JP3659105B2 - Operation method of membrane separator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for operating a membrane separation device such as a microfiltration (MF) membrane separation device, an ultrafiltration (UF) membrane separation device, and a reverse osmosis (RO) membrane separation device. Specifically, the present invention relates to a method for operating a membrane separation apparatus suitable when the membrane module is a spiral membrane module.
[0002]
[Prior art]
As a membrane module used in a membrane separator, there is a spiral membrane module in which a separation membrane is wound around the outer periphery of a water collecting pipe.
[0003]
FIG. 11 is a partially exploded perspective view showing the structure of a conventional spiral membrane module.
[0004]
A plurality of bag-like separation membranes 2 are wound around the outer periphery of the water collecting pipe 1 via mesh spacers 3.
[0005]
The water collecting pipe 1 is provided with a slit-like opening that communicates the inside and outside of the pipe. The separation membrane 2 has a bag shape, and the central portion surrounds the water collecting pipe 1. A channel material 4 made of mesh spacers or the like is inserted into the bag-shaped separation membrane 2, and the inside of the bag-shaped separation membrane (bag-shaped membrane) 2 is a permeate channel.
[0006]
A top ring 6 and an end ring 7 are provided at both ends of the wound body 5 of the bag-like film 2, and a brine seal 8 is provided around the outer periphery thereof.
[0007]
The raw water flows into the raw water flow path between the bag-like membranes 2 from the front end face of the wound body 5, flows as it is in the longitudinal direction of the wound body 5, and flows out as concentrated water from the rear end face of the wound body 5. . While flowing through this raw water flow path, water permeates the bag-like membrane 2 and enters the inside thereof, flows into the water collecting pipe 1 and is taken out of the module from the rear end side of the water collecting pipe 1.
[0008]
The conventional spiral membrane module has the following problems to be solved.
(1) In order to increase the flow rate of the permeate in the water collecting pipe 1, it is necessary to increase the diameter of the water collecting pipe 1, but if this is done, the diameter of the spiral membrane module will also increase.
(2) Since the permeated water that has permeated into the bag-like membrane 2 flows to the water collecting pipe 1 while rotating in the bag-like membrane 2 spirally, the flow resistance in the bag-like membrane 2 is large. Moreover, the flow resistance in the vicinity of the collecting pipe slit portion flowing into the collecting pipe 1 from the bag-like membrane 2 is also large.
(3) The flow rate of raw water flowing through the raw water flow path decreases toward the downstream side. (The raw water flow rate is reduced by the amount of the concentrated raw water.) For this reason, the raw water flow velocity is reduced in the downstream area of the raw water flow path, and dirt is likely to adhere.
[0009]
The present inventor has solved the above-described conventional problems, does not require a water collection pipe, and forms a wound body by winding a bag-shaped membrane around a shaft as a spiral membrane module having low permeate flow resistance. Japanese Patent Laid-Open No. 10-272342 proposes a spiral membrane module in which raw water is supplied from one end face of the body and permeate is taken out from the other end face of the wound body.
[0010]
FIGS. 7 to 10 show a spiral membrane module described in the publication, and FIG. 7 (a) is a perspective view of a bag-like membrane of the spiral membrane membrane and a shaft around which the bag-like membrane is wound, FIGS. 7B and 7C are sectional views taken along lines BB and CC in FIG. 7A, respectively. FIG. 8 is a cross-sectional view showing a method of winding a bag-like membrane around a shaft, FIG. 9 is a perspective view showing an engagement relationship between a wound body and a socket, and FIG. 10 is a side view of a spiral membrane module. is there.
[0011]
The bag-like film 10 has a square or rectangular shape, and has a first side part 11, a second side part 12, a third side part 13, and a fourth side part 14. This bag-like membrane 10 is formed by folding a long separation membrane film into two at the second side portion 12 and separating the separation membrane films folded at the first side portion 11 and the third side portion 13 together. It is bonded with an adhesive or the like, and a part of the fourth side portion 14 has a bag shape that is an open portion without bonding.
[0012]
From the middle of the fourth side 14 to the third side 13, the separation membrane films of the bag-like membrane 10 are not adhered to each other, and an open portion 30 for permeate outflow is formed. Moreover, the separation membrane films of the bag-like membrane 10 are bonded to each other from the middle of the fourth side portion 14 to the first side portion 11, thereby forming a closed portion 31 that prevents the permeated water from flowing out. Yes.
[0013]
A permeate channel material (for example, made of mesh spacers) 15 is inserted and disposed in the bag-like membrane 10. The bag-like membrane 10 is not limited to one long film folded in two at the second side portion 12 portion, and two separation membrane films are overlapped to form the first side portion 11, A part of the second side part 12, the third side part 13, and the fourth side part 14 may be bonded.
[0014]
An adhesive 16 is attached to one surface of the bag-like film 10 and adhesives 17 and 18 are attached to the other surface, and the bag-like film 10 is wound around the shaft 20. The adhesive 16 is attached along the first side 11, and the adhesive 17 is attached along the third side 13. The adhesive 18 is attached along the open portion 30 for flowing out the permeated water from the midway portion in the longitudinal direction of the fourth side portion 14 to the third side portion 13.
[0015]
By winding a plurality of bag-like membranes 10 around the shaft 20, the overlapping bag-like membranes 10 are joined in a watertight manner at the portions of the adhesives 17 and 18. Thereby, the raw | natural water flow path through which raw | natural water (and concentrated water) flows is comprised between bag-like membranes 10 and 10. FIG. When the adhesive 18 is cured, an open portion for outflow of raw water (concentrated water) is formed on the inner peripheral side and a closed portion for preventing raw water outflow is formed on the outer peripheral side on the rear end surface of the wound body. The
[0016]
A fin 19 extends from the boundary portion between the open portion 30 for permeate outflow and the closed portion 31 for permeate outflow prevention of the fourth side portion 14 toward the rear of the wound body. The fins 19 are made of, for example, a synthetic resin film or sheet, and are preferably bonded to the bag-like film 10 by adhesion or the like.
[0017]
Raw water flow path member as shown in FIG. 8 Fukurojomaku 10 around the shaft 20 by winding via a (mesh spacer) 29, the wound body 24 is formed as shown in FIG. The fins 19 extend from the rear end surface of the wound body 24. By providing the fin 19 at the same location in the fourth side portion 14 of each bag-like film 10, the fin 19 is positioned on the same radius from the axis of the wound body 24, and the fin 19 overlaps. The fin 19 forms a ring-shaped protrusion. The rear end of the cylindrical socket 25 is inserted into the ring-shaped protruding portion, and the socket 25 and the fin 19 are joined with an adhesive or the like. The socket 25 may be externally fitted to the fin 19. Further, a slit groove may be provided on the rear end surface of the wound body 24 along the fin 19 with a lathe, and the end portion of the socket 25 may be embedded in the groove.
[0018]
By joining the socket 25 and the fins 19 in this manner, the permeated water outflow region on the outer peripheral side of the rear end surface of the wound body 24 and the concentrated water outflow region on the inner peripheral side of the socket 25 are partitioned.
[0019]
Note that when winding the Fukurojomaku 10 around the shaft 20, as shown in FIG. 8, the raw water flow path member between the adjacent Fukurojomaku 10 advance with intervening (mesh spacer) 29. By interposing these mesh spacers 29, a raw water flow path is configured.
[0020]
As shown in FIG. 10, a top ring 26 and an end ring 27 are formed on the front edge and the rear edge of the wound body 24 by a synthetic resin mold, respectively, and a brine seal 28 is provided around the outer periphery of the top ring 26.
[0021]
In the spiral membrane module thus configured, as shown in FIG. 10, raw water flows from the front end face of the wound body 24 into the raw water flow path between the bag-like membranes 10. This raw water flows through the raw water flow path in a direction substantially parallel to the axial center line of the wound body 24, and is taken out from the inner end face of the socket 25 at the rear end of the wound body 24. And while raw | natural water flows through a raw | natural water flow path in this way, water permeate | transmits in the bag-like film | membrane 10, and permeated water flows out from the outer peripheral side of the socket 25 among the rear-end surfaces of the winding body 24. FIG.
[0022]
In this spiral membrane module, the permeated water flows in the bag-like membrane 10 in the direction parallel to the axial center line of the wound body 24 and is taken out from the rear end surface, so that it is used in the conventional spiral membrane module. No water collection pipe is required. For this reason, there is no flow resistance when flowing from the bag-shaped membrane into the water collecting pipe, and the permeate flow resistance is significantly reduced.
[0023]
Note that the water collecting pipe is omitted, and the length of the bag-like membrane 10 in the winding direction can be increased correspondingly, and the membrane area can be increased. Even if the length of the bag-like membrane in the winding direction is increased, the permeate flow resistance does not increase, and the amount of permeate can be increased.
[0024]
In this spiral membrane module, the outlet portion of the raw water channel is provided only inside the socket 25, and the outlet (the most downstream portion) of the raw water channel is narrowed down. Also on the side, the flow rate of the raw water (concentrated water) becomes sufficiently large, and the adhesion of dirt in the downstream area of the raw water channel can be prevented. The inner area and the outer area of the socket 25 (the length of the adhesive 18 in the direction of the side 14) are preferably determined according to the water recovery rate of the spiral membrane module.
[0025]
Further, in this spiral membrane module, the socket 25 is connected to the wound body 24 using the fins 19, and the connection strength between the socket 25 and the wound body 24 is high. The socket 25 separates the raw water inflow side and the concentrated water outflow side in a watertight manner.
[0026]
In JP-A-11-169684, as a back washing method for this spiral membrane module, a back washing gas is supplied to the permeate side in a state where the permeate exists inside the wound body, and the remaining permeate is A method is disclosed in which the gas flow is continued until the remaining permeated water decreases and then only the gas flows through the gas-liquid mixed state.
[0027]
In JP-A-11-207335, as a back washing method of the membrane module, the first sampling is performed by stopping the sampling of the permeated water while supplying the raw water and supplying the gas to the permeated water side for back washing. A method is described in which a backwashing process and a second backwashing process in which gas is supplied and backwashing is stopped by stopping the flow of raw water.
[0028]
Japanese Patent Laid-Open No. 11-137777 describes an apparatus for cleaning this membrane module with a chemical (cleaning chemical solution).
[0029]
By the way, in general, the membrane module of the membrane separation apparatus is equipped with an air backwash that removes the SS component adhering to the membrane surface at a short interval (for example, once every 8 minutes) and a long interval (for example, one month). In the chemical cleaning performed once).
[0030]
This chemical cleaning requires a chemical cost, and used chemicals to be discharged require a waste liquid treatment.
[0031]
[Problems to be solved by the invention]
An object of this invention is to provide the operating method of the membrane separator which can fully recover | restore the amount of permeated water only by the backwashing with water.
[0032]
[Means for Solving the Problems]
The operation method of the membrane separation apparatus according to claim 1 is the operation method of the membrane separation apparatus including a plurality of membrane modules having a common permeate line. It has between permeated water supplying step of the permeate is supplied to the secondary side of the backwash target membrane module by the discharge pressure of the membrane module, and then a pressurized gas supply step of supplying pressurized gas to the secondary side The permeated water supply step and the pressurized gas supply step are repeated a plurality of times .
The operation method of the membrane separation apparatus according to claim 2 is the operation method of the membrane separation apparatus including a plurality of membrane modules having a common permeate line, and when the backwashing is performed with some of the membrane modules, A permeated water supplying step of supplying permeated water of the membrane module to the secondary side of the membrane module to be backwashed by the discharge pressure , a pressurized gas supplying step of supplying pressurized gas to the secondary side, and a concentrated water flow And a ventilation step of supplying pressurized gas to the passage, and the permeated water supply step, the pressurized gas supply step, and the ventilation step are repeated a plurality of times.
[0033]
According to the operation method of the membrane separation apparatus, the deposits on the membrane surface can be removed with high efficiency by backwashing. In addition, during this backwash, a steady filtration operation is performed in another membrane module, so that filtered water can be stably produced and permeated water from the other membrane module can be supplied to the other membrane module. Since the drain water pressure is used to supply the backwash target membrane module, a backwash pump is not required.
[0034]
Since the water for backwashing is introduced into the secondary side of the membrane module, contamination of the membrane is prevented.
[0035]
After supplying water for backwashing to the secondary side, this water is discharged from the membrane module by supplying pressurized gas to the secondary side. Thus, by discharging water by gas, a small amount of water for backwashing is sufficient. Further, the membrane is backwashed by the gas-liquid mixed phase flow, and the cleaning effect is enhanced.
[0036]
By repeatedly performing this backwashing operation (introducing the permeated water of the other module and then introducing the pressurized gas), it is possible to obtain the same cleaning effect as that of the membrane module with chemicals. Thereby, a chemical cleaning process can be made unnecessary. However, if necessary, a small amount of sodium hypochlorite, mineral acid, alkali, etc. may be added to the permeated water from other membrane modules supplied to the membrane module for back washing of the membrane module. By doing so, the cleaning effect can be further enhanced.
[0037]
The operation method of the membrane separation apparatus of the present invention is the spiral membrane module disclosed in the above-mentioned JP-A-10-272342, that is, a permeate flow path material is arranged inside the bag-like membrane, and between the bag-like membranes. A spiral membrane module in which a raw water channel material is disposed, wherein the bag-like membrane is a substantially rectangular shape having first, second, third and fourth sides, and the first and second And the third side is sealed, the fourth side is partially open and the rest is closed, and the first side perpendicular to the fourth side is applied to the shaft. The bag-like film is wound to form a wound body, the fourth side portion faces the rear end surface of the wound body, and the second side portion facing the fourth side portion is the wound body. The raw water flow path between the bag-like membranes is sealed with the entire third side portion, and the fourth side portion has an opening portion of the bag-like membrane. Portion comprising has a closed section, and portions overlapping with the closure of the bag-shaped film can be particularly suitably applied to what is an open unit.
[0038]
This type of spiral membrane module is not easily damaged even if it is repeatedly backwashed, is easily backwashed, and the amount of permeate is easily recovered by backwashing.
[0039]
In the present invention, examples of raw water include well water, surface water, and factory effluent, but are not limited thereto.
[0040]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a system diagram of a membrane separation apparatus to which the method of the present invention is applied.
[0041]
The spiral membrane modules 40A and 40B having the structure shown in FIGS. 7 to 10 are accommodated in cylindrical pressure-resistant vessels 50A and 50B. A collective raw water line 60 is connected to raw water ports 51A and 51B on the front end surfaces of the vessels 50A and 50B via raw water lines 60A and 60B having valves 61A and 61B. The raw water line 60 is provided with a raw water pump 60P.
[0042]
Backwash drainage discharge lines 62A and 62B branch from the raw water line 60A between the valve 61A and the raw water port 51A and the raw water line 60B between the valve 61B and the raw water port 51B, respectively. 62B is provided with valves 63A and 63B.
[0043]
The socket 25 is fitted in the concentrated water ports 52A and 52B at the center of the rear end faces of the vessels 50A and 50B. Concentrated water lines 70A and 70B having valves 71A and 71B are connected to the concentrated water ports 52A and 52B.
[0044]
Permeate water lines 80A and 80B having valves 81A and 81B are connected to the permeate ports 53A and 53B located on the peripheral side of the rear end surfaces of the vessels 50A and 50B. The permeate water lines 80A and 80B merge with the aggregate permeate water line 83, and the aggregate permeate water line 83 is provided with a valve 83V.
[0045]
Further, gas lines 86A and 86B for backwashing are connected to the permeate lines 80A and 80B between the permeate ports 53A and 53B and the valves 81A and 81B, and the valve 87A is connected to the gas lines 86A and 86B. , 87B. The gas lines 86A and 86B are connected to a pressurized air source such as a compressor 87C through a collective gas line 87.
[0046]
Gas lines 84A and 84B are connected between the concentration ports 52A and 52B and the valves 71A and 71B in the concentrated water lines 70A and 70B. The gas lines 84A and 84B are connected to the compressor 87C via the collective gas line 84 and the collective gas line 87.
[0047]
Next, an operation method of the membrane separation apparatus configured as described above will be described with reference to FIGS.
[0048]
(1) Steady filtration operation (Fig. 2)
At the time of steady filtration operation in which water passage operation (membrane separation operation) is performed in both membrane modules 40A and 40B, the valves 61A, 61B, 71A, 71B, 81A, 81B, and 83V are opened, and the other valves 63A, 63B, and 85A. , 85B, 87A, 87B are closed. The raw water is supplied into the vessels 50A and 50B from the raw water ports 51A and 51B, the concentrated water flows out through the socket 25, the ports 52A and 52B and the concentrated water lines 70A and 70B, and the permeated water is supplied into the vessels 50A and 50B. The permeated water chambers 54A and 54B on the rear side are taken out through the permeated water ports 53A and 53B and the permeated water lines 80A, 80B and 83.
[0049]
(2) During backwash (1st stage: Fig. 3)
When one membrane module, for example, the membrane module 40A is backwashed, air is first introduced into the membrane module 40A and water is discharged. That is, the valves 61A, 71A, 81A are closed, and the valves 63A, 87A are opened. The valve 85A remains closed.
[0050]
At this time, since the membrane module 40B performs a filtration operation, the valves 61B, 71B, and 81B remain open, and the valves 63B, 85B, and 87B remain closed.
[0051]
Then, the compressor 87C is operated to supply gas (air, nitrogen, etc.) to the gas line 87. Thereby, the residual water in the vessel 50A and the membrane module 40A is discharged through the backwash drainage line 62A.
[0052]
(3) During backwash (second stage: Fig. 4)
Next, the compressor 87C is stopped, the valves 63A and 87A are closed, and the valve 81A is opened instead. The other valves are in the same state as in FIG. Thereby, a part of the permeated water of the membrane module 40B flows into the vessel 50A. At this time, since the valves 61A and 63A are closed, the permeated water flows into the vessel 50A while the residual air in the vessel 50A is compressed.
[0053]
At this time, the opening degree of the valve 83V may be adjusted as necessary. Further, in this example, the valve 83V is opened, but the valve 83V may be closed and the total amount of permeated water of the membrane module 40B may be supplied to the vessel 50A.
[0054]
(4) During backwash (3rd stage: Fig. 5)
Next, the valve 81A is closed and the valves 87A and 63A are opened. The other valves remain as shown in FIG. Then, the compressor 87C is operated. As a result, the air pressure propagates to the permeate flow path in the bag-like membrane 10 of the spiral membrane module 40A via the permeate port 53A and the permeate chamber 54A in the vessel 50A, and in the permeate water chamber 54A and the bag-like membrane 10 Water flows into the raw water flow path between the bag-like membranes 10 and flows out through the raw water port 51A and the backwash drainage extraction line 62A.
[0055]
As a result, the membrane module 40A is back-washed, and thereafter returns to the steady filtration operation of (1) . In addition, after implementing the process of the 1st stage-the 3rd stage, recovery of a membrane permeation flux can be aimed at by implementing the process of the 2nd stage-the 3rd stage several times (50-1000 times). .
[0056]
Chemical cleaning may be performed only when the amount of permeated water does not sufficiently recover even when this backwashing is applied, that is, when deposits that cannot be removed without chemical cleaning are collected on the film surface. As a result, the frequency of chemical cleaning is drastically reduced, and not only the cost of chemicals is reduced, but also the amount of drainage can be remarkably reduced.
[0057]
In the above third stage of backwashing (4) , after backflowing water, backwashing by gas-liquid mixed phase flow and backwashing by gas may be performed, and stopped at the stage of backwashing by gas-liquid mixed phase flow. It is also possible to stop at the stage of backwashing with only water.
[0058]
However, by performing water backwashing, gas-liquid mixing backwashing, and gas backwashing, the membrane module can be sufficiently backwashed, and the amount of permeated water can be sufficiently recovered.
[0059]
Further, after the third step (4) of backwashing, the fourth step of ventilation (step (5) ) shown in FIG. 6 may be performed. In FIG. 6, the valve 85A is opened, the 87A is closed, and the other valves are in the same state as in FIG. Thereby, the air from the compressor 87C is supplied to the concentrated water flow path of the membrane module 40A via the concentrated water port 52A. This aeration removes the SS component that has floated to the film surface in the third step (4) of backwashing. However, the step of FIG. 6 may be omitted.
[0060]
Contrary to the above, when the membrane module 40B is back-washed and the membrane module 40A performs a filtration operation, the opening and closing of each valve is completely opposite to the cases (2) to (4) or (2) to (5). You can do it.
[0061]
While continuing the steady filtration operation, the membrane modules 40A and 40B are back-washed for a short time periodically or when necessary. In addition, when performing backwashing for a short time with one membrane module, filtration operation is performed with the other membrane module.
[0062]
In order to increase the backwashing efficiency, it is preferable to place the membrane modules 40A and 40B vertically so that the shaft axial direction is the vertical direction.
[0063]
In the above embodiment, the permeate outflow part is arranged on the outer peripheral side of the socket 25, and the concentrated water outflow part is arranged inside the socket 25. Conversely, the inside of the socket 25 is used as the permeate outflow part, You may comprise so that the outer peripheral side of the socket 25 may be used as a concentrated water outflow part.
[0064]
The present invention can also be applied to cleaning of a membrane separation apparatus provided with a membrane module other than the membrane modules shown in FIGS. Three or more membrane modules may be provided.
[0065]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples.
[0066]
Example 1
In the apparatus shown in FIG. 1, MF membrane modules made of PTFE having a pore diameter of 0.2 μm were used as the membrane modules 40A and 40B. The membrane area is 10 m ² . As raw water, SS water of about 1 mg / L was used.
[0067]
In this filtration operation, backwashing was performed every 8 minutes according to the procedure shown in FIGS. The permeated water injection of the other membrane module shown in FIG. 4 was performed for 20 seconds, and the supply of pressurized air (pressure 0.5 MPa) shown in FIG. 5 was performed for 10 seconds.
[0068]
The membrane permeation flux after 14 days was 2.8 m / d / 100 kPa, 25 ° C.
[0069]
Comparative Example 1
In Example 1, the filtration operation was performed in the same manner as in Example 1 except that the first and second stages of backwashing were omitted and only the third stage was performed. (Thus, backwashing was performed for 10 seconds every 8 minutes and 20 seconds.) The membrane permeation flux after 14 days passed was 1.2 m / d / 100 kPa. at 25 ° C.
[0070]
Example 2
In Comparative Example 1, the membrane permeation flux was 1.2 m / d / 100 kPa and the membrane was lowered to 25 ° C., and the steps of FIGS. 4 to 5 were repeated once / minute. As a result, the membrane permeation flux changes with time as follows. By this, the membrane permeation flux is sufficiently recovered by carrying out the steps of FIGS. 4 to 5 about 50 times, preferably 100 times or more. I understood. In addition, the numerical value in the following [] shows the number of backwashing.
0 hours [-] 1.2 (m / d / 100 kPa at 25 ° C)
0.5 hours [30 times] 1.7 (m / d / 100 kPa at 25 ° C.)
1 hour [60 times] 2.2 (m / d / 100 kPa at 25 ° C.)
2 hours [120 times] 3.1 (m / d / 100 kPa at 25 ° C.)
3 hours [180 times] 3.5 (m / d / 100 kPa at 25 ° C.)
[0071]
【The invention's effect】
As described above, according to the present invention, the amount of permeated water in the membrane separation apparatus can be sufficiently recovered only by water and gas backwashing. For this reason, the cleaning cost can be significantly reduced.
[Brief description of the drawings]
FIG. 1 is a water flow diagram showing a method for cleaning a membrane module according to an embodiment.
FIG. 2 is a water flow diagram showing a method for cleaning a membrane module according to the embodiment.
FIG. 3 is a water flow diagram showing a method for cleaning a membrane module according to the embodiment.
FIG. 4 is a water flow diagram illustrating a method for cleaning a membrane module according to the embodiment.
FIG. 5 is a water flow diagram showing a membrane module cleaning method according to the embodiment.
FIG. 6 is a water flow diagram showing a membrane module cleaning method according to the embodiment.
7A is a perspective view of a bag-like membrane of a spiral membrane module, FIG. 7B is a cross-sectional view taken along line BB in FIG. 7A, and FIG. 7C is a cross-sectional view of FIG. It is sectional drawing which follows CC line.
8 is a cross-sectional view showing a method of winding a bag-like membrane of the spiral membrane module of FIG.
9 is a perspective view showing an engagement relationship between a wound body of the membrane module of FIG. 7 and a socket. FIG.
10 is a side view of the spiral membrane module of FIG.
FIG. 11 is a partially exploded perspective view showing the structure of a conventional spiral membrane module.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Bag-like film | membrane 11 1st edge part 12 2nd edge part 13 3rd edge part 14 4th edge part 15 Channel material 16, 17, 18 Adhesive agent 19 Fin 20 Shaft 24 Winding body 25 Socket 29 Mesh spacer 30 Opening part for permeate outflow 31 Closure part for permeate outflow prevention 40A, 40B Spiral membrane module 50A, 50B Vessel 60, 60A, 60B Raw water line 62A, 62B Backwash drainage discharge line 70A, 70B Concentrated water Line 80A, 80B, 83 Permeated water line 84, 84A, 84B, 86A, 86B, 87 Gas line

Claims (4)

In the operation method of the membrane separation device comprising a plurality of membrane modules having a common permeate line,
And permeated water supplying step to supply to the secondary side of the backwash target membrane module permeated water of other membrane module by the discharge pressure when performing backwash in some membrane modules, then this secondary A pressurized gas supply step for supplying pressurized gas,
The method for operating a membrane separation device, wherein the permeated water supply step and the pressurized gas supply step are repeated a plurality of times . In the operation method of the membrane separation device comprising a plurality of membrane modules having a common permeate line,
A permeated water supply step of supplying permeated water from other membrane modules to the secondary side of the membrane module to be backwashed by the discharge pressure when backwashing in some membrane modules, and then adding to the secondary side. A pressurized gas supply step for supplying pressurized gas, and a ventilation step for supplying pressurized gas to the concentrated water flow path,
The method for operating a membrane separation device, wherein the permeated water supply step, the pressurized gas supply step, and the aeration step are repeated a plurality of times. 3. The operation method of a membrane separation device according to claim 1, wherein the pressurized gas supply step performs backwashing with water and then backwashing with a gas-liquid mixed flow and backwashing with gas. 4. The spiral module according to any one of claims 1 to 3, wherein the membrane module has a permeated water channel material disposed inside a bag-shaped membrane and a raw water channel material disposed between the bag-shaped membranes. A membrane module,
The bag-like membrane has a substantially square shape having first, second, third, and fourth sides, the first, second, and third sides are sealed, and the fourth side is Some are open and the rest are closed.
The first side portion orthogonal to the fourth side portion is applied to the shaft to wind the bag-like film to form a wound body, and the fourth side portion faces the rear end surface of the wound body, The second side facing the fourth side faces the front end face of the wound body,
In the raw water flow path between the bag-like membranes, the entire third side portion is sealed, and a portion overlapping with the open portion of the bag-like membrane is a closed portion in the fourth side portion. A method for operating a membrane separation apparatus, wherein the membrane separation device is a spiral membrane module in which a portion overlapping the closed portion of the bag-like membrane is an open portion.

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