Hollow fiber filtering device

Abstract

The utility model discloses a hollow fiber filtering device 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, and the hollow fiber bundle is divided into a plurality of small hollow fiber bundles by the end cover; at least one end of the small hollow fiber bundle is correspondingly arranged in the inserting groove, a sealing position separating the side opening and the end opening is formed by the small hollow fiber bundle and the inner circumferential face of the inserting groove, the inner diameter of the inserting groove is increased in the direction from the inner surface of the end cover to the outer surface, and the small hollow fiber bundle can keep a large radial gap on the inner surface side of the end cover. The small hollow fiber bundles and the inner walls, close to the outer surfaces, of the inserting grooves are made to have large gaps, large-size sealing positions can be formed, the sealing effect of the sealing positions between the small hollow fiber bundles and the inserting grooves is guaranteed, meanwhile, due to the fact that the inner diameters of the inserting grooves are changed, the inner walls of the inserting grooves are fluctuant, the contact area between the inserting grooves and the sealing positions is larger, and the sealing effect is better. The connection firmness with the sealing position can be improved, and the sealing effect of the sealing position is further improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to filter technical field, especially a kind of hollow fiber filter device. 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 filter 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 may 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 may be inconsistent, and some hollow fiber membranes may 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 may become inconsistent, which affects 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 pouring sealant to package the small bundles of hollow fiber membranes into a hollow fiber filter device, and controls the gap between the small bundles, such as the hollow fiber membrane assembly disclosed in US application US20020179516A1.

[0005] In the design of the existing partition plate, in order to ensure the gap between the small bundles, the overall thickness of the partition plate is generally increased, which causes the space between the partition plates to become smaller. In order to ensure the filtration efficiency of the filter, as many membranes as possible need to be filled between the partition plates, which causes the distance between the membranes and the inner wall of the partition plate to be too close. When pouring sealant is added for packaging, the amount of pouring sealant entering between the membranes and the inner wall of the partition plate is too small, which finally causes the structural strength and sealing performance of the pouring site formed by the membranes and the partition plate to be insufficient, and the pouring site is prone to sealing failure or even leakage. SUMMARY

[0006] In view of the deficiencies of the prior art, the purpose of the utility model is to provide a hollow fiber filter device, which solves the problem that the existing partition plate is prone to structural defects when the thickness is large.

[0007] To achieve the above object, the utility model adopts the following technical scheme:

[0008] A hollow fiber filtration device, comprising:

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

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

[0011] Further comprising: an end cap fixed at the port, the end cap comprising an inner surface, an outer surface, and a slot axially penetrating through the inner surface and the outer surface, so as to separate the hollow fiber bundle into a plurality of hollow fiber sub-bundles, and at least one end of the hollow fiber sub-bundle is arranged in the slot and forms a sealing position separated from the opening and the port with the inner circumferential surface of the slot;

[0012] A plurality of the hollow fiber sub-bundles form radial gaps between adjacent hollow fiber sub-bundles based on different slots, and the inner diameter of the slot increases from the inner surface of the end cap to the outer surface.

[0013] The hollow fiber filtration device of the utility model embodiment utilizes the end cap to fix the end of the hollow fiber bundle and separate it into a plurality of hollow fiber sub-bundles, the end of each hollow fiber sub-bundle is arranged in the slot, and the radial gap between the hollow fiber sub-bundles is maintained by the radial distance between the adjacent slots on the end cap. If the inner diameter of the slot is smaller on the inner surface, the radial gap between the hollow fiber sub-bundles is larger. In order to ensure the membrane filament loading capacity of the hollow fiber sub-bundle, it is necessary to fully utilize the slot space and fill more membrane filaments, so that the distance between the hollow fiber sub-bundle and the inner wall of the slot is closer. Therefore, the inner diameter of the slot increases from the inner surface of the end cap to the outer surface, so that the hollow fiber sub-bundle and the inner wall of the slot close to the outer surface have a larger gap to fill more potting glue, thereby forming a larger sealing position, which ensures the sealing effect of the sealing position between the hollow fiber sub-bundle and the slot and makes it more resistant to impact. At the same time, since the inner diameter of the slot changes, the tortuosity of the inner wall of the slot is increased, the contact area with the sealing position is larger, the connection firmness with the sealing position is improved, and the sealing effect of the sealing position is further improved. In addition, the above structure avoids that the thickness of the solid structure on the end cap is large as a whole, but only the thickness of the solid structure on the inner surface of the end cap is large. The end cap of the above structure will not have a large overall shrinkage during injection molding, which is conducive to reducing defects such as deformation or depression during injection molding and ensuring the stability of the end cap structure.

[0014] Preferably, the insertion slot comprises a starting portion and a terminal portion in the axial direction, the starting portion and the terminal portion are distributed in the axial direction, the starting portion is formed by the outer surface of the end cover extending in the axial direction to the inner surface of the end cover, and the terminal portion ends at the inner surface of the end cover; the inner diameter of the terminal portion is smaller than the inner diameter of the starting portion; it is ensured that there is a larger radial gap between the small bundles of hollow fibers, the flow channel in the lumen is optimized, the feed liquid can be in full contact with the hollow fiber membrane filaments and filtered; at the same time, the starting portion has a larger gap between the inner wall of the insertion slot and the small bundles of hollow fibers for filling and sealing glue, while taking into account the loading amount of the hollow fiber membrane filaments, the contact area of the sealing position between the insertion slot and the small bundles of hollow fibers is increased, and the sealing effect and connection firmness of the sealing position are improved.

[0015] Preferably, the inner diameter of the terminal portion increases in the direction from the inner surface of the end cover to the starting portion; the inner diameter of the starting portion decreases in the axial direction from the outer surface of the end cover to the terminal portion; the solid structure of the end cover corresponding to the insertion slot is thus arranged, and the overall thickness of the end cover also increases in the axial direction from the outer surface to the inner surface, so as to ensure that the small bundles of hollow fibers have a larger radial gap at the inner surface of the end cover and optimize the flow channel; it also makes the starting portion have a larger gap between the inner wall of the insertion slot and the small bundles of hollow fibers for filling and sealing glue; it also makes the inner wall of the insertion slot have a larger surface area, while taking into account the loading amount of the hollow fiber membrane filaments, the sealing effect of the sealing position is ensured.

[0016] Preferably, the insertion slot further comprises an intermediate portion, the intermediate portion is located in the axial middle of the starting portion and the terminal portion, one axial end of the intermediate portion is connected to the starting portion, and the other axial end of the intermediate portion is connected to the terminal portion; the inner diameter of the intermediate portion decreases in the direction from the starting portion to the terminal portion.

[0017] Therefore, the inner wall of the insertion slot corresponding to the starting portion and the intermediate portion has a space for filling and sealing glue between the small bundles of hollow fibers, a sealing position with high structural strength and good sealing effect can be formed, and the tortuosity of the inner wall of the insertion slot is increased, and the contact area of the sealing position between the insertion slot and the small bundles of hollow fibers is increased.

[0018] Preferably, the one axial end of the intermediate portion is arc-shapedly transitioned to the starting portion, and the other axial end of the intermediate portion is arc-shapedly transitioned to the terminal portion; the injection liquid flows more smoothly when the end cover is injection molded, and the injection strength is high; the smooth surface formed by the arc-shaped transition is also conducive to improving the connection firmness of the partition plate and the sealing position.

[0019] Preferably, the radial spacing of the radial gap is D, the total radial cross-sectional area of the hollow fiber bundle is S1, and S1 / D=500-3000 mm is satisfied; S1 represents the total filtration area of the hollow fiber membrane filaments, and the value of S1 / D represents the size relationship between the total filtration area of the hollow fiber membrane filaments and the radial gap. Controlling the ratio within the above range can ensure that the loading amount of the hollow fiber membrane filaments meets the filtration requirements on the one hand, and ensure that the structural strength of the sealing position meets the use requirements on the other hand, which is beneficial to avoid the sealing connection between the inner surface of the end cover and the sealing position being damaged.

[0020] Preferably, the radial spacing of the radial gap is D, the outer periphery of the small bundle of hollow fibers is surrounded by a stop net, the stop net is located in the radial gap, and the minimum radial spacing of adjacent stop nets is d, and D / d=0.1-2.5 is satisfied.

[0021] The function of the stop net is to reduce the deviation and deformation of the hollow fiber membrane filaments during the filtration process, and to improve the stability of the position of the small bundle of hollow fibers, so as to facilitate the stability of the size of the flow gap, reduce the state of the small bundle of hollow fibers and the flow gap being stacked or aggregated due to the external force of the feed liquid, and thus facilitate the small change degree of the spacing between the membrane filaments of the small bundle of hollow fibers, so that the feed liquid can fully contact each small bundle of hollow fibers, and the filtration efficiency is high. However, the stop net itself will occupy some space of the radial gap, and will also have some influence on the flow of the feed liquid. The value of D / d represents the position of the stop net in the radial gap. Controlling the ratio within the above range can make the stop net have a better restraining effect on the hollow fiber membrane filaments, and also avoid the hollow fiber membrane filaments being too tightly restrained.

[0022] Preferably, the first end of the small bundle of hollow fibers corresponds to the insertion slot of one of the end covers to form a first sealing position, the stop net extends axially, and one end is connected to the first sealing position; the axial thickness of the first sealing position is P1, the axial length of the end of the stop net connected to the first sealing position in the first sealing position is Q1, and Q1 / P1=0.2-0.8 is satisfied.

[0023] and / or,

[0024] The number of ports is two, located at the axial ends of the cylinder body, the number of end covers is two, corresponding to one of the ports respectively, the second end of the small bundle of hollow fibers corresponds to the insertion slot of the other end cover to form a second sealing position, the stop net extends axially, and one end is connected to the second sealing position; the axial thickness of the second sealing position is P2, the axial length of the end of the stop net connected to the second sealing position in the second sealing position is Q2, and Q2 / P2=0.2-0.8 is satisfied.

[0025] Q1 and Q2 represent the axial length of the stop net penetrating into the first sealing position and the second sealing position respectively, and the value of Q2 / P2 reflects the axial length of the stop net penetrating into the second sealing position, if the ratio is too large, the end of the stop net is too close to the outer end surface of the first sealing position or the second sealing position, if a small amount of damage occurs in the first sealing position or the second sealing position, the first sealing position or the second sealing position itself does not have sealing failure, but the material liquid can leak through the stop net, leading to sealing failure; if the ratio is too small, the stop net is poor in connecting and fixing effect on the first sealing position and the sealing area on the same side and the second sealing position and the sealing area on the same side, and the stop net is easy to separate from the first sealing position and the sealing area on the same side or the second sealing position and the sealing area on the same side, and is difficult to play a supporting and connecting role.

[0026] Preferably, the stop net comprises an inner net and an outer net, the inner net is circumferentially surrounded around the bundle of hollow fibers along the outer periphery of the bundle of hollow fibers and can move with the bundle of hollow fibers, and the outer net is circumferentially surrounded outside the inner net; the inner net protects the hollow fiber membrane filaments, and the outer net restrains the hollow fiber membrane filaments from expanding or deforming towards the outside.

[0027] Preferably, the hardness of the outer net is greater than the hardness of the inner net, the hardness of the outer net is relatively large, and the restriction on the hollow fiber membrane filaments is good, but the outer net is also easy to wear or scratch the surface of the hollow fiber membrane filaments, therefore, the hardness of the inner net close to the hollow fiber membrane filaments and possibly in contact with the hollow fiber membrane filaments is relatively low, and the inner net can play a good protection role.

[0028] In summary, compared with the prior art, the utility model at least has the following beneficial effects:

[0029] The hollow fiber filtering device of the embodiment of the utility model, utilize end cap fixed end part of hollow fiber bundle, and it is divided into multiple hollow fiber small bundle, the end part of each hollow fiber small bundle is set in each slot correspondingly, the radial clearance between the hollow fiber small bundle is maintained by the radial distance between the adjacent slots on the end cap, the inner diameter of the slot is smaller on the inner surface, then the radial clearance between the hollow fiber small bundle is larger, and in order to guarantee the membrane filament loading capacity of hollow fiber small bundle, need to make full use of the slot space, fill more membrane filament, thus make the distance between the hollow fiber small bundle and the inner wall of the slot close, therefore, the inner diameter of the slot increases from the inner surface of the end cap to the outer surface direction, make the hollow fiber small bundle and the inner wall between the slot close the outer surface have larger gap to fill more filling glue, then form larger volume sealing position, thus guarantee the sealing effect of the sealing position between the hollow fiber small bundle and the slot, simultaneously, because the inner diameter of the slot has variation, increase the tortuosity of the inner wall of the slot, and the contact area of the sealing position is larger, can improve the connection firmness of the sealing position, further improve the sealing effect of the sealing position. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the specific embodiment of the utility model or the technical scheme in prior art, the following will briefly introduce the drawing needed to be used in specific embodiment or prior art description, obviously, the drawing in the following description is some embodiments of the utility model, and for ordinary skilled person in the art, other drawings can be obtained according to these drawings without creative labor.

[0031] Figure 1 It is the cross section schematic view of the hollow fiber filtering device of the embodiment of the utility model.

[0032] Figure 2 It is the schematic view of the hollow fiber small bundle and end cap of the embodiment of the utility model.

[0033] Figure 3 It is the structural schematic view of the end cap of the embodiment of the utility model.

[0034] Figure 4 It is the axial cross section schematic view of the hollow fiber small bundle and end cap of the embodiment of the utility model.

[0035] Figure 5 It is the structural schematic view of the end cap of another embodiment of the utility model.

[0036] EXPLANATION OF REFERENCE NUMERALS

[0037] 10, barrel; 11, inner cavity; 12, side port; 13, end port;

[0038] 20, hollow fiber bundle; 21, hollow fiber bundlelet; 22, first end; 23, second end; 24, first sealing position; 25, second sealing position; 26, radial gap; 27, stop net; 271, inner net; 272, outer net;

[0039] 30, end cap; 31, outer surface; 32, inner surface; 33, insertion slot; 331, starting portion; 332, ending portion; 333, intermediate portion; 34, partition; 35, peripheral portion. DETAILED DESCRIPTION

[0040] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0041] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] 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 side mouth 12 of the communication of inner chamber 11 and the port 13, the number of side mouth 12 can be one, also can be two, side mouth 12 can be set on the lateral wall of cylinder 10, and its side mouth direction is perpendicular to the axial direction of cylinder or presents a certain angle;The port 13 is close to the axial end of cylinder 10, and the number can be one, can be two, in some embodiments, the 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, the port 13 is located on the lateral wall close to the end of cylinder 10, and its side mouth 12 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 axially.As shown in Figure 1 In some embodiments, the hollow fiber bundle 20 extends axially as a whole;In another embodiment, the cylinder 10 is U-shaped, including two straight sections and a turning section, the axial direction of the cylinder 10 refers to the axial direction of the straight section, the two ports 13 are oriented in the same direction and located at the end of the two straight sections, and the overall shape of the hollow fiber bundle 20 is also U-shaped, with part extending axially and part bending along the turning section of the cylinder 10.The hollow fiber bundle 20 includes a plurality of hollow fiber membranes that extend at least partially axially, at least one end of the hollow fiber membranes is open and located at the port 13, and in communication with the port 13.In general, if the cylinder 10 has two ports 13, 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 the cylinder 10 has one port 13, 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 the cylinder 10, hereinafter referred to as the axial direction.

[0044] In this embodiment, as shown in Figure 1 The port 13 is provided at the axial both ends of the cylinder 10, and an end cover 30 is further 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 10 are coaxially arranged.The end cover 30 includes an inner surface 32, an outer surface 31 and a slot 33 axially penetrating the inner surface 32 and the outer surface 31, so as to separate the hollow fiber bundle 20 into a plurality of hollow fiber sub-bundles 21, i.e., the hollow fiber sub-bundles 21 are arranged one by one in the slots 33, at least one end of the hollow fiber sub-bundles 21 is arranged in the slots 33 and forms a sealing position with the inner circumferential surface of the slots 33 to separate the side mouth 12 and the port 13;The radial gaps 26 are formed between the adjacent hollow fiber sub-bundles 21 based on different slots 33;And the inner diameter of the slot 33 increases from the inner surface 32 to the outer surface 31 of the end cover 30.

[0045] The process of forming the sealing position of the hollow fiber bundle 21 and the slot 33 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: (1) After the end cap 30 is fixedly connected with the barrel 10, the pre-processed hollow fibers are divided into a plurality of hollow fiber bundles 21 corresponding to the slots 33;

[0046] (2) One end of each hollow fiber bundle 21 is placed into the slot 33 at one end, and the other end of the hollow fiber bundle 21 is sequentially inserted into the slot 33 at the other end of the inner cavity 11;

[0047] (3) One end of the barrel 10 is fixedly connected with a centrifugal device as a rotation point, and the filling glue (the filling glue 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 under the centrifugal force, and at the same time, the filling glue flows into each slot 33, so that the filling glue fills the slot 33 under the centrifugal force, the filling glue is bonded with each hollow fiber membrane in the hollow fiber bundle 21, and the filling glue is bonded with the side wall of the slot 33, and after the filling glue is cured, the sealing position is formed; then the two ends of the barrel 10 are exchanged to form the sealing position at the other end;

[0048] (4) The outer side surface of the sealing position is cut along the radial direction to be flush with the outer surface 31 of the end cap 30, and the hollow fiber membrane inside the outer surface 31 of the end cap 30 is checked to be in communication with the outside (i.e. the hollow fiber membrane inside is not blocked by the filling glue), which meets the requirements.

[0049] In some embodiments, the slot 33 is an open slot, and the corresponding end cover 30 is a radial structure, which forms a sealing position together with the inner wall of the cylinder body 10; in other embodiments, the slot 33 is a closed slot, which surrounds the end of the hollow fiber bundle 21. The slot 33 is arranged in the end cover 30, that is, the solid structure of the end cover 30 forms the slot 33. The end of each hollow fiber bundle 21 is arranged in the corresponding slot 33, and the radial gap 26 between the hollow fiber bundles 21 is maintained by the radial distance between the adjacent slots 33 on the end cover 30. If the inner diameter of the slot 33 is smaller on the inner surface, the radial gap 26 between the hollow fiber bundles 21 is larger; in order to ensure the membrane fiber loading capacity of the hollow fiber bundle 21, it is necessary to make full use of the space of the slot 33 and fill more membrane fibers, so that the distance between the hollow fiber bundle 21 and the inner wall of the slot 33 is closer. Therefore, the inner diameter of the slot 33 increases from the inner surface 32 to the outer surface 31 of the end cover 30, so that the hollow fiber bundle 21 and the inner wall of the slot 22 near the outer surface 31 have a larger gap, which can accommodate more sealing glue and form a larger sealing position, thereby ensuring the sealing effect of the sealing position between the hollow fiber bundle 21 and the slot 33. At the same time, since the inner diameter of the slot 33 changes, the tortuosity of the inner wall of the slot 33 increases, the contact area with the sealing position is larger, which can improve the connection firmness with the sealing position and further improve the sealing effect of the sealing position.

[0050] On the other hand, the inner diameter of the slot 33 corresponds to the thickness of the solid structure. Generally, the larger the inner diameter of the slot 33, the smaller the thickness of the corresponding solid structure; in some embodiments in which the slot 33 is an open slot, the solid structure is a partition plate 34, and the larger the inner diameter of the slot 33, the smaller the thickness of the partition plate 34 between adjacent slots 33; conversely, the smaller the inner diameter of the slot 33, the larger the thickness of the partition plate 34 between adjacent slots 33; in some embodiments in which the slot 33 is a closed slot, the solid structure includes the partition plate 34 and the outer peripheral part 35, and the larger the inner diameter of the slot 33, the smaller the thickness of the partition plate 34 between adjacent slots 33; conversely, the smaller the inner diameter of the slot 33, the larger the thickness of the partition plate 34 between adjacent slots 33, and the thickness of the outer peripheral part 35 can be determined according to the change of the axial inner diameter of the slot 33. The thickness of the outer peripheral part 35 can be consistent along the axial direction, or can change in the opposite direction following the change of the inner diameter of the slot 33.

[0051] As Figure 2In the shown embodiment, the slot 33 is a closed slot, the solid structure includes a partition plate 34 and a peripheral part 35, the radial gap 26 between adjacent hollow fiber bundles 21 is maintained by the radial distance of the slot 33 on the end cover 30, that is, the thickness of the partition plate 34, the inner diameter of the slot 33 increases from the inner surface 32 to the outer surface 31 of the end cover 30, that is, the inner diameter of the slot 33 on the inner surface 32 is smaller than that on the outer surface 31, and the thickness of the partition plate 34 formed on the inner surface 32 of the end cover 30 is greater than that on the outer surface 31, the hollow fiber bundle 21 can maintain a larger radial gap 26 on the inner surface 32 side of the end cover 30, at the same time, the thickness of the partition plate 34 of the end cover 30 is not large as a whole, but only the thickness of the inner surface 32 of the partition plate 34 is large, the end cover 30 with the above structure will not have a large overall shrinkage during injection molding, which is beneficial to reduce defects such as deformation or depression during injection molding, and at the same time ensures the stability of the structure of the end cover 30, so that the radial gap 26 between the multiple hollow fiber bundles 21 is maintained to be moderate, and the filtering flow channel is optimized.

[0052] As shown in Figure 3 and Figure 4 The slot 33 includes a starting portion 331 and a terminating portion 332 in the axial direction, the starting portion 331 and the terminating portion 332 are distributed along the axial direction, the starting portion 331 is formed by 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, the inner diameter of the starting portion 331 on the outer surface 31 of the end cover 30 corresponds to the thickness of the solid structure on the outer surface 31 of the end cover 30, the terminating portion 332 terminates at the inner surface 32 of the end cover 30, and the inner diameter of the terminating portion 332 on the inner surface 32 of the end cover 30 corresponds to the thickness of the solid structure on the inner surface 32 of the end cover 30, therefore, the inner diameter of the terminating portion 332 is smaller than that of the starting portion 331, that is, the thickness of the solid structure on the outer surface 31 of the end cover 30 is smaller than that on the inner surface 32 of the end cover 30, the injection port of the end cover 30 of the present embodiment is at the center of the outer surface 31 of the end cover 30, and the shrinkage rate of the solid structure with a larger thickness is larger, and the shrinkage rate of the solid structure away from the injection port is smaller, therefore, the solid structure with a larger thickness is arranged on the inner surface 32 side of the end cover 30 away from the injection port, which can ensure that the overall shrinkage rate of the end cover 30 is smaller, and reduce the probability of structural defects due to the injection molding process. In addition, the change in the inner diameter increases the tortuosity of the inner wall of the slot 33, that is, increases the contact area of the sealing position of the slot 33 and the hollow fiber bundle 21, and further improves the sealing effect and connection firmness of the sealing position.

[0053] In some embodiments, the inner diameter of the termination portion 332 increases from the inner surface 32 of the end cap 30 toward the starting portion 331 to ensure that the hollow fiber bundle 21 has a large radial gap 26 at the inner surface of the end cap, thus optimizing the flow channel. Meanwhile, the inner diameter of the starting portion 331 decreases from the outer surface 31 of the end cap 30 toward the termination portion 332 in an axial direction. This results in a larger space for filling potting compound between the inner wall of the slot 33 corresponding to the starting portion 331 and the hollow fiber bundle 21, and also gives the inner wall of the slot 33 a larger surface area. This ensures the sealing effect of the sealing position while taking into account the loading amount of hollow fiber membrane filaments. Furthermore, the overall thickness of the solid structure of the slot 33 corresponding to the end cap 30 also increases from the outer surface 31 toward the inner surface 32 in an axial direction. This gradual increase in the thickness of the solid structure ensures that the injection liquid flows more smoothly in the injection channel of the mold of the end cap 30, and is less prone to air bubbles.

[0054] In such Figure 4 In the illustrated embodiment, the inner diameter of the starting portion 331 remains constant in the axial direction, and the inner diameter of the ending portion 332 also remains constant in the axial direction. The slot 33 further includes a middle portion 333, which is located axially between the starting portion 331 and the ending portion 332. One axial end of the middle portion 333 is connected to the starting portion 331, and the other axial end is connected to the ending portion 332. The inner diameter of the middle portion 333 decreases from the starting portion 331 towards the ending portion 332. Thus, the inner walls of the slots 33 corresponding to the starting portion 331 and the middle portion 333 have a certain gap with the hollow fiber bundle 21. The space used for filling the potting compound can form a sealing position with high structural strength and good sealing effect. At the same time, it increases the inner wall area of ​​the slot 33 and the contact area between the slot 33 and the sealing position of the hollow fiber bundle 21. On the other hand, the middle part 333 also realizes a smooth transition between the starting part 331 and the ending part 332. The inner diameter of the slot 33 transitions from larger to smaller, and the thickness of the corresponding end cap 30 solid structure also transitions from smaller to thicker. This can ensure that the injection liquid flows more smoothly in the injection channel of the end cap 30 mold and is less prone to bubbles.

[0055] In some specific embodiments, the middle portion 333 may include multiple stepped structures to increase the tortuosity of the inner wall of the slot 33, increase the inner surface 32 and the surface area of ​​the inner surface 32 in contact with the potting compound, which is beneficial to improving the bonding strength of the potting compound.

[0056] In such Figure 4In the embodiment shown, the inner wall of the slot 33 corresponding to the middle part 333 is an arc surface, and one axial end of the middle part 333 has an arc transition with the starting part 331, and the other axial end has an arc transition with the ending part 332. This makes the injection liquid flow more smoothly through the starting part 331, the middle part 333 and the ending part 332 when the end cap 30 is injection molded, resulting in high injection strength. The smooth surface formed by the arc transition is also conducive to improving the connection firmness between the partition 34 and the sealing position.

[0057] In such Figure 5 In another embodiment shown, the slot 33 does not distinguish between the starting part, the middle part, and the ending part. Instead, the inner diameter of the slot 33 on the inner surface of the end cover 30 is reduced by the inward inclination of the inner wall. That is, the inner wall of the slot 33 is a slope, making the slot 33 a conical groove. The inner diameter gradually increases from the inner surface 32 of the end cover 30 to the outer surface 31. Although the inner wall area of ​​the slot 33 in this embodiment is small, the slot 33 has a simple structure and is easy to manufacture.

[0058] like Figure 2 As shown, the radial spacing of the radial gap 26 between the hollow fiber bundles 21 is D, and the total radial cross-sectional area of ​​the hollow fiber bundles is S1, satisfying S1 / D = 500-3000 mm; S1 represents the total filtration area of ​​the hollow fiber membrane filaments, and the value of S1 / D represents the relationship between the total filtration area of ​​the hollow fiber membrane filaments and the radial gap 26. Controlling the ratio within the above range ensures that the loading of hollow fiber membrane filaments meets the filtration requirements, and also ensures that the structural strength of the sealing position meets the usage requirements, preventing the sealing connection between the inner surface 32 of the end cap 30 and the sealing position from being easily damaged. If the ratio is too large, it indicates that the radial gap 26 is too large, the loading of hollow fiber membrane filaments is too small, and the filtration efficiency is low; if the ratio is too small, it indicates that the radial gap 26 is too small, and the liquid cannot flow and distribute quickly between the hollow fiber bundles 21, affecting the filtration efficiency.

[0059] like Figure 4As shown, the outer periphery of each bundle of hollow fibers 21 is surrounded by a retaining net 27, which functions to reduce the deviation and deformation of the hollow fiber membranes during the filtration process, thereby helping to ensure the dimensional stability of the radial gap 26 and reducing the likelihood that the bundle of hollow fibers 21 and the flow gap 26 will be in a state of superposition or aggregation due to external forces from the feed liquid, thereby helping to keep the degree of variation in the spacing between the membrane filaments of the bundle of hollow fibers 21 small, allowing the feed liquid to make full contact with each bundle of hollow fibers 21 and achieving a high filtration efficiency. The radial spacing of the radial gap 26 between the bundles of hollow fibers 21 is D, the retaining net 27 is located in the radial gap 26, the minimum radial spacing of adjacent retaining nets 27 is d, and D / d = 0.1-2.5 is satisfied. The retaining net 27 itself occupies some of the space of the radial gap 26 and has some impact on the flow of the feed liquid, and the value of D / d represents the position of the retaining net 27 in the radial gap 26. Controlling the ratio to be within the above range allows the retaining net 27 to better constrain the hollow fiber membranes, while avoiding the retaining net 27 occupying too much of the radial gap 26 and interfering with the flow of the feed liquid; if the ratio is too large, the adjacent retaining nets 27 are too close together, and the retaining nets 27 have a small restraining effect on the hollow fiber membranes, making it easy for the membranes to deviate and separate from each other; if the ratio is too small, the retaining net 27 is too tight around the bundle of hollow fibers 21, and the spacing between the multiple hollow fiber membranes in a single bundle of hollow fibers 21 cannot be maintained, the flow of the feed liquid in the bundle of hollow fibers 21 is poor, and the utilization rate of the hollow fiber membranes is not high, which in turn reduces the filtration efficiency.

[0060] In some embodiments, the end cap 30 is provided only at the first end 22 of the bundle of hollow fibers 21, and thus the sealing site only includes the first sealing site 24, the axial thickness of the first sealing site 24 is P1, and the axial length of the end of the retaining net 27 connected to the first sealing site 24 in the first sealing site 24 is Q1, and Q1 / P1 = 0.2-0.8 is satisfied.

[0061] In other embodiments, the end cap 30 is provided only at the second end 23 of the bundle of hollow fibers 21, and thus the sealing site only includes the second sealing site 25; the axial thickness of the second sealing site 25 is P2, and the axial length of the end of the retaining net 27 connected to the second sealing site 25 in the second sealing site 25 is Q2, and Q2 / P2 = 0.2-0.8 is satisfied.

[0062] In some embodiments, the end cap 30 is two, corresponding to the first end 22 and the second end 23 of the hollow fiber bundle 21 respectively, and the sealing position includes a first sealing position 24 and a second sealing position 25; the axial thickness of the first sealing position 24 is P1, the axial length of the end of the stop net 27 connected with the first sealing position 24 in the first sealing position 24 is Q1, and Q1 / P1 = 0.2-0.8 is satisfied; the axial thickness of the second sealing position 25 is P2, the axial length of the end of the stop net 27 connected with the second sealing position 25 in the second sealing position 25 is Q2, and Q2 / P2 = 0.2-0.8 is satisfied.

[0063] Q1 and Q2 respectively represent the axial length of the stop net 27 into the first sealing position 24 and the second sealing position 25, so that Figure 4 In the embodiments shown in the drawings, Q1 / P1 = 0.2-0.8, and the ratio is controlled within the above range. The part of the stop net 27 into the first sealing position 24 can serve as a support for the first sealing position 24, improving the structural strength of the first sealing position 24, while fixing the end of the stop net 27 so that it can restrict the hollow fiber membrane filaments. This also avoids the stop net 27 damaging the sealing performance of the first sealing position 24, so that the feed liquid leaks through the stop net 27. If the ratio is too large, the end of the stop net 27 is too close to the outer end surface of the first sealing position 24 or the second sealing position 25. If the first sealing position 24 or the second sealing position 25 is damaged slightly, the first sealing position 24 or the second sealing position 25 itself may not fail to seal, but the feed liquid may leak through the stop net 27, resulting in sealing failure. If the ratio is too small, the stop net 27 has poor connection and fixing effect on the first sealing position 24 and the sealing area on the same side, and the second sealing position 25 and the sealing area on the same side. The stop net 27 is easy to separate from the first sealing position 24 and the sealing area on the same side or the second sealing position 25 and the sealing area on the same side, and is difficult to play a supporting and connecting role.

[0064] As shown in Figure 4 The stop net 27 includes an inner net 271 and an outer net 272. The inner net 271 circumferentially surrounds the hollow fiber bundle 21 along the outer periphery of the hollow fiber bundle 21 and can move with the hollow fiber bundle 21. The outer net 272 circumferentially surrounds the outer periphery of the inner net 271. The inner net 271 protects the hollow fiber membrane filaments, and the outer net 272 inhibits the expansion or deformation of the hollow fiber membrane filaments towards the outside. Furthermore, the hardness of the outer net 272 is greater than the hardness of the inner net 271. The outer net 272 has a larger hardness and better restriction effect on the hollow fiber membrane filaments, but is also easy to wear or scratch the surface of the hollow fiber membrane filaments. Therefore, the hardness of the inner net 271 close to the hollow fiber membrane filaments and possibly in contact with the hollow fiber membrane filaments is lower, which can play a better protection role.

[0065] The above-mentioned embodiments are only preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application. Any non-essential changes and replacements made by those skilled in the art on the basis of the present application shall fall within the scope of protection of the present application.

Claims

1. A hollow fiber filtration device, comprising: a cylinder comprising an axially extending inner cavity, an opening in communication with the inner cavity, and a port proximate to an end of the cylinder; a hollow fiber bundle located in the inner cavity and extending at least partially axially, the hollow fiber bundle comprising a plurality of hollow fiber filaments extending at least partially axially, at least one of the two ends of the hollow fiber filaments being open, in communication with the port; characterized in that further comprising: an end cap fixed at the port, the end cap comprising an inner surface, an outer surface, and a slot axially extending through the inner surface and the outer surface, to separate the hollow fiber bundle into a plurality of hollow fiber sub-bundles, and at least one end of the hollow fiber sub-bundles is correspondingly arranged in the slot and forms a sealing position with the inner circumferential surface of the slot, which is separated from the opening and the port; a plurality of the hollow fiber sub-bundles form radial gaps between adjacent hollow fiber sub-bundles based on different slots; and the inner diameter of the slot increases from the inner surface of the end cap to the outer surface.

2. The hollow fiber filtration device of claim 1, wherein, the slot comprises a starting portion and a terminal portion in the axial direction, the starting portion and the terminal portion are distributed in the axial direction, the starting portion is formed by the outer surface of the end cap extending axially towards the inner surface of the end cap, and the terminal portion terminates at the inner surface of the end cap; the inner diameter of the terminal portion is smaller than the inner diameter of the starting portion.

3. The hollow fiber filtration device of claim 2, wherein, the inner diameter of the terminal portion increases from the inner surface of the end cap to the direction of the starting portion; and the inner diameter of the starting portion decreases from the outer surface of the end cap to the direction of the terminal portion.

4. The hollow fiber filtration device of claim 2, wherein, the slot further comprises an intermediate portion, which is axially intermediate between the starting portion and the terminal portion, and one end of the intermediate portion is connected to the starting portion, and the other end of the intermediate portion is connected to the terminal portion; the inner diameter of the intermediate portion decreases from the starting portion to the direction of the terminal portion.

5. The hollow fiber filtration device of claim 4, wherein, the one end of the intermediate portion is arcuately transitioned to the starting portion, and the other end of the intermediate portion is arcuately transitioned to the terminal portion.

6. The hollow fiber filtration device of claim 1, wherein, the radial distance of the radial gap is D, the total radial cross-sectional area of the hollow fiber bundle is S1, and S1 / D = 500-3000 mm.

7. The hollow fiber filtration device of claim 1, wherein, the radial distance of the radial gap is D, the outer periphery of the hollow fiber sub-bundle is surrounded by a stop net, the stop net is located in the radial gap, the minimum radial distance between adjacent stop nets is d, and D / d = 0.1-2.

5.

8. The hollow fiber filtration device of claim 7, wherein, the first end of the hollow fiber sub-bundle corresponds to the first sealing position of the slot of the end cap, the stop net extends axially, and one end of the stop net is connected to the first sealing position; the axial thickness of the first sealing position is P1, the axial length of the end of the stop net in the first sealing position is Q1, and Q1 / P1 = 0.2-0.8; and / or, The number of the ports is two, located at the axial ends of the barrel, the number of the end covers is two, corresponding to one port respectively, the second end of the hollow fiber bundle corresponds to the slot of the other end cover to form a second sealing position, the stop net axially extends, one end of which is connected with the second sealing position; the axial thickness of the second sealing position is P2, the axial length of the one end of the stop net connected with the second sealing position in the second sealing position is Q2, satisfying Q2 / P2=0.2-0.

8.

9. The hollow fiber filtration device of claim 7, wherein, The stop net comprises an inner net and an outer net, the inner net circumferentially surrounds the hollow fiber bundle along the outer periphery of the hollow fiber bundle and can move with the hollow fiber bundle, and the outer net circumferentially surrounds the outer periphery of the inner net.

10. The hollow fiber filtration device of claim 9, wherein, The hardness of the outer net is greater than the hardness of the inner net.

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