Hollow fiber membrane spinning nozzle and spinning module

Abstract

The utility model provides a hollow fiber membrane spinning nozzle which comprises a body, the body is provided with a membrane casting liquid flow channel and a core liquid flow channel, and the core liquid flow channel penetrates through the body in the first direction to form a first liquid inlet and a first liquid outlet. The two ends of the membrane casting liquid flow channel penetrate through the body to form a second liquid inlet and a second liquid outlet, the membrane casting liquid flow channel is provided with a first section, a communicating cavity and a second section which are sequentially connected, the second liquid inlet is located in the first section, and the second liquid outlet is located in the second section; the second section extends in the first direction and is coaxially arranged on the outer side of the core liquid flow channel, the first section extends in the second direction, the first direction intersects with the second direction, the communicating cavity is coaxially arranged on the outer side of the core liquid flow channel, the inner side wall face of the communicating cavity comprises a conical face, and the inner side wall face of the communicating cavity is communicated with the conical face. The conical surface is arranged in the circumferential direction of the core liquid flow channel, and the diameter of the conical surface in the first direction is gradually reduced.

Description

Technical Field

[0001] The present application relates to the field of molding technology, and in particular to a hollow fiber membrane spinneret and a spinneret module. Background Art

[0002] The existing hollow fiber membrane spinneret has a core liquid pipeline, a core liquid flow channel for core liquid to flow through, and a casting liquid flow channel for casting liquid to flow through. The diameter of the core liquid pipeline is relatively small, the liquid outlet of the core liquid flow channel is located inside the liquid outlet of the casting liquid flow channel, and the casting liquid flows out from the annular area between the casting liquid flow channel and the core liquid flow channel; the core liquid flows out from the core liquid flow channel, and when the core liquid flows out from the core liquid flow channel, it is located inside the casting liquid, which can solidify the casting liquid, so that the casting liquid can be quickly formed into a hollow fiber membrane.

[0003] In the prior art, the casting liquid is usually a polymer liquid with a certain viscosity. When the casting liquid flows in the casting liquid flow channel, it flows vertically to the core liquid pipeline and then turns to flow to the liquid outlet of the casting liquid flow channel. In this process, for some casting liquids with higher viscosity, after the fluidity of the casting liquid decreases, the casting liquid is prone to blockage inside the hollow fiber membrane spinneret, resulting in an abnormal situation where the spinning wire cannot be produced, affecting the quality of the membrane wire. Utility Model Content

[0004] The purpose of the present application is to provide a hollow fiber membrane spinneret to reduce the possibility of blockage inside the hollow fiber membrane spinneret.

[0005] The embodiment of the present application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides a hollow fiber membrane spinneret, comprising a body, wherein the body is provided with a casting liquid flow channel and a core liquid flow channel, wherein the core liquid flow channel penetrates the body along a first direction to form a first liquid inlet and a first liquid outlet;

[0007] Both ends of the casting liquid flow channel pass through the body to form a second liquid inlet and a second liquid outlet. The casting liquid flow channel has a first section, a connecting cavity and a second section connected in sequence. The second liquid inlet is located in the first section, and the second liquid outlet is located in the second section; the second section extends along the first direction and is coaxially arranged on the outside of the core liquid flow channel, the first section extends along the second direction, the first direction intersects with the second direction, the connecting cavity is coaxially arranged on the outside of the core liquid flow channel, and the inner wall surface of the connecting cavity includes a conical surface, the conical surface is arranged around the circumference of the core liquid flow channel, and the diameter of the conical surface along the first direction gradually decreases.

[0008] In the above technical solution, the second section of the casting liquid flow channel is arranged on the outside of the core liquid flow channel, and an annular area is formed between the casting liquid flow channel and the core liquid flow channel. The casting liquid enters the casting liquid flow channel from the second liquid inlet, then flows along the first section through the connecting cavity to the annular area between the second section and the core liquid flow channel, and finally flows out from the second liquid outlet to form a hollow fiber membrane. Since the inner wall surface of the connecting cavity includes a conical surface, the conical surface guides the casting liquid, so that the casting liquid in the first section can better change direction and flow into the second section. In particular, for casting liquid with higher viscosity, the hollow fiber membrane spinneret structure provided by the above technical solution can effectively reduce the abnormal situation that the casting liquid is blocked in the hollow fiber membrane spinneret and cannot produce silk.

[0009] In addition, the conical surface increases the contact area between the casting liquid and the inner wall of the connecting cavity. The diameter of the conical surface decreases along the first direction. After the casting liquid enters the connecting cavity from the first section, it contacts the inner wall of the connecting cavity and changes its flow direction under the action of the inner wall, so that the casting liquid moves along the second section. In the process of the casting liquid contacting the conical surface of the connecting cavity, the casting liquid has a small impact force on the inner wall of the connecting cavity and a large contact area with the inner wall of the connecting cavity, which can effectively extend the service life of the hollow fiber membrane spinneret.

[0010] In some optional embodiments, the tapered surface passes through the axis of the first section.

[0011] In the above technical scheme, since the conical surface passes through the axis of the first section, the casting liquid can better contact the conical surface and better change the movement direction under the action of the conical surface, so that less kinetic energy of the casting liquid is converted into impact on the conical surface, thereby further improving the service life of the hollow fiber membrane spinneret.

[0012] In some optional embodiments, the casting liquid flow channel includes a plurality of the first segments uniformly distributed along the circumference of the body, and the plurality of the first segments are all in communication with the connecting cavity.

[0013] In the above technical solution, by feeding the casting liquid into the connecting cavity through a plurality of first sections evenly distributed along the circumference of the body, the casting liquid in the second section can be evenly distributed, thereby making the thickness of the formed hollow fiber membrane uniform.

[0014] In some optional embodiments, the first section is provided with a filter.

[0015] In the above technical solution, by setting a filter in the first section, various foreign matter impurities that are about to enter the hollow fiber membrane spinneret can be effectively intercepted to prevent the hollow fiber membrane spinneret from being blocked due to various foreign matter impurities entering the hollow fiber membrane spinneret.

[0016] In some optional embodiments, the filter is arranged at the end of the first section by snap-fitting.

[0017] In some optional embodiments, the core liquid flow channel has a connected third section and a fourth section, the fourth section is coaxially arranged on the inner side of the second section and the first liquid outlet is located in the fourth section, the first liquid inlet is located in the third section, and the area of ​​the third section away from the fourth section is a conical structure, and along the direction from the fourth section to the third section, the cavity diameter of the conical structure gradually increases.

[0018] In the above technical solution, the core liquid enters the core liquid flow channel from the first liquid inlet of the third section, and then moves to the fourth section through the tapered structure of the third section. In the process of the core liquid passing through the tapered structure, since the diameter of the tapered structure gradually decreases along the direction of the core liquid movement, the core liquid can have a pressure change and acceleration inside the hollow fiber membrane spinneret, effectively reducing the abnormal situation of core liquid pipeline blockage.

[0019] In addition, when the size of the first liquid outlet is constant, due to the above-mentioned conical structure in the third section, the size of the first liquid inlet can be made larger than the size of the first liquid outlet. Such a design can effectively expand the diameter of the first liquid inlet, making it easier for the core liquid end to enter the liquid and the core liquid to enter the liquid more evenly.

[0020] In some optional embodiments, in the first direction, the length of the conical structure accounts for 1 / 3 to 2 / 3 of the total length of the core liquid flow channel.

[0021] In the above technical solution, the ratio of the length of the tapered structure to the total length of the core liquid flow channel is within the above range, which can make the pressure change of the core liquid inside the hollow fiber membrane spinneret more uniform, thereby making the discharge of the core liquid more uniform.

[0022] In some optional embodiments, the main body includes a base and a core liquid pipe; the first section and the second section are both arranged on the base, the middle part of the base is the connecting cavity, the core liquid pipe is connected to the base and extends from the connecting cavity to the second section along the first direction, and the core liquid flow channel passes through the base and the core liquid pipe in sequence; the outer surface of the core liquid pipe includes the conical surface.

[0023] In the above technical solution, the conical surface is arranged on the core liquid pipeline, which can reduce the impact force of the casting liquid on the core liquid pipeline.

[0024] In some optional embodiments, a protective ring is protruding from the base, and the protective ring surrounds the first liquid outlet and the second liquid outlet on the inner side.

[0025] In the above technical solution, a protective ring is arranged on the base body to surround the first liquid outlet and the second liquid outlet on the inner side. When the hollow fiber membrane spinneret is placed flat, the first liquid outlet and the second liquid outlet can be effectively prevented from contacting with other structures and being contaminated. When the hollow fiber membrane spinneret is working, the membrane filaments can be limited from swinging significantly to reduce the occurrence of sticking filaments.

[0026] In the second aspect, an embodiment of the present application provides a spinneret module, comprising a spinneret and the hollow fiber membrane spinneret provided in the first aspect, the spinneret having a first flow channel and a second flow channel inside, the first flow channel and the second flow channel intersecting to form an installation cavity, the hollow fiber membrane spinneret is arranged in the installation cavity, and the core liquid pipeline is connected to the first flow channel, and the casting liquid flow channel is connected to the second flow channel; a sealing ring is arranged between the hollow fiber membrane spinneret and the spinneret to separate the first flow channel from the second flow channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic diagram of the structure of a spinning die set provided in an embodiment of the present application;

[0029] Figure 2 A schematic diagram of the structure of a hollow fiber membrane spinneret provided in an embodiment of the present application;

[0030] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0031] Figure 4 for Figure 2 Schematic diagram of the cross section at the mid-BB position.

[0032] Icons: 110-main body; 111-base; 112-core liquid pipeline; 113-protective ring; 120-core liquid flow channel; 121-first liquid inlet; 122-first liquid outlet; 123-third section; 124-fourth section; 130-casting liquid flow channel; 131-second liquid inlet; 132-second liquid outlet; 133-first section; 134-connecting cavity; 1341-conical surface; 135-second section; 140-filter; 200-sealing ring; 300-spinneret; 310-first flow channel; 320-second flow channel. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0035] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0036] In the description of this application, it should be noted that the terms "center", "upper", "lower", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use, which are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0037] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0038] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0039] The inventors of the present application have discovered that the structure of the existing hollow fiber membrane spinneret for producing hollow fiber membranes is unreasonable. When the casting liquid flows in the casting liquid flow channel, it flows vertically to the core liquid pipeline and then turns to flow at the liquid outlet of the casting liquid flow channel. In this process, for some casting liquids with higher viscosity, after the fluidity of the casting liquid decreases, the casting liquid is prone to blockage inside the hollow fiber membrane spinneret, resulting in an abnormal situation where the filament cannot be produced, thereby affecting the quality of the membrane filament.

[0040] Based on this, the present application provides a spinneret module including a spinneret 300 and a hollow fiber membrane spinneret for a hollow fiber module. The spinneret 300 has a first flow channel 310 and a second flow channel 320 inside, and the first flow channel 310 and the second flow channel 320 intersect to form an installation cavity. The hollow fiber membrane spinneret includes a main body 110, and a core liquid flow channel 120 and a casting liquid flow channel 130 arranged on the main body 110. The hollow fiber membrane spinneret is installed in the installation cavity, and the first flow channel 310 is connected to the core liquid flow channel 120, and the second flow channel 320 is connected to the casting liquid flow channel 130; it is not difficult to understand that the first flow channel 310 is used to pass the core liquid into the core liquid flow channel 120, and the second flow channel 320 is used to pass the casting liquid into the casting liquid flow channel 130. And as Figure 1 As shown, a sealing ring 200 is provided between the hollow fiber membrane spinneret and the spinneret plate 300 to separate the first flow channel 310 from the second flow channel 320, thereby preventing the core liquid in the first flow channel 310 from mixing with the casting liquid in the second flow channel 320 during operation.

[0041] like Figure 2 As shown, the core liquid flow channel 120 passes through the body 110 and forms a first liquid inlet 121 and a first liquid outlet 122; the casting liquid flow channel 130 passes through the body 110 and forms a second liquid inlet 131 and a second liquid outlet 132. In some embodiments, the core liquid flow channel 120 is arranged along a first direction (i.e. Figure 2 The core liquid flows through the body 110 in the direction indicated by the arrow C, that is, the core liquid flow channel 120 extends in a straight line. It is easy to understand that the core liquid enters the hollow fiber membrane spinneret from the first liquid inlet 121 and then flows out from the first liquid outlet 122; the casting liquid enters the hollow fiber membrane spinneret from the second liquid inlet 131 and then flows out from the second liquid outlet 132.

[0042] Furthermore, in the hollow fiber membrane spinneret provided in the present embodiment, the casting liquid flow channel 130 has a first section 133, a connecting cavity 134 and a second section 135 which are sequentially connected, the second liquid inlet 131 is located in the first section 133, and the second liquid outlet 132 is located in the second section 135. That is, the casting liquid passes through the first section 133, the connecting cavity 134 and the second section 135 in sequence in the casting liquid flow channel 130; it is not difficult to understand that the second section 135 is coaxially arranged on the outside of the core liquid flow channel 120, the first liquid outlet 122 is located on the inside of the second liquid outlet 132, and the casting liquid flows through the annular space between the second section 135 and the core liquid flow channel 120 and then flows out from the second liquid outlet 132 to form a hollow fiber membrane. In one embodiment, as Figure 2 and Figure 3 As shown, the first section 133 is along the second direction (ie Figure 2 The first section 134 extends in the direction indicated by the arrow D in the middle, and the second section 135 extends along the first direction, and the first direction intersects the second direction; the first direction and the second direction may be perpendicular to each other, or may form other angles.

[0043] like Figure 2 As shown, in some embodiments of the present application, the body 110 includes a substrate 111 and a core liquid pipeline 112 connected to the substrate 111, and the core liquid flow channel 120 passes through the substrate 111 and the core liquid pipeline 112 in sequence during the process of penetrating the body 110, and the first liquid outlet 122 is provided in the core liquid pipeline 112. The core liquid pipeline 112 extends along the first direction and passes through the inner side of the connecting cavity 134 and the second section 135; Figures 2 to 4 It is not difficult to see that the outer side surface of the core liquid pipeline 112 forms the inner wall surface of the connecting cavity 134 ; after the casting liquid in the first section 133 enters the connecting cavity 134 , it contacts the inner wall surface of the connecting cavity 134 , and then flows to the second section 135 .

[0044] In order to improve the blockage problem inside the above-mentioned hollow fiber membrane spinneret. The inner wall surface of the connecting cavity 134 includes a conical surface 1341, which guides the casting liquid entering the connecting cavity 134, so that the casting liquid can flow to the second section 135 more easily after hitting the conical surface 1341. In order to make the conical surface 1341 play a role in facilitating the casting liquid to flow to the second section 135, it is not difficult to understand that the diameter of the conical surface 1341 along the first direction gradually decreases. Combined with the attached Figure 3 As shown, the diameter of the conical surface 1341 is smaller near the end of the second section 135. Further, the conical surface 1341 is arranged around the circumference of the core liquid flow channel 120, that is, the conical surface 1341 is coaxially arranged outside the core liquid flow channel 120.

[0045] Since the diameter of the conical surface 1341 near the second section 135 is smaller, Figure 3 and 4It is not difficult to know that after the casting liquid enters the connecting cavity 134 from the first section 133, the reaction force of the conical surface 1341 on the casting liquid has a component force toward the second section 135, so that the casting liquid can still have a certain speed of flowing toward the second section 135, which can effectively reduce the abnormal situation that the casting liquid is blocked and cannot produce wire. In addition, the kinetic energy loss of the casting liquid after hitting the conical surface 1341 is small, and accordingly, the impact of the casting liquid on the conical surface 1341 is also small. Therefore, in the hollow fiber membrane spinneret provided by the present application, the core liquid pipeline 112 can also have a longer service life, thereby increasing the service life of the hollow fiber membrane spinneret.

[0046] Further, in some embodiments of the present application, the tapered surface 1341 passes through the axis of the first section 133. Figure 3 As shown, it is not difficult to understand that, since the casting liquid has a certain viscosity, during the flow of the casting liquid in the first section 133, the flow rate of the casting liquid near the axis of the first section 133 is faster, while the flow rate of the casting liquid near the inside of the first section 133 is slower. By setting the conical surface 1341 to pass through the axis of the first section 133, on the one hand, the area of ​​the conical surface 1341 can be larger, and it can contact more casting liquid, so as to further reduce the impact of the casting liquid on the core liquid pipeline 112 and further avoid the blockage of the casting liquid. On the other hand, the conical surface 1341 can contact the casting liquid with greater kinetic energy in the first section 133, and guide this part of the casting liquid to reduce the impact on the core liquid pipeline 112.

[0047] Further, in some embodiments of the present application, Figure 4 As shown, the casting liquid flow channel 130 includes a plurality of first sections 133, and the plurality of first sections 133 are evenly distributed along the circumference of the body 110. The plurality of first sections 133 are all connected to the connecting cavity 134. By providing a plurality of first sections 133 evenly distributed along the circumference, the casting liquid is provided to the connecting cavity 134 from multiple directions, so that the casting liquid can be evenly distributed in the connecting cavity 134 and the second section 135, thereby making the thickness of the formed hollow fiber membrane uniform. In the embodiment where the casting liquid includes a plurality of first sections 133, there is no special restriction on the number of the first sections 133, and the number of the first sections 133 can be three, four, six, etc.

[0048] The inventors of the present application also found that the cause of the blockage of the hollow fiber membrane spinneret also includes the entry of foreign matter and impurities into the hollow fiber membrane spinneret. Based on this, in some embodiments of the present application, the casting liquid flow channel 130 is also provided with a filter screen 140. A preferred embodiment is to set a filter screen 140 at the end of the first section 133 in the casting liquid flow channel 130, such as setting a filter screen 140 at the second liquid inlet 131 to reduce foreign matter and impurities entering the hollow fiber membrane spinneret from the second liquid inlet 131. Setting the filter screen 140 at the second liquid inlet 131 can facilitate the disassembly of the filter screen 140 to clean the filter screen 140. In some embodiments, such as Figure 2 As shown, the filter screen 140 is designed to be concave, that is, Figure 2 As shown in , after the filter screen 140 is installed on the body 110, the center position of the filter screen 140 is closer to the center of the body 110 than the edge position of the filter screen 140. The filter hole structure of the filter screen 140 includes but is not limited to a circular hole or a grid shape with a certain mesh number. Further, in order to facilitate the disassembly and assembly of the filter screen 140, the filter screen 140 and the body 110 are fixedly connected by a snap-on type.

[0049] Similarly, in some embodiments, a filter screen 140 may be provided in the core liquid flow channel 120. A preferred embodiment is to provide a filter screen 140 at the entrance of the core liquid flow channel 120, that is, to provide a filter screen 140 at the first liquid inlet 121, so as to reduce foreign matter and impurities entering the hollow fiber membrane spinneret from the second liquid inlet 131. The filter screen 140 is provided at the second liquid inlet 131, so that the filter screen 140 can be easily disassembled to clean the filter screen 140.

[0050] In some embodiments of the present application, in order to reduce the blockage of the core liquid in the core liquid flow channel 120, the core liquid flow channel 120 has a connected third section 123 and a fourth section 124, the first liquid inlet 121 is located in the third section 123, the first liquid outlet 122 is located in the fourth section 124, and the area of ​​the third section 123 away from the fourth section 124 is a conical structure, and along the direction from the fourth section 124 to the third section 123, the cavity diameter of the conical structure gradually increases, that is, the diameter of the third section 123 is greater than the diameter of the fourth section 124. It is not difficult to understand that in the process of the core liquid flowing from the first liquid inlet 121 to the first liquid outlet 122, it will first pass through the conical structure and then flow out from the first liquid outlet 122. Since the diameter of the third section 123 is greater than the diameter of the fourth section 124, the flow rate of the core liquid will gradually increase in the process of passing through the conical structure. Since the flow rates of the core liquid in the third section 123 and the fourth section 124 are different, the core liquid has a pressure change in the process of moving from the third section 123 to the fourth section 124. The flow rate change and pressure change of the core liquid can effectively reduce the abnormal situation of blockage in the core liquid flow channel 120. In addition, the diameter of the fourth section 124 of the core liquid flow channel 120 is related to the product and is usually smaller in diameter. By setting the above-mentioned conical structure in the core liquid flow channel 120, the core liquid flow channel 120 has a first liquid inlet 121 with a larger diameter, so that the core liquid is easier to enter the core liquid flow channel 120 and the core liquid is more evenly fed.

[0051] Preferably, in the first direction, the length of the tapered structure accounts for 1 / 3 to 2 / 3 of the total length of the core liquid flow channel 120 .

[0052] Combination Figure 3 It is not difficult to know that the fourth section 124 is coaxially arranged on the inner side of the second section 135 of the casting liquid flow channel 130, and accordingly, the first liquid outlet 122 is located on the inner side of the second liquid outlet 132, and the casting liquid flows out from the annular space between the first liquid outlet 122 and the second liquid outlet 132, and the core liquid flows out from the first liquid outlet 122 to solidify the casting liquid.

[0053] In some embodiments, a protective ring 113 is protruded from the base 111, and the protective ring 113 surrounds the first liquid outlet 122 and the second liquid outlet 132 inside to protect the first liquid outlet 122 and the second liquid outlet 132, so as to facilitate the placement of the hollow fiber membrane spinneret.

[0054] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hollow fiber membrane spinneret, characterized in that: The body comprises a casting liquid flow channel and a core liquid flow channel, wherein the core liquid flow channel penetrates the body along a first direction to form a first liquid inlet and a first liquid outlet; Both ends of the casting liquid flow channel pass through the body to form a second liquid inlet and a second liquid outlet. The casting liquid flow channel has a first section, a connecting cavity and a second section connected in sequence. The second liquid inlet is located in the first section, and the second liquid outlet is located in the second section; the second section extends along the first direction and is coaxially arranged on the outside of the core liquid flow channel, the first section extends along the second direction, the first direction intersects with the second direction, the connecting cavity is coaxially arranged on the outside of the core liquid flow channel, and the inner wall surface of the connecting cavity includes a conical surface, the conical surface is arranged around the circumference of the core liquid flow channel, and the diameter of the conical surface along the first direction gradually decreases.

2. The hollow fiber membrane spinneret according to claim 1, characterized in that: The tapered surface passes through an axis of the first section.

3. The hollow fiber membrane spinneret according to claim 1, characterized in that: The casting liquid flow channel includes a plurality of the first sections uniformly distributed along the circumference of the body, and the plurality of the first sections are all communicated with the connecting cavity.

4. The hollow fiber membrane spinneret according to claim 1, characterized in that: The first section is provided with a filter.

5. The hollow fiber membrane spinneret according to claim 4, characterized in that: The filter screen is arranged at the end of the first section by snap-fitting.

6. The hollow fiber membrane spinneret according to any one of claims 1 to 5, characterized in that: The core liquid flow channel has a connected third section and a fourth section, the fourth section is coaxially arranged on the inner side of the second section and the first liquid outlet is located in the fourth section, the first liquid inlet is located in the third section, and the area of ​​the third section away from the fourth section is a conical structure, and along the direction from the fourth section to the third section, the cavity diameter of the conical structure gradually increases.

7. The hollow fiber membrane spinneret according to claim 6, characterized in that: In the first direction, the length of the tapered structure accounts for 1 / 3 to 2 / 3 of the total length of the core liquid flow channel.

8. The hollow fiber membrane spinneret according to any one of claims 1 to 5, characterized in that: The main body includes a base and a core liquid pipeline; the first section and the second section are both arranged on the base, the middle part of the base is the connecting cavity, the core liquid pipeline is connected to the base and extends from the connecting cavity to the second section along the first direction, and the core liquid flow channel passes through the base and the core liquid pipeline in sequence; the outer surface of the core liquid pipeline includes the conical surface.

9. The hollow fiber membrane spinneret according to claim 8, characterized in that: A protective ring is protruding from the base, and the protective ring surrounds the first liquid outlet and the second liquid outlet on the inner side.

10. A spinning die set, characterized in that: It comprises a spinneret and a hollow fiber membrane spinneret as described in any one of claims 1-9, wherein the spinneret has a first flow channel and a second flow channel inside, the first flow channel and the second flow channel intersect to form an installation cavity, the hollow fiber membrane spinneret is arranged in the installation cavity, and the core liquid flow channel is connected to the first flow channel, and the casting liquid flow channel is connected to the second flow channel; a sealing ring is arranged between the hollow fiber membrane spinneret and the spinneret to separate the first flow channel from the second flow channel.

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