JPH0722687B2 - Membrane set for fluid separation device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fluid separation device using a separation membrane using pressure as a driving force, and particularly to a fluid separation device that economically performs microfiltration and ultrafiltration operations. The present invention relates to a separation membrane module used in.

[Prior art]

With the development of culture in recent years, the use of water and energy has increased year by year, producing fresh water from seawater, purifying and recycling used wastewater, or valuable substances and harmful substances in solutions in various processes. Efforts have been made to efficiently and inexpensively carry out the concentration and separation of the above by a process that saves energy as much as possible. As the process, various separation or removal methods such as an evaporation method, an extraction method, an adsorption method, and an activated sludge method are used, and a membrane separation process is also one of the effective separation operations.

As the membrane module device used in this membrane separation process, a hollow fiber type, a tubular type, a spiral type, and a pressure plate type (filter press type) are mainly used, but each module has advantages and disadvantages. The outer shape of the hollow fiber type is
A hollow fiber membrane 2 having a shape as shown in Fig. 15 and a large number of hollow fibers having an inner diameter of 0.8 to 1.4 mm is fixed by the hollow fiber bundle fixed ends 1 at both ends.
Inside the drum, the stock solution 3 is introduced, the filtration solution 4 is taken out from the upper part, and the concentrated solution 5 is taken out from the opposite side. Therefore, if the concentration of the stock solution 3 is high or if large particles are mixed, there arises a problem that the stock solution flow path is easily blocked. Therefore, it is used for the filtration of fairly clean raw water. In this module, the stock solution is supplied at a high flow rate through a narrow gap, so that the pressure loss is large. Further, a high technology is required for fixing the hollow fiber bundle with resin during the film formation of the module, and the hollow fiber bundle is integrated with the pressure resistant container, so that the module price is also expensive.

The tubular module shown in Fig. 16 usually has an inner diameter of 1 to 2.5 cm.
The separation membrane 6 is attached to the inside of the porous tubular support of
Such pipes are connected in series by U-bends, and the stock solution 3 is introduced from one of the pipes, the concentrated liquid 5 is taken out from the other, and the permeated water 7 that has permeated the separation membrane 6 is taken out. In this case, the inside of the tube as described above should have a high flow rate of the stock solution 3
It is a module that has the largest energy consumption per unit filtration amount and the smallest membrane packing density per unit volume since it is filtered by passing. Furthermore, since a one-tube one-tube tubular separation membrane must be attached to the support tube during the module membrane formation, the module is considerably expensive per unit membrane area.

Next, the pressure plate type module is mainly composed of a plate 8, a stop disk 9, a neck ring 10 and a film 11 as shown in FIG. In this module, the undiluted solution 3 flows at a high flow velocity in the gap between the membranes 11, the flow is bent at an acute angle at its end, and is supplied to the gap in the next membrane 11. Therefore, the pressure difference between the inlet of the concentrated solution 3 of the module and the outlet of the permeated water 7 is very large, the energy required for filtration is very large, and the physical cleaning of the membrane is almost impossible. further,
The film of this module is pressed and sealed by a thick pressure plate that is set on the plate and is not deformed by a large force. Thus, membrane replacement can be a cumbersome process, but the equipment is rather expensive.

The spiral type module shown in FIG. 18 is a bag-shaped membrane set in which the upper and lower surfaces of a membrane support that serves as a passage for the permeate are sandwiched by separation membranes in a permeate intake pipe provided at the center of the module. A mesh-like sheet 12 which is sandwiched between membrane sets and serves as a flow path for a stock solution is tightly wound and housed in a cylindrical pressure-resistant container. In this module, the stock solution 3 flows through the support gap of the mesh 12 sandwiched between the membrane sets to cause filtration, and the filtration solution 4 is taken out, but it is tightly wound around the take-out tube. Therefore, the portion where the mesh and the membrane set are in contact does not function as a separation membrane. In addition, solutes and suspensions may be deposited on this contact area with filtration, and they may grow and block the flow path.So viscous fluids, highly concentrated solutions, or solutions with suspensions Cannot be used for processing. Further, the film cleaning due to the aging of the film performance is only chemical cleaning, and physical cleaning is impossible.

In general, when filtration is performed using a separation membrane, the concentration of solutes removed on the membrane surface increases with the filtration of the solvent, which causes a large filtration resistance. Further, the substances removed on the film surface may be deposited or adhered to cause deterioration of the film performance.
In order to reduce such a phenomenon and increase the amount of expensive modules to be processed per unit, the stock solution is sent to the module at a high flow rate, vigorous stirring, pretreatment of raw water, and regular chemical treatment of the membrane. Wash or sponge.
However, when performing filtration using the above module,
Since the amount of module hold-up for the membrane area is large, filtration cannot be achieved by simply passing the raw water through the module once. Has achieved the purpose of. In such a method, there is a large loss of kinetic energy in the flow of raw water due to bending inside and outside the module such as a connecting pipe. Therefore, in the separation operation using a membrane, the ratio of energy cost to the total processing cost is very large. For example, in the case of concentrating 10 times the lignin in the effluent of the pulp exposed by ultrafiltration, 2000-4000
Energy costs account for 70-80% of the total treatment costs using tubular and pressure plate type modules at the permeated water treatment scale of m ³ / day.

[Object of the Invention]

The present invention has been made in order to solve the problems by considering the current state of the conventional filtration module described above.
That is, the conventional module has the following drawbacks.

1) Since the structure is complicated and the membrane and the container are integrated, the deterioration of the performance causes the discarding of the entire membrane module, which makes the module considerably expensive.

2) In the conventional module, the scale of processing is expanded simply by increasing the number of modules, and thus the scale merit is not often present.

3) Since the module cost is high, filtration is performed with a vigorous undiluted solution flow in order to increase the treatment amount per unit membrane module. Therefore, the ratio of energy cost to the total processing cost is high.

4) Since the membrane and the container are integrated to form a module and the structure is fixed and complicated, physical cleaning of the module due to deterioration of the membrane performance is not possible with many membrane modules.

The present invention, in order to solve the above-mentioned problems, the membrane set can be easily attached to the module container, the loss of energy and pressure due to the flow path and the vessel wall due to the flow of the stock solution in the module is small, and easy to clean, Moreover, it is an object of the present invention to provide an inexpensive membrane set for a fluid separation device, which has a large processing capacity per unit volume and has a scale merit.

[Structure of Invention]

To achieve this object, the membrane set for a fluid separation device according to the first invention of the present application is a membrane composed of a flexible support that can serve as a passage for a permeate fluid and a sheet-shaped separation membrane that wraps the support. In addition to stacking a plurality of sheets, all the membrane sheets are fixed to each other only at one location by a mechanism that takes out the permeated fluid from the membrane sheets in the relationship between the membrane sheets, and at the other locations, all the membrane sheets are fixed. Is characterized in that each membrane sheet and the whole can move independently of each other by the flow of fluid.

Here, the “lamination” is meant to include a state in which the respective film sheets are overlapped with a space therebetween and a state in which the film sheets are overlapped with each other partially or wholly in contact with each other.

The membrane sheets can be stacked side by side, ie substantially parallel or in concentric circles.

In addition to the features of the first invention, the membrane set for a fluid separation device according to the second invention of the present application has
The feature is that the whole is wrapped in a net.

Further, the membrane set for a fluid separation device according to the third invention of the present application is characterized in that, in addition to the features of the first invention, a coarse spacer is interposed between the laminated membrane sheets.

[Action]

The raw fluid to be permeated flows along both sides of the membrane sheet and is subjected to a fluid separation treatment by a separation membrane by applying a pressure or pressure reduction operation to the fluid. The permeated fluid passes through the support inside the membrane sheet, and is discharged from the inside of the membrane sheet through the take-out mechanism.

〔Example〕

Next, preferred embodiments of the membrane set according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic longitudinal cross-sectional view of a first embodiment of the membrane set of the present invention with a part thereof omitted in the lengthwise direction, and FIG. 2 is a schematic cross-sectional view of a part omitted with respect to the line 2-2 of FIG. 3 shows a schematic vertical section taken along line 3-3 in FIG.

Reference numeral 20 denotes the entire membrane sheet, and the membrane sheet has two sheet-shaped separation membranes each having a support body 21 serving as a passage of a permeated fluid.
It is formed by enclosing it in a bag shape with 22a and 22b. The sheet-shaped separation membranes 22a and 22b are made to project slightly from the peripheral portion of the support 21, and the peripheral portions of the separation membranes are heat-sealed by ultrasonic waves or bonded with an adhesive. Then, the support is enclosed in the separation membrane.

The shape of the support is generally a flat rectangular parallelepiped. The shape of the sheet-shaped separation membrane is similar to that of the support.

As the support 21, a net made of a known polymer product,
Can be used as a passage for permeated fluid such as porous woven fabrics and nonwoven fabrics.
Known ones can be used. The support 21 is flexible and provides flexibility in the shape of the membrane sheet and thus the membrane set formed therefrom. The separation membranes 22a, 22b of the membrane sheet are provided with holes 23 at either or one of the arbitrary locations. Support 21
Also, holes are formed in the vertical direction at the positions corresponding to the holes formed in the separation membrane, or if the support is a net, place the eyes of the net instead of forming the holes. Good.

A plurality of the above-mentioned membrane sheets 20 are prepared, and a pipe 30 is inserted into each hole to take out the permeated fluid from the inside of the membrane sheet and laminated. The tube 30 is formed with an outlet 31 corresponding to the hole 23 formed in each membrane sheet and communicating with the inside of the membrane sheet. A packing 32 is provided around the tube 30 between the membrane sheets to prevent the permeated fluid from flowing out of the membrane sheet and the fluid to be permeated into the membrane sheet. In contact with the outermost surfaces of the uppermost layer and the lowermost layer of the laminated membrane sheets in this manner, the disc bodies 33a, 33b having female screw holes are screwed into the pipe 30, or an appropriate stopper member is joined. By doing so, it is possible to prevent the laminated film sheets from being separated from each other and to ensure the sealing by the packing.

Between each laminated film sheet 10, a known spacer 24 such as a coarse net made of a known polymer product is interposed,
It is preferable to prevent the membrane sheets 20 from directly contacting each other, to secure a flow path for the original fluid and improve the flow state. The thickness of the spacer should be approximately equal to the distance between the membrane sheets so that the spacer does not exert strong pressure on the separation membrane of the membrane sheet, and the separation membrane performs its function even at the contact point between the spacer and the separation membrane. Make it possible.

Furthermore, if the entire membrane set made of laminated membrane sheets is wrapped with an appropriate net 25, it is possible to avoid cluttering the membrane sheet, and it becomes easy to repair, inspect and handle the membrane set.

The membrane set thus formed is mounted in the tank 40 of the fluid separation device with a gap between both ends, as shown in a schematic vertical sectional view in FIG. A pipe 41 for feeding the raw fluid 50a to be filtered into the tank is connected to one end of the tank. A pipe 42 for extracting the fluid 50b concentrated by filtration is connected to the other end of the case.

A pipe 43 for taking out the permeated fluid is connected to one side surface of the tank 40, and this pipe communicates with the pipe 30 provided in the membrane set.
Reference numerals 44 and 45 denote pumps connected to the pipes 41 and 43, respectively. When the pump 44 is simply used as a flow pump, the pump 45 is used to perform suction filtration. If the pump 44 is a pressure pump, filtration can be performed without using the pump 45.

FIG. 5 shows a second embodiment of the membrane set according to the present invention. In this embodiment, the membrane members are placed in an open state by cutting one end of each membrane sheet and the sealing members 32a are alternately laminated. Together, they are joined to the enlarged portion 43a provided at the tip of the pipe 43 for taking out the permeated fluid so as to keep the airtightness.

When performing suction filtration using the membrane set according to the present invention, it is not required that the tank 40 have a high pressure resistance. Therefore, the membrane set may be a tank as shown in FIG. 6, FIG. 7 or FIG. Mounted on.

On the other hand, when performing filtration under pressure, the tank in which the membrane set is mounted must withstand the pressure, so a cylindrical pressure resistant container as shown in FIG. 8 is preferable. FIG. 9 shows a diametrical longitudinal section of a membrane set used in such a container. This film set includes the laminated film sheets 20
Both sides of a tube 30 for taking out the permeated fluid from the inside of the membrane sheet are concentrically curved and housed in a cylindrical container 60.
Therefore, film sets of various lengths can be easily obtained, and by increasing the number of layers and increasing the diameter of the film sets, the film sets having a large processing capacity can be easily obtained.

Even when the membrane set according to the present invention is put in a cylindrical container, the membrane sheets are not fixed to each other but are only put in a curved shape in the container. It is possible to prevent dirt on the surface of the membrane sheet and blockage of the permeation channel. It is also possible to wash out the surface of the membrane sheet one by one by pulling out the membrane set. In this aspect, the spacer may not be interposed between the membrane sheets. The shaded portion in FIG. 9 is a void portion formed when the membrane set is curved and inserted into a container. To prevent the raw fluid from flowing into this portion and to reduce the permeation efficiency of the membrane set. Then, it is good to stuff and block it. Furthermore, it is possible to mount a plurality of membrane sets in a cylindrical container.

FIG. 10 is a perspective view showing a case where three membrane sets are attached to one cylindrical container 60a, and a raw fluid is passed through the series to be filtered. In the illustrated embodiment, the inside of the cylindrical container 60a is equally divided around the axis thereof into partitions A, B and C by partition walls 61, 62 and 63. One of the three bulkheads 63 extends to the end face of the cylindrical container, while the other two have a space formed between them on the opposite side to the end face of the cylindrical container. It is designed to continue in series. A pipe 41 for inflowing the raw fluid 50a is connected to the section A, and a section C is connected to the section C.
A pipe 42 for connecting the concentrated fluid is connected. Each section has a
As shown in FIG. 11, each membrane set is stored by being curved in an arc shape so as to form a concentric circle. The width of the membrane sheet of each membrane set becomes smaller toward the inner side. In the center of the shaded cylindrical container, insert the appropriate padding as described with respect to FIG.

The raw fluid to be filtered first enters the section A, then flows into the section B from the lower interval of the partition wall 61 between the sections A and B, and further from the upper interval of the partition wall 62 between the sections B and C. Once inside C, it is removed from tube 42 as concentrated fluid 50b.
The permeated fluid is obtained by projecting a tube (not shown) communicating with the inside of each membrane sheet from the side surface of the cylindrical container, or by collecting the tube at the center of the container and pulling it out from the end.
It is recommended to take it out from each membrane sheet.

FIG. 12 and FIG. 13 show a module in which a membrane set in which a number of membrane sheets are laminated is mounted in a cylindrical tank in a flat state. In this module, the membrane set is simply protected by a net-like bag for easy loading and unloading.
It is also possible to arrange a large number of such membrane sets.

Furthermore, a large number of membrane modules, which are composed of tanks without pressure resistance as shown in FIGS. 6, 7, and 14, are arranged in a large cylindrical tank shown in FIG. You can also do it. In this case, individual membrane sets can be easily washed and replaced. In filtration using this module, the original fluid
When 50a is pumped by the pump 44 and the pump 47 is used as a circulation pump for the non-permeate fluid, the energy required for pressurization can be saved.

〔The invention's effect〕

According to the first invention of the present application, a membrane module in which a plurality of membrane sheets are fixed to each other only at one place by a mechanism for taking out a permeated fluid from the membrane sheets in a mutual relation of the membrane sheets in a tank. Since the raw fluid is flown inside and filtered by suction or pressurization, due to the flow resistance due to the violent raw fluid flow and the flow resistance of the module wall, like the filtration of the conventional commercial module system. Since there is almost no energy loss, not only the energy cost is reduced, but also the pressure loss in the module is small, and the large module performance can be maintained with a small driving force (pressure). Further, since the membrane sheet can move due to the flow of fluid, it is difficult for all the membrane sheets to have adhered matter, and even if they are attached, they can be easily peeled off from the membrane sheet surface due to the flow of the membrane sheet.

Moreover, the device does not need to have high pressure resistance. Therefore, the container (tank) can be inexpensive. The membrane is usually formed into a sheet, but the membrane thus formed is cut into an arbitrary length as it is, and a core that serves as a passage for the permeated fluid is placed inside to seal the periphery. Since a number of layers are stacked to make a membrane set,
Unlike the conventional case where a module with a complicated shape is fixed to manufacture a module, the module scale can be easily changed at low cost and the membrane packing density per unit volume is 800 to 400 m ² / m.
³ and very big. Furthermore, the membrane set can be easily installed and removed in the filtration tank, and the maintenance including module cleaning is easy.

Further, according to the second invention of the present application, it is possible to avoid cluttering of the membrane sheet, and it is easy to handle the membrane set during repair, inspection and attachment.

Further, according to the third invention of the present application, it is possible to prevent the membrane sheets from directly contacting each other, and to reliably secure the flow path of the raw fluid.

The device of the present invention can of course be used as a gas separation, diffusion separation or reverse osmosis module,
In particular, it is an extremely effective device for efficiently performing the microfiltration and ultrafiltration processes.

[Brief description of drawings]

1 is a schematic longitudinal sectional view in the longitudinal direction of a first embodiment of a membrane set according to the present invention, FIG. 2 is a schematic transverse sectional view taken along line 2-2 in the same figure, and FIG. 3 is FIG. 3 is a schematic vertical sectional view taken along line 3-3 in FIG. FIG. 4 is a schematic vertical sectional view of a fluid separation device using the membrane set according to the present invention. FIG. 5 is a schematic longitudinal partial longitudinal view of a second embodiment of the membrane sheet according to the present invention. Figures 6, 7 and 14 show
It is a schematic perspective view which shows the tank of a fluid separation apparatus. Figure 8 shows
FIG. 9 is a side view of a cylindrical container for mounting the membrane set according to the present invention, and FIG. 9 is a diametrical cross-sectional view of the membrane set for mounting on the container shown in FIG. FIG. 10 is a perspective view showing another embodiment of the cylindrical container, and FIG. 11 is a diametrical cross section when the membrane set is attached to the container shown in FIG. FIG. 12 is a schematic longitudinal sectional view of yet another cylindrical tank in which the membrane set according to the present invention is mounted, and FIG. 13 is a diametrical sectional view of the tank shown in FIG. 15 to 18 are explanatory views of the prior art. 20 ... Membrane sheet, 21 ... Support, 22a / 22b ... Separation membrane,
30 …… Tube for extracting permeated fluid

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeo Nomura 4-7-55 Kashiwa-cho, Shiki City, Saitama Prefecture (56) Reference JP-A-53-67683 (JP, A)

Claims (4)

[Claims] 1. A plurality of membrane sheets, each of which comprises a flexible support that can serve as a passage for a permeable fluid and a sheet-shaped separation membrane that wraps the support, are laminated, and all the membrane sheets are membranes. In the mutual relationship of the sheets, the mechanism for taking out the permeated fluid from the membrane sheets fixes each other only at one place, and at the other places, all the membrane sheets move independently of each other due to the fluid flow. Membrane set for fluid separation device capable. 2. The membrane set for a fluid separation device according to claim 1, wherein the membrane sheets are fixed to each other only in the vicinity of one end of the membrane sheet by a mechanism for taking out the permeated fluid. 3. A plurality of membrane sheets, each of which comprises a flexible support that can serve as a passage for a permeated fluid and a sheet-shaped separation membrane that wraps the support, and all of the membrane sheets are membranes. In the mutual relationship of the sheets, the mechanism for taking out the permeated fluid from the membrane sheets fixes each other only at one place, and at the other places, all the membrane sheets move independently of each other due to the fluid flow. A membrane set for a fluid separation device in which the laminated membrane sheets can be wrapped in a net. 4. A plurality of membrane sheets, each of which comprises a flexible support that can serve as a passage for a permeated fluid and a sheet-shaped separation membrane that wraps the support, and all of the membrane sheets are membranes. In the mutual relationship of the sheets, the mechanism for taking out the permeated fluid from the membrane sheets fixes each other only at one place, and at the other places, all the membrane sheets move independently of each other due to the fluid flow. A membrane set for a fluid separation device in which a coarse spacer is interposed between the laminated membrane sheets.