JP7555201B2 - Filtration device and cleaning method thereof - Google Patents

Description

The present invention relates to a filtration device and a method for cleaning the same.

2. Description of the Related Art Conventionally, in wastewater treatment processes in the manufacturing processes of chemical products and food ingredients, or at construction sites and ready-mix concrete manufacturing plants, fine particles contained in liquids have been collected by filtration.
For example, examples of such applications include starch refining, treatment of turbid water generated at civil engineering construction sites before it is discharged, and production of mixing water from cement-containing wastewater generated at ready-mix concrete manufacturing plants.
Common filtration methods are roughly divided into dead-end filtration and cross-flow filtration (hereafter referred to as cross-flow type). For example, in the filtration treatment of wastewater containing cement, the raw water is made to flow parallel from one side to the other of the filtration membrane surface (cross-flow type), which enables solid-liquid separation and concentration of the raw water. In other words, by creating a flow parallel to the filtration membrane surface, it is possible to filter the raw water while suppressing the phenomenon of particles in the raw water accumulating on the membrane surface.

The filtration membrane used in such a cross-flow system is made of a hollow fiber membrane, a ceramic membrane, a nonwoven fabric, or the like, and is formed into a cylindrical shape.
Although the above-mentioned cross-flow type prevents the accumulation of particles, there is a risk of clogging due to gradual accumulation on the membrane surface or penetration into the gaps inside the membrane, which also causes a decrease in the filtration rate.

As a countermeasure against these problems, there is a method of cleaning the filter membrane by flowing cleaning water that does not contain particles from the filtrate (outside the filter membrane) side through the inside of the filter membrane to the raw water side (hereinafter referred to as the backwashing method).

As a different measure to the above, Patent Document 1 discloses a method in which air is blown into the filtration device to remove residual water, and then the pressure is released from the air-pressurized state to normal pressure, causing the filter cake to peel off due to the vibration or impact that occurs during this process.

Furthermore, Patent Document 2 discloses a method that includes a cylindrical filter body and an impact means that impacts the filter body from the outside, and prevents deposition on the membrane surface by impacting the filter body with the impact means while the filter body is in an expanded state, thereby preventing clogging of the filter body.

Japanese Unexamined Patent Publication No. 60-190208 Japanese Patent Application Publication No. 9-94413

However, in the backwashing method, the flow rate of the washing water passing from the outside of the filtration membrane to the inside of the filtration membrane is slow, making it difficult to completely remove deposits on the filtration membrane surface and particles that have entered the gaps inside the membrane.
The method of Patent Document 1 also requires a separate device for generating compressed air, which increases costs. In addition, since an impact is applied in the absence of liquid, the filtration membrane vibrates significantly, and there is a risk of the filtration membrane being damaged by collisions with detached deposits.
Furthermore, the method of Patent Document 2 also requires a separate mechanically driven device for striking the filtration membrane within the filtration device, which not only increases the manufacturing cost but also makes the filtration device itself large. Also, the structure of the filtration membrane is complicated, for example, a resin cylindrical net is attached to the periphery of the filtration membrane to protect it from the strikes.

The present invention was made in consideration of these points, and aims to provide a cross-flow filtration device that is inexpensive, has a simple structure, and is highly effective at removing clogging when cleaning the filtration membrane. It also aims to provide a cleaning method using the same.

According to the present invention, a cross-flow type filtration device is provided that includes a membrane module and a housing, the membrane module having a cylindrical body made of a flexible filtration membrane, a guide body arranged at intervals in the circumferential direction within the cylindrical body, and a pair of piping joints, each piping joint being connected to both ends of the cylindrical body and the guide body, the housing has a predetermined gap with the filtration membrane, and houses the membrane module with each piping joint protruding, has a connection port on the side, and is configured such that when the filtration speed decreases, cleaning water is added into the housing from the connection port to deform the filtration membrane and remove particles that have accumulated in or are caught in the filtration membrane.

The filtration device according to the present invention has an inexpensive and simple structure, and when the filtration speed slows down, cleaning water is added to the inside of the housing from a port, which causes the filtration membrane to deform based on the guide body, thereby removing particles that have accumulated on the filtration membrane. It is also possible to remove particles that are caught in the filtration membrane.

1A and 1B are schematic diagrams showing a filtration device according to one embodiment of the present invention, in which FIG. 1A is a membrane module housed inside the filtration device, and FIG. 1B is a perspective view of the filtration device. 2(a) and 2(b) are cross-sectional views of a filtering device according to an embodiment of the present invention, where FIG. 2(a) is a longitudinal cross-sectional view, and FIG. 2(b) is a cross-sectional view taken along the line x in FIG. 2(a). 3A and 3B are diagrams illustrating the operation of a membrane module of a filtration device according to one embodiment of the present invention, in which FIG. 3A shows a filtration membrane with raw water or cleaning water passing through it, and FIG. 3B shows a filtration membrane with cleaning water poured into the side of the housing. FIG. 4 is a partially enlarged schematic diagram of FIG. 3 . 1 is a schematic diagram showing a configuration of a filtration processing system including a filtration device according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a filtering operation state in the filtering treatment system. FIG. 2 is a schematic diagram showing a cleaning operation state in the filtration processing system. FIG. 2 is a schematic diagram showing a cleaning operation state in the filtration processing system. FIG. 2 is a schematic diagram showing a cleaning operation state in the filtration processing system. FIG. 2 is a schematic diagram showing a cleaning operation state in the filtration processing system. 1 is a graph showing a schematic diagram of the relationship between the filtration rate of a filtration membrane and the number of cycles in Test Example 2. 1 is a graph showing a schematic diagram of the relationship between the filtration rate of a filtration membrane and the number of cycles in Test Example 3.

The following describes the embodiments of the present invention with reference to the drawings. The various features shown in the embodiments below are not limited and can be combined with each other.

1. Filtration device In Section 1, the configuration of the filtration device according to this embodiment will be described. Figures 1 to 4 are for explaining the filtration device according to this embodiment, and Figure 1 is a schematic diagram of the filtration device, Figure 1(a) is a membrane module accommodated inside the filtration device, Figure 1(b) is a perspective view of the filtration device, Figure 2 is a cross-sectional view of the filtration device, Figure 2(a) is a vertical cross-sectional view, Figure 2(b) is a cross-sectional view seen from the arrow x in Figure 2(a), Figure 3 is an operation diagram of the membrane module, Figure 3(a) is a filtration membrane in a state where raw water or washing water is passed through it, Figure 3(b) is a filtration membrane in a state where washing water is poured from the side of the housing, and Figure 4 is a partially enlarged schematic view of Figure 3.
As shown in FIGS. 1 and 2, the filtration device 20 according to this embodiment includes a membrane module 10, a housing 21, a lid 22, and the like.

1.1 Membrane Module The membrane module 10 includes a tubular body 11 made of a flexible filtration membrane, guide bodies 12 arranged at intervals in the circumferential direction around the center of the tubular body 11, and a pipe joint 13. Here, the tubular body 11 is preferably cylindrical.

(Guide body)
The guide body 12 is composed of three rod-shaped bodies, and is arranged at 120 degree intervals in the circumferential direction inside the cylindrical body 11. The number of guide bodies 12 needs to be at least three, and can be changed appropriately depending on the shape of the cylindrical body 11.
Depending on the shape, it may be possible to connect the guide bodies 12 with reinforcing materials, but the reinforcing materials may restrict the contraction of the filtration membrane or cause resistance to the flow of raw water, so it is preferable to use less reinforcing materials. More preferably, there is no reinforcing material at all.

(Pipe fittings)
The pipe joint 13 is made of a pair of hollow metal members, and is composed of a cylindrical head 13a and a flange 14. Specifically, the flange 14 extends outward from an edge on one end of the head 13a. Each flange 14 is connected to both ends of the cylindrical body 11 and the guide body 12 in the longitudinal direction, respectively.
This allows raw water to flow within the cylindrical body 11 from one pipe joint 13 to the other pipe joint 13.

(Filtration membrane)
The filter membrane is a cylindrically shaped nonwoven or woven fabric made of polypropylene, polyester, nylon, vinylon, cotton, or the like, which is flexible and woven into a sheet shape. Not limited to this, a commercially available filter fabric for liquids or gases may be molded into a cylindrical shape. Preferably, the woven fabric is woven in a weft rib or plain weave. This enhances the solid-liquid separation performance, resulting in a clearer filtrate or a more concentrated effect.

1.2 Housing The housing 21 is made of a rigid material (e.g., stainless steel) that can withstand the pressure of the fluid flowing inside the housing 21.
A connection port 23 capable of supplying a fluid to the inside of the housing 21 or discharging the fluid from the inside of the housing 21 is provided on the side surface of the housing 21. In the present embodiment, two connection ports 23 are provided along the longitudinal direction, but this is not limited thereto and may be changed as appropriate so long as there is one or more connection ports.
The housing 21 accommodates the membrane module 10 with the pipe joints 13 protruding from it. The number of membrane modules 10 accommodated in the housing 21 is not limited to one, and may be multiple.
As shown in FIG. 2, the filtration membrane is configured with a predetermined gap s between it and the inner circumference of the housing 21. When the filtration speed decreases, cleaning water is added to the inside of the housing from the port, so that the filtration membrane can be deformed to contract, and particles accumulated or trapped in the filtration membrane can be removed.

1.3 Lid The lid 22 has a cylindrical shape with a bottom, and is configured to fit both ends of the housing 21. A fitting hole into which the head 13a of the pipe joint 13 can be fitted is provided at the center of the bottom.

In this way, in the cross-flow filtration device 20 according to the present invention, the membrane module 10 is arranged in the housing 21 with a gap s, and is sealed by the lid 22 so that it cannot move in the radial or longitudinal directions. Specifically, the heads 13a of the pipe fittings 13 at both ends of the membrane module 10 fit into the fitting holes of the lids 22 to restrict radial movement, and the flanges 14 of the pipe fittings 13 are housed in contact with the bottom of the lid 22 to restrict movement in the longitudinal direction.

(Operation of the Filtration Device)
As shown in FIGS. 3 and 4, the operation of the filtering device 20 according to this embodiment generally involves passing raw water from one pipe joint 13 to the other pipe joint 13 .
On the other hand, as shown in FIG. 4(a), particles g gradually accumulate on the inner surface of the filtration membrane or enter gaps inside the membrane, causing clogging and decreasing the filtration rate.
Therefore, by supplying cleaning water from the connection port 23 of the housing 21 into the gap s in the housing, the filtration membrane between the guide bodies 12 is deformed so as to contract (push toward the center) as shown in Fig. 3(b). As a result, as shown in Fig. 4(b), the gaps or weave of the membrane are pushed open, making it possible to remove deposits accumulated on the filtration membrane and particles g that have entered the interior. Next, by supplying cleaning water into the filtration membrane from the pipe joint 13, the filtration membrane is restored to its original shape or deformed to an expanded state. By repeating this operation, the cleaning effect of the filtration membrane can be improved.

(Operation of the Filtration Processing System)
A specific example of the operation of the filtration device 20 in the filtration processing system 1 will be described.
Fig. 5 is a schematic diagram showing the configuration of a filtration system equipped with a filtration device according to one embodiment of the present invention. Fig. 6 is a schematic diagram showing a filtration operation state in the filtration system, Fig. 7 is a schematic diagram showing a cleaning operation state of the outside of the filtration membrane with water as cleaning water in the filtration system, Fig. 8 is a schematic diagram showing a cleaning operation state of the inside of the filtration membrane with water as cleaning water in the filtration system, Fig. 9 is a schematic diagram showing a cleaning operation state of the outside of the filtration membrane with cleaning water and Fig. 10 is a schematic diagram showing a cleaning operation state of the inside of the filtration membrane with cleaning water and filtrate in the filtration system.

As shown in Figures 5 to 10, the filtration device 20 according to this embodiment serves as one component of the filtration processing system 1.

The filtration processing system 1 is composed of a raw water tank 31, a filtrate tank 32, a water tank 33, a filtration device 20, a valve 34, etc. The raw water tank 31 stores raw water 31w, the filtrate tank 32 stores filtrate 32w, and the water tank 33 stores water 33w. Each tank is also provided with a pump for transferring liquid. Specifically, each tank is provided with a pump 31p for transferring raw water 31w in the raw water tank 31, a pump 32p for transferring filtrate 32w in the filtrate tank 32, and a pump 33p for transferring water 33w in the water tank 33.

When filtering raw water 31w, the raw water 31w in the raw water tank 31 is passed through the filtration device 20 and returned to the raw water tank 31. While the raw water 31w is circulated, the raw water 31w is filtered in the filtration device 20, and the filtered filtrate 32w accumulates in the filtrate tank 32. Here, filtrate 32w that does not contain solids accumulates in the filtrate tank 32, and the raw water 31w in the raw water tank 31 is concentrated.

Specifically, as shown in Figure 6, during filtration operation, first the valve 34 in the piping is controlled. In other words, valves 34d 1 to 3 and 34b 2 are controlled to be "closed" so that liquid is not transferred from pumps 32p and 33p to the filtration device 20, and the other valves are controlled to be "open." Here, the black triangles of each valve represent the "closed state," and the white triangles represent the "open state."

The raw water 31w transported by the pump 31p is circulated through the filtration device 20 and returned to the raw water tank 31, so that the raw water 31 is gradually filtered within the filtration device 20, and the filtered filtrate 32w is stored in the filtrate tank 32 through the connection port 23.

If the raw water 31w is continuously filtered, the filtration membrane gradually becomes clogged, and the filtration speed decreases. Therefore, by appropriately opening and closing each valve at the timing of the decrease in filtration speed or at a certain operating time, the outside of the filtration membrane housed inside the filtration device 20 of the present invention is backwashed with cleaning water of water 33w or filtrate 37w from the connection port 23, thereby shrinking the filtration membrane and removing the deposits accumulated on the filtration membrane and particles that have entered the inside. In addition, in order to enhance the cleaning effect of the membrane, after the backwashing, the cleaning water of water 33w or filtrate 37w is continuously passed through the inside of the filtration membrane to restore or expand the filtration membrane, and then backwashing is performed again. By performing this multiple times, an even higher cleaning effect of the membrane can be obtained.

Specifically, as shown in Figure 7, when washing the outside of the filtration membrane in the filtration device 20 with water, valve 1 of valves 34b, 34c, and 34d is closed, and valves 2 and 3 of valves 34a, 34d are opened. This allows water 33w transferred by pump 33p to pass through the gap s between the outside of the filtration membrane and the connection port 23 of the filtration device 20. This causes the filtration membrane to shrink and backwash, and the washing water is stored in the raw water tank 31.

Next, as shown in Figure 8, valves 2 and 3 of 34d are closed and valves 1 and 2 of 34b are opened based on the state of each valve in Figure 7. As a result, water 33w transferred by pump 33p is not transferred to connection port 23, but is passed through pipe joint 13 into the inside of the filtration membrane and collected in raw water tank 31. At this time, the filtration membrane restores or expands, causing the weave of the filter cloth to repeatedly oscillate, thereby improving the cleaning effect.

On the other hand, as shown in Figure 9, when cleaning the outside of the filtration membrane in the filtration device 20 with filtrate, valve 34d 2 is closed and valves 34d 1 and 3 are opened based on the state of each valve in Figure 7. This causes filtrate 32w transferred by pump 32p to pass through the gap s between the outside of the filtration membrane and the connection port 23 of the filtration device 20. This causes the filtration membrane to shrink and backwash, and the cleaning water is stored in the raw water tank 31.

Next, as shown in Figure 10, valve 3 of 34d is closed from the state of each valve in Figure 9, and valves 1 and 2 of 34b and valve 2 of 34d are opened. As a result, the filtrate 32w transferred by pump 32p is not transferred to connection port 23, but is passed through pipe joint 13 into the inside of the filtration membrane and collected in raw water tank 31. At this time, the filtration membrane restores or expands, causing the weave of the filter cloth to repeatedly oscillate, thereby improving the cleaning effect.

Test Example 1
In order to select a filter fabric for use in the filtration device 20 of the present invention, tests were conducted on the solid-liquid separation performance and the degree of recovery of the filtration rate by washing according to the specifications of each filter fabric.
Table 1 shows the specifications of nine types of filter fabric and the results.

In this test example 1, nine types of commercially available filter fabrics with different filter fabric specifications (material, thread structure, weave, thickness, and air permeability) were used, as shown in Table 1. Specifically, four types of filter fabrics (No. 1 to 4) were selected, which were made of polypropylene, had a monofilament thread structure, and were weft rib weave, 5/3 twill weave, and 2/2 twill weave. Four types of filter fabrics (No. 5 to 8) were selected, which were made of nylon, had a monofilament thread structure, and were weft rib weave, plain weave, 5/3 twill weave, and 2/2 twill weave. One type of filter fabric (No. 9) was selected, which was made of nylon, had a multifilament thread structure, and was weave plain weave.
Although other filter fabric specifications could have been tested, they were excluded from the test due to factors such as difficulty in obtaining them and high prices.
In addition, since a commercially available filter cloth was used for the thickness and air permeability, it was not possible to perform the test under conditions where all the values were the same or approximately the same.

(Test Method)
First, each filter cloth was formed into a cylindrical shape (diameter 20 mm), and a cross-sectionally convex pipe joint (filter membrane connection side outer diameter 20 mm, vinyl tube connection side outer diameter 14 mm, through inner diameter 10 mm) was connected to both ends to produce a membrane module (effective membrane length 200 mm). A pair of vinyl tubes (inner diameter 14 mm, length 1,000 mm) was connected to each of the pipe joints at both ends. Specifically, one end of one vinyl tube was connected to one pipe joint, and the other end of the vinyl tube was connected to a small pump (projecting water volume 10 L/min).
Also, one end of the other vinyl tube is connected to the other pipe joint, and the other end of the vinyl tube is left free.
Then, the sludge water (cement concentration: about 15%) was passed through the inside of the filtration membrane by the above-mentioned pump.
The volume (ml/min) of the filtrate seeping out of the filtration membrane over one minute and the absorbance at a wavelength of 660 nm were measured. The results are shown in Table 1.
In this case, the absorbance is 1.000 for sludge water with a cement concentration of about 0.15% or more, and approaches 0.000 as the solid content in the filtrate decreases, indicating improved solid-liquid separation performance.

Looking at the absorbance results in Table 1, filter cloths No. 1, 2, 5, 6, and 9 had values close to 0.000. In other words, it can be said that solid-liquid separation performance varies more with differences in weaving method than with material, thread structure, thickness, or air permeability. In other words, filter cloths with weft rib weave or plain weave weave have high solid-liquid separation performance. The specifications of the filter cloth can be changed in various ways depending on the purpose and application, but when used in the filtration device 20 of the present invention, a weft rib weave or plain weave filter cloth is preferable.

Test Example 2
Filter fabric No. 1 in Table 1 was formed into a cylindrical shape (diameter 50 mm), and pipe joints (outer diameter 49 mm, inner diameter 25 mm) were connected to both ends of the cylindrical shape to prepare a membrane module (effective membrane length 440 mm).
Sludge water (cement concentration: approximately 10%) was passed through a filtration device containing this membrane module in a housing (inner diameter 72 mm) using a submersible pump (1.5 kW) (here, "passing" refers to passing the sludge water through the inside of the membrane module), and the filtrate seeping out to the outside of the membrane module was collected.

At this time, in order to measure the filtration rate immediately after 10 minutes of filtration, filtration was continued until the 2,000 ml container was full, and the time until it was full was measured to calculate the filtration rate (ml/min).

Next, water (an example of cleaning water) was injected once for 30 seconds through a pipe connected to a connection port on the side of the housing (here, "water injection cleaning" refers to cleaning the outside of the membrane module by pressurizing it with water to shrink the filtration membrane).

Next, water (an example of cleaning water) was passed through the inside of the membrane module once for 30 seconds to clean it (here, "water passing cleaning" refers to passing water through the inside of the membrane module to restore or expand the filtration membrane).

In this way, the membrane module was washed by injecting water and then passing water through it, and 87 consecutive tests were performed, with each cycle being counted as one in which the filtration rate was measured.

Figure 11 is a graph showing the relationship between the filtration rate of the filtration membrane and the number of cycles in Test Example 2.

As shown in Figure 11, according to Test Example 2, when using filter cloth No. 1, the filtration device of the present invention was found to be able to perform repeated filtration without a decrease in filtration speed by periodically cleaning the membrane module and filtering.

Test Example 3
Sludge water with varying cement concentrations (cement concentration: about 15%) was passed through the filtration device used in Test Example 2, and the filtrate seeping out to the outside of the membrane module was collected.
As in Test Example 2, in order to measure the filtration rate immediately after 10 minutes of filtration, filtration was continued until the 2,000 ml container was filled, and the time until it was full was measured to calculate the filtration rate (ml/min).

Next, water was poured in once for 30 seconds for cleaning through a pipe connected to a connection port on the side of the housing.
Next, the inside of the membrane module was washed once by passing water through it for 30 seconds.
In this manner, the membrane module was subjected to water injection cleaning and water flow cleaning, and then the cycle of measuring the filtration rate was counted as one cycle, and the test was continuously repeated. When the filtration rate decreased, another set of water injection cleaning and water flow cleaning was performed three times.

Figure 12 is a graph showing the relationship between the filtration rate of the filtration membrane and the number of cycles in Test Example 3. In the figure, the solid black arrows indicate the locations where water injection cleaning and water flow cleaning were performed three times in one set.

As shown in Figure 12, according to Test Example 3, the filtration speed of the filtration device of the present invention gradually decreased when the membrane module was subjected to one set of water injection cleaning and water flow cleaning, but it was found that the filtration speed recovered by performing one set of three times. In other words, it can be said that clogging of the filtration membrane was eliminated.

7. Conclusion As described above, the filtration device of the present invention can filter at a good filtration speed by periodically washing the filtration membrane with water and passing water through it. On the other hand, even if the filtration speed decreases, the filtration speed can be restored to a good level by increasing the number of sets of washing with water and passing water through it. In addition, the filtration membrane used in the filtration device is preferably a filter cloth, and the weave thereof is preferably a weft rib weave or a plain weave.

It may be provided in the following manner:
A filtration device, wherein the filtration membrane is a filter fabric.
A filtration device, wherein the filter fabric is made of a woven fabric having a weft rib or plain weave.
A filtering device, comprising at least three guide bodies.
A filtration device, wherein a plurality of the membrane modules are arranged at circumferential intervals within the housing.
A cleaning method for a cross-flow type filtration device, comprising: a membrane module; and a housing, wherein the membrane module comprises a cylindrical body made of a flexible filtration membrane, a guide body arranged at intervals in the circumferential direction within the cylindrical body, and a pair of piping joints, each of the piping joints being connected to both ends of the cylindrical body and the guide body, the housing has a predetermined gap between the filtration membrane and the housing, and houses the membrane module with each of the piping joints protruding, and has a connection port on a side, the cleaning method comprising: a step a of adding cleaning water into the housing from the connection port; and a step b of deforming the filtration membrane by the step a, thereby removing particles that have accumulated in or are caught in the filtration membrane.
A cleaning method, further comprising, after step b), step c of passing cleaning water through the filtration membrane, and step d of restoring or expanding the filtration membrane by step c, thereby further removing particles deposited in or trapped in the filtration membrane.
A cleaning method comprising steps a to d as one set, the set being repeated multiple times to further remove particles deposited on or trapped in a filtration membrane.
Of course, this is not the case.

Finally, although various embodiments of the present invention have been described, these are presented as examples and are not intended to limit the scope of the invention. The novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The embodiments and their modifications are within the scope and spirit of the invention, and are included in the scope of the invention and its equivalents as set forth in the claims.

REFERENCE SIGNS LIST 1 Filtration treatment system 10 Membrane module 11 Cylindrical body 12 Guide body 13 Pipe joint 13a Head 14 Flange portion 20 Filtration device 21 Housing 22 Lid body 23 Connection port 31 Raw water tank 31w Raw water 31p Pump 32 Filtrate tank 32w Filtrate 32p Pump 33 Water tank 33w Water 33p Pump 34, 34a, 34b, 34c, 34d Valve s Gap g Particles

Claims (8)

In a cross-flow filtration device,
The membrane module and the housing are provided.
The membrane module has a cylindrical body made of a flexible filtration membrane, a guide body arranged at intervals in the circumferential direction within the cylindrical body, and a pair of pipe joints,
Each of the pipe joints is connected to both ends of the cylindrical body and the guide body,
The housing has a predetermined gap between the filtration membrane and the membrane module, and houses the membrane module with each of the pipe joints protruding. The housing has a connection port on a side surface.
When the filtration speed decreases, cleaning water is added into the housing through the connection port to deform the filtration membrane and remove particles that have accumulated on or are caught in the filtration membrane.
Filtration device. 2. The filtration device of claim 1,
The filtration device, wherein the filtration membrane is a filter cloth. 3. The filtration device according to claim 2,
The filter fabric is a woven fabric having a weft rib or plain weave. The filtration device according to any one of claims 1 to 3,
The filtering device includes at least three guide bodies. The filtration device according to any one of claims 1 to 4,
The filtration device, wherein a plurality of the membrane modules are arranged at intervals in the circumferential direction within the housing. A method for cleaning a cross-flow filtration device, comprising:
The membrane module and the housing are provided.
The membrane module has a cylindrical body made of a flexible filtration membrane, a guide body arranged at intervals in the circumferential direction within the cylindrical body, and a pair of pipe joints,
Each of the pipe joints is connected to both ends of the cylindrical body and the guide body,
The housing has a predetermined gap between the filtration membrane and the membrane module, and houses the membrane module with each of the pipe joints protruding. The housing has a connection port on a side surface.
a step a of adding cleaning water into the housing through the connection port;
A step b of deforming the filtration membrane by the step a;
thereby removing particles that have accumulated or become trapped in the filtration membrane;
Cleaning method: 7. The cleaning method according to claim 6,
After the step b, a step c of passing cleaning water through the filtration membrane;
Step d of restoring or expanding the filtration membrane by step c;
thereby further removing particles that have been deposited or trapped in the filtration membrane.
Cleaning method: 8. The cleaning method according to claim 7,
Steps a to d are grouped into one set, and the set is repeated multiple times to further remove particles that have accumulated on or are stuck in the filtration membrane.
Cleaning method:

Images