JPS58199007A - Production of tubular semipermeable membrane module of polysulfone - Google Patents

Abstract

PURPOSE:To prevent the rupture and damage of a tubular membrane of polysulfone having a specific repetitive unit at the sealed end of a module owing to the shrinkage of the membrane in treatment at high temp. by subjecting said membrane to a wet heat treatment at specific temp. then sealing and fixing the same. CONSTITUTION:A soln. of polysulfone is coated on the inside surface of a tubular base material and is immersed in a solidifying bath, whereby a tubular membrane is obtained. The membrane 1 is immersed in hot water of >=50 deg.C and the intended service temp. or above and is thereby subjected to a wet heat treatment prior to attaching of rubber packings 3 to both opening ends of the membrane 1 and sealing and fixing of the membrane to a header 5. Since the membrane is shrunk uniformly in the longitudinal direction of the tube by said treatment, the membrane no longer shrinks even if it is used at elevated temp., and the rupture of the membrane at the sealed end, etc. is obviated; further, the solvent and swelling agent in the stage of forming the membrane remaining in the membrane are removed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing polysulfone-based tubular semi-zero membrane modules.

In general, a small integrated semipermeable membrane with asymmetric lateral movement has a structure in which a dense surface layer called a skin layer is supported by a porous layer called a sponge layer.

Among such semi-xh membranes, semi-permeable membranes made of polysulfone polymers have excellent heat resistance;
It is often used for membrane processing at temperatures as high as ~80°C. However, conventionally known -C F9r
When a polysulfone thread-like semipermeable membrane produced by a so-called wet method is sealed and fixed to appropriate sealing members at both ends to form a module, it becomes a tubular semipermeable membrane when subjected to membrane disturbance at high temperatures. Generally, since the length/diameter ratio is very large, it shrinks significantly in the longitudinal direction of the pipe, causing breakage and damage at the seal end of the membrane module, as well as damage at areas where the membrane is thin, causing problems due to liquid leakage. The permeate may be contaminated by retentate. In many cases, tubular semipermeable membranes are used as reinforced tubular membranes that are integrally formed on the surface of reinforcing tubes made of woven fabrics, nonwoven fabrics, etc., but even in this case, they shrink in the tubular direction, for example, Breakage of the sealing backing may occur.

The present invention was made in order to solve the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing a polysulfone-based tubular semipermeable membrane module that can be used stably at high temperatures.

The method for manufacturing a polysulfone-based tubular semipermeable membrane module according to the present invention is a method for manufacturing a membrane module in which a tubular semipermeable membrane made of a polysulfone polymer as a repeating unit is sealed and fixed at both ends. The method is characterized in that the tubular semipermeable membrane is heat-treated at a warm temperature and then sealed and fixed.

1. Polysulfone tubular semipermeable membranes having the following repeating units are already known, and are formed by applying a polysulfone solution inward to a tubular substrate and then immersing it in a coagulation bath such as water. . Although tubular semi-permeable membranes of various sizes are used, the tubular semi-permeable membrane used in the present invention has an inner diameter in the range of 2 to 395 m, and has a reinforcing tube surface made of textiles, non-woven fabrics, etc. It may also be a reinforced tubular membrane formed into a membrane.

FIG. 1 shows an example of a sealed end of a module with a reinforcing tubular membrane, the tubular semipermeable membrane l being formed inwardly of a perforated reinforcing tube 2, such as a non-woven tube.

-4, and is sealed and fixed to the header 5 at the backing edge that protrudes from the tube end in the tube radial direction.

However, the method of sealing 1^1 is not limited to this.

In the present invention, when a tubular semipermeable Q4 module as illustrated in L is torn down, the tubular semipermeable membrane is subjected to moist heat treatment to shrink in the tube length direction before sealing is performed at both ends of the tubular semipermeable membrane. The temperature of this moist heat treatment is 50°C or higher. As shown in Figure 882, the shrinkage of tubular half &lIQ made of polysulfone polymer having repeating unit 1 is approximately proportional to the treatment temperature, so when the model module is used at high temperature, the tubular half In order to keep the contraction length within a range that does not cause breakage or damage at the fixed end of the membrane or seal,
It is desirable to perform the moist heat treatment at a temperature of 50°C.

However, more preferably, the moist heat treatment temperature is 50"C or higher, and the intended use temperature of the membrane module (
temperature of the stock solution to be treated) or higher.

Through such moist heat treatment, the tubular semipermeable membrane is usually 0.5%
I will collect more than that. If the tubular semipermeable membrane is treated with moist heat at a certain temperature in advance to shrink in the lengthwise direction of the tube, and then the seal is fixed with nails, the semipermeable membrane will no longer contract even with the hot electricity used, so there is no risk of breakage or damage at the fixed end of the seal. It is from. Therefore, the method of the present invention is preferably carried out when the operating temperature of the module is 40°C or higher. ;IQ module 4+
When the operating temperature [r is lower than 40° C., the membrane shrinkage is relatively small, so there is little need to shrink the membrane prior to its utilization in the first floor module.

Specifically, the moist heat treatment under the circumstances is, for example, a tubular $
41+9. This can be done by immersing the membrane in hot water at a predetermined temperature, applying pressure to the inside of the membrane, or without applying pressure (such as passing hot water through it. Taking a module as an example, only one end of the tubular half dam is sealed and fixed to the adapter and header through the backing, and the other end is made slightly longer than the predetermined dimension of the module by constricting the odor tube in the longitudinal direction, and the free end is fixed. Then, pressurized hot water is passed through the tubular membrane.This 1N water pressure depends on whether the tubular semi-circular membrane is reinforced or not, but it is usually 0.
．． 5 to 20 hours 7ctl, preferably 1 to 1 OKP/C-
It is. Although it differs depending on the inner diameter, for example, if the inner diameter is 2vtm rod, the water flow is 0.02 e/volume,
When the inner diameter is about 30 mm, a rate of 5 e/min or more is appropriate.

According to such a method, it is possible to uniformly shrink the tubular semipermeable membrane in the lengthwise direction in a short treatment time of 2 minutes. The permeable membrane can be brought into close contact with the reinforcing tube, thereby preventing it from peeling off from the reinforcing tube.

Note that a tubular semipermeable membrane with an inner diameter within the range described in AiJ should not be immersed in hot water or pressurized (even if it is a reinforced tube).
Even when water is passed through it, there is virtually no diametrical shrinkage. In addition, when a tubular semipermeable membrane is inserted into a metal tube, etc., the above-mentioned pressurized JI11 water is applied to 1,000 pJ.
Because it is 0.2 to 05 degrees larger than the outer diameter of the tube, for this reason, the 1'21id is stretched in the diametrical direction by moist heat treatment, but due to contraction in the longitudinal direction, the horizontal There is no risk of this decreasing.

As mentioned above, hot water is usually used for moist heat treatment, but in the treatment process, organic solvents that do not have a harmful effect on the polysulfone semipermeable membrane, mixed solvents with water, and solutions of water-soluble inorganic salts are used. etc. are also used as wet heat treatment liquids. Suitable organic solvents include lower aliphatic alcohols such as methanol, ethanol and propatool. In addition, the moist heat treatment liquid may contain a detergent, a disinfectant, etc. within a range that does not have a harmful effect on the membrane. Cleaning agent, killer
For example, organic acids such as citric acid, phosphoric acid, orthosilicic acid, inorganic acids or salts thereof, hypochlorite, alkyldimethylbenzylammonium chloride, etc. are used.

The moist heat treated tubular semipermeable membrane is then naturally or forcedly cooled. Generally, it is advantageous for operation to perform forced cooling by immersion in cold water or by passing cold water through it.

As described above, according to the present invention, the olfactory module of the present invention is obtained by sealing and fixing both ends to a polysulfone-based tubular $ permeable membrane 7F-moist heat treated bond and incorporating it into a module. According to such a membrane module, the tubular semipermeable membrane no longer shrinks even when used at high temperatures, and therefore will not break or be damaged at the seal identification end or at a thin part of the membrane ( Therefore, there is no possibility of liquid leakage from the seal identification end or contamination of the permeated liquid (and stable high-temperature processing can be performed for a long period of time).

Among them, by the treatment of the present invention, polysulfone-based half-cells are
The degree of liquid permeability increases compared to O7L treated with moist heat.
However, the separation performance hardly changes. The reason for this is not clear, but moist heat treatment not only expands the membrane pore size but also
This is probably due to some kind of electrification occurring on the membrane surface. In addition, in particular, the pressurized water flow method has the advantage that when the treatment liquid passes through the tube, the organic solvent and swelling residue remaining during film formation can be removed.

The present invention will be explained below using practical examples. The l+ material used in the examples had an inner diameter of 13.01111.
It is an FRP pipe with a length of 4 m and a perforation of 0.8 diameter. In addition, the tubular semipermeable membrane was fabricated inwardly on a reinforcing tube with an outer diameter of 128 mm made of polypropylene fujime 1 (manufactured by Nippon Vilene Co., Ltd.) in accordance with a conventional method, and the membrane was sealed between the reinforcing tubular membrane and the pressure-resistant tube. M determination was carried out by applying 1 ril to the adapter through the backing as described above.For the evaluation of glue performance, a 05% aqueous solution of polyethylene glycol with an average molecular weight of I20000 was used.
Ql/cd, the module was operated at a rate of 14 e/min at 25°C in hot and cold conditions, and the water permeability and removal rate were determined according to the following equations.

Example 1 Polysulfone consisting of f411 repeating unit (A) (Union Carbide Co., Ltd. 11'! P 1700) 2
2 parts (hereinafter, part indicates # part) and N-methyl-2~
A reinforced tubular membrane was manufactured using a membrane forming solution consisting of 78 parts of virolitone. Insert this tubular 11:゛ into a pressure-resistant pipe,
One end is sealed and the 111 end is not fixed and can withstand 1'F.
After being exposed from the end of the tube for 50 minutes, hot water at a temperature of 90° C. was circulated through the tubular membrane for 10 minutes at a pressure of 5 K2z crl and a flow rate of M10 #/min. After this, cold water with a temperature of 110"C was passed through the crotch for 51") to cool the crotch. Through such treatment, the tubular membrane with a length of 305"(16") was made 47" in the length direction of the tube. (1,54%) contraction, -10,000,
Is the glue stretched in the radial direction on the inside of the pressure tube? i [did it. The water permeability was 2.0 m'/II'·day, and the removal rate was 91%. In addition, the amount of water in the untreated lIΔ is 1.52 Il
l''/II'·day, the removal rate was 93%, and the water permeability of the membrane increased by 1!: by the moist heat treatment.

After that, hot water at a temperature of 90° C. was passed through the membrane module d, which was equipped with a moist heat-treated condition, a pressure d, etc., for 10 hours at a pressure of 50 cd, and 31! However, no liquid leakage was observed from the fixed seal end, and the test module was separated.
Ishite b4! As a result of removing and examining the membrane, it was found that there were tubes l,
A power recovery of 611 was not recognized.

Examples 2-4 A! The tubular semipermeable membrane was treated in the same way as the male side 1 and the whole (4, l° ) module was created.

The characteristics of membrane modules are shown in the table below.

(Note) The initial length of the tubular membrane of the jar is 3050m111
It is.

In addition, hot water of the same temperature as 1 citrus of the low-temperature treatment was applied to a module equipped with a moist heat-treated membrane at a pressure of 50 hours/cd for 10 minutes.
Although water was passed through the membrane for a period of time, there was no leakage from the fixed seal end (and the membrane did not turn over even after the membrane module was disassembled).

Comparative Example 1 The tubular semipermeable membrane formed in Example 1 was not subjected to moist heat treatment (both ends were sealed and heated with 90°C water for 5 minutes).
When water was passed under the condition of 0-/cj, liquid leakage was observed from the seal fixed end. When the module was disassembled and the barrel was removed, the tube contracted by 1,811,111 degrees in the longitudinal direction.

Example 5 The tubular semipermeable membrane formed in Example 1 was soaked in 90°C hot water for 10 minutes! When iM was performed, the membrane was 461+81 in the tube length direction.
(1.51%) contracted, but the inner diameter of the membrane remained almost unchanged;
It was 12.811111. The membrane performance after treatment is as follows: water permeation rate is 1.85I11'/ml''・day, removal rate is 93
%Met.

The above membrane module equipped with a moist heat treated tubular semipermeable membrane was heated with +v9o°C hot water for 10 minutes at a pressure of 50 hours/C1l.
Although water was continuously passed through the tube for several hours, liquid leakage was observed from the end of the identification seal, and the membrane removed from the module was found to have slightly shrunk by 2111J1 in the tube length direction.

Example 6 Polysulfone (IO
A reinforced tubular membrane was manufactured using a membrane-forming solution consisting of 18 parts of 600 P (manufactured by Company I), 77 parts of N,N-dimethylformamide, and 5 parts of formamide. This tubular membrane was inserted into a pressure-resistant tube, one end was sealed and fixed, and the other end was made to protrude from the end of the earth-resistant tube to 6011111, and then subjected to moist heat treatment in the same manner as in Example 1. As a result, the tubular membrane has a length of 55 a (1
, 54% J contraction. The performance of this crotch is! City equipment is 3.
At 1♂/11' day, the removal rate was 55%.

The untreated silica membrane had a water permeation rate of 2.311''/■''·day and a removal rate of 59%.

Also,/! After that, hot water at the same temperature as the treatment temperature IW was passed through the module equipped with the 7M-treated membrane for 10 hours at a pressure of 1/2, but there was no leakage from the end of the fixed seal, and the membrane was The membrane did not shrink after disassembly of the module.

Comparative Example 2 Instead of the wet heat treatment in Example 1, the odor was treated with dry heat in a dryer at 90°C for 30 minutes.
(2) As it shrank, a portion of the polysulfone peeled off from the reinforcing tube at the end. The module with this pattern had a water permeability of 0.3♂/wl·day, a removal rate of 98%, and a marked decrease in water permeability.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of the sealed fixed end of a normal semipermeable membrane module, and FIG. 2 is a graph showing the relationship between the wet heat treatment temperature and the shrinkage length of the tubular semi-membrane in the longitudinal direction. 1...-Tubular half membrane, 2... Reinforcement tube, 3... i4 coupling, 4... Adapter, 5... Header. Fig. 2 3040 60 &), 100 suburbs 3 fried fish (6C)

Claims (3)

[Claims] (1) In a method for manufacturing a tubular membrane module in which a tubular semipermeable membrane made of a polysulfone polymer having repeating units and/or is sealed and fixed at both ends, the tubular semipermeable membrane is wetted at a temperature of 50°C or higher. A method for manufacturing a polysulfone-based tubular semi-transparent G9 module, which comprises sealing and fixing after heat treatment. (2) The temperature of the tubular semipermeable membrane is 50°C or higher, and the use of a membrane module! 2. The method for producing a polysulfone-based tubular semipermeable membrane module according to claim 1, wherein the polysulfone tubular semipermeable membrane module is subjected to moist heat treatment at a temperature of i degrees or higher. (3) The tubular semipermeable membrane is treated with moist heat to reduce the temperature by 0.5% in the tube length direction.
A method for manufacturing a polysulfone-based tubular semipermeable membrane module according to claim 1 or 2, characterized in that the module is shrunk by more than 100%.