using the above-mentioned ultraviolet exposure machine by exposing the back side of the flexographic printing plate precursor with an energy of 80 W for 10 seconds. Thereafter, the mask layer was ablated using the imaging machine described above, followed by main exposure by exposing the front surface (the back surface of the back surface) at 80 W for 1,000 seconds. The main-exposed flexographic printing plate precursor was used as a flexographic printing plate precursor after imagewise exposure. The main-exposed flexographic printing plate precursor, i.e., the imagewise-exposed flexographic printing plate precursor, was developed with a brush using the developer and the developing machine described above at a liquid temperature of 50°C to remove uncured resin, thereby obtaining a filtrate with a solid concentration of 2.5% by mass.

[0094] Next, Examples 1 to 9 and Comparative Examples 1 to 3 will be described. (Example 1) In Example 1, the above-described liquid to be filtered was treated using an apparatus in the form of treatment apparatus 20 shown in Figure 10. The filtration method used in Example 1 is called liquid-feed filtration. In Example 1, a cylindrical filter body was used. The filter body was obtained by forming a surface treatment layer on a filter material, as described below. Fujiloy, manufactured by Fuji Filter Industrial Co., Ltd., was used as the filter material. The filter body had an outer diameter of 75 mm, an inner diameter of 45 mm, and a length of 70 mm. The filter body was formed by welding a circular plate to both ends of a cylindrical filter material. The circular plate had a circular hole in its center, the center of which was the same as the circular outline of the circular plate. The circular plate was made of the same material as the filter material, and had an outer diameter of 75 mm and an inner diameter of 45 mm. The filter material was made of SUS (Steel Use Stainless) 304 (thickness 2 mm, width and length 70 mm). An electroless Ni plating layer having a thickness of 2.5 μm was formed as a surface treatment layer on the filter medium by electroless plating. The surface treatment layer was an electroless Ni plating layer having a thickness of 2.5 μm. The filter body had a contact angle of 65° and a mesh size of 25 μm.

[0095] (Example 2) Example 2 differs from Example 1 in that the thickness of the electroless Ni plating layer constituting the surface treatment layer was 14.5 μm, and was otherwise the same as Example 1. In Example 2, an electroless Ni plating layer was formed on the filtration material by electroless plating to a thickness of 2.5 μm. In Example 2, the mesh size was 1 μm. (Example 3) Example 3 differs from Example 1 in that the surface treatment layer was a PTFE-containing Ni plating layer with a thickness of 14.5 μm, and was otherwise the same as Example 1. In Example 3, a PTFE-containing Ni plating layer was formed on the filtration material by electroless plating to a thickness of 14.5 μm. In Example 3, the filter body had a contact angle of 80° and a mesh size of 1 μm.

[0096] Example 4 In Example 4, the above-described liquid to be filtered was treated using a treatment device 40 shown in FIG. 11 . A PC separator manufactured by AION Corporation was used as the treatment device. The filtration method using the PC separator in Example 4 is called vacuum filtration. Fujiloy manufactured by Fuji Filter Industrial Co., Ltd. was used as the filter body. The filter body was configured with circular plates welded to both ends of a cylindrically formed filter material. The disks were made of the same material as the filter material. The disks had a circular hole in their center, and the center of the circular hole was aligned with the outer circle of the disk. The filter body had an outer diameter of 300 mm, an inner diameter of 240 mm, and a length of 300 mm. The disks had an outer diameter of 300 mm, an inner diameter of 240 mm, and a thickness of 10 mm. The filter material was made of SUS304 (thickness: 2 mm, width and length: 70 mm), and the electroless Ni plating layer constituting the surface treatment layer was 14.5 μm thick. In Example 4, an electroless Ni plating layer was formed on the filter material by electroless plating to a thickness of 14.5 μm. In Example 4, the filter body had a contact angle of 65° and a mesh size of 1 μm. A flat plate made of PTFE was used as the scraper. The end of the scraper was pressed against the peripheral surface of the filter body.

[0097] (Example 5) Example 5 is different from Example 4 in that the surface treatment layer is a DLC (diamond-like carbon) layer with a thickness of 14.5 μm, but is otherwise the same as Example 4. In Example 5, a DLC layer is formed on the filtering material by ion implantation so as to have a thickness of 14.5 μm. In Example 5, the filter body has a contact angle of 75°. (Example 6) Example 6 is different from Example 4 in that the filtering material is made of aluminum 1050, and the surface treatment layer is made of alumina (Al 1050) with a thickness of 14.5 μm. ２ O ３ In Example 6, an alumina layer was formed on the filtration material by an anodic oxidation method to a thickness of 14.5 μm. In Example 6, the contact angle of the filtration body was 65°.

[0098] (Example 7) Example 7 differs from Example 1 in that the thickness of the filtration material was 20 mm and the surface treatment layer was an electroless Ni-plated layer with a thickness of 14.5 μm, but was otherwise identical to Example 1. In Example 7, an electroless Ni-plated layer was formed on the filtration material by electroless plating to a thickness of 14.5 μm. In Example 7, the mesh size was 1 μm. (Example 8) Example 8 differs from Example 5 in that the thickness of the filtration material was 0.5 mm and the surface treatment layer was a DLC layer with a thickness of 1 μm, but was otherwise identical to Example 5. In Example 8, a DLC layer was formed on the filtration material by ion implantation to a thickness of 1 μm. In Example 8, the filter body had a contact angle of 75° and a mesh size of 1 μm. Example 9 is different from Example 5 in that the thickness of the filtration material is 30 mm and the surface treatment layer is a DLC layer with a thickness of 1 μm, but otherwise the same as Example 5. In Example 9, a DLC layer with a thickness of 1 μm is formed on the filtration material by ion implantation. In Example 9, the filter body has a contact angle of 75° and a mesh size of 1 μm.

[0099] (Comparative Example 1) Comparative Example 1 differs from Example 1 in that the surface treatment layer was a fluororesin layer having a thickness of 10 μm, and was otherwise identical to Example 1. In Comparative Example 1, the contact angle of the filter body was 80° and the mesh size was 30 μm. In Comparative Example 1, a fluororesin layer was formed as a surface treatment layer on the filtration material as follows. The filtration material was immersed in a fluororesin paint containing PTFE, and then heated in a heating furnace to dry and harden the paint, thereby forming a fluororesin layer having a thickness of 10 μm. (Comparative Example 2) Comparative Example 2 differs from Example 4 in that the surface treatment layer was a fluororesin layer having a thickness of 10 μm, and was otherwise identical to Example 4. In Comparative Example 2, the contact angle of the filter body was 80° and the mesh size was 30 μm. The fluororesin layer of the surface treatment layer was also prepared in the same manner as in Comparative Example 1. (Comparative Example 3) Comparative Example 3 differs from Example 4 in that the filtration material is made of phenolic resin (thickness: 30 mm) and that no surface treatment layer is provided, but otherwise is the same as Example 1. Since no surface treatment layer is provided in Comparative Example 3, "-" is entered in the "Material," "Hardness," and "Thickness" columns for "Surface Treatment Layer." The structure of the filtration material of Comparative Example 3 is a porous structure.

[0100]

[0101] As shown in Table 1, Examples 1 to 9 were better than Comparative Examples 1 to 3 in terms of post-filtration solid removal, filter clogging, and filter wear. Comparative Examples 1 and 2 had a 30 μm mesh size and poor post-filtration solid removal. Comparative Example 2 used a scraper, but the surface treatment layer was made of a fluororesin, resulting in a poor evaluation of filter wear. Comparative Example 3 used a phenolic resin filter without a surface treatment layer, resulting in a poor evaluation of filter clogging. Comparative Example 3 used a scraper, but the filter wear was poor. From Examples 1 and 2, it was found that larger mesh sizes resulted in a good evaluation of filter clogging, while smaller mesh sizes resulted in a good evaluation of post-filtration solid removal. From Examples 2 and 3, it was found that larger contact angles resulted in a better evaluation of filter clogging. The magnitude of the contact angle indicates the degree of lyophobicity. From Examples 1 and 7, it was found that the thinner the filter material, the better the evaluation of clogging of the filter material. From Examples 4 and 5, it was found that the harder the surface treatment layer, the better the evaluation of wear of the filter material. From Examples 5, 8, and 9, it was found that the thicker the surface treatment layer, the better the removability of solid matter after filtration.

[0102] 10, 10d Filter body 10a Surface 10b, 22a, 42a, 60a Interior 10c, 23a, 23b, 48c End 12 Filter material 14 Surface treatment layer 15, 18, 19 Filter component 16 Gap 18a, 19a Hole 20, 40 Treatment device 22, 38, 60 Container 23 Container body 23c Peripheral surface 24a First housing 24b Second housing 25, 28, 31, 36, 53, 55 Piping 26 Tank 27 Pump 29 Recovery tank 30 First switching valve 33 Supply unit 36a End 37 Opening / closing valve 42 Storage tank 42c Bottom surface 43 Gap 44 Pressure reducing unit 46 Drive unit 48 Scraper 48a Surface 48b Back surface 50 Control unit 51a, 51b Side plates 52 Hollow rotating shaft 54 ​​Rotating shaft C Central axis C Ｌ Extending direction C Ｒ Circumferential direction Dr direction G １Liquid flow during filtration G ２ Fluid flow during backwash R １ , R ２ , R ３ Section Sr Filtrate D Length d Thickness x, y direction δ Opening

Claims

1. A filter body for removing solid matter from a liquid to be filtered that contains the solid matter, comprising: a filtering material; and a surface treatment layer provided on the filtering material, wherein the hardness of the surface treatment layer is equal to or greater than the hardness of the filtering material, the mesh size of the filter body is less than 30 μm, and the thickness of the filter body is 0.5 to 30 mm.

2. The filter body according to claim 1, wherein the thickness of the surface treatment layer is 0.005 μm or more and less than 15 μm.

3. The filter body according to claim 1, wherein the surface of the filter body is liquidphobic.

4. The filter body according to claim 1, wherein the solid matter in the liquid to be filtered is a solid matter in a developer for a water-developable flexographic printing plate precursor.

5. The filter body of claim 1, wherein the filter body is constructed of metal.

6. A treatment device for removing solids from a liquid to be filtered that contains the solids, comprising a filtering material and a surface treatment layer provided on the filtering material, the hardness of the surface treatment layer being equal to or greater than the hardness of the filtering material, the mesh size of the filtering body being less than 30 μm, and the thickness of the filtering body being 0.5 to 30 mm.

7. The treatment device according to claim 6, further comprising a backwashing function for removing the filtered material adhering to the surface of the filter body from the filter body by removing the solid matter with the filter body.

8. The treatment device according to claim 6, further comprising a removal section for removing filtered matter adhering to the surface of said filter body as a result of the removal of said solid matter by said filter body.

9. The processing device according to claim 8, wherein the removal unit has a scraper, and the filtered material adhering to the surface of the filter body is removed by the scraper.

10. A method for treating a liquid to be filtered using a filter body that removes solids from the liquid to be filtered containing solids, wherein the filter body has a filtering material and a surface treatment layer provided on the filtering material, the hardness of the surface treatment layer is equal to or greater than the hardness of the filtering material, the mesh size of the filter body is less than 30 μm, and the thickness of the filter body is 0.5 to 30 mm.

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