JP6183606B2 - Filtration apparatus and filtration method - Google Patents

Description

  The present invention relates to a filtration device for filtering a stock solution (treatment liquid) such as turbid water. In particular, the present invention relates to a filtration device and a filtration method that can regenerate a filtration filter.

  As a device for filtering a stock solution such as turbid water and capable of regenerating the filter, there is a device equipped with a means for backwashing the filter with backwash water and a means for disturbing and washing the surface of the filter ( For example, see Patent Document 1.) This filtration device regenerates the filtration filter by washing with backwashing means or disturbing washing means. In particular, this document states that “the filter medium to which the removed suspended solids are attached can be easily removed with less washing water. Is possible "(paragraph [0008]).

However, the regeneration method by backwashing has the following problems (a) to (d), and the film flux cannot be increased.
(B) In the filtration treatment of the stock solution containing particles with good dispersibility, even if fouling progresses, it can be recovered to the initial treatment flow rate by backwashing regeneration, but turbid water containing particles with strong cohesive adhesion force In the case of undiluted solutions containing paste-like substances (for example, polymer flocculants and binders), the degree of recovery from fouling (a phenomenon that reduces the permeation flux) will be Declined.
(B) In the removal of food wastewater and algae, the generated biofilm generates fouling, which increases the frequency of regeneration, resulting in an increase in utilities and a significant decrease in processing capacity.
(C) In the regeneration operation by backwashing, it was necessary to interrupt the filtration process. For this reason, when storing the stock solution and supplying the stock solution from there to the filtration device, it is necessary to increase the stock solution storage amount.
(D) Although the filtrate can be used as the backwashing liquid, even if it is done, the amount used for the backwashing is lost.

JP 2008-93542 A

  Therefore, the main problem to be solved by the present invention is to solve the above problems (a) to (d) and to improve the film flux.

The present invention for solving this problem is as follows.
[Invention of Claim 1]
A filtration container;
A filter provided in the filtration container, the outer surface of which is a filtration surface and having a filtrate passage inside;
Stock solution supply means for supplying a stock solution between the inner surface of the filtration container and the outer surface of the filter;
A filtrate discharge path for discharging filtrate from the filtrate passage inside the filter to the outside of the filtration container;
A concentrate discharging means for discharging the concentrate from between the inner surface of the filtration container and the outer surface of the filter;
A filtration device comprising:
The filter is a pleated filter formed by winding a flat filter medium in a zigzag shape and wound in a cylindrical shape, and the central axis is provided in the filtration container in a posture along the vertical direction, and the central axis is a rotation center. It can be rotated,
An injection nozzle that sprays a cleaning fluid against the filtration surface of the filter is provided, and the filter is rotatably provided so that the filtration surface passes through a spraying range of the cleaning fluid from the injection nozzle .
The said spraying nozzle sprays a cleaning fluid toward the diagonally downward from the slit-shaped spraying opening along the direction of the crease | fold of the said pleat filter, The filtration apparatus characterized by the above-mentioned.

Delete

[Invention of Claim 2 ]
The filtration device according to claim 1 , wherein the filter is made of a filter medium having a two-layer structure in which an outer surface of the membrane layer is covered with a protective layer having a coarser mesh than the membrane layer.

[Invention of Claim 3 ]
The filtration device according to claim 1 or 2 , wherein a part of the undiluted solution supplied to the filtration container is supplied to the injection nozzle and injected as the cleaning fluid.

[Invention of Claim 4 ]
In the filtration container, a filter having an outer surface as a filtration surface and having a filtrate passage inside is provided.
The undiluted solution is supplied between the inner surface of the filtration container and the outer surface of the filter, and the filtrate is discharged to the outside of the filtration container from the filtrate passage inside the filter, and the inner surface of the filtration container and the outer surface of the filter Drain the concentrate from between,
A filtration method comprising:
The filter is a pleated filter formed by winding a flat filter medium in a zigzag shape and wound in a cylindrical shape, and the central axis is provided in the filtration container in a posture along the vertical direction, and the central axis is a rotation center. It can be rotated,
While performing filtration, the cleaning fluid is sprayed from the spray nozzle provided outside the filter to the filter surface of the filter, and the filter surface is passed through the spraying range of the cleaning fluid from the spray nozzle. There line regeneration of the filter by rotating,
The filtration method , wherein the spray nozzle sprays a cleaning fluid obliquely downward from a slit-shaped spray port along a crease direction of the pleated filter .

(Main effects)
In the present invention, since the cleaning fluid is sprayed from the outside of the filter to the filtration surface of the filter, the cleaning force directly acts on the deposits that cause fouling, and can be washed off. Therefore, even if the cause of fouling is a particle having a strong cohesive adhesion, a paste-like substance, or a biofilm, it can be removed from the filter. In addition, since the filter can be regenerated while filtering, it is possible to completely eliminate the pause loss, and by continuously spraying the cleaning fluid and rotating the filter at continuous or short intervals during filtering. Since the fouling can be suppressed, the film flux can be remarkably improved.
In addition, when using a pleated filter, it is difficult to reduce the distance between the ridges because the backwashing method makes it difficult to discharge the deposits from between the ridges. However, as described above, when the configuration in which the cleaning fluid is sprayed obliquely downward from the slit-shaped injection port along the fold direction of the pleat filter, the cleaning fluid can be sprayed to the back of the space between the ridges. Moreover, since the discharge | emission of the deposit | attachment from between ridges is also accelerated | stimulated, compared with the case where a backwash system is employ | adopted, a ridge space | interval can be narrowed and filtration performance can be improved by expansion of a filtration area.
In addition, when using a filter having a two-layer structure in which the outer surface of the film layer is covered with a protective layer having a coarser structure than the film layer, the protective layer is interposed between the spray nozzle and the film layer, The wear of the film layer due to the jetting of the cleaning fluid can be reduced.
Furthermore, when a part of the stock solution is supplied to the spray nozzle and sprayed as a cleaning fluid, there is no loss compared to backwashing using the filtrate, and the concentrated solution can be taken out without being diluted. The magnification is also high.

  According to the present invention, advantages such as improved membrane flux are brought about.

It is a filtration system diagram of a filtration device. It is a longitudinal cross-sectional view of a filtration apparatus. It is a cross-sectional view which shows the principal part of a filtration apparatus. It is a longitudinal cross-sectional view which shows the principal part of a filtration apparatus. It is a cross-sectional view which shows the principal part of a filtration apparatus.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.
As shown in FIG.1 and FIG.2, the filtration apparatus 10 of this form filters the raw | natural liquid W1, such as muddy water, with the filter 12 in the airtight filter container 11, and obtains filtrate W2 and concentrate W3, such as purified water. This is a cross-flow filtration device 10. Although the filtration container 11 of this form is made into the cylindrical shape where a center follows an up-down direction, it is not limited to this, It can be set as a suitable shape.

  In the filtration container 11, a filter 12 having an outer surface as a filtration surface and having a filtrate passage 12r therein is provided. Although the shape and attitude of the filter 12 are not particularly limited, it is preferable that the filter 12 is cylindrical in the present embodiment, and the central axis thereof is arranged in the filtration container 11 in an attitude along the vertical direction. As such a cylindrical filter 12, since the filtration area is wide, as shown in FIG. 3, a pleated filter 12 formed into a cylindrical shape while bending a flat filter medium in a zigzag manner can be suitably used. The filter 12 in the illustrated form is a filter 12 unit in which a filter medium is wound around the outer peripheral surface of a liquid-permeable cylindrical support 21 made of punching metal or the like, and a top plate 22 and a bottom plate 23 are provided above and below it. A filtrate outlet 22x leading to the filtrate passage 12r is formed at the center of the top plate 22, and the lower end of the filtrate passage 12r is closed by a bottom plate 23. The top plate 22 and the bottom plate 23 are made of metal, for example.

The filter 12 is not particularly limited, and a single-layer filtration membrane can be used, but as shown in an enlarged view in FIG. 3, the outer surface of the membrane layer 12m is a protective layer having a coarser mesh than the membrane layer 12m. It is preferably made of a filter medium having a two-layer structure coated with 12c. As the film layer 12m in this case, a nano-level fiber thin film (layer), for example, a film made of a fluororesin such as Teflon (registered trademark) subjected to hydrophilic processing, a nanofiber spunbond film, or the like may be used. it can. The film thickness of the film layer 12m is preferably 0.03 to 0.07 mm, more preferably 0.05 mm. The fiber diameter of the membrane layer 12m is preferably 100 to 300 nm, and the accuracy by the particle counter is particularly preferably 0.15 μm × 99.95%. Further, as the protective layer 12c, for example, a nonwoven fabric such as polyester, nylon, PPS, or a SUS high-density wire mesh can be used, and the thickness is preferably 0.4 to 1.0 mm, more preferably. 0.6 mm. The present inventor has confirmed that according to the filter 12 of such a filter medium, the water flow rate can be made 2 m ³ / H · m ² (fresh water) or more. In addition, this water flow rate reaches 40 times or more in the case of a hollow fiber membrane (0.05 m3 / H · m2).

  Further, in this embodiment, the one side wall at the lower end portion of the filtration container 11 is provided with a stock solution supply port 13 for supplying the stock solution W1 under pressure between the inner surface of the filtration container 11 and the outer surface of the filter 12. . The stock solution W1 is pressurized and supplied to the stock solution supply port 13 from a stock solution supply source such as a stock solution storage tank (not shown) using a stock solution pump 13P. The supply amount of the stock solution W1 can be adjusted, for example, by providing a supply valve in the supply line of the stock solution W1 and adjusting the opening thereof.

  Further, in this embodiment, a concentrated liquid discharge port 14 for discharging the concentrated liquid W3 to the outside of the filtration container 11 passes through the side wall opposite to the stock solution supply port 13 at the lower end portion of the filtration container 11. The concentrate discharge port 14 is led to a storage tank, a drainage destination or the like (not shown).

  Characteristically, the filter 12 is rotatable about its central axis as a rotation center. The rotational drive mechanism of the filter 12 is not particularly limited, but the illustrated embodiment will be described in detail as follows. That is, a rotary table 11t that is rotatable via a bush 11b is provided on the bottom of the filtration container 11, and the filter 12 is placed on the rotary table 11t. On the other hand, a filtrate discharge pipe 15 passes through a portion of the ceiling of the filtration container 11 facing the filtrate outlet 22x of the filter 12, and the lower end inlet of the filtrate discharge pipe 15 and the filtrate outlet 22x of the filter 12 are substantially omitted. They are connected by a tubular connecting body 16. The connection body 16 has a flange portion 16f extending outward from the lower end inlet of the filtrate discharge pipe 15 and the filtrate outlet 22x of the filter 12, and O-rings provided above and below the flange portion 16f, respectively. A ring-shaped elastic body 16r such as is closely attached to the lower surface of the ceiling portion of the filtration container 11 and the upper surface of the top plate 22 of the filter 12. Further, a drive shaft 17 s along the vertical direction that is rotationally driven by a rotational drive source 17 such as a motor attached outside the filtrate discharge pipe 15 is coupled to the connecting body 16 via the filtrate discharge pipe 15. Therefore, the filter 12 is rotatable with respect to the filtration container 11 while maintaining the communication between the filtrate discharge pipe 15 and the filtrate passage 12r by the connecting body 16. The rotation speed of the filter 12 can be determined as appropriate, but in a normal case, for example, the outer peripheral speed of the filter 12 is preferably about 0.2 to 1 m / min, and is preferably set to a constant speed.

  Since there are various causes of fouling, even if cleaning described later is performed, maintenance accompanying replacement of the filter 12 is inevitable. Also, the filter 12 may need to be replaced for causes other than fouling. For this reason, in the illustrated form, together with the swivel mechanism by the connection body 16 described above, a structure in which the ceiling part and the side wall part of the filtration container 11 are detachably connected by a ferrule joint method (the edge part of the ceiling part and the upper edge part of the side wall part) The clamp 12 and the packing fitted in the groove between the ceiling and the side wall are not shown), and the filter 12 can be easily and quickly replaced by opening the ferrule joint.

  Also, characteristically, an injection nozzle 20 is provided on the side wall of the filtration container 11 to spray the cleaning fluid against the filtration surface of the filter 12. The type, arrangement, and jet direction of the spray nozzle 20 consider the spread of the cleaning fluid from the spray nozzle 20 and rotate the filter 12 so that the entire filtration surface can pass through the spraying range of the cleaning fluid from the spray nozzle 20. However, in the case of using the pleated filter 12 as shown in the figure, the injection nozzle 20 having the slit-like injection port is used, and the slit-like injection port is the direction of the fold of the pleat filter 12 (that is, the illustrated example). Then, it is preferable that the nozzles are arranged along the vertical direction, and the injection direction (the direction along the one-dot chain line in the figure) is obliquely downward, particularly 45 degrees downward with respect to the horizontal direction.

  The number of spray nozzles 20 is not particularly limited, but it is preferable that the spray nozzles 20 are arranged in a plurality of rows at intervals in the vertical direction so that the spray ranges partially overlap. Although not shown, a plurality or a plurality of rows can be provided in the circumferential direction. Further, as shown in the figure, when it is difficult to spray the upper part of the filter 12 such as when the direction of the spray nozzle 20 is obliquely downward, the obliquely upward spray nozzle 20 is used to spray the upper part of the filter 12. As shown in FIG. 4, the injection direction of the uppermost injection nozzle 20 is directed horizontally, and the direction of the injection nozzle 20 with respect to the horizontal direction is gradually inclined downward by 45 degrees as it goes downward. It is desirable to keep the angle constant at 45 degrees.

  Further, when the pleated filter 12 is used as shown in the figure, as shown in FIG. 5, the cleaning fluid is respectively inclined in a direction slightly inclined to the left and right sides (for example, about 7.5 degrees) with respect to the direction toward the center of the filter 12. It is also a preferable form to arrange the pair of injection nozzles 20 in a V shape in plan view so as to inject the gas. Such a V-shaped arrangement of the injection nozzles 20 may be applied to all of the injection nozzles 20 in the vertical direction or may be a part. Further, in the illustrated embodiment, the cleaning fluid is supplied in one system to the vicinity of the nozzle, distributed to two systems in the vicinity of the nozzle, and supplied to each of the injection nozzles 20 in the V-shaped arrangement, but is limited to this. Instead, two units of the injection nozzle 20 in the form of FIG. 3 may be used and arranged in a V shape. If the spray nozzle 20 is arranged in a V shape in this way, the cleaning fluid sprayed from the spray nozzle 20 can clean the surface while pushing open the pleat filter 12, so only more effective cleaning is possible. In addition, since the spray is dispersed on the left and right surfaces of the kite, it is possible to reduce wear on the kite. Further, since the wrinkles are spread and washed, the pitch of the wrinkles of the pleated filter 12 can be shortened to increase the surface area per filter. For example, in the case of the pleated filter 12 shown in the drawing, the filtration area can be increased to 75 square meters when the diameter is 400 mm and the height is 1200 mm, and the apparatus can be made compact.

  The cleaning fluid supplied to the spray nozzle 20 is not particularly limited, and can be liquid, gas, or a mixture thereof, and a dedicated cleaning fluid can be separately supplied. However, as shown in FIG. It is preferable that a part of the supplied stock solution W1 is supplied to the spray nozzle 20 and sprayed as a cleaning fluid. In the illustrated embodiment, a stock solution extraction port 18 is provided on the same side wall as the stock solution supply port 13 at the upper end of the filtration container 11, and the stock solution W1 is extracted from the stock solution discharge port 18 by the cleaning pump 18P and supplied to the injection nozzle 20. It has become. Further, a cleaning fluid supply valve 18v is provided in each supply line from the cleaning pump 18P to each injection nozzle 20.

  Even when a compressed gas such as high-pressure air is injected into the stock solution W1 as the cleaning fluid, the cleaning ability equivalent to that when only the liquid is injected is exhibited. When 20 to 50% (flow rate ratio) of compressed gas is mixed in the liquid and jetted as a mixed liquid, the cleaning area in the filter 12 is increased as compared with the case of only the liquid. However, the utility increases compared with the injection of only liquid.

  The injection pressure of the injection nozzle 20, the injection flow rate, and the distance to the filter 12 can be determined as appropriate. However, when only the stock solution W1 is injected, the injection pressure is about 0.2 to 0.3 MPa, and the flow rate is 25 to 35 liters / minute. The distance to the filter 12 (the distance between the tip of the injection nozzle 20 and the filter 12 in the injection center direction) can be about 60 to 180 mm.

  Further, in the illustrated form, partition walls 19 extend in the vertical direction on both sides of the injection nozzle 20, and a concentrate discharge port 14 is provided at the lower end between the partition walls 19.

(Filtration and regeneration)
Next, in order to filter the stock solution W1 using the filtration device 10 of this embodiment, first, the stock solution W1 is supplied into the filtration container 11 from the stock solution supply port 13 using the stock solution pump 13PP. The stock solution W1 supplied into the filtration container 11 is filtered by the filtration filter 12, and the concentrated solution W3 concentrated by this filtration is discharged out of the filtration container 11 from the concentrate discharge port 14, and passes through the filter 12 to pass through the filtrate. The filtrate W2 discharged into the passage 12r is discharged out of the filtration container 11 through the filtrate discharge pipe 15. At the time of this filtration, fouling progresses due to the adhering suspended matter or the like on the filtration surface of the filter 12.

  When the filtration resistance increases due to fouling, the amount of filtrate decreases. Therefore, when the amount of filtrate is made constant, the flow rate of the filtrate W2 discharged from the filtration container 11 is measured by a flow meter, and the stock solution is made so that the measured flow rate becomes constant. It is desirable to control the flow rate of the pump 13P with an inverter or the like.

  Further, since the concentration rate depends on the discharge flow rate of the concentrate, in order to keep the concentration rate constant, it is basically necessary to keep the discharge flow rate of the concentrate constant. However, if the supply pressure of the stock solution changes, the discharge flow rate of the concentrate also changes. Therefore, a flow control valve such as a proportional control valve is provided on the outlet side of the concentrate discharge port 14 to inject the initial value of the concentrate discharge amount. It is desirable to set an appropriate value such as the amount of injection from the nozzle and control the discharge flow rate of the concentrate according to the stock solution supply pressure or a parameter serving as an index thereof. For example, the stock solution supply pressure can be measured by a pressure gauge provided between the stock solution supply port 13 and the stock solution pump 13P, or a pressure gauge attached to the stock solution pump, and the discharge flow rate of the concentrate can be controlled according to this measured value. .

  If the fouling has progressed to a certain extent (for example, a predetermined time has elapsed), the cleaning fluid is sprayed from the spray nozzle 20 and the filter 12 is rotated without stopping the filtration or continuously or at short intervals during the filtration. . When the spray nozzles 20 are provided in a plurality of rows in the vertical direction as shown in the figure, the cleaning fluid may be sprayed from all the nozzles. However, while the filter 12 rotates once, it is sprayed from only one nozzle and When the cleaning fluid is ejected while switching to the lower ejection nozzle 20 every time the filter 12 rotates in order from the upper ejection nozzle 20, there is little reattachment of dirt to the surface of the filter 12, and the amount of the cleaning fluid used is also small. Therefore, it is preferable. In particular, when the cleaning fluid is liquid, if it is ejected from all of the ejection nozzles 20, the concentration ratio is greatly reduced. Therefore, such sequential ejection is desirable.

  By such a regeneration process, the cleaning fluid can be sprayed from the outside of the filter 12 to the filtration surface of the filter 12 to directly wash off the deposits that cause fouling. In particular, when the filter 12 is regenerated while filtering, the pause loss can be completely eliminated. Further, when the cleaning fluid is sprayed and the filter 12 is rotated intermittently during filtration or intermittently at a short interval, fouling can be suppressed, so that the membrane flux can be significantly improved. Of course, the membrane flux is somewhat reduced, but the cleaning fluid can be jetted from the jet nozzle 20 and the filter 12 can be rotated while the filtration (that is, the supply of the stock solution W1) is temporarily stopped.

  In order to detect the progress of fouling, the flow rate of the filtrate W2 discharged from the filtration container 11 is measured by a flow meter, and the regeneration of the filter 12 is started when the measured flow rate is reduced to some extent (for example, about 25%). Or when the pressure on the filtrate W2 side in the filtrate discharge pipe 15 or the like is measured with a pressure gauge and the measured filtration differential pressure reaches a certain level (for example, about 80 kPa). In addition, the regeneration of the filter 12 can be started.

  In this embodiment, since the configuration in which the cleaning fluid is sprayed obliquely downward from the slit-shaped injection port along the fold direction of the pleat filter 12 is adopted, the cleaning fluid can be sprayed to the back of the space between the scissors. Since the discharge of adhering matter from the surface is also promoted, it is possible to improve the filtration performance by narrowing the ridge interval and enlarging the filtration area as compared with the case where the backwashing method is adopted.

  In this embodiment, when the filter 12 having a two-layer structure in which the outer surface of the film layer 12m is covered with a protective layer 12c having a coarser mesh than the film layer 12m is used, the injection nozzle 20 and the film layer 12m By interposing the protective layer 12c therebetween, the wear of the film layer 12m due to the jetting of the cleaning fluid can be reduced. Moreover, even if such a protective layer 12c is present, the cleaning effect is sufficiently exhibited because the eyes are coarser than the film layer 12m.

  Furthermore, in this embodiment, since a part of the stock solution W1 is supplied to the spray nozzle 20 and sprayed as a cleaning fluid, there is no loss and the concentrated solution W3 is diluted compared to backwashing using the filtrate W2. Since it can be taken out without any problems, the concentration factor is high.

  On the other hand, the washed-out deposits from the filter 12 are discharged from the concentrate discharge port 14 together with the concentrate W3. In particular, as shown in the figure, if the injection nozzle 20 is inclined downward, the partition walls 19 are provided on both sides of the injection nozzle 20, and the concentrate discharge port 14 is provided at the lower end between the partition walls 19, the wash-off is performed. There is an advantage that the adhered matter is easily discharged without reattaching to the filter 12.

(Use)
The filter device 10 according to the present embodiment is used in various apparatuses, for example, in civil engineering work, building work, general work, factory wastewater and process wastewater treatment, pretreatment of various operations, various surface treatments, water purification. It can be incorporated and used in steel factories.

  Specifically, for example, tunnel premises drainage, spraying concrete drainage, die slime recovery drainage, batcher plant drainage, river construction dry pit drainage, deep foundation drainage, grout drainage, shield drainage, shield surplus mud , Landfill drainage, caisson construction drainage, cast-in-place drainage, floor surface drainage, well point construction drainage, foundation yard drainage, tire cleaning drainage, core boring drainage, diamond cutter drainage, soil contamination excavation yard drainage, VOC decomposition Cleaning wastewater, incinerator demolition cleaning wastewater, radioactive decontamination work wastewater, wire saw cutting wastewater, water jet cutting wastewater, paper mill process wastewater, pulp factory process wastewater, food factory wastewater, ready-mix factory wastewater, concrete Next Product Factory Wastewater, Crushed Stone Factory Yard Wastewater, Gas Cleaning Scrub Wastewater, waste incinerator quenching tower wastewater, converter gas washing wastewater, arc furnace gas washing wastewater, silver recovery process wastewater, sandwashing equipment wastewater, water washing neutralization wastewater, barrel polishing wastewater, electropolishing wastewater, glass polishing wastewater, wet blasting Drainage, spray painting booth drainage, cation painting drainage, stainless steel pickling drainage, raw material yard drainage, raw material conveyor cleaning drainage, accumulated dust wet recovery drainage, factory yard drainage, continuous casting drainage, rolling cooling drainage, dehumidifying drainage drainage, immersion cutting yard Drainage, slag yard drainage, ship bottom bilge drainage, shipbuilding dog drainage, shellfish drainage, cooling tower blow drainage, dyeing factory drainage, milk plant washing drainage, tunnel wall washing drainage, building exterior wall washing drainage, car wash drainage, golf course drainage, It can be used when filtering wastewater such as industrial landfill leachate.

  Moreover, the filtration apparatus 10 of this form is used for, for example, well water pretreatment, river water pretreatment, RO membrane pretreatment, crude salt water purification, seawater intake purification, plating solution purification, pickling solution purification, and hydroponics. Sanitization purification, sanitization purification for drip cultivation, fish farming pool sanitization purification, milking washing sanitization purification, vegetable sanitization washing, pool sanitization cleaning, hot spring facility sanitization purification, machine tool coolant liquid purification, seabed drilling purification, water It can be used for magnesium oxide recovery, EP dust cleaning recovery, plating sludge recovery, floor flood disaster recovery, etc. Furthermore, the filtration device 10 of the present embodiment can be used by being incorporated into, for example, a bottle washing device, a silicon wafer cutting device, an electric discharge machine, a ballast water treatment device, or the like.

(Test results)
As a result of conducting a turbid water filtration test using a backwashing filtration device of the same scale and a filtration device of the illustrated form, it is possible to improve the membrane flux by about 4 times and the amount of treated water by about 6 times. did it.

  The present invention is applicable as a filtration device for filtering a stock solution such as turbid water.

  W1 ... undiluted solution, W2 ... filtrate, W3 ... concentrate, 10 ... filtration device, 11 ... filtration container, 11b ... bush, 11t ... rotary table, 12 ... filter, 12c ... protective layer, 12m ... membrane layer, 12r ... filtrate passage , 13 ... Stock solution supply port, 13P ... Stock solution pump, 14 ... Concentrate discharge port, 15 ... Filtrate discharge pipe, 16 ... Connection body, 16f ... Flange, 16r ... Ring elastic body, 17 ... Rotation drive source, 17s ... Drive Shaft, 18 ... Stock solution outlet, 18P ... Washing pump, 19 ... Partition wall, 20 ... Injection nozzle, 21 ... Cylindrical support, 22 ... Top plate, 22x ... Filtrate outlet, 23 ... Bottom plate.

Claims (4)

A filtration container;
A filter provided in the filtration container, the outer surface of which is a filtration surface and having a filtrate passage inside;
Stock solution supply means for supplying a stock solution between the inner surface of the filtration container and the outer surface of the filter;
A filtrate discharge path for discharging filtrate from the filtrate passage inside the filter to the outside of the filtration container;
A concentrate discharging means for discharging the concentrate from between the inner surface of the filtration container and the outer surface of the filter;
A filtration device comprising:
The filter is a pleated filter formed by winding a flat filter medium in a zigzag shape and wound in a cylindrical shape, and the central axis is provided in the filtration container in a posture along the vertical direction, and the central axis is a rotation center. It can be rotated,
An injection nozzle that sprays a cleaning fluid against the filtration surface of the filter is provided, and the filter is rotatably provided so that the filtration surface passes through a spraying range of the cleaning fluid from the injection nozzle .
The said spraying nozzle sprays a cleaning fluid toward the diagonally downward from the slit-shaped spraying opening along the direction of the crease | fold of the said pleat filter, The filtration apparatus characterized by the above-mentioned. The filtration device according to claim 1 , wherein the filter is made of a filter medium having a two-layer structure in which an outer surface of the membrane layer is covered with a protective layer having a coarser mesh than the membrane layer. The filtration device according to claim 1 or 2 , wherein a part of the undiluted solution supplied to the filtration container is supplied to the injection nozzle and injected as the cleaning fluid. In the filtration container, a filter having an outer surface as a filtration surface and having a filtrate passage inside is provided.
The undiluted solution is supplied between the inner surface of the filtration container and the outer surface of the filter, and the filtrate is discharged to the outside of the filtration container from the filtrate passage inside the filter, and the inner surface of the filtration container and the outer surface of the filter Drain the concentrate from between,
A filtration method comprising:
The filter is a pleated filter formed by winding a flat filter medium in a zigzag shape and wound in a cylindrical shape, and the central axis is provided in the filtration container in a posture along the vertical direction, and the central axis is a rotation center. It can be rotated,
While performing filtration, the cleaning fluid is sprayed from the spray nozzle provided outside the filter to the filter surface of the filter, and the filter surface is passed through the spraying range of the cleaning fluid from the spray nozzle. There line regeneration of the filter by rotating,
The filtration method , wherein the spray nozzle sprays a cleaning fluid obliquely downward from a slit-shaped spray port along a crease direction of the pleated filter .

Images