JP4896783B2 - Membrane filtration system and membrane cleaning method - Google Patents

Description

The present invention relates to a membrane filtration system suitable for water treatment of fresh water such as surface water and groundwater, sewage such as rainwater storage water, industrial wastewater and sewage, and seawater such as ballast water, and a membrane cleaning method in the membrane filtration system. .

  Conventionally, in the water treatment field, raw water (fresh water such as surface water and groundwater, rainwater storage, industrial wastewater and sewage such as sewage, seawater such as ballast water) is filtered to obtain domestic water, industrial water, and agricultural water As a method, for example, a membrane such as a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, or a reverse osmosis membrane is used.

  The membrane has a high separation performance with respect to solids such as microorganisms, algae, and clay in the raw water, and its application in the water treatment field is expanding. In recent years, it is common to use a hydrophilic material as the material of the membrane. Even when a hydrophobic material is used, it has been studied to improve the filtration performance by hydrophilizing the membrane surface with a sulfuric acid solution of potassium dichromate or the like (see, for example, Patent Document 1).

  However, when the raw water is continuously passed through the membrane, the solute in the raw water accumulates on the outer surface of the membrane or in the pores of the membrane, and the filtration resistance may increase and the filtration performance may deteriorate.

  Therefore, in such a membrane filtration system, physical cleaning with filtered treated water or compressed air is performed at a preset cycle or when the membrane shows a predetermined differential pressure increase, and the membrane outer surface or membrane pore Of the deposits inside, reversible ones are removed.

  On the other hand, deposits that are difficult to remove by such physical cleaning gradually accumulate on the outer surface of the membrane and in the membrane pores, so when the membrane differential pressure exceeds the preset upper limit value, membrane filtration treatment Is stopped and chemical cleaning is performed to remove deposits that could not be removed by physical cleaning.

And even if chemical cleaning, deposits such as the membrane surface and inside can not be removed, and recovery of membrane differential pressure is not recognized, or when the usage period of the membrane exceeds a certain period, The membrane is replaced when it is judged that it has reached the end of its life.
Japanese Patent Laid-Open No. 5-23553

  In such a membrane filtration system, a membrane in which a polymer material that reversibly expands / shrinks at a predetermined temperature is added to the outer surface side of the membrane substrate in order to suppress the cost required for chemical cleaning and membrane replacement. In addition, it has been studied to wash the deposits on the outer surface of the membrane or in the membrane pores with warm water.

  However, in such a membrane filtration system, most of the polymer material that reversibly expands / contracts at a predetermined temperature is added to the outer membrane surface, and the solute in the raw water into the membrane pores and the inner membrane surface. As a result, it is impossible to prevent the penetration of solutes or to trap the invading solutes in the membrane pores and in the membrane inner surface, so that the effect of washing with warm water cannot be sufficiently obtained. In addition, when the membrane substrate is a hydrophobic material, only the outer surface of the membrane is hydrophilized, and the inside of the membrane pores and the inside surface of the membrane are hydrophobic. There was a problem that performance could not be obtained.

The present invention has been made in view of the above, it improves the effect of the warm water washing, and an object thereof is to provide a method of cleaning a membrane filtration system and film Ru can be obtained good water permeation capacity during water flow .

In order to achieve the above object, a membrane filtration system according to the present invention includes a membrane substrate having a plurality of through holes, a temperature on the outer surface side of the membrane substrate and an inner surface of each through hole. In addition, a container having a pore diameter adjusting material added with a polymer material that reversibly expands / shrinks in response to a change in pH is filled into a container and integrated, and the supplied raw water is subjected to membrane filtration, and treated water. A membrane module to be discharged as a membrane , cleaning means for cleaning the membrane by supplying the raw water or the treated water into the membrane module, and changing the temperature and pH around the pore diameter adjusting material, Condition variable means for expanding the pore diameter adjusting material at the time of filtration and contracting the hole diameter adjusting material at the time of cleaning. The condition variable means adjusts the temperature around the hole diameter adjusting material at the time of cleaning. To do Some of the serial raw or the treated water, characterized in that circulating through the periphery of the membrane module while controlling the temperature.

Also, membrane filtration system of the present invention, as described in claim 2, in a membrane filtration system according to claim 1, wherein the film is provided with the hole diameter adjustment member to the inner surface of the membrane substrate It is characterized by.

Moreover, the membrane filtration system of this invention is the membrane filtration system of Claim 1 or 2 as described in Claim 3 , and detects the surrounding temperature or pH of the said pore diameter adjusting material. Detection means, and control means for controlling the condition variable means so that at least one of the ambient temperature and pH of the hole diameter adjusting material becomes a predetermined target value according to a detection result by the detection means. It is characterized by providing .

According to the membrane cleaning method of the present invention, a membrane substrate having a plurality of through-holes and a response to changes in temperature and pH on the outer surface side of the membrane substrate and on the inner surface of each through-hole. A membrane module that is formed by filling a container with a pore size adjusting material added with a polymer material that reversibly expands / shrinks into a container, integrates the membrane, filters the supplied raw water, and discharges it as treated water. A membrane cleaning method in a membrane filtration system comprising a step of changing the pH of a part of the raw water or the treated water, and supplying the raw water or the treated water whose pH has changed into the membrane module, A process of shrinking the hole diameter adjusting material by changing the temperature around the hole diameter adjusting material by circulating a part of the raw water or the treated water through the periphery of the membrane module while adjusting the temperature. When, characterized in that it comprises a step of discharging the water supplied into the membrane module.

According to the membrane cleaning method of the present invention, as described in claim 5 , a temperature is applied to the membrane substrate having a plurality of through holes, and to the outer surface side, the inner surface side, and the inner surfaces of the respective through holes. In addition, a container having a pore diameter adjusting material added with a polymer material that reversibly expands / shrinks in response to a change in pH is filled into a container and integrated, and the supplied raw water is subjected to membrane filtration, and treated water. A method for cleaning a membrane in a membrane filtration system comprising a membrane module that discharges as: a step of changing the pH of a part of the raw water or the treated water; and the raw water or the treated water whose pH has been changed to the membrane module While supplying the raw water or a part of the treated water, the temperature of the hole diameter adjusting material is changed by circulating the circumference of the membrane module while adjusting the temperature, and the hole diameter is changed. Adjustment A step of shrinking the, characterized in that it comprises a step of discharging the water supplied into the membrane module.

Further, the method of cleaning membranes according to the present invention, as described in claim 6, in the membrane cleaning method according to claim 4 or 5, at least one of the temperature or pH of the surrounding of the pore size adjusting agent A step of detecting, and a step of adjusting so that at least one of a temperature and a pH around the hole diameter adjusting material becomes a predetermined target value according to a detection result in the detecting step. And

  According to the present invention, the solute in the raw water is prevented from entering the inside of the membrane pore and the inside surface of the membrane, and the invading solute is captured by the inside of the membrane pore and the inside surface of the membrane, thereby improving the effect of washing with warm water. Furthermore, by making the outer surface of the membrane through which raw water passes, the inside of the pores, and the inner surface of the membrane hydrophilic, good water permeability can be obtained during water flow.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

<First Embodiment of Membrane>
FIG. 1 shows a first embodiment of a membrane according to the present invention.

  As shown in FIG. 1, a membrane 10A according to this embodiment is made of a polymer material such as polyethylene, and responds to a physical or chemical environmental change with a membrane substrate 1 having a plurality of through holes (membrane pores). And a pore diameter adjusting material 2 to which a polymer material that reversibly expands / contracts is added. An example of the pore diameter adjusting material 2 is N-isopropylacrylamide.

  The membrane substrate 1 and the pore diameter adjusting material 2 are composed of carbon atoms, hydrogen atoms, oxygen atoms, and nitrogen atoms, and reversibly expand / contract in response to physical or chemical environmental changes as shown in FIG. To do. In this embodiment, as shown in FIG. 1, the hole diameter adjusting material 2 is added to the outer surface 1 a side of the membrane substrate 1.

  As shown in Fig. 1 (a), raw water containing solute 3 such as solids (fresh water such as river water, groundwater, lake water, sewage such as rainwater storage, industrial wastewater, sewage, seawater such as ballast water, etc.) By the sieving action of the membrane 10A having pores of 100 μm or less, substances larger than the pores are captured by the membrane surface and the pore diameter adjusting material 2. Examples of the solute 3 contained in the raw water include inorganic substances such as silica colloid, bentonite and clay, bacteria such as Escherichia coli, protozoa such as Cryptosporidium and Giardia, and plankton. These solutes 3 have a carboxyl group, an amino group, a hydroxyl group, and the like.

  In the present embodiment, filtration and backwashing are performed using changes in the expansion / contraction of the polymer chain of N-isopropylacrylamide in response to changes in the physical or chemical environment. That is, using the membrane 10A, raw water containing the solute 3 such as solids is passed from the outer surface 1a side of the membrane, and the solute 3 is separated from the raw water by the sieving action by the holes in the membrane substrate 1. In particular, the solute 3 entering the inside of the membrane hole is captured by the hole diameter adjusting material 2 in the vicinity of the hole on the outer surface 1 a of the membrane substrate 1.

  At the time of backwashing, as shown in FIG. 1 (b), when backwashing from below the membrane surface upward, the temperature of the raw water staying above the membrane surface or the wash water supplied from below the membrane surface The polymer material of the pore diameter adjusting material 2 is expanded / contracted by performing at least one of adjustment and pH adjustment.

  As described above, N-isopropylacrylamide is responsive to temperature and pH.

  Filtration and backwashing are performed by utilizing the change in expansion / contraction of the polymer chain of N-isopropylacrylamide corresponding to such a physical or chemical environmental change. That is, using the membrane 10A of this embodiment, raw water is passed from the outer surface 1a side of the membrane to the inner surface 1c side, and the solute 3 in the raw water is captured on the outer surface 1a side. Thereafter, when backwashing from the inner surface 1c side to the outer surface 1a side of the membrane 10A, by performing at least one of temperature adjustment and pH adjustment on the raw water staying on the outer surface 1a side, The polymer chain of N-isopropylacrylamide is contracted. At this time, the pore diameter of the membrane hole expands (opens) as the polymer chain contracts.

  N-isopropylacrylamide expands due to strong interaction between the amide group and water below the lower critical solution temperature (LCST) at which the property changes, but as the temperature rises, the amide group and water Shrink as hydrogen bonds become unstable.

  The pore size adjusting material 2 of N-isopropylacrylamide has an amide group in its side chain, and expands at about 32 ° C. or less, which is LCST, as shown in FIG. However, as shown in FIG. 2 and FIG. 3B, the shrinkage starts when the temperature exceeds about 25 ° C., and the shrinkage is almost saturated around 40 ° C.

  Further, the pore size adjusting material 2 of N-isopropylacrylamide shrinks as the pH becomes an acidic region, and expands as it becomes a neutral or alkaline region. Therefore, when the pH of the cleaning water is adjusted, the pore diameter adjusting material 2 is preferably contracted by setting the pH of the cleaning water to an acidic region.

  In addition, the membrane differential pressure at this time is usually about 5 to 30 kPa, but according to the “Guidelines for Introducing Membrane Filtration Facilities in Small-Scale Waterworks” of the Water Technology Research Center, “Maximum 150 kPa for microfiltration membranes, In the case of an ultrafiltration membrane, it is said that it is 300 kPa or less.

  As described above, in the conventional film, the solute 3 having a carboxyl group, an amino group, a hydroxyl group, and the like adheres to the film surface by hydrogen bonding, so that it is difficult to remove by simply backwashing. For this reason, at the time of backwashing, by performing at least one of temperature adjustment and pH adjustment of the washing water, it is possible to weaken the bonding force between the solid content 3 and the film surface to facilitate peeling.

  According to the film 10A of the present embodiment, the pore diameter adjusting material 2 added to the outer surface 1a captures deposits on the outer surface 1a of the film substrate 1 in addition to the sieving action by the holes in the film substrate 1, and the film 10A. Intrusion of the solute 3 in the raw water into the membrane hole of the substrate 1 can be prevented, and the effect of washing with warm water can be improved.

The polymer material of the pore diameter adjusting material 2 is (1) a polymer obtained by copolymerizing acrylic acid, 2-carboxyisopropylacrylamide, 3-carboxy-n-propylacrylamide with N-isopropylacrylamide, and (2) N -Vinyl isobutyric acid amide-based polymer, (3) poly-N-alkylacrylamide derivative, (4) copolymer of polyacrylamide derivative represented by polyisopropylacrylamide and polyvinyl derivative, (5) N-vinylisobutyric acid amide, etc. A copolymer of N-vinyl C _3-9 acylamide of N-vinyl C _1-3 acylamide such as N-vinylacetamide, (6) polyacrylamide derivative and poly-N-vinylacylamide, (7) N A polymer of monomers composed of isopropylacrylamide, and N-vinyl A monomer polymer composed of ruisobutyric acid amide can be considered. The pore diameter adjusting material 2 is not limited to these polymers, and may be any polymer material that reversibly expands / contracts in response to physical or chemical environmental changes.

<Second Embodiment of Membrane>
FIG. 4 shows a second embodiment of the membrane according to the invention.

  As shown in FIG. 4, the membrane 10 </ b> B according to this embodiment has a configuration in which the pore diameter adjusting material 2 is added to the membrane hole inner surface 1 b of the membrane substrate 1 in addition to the membrane 10 </ b> A shown in FIG. 1.

  Also in this embodiment, filtration and backwashing are performed by utilizing the change in expansion / contraction of the polymer chain of N-isopropylacrylamide in response to a physical or chemical environmental change. That is, using the membrane 10B, raw water containing the solute 3 such as solid content is passed from the outer surface 1a side of the membrane, and the solute 3 is separated from the raw water by the sieving action by the holes in the membrane substrate 1. In particular, as shown in FIG. 4A, the solute 3 such as a solid component that has entered the hole is captured by the hole diameter adjusting material 2 on the inner surface 1 b of the film hole of the film substrate 1.

  At the time of backwashing, as shown in FIG. 4 (b), when backwashing from below the membrane surface upward, the temperature of the raw water staying above the membrane surface or the wash water supplied from below the membrane surface The polymer material is expanded / contracted by performing at least one of adjustment and pH adjustment.

  According to the membrane 10B of the present embodiment, the pore diameter adjusting material 2 added to the outer surface 1a and the membrane hole inner surface 1b is used to add deposits on the outer surface 1a of the membrane substrate 1 in addition to the sieving action by the holes in the membrane substrate 1. In addition to capturing, intrusion can be captured in the membrane hole of the membrane substrate 1, and the effect of warm water cleaning can be improved. Furthermore, the inside of the membrane hole can be made hydrophilic by the pore diameter adjusting material 2 and the water permeability during water passage can be improved.

<Third Embodiment of Membrane>
FIG. 5 shows a third embodiment of the membrane according to the invention.

  As shown in FIG. 5, the film 10 </ b> C according to this embodiment has a configuration in which the hole diameter adjusting material 2 is added also to the inner surface 1 c side of the film substrate 1 with respect to the film 10 </ b> B shown in FIG. 4.

  Also in this embodiment, filtration and backwashing are performed by utilizing the change in expansion / contraction of the polymer chain of N-isopropylacrylamide in response to a physical or chemical environmental change. That is, using the membrane 10C, raw water containing the solute 3 such as solid content is passed from the outer surface 1a side of the membrane, and the solute 3 is separated from the raw water by the sieving action by the holes in the membrane substrate 1. In particular, as shown in FIG. 5A, the solute 3 such as a solid component that has entered the inner surface 1 c side is captured by the hole diameter adjusting material 2 on the inner surface 1 c side.

  At the time of backwashing, as shown in FIG. 5 (b), when backwashing from below the membrane surface upward, the temperature of the raw water staying above the membrane surface or the wash water supplied from below the membrane surface The polymer material is expanded / contracted by performing at least one of adjustment and pH adjustment.

  According to the membrane 10C of the present embodiment, the solute 3 in the raw water entering the inner surface 1c side of the membrane substrate 1 is captured by the pore diameter adjusting material 2 added to the outer surface 1a, the membrane hole inner surface 1b, and the inner surface 1c. It is possible to improve the effect of washing with warm water. Furthermore, the inner surface 1c side is hydrophilized by the pore diameter adjusting material 2, and the water permeability during water passage can be improved.

<Membrane Module Embodiment>
Next, an embodiment of the membrane module according to the present invention will be described.

  If the membrane shape and the module shape are organized, they can be classified as shown in FIG. This classification is taken from the Water Technology Research Center, “New development of membrane filtration technology for water supply”.

  As shown in FIG. 6, the shape of the membrane module is roughly classified into a casing storage type and a bath immersion type. Furthermore, the module shape loaded in each membrane module is divided into a cylindrical membrane and a flat membrane. The casing-containing cylindrical membrane is divided into a hollow fiber type, a tubular type, and a monolith type, and the flat membrane is divided into a spiral type, a blade and frame type, a vibrating disc type, and a pleated type. The tank immersion type cylindrical membrane is divided into a hollow fiber type and a tubular type, and the flat membrane is divided into a plate and frame type and a rotary disk type.

<First Embodiment of Membrane Module>
FIG. 7 shows a first embodiment of the membrane module according to the present invention.

  As shown in FIG. 7, a large number of films are loaded in the cylindrical casing in the cylindrical casing. As the membrane loaded in the membrane module of the present embodiment, at least one of the membranes 10A, 10B, and 10C shown in FIGS. 1, 4, and 5 is used. Raw water is filtered while passing through the membrane, and separated into membrane filtrate (treated water) and concentrated water (drainage).

  In this case, raw water containing solute 3 such as solids (see Fig. 1) (fresh water such as river water, groundwater, lake water, sewage such as rainwater storage, industrial wastewater, sewage, seawater such as ballast water, etc.) A substance larger than the pores is trapped by the membrane surface and the pore diameter adjusting material 2 by the sieving action of the membrane having pores of 100 μm or less. When integrated into a container, the raw water flows along the membrane surface, the treated water flows in a direction perpendicular to the raw water, and a part of the raw water circulates, or the whole amount is filtered without circulating the raw water. It becomes possible to perform filtration by the total amount filtration method.

<Second Embodiment of Membrane Module>
FIG. 8 shows a second embodiment of the membrane module according to the present invention.

  As shown in FIG. 8, this membrane module is configured by laminating a plurality of planarly formed membrane modules. As shown in FIG. 8A, raw water flows into the module from a flat plate surface. Then, as shown in FIG. 8B, it passes through the membrane and becomes membrane filtered water (treated water). As the membrane loaded in the membrane module of the present embodiment, at least one of the membranes 10A, 10B, and 10C shown in FIGS. 1, 4, and 5 is used. This membrane module can be used in a state where it is immersed in a tank (open type or sealed type) into which raw water flows.

  As described above, according to the first and second embodiments of the membrane module, the membrane filtration area can be increased by forming the membrane into a cylindrical shape or a planar shape and filling and integrating with the container. In addition, the system is simple and the membrane can be easily replaced, and the turbidity of the membrane feed water can be simplified by forming it into a cylindrical or flat shape and immersing the membrane in a tank (open or closed) into which raw water flows. Even if it is high, it can drive stably.

  In the present invention, the membrane is formed into a flat shape or a cylindrical shape, and is filled and integrated into a container. However, the present invention is not limited to this. Examples of integrated shapes include hollow fiber type, tubular type, monolith type, spiral type, plate-and-frame type, vibrating disk type, pleated type, and the like, which are further limited to these shapes. not.

  Moreover, in this invention, the film | membrane is shape | molded by planar shape or cylindrical shape, and it is immersed in the tank (open | release type or sealed type) into which raw | natural water flows. Examples of the shape include a hollow fiber type, a tubular type, a plate and frame type, and a rotary disk type, but are not limited to these shapes.

<First embodiment of membrane filtration system>
FIG. 9 is a block diagram showing a first embodiment of a membrane filtration system according to the present invention.

  The membrane filtration system 100 shown in FIG. 9 uses the membrane module 13 having the configuration shown in FIG. 7, and includes a raw water tank 11 for temporarily storing raw water guided by a water pump (not shown), and raw water in the raw water tank 11. Is supplied to the membrane module 13, a membrane module 13 for membrane filtering raw water guided by the raw water pump 12, and a treated water tank 14 for storing treated water membrane-filtered by the membrane module 13. . In addition, a cleaning water tank 15 that introduces and stores a part of the raw water stored in the raw water tank 11 as cleaning water, a heater 16 that heats the raw water stored in the cleaning water tank 15 to a predetermined temperature, and the raw water tank 11 and a chemical injection facility 17 for injecting chemicals for pH adjustment into the washing water tank 15. Further, a compressor 18 for supplying pressurized air at the time of cleaning is also provided. In addition, V1-V12 in the figure shows the valve | bulb provided in each piping.

  FIG. 10 is a diagram for explaining filtration processing in the membrane filtration system according to the present invention, and FIG. 11 is a diagram for explaining an example of physical cleaning in the membrane filtration system according to the present invention. 10 and FIG. 11, only the portions necessary for explaining the filtration process and physical cleaning in the membrane filtration system 100 shown in FIG. 9 are shown.

  In FIG. 10, the raw water is led to the raw water tank 11 by a water pump not shown. The raw water is introduced into the membrane module 13 by pressurization of the raw water pump 12, and the treated water that has permeated through the membrane module 13 is stored in the treated water tank 14.

  Normal cleaning is performed according to the following procedure described with reference to FIG.

(1) Back pressure process The valve V9 is opened and pressurized air is supplied from the treated water side of the membrane by the compressor 18 to apply pressure to the inner surface side of the membrane.

(2) Backflow process) The valve V6 at the top of the membrane module 13 is opened, and the treated water at the top (secondary side) of the membrane module 13 is pushed out to the raw water side and discharged. The discharged water may be returned to the raw water tank 11 in order to improve the recovery rate.

(3) Air scrubbing step While maintaining the pressure, the valve V8 is opened and pressurized air is supplied from the raw water side lower portion of the membrane module 13 by the compressor 18 for a certain time, and the membrane module 13 is swung by the air.

(4) Drain process After air scrubbing for a certain period of time, the valve V12 and the valve V5 below the membrane module 13 are opened to discharge the water in the membrane module 13. At this time, the adhering substance can be discharged more effectively when the compressed air is kept flowing from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(5) Raw Water Rinsing Valves V1 and V4 and valve V6 above the membrane module 13 are opened, the raw water pump 12 is activated, and the membrane module 13 is rinsed. At this time, rinsing can be performed more effectively if the compressed air is allowed to flow from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(6) Filtration The valve V6 at the top of the membrane module 13 is closed and the filtration side valve V7 is opened to resume filtration. If the compressor 18 is moving in the previous process, it stops.

  In the membrane filtration system 100 shown in FIG. 9, normal cleaning is performed according to the above procedure, and cleaning is performed at a predetermined frequency using at least one of temperature adjustment and pH adjustment by chemical addition according to the following procedure.

(1) Drain process The valve V12 and the valve V5 below the membrane module 13 are opened, and the water in the membrane module 13 is discharged. The discharged water may be returned to the raw water tank 11 in order to improve the recovery rate.

(2) Hot water process The chemical injection facility 17 adds chemicals to the raw water introduced into the raw water tank 11 or the washing water tank 15, and the heater 16 adjusts the temperature to the LCST of the polymer material of the pore diameter adjusting material 2 in the washing water tank 15 A portion of the raw water is circulated by the raw water pump 12 through the raw water side in the membrane module 13. In this way, the pore diameter adjusting material 2 added to the outer surface 1a, the membrane inner surface 1b, and the inner surface 1c of the membrane by adjusting the temperature of the raw water in the membrane module 13 or adding chemicals to the raw water. Is reversibly contracted.

(3) Back pressure / back flow process The valve V9 is opened, and pressurized air from the compressor 18 is supplied from the treated water side of the membrane module 13 to apply pressure to the inner surface side of the membrane. Further, the valve V6 at the upper part of the membrane module 13 is opened, and the treated water at the upper part (secondary side) of the membrane module 13 is pushed out to the raw water circulation line.

(4) Air scrubbing step While maintaining the pressure, the valve V8 is opened and pressurized air is supplied from the raw water side lower portion of the membrane module 13 by the compressor 18 for a certain period of time, and the membrane module 13 is swung by the air.

(5) Drain process After air scrubbing for a certain period of time, the valve V12 and the valve V5 below the membrane module 13 are opened to discharge the water in the membrane module 13. At this time, the adhering substance can be discharged more effectively when the compressed air is kept flowing from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(6) Raw Water Rinsing Valves V1 and V4 and the valve V6 in the circulation line above the membrane module 13 are opened, the raw water pump 12 is activated, and the membrane module 13 is rinsed. The rinse water may be discharged out of the system similarly to the raw water rinsing step in the procedure described with reference to FIG. At this time, rinsing can be performed more effectively if the compressed air is allowed to flow from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(7) Filtration The valve V6 at the top of the membrane module 13 is closed, and the filtration side valve V7 is opened to resume filtration. If the compressor 18 is moving in the previous process, it stops.

  According to the present embodiment, by changing the condition of at least one of the temperature and pH of the raw water flowing into the membrane module 13, it expands / contracts reversibly in response to a physical or chemical environmental change. Depending on the characteristics of the polymer material, the solute 3 captured by the pore diameter adjusting material 2 on the outer surface, the inner surface of the membrane hole, and the inner surface of the membrane module 13 can be effectively discharged out of the system.

<Modification of First Embodiment of Membrane Filtration System>
FIG. 12 is a block diagram showing a modification of the first embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 110 shown in FIG. 12 is different from the membrane filtration system 100 shown in FIG. 9 in that a sensor 19 for detecting the temperature, pH value, etc. of the raw water in the washing water tank 15 and the temperature inside the membrane module 13 are used. In this configuration, a sensor 20 for detecting the pH value and the like, and a monitoring control device 21 for controlling the temperature, the pH value and the like according to the values detected by the sensors 19 and 20 are added.

  The washing procedure in the membrane filtration system 110 is the same as that in the membrane filtration system 100. However, the monitoring controller 21 in the hot water process determines the inside of the membrane module 13 (of the pore diameter adjusting material) according to the detection results of the sensors 19 and 20. The heater 16 and the chemical injection equipment 17 are controlled so that at least one of the ambient temperature and pH becomes a predetermined target value. Here, it is preferable to control at least one of the temperature and the chemical addition amount so that the sum of the cost for changing the temperature and the cost required for the chemical addition is minimized.

  According to this modification, by controlling at least one of the temperature and the chemical addition amount according to the temperature and pH of the raw water flowing into the membrane module 13, the cost for changing the temperature and the cost required for the chemical addition are reduced. While suppressing, it is possible to perform effective filtration and washing taking advantage of the characteristics of the polymer material that reversibly expands / contracts in response to physical or chemical environmental changes.

<Second Embodiment of Membrane Filtration System>
FIG. 13 is a block diagram showing a second embodiment of the membrane filtration system according to the present invention.

  A membrane filtration system 120 shown in FIG. 13 stores water in an outer cylinder 13a provided to cover the periphery of the membrane module 13 via a predetermined space and a washing water tank 15 with respect to the membrane filtration system 100 shown in FIG. The raw water pump 22 is supplied to the outer cylinder 13 a and circulated through the outside of the membrane module 13. The chemical injection equipment 17 injects chemicals into the raw water tank 11 but does not inject into the cleaning water tank 15.

  The filtration process and normal washing in the membrane filtration system 120 are performed in the same procedure as the membrane filtration system 100 described above. Then, cleaning is performed at a predetermined frequency using at least one of temperature adjustment and pH adjustment by chemical addition according to the following procedure.

(1) Drain process The valve V12 and the valve V5 below the membrane module 13 are opened, and the water in the membrane module 13 is discharged. The discharged water may be returned to the raw water tank 11 in order to improve the recovery rate.

(2) Hot water process The raw | natural water which added the chemical | medical agent to the raw | natural water tank 11 is supplied in the membrane module 13. FIG. Further, a part of the raw water in the washing water tank 15 whose temperature is adjusted to the LCST of the polymer material of the pore diameter adjusting material 2 by the heater 16 is supplied to the outer cylinder 13a by the raw water pump 22 and circulated through the outside of the membrane module 13. Let In this way, the pore diameter adjusting material 2 added to the outer surface 1a, the membrane inner surface 1b, and the inner surface 1c of the membrane by adjusting the temperature of the raw water in the membrane module 13 or adding chemicals to the raw water. Is reversibly contracted. The circulation may be stopped when the temperature in the membrane module 13 can ensure LCST or higher in the following steps.

(3) Back pressure / back flow process The valve V9 is opened, and pressurized air from the compressor 18 is supplied from the treated water side of the membrane module 13 to apply pressure to the inner surface side of the membrane. Further, the valve V6 at the upper part of the membrane module 13 is opened, and the treated water at the upper part (secondary side) of the membrane module 13 is pushed out to the raw water circulation line.

(4) Air scrubbing step While maintaining the pressure, the valve V8 is opened and pressurized air is supplied from the raw water side lower portion of the membrane module 13 by the compressor 18 for a certain period of time, and the membrane module 13 is swung by the air.

(5) Drain process After air scrubbing for a certain period of time, the valve V12 and the valve V5 below the membrane module 13 are opened to discharge the water in the membrane module 13. At this time, the adhering substance can be discharged more effectively when the compressed air is kept flowing from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(6) Raw Water Rinsing Valves V1 and V4 and the valve V6 in the circulation line above the membrane module 13 are opened, the raw water pump 12 is activated, and the membrane module 13 is rinsed. The rinsed water may be returned to the washing water tank 15 in order to improve the recovery rate. At this time, rinsing can be performed more effectively if the compressed air is allowed to flow from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(7) Filtration The valve V6 at the top of the membrane module 13 is closed, and the filtration side valve V7 is opened to resume filtration. If the compressor 18 is moving in the previous process, it stops.

  According to the present embodiment, by changing the condition of at least one of the temperature and pH of the raw water in the membrane module 13, it is possible to reversibly expand / contract reversibly in response to a physical or chemical environmental change. Depending on the characteristics of the molecular material, the solute 3 captured by the pore diameter adjusting material 2 on the outer surface of the membrane, the inner surface of the membrane hole and the inner surface of the membrane module 13 can be effectively discharged out of the system.

  In addition, since the temperature inside the membrane module 13 is adjusted by circulating the raw water heated by the heater 16 through the outside of the membrane module 13, the heated raw water can be used effectively and the amount of the heated raw water is saved. can do.

  In the above description, the temperature inside the membrane module 13 is adjusted by circulating the temperature-adjusted raw water through the outside of the membrane module 13, but any method can be used to adjust the temperature of the membrane module 13 itself from the outside. It is not limited to the temperature adjustment method described above.

<Modification of Second Embodiment of Membrane Filtration System>
FIG. 14 is a block diagram showing a modification of the second embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 130 shown in FIG. 14 circulates outside the membrane module 13 and the sensor 19 for detecting the temperature, pH value, etc. of the raw water in the washing water tank 15 with respect to the membrane filtration system 120 shown in FIG. In this configuration, a sensor 23 for detecting the temperature, pH value, and the like of the raw water to be performed and a monitoring control device 21 for controlling the temperature, pH value, etc. according to the values detected by the sensors 19, 23 are added.

  The washing procedure in the membrane filtration system 130 is the same as that in the membrane filtration system 120. However, the monitoring controller 21 in the hot water process determines the inside of the membrane module 13 (the pore diameter adjusting material The heater 16 and the chemical injection equipment 17 are controlled so that at least one of the ambient temperature and pH becomes a predetermined target value. Here, it is preferable to control at least one of the temperature and the chemical addition amount so that the sum of the cost for changing the temperature and the cost required for the chemical addition is minimized.

  According to this modification, by controlling at least one of the temperature and the chemical addition amount according to the temperature and pH of the raw water in the membrane module 13, the cost for changing the temperature and the cost required for the chemical addition are suppressed. However, it is possible to perform effective filtration and washing taking advantage of the characteristics of the polymer material that reversibly expands / contracts in response to physical or chemical environmental changes.

<Third embodiment of membrane filtration system>
FIG. 15 is a block diagram showing a third embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 140 shown in FIG. 15 has a washing water tank 25 that introduces and stores a part of the treated water stored in the treated water tank 14 as washing water with respect to the membrane filtration system 120 shown in FIG. This is a configuration in which a backwash water pump 26 for supplying wash water in the wash water tank 25 to the membrane module 13 from the treated water side is added. Further, the chemical injection equipment 17 for injecting chemicals into the raw water tank 11 is replaced with a chemical injection equipment 27 for injecting chemicals into the washing water tank 25.

  FIG. 16 is a view for explaining another example of physical cleaning in the membrane filtration system according to the present invention. In FIG. 16, only the part necessary for explaining the physical cleaning in the membrane filtration system 140 shown in FIG. 15 is shown.

  The filtration process in the membrane filtration system 140 is performed in the same procedure as that of the membrane filtration system 100 described above, but normal cleaning is performed in the following procedure described with reference to FIG.

(1) Back-pressure water process The treated water in the treated water tank 14 is caused to flow backward from the treated water side of the membrane module 13 by the backwash water pump 26 and from the raw water side below the membrane module 13 or from the raw water side above the membrane module 13. Discharge. At this time, the compressed air is supplied from the raw water side below the membrane module 13 by the compressor 18 to swing the membrane module 13.

(2) Raw Water Rinsing The valves V1 and V4 and the valve V6 above the membrane module 13 are opened, the raw water pump 12 is activated, and the membrane module 13 is rinsed. At this time, rinsing can be performed more effectively if the compressed air is allowed to flow from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(3) Filtration The valve V6 at the top of the membrane module 13 is closed and the filtration side valve V7 is opened to resume filtration. At this time, if the compressor 18 is moving, it stops.

  In the membrane filtration system 140 shown in FIG. 15, normal cleaning is performed by at least one of the procedure described with reference to FIG. 16 or the procedure described with reference to FIG. According to the procedure, washing is performed using at least one of temperature adjustment and pH adjustment by chemical addition.

(1) Back-pressure water process Chemicals are added to the treated water introduced into the washing water tank 25 by the chemical injection equipment 27, and backflowed from the treated water side of the membrane by the backwash water pump 26. Or, it is discharged from the raw water side above the membrane module 13. At this time, the compressed air is supplied from the raw water side below the membrane module 13 by the compressor 18 to swing the membrane module 13.

  At the same time, the raw water in the washing water tank 15 whose temperature has been adjusted to the LCST of the polymer material of the hole diameter adjusting material 2 by the heater 16 is supplied to the outer cylinder 13 a by the raw water pump 22 and circulated through the outside of the membrane module 13. In this way, the pore diameter adjusting material added to the outer surface 1a, the membrane inner surface 1b, and the inner surface 1c of the membrane by adjusting the temperature of the raw water in the membrane module 13 or adding chemicals to the treated water. 2 is reversibly contracted. The circulation may be stopped when the temperature in the membrane module 13 can ensure LCST or higher in the following steps.

(2) Raw Water Rinsing The valves V1 and V4 and the valve V6 above the membrane module 13 are opened, the raw water pump 12 is activated, and the membrane module 13 is rinsed. At this time, the rinsing water may be circulated to the washing water tank 15 on the raw water side. At this time, rinsing can be performed more effectively if the compressed air is allowed to flow from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(3) Filtration The valve V6 at the top of the membrane module 13 is closed and the filtration side valve V7 is opened to resume filtration. If the compressor 18 is moving in the previous process, it stops.

  According to the present embodiment, the polymer material that reversibly expands / contracts in response to a physical or chemical environmental change by changing at least one of temperature and pH in the membrane module 13. Due to this characteristic, the solute 3 captured by the pore diameter adjusting material 2 on the outer surface of the membrane, the inner surface of the membrane hole and the inner surface of the membrane module 13 can be effectively discharged out of the system.

  In addition, since the temperature inside the membrane module 13 is adjusted by circulating the raw water heated by the heater 16 through the outside of the membrane module 13, the heated raw water can be used effectively and the amount of the heated raw water is saved. can do.

  In the above description, the temperature inside the membrane module 13 is adjusted by circulating the temperature-adjusted raw water through the outside of the membrane module 13, but any method can be used to adjust the temperature of the membrane module 13 itself from the outside. It is not limited to the temperature adjustment method described above.

<Modification of Third Embodiment of Membrane Filtration System>
FIG. 17 is a block diagram showing a modification of the third embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 150 shown in FIG. 17 circulates outside the membrane module 13 with the sensor 19 for detecting the temperature, pH value, etc. of the raw water in the washing water tank 15 with respect to the membrane filtration system 140 shown in FIG. In this configuration, a sensor 23 for detecting the temperature, pH value, and the like of the raw water to be performed and a monitoring control device 21 for controlling the temperature, pH value, etc. according to the values detected by the sensors 19, 23 are added.

  The washing procedure in the membrane filtration system 150 is the same as that in the membrane filtration system 140. However, the monitoring controller 21 detects the inside of the membrane module 13 (pore diameter adjustment) according to the detection results of the sensors 19 and 23 in the reverse pressure water process. The heater 16 and the chemical injection equipment 27 are controlled so that at least one of temperature and pH around the material becomes a predetermined target value. Here, it is preferable to control at least one of the temperature and the chemical addition amount so that the sum of the cost for changing the temperature and the cost required for the chemical addition is minimized.

  According to this modification, by controlling at least one of the temperature and the chemical addition amount according to the temperature and pH in the membrane module 13, it is possible to suppress the cost of changing the temperature and the cost required for the chemical addition. In addition, effective filtration and cleaning can be performed by taking advantage of the characteristics of a polymer material that reversibly expands / contracts in response to a physical or chemical environmental change.

<Fourth Embodiment of Membrane Filtration System>
FIG. 18 is a block diagram showing a fourth embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 160 shown in FIG. 18 omits the outer cylinder 13a, the washing water tank 15, the heater 16, and the raw water pump 22 with respect to the membrane filtration system 140 shown in FIG. It is the structure which added.

  The filtration process and normal cleaning in the membrane filtration system 160 are performed in the same procedure as the membrane filtration system 140 described above. Then, cleaning is performed at a predetermined frequency using at least one of temperature adjustment and pH adjustment by chemical addition according to the following procedure.

(1) Back-pressure water process Chemicals are added to the treated water introduced into the washing water tank 25 by the chemical injection equipment 27, and backflowed from the treated water side of the membrane by the backwash water pump 26. Or, it is discharged from the raw water side above the membrane module 13. At this time, the compressed air is supplied from the raw water side below the membrane module 13 by the compressor 18 to swing the membrane module 13.

  At the same time, treated water in the washing water tank 25 whose temperature is adjusted to the LCST of the polymer material of the pore diameter adjusting material 2 by the heater 29 is supplied from the treated water side of the membrane module 13 by the backwash water pump 26. In this way, the pore diameter adjusting material 2 added to the outer surface 1a, the membrane inner surface 1b, and the inner surface 1c of the membrane by means of temperature adjustment in the membrane module 13 or addition of chemicals to the treated water. Shrink reversibly.

(2) Raw Water Rinsing The valves V1 and V4 and the valve V6 above the membrane module 13 are opened, the raw water pump 12 is activated, and the membrane module 13 is rinsed. At this time, the rinsing water may be circulated to the raw water tank 11. At this time, rinsing can be performed more effectively if the compressed air is allowed to flow from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(3) Filtration The valve V6 at the top of the membrane module 13 is closed and the filtration side valve V7 is opened to resume filtration. At this time, if the compressor 18 is moving, it stops.

  According to the present embodiment, the polymer material that reversibly expands / contracts in response to a physical or chemical environmental change by changing at least one of temperature and pH in the membrane module 13. Due to this characteristic, the solute 3 captured by the pore diameter adjusting material 2 on the outer surface of the membrane, the inner surface of the membrane hole and the inner surface of the membrane module 13 can be effectively discharged out of the system.

<Modification of Fourth Embodiment of Membrane Filtration System>
FIG. 19 is a block diagram showing a modification of the fourth embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 170 shown in FIG. 19 is different from the membrane filtration system 160 shown in FIG. 18 in that the sensor 20 detects the temperature, pH value, etc. inside the membrane module 13 and the temperature of the treated water in the washing water tank 25. In this configuration, a sensor 30 for detecting the pH value and the like, and a monitoring control device 21 for controlling the temperature, the pH value and the like according to the values detected by the sensors 20 and 30 are added.

  The washing procedure in the membrane filtration system 170 is the same as that in the membrane filtration system 160. However, the monitoring control device 21 detects the temperature in the membrane module 13 or the temperature in the reverse pressure water process based on the detection results of the sensors 20 and 30. The heater 29 and the chemical injection facility 27 are controlled so that at least one of the pHs becomes a predetermined target value. Here, it is preferable to control at least one of the temperature and the chemical addition amount so that the sum of the cost for changing the temperature and the cost required for the chemical addition is minimized.

  According to this modification, the temperature and the chemical addition amount are required by controlling at least one of the temperature and the chemical addition amount according to the temperature and pH of the treated water flowing into the membrane module 13. It is possible to perform effective filtration and cleaning taking advantage of the characteristics of a polymer material that reversibly expands / contracts in response to changes in physical or chemical environment while suppressing costs.

<Fifth Embodiment of Membrane Filtration System>
FIG. 20 is a block diagram showing a fifth embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 180 shown in FIG. 20 has the same configuration as the membrane filtration system 160 shown in FIG.

  The filtration process and normal washing in the membrane filtration system 180 are performed in the same procedure as the membrane filtration system 160 described above. Then, cleaning is performed at a predetermined frequency using at least one of temperature adjustment and pH adjustment by chemical addition according to the following procedure.

(1) Drain process The valve V12 and the valve V5 below the membrane module 13 are opened, and the water in the membrane module 13 is discharged. The discharged water may be returned to the raw water tank 11 in order to improve the recovery rate.

(2) Warm water process Chemicals are added to the treated water introduced into the washing water tank 25 by the chemical injection equipment 27, and the treated water in the washing water tank 25 whose temperature is adjusted to the LCST of the polymer material of the pore diameter adjusting material 2 by the heater 29 is used. The backwash water pump 26 supplies from the treated water side of the membrane module 13, and the membrane module 13 is filled with warm water to which a chemical is added. In order to improve the recovery rate, the hot water to which the chemical discharged from the membrane module 13 is added may be returned to the raw water tank 11. In this way, the pore diameter adjusting material 2 added to the outer surface 1a, the membrane inner surface 1b, and the inner surface 1c of the membrane by means of temperature adjustment in the membrane module 13 or addition of chemicals to the treated water. Shrink reversibly.

(3) Back pressure / back flow process The valve V9 is opened, and pressurized air from the compressor 18 is supplied from the treated water side of the membrane module 13 to apply pressure to the inner surface side of the membrane. Further, the valve V6 at the top of the membrane module 13 is opened, and the treated water at the top (secondary side) of the membrane module 13 is pushed out. At this time, in order to improve the recovery rate, the discharged water may be returned to the raw water tank 11.

(4) Air scrubbing step While maintaining the pressure, the valve V8 is opened and pressurized air is supplied from the raw water side lower portion of the membrane module 13 by the compressor 18 for a certain period of time, and the membrane module 13 is swung by the air.

(5) Drain process After air scrubbing for a certain period of time, the valve V12 and the valve V5 below the membrane module 13 are opened to discharge the water in the membrane module 13. At this time, the adhering substance can be discharged more effectively when the compressed air is kept flowing from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(6) Raw Water Rinsing Valves V1 and V4 and the valve V6 in the circulation line above the membrane module 13 are opened, the raw water pump 12 is activated, and the membrane module 13 is rinsed. The rinsed water may be returned to the raw water tank 11. At this time, rinsing can be performed more effectively if the compressed air is allowed to flow from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(7) Filtration The valve V6 at the top of the membrane module 13 is closed, and the filtration side valve V7 is opened to resume filtration. If the compressor 18 is moving in the previous process, it stops.

  According to the present embodiment, by changing the condition of at least one of the temperature and pH of the treated water supplied to the membrane module 13, the expansion / contraction is reversibly in response to a physical or chemical environmental change. Depending on the characteristics of the polymer material to be used, the solute 3 captured by the pore diameter adjusting material 2 on the outer surface of the membrane, the inner surface of the membrane hole, and the inner surface of the membrane module 13 can be effectively discharged out of the system.

<Modification of Fifth Embodiment of Membrane Filtration System>
FIG. 21 is a block diagram showing a modification of the fifth embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 190 shown in FIG. 21 is different from the membrane filtration system 180 shown in FIG. 20 in that the sensor 20 for detecting the temperature, pH value, etc. of the membrane module 13 and the treated water in the washing water tank 25 are used. In this configuration, a sensor 30 for detecting temperature, pH value, and the like, and a monitoring control device 21 for controlling temperature, pH value, etc. according to the values detected by the sensors 20, 30 are added.

  The washing procedure in the membrane filtration system 190 is the same as that in the membrane filtration system 180. However, the monitoring controller 21 in the hot water process determines the inside of the membrane module 13 (the pore diameter adjusting material) according to the detection results of the sensors 20 and 30. The heater 29 and the chemical injection equipment 27 are controlled so that at least one of the ambient temperature and pH becomes a predetermined target value. Here, it is preferable to control at least one of the temperature and the chemical addition amount so that the sum of the cost for changing the temperature and the cost required for the chemical addition is minimized.

  According to this modification, by controlling at least one of temperature and chemical addition amount according to the temperature and pH of the treated water flowing into the membrane module 13, the cost for changing the temperature and the cost required for chemical addition Thus, it is possible to perform effective filtration and washing taking advantage of the characteristics of a polymer material that reversibly expands / contracts in response to a physical or chemical environmental change.

<Sixth Embodiment of Membrane Filtration System>
FIG. 22 is a block diagram showing a sixth embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 200 shown in FIG. 22 is different from the membrane filtration system 180 shown in FIG. 20 in that the backwash water pump 26 supplies the wash water in the wash water tank 25 to the membrane module 13 from the raw water side. This is the point.

  The filtration process and normal cleaning in the membrane filtration system 200 are performed in the same procedure as the membrane filtration system 100 described above. Then, cleaning is performed at a predetermined frequency using at least one of temperature adjustment and pH adjustment by chemical addition according to the following procedure.

(1) Drain process The valve V12 and the valve V5 below the membrane module 13 are opened, and the water in the membrane module 13 is discharged. The discharged water may be returned to the raw water tank 11 in order to improve the recovery rate.

(2) Warm water process Chemicals are added to the treated water introduced into the washing water tank 25 by the chemical injection equipment 27, and the treated water in the washing water tank 25 whose temperature is adjusted to the LCST of the polymer material of the pore diameter adjusting material 2 by the heater 29 is used. The backwash water pump 26 supplies from the raw water side of the membrane module 13, and the membrane module 13 is filled with warm water to which a chemical is added. In order to improve the recovery rate, the hot water to which the chemical discharged from the membrane module 13 is added may be returned to the raw water tank 11. In this way, the pore diameter adjusting material 2 added to the outer surface 1a, the membrane inner surface 1b, and the inner surface 1c of the membrane by means of temperature adjustment in the membrane module 13 or addition of chemicals to the treated water. Shrink reversibly.

(3) Back pressure / back flow process The valve V9 is opened, and pressurized air from the compressor 18 is supplied from the treated water side of the membrane module 13 to apply pressure to the inner surface side of the membrane. Further, the valve V6 at the top of the membrane module 13 is opened, and the treated water at the top (secondary side) of the membrane module 13 is pushed out. At this time, in order to improve the recovery rate, the discharged water may be returned to the raw water tank 11.

(4) Air scrubbing step While maintaining the pressure, the valve V8 is opened and pressurized air is supplied from the raw water side lower portion of the membrane module 13 by the compressor 18 for a certain period of time, and the membrane module 13 is swung by the air.

(5) Drain process After air scrubbing for a certain period of time, the valve V12 and the valve V5 below the membrane module 13 are opened to discharge the water in the membrane module 13. At this time, the adhering substance can be discharged more effectively when the compressed air is kept flowing from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(6) Raw Water Rinsing Valves V1 and V4 and the valve V6 in the circulation line above the membrane module 13 are opened, the raw water pump 12 is activated, and the membrane module 13 is rinsed. The rinsed water may be returned to the raw water tank 11. At this time, rinsing can be performed more effectively if the compressed air is allowed to flow from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(7) Filtration The valve V6 at the top of the membrane module 13 is closed, and the filtration side valve V7 is opened to resume filtration. If the compressor 18 is moving in the previous process, it stops.

  According to the present embodiment, by changing the condition of at least one of the temperature and pH of the treated water flowing into the membrane module 13, the expansion / contraction is reversibly in response to a physical or chemical environmental change. Depending on the characteristics of the polymer material to be used, the solute 3 captured by the pore diameter adjusting material 2 on the outer surface of the membrane, the inner surface of the membrane hole, and the inner surface of the membrane module 13 can be effectively discharged out of the system.

<Modification of the sixth embodiment of the membrane filtration system>
FIG. 23 is a block diagram showing a modification of the sixth embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 210 shown in FIG. 23 is different from the membrane filtration system 200 shown in FIG. 22 in that the sensor 30 for detecting the temperature, pH value, etc. of the treated water in the washing water tank 25 and the inside of the membrane module 13 This is a configuration in which a sensor 20 for detecting temperature, pH value and the like and a monitoring control device 21 for controlling temperature, pH value and the like according to the values detected by the sensors 30 and 20 are added.

  The washing procedure in the membrane filtration system 210 is the same as that in the membrane filtration system 200. However, the monitoring controller 21 in the hot water process determines the inside of the membrane module 13 (of the pore diameter adjusting material) according to the detection results of the sensors 20 and 30. The heater 29 and the chemical injection equipment 27 are controlled so that at least one of the ambient temperature and pH becomes a predetermined target value. Here, it is preferable to control at least one of the temperature and the chemical addition amount so that the sum of the cost for changing the temperature and the cost required for the chemical addition is minimized.

  According to this modification, by controlling at least one of temperature and chemical addition amount according to the temperature and pH of the treated water flowing into the membrane module 13, the cost for changing the temperature and the cost required for chemical addition Thus, it is possible to perform effective filtration and washing taking advantage of the characteristics of a polymer material that reversibly expands / contracts in response to a physical or chemical environmental change.

<Seventh Embodiment of Membrane Filtration System>
FIG. 24 is a block diagram showing a seventh embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 220 shown in FIG. 24 introduces a portion of the treated water stored in the treated water tank 14 into the membrane filtration system 120 shown in FIG. A heater 29 that heats the treated water stored in the washing water tank 25 to a predetermined temperature, and a backwash water pump 26 that supplies the washing water in the washing water tank 25 to the outer cylinder 13 a and circulates it through the outside of the membrane module 13. And the washing water tank 15, the heater 16, and the raw water pump 22 are omitted. The chemical injection equipment 17 is configured to inject chemicals into the raw water tank 11 and the cleaning water tank 15.

  The filtration process and normal cleaning in the membrane filtration system 220 are performed in the same procedure as the membrane filtration system 100 described above. Then, cleaning is performed at a predetermined frequency using at least one of temperature adjustment and pH adjustment by chemical addition according to the following procedure.

(1) Drain process The valve V12 and the valve V5 below the membrane module 13 are opened, and the water in the membrane module 13 is discharged. The discharged water may be returned to the raw water tank 11 in order to improve the recovery rate.

(2) Hot water process The treated water in the washing water tank 25, the temperature of which has been adjusted to the LCST of the polymer material of the pore diameter adjusting material 2 by the heater 29, is supplied to the outer cylinder 13a by the backwash water pump 26. Circulate. At the same time, raw water added with chemicals in the raw water tank 11 and the washing water tank 15 is supplied to the membrane module 13 by the raw water pump 11. In this way, the pore diameter adjusting material 2 added to the outer surface 1a, the membrane inner surface 1b, and the inner surface 1c of the membrane is reversibly adjusted by adjusting the temperature in the membrane module 13 or adding chemicals to the raw water. Shrink.

(3) Back pressure / back flow process The valve V9 is opened, and pressurized air from the compressor 18 is supplied from the treated water side of the membrane module 13 to apply pressure to the inner surface side of the membrane. Further, the valve V6 at the upper part of the membrane module 13 is opened, and the treated water at the upper part (secondary side) of the membrane module 13 is pushed out to the raw water circulation line.

(4) Air scrubbing step While maintaining the pressure, the valve V8 is opened and pressurized air is supplied from the raw water side lower portion of the membrane module 13 by the compressor 18 for a certain period of time, and the membrane module 13 is swung by the air.

(5) Drain process After air scrubbing for a certain period of time, the valve V12 and the valve V5 below the membrane module 13 are opened to discharge the water in the membrane module 13. At this time, the adhering substance can be discharged more effectively when the compressed air is kept flowing from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(6) Rinsing of raw water The valves V1 and V4 and the valve V6 of the circulation line above the membrane module are opened, the raw water pump 12 is started, and the membrane module 13 is rinsed. The rinsed water may be discharged out of the system. At this time, rinsing can be performed more effectively if the compressed air is allowed to flow from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(7) Filtration The valve V6 at the top of the membrane module 13 is closed, and the filtration side valve V7 is opened to resume filtration. If the compressor 18 is moving in the previous process, it stops.

  According to the present embodiment, by changing the condition of at least one of the temperature and pH of the raw water in the membrane module 13, it is possible to reversibly expand / contract reversibly in response to a physical or chemical environmental change. Depending on the characteristics of the molecular material, the solute 3 captured by the pore diameter adjusting material 2 on the outer surface of the membrane, the inner surface of the membrane hole and the inner surface of the membrane module 13 can be effectively discharged out of the system.

  Moreover, since the temperature inside the membrane module 13 is adjusted by circulating the treated water heated by the heater 29 through the outside of the membrane module 13, the heated raw water can be used effectively, and the amount of the heated raw water can be reduced. Can be saved.

  In the above description, the temperature inside the membrane module 13 is adjusted by circulating the temperature-adjusted treated water through the outside of the membrane module 13. However, the temperature of the membrane module 13 itself may be adjusted from the outside. For example, the present invention is not limited to the temperature adjustment method described above.

<Modification of the seventh embodiment of the membrane filtration system>
FIG. 25 is a block diagram showing a modification of the seventh embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 230 shown in FIG. 25 circulates outside the membrane module 13 with the sensor 19 for detecting the temperature, pH value and the like of the raw water in the washing water tank 15 with respect to the membrane filtration system 220 shown in FIG. In this configuration, a sensor 23 for detecting the temperature, pH value, and the like of the raw water to be performed and a monitoring control device 21 for controlling the temperature, pH value, etc. according to the values detected by the sensors 19, 23 are added.

  The washing procedure in the membrane filtration system 230 is the same as that in the membrane filtration system 220. However, the monitoring control device 21 in the hot water process determines the inside of the membrane module 13 (the pore diameter adjusting material) according to the detection results of the sensors 19 and 23. The heater 29 and the chemical injection equipment 17 are controlled so that at least one of the ambient temperature and pH becomes a predetermined target value. Here, it is preferable to control at least one of the temperature and the chemical addition amount so that the sum of the cost for changing the temperature and the cost required for the chemical addition is minimized.

  According to this modification, by controlling at least one of the temperature and the chemical addition amount according to the temperature and pH of the raw water in the membrane module 13, the cost for changing the temperature and the cost required for the chemical addition are suppressed. However, it is possible to perform effective filtration and washing taking advantage of the characteristics of the polymer material that reversibly expands / contracts in response to physical or chemical environmental changes.

<Eighth Embodiment of Membrane Filtration System>
FIG. 26 is a block diagram showing an eighth embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 240 shown in FIG. 26 is different from the membrane filtration system 140 shown in FIG. 15 in that the heater 29 that heats the treated water stored in the washing water tank 25 to a predetermined temperature and the washing water in the washing water tank 25 are used. A backwash water pump 31 that is supplied to the outer cylinder 13a and circulated through the outside of the membrane module 13 is added, and the wash water tank 15, the heater 16, and the raw water pump 22 are omitted.

  The filtration process and normal cleaning in the membrane filtration system 240 are performed in the same procedure as the membrane filtration system 140 described above. Then, cleaning is performed at a predetermined frequency using at least one of temperature adjustment and pH adjustment by chemical addition according to the following procedure.

(1) Back-pressure water process Chemicals are added to the treated water introduced into the washing water tank 25 by the chemical injection equipment 27, and backflowed from the treated water side of the membrane by the backwash water pump 26. Or, it is discharged from the raw water side above the membrane module 13. At this time, the compressed air is supplied from the raw water side below the membrane module 13 by the compressor 18 to swing the membrane module 13.

  At the same time, treated water in the washing water tank 25 whose temperature is adjusted to the LCST of the polymer material of the pore diameter adjusting material 2 by the heater 29 is supplied to the outer cylinder 13 a by the backwash water pump 31 and circulated through the outside of the membrane module 13. Let In this way, the pore diameter adjusting material 2 added to the outer surface of the membrane, the inner surface of the membrane hole, and the inner surface by at least one of the temperature adjustment of the treated water in the membrane module 13 and the addition of chemicals to the treated water. Shrink reversibly. The circulation may be stopped when the temperature in the membrane module 13 can ensure LCST or higher in the following steps.

(2) Raw Water Rinsing The valves V1 and V4 and the valve V6 above the membrane module 13 are opened, the raw water pump 12 is activated, and the membrane module 13 is rinsed. At this time, the rinsing water may be circulated to the raw water tank 11. At this time, rinsing can be performed more effectively if the compressed air is allowed to flow from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(3) Filtration The valve V6 at the top of the membrane module 13 is closed and the filtration side valve V7 is opened to resume filtration. At this time, if the compressor 18 is moving, it stops.

  According to the present embodiment, the polymer material that reversibly expands / contracts in response to a physical or chemical environmental change by changing at least one of temperature and pH in the membrane module 13. Due to these characteristics, the solute 3 captured by the pore diameter adjusting material 2 on the outer surface 1a, the membrane hole inner surface 1b, and the inner surface 1c of the membrane module 13 can be effectively discharged out of the system.

  Moreover, since the temperature inside the membrane module 13 is adjusted by circulating the treated water heated by the heater 29 through the outside of the membrane module 13, the heated raw water can be used effectively, and the amount of the heated raw water can be reduced. Can be saved.

  In the above description, the temperature inside the membrane module 13 is adjusted by circulating the temperature-adjusted treated water through the outside of the membrane module 13. However, the temperature of the membrane module 13 itself may be adjusted from the outside. For example, the present invention is not limited to the temperature adjustment method described above.

<Modification of Eighth Embodiment of Membrane Filtration System>
FIG. 27 is a block diagram showing a modification of the eighth embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 250 shown in FIG. 27 is different from the membrane filtration system 240 shown in FIG. 26 in that the sensor 23 for detecting the temperature, pH value and the like of the raw water circulating outside the membrane module 13 The sensor 30 for detecting the temperature, pH value, etc. of the treated water and the monitoring control device 21 for controlling the temperature, pH value, etc. according to the values detected by the sensors 23, 30 are added. .

  The washing procedure in the membrane filtration system 250 is the same as that in the membrane filtration system 240. However, the monitoring control device 21 detects the inside of the membrane module 13 (pore diameter adjustment) based on the detection results of the sensors 23 and 30 in the reverse pressure water process. The heater 29 and the chemical injection equipment 27 are controlled so that at least one of temperature and pH around the material becomes a predetermined target value. Here, it is preferable to control at least one of the temperature and the chemical addition amount so that the sum of the cost for changing the temperature and the cost required for the chemical addition is minimized.

  According to this modification, by controlling at least one of the temperature and the chemical addition amount according to the temperature and pH in the membrane module 13, it is possible to suppress the cost of changing the temperature and the cost required for the chemical addition. In addition, effective filtration and cleaning can be performed by taking advantage of the characteristics of a polymer material that reversibly expands / contracts in response to a physical or chemical environmental change.

<Ninth embodiment of membrane filtration system>
FIG. 28 is a block diagram showing a ninth embodiment of a membrane filtration system according to the present invention.

  The membrane filtration system 260 shown in FIG. 28 has the same configuration as the membrane filtration system 240 shown in FIG.

  The filtration process and normal cleaning in the membrane filtration system 260 are performed in the same procedure as the membrane filtration system 140 described above. Then, cleaning is performed at a predetermined frequency using at least one of temperature adjustment and pH adjustment by chemical addition according to the following procedure.

(1) Drain process The valve V12 and the valve V5 below the membrane module 13 are opened, and the water in the membrane module 13 is discharged. The discharged water may be returned to the raw water tank 11 in order to improve the recovery rate.

(2) Hot water process The treated water in the washing water tank 25 whose temperature has been adjusted to the LCST of the polymer material of the pore diameter adjusting material 2 by the heater 29 is supplied to the outer cylinder 13 a by the backwash water pump 31, and passes through the outside of the membrane module 13. Circulate. At the same time, the treated water to which the chemical is added in the washing water tank 25 is supplied from the treated water side of the membrane module 13 by the backwash water pump 26, and the inside of the membrane module 13 is filled with the treated water to which the chemical is added. The treated water to which the chemical has been added may be returned to the raw water tank 11 in order to improve the recovery rate. In this way, the pore diameter adjusting material 2 added to the outer surface 1a, the membrane inner surface 1b, and the inner surface 1c of the membrane by means of temperature adjustment in the membrane module 13 or addition of chemicals to the treated water. Shrink reversibly.

(3) Back pressure / back flow process The valve V9 is opened, and pressurized air from the compressor 18 is supplied from the treated water side of the membrane module 13 to apply pressure to the inner surface side of the membrane. Furthermore, V6 of the upper part (secondary side) of the membrane module 13 is opened, and the treated water is pushed out to the raw water circulation line. At this time, the extruded water may be returned to the raw water tank 11.

(4) Air scrubbing step While maintaining the pressure, the valve V8 is opened and pressurized air is supplied from the raw water side lower portion of the membrane module 13 by the compressor 18 for a certain period of time, and the membrane module 13 is swung by the air.

(5) Drain process After air scrubbing for a certain period of time, the valve V12 and the valve V5 below the membrane module 13 are opened to discharge the water in the membrane module 13. At this time, the adhering substance can be discharged more effectively when the compressed air is kept flowing from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(6) Rinsing of raw water The valves V1 and V4 and the valve V6 of the circulation line above the membrane module are opened, the raw water pump 12 is started, and the membrane module 13 is rinsed. The rinsed water may be discharged out of the system. At this time, rinsing can be performed more effectively if the compressed air is allowed to flow from the compressor 18, but the compressed air may be stopped to reduce the power cost.

(7) Filtration The valve V6 at the top of the membrane module 13 is closed, and the filtration side valve V7 is opened to resume filtration. If the compressor 18 is moving in the previous process, it stops.

  According to the present embodiment, the polymer material that reversibly expands / contracts in response to a physical or chemical environmental change by changing at least one of temperature and pH in the membrane module 13. Due to this characteristic, the solute 3 captured by the pore diameter adjusting material 2 on the outer surface of the membrane, the inner surface of the membrane hole and the inner surface of the membrane module 13 can be effectively discharged out of the system.

  Moreover, since the temperature inside the membrane module 13 is adjusted by circulating the treated water heated by the heater 29 through the outside of the membrane module 13, the heated raw water can be used effectively, and the amount of the heated raw water can be reduced. Can be saved.

  In the above description, the temperature inside the membrane module 13 is adjusted by circulating the temperature-adjusted treated water through the outside of the membrane module 13. However, the temperature of the membrane module 13 itself may be adjusted from the outside. For example, the present invention is not limited to the temperature adjustment method described above.

<Modification of Ninth Embodiment of Membrane Filtration System>
FIG. 29 is a block diagram showing a modification of the ninth embodiment of the membrane filtration system according to the present invention.

  The membrane filtration system 270 shown in FIG. 29 is different from the membrane filtration system 260 shown in FIG. 28 in that the sensor 23 for detecting the temperature, pH value and the like of the raw water circulating outside the membrane module 13 and the inside of the treated water tank 25 The sensor 30 for detecting the temperature, pH value, etc. of the treated water and the monitoring control device 21 for controlling the temperature, pH value, etc. according to the values detected by the sensors 23, 30 are added. .

  The washing procedure in the membrane filtration system 270 is the same as that in the membrane filtration system 260. However, the monitoring control device 21 determines that the inside of the membrane module 13 (the pore diameter adjusting material The heater 29 and the chemical injection equipment 27 are controlled so that at least one of the ambient temperature and pH becomes a predetermined target value. Here, it is preferable to control at least one of the temperature and the chemical addition amount so that the sum of the cost for changing the temperature and the cost required for the chemical addition is minimized.

  According to this modification, by controlling at least one of the temperature and the chemical addition amount according to the temperature and pH in the membrane module 13, it is possible to suppress the cost of changing the temperature and the cost required for the chemical addition. In addition, effective filtration and cleaning can be performed by taking advantage of the characteristics of a polymer material that reversibly expands / contracts in response to a physical or chemical environmental change.

<10th Embodiment of a membrane filtration system>
FIG. 30 is a block diagram showing a tenth embodiment of a membrane filtration system according to the present invention.

  The membrane filtration system 280 shown in FIG. 30 shows a configuration in which the membrane module 55 having the configuration shown in FIG. 8 is immersed in a tank (open type or sealed type) into which raw water flows, and the water guide that guides the raw water. Pump 51, raw water tank 52 for temporarily storing the raw water guided by water transfer pump 51, raw water pump 53 for supplying the raw water in raw water tank 52 to membrane immersion tank 54, and filtering the raw water guided by raw water pump 53 A membrane immersion tank 54, a membrane module 55 immersed in the membrane immersion tank 54, a suction pump 56 for sucking treated water after membrane filtration, and a treated water tank for storing treated water sucked by the suction pump 56 57 and a heater 58 for heating the raw water in the treated water tank 57 to a predetermined temperature. Moreover, the thermometer 59 which measures the raw | natural water temperature of the raw | natural water tank 52, and the heater 60 for heating the raw | natural water in the raw | natural water tank 52 to predetermined temperature are provided. Further, a cleaning water tank 61 that introduces and stores a part of the treated water stored in the processing water tank 57 as cleaning water, a thermometer 62 that measures the temperature of the cleaning water in the cleaning water tank 61, and the cleaning water tank 61. A heater 63 for heating the cleaning water stored therein to a predetermined temperature, and a backwash water pump 64 for supplying the cleaning water in the cleaning water tank 61 to the membrane module 55 are provided. Furthermore, a heater 65 for heating the raw water in the film immersion tank 54, a heater 66 for heating the raw water itself introduced into the film immersion tank 54, and a heater 67 for heating the cleaning water during backwashing are provided. In addition, a chemical injection facility 68 for injecting chemicals for pH adjustment into the raw water tank 52 is also provided. In addition, V31-V41 in the figure shows the valve | bulb provided in each piping.

  In the membrane filtration system 280 shown in FIG. 30, the raw water is guided to the raw water tank 52 by the water transfer pump 51. Raw water is introduced into the membrane immersion tank 54 by the raw water pump 53, and the treated water that has permeated through the membrane module 55 is sucked into the treated water tank 57 by a suction pump 56 disposed outside the tank. In this case, the raw water permeates through the membrane by the differential pressure generated by the water level difference method or the suction method and the combination thereof.

  And at the time of washing | cleaning, after adding a chemical | medical agent to the raw | natural water tank 52 and heating the raw | natural water temperature in the film | membrane immersion tank 54 with either of heater 60,65,66 or those combination, it supplies from the backwash water pump 64. The cleaning water is heated to 25 to 60 ° C. by any one of the heaters 58, 63 and 67 or a combination thereof and supplied to the membrane module 55 to execute the cleaning process. That is, heating on the raw water side is performed by any one of the heaters 60, 65, 66 or a combination thereof, and heating on the treated water side is performed by any one of the heaters 58, 63, 67 or a combination thereof.

  In this way, a simple system can be configured by immersing the membrane module 55 composed of a membrane responsive to a physical or chemical environmental change in the membrane immersion tank 54 into which raw water flows. Exchange of the membrane becomes easy, and stable operation can be executed even when the turbidity of the membrane feed water is high.

  In FIG. 30, the heating on the raw water side is constituted by the heaters 60, 65, 66, and the heating on the treated water side is constituted by the heaters 58, 63, 67. However, the heating is limited to this. It is not a thing. That is, on the raw water side, a heater 60 that heats the raw water in the raw water tank 52, a heater 66 that heats the raw water supplied from the raw water tank 52 to the membrane immersion tank 54, or a heater 65 that heats the raw water in the film immersion tank 54 Any configuration including at least one of them may be used. On the treated water side, a heater 63 that heats the treated water in the cleaning water tank 61, a heater 58 that heats the treated water in the treated water tank 57, or a heater 67 that heats the treated water supplied to the film immersion tank 54. Any configuration including at least one of them may be used. Further, the chemical injection facility 68 may be configured to inject the chemical into the cleaning water tank 61 instead of the raw water tank 52.

  Note that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

It is a section lineblock diagram showing a 1st embodiment of a film concerning the present invention. It is explanatory drawing which shows the relationship between the expansion-contraction rate and liquid temperature in the film | membrane which concerns on this invention. It is a schematic diagram which shows the surface structure of the film | membrane which concerns on this invention. It is a section lineblock diagram showing a 2nd embodiment of a film concerning the present invention. It is a section lineblock diagram showing a 3rd embodiment of a film concerning the present invention. It is explanatory drawing which shows the classification of a membrane module. It is a schematic block diagram of the casing storage type | mold cylindrical membrane module which is an example of the membrane module which concerns on this invention. It is a schematic block diagram of the flat membrane module which is an example of the membrane module which concerns on this invention. It is a lineblock diagram showing a 1st embodiment of a membrane filtration system concerning the present invention. It is a figure for demonstrating the filtration process in the membrane filtration system which concerns on this invention. It is a figure for demonstrating an example of the physical washing | cleaning in the membrane filtration system which concerns on this invention. It is a block diagram which shows the modification of 1st Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows 2nd Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows the modification of 2nd Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows 3rd Embodiment of the membrane filtration system which concerns on this invention. It is a figure for demonstrating another example of the physical washing | cleaning in the membrane filtration system which concerns on this invention. It is a block diagram which shows the modification of 3rd Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows 4th Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows the modification of 4th Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows 5th Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows the modification of 5th Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows 6th Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows the modification of 6th Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows 7th Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows the modification of 7th Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows 8th Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows the modification of 8th Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows 9th Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows the modification of 9th Embodiment of the membrane filtration system which concerns on this invention. It is a block diagram which shows 10th Embodiment of the membrane filtration system which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Membrane substrate 2 Pore diameter adjusting material 3 Solute 10A-10C Membrane 11 Raw water tank 12, 22 Raw water pump 13 Membrane module 14 Treated water tank 15, 25 Washing water tank 16, 29 Heater 17, 27 Chemical injection equipment 18 Compressor 19, 20, 23, 30 Sensor 21 Monitoring and Control Device 26, 31 Backwash Water Pump 51 Water Transfer Pump 52 Raw Water Tank 53 Raw Water Pump 54 Membrane Immersion Tank 55 Membrane Module 56 Suction Pump 57 Treatment Water Tank 58, 60, 63, 65-67 Heater 59, 62 Thermometer 61 Washing water tank 64 Backwash water pump 68 Chemical injection equipment 100-280 Membrane filtration system

Claims (6)

A membrane substrate having a plurality of through holes, and a pore diameter adjusting material in which a polymer material that reversibly expands / contracts in response to changes in temperature and pH is added to the outer surface side of the membrane substrate and the inner surface of each through hole A membrane module that fills and integrates a membrane with a container, filters the supplied raw water, and discharges it as treated water ;
A cleaning means for cleaning the membrane by supplying the raw water or the treated water into the membrane module;
By changing the ambient temperature and pH of the pore diameter adjusting material, the pore diameter adjusting material is expanded at the time of the membrane filtration, and the condition variable means for contracting the pore diameter adjusting material at the time of the cleaning,
The condition variable means circulates part of the raw water or the treated water through the periphery of the membrane module while adjusting the temperature in order to adjust the temperature around the pore diameter adjusting material during the cleaning. A membrane filtration system characterized in that The membrane filtration system according to claim 1, wherein the membrane includes the pore diameter adjusting material on an inner surface side of the membrane substrate. Detecting means for detecting at least one of temperature and pH around the pore diameter adjusting material;
Control means for controlling the condition variable means so that at least one of the ambient temperature and pH of the pore diameter adjusting material becomes a predetermined target value according to a detection result by the detection means. The membrane filtration system according to claim 1 or 2 . Membrane substrate having a plurality of through-holes, and a pore size adjusting material in which a polymer material that reversibly expands / contracts in response to changes in temperature and pH is added to the outer surface side of the membrane substrate and the inner surface of each of the through-holes A membrane cleaning method in a membrane filtration system comprising a membrane module that is integrated by filling a container with a membrane, filtering the supplied raw water and discharging it as treated water,
Changing the pH of a portion of the raw water or the treated water;
The raw water or the treated water having a changed pH is supplied into the membrane module, and a part of the raw water or the treated water is circulated through the periphery of the membrane module while adjusting the temperature. Changing the temperature around the hole diameter adjusting material to shrink the hole diameter adjusting material;
Discharging water supplied into the membrane module;
A method for cleaning a film, comprising: A membrane substrate having a plurality of through holes, and a polymer material that reversibly expands / contracts in response to changes in temperature and pH are added to the outer surface side, the inner surface side, and the inner surface of each through hole. A membrane cleaning method in a membrane filtration system comprising a membrane module that is formed by filling a container with a pore diameter adjusting material and integrating the membrane, filtering the supplied raw water, and discharging it as treated water,
Changing the pH of a portion of the raw water or the treated water;
The raw water or the treated water having a changed pH is supplied into the membrane module, and a part of the raw water or the treated water is circulated through the periphery of the membrane module while adjusting the temperature. Changing the temperature around the hole diameter adjusting material to shrink the hole diameter adjusting material;
Discharging water supplied into the membrane module;
A method for cleaning a film, comprising: Detecting at least one of temperature and pH around the pore diameter adjusting material;
A step of adjusting so that at least one of a temperature and a pH around the pore diameter adjusting material becomes a predetermined target value according to a detection result in the detecting step;
The film cleaning method according to claim 4, further comprising:

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