JPH09117644A - Flat membrane element of dipping type membrane separation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cleaning time and consumption of cleaning chemical liquid in a flat membrane element in which a passing space for water is formed between a base plate and a flat membrane by a method wherein the space is divided into left and right passing spaces from the upper end of the element to an intermediate portion of the element and a passage is formed for communication of the lower parts of the spaces. SOLUTION: A passage spacer 2 is layered on the front and rear plate surfaces of a vertically erected base plate 1 and a flat membrane 3 is layered over the spacer 2 so as to surround it. And a passing space 4 for water passed through the membrane 3 is formed on the plate surface and water intake pipes 5, 6 communicating with the space 4 are erected on the top surface of the plate 1. In such a flat membrane element, a separation means 10 is fitted downwardly from the upper end of the space 4 as far as an intermediate portion thereof to divide the space 4 into a left passing space 4L in communication with the left intake pipe 5 and a right passing space 4R in communication with the right passing intake pipe 6 and the lower portions of the spaces 4L, 4R are connected by a passage 11. As a result, when cleaning is conducted with chemical liquid, the liquid flows over the entire surface of the membrane 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an immersion type for collecting permeated water that has permeated a flat membrane while diffusing from below under water in a treatment tank while vertically arranging them in the front-rear direction at intervals. The present invention relates to a flat membrane element of a membrane separation device.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional flat membrane element, in which flow path spacers 2 made of non-woven fabric or the like are provided on the front and rear vertical plate surfaces of a substrate 1 which is vertically stood, and flat membrane elements such as MF membranes and UF membranes are provided outside thereof. Membranes 3 are laminated, the peripheral edge portion 3'of the flat membrane is fixed to the plate surface, the flow path spacer 2 is surrounded and covered by the flat membrane 3, and the flat film and the flow path spacer penetrate the flat membrane on the plate surface. A flow passage space 4 for the permeated water is formed. Further, on the upper surface of the substrate, two right and left water sampling pipes 5 and 6 communicating with the permeated water circulation space 4 are provided upright. In order to connect the water sampling pipes 5 and 6 to the permeated water circulation space 4, the lateral grooves 7 in the left-right direction are provided at the upper portions of the front and rear plate surfaces, and the through holes 8 and 9 are formed at the left and right ends of the lateral grooves in the front and rear plate surfaces. Are provided on the substrate 1, the left water sampling pipe 5 is inserted into the left through hole 8, and the right water sampling pipe 6 is inserted into the right through hole 9 from the upper surface of the substrate, respectively.

A plurality of these flat sheet membrane elements are vertically arranged side by side in water in a treatment tank to which raw water is supplied with a space in the front-rear direction, and suction pumps are provided in the water collecting pipes 5 and 6 on the left and right of each flat sheet membrane element. When the connected suction headers are connected and the suction pump is operated while air is diffused from below, the flow spaces 4 on the front and rear plate surfaces of each flat sheet membrane element become negative pressure, and the negative pressure suction action causes the flattening in the raw water. The permeated water that has permeated the membrane flows toward the lateral groove 7 in the circulation space as shown in FIG. 5 (a), and from the lateral groove 7, the left and right through holes 8, 9 and the left and right water sampling pipes 5, 6, the suction header, Water is taken through the suction pump.

[0004]

When the operation of collecting the permeated water is continued, SS or sludge in the raw water adheres to the outer surface of the flat membrane to clog the flat membrane, so that the amount of permeated water taken decreases. .
In that case, press the cleaning chemical solution into one of the sampling pipes with a pump and drain it from the other sampling tube, or suck the cleaning chemical solution from one of the sampling tubes with a pump and inhale the cleaning chemical solution from the other sampling tube. Then, drain the water from one of the water sampling pipes or while filling the flow space with a cleaning chemical solution, the cleaning chemical solution is applied to the entire outer surface of the flat membrane to remove the SS and sludge clogging the flat membrane. However, in the conventional flat sheet membrane element, the cleaning chemical solution can freely move in the permeated water circulation space 4, so that, for example, the cleaning chemical solution that has entered the circulation space 4 from the water collection pipe 6 flows into the water collection pipe 5. As shown in FIG. 5B, the flow proceeds in a short-circuited manner, and the entire surface of the flat film cannot be effectively cleaned with one cleaning. In this way, if the permeated water that has been insufficiently washed is collected, the frequency of washing increases and the operating efficiency decreases. In addition, in order to completely clean, the cleaning must be repeated many times, which requires time and labor and also consumes a large amount of cleaning chemicals.

[0005]

Means for Solving the Problems The present invention is to solve the above-mentioned problems. The substrate is covered with a flat film, and a permeated water flow space is formed between the substrate and the flat film. In a flat membrane element of a submerged membrane separation device in which two right and left water sampling pipes that communicate with the permeated water circulation space are erected, in the permeated water circulation space, from the upper end to the lower part, the left water sampling pipe It is characterized by partitioning into a left circulation space communicating with the right circulation space and a right circulation space communicating with the right water sampling pipe, and forming a flow channel communicating between the left circulation space and the right circulation space.

[0006]

1 and 3 show a first embodiment and a second embodiment of the present invention, in which the same components as those of the above-mentioned conventional example are designated by the same reference numerals. Reference numeral 10 denotes a permeated water flow space 4 formed by the flat membrane 3 and the flow path spacer 2 on the plate surface.
Shows a separating means for partitioning a part from the upper end to a lower part into a left distribution space 4L communicating with the left water sampling pipe 5 and a right distribution space 4R communicating with the right water sampling pipe 6, and the separation means 10 is a distribution space. Since it is formed halfway from the upper end to the bottom, the bottom of the left circulation space 4L and the bottom of the right circulation space 4R communicate with each other through the flow passage 11. Since the isolation means 10 is provided downward from the center of the upper end of the circulation space 4, the areas of the left circulation space 4L and the right circulation space 4R are approximately equal. Further, the lateral groove 7L having the through hole 8 communicating with the left water sampling pipe 5 at the end is at the upper part of the left circulation space 4L, and the lateral groove 7R having the through hole 9 communicating with the right water sampling pipe 6 at the end is the right circulation. Each of them is individually provided above the space 4R.

In the embodiment shown in FIGS. 1 and 2, the isolation means 10 is composed of a flat film 3 and a flow path spacer 2 which are coated with an adhesive in the form of a thin strip and adhered to the surface of the substrate to be solidified. I am doing it.

Also, in the embodiment of FIGS. 3 and 4, the isolation means 1
The notch 13 corresponding to 0 is provided in the flow path spacer 2 from the top to the bottom, and the flat film 3 that surrounds the flow path spacer by fixing the peripheral edge portion 3'to the plate surface is provided with the cutout of the flow path spacer. Thirteen
Even the part of the adhesive layer is adhered to the plate surface and hardened, and similarly, the adhesive solidified layer 12
It consists of.

Therefore, by sucking from the water collecting pipes 5 and 6, the permeated water which has permeated the flat membrane can be collected without any trouble as in the conventional flat membrane element. When performing the chemical solution cleaning, for example, the chemical solution that has entered the right circulation space 4R from the water sampling pipe 6 cannot flow in a short circuit to the water sampling pipe 5 because of the isolation means 10. As shown, it flows downward in the right circulation space 4R, turns back under the isolating means 10 through the flow path 11, rises in the left circulation space 4L, and flows out from the water sampling pipe 5.

In the embodiments shown in FIGS. 1 to 4, the substrate 1 is described as a plate, but the substrate is formed in a frame shape with a hollow frame and the front and back membranes are directly adhered to each other to form a separating means. May be provided.

[0011]

As is clear from the above, the flat sheet membrane element of the present invention is provided with two left and right standing from the upper surface of the substrate 1 during cleaning for removing stains such as SS and sludge attached to the outer surface of the flat sheet. When the chemical liquid is injected into either one of the water sampling pipes 5 and 6, the chemical liquid flows downward in the left or right circulation space communicating with the water sampling pipe, and is directed under the isolation means 10 partitioning the left and right circulation spaces. And flows upward through the right or left circulation space where the other water sampling pipe communicates with the other water sampling pipe and flows out from the water sampling pipe. Therefore,
The chemical solution flows in contact with the entire surface of the flat film, and removes contaminants adhering to the outside. As a result, effective cleaning can be performed in a short cleaning time and by using a small amount of cleaning chemicals.

[Brief description of the drawings]

FIG. 1 is an elevational view of a first embodiment of a flat sheet membrane element of the present invention.

FIG. 2 is a sectional view taken along line AB in FIG.

FIG. 3 is an elevational view of a second embodiment of the flat sheet membrane element of the present invention.

4 is a cross-sectional view taken along the line AB of FIG.

FIG. 5A is an elevation view in which a part of a conventional flat sheet membrane element is cut away, an explanatory diagram of a permeated water sampling step, and FIG. 5B is an explanatory diagram of a cleaning step.

[Explanation of symbols]

 1 substrate 2 flow path spacer 3 flat membrane 3'periphery of flat membrane 4 permeated water flow space 4L permeated water left flow space 4R permeated water right flow space 5 water sampling pipe 6 water sampling pipe 8 through hole 9 through hole 10 isolation Means 11 flow path

Claims (1)

[Claims] 1. A dipping method in which a substrate is covered with a flat membrane to form a permeated water flow space between the substrate and the flat membrane, and two right and left water sampling pipes communicating with the permeated water flow space are provided upright. In the flat sheet membrane element of the type membrane separator, the permeated water circulation space is divided from the upper end to the middle part into a left circulation space communicating with the left water sampling pipe and a right circulation space communicating with the right water sampling pipe. At the same time, a flat membrane element for a submerged membrane separation device, characterized in that a flow path communicating between the lower left circulation space and the lower right circulation space is formed.