JP6362748B1 - Membrane separation system and method for cleaning membrane module of membrane separation system - Google Patents

Abstract

A membrane separation system capable of cleaning a plurality of membrane modules connected in parallel substantially evenly.
A membrane separation system (1) in which a plurality of membrane modules (2a-2j) are connected in parallel, a liquid supply header pipe (14), a liquid supply branch pipe (15), a permeate header pipe (16), and a permeate extraction branch. It has a pipe 17, a flushing fluid supply header pipe 18, and a flushing fluid supply branch pipe 19, and flows backwash fluid D from the secondary side 9 to the primary side 7 of the membrane modules 2a-2j for back pressure washing. The flushing fluid supply means 21 is connected to the permeate header pipe 16, and the flushing fluid supply means 22 for supplying the flushing fluid C into the flushing fluid supply header pipe 18 is the flushing fluid supply header pipe 18. The cleaning waste liquid E discharging path 48 discharged from the membrane modules 2a to 2j during cleaning is connected to the other end 14b of the liquid supply header pipe 14 to be processed. .
[Selection] Figure 4

Description

  The present invention relates to a membrane separation system for performing a membrane filtration operation by connecting a plurality of membrane modules in parallel and a method for cleaning the membrane module of the membrane separation system.

  Conventionally, as this type of membrane separation system, for example, as shown in FIG. 11, a plurality of membrane modules 101a to 101j and a treated water A for supplying treated water A to the primary side 102 of each membrane module 101a to 101j. Liquid supply header pipe 103, permeate header pipe 105 through which permeate B taken out from the secondary side 104 of each membrane module 101a to 101j flows, and compressed air C for flushing to the primary side of each membrane module 101a to 101j Some have a flushing air supply header pipe 106 that feeds 102.

  Each of the membrane modules 101 a to 101 j includes a casing 108 and a membrane element 109 accommodated in the casing 108. Further, the water to be treated A is supplied from the other end 103b of the liquid supply header pipe 103 to be processed toward the one end 103a, and the compressed air C for flushing is supplied from the other end 106b of the air supply header pipe 106 for flushing to the one end 106a. The permeated water B is taken out from the other end 105 b of the permeate header pipe 105.

The operation in such a membrane separation system 100 includes the following membrane filtration step, backwashing step, and flushing step.
(1) Membrane filtration step In the membrane filtration step, as shown in FIG. 11, the water to be treated A is supplied to the liquid feed header pipe 103 to be treated by supplying the water to be treated A to the liquid feed header pipe 103 to be treated. Is supplied to the primary side 102 of each of the membrane modules 101a to 101j while flowing from the other end 103b to the one end 103a, and passes through the membrane element 109 from the primary side 102 and flows to the secondary side 104. The membrane modules 101 a to 101 j flow out to the permeate header pipe 105 and are taken out from the other end 105 b of the permeate header pipe 105.
(2) Backwashing process In the backwashing process, as shown in FIG. 12, the backwashing water D is supplied to the permeate header pipe 105 so that the backwash water D is supplied to the other end 105 b of the permeate header pipe 105. Is supplied to the secondary side 104 of each membrane module 101a to 101j while flowing from one side 105a to the one end 105a, passes through the membrane element 109 from the secondary side 104 and flows to the primary side 102, and then from each membrane module 101a to 101j. It flows out into the liquid supply header pipe 103 to be processed and is discharged from the other end 103 b of the liquid supply header pipe 103 to be processed.

Thereby, the foreign matter adhering to the membrane element 109 is peeled off and discharged from the other end 103b of the liquid supply header pipe 103 to be treated together with the backwash water D.
(3) Flushing step In the flushing step, as shown in FIG. 13, while supplying the backwash water D to the permeate header pipe 105, the flushing compressed air C is supplied to the other end 106 b of the flushing air supply header pipe 106. To supply. Thus, the backwash water D is supplied from the other end 105b of the permeate header pipe 105 toward the one end 105a while being supplied to the secondary side 104 of each membrane module 101a to 101j, and the compressed air C is supplied to the flushing air. While flowing from the other end 106b of the header pipe 106 toward the one end 106a, it is supplied to the primary side 102 of each membrane module 101a to 101j, and in the casing 108 of each membrane module 101a to 101j, backwash water D and compressed air C Are mixed into the gas-liquid mixed phase fluid F (backwash water D + compressed air C), and this gas-liquid mixed phase fluid F flows through the membrane modules 101a to 101j and flows out into the liquid supply header pipe 103 to be processed, and the cleaning waste liquid. E is discharged from the other end 103 b of the liquid supply header pipe 103 to be processed.

  Thereby, the turbidity in the membrane modules 101a to 101j is discharged as the cleaning waste liquid E from the other end 103b of the liquid supply header pipe 103 to be processed together with the gas-liquid mixed phase fluid F.

  Note that the membrane module 101a located closest to the one end 106a of the flushing air supply header pipe 106 and the one end 103a of the liquid supply header pipe 103 to be processed is referred to as the membrane module 101a on the one end side. The membrane module 101j located at the location closest to the other end 106b and the other end 103b of the liquid supply header pipe 103 to be treated is referred to as the membrane module 101j on the other end side.

  Moreover, the following patent document 1 describes a membrane separation system for performing a membrane filtration operation by connecting a plurality of membrane modules in parallel.

Japanese Patent No. 5149369

  However, in the conventional type shown in FIG. 13, in the flushing process, the other end 106b of the flushing air supply header pipe 106 passes through the inside of the membrane module 101j on the other end side to the other end 103b of the liquid supply header pipe 103 to be processed. The length of the path to reach is the shortest, and the length of the path from the other end 106b of the flushing air supply header pipe 106 to the other end 103b of the liquid supply header pipe 103 to be processed through the inside of the membrane module 101a on the one end side. The longest.

  As described above, the longer the path from the other end 106b of the flushing air supply header pipe 106 to the other end 103b of the liquid supply header pipe 103 to be processed through the membrane modules 101a to 101j, the more the compressed air C flows. Therefore, the flow rate of the compressed air C flowing through the membrane modules 101a to 101j decreases.

  That is, in FIG. 13, the flow rate of the compressed air C flowing in the membrane module 101j on the other end side is the largest, the flow rate of the compressed air C flowing in the membrane module 101a on the one end side is the smallest, and the other end side The flow rate of the compressed air C decreases from the membrane module 101j closer to the membrane module 101a on the one end side.

  On the other hand, the ease of flow of the backwash water D is the length of the path from the supply to the other end 105 b of the permeate header pipe 105 to the discharge to the other end 103 b of the liquid supply header pipe 103 to be processed. The membrane modules 101a to 101j are almost equal without being affected so much. This is because when the backwash water D passes through the membrane modules 101a to 101j from the secondary side 104 to the primary side 102, the membrane element 109 becomes a resistance, and the backwash water D from each membrane module 101a to 101j This is to act in the direction of equalizing the discharge.

  For this reason, the flow rate of the gas-liquid mixed phase fluid F in which the compressed air C and the backwash water D are mixed is highest in the membrane module 101j on the other end side, lowest in the membrane module 101a on the opposite end side, and on the other end. The membrane module decreases from the membrane module 101j on the side closer to the membrane module 101a on the one end side. Thereby, there is a problem that cleaning of each of the membrane modules 101a to 101j becomes uneven.

  Further, in Patent Document 1, as shown in FIG. 14, a plurality of membrane modules 121a to 121e, a first header pipe 123 communicating with the upstream side of the primary side 122 of each membrane module 121a to 121e, and each membrane module A second header pipe 124 communicating downstream of the primary side 122 of 121a to 121e, a third header pipe 126 communicating downstream of the secondary side 125 of each membrane module 121a to 121e, and upstream of the first header pipe 123 A method for cleaning a membrane filtration device including a closed container 127 in communication and a compressed air supply unit 128 that supplies compressed air to the second header pipe 124 and the closed container 127 is disclosed.

In this cleaning method, a chemical solution transfer process 1 and a chemical solution transfer process 2 as described below are alternately repeated.
● Chemical liquid transfer process 1
After the cleaning chemical solution is filled in each of the membrane modules 121a to 121e and the second header pipe 124, the compressed air is supplied with the cleaning chemical solution always present on the primary side 122 and the secondary side 125 of each of the membrane modules 121a to 121e. Membrane element 129 of membrane modules 121a-121e is sent from compressed air supply unit 128 into second header tube 124, and the above-mentioned filled cleaning chemical is transferred from second header tube 124 in the direction of membrane modules 121a-121e. And the cleaning chemical solution are continuously contacted. Then, the cleaning chemical solution after contact is discharged from the membrane modules 121 a to 121 e to the first header pipe 123 and transferred from the first header pipe 123 into the sealed container 127.
● Chemical solution transfer process 2
In a state where the cleaning chemical solution is always present on the primary side 122 and the secondary side 125 of the membrane modules 121a to 121e, compressed air is sent from the compressed air supply unit 128 into the sealed container 127, and the cleaning chemical solution in the sealed container 127 is sealed. It discharges | emits from the container 127 to the 1st header pipe | tube 123, is transferred to the direction of the membrane modules 121a-121e from the 1st header pipe | tube 123, and the membrane element 129 of the membrane modules 121a-121e and a cleaning chemical | medical solution are made to contact continuously. And the cleaning chemical | medical solution after a contact is transferred in the 2nd header pipe | tube 124 from the membrane modules 121a-121e.

  However, Patent Document 1 does not describe a method of flushing each membrane module 121a to 121e by flowing a gas-liquid mixed phase fluid obtained by mixing backwash water and compressed air into each membrane module 121a to 121e. . Further, when the chemical solution transfer step 1 and the chemical solution transfer step 2 are alternately repeated, the amount of the cleaning chemical solution transferred to the membrane module 121a on one end connected to the location closest to the sealed container 127 increases, and the sealed container There is a possibility that the amount of the cleaning chemical transferred to the membrane module 121e on the other end side connected to the position farthest from 127 may be reduced, and there is a problem that cleaning of each of the membrane modules 121a to 121e becomes uneven.

  An object of this invention is to provide the membrane separation system which can wash | clean the membrane module connected in parallel substantially uniformly, and the washing | cleaning method of the membrane module of a membrane separation system.

In order to achieve the above object, the first aspect of the present invention includes a liquid supply port for supplying a liquid to be processed to the primary side, a permeate outlet for taking out the permeate that has permeated to the secondary side, and a flushing fluid. A membrane separation system for performing membrane filtration operation by connecting a plurality of membrane modules having a flushing fluid supply port supplied to the primary side in parallel,
To-be-processed liquid supply header pipes for supplying the to-be-treated liquid to the to-be-treated liquid supply port of each membrane module;
A flushing fluid supply header pipe for supplying a flushing fluid to a flushing fluid supply port of each membrane module;
Backwash fluid supply means for pressurizing the inside of the permeate header pipe to flow backwash fluid from the secondary side to the primary side of the membrane module and backwashing is connected to the permeate header pipe,
One end of the flushing fluid supply header pipe corresponding to the membrane module, wherein the flushing fluid supply means for supplying the flushing fluid into the flushing fluid supply header pipe is disposed at one end of the plurality of parallel membrane modules. Connected to
In addition to the treatment liquid supply header pipe corresponding to the membrane module disposed at the other end of the plurality of parallel membrane modules, the discharge path of the cleaning waste liquid discharged from the treatment liquid supply port at the time of washing the membrane module is connected to the end,
The cleaning waste liquid is a gas-liquid mixed phase cleaning waste liquid in which a flushing fluid and a backwashing fluid are mixed.
Flushing compressed air is used as the flushing fluid,
Backwash water is used as the backwash fluid .

  According to this, in the flushing step, the flushing fluid is supplied from the flushing fluid supply means to one end of the flushing fluid supply header pipe while the backwash fluid is supplied from the backwash fluid supply means to the permeate header pipe. . Thereby, the backwashing fluid is supplied from the permeate header pipe to the secondary side of each membrane module, and the flushing fluid is supplied from the flushing fluid supply header pipe to the primary side of each membrane module. In the inside, the backwashing fluid and the flushing fluid are mixed to form a gas-liquid mixed phase fluid, and this gas-liquid mixed phase fluid flows through each membrane module and flows out into the liquid supply header pipe to be processed to be covered as cleaning waste liquid. The liquid is discharged from the other end of the processing liquid supply header pipe to the discharge path.

  Thereby, the turbidity in the membrane module is discharged together with the gas-liquid mixed phase fluid from the to-be-processed liquid supply header pipe to the discharge path as cleaning waste liquid.

  In the flushing step, the flushing fluid is supplied to the primary side of each membrane module while flowing from one end to the other end of the flushing fluid supply header tube, and flows out from each membrane module to the liquid supply header tube to be processed. The liquid to be treated is discharged from the other end of the header pipe to the discharge path. Therefore, the length of the path from when the flushing fluid is supplied to one end of the flushing fluid supply header pipe to when it is discharged from the other end of the liquid supply header pipe to be processed to the discharge path is the same for each membrane module. Become. Thereby, the ease of flow of the flushing fluid is equalized between the membrane modules, and the flow rate of the flushing fluid flowing through the membrane modules is almost equalized.

  As for the backwashing fluid, when the backwashing fluid passes through each membrane module from the secondary side to the primary side, the membrane element in the membrane module becomes a resistance. Regardless of the length of the passage from the other end of the treated liquid supply header pipe to the discharge path after being supplied to the header pipe, there is a significant difference in the ease of flow of the backwash fluid in each membrane module. There is no. For this reason, a substantially equal amount of backwash fluid flows through each membrane module.

  As a result, the gas-liquid mixed phase fluid in which the flushing fluid and the backwash fluid are mixed in the flushing step flows almost uniformly in each membrane module, so that each membrane module is almost evenly washed.

  As described above, the flow rate of the flushing fluid in each membrane module is equalized, so that the flushing fluid is not concentrated and supplied to any particular membrane module. It is possible to prevent air accumulation from occurring at the top of the membrane, and there is no shortage of cleaning of the top of any particular membrane module.

The second aspect of the present invention is a liquid supply port for supplying a liquid to be processed to the primary side, a permeate outlet for taking out the permeate that has permeated to the secondary side, and a flushing fluid for supplying a flushing fluid to the primary side. A membrane separation system for performing membrane filtration operation by connecting a plurality of membrane modules having a supply port in parallel,
To-be-treated supply header pipes for supplying the to-be-treated liquid to the to-be-treated liquid supply port of each membrane module, and the permeate header pipe through which the permeate taken out from the permeate outlet of each membrane module flows,
A flushing fluid supply header pipe for supplying a flushing fluid to a flushing fluid supply port of each membrane module;
Backwash fluid supply means for pressurizing the inside of the permeate header pipe to flow backwash fluid from the secondary side to the primary side of the membrane module and backwashing is connected to the permeate header pipe,
The flushing fluid supply means for supplying the flushing fluid into the flushing fluid supply header pipe is a flushing fluid supply header pipe corresponding to the membrane module disposed at the other end of the plurality of parallel membrane modules. Connected to the other end,
A cleaning waste liquid discharging path discharged from the processing liquid supply port when cleaning the membrane module is connected to one end of the processing liquid supply header pipe corresponding to the membrane module disposed at one end of the plurality of parallel membrane modules. Connected ,
The cleaning waste liquid is a gas-liquid mixed phase cleaning waste liquid in which a flushing fluid and a backwashing fluid are mixed.
Flushing compressed air is used as the flushing fluid,
Backwash water is used as the backwash fluid .

  According to this, in the flushing step, the flushing fluid is supplied to the primary side of each membrane module while flowing from the other end to the one end of the flushing fluid supply header tube, and from each membrane module to the liquid supply header tube to be processed. It flows out and is discharged from one end of the liquid supply header pipe to be processed into the discharge path. For this reason, the length of the path from when the flushing fluid is supplied to the other end of the flushing fluid supply header pipe to when it is discharged from one end of the liquid supply header pipe to be processed to the discharge path is equal for each membrane module. Become. Thereby, the ease of flow of the flushing fluid is equalized between the membrane modules, and the flow rate of the flushing fluid flowing through the membrane modules is almost equalized.

  As for the backwashing fluid, when the backwashing fluid passes through each membrane module from the secondary side to the primary side, the membrane element in the membrane module becomes a resistance. Regardless of the length of the path from the end of the liquid supply header pipe to be processed to the discharge path after being supplied to the header pipe, there is a significant difference in the ease of flow of backwashing fluid in each membrane module. No. For this reason, a substantially equal amount of backwash fluid flows through each membrane module.

  As a result, the gas-liquid mixed phase fluid in which the flushing fluid and the backwash fluid are mixed in the flushing step flows almost uniformly in each membrane module, so that each membrane module is almost evenly washed.

The third aspect of the invention is a liquid supply port for supplying a liquid to be processed to the primary side, a permeate outlet for taking out the permeated liquid that has permeated to the secondary side, and a flushing fluid for supplying a flushing fluid to the primary side. A membrane separation system for performing membrane filtration operation by connecting a plurality of membrane modules having a supply port in parallel,
To-be-processed liquid supply header pipes for supplying the to-be-treated liquid to the to-be-treated liquid supply port of each membrane module;
A flushing fluid supply header pipe for supplying a flushing fluid to a flushing fluid supply port of each membrane module;
Backwash fluid supply means for pressurizing the inside of the permeate header pipe to flow backwash fluid from the secondary side to the primary side of the membrane module and backwashing is connected to the permeate header pipe,
Flushing fluid supply means for supplying the flushing fluid into the flushing fluid supply header pipe is connected to an intermediate portion between both ends of the flushing fluid supply header pipe,
A discharge path of cleaning waste liquid discharged from the processing liquid supply port when the membrane module is cleaned is connected to both ends of the processing liquid supply header pipe,
The length of the path from when the flushing fluid is supplied to the intermediate portion of the flushing fluid supply header pipe to when it is discharged from both ends of the liquid supply header pipe to be processed into both discharge paths is equal for each membrane module. Configured ,
The cleaning waste liquid is a gas-liquid mixed phase cleaning waste liquid in which a flushing fluid and a backwashing fluid are mixed.
Flushing compressed air is used as the flushing fluid,
Backwash water is used as the backwash fluid .

According to this, in the flushing process, the flushing fluid is supplied from the flushing fluid supply means to the intermediate portion of the flushing fluid supply header pipe while the backwash fluid is supplied from the backwash fluid supply means to the permeate header pipe. To do. Thereby, the backwashing fluid is supplied from the permeate header pipe to the secondary side of each membrane module, and the flushing fluid is supplied from the flushing fluid supply header pipe to the primary side of each membrane module. In the inside, the backwashing fluid and the flushing fluid are mixed to form a gas-liquid mixed phase fluid, and this gas-liquid mixed phase fluid flows through each membrane module and flows out into the liquid supply header pipe to be processed to be covered as cleaning waste liquid. The liquid is discharged from both ends of the processing liquid supply header pipe to the discharge path.

  Thereby, the turbidity in the membrane module is discharged together with the gas-liquid mixed phase fluid from the to-be-processed liquid supply header pipe to the discharge path as cleaning waste liquid.

In the flushing step, the flushing fluid is supplied to the primary side of each membrane module while flowing from the intermediate portion of the flushing fluid supply header tube toward both ends, and flows out from each membrane module to the liquid supply header tube to be processed. The liquid to be treated is discharged from both ends of the header pipe to be discharged into both discharge paths. For this reason, the length of the path from when the flushing fluid is supplied to the middle part of the flushing fluid supply header pipe to when it is discharged from both ends of the liquid supply header pipe to be processed into both discharge paths is determined by each membrane module. Will be equal. Thereby, the ease of flow of the flushing fluid is equalized between the membrane modules, and the flow rate of the flushing fluid flowing through the membrane modules is almost equalized.

  As for the backwashing fluid, when the backwashing fluid passes through each membrane module from the secondary side to the primary side, the membrane element in the membrane module becomes a resistance. Regardless of the length of the path from the end of the liquid supply header pipe that is supplied to the header pipe to the two outlet paths, there is a significant difference in the ease of backwash fluid flow in each membrane module. There is no. For this reason, a substantially equal amount of backwash fluid flows through each membrane module.

  As a result, the gas-liquid mixed phase fluid in which the flushing fluid and the backwash fluid are mixed in the flushing step flows almost uniformly in each membrane module, so that each membrane module is almost evenly washed.

The membrane separation system according to the fourth aspect of the present invention includes a treatment liquid supply branch pipe branched from the treatment liquid supply header pipe and connected to a treatment liquid supply port of each membrane module;
A flushing fluid supply branch pipe branched from the flushing fluid supply header pipe and connected to the flushing fluid supply port of each membrane module;
When the backwash fluid is passed, the pressure loss of the flushing fluid supply branch pipe is set to be larger than the pressure loss of the liquid supply branch pipe to be treated.

  According to this, in the flushing process, the backwashing fluid supplied from the permeate header pipe to the membrane module through the permeate outlet branch pipe passes from the membrane module to the flushing fluid supply branch pipe, and the flushing fluid supply header pipe It can suppress flowing into the. For this reason, the backwash fluid supplied to the membrane module is surely discharged from the membrane module to the liquid supply header pipe through the liquid supply branch pipe.

  In the membrane separation system according to the fifth aspect of the present invention, the flushing fluid supply branch has a throttle.

  According to this, since the resistance of the flushing fluid supply branch pipe is increased by the throttle portion, the backwashing fluid supplied from the permeate header pipe to the membrane module through the permeate outlet branch pipe is transferred from the membrane module to the flushing fluid. It is possible to suppress the flow into the flushing fluid supply header pipe through the supply branch pipe. For this reason, the backwash fluid supplied to the membrane module is surely discharged from the membrane module to the liquid supply header pipe through the liquid supply branch pipe.

The membrane separation system according to the sixth aspect of the invention includes a backwashing fluid supply means and a flushing fluid supply means having a common pressure vessel and a compressor connected to the pressure vessel,
The inside of the pressure vessel consists of a liquid phase part and a gas phase part,
A permeate header pipe is connected to the liquid phase,
A flushing fluid supply header pipe is connected to the gas phase part,
Liquid phase water is used as backwash fluid,
Compressed air in the gas phase is used as a flushing fluid.

  According to this, the gas phase portion in the pressure vessel is compressed by the compressor, and the liquid phase portion and the gas phase portion in the pressure vessel are pressurized. In the flushing process, the gas in the gas phase is supplied from the pressure vessel to the flushing fluid supply header tube as the flushing fluid while the liquid in the liquid phase is supplied from the pressure vessel to the permeate header as the backwash fluid. To do.

  Further, since the backwashing fluid supply means and the flushing fluid supply means have a common pressure vessel, the number of devices is reduced.

The seventh aspect of the present invention is a treatment liquid supply port for supplying a treatment liquid to the primary side, a permeate outlet for taking out the permeate that has permeated to the secondary side, and a flushing fluid for supplying a flushing fluid to the primary side. A plurality of membrane modules having a supply port are connected in parallel,
To-be-treated supply header pipes for supplying the to-be-treated liquid to the to-be-treated liquid supply port of each membrane module, and the permeate header pipe through which the permeate taken out from the permeate outlet of each membrane module flows,
A flushing fluid supply header pipe for supplying a flushing fluid to a flushing fluid supply port of each membrane module;
The liquid supply header pipe to be processed and the fluid supply header pipe for flushing are pipes extending along the parallel direction of the membrane module,
Backwash fluid supply means for pressurizing the inside of the permeate header pipe to flow backwash fluid from the secondary side to the primary side of the membrane module and backwashing is connected to the permeate header pipe,
A flushing fluid supply means for supplying a flushing fluid into a flushing fluid supply header pipe is a method for cleaning a membrane module of a membrane separation system connected to a flushing fluid supply header pipe,
While supplying the backwashing fluid from the permeate header pipe to the secondary side of each membrane module by the backwashing fluid supply means, the flushing fluid is supplied from the flushing fluid supply header pipe to the primary side of each membrane module by the flushing fluid supply means. A flushing step of discharging the gas-liquid mixed phase fluid of the backwashing fluid and the flushing fluid discharged from each membrane module into the processed liquid supply header pipe from the processed liquid supply header pipe ,
In the flushing process, the direction in which the flushing fluid flows in the flushing fluid supply header pipe, and the gas-liquid mixed phase fluid of the backwashing fluid and the flushing fluid discharged from each membrane module into the liquid feed header pipe are treated. The flow direction in the liquid supply header pipe is the same.

  According to this, in the flushing step, the flushing fluid is supplied from the flushing fluid supply means to the flushing fluid supply header pipe while the backwash fluid is supplied from the backwash fluid supply means to the permeate header pipe. Thereby, the backwashing fluid is supplied from the permeate header pipe to the secondary side of each membrane module, and the flushing fluid is supplied from the flushing fluid supply header pipe to the primary side of each membrane module. In the inside, the backwashing fluid and the flushing fluid are mixed to form a gas-liquid mixed phase fluid, and this gas-liquid mixed phase fluid flows through each membrane module and flows out into the liquid supply header pipe to be processed to be covered as cleaning waste liquid. It is discharged from the processing liquid supply header pipe. Thereby, the turbidity in the membrane module is discharged as cleaning waste liquid from the liquid supply header pipe together with the gas-liquid mixed phase fluid.

  At this time, there are a direction in which the flushing fluid flows in the flushing fluid supply header pipe and a direction in which the gas-liquid mixed phase fluid discharged from each membrane module into the liquid supply header pipe is discharged from the liquid supply header pipe. Since the same is true, the length of the path from when the flushing fluid is supplied to the flushing fluid supply header pipe to when the flushing fluid is discharged from the liquid supply header pipe to be processed is equal for each membrane module. Thereby, the ease of flow of the flushing fluid is equalized between the membrane modules, and the flow rate of the flushing fluid flowing through the membrane modules is almost equalized.

  As for the backwashing fluid, when the backwashing fluid passes through each membrane module from the secondary side to the primary side, the membrane element in the membrane module becomes a resistance. Regardless of the length of the path from being supplied to the header pipe to being discharged from the liquid supply header pipe to be processed, there is no significant difference in the ease of flow of the backwashing fluid in each membrane module. For this reason, a substantially equal amount of backwash fluid flows through each membrane module.

  As a result, the gas-liquid mixed phase fluid in which the flushing fluid and the backwash fluid are mixed in the flushing step flows almost uniformly in each membrane module, so that each membrane module is almost evenly washed.

The membrane module cleaning method of the membrane separation system according to the eighth aspect of the present invention has a backwashing step before the flushing step,
In the backwashing process, the backwashing fluid supply means supplies the backwashing fluid from the permeate header pipe to the secondary side of each membrane module, and the backwashing fluid flowing from the secondary side to the primary side is supplied to each membrane module. To the liquid supply header pipe to be processed and discharged from the liquid supply header pipe to be processed.

  According to this, each membrane module is sufficiently cleaned by performing the flushing step after the backwashing step.

  According to the ninth aspect of the present invention, there is provided a method for cleaning a membrane module of a membrane separation system in which the backwashing fluid supply by the backwashing fluid supply means and the flushing fluid supply by the flushing fluid supply means are performed from a common pressure vessel. It is what is said.

The membrane module cleaning method of the membrane separation system according to the tenth aspect of the present invention is the membrane separation system in which the membrane separation system branches from the liquid feed header pipe to be treated and is connected to the liquid feed inlet of each membrane module. And a flushing fluid supply branch pipe branched from the flushing fluid supply header pipe and connected to the flushing fluid supply port of each membrane module,
The pressure loss of the flushing fluid supply branch when the backwash fluid passes is set to be larger than the pressure loss of the liquid supply branch to be processed.

  As described above, according to the present invention, a plurality of membrane modules connected in parallel can be cleaned almost evenly.

It is a figure which shows the structure of the membrane separation system in the 1st Embodiment of this invention. It is a figure which shows the structure of a membrane separation system similarly, and shows the state which is performing the membrane filtration process. It is a figure which shows the structure of a membrane separation system similarly and shows the state which is performing the backwashing process. It is a figure which shows the structure of a membrane separation system similarly, and shows the state which is performing the flushing process. It is a figure which shows the structure of the membrane separation system in the 2nd Embodiment of this invention, and shows the state which is performing the flushing process. It is a figure which shows the structure of the membrane separation system in the 3rd Embodiment of this invention, and shows the state which is performing the flushing process. It is a figure which shows the structure of the membrane separation system in the 4th Embodiment of this invention, and shows the state which is performing the flushing process. It is a figure which shows the structure of the membrane separation system in the 5th Embodiment of this invention, and shows the state which is performing the flushing process. It is a figure which shows the structure of the membrane separation system in the 6th Embodiment of this invention, and shows the state which is performing the flushing process. It is a figure which shows the structure of the membrane separation system in the 7th Embodiment of this invention, and shows the state which is performing the flushing process. It is a figure which shows the structure of the conventional membrane separation system, and shows the state which is performing the membrane filtration process. It is a figure which shows the structure of a membrane separation system similarly and shows the state which is performing the backwashing process. It is a figure which shows the structure of a membrane separation system similarly, and shows the state which is performing the flushing process. It is a figure which shows the structure of another conventional membrane separation system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
In the first embodiment, as shown in FIG. 1, reference numeral 1 denotes a membrane separation system that performs a membrane filtration operation by connecting a plurality of membrane modules 2a to 2j in parallel, and is used for, for example, water purification treatment. is there. Each of the membrane modules 2 a to 2 j has a casing 4 and a membrane element 5 accommodated in the casing 4.

  The casing 4 has a treated liquid supply port 8 for supplying the treated water A (an example of the treated liquid) to the upstream portion of the primary side 7 and a permeated water B (an example of the permeated liquid) that has permeated the secondary side 9. It has a permeate outlet 10 to be taken out and a flushing fluid supply port 11 for supplying compressed air C for flushing (an example of a flushing fluid) to the downstream portion of the primary side 7.

  Further, the membrane separation system 1 branches from the liquid supply header pipe 14 to be processed for supplying the liquid to be processed A to the liquid supply ports 8 to be processed of the membrane modules 2 a to 2 j and the liquid supply header pipe 14 to be processed. Then, the permeated water B taken out from the permeate outlet 10 of each of the membrane modules 2a to 2j and the permeate B taken out from the permeate outlet 10 of each of the membrane modules 2a to 2j flows. A liquid header pipe 16, a permeate outlet branch pipe 17 branched from the permeate header pipe 16 and connected to the permeate outlet 10 of each membrane module 2a-2j, and a flushing fluid supply for each membrane module 2a-2j A flushing fluid supply header pipe 18 for supplying the compressed air C to the port 11, and a branch from the flushing fluid supply header pipe 18 to contact the flushing fluid supply port 11 of each membrane module 2a to 2j. A flushing fluid supply branch 19 to be is provided.

  Supplying backwashing fluid to pressurize the inside of the permeate header pipe 16 and flow backwashing water D (an example of backwashing fluid) from the secondary side 9 to the primary side 7 of the membrane modules 2a to 2j. Means 21 is connected to the permeate header tube 16. A flushing fluid supply means 22 for supplying the compressed air C into the flushing fluid supply header pipe 18 is connected to the flushing fluid supply header pipe 18.

  The backwash fluid supply means 21 and the flushing fluid supply means 22 share a common pressure vessel 24 (tank) and a compressor 25 (compressor) connected to the pressure vessel 24. The inside of the pressure vessel 24 is composed of a liquid phase portion 26 and a gas phase portion 27. The backwash water D in the liquid phase portion 26 is used as a backwash fluid, and the compressed air C in the gas phase portion 27 is used as a flushing fluid. Is done.

  Further, the flushing fluid supply means 22 includes a flushing fluid supply path 30 connected between the flushing fluid supply header pipe 18 and the pressure vessel 24, and a flushing fluid supply provided in the flushing fluid supply path 30. And a valve 31. The flushing fluid supply path 30 is a pipe line, and one end is connected to the gas phase portion 27 in the pressure vessel 24 and the other end is connected to one end 18 a of the flushing fluid supply header pipe 18. One end 18a of the flushing fluid supply header pipe 18 is an end corresponding to the membrane module 2a disposed at one end 33 of the plurality of membrane modules 2a to 2j.

  Thus, the flushing fluid supply header pipe 18 and the gas phase portion 27 in the pressure vessel 24 are connected via the flushing fluid supply path 30.

  Further, an air vent path 35 for venting the compressed air C in the flushing fluid supply header pipe 18 is branched from the flushing fluid supply path 30. An air vent valve 36 is provided in the air vent path 35.

  Connected to the other end 16 b of the permeate header pipe 16 is a permeate discharge path 39 for discharging the permeate B in the permeate header pipe 16. The other end 16b of the permeate header pipe 16 is an end corresponding to the membrane module 2j arranged at the other end 34 of the plurality of membrane modules 2a to 2j. A permeate discharge valve 40 is provided in the permeate discharge path 39.

  The backwash fluid supply means 21 includes a backwash fluid supply path 41 having one end connected to the liquid phase portion 26 in the pressure vessel 24 and the other end connected to the permeate discharge path 39, and a backwash fluid supply. And a backwash fluid supply valve 42 provided in the path 41.

  Thereby, the permeate header pipe 16 and the liquid phase part 26 in the pressure vessel 24 are connected via the backwash fluid supply path 41.

  A treatment liquid supply path 44 for supplying the treatment water A to the treatment liquid supply header pipe 14 is connected to the other end 14 b of the treatment liquid supply header pipe 14. In the liquid supply path 44, a liquid supply valve 45 and a liquid supply pump 46 are provided. The other end 14 b of the liquid supply header pipe 14 to be processed is an end corresponding to the membrane module 2 j disposed at the other end 34.

  Further, a discharge path 48 for the cleaning waste liquid E discharged from the processing liquid supply port 8 when the membrane modules 2a to 2j are cleaned is branched from the processing liquid supply path 44. A discharge valve 49 is provided in the discharge path 48. As a result, the discharge path 48 is connected to the other end 14 b of the liquid supply header pipe 14 to be processed via a part of the liquid supply path 44 to be processed.

  Note that the gas phase portion 27 in the pressure vessel 24 is compressed by the compressor 25, and the liquid phase portion 26 and the gas phase portion 27 in the pressure vessel 24 are pressurized.

  The backwash fluid supply means 21 and the flushing fluid supply means 22 are arranged next to the membrane module 2j at the other end 34.

  Hereinafter, the operation of the above configuration will be described.

  The operation in the membrane separation system 1 includes the following normal membrane filtration step and a washing step for washing the membrane modules 2a to 2j.

  In the membrane filtration step, as shown in FIG. 2, the permeate discharge valve 40 and the liquid supply valve 45 to be processed are opened, and the other valves 31, 36, 42, and 49 are closed. Thereby, the to-be-processed water A is supplied to the to-be-processed liquid supply header pipe 14 from the to-be-processed liquid supply path 44, flows in into the membrane modules 2a-2j through each to-be-processed liquid supply branch pipe 15, and a membrane element. 5 passes from the primary side 7 to the secondary side 9 and is taken out as permeate B from each permeate outlet branch pipe 17 into the permeate header pipe 16 and from the permeate header pipe 16 through the permeate discharge path 39. And discharged to the outside of the membrane separation system 1. Thereby, the foreign material in the to-be-processed water A is filtered by the membrane element 5 of membrane module 2a-2j.

  Moreover, the washing | cleaning process has the following backwashing processes and flushing processes.

Backwashing process In the backwashing process, as shown in FIG. 3, the backwashing fluid supply valve 42 and the discharge valve 49 are opened, and the other valves 31, 36, 40, 45 are closed. As a result, the backwash water D in the pressure vessel 24 flows through the backwash fluid supply path 41 and is supplied to the permeate header pipe 16, and from the permeate header pipe 16 through each permeate outlet branch pipe 17. 2a to 2j, the membrane element 5 flows backward from the secondary side 9 to the primary side 7, flows out through the liquid supply branch pipes 15 to the liquid supply header pipe 14 to be processed, and is used as cleaning waste liquid E. The liquid to be treated is discharged from the header pipe 14 to the outside of the membrane separation system 1 through the discharge path 48.

  Thereby, the foreign material adhering to the membrane element 5 is peeled off and discharged from the discharge path 48 together with the cleaning waste liquid E.

  In addition, the said backwashing process is performed before the flushing process demonstrated below.

In the flushing step, as shown in FIG. 4, the flushing fluid supply valve 31, the backwash fluid supply valve 42, and the discharge valve 49 are opened, and the other valves 36, 40, 45 are closed. As a result, the backwash water D in the pressure vessel 24 passes through the backwash fluid supply path 41, the permeate header pipe 16, and the permeate outlet branch pipes 17 in the same manner as in the backwash process. The compressed air C in the pressure vessel 24 is supplied from the flushing fluid supply path 30 to the flushing fluid supply header pipe 18, and is supplied from the flushing fluid supply header pipe 18. It is supplied to the primary side 7 in each membrane module 2a-2j via each flushing fluid supply branch pipe 19.

  The compressed air C and the backwash water D supplied into the membrane modules 2a to 2j in this way are mixed in the membrane modules 2a to 2j to form a gas-liquid mixed phase fluid F. The gas-liquid mixed phase fluid F is Then, each membrane module 2a to 2j flows into the liquid supply header pipe 14 through the liquid supply branch pipes 15 to be processed and flows out from the liquid supply header pipe 14 through the discharge path 48 as the cleaning waste liquid E. It is discharged outside the membrane separation system 1.

  Thereby, the turbidity in each of the membrane modules 2a to 2j is discharged together with the gas-liquid mixed phase fluid F from the processing target liquid supply header pipe 14 to the discharge path 48 as the cleaning waste liquid E.

  In the flushing step, the compressed air C flows through the flushing fluid supply branch pipes 19 while flowing from one end 18a of the flushing fluid supply header pipe 18 toward the other end 18b, and the primary side 7 of each membrane module 2a-2j. To the liquid supply header pipe 14 through the liquid supply branch pipe 15 from the membrane modules 2a to 2j, and discharged from the other end 14b of the liquid supply header pipe 14 to the discharge path 48. Is done. For this reason, the length of the path from when the compressed air C is supplied to the one end 18a of the flushing fluid supply header pipe 18 until it is discharged from the other end 14b of the liquid supply header pipe 14 to be processed to the discharge path 48 is It becomes equal in each membrane module 2a-2j. Thereby, the ease of flow of the compressed air C is equalized between the membrane modules 2a to 2j, and the flow rate of the compressed air C flowing through the membrane modules 2a to 2j is substantially equalized.

  For example, for the membrane module 2a at the one end portion 33, a path from the one end 18a of the flushing fluid supply header pipe 18 through the flushing fluid supply branch pipe 19 to the flushing fluid supply port 11 of the membrane module 2a at the one end portion 33. Is the shortest, but the path from the liquid supply port 8 of the membrane module 2a of the one end 33 through the liquid supply branch pipe 15 to the other end 14b of the liquid supply header pipe 14 to be processed. Is the longest.

  Further, the membrane module 2j at the other end 34 passes from the one end 18a of the flushing fluid supply header pipe 18 through the flushing fluid supply branch pipe 19 to the flushing fluid supply port 11 of the membrane module 2j at the other end 34. While the length of the route to reach is the longest, the other end 14b of the target liquid supply header pipe 14 passes through the target liquid supply branch pipe 15 from the target liquid supply port 8 of the membrane module 2j of the other end 34. The length of the route leading to is the shortest.

  For this reason, the length of the path from the one end 18a of the flushing fluid supply header pipe 18 to the other end 14b of the liquid supply header pipe 14 to be processed is equal in each of the membrane modules 2a to 2j.

  Moreover, about the backwash water D, when the backwash water D passes through the membrane modules 2a to 2j from the secondary side 9 to the primary side 7, the membrane element 5 becomes a resistance. Regardless of the length of the path from the supply of the permeated liquid header pipe 16 to the discharge path 48 from the other end 14b of the liquid supply header pipe 14 to be treated, the backwash water in each membrane module 2a to 2j. There is no significant difference in the flowability of D. For this reason, a substantially equal amount of backwash water D flows through each of the membrane modules 2a to 2j.

  As a result, the gas-liquid mixed phase fluid F in which the compressed air C and the backwash water D are mixed in the flushing step flows almost evenly in the membrane modules 2a to 2j, so that the membrane modules 2a to 2j are almost even. Washed.

  As described above, since the flow rate of the compressed air C in each of the membrane modules 2a to 2j is equalized, the compressed air C is not concentratedly supplied to any specific membrane module. It is possible to prevent air accumulation from occurring in the upper part of the membrane module, and there is no shortage of cleaning of the upper part in any particular membrane module.

  Further, since the backwash fluid supply means 21 and the flushing fluid supply means 22 have a common pressure vessel 24 and compressor 25, the number of parts is reduced.

  In the flushing step, the direction in which the compressed air C flows through the flushing fluid supply header pipe 18 and the direction in which the gas-liquid mixed phase fluid F is discharged as the cleaning waste liquid E from the liquid supply header pipe 14 to the discharge path 48. Is the same.

  Thus, the length of the path from when the compressed air C is supplied to the one end 18a of the flushing fluid supply header pipe 18 to when the compressed air C is discharged from the other end 14b of the liquid supply header pipe 14 to be discharged to the discharge path 48 is It becomes equal in each membrane module 2a-2j.

(Second Embodiment)
In the second embodiment, as shown in FIG. 5, the flushing fluid supply header 30 of the flushing fluid supply means 22 corresponds to the membrane module 2j disposed at the other end 34. 18 is connected to the other end 18b.

  Further, the liquid supply path 44 to be processed is connected to one end 14 a of the liquid supply header pipe 14 to be processed corresponding to the membrane module 2 a disposed at the one end 33. The discharge path 48 is branched from the liquid supply path 44 to be processed. Thus, the discharge path 48 is connected to one end 14 a of the liquid supply header pipe 14 to be processed via a part of the liquid supply path 44 to be processed.

  Hereinafter, the operation of the above configuration will be described.

  About the membrane filtration process and the backwash process, since the effect | action and effect similar to the said 1st Embodiment are acquired, description is abbreviate | omitted.

  In the flushing step, the flushing fluid supply valve 31, the backwash fluid supply valve 42, and the discharge valve 49 are opened, and the other valves 36, 40, and 45 are closed. As a result, the backwash water D in the pressure vessel 24 passes through the backwash fluid supply path 41, the permeate header pipe 16, and each permeate outlet branch pipe 17 to the secondary side 9 in each membrane module 2 a to 2 j. In addition, the compressed air C in the pressure vessel 24 is supplied from the flushing fluid supply path 30 to the flushing fluid supply header pipe 18, and the flushing fluid supply header pipe 18 passes through each flushing fluid supply branch pipe 19. Then, it is supplied to the primary side 7 in each membrane module 2a-2j.

  The compressed air C and the backwash water D supplied into the membrane modules 2a to 2j in this way are mixed in the membrane modules 2a to 2j to form a gas-liquid mixed phase fluid F. The gas-liquid mixed phase fluid F is Then, each membrane module 2a to 2j flows into the liquid supply header pipe 14 through the liquid supply branch pipes 15 to be processed and flows out from the liquid supply header pipe 14 through the discharge path 48 as the cleaning waste liquid E. It is discharged outside the membrane separation system 1.

  Thereby, the turbidity in each of the membrane modules 2a to 2j is discharged together with the gas-liquid mixed phase fluid F from the processing target liquid supply header pipe 14 to the discharge path 48 as the cleaning waste liquid E.

  In the flushing step, the compressed air C flows from the other end 18b of the flushing fluid supply header pipe 18 toward the one end 18a while passing through the flushing fluid supply branch pipes 19 to the primary side 7 of each membrane module 2a to 2j. , Flows out from the membrane modules 2a to 2j to the liquid supply header pipe 14 through the liquid supply branch pipe 15, and is discharged from one end 14a of the liquid supply header pipe 14 to the discharge path 48. . For this reason, the length of the path from when the compressed air C is supplied to the other end 18b of the flushing fluid supply header pipe 18 to when the compressed air C is discharged from the one end 14a of the liquid supply header pipe 14 to be discharged to the discharge path 48 is It becomes equal in each membrane module 2a-2j. Thereby, the ease of flow of the compressed air C is equalized between the membrane modules 2a to 2j, and the flow rate of the compressed air C flowing through the membrane modules 2a to 2j is substantially equalized.

  Moreover, about the backwash water D, when the backwash water D passes through the membrane modules 2a to 2j from the secondary side 9 to the primary side 7, the membrane element 5 becomes a resistance. Regardless of the length of the path from the supply of the permeate header pipe 16 to the discharge path 48 from the one end 14a of the liquid supply header pipe 14 to be treated, the backwash water D is used in each of the membrane modules 2a to 2j. There is no significant difference in the ease of flow. For this reason, a substantially equal amount of backwash water D flows through each of the membrane modules 2a to 2j.

  As a result, the gas-liquid mixed phase fluid F in which the compressed air C and the backwash water D are mixed in the flushing step flows almost evenly in the membrane modules 2a to 2j, so that the membrane modules 2a to 2j are almost even. Washed.

  In the flushing step, the direction in which the compressed air C flows through the flushing fluid supply header pipe 18 and the direction in which the gas-liquid mixed phase fluid F is discharged as the cleaning waste liquid E from the liquid supply header pipe 14 to the discharge path 48. Is the same.

(Third embodiment)
In the third embodiment, as shown in FIG. 6, the discharge path 48 is connected to one end 14 a of the liquid supply header pipe 14 to be processed, and the liquid supply path 44 is the other end of the liquid supply header pipe 14 to be processed. 14b.

  According to this, the same operation and effect as in the second embodiment can be obtained. In the flushing step, the direction in which the compressed air C flows through the flushing fluid supply header pipe 18 and the direction in which the gas-liquid mixed phase fluid F is discharged as the cleaning waste liquid E from the liquid supply header pipe 14 to the discharge path 48. Is the same.

(Fourth embodiment)
In the fourth embodiment, as shown in FIG. 7, the backwash fluid supply means 21 and the flushing fluid supply means 22 are arranged next to the membrane module 2 a at the one end 33.

  According to this, the same operation and effect as the first embodiment can be obtained. In the flushing step, the direction in which the compressed air C flows through the flushing fluid supply header pipe 18 and the direction in which the gas-liquid mixed phase fluid F is discharged as the cleaning waste liquid E from the liquid supply header pipe 14 to the discharge path 48. Is the same.

(Fifth embodiment)
In the fifth embodiment, as shown in FIG. 8, the backwash fluid supply means 21 includes a first pressure vessel 55 that stores backwash water D therein, and a first pressure vessel 55 that is connected to the first pressure vessel 55. A compressor 56, a backwash fluid supply path 41 having one end connected to the first pressure vessel 55 and the other end connected to the permeate discharge path 39, and a reverse provided in the backwash fluid supply path 41 And a flush fluid supply valve 42.

  The flushing fluid supply means 22 includes a second pressure vessel 59 storing the compressed air C therein, a second compressor 60 connected to the second pressure vessel 59, and one end connected to the second pressure vessel 59. And a flushing fluid supply path 30 having the other end connected to one end 18 a of the flushing fluid supply header pipe 18. Further, an air vent path 35 is provided to branch from the flushing fluid supply path 30.

  The operation and effect of the above configuration will be described below.

  In the flushing step, the flushing fluid supply valve 31, the backwash fluid supply valve 42, and the discharge valve 49 are opened, and the other valves 36, 40, and 45 are closed. As a result, the backwash water D in the first pressure vessel 55 of the backwash fluid supply means 21 passes through the backwash fluid supply path 41, the permeate header pipe 16, and each permeate outlet branch pipe 17 to each membrane module 2 a. ˜2j and the compressed air C in the second pressure vessel 59 of the flushing fluid supply means 22 is supplied to the flushing fluid supply path 30, the flushing fluid supply header pipe 18, and each flushing. It is supplied to the primary side 7 in each of the membrane modules 2a to 2j through the fluid supply branch pipe 19.

  The compressed air C and the backwash water D supplied into the membrane modules 2a to 2j in this way are mixed in the membrane modules 2a to 2j to form a gas-liquid mixed phase fluid F. The gas-liquid mixed phase fluid F is Then, each membrane module 2a to 2j flows into the liquid supply header pipe 14 through the liquid supply branch pipes 15 to be processed and flows out from the liquid supply header pipe 14 through the discharge path 48 as the cleaning waste liquid E. It is discharged outside the membrane separation system 1.

  In the flushing step, the direction in which the compressed air C flows through the flushing fluid supply header pipe 18 and the direction in which the gas-liquid mixed phase fluid F is discharged as the cleaning waste liquid E from the liquid supply header pipe 14 to the discharge path 48. Is the same.

(Sixth embodiment)
In the sixth embodiment, as shown in FIG. 9, the flushing fluid supply path 30 of the flushing fluid supply means 22 has one end connected to the gas phase portion 27 in the pressure vessel 24 and the other end for flushing. The fluid supply header pipe 18 is connected to an intermediate portion 18c (an example of a midway portion) between both ends 18a and 18b.

  A processing liquid supply path 44 is connected to the other end 14 b of the processing liquid supply header pipe 14, and a processing liquid supply valve 45 and a processing liquid supply pump 46 are provided in the processing liquid supply path 44. .

  In addition, one discharge path 65 of the cleaning waste liquid E discharged from the processing liquid supply port 8 at the time of cleaning the membrane modules 2 a to 2 j is connected to one end 14 a of the processing liquid supply header pipe 14. One discharge path 65 is provided with one discharge valve 66.

  Furthermore, the other discharge path 68 of the cleaning waste liquid E is provided to be branched from the liquid supply path 44 to be processed, and the other discharge path 68 is provided with the other discharge valve 69. Thereby, the other discharge path 68 is connected to the other end 14 b of the liquid supply header pipe 14 to be processed via a part of the liquid supply path 44 to be processed.

  Hereinafter, the operation of the above configuration will be described.

  In the flushing step, the flushing fluid supply valve 31, the backwash fluid supply valve 42, the discharge valves 66, 69 are opened, and the other valves 36, 40, 45 are closed. As a result, the backwash water D in the pressure vessel 24 passes through the backwash fluid supply path 41, the permeate header pipe 16, and each permeate outlet branch pipe 17 to the secondary side 9 in each membrane module 2 a to 2 j. While being supplied, the compressed air C in the pressure vessel 24 passes through the flushing fluid supply path 30, the flushing fluid supply header pipe 18, and the flushing fluid supply branch pipes 19 to be the primary in each of the membrane modules 2a to 2j. Supplied to side 7.

  The compressed air C and the backwash water D supplied into the membrane modules 2a to 2j in this way are mixed in the membrane modules 2a to 2j to form a gas-liquid mixed phase fluid F. The gas-liquid mixed phase fluid F is Then, each membrane module 2a to 2j flows out into the liquid supply header pipe 14 through the liquid supply branch pipes 15 to be processed and flows out from the liquid supply header pipe 14 into the discharge paths 65 and 68 as the cleaning waste liquid E. It is discharged to the outside of the membrane separation system 1 through.

  In the flushing step, the compressed air C flows from the intermediate portion 18c of the flushing fluid supply header pipe 18 toward both ends 18a and 18b, passes through the flushing fluid supply branch pipes 19, and is primary to the membrane modules 2a to 2j. Is supplied to the side 7, flows out from each membrane module 2a-2j through the liquid supply branch pipe 15 to be processed and flows into the liquid supply header pipe 14 to be processed, and is discharged from both ends 14a and 14b of the liquid supply header pipe 14 to be processed. Discharged to 65,68. For this reason, a path from when the compressed air C is supplied to the intermediate portion 18c of the flushing fluid supply header pipe 18 until it is discharged from both ends 14a, 14b of the liquid supply header pipe 14 to be processed into both discharge paths 65, 68. Is equal for each membrane module 2a to 2j. Thereby, the ease of flow of the compressed air C is equalized between the membrane modules 2a to 2j, and the flow rate of the compressed air C flowing through the membrane modules 2a to 2j is substantially equalized.

  Moreover, about the backwash water D, when the backwash water D passes through the membrane modules 2a to 2j from the secondary side 9 to the primary side 7, the membrane element 5 becomes a resistance. Each membrane module 2a-2j is supplied to the permeate header pipe 16 and is not related to the length of the path from the both ends 14a, 14b of the liquid supply header pipe 14 to be discharged to both discharge paths 65, 68. Thus, there is no significant difference in the ease of flow of backwash water D. For this reason, a substantially equal amount of backwash water D flows through each of the membrane modules 2a to 2j.

  As a result, the gas-liquid mixed phase fluid F in which the compressed air C and the backwash water D are mixed in the flushing step flows almost evenly in the membrane modules 2a to 2j, so that the membrane modules are almost evenly washed. .

  In the flushing step, the compressed air C flows in the flushing fluid supply header pipe 18 and the gas-liquid mixed phase fluid F is discharged as cleaning waste liquid E from the liquid supply header pipe 14 to the discharge paths 65 and 68. Is the same direction.

(Seventh embodiment)
The seventh embodiment is a modification of the first embodiment, and as shown in FIG. 10, each flushing fluid supply branch pipe 19 has a throttle 75 (orifice) that serves as a flow resistance. doing. When the backwash water D having the same flow rate is passed, the pressure loss of the flushing fluid supply branch pipe 19 is set to be larger than the pressure loss of the liquid supply branch pipe 15 to be processed by the throttle unit 75. Yes.

  According to this, each of the flushing fluid supply branch pipes 19 is provided with a throttle 75, and the pressure loss of the flushing fluid supply branch pipe 19 is set to be larger than the pressure loss of the liquid supply branch pipe 15 to be processed. Therefore, in the flushing process, part of the backwash water D supplied from the permeate header pipe 16 through the permeate outlet branch pipe 17 into the membrane modules 2a to 2j is supplied from the membrane modules 2a to 2j. It is possible to prevent the flushing fluid supply header pipe 18 from flowing through the branch pipe 19.

  For this reason, the backwash water D supplied to the membrane modules 2a to 2j is reliably discharged from the membrane modules 2a to 2j through the liquid supply branch pipe 15 to the liquid supply header pipe 14 to be processed.

  In the seventh embodiment, the flushing fluid supply branch pipe 19 of the membrane separation system 1 of the first embodiment includes the throttle portion 75. However, the second to sixth embodiments described above. The flushing fluid supply branch 19 of the membrane separation system 1 may be provided with a throttle 75.

  In each of the above embodiments, the liquid supply header pipe 14 to be processed, the permeate header pipe 16, and the flushing fluid supply header pipe 18 are straight pipes each having one end and the other end. It may be a tube. In this case, the arbitrary locations of the opposing positional relationship can be the one end and the other end.

DESCRIPTION OF SYMBOLS 1 Membrane separation system 2a-2j Membrane module 7 Primary side 8 Processed liquid supply port 9 Secondary side 10 Permeate outlet 11 Flushing fluid supply port 14 Processed liquid supply header pipe 14a One end 14b of processed liquid supply header pipe The other end 15 of the liquid supply header pipe to be processed The liquid supply branch pipe 16 The permeate header pipe 17 The permeate discharge branch pipe 18 The flushing fluid supply header pipe 18a The one end 18b of the flushing fluid supply header pipe The flushing fluid supply header pipe The other end 18c of the fluid supply header pipe for flushing (intermediate part)
19 Flushing fluid supply branch pipe 21 Backwash fluid supply means 22 Flushing fluid supply means 24 Pressure vessel 25 Compressor 26 Liquid phase part 27 Gas phase part 33 One end part 34 Other end part 48, 65, 68 Discharge path A Processed Water (liquid to be treated)
B Permeate (permeate)
C Compressed air (fluzing fluid)
D Backwash water (backwash fluid)
E Cleaning waste liquid

Claims (10)

A membrane having a processing liquid supply port for supplying a liquid to be processed to the primary side, a permeate outlet for taking out the permeated liquid that has permeated to the secondary side, and a flushing fluid supply port for supplying a flushing fluid to the primary side A membrane separation system for performing membrane filtration operation by connecting a plurality of modules in parallel,
To-be-treated supply header pipes for supplying the to-be-treated liquid to the to-be-treated liquid supply port of each membrane module, and the permeate header pipe through which the permeate taken out from the permeate outlet of each membrane module flows,
A flushing fluid supply header pipe for supplying a flushing fluid to a flushing fluid supply port of each membrane module;
Backwash fluid supply means for pressurizing the inside of the permeate header pipe to flow backwash fluid from the secondary side to the primary side of the membrane module and backwashing is connected to the permeate header pipe,
One end of the flushing fluid supply header pipe corresponding to the membrane module, wherein the flushing fluid supply means for supplying the flushing fluid into the flushing fluid supply header pipe is disposed at one end of the plurality of parallel membrane modules. Connected to
In addition to the treatment liquid supply header pipe corresponding to the membrane module disposed at the other end of the plurality of parallel membrane modules, the discharge path of the cleaning waste liquid discharged from the treatment liquid supply port at the time of washing the membrane module is connected to the end,
The cleaning waste liquid is a gas-liquid mixed phase cleaning waste liquid in which a flushing fluid and a backwashing fluid are mixed.
Flushing compressed air is used as the flushing fluid,
A membrane separation system using backwash water as the backwash fluid . A membrane having a processing liquid supply port for supplying a liquid to be processed to the primary side, a permeate outlet for taking out the permeated liquid that has permeated to the secondary side, and a flushing fluid supply port for supplying a flushing fluid to the primary side A membrane separation system for performing membrane filtration operation by connecting a plurality of modules in parallel,
To-be-processed liquid supply header pipes for supplying the to-be-treated liquid to the to-be-treated liquid supply port of each membrane module;
A flushing fluid supply header pipe for supplying a flushing fluid to a flushing fluid supply port of each membrane module;
Backwash fluid supply means for pressurizing the inside of the permeate header pipe to flow backwash fluid from the secondary side to the primary side of the membrane module and backwashing is connected to the permeate header pipe,
The flushing fluid supply means for supplying the flushing fluid into the flushing fluid supply header pipe is a flushing fluid supply header pipe corresponding to the membrane module disposed at the other end of the plurality of parallel membrane modules. Connected to the other end,
A cleaning waste liquid discharging path discharged from the processing liquid supply port when cleaning the membrane module is connected to one end of the processing liquid supply header pipe corresponding to the membrane module disposed at one end of the plurality of parallel membrane modules. Connected ,
The cleaning waste liquid is a gas-liquid mixed phase cleaning waste liquid in which a flushing fluid and a backwashing fluid are mixed.
Flushing compressed air is used as the flushing fluid,
A membrane separation system using backwash water as the backwash fluid . A membrane having a processing liquid supply port for supplying a liquid to be processed to the primary side, a permeate outlet for taking out the permeated liquid that has permeated to the secondary side, and a flushing fluid supply port for supplying a flushing fluid to the primary side A membrane separation system for performing membrane filtration operation by connecting a plurality of modules in parallel,
To-be-processed liquid supply header pipes for supplying the to-be-treated liquid to the to-be-treated liquid supply port of each membrane module;
A flushing fluid supply header pipe for supplying a flushing fluid to a flushing fluid supply port of each membrane module;
Backwash fluid supply means for pressurizing the inside of the permeate header pipe to flow backwash fluid from the secondary side to the primary side of the membrane module and backwashing is connected to the permeate header pipe,
Flushing fluid supply means for supplying the flushing fluid into the flushing fluid supply header pipe is connected to an intermediate portion between both ends of the flushing fluid supply header pipe,
A discharge path of cleaning waste liquid discharged from the processing liquid supply port when the membrane module is cleaned is connected to both ends of the processing liquid supply header pipe,
The length of the path from when the flushing fluid is supplied to the intermediate portion of the flushing fluid supply header pipe to when it is discharged from both ends of the liquid supply header pipe to be processed into both discharge paths is equal for each membrane module. Configured ,
The cleaning waste liquid is a gas-liquid mixed phase cleaning waste liquid in which a flushing fluid and a backwashing fluid are mixed.
Flushing compressed air is used as the flushing fluid,
A membrane separation system using backwash water as the backwash fluid . To-be-treated liquid supply branch pipes branched from the to-be-treated liquid supply header pipes and connected to the to-be-treated liquid supply ports of the respective membrane modules;
A flushing fluid supply branch pipe branched from the flushing fluid supply header pipe and connected to the flushing fluid supply port of each membrane module;
The pressure loss of the flushing fluid supply branch pipe is set to be larger than the pressure loss of the liquid supply branch pipe to be treated when the backwash fluid is passed. 4. The membrane separation system according to any one of items 3. The membrane separation system according to claim 4, wherein the flushing fluid supply branch pipe has a throttle portion. The backwash fluid supply means and the flushing fluid supply means have a common pressure vessel and a compressor connected to the pressure vessel,
The inside of the pressure vessel consists of a liquid phase part and a gas phase part,
A permeate header pipe is connected to the liquid phase,
A flushing fluid supply header pipe is connected to the gas phase part,
Liquid phase water is used as backwash fluid,
The membrane separation system according to any one of claims 1 to 5, wherein compressed air in a gas phase part is used as a flushing fluid. A membrane having a processing liquid supply port for supplying a liquid to be processed to the primary side, a permeate outlet for taking out the permeated liquid that has permeated to the secondary side, and a flushing fluid supply port for supplying a flushing fluid to the primary side Multiple modules are connected in parallel,
To-be-treated supply header pipes for supplying the to-be-treated liquid to the to-be-treated liquid supply port of each membrane module, and the permeate header pipe through which the permeate taken out from the permeate outlet of each membrane module flows,
A flushing fluid supply header pipe for supplying a flushing fluid to a flushing fluid supply port of each membrane module;
The liquid supply header pipe to be processed and the fluid supply header pipe for flushing are pipes extending along the parallel direction of the membrane module,
Backwash fluid supply means for pressurizing the inside of the permeate header pipe to flow backwash fluid from the secondary side to the primary side of the membrane module and backwashing is connected to the permeate header pipe,
A flushing fluid supply means for supplying a flushing fluid into a flushing fluid supply header pipe is a method for cleaning a membrane module of a membrane separation system connected to a flushing fluid supply header pipe,
While supplying the backwashing fluid from the permeate header pipe to the secondary side of each membrane module by the backwashing fluid supply means, the flushing fluid is supplied from the flushing fluid supply header pipe to the primary side of each membrane module by the flushing fluid supply means. A flushing step of discharging the gas-liquid mixed phase fluid of the backwashing fluid and the flushing fluid discharged from each membrane module into the processed liquid supply header pipe from the processed liquid supply header pipe ,
In the flushing process, the direction in which the flushing fluid flows in the flushing fluid supply header pipe, and the gas-liquid mixed phase fluid of the backwashing fluid and the flushing fluid discharged from each membrane module into the liquid feed header pipe are treated. A method for cleaning a membrane module of a membrane separation system, characterized in that the flow direction in the liquid supply header tube is the same. There is a backwash process before the flushing process,
In the backwashing process, the backwashing fluid supply means supplies the backwashing fluid from the permeate header pipe to the secondary side of each membrane module, and the backwashing fluid flowing from the secondary side to the primary side is supplied to each membrane module. 8. The method for cleaning a membrane module of a membrane separation system according to claim 7, wherein the membrane module is discharged from the processing liquid supply header pipe to the processing liquid supply header pipe. The supply of the backwashing fluid by the backwashing fluid supply means and the supply of the flushing fluid by the flushing fluid supply means are performed from a common pressure vessel. A method for cleaning a membrane module of a membrane separation system. The membrane separation system branches from the liquid supply header tube to be processed and is connected to the liquid supply inlet of each membrane module, and branches from the fluid supply header tube for flushing and branches from each membrane module. A flushing fluid supply branch connected to the flushing fluid supply port;
10. The pressure loss of the flushing fluid supply branch pipe when the backwash fluid passes is set to be larger than the pressure loss of the liquid supply branch pipe to be processed. A method for cleaning a membrane module of a membrane separation system according to any one of the above.

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