JP2000107572A - Rotary flat membrane apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively peel a cake layer by rotating a rotary flat membrane in the low number of rotations even if the cake layer is formed on the rotary flat membrane in high density. SOLUTION: A spongy member 32 is charged in a membrane separation tank 12 from a charging and recovering apparatus 34 in such a state that rotary flat membranes 16 are rotated and, since the spongy member 32 comes into contact with the cake layers 15 of the rotary flat membranes, the cake layers 15 are shaven off by the spongy member 32. When the peel of the cake layers 15 by the spongy member 32 is completed, the spongy member 32 is recovered in the charging and recovering apparatus 23. Therefore, only when the cake layers 15 are desired to be peeled, the spongy member 32 can be charged in the membrane separation tank 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary flat membrane apparatus, and more particularly to a rotary flat membrane apparatus for filtering water and wastewater using a rotary flat membrane.

[0002]

2. Description of the Related Art A rotary flat membrane device is a wastewater treatment, a pure water device,
It is also applied to separation, purification, concentration, and biotechnology. The biggest problem with liquid treatment using a membrane, such as a rotating flat membrane, is that when the deposits in the liquid to be treated adhere to and deposit on the membrane surface during operation, forming a cake layer of the deposits, Performance is reduced.

Conventionally, in order to peel off the cake layer formed on the rotating flat membrane, the filtration operation is stopped while the rotating flat membrane is periodically rotated, that is, the suction pump is stopped, whereby the rotating flat membrane is centrifuged. The adhesion on the film surface was peeled off by force.

[0004]

However, in order to separate the cake layer of the rotating flat membrane by rotation of the rotating flat membrane as in the prior art, it is necessary to apply a certain level of shearing force due to turbulence to the membrane surface. Therefore, the rotating flat membrane must be rotated at a high speed during the filtration operation. Therefore, it is necessary not only to install a high-power motor that rotates the rotating flat film at high speed just for the peeling operation, but also to make the components of the equipment durable and have high processing accuracy and assembly accuracy. Since it has to be used, there is a disadvantage that the apparatus cost is high.

Further, the peeling of the cake layer only by the rotation of the rotating flat membrane is difficult when the cake layer adheres to the film at a high density because the peeling efficiency is poor and the peeling operation requires a long time. There is a disadvantage that the processing operation time for processing is greatly reduced. The present invention has been made in view of such circumstances, and even when a cake layer of the deposit is formed on the rotating flat film at a high density, the rotating flat film is rotated at a low rotation speed to effectively remove the deposit. It is an object of the present invention to provide a rotary flat membrane device that can be peeled off.

[0006]

In order to achieve the above object, the present invention provides a rotary flat membrane apparatus for filtering a liquid to be treated with a rotary flat membrane provided in a membrane separation tank. Is provided with a charging / collecting device for charging the sponge-like member into the membrane separation tank and recovering the charged sponge-like member.

According to the present invention, the sponge-like member is put into the membrane separation tank from the feeding / recovery apparatus while the rotating flat membrane is rotated, and adheres to the sponge-like member and the rotating flat membrane by filtration. Since the cake layer made of the adhered substance comes into contact, the cake layer is scraped off by the sponge-like member. When the sponge-like member has completely separated the adhering substance, the sponge-like member is collected by the charging / collecting device. Therefore, the sponge-like member can be put into the membrane separation tank only when it is desired to peel the cake layer.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the rotary flat membrane device according to the present invention will be described below in detail with reference to the accompanying drawings. FIG.
FIG. 2 is a longitudinal sectional view showing the entire configuration of the rotary flat membrane device, and FIG. 2 is a top view for explaining the structure of a membrane separation tank having a rotary flat membrane.

As shown in FIG. 1, a rotary flat membrane apparatus 10 according to the present invention includes a membrane separation tank 12 having a rotary flat membrane 16, a storage tank 11 for a liquid to be treated, and a storage tank 11 which covers the membrane from the storage tank 11. It comprises a supply line 13 having a supply pump 19 for supplying the processing liquid, and a return line 17 for returning the liquid to be processed from the membrane separation tank 12 to the storage tank 11. As shown in FIG. 2, two hollow rotating shafts 14 parallel to the left and right are arranged in a rotatable manner in the membrane separation tank 12 to which the liquid to be treated is supplied. Each hollow rotary shaft 14 faces a communication port (not shown) drilled at a predetermined interval in the axial direction thereof.
A plurality of rotating flat membranes 16 having a disc shape are supported. The rotating flat membrane 16 is formed by coating a microfiltration membrane or an ultrafiltration membrane on a water-permeable spacer such as a nonwoven fabric or a net on a membrane support, and the material of the membrane is a polystyrene-based or polypropylene-based membrane. And a polymer resin film of polyethylene, polyolefin, or the like. Rotating flat membrane 1 supported by two hollow rotating shafts 14 arranged side by side
6, the rotating flat films 16 adjacent to each other partially overlap each other. When both ends of the hollow rotary shaft 14 extend outside the membrane separation tank 12, watertightness is secured between the membrane separation tank 12 and the hollow rotary shaft 14 by the shaft sealing means 18. One closed end of the hollow rotary shaft 14 is connected to the motor 2.
0 and 20, respectively, and the other open end is connected to the filtrate pipes 22 and 22, respectively, so that the hollow rotary shaft 14 and the rotary flat membrane 16 are integrally rotated. The filtrate pipe 22 is
A branch pipe 24 connected to each of the two hollow rotary shafts 14,
24, and a main pipe 26 in which the branch pipes 24 merge. A suction pump 28 is provided in the main pipe 26. The connection between the hollow rotary shaft 14 and the branch pipe 24 is connected via connecting devices 30 and 30 for preventing rotation of the hollow rotary shaft 14. Rotating flat membrane 16 supported by two hollow rotating shafts 14
Are rotated in the same direction. In this case, it is preferable to change the number of rotations according to the diameter of the rotating flat film 16. Due to this rotation in the same direction, the direction of rotation becomes opposite in the portion where the rotating flat films 16 overlap, and turbulent flow occurs.

The filtration operation of the liquid to be treated by the rotary flat membrane device 10 configured as described above is performed by the motor 20 using the rotary flat membrane 16.
This is performed by operating the suction pump 28 while rotating. That is, by the operation of the suction pump 28, the inside of the rotary flat membrane 16 becomes negative pressure through the filtrate pipe 22 and the hollow rotary shaft 14, and the liquid to be treated in the membrane separation tank 12 is suction-filtered into the rotary flat membrane 16. As a result, deposits in the liquid to be treated are removed, and a cake layer is formed on the surface of the rotating flat film. The filtered water that has passed through the rotary flat membrane 16 is drawn out of the apparatus 10 through the hollow rotary shaft 14 and the filtrate pipe 22.

As shown in FIG. 1, a sponge-like member 32 is charged into the membrane separation tank 12 at an upper portion in the membrane separation tank 12, and a charging / recovery device for collecting the sponge-like member 32 is provided. 34 are provided. Loading / collecting device 34
Is a lid member 36 that can be opened and closed at both ends, as shown in FIG.
Container 4 having a screen 37 for preventing the sponge-like member 32 from flowing out to the return line 17
0, and motors 42, 42 that can rotate forward and reverse to open and close the lid member 36 of the container 40. The motor 42 is connected to the controller 48 via signal rotation. This allows
The controller 48 rotates the motor 42 in the forward and reverse directions to rotate the rotation shaft 4 for rotatably supporting the lid member 36 on the container 40 main body.
The openings 46, 46 at both ends of the container 40 are opened and closed by rotating the containers 4, 44.

Then, as shown in FIG.
The first branch line 17A is directly connected to the membrane separation tank 12, and the second branch line 17B is connected to the charging / collecting device. The first branch line 17A and the second branch line 17A
Are provided with automatic opening / closing valves 50 and 52, respectively, and are connected to the controller 48 via a signal cable. Also,
The filtrate line 26 is provided with a filtration pressure detector 49 for detecting a filtration pressure, and the detected pressure value is sequentially transmitted to the controller 48 via a signal cable.

Next, the rotary flat membrane 1 is charged into the membrane separation tank 12 and
The sponge-like member 32 for peeling the cake layer 15 formed in 6 will be described. 4 to 9 show sponge-like members 32 of various shapes, FIG. 4 shows a sponge ball shape, FIG. 5 shows a cubic shape, FIG. 6 shows a string shape, and FIG. FIG. 8 shows a thread ball shape. Further, a sponge piece having an irregular shape as shown in FIG. 9 can be used. The size of the sponge-like member 32 is
It is appropriate to use one having a minimum diameter portion of about 1 to 15 mm. The reason is that, when the amount of the sponge-like member 32 charged into the membrane separation tank 12 is constant, the smaller the sponge-like member 32, the larger the total surface area. However, if the sponge-like member 32 is too small, the grinding force for shaving the cake layer 15 will be weak.

Since the relationship between the size of the sponge-like member 32 and the releasability is also affected by the number of revolutions of the rotating flat film 16, it is necessary to change the size of the sponge-like member 32 according to the number of revolutions of the rotating flat film 16. Is also a factor for improving the releasability. The specific gravity of the sponge-like member 32 needs to be substantially equal to the specific gravity of the liquid to be treated so that the sponge-like member 32 is easily dispersed in the liquid to be treated when stirred by the rotating flat film 16. However, it is not necessary to make all the specific gravities of the many sponge-like members 32 to be input the same,
Rather, it is preferable to change the specific gravity. This is because when the rotating flat film 16 is rotated, the flow of the liquid to be processed near the periphery of the rotating flat film 16 is fast, and the flow of the liquid to be processed near the center of the rotating flat film 16 is slow. Sponge-like member 3
This is because the sponge-like member 32 can be easily dispersed evenly over the entire surface of the rotating flat film 16 by mixing and adding the two.
The sponge-like member 32 may be made of any material, such as porous urethane foam or sponge, which does not damage the rotary flat film 16 and can exert a grinding force.

Next, a method of using the charging / collecting device 34 for peeling the cake layer 15 adhered to the film surface of the rotating flat film 16 by the sponge-like member 32 will be described. When performing the filtration treatment of the liquid to be treated, the controller 48 opens the automatic opening / closing valve 50 of the first branch line 17A, and
Closing the automatic on-off valve 52 of the branch line 17B of
Both the lid members 36 of the container 40 are closed so that the sponge-like member 32 does not flow into the membrane separation tank 12. As a result, the liquid to be treated supplied from the storage tank 11 to the membrane separation tank 12 by the supply pump 19 is supplied to the first branch line 17.
A circulation is performed in which the fuel is returned to the storage tank 11 by the return line 17 that flows through A. Thereby, the deposits in the liquid to be treated are filtered by the rotating flat membrane 16.

When the pressure value of the filtration pressure detector 49 becomes equal to or higher than a predetermined value, the controller 48 opens both ends 46 of the container 40 while keeping the automatic on-off valve 52 of the second branch line 17B closed. Swings the lid member 36 as described above. Thereby, the sponge-like member 32 in the container 40
The liquid to be treated flows out of the container 40 into the membrane separation tank 12 according to the swirling flow of the liquid to be treated due to the rotation of the rotating flat membrane 16. The sponge-like member 32 coming out of the container 40 is dispersed throughout the membrane separation tank 12 by the rotation of the rotary flat membrane 16, and
It moves around in a swirling flow generated by the rotation of. Therefore, the sponge-like member 32 comes into contact with the cake layer 15 and the sponge-like member 32 scrapes the cake layer 15.

When the sponge-like member 32 completes the peeling of the cake layer 15, the controller 48 closes the automatic opening / closing valve 50 of the first branch line 17A and closes the second branch line 1A.
7B is opened and the two lid members 3 are opened.
Close one of the six. As a result, a water flow is generated from the inside of the membrane separation tank 12 to the second branch line 17B, so that the sponge-like member 32 put into the membrane separation tank 12
0 is collected in the container 40 from the side of the open opening 46. In this case, when the rotating flat membrane 16 is rotated counterclockwise as shown in FIG. 1, a swirling flow in the direction of the arrow is generated. Therefore, the right lid member 36 in FIG.
It is easier to collect if the is closed.

As described above, in the rotary flat membrane device 10 of the present invention, the feeding / collecting device 34 is provided in the membrane separation tank 12 so that the sponge-like member 32 can be fed / collected automatically. The sponge-like member 32 can be easily charged and collected. Also, the sponge-like member 32 is put into the membrane separation tank 12 only when the cake layer 15 is to be peeled off, and the sponge-like member 3 is not peeled off when the cake layer 15 is not peeled off.
2 can be collected. Therefore, abrasion of the sponge-like member 32 can be minimized, and the sponge-like member 32 does not hinder the filtration process.

As another apparatus for charging and recovering the sponge-like member 32 described in the embodiment of the present invention, a sponge returning from the return pipe 17 is provided with a wire mesh container at the outlet of the return pipe 17. When the sponge-like member 32 is collected into the membrane separation tank 12 and the sponge-like member 32 is put into the membrane separation tank 12, the bottom of the wire mesh container is opened and discharged into the storage tank 11, and the membrane is separated with the liquid to be treated by the supply pump 19. It can also be charged into the tank 12. In this case, it is necessary to select the type of pump so that the sponge-like member 32 is not damaged by the supply pump 19.

[0020]

As described above, according to the rotary flat membrane apparatus of the present invention, since the charging / recovering device can be provided in the membrane separation tank, the charging / recovering operation of the sponge-like member can be easily performed. it can. Also, when the sponge-like member is not used, the sponge-like member can be collected,
Wear of the sponge-like member can be minimized, and the sponge-like member does not hinder the filtration process.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the overall configuration of a microorganism-carrying rotary flat membrane device of the present invention.

FIG. 2 is a top view for explaining the structure of a membrane separation tank in the microorganism-supporting rotary flat membrane device of the present invention.

FIG. 3 is a perspective view illustrating the structure of a charging / collecting device.

FIG. 4 is a perspective view of a sponge-shaped sponge-shaped member.

FIG. 5 is a perspective view of a cubic sponge-like member.

FIG. 6 is a perspective view of a string-like sponge-like member.

FIG. 7 is a perspective view of a sponge-like member having a cloud-like shape.

FIG. 8 is a perspective view of a thread ball-shaped sponge-like member.

FIG. 9 is a perspective view of a sponge member having an irregular shape.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Rotating flat membrane apparatus 11 ... Storage tank 12 ... Membrane separation tank 13 ... Supply line 14 ... Hollow rotating shaft 15 ... Cake layer 16 ... Rotating flat membrane 17 ... Circulation line 17A ... 1st branch line 17B ... 2nd branch Line 19 ... Supply pump 20 ... Motor 22 ... Filtrate piping 28 ... Suction pump 32 ... Sponge-like member 34 ... Supply / recovery device 36 ... Lid member 40 ... Container 42 ... Mounting / recovery device motor 44 ... Rotation of the lid member Axis 46 ... Container opening 48 ... Controller 49 ... Filtration pressure detector 50 ... Automatic opening / closing valve of the first branch line 52 ... Automatic opening / closing valve of the second branch line

Claims (3)

[Claims] 1. A rotary flat membrane device for filtering a liquid to be treated by a rotary flat membrane provided in a membrane separation tank, wherein a sponge-like member is put into the membrane separation tank in the rotary flat membrane apparatus. A rotating flat membrane device, which is provided with a charging / collecting device for collecting the charged sponge-like member. 2. The charging / recovering apparatus according to claim 1, further comprising a circulation line for circulating the liquid to be treated in the membrane separation tank, a lid member provided at an outlet side of the circulation line, and openable and closable at both ends. The rotary flat membrane apparatus according to claim 1, further comprising: a container having a screen for preventing members from flowing out to the circulation line; and an opening / closing means for opening and closing a lid of the container. 3. The rotary flat membrane device according to claim 2, further comprising control means for detecting a filtration pressure of the rotary flat membrane and controlling opening / closing timing of the lid member based on the detected value.