JP3264028B2 - Membrane separation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a membrane separation apparatus, and more particularly to a membrane separation apparatus in which a plurality of bag-shaped separation membranes are stacked.

[0002]

2. Description of the Related Art In recent years, with the development of membrane separation technology, membrane filtration has been used in various fields.

[0003] Membrane filtration in the fields of turbidity removal, bacteria elimination, etc. has been widely used, but a dead-end type membrane which can continue filtration for a long period of time by a cross-flow type membrane module or a regular backwashing operation. With the development of modules, the usable concentration range has been widened.

By using a cross-flow type membrane module or a dead-end type membrane module which periodically performs backwashing, even if there is a turbidity fluctuation, the filtration rate is not reduced to a level that cannot withstand use. Filtration can be continued.

For this reason, river water, industrial water, and clean water are RO
Instead of coagulation / precipitation / filtration, membrane filtration is performed with a UF membrane or MF membrane in the pretreatment for membrane separation, and the pretreatment process can be simplified.

[0006] In wastewater treatment, a membrane filtration device has become possible instead of coagulation, sedimentation and filtration.

As one type of the membrane separation device, there is a device in which a plurality of flat bag-shaped separation membranes each containing a permeated water flow path spacer are suspended in parallel in a water tank in parallel.
This membrane separation device uses a water pressure of a water tank or a suction pump as a driving force for filtration, and can maintain a high flux by repeating suction filtration intermittently.

In order to collect the permeated water from the bag-shaped separation membrane suspended like a noren and take it out of the system, a structure for connecting the inside of the separation membrane to a water collection pipe is required. Conventionally, a porous water collecting pipe is adhered to the end of the flat membrane portion.

In such a connection structure between the separation membrane and the water collection pipe, the packing density of the membrane could not be increased because the outside diameter of the water collection pipe was much larger than the thickness of the separation film. Also,
This required a lot of man-hours and hindered simplification of the apparatus.

As a configuration for extracting permeated water from the inside of the separation membrane, one end or both ends of the noren-shaped separation membrane are adhered and solidified, and the permeated water channel is opened at the end surface where the adhesive solidification is performed, instead of using a water collecting pipe. There is a structure that is cut to make a permeated water outlet. According to this structure, films can be stacked and filled at a high density.

[0011]

In such a structure in which the ends of the separation membrane are adhered and solidified, if cake-like deposits are formed in the gap formed between the flat membrane and the adhesive solidified portion, backwashing or gas-liquid deposition may occur. Even if the deposits are peeled off from the membrane surface by physical washing such as a mixed flow, they are attached to the membrane surface again in the next filtration step without being pulled out from the gap, and gradually grow thicker and denser,
There was a problem that the raw water flow path was blocked. If the film interval is large, such a problem is not so great, but if the film interval is small (1 to 3 mm), it becomes a considerable obstacle.

An object of the present invention is to provide a bag-type separation membrane laminated type membrane separation apparatus capable of increasing the membrane packing density and preventing the side end face of the raw water flow path surrounded by the separation membrane and the adhesive solidification portion from being blocked. It is in.

[0013]

The membrane separation device of the present invention comprises:
A plurality of flat bag-shaped separation membranes containing a permeated water flow path spacer therein are arranged in a stacked manner such that a gap serving as a raw water flow path is interposed between the separation membranes, and A separation membrane laminate in which the separation membranes are arranged such that the permeate outlet provided on one side of the separation membrane is directed to the same side, and a side along the one side of the separation membrane of the separation membrane of the separation membrane laminate A connecting material that connects the edges in a water-tight manner, wherein a water-impermeable portion is provided in a region near the connecting material of one or both separation membranes sandwiching the raw water flow path. It is characterized by the following.

[0014]

According to the membrane separation device of the present invention, at the end of the raw water flow passage near the connecting member, at least one of the separation membranes facing the flow passage end is water-impermeable. Almost no turbidity in raw water adheres to Therefore, the accumulation of the turbidity at the end of the raw water flow path is prevented, and even if the turbidity accumulates, the turbidity can be easily removed by backwashing or passing the gas-liquid mixed flow. .

[0015]

Embodiments will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of the apparatus of the embodiment, in which a plurality of bag-shaped separation membranes 1 are stacked with a gap serving as a raw water flow path interposed therebetween. Both ends of each separation membrane 1 are solidified by a potting material. The solidified material of the potting material is the connecting material 2. By cutting the end face of this potting material, the inside of the bag-shaped separation membrane is exposed to the outer end face of the connecting material 2 as shown in FIG. Note that the separation film may be either an organic film or an inorganic film.

As shown in FIG. 2, a permeated water flow path spacer 3 is inserted inside the separation membrane 1. This separation membrane 1 folds one large separation membrane into two, and sandwiches a permeated water flow path spacer 3 therebetween. Then, the open edge parallel to the folded side is sealed by bonding, welding, sewing or the like. Note that two separation membranes may be overlapped with the spacer 3 interposed therebetween to seal two parallel side edges.

Plates 4 and 5 are superimposed on the upper and lower surfaces of the stack of the separation membrane 1, and flanges 6 and 7 are attached to the side surface on the side of the connecting member 2, thereby forming a main body 8 of the membrane separation apparatus. By attaching end caps 9 and 10 to the flanges 6 and 7, permeate extraction chambers are formed on both side surfaces of the membrane separation device main body 8. The end caps 9 and 10 are provided with outlets 11 and 12 for extracting permeated water from the permeated water extraction chamber. 13 is a packing.

As shown in FIG. 2, one of the two separation membranes 1 and 1 facing the raw water flow path 14 between the separation membranes 1 is subjected to a water-impermeable treatment in the vicinity of the connecting member 2. Thus, the water-impermeable portion 15 is formed. As a method of the water-impermeable treatment, for example, a method is selected from the following methods according to the membrane material.

An impermeable agent is applied to the membrane surface. The film surface is made impermeable by heat treatment or the like. A film is formed from a support cloth provided with an impermeable region by a water impermeable agent or heat treatment. A film is formed by weaving an impermeable material or by laminating a support cloth.

The width W of the water-impermeable portion 15 is determined by
Width T in the thickness direction of 4 (usually about 1 to 3 mm)
It is preferably about 10 times.

The provision of the water impermeable portion 15 prevents turbidity from adhering to the water impermeable portion 15. Even if turbidity adheres, it can be easily removed by backwashing or passing a gas-liquid mixed flow.

The membrane separator 16 configured as described above is
As shown in FIG. 3, the pipes 18 and 1 are immersed in the raw water tank 17 and are connected to the permeated water outlets 11 and 12 of the end caps 9 and 10.
9 is connected, the pipe 18 is connected to the suction pump, and the pipe 19 is provided with a valve 20. Then, the operation is performed by closing the valve 20 and reducing the pressure in the permeated water extracting chamber by the suction pump.

As shown in FIG. 4, raw water end caps 21 and 22 may be attached to the membrane separation device 16 to supply raw water to the raw water flow path under pressure.

According to this membrane separation device, the provision of the water-impermeable portion 15 prevents the adhesion of turbid matter to the water-impermeable portion 15. Even if turbidity adheres, it can be easily removed by the gas-liquid mixed flow.

In the above embodiment, the water impermeable portion 15 is provided on only one of the separation membranes 1 sandwiching the raw water flow path 14, but the water impermeable portions 15 may be provided on both separation membranes.

[0026]

As described above, in the membrane separation device of the present invention, the provision of the water-impermeable portion in the vicinity of the connecting member of the separation membrane facing the raw water prevents adhesion of turbid matter to the water-impermeable portion. You. Even if turbidity adheres, it can be easily removed by backwashing or passing a gas-liquid mixed flow. Therefore, the blockage of the raw water flow path is prevented, and the stability of membrane filtration is dramatically improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a membrane separation device according to an embodiment.

FIG. 2 is a sectional view of a main part of the membrane separation device according to the embodiment.

FIG. 3 is a side view showing an example of use of the membrane separation device according to the embodiment.

FIG. 4 is a plan view showing another example of use of the membrane separation device according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Separation membrane 2 Connecting material 3 Permeated water flow path spacer 14 Raw water flow path 15 Impermeable part 16 Membrane separation device

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 63/08 B01D 63/00 500 B01D 63/00 510

Claims (1)

(57) [Claims] 1. A plurality of flat bag-shaped separation membranes each containing a permeated water flow path spacer therein, which are arranged in a stacked manner such that a gap serving as a raw water flow path is interposed between the separation membranes, and A separation membrane laminate in which the separation membranes are arranged such that a permeated water outlet provided on one side of the bag-shaped separation membrane faces the same side; and the separation membrane of the separation membrane laminate A connecting member that connects the edges along one side in a water-tight manner, wherein a connecting member is provided in one or both separation membranes sandwiching the raw water flow path in a region near the connecting member. A membrane separation device provided with a water permeable portion.