JP6251204B2 - Filter for filtration - Google Patents

Description

  Embodiments described herein relate generally to a filter for filtration.

In recent years, due to industrial development and population increase, effective use of water resources has been demanded. In order to effectively use water resources, it is important to purify and reuse various wastewaters such as industrial wastewater and domestic wastewater. In order to purify the wastewater, it is necessary to separate and remove water insoluble matters and impurities contained in the water.
Examples of a method for separating and removing water-insoluble matter and impurity particles contained in water include a membrane separation method, a centrifugal separation method, an activated carbon adsorption method, an ozone treatment method, and a method for removing suspended solids by adding a flocculant.

  In a filtration method represented by a membrane separation method, water containing suspended substances (hereinafter sometimes referred to as SS particles) that are substances to be removed is added to filters using various forms of membranes and filter media. The SS particles are separated from the water by passing through. As typical filtration mechanisms, there are mechanisms called surface filtration, depth filtration (depth filtration), and cake filtration.

Surface filtration is a mechanism for receiving SS particles contained in water passing through the filter at the surface of the filter. Surface filtration mainly captures SS particles that are larger than the pores of the filter. For example, in a filtration using a membrane, a surface filtration mechanism is mainly used.
The depth filtration is a mechanism that utilizes adhesion of SS particles not only to the surface of the filter but also to the entire surface of the filter in contact with water containing SS particles, such as the inner surface of the pores. In depth filtration, particles smaller than the pores of the filter are mainly captured. For example, in the filtration using a tower filled with a filtering material such as sand, a mechanism of depth filtration is used.
Cake filtration is a mechanism in which SS particles themselves captured by a filter form a cake and function as a filter. Cake filtration captures SS particles that are even smaller than depth filtration.

  Conventionally, a surface filtration mechanism is mainly used in the filtration that separates SS particles from water using a filter using a wire mesh. In a filter using a wire mesh, if a deep layer filtration mechanism is used, particles smaller than the pores of the filter can be captured, the filter is not easily blocked, and the water flow rate is easily secured. However, in a filter using a wire mesh, it is difficult to secure a contact area between the filter and water containing SS particles, and thus there is a case where the mechanism of the depth filtration cannot be used.

  Generally, when water containing SS particles is passed through a filter to remove SS particles from the water, a cake of SS particles is formed and the process proceeds to cake filtration. The filtration performance at this time depends on the formed cake (in other words, depends on SS particles), and a decrease in the filtration flow rate is observed as the cake thickness increases.

  Further, when the filter is washed, if the filter and the SS particles are not smoothly separated, the washing efficiency is lowered, and there is a concern that the consumption of washing water is increased and the performance of the filter is lowered. In addition, in order to remove fine particles, it is necessary to add a flocculant, and there is a problem that the amount of sludge increases.

JP 2008-180206 A

  The problem to be solved by the present invention is a filter for filtration that can capture SS particles in a liquid to be filtered by using a mechanism of deep layer filtration and a mechanism of cake filtration, and can maintain a filtration flow rate even after shifting to cake filtration. Is to provide.

The filter for filtration of embodiment has the filter body which arranged the wire in the surface shape, and the support member which supports the said filter body.
The wire includes a spacing part that separates adjacent wires from each other while maintaining a gap having a predetermined width, and a plurality of fine structures formed on the primary surface side into which at least the liquid to be filtered flows out of the filter body, Is provided.
The fine structure has at least one of a frustum shape, an elliptical cone shape, a polygonal pyramid shape, an elliptical frustum shape, and a polygonal frustum shape.
The formation density of the fine structures is in the range of 1.2 to 10.0 pieces / μm ² .

The schematic block diagram which shows an example of the filtration processing apparatus to which the filter for filtration of embodiment is applied. Sectional drawing which shows the filter for filtration of embodiment. Sectional drawing when the filter for filtration is seen from the end surface side. The principal part expanded sectional view which shows the internal peripheral surface side of the filter for filtration. The principal part expansion schematic diagram which shows the wire in which the fine structure was formed. The SEM photograph at the time of making a fine structure into a needle-like structure. The schematic diagram which shows the wire which formed the separation part. The SEM photograph at the time of making the fine structure 5 into a polyhedral structure. The SEM photograph at the time of making the fine structure 5 into a polyhedral structure. Sectional drawing when the filter for filtration of another embodiment is seen from the end surface side. The principal part expanded sectional view which shows the internal peripheral surface side of the filter for filtration of another embodiment. The principal part expanded sectional view which shows the internal peripheral surface side of the filter for internal pressure type filtration of another embodiment. The principal part expanded sectional view which shows the internal peripheral surface side of the filter for external pressure type filtration of another embodiment. The external appearance perspective view which shows the filter for filtration of another embodiment. The top view which shows the filter for filtration of another embodiment.

  Hereinafter, the filter for filtration of an embodiment is explained.

Hereinafter, the filter for filtration will be described.
Drawing 1 is a schematic structure figure showing an example of a filtration processing device to which a filter for filtration of an embodiment is applied.
The filtration apparatus 100 includes a liquid tank 101 for storing a liquid to be filtered, the filter 10 for filtration according to the embodiment, a treatment liquid tank 103, and a concentrated sludge tank 104. Further, a pump 106 that pumps the liquid to be filtered in the liquid tank 101 to be filtered to the filter 10 for filtration, a pump 107 that discharges the treated water (filtered liquid) in the liquid tank 103 or returns it to the filter 10 for filtration, And a plurality of pipes 108 connecting them.

  The to-be-filtrated tank 101 stores to-be-filtrated liquid. Examples of the liquid to be filtered include water containing SS particles. The to-be-filtrated liquid tank 101 may be provided with a stirrer for stirring the inside of the to-be-filtrated liquid tank 101. The shape, volume, material, and the like of the liquid tank 101 to be filtered can be appropriately determined according to the use of the filtration apparatus 100, and are not particularly limited.

  The filter 10 for filtration removes filtration target objects, such as SS particle | grains, from a to-be-filtered liquid, and produces | generates treated water (filtered liquid). The detailed configuration of the filter 10 for filtration will be described later.

  The processing liquid tank 103 stores the processing liquid. The treatment liquid is generated by passing the liquid to be filtered through the filter 10 for filtration. The shape, capacity, material, and the like of the processing liquid tank 103 can be appropriately determined according to the use of the filtration processing apparatus 100, and are not particularly limited.

  The concentrated sludge tank 104 stores a concentrated liquid containing a lot of SS particles removed from the liquid to be filtered. The concentrated liquid is a processing liquid after being used for washing the filter 10 for filtration. The shape, capacity, material, and the like of the concentrated sludge tank 104 can be appropriately determined according to the use of the filtration apparatus 100, and are not particularly limited.

FIG. 2 is a cross-sectional view showing the filter for filtration according to the embodiment. FIG. 3 is a cross-sectional view when the filter for filtration is viewed from the end surface side.
In the present embodiment, the filtration filter 10 has a substantially cylindrical shape as a whole. For example, the central axis of the cylinder is arranged along the vertical direction. The filter 10 for filtration is provided with the filter body 12 which arranged the wire 11 in planar shape, and the support member 13 which supports this filter body 12. As shown in FIG. In the filter 10 for filtration of embodiment, the filter body 12 consists of what wound the elongate wire 11 in the shape of a coil, and was shape | molded by the hollow cylindrical body. A filter body 12 having a cylindrical surface is formed by the wire 11 thus formed. The wire 11 of the embodiment has a rectangular cross-sectional shape that is perpendicular to the extending direction.

  The wire 11 is formed with a spacing portion 15 that separates the adjacent wires from each other, that is, in the embodiment, between the adjacent peripheral line materials 11 with a predetermined gap therebetween. The spacing portions 15 are formed at, for example, three locations for each turn at an angle of 120 °, for example, along the turn direction of the wire 11.

The slit 15 formed between the inner peripheral surface 12a and the outer peripheral surface 12b of the cylindrical filter body 12 is formed by the separating portion 15 formed in the wire 11 as described above.
In the embodiment, the filter body 12 has an inner peripheral surface 12a as a primary surface into which the liquid to be filtered flows, and an outer peripheral surface 12b as a secondary surface from which treated water filtered by the filter body 12 flows out. In other words, the filter 10 for filtration forms an internal pressure type filter in which the substantially cylindrical inner peripheral surface 12a side is pressurized from the atmospheric pressure by pumping the liquid to be filtered and the outer peripheral surface 12b side is atmospheric pressure.

  The support member 13 is made of, for example, a wire having a rectangular or triangular cross section, and is joined to the wire 11 on the outer peripheral surface 12b side of the filter body 12. The support members 13 are formed at, for example, four locations at equal intervals along the circumferential direction of the wire 11, extend parallel to the central axis of the filter body 12, and support the wound wire 11 from the outer peripheral surface 12 b side. ing. Such a support member 13 and the wire 11 are joined by sintering, for example.

  The filtration filter 10 having such a configuration allows the liquid to be filtered to flow into the substantially cylindrical filter body 12, passes the gap 16, and filters the liquid to be filtered, from the outer peripheral surface 12 b of the filter body 12. The treated water after filtration is discharged.

FIG. 4 is an enlarged cross-sectional view of the main part showing the inner peripheral surface side of the filter for filtration.
In the filter body 12 constituting the filter for filtration 10, a plurality (a large number) of fine structures 5 are formed on the inner peripheral surface (primary surface) 12 a side into which the liquid to be filtered flows and the inner surface of the gap 16. ing.

  The fine structure 5 is formed in, for example, at least one of a truncated cone shape, an elliptical cone shape, a polygonal pyramid shape, a truncated cone shape, an elliptical truncated cone shape, and a polygonal truncated cone shape. The microstructure 5 according to the embodiment is a needle-like structure that is tapered from the proximal end toward the distal end.

FIG. 5 is an enlarged schematic view of a main part showing a wire having a fine structure formed thereon.
The fine structure 5 is composed of a plating layer 3 formed on the wire 11 by, for example, electroplating. In addition, it is preferable that a base layer 4 that further enhances the adhesion between the plating layer 3 and the wire 11 is further formed between the plating layer 3 and the wire 11 constituting the microstructure 5.

  As the wire 11 which forms the fine structure 5, what can be used in the to-be-filtered liquid filtered using the filter 10 for filtration is used. The material of the wire 11 is preferably a metal so that the plating layer 3 or the plating layer 3 and the base layer 4 can be easily formed by using a plating process. As a metal used for the wire 11, for example, iron, nickel, copper, and alloys thereof are preferably used. Among these, as the wire 11, it is preferable to use a stainless steel wire that is excellent in corrosion resistance, low in cost, and easy to process.

The underlayer 4 is provided as necessary in order to improve the adhesion of the plating layer 3 to the wire 11. As a material used for the underlayer 4, for example, when the plating layer 3 made of a nickel alloy is formed on the surface of the wire 11, it is preferable to use nickel or a nickel alloy. Examples of the nickel alloy include those containing one or more elements selected from boron, phosphorus, and zinc.
The thickness of the foundation layer 4 is set to be equal to or greater than the thickness that can improve the adhesion of the plating layer 3 to the wire 11. In addition, the thickness of the underlayer 4 is set to a thickness within a range in which the width of the gap 16 becomes a size suitable for passing the liquid to be filtered containing SS particles through the filter 10 for filtration.

  The plating layer 3 in the embodiment is a composite body in which a plurality of fine structures (in the present embodiment, needle-like structures) 5 are gathered on the surface of the base layer 4. In each microstructure 5, a base 5 a that is a region closer to the wire 11 than the base end 53 a of the microstructure 5 is integrated with a base 5 a of another adjacent microstructure 5. As a result, the base 5 a of the fine structure 5 is continuously formed on the surface of the underlayer 4.

The fine structure 5 in the present embodiment has, for example, a truncated cone shape, an elliptical cone shape, a polygonal pyramid shape, a truncated cone shape, an elliptical truncated cone shape, and a polygonal truncated cone shape. Each of the microstructures 5 having such a pyramid shape or a frustum shape has a tapered shape from the base end 53 a toward the tip 52.
FIG. 6 shows an SEM photograph (secondary electron image (SEI), 15.0 kV, 20000 times) when the microstructure 5 is a needle-like structure.

  Between the fine structures 5 made into the needle-like structures, troughs 53 are formed that become narrower as they approach the base end 53a in a cross-sectional view. The valley 53 is formed so as to surround each microstructure 5 in plan view. The valleys 53 that surround each microstructure 5 are formed so as to be connected to the valley 53 that surrounds another adjacent microstructure 5 in a plan view.

In the filter 10 for filtration shown in FIG. 5, SS particles captured from the liquid to be filtered are attached to some of the fine structures 5.
The number of the fine structures 5 per unit area (1 μm ² ) of the wire 11 is 1.2 to 10.0 / μm ² . When the number of the fine structures 5 per unit area (1 μm ² ) is less than the above range, the contact area between the filter for filtration 1 and the liquid to be filtered containing SS particles is insufficient, and the effect of the mechanism of the depth filtration is obtained. Since it becomes insufficient, it becomes difficult to capture SS particles in the liquid to be filtered.

Further, when the number of the fine structures 5 per unit area (1 μm ² ) is less than the above range, the SS particles are hardly captured by the fine structures 5, so that the cake 7 is hardly formed. However, when the number of the fine structures 5 per unit area (1 μm ² ) exceeds the above range, the SS particles are hardly removed from the fine structures 5 even if the washing is performed, and the detergency becomes insufficient.

When the number of the fine structures 5 per unit area is 1.2 pieces / μm ² or more, the surface area of the filter 1 for filtration becomes sufficiently large, and SS particles are easily caught between the adjacent fine structures 5. For this reason, it can be set as the filter 10 for filtration in which SS particle | grains are easy to be capture | acquired by the mechanism of deep layer filtration, and the cake 7 is easy to be formed with the capture | acquired SS particle | grains.

Therefore, the filter 10 for filtration has the outstanding removal function which can capture | acquire SS particle | grains using the mechanism of depth filtration and the mechanism of cake filtration. The number of the fine structures 5 per unit area is preferably 3.0 / μm ² or more in order to obtain a filter 10 having a higher SS particle removal function.

When the number of the fine structures 5 per unit area is 10.0 pieces / μm ² or less, the gap between the adjacent fine structures 5 is prevented from becoming too narrow. For this reason, as shown in FIG. 5, a sufficiently large space 31 surrounded by the valleys 53 formed between the adjacent microstructures 5 and the cake 7 formed on the plating layer 3 is formed. It is formed. The space 31 functions as a flow path through which the cake-filtered treated water flows when the cake 7 is formed.

For this reason, compared with the filter which does not have the fine structure 5, since the area where the process liquid which passed the cake 7 is obtained becomes large, the filtration flow rate can be enlarged. Therefore, the filter 10 for filtration is easy to remove SS particles and has a large filtration flow rate. The number of the fine structures 5 per unit area is preferably 7.0 pieces / μm ² or less in order to obtain an excellent filter 10 for filtration having a larger filtration flow rate.

The number of fine structures 5 per unit area (1 μm ² ) of the wire 11 is measured by the following method.
The filter for filtration is observed with an electron microscope, and the number of apexes of the needle-like structure existing in a square having a length of 2 μm, a width of 2 μm, and an area of 4 μm ² is measured at four points. Then, the number of apexes of the needle-like structures measured at four locations is averaged, and the number of needle-like structures per unit area (1 μm ² ) is calculated.

  The number of fine structures 5 per unit length (1 μm) in the cross section of the wire 11 is 1.0 to 4.0 / μm. When the number of the fine structures 5 per unit length (1 μm) is less than the above range, the contact area between the filter for filtration 10 and the liquid to be filtered containing SS particles is insufficient, and the depth filtration mechanism Since the effect is insufficient, SS particles in the liquid to be filtered are hardly captured.

  On the other hand, when the number of the fine structures 5 per unit length (1 μm) exceeds the above range, the valleys 53 formed between the adjacent fine structures 5 and the cake formed on the plating layer 3 are formed. Since the space 31 surrounded by 7 becomes narrow, the filtration flow rate may decrease.

When the number of the fine structures 5 per unit length is 1.0 / μm or more, as in the case where the number of the fine structures 5 per unit area is 1.2 / μm ² or more. In addition, it has an excellent removal function capable of capturing SS particles by using a mechanism of deep layer filtration and a mechanism of cake filtration. The number of the fine structures 5 per unit length is preferably 1.5 / μm or more in order to obtain a filter 10 having a higher SS particle removing function.

When the number of the fine structures 5 per unit length is 4.0 pieces / μm or less, similarly to the case where the number of the fine structures 5 per unit area is 10.0 pieces / μm ² or less. It is prevented that the gap between the adjacent fine structures 5 becomes too narrow. For this reason, a sufficiently wide space 31 surrounded by the valleys 53 formed between the adjacent microstructures 5 and the cake 7 formed on the plating layer 3 is formed, and the filtration is performed. It can be set as the filter 10 for filtration with a big flow volume. The number of the fine structures 5 per unit length is preferably 3.0 pieces / μm or less in order to obtain the filter 10 for filtration having a larger filtration flow rate.

The number of fine structures 5 per unit length (1 μm) in the cross section of the wire 11 is measured by the following method.
The filter 10 for filtration is fixed by embedding resin and cut, and the cut surface is smoothed by ion milling and photographed using a scanning electron microscope (SEM). Thereafter, the number of needle-like microstructures per 10 μm is measured along the substantially extending direction of the surface of the filter base material in the photograph of the photographed cross section of the filter base material. Then, the number of fine structures per unit length (1 μm) is calculated from the measured number of fine structures.

  In the present embodiment, the average height H of the needle-like microstructure 5 and the average width D of the base end portion in the cross section of the wire 11 are obtained by measuring the dimensions of the following portions by the following measurement method. is there. As shown in FIG. 5, valleys 53 are formed between adjacent fine structures 5 in the cross section of the wire 11. In the cross section of the wire 11, the base ends 53 a and 53 a, which are the valley bottoms facing each other with the fine structure 5, are connected by a straight line 51, and the lengths are set as the widths D 1 and D 2 of the base end portion of the fine structure 5. . The shortest distance between the tip 52 of the fine structure 5 and the straight line 51 is defined as the heights H1 and H2 of the fine structure 5.

  When the two fine structures 57 and 58 are integrated in the cross section of the wire 11 (the fine structure indicated by reference numeral 59 in FIG. 5), the dimensions of the following parts are set to the fine structures 57 and 58. And the widths D3 and D4 of the base ends of the fine structures 57 and 58.

  First, the straight ends 54 connect the base ends 53a and 53a, which are the valley bottoms facing each other across the fine structure 59 in which the needle-like fine structures 57 and 58 are integrated. Next, a perpendicular line 56 is drawn from the bottom of the valley 55 between the two microstructures 57 and 58 toward the straight line 54. The distances from the intersection of the perpendicular 56 and the straight line 54 to the base ends 53a and 53a are defined as the widths D3 and D4 of the base ends of the fine structures 57 and 58, respectively.

  Further, the shortest distances between the tips 52a and 52b of the fine structures 57 and 58 and the straight line 54 are defined as heights H3 and H4 of the fine structures 57 and 58, respectively. In addition, when the length of the perpendicular 56 is less than 3/4 of both the heights H3 and H4 of the fine structures 57 and 58, it is regarded as two independent fine structures. Further, the criterion that the two fine structures 57 and 58 are integrated is a case other than the case where the two fine structures are regarded as independent.

  In order to measure the height of the needle-like fine structure 5 and the width of the base end portion of the fine structure 5, the filter 10 for filtration is fixed by embedding resin and cut, and the cut surface is polished by ion milling. Then, the image is taken using a scanning electron microscope (SEM). Thereafter, a range of 10 μm in length along the substantially extending direction of the surface of the wire in the enlarged photograph of the cross section of the photographed wire 11 is defined as one measurement region, and all the above-described microstructures 5 present in the four measurement regions. Measure the height and width of the proximal end. The average value of the heights of the four fine structures 5 measured is defined as the average height H of the fine structures 5. Moreover, let the average value of the width | variety of the base end part of the four fine structures 5 measured be the average width D of the base end part of the fine structure 5. FIG.

  The coefficient of variation of the height of the needle-like microstructure 5 in the cross section of the wire 11 is preferably 0.15 to 0.50. The variation coefficient is obtained by dividing the standard deviation of the height distribution of the fine structures 5 in the cross section of the wire 11 described above by the arithmetic average value of the heights of the fine structures 5.

  When the coefficient of variation is in the range of 0.15 to 0.50, the filter 10 for filtration is further excellent in the function of removing SS particles and the detergency. When the variation coefficient is less than 0.15, the flow of the liquid to be filtered containing SS particles on the surface of the filter 10 for filtration is monotonous when the liquid to be filtered containing SS particles is passed through the filter 10 for filtration. Thus, the SS particles are hardly captured by the fine structure 5. Moreover, when the above coefficient of variation exceeds 0.50, it becomes difficult to obtain a function of supporting the cake 7 formed on the surface of the plating layer 3 by the fine structure 5 having a low height.

  When the variation coefficient is 0.15 or more, the height variation of the fine structure 5 is sufficiently large. For this reason, when passing the liquid to be filtered containing SS particles through the filter 10 for filtration, the flow of the liquid to be filtered containing SS particles on the surface of the filter 10 for filtration becomes complicated, and the fine structure with a high height. SS particles are easily caught on the object 5. As a result, the SS particles are easily captured by the deep layer filtration mechanism, and the cake 7 is easily formed on the surface of the plating layer 3 starting from the SS particles caught on the fine structure 5 having a high height. The coefficient of variation is preferably 0.18 or more in order to obtain a filter 10 for filtration in which SS particles are more easily captured.

  If the coefficient of variation is 0.50 or less, the cake 7 formed on the surface of the plating layer 3 is supported by the microstructure 5 having a low height, and thus formed between the adjacent microstructures 5. The space 31 surrounded by the valley 53 and the cake 7 is easily secured. For this reason, after the cake 7 is formed by filtration, the treatment liquid subjected to cake filtration easily flows in the space 31, and the filtration flow rate increases. Therefore, the filter 10 for filtration becomes a thing excellent in the filtration flow volume compared with the filter without a needle-like structure. The coefficient of variation is preferably 0.36 or less in order to obtain a filter 10 having a higher filtration flow rate.

  The aspect ratio H / D between the average width D and the average height H of the base end portion of the needle-like microstructure 5 in the cross section of the wire 11 is preferably 0.5 to 4.0. When the aspect ratio H / D is 0.5 or more, sufficient is surrounded by the valleys 53 formed between the adjacent needle-like microstructures 5 and the cake 7 formed on the plating layer 3. A space 31 having a height is formed.

  For this reason, after the cake 7 is formed by filtration, the treated water subjected to the cake filtration easily flows in the space 31, and the filtration flow rate is excellent. The aspect ratio H / D is preferably 1.0 or more in order to obtain a filter 10 having a higher filtration flow rate. When the aspect ratio H / D is 4.0 or less, the microstructure 5 is excellent in strength, and thus the filter 10 for filtration is excellent in durability. The aspect ratio H / D is preferably 3.0 or less in order to obtain a filter 10 having a further excellent durability.

  The average height H of the needle-like microstructure 5 in the cross section of the wire 11 is preferably 0.2 to 2.5 μm. When the average height H of the fine structure 5 is 0.2 μm or more, the fine structure 5 is surrounded by the valleys 53 formed between the adjacent fine structures 5 and the cake 7 formed on the plating layer 3. A sufficiently high space 31 is formed. For this reason, after the cake is formed at the time of filtration, the cake-filtered processing liquid easily flows in the space 31, and the filtration flow rate is excellent.

The average height H of the fine structure 5 is preferably 0.4 μm or more in order to obtain a filter 10 having a further excellent filtration flow rate. When the average height H of the needle-like fine structure 5 is 2.5 μm or less, the gap between the adjacent fine structures 5 is prevented from becoming too narrow. For this reason, it becomes the filter 10 for filtration excellent in the filtration flow volume by which the space 31 was fully ensured similarly to the case where it is 10.0 piece / micrometer < ² > or less. The average height H of the fine structure 5 is preferably 1.8 μm or less in order to obtain a filter 10 having a further excellent filtration flow rate.

The relationship between the average width D of the base end portion of the needle-like microstructure 5 in the cross section of the wire 11 and the average particle diameter (D ₅₀ ) φ (average particle size of SS particles) of the removal target substance is φ / D It is preferable that ≧ 0.33 is satisfied. When φ / D is 0.33 or more, SS particles are less likely to enter the vicinity of the valley bottom of the valley 53 formed between the adjacent microstructures 5. Therefore, a wide space 31 surrounded by the valleys 53 and the cake 7 formed on the plating layer 3 is easily formed. Therefore, the filter 10 for filtration is easy to flow the cake-filtered processing liquid in the space 31 and has an excellent filtration flow rate.

  The φ / D is preferably 0.50 or more in order to obtain a filter 10 having a higher filtration flow rate. The φ / D is preferably 3.00 or less. When the φ / D is 3.00 or less, the SS particles are more easily caught between the adjacent microstructures 5.

For this reason, it becomes the filter 10 for filtration which SS particle | grains are easy to be further capture | acquired by the mechanism of deep layer filtration, and the cake 7 is easy to be formed with the capture | acquired SS particle | grain. The φ / D is more preferably 2.00 or less in order to obtain a filter 1 for filtration in which SS particles are more easily captured.
Here, the average particle diameter φ is measured by a laser diffraction method. Specifically, it can be measured by a SALD-DS21 type measuring device (trade name) manufactured by Shimadzu Corporation.

  As a metal used for the plating layer 3 formed of the plurality of fine structures 5, a metal capable of depositing the plurality of fine structures 5 on the surface of the wire 11 or the base layer 4 by a process such as electroplating is used. Examples of such a metal include iron, nickel, copper, and alloys thereof. As the metal used for the plating layer 3, nickel or a nickel alloy is preferably used because it is a metal that can easily control the shape of the microstructure 5 and has excellent corrosion resistance. Examples of the nickel alloy include those containing one or more elements selected from boron, phosphorus, and zinc.

FIG. 7 is a schematic diagram showing a wire having a spacing portion.
When the shape of the fine structure 5 is a truncated cone, an elliptical cone, a polygonal cone, a truncated cone, an elliptical truncated cone, a truncated cone, or the like, the inner peripheral surface (primary surface) of the filter body 12 ) The void ratio G, which indicates the ratio of the area of the gap 16 to the area of 12a (planar area of the gap when the inner peripheral surface is viewed in plan), is preferably 0.5% or more and 50% or less.

Here, the void ratio G is such that the spacing between the adjacent spacing portions 15 is a, the width of the spacing portion 15 along the extending direction of the wire 11 is b, the width of the gap 16 between the adjacent wires 11 is c, When the thickness of the wire 11 along the arrangement direction of the wire 11 is defined as d, it is expressed by the following formula 1.
G = [(a × c) / {(a + b) × (c + d)}] × 100 (1)

  In addition, the width | variety of the clearance gap 16 of the wire 11 shown by c is synonymous with the protrusion width of the separation part 15 along the sequence direction of the wire 11. FIG. The width of the gap 16 is preferably 5 μm or more and 1 mm or less.

  When the fine structure 5 is formed into a cone shape or a frustum shape, for example, a needle-like structure, if the porosity G is less than 0.5%, the flow rate of the filtered treated water becomes too small, which is efficient. It becomes difficult to filter the liquid to be filtered. By keeping the porosity G at 0.5% or more, the amount of treated water can be kept appropriately, and the filtrate to be filtered can be efficiently filtered. On the other hand, when the porosity G exceeds 50%, it becomes difficult to form a bridge due to the captured SS, and there is a concern that the filtration performance by cake filtration is lowered. By maintaining the porosity G at 50% or less, the filtration performance by cake filtration can be enhanced.

In the above-described embodiment, the example in which the fine structure 5 is a cone shape or a frustum shape, for example, a needle-like structure has been described. However, it is also preferable that the fine structure 5 is formed in a polyhedral shape.
FIGS. 8 and 9 are SEM photographs (secondary electron image (SEI), 15.0 kV, 2000 times (FIG. 8), and 5000 times (FIG. 9)) when such a fine structure 5 is a polyhedral structure. Show.
When the fine structure 5 is a polyhedral structure, a plurality of polyhedrons are bonded to each other and share a part of the volume. Each of the polyhedral fine structures 5 has a plurality of vertices where three or more planes intersect. As shown in FIGS. 8 and 9, each microstructure 5 has a different shape and a different size, and is formed densely on the surface of the wire 11 or the underlayer 4 (see FIG. 5). ing. As a result, the portion corresponding to the side of the polyhedron shape faces an irregular direction.

  The average value of the maximum outer dimensions of the polyhedral fine structure 5 is preferably 0.5 to 10 μm. When the average maximum outer dimension of the precipitate is within the above range, the SS particles in the liquid to be filtered are easily caught.

  In particular, when the average particle diameter of the SS particles in the liquid to be filtered is 0.1 to 10 μm, the SS particles are easily caught on the plating layer 3. Therefore, when the average particle diameter of the SS particles in the liquid to be filtered is within the above range, the SS particles can be efficiently captured by the mechanism of the depth filtration. Further, when the average maximum outer dimension of the precipitate is within the above range, SS particles are easily caught on the plating layer 3, so that cake is easily formed by the SS particles captured by the filter 10 for filtration. As a result, it becomes easy to capture the SS particles using the cake filtration mechanism, and the filter 10 for filtration having a high function of removing the SS particles is obtained.

  When the average maximum outer dimension of the polyhedral fine structure 5 is less than 0.5 μm, the unevenness of the surface of the plating layer 3 is reduced, and the amount of liquid to be filtered passing through the gaps between the polyhedral precipitates is reduced. As a result, adhesion of SS particles to the plating layer 3 is less likely to occur. The average maximum outer dimension of the polyhedral fine structure 5 is more preferably 2 μm or more. Further, when the average maximum outer dimension of the polyhedral fine structure 5 exceeds 10 μm, the contact area between the plating layer 3 and the liquid to be filtered containing SS particles decreases, and adhesion of SS particles to the plating layer 3 occurs. Less likely to occur. The average maximum external dimension of the polyhedral fine structure 5 is more preferably 8 μm or less.

  The coefficient of variation of the average maximum outer dimension of the polyhedral microstructure 5 is preferably 0.15 to 0.50. When the coefficient of variation is in the range of 0.15 to 0.50, the filter 10 for filtration is further excellent in the function of removing SS particles and the cleaning property. When the variation coefficient is less than 0.15, the flow of the liquid to be filtered containing SS particles on the surface of the filter 10 for filtration is monotonous when the liquid to be filtered containing SS particles is passed through the filter 10 for filtration. Thus, the SS particles are hardly captured by the fine structure 5. Moreover, when the above coefficient of variation exceeds 0.50, it becomes difficult to obtain a function of supporting the cake 7 formed on the surface of the plating layer 3 by the fine structure 5 having a low height.

  When the variation coefficient is 0.15 or more, the height variation of the fine structure 5 is sufficiently large. For this reason, when passing the liquid to be filtered containing SS particles through the filter 10 for filtration, the flow of the liquid to be filtered containing SS particles on the surface of the filter 10 for filtration becomes complicated, and the fine structure with a high height. SS particles are easily caught on the object 5. As a result, the SS particles are easily captured by the deep layer filtration mechanism, and the cake 7 is easily formed on the surface of the plating layer 3 starting from the SS particles caught on the fine structure 5 having a high height. The coefficient of variation is preferably 0.18 or more in order to obtain a filter 10 for filtration in which SS particles are more easily captured.

  If the coefficient of variation is 0.50 or less, the cake 7 formed on the surface of the plating layer 3 is supported by the microstructure 5 having a low height, and thus formed between the adjacent microstructures 5. The space 31 surrounded by the valley 53 and the cake 7 is easily secured. For this reason, after the cake 7 is formed by filtration, the treatment liquid subjected to cake filtration easily flows in the space 31, and the filtration flow rate increases. Therefore, the filter 10 for filtration becomes a thing excellent in the filtration flow volume compared with the filter without a polyhedron structure. The coefficient of variation is preferably 0.36 or less in order to obtain a filter 10 having a higher filtration flow rate.

The average maximum outer dimension of the polyhedral fine structure 5 is measured by the following measuring method.
That is, an enlarged photograph of the filter for filtration 10 is taken using a scanning electron microscope (SEM), and image processing is performed. Specifically, the outer dimensions of the largest portion of the polyhedral fine structure 5 are measured by selecting ten representative locations for one photograph, and the average value is the average maximum outer shape. Defined as a dimension.

  As the metal used for the plating layer 3, a metal that can obtain a plurality of polyhedral fine structures 5 on the surface of the filter substrate by plating is used. Examples of such a metal include iron, nickel, copper, and alloys thereof. As the metal used for the plating layer 3, nickel or a nickel alloy is preferably used because it is a metal whose shape is easily controlled and excellent in corrosion resistance among the above metals. Examples of the nickel alloy include those containing one or more elements selected from boron, phosphorus, and zinc.

  When the shape of the fine structure 5 is a polyhedral shape, the ratio of the area of the gap 16 to the area of the inner peripheral surface (primary surface) 12a of the filter body 12 (planar area of the gap when the inner peripheral surface is viewed in plan) is The porosity G shown is preferably 0.1% or more and 50% or less.

Here, the void ratio G is such that the spacing between the adjacent spacing portions 15 is a, the width of the spacing portion 15 along the extending direction of the wire 11 is b, the width of the gap 16 between the adjacent wires 11 is c, When the thickness of the wire 11 along the arrangement direction of the wire 11 is defined as d, it is expressed by the following formula 1.
G = [(a × c) / {(a + b) × (c + d)}] × 100 (1)

  In addition, the width | variety of the clearance gap 16 of the clearance gap 11 shown by c is synonymous with the protrusion width | variety of the separation part 15 along the sequence direction of the wire 11. FIG. The width of the gap 16 is preferably 1 μm or more and 1 mm or less.

  When the fine structure 5 is a polyhedral structure, if the porosity G is less than 0.1%, the flow rate of the filtered treated water is too small and the filtered liquid is efficiently filtered. It becomes difficult. By keeping the porosity G at 0.1% or more, the flow rate of the treated water can be kept appropriate, and the filtrate to be filtered can be efficiently filtered. On the other hand, when the porosity G exceeds 50%, it becomes difficult to form a bridge due to the captured SS, and there is a concern that the filtration performance by cake filtration is lowered. By maintaining the porosity G at 50% or less, the filtration performance by cake filtration can be enhanced.

The operation of the filtration apparatus to which the filtration filter according to the embodiment described in detail above is applied will be described.
For example, when the filtered liquid containing SS particles is filtered to obtain treated water using the filtration apparatus 100, first, the filtered liquid stored in the filtered liquid tank 101 is filtered by the pump 106. Pump toward the filter 10.

  When the liquid to be filtered enters the inside of the cylindrical filtration filter 10, the liquid to be filtered is composed of a large number of fine structures 5 formed on the inner peripheral surface (primary surface) 12 a of the filtration filter 10 and the inner surface of the gap 16. The SS particles are captured by the plating layer 3. Since the filter for filtration 10 has a plurality of fine structures 5 at a predetermined density, the contact area between the filter for filtration 10 and the liquid to be filtered containing SS particles is large. For this reason, agglomerates of SS particles are rapidly formed at a plurality of locations on the surface of the plating layer 3 starting from the SS particles adhering to the surface of the fine structure 5 by the surface filtration and depth filtration mechanisms.

  The formed aggregate grows and peels by continuing the passage of the liquid to be filtered containing SS particles to the filter 10 for filtration, and moves toward the gap 16 together with the liquid to be filtered containing SS particles. The one or more aggregates that have moved to the gap 16 form a bridge-like cake 7 that closes the gap 16. Thus, in the processing method of this embodiment, not only the surface filtration mechanism but also the depth filtration mechanism and the cake filtration mechanism can be used to remove small SS particles in the liquid to be filtered. Therefore, excellent filtration performance can be obtained.

  The filter 10 for filtration has the trough 53 between the adjacent fine structures 5, as shown in FIG. The valley 53 becomes narrower as it approaches the base end 53a that is the bottom of the valley in a cross-sectional view. For this reason, the SS particles captured by the filtration filter 10 are unlikely to enter the vicinity of the base end 53 a of the valley 53.

  Therefore, in the filter 10 for filtration in which the cake 7 is formed on the surface of the plating layer 3, a sufficiently large space 31 surrounded by the valley 53 and the cake 7 is formed as shown in FIG. After the space 31 is formed, the upper portion of the space 31 is covered with the lid formed by the cake 7 even if the liquid to be filtered containing SS particles is further passed to the filter 10 for filtration. Therefore, SS particles are difficult to enter the space 31. Therefore, if the liquid to be filtered containing SS particles is continuously passed to the filter 10 for filtration, further SS particles are deposited on the cake 7.

  With the plating layer 3 composed of such a large number of fine structures 5, the SS particles can be efficiently and reliably captured and removed from the liquid to be filtered containing the SS particles. Then, the treated water from which the SS particles have been removed passes through the gap 16 formed by the spacing portion 15 of the wire 11 and is discharged from the outer peripheral surface (secondary surface) 12b of the filtration filter 10 to the treatment liquid tank 103.

  Thus, according to the filter 10 for filtration of the embodiment, the filter body 12 formed by winding the wire 11 in a coil shape has, for example, a needle on the inner peripheral surface (primary surface) 12a side into which the liquid to be filtered flows. By forming a large number of fine and polyhedral fine structures 5, it becomes possible to capture and remove SS particles efficiently and reliably from the liquid to be filtered containing SS particles.

  When a large amount of cake accumulates inside the filter 10 for filtration and the water flow rate decreases, the outer peripheral surface (secondary surface) 12b of the filter 10 for filtration is directed toward the inner peripheral surface (primary surface) 12a. It is preferable to carry out backwashing by passing water through. The cake discharged by such back washing is collected in the concentrated sludge tank 104 as sludge. The cleaning water used for the reverse cleaning may be sent back to the outer peripheral surface (secondary surface) 12b side of the filter 10 for filtration by using a part of the processing water stored in the processing liquid tank 103, for example. .

  The backwashing of the filtration filter 10 is preferably performed at a stage where the filtration filter 10 has captured a certain amount of SS particles. The timing for performing the cleaning is not particularly limited, and can be appropriately determined according to the amount of SS particles contained in the liquid to be filtered that is allowed to pass through the filter 10 for filtration. In addition to passing the cleaning liquid in the direction opposite to the direction in which the liquid to be filtered containing SS particles is passed through the filtering filter 10 (back washing), the cleaning liquid is allowed to flow on the surface of the filtering filter 10. It can also be done.

  In this embodiment, when the filter 10 for filtration is backwashed, the cleaning liquid flows into the space 31 from multiple directions through the valleys 53 formed so as to surround each fine structure 5. Accordingly, the cake 7 formed so as to cover at least a part of the upper portion of the valley 53 is pushed up by the cleaning liquid, and the peeling of the cake 7 is promoted. Further, the fine structure 5 of the filter 10 for filtration has a tapered shape from the proximal end 53 a toward the distal end 52. For this reason, the cake 7 pushed up by the cleaning liquid is easily peeled off from the filter 10 for filtration. In addition, since the fine structure 5 has a tapered shape, the SS particles attached to the fine structure 5 are not easily caught in the valleys 53 during backwashing, and are easily separated from the fine structure 5. Therefore, by performing backwashing, SS particles deposited on the filter 10 for filtration are quickly removed, and the filter 10 for water filtration is regenerated.

In the embodiment described above, the internal pressure filtration filter 10 is exemplified, but an external pressure filtration filter that allows the liquid to be filtered to flow from the outer peripheral surface to the inner peripheral surface of the substantially cylindrical filter body may be used. .
FIG. 10 is a cross-sectional view of a filter for filtration according to another embodiment when viewed from the end face side. Moreover, FIG. 11 is a principal part expanded sectional view which shows the internal peripheral surface side of the filter for filtration of another embodiment.
The filter 60 for filtration of the present embodiment includes a filter body 62 in which wire rods 61 are arranged in a planar shape, and a support member 63 that supports the filter body 62. In the filter 60 for filtration of this embodiment, the filter body 62 consists of what wound the elongate wire 61 in the shape of a coil, and was shape | molded by the hollow cylindrical body. A filter body 62 having a cylindrical surface is formed by the wire 61 thus formed. The wire rod 61 of the embodiment has a rectangular cross-sectional shape that is perpendicular to the extending direction.

  The wire member 61 is formed with a spacing portion 65 that separates the wire members adjacent to each other, that is, in the present embodiment, the adjacent peripheral line members 61 are separated from each other while maintaining a gap of a predetermined width. The spacing portions 65 are formed, for example, at three locations for each turn at an angle of 120 °, for example, along the turn direction of the wire 61.

The slit 65 formed between the inner peripheral surface 62a and the outer peripheral surface 62b of the cylindrical filter body 62 is formed by the separating portion 65 formed in the wire 61.
In the embodiment, in the filter body 62, the outer peripheral surface 62b is a primary surface into which the liquid to be filtered flows, and the inner peripheral surface 12a is a secondary surface from which the treated water filtered by the filter body 62 flows out. That is, the filter 60 for filtration of the present embodiment constitutes an external pressure type filter in which the substantially cylindrical outer peripheral surface 62b side is pressurized from the atmospheric pressure by pressure feeding of the liquid to be filtered, and the inner peripheral surface 62a side is atmospheric pressure. ing.

  The support member 63 is made of, for example, a wire having a rectangular or triangular cross section, is disposed inside the filter body 62, and is joined to the wire 61 on the inner peripheral surface 62a side. The support member 63 is formed, for example, in a cross shape inside the filter body 62, and supports the wound wire rod 61 from the inner peripheral surface 62a side. Such a support member 63 and the wire 61 are joined by sintering, for example.

  Among the filter body 62 constituting such a filter 60 for filtration, a plurality (a large number) of fine structures 5 are formed on the outer peripheral surface (primary surface) 62 b side into which the liquid to be filtered flows and the inner surface of the gap 66. Is formed. The fine structure 5 may be, for example, a needle-like structure shown in FIG. 6 or a polyhedral structure shown in FIGS.

In the embodiment described above, an example in which a wire having a rectangular (quadrangle) cross section is used as the wire constituting the filter for filtration, but the filter for filtration may be formed using a wire having a circular cross section, for example. it can.
FIG. 12 is an enlarged cross-sectional view of a main part showing an inner peripheral surface side of an internal pressure filter for filtration according to another embodiment.
The filter 70 for filtration of this embodiment is provided with a filter body 72 in which a wire 71 having a circular cross section perpendicular to the extending direction is wound in a coil shape to form a hollow cylindrical body. The wire 71 is formed with a spacing portion 75 that separates the adjacent wires from each other, that is, in the present embodiment, between the adjacent peripheral line materials 71 with a predetermined gap therebetween. Due to the spacing portion 75 formed in such a wire 71, the cylindrical filter body 72 forms a slit-like gap 76 that penetrates between the inner peripheral surface 72 a and the outer peripheral surface 72 b.

  In the present embodiment, the filter body 72 has an inner peripheral surface 72 a as a primary surface into which the liquid to be filtered flows, and an outer peripheral surface 72 b as a secondary surface from which treated water filtered by the filter body 72 flows out. Among the filter bodies 72 constituting such a filter 70 for filtration, a plurality (a large number) of fine structures 5 are provided on the inner peripheral surface (primary surface) 72 a side into which the liquid to be filtered flows and the inner surface of the gap 76. Is formed. The fine structure 5 may be, for example, a needle-like structure shown in FIG. 6 or a polyhedral structure shown in FIGS.

FIG. 13 is an enlarged cross-sectional view of a main part showing an inner peripheral surface side of an external pressure filtration filter according to another embodiment.
The filter 80 for filtration of this embodiment is provided with a filter body 82 in which a wire 81 having a circular cross section perpendicular to the extending direction is wound in a coil shape to form a hollow cylindrical body. The wire 81 is formed with a spacing portion 85 that separates the adjacent wires from each other, that is, in the present embodiment, between the adjacent peripheral line materials 81 with a gap of a predetermined width. Due to the spacing portion 85 formed in such a wire 81, the cylindrical filter body 82 forms a slit-like gap 86 that penetrates between the inner peripheral surface 82a and the outer peripheral surface 82b.

  In the present embodiment, the filter body 82 has an outer peripheral surface 82b as a primary surface into which the liquid to be filtered flows, and an inner peripheral surface 82a as a secondary surface from which treated water filtered by the filter body 82 flows out. Among the filter bodies 82 constituting such a filter 80 for filtration, a plurality (a large number) of fine structures 5 are formed on the outer peripheral surface (primary surface) 82 b side into which the liquid to be filtered flows and the inner surface of the gap 86. Is formed. The fine structure 5 may be, for example, a needle-like structure shown in FIG. 6 or a polyhedral structure shown in FIGS.

In the above-described embodiment, the cylindrical filtration filter in which the wire is wound in a coil shape is illustrated, but a plurality of wire rods may be arranged on one surface to form a flat filter for filtration.
FIG. 14 is an external perspective view showing a filter for filtration according to another embodiment. FIG. 15 is a plan view showing a filter for filtration according to another embodiment.
The filter for filtration 90 of this embodiment includes a filter body 92 in which a plurality of wire rods 91 are arranged in a planar shape, and a support member 93 that supports the filter body 92. In the filter for filtration 90 of the present embodiment, the filter body 92 is formed by arranging a plurality of wire rods 91 on a plane and forming them into a flat plate shape.

  The wire 91 is formed with a separating portion 95 that separates the adjacent wires 91 with a predetermined width therebetween. The spacing portions 95 are formed by shifting the positions of the adjacent wire rods 91 so as to form a staggered arrangement along the arrangement direction of the wire rods 91, for example.

With the spacing portion 95 formed in such a wire 91, the flat filter body 92 forms a slit-like gap 96 penetrating between the one surface 92a and the other surface 92b.
In the present embodiment, the filter body 92 has a first surface 92a as a primary surface into which the liquid to be filtered flows in and a second surface 92b as a secondary surface from which treated water filtered by the filter body 92 flows out.

  The support member 93 is made of, for example, a wire having a rectangular or triangular cross section, and is joined to the wire 91 on the other surface 92b side of the filter body 92. The support member 93 is formed, for example, so as to extend along the arrangement direction of the wire rods 91 and joins the plurality of wire rods 91 together. Such support member 93 and wire 91 are joined by sintering, for example.

  The filtration filter 90 having such a configuration allows the liquid to be filtered to flow from one surface 92a on the upper side in FIG. 14, passes the gap 96 to filter the liquid to be filtered, and treats the filtered water from the other surface 92b. Spill. A frame body (exterior body) 99 that constitutes a flow path of the liquid to be filtered that passes through the filtration filter 90 may be formed around the filtration filter 90.

  A plurality (a large number) of fine structures 5 are formed on the one surface (primary surface) 92 a side into which the liquid to be filtered flows and the inner surface of the gap 96 in the filter body 92 constituting the filter 90 for filtration. . The fine structure 5 may be, for example, a needle-like structure shown in FIG. 6 or a polyhedral structure shown in FIGS. 8 and 9.

Next, an example of the manufacturing method of the filter for filtration is demonstrated.
In order to manufacture the filter for filtration shown in FIG. 2 in which the wire is provided with a needle-like fine structure, first, the wire 11 is prepared. It is preferable that the wire 11 is a metal so that the plating layer 3 or the plating layer 3 and the base layer 4 can be easily formed using a plating process (see FIG. 5). As a metal used for the wire 11, for example, iron, nickel, copper, and alloys thereof are preferably used. Among these, as the wire 11, it is preferable to use a stainless steel wire that is excellent in corrosion resistance, low in cost, and easy to process.

  Next, the spacing portions 15 are formed in the wire 11 at a predetermined interval (a spacing portion forming step). As a method for forming the separation portion 15, it is possible to form the separation portion 15 by electroforming in which an aqueous metal is electrodeposited on an original model of the separation portion in an electrolytic solution by electrolysis. As the original mold release agent, graphite powder or a thin film of silver iodide can be used.

  Next, the long wire 11 having the separation portions 15 formed at predetermined intervals is wound, and the wire 11 is brought into close contact with each other through the separation portions 15 to form the cylindrical filter body 12. When winding the wire 11 into a cylindrical shape, for example, there is a method of removing the die after winding the wire 11 around the peripheral surface using a columnar die.

  Next, the support member 13 is temporarily fixed to the outer peripheral surface 12b of the filter body 12 in which the wire 11 is wound into a cylindrical shape, and the wire 11 and the support member 13 are bonded by sintering (sintering step). When the wire 11 and the support member 13 are sintered, for example, a method of heating with an electric furnace in a non-oxidizing atmosphere can be mentioned.

  Next, the base layer 4 is formed on the entire surface of the wire 11 formed in a cylindrical shape by plating. As a plating process for forming the underlayer 4, a conventionally known method can be used. For example, in the case where the underlayer 4 is formed on the surface of the wire 11 made of stainless steel before the plating layer 3 made of nickel or nickel alloy is formed, the electrolytic nickel plating process or the electroless nickel plating process is used. Alternatively, it is preferable to form the underlayer 4 made of a nickel alloy.

  Next, a plurality of fine structures 5 are deposited on the entire surface of the wire 11 provided with the base layer 4 by electroplating, and the wire 11 is covered with the plating layer 3 (plating step). As the electroplating process for forming the plating layer 3, a conventionally known method can be used. For example, when the underlayer 4 and the plating layer 3 are made of nickel or a nickel alloy, an additive is added to the plating bath after the formation of the underlayer 4 to continuously perform electrolytic nickel plating treatment or electroless nickel plating. It is preferable to form the plating layer 3 using a treatment.

  In the electroplating process for depositing a plurality of microstructures 5, the shape and size of the microstructures 5 can be changed by changing the type, concentration, and plating time of the additive added to the plating bath. Examples of the additive include ethylenediamine dihydrochloride and ethylenediamine (EDA).

After performing the plating process for forming the plating layer 3, heat treatment may be performed as necessary to promote crystallization of the plating layer 3.
Moreover, after performing the plating process for forming the plating layer 3, if necessary, the surface of the plating layer 3 is made of another metal or organic matter in order to improve the durability of the filter for filtration. Another coating layer may be formed.

  In addition, a plurality of types of modified regions having different affinity for the liquid to be filtered can be formed on the surface of the plating layer 3. Specifically, the modification treatment of the plating layer 3 includes a hydrophilic treatment and a hydrophobic treatment. By performing such modification treatment, the flow of the liquid to be filtered on the surface of the plating layer 3 becomes more complicated, and the SS particles can be easily aggregated on the surface of the plating layer 3.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

Specific examples of the present invention will be described.
As shown in FIG. 2, a filter body 12 was formed by winding a wire 11 having a width of 1000 μm into a coil shape, and a support member 13 was joined. The width between the wires 11 was set to 10 μm. After forming a base layer by nickel phosphorus plating, as shown in Non-Patent Document 1, a needle-like microstructure 5 is formed on the surface of the wire 11 by plating in the presence of ethylenediamine dihydrochloride (EDA) for filtration. A filter 10 was obtained. The width between the wires 11 at this time was 3 μm, and the width of the wire after plating was 1003.5 μm. The hole area ratio at this time was 0.3%.
(Non-Patent Document 1) Tao Hang, Ming Li, Qin Fei and Dali Mao, Characterization of nickel nanocones routed by electrodeposition without any template, Nanotechnology, 19 (2008) 035201 (5pp)

When the surface layer of the plating layer (fine structure 5) of the obtained filter 10 for filtration was observed by SEM, there were 16 to 19 needle-like structures in the range of 4 μm ² (2 μm × 2 μm) (FIG. 6). reference).
Further, this plated layer was fixed with embedded resin, and then cut and observed for cross section. As a result, the average number of needle-like structures per 10 μm was 20, the average height of needle-like structures was 750 nm, and the coefficient of variation was 0.2. 28. The average width of the needle-like structures was 550 nm, and the aspect ratio (height / width) was 1.36.

  Next, the filtration apparatus 100 shown in FIG. 1 was prepared. When the filtration filter 10 produced as described above was installed and the slurry containing 100 mg / L of alumina having a particle size of 0.1 μm was filtered at a constant pressure of 0.1 MPa using the filtration filter 10, it was transparent. Treated water (filtered water) was obtained, and filtration could be performed. When the filtration filter 10 after filtration was fixed with the embedding resin together with the filtration cake (alumina layer) and the cross section was observed, a gap due to irregularities was observed between the cake layer and the filtration filter 10.

  Next, when cleaning water was sent from the treated water side (secondary surface side) of the filtration filter 10 at a pressure of 0.1 Mpa to clean the cake layer, the cake near the gap was cleanly peeled and surface irregularities were observed. Had been restored. When filtration was performed again with this filter, it was confirmed that the same filtration performance as the first filtration was exhibited.

  According to the above examples, it was confirmed that the filtration filter 10 of the embodiment can capture fine particles with certainty and can repeatedly perform filtration without deteriorating the filtration performance by washing.

  DESCRIPTION OF SYMBOLS 5 ... Fine structure, 10 ... Filter for filtration, 11 ... Wire, 12, 62, 82, 92 ... Filter body, 15 ... Separation part, 16 ... Gap.

Claims (16)

A filter for filtration comprising: a filter body in which wires are arranged in a plane; and a support member that supports the filter body,
The wire includes a spacing part that separates adjacent wires from each other while maintaining a gap having a predetermined width, and a plurality of fine structures formed on the primary surface side into which at least the liquid to be filtered flows out of the filter body, equipped with a,
The fine structure has at least one of a truncated cone shape, an elliptical cone shape, a polygonal pyramid shape, an elliptical truncated cone shape, and a polygonal truncated pyramid shape,
A filter for filtration in which the formation density of the fine structures is in a range of 1.2 to 10.0 pieces / μm ² .   The said filter body is a filter for filtration of Claim 1 which consists of a cylindrical body which wound the said wire in coil shape.   The filter for filtration according to claim 1 or 2, wherein the fine structure is also formed on an inner surface of the gap.   The filter for filtration according to any one of claims 1 to 3, wherein the support member is formed on at least a secondary surface side through which the liquid to be filtered flows out.   The filter for filtration according to any one of claims 1 to 4, wherein the wire has a rectangular or circular cross-sectional shape perpendicular to the extending direction. The spacing between the adjacent spacing portions is a, the width of the spacing portion along the extending direction of the wire is b, the width of the gap between the adjacent wires is c, and the spacing along the arrangement direction of the wires When the thickness of the wire is defined as d, the porosity G indicating the area of the gap with respect to the area of the primary surface represented by Formula 1 is 0.5% or more and 50% or less, and the gap c is 5 μm. The filter for filtration according to any one of claims 1 to 5 , wherein the filter is 1 mm or less.
[Equation 1]
G = [(a × c) / {(a + b) × (c + d)}] × 100 (1) The filter for filtration according to any one of claims 1 to 6 , wherein the fine structure is a needle-like structure having a tapered shape from a proximal end to a distal end. The filter for filtration according to any one of claims 1 to 7, wherein the number of the fine structures formed per unit length is in a range of 1 to 4 / µm. The filter for filtration according to any one of claims 1 to 8, wherein an average height of the fine structure is in a range of 0.2 to 2.5 µm. The filter for filtration according to any one of claims 1 to 9 , wherein a coefficient of variation in height of the fine structure is in a range of 0.15 to 0.50.   The filter for filtration according to any one of claims 1 to 5, wherein the fine structure has a polyhedral shape. The spacing between the adjacent spacing portions is a, the width of the spacing portion along the extending direction of the wire is b, the width of the gap between the adjacent wires is c, and the spacing along the arrangement direction of the wires When the thickness of the wire is defined as d, the porosity G indicating the area of the gap with respect to the area of the primary surface of the cylindrical body represented by Formula 1 is 0.1% or more and 50% or less, The filter for filtration according to claim 11 , wherein the gap a is 1 μm or more and 1 mm or less.
[Equation 2]
G = [(a × c) / {(a + b) × (c + d)}] × 100 (1) The filter for filtration according to claim 11 or 12 , wherein an average maximum outer dimension of the fine structure is in a range of 0.5 to 10 µm. The filter for filtration according to any one of claims 11 to 13 , wherein a variation coefficient of an average maximum outer dimension of the fine structure is in a range of 0.15 to 0.50. The filter for filtration according to any one of claims 1 to 14 , wherein the fine structure is formed of a metal or an alloy. The filter for filtration according to claim 15 , wherein the fine structure is formed of nickel or a nickel alloy.