KR20210141912A - Hollow fiber membrane module and its cleaning method - Google Patents

Abstract

The hollow fiber membrane module is a container (1) having a treated water outlet (5) and an upper discharge port (8), and a hollow fiber membrane (2) for solid-liquid separation of raw water, a plurality of vertically arranged in the container (1). The hollow fiber membrane 2 and the upper end of the hollow fiber membrane 2 are fixed, the upper end fixing part 3 arranged on the upper part in the container 1, and the upper end fixing part 3 are formed above each hollow It has a permeated water chamber 7 in which the inside of the desert 2 communicated, a pipe L1 for supplying raw water into the container 1, and a central pipe 4 for performing bubbling washing. The central tube 4 extends in the vertical direction below the upper end fixing part 3, and a plurality of blowing holes 4a for blowing gas are formed on the side circumferential surface.

Description

Hollow fiber membrane module and its cleaning method

The present invention relates to a hollow fiber membrane module and a cleaning method thereof, and more particularly, to a hollow fiber membrane module capable of sufficiently cleaning and removing suspended matter adhering to the membrane and a cleaning method thereof.

The hollow fiber membrane module is widely used in the field of pure water production, wastewater recovery, etc. as a means for removing suspended matter components and organic matter. For the membrane of the hollow fiber membrane module, a microfiltration membrane (MF membrane), a limiting filtration membrane (UF membrane), etc. are used according to the separation target, and the former has a pore size of around 0.1 μm, and the latter generally has pores of 0.005 to 0.5 μm.

When suspended water supplied to the hollow fiber membrane module contains a large amount of suspended matter or organic matter, clogging of the membrane occurs, increasing the frequency of backwashing and chemical cleaning, as well as increasing the frequency of membrane replacement. In order to prevent clogging of the membrane, a method of reducing the amount of water passing per unit area of the membrane is generally used, but this method has a problem that the number of membranes is increased.

In patent document 1, in order to improve the suspension removal property of a film|membrane, the backwashing method using air and water is proposed. However, in this method, depending on the kind and quantity of suspended matter, the suspended matter removability may not improve so much, and a more high-performance backwashing method is calculated|required.

In general air cleaning, air flows from the lower part of the membrane module to the upper part, but since there is a difference in air strength from top to bottom, the air does not spread throughout the membrane module, resulting in a point of insufficient cleaning. In addition, if the lower part is drained during air cleaning, the air is discharged without penetrating into the membrane module, so that it can be drained only from the upper part of the module, for example, from the circulation unit. Therefore, suspended matter of the whole membrane module removed by air washing may adhere to the upper part of the membrane.

Patent Document 2 discloses a container having a treated water outlet and a concentrating outlet outlet, a central pipe for supplying raw water into the container, and a hollow fiber membrane for separating raw water into permeate and concentrated water, arranged in the vertical direction in the container. a plurality of hollow fiber membranes, the upper end of the hollow fiber membrane is fixed, the upper end fixed portion disposed on the upper part of the container, and the permeate water chamber formed above the upper end fixed portion, and in which the inside of each hollow fiber membrane is communicated; and, the central pipe extends in the vertical direction below the upper end fixing part, and a plurality of jet holes for jetting raw water are formed on the side circumferential surface, and in the lower portion of the container, gas from the plurality of jet holes A cleaning method of a hollow fiber membrane module provided with a drain port for discharging cleaning wastewater when performing bubbling cleaning by blowing in A method for cleaning a hollow fiber membrane module discharged from a drain is disclosed.

In Patent Document 2, a central pipe provided with means for introducing raw water and gas is provided in the center of the module, and air is blown into the module from the central pipe, thereby reducing the intensity difference of cleaning air generated above and below the module. In Patent Document 2, since raw water is supplied from the central tube, a higher raw water pressure acts on the central film close to the central tube than the outer peripheral film close to the housing, and the filtration amount of the central film is on the outer peripheral side. more than the membrane of For this reason, non-uniformity arises in the contamination of the film|membrane in a module. In other words, a high load is applied to the hollow fiber membrane on the module center side, and membrane contamination and a decrease in the effective membrane area due to the progress of membrane contamination are likely to occur.

Japanese Laid-Open Patent Publication No. 2005-88008 Japanese Laid-Open Patent Publication No. 2017-176966

The present invention has been made in view of the above conventional circumstances, and an object of the present invention is to provide a hollow fiber membrane module capable of sufficiently removing suspended matter adhered to the hollow fiber membrane evenly and sufficiently, and a cleaning method thereof.

The hollow fiber membrane module of the present invention is a hollow fiber membrane for solid-liquid separation of a container having a treated water outlet at an upper portion, a raw water supply means for supplying raw water to a lower portion of the container, and is disposed in the vertical direction in the container. A plurality of hollow fiber membranes, an upper end fixing part fixed at the upper end of the hollow fiber membrane, and disposed at the upper part in the container, and a permeate water chamber formed above the upper end fixing part and communicating with the inside of each hollow fiber membrane; It has a central tube extending in the vertical direction below the upper fixing part and having a plurality of blowing holes for blowing gas on the side circumferential surface, and discharging means for discharging gas and washing waste water from the container.

In one aspect of the present invention, the lower end of the central tube faces the opening of the bottom surface of the container.

In one aspect of the present invention, a means for supplying a gas to the lower portion of the vessel is formed.

In the cleaning method of the hollow fiber membrane module of the present invention, a first bubbling cleaning in which gas is blown in from a plurality of jet holes of the central tube is performed, and exhaust gas and cleaning wastewater are discharged from the discharge means.

In one aspect of the present invention, at least one of the first bubbling washing in which gas is blown in from the plurality of jet holes of the central pipe and the second bubbling washing in which gas is blown in from a gas supply means formed in the lower part of the container. Bubbling cleaning is performed, and exhaust gas and cleaning waste water are discharged from the discharge means.

In one aspect of the present invention, the second bubbling washing is performed before or after the first bubbling washing, and the washing waste is discharged from the container.

In one aspect of the present invention, backwashing in which backwashing water is supplied from the treated water outlet is performed simultaneously with the first bubbling washing and/or the second bubbling washing.

In one aspect of the present invention, a chemical solution is added to the backwashing water.

In one aspect of the present invention, the flow rate of the gas passing through the central pipe is 50 to 300 NL/min.

In the hollow fiber membrane module of the present invention, since the central tube extends in the vertical direction in the container, and gas is blown in from a plurality of jet holes formed in the central tube to perform bubbling cleaning, air flows throughout the membrane module. , it is possible to evenly and sufficiently remove suspended matter adhering to the hollow fiber membrane.

In addition, by introducing raw water from the lower part of the module, the drift in the filtration process is reduced and the membrane can be used uniformly, so the progress of local membrane contamination and consequent decrease in membrane area are prevented (including suppression). ) do.

By providing a dispersion plate having small pores and dispersing the raw water, the drift of raw water is further reduced.

1 is a cross-sectional view of a hollow fiber membrane module according to an embodiment.
2 is a cross-sectional view of a hollow fiber membrane module according to another embodiment.
3 is a cross-sectional view of a hollow fiber membrane module according to another embodiment.
4 is a cross-sectional view of a hollow fiber membrane module of a conventional example.
5 is a graph showing the results of Example 7 and Comparative Example 3. FIG.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment is described with reference to FIGS.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the structure of the hollow fiber membrane module which concerns on this embodiment. As shown in FIG. 1, the hollow fiber membrane module is provided with the container 1 arrange|positioned as the vertical direction (vertical direction in this embodiment) in the direction of the axial center line of a cylinder. In the container 1, a plurality of hollow fiber membranes 2 are arranged.

The hollow fiber membrane 2 is fixed by the potting part 3 made of synthetic resin as a fixing part in the upper side of the container 1, and is not fixed in the lower part of the container 1. As a synthetic resin of the potting part 3, an epoxy resin can be used, for example.

For example, the hollow fiber membrane 2 is mounted in a U shape, and both ends of the hollow fiber membrane are fixed with the potting part 3 . In this case, the middle part of the hollow fiber membrane 2 is located in the lower part of the container 1 .

Moreover, when using the hollow fiber membrane 2 by which one end was opened and the other end was sealed, the one end side of the opened hollow fiber membrane 2 is fixed with the potting part 3, and the sealed other end is used. The short side is arranged in the lower part of the container (1).

The hollow fiber membrane 2 may be either a UF membrane, an MF membrane, or the like. Although there is no restriction|limiting in particular for the hollow fiber membrane 2, Usually, the thing of about 0.2-1.0 mm inner diameter, 0.5-2.0 mm outer diameter, and effective length of 300-2500 mm is used. It is suitable for the total membrane area of about 5 to 100 m 2 in which 500 to 70,000 pieces of such hollow fiber membranes 2 are loaded in the container 1 . Although there is no restriction|limiting in particular also about the membrane material of the hollow fiber membrane 2, PVDF (polyvinylidene fluoride), polyethylene, polypropylene, etc. can be used.

A treated water chamber (permeated water chamber) 7 and a raw water chamber 10 are respectively partitioned above and below the potting part 3 . The upper end side of the hollow fiber membrane 2 passes through the potting part 3 , the opening at the upper end faces the treated water chamber 7 , and the inside of the hollow fiber membrane 2 communicates with the treated water chamber 7 . When the hollow fiber membrane 2 is mounted in a U shape, both ends of the hollow fiber membrane 2 penetrate the potting part 3 .

The potting part 3 is disk-shaped, for example, and the outer peripheral surface or outer peripheral edge part is in contact with the inner surface of the container 1 watertightly.

Inside the container 1 (raw water chamber 10), the central pipe 4 extends in a substantially vertical direction (axial direction of the container 1). The central tube 4 is arrange|positioned along the central axis of the container 1, for example. The central pipe 4 is a circular pipe with the front end (upper end) closed, and on the side circumferential surface, a plurality of blowing holes 4a are formed as a whole at intervals in the circumferential direction. Although the number of the blowing holes 4a is not specifically limited, For example, it is about 5-50 pieces. Although the size and shape of the blowing hole 4a are not specifically limited, For example, it is a circular shape with a diameter of 5-500 mm. The inner diameter of the central tube 4 is, for example, about 10 to 20 mm.

Although the height (length in the vertical direction) of the central tube 4 is not particularly limited, it is preferable that the upper end of the central tube 4 is located near the lower surface of the potting part 3 . In addition, the upper end of the central tube 4 may be embedded in the potting part 3 .

The lower end of the central tube 4 faces the opening 11 of the bottom surface of the container 1 . A raw water pipe L1 is connected to the opening 11, and a pump P1 and a valve V1 are provided in the raw water pipe L1. On the container 1 side rather than the valve V1 of the raw water piping L1, the piping L2 for air introduction is branched, and the valve V2 is provided in the piping L2 for air introduction.

A pipe L7 for discharging washing water is connected to the container 1 side rather than the valve V1 of the pipe L1, and a valve V7 is provided in the pipe L7.

By switching the opening and closing of the valve V1 and the valve V2, the supply of raw water/air to the container 1 can be switched. Raw water can be supplied from the lower part of the raw water chamber 10 by opening the valve V1, making the valves V2 and V7 closed, and sending out raw water through the raw water pipe L1 by the pump P1.

By closing the valves V1 and V7, opening the valve V2, and supplying air from the air introduction pipe L2, air bubbles are supplied from the opening 11, and the hollow fiber membrane 2 is bubbled and cleaned. can do. The valves V1 and V2 may be opened, and the gas-liquid mixed flow may be ejected from the opening 11 .

An air pipe L8 is connected to the lower portion of the central pipe 4 , and a valve V8 is provided in the pipe L8. By supplying air from the pipe L8, bubbles can be blown out from the blowing hole 4a of the central pipe 4 in a radial direction, and bubbling cleaning of the hollow fiber membrane 2 can be performed.

An outlet 5 of treated water (membrane permeated water) is formed at the top of the container 1 . Moreover, the upper discharge port 8 is formed in the upper part of the side surface of the container 1 . The upper discharge port 8 is formed in the vicinity of the lower surface of the potting part 3 . The distance from the potting portion 3 to the upper edge of the upper outlet 8 is preferably 0 to 30 mm, particularly preferably about 0 to 10 mm. A pipe L5 is connected to the upper outlet 8 , and a valve V5 is provided in the pipe L5.

A treated water outlet pipe L3 is connected to the treated water outlet 5 , and treated water (membrane permeated water) is blown out through the treated water outlet pipe L3 . The treated water is stored in the treated water tank 9 .

One end of a backwashing pipe L4 is connected to the treated water outlet pipe L3 at a position between the valve V3 formed in the treated water outlet pipe L3 and the treated water outlet 5 . The other end of the backwashing water pipe L4 is connected to the treated water tank 9 . A valve V4 and a pump P2 are formed in the backwashing pipe L4. By closing the valve V3, opening the valve V4, and flowing the treated water from the treated water outlet 5 to the raw water chamber 10 through the backwashing pipe L4 by the pump P2, the hollow Backwashing of desert (2) can be carried out. 1 shows a configuration in which the backwash water pipe L4 is connected to the treated water tank 9 and treated water is used for the backwashing water, but the backwashing water may be raw water.

Drainage accompanying backwashing may be discharged from the opening 11 through the pipe L7 , or may be discharged from the upper discharge port 8 through the pipe L5 . The discharge from the opening 11 and the discharge from the upper discharge port 8 may be performed simultaneously or may be performed sequentially (alternately). Suspended matter peeled off from the hollow fiber membrane 2 can be efficiently discharged by discharging the backwashing water from the pipe L7 and discharging the backwashing water from the upper outlet 8 simultaneously or alternately.

A chemical liquid adding means (not shown) for adding a chemical to the backwashing water flowing through the backwashing water pipe L4 may be provided. The chemical solution to be added is sodium hypochlorite, a strong alkali agent, a strong acid agent, or the like, and is selected according to the film adherent. For example, when the film-adhered substance is an organic substance or a turbidity containing an organic substance, it is preferable to add _{sodium hypochlorite so that 0.05 to 0.3 mgCl 2 /L remains.}

In the filtration treatment by the hollow fiber membrane module, the valves V1 and V3 are opened, the valves V2, V4, V5, V7, and V8 are closed, the pump P1 is operated, and the raw water is discharged from the opening 11 . The raw water is supplied to the thread (10). This embodiment is a dead-end flow, and the permeated water which has passed through the hollow fiber membrane 2 is taken out from the treated water outlet 5 as treated water, and is stored in the treated water tank 9 through the treated water take-out pipe L3. do.

However, you may filter by the external pressure type|mold which passes raw water through the outer side of the hollow fiber membrane 2 by a cross-flow system. In this case, the concentrated water that has not passed through the hollow fiber membrane 2 is discharged from the upper discharge port 8 through the pipe L5. You may circulate so that the discharged concentrated water may be mixed with raw water and supplied to the container 1 .

When this filtration process is performed continuously, suspended matter will accumulate in the hollow fiber membrane 2 . Then, after performing a filtration process for a predetermined time, or when the amount of treated water decreases, the washing process which wash|cleans the suspended matter captured by the hollow fiber membrane 2 is performed.

In the first aspect of the method for cleaning the hollow fiber membrane module, the valve V8 is opened and V1 and V2 are closed, and the hollow fiber membrane 2 is removed from the plurality of blowing holes 4a of the central tube 4 . The first bubbling cleaning in which air is blown toward the

At this time, one or both of the valves V5 and V7 are opened to discharge the exhaust gas and the washing waste water. The valves V5 and V7 may be alternately opened.

In the second aspect of the method for cleaning the hollow fiber membrane module, the valve V8 is opened and V1 and V2 are closed, and the hollow fiber membrane 2 is removed from the plurality of jet holes 4a of the central tube 4 . 1st bubbling washing in which air is blown toward At least one bubbling cleaning is performed. At this time, one or both of the valves V5 and V7 are opened to discharge the exhaust gas and the washing waste water. The valves V5 and V7 may be alternately opened.

In one aspect of the second aspect, the second bubbling washing is performed before or after the first bubbling washing, and the washing wastewater is discharged from the container.

In either of the first and second aspects of the cleaning method, backwashing water is supplied from the treated water outlet 5 to the treated water chamber 7 simultaneously with the first bubbling washing and/or the second bubbling washing. You may make it backwashing.

In order to simultaneously perform bubbling cleaning and backwashing in this way, specifically, for example, the valves V1, V3, V7 are closed, the valves V2, V4, V5, V8 are opened, and the opening ( 11) and from the central pipe 4, air is blown into the container 1 and bubbling, while operating the pump P2, the treated water is discharged as backwashing water through the treated water chamber 7 through the hollow fiber membrane ( 2) Send it inside, and perform backwashing. A chemical solution may be added to the backwashing water. The washing wastewater and exhaust air are discharged to the outside of the system from the upper discharge port 8 through the pipe L5. After bubbling, the cleaning wastewater may be discharged from the pipe L7 by opening the valve V7.

In either of the first aspect and the second aspect, the amount of air supplied from the central pipe 4 is preferably about 30 to 500 NL/min, particularly preferably 50 to 300 NL/min.

Since a large number of blowout holes 4a are formed in the central tube 4 over the entire vertical direction, the hollow fiber membrane 2 including the vicinity of the upper end fixing part of the hollow fiber membrane 2 (near the potting part 3). ) By spraying air bubbles all over, the suspended matter can be thoroughly washed and removed. In addition, even if the amount of air during bubbling cleaning is increased, it is possible to prevent distortion or breakage of the hollow fiber membrane 2 compared to a method in which air flows from only the lower part of the module to the upper part.

Backwashing may be air backwashing instead of water bodywashing. In the bubbling cleaning, air may be blown out from only the central pipe 4 . In addition, not air but a gas-liquid mixed flow may be supplied from the central pipe 4 .

In the present invention, as shown in FIG. 2 , a dispersion plate 12 having a plurality of small holes 12a is formed in the lower portion of the container 1 , and raw water from the opening 11 is dispersed in the container 1 . You can do it. In FIG. 2 , the dispersion plate 12 is formed below the lower end of the hollow fiber membrane 2 .

In the present invention, the dispersion plate 12 may be made of a potting material, and the lower end of the hollow fiber membrane 2 may be embedded in the dispersion plate 12 as shown in FIG. 3 . Although the small holes 12a are only partially shown in FIG. 3 , in reality, they are formed over the entire surface of the dispersion plate 12 .

The said embodiment is an example of this invention, and this invention may be made into a form other than illustration.

Example

[Example 1]

The filtration process was performed by passing raw water through the pipe L1 for 30 minutes to the hollow fiber membrane module provided with the hollow fiber membrane module shown in FIG. After storing tap water in the raw water tank and adding 10 mg/L of bentonite and sodium hydrogencarbonate manufactured by Kishida Chemical, the pH was adjusted to 8.0 with sulfuric acid manufactured by Kishida Chemical. Water was supplied from the raw water tank to the coagulation tank with a pump, and the residence time was 10 minutes. What added 100 mg/L of industrial ferric chloride (concentration 38%) before a coagulation tank was used as raw water. The configuration of the hollow fiber membrane module is as follows.

Container (1): inner diameter 200 mm, height 1500 mm

Hollow fiber: UF membrane made of polyvinylidene fluoride with an outer diameter of 1.4 mm, membrane area 32 m

Central tube (4): 1300 mm in length, 13 mm in inner diameter, 18 mm in outer diameter extending in the container (1)

Jet hole (4a): 10 mm in diameter, 48 pcs.

Small holes 12a of the dispersion plate 12: 8 mm in diameter, 44 pieces

After the filtration treatment, air was supplied from the central pipe 4 to perform bubbling cleaning and backwashing. The washing process was performed for 1 minute. Backwashing water was discharged from the upper outlet (8). The supply amount of air for bubbling was set to 80 NL/min. The amount of water supplied for backwashing was 80 L/min, and filtered water was used as the water supply for backwashing.

The filtration treatment and the washing treatment were alternately performed 5 times, respectively. The backwashing water discharged|emitted every cycle was collect|collected, and the suspended mass in the backwashing water was measured. Table 1 shows the amount of suspended mass discharged by backwashing with respect to the total amount of suspended mass supplied in 5 cycles (suspension removal rate).

[Example 2]

The same treatment as in Example 1 was performed except that backwashing water was discharged from the pipe L7 through the opening 11 . Table 1 shows the measurement results.

[Example 3]

Before supplying air from the central pipe 4, backwashing was performed for 30 seconds, and the same treatment as in Example 2 was performed except that the step of draining the backwashing water from the upper outlet 8 was added. Table 1 shows the measurement results.

[Example 4]

The same treatment as in Example 3 was performed except that the supply amount of air for bubbling was 150 NL/min. Table 1 shows the measurement results.

[Example 5]

The same treatment as in Example 4 was performed except that sodium hypochlorite was added to the backwash water so as to be 300 mgCl _{2 /L.} Table 1 shows the measurement results.

[Example 6]

Before supplying air from the central pipe (4), bubbling cleaning is performed in which air is supplied from the lower opening (11) of the vessel (1) at 150 NL/min for 30 seconds, and the drainage and exhaust air are discharged through the upper outlet ( The same treatment as in Example 4 was performed except that the step of discharging from 8) was added. Table 1 shows the measurement results.

[Comparative Example 1]

Using the hollow fiber membrane module in which the central pipe|tube 4 was not formed, the process similar to Example 1 was implemented except having abbreviate|omitted the bubbling washing|cleaning using the central pipe|tube 4. Table 1 shows the measurement results.

[Comparative Example 2]

By using the hollow fiber membrane module in which the central pipe 4 is not formed, air washing using the central pipe 4 is omitted, and instead air for bubbling is discharged from the container lower opening 11 of the hollow fiber membrane module during back washing. The same treatment as in Comparative Example 1 was performed except that 80 NL/min was supplied and backwashing water and exhaust air were discharged from the upper outlet 8 . Table 1 shows the measurement results.

As shown in Table 1, Example 1 had a high turbidity removal rate by washing compared to washing with only back washing (Comparative Example 1) and washing by blowing bubbling air from the bottom of the container (Comparative Example 2).

In Example 2, by draining the washing wastewater from the drain port at the bottom of the container, a higher turbidity removal rate than the washing (Example 1) in which the washing wastewater is discharged from the upper drain port was obtained.

In Example 3, the suspension removal rate higher than Example 2 was obtained by adding back washing before washing|cleaning of Example 2.

In Example 4, the suspension removal rate higher than Example 3 was obtained by increasing the quantity of bubbling air from 80 NL/min to 150 NL/min.

In Example 5, by adding an oxidizing agent to backwashing water, a higher turbidity rejection ratio than the non-addition condition (Example 4) was obtained.

In Example 6, by introducing air washing in which bubbling air was supplied from the bottom of the container before the washing in Example 4, a higher turbidity removal rate than in Example 4 was obtained.

[Example 7]

Well water was passed through the hollow fiber membrane module used in Example 1, and the time-dependent change in the pressure difference between the membranes was measured. The results are shown in FIG. 5 .

[Comparative Example 3]

The test similar to Example 7 was implemented using the hollow fiber membrane module shown in FIG. The results are shown in FIG. 5 .

In addition, in FIG. 4, the opening 11 and the piping L7 for drainage are abbreviate|omitted, and the drainage port 6 is formed in the lower part of the side surface of the container 1 instead. The drain port 6 is formed in the vicinity of the bottom surface of the container 1 . A pipe L6 is connected to the drain port 6 , and a valve V6 is formed in the pipe L6 . Moreover, the pipe L8 for air is abbreviate|omitted, and the pipe L1 is connected to the lower part of the center pipe 4 instead. The configuration of the hollow fiber membrane module of FIG. 4 is as follows.

Container (1): inner diameter 200 mm, height 1300 mm

Hollow fiber: UF membrane made of polyvinylidene fluoride with an outer diameter of 1.25 mm, membrane area of 30 m2

Center tube (4): length 1000 mm, inner diameter 20 mm, outer diameter 25 mm extending in container 1

Jet hole (4a): 10 mm in diameter, 10 pcs.

As shown in Fig. 5 , as compared with Comparative Example 3 in which raw water was supplied from a central pipe, in Example 7 in which raw water was supplied from the lower part of the raw water chamber, the increase in the transmembrane pressure was suppressed and stabilized. This is because, in the structure of the present invention, the flow of raw water in the module is less likely to occur, and the entire membrane can be used for filtration evenly, so that the membrane contamination is not accelerated locally, resulting in a decrease in the effective membrane area. because it didn't happen.

Although this invention was demonstrated in detail using the specific aspect, it is clear to those skilled in the art that various changes are possible without deviating from the intent and scope of this invention.

This application is based on Japanese Patent Application No. 2019-060929 for which it applied on March 27, 2019, The whole is used by reference.

1 container
2 hollow fiber membrane
3 potting part
4 center tube
5 treated water outlet
6 drain
7 treatment room
8 upper outlet
9 treated water tank
10 Marshal's Room

Claims (9)

A container having a treated water outlet at the upper portion,
Raw water supply means for supplying raw water to the lower part of the container;
A hollow fiber membrane for solid-liquid separation of raw water, comprising: a plurality of hollow fiber membranes arranged in the vertical direction in the container;
an upper end fixing part fixed to the upper end of the hollow fiber membrane and disposed on the upper part in the container;
A permeate chamber formed on the upper side of the upper fixing part and communicating with the inside of each hollow fiber membrane;
A central tube extending in the vertical direction below the upper fixing part and having a plurality of jetting holes for jetting gas on the side circumferential surface is formed;
a hollow fiber membrane module having a discharge means for discharging gas and cleaning wastewater from the vessel. The method of claim 1,
The lower end of the central tube is a hollow fiber membrane module, characterized in that facing the opening of the bottom surface of the container. 3. The method according to claim 1 or 2,
A hollow fiber membrane module, characterized in that a means for supplying a gas is formed in the lower part of the container. A method for cleaning the hollow fiber membrane module according to any one of claims 1 to 3, comprising:
A method for cleaning a hollow fiber membrane module, characterized in that a first bubbling cleaning in which gas is blown in from a plurality of jet holes of the central tube is performed, and exhaust gas and cleaning wastewater are discharged from the discharge means. A method for cleaning the hollow fiber membrane module according to claim 3,
bubbling cleaning of at least one of the first bubbling washing in which gas is blown in from the plurality of jet holes of the central pipe and the second bubbling washing in which gas is blown in from a gas supply means formed in the lower part of the container;
A method for cleaning a hollow fiber membrane module, characterized in that exhaust gas and cleaning waste are discharged from the discharge means. 6. The method of claim 5,
Before or after the first bubbling washing, the second bubbling washing is performed, and the washing wastewater is discharged from the container. 7. The method according to any one of claims 4 to 6,
Simultaneously with the first bubbling washing and/or the second bubbling washing, back washing in which back washing water is supplied from the treated water outlet is performed. 8. The method of claim 7,
A method for cleaning a hollow fiber membrane module, characterized in that adding a chemical solution to the backwashing water. 9. The method according to any one of claims 4 to 8,
The cleaning method of the hollow fiber membrane module, characterized in that the flow rate of the gas passing through the central pipe is 50 to 300 NL / min.

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