Hollow fiber ultrafiltration membrane module

Abstract

The application provides a hollow fiber ultrafiltration membrane module, belonging to the technical field of membrane modules, comprising a cylindrical container, a center tube and a membrane shell coaxially installed from inside to outside; a membrane filament filling area fixed between the center tube and the membrane shell through a first end cap and a second end cap, comprising a plurality of membrane filaments, one end of the plurality of membrane filaments being sealed in the first end cap; the other end of the plurality of membrane filaments being arranged in the second end cap and penetrating through the second end cap; and an inner annular flow channel and an outer annular flow channel being respectively formed between the membrane filament filling area and the center tube and the membrane shell. The inner and outer annular flow channels for fluid laminar flow are added, so that raw water can quickly flow to the concentrated water side of the inner and outer annular flow channels, the flow difference between the water inlet side and the concentrated water side of the membrane module is reduced, the fouling speed of the membrane surface of the water inlet side and the concentrated water side is uniformed, the service life of the membrane module is prolonged, and the chemical cleaning frequency is reduced.

Description

Technical Field

[0001] This invention relates to the field of membrane module technology, and more specifically to a hollow fiber ultrafiltration membrane module. Background Technology

[0002] Hollow fiber ultrafiltration membrane modules use hollow fiber ultrafiltration membrane fibers as the core. The walls of the membrane fibers are covered with micropores. The membrane fibers are fixed on supports at both ends of the hollow fiber ultrafiltration membrane module. With the addition of membrane shells and sealing materials, physical isolation between the product water side and the raw water side is achieved, thereby achieving the effect of water filtration.

[0003] In existing technologies, conventional membrane module structures include a membrane shell, membrane fibers, supports for fixing the membrane fibers, a central tube, and end caps. The two ends of the membrane shell are embedded in two end caps, and the two ends of the membrane shell, the two supports, and the two ends of the membrane fibers are sealed together with an adhesive to form a complete cylindrical container. Typically, the design of hollow fiber ultrafiltration membrane modules aims to maximize the number of membrane fibers packed inside a single module, thereby increasing the effective membrane area and improving filtration efficiency. Therefore, the membrane fiber packing area formed by the membrane fibers is essentially in close contact with the membrane shell and the central tube, thus increasing the number of membrane fibers packed. However, such a design will sacrifice the hydraulic radius of the internal flow channel of the membrane module to a large extent. During use, the raw water enters the membrane fiber filling area from the inlet of one end cap and the water distribution channel of the support. The raw water flows in the membrane fiber filling area in a basically turbulent manner, with large flow channel resistance. Moreover, the raw water can only gradually fill the entire membrane fiber filling area, which leads to a serious imbalance in the flow rate between the feed water side and the concentrate side. This can easily cause a serious imbalance in the membrane fiber fouling rate and performance degradation rate between the feed water side and the concentrate side, resulting in fouling of the membrane surface on the feed water side, increasing the filtration resistance and affecting the service life of the overall membrane module. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a hollow microfiltration membrane module that can increase the hydraulic radius of the internal flow channel of the membrane module, reduce the flow channel resistance, and improve the durability of the membrane fibers.

[0005] To achieve the above and other objectives, the present invention is implemented through the following technical solution: The present invention proposes a hollow fiber ultrafiltration membrane module, characterized in that it includes a cylindrical container, comprising a central tube and a membrane shell coaxially mounted from the inside to the outside; a membrane fiber filling area, fixed between the central tube and the membrane shell by a first sealing end and a second sealing end, comprising multiple membrane fibers, one end of the multiple membrane fibers being sealed within the first sealing end; the other end of the multiple membrane fibers being disposed within the second sealing end and penetrating the second sealing end; wherein, an inner annular flow channel and an outer annular flow channel are respectively formed between the membrane fiber filling area and the central tube and the membrane shell.

[0006] In one embodiment, the cross-sectional area of ​​the membrane filament filling region is 1.5 to 2.0 times the sum of the cross-sectional areas of all the membrane filaments.

[0007] In one embodiment, the first and second sealing ends each include a support and resin. The support is connected to the end of the central tube, and the resin bonds the support, the end of the membrane shell, and the end of the membrane filament together to isolate the raw water, concentrate, and product water.

[0008] In one embodiment, the bracket is provided with a mounting groove, which is located at the center of the bracket.

[0009] In one embodiment, the support is further provided with a first type of through hole and a second type of through hole, which are arranged around the outside of the mounting groove; the first type of through hole is used to connect the raw water inlet of the cylindrical container with the membrane fiber filling area and the outer annular flow channel, and the second type of through hole is used to connect the raw water inlet of the cylindrical container with the inner annular flow channel.

[0010] In one embodiment, the bracket includes a water distribution pipe and partition plates. The mounting groove, the first type of through hole, and the second type of through hole are disposed on the water distribution pipe. A plurality of partition plates are disposed at equal intervals on the outer peripheral surface of the water distribution pipe. A water passage groove communicating with the first type of through hole is formed on the partition plate. The second type of through hole is disposed between two partition plates.

[0011] In one embodiment, a plurality of glue injection holes are provided on the end of the partition plate away from the water channel.

[0012] In one embodiment, a mesh layer is provided on the outer periphery of the membrane filament filling area for fixing and binding the membrane filaments.

[0013] In one embodiment, the membrane filament is an external pressure membrane.

[0014] In one embodiment, the working pressure of the hollow fiber ultrafiltration membrane module does not exceed 0.20 MPa, and the chemical cleaning cycle is greater than 30 days.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] 1. This invention adds inner and outer annular flow channels for laminar flow of fluid to the inner and outer sides of the membrane fiber packing area, thereby increasing the laminar flow channels for raw water. As a result, the raw water can flow quickly to the concentrate side of the inner and outer annular flow channels. This not only effectively reduces the turbulence of the raw water in the membrane fiber packing area and reduces the resistance between the membrane fibers and the fluid, but also reduces the flow difference between the feed water side and the concentrate side of the hollow fiber ultrafiltration membrane module. This homogenizes the fouling rate of the membrane surface on both the feed water side and the concentrate side, increases the overall service life of the hollow fiber ultrafiltration membrane module, reduces the frequency of chemical cleaning, and extends its service life.

[0017] 2. The cross-sectional area of ​​the membrane fiber filling area of ​​the present invention is designed to be 1.5 to 2.0 times the total cross-sectional area of ​​all membrane fibers. This can avoid the problem of the adhesive bonding the membrane fibers being prone to cracking due to insufficient cross-sectional area of ​​the membrane fiber filling area, which leads to product defects. At the same time, it can avoid the problem of the cross-sectional area of ​​the membrane fiber filling area being too large, which would result in insufficient size of the inner and outer annular flow channels, resulting in an ineffective balance of the pressure difference between the inlet and the product water end, thereby limiting the improvement of product performance and lifespan.

[0018] 3. The first and second sealing ends of the present invention include a support and resin. The resin, especially epoxy resin, has a strong adhesive force to metals and plastics, and the adhesive strength is very high, which can better achieve the sealing and bonding of the end of the membrane shell and the end of the membrane fiber. The design of the support can further improve the mechanical strength of the sealing end, prevent the bonding of the resin bonding part from being damaged, and at the same time reduce the amount of resin used, thereby reducing the overall production cost of the hollow fiber ultrafiltration membrane module.

[0019] 4. By setting an installation groove in the center of the bracket, the present invention can facilitate the connection between the bracket and the central tube, and can also improve the connection strength between the two by using interference fit, bolt fastening and other connection methods.

[0020] 5. By opening a second type of through hole on the support in addition to the first type of through hole, the present invention increases the channel for raw water to enter the inner annular flow channel, which can increase the speed at which raw water gathers into the inner annular flow channel, better ensure the formation of laminar flow in the cylindrical container, increase the hydraulic radius inside the membrane module, and reduce the flow channel resistance.

[0021] 6. By setting multiple partition plates on the outer periphery of the support, the hollow fiber ultrafiltration membrane module can be divided into multiple equal areas to prevent cross-contamination between areas and further ensure the stability and reliability of the filtration effect; at the same time, each partition plate is provided with a water channel communicating with the first type of through hole, which can ensure that the raw water is evenly distributed to each membrane fiber filling area, thereby improving filtration efficiency and production capacity.

[0022] 7. Multiple injection holes can be opened on the partition plate of the present invention, which can facilitate the flow of resin into the support and improve the bonding strength between the support, the end of the membrane filament and the end of the membrane shell;

[0023] 8. The present invention provides a mesh layer on the outer periphery of the membrane fiber filling area to position the membrane fiber within the membrane fiber filling area and to fix it, thereby better constraining the membrane fiber. Attached Figure Description

[0024] Figure 1 The image shown is an axial cross-sectional view of a hollow fiber ultrafiltration membrane module according to the present invention.

[0025] Figure 2 The image shown is a radial cross-sectional view of a hollow fiber ultrafiltration membrane module according to the present invention.

[0026] Figure 3 The image shown is a first-view perspective three-dimensional structural diagram of the bracket without glue injection holes in this invention.

[0027] Figure 4 The diagram shown is a second-view perspective of the three-dimensional structure of the bracket with injection holes in this invention.

[0028] Figure 5 The diagram shown is a schematic representation of the mesh layer structure in this invention.

[0029] Figure 6 The diagram shows a test apparatus used to measure the chemical cleaning (CIP) cycle of hollow fiber ultrafiltration membrane modules.

[0030] Figure 7 The graph shows the test results of the number of operating days and transmembrane pressure difference for Example 1 and Comparative Example 1.

[0031] In the figure: 1. Cylindrical container; 2. Membrane fiber filling area; 3. Inner annular flow channel; 4. Outer annular flow channel; 5. First sealing end; 6. Second sealing end; 6. End face 61;

[0032] 100 center tube; 200 support; 210 water distribution pipe; 211 mounting groove; 212 first type through hole; 213 second type through hole; 220 partition plate; 221 water channel; 222 glue injection hole; 300 membrane fiber; 400 membrane shell; 500 end cap; 510 raw water inlet; 530 product water outlet; 520 concentrate outlet; 600 resin; 700 mesh layer. Detailed Implementation

[0033] Please see Figures 1 to 7 The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0034] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0035] In this invention, the terms "upper," "lower," "left," "right," "front," and "rear," etc., indicating orientation or positional relationships, are merely for the purpose of clearly describing the invention and do not indicate or imply that the structures or components referred to must have a specific orientation or be constructed in a specific orientation. Therefore, they should not be construed as limitations on the invention. The component numbers assigned in this specification, such as "first," "second," etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. Unless otherwise specified, the term "connection" in this invention includes both direct and indirect connections.

[0036] like Figure 1 and Figure 2 As shown, the present invention provides a hollow fiber ultrafiltration membrane module, including a central tube 100, a support 200, membrane fibers 300, a membrane shell 400, and end caps 500. Two supports 200 are symmetrically sleeved at both ends of the central tube 100. The central tube can be a solid tube or a hollow tube, and its main function is to support the two supports 200. The two ends of multiple membrane fibers 300 are respectively filled into the two supports 200. The membrane fibers 300 are externally pressed membranes, preferably made of polyvinylidene fluoride (PVDF). The membrane shell 400 is coaxially installed on the outside of the central tube 100. The two ends of the membrane shell 400 are respectively embedded in the two end caps 500, and the ends of the membrane shell 400, the support 200, and the membrane fibers 300 are sealed together by resin 600 to form a complete cylindrical container 1.

[0037] In this configuration, one end of each of the multiple membrane filaments 300 is sealed within a first end cap 5 formed by a support 200 and resin 600; the other end of each of the multiple membrane filaments 300 is fixed within a second end cap 6 formed by another support 200 and resin 600, and the other end of each of the multiple membrane filaments 300 extends through the second end cap 6, i.e., the other end of each of the multiple membrane filaments 300 opens at the end face 61 of the second end cap 6. An inner annular flow channel 3 and an outer annular flow channel 4 are formed between the membrane filament filling area 2 formed by the multiple membrane filaments 300, the central tube 100, and the membrane shell 400, respectively. Specifically, the size of the inner annular flow channel 3 can be determined by the outer diameter of the central tube 100 and the water distribution pipe 210 of the support 200 (see...). Figure 3 The size of the membrane fiber filling area 2 is determined by the difference between the outer diameter of the water distribution pipe 210 of the support 200 and the overall outer diameter of the support 200; the outer annular flow channel 4 is determined by the difference between the overall outer diameter of the support 200 and the inner diameter of the membrane shell 400.

[0038] Therefore, when the hollow fiber ultrafiltration membrane module provided by the present invention is in operation, raw water is injected from the raw water inlet 510 of the cylindrical container 1 and can enter the membrane fiber filling area 2, the inner annular flow channel 3 and the outer annular flow channel 4 almost simultaneously. Since there are no membrane fibers 300 in the inner annular flow channel 3 and the outer annular flow channel 4, the laminar flow channel of the raw water is increased. Therefore, the raw water can flow quickly to the concentrate side of the inner annular flow channel 3 and the outer annular flow channel 4. This can not only effectively reduce the turbulence of the raw water in the membrane fiber filling area 2 and reduce the resistance between the membrane fibers and the fluid, but also reduce the flow difference between the feed water side and the concentrate side of the hollow fiber ultrafiltration membrane module, homogenize the fouling speed of the membrane surface on the feed water side and the concentrate side, increase the overall service life of the hollow fiber ultrafiltration membrane module, reduce the frequency of chemical cleaning, and extend the service life.

[0039] Furthermore, the cross-sectional area of ​​the membrane fiber filling area 2 should be 1.5 to 2.0 times the total cross-sectional area of ​​all the membrane fibers 300. This design avoids the problem of insufficient cross-sectional area of ​​the membrane fiber filling area 2 leading to easy cracking of the adhesive bonding the membrane fibers 300 and resulting in product defects. At the same time, it avoids the problem of excessively large cross-sectional area of ​​the membrane fiber filling area 2, which would result in insufficient size of the inner annular flow channel 3 and the outer annular flow channel 4, leading to an ineffective balance of the pressure difference between the inlet and outlet water ends, thereby limiting the improvement of product performance and lifespan.

[0040] It should be noted that, in Figure 1In the illustrated embodiment, the first sealing end 5 and the second sealing end 6 include a support 200. The main function of the support 200 is to provide structural support for the positioning of the membrane filaments 300, enabling the membrane filaments 300 to maintain a stable shape and position, further improving the mechanical strength of the sealing end, and reducing the amount of resin 600 used, thereby reducing the overall production cost of the hollow fiber ultrafiltration membrane module. Since the main function of the first sealing end 5 and the second sealing end 6 is to bond and seal the ends of the membrane shell 400 and the membrane filaments 300, the support 200 is not necessary. In other embodiments, only resin 600 can be used as the sealing end to seal the ends of the membrane shell 400 and the membrane filaments 300. Furthermore, the resin 600 of the present invention can be epoxy resin or polyurethane resin, preferably epoxy resin. Epoxy resin has strong adhesion to metals and plastics, and its bonding strength is very high, which can better achieve the sealing and bonding of the ends of the membrane shell 400 and the membrane filaments 300.

[0041] like Figure 3 and Figure 4 As shown, the support 200 may include a water distribution pipe 210 and a partition plate 220. The center of the water distribution pipe 210 may be provided with an installation groove 211 for connecting the central pipe 100. The installation groove 211 and the central pipe 100 may be connected by an interference fit or by screw fastening to improve the connection strength between the support 200 and the central pipe 100. The water distribution pipe 210 is also provided with a first type of through hole 212 and a second type of through hole 213. Both the first type of through hole 212 and the second type of through hole 213 are arranged around the outside of the installation groove. The first type of through hole 212 connects the raw water inlet 510 of the cylindrical container 1 with the membrane fiber filling area 2 and the outer annular flow channel 4. The second type of through hole 213 connects the raw water inlet 510 of the cylindrical container 1 with the inner annular flow channel 3. Furthermore, a portion of the first type of through hole 212 is formed on the pipe wall of the water distribution pipe 210, which can facilitate communication with the water channel 221 of the partition plate 220.

[0042] like Figure 3As shown, multiple partition plates 220 are evenly spaced on the outer circumferential surface of the water distribution pipe 210, and each partition plate has a water channel 221 communicating with the first type of through hole 212. The water channel 221 can be elongated, and its length can be equal to the annular thickness of the entire membrane fiber filling area 2. By setting multiple partition plates 220, the present invention can divide the membrane fiber filling area 2 into multiple equally divided areas, preventing cross-contamination between areas and further ensuring the stability and reliability of the membrane module's filtration effect. At the same time, the water channel 221 communicating with the first type of through hole 212 on each partition plate 220 can ensure that the raw water is evenly distributed to each membrane fiber filling area, improving filtration efficiency and production capacity.

[0043] Figure 3 and Figure 4 The second type of through hole 213 shown is fan-shaped, and only one second type of through hole 213 is provided between every two partition plates 220. However, this is not necessary. The second type of through hole 213 can also be circular, square, or other shapes required by the design. There can also be multiple second type of through holes 213 between every two partition plates 220.

[0044] like Figure 4 As shown, in order to facilitate the flow of the resin 600 into the support 200, thereby improving the bonding strength between the support 200, the end of the membrane filament 300 and the end of the membrane shell 400, a plurality of glue injection holes 222 may be provided on the end of the partition plate 220 away from the water channel 221.

[0045] like Figure 5 As shown, a mesh layer 700 for fixing and binding the membrane filaments 300 can also be provided on the outer periphery of the membrane filament filling area 2. The mesh layer 700 has multiple mesh holes to facilitate the passage of the resin 600. The mesh layer 700 can be a ring or a ring formed by assembling multiple arc-shaped pieces. When the resin 600 is filled, the end cap 500, membrane shell 400, mesh layer 700 and the ends of the membrane filaments 300 are bonded together. Although not shown in the figure, it can be understood that when the first end cap 5 and the second end cap 6 include a support 200, the mesh layer 700 can be installed on the partition plate 220 of the support 200. When there are multiple mesh layers 700, the two ends of the mesh layer 700 can be installed on two adjacent partition plates 220 respectively. Furthermore, the area of ​​the membrane filament filling area 2 and the outer annular flow channel 4 differs depending on the installation position of the mesh layer 700 on the partition plate 220. That is, when the mesh 700 is provided, the size of the membrane filament filling area 2 is determined by the difference between the outer diameter of the water distribution pipe 210 of the support 200 and the outer diameter of the mesh 700; the outer annular flow channel 4 is determined by the difference between the outer diameter of the mesh 700 and the inner diameter of the membrane shell 400.

[0046] In summary, as Figure 1-5 As shown, the raw water filtration path of the hollow fiber ultrafiltration membrane module provided by the present invention is as follows: Raw water is injected from the inlet 510 of the end cap 500 and flows into the membrane fiber filling area 2, the inner annular flow channel 3 and the outer annular flow channel 4 through the first type of through hole 212 and the second type of through hole 213 of the support 200; as the cavity pressure of the hollow fiber ultrafiltration membrane module 1 increases, under the pressure drive, a portion of the raw water permeates from the outer surface of the membrane fiber 300 into the hollow core of the membrane fiber 300. The permeate flows out from the other end of the membrane filtrate 300, forming permeate (leachate) which flows out from the permeate outlet 530 of another end cap 500; another part of the raw water continues to flow along the arrangement direction of the membrane filtrate 300, or quickly gathers into the inner annular channel 3 and the outer annular channel 4, and finally flows out of the sealed cavity from the first type of through hole 212 and the second type of through hole 213 of another support 200, forming concentrate (concentrate) which flows out from the concentrate outlet 520 of another end cap 500.

[0047] <Analysis and Evaluation> Example 1, 9900 membrane fibers were assembled into a structure with an 8-inch diameter, 80-inch length, and 77m diameter. 2 Hollow fiber ultrafiltration membrane module A has an effective membrane area. The membrane fibers have an average outer diameter of 1.3 mm, the central tube has an outer diameter of 32 mm, the water distribution pipe of the support has an outer diameter of 92 mm, the mesh layer has an outer diameter of 185 mm, the membrane shell has an inner diameter of 211 mm, and the water distribution pipe is DN50. An outer annular flow channel with an outer diameter of 211 mm and an inner diameter of 185 mm is formed between the outermost membrane fiber in the membrane fiber filling area and the membrane shell. The calculated cross-sectional area of ​​this flow channel is 8082 mm². 2 The innermost membrane fiber in the membrane fiber filling area forms an inner annular flow channel with an outer diameter of 92 mm and an inner diameter of 32 mm. The calculated cross-sectional area of ​​the flow channel is 5860 mm². 2 The area of ​​the membrane fiber filling region is 1.524 times the sum of the cross-sectional areas of all membrane fibers.

[0048] Hollow fiber ultrafiltration membrane module A was laid horizontally. Under the conditions of transmembrane pressure difference of 0.100 MPa and water temperature of 25℃, the pure water flux of hollow fiber ultrafiltration membrane module A was measured to be 16.0 m³ / s. 3 / h.

[0049] Comparative Example 1, 9900 membrane fibers were assembled into a structure with an 8-inch diameter, 80-inch length, and 77m diameter. 2Hollow fiber ultrafiltration membrane module B with effective membrane area. The average outer diameter of the membrane fibers is 1.3 mm, the outer diameter of the central tube is 32 mm, the outer diameter of the water distribution pipe of the support is 40 mm, the outer diameter of the mesh layer is 211 mm, the inner diameter of the membrane shell is 211 mm, and the water distribution pipe is DN50. There is no outer annular flow channel between the outermost membrane fiber and the membrane shell in the membrane fiber filling area; an inner annular flow channel is formed between the innermost membrane fiber and the central tube in the membrane fiber filling area, with an outer diameter of 40 mm and an inner diameter of 32 mm. The calculated cross-sectional area of ​​the flow channel is 502 mm². 2 This is negligible. The area of ​​the membrane fiber packing region is 2.539 times the sum of the cross-sectional areas of all membrane fibers.

[0050] Hollow fiber ultrafiltration membrane module B was laid horizontally. Under conditions of transmembrane pressure difference of 0.100 MPa and water temperature of 25℃, the pure water flux of hollow fiber ultrafiltration membrane module B was measured to be 16.0 m³ / s. 3 / h.

[0051] Test methods and results Adopting such Figure 6 The test apparatus shown was used to perform chemical cleaning (CIP) cycle measurements on hollow fiber ultrafiltration membrane modules A and B, respectively. Surface water with a turbidity (NTU≈5) was used as the raw water for constant flow filtration, with a designed product water flow rate of 4.0 m³ / h. 3 The ultrafiltration system achieved a recovery rate of 95% per hour. Backwashing was performed using ultrafiltration permeate at 60-minute intervals and a flow rate of 120 LMH. Chemical cleaning was performed using a pH 2 HCl solution at 72-hour intervals. The inlet water pressure was recorded during operation, and the chemical cleaning (CIP) cycle for the hollow fiber ultrafiltration membrane module was determined when the inlet water pressure reached 0.20 MPa.

[0052] As attached Figure 7 As shown, the chemical cleaning (CIP) cycle for Comparative Example 1 was 30 days; the chemical cleaning (CIP) cycle for Example 1 was 42 days. Compared to Comparative Example 1, the increase in the combined size of the outer and inner annular flow channels in Example 1 was 13440 mm. 2 The increased flow channel area extends the chemical cleaning cycle of the hollow fiber ultrafiltration membrane module from 30 days to 42 days. Furthermore, under the same number of operating days, the transmembrane pressure difference in Example 1 was lower than that in Comparative Example 1. This is because the operating pressure of the hollow fiber ultrafiltration membrane module itself is relatively low, generally not exceeding 0.20 MPa. However, if the membrane fibers are uniformly arranged inside the membrane shell, the fluid in the flow channel will experience greater pressure loss due to fluid resistance, resulting in a larger pressure difference between the feed water and concentrate. This leads to a severe imbalance in membrane flux between the feed water and concentrate sides of the hollow fiber ultrafiltration membrane module, causing concentration polarization and membrane fouling on the side with higher operating pressure, resulting in an increased transmembrane pressure difference and a faster cleaning frequency.

[0053] In summary, this invention increases the laminar flow channels for raw water by adding an inner annular channel 3 and an outer annular channel 4 to the inner and outer sides of the membrane fiber filling area 2. This allows the raw water to flow rapidly to the concentrate side of the inner annular channel 3 and the outer annular channel 4, reducing the turbulence in the membrane fiber filling area 2 and significantly reducing the flow resistance of the membrane fibers 300 to the water within the membrane fiber filling area 2. This also lowers the pressure difference between the raw water inlet and the concentrate outlet of the hollow fiber ultrafiltration membrane module. Furthermore, it reduces the transmembrane pressure difference of the hollow fiber ultrafiltration membrane module, decreases the frequency of chemical cleaning, and extends the service life of the hollow fiber ultrafiltration membrane module.

[0054] Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial applicability. The above embodiments are merely illustrative of the principles and effects of this invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of this invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this invention.

Claims

1. A hollow fiber ultrafiltration membrane module, characterized in that, include A cylindrical container comprising a central tube and a membrane shell coaxially mounted from the inside out; The membrane fiber filling area, fixed between the central tube and the membrane shell by a first sealing end and a second sealing end, includes multiple membrane fibers. One end of each membrane fiber is sealed inside the first sealing end, and the other end of each membrane fiber is disposed inside the second sealing end and passes through the second sealing end. The membrane fiber filling area is connected to the central tube and the membrane shell by an inner annular flow channel and an outer annular flow channel, respectively. Raw water is injected from the raw water inlet of the cylindrical container and can simultaneously enter the membrane fiber filling area, the inner annular flow channel and the outer annular flow channel.

2. The hollow fiber ultrafiltration membrane module according to claim 1, characterized in that, The cross-sectional area of ​​the membrane filament filling region is 1.5 to 2.0 times the sum of the cross-sectional areas of all the membrane filaments.

3. The hollow fiber ultrafiltration membrane module according to claim 2, characterized in that, The first and second sealing ends each include a support and resin. The support is connected to the end of the central tube, and the resin bonds the support, the end of the membrane shell, and the end of the membrane filament together to isolate the raw water, concentrate, and product water.

4. The hollow fiber ultrafiltration membrane module according to claim 3, characterized in that, The bracket is provided with a mounting groove, which is located at the center of the bracket.

5. The hollow fiber ultrafiltration membrane module according to claim 4, characterized in that, The support is also provided with a first type of through hole and a second type of through hole, which are arranged around the outside of the mounting groove. The first type of through hole is used to connect the raw water inlet of the cylindrical container with the membrane fiber filling area and the outer annular flow channel, and the second type of through hole is used to connect the raw water inlet of the cylindrical container with the inner annular flow channel.

6. The hollow fiber ultrafiltration membrane module according to claim 5, characterized in that, The bracket includes a water distribution pipe and partition plates. The mounting groove, the first type of through hole and the second type of through hole are disposed on the water distribution pipe. Multiple partition plates are disposed at equal intervals on the outer circumferential surface of the water distribution pipe. A water passage groove communicating with the first type of through hole is opened on the partition plate. The second type of through hole is disposed between two partition plates.

7. The hollow fiber ultrafiltration membrane module according to claim 6, characterized in that, The partition plate has multiple glue injection holes at the end away from the water channel.

8. The hollow fiber ultrafiltration membrane module according to claim 1, characterized in that, A mesh layer is provided on the outer periphery of the membrane filament filling area to fix and bind the membrane filaments.

9. The hollow fiber ultrafiltration membrane module according to claim 1, characterized in that, The membrane filaments are external pressure membranes.

10. The hollow fiber ultrafiltration membrane module according to claim 1, characterized in that, The working pressure of the hollow fiber ultrafiltration membrane module does not exceed 0.20 MPa, and the chemical cleaning cycle is greater than 30 days.

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