JP2002126800A - Rotary disk type filtration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary disk type filtration device in which an installment cost and an operation cost are cheap, a filtration flux is also high, a processing amount is much, a processing liquid with a high cleanliness is stably obtained, a problem that a cost is increased at a manufacture and a conveyance when a diameter of the disk becomes layer can be solved, a problem that a labor and a time are required for a maintenance and much time and a technique are required for changing a filtration material and a washing means with a high washing effect is provided. SOLUTION: In the rotary disk type filtration device, a driving device for rotating and driving a hollow rotation shaft of a sludge filtration unit is provided. A disk-like sludge filtration module forming the sludge filtration unit is formed by a plurality of sectors circumferentially divided and the inside of the hollow rotation shaft and respective filtration water chambers of the sectors are connected so as to communicate with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary disk type filtration apparatus for filtering sludge generated during biological treatment of sewage to obtain clear treated water.

[0002]

2. Description of the Related Art Conventionally, a sludge mixture obtained by treating organic wastewater with an aerobic or anaerobic biological treatment device such as an activated sludge treatment device or a nitrification / denitrification treatment device is converted into sludge and clear treated water. Separation apparatus using a sedimentation tank or a membrane separation apparatus that permeates through a filtration membrane such as a cylindrical module or a rectangular plate-shaped flat membrane module provided with a microfiltration membrane or an ultrafiltration membrane Is used.

[0003] In the above-mentioned membrane separation device, there are cases where it is arranged in a filtration tank provided separately from the biological treatment tank, and which is fixedly arranged in the biological treatment tank. Filtration membrane cleaning means for preventing sludge from adhering excessively to the filtration membrane surface and peeling off and removing adhering substances by a gas constantly scattered from below the membrane are mainly used. The sludge concentrated in the sedimentation tank or the membrane separation device is partly circulated to or maintained in the biological treatment tank in order to efficiently process organic matter while maintaining high-load operation in the biological treatment tank. The remaining part is treated as surplus sludge by a subsequent sludge treatment device.

[0004] In the sedimentation and separation of sludge in the sedimentation tank, the sludge sedimentation speed is slow, so that the residence time must be lengthened to increase the particle size of the sludge floc and the sedimentation property must be increased. Therefore, a large equipment installation area is required. In addition, when the removal of nitrogen and the like is insufficient, gas is generated in the settling tank to cause the sludge to float, and there is a problem that the concentration of the sludge flowing out of the treated water increases.

[0005] Further, in a filtration apparatus using a filtration membrane separation apparatus in which a microfiltration membrane or an ultrafiltration membrane is stretched, treated water having extremely high clarity can be obtained. Is very small, so that the permeation flux is small, and in order to increase the permeation flux, the suction pressure must be increased, which increases the power cost and the price of the filtration membrane module is high. There is a problem that the equipment cost per quantity is high,
It was difficult to apply to a relatively large-scale sewage treatment plant.

[0006] Further, a turbulent flow is caused by gas diffusion and rotation, and the shear force of the turbulent flow prevents a sludge or the like from adhering to the surface of the filtration membrane and removes and removes the adhering matter. Polymeric substances such as sludge and proteins in the treated water are extremely easy to adhere to the surface of the filtration membrane and are sticky, so they are difficult to peel off, and the turbulence effect alone cannot achieve the expected effect. Scale and slime are formed in a short period of time, and the membrane permeation flux is reduced, the operation is stopped, and the number of times of cleaning is increased. There is.

In view of the above problems, Japanese Patent Laid-Open No. 5-1850
No. 78, JP-A-10-128358 and JP-A-11-290884 disclose a microfiltration membrane or an ultrafiltration membrane such as a nonwoven fabric or a woven fabric on the surface of a water-permeable porous material such as a sponge. Then, a filter medium (hereinafter simply referred to as a filter medium) for forming a sludge filter layer of a water-permeable sheet having an extremely coarse mesh is superimposed thereon, the periphery thereof is sealed to form a rectangular plate-shaped filter, and the filter is placed in an aeration tank. A filtration device (hereinafter referred to as a “sludge filtration layer filtration device”) which is disposed above the aeration section and forms a porous filtration layer (hereinafter referred to as “sludge filtration layer”) by sludge particles on the surface of the filtration body and performs a filtration treatment with the sludge filtration layer. Is disclosed.

In the above-mentioned sludge filter bed filtration device, since the openings are coarse, the flow resistance is small, the filtration flux can be increased at a low filtration pressure, the operating costs such as power costs can be reduced, and the filter material is also made precise. Compared with a filtration membrane or an ultrafiltration membrane, it is inexpensive, and the equipment cost can be reduced. Also, despite the coarse openings, the filtrate can also obtain a filtrate with high clarity, but in order to obtain a filtrate with high clarity,
It is necessary to maintain the sludge filter layer so that it does not become compacted and does not fall off. Therefore, the sludge mixture in the treatment tank is circulated at a constant flow rate to prevent the sludge from adhering excessively. Generally, air circulation in the processing tank is performed by a flow circulation at a relative speed of about 0.03 to 0.5 m / sec.

However, in the conventional rectangular sludge filter bed filtration device, since the sludge is filtered by the sludge filter layer, in the initial operation until the sludge filter layer is formed, the sludge passes through the filter medium and enters the filtrate side. Sludge settles and accumulates on the bottom of the water-permeable spacer member, causing blockage of the filtrate discharge port and the like. Cannot be prevented from occurring such that the filtration flux decreases and it becomes difficult to maintain the allowable filtration rate in a predetermined range.

Therefore, conventionally, as a method of removing the accumulated sludge, a backwashing process of feeding air or water into the inside of the sludge filtration module and extruding the same has been performed. In addition, as the size of the filter becomes larger, the strength of the filter medium becomes weaker. Therefore, there is a problem that the filter medium is likely to be damaged. The turbulence is caused by blowing air, and the sludge filter layer formed on the surface of the filter medium is peeled off and renewed due to the shearing force.However, a large amount of air is required and power costs increase, and air blowing occurs. If it is weak, it is difficult to obtain a uniform cleaning effect, and if the blowing of air is too strong, there is a problem that the possibility of damage to the filter medium increases.

In view of the problem with the above-mentioned rectangular sludge filter bed filtration apparatus, a filtration water chamber is formed by a disk-shaped mesh-shaped spacer member, which was previously filed by the present applicant, and both outer surfaces thereof are provided. A filter medium made of a nonwoven fabric or a woven cloth is stretched over the sludge filter layer. Japanese Patent Application Laid-Open No. H11-226317 discloses a rotating disk-type solid-liquid separation device in which a filtration unit is provided in a treatment tank. The rotating disk-type solid-liquid separation device is more compact than the sedimentation tank, and the sludge container is rotated by shearing force.
Prevention of excessive sticking of scale and scale and proper separation and removal of sticking sludge are performed, so that sludge does not flow into the treated water, and treated water with high clarity is obtained stably. This is a solid-liquid separation device for sludge mixed liquid that can be applied to a sewage treatment plant and the like that has a low facility cost and operation cost, a high filtration flux, and a large throughput, as compared with the device.

[0012]

However, since the rotary disk-type solid-liquid separation device is formed integrally with the disk-shaped sludge filter bed filtration module, the rotary disk-type solid-liquid separation device becomes a large-sized device and has a large diameter. When the size of the filter becomes large, the production and transportation costs are increased, and the maintenance and inspection require much trouble and time. In particular, there is a problem that much time and advanced technology are required to replace the filter medium. Also, in the method of maintaining the filtration speed, a large amount of air is blown into the lower part of the sludge filter bed filtration module to cause turbulence, and the shear force causes the sludge filter layer formed on the surface of the filter medium to be peeled off. Because of this, there is a problem similar to that of the rectangular sludge filter bed filtration device.

The present invention, in view of the circumstances of conventional rectangular and disk-shaped sludge filter filtration apparatuses, further develops the excellent effects of the sludge filter filtration apparatus itself, and reduces the cost of equipment and operation at low cost. High flux, high throughput and stable processing liquid with high clarity.In addition, in the case of a disk-shaped sludge filter device, if the diameter of the disk is large, the production and transportation costs are high. It takes time and effort to perform maintenance and inspection, and in particular, it can solve the problem that requires a lot of time and skill to replace the filter media, etc. An object of the present invention is to provide a rotating disk-type filtration device capable of forming a layer and more stably obtaining a treatment liquid having high clarity.

[0014]

In order to achieve the above object, the gist of the present invention is to provide a water-permeable spacer member forming a filtration water chamber and a water-permeable spacer member. A disc-shaped sludge filtration module made of a non-woven or woven sludge filtration layer forming filter material stretched on the outer surface of the support member, and the disc-shaped sludge filtration module is installed so as to cross the axis; And a sludge filtration unit comprising a plurality of disk-shaped sludge filtration modules and a hollow rotary shaft juxtaposed at regular intervals in the axial direction, rotatably immersed in the liquid to be treated in the treatment tank, In a rotating disk type filtration device provided with a driving device for rotatingly driving the hollow rotary shaft of the sludge filtration unit, the disk-shaped sludge filtration module is formed by a plurality of sector sectors divided in a circumferential direction, Inside the hollow rotary shaft and the sector sector A rotary disk type filtration apparatus characterized by a filtered water chamber each are connected so as to communicate.

Further, in the invention according to claim 2, in the rotary disk type filtration device according to claim 1, the sludge filtration unit is horizontally arranged in the treatment tank, and the liquid level of the liquid to be treated is hollow. 2. The rotating disk type filtering apparatus according to claim 1, further comprising washing means for washing the sludge filtering module projecting above the liquid surface by lowering the sludge filtering module to a position near the rotating shaft.

According to a third aspect of the present invention, in the rotary disk type filtering apparatus according to the first or second aspect, the washing means comprises a hollow rotating shaft which is rotated by a driving means. A plurality of washing nozzles provided at predetermined intervals in the axial direction so as to protrude in a right angle direction in communication with the hollow rotating shaft, and rotate to be positioned between the plurality of disc-shaped sludge filtration modules; It is a rotating disk type filtration device characterized by comprising.

Further, according to the invention described in claim 4, in the rotary disk type filtration device according to any one of the above-mentioned claims 1-3, a sector sector forming a disk-shaped sludge filtration module. Is a rotating disk type filtration device characterized in that a fan-shaped water-permeable spacer member is covered with a fan-shaped nonwoven fabric or woven fabric bag-like sludge filter layer forming filter material.

Further, according to the invention described in claim 5, in the rotary disk type filtration apparatus according to any one of the above-mentioned claims 1-4, a sector sector forming a disk-shaped sludge filtration module. However, at the acute angle portion of the fan-shaped water-permeable spacer member, there is provided a filtrate discharge port connected in communication with the hollow rotary shaft, and the acute-angle end portion and the opposing upper edge portion of the fan-shaped bag-shaped sludge filter layer forming filter medium are provided. Are opened, and the water-permeable spacer member is inserted into the bag-shaped sludge filter layer forming filter medium, and then the both ends are closed by covering the openings, thereby forming a rotary disc-type filtration device. .

Further, according to the invention described in claim 6, in the rotary disk type filtration apparatus according to any one of the above-mentioned claims 1 to 5, a plurality of disk-shaped sludge filtration modules forming a disk-shaped sludge filtration module are provided. A rotating disk type filtering apparatus characterized in that sector sectors are fixed by fixing means that can be attached to each sector.

With the above-described structure, it is easy to manufacture and transport even a large-sized device having a large disk diameter, and it is also possible to perform maintenance and inspections and replace filter media in a short time without requiring advanced technology. it can. Further, due to the sector shape of the sector, sludge that has passed through the filter medium does not settle in the filtration water chamber formed by the water-permeable spacer member, and there is no possibility that the filtrate discharge port or the like will be blocked. Further, in an apparatus provided with a washing means, it is possible to always obtain an optimum filtration efficiency with low power and high washing effect. Note that the fan shape preferably has an arc shape on the upper side facing the acute angle portion on the center side, but may have a straight shape.

The water permeability of the filter module
The member can be a metal plate, a synthetic fiber yarn, a natural fiber yarn, etc., woven with a constant mesh width, a mesh plate, a porous plate having a large number of holes formed in a metal plate or a synthetic resin plate, or the like. ,
A mesh plate in which a metal wire is woven with a constant mesh width is preferable, but any metal plate having a flow path for filtered water, supporting the filter medium, and withstanding filtration pressure may be used. In addition, water permeability
The filter member may form a hollow filtered water chamber surrounded by a plate member. Further, a non-woven fabric or a woven fabric made of synthetic fibers such as nylon, polyester, polyethylene, polypropylene and polyolefin can be used as the filter medium.

The rotation speed of the sludge filter bed filtration unit in the above-mentioned filtration operation is preferably 0.01 m / s to 1.0 m / s as relative speed in consideration of the adhesion and separation of sludge, and 0.01 m / s or less. At a rotation speed of low, the shear force is low and the sludge filter layer becomes excessively thick, the amount of filtrate decreases in a short period of time, and the number of times of stopping operation and washing becomes large.
At a rotational speed of m / s or more, the sludge filter layer may be separated by centrifugal force, resulting in turbidity of the filtered water and a problem of increased power cost.

In order to prevent clogging of the filter medium with sludge and consolidation of the sludge, it is preferable that the suction of the filtered water is performed by a suction pressure of 1 m or less. 10m / to prevent consolidation of sludge filter layer
It is preferably set to be day or less.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic longitudinal sectional view of a rotary disk type filtration apparatus according to an embodiment in which a filtration unit is horizontally disposed in a treatment tank, FIG. 2 is a view taken along the line AA in FIG. 1, and FIG. Installation illustration of the sector sector of the sludge filtration module,
FIG. 4 is an explanatory view of the sector sector, and FIG. 5 is a vertical sectional view of a disk-shaped sludge filtration module mounted at the top of the sector. In the drawings, members having corresponding functions are denoted by the same reference numerals.

In FIGS. 1 and 2, reference numeral 1 denotes a supply port 7 for the sludge mixture and an overflow port 9 for the sludge mixture at the top.
A sludge discharge port 8 for extracting concentrated sludge is provided at a lower portion, and a sludge concentration tank, which is a treatment tank having a closed structure, in which an aerator 10 for circulating and stirring the sludge mixture is disposed. Filter layer filtration unit 21 (hereinafter simply filtration unit 2)
One. ) Is immersed in a sludge mixture, supported rotatably, and arranged horizontally. In addition, as a processing tank,
In addition to the tank having the closed structure, a structure having an open top surface may be used, or a structure in which the filtration unit 21 is disposed in the biological treatment tank itself. Further, the filtration modules of a plurality of filtration units may be wrapped. They may be arranged side by side, and these arrangements and the number of arrangements can be appropriately set according to the processing amount or the like.

Reference numeral 2 denotes a rotary disk type filtration device, which includes a water-permeable spacer member 24 forming a filtered water chamber in FIG. 4, and a non-woven fabric or a woven fabric stretched over the outer surface of the water-permeable spacer member. A sludge filtration module 22 (hereinafter simply referred to as a filtration module 22) comprising a filter medium 25, and a plurality of the filtration modules 22 installed so as to cross the axis. , A filtration unit 21 including a hollow rotary shaft 4 also serving as a filtration water collecting pipe, which is also provided at regular intervals in the axial direction, a driving device 6 for driving the hollow rotary shaft 4 of the filtration unit 21 to rotate, and respective filtration modules. A cleaning means 3 for cleaning the surface of the nozzle 22 is provided.

The filtration module 22 of the filtration unit 21
Is formed in a disk shape by a plurality of sector sectors 23 divided in the circumferential direction, and the filtrate outlet of the sector 23 is formed so that the inside of the hollow rotary shaft 4 and the filtration water chamber of each sector 22 communicate with each other. Reference numeral 26 is connected to a connection port formed in the hollow rotary shaft 4 via a packing. Further, the cleaning means 3
A hollow rotating shaft 31 serving also as a washing liquid supply pipe rotated by a driving means 32, and projecting in a right angle direction in communication with the hollow rotating shaft 31 and rotating to rotate between a plurality of filtration modules 22; A plurality of cleaning nozzles 33 are provided at predetermined intervals in the axial direction so as to be located. Cleaning means having a structure for raising and lowering the vertically extending cleaning nozzles may be used.

As shown in FIG. 4, the sector 23 forming the filtration module 22 has a sector-shaped water-permeable section provided with a filtrate discharge port 26 connected to the hollow rotary shaft 4 at an acute angle. After inserting the support member 24 into the fan-shaped bag-shaped filter medium 25 having an open end at the acute angle end and the opposing upper side end, the openings at both ends of the bag-shaped filter medium 25 are covered by bundling, suturing, bonding or the like. Is formed.

The water-permeable spacer member 24 is woven with a fixed mesh width by a metal wire, a synthetic fiber yarn, a natural fiber yarn, or the like to form a mesh plate, or a large number of metal plates or synthetic resin plates. A perforated plate with holes may be used, but a mesh plate in which metal wires are woven with a constant mesh width is preferable, and their outer peripheral portions are preferably fixed by a frame 27 to maintain the shape. . Further, as the filter medium 25, a nonwoven fabric or a woven fabric made of synthetic fibers such as nylon, polyester, polyethylene, polypropylene, and polyolefin can be appropriately used.

The hollow rotary shaft 4 communicates with the filtrate discharge port 26 provided at the acute angle portion of the sector 23.
As shown in FIG. 3, the fixing means 5 for forming the filter module 22 and fixing it in an attachable manner comprises a plurality of sectors fixed radially projecting from the hollow rotary shaft 4 at predetermined intervals in the circumferential direction of the shaft. Screw rod 51, a long clamp 52 having a U-shaped cross section that fits into the arc side portion of the sector 23, and a screw rod 51 for fixing the sector, which simultaneously presses the adjacent long clamp 52 from above. FIG. 5
As shown in (1), the filter material protruding from the arc side portion of the sector-shaped sector 23 inserted between the respective sector fixing screw rods 51 is bent to cover the long clamp 52, and the adjacent long clamp 52 is fixed by the fixing bracket 53. At the same time hold down from above and screw 5
The filter module 22 can be formed by screwing and fixing to the fixing screw rod 51 in 4.

The filtered water collecting pipe line 11 connected to the hollow rotary shaft 4, which is a filtered water collecting pipe, is configured to discharge the filtered water by a head pressure. A means 11a for controlling the filtration flux to a constant level by appropriately arranging a filtration water suction means such as a mechanism or a pump.
May be provided.

The hollow rotary shaft 4 is provided with appropriate bearings on a pair of opposing side surfaces of the sludge thickening tank 1 and is supported horizontally by the bearings. One end of the hollow rotary shaft 4 protruding outward is provided. The filter unit 21 is rotatably driven by a rotation driving means 6 comprising a motor 61 connected via a pulley 62 and a belt 63 to rotate the entire filtration unit 21 at an appropriate speed.

Next, the operation of the filtration operation for separating and condensing sludge from the mixed sludge by the apparatus having the above-described structure to obtain a clear filtrate will be described. The sludge mixed solution after the biological treatment of the sewage in a separate biological treatment tank (not shown) is continuously supplied into the sludge concentration tank 1 from the supply port 7 of the sludge mixed solution, and is supplied from the overflow port 9. Discharged continuously.

The sludge mixture supplied into the sludge concentration tank 1 is filtered by the filtration module 22 of the filtration unit 21, and the clear filtrate passes through the filtration water chamber formed by the water-permeable spacer member 24. Through the filtrate outlet 26, it flows into the hollow rotary shaft 4 of the filtered water collecting pipe, and is discharged from the filtered water collecting pipe 11 connected to the hollow rotary shaft 4 to the outside of the system with a head difference h.

In the above-mentioned filtration operation, the filter medium 2 made of a non-woven fabric or a woven fabric of the filtration module 22 is used.
The porous filtration layer (sludge filtration layer) formed by the sludge particle group is formed on the surface of No. 5, and the filtration treatment is performed on the sludge filtration layer. The flux can be increased, the operating cost such as the power cost can be reduced, and the cost can be reduced and the equipment cost can be reduced. In addition, a filtrate having a high clarity can be obtained despite the coarse openings.

The sludge mixture is circulated by supplying air from the diffuser 10 so that the sludge does not settle and separate. In the initial operation until the sludge filter layer is formed, the sludge passes through the filter medium 25 and mixes into the filtrate side, and the sludge settles at the bottom of the water-permeable spacer member 24. , And is easily discharged together with the filtrate.
There is no danger of blocking.

In the above-mentioned filtration operation, the filtration unit 21 is slowly rotated by the rotation driving means 6, but the rotation speed of the filtration unit 21 is set to a relative speed of 0.1 in consideration of sludge adhesion and separation. 01m / s-1.0m
/ S is preferable, and at a rotation speed of 0.01 m / s or less,
The shear force is low and the sludge filter layer becomes excessively thick, the amount of filtrate decreases in a short period of time, and the number of times of stopping operation and washing increases,
At a rotation speed of 1.0 m / s or more, the sludge filter layer may be separated by centrifugal force, resulting in turbidity of the filtered water.
This raises the problem of increased power costs.

Since the filtration flux decreases as the filtration operation progresses, the discharge from the filtered water collecting line 11 is stopped when the filtration efficiency reaches a certain level or less, and the sludge concentration tank is connected to the sludge discharge port 8. An operation of discharging the sludge in 1, lowering the liquid level to the vicinity of the hollow rotary shaft 4, and cleaning the surface of the sludge filtration module 22 projecting above the liquid level by the cleaning means 3 is performed. The sludge extracted from the sludge discharge port 8 is returned to a biological treatment tank (not shown). However, a part of the sludge may be discharged outside the system as surplus sludge, and may be treated by a subsequent sludge treatment device (not shown). .

The cleaning operation is performed by the driving means 3 of the cleaning means 3.
By rotating the hollow rotary shaft 31 with 2, the cleaning nozzle 33 is positioned between the filtration modules 22, and the cleaning is performed by spraying the cleaning liquid from the cleaning nozzle 33 through the hollow rotary shaft 31. it can. The above-described washing operation can be sufficiently performed by performing the washing operation for about 1 to 3 minutes while the filtration module 22 rotates a few times. Further, the pressure of the washing water is about the same as the pressure of tap water, and if it is too strong in the case of a non-woven filter medium, misalignment or breakage may occur.

To replace the filter medium 25 due to maintenance of the apparatus, remove the screw 54 fixed to the sector fixing screw rod 51, the fixing bracket 53, and the long clamp 52 fitted to the arc side of the sector sector 23. Thus, the sector 23 can be easily taken out. The bag-like filter medium 25 is removed from the fan-shaped sector 23 taken out, and a new bag-like filter medium 2 is removed.
In order to attach 5, the fan-shaped water-permeable spacer member 24 is
After being inserted into the fan-shaped bag-shaped filter medium 25, it can be formed by covering both ends of the bag-shaped filter medium 25 by closing the openings. Therefore, even a large-sized apparatus having a large disk diameter can be performed in a short time without requiring advanced technology for maintenance and inspection and replacement of the filter medium.

[0041]

The present invention further develops the excellent effects of the sludge filter bed filtration apparatus itself, and has a low equipment cost and operation cost, a high filtration flux, a large amount of treatment, and a stable and high clarity treatment. A liquid is obtained, and in a disk-shaped sludge filter bed filtration apparatus, the problem that the cost of production and transportation increases when the diameter of the disk is increased,
It takes time and effort to perform maintenance and inspection, and in particular, it can solve the problem that requires much time and skill to replace the filter media, etc. is there.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a rotating disk type filtration device according to an embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrows AA in FIG. 1;

FIG. 3 is an explanatory view of installation of a sector sector of the disc-shaped sludge filtration module.

FIG. 4 is an explanatory diagram of a sector sector.

FIG. 5 is a vertical sectional view showing the mounting of the disk-shaped sludge filtration module at the top of the sector.

[Explanation of symbols]

 1: Sludge thickening tank (treatment tank) 2: Rotating disk type filter 3: Cleaning means 4: Hollow rotating shaft 5: Fixing means 6: Rotation driving means 21: Filtration unit 22: Sludge filtration module 23: Sector sector 24: water-permeable spacer member 25: sludge filter layer forming filter medium 26: filtrate outlet 27: frame 31: hollow rotating shaft 32: driving means 33: washing nozzle

Claims (6)

[Claims] 1. A disk-shaped sludge comprising a water-permeable spacer member forming a filtration water chamber, and a non-woven or woven sludge filter layer-forming filter medium stretched over the outer surface of the water-permeable spacer member. A filtration module and a hollow rotary shaft in which the disk-shaped sludge filtration module is installed so as to cross the axis, and a plurality of disk-shaped sludge filtration modules are juxtaposed at regular intervals in the axial direction. A sludge filtration unit rotatably immersed in the liquid to be treated in the treatment tank, and a rotary disk type filtration device provided with a driving device for rotating and driving the hollow rotary shaft of the sludge filtration unit. A disc-shaped sludge filtration module is formed by a plurality of sector sectors divided in a circumferential direction, and the inside of the hollow rotary shaft and the respective filtered water chambers of the sector sectors are connected so as to communicate with each other. Rotating disk type filtration device. 2. A cleaning means for horizontally disposing a sludge filtration unit in a treatment tank, lowering the liquid level of the liquid to be treated to near a hollow rotary shaft, and cleaning the sludge filtration module projecting above the liquid surface. The rotary disk-type filtration device according to claim 1, further comprising: 3. A plurality of disc-shaped sludge filtration modules, wherein the washing means is provided with a hollow rotating shaft which is rotated by the driving means, and is protruded in a right angle direction in communication with the hollow rotating shaft. 3. The rotating disk type filtering apparatus according to claim 1, comprising a plurality of washing nozzles provided at predetermined intervals in an axial direction so as to be positioned at every interval. 4. The fan-shaped sector forming the disk-shaped sludge filtration module is formed by covering a fan-shaped water-permeable spacer member with a fan-shaped nonwoven fabric or woven bag-shaped sludge filter layer forming filter material. The rotating disk-type filtration device according to any one of claims 1 to 3, characterized in that: 5. A fan-shaped sector forming a disc-shaped sludge filtration module is provided with a filtrate discharge port connected to a hollow rotary shaft at an acute angle portion of a fan-shaped water-permeable spacer member, the sector being formed in a sector shape. After opening the acute-angled end and the opposite upper end of the bag-shaped sludge filter layer forming filter medium, inserting the water-permeable spacer member into the bag-shaped sludge filter layer forming filter medium, and closing the openings at both ends. The rotating disk type filtering device according to any one of claims 1 to 4, wherein the filtering device is formed by coating. 6. The disk-shaped sludge filtration module according to claim 1, wherein said plurality of sector-shaped sectors are fixed by fixing means which can be attached to each sector. Item 2. The rotating disk type filtration device according to Item 1.