JPH0713832Y2 - Membrane module of activated sludge treatment equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a membrane module of an activated sludge treatment device for organic wastewater.

Conventional technology Conventionally, in the activated sludge treatment device of organic wastewater,
For example, as shown in FIG. 4, a rectangular box frame 2 whose upper and lower surfaces are open is provided in the aeration tank 1, and a plurality of membrane modules 3 are vertically arranged in the box frame 2 at regular intervals a. The air diffusing tube 4 is arranged below the membrane module 3. Reference numeral 5 is a raw water supply pipe opening to the aeration tank 1, and 6 is a sludge drawing pump connected to the bottom of the aeration tank 1. The membrane module 3 is formed by coating both sides of a membrane support 7 curved in an uneven shape with a filtration membrane 8, and a permeate collection pipe via a permeate suction pipe 9 connected to the upper end of the membrane support 7. Connected to 10. The permeated liquid collecting pipe 10 is provided with a suction pump 11 on the way and opens into a permeated liquid tank 12. The air diffuser 4 is a blower via the air supply pipe 13.
Connected to 14.

The raw water 15 supplied from the raw water supply pipe 5 into the aeration tank 1 is digested by activated sludge in the tank to become digested water 16. At that time, the air diffuser 4 supplies the aeration gas 17 containing oxygen such as air supplied from the blower 14 to the membrane module 3
It is blown in between to supply oxygen to the microorganisms in the activated sludge. The digested water 16 is sucked by the suction pump 11 through the membrane module 3 and is solid-liquid separated by the membrane module 3. That is, the sludge in the digested water 16 is captured by the filtration membrane 8, while the washed permeate 18 that has permeated the filtration membrane 8
Is stored in the permeate tank 12 from the permeate suction pipe 9 through the permeate water collecting pipe 10. At that time, an ascending flow of the digestion-treated water 16 which is good for the air lift action of the bubbles of the aeration gas 17 is generated between the membrane modules 3, and this ascending flow removes the sludge adhering to the filtration film 8 from the filtration film 8. The filter membrane 8 is detached to prevent clogging of the filtration membrane 8.

However, in the above-mentioned conventional membrane module 3, in the suction state, a part of the filtration membrane 8 is brought into close contact with the convex portion of the membrane support 7 and the flow of the permeate 18 between the two is generated. When the passage is eliminated, the suction force does not act effectively on that portion, and the filtration function is deteriorated. Therefore, there is a problem that the effective filtration area of the filtration membrane 8 is reduced and the filtration efficiency is reduced. Further, since the membrane module 3 has a complicated structure and a large thickness, it becomes large and heavy, and there is a problem that it is not easy to operate during maintenance such as cleaning and replacement of the filtration membrane 8.

An object of the present invention is to improve the conventional membrane module and eliminate such problems.

Means for Solving the Problems In order to achieve the above object, the membrane module of the activated sludge treatment device of the present invention is immersed in an aeration tank to arrange a plurality of membrane modules vertically and in parallel, and A membrane module in an activated sludge treatment device in which a constant gap is formed between the membrane modules, and an air diffusing means is provided below the membrane module, the endless frame having a flow passage space for permeate in the center The membrane support is formed by providing a communication hole that communicates the inside and outside of the frame body, and both sides of the membrane support are covered with a filtration membrane, and a filtration membrane is provided between the front and back sides of the membrane support and the filtration membrane. A spacer through which the permeated liquid that has permeated can be provided, and the spacer is formed of a grid net having rigidity.

Action In the above configuration of the present invention, when a suction force is applied from the outside to the communication hole, the digested water is sucked through the filtration membrane,
Solid-liquid separation is performed. That is, the sludge in the digested water is captured by the filtration membrane, while the washed permeate that has passed through the filtration membrane passes through the spacer, flows into the inside of the frame of the membrane support, and is sucked to the outside from the communication hole. To be done. At this time, the filtration membrane covering both the front and back surfaces of the desupport is sucked inward by the suction force, but since it is supported by the spacer, the spacer always provides a permeate flow path between the two filtration membranes. It is maintained over the entire surface of the filtration membrane. Therefore, the suction force acts on the entire surface of the filtration membrane, the reduction of the effective filtration area of the filtration membrane is prevented, and the filtration efficiency is improved. Further, since the membrane support is a frame body having a simple structure, and is thin and lightweight, the membrane module is also small and lightweight. for that reason,
It can be easily operated during maintenance such as cleaning and replacement of the filtration membrane.

Embodiment An embodiment of the present invention will be described below with reference to FIGS.

In the activated sludge treatment device of this embodiment, as shown in FIG. 3, a rectangular box frame in which both upper and lower sides are opened in the aeration tank 21.
22 is provided, a plurality of membrane modules 23 are vertically arranged in the box frame 22 at a constant interval A, and are arranged in the air diffusing pipe 24 below the membrane module 23. To the aeration tank 21, a raw water supply pipe 25 is opened at the upper side, and a sludge drawing pipe 27 having a sludge drawing pump 26 at the bottom is connected. Further, a permeated liquid collection pipe 29 is connected to the membrane module 23 via a permeated liquid suction pipe 28. The permeated liquid collecting pipe 29 is provided with a suction pump 30 in the middle thereof and opens above the permeated liquid tank 31. In addition, the air diffuser
The blower 32 is connected to the unit 24 via an air supply pipe 32.

The membrane module 23, as shown in FIG. 1 and FIG.
Both sides of the membrane support 34 are covered with a filtration membrane 35, and a spacer 36 is inserted between both sides of the membrane support 34 and the filtration membrane 35. The membrane support 34 is an endless rectangular frame formed by a method such as hollowing out the center of a rectangular plate made of vinyl chloride into a rectangle, and has a communication hole 37 that communicates with the inside and outside of the frame on the upper side. The hollowed-out hole in the central portion forms a flow passage space 38 for the permeated liquid 42 described later. A permeated liquid suction tube 28 is connected to the communication hole 37. The filtration membrane 35 is adhered to the membrane support 34 with an adhesive or a double-sided adhesive tape. Spacer 36
Is required to be able to pass the permeated liquid 42 in order to prevent the permeated liquid 42 from effectively adhering to the flow path space 38 by preventing the filtration membranes 35 that have received suction force from adhering to each other. A plastic grid net is suitable.

Next, the operation of the above configuration will be described.

When the raw water 39 is supplied from the raw water supply pipe 25 into the aeration tank 21, the raw water 39 is digested by the activated sludge in the tank to be the digested water.
40. At that time, the air diffuser 24 blows the aeration gas 41 containing oxygen such as air supplied from the blower 33 into the space between the membrane modules 23 to supply oxygen to the microorganisms in the activated sludge. The digested water 40 is sucked by the suction pump 30 through the membrane module 22, and is solid-liquid separated by the membrane module 23. That is, the sludge in the digested water 40 is filtered by the filtration membrane 35.
On the other hand, the clean permeated liquid 42 filtered by the filtration membrane 35 passes through the spacer 36 and the flow passage space 38 of the membrane support 34.
It flows into the inside, is sucked into the permeated liquid collecting pipe 29 from the communication hole 37 via the permeated liquid suction pipe 28, and is stored in the permeated liquid tank 31. At that time, an ascending flow of the digestion-treated water 40 is generated between the membrane modules 23 due to the air-lifting action of the bubbles of the aeration gas 41, and this ascending flow removes the sludge adhering to the filtration membrane 35 to the filtration membrane.
It is separated from 35 to prevent clogging of the filtration membrane 35.

Then, when the membrane module 23 performs solid-liquid separation of the digested and treated water 40, the filtration membrane 35 is sucked inward by the suction force of the suction pump 30, but is supported by the spacer 36, so that the filtration membranes 35 are separated from each other. Prevents close contact. Therefore, the flow path of the permeated liquid 42 is always maintained over the entire surface of the filtration membrane 35 by the spacer 36 between the both filtration membranes 35. Therefore,
The suction force acts on the entire surface of the filtration membrane 35 to prevent the effective filtration area of the filtration membrane 35 from decreasing and improve the filtration efficiency. Further, since the membrane support 34 is a frame body having a simple structure, and is thin and lightweight, the membrane module 23 is also small and lightweight. Therefore, the filter membrane 35 can be easily operated during maintenance such as cleaning and replacement.

Effect of the Invention As described above, according to the present invention, the filtration membrane covering both the front and back sides of the membrane support composed of the frame is supported by the spacers, so that the filtration membranes that have received suction force are closely attached to each other. Is prevented. Therefore, the suction force acts on the entire surface of the filtration membrane, the reduction of the effective filtration area of the filtration membrane is prevented, and the filtration efficiency is improved. Further, since the membrane support is a frame body having a simple structure, and is thin and lightweight, the membrane module is also small and lightweight. Therefore, the filter membrane can be easily operated during maintenance such as cleaning and replacement.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a membrane module showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is an activated sludge treatment using the membrane module. FIG. 4 is an overall configuration diagram of the device, and FIG. 4 is an overall configuration diagram showing an example of a conventional activated sludge treatment device. 23 ... Membrane module, 34 ... Membrane support, 35 ... Filtration membrane, 36 ... Spacer, 37 ... Communication hole, 42 ... Permeate.

Claims (1)

[Scope of utility model registration request] 1. A plurality of membrane modules are vertically and parallelly arranged by immersing the membrane modules in an aeration tank, and a constant gap is formed between adjacent membrane modules, and an air diffusing means is provided below the membrane module. A membrane module in an activated sludge treatment device, wherein an endless frame body having a flow passage space for permeate in a central portion is provided with a communication hole for communicating the inside and outside of the frame body to form a membrane support, Both the front and back surfaces of the support are covered with a filtration membrane, and a spacer is provided between the front and back surfaces of the membrane support and the filtration membrane to allow passage of the permeate that has permeated the filtration membrane. A membrane module for an activated sludge treatment device characterized by being formed.