JP2002028652A - Membrane separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a membrane separator which is capable of efficiently carrying out separation of solid from liquid and allows the easy application to a circular sedimentation basin disposed at existing drinking water treatment equipments. SOLUTION: Immersion type filter membranes 14 are radially installed in a state rotatable around a supporting shaft 12 erected at the center of a filtration treatment chamber 11 of a circular sedimentation basin type at the circumference of this supporting shaft 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a membrane separation device, and more particularly to a membrane separation device capable of performing effective membrane separation by using an existing circular sedimentation tank as a filtration tank for membrane separation.

[0002]

2. Description of the Related Art In a final sedimentation basin in various water purification facilities,
Degradation of settling properties due to bulking or the like of activated sludge lowers the processability and may cause a phenomenon that the quality of treated water is significantly impaired. For this reason, daily maintainability of the sedimentation basin and the like has become a problem, and the transition to membrane separation that enables stable processing has been started.

[0003]

However, in order to install a membrane separation apparatus in an existing water purification facility, the existing final sedimentation basin must be demolished and a new filtration tank for membrane separation must be constructed. A great deal of money and time.

Accordingly, the present invention provides a membrane separation system capable of efficiently performing solid-liquid separation and forming the same using the structure and equipment of a circular sedimentation basin provided as a final sedimentation basin in an existing water purification facility. It is intended to provide a device.

[0005]

In order to achieve the above object, a membrane separation apparatus according to the present invention is provided around a support shaft erected at the center of a filtration tank of a circular sedimentation tank type. It is characterized in that a submerged filtration membrane is installed radially in a rotatable state.

As a more specific structure, a support shaft erected at the center of a filtration tank of a circular sedimentation tank type, a plurality of filter membrane support members provided radially from the support shaft, and the support member An immersion-type filtration membrane that is supported and installed radially in a filtration tank, a membrane-treated water suction pipe that is provided along the filtration-membrane support member, and that gathers at the spindle portion; A membrane-treated water suction pump connected to a main suction pipe through a swivel joint, a driving means for rotating the filtration membrane support member about a support shaft, and air scrubbing of the immersion filtration membrane. And a chemical cleaning tank for cleaning the immersion-type filtration membrane with a chemical solution is provided adjacent to the filtration treatment tank.

[0007]

1 and 2 show an embodiment of a membrane separation apparatus according to the present invention. FIG. 1 is a longitudinal sectional view and FIG. 2 is a plan view. This membrane separation device is formed by modifying an existing circular sedimentation basin, and includes a support shaft 12 provided at the center of a filtration tank 11 using the circular sedimentation basin, and a radial shaft from the support shaft 12. A plurality of filtration membrane support members 13 provided at equal angular intervals, a submerged filtration membrane (submerged membrane module) 14 supported by the support members 13 and radially installed in the filtration tank 11; A membrane-treated water suction pipe 15 provided along the membrane support member 13 and gathering at the support shaft; and a suction main pipe 1 on which the membrane-treated water suction pipe 15 is gathered
6 and a membrane treated water suction pump 18 connected via a swivel joint 17 to the filtration membrane support member 13.
A speed reducer 19 which is a driving means for rotating around
The immersion filter membrane 14 is formed by an air diffuser 20 and a blower 21 which are air diffusers for performing air scrubbing of the immersion filter membrane 14, and a chemical cleaning tank 22 for cleaning the immersion filter membrane 14 with a chemical.

The filtration tank 11 has a raw water inflow path 23 at the upper center and a sludge (concentrated water) extraction path 24 at the bottom center. These routes 23,
As for 24, what was provided in the circular sedimentation basin can be used as it is.
Also, it is possible to use the sludge scraper provided in the circular sedimentation pond, including the bearing member 25 supporting the lower end of the support shaft and the deck 26 supporting the upper portion of the support shaft and installing the speed reducer 19. It is possible.

[0009] The filtration membrane support member 13 includes an upper support member 13a.
The lower and upper support members 13b support the upper and lower portions of the immersion type filtration membrane 14, respectively. The immersion type filtration membrane 14 is detachably supported by an appropriate support structure, for example, a fitting structure or the like. . One immersion type filtration membrane 14 is
It is formed into a unit using an appropriate frame or the like, and is formed so that it can be easily attached to and detached from the filtration membrane support member 13. At this time, if the filtration membrane used is a flat membrane,
It is desirable that the film be attached so that the film surface faces in the circumferential direction.

The membrane-treated water suction pipe 15 has a filtration membrane side removably attached to the immersion filtration membrane 14, and a spindle side directly or directly attached to a suction main pipe 16 inserted into the spindle 12. They are connected after being assembled appropriately. Further, a part of the chemical solution washing tank 22 is provided with the filtration membrane support member 1.
Appropriate transport means, for example, a crane 27, for transferring the immersion type filtration membrane 14 to the chemical solution washing tank 22 and the chemical solution washing tank 22 are provided.

When the membrane separation apparatus thus formed is used as, for example, a final sedimentation basin, the treated water treated by the activated sludge method or the like flows in from the raw water inflow path 23 while the membrane treated water suction pump 18 is used. Is operated to suck the membrane-treated water from the immersion-type filtration membrane 14, thereby performing solid-liquid separation. At this time, by operating the speed reducer 19 and rotating the immersion type filtration membrane 14 continuously or intermittently, a shearing force is applied to the filtration membrane, and the adhesion of sludge to the membrane surface can be suppressed.

By operating the blower 21 continuously or intermittently, air scrubbing and cleaning can be performed on the immersion type filtration membrane 14 located above the air diffuser 20. This air scrubbing cleaning is performed on all of the immersion filtration membranes 14 by rotating the immersion filtration membrane 14 at a predetermined position, regardless of the number of immersion filtration membranes 14 installed, with one diffuser 20. Therefore, it is sufficient to provide only one diffuser tube 20 and blower 21 in the filtration tank 11, and it is possible to reduce equipment costs and running costs required for these. The air diffuser 20
May be provided at a plurality of locations as needed.

When the chemical cleaning of the immersion type filtration membrane 14 is performed, the immersion type filtration membrane 14 to be targeted is stopped at the crane 27 and removed from the filtration membrane support member 13 and transferred to the chemical cleaning tank 22 by the crane 27. And do it. At this time, a membrane-treated water suction pipe 15 connected to the immersion type filtration membrane 14 is used.
Is closed by a valve or the like, so that the filtration process by another immersion-type filtration membrane 14 can be continuously performed even during the cleaning of the chemical solution. Further, it is also possible to prepare a preliminary immersion type filtration membrane 14 and perform the chemical cleaning while sequentially replacing each filtration membrane.

The operation can be carried out in the same manner as in a general membrane separation apparatus, and the air scrubbing and chemical cleaning may be carried out in the same manner. Further, the number of immersion type filtration membranes, the supporting structure, and the structure of each part can be appropriately designed according to the size and type of the circular sedimentation basin to be used, the type of separation membrane, and the like. Furthermore, even when a membrane separation device having a similar structure is newly installed, the same effect as that of the prevention of sludge adhesion to the membrane surface and the reduction of air diffusion means can be obtained.

[0015]

As described above, according to the membrane separation apparatus of the present invention, the circular sedimentation basin used for the final sedimentation basin and the like is used for the filtration treatment tank for membrane separation, and the existing structure is used. Can be used to form a membrane separation device,
It is easy to maintain and control, and the conversion to membrane separation that can perform stable solid-liquid separation can be performed at low cost. Furthermore, by rotating the immersion type filtration membrane using a reduction device for a sludge scraper, it is possible to suppress the adhesion of sludge to the membrane surface and to continue an efficient operation in a stable state. In addition, since only one air diffusion means for performing the air scrubbing needs to be provided, the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a membrane separation device of the present invention.

FIG. 2 is a plan view of the same.

[Explanation of symbols]

11 ... filtration treatment tank, 12 ... spindle, 13 ... filtration membrane support member, 14 ... immersion filtration membrane, 15 ... membrane treated water suction pipe, 16
... suction main pipe, 17 ... swivel joint, 18 ... membrane treatment water suction pump, 19 ... reducer, 20 ... diffuser pipe, 21 ... blower, 22 ... chemical cleaning tank, 23 ... raw water inflow path, 24 ...
Sludge (concentrated water) extraction path, 25 ... bearing member, 26 ... deck, 27 ... crane

Claims (3)

[Claims] An immersion type filtration membrane is installed radially around a support shaft erected in the center of a filtration tank of a circular sedimentation tank type so as to be rotatable around the support shaft. Circular sedimentation tank type membrane separation device. 2. A support shaft erected in the center of a circular sedimentation tank type filtration treatment tank, a plurality of filtration membrane support members provided radially from the support shaft, and a filtration treatment tank supported by the support member. A immersion-type filtration membrane radially installed in the inside, a membrane-treated water suction pipe provided along the filtration membrane support member and gathering at the spindle, and a suction main pipe with the membrane-treated water suction pipe gathered A membrane-treated water suction pump connected via a swivel joint, a driving unit for rotating the filtration membrane support member about a support shaft, and an air diffusion unit for performing air scrubbing of the immersion filtration membrane. A membrane separation device, comprising: 3. The membrane separation device according to claim 2, wherein a chemical cleaning tank for cleaning the immersion type filtration membrane with a chemical is provided adjacent to the filtration tank.