JPS6019001A - Flowline material for liquid separation apparatus and preparation thereof - Google Patents

Abstract

PURPOSE:To lower the flow resistance of a flowline material, by forming the same from a tricot knitted fabric having a backing structure part and a ridge part knitted from a thermoplastic synthetic fiber filament yarn. CONSTITUTION:A three-ply shuttle knitted fabric has a backing structure part knitted from yarns F, M each having relatively fine denier and a ridge part knitted with a yarn B having denier thicker than that of the yarns F, M. The yarns F, M with fine denier are respectively supplied to a front shuttle and a middle shuttle to be knitted into double Denbigh stitch of [1/1] as shown by the drawings A, B while the yarn B is supplied to a back shuttle to be knitted into chain stitch of [1/0] as shown by the drawing C. The sinker loop part of stitch formed by the front shuttle and the middle shuttle comes to the backing structure part and a needle loop part and the chain stitch formed by the back shuttle comes to the ridge part.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow channel material that supports the back side of a semipermeable membrane that receives pressure on a stock solution in a liquid separation device, and a method for manufacturing the same.

In a liquid separation device using a semipermeable membrane, the semipermeable membrane is generally formed into a long envelope shape (bag shape), and the envelope supports the pressure of the stock solution applied from the semipermeable membrane side and prevents permeation. A spiral type, in which a channel material that becomes a channel for guiding the liquid is inserted, and the open end side of the envelope into which the channel material is inserted is fixed to a hollow shaft and wound tightly in a spiral shape, or There is a tubular type in which the open end sides of a large number of semipermeable membrane envelopes are held tightly by a holding plate and housed in a container. In both cases, a high-pressure stock solution is passed through the outside of a semipermeable membrane envelope that is supported from the inside by a channel material, and the permeated liquid that has passed through the semipermeable membrane is taken out while being guided by the channel material. Such fluid separation devices are widely put into practical use as water supply devices for pre-treatment of boiler water, reuse of wastewater, desalination of seawater, etc.

By the way, the channel material of the above-mentioned fluid separation device is generally a porous fabric such as a woven fabric or a knitted fabric and has fine grooves, but the high pressure of the stock solution acts on this channel material through a semipermeable membrane. Therefore, when the flow resistance is large, the permeate flow rate decreases,
There is a problem of reducing the amount of permeate produced per unit volume.If you try to lower the flow resistance to solve this problem, you will have to increase the thickness of the channel material. There is a problem in that it is disadvantageous to downsizing the fluid separation device per unit production amount of liquid.

The purpose of the present invention is to reduce the flow resistance without increasing the thickness of the channel material, thereby increasing permeate productivity, and furthermore, to achieve liquid separation that can maintain its performance for a long period of time. The object of the present invention is to provide a channel material for devices. Still another object of the present invention is to provide a manufacturing method that can efficiently produce the channel material.

The channel material for a fluid separation device of the present invention that achieves the above object is as follows:
In a channel material for a liquid separation device that supports the back side of a semipermeable membrane that receives pressure on a stock solution, the channel material is made of a tricot knitted fabric having a ground texture portion and a ribbed portion knitted from thermoplastic synthetic fiber filament threads. The ridge portion is characterized by knitting yarns having a thicker fineness than the yarns constituting the ground weave portion, and the yarns adhere to each other to make the tricot l-knitted fabric in a rigid state. It is something to do.

In addition, the manufacturing method includes knitting the ground weave part with at least two sets of thermoplastic synthetic fiber filament yarns of fineness using a tricot knitting machine having at least three reeds, and also knitting the needle loop part of the cough ground weave part. knitting a tricot knitted fabric in which ridges are formed by weaving at least one set of thick thermoplastic synthetic fiber filament yarns into the fabric,
Furthermore, the knitted fabric metal body is made rigid by bonding the yarns in the Tricot +-m ground to each other.

The tricot l-I and I fabrics, which are the raw materials for the channel material of the present invention, are knitted by a tricot knitting machine having at least three or more strands. A three-piece reed knitted fabric, which is an example of the knitted fabric, is shown in FIGS. 1 and 2 A, B, and C.

In the three-ply reed knitted fabric shown in Fig. 1, the ground weave is knitted with relatively fine yarns F and M, and the ridges are knitted with yarns F and M of relatively fine fineness.
It has a structure in which yarns B, which are thicker than yarns M, are woven together. The above-mentioned fine yarns F and M are supplied to the front woven fabric and the middle woven fabric, respectively, and are knitted into a (1/1) double woven knit as shown in Fig. 2 A and B. Yarn B having a fineness is fed to a hack ossa and knitted into a (110) chain stitch as shown in FIG. 2C. With such knitting, the songka loop part of the stitches formed by the front recess and middle recess becomes the ground weave part, and the chain stitch formed by the needle loop part and bank recess becomes the ridge part.

That is, the 1-Ricosoto knitted fabric of the channel material material of the present invention comprises at least one set of thick thermoplastic synthetic fiber filament threads and at least two sets of fine thread thermoplastic synthetic fiber filament threads. It can be knitted using at least three sets of warped thermoplastic synthetic fiber filament yarns, using a tricot knitting machine with at least three reeds, and the two sets of yarns on the fineness side create a ground texture. Organize the parts and make this 2
A ridged part is formed by weaving another set of thicker yarns into the needle loop part formed by one set of yarns, and this creates a tricontre knitted fabric with a ground texture part and a ridged part. is formed.

In this way, the ground weave portion is knitted with at least two threads of fineness, and the ridge portion is further knitted with at least one thread of thicker fineness than the threads forming this ground weave portion. As a result, a structure is formed that is thinner in the ground tissue and thicker in the ridges. Therefore, a space for a flow path with a U-shaped cross section connected by a thin ground structure is formed between two adjacent ridges.

In order to make the relationship between thickness and thinness between the ridges and the ground texture part more noticeable, the fineness of the large fineness yarns that make up the ridges should be set to 1. .It is preferable to increase the size by 2 times or more. In addition, its fineness is
The ridge part is 50-70 denier, the ground texture part is 30-5 denier.
It is preferable to select within the range of 0 denier and 0 denier.

The Trikotsu H and liA fabrics knitted as described above must be made rigid by bonding the yarns together, so that they will not be easily crushed by high-pressure stock solutions.

Such adhesion treatment may be carried out by resin processing in which melamine resin is attached, or by making the thermoplastic synthetic fiber filament threads constituting the tricot knitted fabric into a composite structure consisting of a low-melting point component and a high-melting point component. It can also be carried out by melting only the melting point components by heat treatment and fusing the yarns together. In particular, the latter method of fusing low melting point components is advantageous in applications where it is necessary to produce highly purified permeated water, since there is no eluate in the permeated water compared to the case of resin processing.

The thermoplastic synthetic fiber filament yarn consisting of a low melting point component and a high melting point component may be in the form of a composite yarn, a mixed fiber yarn, or the like. In the case of composite yarns, both core-sheath type composite yarns in which a low melting point component is placed on the sheath side and high melting point component on the 8th side, and bimetal type composite yarns in which both components are laminated from both the left and right sides can be used. It is. The mixed fiber yarn is a mixture of filaments having a low melting point component and filants having a high melting point component.

The ratio of the two different components is 5 for the low melting point component that becomes the adhesive.
Although it is preferable that the content does not exceed 0%, this is not the case as long as the high melting point component that becomes the skeleton after melting functions sufficiently in terms of strength. Further, it is sufficient that the difference in melting point between the two components is at least 10°C, preferably 20°C or more.

Typical combinations of high melting point components and low melting point components include high melting point polyester and low melting point polyester, high melting point polyamide and low melting point polyamide, and high melting point polyolefin and low melting point polyolefin. A combination of a high melting point polyester and a low melting point polyester is preferred from the viewpoint of rigidity. A low melting point component can generally be easily obtained by using a polymer copolymer, and the difference in melting point can be determined by changing the copolymerization ratio, adding a copolymer component, changing the copolymer component, stereoregularity, or polymerization degree. It can be changed by modification or the like. Alternatively, a combination with different polymers having different melting points may be used.

The thermoplastic synthetic fiber filament yarn consisting of a combination of both of the above-mentioned components must be used in the ground texture part and the ridge part, and the low melting point component used in the image part must have the same melting point. is desirable.

FIGS. 3 and 4 illustrate a spiral type fluid separation device using the above-mentioned channel material.

1 is a fluid separation element, and 2 is a cylindrical container housing this fluid separation element 1. The fluid separation element 1 is sealed at one end with a sealing material 3 within a cylindrical container 2, and has a permeate discharge pipe 4 at the other end protruding to the outside of the cylindrical container 2. The cylindrical container 2 is provided with a stock solution supply pipe 5 on the peripheral wall and a stock solution discharge pipe 6 on the side wall.

As shown in Fig. 4, the fluid separation element 1 has a permeate discharge pipe 4 made of a hollow pipe with a small hole 7 in the center, and an envelope-shaped semi-transparent layer 11*9 is spirally wound around the outside of the permeate discharge pipe 4. It's spinning. The envelope-shaped semipermeable membrane 9 has a permeate channel material 1o according to the present invention inserted thereinto, and its open end faces the small hole 7 and communicates with the inside of the permeate discharge pipe 4. In addition, a concentrate channel material 11 is interposed between the outer surfaces of the spirally wound envelope-shaped semipermeable membrane 9, and extends from the concentrate 12 on the surface of the fluid separation element to the concentrate outlet 13 in the center. , this stock solution outlet 13 communicates with the stock solution discharge pipe 6 of the cylindrical container 2.

Therefore, in the liquid separation device, the stock solution supply pipe 5
While the high-pressure stock solution supplied from the liquid bone Rs. The permeate is guided by the permeate channel material 10 and taken out from the permeate discharge pipe 4 . The residual liquid of the stock solution is discharged from the stock solution discharge pipe 6 via the stock solution outlet 13.

According to the channel material according to the present invention described above, it is made of a tricot knitted fabric having a rigid ground structure portion and a ridge portion,
In addition, since the ground texture part is thin and the ridge part is thick due to the weaving of large fineness yarns, there is a space between two adjacent ridge parts where the cross-sectional ratio to the total cross-sectional area of the knitted fabric is relatively large. Forms a letter-shaped flow path. Therefore, although the overall thickness of the channel material is the same as that of conventional channel materials, the flow resistance in the liquid bone Ilt operation described above is significantly reduced, and the permeate production volume is increased while maintaining a compact device capacity. can be improved. Furthermore, as will be clear from the Examples described below, the good performance of the channel material can be maintained over a long period of time, and the durability can be improved.

Example 1 Three types of filament yarns, G, H, and I, made of polyethylene terephthalate 1 and having the following denier and number of filaments were prepared.

G17.5 denier, 18 filament] (: 25 denier, 12 filament I: 15 denier, 12 filament
Three types of filament yarns (g+h, i) made of polymers copolymerized with O mol % and having the following denier and number of filaments were prepared.

g: 37.5 denier, 18 filament h: 25 denier, 12 filament i: 15 denier, 12 filament Furthermore, the above filament yarns were mixed at a ratio of 1:1 between G2g, H and h, and I and i, respectively. Mixed fiber yarns J and L of 75 denier, 50 denier, and 30 denier were prepared, respectively.

Next, according to the knitting structure shown in Fig. 1.2, the above-mentioned mixed fiber yarn was supplied to the front woven fabric and the middle woven fabric, and the above-mentioned mixed fiber yarn K was supplied to the back woven fabric to form a 32 gauge, 3-woven fabric. Made of tricot knitted fabric. After refining this knitted fabric, the well and course densities after heat treatment are 47/25 mm, respectively.
, 60/25mm and 48/25mm, , 73/2
After determining the tensile conditions so that the thickness was 5 mm, heat-sealing was performed at 250 ''C for 1 minute, and two types of channel materials P and Q corresponding to the present invention (the former and the latter with the well and course densities described above, respectively) were prepared. corresponding) was created.

On the other hand, as a comparison product, a 32-gauge, double-densified fabric was knitted using the mixed fiber yarn J using two-layer tricot fabric. After refining this knitted fabric, the well and course densities after heat treatment are 40/25 mm and 54/25 mm, respectively.
Tenter conditions were determined so that m was obtained, and heat fusion processing was performed at 250° C. for 1 minute to create channel material R.

For these channel materials P, Q, and R, the flow resistance coefficient 11 measured by a pressure drop measuring device shown in FIG. 5, which will be described later, and the thickness of the channel materials were compared, and the results shown in Table 1 were obtained.

The size of the channel material in the test was 0.024nr (rlJo, 08m x length O, '3) within the sealing area.
m), the pressure of high-pressure water was 30 kg/c+A, the differential pressure Δp was 2 kg/c+A, and the water temperature was 25°C.

Table 1 Sample Flow resistance coefficient H thickness mm) P 3.1 0.244 Q 3.6 0.247 R5,10,285 As is clear from Table 1, the channel material P according to the present invention
, Q has a small thickness and a small flow resistance coefficient 1],
It is superior to the comparative channel material R on both sides.

Subsequently, the pressure of high-pressure water was increased to 70 kg/c+a,
Further, the water temperature was raised to 40°C and the test was continued for 200 hours, after which the flow resistance coefficient I] and the thickness were measured and the changes were calculated 8 times, and the results shown in Table 2 were obtained.

Table 2 Sample Flow resistance coefficient 11 Thickness mm) P 7.0 0
．． 209 Q 8.2 0.215 R19,50,252 As is clear from Table 2, the channel material P according to the present invention
, Q has a smaller increase in flow resistance coefficient H than comparative product R, indicating that its performance is stable over a long period of time.

Example 2 In Example 1, flow channel materials P and Q were organized as a stack 2.
The three-layer tricot knitted fabric was further calendered to create thinner channel materials S and T. The same measurements as in Example 1 were carried out on these, and the results in Table 3 were obtained when the water temperature was 25°C.
After 200 hours at °C, the results shown in Table 4 were obtained.

Table 3 Sample Flow resistance coefficient H Thickness mm) S 6.6 0.184 T 6.1 0.198 Table 4 Sample Flow resistance coefficient H Thickness mm) s 14.5 0.178 T 11.5 0 .189 As is clear from Tables 3 and 4 above, the flow resistance coefficient I] has increased slightly due to thinning through calendering, but the thickness has further decreased, which is advantageous for making the device more compact. There is.

Also, compared to the measured value at a water temperature of 25°C, at 40°C, 2
It can be seen that the rate of change in the measured values after 00 hours has passed is small, indicating that the performance is stable over a long period of time.

(Description of pressure drop measuring device) As shown in FIG.
1 and sandwiched between the upper and lower support frames 52 and 530. High-pressure water is supplied from a high-pressure water supply pipe 55 to a flow path 54 formed on the semipermeable membrane 51 side and discharged from a discharge pipe 56, and low-pressure water is supplied to a flow path 57 on the flow path material 50 side. Low pressure water is supplied from the pipe 58 and discharged from the discharge pipe 59. A measuring device 60 is provided at the end of the discharge pipe 59,
It is possible to measure the amount of liquid flowing out.

Now, when high-pressure water corresponding to the stock solution is supplied from the high-pressure water supply pipe 55, and low-pressure water corresponding to the permeate is supplied from the low-pressure water supply pipe 58 while maintaining this state, the pressure of the high-pressure water is As the height increases, the channel material 50 is deformed under pressure, and the flow rate of low-pressure water decreases. From this, the degree of deformation of the channel material 50 can be determined by the pressure drop (differential pressure) Δp of this low-pressure water and the flow rate q.
By measuring this, it can be expressed as the flow resistance coefficient H.

That is, the flow rate q is generally given by the following formula.

q-(1/H) (dΔp/Δ1)W (where l is the length of the flow path, W is the width of the flow path) By solving this, the flow resistance coefficient H is obtained as in the following formula. .

H=K (Δp/q) (atm/lon/
day ) (where K is a constant determined by the device) Therefore, by measuring Δp and q, the flow resistance coefficient H can be calculated.

[Brief explanation of the drawing]

Figure 1 shows the tricot m material (
Figure 3 is an enlarged plan view of the main parts of the 3-layer I-woven tricot fabric; Figures A, B, and C are organization charts for each of the tricot I fabrics, and Figure 3 is an example of a fluid separation device using the same channel material. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3, and FIG.
The figure is a schematic diagram of a pressure drop measuring device. F...Front reel thread, M...Middle reel thread, B...Hack reel thread L--Fluid separation element, 9...Envelope-shaped semipermeable membrane, 10...Flow Road material. Agent: Patent Attorney Shin Ogawa - Patent Attorney Ken Noguchi Teru Patent Attorney Kazuhiko Saishita Figure 1 (A) (B) (C) Figure 2 Figure 3

Claims (1)

[Scope of Claims] (11) In a channel material of a liquid separation device that supports the back side of a semipermeable membrane that receives pressure on an undiluted solution, the channel material has a base structure portion knitted from thermoplastic synthetic fiber filament threads and ridges. The ridge portion is made of a tricontre knitted fabric having a portion, and the rib portion is knitted with yarn having a fineness thicker than that of the yarn constituting the ground weave portion,
A channel material for a liquid separation device, characterized in that the threads adhere to each other to make the tricot knitted fabric rigid. (2) The thermoplastic synthetic fiber filament thread is formed from a low melting point component and a high melting point component, and the low melting point component melts and solidifies to bond the threads together.
A channel material for a liquid separation device as described in Section 2. (3) Using a truffle throat knitting machine having at least three sheets, the ground fabric is knitted from at least two sets of fine-grained thermoplastic synthetic fiber filament yarns, and at least A tricot knitted fabric is knitted with a set of thick thermoplastic synthetic fiber filament yarns to form ridges, and the threads in the tricot knitted fabric are bonded to each other to make the entire knitted fabric rigid. 1. A method for producing a channel material for a liquid separation device, the method comprising: (4) A thermoplastic synthetic fiber filament thread is formed from a low-melting point component and a high-melting point component, and the fabric knitted from the thermoplastic synthetic fiber filament thread is heat-treated to remove only the low-melting point component. 4. The method for producing a channel material for a liquid separation device according to claim 3, wherein the threads are melted and the melted low melting point component adheres the threads to each other.