JP2939644B2 - Hollow fiber type membrane separation unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a hollow fiber membrane separation unit in which a plurality of hollow fiber membranes made of a polymer material are bound and a gap between the hollow fiber membranes at the bound end of the hollow fiber membrane is sealed with a sealant.

[Prior art]

In general, functional membranes made of various organic materials such as polymers or inorganic materials such as glass and ceramics are used for gas-removal such as reverse osmosis, ultrafiltration, microfiltration, dialysis and gas separation.
It is effectively used in various industrial fields in the separation of gas, gas-liquid, gas-solid, liquid-liquid, liquid-solid and the like. Among them, most of the polymer materials such as regenerated cellulose, cellulose ester, polyamide, polycarbonate, polyvinyl chloride, polyester, polyacrylonitrile, polymethyl methacrylate, polysulfone, polyolefin, and fluororesin can be used. They are used properly depending on the nature, purpose of separation, operating conditions, and the like. The shape of the separation membrane is roughly classified into a flat membrane and a hollow fiber membrane. As described above, various types of separation membranes are used depending on the properties of the target fluid, the purpose of separation, operating conditions, and the like.However, when actually used, the separation membrane is rarely used alone, and the membrane support and protection It is assembled with a reinforcing member such as a tube and used as a unit as a module or a cartridge. In this case, in any case, the film material and the reinforcing material of the film are naturally the same type of material, and in the case of a flat film, the reinforcing material is substantially made of the same material as the film. However, on the other hand, in the hollow fiber type membrane separation unit, it is difficult to directly apply the flat plate membrane assembling method because the gap between the hollow fiber membranes is minute. For this reason, in the case of the hollow fiber membrane separation unit, as a known means for filling the gap between the hollow fiber membranes at the binding end portion of the hollow fiber membrane, urethane resin or epoxy resin in which two kinds of liquids are mixed and cured by reaction are used. Only the means of using is implemented.

[Problems to be solved by the invention]

For this reason, in the conventional hollow fiber type membrane separation unit, when solvent resistance, chemical resistance, and water resistance are required, a membrane material having sufficient resistance, for example, a membrane made of fluorine resin such as polytetrafluoroethylene, etc. Even if a material is selected, the characteristics of the separation unit itself are influenced by the material such as urethane resin or epoxy resin which is a sealing agent. Therefore, the application of the hollow fiber type membrane separation unit has been limited while having the advantage that the size can be reduced as compared with the flat type membrane separation unit. The present invention focuses on the problems of such a hollow fiber type membrane separation unit, and provides a sealing agent for sealing the gap between the hollow fiber membranes and the hollow fiber membranes at the ends of the hollow fiber membranes, which is chemically resistant. To provide a hollow fiber type membrane separation unit which is excellent in solvent resistance and chemical resistance by adopting a material which is relatively excellent in solvent resistance, and which is inexpensive and can be downsized. It is an object.

[Means for Solving the Problems]

In order to achieve the above object, the present invention binds a plurality of hollow fiber membranes made of a polymer material, and seals a gap between the hollow fiber membranes at an end of the bundle of the hollow fiber membranes with a sealant, In the hollow fiber membrane separation unit in which the hollow fiber membrane sealing the binding end is housed in the housing, the material of the hollow fiber membrane is polypropylene among olefin-based resins,
The material of the sealant is polyethylene among the olefinic resins, and the melting point of the sealant is lower than the melting point of the hollow fiber membrane, is equal to or lower than the melting point of the hollow fiber membrane, and is lower than the melting point of the sealant. After the sealing agent is melted and fluidized at the processing temperature under the above atmosphere, it is cooled and solidified to seal the binding end of the hollow fiber membrane, and furthermore, the same housing as a liquid contact member constituting the separation unit is used. It is a hollow fiber membrane separation unit molded with a series of olefin-based resins.

[Action]

Therefore, according to the present invention, both the hollow fiber membrane and the sealing agent for sealing the gap between the hollow fiber membranes at the end of the bundle of hollow fiber membranes are excellent in chemical resistance, solvent resistance, and general-purpose and inexpensive polypropylene. By using an olefin resin represented by polyethylene, etc., the separation unit has solvent resistance,
The separation unit can be made excellent in chemical resistance and the like, and the conventional problems of the hollow fiber membrane separation unit can be solved.

【Example】

Hereinafter, a preferred embodiment of the module or cartridge of the hollow fiber membrane separation unit in the embodiment will be described in detail. (Example 1) In FIG. 1, a plurality of hollow fiber membranes 1 made of an olefin-based resin are bound in a U-shape, and a gap between the hollow fiber membranes 1 at the binding end of the hollow fiber membranes 1 is made of olefin. The hollow fiber membrane 1 is sealed with a sealant 2 which is a system resin, and the hollow fiber membrane 1 is covered with a protective outer cylinder 3 a having an inflow hole 5 and a cap having an outflow hole 6.
The hollow fiber membrane separation unit is housed inside the housing 3 made of 4a. The shape, structure, and the like of the housing 3 can be arbitrarily designed according to the implementation, and the material is the same type of olefin-based resin as in the above. Here, a specific example of the manufacturing method of Example 1 is shown in FIGS.
It will be described according to. The separation unit in FIG. 1 is a polypropylene hollow fiber membrane (maximum pore size = 0.1
μm, inner diameter = 270 μm, outer diameter = 400 μm) 300 are bundled in a U-shape in a polypropylene housing 3 in a bundle of 200 mm in length, and the method is as follows. is there. Fine powder of polyethylene as the second olefin resin (particle size = 100-500 μm, melt index = 80) 16
Into a glass beaker (or mold) 15, add approximately the same amount of purified water (water: ethanol = 1: 1) 17 and stir 1
8 Next, while adding ethyl alcohol little by little, the specific gravity of the floating polyethylene fine powder and the specific gravity of the water-alcohol mixed solvent become almost the same, and the fine powder is added to the floating state. After the adjustment of the specific gravity between the polyethylene fine powder and the mixed solution is completed, an appropriate amount of polyethylene fine powder is further added to adjust the viscosity. This is used as a sealant dope, and an appropriate amount of the dope 19 is poured into the stainless steel cup 15a, and the bundled end portion of the hollow fiber membrane 1 previously sealed is immersed. While maintaining this state, the mixture is allowed to stand in an oven heated to a temperature lower than the melting point of polypropylene and higher than the melting point of polyethylene, preferably at 110 to 120 ° C. at which the water-ethyl alcohol mixture does not boil. After the water-alcohol evaporates, when the polyethylene fine powder is in a molten and fluidized state, it is taken out of the oven and solidified slowly at room temperature. To complete the separation unit, the end face was sliced by a conventional method to expose the open end of the hollow fiber membrane 1. Example 2 Next, in FIG. 2, both ends of a plurality of linear hollow fiber membranes 7 made of a polymer material are bound, and a gap between the hollow fiber membranes 7 at both bound ends of the hollow fiber membranes 7 is formed. The sealant 8a, 8b
The material of the hollow fiber membrane 7 and the sealants 8a and 8b at the binding ends of the hollow fiber membrane 7 is an olefin resin. Further, the hollow fiber membrane 7 is housed in a housing 9 comprising a protective outer cylinder 9a having an outflow hole 14, a cap 10a having an inflow hole 12, and a cap 11a having an outflow hole 13, to constitute a hollow fiber membrane separation unit. doing. Of course, the shape and structure of the housing 9 can be arbitrarily designed according to the implementation, and the material is preferably an olefin-based resin of the same system as described above. Here, a specific example of the manufacturing method of Example 2 is shown in FIGS.
It will be described according to. Hollow fiber membrane made of polypropylene as the first olefin resin (maximum pore diameter = 0.1 µm, inner diameter = 270 µm, outer diameter = 400
μm) 7 and a bundle having a length of 200 mm are substantially linearly put in a housing 9 made of polypropylene and bound and stored. The method is as follows. An appropriate amount of polyethylene fine powder (particle diameter = 100-500 μm, melt index = 80) 16 as a second olefin resin is placed in a glass beaker 15, and approximately the same volume of purified water 17 is added and stirred 18. Next, while adding ethyl alcohol little by little, the specific gravity of the floating polyethylene fine powder and the specific gravity of the water-alcohol mixed solvent become almost the same, and the fine powder is added to the floating state. After the adjustment of the specific gravity between the polyethylene fine powder and the mixed solution is completed, an appropriate amount of polyethylene fine powder is further added to adjust the viscosity. Using this as a sealant dope, an appropriate amount of the dope 15a is poured into the stainless steel cup 19, and the previously-sealed bound end of the hollow fiber membrane 7 is immersed. While maintaining this state, the stainless steel cup 19 is placed on a plate heater and heated to 60 ° C. After the water-alcohol mixture evaporates, the temperature of the plate heater is raised to 120 ° C., and when the polyethylene fine powder flows, it is maintained for about 3 hours and left to cool at room temperature. The sealing at the binding other end 8a or 8b of the hollow fiber membrane 7 is ~
By repeating the above operation. To complete the separation unit, the end face was sliced by a conventional method to expose both open ends of the hollow fiber membrane 7.

【The invention's effect】

As is clear from the above, according to the present invention, the entire separation unit as a module or a cartridge is solvent-resistant by using an olefin-based resin as a sealant at least at the hollow fiber membrane and the hollow fiber membrane binding end, It is possible to provide a hollow fiber type membrane separation unit that is not only excellent in chemical resistance and the like, but also inexpensive and can be downsized.
Further, even with an olefin-based resin, there is a difference in melting point between the hollow fiber membrane and the sealant, and there is also a difference in fluidity during melting, so that the end of the hollow fiber membrane can be reliably sealed. It has a remarkable effect such as possible. Further, all the liquid contact members such as the housing of the separation unit may be made of the same type of resin, which is an olefin resin, so as to be more effective.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the hollow fiber membrane separation unit of the present invention, FIG. 2 is a cross-sectional view showing another embodiment of the hollow fiber membrane separation unit of the present invention, and FIG. (A) to (D) are explanatory views showing a method for producing a hollow fiber membrane separation unit according to the present invention. DESCRIPTION OF SYMBOLS 1 ... Hollow fiber membrane, 2 ... Sealing agent 3 ... Housing, 7 ... Hollow fiber membrane 8a ... Sealing agent, 8b ... Sealing agent 9 ... Housing

Claims (1)

(57) [Claims] 1. A plurality of hollow fiber membranes made of a polymer material are bound, a gap between the hollow fiber membranes at a bound end of the hollow fiber membrane is sealed with a sealing agent, and the bound end is sealed. In the hollow fiber membrane separation unit in which the hollow fiber membrane thus obtained is housed in a housing, the material of the hollow fiber membrane is made of polypropylene among olefin resins, and the material of the sealant is made of polyethylene among olefin resins. The melting point of the sealant is in a lower temperature range than the melting point of the hollow fiber membrane, and after the sealant is melted and fluidized at a processing temperature under an atmosphere that is equal to or lower than the melting point of the hollow fiber membrane and equal to or higher than the melting point of the sealant. A hollow fiber membrane separation unit, wherein the solidified end of the hollow fiber membrane is sealed by cooling and solidifying, and furthermore, a housing which is a liquid contact member constituting the separation unit is formed of the same olefin resin. .