Filtration system

Abstract

To provide a filtration system whose filtration means is unlikely to be damaged in maintenance for improving transmission of an object to be filtered, the maintenance being performed when clogging occurs to the filtration means.SOLUTION: A filtration system 1 has: a supply port 7 of liquid A to be processed; a container 11 having an exhaust port 6 for processing liquid B obtained by filtering the liquid A to be processed; bag-shaped filtration means 15 provided inside the container 11 and having an opening 16; a vertical moving body 9 vertically moving the filtration means 15; a processing liquid exhaust pipe 22 one end of which is connected to the opening 16 of the filtration means 15, the other end of which is disposed outside the container 11, and which exhausts the processing liquid B outside the container 11; and suspension means 10 suspending the filtration means 15 in an internal space of the container 11 in a suspension state. The suspension means 10 absorbs swing transmitted by vertical movement of the filtration means 15; the processing liquid exhaust pipe 22 absorbs swing transmitted by vertical movement of the filtration means 15.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a filtration system used to obtain drinking water, pure water, etc. [Background technology]

[0002] Raw water obtained from oceans, lakes, rivers, etc. contains a large amount of clay minerals, organic compounds trapped between the layers of those clay minerals, hard particles such as sand and rock fragments, soft particles such as plant debris, and particles such as microplastics. If this raw water is passed directly through a filtration device equipped with an RO membrane (reverse osmosis membrane; the same applies below), problems such as the membrane becoming easily clogged can occur. Disposable wound or pleated filters are commonly used, especially in small filtration devices, but because the surface area required for filtration is small, they quickly become clogged after the raw water starts passing through.

[0003] A technology for eliminating this clogging is proposed in the following Patent Document 1. Patent Document 1 discloses a technology in which a spray nozzle is provided to spray a cleaning fluid onto the surface of a filtration filter, and when clogging occurs, the surface of the filtration filter is cleaned by spraying the cleaning fluid from the spray nozzle as maintenance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-104683 Summary of the Invention [Problem to be solved by the invention]

[0005] Although this technique does indeed eliminate clogging of the filter, if the spraying is repeated every time clogging occurs, another problem occurs in that the filter surface is damaged by the spraying.

[0006] Therefore, the main problem to be solved by the present invention is to provide a method for removing the object to be filtered when clogging occurs in the filtering means. liquid To provide a filtration system in which the filtering means is hardly damaged during maintenance for improving the permeation of water. [Means for solving the problem]

[0007] In order to solve the above problems, the following aspects can be adopted. (First aspect) a container having a supply port for a liquid to be treated and a discharge port for a treated liquid obtained by filtering the liquid to be treated; a bag-shaped filtering means provided inside the container and having an opening; The filtering means vibration to make vibration Body and a treated liquid discharge pipe having one end connected to the opening of the filtering means and the other end disposed outside the container, through which the treated liquid is discharged to the outside of the container; a suspending means for suspending the filtering means in the internal space of the container in a suspended state; The suspension means is vibration It absorbs vibrations transmitted by The treated liquid discharge pipe is vibration It is designed to absorb the vibrations transmitted by the A filtration system characterized by:

[0008] In a so-called filtration system that purifies a liquid to be treated using a filtration means, as the filtration of the liquid to be treated continues, foreign matter such as solids contained in the liquid to be treated gradually adheres to the filtration means and accumulates, forming a cake. The cake in the early stages of formation acts like a precoat filter that captures subsequent foreign matter, but as the cake layer becomes thicker, it acts to hinder filtration, significantly reducing filtration efficiency. In order to restore the filtration efficiency of the filtration system, for example, the cake that has adhered to the filtration means is removed. In the filtration system of this embodiment, the filtration means vibration The cake shakes with your body. vibrationThe kinetic energy generated by the flow causes the solid and liquid components inside the cake to fluidize. As the cake fluidizes, it is no longer able to maintain its layered shape, collapses, and separates from the filtering means. When the cake separates from the filtering means, there is no longer anything that can hinder the filtering of the liquid to be treated by the filtering means, and the filtering efficiency of the filtering system is improved.

[0009] In the conventional filtration system disclosed in Patent Document 1, a spray nozzle is provided to spray a cleaning fluid onto the filtration means to remove the cake, but spraying the cleaning fluid can cause damage to the filtration means. On the other hand, the filtration system of this embodiment does not vibration The purpose of this method is to promote the separation of the cake by spraying the cleaning fluid, and the filtering means is therefore less likely to be damaged.

[0010] In addition, in the conventional filtration system, for example, the filtering means is fixed to the casing, so the filtering means vibration When you do this, the vibration, vibration The kinetic energy of the vibrations is transmitted to the casing, making the entire filtration system unstable. For example, the transmission of vibrations may cause the filtration system to shift from its original installation location. On the other hand, the filtration system of this embodiment has a suspending means for suspending the filtration means in the internal space of the container in a suspended state. vibration The treated liquid discharge pipe absorbs the vibrations transmitted by the filtering means. vibration Since the vibrations transmitted by the filter are absorbed, vibrations of the filter are less likely to be transmitted to the container or piping connected to the filter.

[0011] (Second aspect) the container has a peripheral plate portion, an upper plate portion connected to one end of the peripheral plate portion, and a lower tapered portion connected to the other end of the peripheral plate portion; The hanging means is supported on the upper plate portion of the container and hangs the filtering means. 1 is a filtration system according to a first embodiment.

[0012] In the second aspect, in addition to the first aspect, the container has a peripheral plate portion, an upper plate portion connected to one end of the peripheral plate portion, and a lower tapered portion connected to the other end of the peripheral plate portion, and the hanging means is supported on the upper plate portion of the container and hangs the filtering means, so that vibrations transmitted from the filtering means are absorbed by the hanging means and are less likely to be transmitted to the container.

[0013] (Third aspect) Further, a backwash water supply means for supplying backwash water into the bag of the filtering means is provided, The backwash water contains fine bubbles having an average particle size of 100 μm or less. 1 is a filtration system according to a first embodiment.

[0014] Since the third aspect is the above-mentioned aspect, the fine bubbles collide with cake adhering to the filtering means or fine particles stuck in the filter mesh of the filtering means, pushing the fine particles out of the filtering means, promoting the separation of the cake and further eliminating clogging of the filtering means.

[0015] (Fourth aspect) vibration The body per second vibration do frequency The frequency is 100 to 500 Hz. 1 is a filtration system according to a first embodiment.

[0016] vibration The body per second vibration do frequency Since the frequency is 100 to 500 Hz, foreign matter adhering to the filtering means is easily fluidized.

[0017] (Fifth aspect) the treated liquid discharge pipe is an expandable pipe or a flexible pipe; 1 is a filtration system according to a first embodiment.

[0018] Since the treated liquid discharge pipe is an expandable pipe or a flexible pipe, vibrations transmitted from the filtering means are absorbed by the pipe and are unlikely to be transmitted to anything connected to the downstream end of the pipe. [Effects of the Invention]

[0019] According to the present invention, when clogging occurs in the filtering means, liquid It is possible to provide a filtration system in which the filtration means is less likely to be damaged during maintenance to improve the permeation of the filtration means. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is an overall configuration diagram of a filtration system according to the present invention. [Figure 2] 1 is an overall configuration diagram of a filtration system according to the present invention. [Figure 3] FIG. 2 is a diagram illustrating a suspended state of the filtering means 15. [Figure 4] 4 is a cross-sectional view of the filtering means of FIG. 3 taken along line XX. [Figure 5] FIG. 4 is a diagram illustrating the pleated structure of the filtering means. [Figure 6] FIG. 2 is a diagram mainly showing the relationship between the upper end of the filtering means, the upper filtering filter seal portion, and the hanging means. [Figure 7] FIG. 4 is a diagram mainly showing the relationship between the lower end of the filtering means and a lower filtration filter seal portion. [Figure 8] FIG. 2 is a diagram showing the internal structure of the pleats of the filtering means. [Figure 9] FIG. 2 is a diagram mainly showing the relationship between the upper end of the filtering means, the upper filtering filter seal portion, and the hanging means. DETAILED DESCRIPTION OF THE INVENTION

[0021] Filtration systems using filters, particularly pleated filters, have already been put to practical use. When such a filtration system is used to filter a liquid A containing suspended particles, the suspended particles accumulate on the filter surface, forming a layer of cake. The initial cake acts like a precoat filter, capturing subsequent particles. However, as the cake layer thickens, it begins to impede filtration, significantly reducing filtration efficiency. To restore the filtration efficiency of a filtration system, for example, operations must be performed to remove cake that has adhered to the filtering means. Techniques for removing suspended particles from filters and restoring clogged filters include directing a water jet from a slit nozzle at the filter surface where the cake has adhered, or spraying a water jet containing plastic beads onto the filter surface to abrasively clean and remove the cake. However, while these techniques are somewhat effective in regenerating filters, repeated use can damage the filter surface. Furthermore, such water jet cleaning and abrasive cleaning often involves strong water jets in the air, which can damage the filter surface over the long term, shortening the filter's lifespan and ultimately increasing running costs. Furthermore, water jet cleaning using a slit nozzle requires the construction of a pump system for water jet injection, as well as the installation of water distribution valves for draining the vessel and supplying water to the cleaning nozzle, resulting in complex valve control and the construction of a filtration system with various functions, which can increase manufacturing and installation costs. In addition, water jet cleaning uses a large amount of wash water to remove the cake, and although the wastewater generated by the cleaning operation contains the suspended particles, the concentration of suspended particles is low, making the subsequent dewatering process complicated. Furthermore, cleaning using a water jet containing beads can achieve some cake removal by spraying beads or other particles onto the filter surface and physically abrading it. However, this still damages the filter surface, causing wear and tear, resulting in increased running costs. Furthermore, an additional step is required to separate the beads and suspended particles contained in the waste liquid using a device such as a classifier, and the amount of beads must be replenished as they are worn out, and the amount of beads must be controlled.

[0022] On the other hand, there is also a method of removing cake using high-temperature or low-temperature wash water, but in this case, it is necessary to provide a device for heating or cooling the wash water or a device for keeping the wash water warm, which makes the entire filtration system complicated. Also, when removing suspended particles using chemical solutions such as alkali or acid, the inner wall of the vessel that comes into contact with the chemical solution is treated with, for example, a durable film (Teflon (registered trademark), polyvinyl chloride, etc.), but it is necessary to provide a container for storing the chemical solution and piping for transporting the solution, which makes the filtration system structure complicated.

[0023] The majority of filter fouling is caused by physical fouling, which inhibits water flow through the filter, leading to the removal of the accumulated cake. The foreign matter contained in the treated liquid A includes minute particles. However, nano-sized particles that cause physical fouling are often difficult to remove once they adhere to the filter due to the stronger van der Waals forces. Furthermore, some nano-sized particles can penetrate the interior of the filter through the surface and become trapped (imbedded), resulting in filter clogging. Such trapped particles are difficult to remove even with water jets from a slit nozzle, and chemical cleaning is required to remove them. However, chemical cleaning requires the preparation of chemicals, which can be costly.

[0024] As described above, conventional filtration devices have various advantages and disadvantages.

[0025] On the other hand, the filtration system of the present invention has a simple mechanism and structure, yet effectively eliminates clogging and regenerates the filter. Next, a preferred embodiment of the present invention will be described. Note that the following description and drawings merely illustrate one embodiment of the present invention, and the contents of the present invention should not be interpreted as being limited to this embodiment.

[0026] (filtration system) The filtration system 1 according to this embodiment includes a container 11 having a supply port 7 for a liquid A to be treated and a discharge port 6 for a treated liquid B obtained by filtering the liquid A to be treated, a bag-shaped filtering means 15 provided inside the container 11 and having an opening 16, and a filter 15 for filtering the filtering means 15. vibration to make vibration the filter means 15 is connected to the opening 16 of the filter means 15 and the other end is disposed outside the container 11, and the treated liquid discharge pipe 22 is discharged to the outside of the container 11, and the filter means 15 is suspended in the internal space of the container 11, and the suspended means 10 is vibration The treated liquid discharge pipe 22 absorbs vibrations transmitted by the filtering means 15. vibration It is characterized by absorbing vibrations transmitted by 。

[0027] The filtration system 1 according to this embodiment filters a liquid to be treated A, which can be, for example, water from rivers or lakes, seawater, groundwater, spring water, wastewater from factories or homes, etc. The liquid to be treated A contains substances that are normally contained in water from rivers or lakes, seawater, groundwater, spring water, wastewater from factories or homes, etc., but also includes, for example, clay minerals, organic compounds trapped between the layers of the clay minerals, hard particles such as sand and rock fragments, soft particles such as plant fragments, fine particles such as microplastics, food residues, oils, detergents, etc.

[0028] The filtration system 1 according to this embodiment includes, for example, a storage tank 31 for temporarily storing a liquid to be treated A. The storage tank 31 is equipped with a liquid to be treated pipe 34 for guiding the liquid to be treated A to a container 11 and a liquid to be treated pump 32 for pumping the liquid to be treated A. The downstream end of the liquid to be treated pipe 34 is connected to a three-way valve 61, which is connected to the supply port 7 of the container 11 and the upstream end of a backwash water discharge pipe 48. The liquid to be treated A supplied to the container 11 passes through the filtration means 15 and is filtered to become a treated liquid B. The upstream end of the treated liquid discharge pipe 22 is connected to the discharge port 6 of the container 11, and the treated liquid B passes through the discharge port 6 and the treated liquid discharge pipe 22 to flow out of the system. A separate treated liquid outlet pipe 35 may be connected to the downstream end of the treated liquid discharge pipe 22. The treated liquid outlet pipe 35 may be equipped with an on-off valve 62 for opening and closing the inside of the pipe to control the flow of the treated liquid B.

[0029] Meanwhile, the filtration system 1 according to this embodiment is provided with a backwash water supply means for eliminating clogging caused by cake adhering to the filtration means 15. The liquid to be treated A contains solids, which are collected by the filtration filter 12 provided in the filtration means and deposit on the outer surface of the filtration filter 12 to form cake. The backwash water supply means may include, for example, a flow straightener 43, a fine bubble nozzle 46, and a pulse air generator 52 provided from the upstream side in the flow direction of the backwash water W. The flow straightener 43 is a device equipped with an inlet and an outlet, and is a device for straightening the flow of the backwash water W to be supplied to the vessel 11. The downstream end of the first backwash water pipe 41 is provided at the inlet of the flow straightener 43. The first backwash water pipe 41 has an on-off valve 63 and a backwash water pump 42 that pumps backwash water W. By operating the on-off valve 63 and the backwash water pump 42, backwash water W can be introduced into the first backwash water pipe 41 from its upstream end and directed to the flow straightener 43. The outlet of the flow straightener 43 is connected to the discharge port 6 of the vessel 11 by a second backwash water pipe 45. The second backwash water pipe 45 may be provided with, for example, a fine bubble nozzle 46, a pulsed air generator 52, and an on-off valve 64 from the upstream side. The fine bubble nozzle 46 is a device that generates fine bubbles. When the fine bubble nozzle 46 is activated, fine bubbles are generated as the backwash water W passes through the fine bubble nozzle 46, resulting in backwash water containing fine bubbles. The fine bubble nozzle 46 can be activated and deactivated, for example, by an ON / OFF switch provided on the fine bubble nozzle 46. The type of the fine bubble nozzle 46 is not particularly limited, but for example, a pressure reducing nozzle, an orifice, a venturi nozzle, a metal mesh, or the like can be used.

[0030] In addition to a configuration in which the downstream end of the second backwash water pipe 45 is connected to the opening 16 of the filtering means 15 and the backwash water W is supplied into the bag of the filtering means 15, a configuration in which the downstream end of the second backwash water pipe 45 is connected to the treated liquid discharge pipe 22 and the backwash water W is merged with the treated liquid flowing through the treated liquid discharge pipe 22 and supplied into the bag of the filtering means 15 may also be adopted. In addition, a configuration in which the upstream end of the treated liquid outflow pipe 35, the downstream end of the treated liquid discharge pipe 22, and the downstream end of the second backwash water pipe 45 are connected to the manifold 21 and the flow of the backwash water W and the treated liquid B is controlled by operating the on-off valves 62 and 64 may also be adopted.

[0031] The backwash water W supplied into the bag of the filtering means 15 passes through the filtering means 15 from the inside to the outside, flows out of the container 11 through the supply port 7 of the container 11, and flows through the backwash water discharge pipe 48 from the upstream end to the downstream end via the three-way valve 61. The downstream end of the backwash water discharge pipe 48 is connected to a recovery device 49 that recovers foreign matter such as cake that was not filtered. The recovery device 49 has a filter 50 (e.g., a bag filter) and a conduit 51 that leads the water that has passed through the filter 50 to the storage tank 31. When the backwash water W that has flowed into the recovery device 49 passes through the filter 50, the water that cannot pass through the meshes of the filter 50 (e.g., water containing foreign matter such as cake) is recovered, and the remainder flows into the storage tank 31.

[0032] (container) The filtration system 1 according to this embodiment includes a container 11. The container 11 may include, for example, a filtering means 15 therein, which filters the supplied liquid A to be treated and discharges the filtered liquid B. The container 11 includes a peripheral plate portion 3, an upper plate portion 4 connected to one end of the peripheral plate portion 3, and a lower tapered portion 5 connected to the other end of the peripheral plate portion 3. The container 11 also includes a supply port 7 and a discharge port 6. Note that the lower tapered portion 5 preferably has a tapered shape that decreases in diameter downward, which facilitates the discharge of peeled cake. The supply port 7 may be, for example, a portion through which the liquid A to be treated is supplied and from which backwash water W containing foreign matter such as cake is discharged. On the other hand, the discharge port 6 may be, for example, a portion through which the treated liquid B is discharged and from which the backwash water W is supplied. The supply port 7 may be provided, for example, in the lower tapered portion 5 of the container 11, although this is not particularly limited. On the other hand, the outlet 6 for discharging the treated liquid B, from which solids have been removed from the liquid to be treated A, is not particularly limited, and may be provided, for example, above the peripheral plate portion 3 or on the upper plate portion 4. The container 11 is not particularly limited, and may be installed with the upper plate portion 4 facing upward and the lower tapered portion 5 facing downward, or may be installed so that the direction connecting the upper plate portion 4 and the lower tapered portion 5 is horizontal. On the other hand, the filtration system 1 according to this embodiment performs filtration by a so-called dead-end filtration method, in which the liquid to be treated A supplied to the container 11 is entirely passed through the filtration means 15.

[0033] The vessel 11 is provided with a filtering means 15 for filtering the liquid to be treated A. The filtering means 15 has a cylindrical body 12s with through-holes for the treatment liquid B formed in its wall and a treatment liquid passage 12r formed inside. The one shown in the figure is cylindrical and is placed in the vessel 11 with its central axis aligned along the vertical direction of the vessel 11. The shape and orientation of the cylindrical body 12s are not particularly limited; the shape of the cylindrical body 12s may be changed to any known shape, such as a rectangular cylinder, or the cylindrical body 12s may be placed in the vessel 11 with its central axis aligned horizontally. The illustrated cylindrical body 12s is formed by molding a flat plate with through-holes, such as punched metal, into a cylindrical shape, and the space inside the cylindrical body 12s serves as the treatment liquid passage 12r.

[0034] A filtration filter 12 is provided on the outer side of the wall surface of the cylindrical body 12s. Because the surface area (filtration area) of this filtration filter 12 is large, it is preferable to use a pleated filter formed by folding a flat filter material in a zigzag pattern (like an accordion) and wrapping it around the outer peripheral surface of the cylindrical body 12s to form a cylindrical shape. Compared to a simple flat filter with an unfolded filter material, the use of a pleated filter increases the surface area of ​​the filter, thereby significantly increasing the filtration capacity of the liquid A to be treated per unit time.

[0035] Multiple pleats 18 can be formed by folding the filter material in a zigzag pattern. This pleated filter has the advantage that the spacing between the wall surfaces of adjacent pleats 18 gradually increases from the center of the pleated filter toward the radially outward direction, making it easier to peel and discharge cake. The length L1 between the tips 18p of adjacent pleats can be, for example, 4 to 10 mm, and the length L2 from the tips 18p of the pleats to the base ends 18b can be, for example, 30 to 100 mm.

[0036] The filter 12 can be single-layered or multi-layered. Examples of materials (filter media) that can be used for the filter 12 include polytetrafluoroethylene (also known as "Teflon" (registered trademark)), polyester, polyphenylene sulfide (PPS) resin, nylon, and stainless steel. The filter 12 preferably has a membrane thickness of 0.3 mm to 0.7 mm, more preferably 0.6 mm. The filter media's fiber diameter (referring to a projected area circle equivalent diameter, or Heywood diameter; the same applies hereinafter) is preferably 0.1 μm to 3 μm, more preferably 0.1 μm. Using fibers with a diameter smaller than 0.1 μm increases the resistance during filtration and reduces the apparent surface area. Using fibers with a diameter larger than 3 μm allows suspended particles in the liquid A to pass through the gaps between the fibers of the filter 12. Therefore, it is preferable to form the filter 12 with a certain degree of mesh size using a filter media with a fiber diameter of 0.1 μm to 3 μm. During filtration, suspended particles in the liquid A to be treated that adhere to the surface of the filtration filter 12 act as a filtration layer by this filtration filter 12. The length of the filtration filter 12 wrapped around the outer peripheral surface of the cylindrical body 12s in the direction corresponding to the circumferential direction of the cylindrical body 12s (i.e., the longitudinal direction) can be adjusted by the number of pleats 18 to be formed, and can be set to, for example, 150 mm to 750 mm.

[0037] In this embodiment, front surface 12f of filtration filter 12 refers to the surface facing container 11 and in contact with treatment liquid A. On the other hand, back surface of filtration filter 12 refers to the surface facing cylindrical body 12s and in contact with treatment liquid B. Note that the portions of the back surfaces of filtration filters 12 where pleats 18 are formed are arranged so that filtration filters 12 face each other.

[0038] It is also preferable to use a filter 12 having a predetermined strength or more so that the surface 12f of the filter 12 can withstand repeated backwashing processes. For example, in the measurement method of JIS L-1906, the tensile strength (N / 5cm) is 1200 in the vertical direction and 700 in the horizontal direction, and the burst strength (kgf / cm 2 )It is recommended to use one with a vertical length of 25.

[0039] The pleated filter 12 has pleats 18 whose axial center is aligned in the vertical direction, and the upper and lower ends of the pleats 18 are sealed to prevent the liquid to be treated A from flowing into the treatment liquid passage 2r without passing through the filter 12. The sealed portion at the upper end of the filter 12 is referred to as the upper filter seal portion 14a, and the sealed portion at the lower end of the filter 12 is referred to as the lower filter seal portion 14b. However, the upper filter seal portion 14a may preferably have an opening 16 in its center. By providing the opening 16 in the upper filter seal portion 14a at a portion that overlaps with the treatment liquid passage 12r, the flow of the treatment liquid B from the treatment liquid passage 12r to the discharge port 6 is ensured.

[0040] That is, the filtering means 15 of this embodiment has a filtering filter 12 and an opening 16, and has an upper filtering filter seal portion 14a that seals the upper end of the filtering filter 12, and a lower filtering filter seal portion 14b that seals the lower end of the filtering filter 12, so that the opening 16 forms a bag-like shape.

[0041] It is preferable to arrange a support plate (filter support plate 29) made of a honeycomb mesh, wire mesh, or the like folded in a zigzag pattern on the inner surface of the pleats 18 (so as to be in contact with the back surface 12q of the filtration filter 12) so as to follow the shape of the pleats from the base end side BS to the tip end side HS in the extension direction GS of the pleats 18. Figure 8 is an enlarged cross-sectional view of the pleats of the filtration filter 12. As cakes accumulate on the surface 12f of the filtration filter 12 (the surface facing the liquid A to be treated), the pleats 18 of the pleated filter are crushed, which may narrow the space within the pleats 18 and cause "blockage." However, the provision of the filter support plate 29 can prevent this blockage.

[0042] Since the filtering means 15 is arranged inside the container 11, the diameter of the filtering means 15 including the pleats 18 is preferably shorter than the diameter of the inside of the container 11.

[0043] The filtering means 15 according to this embodiment is preferably suspended in the internal space of the container 11 by the suspension means 10. The filtering means 15 according to this embodiment is vibration By Body 9 Vibrate On the other hand, the container 11 vibration It is preferable to avoid the influence of shaking caused by the body 9 as much as possible. Therefore, in order to absorb the shaking of the filtering means 15 as much as possible and prevent the kinetic energy caused by the shaking from being transmitted to the container 11, the filtering system 1 according to this embodiment is provided with a hanging means 10. The hanging means 10 is vibration It is preferable that the suspension means 10 be capable of absorbing vibrations transmitted by the suspension means 10, and is not particularly limited, but examples thereof include tubular rubber, multiple suspension dampers, multiple springs, etc. The suspension means 10 in Fig. 6 is an embodiment of tubular rubber, and the suspension means 10 in Fig. 9 is an embodiment of suspension dampers or springs.

[0044] Preferably, the hanging means 10 according to this embodiment is supported by the upper plate 4 of the container 11 and suspends the filtering means 15. Taking the case where the hanging means 10 is a tubular rubber as an example, the hanging means 10 can be installed by fixing the lower end of the hanging means 10 to the upper filtration filter seal 14a and fixing the upper end to the inner surface of the upper plate 4 of the container 11 (the surface on the interior side of the container 11). When the hanging means 10 is a tubular rubber, flanges may be provided at the upper and lower ends to facilitate fixing the upper and lower ends, and the upper flanges may be fixed to the upper plate 4 of the container 11 and the lower flanges may be fixed to the upper filtration filter seal 14a. When a tubular hanging means 10 is installed, a treated liquid discharge pipe 22 may be disposed inside the pipe along the axial direction of the pipe. It is preferable that the lower end of the treated liquid discharge pipe 22 is fixed to the upper filtration filter seal portion 14a (or the cylindrical body 12s). When the treated liquid A is filtered using the filtration system 1, the treated liquid A accumulates outside the treated liquid discharge pipe 22 in the container 11, and the treated liquid B flows inside the treated liquid discharge pipe 22. However, by connecting the lower end of the treated liquid discharge pipe 22 to the upper filtration filter seal portion 14a (or the cylindrical body 12s) in a manner that does not cause liquid leakage, the treated liquid A does not flow directly into the treated liquid discharge pipe 22 without passing through the filtration filter 12, thereby improving filtration efficiency.

[0045] In another embodiment, a support for supporting the hanging means 10 is provided above the upper plate 4 of the container 11, the lower end of the hanging means 10 is fixed to the upper filtration filter seal portion 14a, the tubular body of the hanging means 10 extends outward from the container 11 through the outlet 6 of the container 11, and the upper end of the hanging means 10 is fixed to the support. In this case, the outlet 6 is preferably sealed with the outer peripheral surface of the hanging means 10 to prevent unfiltered liquid A from leaking out of the container 11 through the outlet 6. The support can be fixed to the outer surface of the upper plate 4 of the container 11. Here, when the hanging means 10 is a tubular rubber, it is preferable that the hanging means 10 is impermeable to liquids, since the liquid A does not pass through the hanging means 10 and flow into the inside of the tube.

[0046] On the other hand, the filtering means 15 vibration The filtering means 15 vibration If the treated liquid discharge pipe 22 is shaken, the vibration will be transmitted to the treated liquid discharge pipe 22 connected to the filtering means 15. If the treated liquid discharge pipe 22 shakes, the objects connected to the treated liquid discharge pipe 22 will also shake. vibration The treated liquid discharge pipe 22 may be an expansion pipe (sleeve type expansion pipe, bellows type expansion pipe, etc.), flexible pipe, etc.

[0047] ( vibration body) The filtration system 1 according to this embodiment includes a filtration means 15. vibration To make vibration The liquid to be treated A has a body 9. The liquid to be treated A contains foreign matter such as suspended particles, and as a result of filtration, the foreign matter accumulates and grows on the surface 12f of the filtration filter 12, forming a cake. Here, carbon dioxide, oxygen, etc. are usually dissolved in the liquid to be treated A. Therefore, some of the dissolved carbon dioxide, oxygen, etc. may turn into bubbles in the cake formed on the filtration filter 12. As the thickness of the cake increases, the filtration speed decreases, and therefore the cake is removed to restore the decreased filtration speed. The filtration system 1 according to this embodiment uses a filtration means 15 to remove the cake. Vibrate it The filter 12 in the container 11 is immersed in the liquid, and the filter 12 is then removed. Vibrate When this occurs, the liquid penetrates into the cake, and carbon dioxide, oxygen, etc. that have bubbled in the cake rise within the cake, causing the foreign matter that forms the cake to become fluidized, causing the cake to collapse and facilitating its separation from the filtration filter 12.

[0048] Filtration means 15 vibration to make vibration Body 9, per second frequency The frequency (Hz) is not particularly limited as long as it is sufficient to promote the peeling of the cake, but for example, 100 to 500 Hz is preferred, and 200 to 400 Hz is more preferred. frequencyAt a few Hz, the fluidization of the foreign matter that forms the cake occurs easily. vibration The body 9 is not particularly limited, but may be: Piston vibrator, High frequency vibrator, ball vibrator Vibrators such as , an electromagnetic solenoid, an air knocker, etc. can be used. vibration The body 9 is connected to the filtering means 15 vibration For example, it can be attached in a form that allows it to come into contact with the lower part of the filtering means 15 (or in a form that is fixed to the lower part of the filtering means 15). vibration The body 9 may be provided inside a container 11, and vibration The start and stop of the body 9 is preferably controlled from outside the vessel 11 .

[0049] The surface of the filtration filter 12 according to this embodiment is a surface of the filtration means 15. vibration By doing so, the cake formed on the filtration filter 12 vibration As a result of the vibrations being transmitted, the cake vibration The solid and liquid components inside the cake are fluidized by the kinetic energy of the filtration means 15, and the cake is no longer able to maintain its layered shape and is separated. vibration occurs in the direction connecting the upper plate portion 4 and the lower tapered portion 5 inside the container 11, vibration While the filtering means 15 is vibrating, it does not come into contact with the container 11. In other words, it is preferable to vibrate the filtering means 15 in a direction perpendicular to the up-down direction as little as possible. This is to prevent cake formed on the filtering means 15 or the surface 12f of the filtration filter 12 from coming into contact with the inner wall of the container 11 and to suppress the transmission of kinetic energy associated with the vibration to the container 11. If the filtering means 15 were to vibrate in a direction perpendicular to the up-down direction, there is a concern that part of the cake in contact with the filtration filter 12 may get stuck in the mesh of the filtration filter 12 and cause clogging.

[0050] On the other hand, in the filtration system 1 according to this embodiment, backwash water W flows from the treated liquid discharge pipe 22 into the inside of the filtration means 15 and can pass through the filtration filter 12 from the rear surface 12q to the front surface 12f. As the filtration filter 12 filters the liquid to be treated A, foreign matter adheres to the front surface 12f, and fine particles get caught in the filter's meshes, causing the foreign matter to grow and form a cake. When backwash water W is flowed while this cake has formed, the foreign matter adhering to the filtration filter 12 peels off from the front surface 12f of the filtration filter 12 and flows out of the filtration filter 12 together with the backwash water W. This eliminates the decrease in filtration speed.

[0051] Furthermore, the filtration system 1 according to this embodiment may be configured such that the backwash water W contains fine bubbles. The fine bubbles according to this embodiment refer to bubbles with a diameter of less than 1 mm. Examples of fine bubbles include, but are not limited to, microbubbles with a diameter of 0.001 mm or more but less than 0.1 mm, micro-nanobubbles with a diameter of 0.0001 mm or more but less than 0.001 mm, and nanobubbles with a diameter of 0.0000001 mm or more but less than 0.0001 mm. The fine bubbles contained in the backwash water W pass through the meshes of the filter 12, but repeatedly collide with the fine particles trapped in the filter mesh, pushing the fine particles out of the filter 12. Furthermore, the fine bubbles are sufficiently small relative to the meshes of the filter 12 to easily pass through the filter 12. Therefore, a large number of fine bubbles repeatedly collide with the cake from the rear surface 12q of the filtration filter 12 toward the inner surface of the container 11, causing the fine bubbles to drive wedges into the cake layer, digging into the cake and promoting cracking of the cake. Due to these actions, the cake easily peels off from the surface 12f of the filtration filter 12.

[0052] When backwashing, if backwash water W is continuously flowed at a predetermined flow rate, depending on the degree of clogging inside the filter 12, some areas will be more easily flowing than others. As a result, most of the backwash water W will flow through the more easily flowing areas. This can leave the clogged areas in the filter 12 unresolved, potentially preventing the effects of backwashing from reaching the entire filter 12. Therefore, it is preferable to pulsate the backwash water W, i.e., to make the flow of the backwash water W a pulsating flow. When the backwash water W flows in a pulsating flow, the water pressure of the backwash water W fluctuates over time. The backwash water W reaches the back surface 12q of the filter 12 with varying water pressure, and the pulsation causes the less easily flowing areas to be unclogging. This facilitates the removal of cake and fine particles trapped inside the filter 12. As a result, the filter 12 is regenerated to a state where water can pass through it completely.

[0053] Furthermore, in the backwash water supply means according to this embodiment, it is more preferable that the flow of the backwash water W is a pulsating flow and that the backwash water W contains fine bubbles with an average particle size of 100 μm or less. The fine bubbles pass through the meshes of the filtration filter 12, but if there are fine particles stuck in the meshes of the filter, they repeatedly collide with the fine particles, thereby having the effect of pushing the fine particles out of the filtration filter 12. In addition to this effect, the pulsating flow of the backwash water W also has the added effect of clearing blockages in areas inside the filtration filter 12 where backflow water has difficulty flowing, facilitating the removal of cake and restoring the filtration filter 12 to a state closer to its original state.

[0054] Although there is no particular limitation, the flow of the backwash water W can be made to pulsate by providing a pulse air generator 52 to the backwash water supply means and sending pulse air to the backwash water W. The pulse air may be, for example, compressed air of 5 Hz to 50 Hz. Although there is no particular limitation, the pulse air generator 52 may be, for example, a "Pulse Blow Unit" manufactured by Koganei Corporation.

[0055] (Example of use) Next, a detailed description will be given of an example of how to use the filtration system 1 according to this embodiment. However, this example is just one example, and other ways of use are of course possible.

[0056] (filtration process) 1, the process of filtering the treated liquid A will be described. First, the three-way valve 61 is closed to prevent flow to the backwash water discharge pipe 48, and adjustments are made so that the treated liquid A flows from the treated liquid pipe 34 to the supply port 7. The on-off valve 62 is opened, and the on-off valves 63 and 64 are closed. The backwash water pump 42 and the fine bubble nozzle 46 are stopped.

[0057] When the treated liquid pump 32, which sends the treated liquid A into the treated liquid pipe 34, is started, the treated liquid A stored in the storage tank 31 is supplied from the treated liquid pipe 34 through the supply port 7 to the container 11. The liquid level of the treated liquid A in the container 11 gradually rises, and when it reaches the lower end of the filtration filter 12, the treated liquid A is filtered by the filtration filter 12 to become treated liquid B, and treated liquid B begins to accumulate in the cylindrical body 12s inside the filtration filter 12. As the liquid A is further supplied, the liquid levels of the treated liquid A and the treated liquid B rise, and when the liquid level of treated liquid B reaches the treated liquid discharge pipe 22 connected to the filtration means 15, the treated liquid B flows through the treated liquid outflow pipe 35 and is discharged to the outside of the system. Note that the entire amount of the treated liquid A supplied into the container 11 passes through the filtration filter 12 to become treated liquid B, which is then discharged through the discharge port 6 of the container 11. The liquid to be treated A will not be discharged through the outlet 6 without passing through the filtration filter 12. Conversely, the treated liquid B will not leak into the space within the container 11 but outside the filtering means 15 (i.e., the space where the liquid to be treated A accumulates) without passing through the filtration filter 12. In Figure 1, an example of the flow of the liquid to be treated A and the treated liquid B within the container 11 is shown by dashed arrows.

[0058] The flow rate of the liquid A to be treated supplied into the container 11 during the filtration process depends on the concentration and particle size of the suspended particles contained in the liquid A to be treated, but is preferably about 0.05 m / h to 0.5 m / h (FLUX of 50 LMH to 500 LMH), and more preferably about 0.1 m / h to 0.3 m / h.

[0059] As the filtration of the liquid to be treated A continues, suspended particles accumulate on the surface 12f of the filtration filter 12, growing into a cake layer. As the cake layer thickens, the filtration rate gradually decreases. The filtration process is terminated due to a decrease in filtration efficiency. The pressure difference can be used as an indicator to determine when to terminate the filtration process. The pressure of the liquid to be treated A flowing through the supply port 7 of the container 11 is measured with a pressure gauge (not shown), and the pressure of the liquid to be treated B flowing through the outlet 6 for the liquid to be treated B is also measured with a pressure gauge (not shown). The filtration process can be terminated when the pressure difference reaches a certain value or greater. Another indicator that can be used is the flow rate. For example, a flow meter (not shown) can be installed at the outlet 6 to measure the amount of liquid to be treated B discharged per unit time. The filtration process can be terminated when this amount falls below a certain value. The filtration process may be terminated after a predetermined time (for example, 10 to 120 seconds) has elapsed since the start of the filtration process, or the thickness of the cake may be measured and terminated when the cake thickness reaches approximately 1 mm to 2 mm.

[0060] (Cleaning process) The cleaning step following the filtration step will be described with reference to Figure 2. The treated liquid pump 32 is stopped, and the three-way valve 61 is closed to prevent backwash water W from flowing into the treated liquid pipe 34, and the backwash water W is adjusted to flow from the supply port 7 to the backwash water discharge pipe 48. The on-off valve 62 is closed, and the on-off valves 63 and 64 are opened. The container 11 is filled with the treated liquid A and the treated liquid B.

[0061] The backwash water pump 42 is started, and the prepared backwash water W is passed through the first backwash water pipe 41 and supplied to the rectifier 43. The backwash water W rectified by the rectifier 43 flows through the second backwash water pipe 45 and is supplied to the cylindrical body 12s from the opening 16 of the filtration means 15. The liquid in the container 11, in an amount equal to the amount of backwash water W that entered the container 11, is pushed out from the supply port 7 to the backwash water discharge pipe 48. At this time, if the fine bubble nozzle 46 is started, the backwash water W that has passed through the fine bubble nozzle 46 will contain fine bubbles. In FIG. 2, an example of the flow of the backwash water W in the container 11 is shown by dashed arrows.

[0062] Furthermore, when backwash water W containing fine bubbles is supplied into the container 11, the average particle size of the fine bubbles is preferably 100 μm or less, more preferably 60 μm or less. 100 If the fine bubbles are less than 1 μm in size, multiple fine bubbles will collide with the cake and penetrate into the cake layer as they rise, causing the cake to lose its layer shape and accelerating collapse. Although the average particle size of the fine bubbles is as described above, it is preferable that many of these fine bubbles have a particle size of 0.01 to 1 μm. Such fine bubbles with a particle size of 0.01 to 1 μm have the advantage of easily penetrating minute voids formed inside the cake as suspended particles adhere to the filtration filter 12 and grow into a cake, thereby accelerating the collapse of the cake.

[0063] The fine bubbles supplied into the container 11 rise to the upper side of the container 11 and then break down over time.

[0064] The particle size and average particle size of the microbubbles can be measured by known methods such as image analysis, laser diffraction, etc. Specifically, they can be measured based on the calculation method listed in the catalog of a commercially available microbubble particle size measuring device.

[0065] On the other hand, it is also preferable to start the pulse air generator 52 to make the flow of the backwash water W a pulsating flow. The pulse air generator 52 and the fine bubble nozzle 46 can be controlled independently, and of the pulse air generator 52 and the fine bubble nozzle 46, only the pulse air generator 52 may be started to make the flow of the backwash water W a pulsating flow, or only the fine bubble nozzle 46 may be started to make the backwash water W contain fine bubbles. Furthermore, the pulse air generator 52 and the fine bubble nozzle 46 may be started to make the backwash water W contain fine bubbles, and then the flow of the backwash water W may be made a pulsating flow.

[0066] The flow rate of the backwash water W supplied into the vessel 11 in the cleaning step is preferably about 0.1 m / h to 1 m / h (flux of 100 LMH to 1000 LMH), and more preferably about 0.2 m / h to 0.5 m / h, regardless of whether it contains fine bubbles or whether the flow is pulsating. By setting the flow rate within this range, damage to the filtration filter 12 is minimized and the collapse of cake formed on the surface 12f of the filtration filter 12 is promoted.

[0067] By continuously supplying the backwash water W into the container 11, the cake adhering to the filtration filter 12 collapses and begins to peel off. The supply of the backwash water W into the container 11 is not particularly limited, but it is preferable to supply the backwash water W for, for example, 10 to 300 seconds.

[0068] In the cleaning process, vibration Activating the body 9 and filtering means 15 vibration It can be done. vibration The body 9 may be started at the same time as the supply of backwash water W into the container 11 begins, or before the supply of backwash water W begins, or after a certain amount of time has elapsed since the supply of backwash water W began. vibration of the filtering means 15 by the body 9 vibration is not particularly limited, and may be performed, for example, while the backwash water W is being supplied into the container 11, or may be performed for 5 to 60 seconds while the backwash water W is being supplied into the container 11.

[0069] In particular, the backwash water supply means and the filtering means 15 using backwash water containing fine bubbles vibration By combining these, the cake formed on the surface 12f of the filtration filter 12 is broken down and peeled off in a short time, which is efficient.

[0070] As described above, the filtration system 1 according to this embodiment supplies the backwash water W into the container 11 and filters the filtration means 15. vibration This will eliminate clogging of the filtering means and liquidThe filtration system 1 according to this embodiment does not spray a cleaning fluid onto the filtration filter using a spray nozzle as disclosed in the technology of Patent Document 1, and therefore has the advantage that the filtering means 15 is less likely to be damaged.

[0071] The cake peeled off from the filtration filter 12 flows together with the backwash water W, passes through the supply port 7 and the backwash water discharge pipe 48, and reaches the recovery device 49. In the recovery device 49, solids such as the cake and suspended particles resulting from the collapse of the cake are collected, and the solids are collected by a filter 50 that allows the residue to pass through. The residue that passes through the filter 50 flows into the storage tank 31 through a conduit 51.

[0072] The cleaning step may be ended, for example, after the supply of the backwash water W has continued for 10 to 300 seconds, or after the supply of the backwash water W has ended and vibration The process may be terminated when the operation of the unit 9 is stopped. After the backwashing process is completed, the filtration process is started again to filter the liquid A to be treated.

[0073] As described above, the filtration system 1 according to this embodiment has a simple mechanism and structure, yet is capable of effective regeneration of clogged pores, and is capable of easily removing cake formed on the filtration filter 12. vibrationBy supplying backwash water containing fine bubbles at the same time, fine particles that have entered the filtration filter 12 can also be removed, resulting in excellent efficiency in regenerating clogged parts. On the other hand, since maintenance operations such as removing the filtration means 15 from the container 11 are not required, operational efficiency is also high. While chemical solutions can be used to clean the filtration filter 12, the fine particles that have entered the filtration filter 12 can be removed by the action of the fine bubbles, which significantly reduces the amount of chemicals used and reduces dependency on chemical solutions. This reduces wear on the filtration filter 12 and allows for long-term operation. On the other hand, since the filtration filter 12 is not cleaned by a water jet as in conventional systems, the concentration of suspended particles in the treatment liquid is high, and the suspended particles can be easily separated by dehydrating the treatment liquid after filtration, for example. Furthermore, if the concentration of impurities other than suspended particles in the treatment liquid is low (i.e., the rate of contamination is low) and the concentration of suspended particles is high, the treatment liquid can be reused as a resource. [Explanation of symbols]

[0074] 1...filtration system, 3...periphery plate portion, 4...upper plate portion, 5...bottom plate portion, 6...discharge port, 7...supply port, 9... vibration Body, 10...hanging means, 11...container, 12...filtration filter, 12f...surface of filtration membrane (outer surface of filtration filter), 12r...filtration passage, 12s...cylindrical body, 14a...upper filtration membrane seal portion, 14a'...inner edge of upper filtration membrane seal portion, 14b...lower filtration membrane seal portion, 15...filtration means, 16...bag opening, 18...pleats, 18b...base end of pleats, 18n...gaps between pleats, 18p...tip end of pleats, 22...treated liquid discharge pipe, 29...filter support plate, 31...storage tank, 32...treated liquid Liquid pump, 34... treated liquid pipe, 35... treated liquid outflow pipe, 41... first backwash water pipe, 42... backwash water pump, 43... rectifier, 45... second backwash water pipe, 46... fine bubble nozzle, 48... backwash water discharge pipe, 49... recovery device, 50... filter, 51... conduit, 52... pulse air generator, 61... three-way valve, 62... on / off valve, 63... on / off valve, 64... on / off valve, A... treated liquid, B... treated liquid (filtrate), GS... extension direction of pleats, HS... tip side, BS... base side, W... backwash water

Claims

1. a container having a supply port for a liquid to be treated and a discharge port for a treated liquid obtained by filtering the liquid to be treated; a bag-shaped filtering means provided inside the container and having an opening; A vertical moving body that moves the filtering means up and down; a treated liquid discharge pipe having one end connected to the opening of the filtering means and the other end disposed outside the container, through which the treated liquid is discharged to the outside of the container; a suspending means for suspending the filtering means in the internal space of the container in a suspended state; The suspension means absorbs vibrations caused by the up and down movement of the filtering means, The treated liquid discharge pipe is configured to absorb vibrations caused by the up and down movement of the filtering means. A filtration system characterized by:

2. the container has a peripheral plate portion, an upper plate portion connected to one end of the peripheral plate portion, and a lower tapered portion connected to the other end of the peripheral plate portion; The hanging means is supported on the upper plate portion of the container and hangs the filtering means. The filtration system of claim 1 .

3. Further, a backwash water supply means for supplying backwash water into the bag of the filtering means is provided, The backwash water contains fine bubbles having an average particle size of 100 μm or less. The filtration system of claim 1 .

4. The number of times the vertically moving body moves up and down per second is 100 to 500 Hz. The filtration system of claim 1 .

5. the treated liquid discharge pipe is an expandable pipe or a flexible pipe; The filtration system of claim 1 .

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