JP2005270809A - Filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water cleaning filter capable of suppressing the clogging of cells with a peeled suspended substance when the suspended substance accumulated on a partition wall by filtration operation is peeled by backwashing. <P>SOLUTION: The filter 1 is composed of a filter element 3 having partition walls comprising a porous material and having cells becoming liquid flow channels 4 formed thereto by the partition walls and a casing 2 capable of housing the filter element 3 and constituted so that the filter element 3 is built in the casing 2 so as to allow a liquid to flow in a vertical direction G. The filter element 3 is formed so that the cells 4 become small in diameter in a tapered state from one end parts 4b of the cells to the other end parts 4a thereof and built in the casing so that a raw liquid flows in the cells 4 from one end parts 4b of the cells and the foreign matter deposited on the partition walls in the cells 4 can be discharged toward one end parts 4b at the time of backwashing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a filter for water purification, and more particularly to a filter that can prevent suspended substances and the like from being clogged in a cell when a filter element is backwashed.

  In recent years, in addition to the global water shortage, problems of pathogenic microorganisms such as Cryptosporidium and O-157 have become serious, and a water purification process that can easily produce high-quality water with high safety is required. ing. Microfiltration (MF) and ultrafiltration (UF) using a filter element with a porous medium as a filter medium are toxic substances such as suspended substances and pathogenic microorganisms in liquids by simple operations. (Hereinafter, sometimes referred to as “foreign matter” or “suspension material”) is attracting attention as a water purification process that can effectively remove it. As filter elements used for microfiltration and ultrafiltration, a filter element having a partition made of a porous material such as resin or ceramic, and having a cell forming a liquid flow path by the partition is generally used. ing.

  For example, a hollow fiber membrane filter is a filter element in which a plurality of hollow fibers are used as a filter medium, and has a capillary-shaped partition wall made of a porous resin, and a cell penetrating the central portion is formed by the partition wall. It has a structured. In this structure, when the liquid to be treated (raw solution) is supplied to the outside of the hollow fiber at a predetermined pressure, the liquid flows through the partition made of porous resin and flows into the cell penetrating the center of the hollow fiber. At this time, harmful substances such as suspended substances and pathogenic microorganisms are removed in the partition wall, and the liquid flowing into the cell can be recovered as a purified treated liquid (filtrate). That is, in the hollow fiber membrane filter, the cell formed by the partition is used as a filtrate flow path for circulating the filtrate.

  A monolithic filter 31 shown in FIG. 4 is a filter element in which a ceramic porous body is used as a filter medium and a large number of cells 32 are formed so that the liquid flow paths are parallel to each other. This filter element has a lattice-shaped partition wall made of a ceramic porous body, and has a honeycomb structure in which a large number of cells 32 divided by the partition wall are formed. In this structure, when a liquid to be treated (raw solution) is supplied to the inside of a large number of cells 32 at a predetermined pressure, the liquid permeates the partition made of a ceramic porous body and flows out of the cells. At this time, harmful substances such as suspended substances and pathogenic microorganisms are removed in the partition wall, and the liquid flowing out of the cell and thus outside the monolith can be recovered as a purified treated liquid (filtrate). That is, in the monolithic filter 31 shown in FIG. 4, the cell 32 formed by the partition is used as a stock solution flow path for circulating the stock solution.

  When the above filter element is used for microfiltration or ultrafiltration, it is often used in the form of a filter in which the filter element is built in a casing. The above filter elements have a structure in which the stock solution flow path and the filtrate flow path are separated by a partition, although there is a difference between using the cell as a filtrate flow path or as a stock flow path. Yes. Therefore, only the filtrate can be separated and recovered by incorporating the filter element in the casing and having a structure in which the raw liquid flow path and the filtrate flow path are separated liquid-tightly by a sealing material such as an O-ring. Is possible. Usually, in such a filter, the filter element is built in the casing so that the liquid flows in the vertical direction.

  When the filter as described above is continuously filtered, suspended substances and the like that have been separated by filtration gradually accumulate on the surface of the partition wall of the filter element, so that the amount of water permeation gradually decreases. Accordingly, “backwashing” in which clarified water, a cleaning chemical solution, or the like is circulated through the filter element in a direction opposite to the filtration (that is, from the filtrate flow path side to the stock solution flow path side) under pressure or periodically. The washing operation called is performed. By this backwashing, suspended substances and the like deposited on the surface of the partition wall of the filter element can be peeled and removed, and the water permeability can be recovered to a level close to the initial level.

However, there has been a problem that the suspended substance may clog the cell when the suspended substance separated during backwashing is discharged to the outside through the cell (see, for example, Patent Document 1).
JP-A-7-251041

  In particular, in the case of a monolithic filter element, there is a problem that suspended cells and the like are easily clogged because the cell diameter (cell hole diameter) is small.

  The present invention has been made in view of the above-mentioned problems, and suppresses clogging of cells due to the suspended suspended matter when the suspended matter deposited on the partition wall is separated by backwashing by backwashing. The present invention provides a filter for water purification that can be used.

  The following filter is provided by the present invention.

[1] A partition having a partition made of a porous body, a filter element in which a cell serving as a liquid flow path is formed by the partition, and a casing in which the filter element can be built, wherein the filter element A filter built in the casing so as to circulate in a vertical direction and capable of filtering a liquid to be treated (raw solution), wherein the filter element has one end of the cell (cell One end of the cell is formed so that the diameter decreases in a tapered manner from the other end to the other end, and when the liquid to be treated (raw solution) is filtered, the one end of the cell The filter so that the stock solution flows into the cell from the side, and foreign matter accumulated on the partition in the cell during backwashing can be discharged to one end side of the cell. Remento filter that is built in the casing.

[2] The filter according to [1], wherein the filter element is built in the casing with one end of the cell being vertically downward.

[3] A stock solution supply port through which the casing can supply a stock solution to the filter element, a filtrate delivery port through which a treated liquid (filtrate) can be sent out from the filter element, and a stock solution from which the stock solution can be discharged from the filter element The filter according to [1] or [2], wherein a discharge port is formed.

[4] The monolithic filter element according to any one of [1] to [3], wherein the filter element is made of a ceramic porous body and has a number of cells formed so that the liquid flow path directions are parallel to each other. A filter according to the above.

  The filter of the present invention is configured such that when the stock solution is filtered, the stock solution flows into the cell from the end of the cell having the larger diameter (one end of the cell), and pressurizes clear water or the like When it is circulated and backwashed, it is configured such that suspended substances and the like deposited on the inner wall surface of the cell can be discharged from the one end side. And since the diameter of the cell becomes larger toward the end on the side where the suspended solids are discharged, it is possible to prevent the cell from being clogged with the discharged suspended solids during backwashing. .

  Hereinafter, the best mode for carrying out the filter of the present invention will be specifically described with reference to the drawings, but the present invention is not limited to the following embodiments.

  FIG. 1 is a cross-sectional view schematically showing one embodiment of the filter of the present invention. As shown in FIG. 1, one embodiment of the filter according to the present invention includes a filter element 3 and a casing 2 in which the filter element 3 can be built, and the filter element 3 circulates liquid in the vertical direction G. As shown in FIG. And as for the filter element 3 which comprises the filter 1 of this Embodiment, the cell 4 is changed from the one edge part 4b (one edge part of a cell) to the other edge part 4a (the other edge part of a cell). It is formed so that the diameter decreases toward the taper. When the liquid to be treated (stock solution) is filtered, the stock solution flows into the cell 4 from the one end 4b side of the cell. After the stock solution is filtered, the foreign matter ( The filter element 3 is built in the casing 2 so that the suspended substance or the like can be discharged to the one end 4b side of the cell. The filter 1 of the present embodiment is configured such that the stock solution flows in from the lower side in the vertical direction G of the filter 1 toward the upper side. Therefore, the filter element 3 is connected to the one end 4b side of the cell. In the casing 2, the vertical direction G is below (downward).

  When the stock solution is filtered by the filter 1 of the present embodiment shown in FIG. 1, when the stock solution is supplied from the stock solution supply port 5 of the bottom cap 13 into the cell 4 of the filter element 3 at a predetermined pressure, the stock solution is The filtrate is filtered when passing through the partition walls partitioning the cell, and the filtrate is passed from the outer peripheral surface 3a of the filter element 3 to the space 18 formed between the outer peripheral surface 3a of the filter element 3 and the inner peripheral surface 11a of the casing body 11. As spills. This filtrate is stored in the space 18 and finally recovered from the filtrate outlet 6 of the casing body 11. In this way, when the stock solution is filtered with the filter 1 of the present embodiment, the filtration efficiency deteriorates because suspended substances and the like in the stock solution are deposited on the partition walls. Therefore, it is necessary to remove suspended substances and the like accumulated on the partition walls by backwashing. When the filter 1 is back-washed, wash water or the like (clarified water or the like) is supplied from the filtrate outlet 6 at a high pressure, and the wash water is allowed to flow through the partition wall and flow into the cell 4 and flow through the cell 4. To be discharged from the stock solution supply port 5. At this time, suspended substances and the like deposited on the partition walls are released from the partition wall surfaces, and a part thereof is discharged from the stock solution supply port 5 together with the cleaning water. In addition, there may be suspended substances etc. that stay in the vicinity of the partition even if they are released from the partition wall, and further supply compressed air from the stock solution discharge port 7 to remove the suspended substance etc. that has been released. It is discharged from the stock solution supply port 5 as if it is blown away.

  When the filter is backwashed as described above, if the diameter of one end of the cell is the same as the diameter of the other end, or one of the cells on the side from which washing water or compressed air for backwashing is discharged When the diameter of one end is smaller than the diameter of the other end, there is a problem that the suspended matter or the like is clogged in the cell before being discharged from the cell. On the other hand, in the filter of the present embodiment, the cell is tapered from one end thereof (the end on the side from which washing water or compressed air for backwashing is discharged) toward the other end. Since the diameter is reduced, the cells can be prevented from being clogged. This is because the cell diameter increases in the direction of travel of suspended matter, etc. Even if it is clogged, if it can move a little in the direction of travel, the flow path (diameter) will increase and clogging will be eliminated and it will be easy from the cell. This is because it can be discharged.

  Hereinafter, the filter element, the casing, and the filter will be described in more detail.

(1) Filter element In this specification, the term “filter element” means a cell having a partition made of a porous material, and a cell forming a liquid flow path formed by the partition. According to such a filter element, when the stock solution permeates the partition wall and flows into the cell, or when the stock solution permeates the partition wall and flows out of the cell, suspended matter, pathogenic microorganisms, etc. The harmful substances (foreign substances) are removed, and the liquid flowing into the cell or the liquid flowing out of the cell can be recovered as a purified treated liquid (filtrate). And harmful substances (foreign substances) such as suspended substances and pathogenic microorganisms are deposited on the partition walls in the filter element cell.

  The material constituting the filter element is preferably a ceramic porous body.

As the ceramic constituting the filter element, for example, alumina (Al ₂ O ₃ ), titania (TiO ₂ ), mullite (Al ₂ O ₃ · SiO ₂ ), zirconia (ZrO ₂ ), or the like is used. Among these, alumina is suitably used because it is easy to obtain a raw material with a controlled particle size, can form a stable slurry, and has high corrosion resistance. Ceramics are highly reliable due to their excellent mechanical strength and durability, and have high corrosion resistance, so there is little deterioration during chemical cleaning with acids, alkalis, etc., and furthermore, precise control of the average pore size that determines the filtration capacity Has various advantages such as being possible.

  As a filter element made from ceramic, a tubular filter and the monolithic filter already demonstrated can be mentioned as a typical example. The tubular filter has a cylindrical partition wall made of a ceramic porous body, and has a structure in which a single cell penetrating the central portion, which is divided by the partition wall, is formed. On the other hand, the monolithic filter has a honeycomb structure in which lattice-shaped partition walls made of a ceramic porous body are formed and a large number of cells divided by the partition walls are formed. Among them, a monolithic filter having a large filtration area per unit volume and high processing capability is preferably used.

  As a tubular filter or a monolithic filter, a substrate having a partition made of a ceramic porous body, a plurality of cells formed by the partition so that the liquid flow direction is parallel, and the surface of the partition What was comprised from the filter membrane which consists of a ceramic porous body formed in (namely, inner peripheral surface of a cell) and whose average pore diameter is smaller than a base material can be used suitably.

  In such a structure, since the filtration function is exhibited exclusively by the filtration membrane, the average pore diameter of the substrate can be increased. Therefore, it is possible to reduce the flow resistance when the liquid that has permeated through the partition walls and has flowed out of the cell permeates the inside of the base material, and the amount of water permeation can be increased.

  The average pore size of the ceramic porous body constituting the filtration membrane varies depending on the required filtration performance (particle size of the substance to be removed), but in the case of a filter element used for microfiltration or ultrafiltration, it is 0. About 0.01 to 1.0 μm. On the other hand, the average pore diameter of the ceramic porous body constituting the substrate is determined in consideration of the balance between mechanical strength and water permeability. Usually, a ceramic porous body having an average pore diameter of about 1 to several 100 μm is used as the substrate.

  In the filter of the present embodiment, the shape of the cell of the base material is tapered so that the diameter decreases in a tapered manner from one end of the cell toward the other end. However, as shown in FIG. 2, the thickness of the filtration membrane 22 can be reduced by reducing the thickness of one end 4b of the cell and increasing the thickness of the other end 4a of the cell. Thus, the cell can be tapered. In this case, the thickness of the filtration membrane 22 (thin side filtration membrane) formed at one end 4b of the cell is preferably 100 to 250 μm, and the filtration membrane formed at the other end 4a of the cell. The thickness of 22 (thick filtration membrane) is preferably 150 to 300 μm. The difference between the thickness of the thin filtration membrane and the thickness of the thick filtration membrane is preferably 10 to 100 μm. Here, FIG. 2 is a partial cross-sectional view schematically showing one cell of the filter element constituting the filter of the present embodiment. In FIG. 2, the distance (diameter) between the partition walls 21 of the substrate is the same from one end of the substrate to the other end. In addition, an intermediate layer (not shown) is formed between the base material and the filtration membrane, and the thickness of the intermediate layer is gradually changed from one end side to the other end side, thereby forming a cell. May be tapered. Here, in the present embodiment, the taper shape means a shape in which the cell diameter (diameter) continuously decreases from one end portion toward the other end portion, but the diameter is a constant ratio. May be changed, or the ratio of the change may be partially changed to form a step in the middle.

  The base material can be obtained by a method of forming a clay containing aggregate particles, drying and firing, and the filtration membrane is formed by forming a slurry containing aggregate particles on the partition wall surface of the base material and drying And can be formed by a firing method or the like. The film formation can be performed by a conventionally known film formation method such as a dip film formation method, but by a filtration film formation method (see Japanese Patent Publication No. 63-66566) that can effectively prevent film defects such as pinholes. Preferably it is done.

  As a method of forming the filter element cells in a tapered shape, a filtration film-forming method can be employed in the above-described substrate manufacturing method. In the filtration film forming method, after the inside of the pores of the base material (porous body) is replaced with liquid, the surface of the base material where the filtration membrane should be formed and the surface where the filtration membrane is not formed are hermetically isolated , A film-forming slurry containing aggregate particles made of ceramic is continuously fed to and brought into contact with the surface on which the filtration membrane is to be formed. This is a method of forming a ceramic film on the surface of the substrate by applying a filtration differential pressure between the surface not to be formed. When a filtration membrane is formed on the inner wall surface (partition wall surface) of the cell by the filtration membrane formation method, the slurry is allowed to flow from the slurry inflow side end, flow through the cell, and flow out from the slurry outflow side end. The ceramic contained in the slurry is formed on the inner wall surface (partition wall surface) of the cell by sucking the slurry from the inside to the partition side. Thus, when a ceramic membrane (filtration membrane) is formed on the inner wall surface of the cell, the filtration membrane is formed thicker as it is closer to the slurry inflow end, and the filtration membrane is formed thinner as it is closer to the slurry outflow end. Can. During film formation, it is possible to create a difference in film thickness (upper side is thin and lower side is thick) by making the element stand upright. The filter element thus obtained may be built in the casing so as to face downward in the vertical direction, with the end of the cell on the side where the formed filtration membrane is thin as one end of the cell.

  Usually, the average pore diameter of the base material and the filtration membrane is controlled by the average particle diameter of the aggregate particles constituting them. That is, if aggregate particles having a large average particle diameter are used, a substrate or a filtration membrane having a large average pore diameter can be formed, and if aggregate particles having a small average particle diameter are used, a substrate having a small average pore diameter is used. Or a filtration membrane.

  In addition, as described above, an embodiment in which at least one interlayer film made of a ceramic porous body having an intermediate average pore diameter between these is formed between the base material and the filtration membrane is also one preferred embodiment. is there. When a slurry containing aggregate particles having a small average particle diameter is formed on the partition wall surface of the base material having a large average pore diameter to form a filtration membrane, the aggregate particles in the slurry are placed inside the pores of the base material. May enter and block the pores, resulting in a decrease in water permeability. In the above structure, the aggregate particles in the slurry for forming the filtration membrane can be trapped on the surface of the intermediate film, so that it is possible to prevent the aggregate particles from entering the pores of the base material. It is preferable in terms.

  Moreover, as a monolithic filter composed of the base material and the filtration membrane as described above, at least the end face of the monolith (portion other than the cell opening) is covered with a coating made of an impermeable material such as glass. Can be preferably used (see, for example, JP-A Nos. 61-8106 and 2001-300303).

  Usually, no filtration membrane is formed on the end face of the monolith, and the base material having a large average pore diameter is exposed. Therefore, the stock solution that has entered the base material from that portion has already permeated through the filtration membrane. In some cases, it may be mixed into the filtrate circulating in the material. The above structure is preferable in that the situation in which the stock solution is mixed into the filtrate can be avoided and the filtrate can be prevented from being contaminated.

  Further, as the monolithic filter, for example, a large number of cells 32 are formed as in the monolithic filter 31 shown in FIG. 3, and a group of cells and a monolith arranged in parallel in a part of the longitudinal direction. A water collecting slit 34 that communicates with the external space 33 is formed, and a cell (water collecting cell) that communicates with the water collecting slit 34 is plugged at both ends with plugging members 35. Can be used.

  In a monolithic filter, the flow resistance when the filtrate flows out of the monolith is larger in the cells near the center, so only the cells near the outer periphery where the flow resistance is small when the filtrate flows out of the monolith are used for filtration. It can happen that the substantial filtration area and thus the water permeability is reduced. With the above structure, the filtrate flowing out from the cell in the vicinity of the central portion can be quickly discharged into the external space of the monolith via the water collecting slit. Therefore, the cell in the vicinity of the central portion can be effectively used, and the substantial filtration area and consequently the water permeation amount can be greatly increased. Such a structure is particularly effective in the case of a large monolithic filter (for example, having an outer diameter of 50 to 300 mmφ) having a long distance from the cell near the center to the outer periphery of the monolith. In addition, about the water collection cell, since it is set as the structure which plugs the both-ends opening part of a cell, undiluted | mixed liquid does not mix from a cell opening part.

  The water collecting slit can be formed by breaking a group of cells arranged in parallel so as to communicate with the external space of the monolith. The rupture of the cell may be performed at the stage of the formed body before firing and the dried body, or may be performed at the stage of the sintered body after firing. Further, the plugging of the cell opening is performed by, for example, a method of drying and firing after filling the cell opening to be plugged with a clay (plugging material) made of the same material as the monolith. be able to. As shown in FIG. 3, the water collecting slits 34 are often formed in the vicinity of both end faces of the monolith 33. And it is common that each water collecting slit 34 is formed so that it may mutually be parallel.

  The shape of the tube filter or monolith filter is not particularly limited as long as the filtration function is not hindered. Examples of the overall shape include a columnar shape as shown in FIG. 4, a quadrangular prism shape, a triangular prism shape, and the like. Among them, a columnar shape that is easy to be extruded, has little firing deformation, and is easy to seal with the casing is preferably used. When used for microfiltration or ultrafiltration, it is preferable to use a cylindrical shape having an outer diameter of about 30 to 300 mmφ and a length of about 150 to 2000 mm.

  Examples of the cell shape (shape in a cross section orthogonal to the liquid flow direction) include shapes such as a square cell, a hexagonal cell, and a triangular cell in addition to a circular cell as shown in FIG. Among them, a circular cell that can be easily removed by separating and removing suspended substances deposited on the surface of the partition wall during backwashing is preferably used. The diameter (diameter) of the cell is preferably 0.5 to 10 mm. If it is smaller than 0.5 mm, the filtration resistance may increase and the filtration efficiency may decrease. If it is larger than 10 mm, the filtration area becomes small and the filtration efficiency may be lowered. In particular, when used for microfiltration or ultrafiltration, a circular cell having a cell diameter of about 1 to 5 mmφ is preferable.

(2) Casing In this specification, the term “casing” means a container that can contain a filter element. That is, an internal space is formed in the casing, and the filter element can be built in the internal space. As described above, columnar elements are generally used as filter elements, and therefore the casing is often configured in a cylindrical shape that can incorporate these columnar bodies. For example, when a columnar filter element is used, a cylindrical casing is preferably used.

  For example, as shown in FIG. 1, the filter element 1 is configured by incorporating a filter element 3 in the casing 2 so that the liquid flows in the vertical direction. For example, if a cylindrical monolithic filter is used as the filter element 3, the monolithic filter is built in a vertical arrangement so that the cell opens toward the vertical direction G. In such a filter 1, when the stock solution is supplied from the lower end side (one end 4 b side of the cell) of the filter element 3 and circulates toward the upper end side (the other end 4 a side of the cell). Filtration takes place (so-called upward flow filtration). After the stock solution is filtered, foreign substances (suspended substances and the like) deposited on the partition walls in the cell 4 by backwashing are discharged to the one end 4a side of the cell.

  Further, the casing 2 has a stock solution supply port 5 through which the stock solution can be supplied to the filter element 3, a filtrate delivery port 6 through which the filtrate can be sent from the filter element 3, and a stock solution from the filter element 3 so as to communicate with the internal space. Three types of openings, namely, a stock solution discharge port 7 capable of discharging water, are formed. Generally, these openings are provided with flanges so that they can be easily connected to piping.

  The stock solution supply port is an opening for supplying the stock solution to the filter element, and is also used when discharging the backwash drainage liquid. In a filter that performs upward flow filtration, since the stock solution is supplied from the lower end side of the filter element, the stock solution supply port 5 is often formed on the lower end side of the casing 2 as shown in FIG.

  The filtrate outlet is an opening for delivering filtrate from the filter element, and is also used when supplying clear water for backwashing. From the viewpoint of facilitating air bleeding in the casing, it is preferable to form a filtrate outlet 6 on the upper end side of the casing 2 as shown in FIG.

  The stock solution discharge port is an opening for discharging the stock solution from the filter element, and is also used when supplying compressed air for backwashing. Examples of the stock solution discharged from the filter element include drainage wastewater at the time of water filling operation and circulating stock solution at the time of cross-flow operation (a method of continuously filtering while circulating the stock solution through the filter element). .

  In a filter that performs upward flow filtration, since the stock solution is discharged from the upper end side of the filter element, the stock solution discharge port 7 is generally formed on the upper end side of the casing 2 as shown in FIG. .

  In addition, the casing does not need to be comprised integrally, and may be comprised by some members. For example, like the casing 2 shown in FIG. 1, the thing comprised from the hollow cylindrical casing main body 11, the top cap 12 with which the upper end is mounted | worn, and the bottom cap 13 with which the lower end is mounted | worn is mentioned. In the casing 2, a filtrate delivery port 6 is formed in the vicinity of the upper end of the casing body 11, a stock solution discharge port 7 is formed at the top of the upper cap 12, and a stock solution supply port 5 is formed at the lower end of the bottom cap 13.

  When the casing is composed of several members, it is preferable to connect the members using a flange. At this time, as shown in FIG. 1, sealing members such as O-rings 14 and 15 made of an elastic material such as rubber or a ring-shaped flat packing are interposed between the members to be connected to ensure liquid tightness. It is preferable to connect each member in the state which was carried out. For example, a method of arranging a sealing material along the flanges of both members to be connected, providing bolt holes on the outer peripheral side of the sealing material arrangement portion of the flange, and fixing with bolts and nuts, etc., can be mentioned. At this time, in order to facilitate the arrangement of the sealing material and to perform reliable fixing, a concave groove for arranging and fixing the sealing material may be provided on the flange.

  The casing is preferably made of a material that is impermeable and has high corrosion resistance. In the case of a ceramic filter element, a stainless steel casing or the like is preferably used.

(3) Filter When the filter of the present embodiment is formed, a structure in which the filter element is built in the casing in a state in which the raw solution flow path and the filtrate flow path are liquid-tightly separated by a sealing material; It is necessary to. The structure is not particularly limited, but usually, a structure in which a sealing material is arranged along the outer edge of both end faces of the filter element so as not to close the cell opening, and the sealing material is in contact with a part of the casing. Adopted. Then, when filtering the liquid to be treated (stock solution), the filter element is built in the casing so that the stock solution flows into the cell from the end portion (one end portion) on the larger diameter side of the cell. Like that.

  The shape, structure, material, and the like of the sealing material are not particularly limited, and may be, for example, an O-ring made of an elastic material such as rubber, a ring-shaped flat packing, or the like. By arranging an O-ring or ring-shaped flat packing so as to surround all of the plurality of cell openings along the outer edge of the end face of the filter element, the above two functions can be ensured.

  However, when a monolithic filter is used as the filter element, it is preferable to use seal caps 16 and 17 as the sealing material as shown in FIG. In this specification, the term “seal cap” means a cap-like seal material used by being attached to the end of a columnar body such as a filter element (see, for example, Japanese Patent Laid-Open No. 10-184919). Such a cap-shaped sealing material is preferable in terms of ensuring high liquid-tightness in addition to being able to be easily and reliably fixed to the filter element, as compared to O-rings and ring-shaped flat packings.

  5 (a) and 5 (b) are explanatory views schematically showing one embodiment of a seal cap. FIG. 5 (a) is a top view, and FIG. 5 (b) is FIG. 5 (a). It is an AA 'sectional view of). A seal cap 16 shown in FIGS. 5A and 5B is an annular member having an L-shaped cross section made of an elastic material such as rubber, and a body portion 16b extending in the vertical direction. It consists of a top portion 16a extending in the horizontal direction and has a central opening portion 16c.

  6A and 6B are explanatory views schematically showing the use state of the seal cap, in which FIG. 6A is a top view and FIG. 6B is A in FIG. 6A. It is -A 'sectional drawing. As shown in FIGS. 6A and 6B, the seal cap 16 has the body portion 16 b in close contact with the outer peripheral surface 31 a of the monolithic filter 31 and the top portion 16 a in close contact with the end surface of the monolithic filter 31. And attached to the end of the monolithic filter 31. The central opening 16c is formed so that all the many cells 32 of the monolithic filter 31 are exposed, and is configured so that all the cells 32 can be used effectively.

  The filter 1 of the present embodiment shown in FIG. 1 is preferably used as a dead-end type filter by closing the stock solution outlet 7 at the top of the upper cap 12 with a valve or the like. However, the undiluted solution discharge port 7 and the undiluted solution supply port 5 are connected by a pipe or the like so that the undiluted solution circulates in the filter 1 so that it can be used as a cross-flow type filter.

  When it is used as a large-scale filtration facility such as a water purification plant or a factory and it is required to process a large amount of undiluted solution, a large number of filters of this embodiment can be connected and used. In that case, the stock solution supply port of each filter is connected via a flange to a stock solution supply header pipe for supplying the stock solution to each filter, and the filtrate delivery port is a filtrate for collecting the filtrate together. It is preferable to be connected to the recovery header pipe through a flange, and the stock solution discharge port is connected to a stock solution recovery header pipe for collecting the stock solution after filtration through the flange.

  The filter of the present invention removes harmful substances such as suspended substances and pathogenic microorganisms in liquids in a wide range of fields such as drinking water and industrial water production, medicine and food, or purification of sewage and industrial wastewater. Used to do.

It is sectional drawing which shows typically one Embodiment of the filter of this invention. It is a fragmentary sectional view showing typically one cell of filter element which constitutes one embodiment of a filter of the present invention. It is a perspective view showing typically the filter element which constitutes one embodiment of the filter of the present invention. It is a perspective view showing typically one embodiment of a filter element. 5A and 5B are explanatory views schematically showing an embodiment of a seal cap, in which FIG. 5A is a top view and FIG. 5B is a cross-sectional view taken along line A-A ′ of FIG. FIGS. 6A and 6B are explanatory views schematically showing a usage state of the seal cap, in which FIG. 6A is a top view and FIG. 6B is a cross-sectional view taken along line A-A ′ of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Filter, 2 ... Casing, 3 ... Filter element, 3a ... Outer peripheral surface of filter element, 4, 32 ... Cell, 4a ... Other end part of cell, 4b ... One end part of cell, 5 ... Stock solution supply Mouth, 6 ... Filtrate outlet, 7 ... Stock solution outlet, 11 ... Casing body, 11a ... Inner peripheral surface of casing body, 12 ... Upper cap, 13 ... Bottom cap, 14, 15 ... O-ring, 16, 17 ... Seal cap, 16a ... top, 16b ... body, 16c ... center opening, 18 ... space, 21 ... partition, 22 ... filtration membrane, 31 ... monolith filter, 31a ... peripheral surface of monolith filter, 33 ... monolith, 34 ... Water collecting slit, 35 ... Sealing member, G ... Vertical direction.

Claims (4)

A filter element having a partition wall made of a porous material, a cell in which a cell serving as a liquid flow path is formed by the partition wall, and a casing in which the filter element can be built, wherein the filter element allows the liquid to flow vertically. A filter that is built in the casing so as to circulate and can filter a liquid to be treated (raw solution),
The filter element is formed such that the diameter of the cell decreases in a tapered shape from one end portion (one end portion of the cell) to the other end portion,
When the liquid to be treated (stock solution) is filtered, the stock solution flows into the cell from one end side of the cell, and the foreign matter deposited on the partition walls in the cell during backwashing is removed from the cell. A filter in which the filter element is built in the casing so that it can be discharged to one end side.   The filter according to claim 1, wherein the filter element is built in the casing with one end of the cell being vertically downward.   A raw solution supply port through which the casing can supply a stock solution to the filter element, a filtrate delivery port through which a treated liquid (filtrate) can be sent out from the filter element, and a stock solution discharge port through which the stock solution can be discharged from the filter element The filter according to claim 1 or 2, wherein the filter is formed.   The filtration according to any one of claims 1 to 3, wherein the filter element is a monolithic filter element made of a ceramic porous body and having a number of cells formed so that the liquid flow path directions are parallel to each other. vessel.

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