JP4710107B2 - 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. More specifically, the present invention relates to a method for operating a membrane separation apparatus with an improved cleaning process.
[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. 9 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 permeated water in the water collecting pipe 1, it is necessary to increase the diameter of the water collecting pipe 1. However, if this is done, the diameter of the spiral membrane module will also increase.
{Circle around (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]
5 to 8 show a spiral membrane module described in the publication, and FIG. 5A 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, FIG. (B), (c) is sectional drawing which follows the BB line and CC line of Fig.5 (a), respectively. FIG. 6 is a cross-sectional view showing a method for winding a bag-like membrane around a shaft, FIG. 7 is a perspective view showing an engagement relationship between a wound body and a socket, and FIG. 8 is a side view of a spiral membrane module.
[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]
A wound body 24 is formed as shown in FIG. 7 by winding the bag-shaped membrane 10 around the shaft 20 via a raw water channel material (mesh spacer) 29 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]
When the bag-like membrane 10 is wound around the shaft 20, as shown in FIG. 6, a raw water channel material (mesh spacer) 29 is interposed between the bag-like membranes 10. By interposing these mesh spacers 29, a raw water flow path is configured.
[0020]
As shown in FIG. 8, 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 configured as described above, as shown in FIG. 8, 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]
The membrane module of the membrane separation apparatus performs backwashing and a long interval (for example, several days to several days to several minutes to several tens of minutes) to remove the SS component adhering to the membrane surface by water operation. It is carried out by chemical cleaning performed once a few weeks).
[0027]
Since membrane filtration water cannot be obtained from the membrane module during this chemical cleaning, a plurality of membrane modules are arranged in parallel to prevent production of membrane filtration water from being interrupted. Alternatively, there is a case where a so-called merry-go-round type membrane module operating method in which filtered water is produced in another membrane module while washing one group of membrane modules (Japanese Patent Laid-Open No. 7-24265, 11-24265, 11-70325).
[0028]
[Problems to be solved by the invention]
In the conventional merry-go-round operation schedule, as shown in FIG. 4, when one or one group of membrane modules is cleaned, the next one or group of membrane modules is cleaned. Frequent. The chemical cleaning of the membrane module requires a chemical cost, and the discharged chemical solution needs to be treated as a waste solution.
[0029]
An object of the present invention is to provide a method for operating a membrane separation apparatus that can efficiently produce membrane filtrate by reducing the frequency of chemical cleaning as much as possible.
[0030]
[Means for Solving the Problems]
The operation method of the membrane separation apparatus of the present invention is an operation method of a membrane separation apparatus comprising a plurality of membrane modules, and when the membrane cleaning of some of the membrane modules is performed, the raw water is supplied to other membrane modules. In the operation method of the membrane separation apparatus performing the steady filtration operation for filtering, the chemical cleaning is performed by circulating a chemical solution to the raw water / concentrated water side of the raw water / concentrated water side and the permeated water side of the membrane module. The concentrated water side is subjected to chemical cleaning, and some of the membrane modules are put into a resting state before and / or after the chemical cleaning. An operation method of a membrane separation device, wherein the membrane module is accommodated in a vessel, and the vessel is partitioned into a raw water / concentrated water side and a permeate side by the membrane module, and the vessel A raw water port and a concentrated water port are provided on the raw water / concentrated water side, and a permeated water port is provided on the permeated water side of the vessel. In the steady filtration operation, raw water flows into the vessel from the raw water port. The permeated water is taken out from the permeated water port, and the concentrated water is taken out from the concentrated water port. The chemical cleaning supplies the chemical solution from the raw water port into the vessel and removes it from the concentrated water port. 1 operation | movement and the 2nd operation | movement which takes out from a raw | natural water port while supplying a chemical | medical solution into this vessel from this concentrated water port are performed repeatedly. It is characterized by this.
[0031]
According to the operation method of the membrane separation apparatus, in the operation method of producing membrane filtrate with other membrane modules while washing some membrane modules, the frequency of washing the membrane modules is reduced and washing is performed. Cost can be greatly reduced.
[0032]
In the present invention, it is preferable to continue the filtration operation as long as possible within the range of the permissible differential pressure limit of the membrane module.
[0033]
In the present invention, it is preferable that the membrane module is rinsed with raw water at the later stage of the cleaning process, and after the cleaning is finished, the raw water is left in the membrane module to make the above-mentioned resting state.
[0034]
Thus, by using raw | natural water for rinse water, compared with the case where filtered water is used for rinse water, water cost can be reduced and the acquisition rate of production water is also improved. In addition, by leaving the raw water in the membrane module, it is possible to quickly start up when the operation is resumed.
[0035]
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.
[0036]
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.
[0037]
The membrane module used in the present invention is preferably an MF membrane module having a membrane pore diameter of 1 μm or more, for example 1 to 100 μm, particularly 2 to 10 μm, especially 2 to 5 μm. A membrane having a pore diameter of less than 1 μm has a small amount of permeated water.
[0038]
In the present invention, examples of raw water include well water, surface water, and factory effluent, but are not limited thereto.
[0039]
When the raw water contains organic substances to be removed such as chromaticity components, humic substances, and humic substances, an inorganic flocculant may be added, but it is usually unnecessary to add an inorganic flocculant.
[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, 40B, 40C and 40D having the structure shown in FIGS. 5 to 8 are accommodated in cylindrical pressure-resistant vessels 50A, 50B, 50C and 50D. The collective raw water line 60 is connected to the raw water ports 51A, 51B, 51C, and 51D on the front end surfaces of the vessels 50A to 50D via raw water lines 60A, 60B, 60C, and 60D having valves 61A, 61B, 61C, and 61D. ing. The raw water lines 60A-60D between the valves 61A-61D and the raw water ports 51A-51D are connected to the backwash drainage discharge line 62 via the backwash water discharge valves 63A, 63B, 63C, 63D. .
[0042]
The socket 25 is fitted in the concentrated water ports 52A, 52B, 52C, 52D at the center of the rear end surfaces of the vessels 50A to 50D. The concentrated water ports 52A to 52D are connected to the concentrated water line 70 via valves 71A, 71B, 71C, 71D.
[0043]
The permeate ports 53A, 53B, 53C, 53D located on the peripheral side of the rear end surfaces of the vessels 50A-50D are permeate lines 80A, 80B, 80C, 80D, tanks 81A, 81B, 81C, 81D and valves 82A, 82B, 82C and 82D are connected to the collective permeate water line 83. In addition, air passes from the pressurized air source such as a compressor to the permeate water lines 80A to 80D between the tanks 81A to 81D and the valves 82A to 82D via the gas line 84 and the valves 85A, 85B, 85C, 85D. It can be supplied.
[0044]
In order to clean the membrane modules 40A to 40D with the cleaning chemical, two chemical tanks 91 and 92 are connected to the vessels 50A to 50D.
[0045]
A pipe 93 having a pump 101 is connected to the chemical solution tank 91, and this pipe 93 is connected to the concentrated water ports 52A to 52D of the vessels 50A to 50D via valves 93A, 93B, 93C, and 93D. .
[0046]
A pipe 98 having a pump 102 is connected to the chemical tank 92, and this pipe 98 is connected to the raw water ports 51A to 51D of the vessels 50A to 50D via valves 98A, 98B, 98C, and 98D.
[0047]
The membrane modules 40A to 40D are rinsed after being rinsed with a chemical solution. In order to discharge the rinse waste water, the concentrated water ports 52A to 52D of the vessels 50A to 50D are connected via valves 94A, 94B, 94C, and 94D. The rinse drain discharge line 94 is connected.
[0048]
Pipes 95 and 105 branched from the pipes 93 and 98 so as to bypass the pumps 101 and 102 are routed to the upper portions of the tanks 91 and 92, and valves 96 and 106 are provided in the pipes 95 and 105. These valves 96 and 106 are opened as necessary when the membrane module is chemically cleaned. The pumps 101 and 102 are also operated as necessary when the membrane module is chemically cleaned.
[0049]
In the membrane separation apparatus configured as described above, any one of the membrane modules is placed in a chemical cleaning state or a resting state, and a steady filtration operation is performed with the remaining three membrane modules.
[0050]
For example, when the membrane module 40A is in the steady filtration operation state, the valves 61A, 71A, and 82A are opened, and the valves 63A, 98A, 93A, 94A, and 85A are closed. The raw water flows into the vessel 50A from the lines 60, 60A and is subjected to membrane separation processing by the membrane module 40A. The permeated water is taken out from the port 53A through the lines 80A and 83, and the concentrated water is taken out from the port 52A through the line 70. Similarly, when other membrane modules are in a steady filtration operation state, raw water, permeated water, and concentrated water flow.
[0051]
Note that the membrane module is backwashed at short intervals during this steady filtration operation. When the membrane module 40A is backwashed, the valves 61A, 98A, 71A, 82A, 93A, 94A are closed, and the valves 63A, 85A are opened. As a result, the air pressure from the pressurized air source is applied to the tank 81A, the permeate in the tank 81A flows back into the vessel 50A via the port 53A, and the raw water from the permeate side (secondary side) of the membrane module 40A. Alternatively, the permeate flows back to the concentrated water side (primary side), and the membrane module 40A is backwashed. After all the permeated water in the tank 81A has flowed out, air flows from the secondary side to the primary side of the membrane module 40A, and air backwashing is performed.
[0052]
This backwash waste water is discharged through a line 62. This backwashing with permeated water or air is performed at a short interval (for example, once every several minutes to several tens of minutes). This backwashing is performed as part of the steady filtration operation, and naturally differs from the chemical cleaning described later.
[0053]
In this embodiment, the permeated water is stored in the tanks 81A to 81D and the membrane module is backwashed with the permeated water. However, the tanks 81A to 81D are omitted, and the backwashing is substantially performed only with air. You may do it.
[0054]
A part or the whole amount of the backwash drainage flowing out from the backwash drainage line 62 may be used as raw water.
[0055]
If this steady filtration operation is continued, the membrane permeation differential pressure of the membrane module gradually increases even if backwashing is performed at predetermined intervals. The membrane module is placed in the chemical cleaning step at the timing when the membrane permeation differential pressure reaches an allowable value, and the membrane module that has been in the chemical cleaning state or in the resting state is returned to the steady filtration operation step. For example, the membrane module 40A is changed from the steady filtration operation to the chemical cleaning or resting state, and the membrane module 40D is returned to the steady filtration operation instead.
[0056]
As shown in FIG. 2, the membrane modules to be cleaned (W) or in a resting state (S: standby) are sequentially replaced. F indicates a steady filtration operation.
[0057]
In FIG. 2, the membrane module is in a resting state (S) in which chemical cleaning (W) is performed (W → S), but may be first in a resting state and then cleaned in chemicals (S → W). You may make it be set as a rest state, a chemical | medical agent washing | cleaning, and a rest state sequentially (S->W-> S).
[0058]
The operation procedure of this chemical cleaning process will be described below by taking as an example the case of chemical cleaning the membrane module 40A.
[0059]
The valves 61A, 63A, 94A, 71A, 85A, 82A are closed. Further, the valve 96 is also closed and the valve 106 is opened. The valves 93A and 98A are opened.
[0060]
In this state, the pump 101 is operated, and the chemical solution in the tank 91 is supplied from the pipe 93 to the primary side of the membrane module 40A through the port 52A. The chemical solution that has passed through the primary side of the membrane module 40A is introduced into the tank 92 from the port 51A through the pipe 105.
[0061]
After the chemical liquid is circulated from the tank 91 side to the tank 92 side for a predetermined time to the membrane module 40A, the chemical liquid flow is reversed and the chemical liquid in the tank 92 is circulated to the membrane module 40A toward the tank 91 side. That is, the pump 101 is stopped, the valve 96 is opened, the valve 106 is closed, and the pump 102 is operated. Thereby, a chemical | medical solution distribute | circulates the inside of the primary side flow path of the membrane module 40A from the tank 92 side to the tank 91 side.
[0062]
In this way, the reciprocating operation of flowing the chemical solution from the tank 91 to the tank 92 and returning it again from the tank 92 to the tank 91 is repeated a plurality of times as necessary to clean the primary side of the membrane module 40A with the chemical solution.
[0063]
After the chemical solution reciprocates as many times as necessary and returns from the tank 92 side to the tank 91, the membrane module 40A is rinsed. In this embodiment, raw water is used as rinsing water. That is, in order to perform this rinsing, the valves 98A and 93A are closed and the valves 61A and 94A are opened. The valves 63A, 71A and 82A remain closed. As a result, the raw water flows to the primary side of the membrane module 40A via the lines 60, 60A and the port 51A, and the cleaning chemical remaining in the primary side and the vessel 50A is discharged via the line 94. . After flowing a sufficient amount of raw water necessary for rinsing, the valve 94A is closed. Thereby, the chemical cleaning and rinsing of the membrane module 40A are completed.
[0064]
In this embodiment, after the end of the rinsing, the membrane module 40A is in a resting state (S). That is, the raw water is held in the vessel 50A (and the primary side of the membrane module 40A) with the valve 94A closed, and the next steady filtration operation return is awaited. When returning to the steady filtration operation, it is only necessary to open the valve 82A. Since the inside of the vessel and the primary side of the membrane module are filled with raw water, the steady filtration operation starts immediately.
[0065]
As is clear from FIG. 2, by combining the chemical solution cleaning and the resting state, the duration time of the steady filtration operation becomes longer and the operation cost becomes lower. That is, in the conventional example of FIG. 4, since the normal filtration operation is immediately resumed after the chemical cleaning, the chemical cleaning frequency is high, and the chemical cost and the waste chemical processing cost are high. On the other hand, in FIG. 2, the chemical cleaning frequency is reduced, and the chemical cost and the waste chemical processing cost are significantly reduced.
[0066]
FIG. 3 is a schematic diagram showing the change over time of the membrane permeation differential pressure in the case of the present invention example of FIG. 2 and the case of the conventional example of FIG. The illustration of the recovery of the membrane permeation differential pressure due to the above and the time-dependent increase in the membrane permeation differential pressure between the backwashes is omitted).
[0067]
As shown in FIG. 3, in the conventional example, chemical cleaning is frequently performed, so that the transmembrane pressure difference is maintained at a low level. However, as described above, the cost is high. In the example of the present invention, chemical cleaning is not performed until the membrane permeation differential pressure reaches the allowable upper limit, so that considerable cost reduction is possible.
[0068]
In addition, in order to improve backwashing efficiency, it is preferable to place the membrane modules 40A to 40D vertically so that the shaft axial direction is the vertical direction.
[0069]
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.
[0070]
In addition, this invention is applicable also to washing | cleaning of the membrane separator provided with membrane modules other than the membrane module of FIGS. Further, two, three, five or more membrane modules may be provided in parallel.
[0071]
【The invention's effect】
As described above, according to the present invention, the frequency of chemical cleaning of the membrane separation apparatus can be remarkably reduced, and the cleaning cost can be significantly reduced.
[Brief description of the drawings]
FIG. 1 is a water flow diagram showing a method for operating a membrane module according to an embodiment.
FIG. 2 is an operation schedule diagram of an example of the present invention.
FIG. 3 is a time-dependent change diagram of transmembrane pressure difference.
FIG. 4 is an operation schedule diagram of a conventional example.
5A is a perspective view of a bag-like membrane of a spiral membrane module, FIG. 5B is a cross-sectional view taken along line BB in FIG. 5A, and FIG. 5C is a cross-sectional view of FIG. It is sectional drawing which follows CC line.
6 is a cross-sectional view showing a method for winding a bag-like membrane of the spiral membrane module of FIG. 5;
7 is a perspective view showing an engagement relationship between a wound body of the membrane module of FIG. 5 and a socket. FIG.
8 is a side view of the spiral membrane module of FIG.
FIG. 9 is a partially exploded perspective view showing the structure of a conventional spiral membrane module.
[Explanation of symbols]
10 Bag-like membrane
11 First side
12 Second side
13 Third side
14 Fourth side
15 Channel material
16, 17, 18 Adhesive
19 Fin
20 shaft
24 rolls
25 socket
29 Mesh spacer
30 Opening for permeate outflow
31 Closure for permeate outflow prevention
40A, 40B, 40C, 40D Spiral membrane module
50A, 50B, 50C, 50D Vessel
60, 60A, 60B, 60C, 60D Raw water line
62 Backwash drainage line
70 Concentrated water line
80A, 80B, 80C, 80D Permeate line
81A, 81B, 81C, 81D Permeate tank
84 Gas line
91,92 Chemical tank
94 Rinse drainage discharge line
101,102 pump

Claims (5)

A method for operating a membrane separation device comprising a plurality of membrane modules,
In the operation method of the membrane separation device that performs steady filtration operation of filtering raw water with other membrane modules when chemical cleaning of some membrane modules is performed,
The chemical cleaning is a chemical cleaning of the raw water / concentrated water side by circulating a chemical solution to the raw water / concentrated water side among the raw water / concentrated water side and the permeated water side of the membrane module,
A method of operating a membrane separation apparatus that puts some of the membrane modules into a dormant state before and / or after this chemical cleaning ,
The membrane module is accommodated in a vessel, and the vessel is partitioned into a raw water / concentrated water side and a permeate side by the membrane module,
A raw water port and a concentrated water port are provided on the raw water / concentrated water side of the vessel, and a permeated water port is provided on the permeate side of the vessel,
In the steady filtration operation, raw water flows into the vessel from the raw water port, permeate is taken out from the permeate water port, and concentrated water is taken out from the concentrate water port.
The chemical cleaning includes a first operation of supplying a chemical solution from the raw water port into the vessel and taking out the concentrated water port, and supplying a chemical solution from the concentrated water port into the vessel and taking out the second solution from the raw water port. A method for operating a membrane separation device, wherein the operation is repeated .   2. The operation method of a membrane separation apparatus according to claim 1, wherein the time of the resting state is set within a range until the membrane permeation differential pressure of the membrane module during the steady filtration operation reaches an allowable differential pressure.   3. The membrane separation apparatus according to claim 1 or 2, wherein the membrane module is rinsed with raw water at a later stage of the washing step, and the raw water is left in the membrane module after the washing is finished to make the dormant state. Driving method. 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 rectangular 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 part orthogonal to the fourth side part is applied to the shaft to wind the bag-like film to form a wound body, and the fourth side part 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 whole of the third side portion is sealed, and in the fourth side portion, a portion overlapping the open portion of the bag-like membrane is a closed portion. And a method of operating the membrane separation device, characterized in that the membrane separator is a spiral membrane module in which a portion overlapping the closed portion of the bag-like membrane is an open portion. The membrane separation apparatus according to any one of claims 1 to 4 ,
A raw water line connected to the raw water port of the vessel via a raw water valve;
A concentrated water line connected to the concentrated water port of the vessel via a concentrated water valve;
A permeate line connected to the permeate port of the vessel via a permeate valve;
A raw water side chemical liquid tank connected to the raw water port via a raw water side chemical liquid valve;
A concentrated water side chemical liquid tank connected to the concentrated water port via a concentrated water side chemical liquid valve;
A raw water side chemical liquid pump for supplying a chemical liquid from the raw water side chemical liquid tank to the raw water port;
A concentrated water side chemical liquid pump for supplying a chemical liquid from the concentrated water side chemical liquid tank to the concentrated water port;
With
In the steady filtration operation, the raw water valve, the concentrated water valve and the permeated water valve are opened, the concentrated water side chemical liquid valve and the raw water side chemical liquid valve are closed, and the raw water is supplied from the raw water port through the raw water line. Flowing into the vessel and removing concentrated water from the concentrated water port via the concentrated water line, and removing permeated water from the permeated water port via the permeated water line;
In the chemical cleaning, the raw water valve, the concentrated water valve and the permeated water valve are closed, the concentrated water side chemical liquid valve and the raw water side chemical liquid valve are opened,
At the time of the first operation, the raw water side chemical liquid pump is operated to supply the chemical liquid in the raw water side chemical liquid tank from the raw water port into the vessel and take out from the concentrated water port and introduce it into the concentrated water side chemical liquid tank And
During the second operation, the concentrated water side chemical solution pump is operated to supply the chemical solution in the concentrated water side chemical solution tank from the concentrated water port into the vessel and take out from the raw water port to the raw water side chemical solution tank. A method for operating a membrane separation apparatus, characterized by being introduced .

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