JPS61245802A - Preparation of porous hollow yarn membrane module - Google Patents

Abstract

PURPOSE:To simplify a process for manufacturing a hollow yarn membrane module while preventing the clogging of the opening part of each hollow yarn, by receiving a hollow yarn bundle bundled in a reel form in a housing as it is and subsequently injecting a liquid resin in the housing to cure the same. CONSTITUTION:All of hollow yarns 3 constituting a module are bundled in a reel form and the winding start part 4 and winding terminal part 5 thereof are drawn out from the end part of the formed hollow yarn bundle. The reel shaped hollow yarns are inserted in a housing so that both ends of the bent reel (the bent part of a fixing side in a module wherein hollow yarns are bundled in a U-shape) are issued to the outside and a liquid resin is injected in the both (or single) bent parts and cured to fix the hollow yarn bundle and the hollow yarns are subsequently cut along with the cured resin to provide the open end surface of the hollow yarn bundle.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for manufacturing a porous hollow fiber membrane module. [Prior art] The recent development of porous hollow fiber membranes has been remarkable, and their applications include the chemical industry, food industry, pharmaceutical industry, fermentation industry, cosmetics manufacturing industry, semiconductor manufacturing industry, medical field, nuclear power generation, Products with various performances are used in various fields, from seawater desalination and wastewater treatment to water purifiers for general household use. Hollow fiber filtration membranes, which are made of homogeneous membranes or porous membranes, can have a larger membrane area than flat membranes, and can be assembled into a compact shape. Since the membrane wall forming the thread is used as a filtration membrane, the liquid to be treated is generally supplied from the outer periphery of the hollow fiber.
The filtrate filtered through the membrane wall passes through the hollow part of the hollow fiber and is taken out from the opening at the end of the hollow fiber. Therefore, the open ends at the ends of the hollow fibers need to be fixed with resin or the like, and must be isolated from the outer periphery of the hollow fibers, which is the intake surface for the liquid to be treated. For this reason, hollow fiber filtration membranes are generally used in which a large number of hollow fibers are formed into a bundle or bundled into a U-shape to form a module. Conventionally, for example, in manufacturing a hollow fiber membrane module in which a bundle of U-shaped loops is collected and fixed, the hollow fibers are cut to a predetermined length and bundled in a U-shape, and then set in the housing of the module. It was common to temporarily fix the fixing member, inject the liquid resin that is the raw material for the fixing member into the housing and harden it, and finally cut the end face of the fixing member. In other words, the conventional hollow In the method for manufacturing fiber membrane modules, hollow fibers cut to a predetermined length are set in a housing, the open ends of the hollow fibers are temporarily closed in a fixing process, and then the hollow fibers are fixed with liquid resin. Finally, the portion temporarily closed by fixing was cut together with the fixing member to open the end of the hollow fiber again. The reason why the ends of the hollow fibers are closed during the temporary fixing process is that when the liquid resin, which is the raw material for the fixing member, is injected into the housing, the liquid resin enters the hollow interior of the hollow fibers from the open end of the hollow fibers, causing clogging. This was to prevent this from occurring. In other words, epoxy resins, polyurethane resins, etc. are generally used as liquid resins for fixing hollow fibers in porous hollow fiber membrane modules. It reacts and hardens over time. The porous hollow fibers form a microfibril layer on the side wall, but the viscosity of the liquid resin used is adjusted to such a level that it does not pass through this fibril layer. However, since the hollow portion of the hollow fiber has a pore diameter several thousand times larger than that of the microfibril layer, the liquid resin easily enters from the open end. Therefore, in the conventional method, temporarily fixing the hollow fibers was an essential step. However, it was difficult to completely close the open ends of the hollow fibers, which were covered with thousands of water, by temporary fixing. If the temporary fixation is insufficient, some of the hollow fiber membranes within the module will remain occluded, making it impossible to use the entire membrane area of the installed hollow fibers, and if the temporary fixation is extremely insufficient. For certain substances, sufficient filtration cannot be performed. Therefore, this temporary fixing step has become a step that requires extreme attention in the production of porous hollow fiber membrane modules. Conventionally, methods for temporary fixation include (1) applying liquid resin to the open ends of the hollow fibers and curing them; (2) in the case of hollow fibers made of thermoplastic resin, melting and welding the open ends; (3) For hollow fibers with large hollow portions, the following methods have been implemented: (3) A method in which the open end is physically stuffed with material; (4) A method in which the hollow portion is closed by pressure-bonding with nippers, etc. . However, none of the above temporary fixing methods is perfect, and it is difficult to completely prevent clogging due to poor temporary fixing.

[Problems to be solved by the invention]

An object of the present invention is to provide a method for manufacturing a porous hollow fiber membrane module that can prevent clogging of porous hollow fibers due to such poor temporary fixation. Another object of the present invention is to cut the hollow fibers, set the hollow fibers together in a housing, temporarily fix the ends of the hollow fibers, fix the hollow fibers by curing the liquid resin, and cut off one end of the cured resin. It is an object of the present invention to provide a method for manufacturing a porous hollow fiber membrane module that simplifies the complicated manufacturing process. [Means for solving the problems] That is, the method for manufacturing a hollow fiber membrane module of the present invention is as follows:
In a method for manufacturing a porous hollow fiber membrane module having a housing and a large number of porous hollow fibers bundled and fixed in the housing by a fixing member, a bundle of porous hollow fibers bundled in a wind shape is The strand-like structure is stored in the housing, and then liquid resin, which is the raw material for the fixing member, is injected into the housing and cured. One end of the cured fixing member is cut, and the open end of the hollow fiber is inserted into the cut surface. It is characterized by having a step of forming. [Preferred embodiments for carrying out the invention] FIGS. 1 to 4 are schematic diagrams showing a method for manufacturing a hollow fiber membrane module of the present invention. This method will be explained in detail. The hollow fiber membrane module manufactured by the method of the present invention is
Basically, the housing 1 includes a housing 1, a fixing member 2, and a porous hollow fiber 3, and various other members may be attached as desired.The housing 1 includes the entire hollow fiber filtration module. It performs a supporting function, and typically has a cylindrical shape, but may also have a rectangular or other cross-sectional shape. In the method for manufacturing a hollow fiber membrane module of the present invention, first, as shown in FIG. 1, all the hollow fibers 3 constituting the module are bundled into a strand shape. The winding start part 4 and the winding end part 5 of the winding hollow fiber are pulled out to the end on the side that is fixed to the liquid resin. Figure 2 shows a method for manufacturing a module in which both ends of the hollow fiber are fixed. This figure shows the state in which hollow fibers bundled in a wind-like shape are inserted into the housing, and both ends of the bent windings are arranged so as to protrude outside the housing. After liquid resin is injected into both bent portions and cured to fix the hollow fiber bundle, the hollow fibers are cut together with the cured resin to provide open end surfaces of the hollow fibers. On the other hand, FIG. 3 shows an example of a module (one side fixed type) in which the liquid resin is cured only at one bent portion and the hollow fibers are bundled in a U-shape. In this case, the winding start part 4 and winding end part 5 of the hollow fiber are pulled out to the end on the side to be fixed to the liquid resin, and at least the bent part on the side to be fixed is exposed to the outside of the housing. Place it like this. FIG. 4 shows the one side fixed module shown in FIG. 3 set in a jig 6 for injecting liquid resin. When liquid resin is injected from the resin injection lower of the jig 6, it is filled through the space of the jig and the gap between the hollow fiber bundle and into the inside of the jetting ring. After injecting the liquid resin, these jigs and modules are usually set in a centrifuge to cure the liquid resin. After the resin is almost cured,
The hollow fiber membrane module is assembled by removing the jig from the module, cutting and removing unnecessary portions of the fixing member (cured resin) protruding inside and outside the housing together with the hollow fibers, and making the ends of the hollow fibers 3 open. Manufactured. As described above, according to the method of the present invention, the conventional process of cutting the hollow fibers to a predetermined length and temporarily fixing them is unnecessary, and the hollow fibers are bundled into a skein shape when the liquid resin is injected. The only open ends of the hollow fiber are the winding start part 4 and the winding end part 5, and if even these parts are carefully closed, the liquid resin will not be able to enter the hollow part of the hollow fiber. After the fixing member is cut, the openings of the hollow fibers are hardly ever blocked. FIG. 5 illustrates a method of converging hollow fibers into a skein shape in the method of the present invention. When a skein is made by bundling a large number of hollow fibers, the radius of curvature of the turning portions at both ends of the skein tends to become large, and the difference between the curvature of the fibers located inside the skein and the curvature of the threads located outside becomes large. In order to form an open end in each of the bundled hollow fibers by cutting the fixing member, it is necessary to bring out the turning portion of the portion fixed with the resin out of the housing. However, as the skein becomes thicker, the protruding part of the housing inevitably becomes thicker, but this part is discarded by cutting after being fixed with resin, and in order to effectively utilize the hollow fibers, it must be as small as possible. preferable. In order to reduce this loss, it is effective to reduce the variation in the radius of curvature of the hollow fiber bundle by reducing the radius of curvature of the skein. It is preferable to use a folded skein or a bundle of several skeins. However, the number of skeins at the beginning and end of winding increases in proportion to the number of skeins used. Therefore, it is not preferable to use too many winds together. Figures 5 to 8 illustrate the folded state of the wind.
Figure 5 shows the item folded once, Figure 6 shows the item folded once and twisted once, Figure 7 shows the item folded twice, and Figure W48 shows the item folded three times. In the case of a one-sided fixed type module, both the winding start part 4 and the winding end part 5 need to be located on the resin fixed side. In order to reduce loss at the hollow fiber ends, it is effective to form a thin and large skein and use it by bending it as described above. Further, in order to make the hollow fiber bundle as large as possible, a twist may be added to the wind. [Effects of the Invention] According to the method for manufacturing a hollow fiber filtration module of the present invention, since the hollow fibers are bundled into a skein shape when the liquid resin is injected, the liquid resin does not enter the hollow portion of the hollow fibers. Therefore, clogging of the openings of the hollow fibers can be almost completely prevented, and the membrane area of the hollow fibers can be used effectively. Therefore, it is possible to increase the filtration flow rate compared to those produced by conventional methods. Further, the process of cutting the hollow fibers to a predetermined length and the process of temporarily fixing the hollow fibers are no longer necessary, making the manufacturing process simpler than the conventional manufacturing process. Furthermore, by bending the strands and filling them into the housing, the module can be manufactured with minimum cut loss of the hollow fibers. [Examples] Example 1 A polyethylene porous hollow fiber (EHF 27QT, trade name, manufactured by Mitsubishi Rayon ■) was formed into a wind wind of 2880 turns so that the average loop length was 28 cm. The beginning and end of winding of the wind were completely closed by heating and melting. This skein is housed in a housing so that the beginning and end of the winding are on the resin fixed side, liquid resin (polyurethane resin) is injected into the housing, and the liquid resin is cured while being set in a centrifuge. The cured resin protruding further was cut to create a hollow fiber membrane module. The hollow fiber U-shaped loop length of this module averaged about 20 c+w, and the membrane area was 0.8 as2. This module was immersed in ethanol (100%) and then replaced with water to make it hydrophilic, and then 0.3 kg of 25°C water was added.
The amount of filtrated water when pressurized at a pressure of /am2 was measured as water flux. In addition, the open end surface of the hollow fiber was observed using a microscope, and the rate of clogging was measured. These results are the first
Shown in the table. Example 2 Polyethylene porous hollow fibers with an average loop length of 54.4
Example 1 was carried out in exactly the same manner as in Example 1, except that a 144° winding was formed so as to have a length of 144 cm, and this was folded twice as shown in Fig. 5. A hollow fiber membrane module similar to that was created. The evaluation results for this module are also shown in Table 1. Comparative Example 2880 polyethylene porous hollow fibers cut to a length of 280 mm were bundled into a U-shape and housed in a housing.Then, the open ends of the hollow fibers were placed on a heating plate at 200°C. After temporarily fixing by pressing and heat fusing, a liquid resin was injected, and the following steps were carried out in the same manner as in Example 1 to create a hollow fiber membrane module similar to that in Example 1. The evaluation results for this module are also shown in Table 1. Table 1 H: Length of the eastern part of the hollow that protrudes from the housing

[Brief explanation of drawings]

1 to 4 are schematic diagrams showing the method for manufacturing a hollow filtration module of the present invention, and FIGS. 5 to 8 are schematic diagrams showing a state in which the skein is bent. l: Housing 2: Fixing member 3: Porous hollow fiber membrane 4: Winding start part 5: Winding end part 6: Jig 7: Resin injection port

Claims (1)

[Claims] 1) In a method for manufacturing a porous hollow fiber membrane module having a housing and a large number of porous hollow fibers bundled and fixed in the housing by a fixing member, the porous hollow fibers bundled in a skein shape are provided. The bundle is stored in a housing in the form of a strand, and then liquid resin, which is the raw material for the fixing member, is injected into the housing and cured. One end of the cured fixing member is cut, and a hollow fiber opening is formed on the cut surface. A method for producing a porous hollow fiber membrane module, comprising the step of forming an end.