JPH0355173B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention comprises a liquid collection section in which a membrane such as a UF membrane or an RO membrane is stretched, and a plate having a liquid passage gap on the surface of the membrane. A block consisting of a plurality of blocks stacked in a row in the front and rear direction facing each other was pressed between the front and rear end plates, and the stock solution was allowed to pass through the membrane by flowing into the liquid passage gap of the plates in contact with the membrane. for separating the liquid and the concentrated liquid that does not permeate.
This invention relates to a flat membrane device that performs solid-liquid separation using an operation similar to that of a filter press.

(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. Plate 2'; one or more partition plates 5, here three partition plates...
...and; Suspend a plurality of plates 6... placed between the fixed end plate 2 and the partition plate, between the partition plates, and between the partition plate and the movable end plate, for example, between the fixed end plate 2 and the movable end plate. By tightening the nut 7' of the bolt 7 passed between the plates 2', a block consisting of the partition plate 5 and a plurality of plates 6 is compressed between the end plates 2 and 2'.

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 on 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 is A device having an upper relay port 10' communicating with the upper liquid passage port 10 is used, and the movable end plate 2' is provided with a liquid drain port 14 communicating with the upper liquid passage port 10 of the fourth block.

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 collection recesses 8 are discharged from the respective extraction holes 12, and the stock liquids that have not passed through the membrane are 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 through the liquid passage gaps 9' of all the plates of the second block, and then flows upward. At this time, the liquid that permeates through the membrane and is obtained in the liquid collecting recess is discharged to the outside of 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 intermediate 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 contacts the membrane in each liquid passage gap of the previous stage block and flows upward (or downward) flows through the liquid passage gap of the next stage block, contacts 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 provides a liquid passage gap in each plate that is pinched between the front and rear end plates to form a block so that the liquid flows in one direction in contact with the membrane and permeates through the membrane. The present invention is characterized by alternately providing guide ports for causing the drained stock solution to flow in the opposite direction to the liquid passage gaps of adjacent plates.

(Function) As a result, the liquid flows in one direction through the liquid passage gap of the plates constituting the block in contact with the membrane, and the stock solution that has not passed through the membrane passes through the inlet in one plate.
The liquid is guided to the liquid passage gap of the adjacent plate, and then flows through this liquid passage gap in the other direction in the opposite direction, in contact with the membrane.
In this way, the liquid sequentially changes direction in one direction and then the other direction and flows in a meandering manner through the liquid passage gaps of all the plates constituting the block.

(Embodiment) In each of the illustrated embodiments, the same components as in the conventional example shown in FIGS. 16 and 17 are denoted by the same reference numerals.
In addition, in each example, among the plurality of boards constituting the block, . I will explain.

In the first embodiment shown in FIGS. 1 to 7, the odd-numbered plates 6- have lower inlet ports 15, which correspond to the lower liquid passage ports 11 of the conventional plate, on the step where the membrane 8' is stretched, and the even-numbered plates 6- The plate 6- has an upper guide port 16 corresponding to the upper liquid passage port 10 of the conventional plate in the step where the membrane 8' is stretched.

When the plates 6- and 6- are alternately stacked and pressed in a line in the front-rear direction to form a block, etc., the lower guide port 15 of the plate 6- is the liquid collection part of the adjacent even-numbered plate 6-. Similarly, the upper guide port of the plate 6- faces above the liquid collection portion 9 of the adjacent odd-numbered plate 6- with a liquid passage gap 9' in between.

In this embodiment, the fixed end plate 2 and each partition plate 5 are connected to the left end plate 6- of each block, .
A supply hole 17 for supplying the stock solution is provided above the liquid passage gap 9' on the left side of the block, and a liquid passage gap 9' on the right side of the right end plate of each block is provided in the movable end plate 2' and each partition plate 5.
Discharge hole 1 for discharging unfiltered concentrate from the
A flexible hose 1 is provided between the header pipe 19 for the stock solution that leads the stock solution from the pump and each supply hole 17, and between the header pipe 20 that leads the concentrated water and each discharge hole 18, respectively.
Connect with 9'..., 20'... The purpose of connecting with a flexible hose was to allow the cloth to be washed by interrupting operation and releasing the pressure between the end plates to maintain the distance between the plates.

As a result, when the stock solution is supplied to each block, . . . through the header pipe 19, the stock solution is supplied to the fixed end plate,
The leftmost board 6- of each block facing the partition board
After flowing downward through the liquid passage gap 9' on the left side of the plate, it passes through the lower guide port 15, and flows through the liquid passage gap on the right side of this plate and the liquid passage gap on the left side of the second plate 6- opposite thereto. It flows upward, passes through the upper guide port 16 of the second plate, and then flows downward.

In this way, the liquid flows alternately downward and upward through the gaps between the plates of each block while contacting the membrane.
The liquid (flux) F that has passed through the membrane 8' and obtained in the liquid collecting recess 8 is discharged to the outside of each plate through the extraction port 12, and finally flows through the liquid passage gap 9' on the right side of the rightmost plate of the block. The concentrated water is discharged into the header pipe 20 through the discharge hole 18.

The difference between the second embodiment shown in FIG. 8 and the first embodiment described above is that the liquid supply hole 17 provided in the fixed end plate 2 is provided in an auxiliary plate 21 sandwiched between the fixed end plate and the left end plate of the block. , drain hole 18 provided in the movable end plate 2'
is provided on the auxiliary plate 22 sandwiched between the movable end plate and the right end plate of the block.

Further, in the embodiment shown in FIG. 9, every other partition plate 5-
An inverted T-shaped liquid supply hole 17 is provided in order to supply the stock solution to the left and right blocks, and the partition plate 5- located between the partition plates 5- is provided with the left and right blocks and the upper and lower blocks. A T-shaped drain hole 18 is provided to drain the concentrated liquid that flows in a meandering direction and does not pass through the membrane. The concentrated water is discharged from the left side of the plate at the left end of the block and the liquid passage gap through the liquid drainage hole provided in the fixed end plate 2, and from the liquid passage gap on the right side of the right side plate of the block opposite to the movable end plate. Concentrated water is discharged from drain holes provided in the movable end plates, but the partition plate 5 of the first embodiment and the auxiliary plate 22 of the second embodiment are used without providing drain holes in each end plate. It may be used and discharged.

In this embodiment, the same plates 6- and 6- as used in the first embodiment can be used, and in the even-numbered blocks, the plates 6- and 6- are alternately stacked in the same arrangement, but in the odd-numbered blocks, Liquid supply hole 1
Based on the partition plate 5- having the number 7, the odd-numbered plates counting from the partition plate to the right are numbered 6-, and the even-numbered plates are numbered 6-.

In this embodiment, one partition plate is used to supply stock solution to the left and right blocks, and to extract concentrated water from the left and right blocks, so the number of flexible hoses used to connect each header pipe 19, 20 and the partition plate is reduced. Reduce by half.

The embodiment shown in FIGS. 10 to 15 is also similar to the first embodiment, but in this embodiment, each plate 6-, 6-
A continuous liquid passage port 23 for the stock solution and a continuous liquid passage port 24 for the concentrated liquid are provided at the upper and lower parts of the peripheral edge formed by the gasket.

Therefore, correspondingly, communication ports 25 and 26 are provided in each partition plate 5 to communicate with the upper and lower liquid passage ports 23 and 24, and the upper communication port 25 is connected to the left end plate of each block. Notch 25' for supplying the stock solution to the liquid passage gap 9' on the left side of 6-, the lower communication port 2
6 is provided with a notch 26' for introducing concentrated water from the liquid passage gap on the right side of the right end plate of each block, and
The fixed end plate 2 has communication ports 27 and 28 that are connected to the upper and lower liquid passage ports 23 and 24, and a notch 27' that supplies the stock solution from the communication port 27 to the liquid passage gap on the left side of the left end plate of the left end block. The movable end plate 2' is provided with a recess 29 that is connected to the lower liquid passage port 24 and that allows concentrated water to be taken in from the liquid passage gap on the right side of the right end plate of the right end block.

This allows the stock solution supply pipe 30 from the pump to be connected to the communication port 27 on the fixed end plate, and the concentrated water take-out pipe 31
If you connect it to the connection port 28 below, each block,
Liquid passage port 23 on all plates 6-, 6- of...
Comrade 24 and Comrade 24 are communication ports 25 and 2 of partition plate 5, respectively.
6, and the notch 27' of the fixed end plate,
From the notch 25' of each partition plate 5, each block,
The stock solution is supplied to the liquid passage gap on the left side of the left end plate 6-, and the liquid passage gap between the opposing plates in each block is meandered in the vertical direction to perform filtration, and the concentrated water is passed through each partition plate. The liquid can flow through the notch 26' and the recess 29 of the movable end plate 2' to the liquid passage port 24, and can be taken out to the extraction pipe 31 connected to the fixed end plate.

In this embodiment, the header pipes 19 and 20 for undiluted solution and concentrated water as in the first embodiment are connected to flexible hoses 19' and 2.
0' eliminates the need to connect to the partition plate.

In each of the embodiments described above, the stock solution is supplied in a downward flow to the first liquid passage gap of the block, but the stock solution is not limited to this and may be supplied in an upward flow.

Further, the tightening for pressing the movable end plate 2' toward the fixed end plate 2 is not limited to bolts and nuts 7, 7', and may be performed using a piston-cylinder type jack using fluid pressure.

(Effect of the invention) In this invention, the stock solution flows in contact with the membrane while meandering sequentially through the liquid passage gap between a plurality of opposing plates constituting one block. Assuming that the amount of the stock solution flowing through the liquid passage gap to obtain the required flow rate is Q, the formula is Q x the number of blocks, regardless of the number of plates constituting one block.

Therefore, for example, in the conventional example, if 10 plates constitute one block and the number of blocks is 4, the required amount of stock solution is Q x 10 (number of plates constituting one block).
In contrast, in the present invention, Q×1 (number of blocks)
This means that while using the same 40 plates, a pump with a much smaller capacity can be used, resulting in lower equipment and running costs.

Furthermore, since the stock solution flows in a meandering manner through the liquid passage gaps in the block, the flow rate of the stock solution flowing through the liquid passage gaps on the downstream side decreases compared to the liquid passage gaps on the upstream side, but the flow rate is almost the same. Because it is constant, both the upstream plate membrane and the downstream plate membrane are less likely to be clogged with solids in the liquid.

[Brief explanation of drawings]

Figures 1 to 7 are the first embodiment of the present invention; Figure 1 is a schematic explanatory diagram showing the overall cross section; Figures 2 and 3, and Figures 4 and 5 are used for Figure 1. A front view and a sectional view of the two types of plates; FIGS. 6 and 7 are a front view and a sectional view of the partition plate used in FIG. 1; FIG. FIG. 9 is a schematic explanatory diagram with some parts omitted; FIG. 9 is a schematic explanatory diagram with some parts omitted; FIG.
Figures 10 to 15 show still another embodiment of the present invention.
The figure is a schematic diagram showing the overall cross section; Figures 11 and 12 are front views of the two types of plates used in Figure 10; Figures 13 and 14 are the partition plates used in Figure 10. 15 is an enlarged sectional view of a portion of FIG. 10; FIG. 16 is a side view of the entire conventional device; FIG. 17 is an enlarged sectional view of a portion of FIG. 16; In the figure, 2 is a fixed end plate, 2' is a movable end plate, and 5
is a partition plate, 6-, 6- is a plate, 8' is a membrane,
9 is the liquid collection part of the plate, 9' is the liquid passage gap, 15 and 16
indicates a guide port, and ,,, indicates a block made of multiple plates.

Claims (1)

[Scope of Claims] 1. A block consisting of a liquid collection part with a membrane stretched thereon, and a plurality of plates stacked in a row in the front-rear direction with the plates facing each other across the liquid passage gap. In a flat membrane device that separates the stock solution into a liquid that has passed through the membrane and a concentrated liquid that has not permeated by applying pressure between front and rear end plates and flowing the stock solution in contact with the membrane through the liquid passage gap between the plates; Each plate constituting the block is provided with a guide port for flowing in one direction through the liquid passage gap in contact with the membrane, and allowing the stock solution that has not passed through the membrane to flow in the opposite direction through the liquid passage gap in the adjacent plate. A flat membrane device characterized by being provided in alternating patterns. 2. The flat membrane device according to claim 1, wherein the block is constructed between an end plate and a partition plate or between a partition plate and a partition plate. 3. In the flat membrane device according to claim 1 or 2, each block includes a liquid supply means for supplying the stock solution to the first liquid passage gap, and a drain for discharging the concentrated liquid from the last liquid passage gap. Flat membrane device equipped with liquid means. 4. The flat membrane device according to claim 2 or 3, in which the undiluted solution supply means or the concentrated solution drain means is provided on the end plate or the partition plate. 5. A flat membrane device according to any one of claims 1 to 4, in which each plate is provided with a liquid passage port for configuring a stock solution supply system or a concentrated solution discharge system. .