JP4857538B2 - Hollow fiber membrane module - Google Patents

Description

  The present invention relates to a hollow fiber membrane module. More specifically, the present invention relates to a ceramic hollow fiber membrane module having excellent airtightness at a module sealing portion.

Dry and wet spinning is performed using a spinning stock solution in which a ceramic powder such as Al ₂ O ₃ , SiO ₂ , ZrO _2, etc. is highly filled in an organic solvent solution of a film-forming polymer substance, and the resulting composite hollow fiber membrane is fired Thus, it is well known that a porous ceramic hollow fiber membrane having a pore diameter of about 0.1 to 6 μm and an outer diameter of about 0.5 to 4 mm can be obtained.
Japanese Patent Publication No. 5-66343

  Although this porous ceramic hollow fiber membrane can be used alone as a filter membrane for water treatment, etc., it is used as a support, and a functional separation layer such as a silica layer is composited and formed on the surface of the hollow fiber membrane. As a result, it can be used as a gas separation membrane. In this case, these porous ceramic hollow fiber membranes are used in the state of a membrane module in which one to several hundreds are accommodated in a bundled tube made of alumina, silica or the like.

When the hollow fiber membrane is accommodated in the bundled tube, in addition to fixing the hollow fiber membrane, it is also required to provide airtightness to prevent the separation medium from leaking from other than the membrane function portion. The present applicant has previously described a method for manufacturing a membrane module by bundling hollow fiber membranes that satisfies such a requirement, and a bundled material contact portion and a module at the end of a ceramic hollow fiber membrane group sealed with a bundling material. A method of covering the sealing end face with a glass material is proposed.
Japanese Patent Laid-Open No. 11-226370

  In this membrane module manufacturing method, the tip of a porous ceramic hollow fiber membrane coated with a glass material is sealed in advance with an adhesive such as an epoxy resin, and a bundling material is enclosed and fixed at the end of the hollow fiber membrane group. Thereafter, a method is used in which a part of the bundle of the adhesive-sealed portion is cut and then the module end face is covered with a glass material.

  In such a manufacturing method, the volume of the glass material is large, and a slight difference in linear expansion coefficient between the hollow fiber membrane and the bundled tube causes a minute gap to be formed in the cooling process after the glass material is heated and melted, resulting in leakage. There was a problem that it became easier.

In order to solve this problem, a hollow fiber membrane 3 is inserted into each through-hole using a plate 2 having a plurality of through-holes as shown in FIG. And the method of sealing between the eye plate 2 and the hollow fiber membrane 3 with a glass material is proposed. According to this method, it is possible to reduce the volume of the glass material and reduce the occurrence of leakage, but also in this method, the gap volume between the bundled tube and the eye plate is increased by increasing the diameter of the module. It was not possible to completely prevent leaks due to the same cause.
JP 2003-181249 A JP 2003-251164 A

In addition, expansion damage that can be expanded and contracted to at least one end side of the bundled tube is one of the problems when using at high temperatures due to the difference in thermal expansion coefficient between the housing and the ceramic hollow fiber membrane module. It has been proposed to solve this problem by using a tube, but in this case as well, due to the difference in the linear expansion coefficient between the ceramic hollow fiber membrane and the bundled tube, the difference in the amount of expansion and contraction during heating and cooling causes There was a problem that the strain was concentrated and the glass material was easily damaged.
JP 2003-019422 A

  An object of the present invention is to provide a hollow fiber membrane module in which a porous ceramic hollow fiber membrane is inserted into a through-hole of a through-hole perforated plate fitted into a bundled tube end portion. In addition, the distortion generated in the glass material for fixing the hollow fiber membrane caused by the difference in thermal expansion coefficient between the hollow fiber membrane and the bundled tube is reduced without being affected by the size of the module. An object of the present invention is to provide a caulked hollow fiber membrane module.

An object of the present invention is to provide a hollow fiber membrane module in which one end of the through hole provided in the eye plate has a large diameter part and the other end forms a small diameter part, and the inside of the through hole extends from the large diameter part to the small diameter part. the has a stepped portion allowed to narrowing, than the hollow fiber membrane outer diameter larger 0.5~0.7mm the inner diameter of the large diameter portion, the inner diameter of the small diameter portion 0.2~0.5mm set large, the large diameter portion and a small diameter portion This is achieved by a hollow fiber membrane module in which a gap between the through hole and the hollow fiber membrane whose inner diameter difference is set to 0.1 to 0.4 mm is sealed with a glass material. In this hollow fiber membrane module, it is preferable that the bundled tube and the eye plate are integrally formed, and it is preferable to have a fitting structure in which the bundled tube is divided into two parts.

In a hollow fiber membrane module in which a porous ceramic hollow fiber membrane is inserted into a through hole of a through hole drilled plate fitted into the end of a bundled tube, the inside of the through hole is narrowed in the through hole provided in the plate. the provided stepped portion allowed to reduction, it is possible to improve the sealability by seal processing glass material by utilizing the stepped portion. In addition, by integrally forming the bundling tube and the eye plate, it is possible to suppress the occurrence of leakage due to a minute gap that occurs in the cooling process after heating and melting the glass material. Furthermore, by adopting a fitting structure in which the bundled tube is divided into two parts, the difference in expansion and contraction between the hollow fiber membrane and the bundled tube at the time of heating and cooling is absorbed. It is possible to reduce distortion occurring in the glass material in the meantime and reduce leakage.

As the porous ceramic hollow fiber membrane, generally used is an organic solvent solution of a polymer material in which powders of Al ₂ O ₃ , Y ₂ O ₃ , MgO, SiO ₂ , Si ₃ N ₄ , ZrO _{2 and the} like are dispersed. A porous hollow fiber membrane having a pore diameter of about 0.1 to 6 μm, preferably about 0.2 to 2 μm, obtained by dry-wet spinning is used. These porous hollow fiber membranes have an outer diameter of about 0.5 to 4 mm, preferably about 1 to 3 mm, and a thickness of about 0.1 to 0.5 mm, preferably about 0.15 to 0.3 mm. Is used in a state where it is partially or wholly accommodated in a ceramic bundle tube made of alumina, zirconia, titania or the like.

In these hollow fiber membrane groups, the surfaces of both end portions including portions that are glass-sealed by the through-holes of the eye plate before accommodating the bundled tube are covered with a glass material in advance. As glass material, Na ₂ OB ₂ O ₃ —SiO ₂ type, Na ₂ OB ₂ O ₃ —ZnO type or Li ₂ O—ZnO type general glass powder, α-terpineol with viscosity modifier added, etc. A paste that is dispersed in the above solvent is used, and coating is performed by brushing, troweling, dipping, or the like. The glass material coated with a thickness of about 1 mm or less, preferably about 0.1 to 0.5 mm is heat-treated at about 400 to 1300 ° C., preferably about 500 to 1200 ° C. for about 5 to 30 minutes.

  As illustrated in FIG. 1, a porous ceramic hollow fiber membrane 3 coated with a glass material is inserted into a plate 2 arranged at both ends of a bundled tube, and a through hole and a hollow fiber provided in the plate. As shown in FIG. 2, paste-like glass seal material 4 is applied to the membrane joining portions, and the members are sealed by baking at 600 to 1100 ° C., thereby producing a hollow fiber membrane module.

As shown in FIG. 2, the through hole provided in the eye plate is provided with a stepped portion that narrows the inside of the through hole, and the gap between the stepped portion and the hollow fiber membrane is sealed with a glass material 4, Sealed. The stepped portion is constituted by a small diameter portion having a large diameter portion and the inner diameter D ₁ having an inner diameter D _2, in general than the hollow fiber membrane outer diameter is large diameter portion 0.5~0.7mm its inner diameter, preferably The inner diameter of the small diameter portion is set to about 0.2 mm, preferably about 0.4 mm larger, and the inner diameter difference between the large diameter portion and the small diameter portion is set to 0.1 to 0.4 mm. In addition, the level | step-difference part which consists of a large diameter part and a small diameter part includes a thing of two steps or more other than the two steps shown in FIG. 2, and may be conical.

If the difference in inner diameter (D ₂ -D ₁ ) between the large diameter portion and the small diameter portion is smaller than 0.1 mm, the glass material is difficult to enter, while if larger than 0.4 mm, the glass material is broken, Thus, it becomes possible to improve a sealing performance by setting it as the level | step-difference part of two steps or two steps or more. In addition, although arrangement | positioning with a large diameter part and a small diameter part is arbitrary, it is preferable to make a hollow fiber membrane terminal side into a large diameter part.

  Furthermore, it is preferable that the bundling tube and the eye plate are integrally formed as shown in FIGS. The gap between the bundling tube and the eye plate that causes the leak is eliminated by integrally forming, and it is possible to suppress the occurrence of the leak due to the minute gap generated in the cooling process after heating and melting the glass material.

  As the bundled tube in which the hollow fiber membrane is accommodated, a bundled tube having two divided fitting structures 5 and 6 as shown in FIG. 3 is preferably used. The split bundled tube absorbs the difference in expansion and contraction between the hollow fiber and the bundled tube during heating / cooling due to the fitting structure such as the slide structure and screwed structure. The distortion which arises in the glass material between these can be reduced, and a leak can be reduced.

  Next, the present invention will be described with reference to examples.

Example 1
Paste glass material (Nippon Electric Glass Product GA-13) was applied to the entire surface of porous alumina hollow fiber membrane (outer diameter 2.9mm) for sealing test, and heat-treated at 1150 ° C to seal A glass material-coated hollow fiber membrane for testing was obtained. The four glass fiber-coated hollow fiber membranes obtained in this way were bundled with a countersunk provided with through holes having stepped portions with an inner diameter D ₂ = 3.5 mm and D ₁ = 3.3 mm as shown in FIG. A porous glass hollow fiber membrane module was manufactured by inserting into a tube and applying a paste-like glass material (Asahi Techno Glass product SK360) between them and heat-treating it at 800 ° C. for sealing.

A leakage test was performed on the obtained membrane module. As shown in FIG. 4, the hollow fiber membrane module 7 is attached to a SUS housing using an O-ring 8 and then the outlet 9 is sealed and air having a pressure of 2 kg / cm ² is supplied from the inlet 10. Thus, the presence or absence of leakage from the outlet 12 was measured. As a result, no leakage was observed, and it was confirmed that the sealed state was good.

Comparative Example 1
In Example 1, the same conditions as in Example 1 were used as the bundling tube with a baffle, in which a paste-like glass material (SK360) was applied between the baffle 2 and the bundling tube 1 shown in FIG. A heat treatment was performed below to determine the presence or absence of leakage. As a result, leakage was confirmed even when the number of heat treatments was increased.

Example 2
In Example 1, the number of glass material-coated hollow fiber membranes was changed to 91 and used.

Comparative Example 2
In Example 2, the inner diameter of the stepped portion of the bundled tube with the countersunk was changed to 3.3 mm for both D ₁ and D ₂ and the sealing process was performed.

The relationship between the number of heat treatments and the presence or absence of leakage in Example 2 and Comparative Example 2 is shown in the following table.
table
Number of heat treatments Example 2 Comparative example 2
1 Below detection limit 1355 ml / min
2 〃 272.4 ml / min
10 〃 197.1 ml / min
20 〃 285.6 ml / min
(Below detection limit: 2 ml / min or less)

It is sectional drawing which shows the hollow fiber membrane module comprised by accommodating the ceramic hollow fiber membrane in the eyepiece integrated bundled tube which shows one Embodiment of this invention. It is sectional drawing of the through-hole which has the level | step-difference part provided in the eye plate which fixes a ceramic hollow fiber membrane. It is sectional drawing of the bundling pipe | tube which has two divided and has a slide structure which shows other embodiment of this invention. It is sectional drawing which shows the aspect which sets the hollow fiber membrane module of this Embodiment to a leak evaluation test apparatus, and performs a gas leak test. It is sectional drawing which shows an example of the conventional hollow fiber membrane module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bundled pipe 2 Eyepiece 3 Porous ceramic hollow fiber membrane 4 Glass material 5,6 Bundled pipe slide part 7 Hollow fiber membrane module

Claims (5)

In a hollow fiber membrane module in which a porous ceramic hollow fiber membrane is inserted into a through-hole of a through-hole drilled pan fitted into a bundled tube end , one end of the through-hole provided in the pan is The large diameter portion, the other end portion forms a small diameter portion, and has a step portion that narrows the inside of the through hole from the large diameter portion to the small diameter portion, and the inner diameter of the large diameter portion is 0.5 to 0.7mm large, the inner diameter of the small diameter portion is set 0.2~0.5mm large, sealed treated glass material between the through-holes and the hollow fiber membrane set an inner diameter difference between the large diameter portion and a small diameter portion to 0.1~0.4mm A hollow fiber membrane module. The hollow fiber membrane module according to claim 1, wherein the large-diameter portion is disposed on the end side of the hollow fiber membrane.   The hollow fiber membrane module according to claim 1, wherein the bundled tube and the eye plate are integrally formed.   The hollow fiber membrane module according to claim 1 or 3, wherein the bundled tube has a two-part fitting structure. A paste-like glass sealing material is applied to the joint between the through-hole having a stepped portion provided on the end plate where the porous ceramic hollow fiber membrane is inserted and the hollow fiber membrane, which is arranged at both ends of the bundled tube, The method for producing a hollow fiber membrane module according to claim 1 , wherein the sealing between the through hole and the hollow fiber membrane is performed by firing at 1100 ° C.

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