JPH0938470A - Filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive filter having a simple structure, which is capable of evenly supplying a gas for cleaning to plural hollow yarn membrane modules. SOLUTION: A parting plate 20 is provided below the bottom end of a module cylinder 14 in a vessel 11 and a ventilation hole 21 is provided directly below the module cylinder 14 of the parting plate 20 in one-to-one. Water pipes 22 are provided among the plural ventilation holes (for example, one water pipe 22 to 3 ventilation holes 21 are provided). An intake gas pipe 16 is connected to a vessel 11 below the parting plate 20 and an intake gas diffusing pipe 10 having plural intake gas holes 31 is connected to the intake gas pipe 16. At the time of purifying, the gas supplied from the intake gas pipe 16 forms a gas layer having uniform thickness at the lower part of the parting plate 20 and uniformly flows into the respective module cylinders 14 through the ventilation holes 21 to give an adequate vibration to a hollow yarn membrane 13 to remove impurities.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter device for filtering a liquid to be purified by passing a liquid to be purified through a plurality of filtration modules, and more particularly to cleaning the filtration module with a simple structure. It relates to a suitable filtration device.

[0002]

2. Description of the Related Art In a filtration device for filtering a liquid to be purified, if the filtration performance of a filtration module deteriorates due to long-term purification, it is washed and reused. In a filtration device using a hollow fiber membrane module, a gas such as air is introduced from below the hollow fiber membrane module to shake the hollow fibers for cleaning.
At this time, if the gas flow rate to be supplied to each hollow fiber membrane module is too low, the cleaning effect will be reduced, and if it is too high, the life of the hollow fiber will be reduced, so that the gas is evenly supplied to each hollow fiber membrane module. There is a need to.

As a typical example of a conventional filtration device using a hollow fiber membrane module, there is one described in JP-A-61-222509. This known technique is based on each hollow fiber membrane module.
A partition plate having an outlet for the liquid to be purified is provided directly under the partition, and a cylinder having upper and lower openings is connected to the lower outlet of the partition plate. A plurality of small holes are attached to the side wall of the cylinder in the length direction. During cleaning, the compressed gas supplied from the air supply pipe below the partition plate is accumulated in layers under the partition plate, and then it is supplied to each hollow fiber membrane module through the small hole in the cylinder and the outlet of the partition plate. Is.

As a different type, Japanese Patent Application No. 4-6
There is one described in Japanese Patent No. 2770. According to this known technique, a partition plate or a water passage tube is not provided as in the above example, an air supply pipe is arranged for each row of hollow fiber membrane modules, and the pipes are provided directly under each hollow fiber membrane module. A small hole is provided in the air supply pipe,
Air is directly supplied to each hollow fiber membrane module through the small holes.

[0005]

However, the above-mentioned known technology has the following problems.

That is, in the technique disclosed in JP-A-61-222509, the cylinder connected to the partition plate serves both as the passage of the liquid to be purified during the cleaning operation and the supply of air during the cleaning. Since air supply to each hollow fiber membrane module by this system is ultimately performed by buoyancy, one hollow fiber membrane module needs one cylinder immediately below it, and the partition plate A large number of cylinders are attached to the. Moreover, during air supply, the inside of the cylinder becomes a gas-liquid two-phase and the flow becomes unstable, and the hydrostatic head for air supply decreases, so that the cylinder needs to be lengthened, resulting in high equipment costs.

Further, in the technique of Japanese Patent Application No. 4-62770, an air supply pipe is provided for each row of hollow fiber membrane modules. Therefore, the inner volume of the container increases, and the structure for removing the air supply pipe at the time of inspecting the bottom of the container becomes complicated.

The object of the present invention is to provide a plurality of hollow fiber membrane modules.
It is an object of the present invention to provide a filtration device which can supply a liquid to be purified at the time of cleaning and a gas at the time of cleaning and which has a simple structure and is inexpensive.

[0009]

SUMMARY OF THE INVENTION The above objects of the present invention are as follows.
A container, a separator plate inside the container, a plurality of filtration modules connected to the separator plate, a water supply pipe for supplying the liquid to be purified and an air supply pipe for supplying gas into the container, In a filtration device for purifying the liquid to be purified by passing a purification liquid through the filtration module, a partition plate for forming a layer of supply gas is provided below the filtration module under the filtration module. It is provided substantially horizontally above the air supply pipe, a ventilation hole is provided in the partition plate immediately below it corresponding to the filtration module, and a water passage portion that communicates the liquid to be purified above the partition plate is provided. This is achieved by providing it separately from the ventilation hole.

The water passage portion is arranged in a partition plate between the ventilation holes so as not to include the ventilation holes, or is formed in a gap portion with the container by opening the outer peripheral portion of the partition plate. .

Further, the water passage portion is characterized in that a water passage pipe whose upper and lower sides are opened and an upper end thereof is connected to the partition plate is arranged between the plurality of ventilation holes.

Further, a plurality of the ventilation holes are arranged in a staggered manner on the plane of the partition plate, and the upper end of the water pipe is arranged at the central portion of a triangle having the three ventilation holes adjacent to each other as vertices. And

Further, the upper ends of the ventilation pipes having different lengths are connected to the plurality of ventilation holes.

Further, there is provided a support plate which is inscribed in the container and has an opening smaller than the outer periphery of the partition plate to detachably support the partition plate, and further, a drain pipe having an upper end connected to the support plate. Is provided.

Further, there is provided an air supply outflow pipe which is connected to the air supply pipe and has an outlet above a connecting portion between the container and the air supply pipe, and the opening forms a gas layer formed below the partition plate during cleaning. It is characterized by opening.

[0016]

As described above, in the structure of the present invention, a partition plate is provided below the lower end of the filtration module in the container substantially horizontally (horizontally so that the gas layer is substantially even), and the filtration module is provided. Ventilation holes are provided directly below each filtration module of the partition plate corresponding to each module. Further, a water passage portion for communicating the liquid to be purified upward from below the partition plate is arranged independently of the ventilation hole. The water passage portion is composed of a plurality of water pipes whose upper ends are connected to the openings provided between the plurality of ventilation holes of the partition plate, or as a configuration for opening between the outer peripheral portion of the partition plate and the container,
It is possible to realize a water passage portion independent of the ventilation hole.

At the time of cleaning the filtration module, the gas supplied from the air supply pipe connected to the container forms a gas layer below the partition plate, and passes through the ventilation holes provided in the partition plate to reach each filtration module. Inflow. At this time, the gas that has exited the ventilation hole flows into the filtration module by the buoyancy of water in the upper side of the partition plate, so that it is possible to supply air by providing the ventilation hole directly below the filtration module as in the present invention. Become. On the other hand, since the water passage for supplying the liquid to be purified at the time of purification does not need to be directly under the filtration module or one-to-one with the filtration module, the ventilation hole as in the present invention. It is separated from the above, and an independent configuration becomes possible.

According to the present invention as described above, the degree of freedom in designing the water passage portion is increased, the number of water passage pipes can be reduced, and a construction in which the partition plate does not have a water passage pipe is possible. The structure is simple, and it is possible to downsize and reduce the equipment cost.

Further, the inside of the water passage is always a liquid single phase,
Since the flow is stable and the static head for air supply is large, the water passage can be shortened.

Further, a plurality of ventilation holes are provided immediately below each filtration module, and ventilation pipes having different lengths are connected to the ventilation holes. As a result, when increasing the air supply flow rate,
The gas layer formed under the partition plate excluding the water passage portion becomes thicker, but the gas flows in order from the short ventilation pipes, so the number of ventilation pipes through which the gas flows increases, and the gas layer thickness increases rapidly. The increase can be suppressed. As a result, the water passage portion can be shortened even when the supply air flow rate is large.

Further, by providing a support plate for the partition plate which is inscribed in the container and has an opening smaller than the outer circumference of the partition plate, and by providing a drain pipe whose upper and lower sides are opened and whose upper end is connected to the support plate, at the time of inspecting the container bottom part. The partition plate can be easily removed, and liquids and impurities accumulated on the support plate can be easily drained from the drain pipe.

Further, by providing the air supply outflow pipe having an opening above the connecting portion between the container and the air supply pipe, the gas supply flow rate is small and the gas layer formed below the partition plate excluding the water passage part. Even when the thickness is small, the opening of the supply air outflow pipe is not exposed in the gas layer and disturbs the liquid surface, and the supply air amount to each filtration module can be stabilized and equalized.

Further, by providing an air supply dispersion pipe having a plurality of openings, which is connected to the air supply pipe, in the container, the thickness of the gas layer formed below the partition plate is made uniform, and each filtration module is provided. It is possible to equalize the amount of air supplied to.

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings. The same parts are denoted by the same reference numerals throughout the drawings.

A first embodiment of the present invention will be described with reference to FIGS. 1 is a longitudinal sectional view of a filter device according to a first embodiment, FIG. 2 is a view taken along the line AA of FIG. 1, and FIG. 3 is a partial detailed view of a horizontal plate.

The filtration device comprises a container 11, a hollow fiber membrane 13 arranged inside the container 11 and having a filtering function, and a module cylinder 1.
4, a hollow fiber membrane module, a separator 12 for supporting the hollow fiber membrane module, a ventilator 21 and a water pipe 22 arranged below the lower end of the hollow fiber membrane module. Partition plate 20 and water supply pipe 15 for supplying liquid to be purified
An air supply pipe 16 for supplying gas when cleaning the hollow fiber membrane 13, an outflow pipe 17 connected to the upper part of the container 11, an exhaust pipe 18 connected below the separator 12, and an exhaust pipe 18 of the container 11. It has a drainage pipe 19 connected to the bottom.

In the filtration apparatus of this embodiment, during the normal purification operation, the liquid to be purified flows in from the water supply pipe 15 and passes through the water pipe 22 connected to the partition plate 20 to each module cylinder 14.
It evenly flows into the inside, and after impurities such as clad are filtered by the hollow fiber membrane 13, it flows out from the outflow pipe 17. When impurities are captured in the hollow fiber membranes 13 by such a filtration operation and the filtration function of the hollow fiber membranes 13 deteriorates, the supply of the liquid to be purified is stopped and the gas (usually air) is supplied to the air supply pipe 16 and the air supply dispersion. Supply through tube 30. At this time, the inside of the container below the separator 12 is full of water.

The supplied gas forms a gas layer 24 below the partition plate 20 in the container 11 except the water pipe 22, and the gas flowing out from the ventilation hole 21 of the partition plate 20 has a buoyancy force in the liquid to be purified. Then, the hollow fiber membrane 13 is caused to flow into the module cylinder 14 immediately above by the flow of the gas, the trapped impurities are removed, and after the cleaning is completed, the impurities are discharged from the drain pipe 19 together with the liquid to be purified. The gas supplied to each filtration module flows out from the hole provided in the upper part of the cylinder 14 in the module and is exhausted from the exhaust pipe 18. Module tube 14
If the flow rate of gas flowing into the filter is too low, the cleaning effect on the hollow fiber membranes 13 will be weak, and if it is too high, the life of the hollow fiber membranes 13 will be shortened. Therefore, it is important that the gas flow rates are uniformly supplied to each filtration module. is there.

Ventilation holes 21 are provided in the partition plate 20 immediately below the module cylinder 14, and water passages 22 are provided in openings 23 between the plurality of ventilation holes 21 (three ventilation holes in this embodiment). The upper end is connected to form a water passage. An air supply dispersion pipe 30 having a plurality of air supply holes 31 is connected to the air supply pipe 16.

During normal purification operation, the liquid to be purified flows in from the water supply pipe 15 and into each module cylinder 14 through the water passage pipe 22 connected to the partition plate 20, but the water passage pipe 22 has a vent hole. Since it is independent of 21, it is not necessary to provide the water pipe 22 for each module cylinder 14. As in this embodiment, for example, one water pipe 22 for three module cylinders 14 is sufficient, and the number of water pipes 22 can be reduced. For example, container 1
When the diameter of 1 is about 1.5 m, the diameter of the water pipe is 10 cm
The diameter of the vent hole 21 is about 1 cm, and it can be seen that the effect of reducing the number of water passages is great.

Moreover, the degree of freedom in design is increased by the structure in which the vent hole and the water pipe are independent. Usually, the filtration modules are arranged in a triangular lattice (or zigzag) in order to increase the occupation rate in the horizontal section and downsize the container 11.
In this case, as shown in the figure, one water pipe is arranged at the center of a triangle (dotted line) formed with the three module tubes 14 as vertices. The liquid to be purified that has passed through the water pipe 22 is dispersed and supplied to the three modules 14 in the surroundings, but since the water pipe 22 and each module 14 are arranged at the shortest distance and at the same distance, the liquid to be purified is to be supplied to each module. There is an advantage that it can be evenly distributed in the container and that the disturbance of the water in the container can be prevented.

By the way, in the steady state at the time of cleaning, the total amount of air supplied from the air supply pipe 16 and the total amount of air passing through the vent hole 21 are balanced by the relationship of the equation 1, and the thickness of the gas layer at that time is H Becomes

[0033]

## EQU1 ## ρ.g.H = 1 / 2..zeta..rho.g.Vg ² where ζ is the resistance coefficient of the vent hole 21, ρg is the gas density, ρ is the fluid density of the water passage portion 23, g : Gravity acceleration, V
g: outflow rate of gas from the vent hole 21. From this, Vg at the time of washing is

[0034]

## EQU2 ## It can be expressed as (Vg) ² = (2 / ζ)  (ρ / ρg) gH

In the above-mentioned conventional technique, since the water passage is provided with the vent hole, the inside of the water passage becomes a gas-liquid two phase and the fluid density ρ decreases. However, in this embodiment, the inside of the water flow pipe 22 is a liquid single phase, and the fluid density ρ is the density of the liquid. As a result, the thickness H of the gas layer 24 for obtaining the same outflow velocity Vg can be reduced, and the water pipe can be shortened accordingly.

Further, the gas is dispersed and supplied by the air supply dispersion pipe 30 having a plurality of air supply holes 31, the thickness distribution of the gas layer 24 is made uniform, and the amount of air supplied to each module cylinder 14 is adjusted. It can be made uniform. The air supply hole 31 is provided mainly on the side surface of the air supply dispersion pipe 30 so that the clad does not enter, but is provided on the lower surface near the tip for drainage after the start of air supply, and on the upper surface for exhaust after the end of air supply. Is also provided.

As described above, according to the filtration device of this embodiment, the ventilation hole 21 and the water passage 22 of the partition plate 20 can be provided independently, so that the number of water passages 22 can be reduced and Since the inside of the water pipe 22 becomes a liquid single phase, the water pipe 22 can be shortened and the economical efficiency can be improved.

FIG. 4 is a partial detailed view of a filter device according to a modification of the first embodiment. This modification is different from the first embodiment in that a plurality of ventilation holes 21a, 21b,
21c, and ventilation pipes 27b and 27c of different lengths are connected to the ventilation holes 21b and 21c, respectively.
That is, the lengths of b and 21c are different.

Generally, the amount of air supplied during cleaning of the hollow fiber membrane is constant. However, for example, when it becomes necessary to greatly increase the supply air amount, the gas layer 24 becomes clear from (Equation 1).
The thickness H of the abruptly increases in proportion to the square of the air supply amount. In this modification, when the supply amount of air is significantly increased and the thickness of the gas layer 24 is increased, the number of ventilation holes for supplying gas is 21a, 2a.
It increases sequentially like 1b and 21c. Therefore, the increase in the thickness of the gas layer 24 can be suppressed, and the water pipe 22 can be shortened even when the supply amount of air changes significantly.

Next, a second embodiment of the present invention will be described with reference to FIGS.
This will be described below.

FIG. 5 is a longitudinal sectional view of a filter device according to a second embodiment of the present invention, FIG. 6 is a view taken along the line AA of FIG. 5, and FIG. 7 is a partial detailed view of a partition plate.

The present embodiment is different from the first embodiment in that the air supply dispersion pipe 30 of the first embodiment is not provided and a plurality of air supply pipes 16 are connected to the container 11 instead.
Further, one water pipe 22 is provided for one module cylinder 14. This is a preferable example, but it is not a necessary condition.

When cleaning the hollow fiber membranes 13, a plurality of air supply pipes 1
The gas dispersedly supplied from 6 forms a gas layer 24 in the lower part of the partition plate 20, and is supplied to each module cylinder 14 through the ventilation hole 21.

The feature of this embodiment is that when the number of the water flow pipes 22 is large and it is difficult to arrange the air supply dispersion pipes 30,
The thickness distribution of the gas layer 24 is made uniform, and each module cylinder 14
It is effective to make the air supply to the air uniform. It should be noted that increasing the number of water passage pipes 22 can reduce the flow velocity in the pipes.

FIG. 8 is a horizontal sectional view of a filter device according to a modification of the second embodiment as seen from below, FIG. 9 is a partial vertical sectional view thereof, and FIG. 10 is a partial vertical sectional view at another position thereof. is there.

In this modification, the first difference from the second embodiment is that a support plate 125 for supporting the partition plate 20 is provided,
That is, the drain pipe 126 is provided on the support plate 125. The partition plate 20 and the support plate 125 are locked by fastening means (not shown). The second point is that the opening of the air supply pipe 16 is higher than the connecting portion between the air supply pipe 16 and the container 11, and the outlet 13
That is, the supply air outflow pipe 132 having No. 3 is provided. Note that these first and second points do not require each other as a necessary condition.

By separating the support plate 125 connected to the container 11 from the partition plate 20, the partition plate 20 can be easily removed when the bottom of the container 11 is inspected. In this case, liquids and impurities are collected on the support plate 125 between the container 11 and the partition plate 20, but the drain pipe 126 connected to the support plate 125 can drain the liquid and impurities, and the length of the drain pipe 126 can increase the length of the water passage pipe 22. By making the length the same, the gas does not flow out when the hollow fiber membrane is washed.

In addition, in the second embodiment (FIG. 7),
When the air supply amount is small and the air layer 24 is thin and the water surface is higher than the air supply pipe 16, the liquid surface is disturbed by the air supply, and the air flow amount from the ventilation hole 21 is changed. In this modification, the supply air outflow pipe 132 is bent upward as shown in FIG. 9, and the position of the outlet 133 at the tip thereof is higher than the connection position with the supply air pipe 16, so that the supply air amount is small. Even if the thickness of the air layer 24 becomes thin, the amount of ventilation from the ventilation hole 21 does not fluctuate, and stable supply is possible.

FIG. 11 is a partial longitudinal sectional view of another modification of the second embodiment, which is equivalent to FIG.

In this modification, the difference from the modification of FIG. 9 is that the upward end of the supply air outflow pipe 132 is closed and the outlet 134 is provided on the center side of the container 11 by the pipe wall near the end. is there. According to this, the outlet 13 of the supply air outflow pipe 132
Since the gas flows out horizontally from 4 and easily spreads below the partition plate 20, the thickness distribution of the gas layer can be made uniform, and the gas can be evenly supplied to each module cylinder 14.

Next, a third embodiment of the present invention will be described with reference to FIGS. 12 is a vertical sectional view of a filter device according to a third embodiment, FIG. 13 is a view taken along the line AA of FIG. 12, and FIG.
4 is a partial detailed view of the partition plate.

This embodiment is different from the first and second embodiments in that the water pipe 2 provided on the partition plate 20 is different.
That is, there is no 2 and the water passage portion 220 is formed between the outer peripheral plate 201 provided downward on the outer edge portion of the partition plate 20 and the container 11.

In this embodiment, since the other large number of water pipes provided in the partition plate 20 are not provided, the structure is extremely simple, the equipment cost can be reduced, and the size can be reduced. However, since a lateral flow toward the center of the container 11 occurs after leaving the water passage 220, the fluid force on the module cylinder 14 increases, and thus the treatment flow rate of the liquid to be purified is restricted.

Further, in this embodiment, a plurality of (two in the figure) air supply pipes 16 are provided, and the air supply dispersion pipe 230 connected to the air supply pipes 16 is formed in a header shape. As shown in the figure, the header portion of the air supply dispersion pipe 230 is formed in an arc shape inside the outer peripheral plate 201 and is provided with a plurality of air supply holes 231. Since there are no obstructions such as water passages, the gas distributed and supplied from a large number of air supply holes forms a gas layer 24 having a uniform thickness distribution in the lower part of the partition plate 20, and passes through the air holes 21 to form a gas layer 24. Module tube 14
Is supplied to. With this configuration, it is easy to inspect the lower part of the container.

As described above, the water passage portion and the air supply portion having different shapes are applied from the first embodiment to the third embodiment of the present invention, but it is obvious that any combination thereof may be used.

[0056]

According to the present invention, a horizontal partition plate is provided below the lower end of the hollow fiber membrane module in the container, and the hollow fiber membrane module has a one-to-one ventilation hole in the partition plate immediately below. Since a water passage that connects the lower part of the partition plate to the upper part is provided independently of this ventilation hole, the degree of freedom in design is increased,
The number of water pipes provided between the ventilation holes at the bottom of the partition plate can be reduced, or the water pipes can be eliminated to form water passages at the peripheral edge of the partition plate, simplifying the structure of the filtration device and making it smaller. It also has the effect of reducing equipment costs.

Further, by making the position of the opening of the supply air outflow pipe connected to the supply air pipe higher than the connection position between the supply air pipe and the container, the liquid level can be obtained even when the amount of supply air is small and the gas layer is thin. Can be supplied without disturbing, or the gas can be dispersed and supplied by the air supply dispersion pipe, the thickness distribution of the gas layer is made uniform, the air supply amount to each hollow fiber membrane module is made uniform, and filtration is performed. The cleaning ability of the device can be improved.

Further, since the partition plate is detachably provided by the support plate and the header of the air supply dispersion pipe is provided in an arc shape along the peripheral portion of the partition plate, there is an effect that the bottom of the container can be easily inspected.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a filtration device according to a first embodiment of the present invention.

FIG. 2 is a horizontal sectional view of the filtering device according to the first embodiment of the present invention.

FIG. 3 is a partial detailed view of a partition plate according to the first embodiment of the present invention.

FIG. 4 is a partial detailed view of a modification of the first embodiment.

FIG. 5 is a vertical sectional view of a filtering device according to a second embodiment of the present invention.

FIG. 6 is a horizontal sectional view of a filter device according to a second embodiment of the present invention.

FIG. 7 is a partial detailed view of a partition plate according to a second embodiment of the present invention.

FIG. 8 is a horizontal sectional view according to a modification of the second embodiment.

FIG. 9 is a partial vertical sectional view according to a modification of the second embodiment.

FIG. 10 is a partial vertical cross-sectional view of another position according to a modification of the second embodiment.

FIG. 11 is a partial vertical sectional view according to another modification of the second embodiment.

FIG. 12 is a vertical sectional view of a filter device according to a third embodiment of the present invention.

FIG. 13 is a horizontal sectional view of a filter device according to a third embodiment of the present invention.

FIG. 14 is a partial detailed view of a partition plate according to a third embodiment of the present invention.

[Explanation of symbols]

11 ... Container, 13 ... Hollow fiber membrane, 14 ... Module cylinder, 1
5 ... Water supply pipe, 16 ... Air supply pipe, 20 ... Partition plate, 21 ... Vent hole, 22 ... Water supply pipe, 23 ... Opening, 24 ... Gas layer, 27 ...
Vent pipe, 30 ... Air supply dispersion pipe, 31 ... Air supply hole, 125 ... Support plate, 126 ... Drain pipe, 132 ... Air supply outflow pipe, 133
Outlet, 134 ... Outlet, 201 ... Outer peripheral plate, 220 ... Water passage part, 230 ... Air supply dispersion pipe, 231 ... Air supply hole.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Seiichi Kazama 3-1-1, Sakaicho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd. Hitachi Plant

Claims (11)

[Claims] 1. A container, a separator in the container, a plurality of filtration modules connected to the separator, a water supply pipe for supplying a liquid to be purified and an air supply pipe for supplying gas into the container. In the filtration device for purifying the liquid to be purified by passing the liquid to be purified to the filtration module, a partition plate for forming a layer of supply gas is provided below the filtration module. Is provided substantially horizontally above the water supply pipe and the air supply pipe, a ventilation hole is provided in the partition plate immediately below the water supply pipe and the air supply pipe, and the liquid to be purified is communicated above the partition plate. A filtering device, wherein a water passage portion is provided separately from the ventilation hole. 2. A container, a separator in the container, a plurality of filtration modules connected to the separator, a water supply pipe for supplying a liquid to be purified and an air supply pipe for supplying gas into the container. A filtration device for purifying the liquid to be purified by passing the liquid to be purified to the filtration module, wherein the liquid is below the lower end of the filtration module in the container and above the water supply pipe and the air supply pipe. A substantially horizontal partition plate, corresponding to the filtration module, a ventilation hole is provided directly below the filtration module, and a water passage portion is provided on the partition plate so as not to include the ventilation hole. apparatus. 3. The filtration device according to claim 2, wherein the water passage portion has an upper end of a water pipe connected to an opening provided between the plurality of ventilation holes of the partition plate. apparatus. 4. The filtering device according to claim 2, wherein the plurality of ventilation holes are arranged in a staggered pattern on a plane of the partition plate, and the ventilation holes are provided in a central portion of a triangle having three ventilation holes adjacent to each other. A filtering device having a water pipe. 5. The filtering device according to claim 2, 3 or 4, wherein ventilation pipes having different lengths are connected to the plurality of ventilation holes, respectively. 6. The filtering device according to claim 2, further comprising a support plate that is inscribed in the container and has an opening that is smaller than an outer circumference of the partition plate and that detachably supports the partition plate. A filtering device characterized in that 7. The filtering device according to claim 6, wherein a drain pipe having an upper end connected to the support plate is provided. 8. A container, a separator in the container, a plurality of filtration modules connected to the separator, a water supply pipe for supplying a liquid to be purified and an air supply pipe for supplying gas into the container. A filtration device for purifying the liquid to be purified by passing the liquid to be purified to the filtration module, wherein the liquid is below the lower end of the filtration module in the container and above the water supply pipe and the air supply pipe. The container is provided with a partition plate substantially horizontally, a ventilation hole is provided in the partition plate immediately below the partition plate corresponding to the filtration module, and an outer peripheral portion in which an edge portion of the partition plate is extended downward and the A filtration device, wherein a water passage portion is formed between the container and the liquid to be purified above the partition plate. 9. The filtration device according to claim 1, further comprising: an air supply outflow pipe that is connected to the air supply pipe and has an outlet above a connecting portion between the container and the air supply pipe. Is opened in a gas layer formed below the partition plate during washing. 10. The filtering device according to claim 9, wherein the supply air outflow pipe is provided with a plurality of outlets. 11. The filtration device according to claim 1, wherein the filtration module is a hollow fiber membrane module and includes a hollow fiber membrane and a module tube surrounding the hollow fiber membrane. A filtering device characterized by being configured.