JPH05161830A - Hollow yarn membrane bundle, production thereof and reel for taking up hollow yarn membranes - Google Patents

Abstract

PURPOSE:To obtain a hollow yarn membrane bundle of good quality by rolling spun hollow yarn membranes round a reel to form an endless bundle having a circular or semicircular cross section and cutting the bundle at a specific region in the rolling direction thereof to insert the cut bundle in a cylindrical case even when the bundle is not rearranged. CONSTITUTION:A hollow yarn membrane taking-up reel (a) to be used is formed so that the hollow yarn membrane support part thereof becomes a recessed shape as viewed from the advance direction of hollow yarn membranes. When the number of turns of the hollow yarn membranes on the recessed reel (a) is made large toward the center part of the reel (a), the hollow yarn membranes are taken up so as to have a circular cross section. When the taking-up of the hollow yarn membranes is stopped at the point of time when the traverse of the hollow yarn membranes becomes semicircular, an endless hollow yarn membrane bundle having a semicircular cross section is formed. This bundle is cut at a specific region in its rounding direction. By this constitution, since the hollow yarn bundle can be inserted in a cylindrical case even when the bundle is not rearranged, the damage and leak of the hollow yarn bundle can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a hollow fiber membrane for fluid separation, and a hollow fiber membrane spun from a spinning device, which is wound around a frame to form an endlessly wound hollow fiber membrane bundle, The present invention relates to a method for producing a hollow fiber membrane bundle, which is obtained by cutting the hollow fiber membrane bundle at a specific position in the circumferential direction to obtain an endless circular hollow fiber membrane bundle.

[0002]

2. Description of the Related Art Recently, hollow fiber membrane modules for fluid separation have come to play an active role in applications requiring particularly high cleanliness, such as supplying ultrapure water for pyrogen-free pharmaceutical production. Came. Therefore, it is essential that defects such as scratches do not exist or occur even in the hollow fiber membrane. For that purpose, it is necessary to build quality in such a manner that the above-mentioned problems can be solved even in the production stage of the hollow fiber membrane. As a general method for producing a hollow fiber membrane bundle, a hollow fiber membrane fed from a spinning device is wound around a frame to form an endless circular hollow fiber membrane bundle, and then the endless circular hollow fiber membrane bundle is A method is known in which an end-shaped hollow fiber membrane bundle is obtained by cutting at a specific portion in the circumferential direction. When wound around the frame, a traverse is applied so as to be evenly wound around the frame, but the cross-section of the end-shaped hollow fiber membrane bundle after cutting is conventionally rectangular and not circular. Therefore, when inserting into a cylindrical module case, it was necessary to apply an external force to rearrange the bundle so as to have a circular cross section. As a result, the hollow fiber membranes may be rubbed with each other to damage the hollow fiber membranes, or in some cases, to leak from the hollow fiber membranes, thereby impairing the integrity of the membrane module.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems such as scratches and leaks, and does not need to rearrange the bundle when inserting it into a cylindrical module case. The present invention provides a good circular hollow fiber membrane bundle and a method for producing the same.

[0004]

The present invention is characterized in that (1) the cross-sectional shape of an endlessly wound hollow fiber membrane bundle wound around a hollow fiber membrane winding frame is circular or semicircular. (2) A hollow fiber membrane bundle spun from a spinning device is wound around a frame to form an endlessly wound hollow fiber membrane bundle, and the endlessly wound hollow fiber membrane bundle is wound around the hollow fiber membrane bundle. In the method for producing a hollow fiber membrane bundle, which is obtained by cutting at a specific site in a direction to obtain an endless hollow fiber membrane bundle,
(A) A frame in which the hollow fiber membrane supporting portion of the hollow fiber membrane take-up frame is concave when viewed from the direction of travel of the hollow fiber membrane is used, and (b) the hollow fiber membrane is closer to the center of the hollow fiber membrane. A method for producing a hollow fiber membrane bundle, which comprises traversing in such a manner that the number of windings is increased, and (3) a hollow fiber membrane winding frame, wherein the winding frame is arranged in a direction in which the hollow fiber membrane advances. The hollow fiber membrane winding frame is characterized in that it has a semicircular recess in the cross section as viewed.

The present invention will be described below. One embodiment of the present invention is shown in FIG. The endless winding means that the hollow fiber membrane is not open except at two points, that is, the beginning and the end of winding, and the hollow fiber membrane is wound around the frame. The hollow fiber membrane bundle may have a single fiber membrane wound around it, or may have a plurality of hollow fiber membranes aligned and wound around it. The circular cross-sectional shape of the endlessly wound hollow fiber membrane bundle means that the ratio of the minimum diameter of the bundle to the maximum diameter of the bundle is between 0.8 and 1.0. Since a step corresponding to the outer diameter of the hollow fiber membrane is inevitably generated and the thread may be collapsed to some extent, this level is unavoidable. This value is 1
The closer to, the higher the packing density of the hollow fiber membrane in the module can be made, which is preferable. If it is less than 0.8, the packing density is significantly reduced.

Next, a method for manufacturing the hollow fiber membrane bundle of the present invention will be described with reference to the drawings. One embodiment of the frame used in the present invention is shown in FIG. FIG. 1 is a front view (a) and a side view (b) of a winding frame having four corners, and FIG. 3 is a front view (a) and a side view of a winding frame having two corners ( b). The cross section of the hollow fiber membrane bundle taken along the line AA ′ in FIG. 1 is shown in FIG.

In order to wind the hollow fiber membrane around these frames, there is a method of rotating the frame or winding the hollow fiber membrane around a stationary frame by guiding the hollow fiber membrane with a pulley or the like. The present invention can be implemented by either method, but the former is preferable because the control structure is simpler. In the present invention, as a method of winding the hollow fiber membrane so that the cross section has a circular shape, a frame in which the hollow fiber membrane supporting portion of the hollow fiber membrane winding frame is concave when viewed from the traveling direction of the hollow fiber membrane is used. It is necessary to traverse the hollow fiber membrane on the concave frame so that the number of windings of the hollow fiber membrane increases toward the central portion. When such a method is adopted, the hollow fiber membrane is wound into a circular shape as shown in FIG. Further, as another method in which the end-shaped hollow fiber membrane bundle has a circular cross section in connection with the method of the present invention, the traverse of the hollow fiber membrane in the above method is shown in FIG. 2 (b). When it becomes a semi-circular shape, the winding is stopped,
An endless circular hollow fiber membrane bundle having a semicircular cross section formed is cut at a specific portion in the circumferential direction, and the obtained two semicircular endless hollow fiber membrane bundles are used. It is also possible to turn over the bundle and obtain a hollow fiber membrane bundle having a semicircular chord and a circular cross section.

However, in the traverse method in the conventional yarn winding device, the hollow fiber membrane guide pulley is normally moved along a groove formed in a sine curve shape on a rotating cylindrical surface as shown in FIG. It is generally done. According to this method, only the winding layer having a constant thickness can be formed on the frame of the hollow fiber membrane as shown by the diagonal lines in FIG. 4 (b).
However, in order to be able to use the traverse method using the rotating cylinder in the present invention, it is possible to perform a traverse in which the number of turns increases toward the center of the frame in order to make the cross-sectional shape of the hollow fiber membrane bundle circular. To achieve this, it is necessary to engrave the groove on the surface of the rotating cylinder into a curve whose swing width changes as shown in FIG. Therefore, in the present invention, a method of controlling the swing width with a personal computer or the like is adopted. FIG. 7 shows an example of the system. A bar Q having a hollow fiber membrane guide pulley P has a rack gear R at its end and is in contact with a pinion gear G. The pinion gear G is in contact with another pinion gear G2 fixed to the shaft of the traverse control motor M, and shifts the rotation speed to an appropriate value. In the method of controlling the swing width by a personal computer, a plurality of parallel strings are drawn in advance on an arc corresponding to the cross section of the hollow fiber membrane bundle with the outer diameter of the hollow fiber membrane as intervals, as shown in FIG. The length of each string gives the swing width. When the swing width, that is, the intersection of the chord and the arc is reached, the motor reverses and the pulley P moves backward. Specifically, when the winding on the frame is started, the pulley P is set near the center c of the frame. When the sensor detects that the winding has progressed to point d, the motor M reverses and P is reached until point e is reached.
To send. By repeating this, the cross section of the hollow fiber membrane bundle wound on the frame is made circular. This control can be performed using a sequencer or a personal computer. Since the swing width can be freely changed by changing the program, the degree of freedom in selecting the diameter of the hollow fiber membrane bundle is higher than that in the conventional traverse method using a cylinder.

Further, the winding frame used in the present invention is 2
It is preferable that the frame has the above-mentioned corners, that is, the hollow fiber membrane supporting portion. Those having 2 to 6 corners are more preferable. If the winding frame is circular, that is, if the supporting portion of the hollow fiber membrane extends over the entire circumference of the circle, the hollow fiber membrane bundle may be wound up depending on the type of polymer forming the hollow fiber membrane and the diameter of the hollow fiber membrane. If the bundle is removed from the frame, the bundle may be twisted or curled, and the bundle may not be smoothly accommodated in the module case. Therefore, in the present invention, it is preferable that the winding frame has a corner and the end-shaped bundle is cut out from each side. 1 has four corners, 2 in FIG.
This is the case with one corner.

[0010]

EXAMPLES The present invention will be described more specifically by way of examples.

[0011]

Example 1 An endless inner diameter of 0.
A hollow fiber single yarn made of polyacrylonitrile having a diameter of 75 mm and an outer diameter of 1.35 mm was wound using a frame shown in FIG. The frame is rotated 2350 times while traversing so that the bundle has a circular cross-section, and the wound cross-sectional shape is a circular endless loop-shaped bundle of hollow fiber having a diameter of 70 mm.
The hollow fiber membrane bundle having a length of 1300 mm was obtained by cutting at the frame end. The traverse was controlled by a personal computer. The minimum diameter of this hollow fiber membrane bundle is 68 mm, the maximum diameter is 71 mm, and the ratio is 0.1.
It was 96 and could be accommodated in a module case with an inner diameter of 83 mm and a total length of 1000 mm without applying any external force. Both ends were sealed with gypsum, bonded to a case with epoxy resin, and then cut at the bonded parts. Compressed air was sent from the outside of the hollow fiber membrane in the water tank, but no leak was observed.

[0012]

[Embodiment 2] In the frame shown in FIG. 3, inner diameter = 0.8 mm, outer diameter =
A 1.4 mm polyacrylonitrile hollow fiber membrane was wound up. The frame was made of stainless SUS316 and the inner surface was buffed. The spinning speed was 20 m / min. When the frame was rotated 1175 by traversing under the control of a personal computer and the frame was rotated 1175, the endless circular hollow fiber membrane bundle had a semicircular cross section with a diameter of 70 mm. The hollow fiber membrane bundle was fixed with a semicircular cross section and cut at the end. Two hollow fiber membrane bundles with a semi-circular cross section were obtained from one frame, and these plane portions were opposed to each other and fixed again to obtain a hollow fiber membrane bundle with a circular cross section. The minimum diameter of this hollow fiber membrane bundle was 66 mm, the maximum diameter was 73 mm, and the ratio was 0.90, and it could be housed in a module case with an inner diameter of 83 mm and a total length of 1000 mm without any external force. Both ends were sealed with gypsum, bonded to a case with epoxy resin, and then cut at the bonded parts. Compressed air was sent from the outside of the hollow fiber membrane in the water tank, but no leak was observed.

[0013]

Comparative Example The same polyacrylonitrile hollow fiber single yarn as in Example 1 was wound using the frame shown in FIG. The frame was rotated 2350 times while traversing the single yarn so that the thickness was constant, and then cut at the skein end to obtain a hollow fiber membrane bundle having a length of 1300 mm. Since the cross-sectional shape of this hollow fiber membrane bundle was a rectangle with a vertical length of about 100 mm and a horizontal length of about 50 mm (the ratio of the minimum diameter to the maximum diameter was about 0.5), an external force was applied so that the bundle was cylindrical with both hands. It could not be accommodated in the module case without adding. The cross-sectional shape was a circle having a diameter of 78 mm. Both ends were sealed with gypsum, then bonded to a case with an epoxy resin and then cut. When compressed air was fed from the outside of the hollow fiber membrane in the water tank, there was a leak in two places in the bundle on one side. When the case was disassembled, thread crushing and scratches that occurred when the bundle was rearranged by applying an external force were observed in several places, and two of them were crushed and caused leakage.

[0014]

The hollow fiber membrane bundle of the present invention can be inserted into a cylindrical case without rearranging the bundle by applying an external force, so that the hollow fiber membrane can be prevented from being scratched or leaked. The modular integrity can be greatly increased.
Further, conventionally, it is expected that fine particles due to breakage of the hollow fiber membrane caused by friction when rearranging the bundle can be prevented, and that it can contribute to improvement of cleanliness.

[Brief description of drawings]

FIG. 1 is a view showing a winding frame having four corners according to an embodiment of the present invention, in which (a) is a front view and (b) is a side view.

FIG. 2 is a view showing a cross section of a hollow fiber membrane bundle of the present invention,
FIG. 6A is a cross-sectional view showing a circular bundle and FIG.

3A and 3B are views showing a winding frame having two corners according to one embodiment of the present invention, where FIG. 3A is a front view and FIG. 3B is a side view.

FIG. 4 is an example of a conventional winding frame, in which (a) is a front view and (b) is a side view.

FIG. 5 is a schematic view of a groove pattern engraved on a rotating cylinder used in a conventional traverse method.

FIG. 6 is a schematic view of a groove pattern engraved on a rotating cylinder used in the traverse method of the present invention.

FIG. 7 is a schematic view showing a traverse device controlled by a personal computer according to the present invention.

FIG. 8 is an explanatory diagram of a personal computer-controlled traverse method of the present invention.

FIG. 9 is a band for bundling a semicircular bundle used in the present invention.

[Explanation of symbols]

 P Pulley Q Bar G, G2 Pinion gear R Rack gear M Traverse control motor Y Hollow fiber membrane bundle B Band H Clasp

Claims (3)

[Claims] 1. A hollow fiber membrane bundle having a circular or semi-circular cross-sectional shape of the endlessly wound hollow fiber membrane bundle wound on a hollow fiber membrane winding frame. 2. A hollow fiber membrane spun from a spinning device is wound on a frame to form an endlessly wound hollow fiber membrane bundle, and the endlessly wound hollow fiber membrane bundle is then wound at a specific portion in the circumferential direction. In the method for producing a hollow fiber membrane bundle, which is obtained by cutting to obtain an end-shaped hollow fiber membrane bundle, (a) the hollow fiber membrane supporting portion of the hollow fiber membrane winding frame is concave when viewed from the traveling direction of the hollow fiber membrane. A method for producing a hollow fiber membrane bundle, characterized in that a certain frame is used, and (b) the hollow fiber membrane is traversed and wound so that the number of windings of the hollow fiber membrane is increased toward the center of the frame. 3. The hollow fiber membrane winding frame, wherein the winding frame has a semicircular recess in a cross section as viewed from the direction of travel of the hollow fiber membrane.