JP3359516B2 - Filtration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtration device using a hollow fiber membrane module, and more particularly to a method for flushing a hollow fiber membrane module from both directions, thereby effectively removing dirt deposited on the hollow fiber membrane. Related to removal technology.

[0002]

2. Description of the Related Art Conventionally, in a filtration apparatus used for reusing a washing liquid or performing a drainage treatment, a fluid to be filtered is transmitted through a membrane surface of a hollow fiber membrane using a hollow fiber membrane module. Some perform microfiltration or ultrafiltration.

FIG. 6 is a diagram showing a basic configuration of a filtering apparatus 101 employing a cross flow filtration method.

[0004] The fluid L101 to be filtered is stored in the retention tank 1
02 is supplied from a supply path 103 into a circulation path 106 having a circulation pump 104 and a hollow fiber membrane module 105. In the circulation path 106, the fluid L1
01 is pressurized by the circulation pump 104 and the arrow A101
Circulates in the direction indicated by.

[0005] When the fluid L101 is introduced into the hollow fiber membrane module 105 from the introduction portion 105a,
The fluid L101 flows in one direction through the inner tube portion of the hollow fiber membrane 105c, and a part of the flowing fluid L101 passes through the membrane surface of the hollow fiber membrane 105c from the inside to the outside due to the pressure difference between the inside and outside of the membrane. Filtration is performed. Fluid L101 which did not permeate the membrane surface
Is returned to the circulation path 106 from the deriving unit 105b.

[0006] The treatment liquid L102 as a fluid that has been filtered through the membrane surface of the hollow fiber membrane 105c is applied to the hollow fiber membrane 105c.
The fluid L101 to be filtered is returned from the inside of the housing of the hollow fiber membrane module 105 on the outside to the retention tank 102 by the treatment liquid return path 107 and accumulated in the retention tank 102, and is sequentially filtered and purified.

On the other hand, the fluid L10 that has not permeated the membrane surface
1 again circulates through the circulation path 106,
In 06, the concentration of the dirt component contained in the fluid L101 to be filtered increases with time.

[0008] Usually, in order to prevent this, a recovery means (not shown) for removing dirt components in the circulation path 106.
The filtration process is performed while keeping the concentration of the dirt component in the circulation path 106 within a certain range.

[0009] As a filtration system using a hollow fiber membrane module, there is a whole volume filtration system in addition to a cross flow filtration system. The whole filtration method is a method in which one end of the hollow fiber membrane is closed, a fluid to be filtered is introduced from the other end, and the fluid introduced into the inner tube of the hollow fiber membrane is completely filtered. is there. However, in this total filtration method, dirt and the like contained in the fluid tend to accumulate on the hollow fiber membrane, and the fluid permeates in the direction opposite to the direction of the membrane permeation of the fluid during normal filtration, and adheres to the membrane surface of the hollow fiber membrane. It is necessary to frequently perform a function recovery process called "backwashing" for removing dirt and the like ("backwashing" is not limited to the total amount filtration system but is generally performed also in the cross flow filtration system).

[0010]

However, in this cross-flow filtration system, the fluid L101 to be filtered is used.
Flows in one direction through the inner tube portion of the hollow fiber membrane 105c, so that the dirt component adheres little to the membrane surface and enables continuous treatment. In addition to the "backwashing" process, a function recovery process called "flushing" is also performed together or independently.

FIG. 7 is a diagram schematically illustrating the principle of "flushing". FIG. 7A is an enlarged view of the vicinity of the hollow fiber membrane module 105 in FIG. 6, and is different from the configuration in that a valve 110 is provided in the treatment liquid return path 107, and a state in which flushing is performed. FIG.

FIG. 7 (b) shows the D in FIG. 7 (a) on the left side of the figure.
A diagram illustrating the state of the hollow fiber membrane 105 in which the 101 part is enlarged, and a diagram schematically showing the pressure P101 in the housing of the hollow fiber membrane module 105 and the pressure P102 in the tube of the hollow fiber membrane 105 are shown on the right side of the figure. ing. The pressure P101 in the housing is almost constant, but the fluid L10
Due to the pressure gradient of 1, the pipe pressure P102 is high on the upstream side,
It decreases as it goes downstream.

In FIG. 7A, to perform flushing, first, the valve 110 is closed and the processing liquid return path 107 is opened.
The discharge of the processing liquid L102 from is stopped. In this state, the circulation pump 104 is operated to supply the fluid L101 to be filtered to the hollow fiber membrane module 105.

Then, as shown on the right side of FIG. 7 (b), the fluid L101 introduced into the hollow fiber membrane 105c has a pressure P102 in the pipe of the hollow fiber membrane 105c higher than a pressure P101 in the housing of the hollow fiber membrane module 105. In the high pressure region R101 (the lower half region of the hollow fiber membrane 105c),
Filtration is performed by passing through the membrane surface of the hollow fiber membrane 105c from the inside to the outside.

The pressure P10 in the pipe of the hollow fiber membrane 105c
2 is the pressure P1 in the housing of the hollow fiber membrane module 105
Region R102 (the hollow fiber membrane 105c)
In the upper half region), the processing liquid L102 permeates from the outside to the inside of the membrane surface of the hollow fiber membrane 105c, and at that time, the foreign matter 115 attached to the membrane surface in the tube of the hollow fiber membrane 105c is removed.

The peeled foreign matter 105 becomes a floating foreign matter 105a mixed in the fluid L101, and the membrane surface in the tube of the hollow fiber membrane 105c is cleaned by such a principle to recover the function.

However, in the configuration in which the valve 110 is provided in the treatment liquid return path 107 of the filtration device 101 in FIG.
As described in FIG. 7B, the region R of the hollow fiber membrane 105c
On the 102 side, cleaning by flushing is effectively performed, but on the region R101 side (that is, the lower half region of the hollow fiber membrane 105c), there is a problem that the cleaning efficiency by flushing is low.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to perform the cleaning action of the hollow fiber module by flushing when the hollow fiber membrane module is cleaned by "flushing". An object of the present invention is to provide a filtration device capable of effectively performing the filtration over the entire region of the membrane and increasing the filtration flow rate and extending the life of the hollow fiber membrane module.

[0019]

According to the present invention, a hollow fiber membrane loaded in a housing and a fluid to be filtered are introduced into an inner tube portion of the hollow fiber membrane. An introduction unit, an extraction unit for extracting a filtration target fluid that has passed through the inner tube portion of the hollow fiber membrane, and a discharge unit for discharging the membrane-permeable fluid filtered by permeating the membrane surface of the hollow fiber membrane. A hollow fiber membrane module provided, and a circulation path that connects an introduction portion and an outlet portion of the hollow fiber membrane module, and circulates and supplies a fluid to be filtered to the hollow fiber membrane module;
A discharge path for discharging a membrane-permeable fluid from a discharge section of the hollow fiber membrane module, wherein the discharge path includes a first valve means, and the first valve means is closed. In the state, the hollow fiber membrane module is provided with a washing unit that allows the fluid to be filtered to flow in both directions from the introduction part to the extraction part and the direction from the extraction part to the introduction part. I do.

According to this, when the fluid to be filtered is caused to flow in the forward direction through the hollow fiber membrane module with the first valve means closed, the membrane permeating fluid once permeating into the housing of the hollow fiber membrane module becomes hollow. Flushing that removes dirt and foreign matter deposited on the inner tube of the hollow fiber membrane is performed by passing the fiber from the outside to the inside in the opposite direction to the normal direction, and the function recovery of the hollow fiber membrane is performed. Done.

This flushing is more effectively performed on the downstream side in the flow direction of the fluid to be filtered, due to the pressure gradient inside the hollow fiber membrane with respect to the hollow fiber membrane module.
Since the fluid to be filtered flows into the hollow fiber membrane module from both directions, the area where flushing is effectively performed can be expanded.

The washing means may include an accumulator provided in a circulation path downstream of the hollow fiber membrane module for accumulating and discharging the fluid to be filtered, and a second valve in a circulation path downstream of the accumulator. And means.

According to this, the fluid to be filtered is accumulated in the accumulator at the time of ordinary filtration or flushing in the forward direction, and the fluid to be filtered accumulated in the accumulator is discharged after closing the second valve means. The fluid to be filtered flows into the yarn membrane module from the opposite direction, and flushing in the opposite direction can be performed.

Further, the circulation path includes pump means for circulating a fluid to be filtered, and the washing means branches off from a circulation path between the pump means and the hollow fiber membrane module and is located downstream of the hollow fiber membrane module. A bypass path that allows the fluid to be filtered to flow into the hollow fiber membrane module from the opposite direction by connecting to a circulation path, and a path through which the fluid to be filtered flows from the pump means is changed to either a bypass path or a circulation path. Switching means, a second valve means in a circulation path downstream of a connection part of the bypass path, and an outflow path for flowing out a fluid derived in a reverse direction from the introduction part of the hollow fiber membrane module to the circulation path, It is also preferable to provide

According to this, when the first valve means in the discharge path is closed and the fluid to be filtered flows through the circulation path by the switching means, forward flushing can be performed. Further, the flushing in the reverse direction is performed by introducing the fluid to be filtered into the bypass path by the switching means and closing the second valve means in the circulation path so that the fluid to be filtered flows into the hollow fiber membrane module from the reverse direction. Done. In this case, the fluid to be filtered, which is led in the opposite direction from the introduction portion of the hollow fiber membrane module, flows out of the circulation path out of the outflow path.

The circulation path includes pump means capable of switching the circulation direction of the circulation path. When the pump means is reversed to switch the circulation direction, a reverse flow to the supply path is prevented. It is also preferred to have two valve means.

According to this, the first valve means in the discharge path and the second valve means for preventing backflow to the supply path are closed, and the operation direction of the pump means is switched, so that when the flushing is performed in the forward direction, Flushing can be performed by flowing the fluid to be filtered in the circulation path in the same direction as during normal filtration, and performing flushing in the reverse direction by flowing the fluid to be filtered in the opposite direction to that during normal filtration.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment.

(First Embodiment) FIG. 1 shows a first embodiment of a filtration device to which the present invention is applied. This filtration device 1
Is a water purification device that removes, for example, fine foreign substances as dirt components contained in water (tap water or water stored in a water tank) as a fluid to be filtered, and water as a fluid to be filtered as a main component. The present invention can be used for an oil-water separator for separating an oil component suspended in a washing solution to be washed.

Here, as an embodiment, a description will be given of a filtration device 1 having only a basic configuration for applying the present invention to the above-described oil-water separation device.

In FIG. 1 (a), a fluid L1 to be filtered is accumulated in a retention tank 2, and is supplied from a supply path 3 into a circulation path 7 having a circulation pump 4 and a hollow fiber membrane module 5. You. In the circulation path 7, the fluid L1
Is circulated by the circulation pump 4 in the direction indicated by the arrow A1.

The circulation path 7 includes the hollow fiber membrane module 5
Can be used by the cross-flow filtration method. When the cross-flow filtration is performed, the fluid L
1 is introduced into the inside of the hollow fiber membrane module 5 from the introduction part 5a at one end of the housing, flows through the inner tube part of the hollow fiber membrane 5c in one direction (upward in the drawing), and flows inside and outside the membrane. Due to the transmembrane pressure difference, a part of the flowing fluid L1 permeates through the membrane surface of the hollow fiber membrane 5c loaded inside the housing and is filtered.

The fluid L1 which has not permeated the membrane surface of the hollow fiber membrane 5c is led out from the outlet part 5b at the other end of the housing and returned to the circulation path 7. The membrane-permeable fluid L2 that has passed through the membrane surface of the hollow fiber membrane 5c and has been filtered is returned from the discharge portion 5d connected to the side surface of the housing of the hollow fiber membrane module 5 to the retention tank 2 via the discharge path 8, and stays there. The fluid L1 accumulated in the tank 2 and to be filtered is sequentially filtered.

The fluid L1 which has not permeated the membrane surface recirculates through the circulation path 7 via the shutoff valve 10 which has been opened.
In the circulation path 7, the concentration of the dirt component contained in the fluid L1 to be filtered increases with time. In order to prevent this, a collecting means (not shown in the first embodiment but a floating oil collecting means and the like exemplified in the second embodiment) is provided in the circulation path 7 for removing the dirt component. It is also preferable to carry out a countermeasure such as connection of the filter and to perform the filtration process while keeping the concentration of the dirt component in the circulation path 7 within a certain range.

At the time of ordinary filtration for obtaining the membrane-permeable fluid L2, a shutoff valve 9 provided as a first valve means provided in the discharge path 8 and a downstream side of the hollow fiber membrane module 5 in the circulation path 7 are provided. Shut-off valve 10 as second valve means
Is open.

In the filtration device 1, the fluid L1 flowing through the circulation path 7 between the hollow fiber membrane module 5 and the cutoff valve 10 in the circulation path 7 can be accumulated and discharged in order to perform flushing in the reverse direction, which will be described later. An accumulator 11 is provided.

FIG. 1B shows the purpose of removing dirt and the like when dirt or foreign matter adheres or accumulates on the inner tube portion of the hollow fiber membrane 5c of the hollow fiber membrane module 5 by the operation of the filtration device 1. FIG. 8 is a view showing a state in which flushing is performed in the forward direction (the same A1 direction as the flow of the fluid L1 during normal filtration of the circulation path 7) (the flushing has been described in more detail in FIG. 7; The explanation is omitted again.)

The circulation pump 4 is operated with the shut-off valve 9 closed, and the fluid L1 is circulated in the circulation path 7 in the forward direction of the arrow A1. At this time, "flushing" is performed according to the principle described in detail in the section of the prior art with reference to FIG.
In addition, from the characteristics of flushing, the hollow fiber membrane 5c of the fluid L1 is used.
The cleaning efficiency in the lower side R2 is low, and the cleaning efficiency in the upper side R1 is high.

The fluid L1 is stored in the accumulator 11 during normal filtration or flushing in the forward direction. The fluid accumulation amount of the accumulator 11 is 0.5 per 1 m ² of the membrane area of the hollow fiber membrane module 5.
1 and the accumulation pressure is preferably about 0.3 MPa.

Next, referring to FIG. 1C, a state in which flushing in the reverse direction is performed will be described. After the forward flushing is completed in FIG. 1B, the circulation pump 4 is stopped, and the shutoff valve 10 is closed.

The fluid L1 accumulated in the accumulator 11 is discharged to the circulation path 7 in the direction of arrow A2, and is introduced from the outlet 5b of the hollow fiber membrane module 5 in the opposite direction to perform flushing in the opposite direction. . In this case, the cleaning efficiency of the fluid L1 on the upper side R1 of the hollow fiber membrane 5c is low, and the cleaning efficiency on the lower side R2 is high.

Fluid L used for flashing in the reverse direction
Reference numeral 1 denotes a dashed line from the introduction portion 5a of the hollow fiber membrane module 5, if necessary, for example, when the circulation pump 4 is a positive displacement type and cannot be used as a buffer for the fluid L1 discharged from the accumulator 11. Outflow path 12 indicated by
And, it flows out of the circulation path 7 (arrow A3) by the shut-off valve 13 in the open state.

By adjusting the flow rate passing through the shutoff valve 13, efficient flushing can be performed.

As described above, by performing the flushing in the forward direction and the reverse direction, the flushing is sufficiently performed over the entire region of the hollow fiber membrane 5c, and the function of the hollow fiber membrane module is restored, and the filtration device is removed. (1) An increase in the filtration flow rate and a prolonged life of the hollow fiber membrane module can be obtained.

(Embodiment 2) FIG. 2 shows a second embodiment of a filtration device to which the present invention is applied. This filtering device 21
Is connected to the circulation path 7 of the first filtration device 1 with the floating oil recovery means 22 for removing the oil component in the fluid L1. still,
The same components as those in the first embodiment are denoted by the same reference numerals in the following drawings and description.

In FIG. 2 (a), the fluid L1 pressurized by the circulation pump 4 is supplied to the hollow fiber membrane module 5 at the branch 7a.
And it is branched to the floating oil removing means 22 side. Fluid L1 flowing to the hollow fiber membrane module 5 side is subjected to ordinary filtration.

The fluid L1 flowing into the floating oil collecting means 22 from the branch portion 7a through the path 23 passes through a fibrous filter called a coalescer filter (22a), so that the oil component contained therein easily floats. It becomes large particles and floats above the main body tank of the floating oil recovery means 22 (oil component L1a). Then, the oil component L1a is discharged to the outside, and the fluid L1 in which the concentration of the oil component is reduced is re-introduced into the circulation path 7 through the path 24. 25 is the route 23
, Which is closed during filtration.

FIG. 2B is a view showing a state in which forward flushing is performed. Except that a part of the fluid L1 flows into the floating oil recovery means 22 from the branch portion 7a,
Flushing similar to that in FIG. 1 (b) is performed.

Then, as shown in FIG. 2C, when the circulation pump 4 is stopped and the shut-off valve 10 is closed, the fluid L1 accumulated in the accumulator 11 is diverted to arrows A4 and A5. And flows back to the hollow fiber membrane module 5 and the floating oil collecting means 22. Among them, the flushing action when the hollow fiber membrane module 5 flows backward is the same as in the first embodiment, and is discharged to the outside from the shut-off valve 25 in the open state according to the arrow A6.

The fluid L1 flowing back to the floating oil collecting means 22
Flows through the coalescer filter 22a in the reverse direction, and dirt, foreign matter, and the like captured by the fibrous filter are discharged to the outside from the shutoff valve 25 from the path 23 according to the arrow A7.

Therefore, in the filtering device 21 provided with the floating oil collecting means 22, it becomes possible to perform the flushing of the hollow fiber membrane module 5 and the backwashing of the floating oil collecting means 22.

(Embodiment 3) FIG. 3 shows a third embodiment of a filtration device to which the present invention is applied. This filtering device 31
Is branched from between the circulation pump 4 and the hollow fiber membrane module 5 of the circulation path 7 of the first filtration device 1 and connected to the circulation path 7 on the downstream side of the hollow fiber membrane module 5 (the connection part 7).
b) A bypass path 32 that allows the fluid L1 to flow into the hollow fiber membrane module 5 from the opposite direction is provided.

Reference numeral 33 denotes a switching valve as switching means for changing the flow path of the fluid L1 from the circulation pump 4 to either the bypass path 32 or the circulation path 7.

The position of the shut-off valve 10 as the second valve means is provided in the circulation path 7 downstream of the connection portion 7b.

Reference numeral 34 denotes an outflow path for flowing out the fluid L1 derived in the reverse direction from the introduction portion 5a of the hollow fiber membrane module 5 to the circulation path 7 during flushing in the reverse direction. It is.

FIG. 3A shows a state at the time of ordinary filtration, in which the switching valve 33 is set so that the fluid L1 flows in the direction of arrow A8.
To operate the filter device 31 with the shutoff valves 9 and 10 opened and the shutoff valve 35 closed.

FIG. 3B shows a state in which forward flushing is being performed. In the state shown in FIG. 3A, only the shutoff valve 9 is closed, and the fluid L1 flows through the circulation path 7 in the forward direction. Circulating.

FIG. 3C shows a state in which flushing is performed in the reverse direction.
Is closed, the switching valve 33 is switched in the direction in which the fluid L1 flows through the bypass path 32 (the direction of the arrow A9), and the shutoff valve 35 is opened.

When the circulating pump 4 is operated in such a state, the fluid L1 is introduced into the hollow fiber membrane module 5 from the opposite direction, thereby performing flushing in the opposite direction. In this case, the fluid L1 led in the opposite direction from the introduction section 5a of the hollow fiber membrane module 5 is discharged from the circulation path 7 through the outflow path 34 and the shutoff valve 35 in the open state.

(Embodiment 4) FIG. 4 shows a fourth embodiment of a filtering apparatus to which the present invention is applied. This filtering device 41
Has a circulation pump 4A capable of switching the circulation direction of the circulation path 7 and a shutoff valve 42 as second valve means in the supply path 3.

At the time of the filtration shown in FIG. 4A, the shutoff valve 9 and the shutoff valve 42 are opened, the fluid L1 is circulated in the direction of the arrow A1 by the circulation pump 4A, and the membrane permeable fluid L2 that has passed through the hollow fiber membrane 5c is removed. The gas is discharged from the discharge path 8 via the shut-off valve 9 in the open state.

FIG. 4B shows a state in which forward flushing is performed, and only the shut-off valve 9 is closed. Here, when the fluid L1 that has passed through the hollow fiber membrane module 5 flows into the supply path 3, the shut-off valve 42 may be closed to prevent backflow in the supply path 3.

FIG. 4C shows a state in which flushing is performed in the reverse direction, and the fluid L1 is circulated in the direction of arrow A11 by the circulation pump 4A with the shutoff valve 9 closed. At this time, the fluid L1 pressurized by the circulating pump 4A directly flows into the supply path 3 to generate a backflow in the supply path 3, so that the shut-off valve 42 is closed to prevent the backflow in the supply path 3. I do.

(Embodiment 5) FIG. 5 shows a fifth embodiment of the filtering apparatus to which the present invention is applied. This filtering device 51
Then, the water component is separated and discharged from the suspension L5 stored in the concentration tank 52 to increase the concentration of the suspension component, thereby increasing the suspension L5.
It functions to concentrate 5.

The filtering device 51 is provided with a concentration path 53 composed of paths 53a, 53b and 53c corresponding to the circulation paths of the above embodiments. The path 53a is provided with a pump 56 for pressurizing and feeding the suspension L5 from the concentration tank 52 to the hollow fiber membrane module 5, and the path 53b downstream of the pump 56 is provided with the hollow fiber membrane module 5. ing. Then, a path 53c from the outlet 5b of the hollow fiber membrane module 5 to the concentration tank 52 is arranged. 54, 55
Is a shut-off valve.

The accumulator 1 temporarily accumulates the suspension L5 flowing through the passage 53c and discharges the suspension L5 in order to perform flushing in the reverse direction in the passage 53c.
1 is provided.

Therefore, in this embodiment, in other words, it can be interpreted as a configuration provided with a concentration tank in the middle of the circulation path of the first embodiment in FIG.

At the time of concentration in FIG. 5A, the shut-off valve 9 and the shut-off valve 54 are opened, and the suspension
5, and the permeated fluid L2 that has passed through the hollow fiber membrane 5c is discharged from the discharge path 57 via the shutoff valve 9 in the open state. The shut-off valve 55 is in a closed state.

FIG. 5B shows a state in which flushing in the forward direction is performed, and only the shutoff valve 9 is closed from the state shown in FIG. 5A. Suspension L fed by pump 56
5 performs flushing while passing through the hollow fiber membrane module 5, and is returned to the concentration tank 52 from the path 53 c.

FIG. 5C shows a state in which the flushing in the reverse direction is performed. The pump 4 is stopped, the shutoff valve 56 is closed, and the accumulator 1 is opened with the shutoff valve 55 opened.
By feeding the suspension L5 in the reverse direction by 1
The flushing in the opposite direction is performed while passing through the hollow fiber membrane module 5. At this time, the excess suspension L5 discharged from the accumulator 11 is discharged to the outside of the concentration path 53 from the shut-off valve 55 in the open state.

As described above, the filtration device 5 for the purpose of concentration is used.
The present invention is also applicable to the hollow fiber membrane module 5 incorporated in the first embodiment, and the flushing performed in both directions effectively recovers the function of the hollow fiber membrane module 5 and separates the water component. The concentration performance can be improved by increasing the flow rate. In the present embodiment, the water component was separated, but the present invention is not limited to this. Oil and chemicals permeating the membrane surface of the hollow fiber membrane of the hollow fiber membrane module are separated, It is also possible to concentrate the contained suspension components (fine solids that do not pass through the membrane surface of the hollow fiber membrane).

[0072]

According to the filtration device having the above-described structure and operation, flushing is performed from both directions of the hollow fiber membrane module, so that the hollow fiber membrane can be effectively cleaned by flushing over the entire area. A filtration device that can increase the filtration flow rate and extend the life of the membrane module is obtained.

By providing an accumulator and discharging the fluid to be filtered accumulated in the accumulator, the fluid to be filtered can flow into the hollow fiber membrane module from the opposite direction, thereby performing the flushing in the opposite direction.

[0074] Also by the bypass path, the fluid to be filtered can flow into the hollow fiber membrane module from the reverse direction, and flushing in the reverse direction can be performed.

The provision of the pump means capable of switching the circulation direction of the circulation path also enables the fluid to be filtered to flow into the hollow fiber membrane module from the opposite direction, thereby performing the flushing in the opposite direction.

[Brief description of the drawings]

FIG. 1 is a diagram of a filtration device according to a first embodiment of the present invention.

FIG. 2 is a diagram of a filtration device according to a second embodiment of the present invention.

FIG. 3 is a diagram of a filtration device according to a third embodiment of the present invention.

FIG. 4 is a diagram of a filtration device according to a fourth embodiment of the present invention.

FIG. 5 is a diagram of a filtering device according to a fifth embodiment of the present invention.

FIG. 6 is a diagram of a conventional cross-flow type filtration device.

FIG. 7 is a view for explaining the principle of flushing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filtration apparatus 2 Reservoir 3 Supply path 4 Circulation pump 5 Hollow fiber membrane module 5a Introducing part 5b Outlet part 5c Hollow fiber membrane 7 Circulation path 8 Discharge path L1 Fluid (filtration object fluid) L2 Membrane permeating fluid

Claims (4)

(57) [Claims] 1. A hollow fiber membrane loaded in a housing,
An introduction part for introducing a fluid to be filtered into the inner tube part of the hollow fiber membrane, a derivation part for leading out a fluid to be filtered that has passed through the inner tube part of the hollow fiber membrane, and passing through the membrane surface of the hollow fiber membrane. A hollow fiber membrane module having a discharge part for discharging the membrane permeated fluid filtered by the above, and an introduction part and a discharge part of the hollow fiber membrane module are connected to circulate a fluid to be filtered through the hollow fiber membrane module. A filtration path comprising: a circulation path that can be supplied by being supplied; and a discharge path that discharges a membrane-permeable fluid from a discharge section of the hollow fiber membrane module, wherein the discharge path includes a first valve means, In a state where the first valve means is closed, it is possible to flow the fluid to be filtered in the hollow fiber membrane module in both directions from the introduction section to the exit section and from the exit section to the introduction section. Cleaning means Filtration device. 2. The accumulator provided in a circulation path downstream of the hollow fiber membrane module to accumulate and discharge a fluid to be filtered, and a second valve in a circulation path downstream of the accumulator. The filtering device according to claim 1, comprising: 3. The circulation path includes pump means for circulating a fluid to be filtered, and the washing means branches off from a circulation path between the pump means and the hollow fiber membrane module and is located downstream of the hollow fiber membrane module. And a bypass path for connecting the fluid to be filtered into the hollow fiber membrane module from the opposite direction by connecting to the circulation path, and changing the flow path of the fluid to be filtered from the pump means to either a bypass path or a circulation path. Switching means, a second valve means in a circulation path downstream of a connection part of the bypass path, and an outflow path for flowing out a fluid derived in the reverse direction from the introduction part of the hollow fiber membrane module to the circulation path, The filtration device according to claim 1, further comprising: 4. The circulating path includes pump means capable of switching a circulating direction of the circulating path, and preventing reverse flow to the supply path when the circulating direction is switched by reversing the pump means. The filtering device according to claim 1, further comprising two valve means.