JP6509622B2 - Processing system and processing method - Google Patents

Description

  Embodiments of the present invention relate to a processing system and method.

As a method of separating and removing suspended matter contained in water (hereinafter sometimes referred to as "SS particles"), there is a method of filtering using a filter.
When the water to be treated containing SS particles is filtered by a filter, a cake of SS particles is formed on the surface of the filter, and the cake filtration proceeds. In cake filtration, the filtration flow rate decreases as the thickness of the cake increases. For this reason, the filtration is intermittently stopped, and cleaning is performed to remove cake from the filter using clear water.

  However, in the prior art, there were cases where the SS particles could not be sufficiently removed from the filter even by washing. In the prior art, since filtration is stopped and washing is performed, the operation rate (filtration time / treatment system operation time) is lowered as the number of times of washing and the washing time are increased in order to enhance the washing effect. The

JP, 2008-180206, A JP 2007-216102 A JP, 2013-248607, A

Tao Hang, Ming Li, Qin Fei and Dali Mao, Characterization of nickel nanowires routed by electrodeposition without any template, Nanotechnology, 19 (2008) 035201 (5 pp) S. Chakraborty of organic additives in nickel planting, Transactions of the Metal Finishers' Association of india, Vol. 12, No. 3-4 (2003)

  The problem to be solved by the present invention is to provide a processing system and a processing method capable of continuing the filtration of the liquid to be treated even at the time of the cleaning step and obtaining a high cleaning effect.

The processing system of the embodiment includes a processing tank, an air bubble generator, a detection unit, and a control unit.
The treatment tank is supplied to a supply unit to which the liquid to be treated is supplied, a filter for filtering solid content in the liquid to be treated, a first discharge unit to discharge the treatment liquid having passed through the filter, and the supply unit. It has a 2nd discharge part which discharges a part of said processed liquid. The filter has a plurality of through holes, and a plurality of microstructures which are formed on at least a surface on the primary surface side to which the liquid to be treated flows and which has a smaller maximum outside dimension than an average pore diameter of the through holes.
The bubble generation device can supply bubbles to the liquid to be treated supplied to the supply unit.
The detection means is for detecting the filtration performance of the filter.
The control unit determines whether or not the filter needs to be cleaned based on the output from the detection means. When it is determined that the cleaning is necessary, the control unit supplies the liquid to be treated to which bubbles are added by the air bubble generation device to the supply unit, and filters a part of the liquid to be treated with the filter. The remaining part of the liquid to be treated is discharged from the second discharge part together with the solid content deposited on the filter. When it is determined that the cleaning is unnecessary, the control unit supplies the liquid to be treated without adding the air bubbles to the supply unit, filters a part of the liquid to be treated with the filter, and the liquid to be treated A process of discharging the remaining portion of the second discharge unit from the second discharge unit is performed.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic diagram which shows the processing system of 1st Embodiment. The plane schematic diagram which shows the filter installed in the processing tank. The principal part expansion schematic diagram which shows a part of filter. The SEM photograph in case a microstructure is an acicular structure. The SEM photograph in case a microstructure is polyhedron shape. The SEM photograph in case a microstructure is polyhedron shape. The schematic diagram which shows the processing system of 2nd Embodiment. Explanatory drawing for demonstrating the processing system by which the other washing | cleaning nozzle was installed in the processing tank. The external appearance perspective view which showed the filter other example. Sectional drawing when the filter shown in FIG. 9 is seen from the end surface side. The plane schematic diagram which showed the other example of the filter. The plane schematic diagram which showed the other example of the filter. The plane schematic diagram which showed the other example of the filter. The schematic which showed the other example of the filter formed cylindrically. Sectional drawing when the filter shown in FIG. 14 is seen from the end surface side. The principal part expanded sectional view which shows the inner peripheral surface side of the filter shown in FIG. The principal part expanded sectional view which shows the inner peripheral surface side in the other example of a filter. The external appearance perspective view which shows the other example of a filter. The external appearance perspective view which shows the other example of a filter. The SEM photograph of the filter of Example 1 after a filtration test. Photograph of the filter of Example 1 before washing. Photograph of the filter of Example 1 after washing.

First Embodiment
Hereinafter, a processing system and a processing method of the embodiment will be described with reference to the drawings.
FIG. 1 is a schematic view showing a processing system of the first embodiment. The treatment system 100 has a treatment liquid tank 101, a treatment tank 102, a pump 106, an air bubble generator 109, a treatment liquid tank 103, a concentrated sludge tank 104, and a pipe connecting these. . The treatment system 100 shown in FIG. 1 is of a cross flow type in which filtration is performed by the filter 10 while flowing the treatment liquid substantially in parallel to the surface of the filter 10 on the treatment liquid region 102 a side.

  The liquid tank 101 stores the liquid to be treated. Examples of the liquid to be treated include water containing SS particles. A stirrer for stirring the inside of the to-be-treated liquid tank 101 may be installed in the to-be-treated liquid tank 101. The shape, volume, material, and the like of the liquid tank 101 to be treated can be appropriately determined according to the application of the processing system 100 and the like, and is not particularly limited.

The treatment tank 102 includes a supply unit 141 to which the liquid to be treated is supplied, a filter 10 for filtering solid content in the liquid to be treated, a first discharge unit 142 to discharge the treatment liquid having passed through the filter 10, and a supply unit. And a second discharge unit 143 configured to discharge a part of the liquid supplied to 141.
In the treatment tank 102, the liquid to be treated is filtered by the filter 10 to remove the object to be filtered (solid content) such as SS particles from the liquid to be treated, thereby producing the treatment liquid. The external shape of the processing tank 102 is not particularly limited, and, for example, a flat shape having a wide area in a plan view and a small area in a side view is used.

  The processing tank 102 is divided by the filter 10 into a liquid processing area 102 a and a processing liquid area 102 b. The filter 10 installed in the processing tank 102 is installed substantially horizontally at a substantially central portion in the vertical direction of the processing tank 102. Therefore, the inside of the processing tank 102 is divided up and down by the filter 10. The upper side of the filter 10 is the liquid processing area 102a, and the lower side of the filter 10 is the processing liquid area 102b.

The inflow pipe 108 a is connected to the liquid tank 101 and the supply unit 141 of the processing tank 102. The supply unit 141 of the processing tank 102 is provided on the upper wall surface of the processing tank 102.
The pump 106 is installed in the inflow piping 108 a. The pump 106 pressure-feeds the liquid to be treated stored in the liquid tank 101 to the supply unit 141 of the treatment tank 102.

  An air bubble generator 109 is connected to the inflow pipe 108 a via a pipe 108 c. The bubble generation device 109 can supply bubbles to the liquid to be treated supplied to the supply unit 141. In the present embodiment, the air bubble generation device 109 supplies air bubbles to the liquid to be treated, which passes through the inside of the inflow pipe 108a, through the pipe 108c at the time of cleaning, which will be described later, to generate an air bubble containing liquid.

  A conventionally known device can be used as the bubble generation device 109, and it is preferable to use a device capable of producing a bubble-containing liquid to be treated containing bubbles of 1 to 100 μm. Examples of the bubble generating apparatus 109 capable of generating a bubble-containing liquid containing bubbles of 1 to 100 μm include, for example, an air introducing unit for introducing air into the liquid to be treated, and air introduced into the liquid to be treated. And the like. As a mixing unit used for the air bubble generation device 109, for example, a device for passing the solution to be treated and the introduced air to an orifice having a plurality of small holes, and mixing the solution to be treated and the introduced air by a static mixer. An apparatus etc. are mentioned.

  The outflow pipe 108 f is connected to the second discharge portion 143 of the processing tank 102 and the valve 107. The second discharge unit 143 of the processing tank 102 is provided on the upper wall surface of the processing tank 102. The connection position (the second discharge part 143) between the outflow pipe 108f and the processing tank 102 is substantially the same as the connection position (supply part 141) between the inflow pipe 108a and the processing tank 102 via the central portion in plan view of the processing tank 102. It is in the opposite position.

  The valve 107 is a three-way valve. By switching the valve 107, the outflow pipe 108f is in communication with the second discharge part 143 of the processing tank 102 and the return pipe 108b or the exhaust pipe 108d. The return pipe 108 b is connected to the liquid tank 101. Therefore, the liquid to be treated can be circulated between the liquid to be treated tank 101 and the treatment tank 102 through the inflow piping 108 a, the outflow piping 108 f, and the return piping 108 b. The discharge pipe 108 d is connected to the concentrated sludge tank 104.

  The treatment liquid tank 103 stores the treatment liquid supplied from the first discharge unit 142 of the treatment tank 102 via the treatment liquid pipe 108 e. The treatment liquid is generated by the treatment liquid passing through the filter 10 in the treatment tank 102 from the primary surface 11 a side to the secondary surface 11 b side. The shape, volume, material, and the like of the processing liquid tank 103 can be appropriately determined according to the application of the processing system 100 and the like, and is not particularly limited.

  A flowmeter 110 for measuring the flow rate of the processing liquid passing through the inside of the processing liquid pipe 108e is installed in the processing liquid pipe 108e as a detection means for detecting the filtration performance of the filter 10. As the flow meter 110, one that measures the flow rate of the processing liquid continuously may be used, or one that measures at predetermined time intervals may be used. The measurement result of the flow rate of the liquid to be treated measured by the flow meter 110 is sent to the control unit 120.

  The control unit 120 determines the necessity of cleaning of the filter 10 based on the output from the flow meter 110 (detection means), and executes cleaning when it is determined that cleaning is necessary, and determines that cleaning is unnecessary. In this case, execute the process. In the present embodiment, the control unit 120 determines whether or not cleaning of the filter 10 is necessary depending on whether the measurement result of the flow rate of the processing liquid sent from the flow meter 110 is equal to or less than a predetermined threshold value. Thus, the air bubble generator 109 and the valve 107 are controlled. The determination as to whether or not the filter 10 needs to be cleaned by the control unit 120 may be performed each time a measurement result of the flow rate of the processing liquid is sent from the flow meter 110 or may be performed at regular intervals.

  The function of determining whether the measurement result of the flow rate of the processing liquid in the control unit 120 is equal to or less than a threshold and the function of controlling the bubble generation device 109 and the valve 107 based on the determination result are It is realized by the functions provided to the central processing unit.

  When the control unit 120 determines that cleaning is necessary, the control unit 120 controls the air bubble generating device 109 and the valve 107 to drive the air bubble generating device 109, and switch the valve 107 to output the outflow pipe 108f and The exhaust pipe 108d is made to communicate. As a result, the treatment liquid (bubble-containing treatment liquid) to which the bubbles supplied from the bubble generation device 109 are added is supplied to the supply unit 141, and a part of the treatment liquid contained in the bubble-containing treatment liquid is filtered. And the remaining portion is drained from the second discharge portion 143 together with the solid content deposited on the filter 10.

  If the control unit 120 determines that cleaning is not necessary, the control unit 120 controls the air bubble generation device 109 and the valve 107 to switch the valve 107 in a state where the air bubble generation device 109 is stopped and to execute the outflow piping. 108f and the discharge pipe 108d are communicated. As a result, the process liquid to which the bubbles are not added is supplied to the supply unit 141, a part of the process liquid is filtered by the filter 10, and the process of discharging the remaining process liquid from the second discharge unit 143 is performed. .

  The concentrated sludge tank 104 stores a concentrate containing a large amount of SS particles removed from the liquid to be treated. The concentrated sludge tank 104 is supplied from the to-be-treated region 102a of the treatment tank 102 through the outflow pipe 108f and the discharge pipe 108d. The shape, capacity, material, and the like of the concentrated sludge tank 104 can be appropriately determined according to the application of the treatment system 100 and the like, and is not particularly limited.

FIG. 2 is a schematic plan view showing a filter installed in the processing tank 102. As shown in FIG.
The filter 10 has a plurality of through holes 13, 13... And a plurality of microstructures formed on the surface of the primary surface 11a side (see FIG. 1) into which at least the liquid to be treated flows. In the present embodiment, the microstructure is formed on the entire surface of the filter 10. That is, the microstructure is formed to cover the primary surface (inflow surface) 11 a of the filter 10, the secondary surface (outflow surface) 11 b from which the liquid to be treated flows out, and the inner wall surface of the through hole 13. . The microstructure has a maximum outside dimension smaller than the average pore diameter of the through holes 13. The microstructure is preferably formed of a metal or an alloy.

  The average pore diameter of the through holes 13 is preferably 0.1 μm to 5 mm. When the average pore diameter of the through holes 13, 13 ... is 0.1 μm or more, the filtration flow rate can be easily secured in the processing system 100, and the liquid to be treated can be efficiently filtered. If the average pore diameter of the through holes 13, 13 ... is 5 mm or less, the cake is easily formed, so that the filtration performance by the cake filtration can be enhanced, and a high-quality treatment liquid in which SS particles are sufficiently removed can get. The average hole diameter of the through holes 13, 13... Means the average value of the inscribed circle diameters of the plurality of through holes 13, 13.

  The fine structure may have at least one of a conical shape, an elliptical cone shape, a polygonal pyramid shape, a truncated cone shape, an elliptical truncated cone shape, and a polygonal pyramid shape, or may have a polyhedral shape. It may be

  Next, referring to FIG. 3 and FIG. 4, when the microstructure is in the shape of at least one of a cone, an ellipse, a polygon, a truncated cone, an ellipse, and a polygon. For example, the case where the microstructure is a needle-like structure having a tapered shape from the proximal end to the distal end will be described. FIG. 3 is a main part enlarged schematic view showing a part of the filter. FIG. 4 shows an SEM photograph (secondary electron image (SEI), 15.0 kV, 20000 ×) when the microstructure is a needle-like structure. When the microstructure is a needle-like structure, having the maximum outside dimension smaller than the average pore diameter of the through holes 13 means that the height dimension of the needle structures is smaller than the average pore diameter of the through holes 13 .

In the filter 10 shown in FIG. 3, SS particles captured from the liquid to be treated adhere to a part of the plurality of microstructures 5.
The microstructure 5 shown in FIG. 3 is formed of the plating layer 3 disposed on the substrate 11. Underlayer 4 is formed between plating layer 3 and substrate 11.

  In the present embodiment, a mesh-like substrate is used as the substrate 11. As the mesh-like base material 11, as shown in FIG. 2, the wire may be twill weave or plain weave. In the present embodiment, since the mesh-like material is used as the base material 11, the through holes 13 are regularly arranged.

  As a material of the base material 11, what can be used in the to-be-processed liquid filtered using the filter 10 is used. The material of the substrate 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 using a plating process. As a metal used for the base material 11, it is preferable to use iron, nickel, copper, zinc, aluminum, and these alloys etc., for example. Among them, it is particularly preferable to use stainless steel which is excellent in corrosion resistance, low in cost and easy to process as the material of the base material 11.

  The foundation layer 4 is provided as necessary to enhance the adhesion of the plating layer 3 to the substrate 11. As a material used for base layer 4, when forming plating layer 3 which consists of nickel alloys on the surface of substrate 11, for example, it is preferred to use nickel or nickel alloy. As a nickel alloy, what contains one or more elements chosen from boron, phosphorus, and zinc is mentioned.

  The thickness of the foundation layer 4 is set to be equal to or more than the thickness that can improve the adhesion of the plating layer 3 to the base material 11. Further, the thickness of the base layer 4 is set to such a range that the diameter of the through hole 13 is a size suitable for passing the liquid containing the SS particles through the filter 10.

  As a metal or alloy used for the plating layer 3 formed of the plurality of microstructures 5, a metal or alloy capable of depositing the plurality of microstructures 5 on the surface of the substrate 11 or the underlayer 4 by a process such as electroplating Use. Such metals include iron, nickel, copper, and alloys thereof. Among the above-mentioned metals, as the metal used for the plating layer 3, it is preferable to use nickel or a nickel alloy, since the shape of the microstructure 5 can be easily controlled and the corrosion resistance is excellent. As a nickel alloy, what contains one or more elements chosen from boron, phosphorus, and zinc is mentioned.

  The plating layer 3 is a composite in which a plurality of microstructures (needle-like structures) 5 are gathered on the surface of the underlayer 4. In each microstructure 5, the base 5 a which is a region closer to the base 11 than the proximal end 53 a of the microstructure 5 is integrated with the bases 5 a of the adjacent other microstructures 5. As a result, the base 5 a of the microstructure 5 is continuously formed on the surface of the base layer 4.

  A valley 53 is formed between the adjacent microstructures 5 and the width becomes narrower as it approaches the proximal end 53a in a cross sectional view. The valleys 53 are formed to surround each of the microstructures 5 in a plan view. The valley 53 surrounding each microstructure 5 is formed in plan view in connection with the valley 53 surrounding another adjacent microstructure 5.

The number of microstructures 5 (formation density of microstructures) per unit area (1 μm ² ) of the base material 11 is preferably 1.2 to 10.0 / μm ² .
When the number of microstructures 5 per unit area is 1.2 pieces / μm ² or more, the surface area of the filter 10 becomes sufficiently large, and SS particles are easily caught between the adjacent microstructures 5. Therefore, it is possible to make the filter 10 in which the SS particles are easily captured by the depth filtration mechanism and the cake 7 is easily formed by the captured SS particles.
Therefore, the filter 10 has an excellent removal function that can capture SS particles using the depth filtration mechanism and the cake filtration mechanism. The number of microstructures 5 per unit area is preferably 3.0 particles / μm ² or more in order to obtain a filter 10 having a higher function of removing SS particles.

If the number of microstructures 5 per unit area is 10.0 pieces / μm ² or less, the space between adjacent microstructures 5 is prevented from being too narrow. For this reason, SS particles are easily removed from the microstructure 5 by washing.
In addition, when the number of microstructures 5 per unit area is 10.0 pieces / μm ² or less, as shown in FIG. 3, valleys 53 formed between adjacent microstructures 5, and a plating layer A space 31 of sufficient size surrounded by the cake 7 formed on 3 is formed. The space 31 functions as a flow path through which the cake-filtered processing liquid 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 which can obtain the process liquid which passed cake 7 becomes large, filtration flow volume can be enlarged. Therefore, the filter 10 is easy to remove SS particles, and has a large filtration flow rate. The number of microstructures 5 per unit area is preferably 7.0 pieces / μm ² or less in order to obtain an excellent filter 10 with a larger filtration flow rate.

The number of microstructures 5 (density of formation of microstructures) per unit area (1 μm ² ) of the substrate 11 when the microstructure 5 is a needle-like structure is measured by the method described below is there.
The filter was observed with an electron microscope, the vertical 2 [mu] m, the horizontal 2 [mu] m, the number of vertices of the needle-like structures present in the square area 4 [mu] m ^2, measured four locations (see Fig. 4). Then, the number of apexes of the acicular structures measured at four locations is averaged to calculate the number of acicular structures per unit area (1 μm ² ).

The number of microstructures 5 per unit length (1 μm) in the cross section of the substrate 11 (the number of formations per unit length of the microstructures) is preferably 1.0 to 4.0 / μm.
If the number of microstructures 5 per unit length is 1.0 or more, as in the case where the number of microstructures 5 per unit area is 1.2 or more ² or more Using the deep bed filtration mechanism and the cake filtration mechanism, an excellent removal function is obtained that can capture SS particles. The number of microstructures 5 per unit length is preferably 1.5 / μm or more in order to obtain a filter 10 having a higher function of removing SS particles.

If the number of microstructures 5 per unit length is 4.0 / μm or less, as in the case where the number of microstructures 5 per unit area is 10.0 / μm ² or less The space between the adjacent microstructures 5 is prevented from becoming too narrow. For this reason, a space 31 of a sufficient size surrounded by the valley 53 formed between the adjacent microstructures 5 and the cake 7 formed on the plating layer 3 is formed, and filtration is performed. A large flow rate filter 10 can be used. The number of microstructures 5 per unit length is preferably 3.0 / μm or less in order to obtain a filter 10 with a still higher filtration flow rate.

The number of microstructures 5 per unit length (1 μm) in the cross section of the substrate 11 is measured by the method described below.
The filter 10 is fixed with the embedded 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 substrate in the enlarged cross-sectional photograph of the substrate taken. Then, the number of microstructures per unit length (1 μm) is calculated from the number of the microstructures 5 measured.

In the present embodiment, the average height H and the average width D of the base end portions of the needle-like microstructures 5 in the cross section of the base material 11 are those obtained by measuring the dimensions of the portions shown below by the measurement methods shown below It is.
As shown in FIG. 3, valleys 53 are formed between adjacent microstructures 5 in the cross section of the base material 11. In the cross section of the base 11, between the base ends 53a and 53a which are valley bottoms facing each other across the microstructure 5 are connected by a straight line 51, and the lengths thereof are widths D1 and D2 of the base end of the microstructure 5 and Do. Further, the shortest distance between the tip 52 of the microstructure 5 and the straight line 51 is taken as the heights H 1 and H 2 of the microstructure 5.

  When two microstructures 57 and 58 are integrated in the cross section of the substrate 11 (a microstructure indicated by reference numeral 59 in FIG. 3), the dimensions of the portions shown below are the microstructures 57, The heights H3 and H4 of 58 and the widths D3 and D4 of the proximal end portions of the fine structures 57 and 58 were used.

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

  The shortest distance between the tips 52a and 52b of the respective microstructures 57 and 58 and the straight line 54 is defined as the heights H3 and H4 of the respective microstructures 57 and 58. When the length of the perpendicular line 56 is less than 3/4 of the heights H3 and H4 of the microstructures 57 and 58, it is considered as two independent microstructures. In addition, the reference on which the two microstructures 57 and 58 are integrated is assumed to be other than the case where it is regarded as the two independent microstructures.

  In order to measure the height of the needle-like microstructure 5 and the width of the proximal end of the microstructure 5, the filter 10 is fixed with embedded resin and cut, and the cut surface is polished by ion milling, Images are taken using a scanning electron microscope (SEM). After that, a range of 10 μm in length along the substantially extending direction of the surface of the base material in the enlarged cross section of the base material 11 taken is taken as one measurement area, and all the above-mentioned microstructures present in the four measurement areas Measure the height of the object 5 and the width of the proximal end. Then, the average value of the heights of the measured four microstructures 5 is taken as the average height H of the microstructures 5. Further, the average value of the widths of the base end portions of the four microstructures 5 measured is taken as the average width D of the base end portions of the microstructure 5.

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

When the above variation coefficient is in the range of 0.15 to 0.50, the filter 10 is further excellent in the SS particle removal function and the cleaning property.
When the above variation coefficient is 0.15 or more, the variation in the height of the microstructure 5 becomes sufficiently large. For this reason, when passing the to-be-processed liquid containing SS particle | grains to the filter 10, while the flow of the to-be-processed liquid containing SS particle | grains in the surface of the filter 10 becomes complicated, the microstructure 5 with high height is SS. It becomes easy to catch particles. As a result, SS particles are easily captured by the mechanism of depth filtration, and cake 7 is easily formed on the surface of the plating layer 3 starting from the SS particles caught by the high-height microstructure 5. The above-mentioned coefficient of variation is preferably 0.18 or more in order to make the filter 10 easier to capture SS particles.

  The microstructure 7 having a low height supports the cake 7 formed on the surface of the plating layer 3 with the above variation coefficient of 0.50 or less, so that it is formed between the adjacent microstructures 5 The area of the space 31 surrounded by the valley 53 and the cake 7 can be easily secured. For this reason, after the cake 7 is formed by filtration, the cake-filtered treatment liquid easily flows in the space 31, and the filtration flow rate increases. Therefore, the filter 10 has an excellent filtration flow rate as compared with the filter without the needle-like structure. The above-mentioned coefficient of variation is preferably 0.36 or less in order to obtain a filter 10 with a still higher filtration flow rate.

  It is preferable that aspect-ratio H / D of the average width D of the base end part of the needle-like microstructure 5 in the cross section of the base material 11, and the average height H is 0.5-4.0. When the aspect ratio H / D is 0.5 or more, a sufficient space 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 of height is formed. Therefore, after the cake 7 is formed by filtration, the cake-filtered treatment liquid easily flows in the space 31, and the filtration flow rate becomes excellent. The aspect ratio H / D is preferably 1.0 or more in order to further increase the filtration flow rate of the filter 10.

  When the aspect ratio H / D is 4.0 or less, since the fine structure 5 having excellent strength is obtained, the filter 10 having excellent durability is obtained. The aspect ratio H / D is preferably 3.0 or less in order to make the filter 10 further excellent in durability.

  The average height H of the needle-like microstructures 5 in the cross section of the substrate 11 is preferably 0.2 to 2.5 μm. If the average height H of the above-mentioned microstructure 5 is 0.2 μm or more, it is surrounded by the valley 53 formed between the adjacent microstructures 5 and the cake 7 formed on the plating layer 3 A space 31 of a sufficient height is formed. For this reason, after a cake is formed at the time of filtration, the cake-filtered treatment liquid easily flows in the space 31, and the filtration flow rate becomes excellent. The average height H of the microstructure 5 is preferably 0.4 μm or more in order to make the filter 10 further excellent in filtration flow rate.

  If the average height H of the needle-like microstructures 5 is 2.5 μm or less, it is possible to prevent the space between the adjacent microstructures 5 from being too narrow. For this reason, it becomes the filter 10 excellent in the filtration flow volume by which the space 31 was fully ensured. The average height H of the microstructure 5 is preferably 1.8 μm or less in order to make the filter 10 further excellent in filtration flow rate.

The filter 10 is an aperture having a ratio [(area of through hole 13 / area of whole primary surface 11 a) × 100] of the through hole 13 to the plane area of the whole primary surface 11 a when the primary surface 11 a side is viewed in plan. Preferably, the ratio is 0.46% or more and 63.0% or less.
When the microstructure 5 is a needle-like structure, the filtration flow rate can be easily secured when the porosity is 0.46% or more, and the liquid to be treated can be efficiently filtered. On the other hand, the filtration performance by cake filtration can be improved as an open area ratio is 63.0% or less, and the high-quality processing liquid from which SS particle | grains were fully removed is obtained.

  When the microstructure 5 is needle-like, the average pore diameter of the through holes 13 is preferably 0.5 μm or more and 20 μm or less. When the average pore diameter of the through holes 13 is 0.5 μm or more, the filtration flow rate can be more easily secured, and the liquid to be treated can be efficiently filtered. When the average pore diameter of the through holes 13 is 20 μm or less, the cake 7 is formed more easily, so that the filtration performance by the cake filtration can be enhanced.

Next, a method of manufacturing the filter 10 when the microstructure 5 is a needle-like structure will be described.
First, the base material 11 which is twill-woven and has a mesh shape is prepared. Then, the base layer 4 is formed on the surface of the base material 11 having the plurality of through holes 13, 13. A conventionally known method can be used as the plating treatment for forming the underlayer 4. For example, in the case where the underlayer 4 is formed on the surface of the base 11 made of stainless steel before forming the microstructure 5 made of nickel or a nickel alloy, electrolytic nickel plating or electroless nickel plating is used. It is preferable to form the underlayer 4 made of nickel or nickel alloy.

  Next, a plurality of microstructures 5 are deposited by electroplating on the surface of the base material 11 provided with the base layer 4, and the base material 11 is coated with the plating layer 3. A conventionally known method can be used as the electroplating process for forming the plating layer 3. For example, when base layer 4 and plating layer 3 are made of nickel or nickel alloy, after formation of base layer 4, an additive is added to the plating bath to carry out electrolytic nickel plating treatment or electroless nickel plating continuously. It is preferable to form the plating layer 3 using a process.

  Moreover, as a method of depositing the fine structure only on a part of the surface of the base material 11 provided with the foundation layer 4, for example, after masking the portion which does not cause the fine structure to precipitate, using a known method The method of performing a plating process is mentioned. Also, by performing the electroplating process under the condition that fine precipitates are likely to be deposited on the primary surface side of the base material 11 provided with the base layer 4, a portion where the fine structure is not deposited on part of the surface of the base material 11 May be formed.

  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 (ethylenediamine dihydrochloride) and ethylenediamine (EDA).

After the plating process for forming the plating layer 3, heat treatment may be performed as necessary to promote crystallization of the plating layer 3.
In addition, after the plating process for forming the plating layer 3, another metal or organic substance is used on the surface of the plating layer 3 to improve the durability of the filter, if necessary. A cover layer may be formed.

  Further, the surface of the plating layer 3 may be subjected to a modification treatment to form a plurality of kinds of modification regions having different affinities with the liquid to be treated. Specifically as a modification process of the plating layer 3, a hydrophilization process and a hydrophobization process are mentioned. By performing such a modification process, the flow of the liquid to be treated 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.

Next, a treatment method for treating the liquid to be treated using the treatment system 100 of the present embodiment will be described.
In the present embodiment, the outflow pipe 108 f and the return pipe 108 b are connected by switching the valve 107 before starting the treatment of the liquid to be treated, and the communication between the treatment tank 102 and the sludge concentration tank 104 is shut off.
Next, a liquid to be treated such as water containing SS particles is introduced into the liquid to be treated tank 101 and stored. And the to-be-processed liquid in the to-be-processed liquid tank 101 is stirred by a stirrer as needed.

  Next, the first processing step is performed. In the first processing step, the pump 106 is driven to pump the liquid to be treated toward the supply portion 141 of the processing tank 102 from the liquid tank 101 via the inflow piping 108 a. Then, part of the treatment liquid supplied from the supply unit 141 to the treatment liquid region 102a flows into the filter 10 from the primary surface 11a side, flows out from the secondary surface 11b, and is filtered to be a treatment liquid. The processing liquid generated by passing through the filter 10 is supplied from the first discharge unit 142 of the processing tank 102 to the processing liquid tank 103 via the processing liquid pipe 108 e and stored.

  Moreover, the to-be-processed liquid which did not pass through the filter 10 among the to-be-processed liquid supplied to the to-be-processed liquid area | region 102a is discharged | emitted from the 2nd discharge part 143, and is processed via the outflow piping 108f and the return piping 108b. It is returned to the processing liquid tank 101. Therefore, in the present embodiment, the liquid to be treated is filtered while being circulated between the liquid to be treated tank 101 and the treatment tank 102.

Here, the filtration performance of the processing system 100 in the case where the microstructure 5 of the filter 10 installed in the processing tank 102 is a needle-like structure will be described.
Since the filter 10 has a plurality of needle-like microstructures 5, the contact area between the filter 10 and the liquid to be treated containing SS particles is large. For this reason, when filtration of the liquid to be treated is started, SS particles attached to the surface of the microstructure 5 by the mechanism of surface filtration and deep layer filtration serve as a starting point, and SS particles are promptly dispersed at a plurality of locations on the surface of the plating layer 3 Aggregates are formed.

  The formed aggregate is grown and exfoliated by continuing filtration of the treatment liquid containing SS particles to the filter 10, and moves toward the through hole 13 together with the treatment liquid containing SS particles. The one or more aggregates moved to the through hole 13 become a bridge-like cake 7 blocking the through hole 13. Therefore, a predetermined SS particle removal performance can be obtained in a short time after the start of filtration of the liquid to be treated. In addition, in the treatment method of the present embodiment, small SS particles in the liquid to be treated can be removed using not only the mechanism of surface filtration but also the mechanism of deep bed filtration and the mechanism of cake filtration. Thus, excellent filtration performance can be obtained.

  The filter 10 has valleys 53 between adjacent microstructures 5, as shown in FIG. The valley 53 narrows in width as it approaches the base end 53a which is a valley bottom in a cross sectional view. For this reason, the SS particles captured by the filter 10 hardly enter near the proximal end 53 a of the valley 53.

  Therefore, in the filter 10 in which the cake 7 is formed on the surface of the plating layer 3, as shown in FIG. 3, a space 31 having a sufficient size surrounded by the valley 53 and the cake 7 is formed. After the space 31 is formed, even if the supply of the liquid to be treated including the SS particles to the filter 10 is continued, the upper part of the space 31 is covered with the lid formed of the cake 7. , SS particles do not easily enter space 31. Therefore, even if the filtration of the liquid to be treated containing SS particles to the filter 10 is continued, the filtration flow rate is secured.

  In the present embodiment, the first processing step is performed while the flow rate of the processing liquid passing through the processing liquid pipe 108 e is measured by the flow meter 110. The measurement of the flow rate of the processing liquid passing through the inside of the processing liquid pipe 108e by the flow meter 110 may be performed continuously during the first processing step, or may be performed at predetermined time intervals. The measurement result of the flow rate of the processing liquid measured by the flow meter 110 is sent to the control unit 120.

  If the first treatment step is continued, more SS particles will be deposited on the cake 7 formed in the filter 10, and the filtration flow rate will gradually decrease. In the present embodiment, based on the measurement result of the flow rate of the processing liquid passing through the processing liquid pipe 108 e output from the flow meter 110, the control unit 120 determines the necessity of cleaning the filter 10. Specifically, the control unit 120 determines whether the flow rate of the processing liquid passing through the processing liquid pipe 108 e measured by the flow meter 110 is equal to or less than a threshold. As a result, if the flow rate of the processing liquid is above the threshold value, it is determined that cleaning is unnecessary, and the first processing step is continued.

  On the other hand, if it is determined by the control unit 120 that the flow rate of the processing liquid is equal to or less than the threshold value, it is determined that cleaning is necessary. When it is determined that the cleaning is necessary, the control unit 120 controls the air bubble generator 109 and the valve 107 to switch from the first processing step to the cleaning step. Specifically, the air bubble generation device 109 is driven to supply air bubbles to the liquid to be treated which passes through the inflow piping 108a through the piping 108c, and the valve 107 is switched to set the outflow piping 108f and the discharge piping 108d. Make it communicate. As a result, the treatment liquid (bubble-containing treatment liquid) to which the bubbles supplied from the bubble generation device 109 are added is supplied to the supply unit 141, and a part of the treatment liquid contained in the bubble-containing treatment liquid is filtered. , And the remaining portion is discharged from the second discharge portion 143 together with the solid content deposited on the filter 10. That is, in the cleaning step, the bubble-containing to-be-treated liquid supplied from the supply unit 141 to the primary surface 11 a side (to-be-treated liquid region 102 a) in the to-be-treated liquid region 102 a filters the filter 10 while washing the filter 10. Filtered.

  It is preferable that it is 1-100 micrometers, and, as for the magnitude | size of the bubble contained in a bubble containing to-be-processed liquid, it is more preferable that it is 10-50 micrometers. When the size of the bubbles contained in the bubble-containing liquid to be treated is 1 μm or more, the collapse of the cake due to the collision of the bubbles with the cake 7 is promoted. For this reason, the cleaning effect by containing air bubbles becomes remarkable, and is preferable. In addition, when the size of the bubbles contained in the bubbles-containing liquid to be treated is 100 μm or less, the floating speed of the bubbles is not too fast, and the bubbles are uniformly dispersed in the bubbles-containing liquid to be treated. For this reason, the collapse of the cake 7 due to the collision of the bubbles becomes even, and the collapse of the cake is promoted.

  In the present embodiment, the size of the bubbles contained in the bubble-containing liquid to be treated means the diameter of the bubbles obtained when air is introduced into tap water under the same conditions as the air introduced into the liquid to be treated. The conditions under which air is introduced into the liquid to be treated refer to the pressure and flow rate of air when air is introduced in an actual device, and the pressure and flow rate of the liquid to be treated introduced. Moreover, the diameter of the air bubble obtained when air is introduced into tap water is the diameter at 25 ° C. and 1 atm, which is, for example, the mode of the distribution obtained by measurement by a laser diffraction method or the like.

Next, the washability of the filter 10 when the microstructure 5 is a needle-like structure will be described.
When the microstructure 5 is a needle-like structure and the washing step is performed, the cake 7 formed on the filter 10 is swept away by the bubble-containing liquid to be treated. At this time, in the space 31 (see FIG. 3) existing in the through hole 13 and on the primary surface 11 a side of the filter 10, the cleaning liquid is viewed from many directions through the valleys 53 formed to surround each microstructure 5 Flows in. By this, the cake 7 formed so as to cover at least a part of the upper part of the valley 53 is pushed up by the bubble-containing liquid to be treated, and the peeling of the cake 7 is promoted. The microstructure 5 also has a tapered shape from the proximal end 53 a to the distal end 52. For this reason, the cake 7 pushed up by the bubble-containing liquid to be treated is easily peeled from the filter 10 by the flow of the bubble-containing liquid to be treated which is going to pass through the treatment tank 102.

  Moreover, in the present embodiment, the collapse of the cake 7 is promoted by the fact that the bubbles contained in the bubble-containing liquid to be treated collide with the cake 7. When the cake 7 collapses, the bubble-containing liquid is easily introduced into the collapsed part of the cake 7 and the further collapse of the cake 7 is promoted. In addition, the broken cake 7 becomes SS particles and is easily washed away by the bubble-containing treatment liquid. As a result, the cake 7 formed on the filter 10 is rapidly removed, and a high cleaning effect is obtained.

  In the cleaning step, the bubble-containing treated liquid supplied to the treated liquid region 102 a of the treatment tank 102 passes through the treated liquid region 102 a to form a concentrated treated target containing SS particles removed from the filter 10. It becomes a liquid. The concentrated liquid to be treated generated in the washing step is sent from the liquid to be treated area 102a to the concentrated sludge tank 104 through the outflow pipe 108f and the discharge pipe 108d.

  When the washing step is continued, the cake 7 and SS particles formed on the filter 10 are removed, and the filtration flow rate is gradually improved. In the present embodiment, the cleaning process is performed while the flow rate of the processing liquid passing through the processing liquid pipe 108 e is measured by the flow meter 110. The measurement of the flow rate of the processing liquid passing through the inside of the processing liquid pipe 108 e by the flow meter 110 may be performed continuously while performing the cleaning step, or may be performed at predetermined time intervals.

  The measurement result of the flow rate of the processing liquid measured by the flow meter 110 is sent to the control unit 120. In the present embodiment, based on the measurement result of the flow rate of the processing liquid passing through the processing liquid pipe 108 e output from the flow meter 110, the control unit 120 determines the necessity of cleaning the filter 10. Specifically, the control unit 120 determines whether the flow rate of the processing liquid passing through the processing liquid pipe 108 e measured by the flow meter 110 is equal to or less than a threshold. As a result, when the flow rate of the processing liquid is equal to or less than the threshold value, it is determined that cleaning is necessary, and the cleaning process is continued.

On the other hand, when the flow rate of the processing solution is above the threshold value, it is determined that the cleaning is unnecessary. If it is determined that cleaning is not necessary, the control unit 120 controls the air bubble generation device 109 and the valve 107 to switch from the cleaning process to the second processing process. Specifically, the driving of the air bubble generation device 109 is stopped to stop the supply of air bubbles to the liquid to be treated, and the valve 107 is switched to connect the outflow pipe 108f and the return pipe 108b to communicate the liquid to be treated. The communication between the treatment tank 102 and the sludge concentration tank 104 is blocked by circulating between the liquid tank 101 and the treatment tank 102. As a result, as in the first processing step, the liquid to be treated without air bubbles is supplied to the supply portion 141, a part of the liquid to be treated is filtered by the filter 10, and the remaining portion of the liquid to be treated is the second discharge portion. Perform a second treatment step to drain from 143.
In the processing method of the present embodiment, after the second processing step, it is preferable to repeatedly perform the same cleaning step and the second processing step as described above a plurality of times, if necessary.

  In the processing system 100 according to the present embodiment, the control unit 120 determines whether or not cleaning of the filter is necessary based on the output from the flow meter 110, and when it is determined that cleaning is necessary, The supplied liquid to be treated is supplied to the supply portion 141, and a part of the liquid to be treated is filtered by the filter 10, and the remaining portion of the liquid to be treated is discharged from the second discharge portion 143 together with the solid content deposited on the filter 10. Run Therefore, in the treatment system 100 of the present embodiment, filtering can be performed while the filter 10 is washed by performing the above-described washing in the washing step.

Therefore, according to the present embodiment, the filtration of the liquid to be treated can be continued not only at the treatment step (the first and second treatment steps) but also at the washing step. As a result, the operation rate does not decrease even if the cleaning step is performed, and the liquid to be treated can be processed efficiently.
Moreover, in the present embodiment, since the filter 10 having the plurality of microstructures 5 is cleaned using the bubble-containing liquid to be treated, a high cleaning effect can be obtained. For this reason, it is not necessary to use the clear water for washing the filter 10 as in the case of washing the primary face 11 a of the filter 10 using, for example, clear water containing no bubbles. Further, in the present embodiment, since the bubble-containing treated liquid is generated by the bubble generating device 109 only at the time of the cleaning step, for example, the bubble-generating treated liquid is generated by the bubble generating device 109 also in the treatment step and filtered. The processing cost is lower than in the case, which is preferable.

  In addition, the processing system 100 according to the present embodiment has the filter 10 having a plurality of microstructures 5 each having a smaller maximum outside dimension than the average hole diameter of the through holes 13 on at least the surface on the primary surface 11a side to which the liquid flows. Since it has, by filtering a to-be-processed liquid with the filter 10, the high quality processing liquid from which SS particle | grains were fully removed is obtained.

  Next, an example where the microstructure 5 has a polyhedral shape will be described using FIGS. 5 and 6. 5 and 6 show SEM photographs (secondary electron image (SEI), 15.0 kV, 2000 times (FIG. 5), 5000 times (FIG. 6)) when the microstructure 5 has a polyhedral shape.

In the polyhedron-shaped microstructure 5, a plurality of polyhedrons are mutually connected to share a part of the volume. The polyhedron-shaped microstructure 5 has a plurality of apexes at which three or more planes intersect each other. Each microstructure 5 has a different shape and a different size, as shown in FIGS. 5 and 6. The microstructures 5 are densely formed on the surface of the substrate 11 or the surface of the underlayer 4 (see FIG. 3) formed on the substrate 11. As a result, the portions corresponding to the sides of the polyhedron shape face in an irregular direction.
As the material of the polyhedron-shaped microstructure 5, the same material as that used for the microstructure 5 formed of a needle-like structure can be used.

  The average maximum outside dimension of the polyhedral-shaped microstructure 5 is preferably 0.5 to 10 μm. When the average maximum outside dimension of the precipitate is in the above range, the SS particles in the liquid to be treated are easily caught. Therefore, a cake is easily formed by the SS particles captured by the filter 10. As a result, it becomes easy to capture SS particles using the mechanism of cake filtration, and it becomes a high-performance filter 10 having a function of removing SS particles.

While the unevenness of the surface of plating layer 3 decreases that the average maximum outside dimension of polyhedron-shaped microstructure 5 is less than 0.5 μm, the amount of liquid to be treated passing through the gaps between polyhedron-shaped precipitates is reduced As a result, the adhesion of SS particles to the plating layer 3 may be difficult to occur. It is more preferable that the average maximum outside dimension of the polyhedral-shaped microstructure 5 is 2.0 μm or more.
In addition, when the average maximum outside dimension of the polyhedron-shaped microstructure 5 exceeds 10 μm, the contact area between the plating layer 3 and the liquid to be treated containing SS particles decreases, and the adhesion of the SS particles to the plating layer 3 It may be difficult to happen. It is further preferable that the average maximum outside dimension of the polyhedral-shaped microstructure 5 is 8.0 μm or less.

It is preferable that the variation coefficient of the average largest outside dimension in the polyhedral-shaped microstructure 5 is 0.15 to 0.50. When the coefficient of variation is in the range of 0.15 to 0.50, the filter 10 is further excellent in the SS particle removal function and the washability. In the present embodiment, the standard deviation of the maximum external dimension of the microstructure 5 is divided by the arithmetic mean value of the maximum external dimensions of the microstructure 5 with the variation coefficient of the average maximum external dimension of the microstructure having a polyhedral shape. Means what you
When the above-mentioned coefficient of variation is less than 0.15, when the treatment liquid containing SS particles is allowed to pass through the filter 10, the flow of the treatment liquid containing SS particles on the surface of the filter 10 becomes monotonous. SS particles are less likely to be captured by the structure 5. In addition, when the above variation coefficient exceeds 0.50, it is difficult to obtain the function of supporting the cake 7 formed on the surface of the plating layer 3 by the microstructure 5 having a small external dimension.

  When the above variation coefficient is 0.15 or more, the variation in the external dimensions of the microstructure 5 is sufficiently large. For this reason, when passing through the filter 10 the liquid to be treated containing SS particles, the flow of the liquid to be treated containing SS particles on the surface of the filter 10 becomes complicated, and the microstructure 5 having a large outside dimension It becomes easy to catch particles. As a result, the SS particles are easily captured by the mechanism of the depth filtration, and the cake 7 is easily formed on the surface of the plating layer 3 starting from the SS particles caught by the microstructure 5 having a large outside dimension. The above-mentioned coefficient of variation is preferably 0.18 or more in order to make the filter 10 easier to capture SS particles.

The average maximum outside dimension of the polyhedral-shaped microstructure 5 is measured by the measurement method described below.
A photograph of the enlarged filter 10 is taken using a scanning electron microscope (SEM), and image processing is performed. Specifically, the external dimensions of the largest portion of the polyhedral-shaped microstructure 5 are measured at 10 representative locations for one photograph, and the average value is the average maximum external shape. Define as dimension.

Next, a method of manufacturing the filter 10 when the microstructure 5 is a polyhedral structure will be described.
The filter 10 in the case where the microstructure 5 is a polyhedral structure is the same as the filter 10 in the case where the above-mentioned microstructure is a needle-like structure, except for the conditions of the electroplating process for precipitating the microstructure. It can be manufactured. That is, the polyhedral structure shown in FIG. 5 and FIG. 6 can be deposited by setting the conditions of the electroplating process to, for example, the conditions described in Non-Patent Document 2. In the electroplating process for depositing the polyhedral structure, the shape and size of the polyhedral structure can be changed by changing the type, concentration and plating time of the additive added to the plating bath. Examples of the additive include 2-butyne-1,4-diol and the like.

Next, a treatment method for treating the liquid to be treated using the treatment system 100 having the filter 10 in which the microstructure 5 is a polyhedral structure will be described.
In this case, since the fine structure 5 is the same as the needle-like structure described above except for the filtration performance and the washing property of the filter 10, the description of the same portion is omitted.

  In the case where the microstructure 5 is a polyhedral structure, the filter 10 has a plurality of polyhedral structures, so the contact area between the filter 10 and the liquid to be treated containing SS particles is large. For this reason, when passage of the liquid to be treated is started, SS particles adhere to the surface of the polyhedral structure, and aggregates of the SS particles are rapidly formed. Furthermore, the formed aggregate is grown by continuing the filtration of the liquid to be treated, and becomes a cake 7 blocking the through holes 13. Therefore, the predetermined SS particle removal performance can be obtained in a short time after the passage of the liquid to be treated is started. In addition, in the treatment method of the present embodiment, small SS particles in the liquid to be treated can be removed using not only the mechanism of surface filtration but also the mechanism of deep bed filtration and the mechanism of cake filtration. Thus, excellent filtration performance can be obtained.

  Further, in the filter 10 in the case where the microstructure 5 is a polyhedral structure, when the cake 7 is formed, a space surrounded by the gap formed between adjacent polyhedral structures and the cake 7 is formed. Ru. The upper part of the space is in a state in which the lid formed of the cake 7 is covered, so that SS particles are less likely to enter the space even if the filtration of the liquid to be treated is continued. Therefore, even if the filtration of the liquid to be treated containing SS particles to the filter 10 is continued, the filtration flow rate is secured.

  Even in the case where the processing system 100 having the filter 10 in which the microstructure 5 is a polyhedral structure is used, in the cleaning step, a bubble-containing treated liquid containing bubbles is generated in the inflow piping 108a, and the bubble-containing treated liquid is The liquid is supplied to the liquid processing area 102 a of the processing tank 102.

  Even when the microstructure 5 is a polyhedral structure, the size of the bubbles contained in the bubble-containing liquid to be treated is preferably 1 to 100 μm, and more preferably 10 to 50 μm. When the size of the bubbles contained in the bubble-containing liquid to be treated is 1 μm or more, the collapse of the cake due to the collision of the bubbles with the cake 7 is promoted. For this reason, the cleaning effect by containing air bubbles becomes remarkable, and is preferable. In addition, when the size of the bubbles contained in the bubbles-containing liquid to be treated is 100 μm or less, the floating speed of the bubbles is not too fast, and the bubbles are uniformly dispersed in the bubbles-containing liquid to be treated. For this reason, the collapse of the cake 7 due to the collision of the bubbles becomes even, and the collapse of the cake is promoted.

  When the microstructure 5 is a polyhedral structure and the washing step is performed, the cake 7 formed on the filter 10 is swept away by the bubble-containing liquid to be treated. At this time, the cleaning solution flows from many directions into the space present in the through holes 13 and on the primary surface 11 a side of the filter 10 through the valleys formed so as to surround each of the microstructures 5. As a result, the cake 7 formed so as to cover at least a part of the top of the valley is pushed up by the bubble-containing liquid to be treated, and the peeling of the cake 7 is promoted.

  Moreover, in the present embodiment, the collapse of the cake 7 is promoted by the fact that the bubbles contained in the bubble-containing liquid to be treated collide with the cake 7. When the cake 7 collapses, the bubble-containing liquid is easily introduced into the collapsed part of the cake 7 and the further collapse of the cake 7 is promoted. In addition, the broken cake 7 becomes SS particles and is easily washed away by the bubble-containing treatment liquid. As a result, the cake 7 formed on the filter 10 is rapidly removed, and a high cleaning effect is obtained.

In the processing system of the present embodiment, even when the microstructure 5 is a polyhedral structure, the control unit 120 determines whether or not the filter needs to be cleaned based on the output from the flow meter 110, and the cleaning is necessary. If it is determined, the liquid to be treated to which air bubbles have been added is supplied to the supply unit 141 by the bubble generation device 109, a part of the liquid to be treated is filtered by the filter 10, and the remaining portion of the liquid to be treated is deposited on the filter 10. The washing which is discharged from the second discharge unit 143 together with the solid content is performed. Therefore, filtering can be performed while washing the filter 10 by performing the above-described washing in the washing step. Therefore, the filtration of the liquid to be treated can be continued not only in the treatment step but also in the washing step.
Further, even when the microstructure 5 is a polyhedral structure, the filter 10 is cleaned using the bubble-containing to-be-treated liquid, so a high cleaning effect can be obtained.
In addition, even when the microstructure 5 is a polyhedral structure, by filtering the liquid to be treated with the filter 10, a high quality treatment liquid in which SS particles are sufficiently removed can be obtained.

Second Embodiment
FIG. 7 is a schematic view showing a processing system of the second embodiment.
A treatment system 100A shown in FIG. 7 includes a liquid tank 101, a treatment tank 102A, a pump 106, an air bubble generator 109, a treatment liquid tank 103, a concentrated sludge tank 104, and pipes connecting these components. Have. The processing system 100A shown in FIG. 2 is a cross flow type in which the liquid to be treated is filtered by the filter 10 while flowing substantially parallel to the surface of the filter 10 on the side of the liquid to be treated 102a.
About the processing system 100A shown in FIG. 7, the same code | symbol is attached | subjected about the same member as the processing system 100 shown in FIG. 1, and description is abbreviate | omitted.

  The processing tank 102A has a cylindrical outer shape that extends in a substantially horizontal direction. The filter 10 installed in the processing tank 102A is a cylindrical filter 10 installed in the processing system 100 shown in FIG. In the processing system 100A shown in FIG. 7, the central axis direction of the cylindrical filter 10 and the central axis direction of the cylindrical processing tank 102A are substantially the same.

  Further, in the processing system 100A shown in FIG. 7, the inside of the filter 10 is on the primary surface 11a side where the liquid to be treated flows in, and the outside of the filter 10 is on the secondary surface 11b side where the liquid to be treated flows out. The inside of the processing tank 102A is divided into the inside and the outside of the cylindrical filter 10. Then, the inside of the filter 10 is a treated liquid area 102a, and the outside of the filter 10 is a treated liquid area 102b.

  The processing tank 102A is provided with a first supply part 141a connected to the processing pipe 108h and a second supply part 141b connected to the cleaning pipe 108g as a supply part to which the liquid to be processed is supplied. There is. The first supply portion 141a and the second supply portion 141b are formed on one of the two end surfaces of the cylindrical processing tank 102A. The first supply portion 141 a is disposed in the vicinity of the filter 10 inside the filter 10 in contact with one end face. The second supply portion 141 b is disposed at a position substantially at the central axis of the filter 10 in contact with one end face.

Further, the processing tank 102A is provided with a second discharge part 143 for discharging a part of the processing liquid supplied to the supply part. The second discharge portion 143 is formed on the other end surface opposite to the end surface on which the first supply portion 141a is provided among the two end surfaces of the cylindrical processing tank 102A. The second discharge portion 143 is disposed at a position substantially at the central axis of the filter 10 in contact with the other end face.
In addition, a first discharge unit 142 that discharges the processing liquid that has passed through the filter 10 is formed in the lower part of the side surface of the processing tank 102A.

  The second supply portion 141 b may be formed on the end surface of the cylindrical processing tank 102 A on the side where the second discharge portion 143 is not provided, or the second discharge portion 143 may be provided. It may be formed on the end face of the Because the liquid to be treated is supplied from the second supply unit 141 b via the cleaning nozzle 121 described later, the liquid is supplied via the cleaning nozzle 121 regardless of the distance between the second supply unit 141 b and the second discharge unit 143. The liquid to be treated and the filter 10 can be sufficiently brought into contact with each other.

  A cleaning nozzle 121 is installed in the liquid processing area 102 a of the processing tank 102 A. The cleaning nozzle 121 ejects the liquid to be treated (the liquid containing bubbles) toward the primary surface 11 a of the filter 10. The cleaning nozzle 121 has a cylindrical main body 121 b sealed at one end, and a plurality of jets 121 a and 121 a for discharging the bubble-containing liquid to be treated from the main body 121 b toward the outer peripheral direction. The end on the unsealed side of the main body 121 b is connected to the second supply unit 141 b.

The outer diameter of the main body 121 b of the cleaning nozzle 121 is smaller than the inner diameter of the cylindrical filter 10. Further, the cleaning nozzle 121 is installed such that the central axial direction of the main body 121b is substantially the same as the central axial direction of the filter 10 and the processing tank 102A.
The spouts 121a are formed at regular intervals in the longitudinal direction and the circumferential direction of the main body 121b. It is preferable that the internal diameter of the jet nozzle 121a is larger than the size of the bubbles contained in the bubble-containing treated liquid so that the cleaning effect by the bubble-containing treated liquid containing the bubbles is sufficiently obtained. The shape of the jet nozzle 121a is not particularly limited. When the shape of the jet nozzle 121a is not circular in plan view, the inner diameter of the jet nozzle 121a means the diameter of the inscribed circle of the jet nozzle 121a.

In the processing system 100A shown in FIG. 7, the inflow piping 108a is connected to the liquid processing tank 101 and the cleaning piping 108g and the processing piping 108h branched from the inflow piping 108a.
The processing pipe 108 h is connected to or disconnected from the first supply unit 141 a by switching the valve 107 a.
An air bubble generator 109 is connected to the cleaning pipe 108g via a pipe 108c. The cleaning pipe 108g is connected to or disconnected from the cleaning nozzle 121 via the second supply unit 141b by switching the valve 107b.

  The control unit 120 determines the necessity of cleaning of the filter 10 based on the output from the flow meter 110 (detection means), and executes cleaning when it is determined that cleaning is necessary, and determines that cleaning is unnecessary. In this case, execute the process. In the present embodiment, the control unit 120 determines whether or not cleaning of the filter 10 is necessary depending on whether the measurement result of the flow rate of the processing liquid sent from the flow meter 110 is equal to or less than a predetermined threshold value. Control the air bubble generator 109 and the valves 107, 107a, 107b.

  If the control unit 120 determines that cleaning is not necessary, the control unit 120 controls the air bubble generation device 109 and the valves 107, 107a, and 107b to stop the air bubble generation device 109, and the valve 107 is thus stopped. , 107a and 107b to connect the outflow pipe 108f and the discharge pipe 108d, and connect the inflow pipe 108a and the first supply unit 141a via the process pipe 108h. As a result, the process liquid to which the air bubbles are not added is supplied to the first supply unit 141a, a part of the process liquid is filtered by the filter 10, and the remaining portion of the process liquid is discharged from the second discharge unit 143. Run it.

  When the control unit 120 determines that cleaning is necessary, the control unit 120 controls the air bubble generation device 109 and the valves 107, 107a, and 107b to drive the air bubble generation device 109, and the valves 107, 107a, and 107a. The outlet pipe 108f and the outlet pipe 108d are communicated with each other by switching the port 107b, and the inlet pipe 108a and the second supply portion 141b are communicated via the cleaning pipe 108g. As a result, the liquid to be treated (the liquid containing bubbles) supplied from the air bubble generator 109 is supplied to the second supply portion 141b, and a portion of the liquid to be treated contained in the liquid containing bubbles is treated. The filter 10 is filtered, and the remaining portion is washed with the solid content deposited on the filter 10 and discharged from the second discharge portion 143.

Next, a treatment method for treating the liquid to be treated using the treatment system 100A of the present embodiment will be described.
In the present embodiment, the inflow piping 108a and the first supply unit 141a are connected by switching the valve 107a before starting the treatment of the liquid to be treated. Moreover, the inflow piping 108a and the 2nd supply part 141b are interrupted | blocked by switching valve 107b. Further, by switching the valve 107, the outflow pipe 108f and the return pipe 108b are connected, and the communication between the treatment tank 102A and the sludge concentration tank 104 is shut off.

Thereafter, the first processing step is performed in the same manner as in the case of processing the liquid to be processed using the processing system 100 of the first embodiment.
Then, as in the first embodiment, based on the measurement result of the flow rate of the processing liquid passing through the processing liquid pipe 108 e output from the flow meter 110, the control unit 120 determines whether or not the filter 10 needs cleaning. Do. As a result, if the flow rate of the processing liquid is above the threshold value, it is determined that cleaning is unnecessary, and the first processing step is continued.

  On the other hand, when the flow rate of the processing solution is equal to or less than the threshold value, it is determined that cleaning is necessary. When it is determined that cleaning is necessary, the control unit 120 controls the air bubble generation device 109 and the valves 107, 107a, and 107b to switch from the first processing step to the cleaning step. Specifically, the air bubble generation device 109 is driven to supply air bubbles to the liquid to be treated which passes through the cleaning pipe 108g through the pipe 108c, and the inflow pipe 108a and the second supply portion 141b are cleaned. Communication is made via 108g, the inflow piping 108a and the first supply portion 141a are shut off, and the outflow piping 108f and the discharge piping 108d are connected.

  As a result, the liquid to be treated (bubble-containing liquid to be treated) to which the bubbles supplied from the bubble generator 109 are added is supplied to the second supply portion 141 b and directed to the primary surface 11 a of the filter 10 through the cleaning nozzle 121. It spouts. A part of the liquid to be treated contained in the bubble-containing liquid to be treated is filtered by the filter 10, and the remaining portion is discharged from the second discharge part 143 together with the solid content deposited on the filter 10. That is, in the cleaning step, the bubble-containing to-be-treated liquid supplied to the primary surface 11a side (to-be-treated liquid region 102a) in the to-be-treated liquid region 102a of the treatment tank 102A cleans the filter 10 while the filter 10 is washed. Filtered.

  In the present embodiment, in the cleaning step, the bubble-containing liquid to be treated is ejected from the plurality of ejection ports 121 a of the cleaning nozzle 121, whereby the bubble-containing target is substantially perpendicular to the extending direction of the primary surface 11 a of the filter 10. Processing solution is supplied. As a result, the decay of the cake 7 is promoted, the cake 7 formed on the filter 10 is rapidly removed, and a high cleaning effect is obtained.

  Also in the present embodiment, as in the first embodiment, the cleaning process is performed while the flow rate of the processing liquid passing through the processing liquid pipe 108 e is measured by the flow meter 110. Then, as in the first embodiment, based on the measurement result of the flow rate of the processing liquid passing through the processing liquid pipe 108 e output from the flow meter 110, the control unit 120 determines whether or not the filter 10 needs cleaning. Do. As a result, when the flow rate of the processing liquid is equal to or less than the threshold value, it is determined that cleaning is necessary, and the cleaning process is continued.

  On the other hand, when the flow rate of the processing solution is above the threshold value, it is determined that the cleaning is unnecessary. When it is determined that the cleaning is not necessary, the control unit 120 controls the air bubble generation device 109 and the valves 107, 107a, and 107b to switch from the cleaning process to the second processing process. Specifically, the driving of the air bubble generation device 109 is stopped to stop the supply of air bubbles to the liquid to be treated, and the valves 107, 107a and 107b are switched to connect the outflow pipe 108f and the return pipe 108b, The pipe 108a and the first supply unit 141a are communicated with each other through the process pipe 108h to circulate the liquid to be treated between the liquid tank 101 and the treatment tank 102A, and the inflow pipe 108a and the second supply unit 141b. And the communication between the treatment tank 102A and the sludge concentration tank 104 is shut off.

As a result, as in the first processing step, the liquid to be treated without air bubbles is supplied to the first supply portion 141a, a part of the liquid to be treated is filtered by the filter 10, and the remaining portion of the liquid to be treated is The second processing step of discharging from the discharge unit 143 is performed.
In the processing method of the present embodiment, after the second processing step, it is preferable to repeatedly perform the same cleaning step and the second processing step as described above a plurality of times, if necessary.

  Also in the processing system 100A shown in FIG. 7, the control unit 120 determines whether or not cleaning of the filter is necessary based on the output from the flow meter 110, and when it is determined that cleaning is necessary, The liquid to be treated is supplied to the second supply portion 141b, a part of the liquid to be treated is filtered by the filter 10, and the remaining portion of the liquid to be treated is accumulated from the second discharge portion 143 together with the solid content deposited on the filter 10. Run a wash to drain. Therefore, in the treatment system 100A of the present embodiment, filtering can be performed while the filter 10 is washed by performing the above-described washing in the washing step. Therefore, the same effect as the first embodiment described above can be obtained.

In the processing system 100A shown in FIG. 7, an example of a cleaning nozzle 121 having a cylindrical main body 121 b and a plurality of ejection ports 121 a for ejecting a bubble-containing liquid to be treated outward from the main body 121 b is exemplified. However, the cleaning nozzle 121 is not limited to the example shown in FIG.
FIG. 8 is an explanatory view for explaining a processing system in which another cleaning nozzle is installed in the processing tank. Since the processing system shown in FIG. 8 and the processing system 100A shown in FIG. 7 are the same except for the cleaning nozzle, the same reference numerals are given to the same members, and the description will be omitted.

The cleaning nozzle 122 shown in FIG. 8 ejects the bubble-containing liquid to be treated toward the primary surface 11 a of the filter 10. The cleaning nozzle 122 is disposed such that the direction of the bubble-containing liquid to be ejected is substantially tangential to the inner periphery of the filter 10.
Also, the outer diameter of the cleaning nozzle 122 is smaller than the inner diameter of the cylindrical filter 10. Further, the jet nozzle of the cleaning nozzle 122 may have an inner diameter larger than the size of the bubbles contained in the bubble-containing liquid to be treated so that the cleaning effect due to the bubble-containing liquid to be treated is sufficiently obtained. preferable.

  When the cleaning process is performed using the processing system having the cleaning nozzle 122 shown in FIG. 8, the bubble-containing liquid to be treated is supplied from the cleaning nozzle 122 to the filter 10, whereby the swirling flow along the inner peripheral surface of the filter 10 is It is formed. As a result, the decay of the cake 7 is promoted, the cake 7 formed on the filter 10 and the SS particles adhering on the filter 10 are rapidly removed, and a high cleaning effect is obtained.

In each said embodiment, although the filter 10 which used the network-like thing was mentioned as an example and demonstrated as the base material 11, the base material 11 of the filter 10 is not limited to said example.
For example, as a substrate, a filter having a plate-like substrate in which a plurality of through holes are formed may be used.

FIG. 9 is an external perspective view showing another example of the filter. FIG. 10 is a cross-sectional view when the filter shown in FIG. 9 is viewed from the end face side.
The plate-like base material 211 which the filter 212 has is formed with the same material as the mesh-like base material 11 in each said embodiment. Hereinafter, in the description of the filter 212, the description of the same configuration as that of the filter 10 in each of the above embodiments is omitted.

  The plate-like base material 211 is formed with a plurality of through holes 213, 213,... Penetrating in the thickness direction. The through holes 213, 213, ... are cylindrical holes connecting the primary surface 211a of the base material 211 and the secondary surface 211b. The through holes 213, 213,... Are arranged in a staggered arrangement along the primary surface 211a.

The average pore diameter of the through holes 213 is preferably 1 μm to 5 mm. When the average pore diameter of the through holes 213, 213... Is 1 μm or more, the filtration flow rate can be easily secured in the processing system having the filter 212, and the liquid to be treated can be efficiently filtered. The cake is easily formed when the average pore diameter of the through holes 213, 213... Is 5 mm or less, so that the filtration performance by the cake filtration can be enhanced, and a high quality treatment liquid in which SS particles are sufficiently removed can get.
The average hole diameter of the through holes 213, 213... Means the average value of the diameters of the inscribed circles of the plurality of through holes 213, 213.

  A plurality of microstructures 205 are formed on the entire surface of the filter 212. That is, the microstructures 205 are formed to cover the primary surface (inflow surface) 211 a of the filter 212, the secondary surface (outflow surface) 211 b from which the liquid to be treated flows out, and the inner wall surface of the through hole 213. There is. As the microstructures 205, the needle-like structures or the polyhedron structures in the above-described embodiments are formed. The fine structure 205 has a maximum outside dimension smaller than the average hole diameter of the through holes 213.

  The filter 212 shown in FIG. 9 can be manufactured in the same manner as the filter 10 in each of the above-described embodiments, except that the base material 11 of the filter 10 in each of the above-described embodiments is used.

  In the filter 212 shown in FIGS. 9 and 10, the primary surface 211a side into which the liquid to be treated flows is a flat surface, and a plurality of microstructures 205 are formed. Therefore, the fluid pressure at the time of the inflow of the to-be-processed liquid with respect to the filter 212 becomes uniform, and fluid pressure does not concentrate locally on the surface of the filter 212. For this reason, in the filter 212 shown in FIG. 9, the durability of the filter 212 against the fluid pressure when the treatment liquid flows in is enhanced, and the formation of a cake is promoted.

In the filter 212 shown in FIG. 9, the through holes 213 circular in plan view are arranged in a staggered arrangement in the base material 211, but the shape and the arrangement of the individual through holes are not limited.
11 to 13 are schematic plan views showing other examples of the filter. In the filter 291 shown in FIG. 11, the through holes 292 having a rectangular planar shape are arranged at equal intervals in a lattice. In the filter 294 shown in FIG. 12, the through holes 295 having a rectangular planar shape are formed in a staggered arrangement. In the filter 297 shown in FIG. 13, the through holes 298 having a hexagonal planar shape are formed in a staggered arrangement.

Other than this, the planar shape of the through hole formed in the base material may be various shapes such as polygonal shapes such as triangles and pentagons, oval shapes, and cross shapes, and is not particularly limited.
Also, the arrangement form of the plurality of through holes may be, for example, an equal arrangement as in the filter 291 shown in FIG. 11, or the filters 212, 294, 297 shown in FIG. 9, FIG. 12, FIG. As in the above, it may be a staggered arrangement, or may be arranged randomly, and is not particularly limited.
The average pore diameter of the through holes having these planar shapes means the average value of the diameters of the inscribed circles of the plurality of through holes penetrating the filter.

  Similar to the filter 212 shown in FIG. 9, a plurality of microstructures 205 are formed on the entire surface of the filters 291, 294, and 297. As the microstructures 205, the needle-like structures or the polyhedron structures in the above-described embodiments are formed. The fine structure 205 has a maximum outside dimension smaller than the average hole diameter of the through holes 213.

  The filters 212, 291, 294, and 297 shown in FIGS. 9 to 13 may be used as they are in the form of a plate, or may be formed, for example, in a cylindrical shape.

  Moreover, it has the filter body which arranged the wire in planar shape as a base material, and the supporting member which supports the said wire, A clearance gap is formed between the said adjacent wires mutually, The wire rod facing the primary surface side into which the liquid to be treated flows may use a filter having a base material forming a flat surface.

FIG. 14 is a schematic view showing another example of the cylindrically formed filter. FIG. 15 is a cross-sectional view when the filter shown in FIG. 14 is viewed from the end face side. FIG. 16 is an enlarged sectional view of an essential part showing the inner peripheral surface side of the filter shown in FIG.
The base 310 of the filter 300 shown in FIG. 14 is formed of the same material as the mesh base 11 in each of the above embodiments. Hereinafter, in the description of the filter 300, the description of the same configuration as that of the filter 10 in each of the above embodiments will be omitted.

  The base 310 of the filter 300 is formed of a filter body 312 in which wires 311 are arranged in a plane, and a support member 313 for supporting the wires 311. The filter body 312 is formed by winding a long wire 311 in a coil shape and forming it into a hollow cylindrical body.

  The wire 311 has a triangular cross-sectional shape perpendicular to the drawing direction. The wires 311 are supported by the support member 313 so as to be separated with a gap of a predetermined width between adjacent wires. Thereby, a slit-shaped gap 316 is formed in the cylindrical filter body 312 so as to penetrate between the inner peripheral surface 312a and the outer peripheral surface 312b.

  The support member 313 is a wire having a square cross section. The support member 313 is joined to the wire 311 on the outer peripheral surface 312 b side of the filter body 312. The support members 313 are formed in four places at equal intervals, for example, along the circumferential direction of the wire 311. The support member 313 extends parallel to the central axis of the filter body 312 and supports the wound wire 311 from the outer peripheral surface 312 b side. The support member 313 and the wire rod 311 are joined, for example, by sintering.

  The wire 311 facing the inner circumferential surface 312 a of the filter body 312 has a flat surface 311 f. That is, one side of the triangle of the wire 311 whose sectional shape is a triangle is arranged along the inner circumferential surface 312a. The wire 311 is joined to the support member 313 at the apex of the triangle opposite to one side of the triangle along the inner circumferential surface 312 a of the wire 311.

  In the filter 300 shown in FIG. 14, the liquid to be treated is allowed to flow toward the inner peripheral surface 312 a of the filter body 312, and the liquid to be treated is filtered through the gap 316 and the treated water after filtration is filtered from the outer peripheral surface 312 b. Let out. By using the wire 311 having a triangular cross section, the gap 316 between the wires 311 and 311 adjacent to each other due to the difference in circumference is the outer periphery from which the treatment liquid flows out from the inner peripheral surface (primary surface) 312a side into which the treatment liquid flows. The width is formed to expand toward the surface (secondary surface) 312 b side.

  In the filter 300 shown in FIG. 14, the average hole diameter of the through holes means the average distance of the narrowest portion in the gap 316 between the wires 311. In other words, the average hole diameter of the through holes in the filter 300 means the distance between the adjacent flat surfaces 311f facing the inner peripheral surface 312a.

In the filter 300, a plurality of microstructures 305 are formed on the inner peripheral surface 312a side (in other words, the flat surface 311f of the wire 311 facing the inner peripheral surface 312a (see FIG. 16)) into which the liquid to be treated flows. There is. As the plurality of microstructures 305 included in the filter 300, the needle-like structures or the polyhedral structures in the above-described embodiments are formed. The microstructure 305 has a maximum outside dimension smaller than the average pore diameter of the through holes.
The microstructures 305 may be formed on the entire surface of the filter 300.

  The filter 300 shown in FIG. 14 is different from the base material 11 of the filter 10 in each of the above embodiments except that a base material 310 obtained by sintering and bonding the wire member 311 wound in a coil shape and the support member 313 is used. Can be manufactured in the same manner as the filter 10 in each of the above embodiments.

  In the filter 300 shown in FIG. 14, a plurality of microstructures 305 are formed on the flat surface 311 f of the wire 311 that constitutes the inner circumferential surface 312 a into which the liquid to be treated flows. Therefore, the fluid pressure to the filter 300 at the time of the inflow of the to-be-treated liquid becomes uniform, and the fluid pressure does not concentrate locally on the surface of the filter 300. Therefore, in the filter 300 shown in FIG. 14, the durability of the filter 300 against the fluid pressure when the treatment liquid flows in is enhanced, and the formation of cake is promoted.

In the filter 300 shown in FIG. 14, an example in which a wire rod having a triangular cross section is used is shown, but the cross sectional shape of the wire rod is not limited to a triangle, and may be, for example, a trapezoid.
FIG. 17 is an enlarged sectional view of an essential part showing an inner peripheral surface side in another example of the filter. The filter 370 shown in FIG. 17 is provided with a filter body 372 in which a wire 371 having a trapezoidal cross-sectional shape perpendicular to the drawing direction is wound in a coil shape to form a hollow cylindrical body. The wire 371 is supported by the support member 373 on the outer peripheral surface 372 b side so as to separate the wires 371 having a predetermined width between adjacent wires 371.

  In the filter 370 shown in FIG. 17, the inner peripheral surface 372a of the filter body 372 is the primary surface to which the liquid to be treated flows in, and the outer peripheral surface 372b is the secondary surface from which the treated water filtered by the filter body 372 flows out. Be done. Of the filter body 372, the wire 371 facing the inner circumferential surface 372a has a flat surface 371f. The wire 371 having a trapezoidal cross-sectional shape is disposed such that one long side of the two parallel parallel sides of the trapezoidal shape is along the inner circumferential surface 372a, and one short side of the two parallel sides is joined to the support member 313 ing.

  In the filter 370, a plurality of microstructures 305 are formed on the flat inner circumferential surface 372a side into which the liquid to be treated flows and the inner surface of the gap 376. The fine structure 305 may be formed on the inner peripheral surface 372 a (primary surface) side of the filter body 372, and may be formed on the entire surface of the filter 370.

In the filters 300 and 370 shown in FIGS. 14 and 17, the wire is wound in a coil to form a hollow cylindrical body, but a plurality of wires may be arrayed on one surface to form a flat plate. Good. FIG. 18 is an external appearance perspective view showing another example of the filter.
The filter 390 shown in FIG. 18 includes, as a base material, a filter body 392 in which a plurality of wires 391 are arranged in a plane, and a support member 393 for supporting the wires 391. The filter body 392 is formed by arranging a plurality of wire rods 391 having a triangular cross-sectional shape perpendicular to the stretching direction on a flat surface and forming the flat surface.

  The wire 391 is fixed to the support member 393 so as to maintain a slit-like gap 396 having a predetermined width between the adjacent wires 391 and 391. In the filter 390, a wire 391 facing the upper surface 392a in FIG. 18 forms a flat surface 391f. In the case of a wire 391 whose cross-sectional shape is a triangle, one side of the triangle is disposed along the one surface 392a, and the one side of the triangle is joined to the support member 393 at the apex of the triangle.

  The support member 393 is made of, for example, a wire having a rectangular or triangular cross section, and is joined to the wire 391 on the other surface 392 b side of the filter body 392. The support member 393 extends along the arrangement direction of the wires 391 and is joined to the plurality of wires 391. The support member 393 and the wire 391 are joined, for example, by sintering.

In the filter 390, the liquid to be treated is allowed to flow in from the side (primary surface) 392a that is the upper side in FIG. 18, and the treated water after filtration is made to flow out from the other surface (secondary surface) 392b.
In the filter 390, a plurality of microstructures 305 are formed on a flat surface 392a into which the liquid to be treated flows. The fine structure 305 may be formed on one surface 392 a (primary surface) side of the filter body 392, and may be formed on the entire surface of the filter 390.

In the filters 300, 370, and 390 shown in FIG. 14, FIG. 17 and FIG. 18, there is shown an example in which a gap is formed between adjacent wires by a support member for supporting the wires. The adjacent wires may be separated by keeping a gap of a predetermined width.
FIG. 19 is an external appearance perspective view showing another example of the filter.

The filter 90 shown in FIG. 19 includes a filter body 92 in which a plurality of wires 91 are arrayed on a flat surface and formed into a flat plate shape as a base material, and a support member 93 for supporting the wires 91.
The wire 91 has a rectangular cross section, and convex portions 95 are formed at predetermined intervals on one side of the rectangle. The convex portion is for separating the adjacent wire members 91 while maintaining a gap of a predetermined width. For example, when the filter body 92 is viewed in a plan view, the convex portions 95 are formed by shifting the positions of the adjacent wire members 91 so as to form a staggered arrangement along the arrangement direction of the wire members 91.

In the flat filter body 92 of the filter 90 shown in FIG. 19, a slit-like gap 96 is formed by the convex portion 95 formed on the wire 91 so as to penetrate between the one surface 92 a and the other surface 92 b.
In the filter 90 shown in FIG. 19, the average hole diameter of the through holes means the average distance of the gaps 96 between the wires 91.

  The support member 93 is, for example, a wire having a rectangular or triangular cross section (rectangular in FIG. 19). The support member 93 is formed to extend, for example, along the direction in which the wires 91 are arranged. The support member 93 is joined to the plurality of wires 91 on the other surface 92 b side of the filter body 92. The support member 93 and the wire 91 are joined, for example, by sintering.

The base material of the filter 90 shown in FIG. 19 (filter body 92 and support member 93 in FIG. 19) is formed of the same material as the mesh-like base material 11 in each of the above embodiments.
In the filter 90, a plurality of microstructures 305 are formed on the one surface (primary surface) 92a side where the liquid to be treated flows in, and the inner surface of the gap 96. As the plurality of microstructures 305 of the filter 90, the needle-like structure or the polyhedron structure in each of the above embodiments is formed. The microstructure 305 has a maximum outside dimension smaller than the average pore diameter of the through holes.
The microstructures 305 may be formed on the entire surface of the filter 90.

The filter 90 shown in FIG. 19 is a filter in each of the above embodiments except that a support member 93 and a wire 91 are sintered and bonded instead of the base material 11 of the filter 10 in each of the above embodiments. It can be manufactured in the same manner as 10).
The filter 90 shown in FIG. 19 may be used as it is in the form of a plate or, for example, may be formed into a cylindrical shape.

  The treatment system (treatment apparatus) and treatment method of each of the above embodiments are suitable for treating the water to be treated as the treatment liquid, but the treatment system and treatment method of the embodiments are treatment for treating the water to be treated It is not limited to the system and processing method.

In each of the above embodiments, the flowmeter is described as an example of the detection means for detecting the filtration performance of the filter. However, the invention is not limited to the flowmeter. For example, a pressure gauge may be used. .
Next, as an example in the case of using a pressure gauge as the detection means, in the treatment system 100 shown in FIG. 1, a pressure gauge is provided to measure the pressure of the treatment liquid supplied from the supply unit 141 to the treatment liquid region 102a. Will be described by way of example.
The installation position of the pressure gauge may be any pressure on the treatment liquid supplied from the supply unit 141 to the treatment liquid region 102a, and any position on the supply unit 141 side relative to the connection portion with the pipe 108c in the inflow pipe 108a. It can be installed at a position.

  As the pressure gauge, one that continuously measures the pressure of the treatment liquid supplied from the supply unit 141 to the treatment liquid region 102a may be used, or one that measures at predetermined time intervals may be used. . The measurement result of the pressure of the to-be-processed liquid supplied to the to-be-processed liquid area 102a from the supply part 141 measured by the pressure gauge is sent to the control part 120.

The measurement of the pressure of the liquid to be processed by the pressure gauge is performed in a state where the flow rate of the processing liquid discharged from the first discharge part 142 of the processing tank 102 passing through the processing liquid pipe 108 e becomes constant. .
Specifically, the flow rate of the treatment liquid passing through the treatment liquid pipe 108e may be made constant by adjusting the output of the pump 106 for pressure-feeding the treatment liquid to the supply unit 141, or the treatment liquid The flow rate adjustment valve may be provided in the pipe 108 e and the flow rate of the process liquid passing through the process liquid pipe 108 e may be made constant by opening and closing the flow rate adjust valve.
In the present embodiment, since the flow rate of the treatment liquid passing through the treatment liquid pipe 108e is constant, the flow rate of the treatment liquid discharged from the outflow pipe 108f as the SS particles are deposited on the filter. The pressure of the liquid to be treated supplied from the supply unit 141 to the liquid to be treated area 102a increases.

  The control unit 120 determines the necessity of cleaning of the filter 10 based on the output from the pressure gauge (detection means), and when it is determined that the cleaning is necessary, executes the cleaning and determines that the cleaning is unnecessary. Let the process run. In the present embodiment, the control unit 120 determines whether the cleaning of the filter 10 is necessary depending on whether the measurement result of the pressure of the liquid to be processed sent from the pressure gauge is less than or equal to a predetermined threshold value. Thus, the air bubble generator 109 and the valve 107 are controlled. The determination as to whether or not the filter 10 needs to be cleaned by the control unit 120 may be performed each time a measurement result of the pressure of the liquid to be processed is sent from the pressure gauge, or may be performed at regular intervals.

  According to at least one embodiment described above, a supply unit to which the liquid to be treated is supplied, a filter for filtering solid content in the liquid to be treated, a first discharge unit to discharge the treatment liquid having passed through the filter, And a treatment tank having a second discharge unit for discharging a part of the liquid to be treated supplied to the supply unit, and an air bubble generator capable of supplying air bubbles to the liquid to be treated supplied to the supply unit; Based on the detection means for detecting the filtration performance of the filter and the output from the detection means, it is determined whether or not cleaning of the filter is necessary, and when it is determined that the cleaning is necessary, air bubbles are generated by the air bubble generating device. The liquid to be treated is added to the supply portion, and a portion of the liquid to be treated is filtered by the filter, and the remaining portion of the liquid to be treated is deposited on the filter together with the solid content, the second discharge portion From When it is determined that the cleaning is unnecessary, the liquid to be treated without adding the air bubbles is supplied to the supply unit, and a part of the liquid to be treated is filtered with the filter to obtain the liquid to be treated. And a control unit for executing a process of discharging the remaining portion from the second discharge unit, wherein the filter is formed on a plurality of through holes and a surface on the primary surface side to which the liquid to be treated flows. By setting the treatment system having a plurality of microstructures whose maximum outside diameter is smaller than the average pore diameter of the above, the filtration of the liquid to be treated can be continued even in the washing step, and a high washing effect can be obtained.

Hereinafter, the present invention will be described in detail using examples.
Example 1
A plain weave wire mesh (mesh size 34 μm, wire diameter 30 μm) made of stainless steel was prepared. This was immersed in a plating bath containing phosphorus, zinc and nickel to carry out nickel plating treatment. As a result, a wire mesh formed of stainless steel wire (wire material) was covered with a base layer made of a nickel zinc alloy.

Thereafter, boric acid and ethylenediamine (EDA) as an additive were added to the plating bath in which the underlayer was formed to carry out nickel plating treatment. By this, the plating layer which coat | covers the whole surface of the wire covered with the base layer was formed, and the filter of Example 1 was obtained.
The surface of the filter of Example 1 was observed with a scanning electron microscope (SEM) to confirm whether or not a microstructure was formed on the surface. As a result, a plurality of needle-like structures were formed on the surface.

Next, with respect to the filter of Example 1, the average pore diameter of the through holes was examined. Further, for the filter of Example 1, the number of needle-like structures per unit area (1 μm ² ), the number of needle-like structures per unit length (1 μm) in the cross section, the average height of the needle-like structures, the needle-like structures The variation coefficient of the height, and the aspect ratio H (μm) / D (μm) of the average width D of the proximal end of the needle-like structure in the cross section and the average height H were examined by the above-described methods. Also, to calculate the number of needle-like structures per unit area (1 μm ² ), to calculate the number of needle-like structures per 4 μm ^{2, and the} number of needle-like structures per unit length (1 μm) in the cross section The number of needle structures was also examined.

As a result, the average pore diameter of the through holes was 4 μm. The number of needle-like structures per 4 μm ² was 16 to 19 (the number of needle-like structures per unit area (1 μm ² ) (forming density) was 3.75) (see FIG. 4). In addition, after fixing this plating layer with the embedded resin, cutting and cross-sectional observation showed that the number of needle-like structures per 10 μm was 20 (the number of needle-like structures per unit length (1 μm in the cross section was 2) Pieces). The average height H of the needle-like structure was 750 nm, and the coefficient of variation of the height of the needle-like structure was 0.28. Moreover, the average width D of the proximal end of the needle-like structure in the cross section was 550 nm, and the aspect ratio was 1.36.
Further, the width between the wires was 4 μm, and the wire width was 60 μm.

"Filtration test"
Next, the filter of Example 1 was installed in a treatment tank simulating the treatment system shown in FIG. 1, and a filtration test was performed under the conditions shown below.
In tap water, alumina particles having an average particle diameter of 3.0 μm as SS particles were dispersed at a concentration of 1000 mg / L to form a liquid to be treated, and pressure-fed to a treatment tank through piping. Then, by adjusting the output of the pump, a filtration test was conducted to make the filtration pressure constant at 0.1 MPa, and the treatment liquid turbidity was measured by the method shown below.
As a result, the turbidity was 0.5 NTU. Moreover, the processing liquid obtained by conducting the filtration test was transparent.

"Processed solution turbidity in filtration test"
Thirty seconds after the supply of the liquid to be treated to the treatment tank was started, the turbidity of the treatment liquid passed through the filter was measured to obtain the turbidity of the treatment liquid.

  Also, the filter after the filtration test is embedded in the embedded resin, and the cross section is observed with a scanning electron microscope (SEM), and the distance to the valley bottom between the cake and the microstructure (height of the gap between the cake and the filter) Three points were measured, and the average value was calculated. FIG. 20 is a SEM photograph of the filter of Example 1 after the filtration test, and is a photograph showing the result of measuring the distance from the cake to the valley bottom of the microstructure. In the filter of Example 1 after the filtration test shown in FIG. 20, the average value of the distance from the cake to the valley bottom of the microstructure was 0.7 μm.

"Washing test"
After the treatment process is performed in the same manner as the above-mentioned filtration test for 10 minutes after the supply of the treatment liquid to the treatment tank is started, as described below, the bubbles are formed in the treatment liquid using a bubble generator. It supplied and produced | generated the bubble-containing to-be-processed liquid, and pressure-fed to the processing tank. Then, by adjusting the output of the pump, a washing test was conducted at a constant filtration pressure of 0.1 MPa for 1 minute, and the treatment liquid turbidity in the washing test was measured by the method described below.
As a result, the turbidity was 0.7 FTU. In addition, the treatment liquid obtained by conducting the washing test was transparent.

  The bubble-containing liquid to be treated introduces high-pressure air into the liquid to be treated that moves in the pipe from the air introduction part of the bubble generator installed in the pipe that supplies the liquid to be treated to the treatment tank to supply bubbles. The liquid to be treated and the bubbles were generated by passing through the orifice which is the mixing unit of the bubble generation device.

  In addition, as for the introduction conditions of high pressure air introduced into the liquid to be treated, the diameter of air bubbles obtained when air at 25 ° C. and 1 atm is introduced into tap water is 10 to 40 μm under 25 ° C. and 1 atm. It was taken as the introduction condition decided beforehand which becomes the mode of. The diameter of the bubbles was immediately analyzed by laser diffraction of tap water supplied to the treated liquid area of the treatment tank.

In addition, the surface of the filter after the washing test was observed. The results are shown in FIGS. 21 and 22.
FIG. 21 is a photograph of the filter of Example 1 before washing. FIG. 22 is a photograph of the filter of Example 1 after washing. As shown in FIGS. 21 and 22, the cake on the surface of the filter was peeled off by the washing test.

"Processed solution turbidity in washing test"
One minute after the washing test was started (the supply of air bubbles to the liquid to be treated was started), the turbidity of the liquid to be treated which had passed through the filter was measured one minute to obtain a treated liquid turbidity.

  After such a washing test, the air bubble generation device is stopped, and the treatment process is performed for 10 minutes in the same manner as the above-mentioned filtration test, and the treatment liquid turbidity in the filtration test after washing is measured by the following method. did. As a result, the turbidity was 0.9 NTU.

"Processed solution turbidity in filtration test after washing"
Thirty seconds after the washing test was stopped (the supply of air bubbles to the liquid to be treated was stopped), the turbidity of the liquid to be treated which had passed through the filter was measured to obtain a treated liquid turbidity.

  Also, the filtration rate in the filtration test before washing and in the filtration test after washing is determined, and the filtration rate in the filtration test after washing (10 minutes) with respect to the filtration rate in the filtration test before washing (10 minutes) The recovery rate {= (after washing / before washing) × 100 (%)}, which is a ratio of “was calculated. As a result, the recovery rate was 75%.

(Comparative example 1)
In the washing test, before and after washing in the same manner as in Example 1, except that the tap water containing no bubbles was pressure-fed to the treatment tank in place of the bubble-containing treated liquid in a state where the bubble generating apparatus was stopped. The filtration rate in the filtration test was measured, and the recovery rate was examined in the same manner as in Example 1. As a result, the recovery rate of Comparative Example 1 was 65%.
From this, it is possible to continue filtration of the liquid to be treated even in the washing step by supplying the bubble-containing liquid to the primary side of the filter and washing the filter while washing, and the recovery rate is high and excellent. It turned out that an effect could be obtained.

(Example 2)
A stainless steel cross-sectionally square wire of 900 μm in width is wound around a support member and joined by sintering, and the width between the wires is 30 μm, and a cylindrical base in which the support member extends substantially parallel to the central axis The material was made. The base was plated with nickel and coated with a base layer made of nickel.
Thereafter, 2-butyne-1,4-diol as an additive was added to the plating bath in which the underlayer was formed, and a nickel plating treatment was performed. By this, the plating layer which coat | covers the whole surface of the base material coat | covered with the base layer was formed, and the filter of Example 2 was obtained.

  The surface of the filter of Example 2 was observed with a scanning electron microscope (SEM) to confirm whether or not a microstructure was formed on the surface. As a result, a plurality of polyhedral structures were formed on the surface.

Next, with respect to the filter of Example 2, the average hole diameter and the average maximum outer dimension of the through holes were examined by the methods described above.
As a result, the width between the wires (average pore diameter of through holes) was 6 μm, and the average maximum external dimension was 4 μm. The wire width was 924 μm.

"Filtration test"
Next, the filter of Example 2 was installed in a treatment tank simulating the treatment system shown in FIG. 7, and a filtration test was performed under the conditions shown below.
In tap water, alumina particles having an average particle diameter of 0.1 μm were dispersed as SS particles at a concentration of 100 mg / L, and pressure-fed to a treatment tank via a pipe for supplying a liquid to be treated. Then, by adjusting the output of the pump, a filtration test was conducted to make the filtration pressure constant at 0.1 MPa, and in the same manner as in Example 1, the turbidity of the treated liquid was measured.
As a result, the turbidity was 0.6 FTU. Moreover, the processing liquid obtained by conducting the filtration test was transparent.

  Further, the cross section of the filter after the filtration test was observed in the same manner as in Example 1, and the average value of the heights of the gaps was calculated in the same manner as in Example 1. As a result, the average value of the heights of the gaps was 0.7 μm.

"Washing test"
After the treatment process is performed in the same manner as the above-mentioned filtration test for 10 minutes after the supply of the treatment liquid to the treatment tank is started, as described below, the bubbles are formed in the treatment liquid using a bubble generator. The solution was supplied to generate a bubble-containing liquid to be treated, and was pressure-fed to the treatment tank through the washing nozzle. Then, by adjusting the output of the pump, a washing test with a constant filtration pressure of 0.1 MPa was carried out for 1 minute, and in the same manner as in Example 1, the treatment liquid turbidity in the washing test was measured.
As a result, the turbidity was 0.7 NTU. In addition, the treatment liquid obtained by conducting the washing test was transparent.

The bubble-containing to-be-treated liquid was produced in the same manner as in Example 1.
The conditions for introducing high pressure air introduced into the liquid to be treated are that the diameter of air bubbles obtained when air at 25 ° C. and 1 atm. Is introduced into tap water is 0.5 to 10 μm at 25 ° C. and 1 atm. Is a predetermined introduction condition where the mode is the distribution mode. The diameter of the bubbles was immediately analyzed by laser diffraction of tap water supplied to the treated liquid area of the treatment tank.

As the cleaning nozzle, one having a cylindrical main body with one end sealed and a plurality of jet nozzles having an inner diameter of 2 mm and having a circular plan view shape for discharging the bubble-containing liquid to be processed outward from the main body was used.
In addition, the surface of the filter after the washing test was observed with a scanning electron microscope (SEM). As a result, as in Example 1, the cake on the surface of the filter was exfoliated.

After such washing test, the air bubble generation device is stopped, and the treatment process is performed for 10 minutes in the same manner as the above-mentioned filtration test, and in the same manner as in Example 1, turbidity of the treatment liquid in the filtration test after washing Was measured. As a result, the turbidity was 0.9 NTU.
In addition, the filtration rate in the filtration test (10 minutes) before washing and the filtration test (10 minutes) after washing was determined, and the recovery rate was calculated in the same manner as in Example 1. As a result, the recovery rate was 75%.

(Example 3)
The bubble generation device 109 is connected to the treatment pipe 108 h through the pipe 108 c, and in the cleaning test, the treatment liquid (bubble-containing treatment liquid) to which the bubbles supplied from the bubble generation device 109 are added is supplied to the first supply portion 141 a. The filtration rate in the filtration test before and after washing was measured in the same manner as in Example 2 except that it was supplied, and the recovery rate was examined in the same manner as in Example 1. As a result, the recovery rate of Example 3 was 70%.

(Comparative example 2)
Before and after washing in the same manner as in Example 2 except that in the washing test, the bubble-containing treatment liquid is stopped and the treatment liquid without bubbles added is pumped to the treatment tank instead of the bubble-containing treatment liquid. The filtration rate in the filtration test was measured, and the recovery rate was examined in the same manner as in Example 1. As a result, the recovery rate of Comparative Example 2 was 60%.

From the results of Example 2 and Comparative Example 2, it is possible to continue filtration of the liquid to be treated even in the washing step by supplying the bubble-containing liquid to the primary side of the filter and filtering while washing the filter. It was found that the recovery rate was high and an excellent cleaning effect was obtained.
Further, it was found from the results of Example 2 and Example 3 that a higher cleaning effect can be obtained by spouting the liquid to be treated to which air bubbles have been added toward the primary surface of the filter by the cleaning nozzle.

(Comparative example 3)
In the same manner as in Example 2, except that a stainless wire mesh (wire diameter 40 μm, mesh size 10 μm, twill weave) capable of capturing 11.5 μm alumina particles was used as a filter, filtration tests before and after washing were performed in the same manner. The filtration rate was measured, and the recovery rate was examined in the same manner as in Example 1. As a result, the recovery rate of Comparative Example 3 was 60%.
From the results of Example 2 and Comparative Example 3, it was found that the cleaning effect is improved by using a filter in which a plurality of polyhedral structures are formed on the surface.

(Example 4)
The same cross sectional view of square wires made of stainless steel of 900 μm in width as in Example 2 is arranged in parallel, joined by sintering on a support member extending in a direction substantially orthogonal to the wires, and the width between the wires is 30 μm A plate-like substrate was produced. The plate-like substrate thus obtained is processed into a cylindrical shape, and in the same manner as in Example 1, a plating layer is formed to cover the entire surface of the substrate coated with the underlayer, I got a filter.

  The surface of the filter of Example 4 was observed with a scanning electron microscope (SEM) to confirm whether or not a microstructure was formed on the surface. As a result, a plurality of needle-like structures were formed on the surface.

Next, for the filter of Example 4, in the same manner as in Example 1, the average pore diameter of the through holes, the number of needle-like structures per unit area (1 μm ² ), and the needle-like structures per unit length (1 μm) in the cross section Number of objects, average height of needle-like structures, variation coefficient of height of needle-like structures, aspect ratio H (μm) of average width D and average height H of proximal end of needle-like structures in cross section D (μm) was examined. Also, to calculate the number of needle-like structures per unit area (1 μm ² ), to calculate the number of needle-like structures per 4 μm ^{2, and the} number of needle-like structures per unit length (1 μm) in the cross section The number of needle structures was also examined.

As a result, the average pore diameter of the through holes was 10 μm. The number of needle-like structures per 4 μm ² was 15, and the number of needle-like structures per unit area (1 μm ² ) was 3.75. The number of needle-like structures per 10 μm was 20, and the number of needle-like structures per unit length (1 μm) in the cross section was two. The average height H of the needle-like structure was 750 nm, and the coefficient of variation of the height of the needle-like structure was 0.28. Moreover, the average width D of the proximal end of the needle-like structure in the cross section was 550 nm, and the aspect ratio was 1.36.
Further, the width between the wires was 6 μm, and the wire width was 924 μm.

"Filtration test"
Next, the filter of Example 4 is installed in a treatment tank simulating the treatment system shown in FIG. 8, and a filtration test is conducted in the same manner as in Example 2 and the treatment liquid turbidity is measured in the same manner as in Example 1. did.
As a result, the turbidity was 0.6 FTU. Moreover, the processing liquid obtained by conducting the filtration test was transparent.

  Further, the cross section of the filter after the filtration test was observed in the same manner as in Example 1, and the average value of the heights of the gaps was calculated in the same manner as in Example 1. As a result, the average value of the heights of the gaps was 0.7 μm.

"Washing test"
After the treatment process is performed in the same manner as the above-mentioned filtration test for 10 minutes after the supply of the treatment liquid to the treatment tank is started, as described below, the bubbles are formed in the treatment liquid using a bubble generator. The solution was supplied to generate a bubble-containing liquid to be treated, and was pressure-fed to the treatment tank through the washing nozzle. Then, by adjusting the output of the pump, a washing test with a constant filtration pressure of 0.1 MPa was carried out for 1 minute, and in the same manner as in Example 1, the treatment liquid turbidity in the washing test was measured.
As a result, the turbidity was 0.7 NTU. In addition, the treatment liquid obtained by conducting the washing test was transparent.

The bubble-containing to-be-treated liquid was produced in the same manner as in Example 1. The conditions for introducing high pressure air introduced into the liquid to be treated were the same as in Example 1.
The cleaning nozzle was arranged such that the direction of the bubble-containing liquid to be ejected was substantially tangential to the inner periphery of the filter. In addition, as the cleaning nozzle, there is a nozzle having an inner diameter of 5 mm, and a swirling flow along the inner peripheral surface of the filter is formed by the bubble-containing treatment liquid ejected from the cleaning nozzle during the cleaning test. It was.

  In addition, the surface of the filter after the washing test was observed with a scanning electron microscope (SEM). As a result, as in Example 1, the cake on the surface of the filter was exfoliated.

After such washing test, the air bubble generation device is stopped, and the treatment process is performed for 10 minutes in the same manner as the above-mentioned filtration test, and in the same manner as in Example 1, turbidity of the treatment liquid in the filtration test after washing Was measured. As a result, the turbidity was 0.9 NTU.
In addition, the filtration rate in the filtration test (10 minutes) before washing and the filtration test (10 minutes) after washing was determined, and the recovery rate was calculated in the same manner as in Example 1. As a result, the recovery rate was 75%.

(Example 5)
The bubble generation device 109 is connected to the treatment pipe 108 h through the pipe 108 c, and in the cleaning test, the treatment liquid (bubble-containing treatment liquid) to which the bubbles supplied from the bubble generation device 109 are added is supplied to the first supply portion 141 a. The filtration rate in the filtration test before and after washing was measured in the same manner as in Example 4 except that it was supplied, and the recovery rate was examined in the same manner as in Example 1. As a result, the recovery rate of Example 5 was 70%.

From the results of Example 4, it is possible to continue filtration of the liquid to be treated even in the washing step by supplying the bubble-containing liquid to the primary side of the filter and washing the filter, and the recovery rate is high. It was found that an excellent cleaning effect was obtained.
Moreover, it was found from the results of Example 4 and Example 5 that a higher cleaning effect can be obtained by ejecting the liquid to be treated with air bubbles toward the primary surface of the filter by the cleaning nozzle.

(Example 6)
The conditions for introducing high pressure air introduced into the liquid to be treated are as shown below, and the size of the air bubble in the liquid to be treated containing air bubbles was adjusted to 0.1 μm, as in Example 2. The filtration rate in the filtration test before and after washing was measured, and the recovery rate was examined in the same manner as in Example 1.
When using a nano bubble generator that generates bubbles of 1 μm or less as the bubble generator 109, the diameter of the bubbles obtained when air at 25 ° C. and 1 atm is introduced into tap water is 100 to 200 nm at 25 ° C. and 1 atm. There are predetermined introduction conditions in which the distribution mode is 140 nm. The diameter of the bubbles was immediately analyzed by laser diffraction of tap water supplied to the treated liquid area of the treatment tank.
The recovery rate of Example 6 was 67%.

(Example 7)
The conditions for introducing high pressure air introduced into the liquid to be treated are as follows, and the size of the air bubble in the liquid to be treated containing air bubbles is 50 mm in the same manner as in Example 1. The filtration rate in the filtration test before and after washing was measured, and the recovery rate was examined in the same manner as in Example 1.
The bubble diameter obtained when air at 25 ° C. and 1 atm is introduced into tap water using a compressor as the bubble generation device 109 is 30 to 100 mm under 25 ° C. and 1 atm, and 50 mm is the mode of distribution It was set as the introductory condition decided beforehand. The diameter of the bubbles was immediately analyzed by laser diffraction of tap water supplied to the treated liquid area of the treatment tank.
The recovery rate of Example 7 was 68%.

  In Examples 1 to 7 and Comparative Examples 1 to 3, the size of air bubbles in the liquid to which the air bubbles are added, the shape of the microstructure, the average pore diameter of the through holes, the formation density of the microstructure, and the unit of the microstructure. The number of formations per length, the average height of the microstructures, the variation coefficient of the height of the microstructures, the average maximum external dimension, and the recovery rate are shown in Table 1.

  While certain embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and the equivalents thereof as well as included in the scope and the gist of the invention.

10, 90, 212, 291, 294, 297, 300, 370, 390 ... filters, 3 ... plating layers, 4 ... foundation layers, 5, 205, 305 ... microstructures, 7 ... cakes, 13, 213 ... through holes 100, 100A: treatment system, 101: treated liquid tank, 102, 102A: treated tank, 102a: treated liquid area, 102b: treated liquid area, 103: treated liquid tank, 104: concentrated sludge tank, 106: 106 , 109 ... air bubble generating device.

Claims (13)

A supply unit to which the liquid to be treated is supplied, a filter for filtering solid content in the liquid to be treated, a first discharge unit to discharge the treatment liquid having passed through the filter, and the liquid to be treated supplied to the supply unit A processing tank having a second discharge unit that discharges a portion of the
An air bubble generator capable of supplying air bubbles to the liquid to be treated supplied to the supply unit;
Detection means for detecting the filtration performance of the filter;
Based on the output from the detection means, it is determined whether or not the filter needs cleaning.
When it is determined that the cleaning is necessary, the liquid to be treated to which air bubbles have been added is supplied to the supply unit by the air bubble generation device, and a part of the liquid to be treated is filtered by the filter. The remainder of the water from the second discharge section together with the solid content deposited on the filter,
When it is determined that the cleaning is unnecessary, the liquid to be treated without adding the bubbles is supplied to the supply unit, a part of the liquid to be treated is filtered by the filter, and the remaining portion of the liquid to be treated is A control unit that executes a process of discharging the second discharge unit ;
And a cleaning nozzle for spouting the liquid to be treated to which the air bubbles have been added toward a primary surface of the filter on which the liquid to be treated flows .
The filter is a processing system having a plurality of through holes and a plurality of microstructures which are formed on at least a surface on the primary surface side to which the liquid to be treated flows in, and whose maximum outside dimension is smaller than the average hole diameter of the through holes. .   The processing system according to claim 1, wherein the detection means is a flow meter. The processing system according to claim 1 or 2 , wherein the liquid to be treated to which the bubbles are added includes a bubble of 1 to 100 μm. The processing system according to any one of claims 1 to 3 , wherein an average pore diameter of the through holes is 0.1 μm to 5 mm. The microstructures are conical, elliptical conical, pyramidal, frustoconical, elliptical frustum shape, of the truncated pyramid-shaped, any one of claims 1 to 4 which forms at least one of the shape Processing system described in. The processing system according to claim 5 , wherein the formation density of the microstructures is in a range of 1.2 to 10.0 pieces / μm ² . The processing system according to claim 5 or 6 , wherein the number of formation of the microstructure per unit length is in a range of 1.0 to 4.0 / μm. The processing system according to any one of claims 5 to 7 , wherein the average height of the microstructures is in the range of 0.2 to 2.5 μm. The processing system according to claim 8 , wherein the variation coefficient of the height of the microstructure is in the range of 0.15 to 0.50. The processing system according to any one of claims 1 to 4 , wherein the microstructure has a polyhedral shape. The processing system according to claim 10 , wherein the average maximum outside dimension of the microstructure is in the range of 0.5 to 10 m. The processing system according to any one of claims 1 to 11 , wherein the microstructure is formed of a metal or an alloy. A supply unit to which the liquid to be treated is supplied, a filter for filtering solid content in the liquid to be treated, a first discharge unit to discharge the treatment liquid having passed through the filter, and the liquid to be treated supplied to the supply unit A processing tank having a second discharge unit that discharges a portion of the
An air bubble generator capable of supplying air bubbles to the liquid to be treated supplied to the supply unit;
Detection means for detecting the filtration performance of the filter ;
And a cleaning nozzle for spouting the liquid to be treated to which the air bubbles have been added toward the primary surface of the filter on which the liquid to be treated flows .
A processing system comprising: a plurality of through holes; and a plurality of microstructures formed at least on the surface on the primary surface side where the liquid to be treated flows, and having a maximum outside dimension smaller than the average hole diameter of the through holes. Processing method using
Determining whether or not the filter needs to be cleaned by the control unit based on the output from the detection unit;
When it is determined that the cleaning is necessary, the liquid to be treated to which air bubbles have been added is supplied to the supply unit by the air bubble generation device, and a part of the liquid to be treated is filtered by the filter. A cleaning step of discharging the second discharge section together with the solid content deposited on the filter,
When it is determined that the cleaning is not necessary, the liquid to be treated without adding the bubbles is supplied to the supply unit, a part of the liquid to be treated is filtered by the filter, and the remaining part of the liquid to be treated is And a processing step of discharging from the second discharge part.