JPS6041505A - Liquid separator - Google Patents

Abstract

PURPOSE:To obtain stably a high-purity permeated liquid for many hours when used at high temps. and pressure by specifying the relation between the yarn density of woven fabric as a base material for supporting a semipermeable membrane and the yarn density of woven and knitted fabric as a passage material. CONSTITUTION:The semipermeable membranes 17 and 17' are formed on base materials 25 and 25', and the base materials 25 and 25' are placed on each other at a position to hold a passage material 24 in between from both sides. The passage material 24 is provided with ribs having suitable height, and a permeated liquid flows through the clearance as a passage 23 formed by the grooves between the ribs and the base material 25. The base material 25 and 25' are formed of woven fabric A and the passage material 24 of woven and knitted fabric B. The relation between the yarn density Nb (number/25mm.) of the woven and knitted fabric B in the direction of the woven and knitted fabric B vertical to the direction of the passage 23 and the yarn density Na (number/25mm.) of the woven fabric A in the same direction is regulated to Nb<=Na-13 or Na+8<=Nb. The yarn density Na of the woven fabric A as a basis is regulated to about 60- 80/25mm..

Description

[Detailed description of the invention] C Technical component of the present invention yf] The present invention relates to a liquid separation device using a semipermeable membrane.

More specifically, the present invention relates to the flow path through which a permeated liquid passes in a liquid separation device using a reverse osmosis membrane and the structure of a base material that holds a semipermeable membrane.

[Prior art and its problems]

Conventionally, a liquid separation device using the reverse osmosis method consists of forming two semipermeable membranes into an envelope shape, communicating the open end of the envelope with the hollow part of a hollow shaft tube, and wrapping the envelope around the hollow shaft tube. The interstitial fluid fills the inside of the envelope.

There is a so-called spiral type that has a structure in which the undiluted solution flows around the outside of the envelope.

This liquid separation device passes a high-pressure stock solution that is higher than the reverse osmosis pressure of the membrane through the outside of the envelope, and the permeate that has passed through the membrane is taken out through the inside of the envelope. Because the pressure is applied, it crushes the channel material inserted as a flow path for the permeated liquid, impairing the flow of the liquid, so generally speaking, even if the outside of the envelope is pressurized, the flow of the permeated liquid will be suppressed. In order to prevent the channel material forming the channel from being crushed, the channel material itself is made rigid so that it can withstand deformation.

The material used for this channel material was woven fabric.

Porous fabrics such as knitted fabrics with fine grooves extending inside them were used, especially fabrics with grooves on the surface. These fabrics were impregnated with melamine resin to make them rigid so that they would not easily deform due to the pressure applied to the raw solution through the membrane. On the other hand, since the semipermeable membrane itself is easily torn under pressure, it has been supported with a fabric as a base material to increase its durability.

Conventionally, there has been a difference in thread density between the woven and knitted fabric B as the flow channel advantage and the woven fabric B as the base material supporting the semipermeable membrane.
``i'' was at most about 5 to 6 pieces/25 miles.

However, with such a conventional structure, there is no problem when used at low temperatures, but when used at high temperatures and high pressures, there is a drawback that the purity of permeated water tends to decrease during long-term operation.

Also, there was a drawback that the flow path resistance was high and the amount of pure water taken out was reduced.

[Object of the present invention]

The present invention improves the drawbacks of the conventional examples and provides a device that ensures stable pure water permeability over a long period of time even when used at high temperatures and high pressures. More specifically, the thread density Na of the fabric A as the base material supporting the semipermeable membrane and the thread density Na of the woven fabric B as the channel material 1. To specify the relationship with Ib
The purpose is to be able to stably obtain a high-purity permeate for a long period of time with high efficiency even when used at high temperature and high pressure.

[Configuration of the present invention]

The present invention consists of the following configuration.

[Fabric A is provided as a base material to support the semipermeable membrane.

In a liquid separation device provided with a woven or knitted fabric B as a channel material,
The relationship between the yarn density N1) (strands/25 mm) of the woven or knitted fabric B in the direction orthogonal to the flow path direction of the woven or knitted fabric B and the thread density Na (strands/25 mm) of the fabric A in the same direction is Nb≦
A liquid separation device characterized in that Na-13 or Na+8≦Nb. ” The present invention will be further explained in detail.

As the fabric A used as the base material of the semipermeable membrane according to the present invention, tank, twill, etc. can be used.

It is preferable to use a high-density silk fabric (such as taffeta) made of one synthetic fiber filament, which has a smooth surface, is as thin as possible, and has little change in shape. As the woven or knitted fabric B that serves as a channel material, it is preferable to use a structure with a cross stitch or adze in the length direction. A modified tissue tricot can be used. In particular, the woven and knitted fabric B, which forms the flow path, has a large number of fine grooves and mutually communicating holes necessary for flowing the permeate that has passed through the semipermeable membrane toward the permeate outlet such as a hollow shaft tube. be. The groove width is dog-like.

A large number of grooves per unit length is good for allowing permeated water to flow without resistance, but if the grooves are too wide or there are too many grooves, the semipermeable membrane may When pressurized, the semipermeable membrane deforms and falls into the groove, blocking the groove that was originally supposed to be a flow path for the permeate, reducing the liquid separation capacity of the device, such as the amount of water produced. Because I do.

Needless to say, there are limits. The structure of the channel material that satisfies the above conditions has a groove width of 100 μm to 500 pm,
Thickness: 15071m ~ 500μi. The number of grooves may be 4/Cl11 to 40/line.

Furthermore, the woven or knitted fabric B that serves as the channel material needs to be made rigid, but this can be done by adding a resin or the like to it and solidifying it at the stage of finishing the greige of the woven or knitted fabric B into the channel material. Alternatively, a mixture of synthetic fiber yarns made of two types of polymers with different melting points may be used as the yarn forming the woven or knitted fabric B, or a low melting point polymer may be used on the sheath side. Woven and knitted fabric B is produced by using core-sheath composite yarns of two types of polymers with different melting points arranged, and then the whole is made rigid by melting and solidifying only the low melting point polymer by means such as heat setting. It may be something that becomes

Next, the yarn density relationship between the woven and knitted fabric A and the woven and knitted fabric B according to the present invention will be explained. The woven or knitted fabric B constitutes a channel material, and preferably has ribs or creases in the length direction. That is, the woven or knitted fabric B needs to form a flow path, and the shape and size of the flow path greatly influences the performance of the liquid separation device. For this reason, sufficient consideration has been given to the yarn arrangement in the flow path direction of the woven or knitted fabric B, particularly the yarn density of the woven or knitted fabric. On the other hand, the yarn arrangement in the direction perpendicular to the flow path of the woven or knitted fabric B was hardly considered, and was determined based on the woven or knitted fabric B fi, ease of formation, and general knowledge regarding clothing with respect to woven or knitted fabrics.

The woven or knitted fabric A is used as a base material to hold the semipermeable membrane, and the thread arrangement of the woven or knitted fabric A is determined based on the smoothness of the surface of the woven or knitted fabric, the dimensional stability of the thickness, and the stability of the semipermeable membrane. It was determined solely by ease of application. We have repeatedly investigated the improvement of woven and knitted fabrics A-B from the viewpoints of 2. Conventionally, we have obtained a product that is almost satisfactory as long as the temperature and pressure of the stock solution is within about 40" (+30 kg/cm'). However, when the stock solution When the temperature and pressure become even higher, a major problem arises in that the purity of the permeate drops significantly.

It has become clear that a satisfactory liquid separation device cannot be obtained with the above considerations alone. The present invention was obtained through various studies to solve this problem, and the yarn density in the direction perpendicular to the flow path of the woven or knitted fabric B is Nb (threads/25 mm).
It has been found that the yarn density Na (strands/25n]III+) in the direction perpendicular to the flow path in the liquid separation device of the woven or knitted fabric A are related to each other and greatly influence the performance of the liquid separation device.

C book/25 mm).

It is necessary to satisfy the relationship Nb≦Na-13 or Na+8≦Nb. This is the difference between the yarn density of woven fabric A and woven fabric B in the direction perpendicular to the flow path of the permeate in the liquid separation device.
This means that the thread density must be 1d-1'3 or more or +8 threads 725 mm or more apart. More preferably.

The relationship of Nb5Na -15 or Na+12≦Nb is fully satisfied.

The thread density Na of the basic fabric A is 60 to 80/
Approximately 25 mm is preferable.

Next, it will be explained using drawings.

FIG. 1 is a longitudinal sectional view showing an example of the device according to the present invention, and FIG. 2 is a sectional view taken along the line x-X shown in FIG.

In the apparatus shown in FIGS. 1 and 2, the liquid component 1f element 8 is entirely housed in a cylindrical container 5, and is sealed using side lids 6 and 7. The shredded cylindrical container 5 is provided with a supply pipe 9 for the stock solution, which is the liquid to be separated.
Further, the limb separation element 8 is connected to a permeate discharge pipe 11 for taking out the permeate separated by the liquid separation element. Further, seal portions 16 are provided at both ends of the liquid separation element 8 for sealing the stock solution between the liquid separation element 8 and the cylindrical container 5.

The stock solution is fed from the stock solution supply pipe 9 at a pressure higher than the osmotic pressure of the stock solution and fills the space 15 of the cylindrical container 5. After that, the liquid separation element 8 has an opening 112 on the outer peripheral generatrix and the ffi
The raw liquid flows into the raw liquid passage 19 extending spirally in the direction perpendicular to the line.

As shown in FIG. 2, the liquid separation element includes a hollow tube 16 having a small hole 14 in the center, and two semipermeable membranes 17 and 17' are placed at one end of the hollow tube with the small hole 14 in between. It is installed by gluing. A stock solution passage 19 is formed on the side of the hollow tube of the semipermeable membrane that does not sandwich the small hole 14, and a porous sheet-like material is used as the stock solution passage material to allow the stock solution to flow smoothly in the stock solution passage. It is inserted as 22. On the other hand, semipermeable membrane 17
, 177, a permeate flow path 23f is formed on the side sandwiching the small holes.

A channel material 24 is inserted into this permeate channel 23, and the semipermeable membrane 17 is
, 17/ are joined together by bringing together the ends opposite to the ones glued to the hollow tube 16. Semi-transparent 131 arranged in this way
7, 17', channel material for concentrate 22. After the passage material 24 for the permeated liquid is integrally wrapped around the hollow tube 16, seal portions 20 and 21 are formed at both ends as shown in FIG.

Therefore, the obtained liquid separation element 8 has a spiral-shaped raw liquid passage 19.
A permeate flow path 23 is formed, and a stock liquid path 19 is formed.
As mentioned above, the opening 1 is located on the outer peripheral generatrix of the liquid separation element 8.
2. Further, a stock solution passage 71, .
18 is provided, from which the raw liquid flows out from the liquid separation element.

FIG. 6 is a sectional view showing a different aspect of the device from FIG. 2. The one in Figure 2 has one stock solution passage 19 and one permeate passage 23 for one hollow tube, while the one in Figure 6 has small holes 14 in three locations. , stock solution passage 1
9. Three permeate passages 23 are provided, and the length of each passage is shortened.

4 and 5 show the semipermeable membranes 17, 177, the permeate flow path 23. FIG. 4 is a sectional view schematically showing the positional relationship between the channel material 24 and the base materials 25' and 25', and FIG.
-Z sectional view, and FIG. 5 is a YY sectional view of FIG. The semipermeable membranes 17 and 17' are formed on the base materials 25 and 25/, and the base materials 25 and 25' are overlapped at positions sandwiching the channel material 24 from both sides. The flow path material 24 has a structure with a groove of an appropriate height, and the space formed by the groove between the lies and the base material 25 becomes a flow path 26 through which the permeated liquid flows. The stock solution flows on both sides of the outside of the semipermeable membrane 17.177. In the present invention, the woven or knitted fabric A forms the base material 25, 25', and the woven or knitted fabric B becomes the channel material 24. Therefore, the yarn density Nb in the direction perpendicular to the flow path of the woven or knitted fabric B in the present invention (Book 7'
25 mm ) and the yarn density IJa in the direction perpendicular to the flow path in the liquid separation device of the woven or knitted fabric A, in the case of FIG.
・And 215 m of thread a, a, a,...
Equal to the number of lines between m.

Furthermore, it is common for the length direction of the original woven or knitted fabrics A and B to match the direction of the flow path when used as a liquid separation device for both the base material and the channel material, and in this case, NIL.

Nb is the weft density of the woven and knitted fabrics A and H. Furthermore, in the case of knitted fabrics, it is the course density.

[Actions and effects of the present invention]

The liquid separation device of the present invention allows the purity of the permeate to be maintained at a sufficiently high level even when the stock solution is exposed to high temperatures and high pressures. The most important characteristic of a liquid separation device is how much highly purified permeate it can extract, and the economic efficiency and durability of the device are determined by this. A typical example is seawater desalination, and the most effective way to increase the amount of permeate extracted is to apply high pressure to the raw solution. This requirement is strong in areas in the Middle East that are not blessed with fresh water, and in such areas it is often necessary to operate liquid separation equipment at high pressure using high temperature seawater as the raw liquid. Under such conditions, a phenomenon called "slumping of the semipermeable membrane" occurs. To explain this with reference to FIG. 4, the semipermeable membranes 17, 17
/, High temperature and high pressure are applied to the base material 25, 25' and the channel material 24, reducing the rigidity of each member, and the semipermeable membrane and the base material are deformed by the high pressure and fall into the channel 23 part of the channel material 24. It is a phenomenon. When such a phenomenon occurs, the cross-sectional area of the flow path 26 decreases, and the amount of permeate taken out decreases.

Further, a depression is formed on the surface of the semipermeable membrane 17 depending on the degree of "depression". While such dents are minor, there is no major problem, but as the depth of the dent increases, fine cracks occur in the semipermeable membrane near the dent, causing leakage of the stock solution to the permeate side, which prevents permeation. Significantly reduces liquid purity. This “down”
This phenomenon is an extremely important problem for liquid separators, and this problem becomes particularly serious when the temperature and pressure of the stock solution are increased.

The liquid separation device of the present invention has the remarkable effect of providing a solution to this problem.

That is, even in use 1 when the product temperature and pressure is high, for example, in seawater desalination in the Middle East, it was possible to prevent the "drop" phenomenon and enable stable water purification operation for a long period of time.

Next, examples will be explained in more detail.

Example 1 Filter Z5 denier made of polyethylene terephthalate,
An 18-filament yarn and a 37.5-denier, 18-filament yarn consisting of a polymer obtained by copolymerizing polyethylene terephthalate with 6iomol of isofucuric acid were prepared by a conventional method. Both yarns were pulled together and mixed to obtain a mixed yarn of 75 denier and 36 filaments, and the mixed yarn was made into a 62 gauge yarn.

The material was fed to a knitting machine to produce a gray fabric with a course density of 43.54°7 (strand/25 mm). After the knitted fabric was completely relaxed and refined, the course density after heat treatment was 48.5.
0,54,60,68,73,76.80 lines 725 m
m.

The tenter conditions were determined so that the wale density was 40 and 725 mm, and thermal fusion processing was performed for 25 (]'axI minutes. These eight types of tricot fusion processed products were used as channel materials. On the other hand, as a base material is made of 150 denier, 48 filament yarn made of polyethylene terephthalate,
Taffeta-1 used as weft yarn (warp yarn density 89 pieces 7
25 m+n, weft thread density 66 threads 725 mm) and taffeta-2 using the same yarn (warp thread density 93 threads 7
25 mm, weft density: 76 threads (725 mm). A synthetic composite membrane was applied to these profiteers and combined with 8 types of flow path materials to create a HTT device for 16 types of liquids, and a performance evaluation test was conducted. The liquid separation device was created by matching the length direction of the channel (') with the length direction of the profiteering channel.

Therefore, N& is the weft density of taffeta, and Nb is Trikotsu! - Course density and attack. Examples of performance test results are shown in FIGS. 6 and 7. Figure 6 shows the economic change in permeation number purity, and Figure 7 shows the economic change in the amount of permeate removed. This is a test example of a poor liquid separation device (l). It can be seen that the purity of the permeate decreases with the passage of operating time. It can be seen that the amount of permeate removed (expressed in one day's amount removed per semi-permeable 1+r+'') varies considerably.

Table 1 shows the presence or absence of a decrease in permeate purity over time and the stability of the output amount for 16 types of liquid separation devices. It can be seen that in the liquid separation device of the present invention, there is almost no decrease in the purity of the permeated liquid over time, and the stability of the amount of permeated liquid taken out is also stable without any problems.

[Brief explanation of drawings]

Figures 1 to 6 illustrate the structure of the liquid separation device according to the present invention. Figure 2 is a front view, and Figures 3 and 4 are X in Figure 2.
-X cross section is shown. 4 and 5 are cross-sectional views showing the positional relationships among the semipermeable membrane, channel material, and base material in model form. A YY cross section of the figure is shown. Figures 6 and 7
The figures show the changes in permeate purity and permeate withdrawal amount over the operating time, respectively. 17. 17': Semi-permeable membrane 19: Stock solution passage 26: Permeated liquid passage 24: Channel material 25, 25': Base material Patent applicant Toshi Co., Ltd. Figure 1 t+Figure 5'/327

Claims (3)

[Claims] (1) Fabric A is provided as a base material that supports the semipermeable membrane. In a liquid separation device provided with a woven or knitted fabric B as a flow path,
The relationship between the yarn density Nb (725 mm 2) of the woven or knitted fabric B in the direction perpendicular to the flow path direction of the woven or knitted fabric B and the thread density Na (725 mm 2) of the woven fabric A in the same direction is Nt)s;
, Na, -16 or Na +8≦Nb. (2) The relationship between thread density Na and N1) is Nb≦Na −
15 or Na + 12≦Nb. (3) The liquid separation device according to claim (1), wherein the fabric A is taffeta, and the woven or knitted fabric B is tricot.