JP2013233484A - Membrane filtration apparatus using membrane module and method of cleaning filter membrane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a membrane filtration apparatus capable of improving performance of cleaning a membrane module and a method of cleaning a filter membrane.SOLUTION: A membrane filtration apparatus 1 includes a membrane module unit 7 comprising two or more membrane modules 5 arranged at constant intervals in an immersion vessel 3 and an air diffuser 11 arranged below the membrane module unit 7 in the immersion vessel 3 and discharging air toward the membrane surface of the membrane modules 5. The apparatus 1 also has a water discharging unit 15 arranged above the membrane module unit 7 and discharging cleaning water toward the membrane surface of the membrane modules 5. The water discharging unit 15 is set in such a way as to discharge cleaning water when at least a part of the membrane modules 5 is exposed to the air from to-be-treated water W in the immersion vessel 3.

Description

  The present invention relates to a membrane filtration device using a membrane module and a filtration membrane cleaning method, and in particular, a membrane filtration device using a membrane module that filters a highly turbid and highly viscous liquid, and a filtration membrane of such a membrane filtration device The present invention relates to a cleaning method.

  In recent years, membrane separation methods have been used in various fields for the purpose of energy saving, space saving, labor saving and improvement of filtered water quality. Examples of membrane separation methods include the application of microfiltration membranes and ultrafiltration membranes to water purification processes that produce industrial water and tap water from river water, groundwater and treated sewage, and seawater desalination reverse osmosis Application to pretreatment in the film treatment process is mentioned.

  When the raw water is filtered using the membrane separation method, the turbidity and organic matter contained in the raw water accumulate on the membrane surface, and the membrane clogging occurs, so the membrane filtration performance increases as the membrane filtration resistance increases. Decreases. Therefore, it is necessary to clean the membrane in order to maintain the membrane filtration performance of the membrane filtration device. As a film cleaning method, for example, those described in Patent Documents 1 to 4 are known.

JP 2007-289940 A JP 2001-79366 A JP 11-342320 A Japanese Patent Laid-Open No. 10-15365

  In Patent Document 1, after the membrane filtration treatment, the membrane is brought into contact with the chemical solution for a certain period of time, and the membrane is exposed to the air by discharging the chemical solution, and then air cleaning and backwashing are performed simultaneously. A method for cleaning a membrane is described. Patent Document 2 describes a method in which backwashing is performed using water containing chlorine, followed by air washing simultaneously with membrane filtration. Patent Document 3 describes a method of performing air cleaning while supplying raw water to the membrane module. Patent Document 4 describes a cleaning method in which chlorine water is allowed to flow backward from the secondary side to the primary side, the chlorine water and the membrane are brought into contact with each other for a certain period of time, and then the chlorine water is discharged.

  However, in the above-mentioned Patent Documents 1 to 4, either air cleaning and back-flow cleaning are performed by exposing the membrane to air, or air cleaning and back-flow cleaning are performed while the membrane is immersed in a liquid. However, there is a problem that a sufficient cleaning effect cannot be obtained.

  Then, this invention is made | formed in order to solve the problem mentioned above, and it aims at providing the membrane filtration apparatus which can improve the washing | cleaning performance of a membrane module, and the washing | cleaning method of a filtration membrane.

  In order to solve the above-described problems, the present invention provides a membrane module unit that is arranged in a dipping bath and in which a plurality of membrane modules are arranged at regular intervals, and is arranged below the membrane module unit in the dipping bath. A membrane filtration device comprising an air diffuser for releasing air toward the membrane surface, comprising a water discharge means disposed above the membrane module unit for discharging cleaning water toward the membrane surface of the membrane module. The means is configured to discharge cleaning water when at least a part of the membrane module is exposed to the gas from the water to be treated in the immersion tank.

  According to the present invention configured as described above, when at least a part of the membrane module is exposed to the gas, the washing water can be discharged from the water discharge means toward the membrane module. And when at least a part of the membrane module is exposed in the gas, the washing water is discharged from the water discharge means toward the membrane surface of the membrane module, so that it adheres to the membrane surface of the membrane module with the water pressure of the washing water. The object to be removed can be removed.

  In the present invention, it is preferable that the water discharge means discharges the cleaning water toward the membrane surface of the membrane module through the gap between adjacent membrane modules among the plurality of membrane modules arranged at regular intervals. Yes.

  According to the present invention configured as described above, the cleaning water can be applied to the membrane surface of the membrane module through the gap between the adjacent membrane modules. As a result, the washing water can be reliably applied to the membrane surfaces of all the membrane modules arranged.

  Preferably, in the present invention, the water discharge means is connected to the first pipe connected to the cleaning water supply means, and the first pipe is connected to the first pipe and extends along a gap between adjacent membrane modules among the plurality of membrane modules. Two pipes and a flush water outlet formed in the second pipe are provided.

  According to the present invention configured as described above, washing water can be reliably applied to the membrane surfaces of all the membrane modules arranged using a membrane filtration device having a simple structure.

  Preferably, in the present invention, the membrane module unit is provided with lifting means for lifting the membrane module unit upward, and the water discharge means is configured such that the membrane module unit is lifted by the lifting means, and at least a part of the membrane module is gas from the water to be treated in the immersion tank. It is designed to discharge cleaning water when exposed inside.

  According to the present invention thus configured, the membrane module can be lifted upward by the lifting means. And in the state which the membrane module was lifted, the membrane surface of a membrane module can be wash | cleaned using a water discharge means. Thereby, the membrane module can be washed above the immersion tank, and the washing water can be prevented from scattering around the immersion tank.

  In the present invention, it is preferable that the lifting means includes a weight measuring means for measuring the weight of the membrane module unit to be lifted.

  According to the present invention configured as described above, by measuring the weight of the membrane module unit after washing, it is possible to calculate the weight of turbidity adhering to the membrane module unit. You can know the cleaning effect.

  In the present invention, preferably, a plurality of membrane module units are arranged, and provided with moving means for moving the water discharge means above the plurality of arranged membrane module units.

  According to the present invention configured as described above, since the water discharge means can be moved by the moving means, a plurality of membrane module units can be washed by one water discharge means.

  In order to solve the above-described problems, the present invention provides a membrane module unit in which a plurality of membrane modules are arranged at regular intervals in a dipping bath, and a membrane arranged below the membrane module unit in a dipping bath. An air diffuser that releases air toward the membrane surface of the module, and a membrane filter that uses a membrane filtration device that is disposed above the membrane module unit and has a water discharge means that discharges cleaning water toward the membrane surface of the membrane module. In this cleaning method, at least a part of the membrane module is exposed to the gas from the water to be treated in the immersion bath, and the membrane module is discharged and washed by discharging the cleaning water from the water discharge means.

  According to the present invention configured as described above, when at least a part of the membrane module is exposed to the gas, the washing water can be discharged from the water discharge means toward the membrane module. And when at least a part of the membrane module is exposed in the gas, the washing water washing water is discharged from the water discharge means toward the membrane surface of the membrane module, so that it adheres to the membrane surface of the membrane module with the washing water washing water pressure. The removed object can be removed.

  In the present invention, preferably, after the water discharge cleaning, the immersion tank is filled with the water to be treated, and the air diffuser is operated to perform the air diffusion cleaning.

  According to the present invention configured as described above, the membrane module can be cleaned by two different cleaning methods, namely, water discharge cleaning and aeration cleaning. Thereby, a membrane module can be washed more effectively.

  Further, in the present invention, preferably, the water discharge cleaning and the aeration cleaning are repeatedly performed at least twice.

  According to the present invention configured as described above, the membrane module can be more effectively cleaned by repeatedly performing water discharge cleaning and air diffusion cleaning.

  In the present invention, preferably, after performing water discharge cleaning, the pressure loss of water to be treated that passes through the membrane module is monitored, and when the pressure loss is greater than a predetermined value, water discharge cleaning is performed again. .

  According to the present invention configured as described above, the cleaning state of the membrane module can be monitored by monitoring the pressure loss of the water to be treated that passes through the membrane module. And when washing | cleaning of a membrane module is inadequate, water discharge washing | cleaning can be performed again.

  In the present invention, preferably, the membrane filtration device includes a lifting means for lifting the membrane module unit upward, and when performing water discharge cleaning, the membrane module unit is lifted by the lifting means, and at least a part of the membrane module is immersed in the immersion tank. The cleaning water is discharged after being exposed to gas from the water to be treated.

  According to the present invention thus configured, the membrane module can be lifted upward by the lifting means. And in the state which the membrane module was lifted, the membrane surface of a membrane module can be wash | cleaned using a water discharge means. Thereby, the membrane module can be washed above the immersion tank, and the washing water can be prevented from scattering around the immersion tank.

  In the present invention, preferably, after performing water discharge cleaning, the membrane module is immersed in the water to be treated in the immersion tank, and the air diffuser is operated to perform the air diffusion cleaning.

  According to the present invention configured as described above, the membrane module can be cleaned by two different cleaning methods, namely, water discharge cleaning and aeration cleaning. Thereby, a membrane module can be washed more effectively.

  Further, in the present invention, preferably, the water discharge cleaning and the aeration cleaning are repeatedly performed at least twice.

  According to the present invention configured as described above, the membrane module can be more effectively cleaned by repeatedly performing water discharge cleaning and air diffusion cleaning.

  In the present invention, preferably, the membrane filtration device includes a weight measuring unit for measuring the weight of the membrane module unit to be lifted, and after performing water discharge cleaning or aeration cleaning, the membrane module is used by the weight measuring unit. When the membrane module unit has not been sufficiently cleaned according to the measurement result, water discharge cleaning or aeration cleaning is performed again.

  According to the present invention configured as described above, after the water discharge cleaning or the aeration cleaning is performed once, the weight of the membrane module unit is measured, and the water discharge cleaning or the aeration cleaning is performed again according to the measurement result. be able to. If the cleaning effect in the water discharge cleaning or aeration cleaning performed earlier is insufficient and the object to be removed is not sufficiently removed from the membrane module, the weight of the membrane module unit remains relatively heavy. End up. In this case, the water discharge cleaning or the aeration cleaning can be performed again.

  In the present invention, the washing water is preferably water to be treated or filtered water filtered by a membrane filtration device.

  As described above, according to the present invention, the cleaning performance of the membrane module can be improved.

It is a block diagram which shows the membrane filtration apparatus by the 1st Embodiment of this invention. It is a perspective view showing a membrane module and a water discharge device of a membrane filtration device by a 1st embodiment of the present invention. It is a side view showing a membrane module and a water discharge device of a membrane filtration device by a 1st embodiment of the present invention. It is a side view which shows the membrane filtration apparatus by the 2nd Embodiment of this invention. It is a side view which shows the membrane filtration apparatus by the 3rd Embodiment of this invention.

  Hereinafter, a membrane filtration device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a membrane filtration device according to the first embodiment.

  First, as shown in FIG. 1, the membrane filtration device 1 includes an immersion tank 3 that stores the water to be treated W, and a membrane module unit 7 that has a plurality of membrane modules 5 that are immersed in the water to be treated in the immersion tank 3. A diffuser 11 that is disposed below the membrane module unit 7 and discharges air supplied from the air supply source 9 toward the membrane module unit 7, and cleaning water supplied from the cleaning water supply source 13. And a water discharge device 15 for discharging.

FIG. 2 is a perspective view showing a membrane module and a water discharge device of the filtration device.
As shown in FIG. 2, the membrane module unit 7 includes a plurality of membrane modules 5 arranged with a constant interval. Each membrane module unit 7 has a hollow fiber membrane 17 arranged in a sheet shape, and a water collection pipe 19 for collecting filtrate water filtered by the hollow fiber membrane 17. Each membrane module 5 is arranged so that its membrane surface faces the membrane surface of the adjacent membrane module 5. Each membrane module 5 is held at a predetermined position by holding means (not shown), and a fixed gap S is formed between the membrane modules 5 by the holding means. The gap S between the adjacent membrane modules 5 is for allowing the water to be treated W and the air discharged from the air diffuser 11 to pass between the adjacent membrane modules 5 satisfactorily. If this gap S is too narrow, there is a risk that the accumulation of contaminants and sludge between the membrane modules 5 will be accelerated. On the other hand, if the gap S is too wide, the installation efficiency of the membrane module 5 will be reduced. Accordingly, the gap S between the adjacent membrane modules 5 is an element that is appropriately determined according to the properties of the water to be treated W, but is preferably 2 mm to 30 mm.

  The membrane module 5 is formed by fixing a laminate of hollow fiber membranes 17 arranged in a sheet shape to a water collecting pipe 19 with a fixing resin. One end of the hollow fiber membrane 17 is cut and opened, and the inside of the hollow fiber membrane 17 communicates with the inside of the water collecting pipe 19.

  The material of the hollow fiber membrane 17 is not particularly limited, and examples thereof include polysulfone resins, polyacrylonitrile, cellulose derivatives, polyolefins such as polyethylene and polypropylene, fluorine resins such as polyvinylidene fluoride and polytetrafluoroethylene, Examples include chlorinated resins such as polyvinyl chloride and polyvinylidene chloride, polyamides, polyesters, polymethacrylates, and polyacrylates. In addition, copolymers of these resins or those having a substituent introduced into a part thereof may be used. Furthermore, what mixed 2 or more types of resin may be used. In addition, as long as it is a hollow fiber membrane that can be used as a filtration membrane, its pore diameter, porosity, film thickness, outer diameter and the like are not particularly limited, but for example, the outer diameter is 20 to 4000 μm, the pore diameter Is preferably 0.001 to 5 μm, the porosity is 20 to 90%, and the film thickness is preferably 5 to 300 μm. The length of the hollow fiber membrane is preferably in the range of 200 mm to 2000 mm from the viewpoint of handleability, and is preferably determined appropriately from the inner diameter and outer diameter of the hollow fiber membrane to be used, the water passage performance and the filtration performance depending on the use conditions. . Similarly, the number of hollow fiber membranes constituting the hollow fiber membrane bundle is preferably determined as appropriate from the water passage performance and filtration performance depending on the use conditions.

  Further, the separation membrane of the membrane module 5 is not limited to a hollow fiber membrane, and a flat membrane, a tubular membrane, a spiral membrane, or the like may be used.

  The water collecting pipe 19 of the membrane module 5 communicates with the open end of the membrane module 5 and collects filtrate water therein. The size of the water collecting pipe 19 is preferably 100 mm or less, and 75 mm or less, so that the water W to be treated can flow between the adjacent membrane modules 5 by forming a gap. Is more preferable. Moreover, it is preferable that the cross-sectional area of the water collecting pipe 19 is determined by ensuring the cross-sectional area of the internal space through which liquid can flow and the thickness of the fixing resin. The thickness of the water collecting pipe 19 with respect to the thickness of the fixing resin is not particularly limited as long as the pressure resistance required for the membrane module 5 and the thickness of the fixing portion of the hollow fiber membrane 17 can be satisfied. The range of 1-20 mm is preferable, and the range of 1-15 mm is more preferable. Moreover, it is preferable that the fixing resin and the water collecting pipe 19 satisfy mechanical characteristics such as repeated pressure resistance required by the use of the membrane module 5 when the hollow fiber membrane 17 is fixed to the water collecting pipe 19.

  As shown in FIGS. 1 and 2, the water discharge device 15 includes a first pipe 21 connected to the cleaning water supply source 13, a plurality of second pipes 23 connected to the first pipe 21, and a plurality of second pipes 23. 2 and a support member 25 supporting the tip of the pipe 23. The water discharge device 15 discharges the cleaning water supplied from the cleaning water supply source 13 toward the membrane surface of the membrane module 5. The cleaning water supply source 13 is configured to pressurize and supply cleaning water to the water discharge device 15 using, for example, a pump. If the pressurized pressure of the washing water at this time is too high, the discharged water pressure from the water discharging device 15 is increased, and the hollow fiber membrane 17 may be damaged. On the other hand, if the pressurized pressure is too low, sufficient washing is performed. The effect cannot be expected. Therefore, the water pressure when supplying the cleaning water from the cleaning water supply source 13 to the water discharging device 15 is preferably adjusted so that the water pressure of the cleaning water discharged from the discharge device 15 is 30 kPa or more and 400 kPa or less.

  Moreover, the 1st piping 21 of the water discharging apparatus 15 is extended along the sequence direction of the membrane module 5, The several 2nd piping 23 is connected to the side part. The second pipe 23 extends orthogonally to the first pipe 21. Further, the second pipe 23 is attached to the first pipe 21 so as to be positioned above the gap S between the adjacent membrane modules 5. A plurality of water outlets 27 are formed at the bottom of the second pipe 23 for discharging the wash water flowing from the first pipe 21. The plurality of water outlets 27 are arranged along the extending direction of the second pipe 23 at the bottom of the second pipe 23. Therefore, the water outlet 27 formed at the bottom of the second pipe 23 is located directly above the gap S between the adjacent membrane modules 5.

  The water outlet 27 is configured to discharge the wash water flowing into the second pipe 23 toward the membrane surface of the membrane module 5. As the water discharge port 27, one having a shape that diffuses and discharges wash water can be used. By using such a water outlet 25, the entire membrane surface can be cleaned. Alternatively, only one water outlet 27 may be formed in the second pipe 23 and the water outlet 27 may be moved in the axial direction of the second pipe 23. The liquid used as the washing water is preferably fresh water, but filtered water filtered by the membrane filtration device 1 or water to be treated W before filtration may be used.

  Next, the effect | action of the membrane filtration apparatus 1 mentioned above is explained in full detail.

  In the membrane separation process, a negative pressure is applied to the water collection pipe 19 of the membrane module 5 in a state where the membrane module unit 7 is immersed in the water to be treated W in the immersion tank 3. Thereby, the to-be-processed water W around the hollow fiber membrane 17 is filtered through the hollow fiber membrane 17 and flows into the water collection pipe 19. And the filtered water inside the water collection pipe 19 is taken out from the membrane module unit 7 through a water intake (not shown).

  Then, after performing the membrane separation process for a certain time, the membrane module 5 is cleaned.

  In the cleaning treatment, the water to be treated W in the immersion tank 3 is discharged, and a part or all of the membrane module 5 is exposed from the water to be treated W to make the surroundings of the membrane surface a gaseous environment. Then, the water discharge device 15 is operated to discharge the cleaning water supplied from the cleaning water supply source 13 from the water discharge port 27 of the second pipe 23. Then, the discharged washing water is discharged toward the membrane surface, whereby the removal target adhered to the membrane surface can be removed from between the membrane surface and the hollow fiber membrane. And after operating the water discharging apparatus 15 for the predetermined time, the water discharging apparatus 15 is stopped, and after the immersion tank 3 is again filled with the to-be-processed water W, the membrane separation process is restarted. Further, the membrane filtration device 1 performs membrane cleaning using the air diffuser 11 in addition to membrane cleaning using the water discharge device 15. In membrane cleaning using the air diffuser 11, the membrane separation process is temporarily stopped, and then air is released from the air diffuser 11 toward the membrane surface. And the hollow fiber membrane 17 is shaken with this air, and the removal target object adhering to the surface of the hollow fiber membrane 17 is removed.

  As described above, by providing the water discharge device 15 above the membrane module 5 and cleaning with the cleaning water discharged from the water discharge device 15, the cleaning efficiency of the membrane module 5 can be increased. Further, since the water discharge device 15 can discharge the washing water along the extending direction of the hollow fiber membranes constituting the membrane module 5, the removal target sandwiched between the surface of the hollow fiber membrane 17 and the hollow fiber membrane 17. Things can be washed efficiently. Further, the membrane module 5 can be removed from the holding means during the cleaning process of the membrane module 5 by draining the water to be treated in the immersion bath 3 once and allowing the membrane module 5 to be cleaned in the immersion bath 3. Thus, it is not necessary to separately secure a space for cleaning the detached membrane module 5. Moreover, since the removal target object detached from the membrane module 5 when the membrane module 5 is washed remains in the immersion tank 3 as it is, it is possible to prevent the removal target object from being scattered. Processing can be performed easily.

  Further, in order to further improve the cleaning efficiency of the membrane module 5, the cleaning treatment is once performed by the water discharge device 15 to fill the immersion tank 3 with the water to be treated, and then the aeration device 11 is further operated to clean the membrane module 5. It is preferable to do. Confirmation of the cleaning effect at this time can be performed by visual confirmation, monitoring the pressure during filtration operation, or monitoring the weight of the membrane module 5.

  As a method of monitoring the pressure during the filtration operation, there is a method of cleaning the membrane module 5 and then passing the treated water W through the membrane module 5 and monitoring the pressure loss at that time. When the pressure loss of the membrane module 5 is higher than, for example, a predetermined value, the membrane module 5 has not been sufficiently cleaned. Therefore, the membrane separation process can be stopped and the cleaning process can be performed again. When performing the washing treatment again, the membrane filtration device 1 once drains the water to be treated in the immersion tank 3, cleans the membrane surface with the water discharge device 15, and then fills the inside of the immersion tank with the water to be treated again. Monitor the pressure loss of the membrane module. Alternatively, the membrane module 5 may be cleaned using the air diffuser 11 before starting to monitor the pressure loss of the membrane module 5. And when pressure loss does not fully fall, washing with water discharger 15 and washing with diffuser 11 can be performed repeatedly.

  Next, a second embodiment of the present invention will be described in detail. FIG. 4 is a side view showing the membrane filtration device according to the second embodiment.

  As shown in FIG. 4, the membrane filtration device 31 includes a lifting device 33 that lifts the membrane module unit 7 disposed in the immersion tank 3 upward. The lifting device 33 lifts the air diffuser 11 attached to the membrane module unit 7 together with the membrane module unit 7.

  The lifting device 33 includes a hook portion 35 attached to the membrane module unit 7 and a weight measuring device 37 for measuring the weight of the lifted membrane module unit 7. Further, the water discharge device 15 is attached to the lifting device 33. In the water discharge device 15, when the membrane module unit 7 is lifted, the water discharge port 27 is positioned directly above the gap S between adjacent membrane modules 5.

Next, the operation of the membrane filtration device 31 according to the second embodiment will be described in detail.
When performing the cleaning process, the membrane filtration device 31 stops the membrane separation process and moves the lifting device 33 to above the membrane module unit 7. The hook unit 35 of the lifting device 33 is hooked on the membrane module unit 7 to connect the lifting device 33 and the membrane module unit 7. Then, the lifting device 33 is operated to lift the membrane module unit 7 upward so that the membrane module 5 is exposed in the gas from the water W to be treated in the immersion bath 3. Then, the water discharge device 15 is operated to discharge the cleaning water cleaning water from the water outlet 27 toward the membrane surface. Thereby, the membrane module 5 can be cleaned.

  Further, when the cleaning process is performed, the weight measuring device 37 measures the weight of the membrane module unit 7 before cleaning and the weight of the membrane module unit 7 after cleaning, and compares the two, thereby comparing the membrane module unit 7. It is possible to detect the weight of the object to be removed that can be detached from the object. When the membrane module 5 is washed by the water discharge device 15, the total weight of the membrane module unit 7 lifted by the lifting device 33 is reduced. And the membrane filtration apparatus 31 performs a washing process until the weight of the membrane module unit 7 becomes a predetermined weight, or until the variation | change_quantity of a weight becomes smaller than the predetermined amount. In this case, it is preferable to measure the weight of the membrane module unit 7 after stopping the cleaning process so that the measurement result by the weight measuring device 37 does not have an error due to the water pressure of the cleaning water.

  Thus, the membrane module unit 7 is lifted using the lifting device 33 and the cleaning process is performed, so that the cleaning efficiency of the membrane module 5 can be increased in the same manner as the membrane filtration device 1 according to the first embodiment. Further, the water discharge device 15 is attached to the lifting device 33, and at the time of the cleaning process, the water discharge device 15 comes into contact with the water to be treated W in the immersion tank 3 by lifting the membrane module unit 7 with the lifting device 33 so that the membrane module unit 7 can be cleaned. Can reduce the opportunity to do. Thereby, it can prevent that the water discharging apparatus 15 deteriorates with the to-be-processed water W, or the water outlet 27 of the water discharging apparatus 15 is clogged. Further, by performing the cleaning process while monitoring the weight of the membrane module unit 7 by the weight measuring device 37, it is possible to improve the cleaning efficiency and prevent the processing capacity during the membrane separation from being lowered.

Next, a third embodiment of the present invention will be described in detail.
FIG. 5 is a side view showing a membrane filtration device according to the third embodiment. The membrane filtration device 41 according to the third embodiment has a plurality of membrane module units 7a, 7b, 7c arranged in the immersion tank 3, and a diffuser provided corresponding to each membrane module unit 7a, 7b, 7c. The apparatus 11a, 11b, 11c, the water discharging apparatus 15 arrange | positioned above the immersion tank, and the moving apparatus 43 for moving the water discharging apparatus 15 are provided.

  The plurality of membrane module units 7a, 7b, 7c are arranged in a straight line so that the membrane surfaces of the membrane modules 5 are parallel to each other. Therefore, the gap S between adjacent membrane modules 5 is also parallel to the membrane surface.

  The moving device 43 includes two guide rails 45 extending along the arrangement direction of the membrane module units, and a drive unit 47. The moving device 43 moves the water discharge device 15 along the guide rail 45, that is, along the arrangement direction of the membrane modules 5.

  The water discharge device 15 conveyed by the moving device 43 only needs to have at least one second pipe and a plurality of water discharge ports formed therein. At the time of the cleaning process, the water discharging device 15 is moved along the guide rail 45 by the moving device 43 while passing above all the membrane modules 5. Thereby, the water discharging apparatus 15 can be passed over all the gaps S between the membrane modules 5. Thereby, all the membrane modules 5 of the plurality of membrane module units 7 arranged can be cleaned.

1, 31, 41 Membrane filtration device 5 Membrane module 7 Membrane module unit 11 Air diffuser 15 Water discharge device 17 Hollow fiber membrane 19 Water collecting pipe 21 First pipe 23 Second pipe 27 Water outlet 33 Lifting device 43 Moving device

Claims (15)

A membrane module unit arranged in a dipping tank and arranged with a plurality of membrane modules at regular intervals;
A membrane filtration device comprising an air diffuser that is disposed below the membrane module unit in the immersion tank and discharges air toward the membrane surface of the membrane module;
A water discharge means that is disposed above the membrane module unit and discharges cleaning water toward the membrane surface of the membrane module;
The water discharging means is a membrane filtration device that discharges the cleaning water when at least a part of the membrane module is exposed to the gas from the water to be treated in the immersion tank.   The said water discharge means discharge | releases wash water toward the membrane surface of the said membrane module through the clearance gap between adjacent membrane modules among these membrane modules arranged at fixed intervals. The membrane filtration apparatus described.   The water discharge means includes a first pipe connected to the cleaning water supply means, a second pipe connected to the first pipe and extending along a gap between adjacent membrane modules among the plurality of membrane modules, and the first pipe. The membrane filtration device according to claim 1, further comprising a flush water outlet formed in the two pipes.   The membrane module unit includes lifting means for lifting the membrane module unit upward, and the water discharge means is configured such that the membrane module unit is lifted by the lifting means, and at least a part of the membrane module enters the gas from the water to be treated in the immersion tank. The membrane filtration device according to any one of claims 1 to 3, wherein the washing water is discharged when exposed.   The membrane filtration device according to claim 4, wherein the lifting means includes weight measuring means for measuring the weight of the membrane module unit to be lifted.   4. The membrane module unit according to claim 1, wherein a plurality of the membrane module units are arranged, and moving means for moving the water discharge means above the plurality of arranged membrane module units. 5. The membrane filtration apparatus described. A membrane module unit arranged in a dipping tank and arranged with a plurality of membrane modules at regular intervals;
An air diffuser that is disposed below the membrane module unit in the immersion tank and discharges air toward the membrane surface of the membrane module;
A method for cleaning a filtration membrane using a membrane filtration device provided with a water discharge means that is disposed above the membrane module unit and discharges cleaning water toward the membrane surface of the membrane module,
A filtration membrane cleaning method, wherein at least a part of the membrane module is exposed to a gas from the water to be treated in the immersion tank, and the cleaning water is discharged from the water discharge means to discharge and wash the membrane module.   The filtration membrane cleaning method according to claim 7, wherein after the water discharge cleaning is performed, the immersion tank is filled with water to be treated, and the air diffuser is operated to perform the air diffusion cleaning.   The method for cleaning a filtration membrane according to claim 7 or 8, wherein the water discharge cleaning and the aeration cleaning are repeated at least twice or more.   The water loss cleaning is performed after the water discharge cleaning, and the pressure loss of the water to be treated that passes through the membrane module is monitored. If the pressure loss is larger than a predetermined value, the water discharge cleaning is performed again. The cleaning method of the filtration membrane of description. The membrane filtration device comprises lifting means for lifting the membrane module unit upward,
When performing the water discharge cleaning, the membrane module unit is lifted by the lifting means, and at least a part of the membrane module is exposed in the gas from the water to be treated in the immersion tank, and then the cleaning water is discharged. The method for cleaning a filtration membrane according to any one of claims 7 to 10.   The filtration according to claim 11, wherein after performing the water discharge cleaning, the membrane module is immersed in water to be treated in the immersion tank, and the air diffuser is operated to perform the air diffusion cleaning. Method for cleaning the membrane.   The filtration membrane cleaning method according to claim 12, wherein the water discharge cleaning and the aeration cleaning are repeatedly performed at least twice.   The membrane filtration device includes a weight measuring unit for measuring the weight of the membrane module unit to be lifted, and after performing the water discharge cleaning or the aeration cleaning, the weight of the membrane module is measured by the weight measuring unit. The filtration membrane according to any one of claims 11 to 13, wherein the membrane module unit is measured and, when the membrane module unit is not sufficiently cleaned, the water discharge cleaning or the aeration cleaning is performed again. Cleaning method.   The method for washing a filtration membrane according to any one of claims 11 to 14, wherein the washing water is filtered water filtered by the treated water or the membrane filtration device.

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