JPH084721B2 - Flat membrane device - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention is directed to a liquid collecting part having membranes such as UF membrane and RO membrane stretched on both sides, upper and lower liquid passage openings, and an upper end. A plate having an upper liquid passage opening and a lower end connected to the lower liquid passage opening and having a liquid passage gap through which the liquid can flow vertically on the surface of the membrane, facing each other in the liquid passage gap. A plurality of blocks are formed by stacking a plurality of them in the same direction, and a first partition plate having a lower relay port communicating with the lower end of the liquid passage gap of the plate between the blocks and the upper end of the liquid passage gap. Alternately sandwich the second partition plate having an upper relay port that communicates with each other, and press in a row by the front and rear end plates to separate the partition plates and place the undiluted solution in the facing liquid passage gap of the plate of one adjacent block. Flow in contact with the membrane in countercurrent (or downward flow),
Repeatedly flowing the undiluted undiluted solution through the upper (or lower) relay port of the partition plate into the opposed liquid passage gaps of the plate of the other block in a downward flow (or upward flow) in contact with the membrane, The present invention relates to a flat sheet membrane device that separates a stock solution into a solution that has permeated a membrane and a concentrated solution that does not permeate.

(Prior Art) Such a flat membrane device is known from Japanese Patent Publication No. 52-10113. As shown in FIGS. 4 to 6, this conventional device has one movable end movably along a horizontal support member 4 provided between a fixed end plate 2 and a fixed support plate 3 opposed to each other on a bed 1. Board 2 '
And one or more, here three partition plates 5a, 5a, 5b
And a plurality of plates 6 ... Suspended respectively, which are located between the fixed end plate 2 and the partition plate 5a, between the partition plates 5a and 5b, and between the partition plate 5a and the movable end plate 2 '. For example, a block I consisting of a partition plate 5 ... And a plate 6 addressed to a plurality of sheets at both end plates 2 and 2'by tightening a bolt 7 passed between the fixed end plate 2 and the movable end plate 2'with a nut 7 '. … Clamp the IV.

A front plate-shaped liquid collecting recess 8 is formed on the front and rear surfaces of each plate 6 inside the peripheral edge portion made of a gasket, and a film 8 covering the peripheral liquid recess 8 is formed on the entire circumference of the first stage. ′ Is stretched to form the liquid collecting portion 9, and liquid passage ports 10 and 11 are opened at the upper and lower portions of this stage, respectively, and addressed to a plurality of sheets constituting each block I, II, III, IV. The upper liquid passage 10 and the lower liquid passage 11 of the plate 6 are connected in series with each other through the liquid passage gaps 9'between the opposed plates. Then, each plate 6 has an extraction hole 12 through which the liquid obtained in the liquid collection recess 8 through the membrane 8'is extracted from the periphery of the plate.

In order to carry out the separation, the stock solution is pumped to the liquid supply port 13 communicating with the upper liquid flow port 10 of the first block I on the fixed end plate 2, and between the first block I and the second block II. Each first partition plate 5a between the third block III and the fourth block IV
Is the lower relay port 11 'communicating with the lower liquid passage port 11 of each block.
And the second partition plate 5b between the second block II and the third block III has an upper relay port 10 'communicating with the upper liquid passage port 10 and a movable end. The plate 2'is provided with an outlet 14 which communicates with the upper liquid passage 10 of the fourth block IV.

As a result, the stock solution supplied from the liquid supply port 13 of the fixed end plate 2 to the upper liquid passage port 10 connected in series in the first block is
The liquid flows in a downward flow by coming into contact with the membrane in the liquid passage gap 9'of all the ribs of the block, and at that time, the liquids that have permeated the membrane and obtained in the liquid collecting recesses 8 are discharged from the discharge holes 12, respectively. The undiluted solution that did not permeate the membrane passed from the lower liquid passage port 11 of the first block to the lower liquid passage port 11 connected to the series of the second block through the lower relay port 11 'of the partition plate between the second block and the second block. The liquid flows in, contacts the membrane in the liquid passage gaps 9'of all the plates of the second block, and then flows in an upward flow. At this time, the liquid that has passed through the membrane and obtained in the liquid collecting recesses is a discharge hole. The undiluted solution that was discharged to the outside of the plate at 12 and did not permeate passes through the upper relay port 10 'of the partition plate between the upper block liquid passage port of the second block and the third block, and the series of upper liquid pipettes of the third block. It flows into the mouth 10 and, in turn, in a downward flow in contact with the membrane in the liquid passage gaps 9'of all the plates of the third block.

In this way, the liquid flowing in the upward flow (or downward flow) in contact with the membrane in each liquid passage gap of the preceding block comes into contact with the membrane in the liquid passage gap of the next block and flows in the opposite direction. Flow in a downward flow (or upward flow), thus repeating meandering flow in each block, and in the final stage, in this case, flowing in contact with the membrane in the liquid passage gap of the fourth block. The concentrated liquid that has not permeated the membrane is discharged from the liquid discharge port 14 of the movable end plate.

By the way, such a flat membrane device is often used for wastewater treatment, food production process, etc., once a week for wastewater treatment, and daily for food production,
It was necessary to perform an open frame work to separate a large number of laminated plates into one sheet, to physically wash the plates by spraying cleaning water, and to perform a reassembly work to pinch the laminated plates again after cleaning. .

It is because undiluted liquid or concentrated liquid remains in the liquid passage gap between the plates in the device when the operation is stopped, and the liquid decomposes or deteriorates.
This is because the membrane is clogged and the function is deteriorated.

(Problems to be solved by the invention) Therefore, as shown in FIG. 4, after the operation is stopped, the stock solution supply port 13 is supplied with the stock solution in the stock solution tank 15 which has been supplied until then as the cleaning solution in the cleaning tank 16. It is switched to supply with a pump, and this cleaning solution is used to push out the undiluted solution and concentrated solution remaining in the equipment from the drain port 14, but in this case, a very large amount of cleaning water is required and cleaning is performed with a chemical solution. If you do, the usage fee for the chemicals will increase. Further, in the block where the undiluted solution flows upward in the liquid passing gaps of the plates, an air pool is generated in the upper part, which is blocked by the air and cannot be completely washed with water or a chemical solution.

(Means for Solving Problems) Therefore, the present invention provides a first partition plate having a lower relay port for alternately partitioning blocks of a plate and a lower partition port of a second partition plate having an upper relay port. The first partition plate has a liquid draining means whose upper end communicates with the lower relay port, a ventilation means communicating with the upper liquid passage of the plate of the block that causes the raw liquid to flow downward in the liquid passage gap of the opposing plate, and a cleaning liquid. It is characterized in that the supply means is provided via an on-off valve, respectively.

(Embodiment) In the embodiment shown in FIG. 1, constituent elements having the same functions as those of the conventional example described above are designated by the same reference numerals.

The plates 6 for a plurality of sheets are knitted into four blocks I, II, III, IV in the same manner as in the conventional example with the first and second partition plates 5a, 5b sandwiched therebetween, and thus, in the same manner as in the conventional example. The stock solution is separated into a solution and a concentrated solution, the concentrated solution is returned to the stock solution tank 15, diluted and circulated, and the solution is supplied to the cleaning solution tank 16 as necessary.

The first partition plate 5a for partitioning between the first block and the second block and between the third block and the fourth block serves as a liquid draining means whose upper end communicates with the lower relay port 11 'according to the present invention.
And the first block and the third block in which the undiluted liquid flows in contact with the membrane in a downward flow in the liquid passage gaps facing each other.
A ventilation pipe 19 as a ventilation means communicating with the upper liquid passage 10 of the block plate, and a cleaning liquid supply pipe as a cleaning liquid supply means.
20 is mounted upward. Valves 18 ', 19', 20 'for opening and closing the pipes 18, 19, 20 are provided for one of the pipes like the vent pipe 19. In addition, the pipes 19 and 20 may be provided with a recess 21 facing the upper liquid passage port 10 of the plate as shown in the drawing on the upper part of the first partition plate, and may be mounted so that the lower end is opened in the recess 21.

As a result, when the valve 18 'of the discharge pipe 18 and the valve 19' of the ventilation pipe 19 are opened when the operation is stopped, the inside of the device is communicated with the atmosphere by the ventilation pipe 19, so that the liquid passage gap between the first block and the second block and The stock solution in the series of lower liquid passage ports 11 is discharged from the discharge pipe 18 of the first partition plate 5a between the blocks I and II, the liquid passage gap between the third block and the fourth block, and the series of lower liquid passages. The stock solution in the mouth can be discharged from the discharge pipe 18 of the first partition plate 5a between the blocks III and IV, respectively.

Then, the valve 20 'is opened to supply the cleaning liquid from the cleaning liquid tank 16 into the apparatus through the cleaning liquid supply pipe 20. The cleaning liquid tank 16 may be installed above the device and supplied by a drop or by a pump.

The cleaning wastewater is discharged from the discharge pipe 18.

Then, the valve 18 'of the discharge pipe 18 is closed, the flush water is filled into the apparatus, and then the valves 19' and 20 'are closed. As a result, when the cleaning liquid is water, the operation can be restarted.

Further, when cleaning is performed with a cleaning solution in which a chemical solution, for example, NaOH is dissolved in a predetermined concentration, the above operation is repeated, for example, three times. That is, it is sufficient to first wash with water, then with a chemical solution, and finally with water, and then restart the operation.

The discharge tube 18 'and the vent valve 19' can also be opened automatically in connection with the shut-down of the pump 17.

In addition, a hose 12 'is connected to the outlet 12 of each plate, and a part or all of the above hoses are plural or one collective pipe.
It is also possible to connect to 22 and to provide an on-off valve 22 'on this collecting pipe 22 and open this on-off valve 22' so that the liquid obtained on each plate merges with the collecting pipe and flows. In this case, when the operation of the pump 17 is stopped, the above-mentioned on-off valve 22 'is opened in addition to the valve 18' of the discharge pipe and the valve 19 'of the ventilation pipe so that the liquid flows to the collecting pipe 22 to collect the liquid of the plate. Make sure that the cleaning solution also flows on the part side.
This allows cleaning of the surface and inside of the membrane.

Further, a rising pipe 23 whose upper end reaches the upper end of the device is connected in parallel with the on-off valve 22 'to the collecting pipe 22,
If the connecting pipe 22 is connected in front of it by the connecting pipe 24 having an opening / closing valve 24 'in front of the valve 18' of the discharge pipe 18, the cleaning liquid fills the liquid collecting part, so that it is possible to clean the upper part of the device that could not be cleaned conventionally. Can be increased.

 Sludge separation of activated sludge was performed using the apparatus of FIG.

 The undiluted MLSS is approximately 20000 mg /.

The total area of the membranes on both sides of the plate is about 0.3 m ² , and 30 plates are divided into 6 blocks with 5 plates, and the first and second blocks, the third and fourth blocks, and the fifth and sixth blocks between the blocks. The first partition plate 5a is sandwiched between the second and third blocks, the second partition plate 5b is located between the fourth and fifth blocks, and the entire partition plate is clamped between the fixed end plate and the movable end plate. The operation was performed at an inlet pressure of 2.8 kg / cm ² entering and a flow rate of 1.5 m / s at which the stock solution flows in contact with the membrane.

Conventionally, while operating under similar conditions, if the operation was interrupted for 1 hour and restarted, SS would adhere to the membrane in a cake shape, which could only be operated after opening the frame, cleaning, and reassembling. Even if the operation was stopped, the washing was performed, and the operation was restarted 1 hour later, the operation could be performed at the raw water inlet pressure of 2.8 kg / cm ² .

Further, when cleaning is performed by the conventional method, since the volume of the pipe and the apparatus is about 300, the cleaning liquid requires at least 300, but according to the present invention, the volume of the pipe and the apparatus is about 30, so the cleaning solution is The required amount of 30 is about 1/10.

(Effect of the Invention) According to the present invention, the amount of the cleaning liquid used is small, and the upper end of the apparatus can be completely cleaned with the cleaning liquid.

Therefore, even with a stock solution containing a high concentration of SS, it is possible to recover the membrane separation ability by performing cleaning with a cleaning solution, and thus it is possible to reduce the number of physical cleaning operations involving a troublesome open frame work.

[Brief description of drawings]

1 is a schematic sectional view showing an embodiment of the present invention, FIG. 2 is a front view of a first partition plate used in the apparatus of FIG. 1, FIG. 3 is a sectional view of FIG. 2, and FIG. Is a side view of a conventional flat sheet membrane apparatus, FIG. 5 is an enlarged cross-sectional view of the main part of the apparatus of FIG. 4, and FIG.
FIG. 2 is a front view of a plate used in the apparatus shown in the figure, in which 2 is a fixed end plate, 2'is a movable end plate, 5a is a first partition plate, 5b is a second partition plate, 6 is a plate, and 8 is a liquid collecting plate. Recessed portion, 8'membrane, 9 liquid collecting portion, 9'liquid passing gap, 10 lower liquid inlet of plate, 10 'lower liquid inlet of first partition plate, 11 upper liquid inlet of plate , 13 is a liquid supply port, 14 is a liquid discharge port, 18 is a discharge pipe, 18 'is its valve, 19 is a vent pipe, 19' is its valve, 20 is a cleaning liquid supply pipe, and 20 'is its valve.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeki Kayoshi 3-4-7 Nishishinjuku, Shinjuku-ku, Tokyo Kurita Industry Co., Ltd. (72) Kensuke Matsui 3-4-7 Nishishinjuku, Shinjuku-ku, Tokyo Kurita Kogyo Co., Ltd. (72) Inventor Takero Misaki 3-4-7 Nishishinjuku, Shinjuku-ku, Tokyo Kurita Kogyo Co., Ltd. (72) Hideo Komune 3-4-7 Nishishinjuku, Shinjuku-ku, Tokyo Kurita Within Kogyo Co., Ltd. (56) Reference JP 61-141992 (JP, A) JP 62-227405 (JP, A) JP 49-44363 (JP, A) Actual development JP 62-48402 (JP , U)

Claims (1)

[Claims] 1. A liquid collection part having membranes stretched on both sides, upper and lower liquid passages provided above and below the liquid collection part, an upper end is the upper liquid passage, and a lower end is the lower liquid passage. A plurality of blocks are formed by stacking a plurality of liquids having a liquid passage gap that allows the liquid to flow vertically on the surface of the membrane, facing each other in the liquid passage gap in the front-rear direction. A first partition plate having a lower relay port communicating with the lower end of the liquid passage gap and a second partition plate having an upper relay port communicating with the upper end of the liquid passage gap are alternately sandwiched between the blocks. With the front and rear end plates, the plates are pinched in a line, and the stock solution is made to come into contact with the membrane in an upward flow (or a downward flow) into the facing liquid passage gap of the liquid in one of the blocks adjacent to each other by separating the above partition plates. , The undiluted stock solution passed through the upper (or lower) relay port of the partition plate, and passed through the plate of the other block facing each other. A flat membrane device for separating a stock solution into a liquid that has permeated through the membrane and a concentrated liquid that does not permeate by repeating a flow in a gap by contacting the membrane with a downward flow (or an upward flow), and having the lower relay port. The first partition plate has a liquid draining device whose upper end communicates with the lower relay port, a venting device which communicates with the upper liquid passing port of the plate of the block which causes the raw liquid to flow downward in the liquid passing gap facing each other, and the cleaning liquid supply A flat membrane device, characterized in that each means is provided via an on-off valve.