【発明の詳細な説明】[Detailed description of the invention]
〔産業上の利用分野〕
本発明は中空糸過膜の整束方法に関するもの
であり、腰の弱い中空糸過膜をよれ、曲がり等
のない状態で膜束とすることのできる整束方法に
関するものである。
〔従来技術〕
一般に溶液やエマルジヨン、サスペンジヨンの
ような液体混合物の中の特定の成分を選択的に透
過させる膜を選択性透過膜と呼んでいるが、これ
らの中で限外過膜はコロイド、タンパク質、合
成高分子物質、微生物等を含む溶液やエマルジヨ
ンからその溶媒や分散媒を分離することができる
ので、工場排水の処理、下水浄化、食品、医薬、
醸造、発酵等の分野における精製、濃縮工程に用
いられている。このような限外過膜としては酢
酸セルロースを素材とするものをはじめ、芳香族
ポリアミド、ポリスルホン、ポリアクリロニトリ
ル、ポリビニルアルコール等種々の素材の膜が利
用されている。一方膜の形状としては平膜、管状
膜、中空糸膜などがあるが、中でも中空糸膜は
過モジユールとしての膜の充填密度を高くする事
が出来、過装置の小型・軽量化が図れるため純
水製造、食品加工、その他の分野で広く用いられ
ている。
しかしながら中空糸膜は通常、数百本乃至数千
本の膜を一束とした過エレメントの形で使用に
供されるため、製膜後、エレメント化の工程が必
要である。このエレメント化の工程とはハウジン
グと呼ばれる過容器に中空糸膜を束として装填
するために、束の両端の少なくとも一方を開口し
た状態で接着固定する工程であるが、この工程に
おいて中空糸膜自体によれ、曲がり等があると、
束から離脱した状態で膜が接着固定されたり、或
いは膜端末の接着固定がなされず液もれなどの不
良を生じやすい。中空糸膜は概して腰が弱く、製
膜時にドラム或いはカセによる巻取りの際に巻き
ぐせによる膜の曲がりや、また巻きのずれからく
る膜のよれが生じやすく、エレメント化工程に支
障をきたすため、よれ、曲がりのない整束方法が
望まれていた。
〔発明の目的〕
本発明はかかる状況にかんがみ種々検討した結
果、中空糸膜製造において、よれ、曲がりが発生
しても、水の流れを利用することにより、よれ、
曲がりのない状態に膜束を真直ぐ整束できること
を見出し、本発明をなすに至つた。
〔発明の構成〕
本発明は中空糸過膜製造後、該過膜を複数
本束ねる整束工程において、膜束上部を保持し、
膜束の上方周囲より下方向へ水をかけ、膜束をそ
ろえる事を特徴とする中空糸過膜の整束方法で
ある。
本発明に用いる中空糸過膜は酢酸セルロース
を素材とするものをはじめ、芳香族ポリアミド、
ポリスルホン、ポリアクリロニトリル、ポリエー
テルイミド、ポリビニルアルコール等種々の素材
の膜が用いられる。
また膜の内径・肉厚・長さにおいても特に限定
されることはなく、一束当りの膜本数も任意に選
ぶことが出来る。
中空糸膜の製造法については膜素材となる樹脂
を溶媒に溶解した樹脂原液を一つ、或いは複数個
のホールを有する環状ノズルから凝固液内に押出
す湿式法が通常用いられる。
また所定長さの膜を得る方法としては、通常、
円形のドラムに巻取るか、或いは多角形のカセに
巻取るかした後、束全体として所定長さで一度に
切断する方法、または連続的に押出されてくる膜
を巻取ることなしに、１本ずつ切断する方法がと
られる。
膜のよれ、曲がりは巻取り、切断時に発生する
のが大部分である。即ち、円形のドラムに巻取る
場合、切断された膜はドラムに浴つた巻きぐせが
ついており、これが膜の曲がりとなつて残る。ま
た、カセに巻取る場合でも膜どうしの重なりが均
一でなく、ずれが発生した時によれが生じる。さ
らに膜一本ずつ連続的に切断する場合においても
切断された膜同士がからみ合い、よれ、曲がりが
生じる。
このよれ、曲がりは膜が長くなる程、又細くな
る程生じやすく、エレメント化工程への支障が大
きい。
本発明における整束の方法であるが、まず所定
本数の膜の一端をそろえ、固定する。固定につい
ては膜束の大きさに合わせた治具を使つてもいい
し、又テープ等でしばつても良い。次にこの固定
部を上部として膜束が垂直に垂れる様、固定部を
保持する。この時保持部分は前後・左右に動かせ
る様にする事が好ましい。
水は固定部のすぐ下から膜束にかけるが、膜束
に対して平行ではなく角度を持たせる事が必要で
ある。膜束に対して平行であると膜束内部に水が
いきわたらず、内部に存在するよれ、曲がりを直
すことが出来ない。また角度が大きすぎてもかえ
つて膜のよれを発生する事になりかねない。この
角度は膜束の大きさ、水の流量等によつて適宜最
適条件を見出す必要があるが、多くの場合、膜束
に対し、15度〜75度が好適であり、整束中に角度
を変える事により、膜束の隅々まで水をいきわた
らすことができる。また水の吐出口であるが、膜
束全体に均等に水をかける事が好ましいため、膜
束周囲に等間隔に並べる方が良く、少くとも３ケ
所以上必要である。
水の流量は膜束の大きさにより必要量が異なる
が、70ｍ／ｍφの束の場合15／min程度必要で
あり、膜束がこれ以上大きければより多くの流量
が必要である。また時間的には30秒〜１分間で充
分であるが、水をかける時に膜束全体を小きざみ
に前後左右に動かすのが効果的であり、この操作
を同時に行うことにより時間を短縮する事も可能
である。
〔発明の効果〕
本発明方法によれば簡単な方法でよれ、曲がり
のない中空糸膜束を得ることができ、次のエレメ
ント化工程での工数削減、不良率の低減が図れる
ため、中空糸膜束の整束方法として極めて有用で
ある。
実施例 １
ポリスルホン樹脂（UdelＰ−1700）640ｇを
Ｎ−メチル―２―ピロリドン3360ｇに溶解した樹
脂原液を内部凝固液である水と共に環状ノズルか
ら水中に押出し、内径1.0ｍ／ｍφ、肉厚0.3ｍ／
ｍの中空糸膜を得た。この中空糸膜を直径600
ｍ／ｍφの円形ドラムに200本、400本、800本を
それぞれ巻取り、長さ1884ｍ／ｍの膜束３本を得
た。
次にこの膜束を表１の条件にて整束し、膜のよ
れ、曲がりを観察したところ、３束共よれ、曲が
りを認めなかつた。
[Industrial Application Field] The present invention relates to a method for bundling hollow fiber membranes, and relates to a method for bundling hollow fiber membranes that are weak in stiffness and can be made into a membrane bundle without twisting or bending. It is something. [Prior art] In general, membranes that selectively permeate specific components in liquid mixtures such as solutions, emulsions, and suspensions are called selectively permeable membranes. It is possible to separate solvents and dispersion media from solutions and emulsions containing proteins, synthetic polymers, microorganisms, etc., so it can be used for industrial wastewater treatment, sewage purification, food, medicine, etc.
It is used in purification and concentration processes in fields such as brewing and fermentation. As such ultrafiltration membranes, membranes made of various materials such as those made of cellulose acetate, aromatic polyamide, polysulfone, polyacrylonitrile, and polyvinyl alcohol are used. On the other hand, membrane shapes include flat membranes, tubular membranes, and hollow fiber membranes, among which hollow fiber membranes can increase the packing density of the membrane as a supermodule, making it possible to reduce the size and weight of the filtration equipment. Widely used in pure water production, food processing, and other fields. However, since hollow fiber membranes are usually used in the form of an element made up of a bundle of several hundred to several thousand membranes, a step of forming elements is required after membrane formation. This process of forming elements is a process of adhesively fixing the bundle with at least one of both ends open in order to load the hollow fiber membranes as a bundle into a container called a housing.In this process, the hollow fiber membranes themselves are If there is a twist or bend, etc.
The membrane is likely to be adhesively fixed in a state separated from the bundle, or the ends of the membrane may not be adhesively fixed, resulting in defects such as liquid leakage. Hollow fiber membranes are generally weak, and during film production, when wound up using a drum or skein, the membrane tends to bend due to curling, and the membrane tends to twist due to misalignment of the winding, which hinders the element formation process. There was a desire for a method of bundling that does not cause kinks or bends. [Object of the Invention] As a result of various studies in view of the above situation, the present invention has been developed to eliminate twisting and bending by utilizing water flow even if twisting or bending occurs in hollow fiber membrane manufacturing.
It was discovered that a membrane bundle can be straightened without bending, and the present invention was completed. [Structure of the Invention] The present invention involves holding the upper part of the membrane bundle in the bundling step of bundling a plurality of hollow fiber membranes after manufacturing the hollow fiber membranes,
This method of bundling hollow fiber membranes is characterized by spraying water from the upper circumference of the membrane bundle downward to align the membrane bundle. The hollow fiber membranes used in the present invention include those made of cellulose acetate, aromatic polyamide,
Membranes made of various materials such as polysulfone, polyacrylonitrile, polyetherimide, and polyvinyl alcohol are used. Furthermore, the inner diameter, wall thickness, and length of the membranes are not particularly limited, and the number of membranes per bundle can be arbitrarily selected. As for the manufacturing method of hollow fiber membranes, a wet method is usually used in which a resin stock solution in which a resin serving as a membrane material is dissolved in a solvent is extruded into a coagulating liquid through an annular nozzle having one or more holes. In addition, as a method for obtaining a film of a predetermined length, there are usually
A method in which the entire bundle is cut into a predetermined length at once after being wound on a circular drum or a polygonal skein, or without winding up the continuously extruded membrane. The method is to cut each book one by one. Most of the twisting and bending of the film occurs during winding and cutting. That is, when the film is wound around a circular drum, the cut film has curls on the drum, which remain as bends in the film. Further, even when the film is wound up into a skein, the overlap between the films is not uniform, and when misalignment occurs, kinks occur. Furthermore, even when the membranes are continuously cut one by one, the cut membranes become entangled with each other, causing twisting and bending. The longer or thinner the film is, the more likely this twisting and bending will occur, and the greater the hindrance to the element-forming process. In the bundling method of the present invention, first, one ends of a predetermined number of membranes are aligned and fixed. For fixing, a jig that matches the size of the membrane bundle may be used, or it may be tied with tape or the like. Next, the fixing part is held so that the membrane bundle hangs vertically with this fixing part at the top. At this time, it is preferable that the holding part be movable back and forth and left and right. Water is applied to the membrane bundle from just below the fixing part, but it is necessary to spray it at an angle rather than parallel to the membrane bundle. If it is parallel to the membrane bundle, water will not flow inside the membrane bundle, making it impossible to correct any kinks or bends that exist inside the membrane bundle. Furthermore, if the angle is too large, it may even cause the film to twist. It is necessary to find the optimum conditions for this angle depending on the size of the membrane bundle, the flow rate of water, etc., but in most cases, 15 degrees to 75 degrees is suitable for the membrane bundle, and the angle is By changing the temperature, water can be distributed to every corner of the membrane bundle. Regarding the water discharge ports, it is preferable to spray water evenly over the entire membrane bundle, so it is better to arrange them at equal intervals around the membrane bundle, and at least three or more are required. The required flow rate of water varies depending on the size of the membrane bundle, but in the case of a bundle of 70 m/mφ, approximately 15/min is required, and if the membrane bundle is larger than this, a larger flow rate is required. In addition, 30 seconds to 1 minute is sufficient time, but it is effective to move the entire membrane bundle back and forth and left and right in small increments when applying water, and it is possible to shorten the time by performing these operations at the same time. is also possible. [Effects of the Invention] According to the method of the present invention, a hollow fiber membrane bundle without twisting and bending can be obtained in a simple manner, and the number of man-hours in the next element formation process can be reduced and the defect rate can be reduced. This method is extremely useful as a method for aligning membrane bundles. Example 1 A resin stock solution in which 640 g of polysulfone resin (UdelP-1700) was dissolved in 3360 g of N-methyl-2-pyrrolidone was extruded into water through an annular nozzle together with water as an internal coagulating liquid, and the inner diameter was 1.0 m/mφ and the wall thickness was 0.3 m. /
A hollow fiber membrane of m was obtained. This hollow fiber membrane has a diameter of 600
200, 400, and 800 membranes were respectively wound around a circular drum of m/mφ to obtain three membrane bundles each having a length of 1884 m/m. Next, the membrane bundles were bundled under the conditions shown in Table 1, and when the membranes were observed for twisting and bending, all three bundles were twisted and no bending was observed.
【表】
実施例 ２
実施例１と同じ方法にて膜本数1000本の膜束を
５束得、それぞれ表２の条件にて整束し、膜のよ
れ、曲がりを観察したところ、５束共よれ、曲が
りを認めなかつた。その後、この膜束を内径70
ｍ／ｍ、外径80ｍ／ｍの型に装入し、液状エポキ
シ樹脂を型内に注入、硬化させ、膜有効長1700
ｍ／ｍの過エレメントを得た。この過エレメ
ントに１Kg／cm2の圧力で窒素ガスを流し、圧力チ
エツクを行つたところ、圧力モレもなく、すべて
合格であつた。[Table] Example 2 Five membrane bundles each containing 1000 membranes were obtained using the same method as in Example 1, and each bundle was aligned under the conditions shown in Table 2. When the membranes were observed for twisting and bending, all five bundles were found to be I didn't notice any twisting or bending. Then, this membrane bundle was
m/m, outside diameter 80 m/m, inject liquid epoxy resin into the mold, harden it, and obtain a film with an effective length of 1700 m/m.
A cross-element of m/m was obtained. When a pressure check was performed by flowing nitrogen gas at a pressure of 1 kg/cm 2 through this filter element, there was no pressure leakage, and everything passed the test.
【表】
比較例
実施例１と同じ方法にて膜本数1000本の膜束を
５束得、膜のよれ、曲がりを観察したところ、５
束共、両端部分にカールを認め、よれを認めたも
のが３束あつた。
その後、実施例２と同じ方法にて過エレメン
トを得、圧力チエツクを行つたところ、よれのあ
る束から得られた過エレメントは３本中２本に
圧力モレがあつた。[Table] Comparative Example Five membrane bundles each containing 1000 membranes were obtained using the same method as in Example 1, and when the membranes were observed for twisting and bending, 5.
Curls were observed at both ends of the bundles, and three bundles were found to be twisted. Thereafter, when the filter elements were obtained in the same manner as in Example 2 and a pressure check was performed, pressure leakage occurred in two out of three filter elements obtained from the kinked bundle.