JPH0355174B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention comprises a liquid collecting section on which a membrane is stretched, and a plate having a liquid passage gap on both sides on the surface of the membrane. A plurality of blocks, which are stacked in multiple directions, are pressed together in a row between the front and rear end plates,
The present invention relates to a flat membrane device for separating the stock solution into a liquid that has passed through the membrane and a concentrated liquid that has not passed through the membrane by flowing the stock solution in contact with the membrane through the liquid passage gap between the plates of each of the blocks.

(Prior Art) Such a flat membrane device is known from Japanese Patent Publication No. 52-10113. As shown in FIGS. 16 and 17, this conventional device has a single movable end that can be moved along a horizontal support 4 that is installed between a fixed end plate 2 and a fixed support plate 3 that are opposed in the front and back on a bed 1. A plate 2', one or more partition plates 5, in this case three partition plates 5..., located between the fixed end plate 2 and the partition plates, between each partition plate, and between the partition plate and the movable end plate, respectively. By suspending plates 6 for multiple sheets, for example, by tightening bolts 7 passed between the fixed end plate 2 and the movable end plate 2' with nuts 7', the partition plates 5... and a block consisting of a plurality of plates 6... is compressed.

On the front and rear surfaces of each plate 6, a washboard-like liquid collection recess 8 is formed by recessing two steps inside the peripheral edge made of a gasket, and a membrane 8 covering the liquid collection recess 8 is formed around the entire circumference of the first step. ' is stretched to form the liquid collection part 9,
Liquid passage ports 10 and 11 are opened at the top and bottom of this stage, and the upper liquid passage ports 10 and the lower liquid passage ports 11 of the board 6 for multiple sheets constituting each block are opposite to each other. Each liquid passage gap 9' between the plates
They are connected in a series with a distance between them. Each plate 6 has an extraction hole 12 through which the liquid that has passed through the membrane 8' and obtained in the liquid collection recess 8 is extracted from the periphery of the plate.

To carry out the separation, the stock solution is supplied by a pump to the liquid supply port 13 in the fixed end plate 2 that communicates with the upper liquid passage port 10 of the first block, and between the first and second blocks and between the third block. Each partition plate between the second block and the fourth block has a lower relay port 11' that communicates with the lower liquid passage port 11 of each block, and the partition plate between the second block and the third block has an upper The one with the upper relay port 10' communicating with the liquid passage port 10 is used, and the movable end plate 2' has a fourth
Liquid drain port 1 communicating with the upper liquid passage port 10 of the block
4 will be provided.

As a result, the stock solution supplied from the liquid supply port 13 of the fixed end plate 2 to the continuous upper liquid passage port 10 of the first block passes through the liquid passage gaps 9' of all the plates of the first block to the membrane. contact and flow downward, at which time,
The liquids that have passed through the membrane and obtained in the liquid collecting recesses 8 are discharged from the respective extraction holes 12, and the stock liquid that has not passed through the membrane is discharged from the partition between the lower liquid passage port 11 of the first block and the second block. It flows through the lower relay port 11' of the plate into the series of lower liquid passage ports 11 of the second block, contacts the membrane in the soil liquid gaps 9' of all the plates of the second block, and then flows upward. At this time, the liquid that has passed through the membrane and obtained in the liquid collection recess is discharged outside the plate through the extraction hole 12, and the stock liquid that has not permeated is transferred from the upper liquid passage port of the second block to the third block. 3rd through the upper relay port 10' of the partition plate between the block and
It flows into a series of upper passage ports 10 of the block and now flows in a downward flow through the passage gaps 9' of all plates of the third block against the membrane.

In this way, the liquid that has flowed upward (or downward) through each liquid passage gap of the block in the previous stage by coming into contact with the membrane through the liquid passage gaps of the next stage blocks is in contact with the membrane and flows in the opposite direction. The liquid flows in a downward flow (or upward flow), repeats a meandering flow in the vertical direction for each block, and flows in contact with the membrane through the liquid passage gap in the final stage, here the fourth block. The concentrated liquid that has not passed through the membrane is discharged from the drain port 14 of the movable end plate.

(Problem to be solved by the invention) By the way, in such membrane separation, if the liquid does not flow through the liquid passage gap at a constant flow rate, a concentration distribution will occur on the membrane surface, and the yield of the liquid passing through the membrane will vary. It has the property that (flux) decreases.

In the above conventional example, a block is constructed by stacking multiple plates in a line in the front-rear direction, so the amount of stock solution required to flow through the liquid passage gap of one plate in contact with the membrane to obtain the required flow rate is Q. If 10 boards make up one block, then 10×
Supply port 13 for stock solution with a large capacity pump of Q=10Q
It is necessary to supply the same amount of water to the equipment, which not only increases equipment costs but also increases running costs.

Furthermore, a large amount of the liquid flowing into the liquid passage ports 10 at the upper or lower part of the series of plates constituting each one block is supplied to the liquid passage gap on the downstream side, and the liquid is supplied to the liquid passage gap on the upstream side. The amount tends to decrease compared to the downstream side, and the flow velocity in the liquid passage gap on the upstream side becomes small, resulting in the problem that the membrane on the upstream plate is easily clogged with solids in the liquid. be.

(Means for Solving the Problems) Therefore, the present invention considers two adjacent blocks at the front and back of a plurality of blocks pressed between end plates as one unit, and the two blocks at the front and rear which constitute each unit mentioned above. A liquid supply plate is sandwiched in between to introduce the stock solution into the liquid passage gap on both sides, and the plates of the front and rear blocks contact the membrane through the liquid passage gap and flow in one direction, allowing the liquid that has not passed through the membrane to pass through the liquid passage gap. Liquid passage ports for flowing in the opposite direction are provided alternately in the liquid passage gaps between adjacent plates, and the concentrated liquid that has flowed through the liquid passage gaps between the plates of each block and has not passed through the membrane is placed in the front. The first block is characterized in that the liquid is discharged from the liquid passage gap in the front end plate, and the latter block is discharged from the liquid passage gap in the rear end plate.

(Function) As a result, a liquid supply plate is interposed approximately in the middle of each unit, and the stock liquid is introduced into the liquid passage gaps on both the front and rear surfaces thereof, and flows in contact with the respective membranes. The stock solution that has flowed through the liquid passage gap at the front and has not passed through the membrane meanders forward through the liquid passage gaps between the facing plates of the front block while sequentially changing direction in one direction and then in the other direction. The stock solution that continues to flow but still does not pass through the membrane is discharged from the front plate as a concentrated solution. In addition, the stock solution that did not pass through the membrane after flowing through the liquid passage gap on the rear surface of the liquid supply plate snakes its way through the liquid passage gaps that are opposed to each other on the plates that make up the latter block, while sequentially changing its direction in one direction. The stock solution that flows backwards but still does not pass through the membrane is discharged from the plate at the rear end as a concentrated solution.

(Embodiment) In the illustrated embodiment, the same components as in the conventional example shown in FIGS. 16 and 17 are denoted by the same reference numerals.
Also, for convenience, this embodiment will be described with the front and back as left and right.

In FIG. 1, and indicate the front and rear blocks constituting one unit A, and the front and rear blocks constituting another unit B, and a liquid supply plate 6a is sandwiched between each of the front and rear blocks and and. , and between each unit A and B, that is, between the block after one unit A and the block before one unit B, a drain plate 6f is sandwiched, and these are connected to the fixed end plate 2 and the movable end plate 2. ′
Press between. The blocks in front of each unit A, B are a plate 6b in front of the liquid supply plate 6a,
6c...6e are stacked one after another, and the later blocks are similar plates 6b, 6c...6 after the liquid supply plate 6a.
e are stacked one on top of the other.

Although these six types of plates 6a, 6b, . . . , 6f may be manufactured individually, in this embodiment they are made from a basic plate 6' that can be transformed into the six types of plates with a slight processing.

Figures 3 and 4 show an example of the basic plate, which has a vertically long rectangular shape similar to the conventional example described above, and has upper partitions above the upper ends of the liquid collection parts 8 that cover the membranes 8' on both sides of the plate. A liquid supply port 16 is opened separated by a piece 15, and a liquid drain port 18 is similarly opened below the lower end, separated by a lower partition piece 17, and both ends are opened in the liquid collecting recesses 8, 8 on both sides of the plate. and the upper liquid passage hole 1 on the upper part.
9. Open a lower liquid passage hole 20 in the lower part.

Here, a concave surface 21 is provided above each upper partition piece 15 and below the lower partition piece 17 at the same level as the stepped surface on which the membrane 8' is applied, and the liquid supply port 16 and the liquid drain port 18 are provided in the concave surface 21. Although both ends are open, for example, the lower edge of the liquid supply port 16 may be placed along the upper edge of the upper partition piece 15, or the liquid drain port 18 may be placed along the lower edge of the lower partition piece 17.
The concave surface 21 can be omitted if the upper edge of the concave surface 21 is aligned.

Further, in order to facilitate removal of the upper and lower partition pieces 15 and 17, it is preferable that the thin fragile parts 15' and 17' be made of hard vinyl chloride or the like and integrally molded with the substrate 6'.

Figures 5 to 10 are front views of six types of boards made from the basic boards shown in Figures 3 and 4 above. The left half shows the left side of each board in Figure 1, and the right half shows the right side. X indicates a closed liquid passage hole.

As shown in FIG. 5, this liquid supply plate 6a has upper partition pieces 15 removed from both the left and right sides, and upper and lower liquid passage holes 1.
Block both 9 and 20. To close each liquid passage hole, as shown in Fig. 2, apply adhesive to a blind plate 22 or plug 23 that fits snugly into the hole, push it in, and fix it.
The membrane 8' has no holes at positions corresponding to the liquid passage holes.

For the plate 6b adjacent to the liquid supply plate 6a, only the upper partition piece on the left side facing the plate 6a is removed, and only the upper part 19 of the liquid passage hole is closed, and the lower part 20 is left open. To open the liquid passage holes, as shown in Figure 2, holes of the same size were made in the corresponding parts of the membrane on both sides, and adhesive was applied from the membrane hole into each liquid passage hole. The eyelet-shaped crimp 24 is pushed in and fixed to prevent the stock solution from leaking into the liquid collection recess through the membrane pores.

The plate 6b adjacent to the liquid supply plate 6a with the block may be formed in the same manner as described above, and its orientation may be reversed so that the surface with the upper partition piece cut away faces the liquid supply plate.

As a result, the raw liquid flowing through the series of liquid supply ports of each plate is transferred to the liquid supply plate 6a and the adjacent plate 6b of each block. liquid passage gap 9′,
9', the stock solution flows in a downward flow, and the solution that permeates through the membrane when it comes into contact with the membrane enters the liquid collecting recess 8 and is extracted from the extraction hole 12, and the stock solution that has not passed through is drained from both plates. Since the lower partition pieces 17 of the plates 6a and 6b face each other and close the lower end of the liquid collection section, they pass through the lower liquid passage hole 20 of the plate 6b. In FIG. 2, D indicates a state in which the upper or lower partition pieces face each other and close the upper or lower end of the liquid collecting section.

The plate 6c adjacent to the plate 6b closes only the lower liquid passage hole 20 as shown in FIG. 7, and the plate 6d adjacent to the plate 6c closes only the upper liquid passage hole 19 (the eighth
), the plate 6e adjacent to the plate 6d closes the lower liquid passage hole 20, and the lower partition piece 17 on the surface facing the plate 6f is removed (Fig. 9), and the liquid drainage plate 6
At f, the upper and lower liquid passage holes 19 and 20 are closed, and the lower partition pieces 17 on both the left and right sides are removed (FIG. 10).

As a result, the stock solution that has entered the lower liquid passage hole 20 of the plate 6b is transferred to the liquid passage gap 9' between the opposing plates 6b and 6c.
After flowing upward through 9′ and contacting the membrane, plate 6c
The liquid passes through the upper liquid passage hole 19 and flows downward through the opposed liquid passage gap between plates 6c and 6d, and then passes through the lower liquid passage hole 20 of plate 6d and flows upward through the opposed liquid passage gap between plates 6d and 6e. The liquid flows counter-currently through the upper liquid passage hole of the plate 6e, and flows downward through the liquid passage gap of the plate 6e facing the end plates 2 and 2' with the block, and the liquid flows through the liquid passage between the opposite plates 6e and 6f with the block. The concentrated liquid flowing downward through the gap and thus not passing through the membrane is collected by a lower partition piece 17 that closes the lower end of the liquid passage gap.
Since there is no drain, the liquid flows into a series of drain ports 18 and is discharged.

In short, the liquid is supplied in a downward flow between both surfaces of the liquid supply plate 6e located between one unit A made up of the blocks and one unit B made up of the blocks, and the opposing surface of the adjacent plate 6b. In the first block, solid-liquid separation is performed by moving the stock solution toward the fixed end plate, and in the second block, moving the stock solution in a meandering manner in the vertical direction. By increasing or decreasing the number of blocks, it is possible to arbitrarily determine the number of boards to be used in each block, or even in each unit.

The plate has an upper liquid passage port 16, a liquid collection part 8, and a lower liquid passage hole 18 formed on each side in the shape of a table of contents as shown in Figures 3 and 4. A central vertical beam 25 provided integrally with the partition pieces 15 and 17 of
A plurality of them may be formed, such as two on both sides of the partition.

In addition, as shown in FIGS. 13, 14, and 15, partition pieces 15 and 17 are provided to surround the liquid supply port 16 and liquid drain port 18, and liquid passage holes 19 and 20 are provided in the liquid collection recess 8.
It may be provided between the liquid supply port 16 and the liquid drain port 18. In this case, when cutting out the partition piece, it is only necessary to cut out only the liquid collecting recess side without cutting off the partition piece entirely.

In addition, gasket 2 seals between the opposing plates.
6 is provided by adhesive or the like only on the peripheral edge of one side of each plate, so that when stacked one on top of the other, the side of the opposing plate that does not have a gasket will come into contact with the gasket.

Further, the above-mentioned partition pieces 15, 17, liquid supply port 16, and liquid drain port 18 are designed to be cut out or closed at necessary locations, but when integrally molding the substrate 6' by injection molding, Then, a core may be placed in the cut or closed part and molded to obtain the several types of plates mentioned above. In that case, it is convenient because machining for excision or operation for occlusion can be omitted.

Extraction holes 12 for extracting the liquid obtained in the liquid collection recess 8 after passing through the membranes on both the front and rear surfaces of each plate 6a, 6b...6f are provided independently for each liquid collection recess on the front and rear surfaces. Alternatively, it may be provided in a T-shape with respect to a communication hole that communicates both the liquid collection recesses on the front and rear surfaces.

Although it does not matter if the extraction holes 12 are provided individually in each of the liquid collection recesses on the front and rear surfaces, the extraction holes 12 are provided in a T-shape with respect to the communication hole that communicates both the liquid collection recesses on the front and rear surfaces.
In the case where the liquid supply plate 6a and the liquid drainage plate 6f are provided with respective membranes 8'...
...Since the water pressure of the stock solution applied to 8' becomes even, the membrane will not be damaged or peeled off. This is the same for the other plates 6b...6e, as the difference between the water pressure of the undiluted solution flowing in contact with the front membrane and the water pressure of the undiluted solution flowing in contact with the rear membrane is small. Even if the liquid collection recesses communicate with each other through the extraction hole 12, the membrane will not be damaged or peeled off.

(Effects of the Invention) In the flat membrane device of the present invention, the stock solution passes through the liquid passage gap between the plurality of opposing plates of the front and rear blocks constituting one unit, sequentially in a forward direction in the front block and in a backward direction in the rear block. Since it flows in contact with the membrane while meandering, if the amount of stock solution to obtain the required flow rate through the liquid passage gap of one plate is Q as described above, then the number of plates in each block before and after is Regardless, it will be Q x (twice one unit).

Therefore, for example, in the conventional example, if 10 plates constitute each block before and after, and one unit is 2, the required amount of stock solution is Q x 10 (number of plates making up 1 block).
In contrast, in the present invention, the number of units is Q x 4 (twice the number of units 2), so a pump with a much smaller capacity can be used while using the same 40 plates, and the equipment cost and running cost are low. It's over.

Furthermore, since the stock solution flows in a meandering manner through the liquid passage gaps in the block, the amount of stock solution flowing through the downstream liquid passage gaps is smaller than that of the upstream liquid passage gaps, but the flow rate is Since it is almost constant, the membranes of the upstream plate and the downstream plate are less likely to be clogged with solids in the liquid.

Also, to supply the stock solution to the front and rear blocks of each unit and to discharge the concentrated solution, the stock solution comes in contact with the membrane and flows through the plate, and no partition plate is used at all because it does not have an overactive effect. Therefore, since there is no partition plate, the number of plates to be pressed between the fixed and movable end plates is reduced, and the number of cleaning steps can be reduced accordingly.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of one embodiment of the flat membrane device of the present invention, FIG. 2 is an enlarged cross-sectional view of the part surrounded by the line in FIG. 1, and FIG. 3 is various types of the flat membrane device of FIG. Figure 4 is a cross-sectional view taken along the - line in Figure 3, and Figures 5 to 10 are the respective plates used in the flat membrane device in Figure 1. Figure 11 is a front view of the second example of the basic board, and Figure 11 is a front view of the second example of the basic board.
Figure 2 is a step view taken along line A-B in Figure 11, Figure 13 is a front view of another example of the basic board, and Figure 14 is a step view taken along the line A-B in Figure 11.
3, FIG. 15 is a sectional view taken along line C-D in FIG. 13, FIG. 16 is a side view of the entire conventional device, and FIG. 17 is a sectional view of FIG. 16. This is an enlarged cross-sectional view of a portion of the figure. In the figure, 2 is a fixed end plate, 2' is a movable end plate,
6a is a liquid supply plate, 6b...6e is a plate, 8' is a membrane, 9 is a liquid collection part of the plate, 9' is a liquid passage gap, 16
is the liquid supply port, 18 is the liquid drain port, 19 and 20 are the liquid passage ports,
A and B each represent one unit, ``A'' and ``B'' respectively refer to blocks before and after forming one unit A, and `A and B' indicate blocks before and after forming one unit B.

Claims (1)

[Scope of Claims] 1. A block consisting of a liquid collection part with a membrane stretched thereon, and a plurality of plates having liquid passage gaps on both sides of the membrane surface, stacked one on top of the other in the front and back direction, facing each other at the liquid passage gap. A plurality of blocks are compressed in a line between the front and rear end plates, and the stock solution is allowed to flow through the liquid passage gap between the plates of each block in contact with the membrane, thereby separating the stock solution into the liquid that permeates through the membrane and the concentrated liquid that does not permeate. In the flat membrane device, the two blocks adjacent to the front and rear of the above block are considered as one unit, and a liquid supply plate is provided between the front and back two blocks constituting each unit to introduce the stock solution into the liquid passage gap on both sides. Sandwiched between the front and rear plates of each block, there is a liquid passage gap in which the liquid flows in one direction by contacting the membrane, and the stock solution that has not passed through the membrane flows in the opposite direction into the liquid passage gap between the adjacent plates. The liquid passage ports are arranged alternately, and the concentrated liquid that has flowed through the liquid passage gap between the plates of each block and has not passed through the membrane is passed through the liquid passage gap of the front end plate in the front block, and the rear one in the later block. A flat membrane device characterized in that liquid is discharged from a gap in an end plate. 2. The flat membrane device according to claim 1, in which a liquid drainage plate is sandwiched between each unit for draining the stock liquid from the liquid passage gaps on both sides.