A hollow fiber membrane module, an encapsulation fixture, and a manufacturing method thereof.

Abstract

This invention relates to a hollow fiber membrane module, a packaging fixture, and a manufacturing method, belonging to the technical field of membrane separation equipment. The technical solution of this invention addresses the problems of complex steps and poor sealing effects in the end-sealing operation during the manufacturing process of hollow fiber membranes. This method uses a set of fixtures to assist in the end sealing of the hollow fiber membrane. This method eliminates the need to cut excess end membrane fibers and prevents the pores of the hollow fiber membrane from being blocked by adhesive.

Description

Technical Field

[0001] This invention relates to a method for manufacturing hollow fiber membranes, belonging to the technical field of membrane separation equipment. Background Technology

[0002] Since the 1970s, membrane bioreactors (MBRs) have been widely used in North America and Europe, and began to be used in my country in the late 1990s. It is a new type of biological treatment device that combines membrane modules from membrane separation technology with bioreactors from biological treatment engineering. Currently, hollow fiber membranes are the most commonly used type of membrane bioreactor.

[0003] Hollow fiber membranes are primarily obtained through spinning, with a radius of approximately 1-3 mm. However, a major challenge in manufacturing them into membrane modules is sealing the joints of the membrane fiber bundles. This typically requires complex operations to seal the ends of numerous membrane fibers, a process prone to issues such as incomplete sealing or blockage of the fiber pores, resulting in a low yield.

[0004] For example, patent CN113731180A discloses a method for encapsulating hollow fiber membrane curtain modules. This method first requires sealing the ends of the hollow fiber membrane filaments, then applying a soft adhesive to the circumferential side of the sealed ends. This process reduces efficiency in actual production, and the sealed filaments suffer from length loss after recutting. Furthermore, some sealed filaments cannot be removed during the cutting process, affecting the effective filtration performance of the membrane bundle. Another example is patent CN113731181A, which discloses a polyurethane potting process for hollow fiber membrane modules and a method for preparing the potting compound. This method also requires sealing one end of the membrane bundle with a plugging agent, then placing the hollow fiber membrane bundle in a housing, and using a vibration and gradual vacuum injection method to inject a moderately thixotropic polyurethane potting compound into the end containing the plugging agent. This operation also requires repeated sealing and cutting of the membrane bundle, increasing the number of steps and resulting in a low yield. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of complex steps and poor sealing effect in the end-sealing operation during the manufacturing process of hollow fiber membranes. This invention provides a method for preparing hollow fiber membranes. This method uses a set of fixtures to assist in the end sealing of the hollow fiber membrane. This method eliminates the need to cut excess end membrane fibers and prevents the pores of the hollow fiber membrane from being blocked by adhesive.

[0006] The technical solution is:

[0007] A hollow fiber membrane module includes a hollow fiber membrane bundle, wherein the ends of the hollow fiber membrane bundle are fitted around a side groove, and the outside of the side groove is fitted into a head.

[0008] Curing adhesive is used to fill the space between the end cap and the hollow fiber membrane bundle, between the side groove and the hollow fiber membrane bundle, and between the membrane fibers at the end of the hollow fiber membrane bundle.

[0009] In this hollow fiber membrane bundle, the end faces of the membrane fibers at the ends are not on the same plane, and the channels of the membrane fibers are not blocked.

[0010] The curing adhesive is selected from one of the following: epoxy resin adhesive, polyurethane adhesive, phenolic resin adhesive, polyisocyanate adhesive, polyvinyl acetate adhesive, polyethylene ethyl ester adhesive, acrylate adhesive, polystyrene adhesive, alkyd resin adhesive, and cellulose adhesive.

[0011] In one embodiment, the diameter of the membrane filaments in the hollow fiber membrane bundle is 0.5-5 mm.

[0012] In one embodiment, the membrane filaments in the hollow fiber membrane bundle are made of polymer.

[0013] A hollow fiber membrane encapsulation fixture, comprising:

[0014] Side groove with internal opening for attaching the end of the hollow fiber membrane bundle;

[0015] End cap, used to fit the side groove;

[0016] The base plate has an elastic film layer on one side, and the elastic film layer is fixed to the base plate around its perimeter, with air gaps between the elastic film layer and the base plate. A compressed air interface is provided on the other side of the base plate, and the compressed air interface is connected to the gap between the elastic film layer and the base plate.

[0017] In one embodiment, a binding ring is also included for securing the hollow fiber membrane bundle.

[0018] In one embodiment, it further includes: reinforcing ribs for improving the strength of the hollow fiber membrane bundles.

[0019] A method for manufacturing a hollow fiber membrane includes the following steps:

[0020] Step 1: Tie the membrane fibers into hollow fiber membrane bundles and place one end of the hollow fiber membrane bundle into the side groove for fixation;

[0021] Step 2: Place the side groove into the end cap, leaving a gap between the end cap and the hollow fiber membrane bundle;

[0022] Step 3: After applying a release agent to the side of the base plate with the elastic film layer, press the side with the elastic film layer tightly to the end of the hollow fiber membrane bundle located in the end cap.

[0023] Step 4: Inject compressed air into the compressed air interface to cause the elastic film layer to expand upward and adhere to the end of the membrane fiber;

[0024] Step 5: Inject adhesive into the gap between the hollow fiber membrane bundle and the end cap;

[0025] Step 6: Remove the compressed air and wait for the adhesive to cure before removing the base plate to obtain the sealed hollow fiber membrane bundle.

[0026] Before step 4, reinforcing ribs need to be inserted between the filaments of the hollow fiber membrane bundle.

[0027] Before step 5, binding rings need to be placed on the hollow fiber membrane bundle to fix it in place. In one embodiment, the internal opening of the side groove is circular or square.

[0028] In one embodiment, the elastic film layer is made of nylon or ethylene-vinyl acetate copolymer.

[0029] Beneficial effects

[0030] The hollow fiber membrane manufacturing process provided by this invention utilizes a fixture to assist in sealing the membrane fibers, eliminating the need for complex end-cutting operations and preventing the problem of glue clogging the membrane fiber channels, which would reduce the number of effective membrane fibers, thus improving the utilization rate of the membrane fibers. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the manufacturing method of the present invention;

[0032] Figure 2 This is a schematic diagram of the adhesive sealing at the end.

[0033] Figure 3 This is a schematic diagram of the adhesive sealing at the end.

[0034] Figure 4 This is a schematic diagram of the end structure of the obtained hollow fiber membrane module;

[0035] Figure 5 This is an enlarged view of the end portion of the obtained hollow fiber membrane bundle;

[0036] The components include: 1. Hollow fiber membrane bundle; 2. Side groove; 3. End cap; 4. Card slot; 5. Base plate; 6. Elastic film layer; 7. Binding ring; 8. Glue injection tube; 9. Compressed air interface; 10. Glue; 11. Curing adhesive; 12. Reinforcing rib. Detailed Implementation

[0037] The sealing process of the hollow fiber membrane module of this patent will be described below with reference to the accompanying drawings. Figure 1 As shown, firstly, the hollow fiber membrane bundle 1 is bundled together, and one end is inserted into the side groove 2 for fixation. The side groove 2 can be flat with a hole in the middle for placing the membrane bundle. Its planar shape can be adjusted according to the actual design of the membrane module, and this patent does not impose any restrictions. Next, the membrane bundle with the side groove 2 is placed into the end cap 3. This structure is the shape of the final hollow fiber membrane module. After sealing, it can be installed in the required hollow fiber membrane equipment, and the module structure design can be adjusted according to the actual situation.

[0038] The installation fixture also includes a base plate 5, the area of ​​which is approximately slightly larger than the cross-sectional area of ​​the hollow fiber membrane bundle 1. Both ends of the base plate 5 are fixed to the side grooves 2 via slots 4, facilitating installation and disassembly. An elastic film layer 6 is also provided on one side of the base plate 5. The elastic film layer 6 is made of polymer material and is elastic. The space between the elastic film layer 6 and the base plate 5 is hollow. A compressed air inlet 9 is provided on the other side of the base plate 5, communicating with the interior of the elastic film layer 6. When compressed air is turned on, the elastic film layer 6 expands outwards. After applying a release agent to the surface of the elastic film layer 6, the base plate 5 is fixed in the slots 4, and the elastic film layer 6 and the hollow fiber membrane bundle 1 are bonded together. At this point, as... Figure 1 In the structure shown, some gaps are formed, such as between the side groove 2 and the hollow fiber membrane bundle 1, between the inner wall of the end cap 3 and the hollow fiber membrane bundle 1, and between the membrane fibers. These spaces are used for injecting glue and curing.

[0039] In actual processing, perfect alignment between the hollow fiber membrane bundle 1 and the elastic film layer 6 is impossible. Because the membrane fibers are tightly bound, their relative movement is not entirely smooth, resulting in some membrane fibers adhering to the elastic film layer 6 while others do not. Figure 2 As shown. In this case, during glue injection, some dehydrated material enters the pores of the membrane fibers through the non-adhesive areas. After curing, this blocks the pores of the membrane fibers, leading to a decrease in the number of effective membrane fibers. Figure 2 The two membrane fibers on the left side were unable to adhere to the lower surface due to the inability of their ends to allow adhesive to seep in, while the membrane fiber on the right side was able to retain the adhesive on the outside of the membrane fiber.

[0040] At this point, the binding ring 7 from the fixture is placed over the hollow fiber membrane filament 1 and pressed tightly between the end cap 3 and the hollow fiber membrane filament bundle 1. The binding ring 7 should have a certain degree of tension to press the hollow fiber membrane filament 1 inside, which can prevent the bound membrane filament from shaking and shifting. In addition, some rigid reinforcing ribs 12 can be inserted between the membrane filaments to improve the overall stability of the membrane filament bundle. Then, the glue injection tube 8 is inserted between the binding ring 7 and the end cap 3 to inject glue into the gap between the hollow fiber membrane filament bundle 1 and the end cap 3. Then, slightly positive pressure compressed air is added to the compressed air inlet 9 to pressurize the inside of the elastic film layer 6. The bottom elastic film layer 6 will expand upward. For those membrane filaments that cannot completely adhere to the elastic film layer 6, the elastic film layer 6 can tightly close the pores of the membrane filaments to prevent glue from seeping in. After the glue cures, the pores of these membrane filaments can be prevented from being closed, increasing the number of effective pores after sealing.

[0041] After the adhesive has cured, the base plate 5 can be directly removed because the surface of the elastic film layer 6 is coated with a release agent. This results in a hollow fiber membrane bundle 6 that has been sealed with adhesive. The side of the end of the bundle has a cap 3, which can be installed in a suitable component.

[0042] The structure of the hollow fiber membrane module prepared by the above method is as follows: Figure 4 As shown, the ends of the hollow fiber membrane bundle 1 are fitted around the side groove 2, and the outside of the side groove 2 is fitted into the end cap 3. The end cap 3 and the hollow fiber membrane bundle 1, the side groove 2 and the hollow fiber membrane bundle 1, and the membrane fibers at the ends of the hollow fiber membrane bundle 1 are all filled with curing adhesive 11. Due to the bulging and squeezing effect of the elastic film layer 6, the membrane fibers no longer need to be cut at the ends. Although the ends of the membrane fibers are not on the same plane, they are still protected by the elastic film layer 6, and there will be no glue penetration. Moreover, the channels of the membrane fibers are not blocked.

Claims

1. A method for manufacturing a hollow fiber membrane based on a hollow fiber membrane encapsulation fixture, characterized in that, The packaging fixture includes: Side groove (2) with an internal opening for attaching the end of the hollow fiber membrane bundle (1); End cap (3) is used to fit the side groove (2); A base plate (5) is provided on one side of the base plate (5), and the elastic film layer is fixed to the base plate around its perimeter, with air left between the elastic film layer and the base plate; a compressed air interface (9) is provided on the other side of the base plate (5), and the compressed air interface (9) is connected to the gap between the elastic film layer (6) and the base plate (5). The manufacturing method includes the following steps: Step 1: Tie the membrane fibers into hollow fiber membrane bundles and place one end of the hollow fiber membrane bundle into the side groove for fixation; Step 2, place the side groove (2) into the end cap, leaving a gap between the end cap (3) and the hollow fiber membrane bundle; Step 3: After applying a release agent to one side of the base plate (5) with the elastic film layer (6), press one side of the elastic film layer (6) against the end of the hollow fiber membrane bundle (1) located in the end cap (3). Step 4: Inject compressed air into the compressed air interface (9) to make the elastic film layer (6) expand upward and adhere to the end of the membrane fiber; Step 5: Inject glue (10) into the gap between the hollow fiber membrane bundle (1) and the end cap (3); Step 6: Remove the compressed air and wait for the glue (10) to cure. Then remove the base plate (5) to obtain the sealed hollow fiber membrane bundle (1).

2. The method for manufacturing a hollow fiber membrane according to claim 1, characterized in that, Before step 4, reinforcing ribs (12) need to be inserted between the membrane fibers of the hollow fiber membrane bundle (1).

3. The method for manufacturing a hollow fiber membrane according to claim 1, characterized in that, Before step 5, a binding ring needs to be put on the hollow fiber membrane bundle (1) to fix the hollow fiber membrane bundle.

4. The method for manufacturing a hollow fiber membrane according to claim 1, characterized in that, The internal openings of the side groove are circular or square; the elastic film layer is made of nylon or ethylene-vinyl acetate copolymer.

5. The method for manufacturing a hollow fiber membrane according to claim 1, characterized in that, The adhesive (10) is selected from one of the following: epoxy resin adhesive, polyurethane adhesive, phenolic resin adhesive, polyisocyanate adhesive, polyvinyl acetate adhesive, polyethylene-ethyl ethylene ester adhesive, acrylic adhesive, polystyrene adhesive, alkyd resin adhesive, and cellulose adhesive.

6. The method for manufacturing a hollow fiber membrane according to claim 1, characterized in that, The diameter of the membrane filaments in the hollow fiber membrane bundle is 0.5-5 mm, and the material of the membrane filaments in the hollow fiber membrane bundle is polymer.

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