Hollow fiber filter

Abstract

The utility model discloses a hollow fiber filter which comprises a cylinder body and a hollow fiber bundle positioned in an inner cavity of the cylinder body, and further comprises an end cover, the end cover comprises a central part and a plurality of partition plates, the central part is axially connected with an inner surface and an outer surface, and a slot axially penetrating through the inner surface and the outer surface of the end cover is formed between adjacent partition plates. At least one end of each small hollow fiber bundle is correspondingly arranged in the corresponding insertion groove, and a sealing position for separating the end opening from the opening is formed by each small hollow fiber bundle and the inner circumferential surface of the corresponding insertion groove; the side, close to the outer surface, of the partition plate comprises a fixing section and a connecting section, and the thickness of the fixing section perpendicular to the radial direction is larger than that of the connecting section perpendicular to the radial direction. According to the end cover structure, the side, close to the port, of the partition plate is zigzag, the contact area between the outer surface of the partition plate and the sealing position of the small hollow fiber bundle is increased, and therefore the connection strength and firmness of the sealing position and the outer surface of the end cover are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to filter technical field, especially a kind of hollow fiber filter. BACKGROUND

[0002] Hollow fiber filters are widely used in water purification, separation of components from biological fluids, dialysis, reverse osmosis, gas separation, cell culture devices, and many other fields in tangential flow (alternating reciprocating tangential flow and circulating tangential flow, etc.) and normal flow filtration systems. Hollow fiber filters include a cylinder and a hollow fiber membrane bundle axially fixed in the cylinder, both ends of the membrane bundle are sealed and fixed to the inner wall of the cylinder by pouring sealant, and at least one end of the membrane bundle is open for discharging filtrate.

[0003] In large hollow fiber filtration devices, a large number of hollow fiber membranes are needed to be filled. However, after a large number of hollow fiber membranes are gathered, the spacing between the hollow fiber membranes is too compact, and the following problems usually exist: the peripheral hollow fiber membranes can generate a large resistance to the flow of filtrate in the internal hollow fiber membranes, resulting in poor flow of filtrate and affecting the filtration efficiency; due to the existence of flow resistance, the filtration load borne by different hollow fiber membranes can be inconsistent, and some hollow fiber membranes can reach saturation state earlier than other hollow fiber membranes, thereby failing prematurely; due to the uneven distribution of filtration load, the production rate of filtrate from all hollow fiber membranes can become inconsistent, which can affect the overall performance of the filter.

[0004] In order to solve the above problems, the hollow fiber filter of the prior art generally divides the hollow fiber membranes into a plurality of small bundles of hollow fiber membranes first, inserts a partition plate between the small bundles to form a gap, and adds a pouring agent to package the small bundles of hollow fiber membranes into a hollow fiber filtration device, and controls the gap between the small bundles, such as the hollow fiber membrane assembly disclosed in US application US20020179516A1.

[0005] The inner wall of the existing partition plate is generally smooth single-arc or flat straight, and the surface area is small. When the small bundles are packaged to form a pouring portion, the pouring portion and the inner wall of the partition plate can be easily separated, the connection between the pouring portion and the partition plate is not firm, the sealing effect of the pouring portion is unstable, and leakage can occur during use; in addition, when designing these partition plates, the thickness needs to be as large as possible on the basis of ensuring filtration efficiency, so as to ensure the gap between the small bundles. These partition plates are generally made by injection molding process; due to process defects, when the thickness of the partition plate is large, the surface of the partition plate can be uneven or have internal bubbles, which can further cause structural defects or mechanical strength reduction of the partition plate, and affect the sealing performance of the hollow fiber membrane bundle. SUMMARY

[0006] The hollow fiber filter solves the problem that the existing partition plate is prone to defects during injection molding.

[0007] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

[0008] A hollow fiber filter comprises:

[0009] The barrel comprises an inner cavity extending in an axial direction, an opening communicating with the inner cavity, and a port close to an end of the barrel;

[0010] The hollow fiber bundle is located in the inner cavity and extends at least partially in an axial direction, and comprises a plurality of hollow fiber membranes extending at least partially in an axial direction, at least one end of the hollow fiber membranes being open and communicating with the port;

[0011] Further comprising: an end cover fixed at the port, the end cover comprising an inner surface and an outer surface arranged in an axial direction, and a center portion and a plurality of partition plates axially connecting the inner surface and the outer surface, the plurality of partition plates being distributed radially around the center portion, adjacent partition plates forming a slot axially penetrating the inner surface and the outer surface of the end cover to separate the hollow fiber bundle into a plurality of small bundles of hollow fibers, at least one end of the small bundles of hollow fibers being arranged in the slot and forming a sealing position with the inner circumferential surface of the slot to separate the port and the opening;

[0012] The side of the partition plate close to the outer surface comprises a fixed segment and a connecting segment, and a plurality of fixed segments are respectively connected to the center portion close to one end of the center portion;

[0013] The thickness of the fixed segment in a direction perpendicular to the radial direction is greater than the thickness of the connecting segment in a direction perpendicular to the radial direction.

[0014] The hollow fiber filter fixes the end of the hollow fiber bundle by the end cover, the end cover is located between the opening and the port in the axial direction of the cylinder body, the inner surface of the end cover faces the inside of the cylinder body, and the outer surface of the end cover is opposite to the inner surface in the axial direction, since the material liquid exchanges at the outer surface, the sealing position is easily impacted, the connection between the sealing position and the outer surface is easily damaged, and the sealing position is even invalid, therefore, the side of the baffle close to the outer surface comprises a fixed section and a connecting section, the thickness of the fixed section is greater than the thickness of the connecting section, the side of the baffle close to the outer surface is zigzag-shaped, the contact area between the outer surface of the baffle and the sealing position of the hollow fiber small bundle is improved, and therefore, the connection strength and the firmness of the sealing position and the outer surface of the end cover are improved; in addition, the end close to the center of the end cover is connected with the center part respectively; the thickness of the fixed section in the direction perpendicular to the radial direction is greater than the thickness of the connecting section in the direction perpendicular to the radial direction, when the end cover is injection molded, the center part is generally an injection molding port, the size of the center part is not less than the thickness of the fixed section, therefore, the area of the corresponding injection molding port can also be set to be relatively large, the compression loss of injection molding is smaller, and therefore, the structure depression of the end cover as a whole in the place with large thickness is reduced, and the structural integrity and stability are improved.

[0015] Preferably, the baffle further comprises a free section extending in the radial direction, the connecting section is located between the free section and the fixed section, and the thickness of the free section in the direction perpendicular to the radial direction is greater than the thickness of the connecting section in the direction perpendicular to the radial direction.

[0016] The free section is the area of the baffle close to the inner wall of the cylinder body, and the greater thickness of the free section is beneficial to improve the connection strength between the baffle and the inner wall of the cylinder body, and avoid the shaking of the end cover and the hollow fiber bundle in the inner cavity; on the other hand, the thickness of the free section is greater than the thickness of the connecting section, so that the side of the baffle close to the port becomes more zigzag-shaped, and the contact area with the sealing position is larger, thereby improving the connection strength and firmness of the sealing position and the outer surface of the end cover.

[0017] Preferably, the center part and the fixed section are arc-shaped transitioned.

[0018] The arc-shaped transition refers to that the two side walls on both sides of the connection between the center part and the fixed section of the baffle are smooth surfaces without obvious protrusions or steps; the center part can be provided with a fillet so that the side wall of the center part and the side wall of the fixed section are smoothly transitioned, or an arc-shaped surface can be arranged at the connection between the center part and the fixed section so that the side wall of the center part and the side wall of the fixed section are smoothly transitioned; the arc-shaped transition is beneficial to reduce stress concentration, improve the structural strength of the end cover, and further improve the connection firmness between the side wall of the end cover and the sealing position; and the fillet makes the size of the center part larger, the size of the injection molding port can be further increased, the compression is reduced, and the yield of the end cover is improved.

[0019] Preferably, the arc-shaped transition between the fixed section and the connecting section means that the fixed section and the connecting section with different thicknesses are connected through an arc-shaped section with gradually reduced thickness, realizing smooth transition from the fixed section with larger thickness to the connecting section with smaller thickness, and the two side walls of the baffle corresponding to the connection between the fixed section and the connecting section are smooth surfaces without obvious protrusions or steps, thereby reducing the stress concentration at the connection between the fixed section and the connecting section, improving the structural strength of the end cover, and also making the molten liquid flow more smoothly through the connection between the fixed section and the connecting section during injection molding, improving the injection strength, and further improving the connection firmness between the side wall of the end cover and the sealing position.

[0020] Preferably, the arc-shaped transition between the connecting section and the free section means that the connecting section and the free section with different thicknesses are connected through an arc-shaped section with gradually increased thickness, realizing smooth transition from the connecting section with smaller thickness to the free section with larger thickness, and the two side walls of the baffle corresponding to the connection between the connecting section and the free section are smooth surfaces without obvious protrusions or steps, thereby reducing the stress concentration at the connection between the free section and the connecting section, improving the structural strength of the end cover, and also making the molten liquid flow more smoothly through the connection between the connecting section and the free section during injection molding, improving the injection strength, and further improving the connection firmness between the side wall of the end cover and the sealing position.

[0021] Preferably, the baffle has a side wall axially connecting the inner surface and the outer surface, the side wall includes a starting portion and a terminal portion, the starting portion and the terminal portion are axially distributed, the starting portion is formed by the connecting section, the free section, and the fixed section extending from the outer surface of the end cover to the inner surface of the end cover in the axial direction, and the terminal portion terminates at the inner surface of the end cover.

[0022] The thickness of the baffle corresponding to the terminal portion in the direction perpendicular to the radial direction is greater than the thickness of the baffle corresponding to the starting portion in the direction perpendicular to the radial direction.

[0023] The inner surface of the end cover faces the inside of the barrel, and the size of the inner surface of the baffle determines the size of the flow gap between adjacent small bundles of hollow fibers. Therefore, the closer to the inner surface, the greater the thickness of the baffle, that is, the thickness of the baffle in the region corresponding to the terminal portion is greater than the thickness of the baffle in the region corresponding to the starting portion, and the different thicknesses make the starting portion and the terminal portion have undulations in the axial direction, thereby making the side wall area of the baffle larger and the contact area with the sealing position larger, improving the connection firmness of the baffle and the sealing position. At the same time, compared to the inner surface, the space on the side closer to the outer surface of the end cover is larger and can accommodate more potting glue to seal and fix the small bundles of hollow fibers, and the formed sealing position is more impact-resistant.

[0024] Preferably, the side wall of the partition further comprises an intermediate portion, which is located axially between the start portion and the end portion, and has an arc-shaped transition between one axial end and the start portion and between the other axial end and the end portion.

[0025] The intermediate portion serves to achieve a smooth transition between the start portion and the end portion, and the thickness of the partition gradually changes from small to large; the arc-shaped transition makes the molten liquid flow more smoothly when the end cap is injection molded, and the injection strength is high; the smooth surface formed by the arc-shaped transition also helps to improve the connection stability of the partition and the sealing site.

[0026] Preferably, the end cap further comprises an annular outer peripheral portion, and the two radial ends of the partition are connected to the central portion and the outer peripheral portion respectively, and the radial outer end of the free section is connected to the outer peripheral portion.

[0027] The outer peripheral portion connects the plurality of partitions in the circumferential direction, thereby enhancing the stability of each partition, avoiding deformation or size change of the partition under external force, ensuring that the size of each slot is basically unchanged, and the connection between the sealing site in the slot and the end cap is more stable and less likely to be separated; and the outer peripheral portion increases the connection area and connection strength between the end cap and the inner wall of the cylinder, so that the end cap and the end portion of the hollow fiber bundle are more stable and less likely to shake relative to the cylinder, and the flow gap between adjacent small bundles of hollow fibers is more stable, which is conducive to the flow of feed liquid or filtrate and improves the filtration efficiency.

[0028] Preferably, the outer peripheral portion has an inner side wall connecting the inner surface and the outer surface of the end cap in the axial direction, and the inner side wall comprises a first connecting portion and a second connecting portion arranged axially from the outer surface to the inner surface, the radial width of the first connecting portion is smaller than the radial width of the second connecting portion, and the first connecting portion connects adjacent start portions and the second connecting portion connects adjacent end portions.

[0029] The sealing site of the end cap and the small bundle of hollow fibers is also connected to the inner side wall of the outer peripheral portion, therefore, the first connecting portion and the second connecting portion with different radial widths make the inner side wall of the outer peripheral portion undulate, thereby increasing the contact area of the outer peripheral portion and improving the connection strength between the sealing site and the inner side wall of the outer peripheral portion; at the same time, since the second connecting portion is relatively close to the inner surface of the end cap, by making the radial width of the second connecting portion larger, it is beneficial to increase the distance between the small bundle of hollow fibers and the inner wall of the cylinder (i.e., farther away from the opening on the inner wall of the cylinder), which on the one hand reduces the disturbance of the liquid flowing into or out of the opening to the hollow fiber membrane, and on the other hand, leaves a wider liquid flow channel, which is conducive to the flow of feed liquid or filtrate.

[0030] Preferably, the area of the outer surface of the end cover is S1, the total area of all the insertion slots is S2, and S2 / S1 = 2-5; if the area ratio of the insertion slots is too large, the mechanical strength of the entire end cover will be reduced, and if the area ratio of the insertion slots is too small, the loading capacity of the hollow fiber membrane filaments will be too small and the filtration efficiency will be low; by controlling the area ratio to be 2-5, on the one hand, the loading capacity of the hollow fiber membrane filaments meets the filtration requirements, and on the other hand, the structural strength of the end cover meets the use requirements, avoiding the sealing connection between the outer surface of the end cover and the sealing position being easily damaged.

[0031] Preferably, the end cover is in the shape of a cylinder and has high stability, the insertion slots are four quarter sectors, and the four insertion slots are radially arranged around the center portion, and the corresponding hollow fiber bundles are also divided into four hollow fiber small bundles, corresponding to four axially extending flow gaps, which is beneficial to the uniform distribution and interconnection of the multiple hollow fiber small bundles and the flow gaps therebetween, and the flow gaps are interconnected in the inner cavity, meeting the flow requirements of the feed liquid or the filtrate and improving the filtration efficiency.

[0032] Preferably, the inner cavity is provided with a baffle, the baffle axially extends and surrounds all the hollow fiber small bundles, the radial projection of the baffle covers the opening, and the baffle is provided with a channel for the flow of the feed liquid.

[0033] The outer peripheral portion of the end cover is provided with a receiving groove at one end facing the baffle, and the axial end portion of the baffle is fixedly connected with the receiving groove.

[0034] In some cases of open inlet or open outlet, the feed liquid entering or flowing out of the opening will cause radial impact on the hollow fiber small bundles, causing the hollow fiber small bundles to deviate from the position relative to the sealing position and the end cover, affecting the sealing performance, therefore, the inner cavity is provided with a baffle and the radial projection of the baffle covers the opening, so that the feed liquid can only contact the hollow fiber small bundles through the channel on the baffle, greatly reducing the direct impact on the hollow fiber small bundles and reducing the positional deviation of the hollow fiber small bundles and the flow gaps, improving the stability of the hollow fiber small bundles and the flow gaps, and making the feed liquid fully contact each hollow fiber small bundle, thereby improving the filtration efficiency; in addition, the outer peripheral portion of the end cover is fixedly connected with the baffle through the receiving groove, improving the stability of the end cover and the firmness of the connection with the inner wall of the cylinder, which is also beneficial to improving the stability of the flow gaps between the hollow fiber small bundles.

[0035] Preferably, the axial distance between the bottom of the receiving groove and the inner surface of the end cover is H1, the axial distance between the end of the termination part close to the starting part and the inner surface of the end cover is H2, and H1 / H2=0.7-0.95; the receiving groove will damage the structural strength of the end cover to some extent, and therefore, the depth of the receiving groove, i.e., the axial distance between the bottom of the receiving groove and the inner surface of the end cover, needs to be limited; if H1 / H2 exceeds the ratio range, the depth of the receiving groove is too deep, the axial distance between the receiving groove and the outer surface of the end cover is too close, and the outer peripheral part is prone to breakage; if H1 / H2 is less than the ratio range, the receiving groove is too shallow, the depth of the end part of the baffle that can be accommodated is insufficient, and the connection strength of the outer peripheral part and the baffle is insufficient; therefore, H1 / H2 is controlled in the above range, which not only ensures the structural strength of the end cover itself, but also ensures the connection firmness of the end cover and the baffle.

[0036] In summary, compared with the prior art, the utility model has at least the following beneficial effects:

[0037] The hollow fiber filter of the utility model utilizes the end cover to fix the end part of the hollow fiber bundle, the end cover is located between the opening and the port in the axial direction of the cylinder, the inner surface thereof faces the inside of the cylinder, and the outer surface thereof is the end opposite to the inner surface in the axial direction; since the material liquid exchanges at the outer surface, the sealing position is easily impacted, the connection between the sealing position and the outer surface is easily damaged, and the sealing position is even likely to fail; therefore, the side of the baffle close to the outer surface comprises a fixed section and a connection section, the thickness of the fixed section is greater than the thickness of the connection section, the side of the baffle close to the outer surface is zigzag-shaped, the contact area between the outer surface of the baffle and the sealing position of the hollow fiber small bundle is increased, and the connection strength and firmness of the sealing position and the outer surface of the end cover are improved; in addition, the ends of the fixed sections close to the center of the end cover are connected with the center part respectively; the thickness of the fixed section in the direction perpendicular to the radial direction is greater than the thickness of the connection section in the direction perpendicular to the radial direction; when the end cover is injection molded, the center part is generally an injection port, the size of the center part is not lower than the thickness of the fixed section, and therefore, the area of the corresponding injection port can also be set to be relatively large, the pressure loss of injection is smaller, the structural depression of the end cover as a whole at the place with large thickness is reduced, the structural integrity and stability are maintained, the area of the injection port is large, the shrinkage of the molten liquid is small but the directionality is large, the thickness of the center part to the fixed section and then to the connection section gradually decreases, and the molten liquid flow is guided, and the shrinkage rate and mechanical strength of the end cover as a whole are reduced. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the description of the specific embodiments or the prior art. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0039] Figure 1 A cross-sectional view of the hollow fiber filter of the present application.

[0040] Figure 2 A schematic view of the end cover and the cylinder of the first embodiment of the present application.

[0041] Figure 3 A schematic view of the end cover and the cylinder of the second embodiment of the present application.

[0042] Figure 4 A schematic view of the structure of the end cover of the third embodiment of the present application.

[0043] Figure 5 A schematic view of the end cover, the cylinder and the hollow fiber bundle of the third embodiment of the present application.

[0044] Explanation of reference signs

[0045] 10, cylinder; 11, inner cavity; 12, opening; 13, port;

[0046] 20, hollow fiber bundle; 21, small hollow fiber bundle; 22, sealing position;

[0047] 30, end cover; 31, outer surface; 32, inner surface; 33, center part; 34, partition; 341, fixed segment; 342, connecting segment; 343, free segment; 344, starting part; 345, middle part; 346, ending part; 35, insertion slot; 36, peripheral part; 361, receiving slot; 362, first connecting part; 363, second connecting part;

[0048] 40, baffle; 41, passage. DETAILED DESCRIPTION

[0049] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0050] In the description of the utility model, it is necessary to explain, the term "center", "upper", "lower", "left", "right", "vertical", "horizontal", "internal", "external" and so on indicate the orientation or positional relationship is based on the orientation or positional relationship shown in the drawing, only for the convenience of describing the utility model and simplifying the description, and is not indicating or implying that the device or element indicated must have a particular orientation, a particular orientation structure and operation, therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0051] In the description of the utility model, it is necessary to explain, unless otherwise expressly provided and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, can also be detachably connected, or integrally connected, can be mechanically connected, can also be electrically connected, can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to specific circumstances.

[0052] As Figures 1 to 5As shown, the hollow fiber filter of the utility model embodiment, including cylinder 10 and hollow fiber bundle 20 in cylinder 10, cylinder 10 includes the inner chamber 11 of axial extension, the opening 12 of the communication of inner chamber 11 and port 13, the number of opening 12 can be one, can also be two, opening 12 can be set on the lateral wall of cylinder 10, and its opening direction is perpendicular to the axial direction of cylinder or presents a certain angle;Port 13 is close to the axial end of cylinder 10, and the number can be one, can be two, in some embodiments, port 13 is located at the axial both ends of cylinder 10, and the number is two, and is opened along the axial direction of cylinder 10;In another embodiment, port 13 is located on the lateral wall close to the end of cylinder 10, and its opening direction is perpendicular to the axial direction of cylinder 10 or presents a certain angle.Hollow fiber bundle 20 is located in the inner chamber 11 of cylinder 10 and at least partially extends in the axial direction, in some embodiments, hollow fiber bundle 20 is axially extended as a whole;In another embodiment, cylinder 10 is U-shaped, including two straight sections and a turning section, the axial direction of cylinder 10 refers to the axial direction of the straight section, two ports 13 are oriented in the same direction and are located at the end of the two straight sections, and the overall shape of hollow fiber bundle 20 is also U-shaped, part of which extends in the axial direction and part of which bends along the turning section of cylinder 10.Hollow fiber bundle 20 includes a plurality of hollow fiber membranes that extend at least partially in the axial direction, at least one end of the hollow fiber membranes is open and located at port 13, and is in communication with port 13.In general, if cylinder 10 has two ports 13, then the two ends of the hollow fiber membranes extend to the corresponding ports 13, respectively, and the interior of the hollow fiber membranes is in communication with the ports 13;If cylinder 10 has one port 13, then one end of the hollow fiber membranes extends to the port 13, and the interior of the hollow fiber membranes is in communication with the port 13.For convenience of description, the axial direction of each embodiment of the utility model is the axial direction of cylinder 10, hereinafter referred to as the axial direction.

[0053] In the present embodiment, as Figure 1As shown, the ports 13 are arranged at the axial ends of the cylinder body 10, and an end cover 30 is fixed at each port 13 to fix the hollow fiber bundle 20, and the hollow fiber bundle 20, the end cover 30, the port 13 and the cylinder body 10 are coaxially arranged. The end cover 30 includes an inner surface 32 and an outer surface 31 arranged axially, and a center part 33 and a plurality of partitions 34 connecting the inner surface 32 and the outer surface 31 axially, the plurality of partitions 34 are distributed radially around the center part 33, that is, all the partitions 34 are connected with the center part 33, the center part 33 can be circular, square or other irregular shape, has a large size, and the adjacent partitions 34 form a slot 35 axially penetrating the inner surface 32 and the outer surface 31 of the end cover 30, so as to separate the hollow fiber bundle 20 into a plurality of hollow fiber small bundles 21, and at least one end of the hollow fiber small bundle 21 is arranged in the slot 35 and forms a sealing position 22 with the inner circumferential surface of the slot 35, so as to separate the port 13 and the opening 12, so that the feed liquid can only pass through the hollow fiber membrane between the port 13 and the opening 12 to realize filtration.

[0054] The process of forming the sealing position 22 of the hollow fiber small bundle 21 and the slot 35 can be formed by any process known to those skilled in the art, such as centrifugal filling or adhesive method. In this embodiment, the process by centrifugal filling is as follows:

[0055] (1) After the end cover 30 is fixedly connected with the cylinder body 10, the pretreated hollow fibers are divided into a plurality of hollow fiber small bundles 21 corresponding to the slots 35;

[0056] (2) One end of each hollow fiber small bundle 21 is put into the slot 35 at one end, and the other end of the hollow fiber small bundle 21 is sequentially put into the slot 35 at the other end located in the inner cavity 11;

[0057] (3) One end of the cylinder body 10 is fixedly connected with a centrifugal device as a rotation point, and the filling adhesive (the filling adhesive can be epoxy resin or other curing agent commonly used in hollow fiber membrane filling process) is injected into the port 13 at the other end, and at the same time, the filling adhesive flows into each slot 35, so that the filling adhesive fills the slot 35 under the rotation centrifugal force, the filling adhesive is bonded with each hollow fiber membrane in the hollow fiber small bundle 21, and also bonded with the side wall of the slot 35, and the sealing position 22 is formed after the filling adhesive is cured; then the two ends of the cylinder body 10 are exchanged to form the sealing position 22 at the other end;

[0058] (4) The outer side surface of the sealing position 22 is cut along the radial direction to be flush with the outer surface 31 of the end cover 30, and the hollow fiber membrane inside the outer surface 31 of the end cover 30 is checked to communicate with the outside (that is, the hollow fiber membrane inside is not blocked by the filling adhesive), which meets the requirements.

[0059] Therefore, the connection firmness of the sealing position 22 and the end cover 30 is related to the side wall surface area of the insertion slot 35. The end cover 30 is located between the port 13 and the opening 12 in the axial direction, the inner surface 32 faces the inside of the cylinder body 10, and the outer surface 31 is the end opposite to the inner surface 32 in the axial direction. In some application scenarios, the feed liquid enters from the opening 12, contacts the hollow fiber membrane filaments, and the filtrate flows out of the open end of the hollow fiber membrane filaments, is collected in the space between the end cover 30 and the port 13, and flows out of the port 13. In other application scenarios, the feed liquid can also enter from the port 13, and then flow into the hollow fiber membrane filaments from the open end of the hollow fiber membrane filaments, and the filtrate seeps out of the hollow fiber membrane filaments and then flows out of the opening 12. Regardless of which application scenario, the outer surface 31 of the end cover 30 needs to be in contact with the filtrate or the feed liquid. After a long time, the sealing position 22 of the hollow fiber bundle 20 is prone to separation from the outer surface 31 of the end cover 30, thereby causing the sealing position 22 to fail. Therefore, the side of the partition plate 34 close to the outer surface 31 includes a fixed section 341 and a connecting section 342 in the embodiment of the utility model. The thickness D1 of the fixed section 341 is greater than the thickness D2 of the connecting section 342, the profile of the outer surface 31 of the partition plate 34 is zigzag-shaped, the contact area of the sealing position 22 of the hollow fiber bundle 21 is increased, the connection strength of the sealing position 22 and the outer surface 31 of the partition plate 34 is enhanced, and the risk of cracking of the sealing position 22 is reduced. In addition, the ends of the plurality of fixed sections 341 close to the center of the end cover 30 are respectively connected with the center part 33. The thickness D1 of the fixed section 341 in the direction perpendicular to the radial direction is greater than the thickness D2 of the connecting section 342 in the direction perpendicular to the radial direction. When the end cover 30 is injection molded, the center part 33 is generally an injection molding port, and the size of the center part 33 is not less than the thickness D1 of the fixed section 341. Therefore, the area of the corresponding injection molding port can also be set to be relatively large, the pressure loss of injection molding is smaller, and the structure of the end cover 30 is not recessed in the place with large thickness, thereby being beneficial to maintaining the structural integrity and stability.

[0060] In Figure 2 In the first embodiment shown in the figure, the end cover 30 is cross-shaped, the insertion slot 35 formed thereby is an open slot, the connecting section 342 is fixedly connected with the inner wall of the cylinder body 10, and the hollow fiber bundle 21 in the insertion slot 35 and the end cover 30 and the inner wall of the cylinder body 10 together form the sealing position 22.

[0061] In Figure 3The difference between the shown embodiment two and the embodiment one is that the baffle plate 34 further comprises a radially extending free section 343, the connecting section 342 is located between the free section 343 and the fixed section 341, the thickness of the free section 343 in the direction perpendicular to the radial direction is greater than the thickness of the connecting section 342 in the direction perpendicular to the radial direction, the free section 343 is the area of the baffle plate 34 close to the inner wall of the cylinder body 10, and the greater thickness is conducive to improving the connection strength between the baffle plate 34 and the inner wall of the cylinder body 10, avoiding the shaking of the end cover 30 and the hollow fiber bundle 20 in the inner cavity 11, and on the other hand, the thickness of the free section 343 is greater than the thickness of the connecting section 342, so that the outer surface 31 of the baffle plate 34 becomes more tortuous, and the contact area with the sealing position 22 is larger, thereby improving the connection strength and firmness of the sealing position 22 and the outer surface 31 of the end cover 30.

[0062] As shown in the above two embodiments, Figure 2 and Figure 3 The center part 33 refers to the area surrounded by the center dotted line of the end cover 30, and the arc transition between the center part 33 and the fixed section 341 means that the two side walls of the baffle plate 34 corresponding to the connection between the center part 33 and the fixed section 341 are smooth surfaces without obvious protrusions or steps. The center part 33 in the embodiment is approximately square in shape, and concave rounded corners are arranged at the four corners, respectively. The concave rounded corners are connected with the adjacent fixed sections 341, respectively, so that the side wall of the center part 33 and the side wall of the fixed section 341 are smoothly transitioned. Of course, in other embodiments, the center part 33 can be circular or square, and a rounded corner or an arc surface is arranged at the connection between the center part 33 and the fixed section 341, so that the side wall of the center part 33 and the side wall of the fixed section 341 are smoothly transitioned. The arc transition is conducive to reducing stress concentration and improving the structural strength of the end cover 30, and further increases the contact area between the side of the center part 33 and the sealing position 22, thereby improving the connection firmness between the side wall of the end cover 30 and the sealing position 22. In addition, the rounded corner makes the size of the center part 33 larger, which can further increase the size of the injection port, reduce pressure loss, and improve the yield of the end cover 30. Similarly, the arc transition between the fixed section 341 and the connecting section 342 means that the fixed section 341 and the connecting section 342 with different thicknesses are connected through an arc section with gradually reduced thickness, so as to smoothly transition from the fixed section 341 with greater thickness to the connecting section 342 with smaller thickness, and the two side walls of the baffle plate 34 corresponding to the connection between the fixed section 341 and the connecting section 342 are smooth surfaces without obvious protrusions or steps. Therefore, the stress concentration at the connection between the fixed section 341 and the connecting section 342 is reduced, the structural strength of the end cover 30 is improved, and the molten liquid flows more smoothly at the connection between the fixed section 341 and the connecting section 342 during injection molding, so as to improve the connection firmness between the side wall of the end cover 30 and the sealing position 22. Figure 3As shown, in the second embodiment, the arc-shaped transition between the connecting section 342 and the free section 343 means that the connecting section 342 and the free section 343 with different thicknesses are connected through an arc-shaped section with gradually increasing thickness, to achieve smooth transition from the connecting section 342 with smaller thickness to the free section 343 with larger thickness, and the two side walls of the baffle 34 corresponding to the connection between the connecting section 342 and the free section 343 are smooth surfaces without obvious protrusions or steps. Thus, the stress concentration at the connection between the free section 343 and the connecting section 342 is reduced, the structural strength of the end cover 30 is improved, and when the end cover 30 is injection molded, the molten liquid flows more smoothly through the connection between the connecting section 342 and the free section 343, the injection strength is high, and the connection between the side wall of the end cover 30 and the sealing position 22 is further improved.

[0063] Since the end cover 30 has a certain axial thickness, the baffle 34 has a side wall connecting the inner surface 32 and the outer surface 31, the side wall constitutes at least part of the boundary of the insertion slot 35, and the hollow fiber bundle 21 in the insertion slot 35 forms a sealing position 22 with the side wall. Therefore, the shape of the side wall also affects the sealing position 22, such as Figure 4 As shown in the third embodiment, the side wall includes a starting portion 344 and a terminating portion 346, the starting portion 344 and the terminating portion 346 are distributed in the axial direction, the starting portion 344 is formed by the connecting section 342, the free section 343, and the fixed section 341 extending from the outer surface 31 of the end cover 30 to the inner surface 32 of the end cover 30 in the axial direction, and the terminating portion 346 terminates at the inner surface 32 of the end cover 30. The thickness of the baffle 34 corresponding to the terminating portion 346 in the direction perpendicular to the radial direction is greater than the thickness of the baffle 34 corresponding to the starting portion 344 in the direction perpendicular to the radial direction. The different thicknesses make the starting portion 344 and the terminating portion 346 have a zigzag shape in the axial direction, thereby increasing the contact area between the baffle 34 and the sealing position 22 and improving the connection firmness of the baffle 34 and the sealing position 22.

[0064] On the other hand, the inner surface 32 of the end cover 30 faces the inside of the barrel 10, and the size of the inner surface 32 of the baffle 34 determines the size of the flow gap between adjacent hollow fiber bundles 21. Therefore, the closer to the inner surface 32, the greater the thickness of the baffle 34, that is, the thickness of the baffle 34 in the region corresponding to the terminating portion 346 is greater than the thickness of the baffle 34 in the region corresponding to the starting portion 344. Thus, the flow gap between the hollow fiber bundles 21 is larger, which is conducive to the flow of feed liquid or filtrate; at the same time, compared to the inner surface, the space on the side of the insertion slot close to the outer surface of the end cover is larger, which can accommodate more sealing glue to seal and fix the hollow fiber bundles, and the formed sealing position is more impact-resistant.

[0065] In addition, from the injection angle of the end cap 30, after the molten liquid is injected through the injection port corresponding to the center part 33, it flows radially in the order of fixed section 341-connecting section 342-free section 343, and axially in the order of starting part 344-ending part 346. The thickness of the partition 34 in the area corresponding to the ending part 346 is greater than the thickness of the partition 34 in the area corresponding to the starting part 344, which reduces the resistance to the flow of molten liquid and avoids the problem of defects easily occurring during injection molding due to the large overall thickness of the end cap 30.

[0066] like Figure 4 As shown, the sidewall of the partition 34 also includes a middle portion 345, which is located in the axial middle between the starting portion 344 and the ending portion 346. One end of the middle portion 345 has an arc transition with the starting portion 344, and the other end of the middle portion 345 has an arc transition with the ending portion 346. The function of the middle portion 345 is to achieve a smooth transition between the starting portion 344 and the ending portion 346, and the thickness of the partition 34 gradually transitions from a smaller to a larger thickness. The arc transition makes the molten liquid flow more smoothly through the starting portion 344, the middle portion 345 and the ending portion 346 during the injection molding of the end cap 30, resulting in high injection molding strength. The smooth surface formed by the arc transition also helps to improve the connection strength between the partition 34 and the sealing position 22.

[0067] In such Figure 4 and Figure 5 In the third embodiment shown, the difference from the first and second embodiments is that the end cap 30 also includes an annular outer peripheral portion 36. The radial ends of the partition 34 are connected to the central portion 33 and the outer peripheral portion 36 respectively, and the radial outer end of the free section 343 is connected to the outer peripheral portion 36. The slot 35 formed therefrom is a closed slot. The outer peripheral portion 36 connects multiple partitions 34 in the circumferential direction, which enhances the stability of each partition 34 and prevents the partitions 34 from deforming radially or changing in size due to external forces. This ensures that the size of each slot 35 remains basically unchanged. The connection between the sealing position 22 located in the slot 35 and the end cap 30 is more stable and less likely to detach. In addition, the outer peripheral portion 36 increases the connection area and connection strength between the end cap 30 and the inner wall of the cylinder 10, making the end cap 30 and the hollow fiber bundle 20 more stable and less likely to shake relative to the cylinder 10. The flow gap between adjacent hollow fiber bundles 21 is more stable, which is conducive to the flow of liquid or filtrate and improves filtration efficiency.

[0068] like Figure 4As shown, the outer surface 31 and the inner surface 32 of the end cap 30 are both flat surfaces, the outer peripheral portion 36 has an inner side wall connecting the inner surface 32 and the outer surface 31 of the end cap 30 in the axial direction, and the sealing position 22 of the hollow fiber bundle 21 is also connected to the inner side wall of the outer peripheral portion 36; the inner side wall includes a first connecting portion 362 and a second connecting portion 363 arranged in the axial direction from the outer surface 31 to the inner surface 32, the first connecting portion 362 connects adjacent starting portions 344, and the second connecting portion 363 connects adjacent ending portions 346, so that the end cap 30 is an integral structure, preferably an integral injection molding; the radial width of the first connecting portion 362 is smaller than the radial width of the second connecting portion 363, and the first connecting portion 362 and the second connecting portion 363 with different radial widths make the inner side wall of the outer peripheral portion 36 undulate, increase the contact area of the outer peripheral portion 36, and improve the connection strength of the sealing position 22 and the inner side wall of the outer peripheral portion 36. At the same time, the second connecting portion 363 is relatively close to the inner surface 32 of the end cap 30, the radial width of the second connecting portion 363 is larger, so that the distance between the hollow fiber bundle 21 and the inner wall of the cylinder 10 is farther, i.e., farther from the opening 12 on the inner wall of the cylinder 10. On the one hand, it reduces the disturbance of the liquid flowing into or out of the opening 12 to the hollow fiber membrane, and on the other hand, it leaves a wider liquid flow channel, which is conducive to the flow of the feed liquid or the filtrate.

[0069] Based on the above embodiment, the area of the inner surface 32 of the end cap 30 is larger than the area of the outer surface 31 of the end cap 30, the outer surface 31 is the smallest solid area of the end cap 30, which corresponds to the weakest part of the structural strength of the end cap 30, the area of the outer surface 31 of the end cap 30 is S1, the total area of all the insertion grooves 35 in the axial direction is S2, and S2 / S1 = 2-5. If the area ratio of the insertion grooves 35 is too large, the mechanical strength of the entire end cap 30 will be reduced, especially the mechanical strength of the part close to the outer surface 31 of the end cap 30, which makes the sealing connection between the outer surface 31 of the end cap 30 and the sealing position 22 more easily damaged. If the area ratio of the insertion grooves 35 is too small, the loading capacity of the hollow fiber membrane will be too small, and the filtration efficiency will be low. Controlling the area ratio to be 2-5 can ensure that the loading capacity of the hollow fiber membrane meets the filtration requirements, and at the same time, the structural strength of the end cap 30 meets the use requirements, avoiding the sealing connection between the outer surface 31 of the end cap 30 and the sealing position 22 being easily damaged.

[0070] As a preferred, as Figure 4In the third embodiment shown, the end cap 30 is cylindrical, which not only has high stability but also fits the cylindrical body 10. The slots 35 are four quarter-fan shapes, and the four slots 35 are arranged radially around the central part 33, which is conducive to the uniform distribution of multiple hollow fiber bundles 21 and the flow gaps between them, and they are interconnected. In this embodiment, there are four slots 35 to avoid an excessive number of slots 35 that would increase the number of partitions 34 and occupy the space of the hollow fiber bundles 21. The corresponding hollow fiber bundles 20 are also divided into four hollow fiber bundles 21, each with four axially extending flow gaps, and each flow gap is interconnected in the inner cavity 11, which meets the flow requirements of the liquid or filtrate and improves the filtration efficiency.

[0071] like Figure 1 In the illustrated embodiment, the end cap 30 inside the cylinder 10 can be any one of Embodiment 1 to Embodiment 3. The cylinder 10 is provided with two openings 12 and two ports 13. One opening 12 serves as a liquid inlet, and the other opening 12 serves as a liquid outlet. Both ports 13 are filtrate outlets. The liquid entering or flowing out through the opening 12 will cause radial impact on the hollow fiber bundles 21, causing the hollow fiber bundles 21 to undergo radial displacement relative to the sealing position 22 and the end cap 30, moving away from or closer to the opening 12. This not only affects the sealing performance of the sealing position 22, but also easily leads to bending damage of the membrane fibers in the hollow fiber bundles 12, and changes in the flow gap between the hollow fiber bundles 12, affecting the flow of the liquid. Therefore, in this embodiment, a baffle 40 is provided inside the inner cavity 11. The baffle 40 extends axially and surrounds all the hollow fiber bundles 21. The radial projection of the baffle 40 covers the opening 12. The baffle 40 is provided with a channel 41 for the flow of the liquid. The liquid can only contact the hollow fiber bundles 21 through the channel 41 on the baffle 40, avoiding direct impact of the liquid on the hollow fiber bundles 21. This greatly reduces the direct impact on the hollow fiber bundles 21, improves the stability of the hollow fiber bundles 21 and the flow gap, and ensures that the liquid is in full contact with each hollow fiber bundle 21, resulting in high filtration efficiency.

[0072] To fix the baffle 40, a receiving groove 361 is provided at one end of the outer peripheral portion 36 facing the baffle 40. The axial end of the baffle 40 is fixedly connected to the receiving groove 361. At the same time, the axially extending baffle 40 can play an auxiliary positioning role for the two end caps 30. The outer peripheral portion 36 of the end cap 30 and the baffle 40 are fixedly connected through the receiving groove 361, which improves the stability of the end cap 30 and the firmness of the connection with the inner wall of the cylinder 10. It also helps to improve the stability of the flow gap between the hollow fiber bundles 21.

[0073] Meanwhile, the receiving groove 361 will compromise the structural strength of the end cap 30 to some extent. Therefore, it is necessary to limit the depth of the receiving groove 361, that is, the axial distance between the bottom of the receiving groove 361 and the inner surface 32 of the end cap 30. Furthermore, since the radial thickness of the outer peripheral portion 36 corresponding to the second connecting portion 363 is relatively large, and the second connecting portion 363 is connected to the termination portion 346, the receiving groove 361 is disposed within the area of ​​the outer peripheral portion 36 corresponding to the second connecting portion 363. Figure 1 As shown, the axial distance between the bottom of the receiving groove 361 and the inner surface 32 of the end cap 30 is H1, and the axial distance between the end of the termination part 346 near the starting part 344 and the inner surface 32 of the end cap 30 is H2. That is, the axial height of the partition 34 area corresponding to the termination part 346 is H2, and H1 / H2 = 0.7-0.95. If H1 / H2 exceeds the ratio range, the depth of the receiving groove 361 is too deep, and its axial distance with the outer surface 31 of the end cap 30 is too close, making the outer peripheral part 36 prone to breakage. If H1 / H2 is less than the ratio range, the depth of the receiving groove 361 is too shallow, and the depth of the end of the baffle 40 that can be accommodated is insufficient, resulting in insufficient connection strength between the outer peripheral part 36 and the baffle 40. Therefore, controlling H1 / H2 within the above range ensures both the structural strength of the end cap 30 itself and the firmness of its connection with the baffle 40.

[0074] The above embodiments are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. A hollow fiber filter, comprising: A cylindrical body includes an axially extending inner cavity, an opening communicating with the inner cavity, and a port, the port being located near the end of the cylindrical body; A hollow fiber bundle is located in the inner cavity and extends at least partially axially. The hollow fiber bundle includes a plurality of hollow fiber membrane filaments that extend at least partially axially. At least one end of each hollow fiber membrane filament is open and communicates with the port. Its characteristic is that it further includes: An end cap, fixed at the port, includes an axially arranged inner surface and an outer surface, a central portion axially connecting the inner surface and the outer surface, and a plurality of partitions. The partitions are radially distributed around the central portion, and slots are formed between adjacent partitions that axially penetrate the inner and outer surfaces of the end cap to separate the hollow fiber bundle into multiple small hollow fiber bundles. At least one end of each small hollow fiber bundle is correspondingly disposed in the slot and forms a sealing position with the inner circumferential surface of the slot to separate the port and the opening. The partition plate includes a fixed section and a connecting section on the side near the outer surface, and the fixed sections are respectively connected to the central part at one end near the center of the end cap; The thickness of the fixed section in the radial direction is greater than the thickness of the connecting section in the radial direction.

2. The hollow fiber filter as described in claim 1, characterized in that, The partition also includes a free segment extending radially, and the connecting segment is located between the free segment and the fixed segment, wherein the thickness of the free segment in the radial direction is greater than the thickness of the connecting segment in the radial direction.

3. The hollow fiber filter as described in claim 1, characterized in that, There is an arc-shaped transition between the central part and the fixed section.

4. The hollow fiber filter as described in claim 2, characterized in that, The fixed segment and the connecting segment have an arc-shaped transition; and / or There is an arc transition between the connecting segment and the free segment.

5. The hollow fiber filter as described in claim 2, characterized in that, The partition has a sidewall axially connecting the inner surface and the outer surface. The sidewall includes a starting portion and a terminating portion, which are axially distributed. The starting portion is formed by the connecting section, the free section, and the fixed section extending axially from the outer surface of the end cap towards the inner surface of the end cap. The terminating portion terminates on the inner surface of the end cap. The thickness of the partition corresponding to the termination portion in the radial direction is greater than the thickness of the partition corresponding to the starting portion in the radial direction.

6. The hollow fiber filter as described in claim 5, characterized in that, The sidewall of the partition also includes a middle section, which is located axially between the starting section and the ending section. One end of the middle section has an arc transition with the starting section, and the other end of the middle section has an arc transition with the ending section.

7. The hollow fiber filter as described in claim 2, characterized in that, The end cap also includes an annular outer peripheral portion, and the radial ends of the partition are respectively connected to the central portion and the outer peripheral portion. The radial outer end of the free segment is connected to the outer peripheral portion; and / or The outer peripheral portion has an inner sidewall that axially connects the inner surface and the outer surface of the end cap. The inner sidewall includes a first connecting portion and a second connecting portion that are axially disposed along the outer surface to the inner surface. The radial width of the first connecting portion is smaller than the radial width of the second connecting portion. The first connecting portion connects to an adjacent starting portion and the second connecting portion connects to an adjacent ending portion.

8. The hollow fiber filter according to any one of claims 1 to 7, characterized in that, The area of ​​the outer surface of the end cap is S1, and the projected area of ​​the total area of ​​all the slots in the axial direction is S2, which satisfies that S2 / S1 = 2-5.

9. The hollow fiber filter according to any one of claims 1 to 7, characterized in that, The end cap is cylindrical, and the slots are four quarter-fan shapes, with the four slots radiating around the center.

10. The hollow fiber filter as described in claim 7, characterized in that, The inner cavity is provided with a baffle, which extends axially and surrounds all the hollow fiber bundles. The radial projection of the baffle covers the opening, and the baffle is provided with a channel for the flow of the feed liquid. The outer periphery is provided with a receiving groove at one end facing the baffle, and the axial end of the baffle is fixedly connected to the receiving groove.

11. The hollow fiber filter as described in claim 10, characterized in that, The axial distance between the bottom of the receiving groove and the inner surface of the end cap is H1, and the axial distance between the end of the termination part near the starting part and the inner surface of the end cap is H2, where H1 / H2 = 0.7-0.95.

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