JP2012210553A - Hollow fiber membrane module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hollow fiber membrane module in which a hollow fiber membrane is adhered to a cylindrical case inner circumferential surface by a resin, and the leakage failure due to the damage of the hollow fiber membrane in which the adhered zone is peeled off in a filter operation is surely prevented.SOLUTION: The hollow fiber membrane module includes: a hollow fiber membrane bundle; a cylindrical case that stores the hollow fiber membrane bundle; and a resin part in which at least one side end of the hollow fiber membrane bundle is adhered/fixed to the cylindrical case. A groove is prepared at the inner circumferential surface of the cylindrical case in at least a portion of a part in which the resin part is prepared at about the longitudinal direction of the hollow fiber membrane module, an arc ring is prepared to fit in the groove and to be located between the cylindrical case and the hollow fiber membrane bundle, the arc ring has an overlap part at the circumferential direction, and the inner circumferential surface contacts to the outer periphery of the hollow fiber membrane bundle.

Description

  The present invention relates to a hollow fiber membrane module for fluid separation. More specifically, the present invention relates to a hollow fiber membrane module suitable for producing a large amount of industrial water or tap water by membrane filtration using river water, lake water, ground water, seawater, domestic wastewater, industrial wastewater, or the like as raw water.

  In recent years, microfiltration membranes and ultrafiltration membranes have been applied to water treatment processes for producing industrial water and tap water from river water, lake water, groundwater, seawater, domestic wastewater, and industrial wastewater. In addition, these water treatment processes are used for a long time for a large amount of stock solution with a relatively large amount of turbidity, so a high filtration membrane area for treating a large amount of raw water, a pressure resistant structure that can withstand strong filtration pressure for a long time. There is a need for an air scrubbing function for cleaning hollow fiber membranes contaminated with turbidity.

  In such a water treatment process, an external pressure type hollow fiber membrane module that filters from the outside to the inside of the hollow fiber membrane is frequently used. The external pressure type hollow fiber membrane module is a hollow case filled with a hollow fiber membrane bundle formed by bundling hundreds to tens of thousands of hollow fiber membranes into a straight shape, and both ends of the hollow fiber membrane bundle are filled with resin. It is configured to be bonded and fixed to a cylindrical case, and raw water is supplied to the outside of the hollow fiber membrane bundle to permeate the hollow fiber membrane, and the permeated filtered water is taken out from the open end of the hollow fiber membrane. ing.

  During operation of the external pressure type hollow fiber membrane module, air scrubbing is used to vibrate the surface of the hollow fiber membrane with air blown to the outer surface of the membrane, and in the process of filtering raw water, the turbid components adhering to the outer surface of the membrane are removed. Cleaning methods can be employed intermittently. In this method, one or a plurality of through holes are formed in the resin partition wall on the side where the hollow part of the hollow fiber membrane is sealed, and air is blown into the entire hollow fiber membrane bundle from the through hole so that cleaning is efficient. Can be done automatically. At this time, by fixing both ends of the hollow fiber membrane bundle to the inner wall of the housing in advance so that the hollow fiber membrane bundle has a slack in the outer cylinder, the hollow fiber membranes swayed during air scrubbing are rubbed together and washed. Furthermore, it can be performed efficiently. In addition to air scrubbing, a washing method that removes turbid components that block the pores of the membrane by flowing backwash water from the filtered water side to the raw water side of the hollow fiber membrane module can also be adopted intermittently. .

  Such a hollow fiber membrane module has various advantages such as a simple seal structure that separates the stock solution before membrane filtration and the permeate after membrane filtration, and easy operation management. The greatest feature is that the filtration membrane area per unit volume of the module can be made very large, that is, the filtration capacity (filtered water amount) can be easily improved. As one method for increasing the filtration membrane area per unit volume of the module, basically, a hollow fiber membrane bundle is constituted by as many hollow fiber membranes as possible, and the filling rate of the hollow fiber membranes is increased. Is desirable. However, as the number of hollow fiber membranes increases, it becomes more difficult to load the hollow fiber membrane bundle into the cylindrical case. Furthermore, if the hollow fiber membrane is too close to the inner peripheral surface of the cylindrical case, the resin is likely to penetrate between the hollow fiber membrane and the inner peripheral surface of the cylindrical case due to capillary action, so that both ends of the hollow fiber membrane bundle are In the vicinity of the end face on the inner side in the module longitudinal direction of the resin part bonded and fixed, the hollow fiber membrane outer periphery is bonded to the cylindrical case inner peripheral surface with a resin with a small area. When subjected to the filtration operation in such a state, the adhesive portion between the hollow fiber membrane and the inner peripheral surface of the cylindrical case is peeled off by an external force such as air scrubbing during the operation, and the hollow fiber membrane is damaged at that time. So-called leakage occurs in which raw water before filtration is mixed with permeated water after filtration.

  In order to improve this, for example, Patent Document 1 discloses an area A1 of a portion surrounded by the hollow fiber membrane disposed on the outermost periphery of the hollow fiber membrane bundle on the end surface of the potting portion facing the outside of the cylindrical casing. The area A2 of the portion surrounded by the hollow fiber membrane disposed on the outermost periphery of the hollow fiber membrane bundle on the end surface facing the inside of the cylindrical casing satisfies A1 ≦ 0.85 × A2. This is disclosed. As a specific means, a method is disclosed in which a potting jig is provided with a small-diameter portion, and the hollow fiber membrane is focused on the radial center in the cross section of the hollow fiber membrane module. However, in this method, the location where the hollow fiber membranes are focused and supported is separated from the interface on the center side in the longitudinal direction of the hollow fiber membrane module of the resin that bonds and fixes the hollow fiber membrane and the cylindrical case. As a result, the hollow fiber membrane hangs down due to its own weight, and eventually the hollow fiber membrane and the inner peripheral surface of the cylindrical case approach each other.

JP 2001-276583 A

  The objective of this invention is providing the hollow fiber membrane module which eliminates the leak of a hollow fiber membrane more reliably, eliminating the conventional problem mentioned above.

The hollow fiber membrane module of the present invention that achieves the above object has a configuration described in any of the following.
(1) A hollow fiber membrane having a hollow fiber membrane bundle, a cylindrical case containing the hollow fiber membrane bundle, and a resin part in which at least one end of the hollow fiber membrane bundle is bonded and fixed to the cylindrical case In the hollow fiber membrane module, a groove is provided in an inner peripheral surface of the cylindrical case at least in a part of the hollow fiber membrane module where the resin portion is provided in the longitudinal direction. And an arc ring is provided so as to be positioned between the cylindrical case and the hollow fiber membrane bundle, and the arc ring has an overlap portion in the circumferential direction and has an inner peripheral surface. Is in contact with the outer periphery of the bundle of hollow fiber membranes.
(2) The hollow fiber membrane module according to (1), wherein the arc ring has irregularities on an outer peripheral surface.

  In the hollow fiber membrane module of the present invention, the potting resin portion is provided in the longitudinal direction of the hollow fiber membrane module and is positioned between the cylindrical case and the hollow fiber membrane bundle. An arc ring is provided. The arc ring has an overlap portion in the circumferential direction, and an inner peripheral surface is in contact with the outer periphery of the hollow fiber membrane bundle. Therefore, the hollow fiber membranes constituting the hollow fiber membrane bundle can be converged toward the radial center of the module near the module longitudinal inner interface of the potting resin portion, and thereby the hollow fiber membrane and the inner circumferential surface of the cylindrical case Can be avoided. As a result, the hollow fiber membrane is bonded near the inner side of the module longitudinal direction of the resin part at a position that is too close to the cylindrical case, and the adhesion is peeled off during operation to prevent the hollow fiber membrane from being damaged and leaking. it can. In the present invention, since the arc ring has an overlap portion in the circumferential direction, the arc ring can be widened and attached to the hollow fiber membrane bundle. The occurrence of damage to the hollow fiber membrane can be prevented, and the hollow fiber membrane can be focused without any leakage. Furthermore, in the hollow fiber membrane module of the present invention, a groove is provided on the inner peripheral surface of the cylindrical case, and the arc ring is provided so as to fit into the groove. Therefore, not only can the hollow fiber membrane be damaged or leaked at the bonded portion between the hollow fiber membrane and the cylindrical case, but also the peeling at the bonded portion between the arc ring and the cylindrical case can be prevented. Can be more reliably prevented.

It is a schematic longitudinal cross-sectional view which shows one Embodiment of the hollow fiber membrane module which concerns on this invention. It is a schematic diagram which shows one Embodiment of the circular ring used for the hollow fiber membrane module of this invention. It is a schematic diagram which shows one Embodiment of the circular ring of L-shaped cross section used for the hollow fiber membrane module of this invention. It is a schematic diagram of the C-shaped ring with a part and notch used in Comparative Example 2.

  Hereinafter, embodiments for carrying out the present invention will be described in detail.

  FIG. 1 is a schematic longitudinal sectional view showing an embodiment of a hollow fiber membrane module 1 according to the present invention.

  The hollow fiber membrane module 1 includes a hollow fiber membrane bundle 2 in which several hundred to several tens of thousands of hollow fiber membranes are bundled into a straight shape, a cylindrical case 10 and the like. The cylindrical case 10 is configured by providing nozzles 13 a and 13 b on the cylindrical side surface of the case body 11. The nozzle 13a can be used as a raw water discharge port, and the nozzle 13b can be used as a raw water supply port. The hollow fiber membrane bundle 2 having both ends cut into a fixed length is inserted into the cylindrical case 10, and both ends thereof are bonded and fixed by a resin 20. The nozzles 13a and 13b may be provided as necessary, and are not particularly limited to the present embodiment.

  The material of the hollow fiber membrane used in the present invention is not particularly limited as long as it is a porous hollow fiber membrane, but polyethylene, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, polytetrafluoro Ethylene, polyvinyl fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and chlorotrifluoroethylene-ethylene copolymer, polyvinylidene fluoride, polyacrylonitrile, polysulfone and An ultrafiltration membrane or a microfiltration membrane made of polyethersulfone or other material can be used as appropriate. Furthermore, a filtering material made of a sintered body of these polymers can also be preferably used. The inner and outer diameters of the hollow fiber membrane are not particularly limited, and various inner and outer diameters and cross-sectional structures can be used.

  Caps 14a and 14b are fastened and fixed to both ends of the cylindrical case 10 by, for example, cap nuts 15a and 15b. The caps 14a and 14b may be fixed to the cylindrical case 10 by direct engaging means such as screwing.

  In adhering and fixing the hollow fiber membrane bundle 2 to the inner peripheral surfaces of both ends of the cylindrical case 10 with the resin 20, on the nozzle 13a side (the nozzle side serving as a raw water drain port), the hollow fiber membranes are sealed between each other, And the hollow part of each hollow fiber membrane is made into the open state in the edge part. On the other hand, the end portion of the hollow fiber membrane bundle 2 on the nozzle 13b side (nozzle side serving as a raw water supply port) is sealed by the resin 20 entering the end portion of the hollow fiber membrane. However, the hollow part of the hollow fiber membrane may also be opened at the end, as in the nozzle 13a side.

  In the present invention, when the both ends of the hollow fiber membrane bundle 2 are bonded and fixed with the resin 20 as described above, the arc ring 16 is inserted and fixed to the inner wall of the end of the cylindrical case 10.

  FIG. 2 illustrates an arc ring 16 used as a converging means for the hollow fiber membrane bundle when both ends of the hollow fiber membrane bundle 2 are bonded and fixed with the resin 20 as described above ((a)). Front view, (b) side view).

  The arc ring 16 is not a closed annular member, but intersecting portions are alternately overlapped, and is formed so as to cover the entire circumference of the hollow fiber membrane bundle in a circular shape. Since the arc ring 16 is not closed by a ring, it can be reduced in diameter by deformation, for example, like a C-type retaining ring, and can be easily inserted into a cylindrical case. Further, since the arc ring can be expanded and attached to the hollow fiber membrane bundle, the occurrence of damage to the hollow fiber membrane can be prevented. Further, since the intersecting portions of the arc ring 16 are alternately overlapped, the hollow fiber membrane does not enter the portion where the arc ring 16 is not connected. Therefore, when the end portion of the hollow fiber membrane bundle 2 is bonded and fixed with the resin 20 at the end portion of the cylindrical case 10, the hollow fiber can be obtained by inserting the arc ring 16 into the end portion of the cylindrical case 10 as described above. The end of the film bundle 2 can be more reliably focused toward the center in the radial direction. And by this focusing, the hollow fiber membrane can be kept away from the inner peripheral surface of the cylindrical case.

  When the arc ring 16 is mounted, the groove portion 12 is provided in the cylindrical case 10, and the arc ring 16 is fitted and fixed to the groove portion 12. Therefore, for example, when the resin is fixed, even if a centrifugal force is applied to fill the end portion of the cylindrical case 10 with the resin 20, the positional deviation can be prevented. As a result, it is possible to prevent peeling at the bonding portion between the arc ring and the cylindrical case, and it is possible to more reliably prevent the occurrence of leakage.

  In the hollow fiber membrane module 1, the arc ring 16 is installed so as to enter the resin 20, but the position of the arc ring 16 is in the longitudinal direction of the hollow fiber membrane module with respect to the module longitudinal inner interface 21 of the resin 20. Outside. As the arc ring 16 and the interface 21 are closer, the hollow fiber membrane bundle 2 can be separated from the inner peripheral surface of the cylindrical case 10 at a position closer to the raw water drainage port or the raw water supply port. In addition, the problem that the resin oozes up by capillary action in the gap between the hollow fiber membrane and the inner peripheral surface of the cylindrical case 10 and damages the hollow fiber membrane at the time of filtration operation is the inside of the resin 20 in the longitudinal direction of the module. Although it occurs at the interface 21, the closer the arc ring 16 and the interface 21 are, the more the hollow fiber membrane bundle 2 can be separated from the inner peripheral surface of the cylindrical case 10 near the interface 21. Can be avoided.

  Further, FIG. 2 shows the circular arc ring 16 having a square cross-sectional shape, but instead of this, an L-shaped circular arc ring 17 as shown in FIG. 3 may be used ((a) front view, (b) )Side view). In the L-shaped arc ring 17, the arc ring 17 enters deeply in the longitudinal direction of the cylindrical case 10. For this reason, the length for converging and supporting the hollow fiber membrane bundle is extended, and a higher converging effect than that of the arc ring shown in FIG. 2 can be obtained. The cross-sectional shape is not limited to these examples, and an irregular polygon or other shape including a curve can be selected.

  Moreover, it is preferable to provide unevenness on the outer circumferences of the arc rings 16 and 17 so as to form a flow path 18 of resin or the like as shown in FIGS. When the resin 20 for bonding and fixing the cylindrical case 10, the arc rings 16 and 17, and the hollow fiber membrane bundle 2 is injected, the flow path 18 is filled with the resin 20 and / or the resin 20. Since air (not shown) existing in the air can flow through the flow path 18, the resin 20 and air can be easily replaced, and an air void (not shown) is formed inside the resin 20. Can be prevented.

  The material of the cylindrical case 10, the nozzles 13a and 13b, and the arc rings 16 and 17 are conveniently selected from metals such as stainless steel, plastics such as FRP, ABS, AES, polyvinyl chloride, polycarbonate, and polysulfone. be able to. In particular, plastics that can be easily reduced in weight and inexpensively mass-produced are preferable.

  Further, by providing a plurality of arc rings 16 and 17 of FIG. 2 or FIG. 3, the focusing effect can be further increased.

  In the above-described embodiment, the case where the hollow fiber membrane bundle is stored in a straight shape in the cylindrical case has been described. However, the hollow fiber membrane bundle may be bent into a U shape and stored in the cylindrical case.

  The raw water treatment by the hollow fiber membrane module 1 is performed as follows.

  Raw water is supplied into the cylindrical case 10 from the raw water supply port 13b. While the raw water is discharged from the drain port 13a via the inside of the cylindrical case 10, a part of the raw water permeates through each hollow fiber membrane of the hollow fiber membrane bundle 2 and enters the hollow portion of the hollow fiber membrane. The filtered water that has entered the hollow portions of the hollow fiber membranes is collected from the end of the hollow fiber membrane bundle 2 by the cap 14a and taken out. Moreover, you may make it permeate | transmit the hollow fiber membrane hollow part by making each hollow fiber membrane permeate | transmit the whole quantity of the supplied raw | natural water by closing the discharge port 13a.

<Example 1>
A cylindrical case 10 was configured by providing a nozzle 13 a and a nozzle 13 b in a case body 11 having an inner diameter / outer diameter of 193 mm / 216 mm, which was obtained by cutting a VP20 pipe (vinyl chloride pipe for water supply) at a fixed length. Then, groove portions 12 are provided inside both ends of the cylindrical case 10, 9000 hollow fiber membranes having a membrane permeability coefficient at 50 kPa of 1 m ³ / m ² / h are inserted, and an inner diameter / outer diameter is 170 mm / 200 mm An arc ring 16 having a width of 21 mm was inserted in the longitudinal direction of the shaped case 10 and fixed to the inner surface of the nozzle by fitting with the groove 12. Further, resin injection caps (not shown) were attached to both ends of the cylindrical case 10, and then the resin 20 was sealed at both ends of the cylindrical case 10 with a centrifugal resin injection machine. The amount of the resin 20 was adjusted so that the depth from the interface 21 of the resin 20 to the arc ring 16 was about 40 mm.

  After the resin 20 was cured, the resin injection cap was removed, and the resin fixing portion at one end of the cylindrical case 10 was cut. Two hollow fiber membrane modules were manufactured by the above method, and it was visually confirmed whether or not the resin 20 was filled between the hollow fiber membranes. As a result, both hollow fiber membranes converged away from the inner wall of the cylindrical case. It had been.

<Comparative Example 1>
One hollow fiber membrane module 1 was manufactured in the same manner as in Example 1 except that the arc ring 16 was not used.

  After the resin 20 is cured, the resin injection cap is removed, the resin fixing part at one end of the cylindrical case 10 is cut, and it is checked visually whether the resin 20 is filled between the hollow fiber membranes. The yarn membrane bundle 2 is not converged into a uniform circular shape, and the hollow fiber membrane bundle 2 is biased toward the lower portion in the radial direction in the cross section of the hollow fiber membrane module by its own weight, and the hollow fiber membrane is placed on the inner peripheral surface of the cylindrical case 10. I was approaching.

<Comparative example 2>
One hollow fiber membrane module 1 was manufactured in the same manner as in Example 1 except that the arc ring 16 was not overlapped and a C-shaped ring 19 having a notch as shown in FIG. 4 was used. .

  After the resin 20 is cured, the resin injection cap is removed, the resin fixing part at one end of the cylindrical case 10 is cut, and it is checked visually whether the resin 20 is filled between the hollow fiber membranes. The yarn membrane bundle 2 was not converged into a uniform circle, and the hollow fiber membrane entered the notch, and the hollow fiber membrane was approaching the inner peripheral surface of the cylindrical case 10.

DESCRIPTION OF SYMBOLS 1 Hollow fiber membrane module 2 Hollow fiber membrane bundle 10 Cylindrical case 11 Case trunk | drum 12 Groove part 13a, 13b Nozzle 14a, 14b Cap 15a, 15b Cap nut 16 Arc ring 17 L-shaped arc ring 18 Channel 19 C-type ring 20 Resin 21 Interface inside the module longitudinal direction of resin

Claims (2)

  A hollow fiber membrane module having a hollow fiber membrane bundle, a cylindrical case storing the hollow fiber membrane bundle, and a resin part in which at least one end of the hollow fiber membrane bundle is bonded and fixed to the cylindrical case. In addition, a groove is provided on the inner peripheral surface of the cylindrical case in at least a part of the portion of the hollow fiber membrane module where the resin portion is provided in the longitudinal direction, and the groove is fitted into the groove. In addition, an arc ring is provided so as to be positioned between the cylindrical case and the hollow fiber membrane bundle, and the arc ring has an overlap portion in the circumferential direction, and an inner peripheral surface thereof is hollow. A hollow fiber membrane module, which is in contact with an outer periphery of a yarn membrane bundle.   The hollow fiber membrane module according to claim 1, wherein the arc ring has irregularities on an outer peripheral surface.

Images