Method, device and application for improving the filtering effect of a spinning coagulation bath

Abstract

The application discloses a method for improving the filtering effect of a spinning coagulation bath, comprising a filtering step of filtering the coagulation bath in a storage device, and returning the filtered coagulation bath to the storage device for storage; wherein, before the filtering step, a pre-deposition step is further arranged; the coagulation bath is pre-deposited before being filtered; in the pre-deposition process, the coagulation bath is sent into a container, and the impurities in the dispersed phase of the coagulation bath are kept moving to the bottom of the container; the continuous phase of the bath flows out from the side wall of the container halfway; and the coagulation bath flowing out from the side wall of the container is subjected to the filtering step. The application greatly reduces the burden of the filter, reduces the labor intensity and the discharge of cleaning waste water, and prolongs the service life of the filter. The application further provides a device for improving the filtering effect of a spinning coagulation bath and application.

Description

Technical Field

[0001] This invention relates to a method for purifying and reusing coagulation baths in the field of chemical fiber production, specifically a method, apparatus, and application for improving the filtration effect of spinning coagulation baths, belonging to the field of chemical fiber technology. Background Technology

[0002] Some polymers that are difficult to form using melt spinning, such as acrylic fibers, vinylon, viscose fibers, spandex, and aramid fibers, are generally produced by wet spinning. Wet spinning first involves dissolving the polymer in a solvent to create a spinning solution. After degassing during spinning, the solution is extruded from the spinneret using a metering pump, solidified in a coagulation bath, and stretched by the spinneret to form nascent fibers. The fiber-forming polymer usually contains impurities and low-molecular-weight polymers, which enter the coagulation bath along with the solvent during wet spinning and solidify into flocculent matter, severely affecting the transparency and recyclability of the coagulation bath.

[0003] Currently, filtration is the primary method used to remove impurities from the coagulation bath. For example, Chinese patent document CN203112984U discloses a spinning apparatus including a coagulation bath circulation device. This device comprises a coagulation bath auxiliary tank, a circulation pump, a metering pump, a coagulation bath tank, a filter, and a membrane filtration assembly. The coagulation bath auxiliary tank is connected to a main pipe via a centrifugal pump. The main pipe is connected to the coagulation bath tank via the metering pump. The coagulation bath tank is connected to a return main pipe via the filter. The return main pipe is connected to the circulation pump via the membrane filtration assembly. The circulation pump is connected to the coagulation bath auxiliary tank. In this invention, the coagulation bath tank is connected to the filtration equipment via a bath liquid circulation pipe. The filtered coagulation bath liquid, having removed impurities, is then sent back to the coagulation bath tank for reuse after passing through a heat exchanger. Therefore, there is no frequent wastewater discharge, preventing environmental pollution. Furthermore, the recycling of the coagulation bath liquid saves a significant amount of the pharmaceuticals used in its preparation, reducing product costs.

[0004] Chinese patent document CN111544954A discloses a method for purifying a coagulation bath in the production of flame-retardant viscose fibers. This method includes primary filtration and fine filtration. The acid bath purification method of this invention can remove impurities such as sulfides, hemicellulose, and ash lumps from the acid bath, and can also remove silica gel. The transparency of the acid bath is significantly improved; the silica gel content in the acid bath decreases from 0.3-0.4 g / L to <0.02 g / L, the transparency increases from ≤30 mm to ≥1000 mm, and the appearance changes from milky white to colorless and transparent. In the acid bath purification method of this invention, the concentrations of sulfuric acid, zinc sulfate, and sodium sulfate in the acid bath components remain constant before and after treatment. In the prior art, a plate and frame filter is used for primary filtration. The plate and frame filter first performs preliminary filtration of the coagulation bath, and the polypropylene felt or double-sided fleece on the filter plate traps solid impurities, achieving solid-liquid separation.

[0005] For example, Chinese patent document CN114606585A discloses a method for improving the transparency of a coagulation bath, including the following steps: pre-filtration of the coagulation bath liquid through a Y-type filter; and secondary filtration of the pre-filtered coagulation bath liquid through a secondary filter. The method of this invention can significantly improve the transparency of the coagulation bath, thereby ensuring the product quality of the produced polyvinyl alcohol fibers.

[0006] In the aforementioned existing technologies, filtration equipment is used to filter the coagulation bath to remove impurities from the coagulation bath liquid. However, since the filtration capacity of the filtration equipment is limited, when there are many impurities in the coagulation bath, in order to ensure the filtration effect, it is necessary to frequently replace and clean the filter material, or perform backwashing, which increases labor intensity and the amount of cleaning wastewater discharged. Summary of the Invention

[0007] In order to solve the technical problems of high labor intensity and large amount of cleaning wastewater discharge in the filtration operation of the prior art, the present invention provides a method to improve the filtration effect of spinning coagulation bath, including the following filtration steps: filtering the coagulation bath in the storage device, and returning the filtered coagulation bath to the storage device for storage. Among them, a pre-precipitation step is set before the filtration step: the coagulation bath is pre-precipitated before filtration. During the pre-precipitation process, the coagulation bath is sent into the container and the impurities of the dispersed phase in the coagulation bath are kept moving towards the bottom of the container. The continuous phase bath liquid flows out from the side wall of the container halfway. The coagulation bath flowing out from the side wall of the container is used for the filtration step.

[0008] In existing technologies, filtration is the main method used to remove impurities from the coagulation bath. Physical filtration methods include setting up filters, filter membranes, and other structures for filtration. Some methods also use pre-coated diatomaceous earth for filtration. However, the filtration capacity of these methods is limited, which requires frequent replacement of the filter structure or cleaning of the filter material.

[0009] Compared with existing technologies, this solution incorporates a pre-sedimentation step before the coagulation bath enters the filter. This pre-sedimentation step settles most of the impurities in the coagulation bath, removing a large portion of the sediment before it enters the filter for secondary filtration. Because most impurities have been separated in the pre-sedimentation step, the amount of sediment in the coagulation bath entering the filter for secondary filtration is significantly reduced. Therefore, only a small portion of the impurities need to be filtered. Even with filters that have limited filtration capacity, the reduced amount of impurities in the coagulation bath allows the filter to operate for a longer period, reducing labor intensity and wastewater discharge. This also significantly reduces the burden on the filter, extends its service life, and lowers the cost of coagulation bath filtration.

[0010] Furthermore, in the wet spinning process of chemical fibers, due to the large circulation volume of the coagulation bath, relying solely on natural sedimentation is insufficient to filter most impurities. This solution separates impurities from the coagulation bath by allowing the dispersed phase impurities to move towards the bottom of the container while the continuous phase flows out from the side wall midway. Throughout the process, the existing conveying power is used, eliminating the need for additional power. After entering the rectifier tube, the coagulation bath flows along the tube under its own gravity, further reducing filtration costs.

[0011] Preferably, in the pre-precipitation step, the coagulation bath flows in a rectifier tube within the container, maintaining a stable laminar flow. In this design, maintaining a stable laminar flow in the coagulation bath allows for better separation of the continuous phase of the bath liquid and the dispersed phase impurities, thus achieving better separation and precipitation.

[0012] Preferably, the diameter of the rectifier tube and the flow velocity of the coagulation bath within the rectifier tube are selected to ensure that the coagulation bath maintains a stable laminar flow state within the rectifier tube. Since the density and viscosity of a given coagulation bath are fixed, selecting an appropriate tube diameter and flow velocity is sufficient to ensure that the coagulation bath maintains a stable laminar flow state within the rectifier tube, thereby guaranteeing the normal progress of separation and precipitation.

[0013] Preferably, the coagulation bath is distributed by a distribution plate after entering the container and before entering the rectifier tubes, so that the distributed coagulation bath can flow evenly into each rectifier tube. This scheme can further ensure the separation and sedimentation effect.

[0014] Preferably, a flow is added into the rectifier tubes while the coagulation bath is flowing uniformly into each rectifier tube. This scheme further ensures the separation and sedimentation effect.

[0015] Preferably, the continuous phase of the bath flows out along a collection loop formed on the side wall of the container halfway through the process. This design further ensures the separation and precipitation process.

[0016] Preferably, during the pre-precipitation step, the accumulated precipitate inside the container is also drained from the bottom of the container. This method can prevent the precipitate from accumulating in large quantities inside the container.

[0017] Preferably, in the pre-precipitation step, the coagulation bath is pressurized by a transfer pump before entering the container. This method ensures that the coagulation bath smoothly enters the pre-precipitation container, thereby guaranteeing the smooth progress of the pre-precipitation operation.

[0018] Secondly, the present invention also provides an apparatus for improving the filtration effect of a spinning coagulation bath, comprising a pre-precipitation container, wherein the container is provided with a pre-precipitation structure, and the pre-precipitation structure performs a pre-precipitation operation on the coagulation bath using the above-mentioned method for improving the filtration effect of a spinning coagulation bath.

[0019] Thirdly, the present invention also provides an application of a method for improving the filtration effect of a spinning coagulation bath in wet spinning forming.

[0020] The present invention has the following beneficial effects: 1. Compared with existing filtration methods that employ filters, filter membranes, and pre-coated diatomaceous earth, which have limited effectiveness, this invention relies on gravity and inertia to achieve sedimentation, thereby pre-sedimenting and separating impurities in the coagulation bath. After pre-sedimentation and separation, the coagulation bath entering the filter contains only a small amount of impurities. Therefore, only a small portion of impurities needs to be filtered, resulting in less impurity buildup in the filter even after prolonged use. This extends the filter's lifespan, reduces labor intensity and wastewater discharge, significantly lightens the filter's workload, extends its service life, and lowers the cost of coagulation bath filtration.

[0021] 2. The equipment is small in size, and the processing time for separating impurities in the coagulation bath is faster; moreover, the present invention does not require additional conveying power. When flowing in the rectifier tube, the gravity and inertial force of the coagulation bath itself serve as the flow power, resulting in low fluid resistance. After pre-precipitation treatment, subsequent filtration treatment can be carried out continuously.

[0022] 3. By having the impurities in the dispersed phase of the coagulation bath move towards the bottom of the container and the continuous phase of the bath liquid flow out from the side wall of the container halfway through, the impurities are separated from the coagulation bath, thus achieving effective separation of impurities. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the pre-precipitation container in an embodiment of the method, apparatus and application of the present invention for improving the filtration effect of a spinning coagulation bath; Figure 2 for Figure 1 Diagram showing uniform arrangement of intermediate rectifier tubes; Figure 3 A flowchart illustrating the entire process of achieving transparency in the coagulation bath. Detailed Implementation

[0024] The following detailed description illustrates the specific implementation method: 1. Definition Melt spinning, also known as melt spinning, is one of the main methods for forming chemical fibers. Its main characteristics are high winding speed, no need for solvents or precipitants, simple equipment, and a short process flow. Melt spinning is a monolithic system, primarily involving heat transfer between the polymer melt filament and the cooling medium; the spinning system itself does not undergo compositional changes. Its main processes include the preparation of the spinning melt, extrusion of the melt from the spinneret, stretching, cooling, and solidification of the melt filament, as well as oiling and winding the filament.

[0025] Chemical fibers are fibers with textile properties produced from natural or synthetic polymers through processes such as preparing spinning solutions, spinning, and post-processing. The preparation of chemical fibers typically involves first creating a spinning melt or solution from natural or synthetic polymers or inorganic substances. This melt or solution is then filtered, metered, and extruded through a spinneret (spinneret) into a liquid stream, which then solidifies into fibers. At this stage, the fiber is called nascent fiber, and its mechanical properties are very poor. It must undergo a series of post-processing steps to meet the requirements of textile processing and use. Post-processing mainly involves stretching and heat setting to improve the fiber's mechanical properties and dimensional stability. Stretching orients the macromolecules or structural units in the nascent fiber along the fiber axis; heat setting primarily relaxes the internal stress within the fiber. Post-processing of wet-spun fibers also includes washing, oiling, and drying. When spinning filaments, the above processes allow for winding into a bobbin; when spinning staple fibers, additional processes such as crimping, cutting, and packaging are required.

[0026] Wet spinning: one of the main spinning methods for chemical fibers, abbreviated as wet spinning. The steps included in wet spinning are: (1) preparing spinning solution; (2) pressing the solution out of the spinneret to form a fine stream; (3) solidifying the fine stream of solution into nascent fibers; (4) packaging the nascent fibers or directly performing post-processing. The fiber-forming polymer is dissolved in a suitable solvent to obtain a solution with a certain composition, a certain viscosity and good spinnability, which is called spinning solution. The spinning solution can also be obtained directly from homogeneous solution polymerization. Before dissolving, the polymer first swells, that is, the solvent first penetrates into the polymer, causing the distance between macromolecules to increase continuously, and then dissolves to form a homogeneous solution. The whole process takes a long time, and the rate of swelling has an important influence on the dissolution rate. Before spinning, the polymer solution must undergo pre-spinning preparation processes such as mixing, filtering and degassing to make the properties of the spinning solution uniform, remove the gel blocks and impurities entrained in it and remove the air bubbles in the solution. In viscose fiber production, pre-spinning preparation also includes a curing process to give viscose the necessary spinnability.

[0027] Polymers: generally refer to high molecular weight compounds, which are compounds with relative molecular masses ranging from several thousand to several million. The vast majority of high molecular weight compounds are mixtures of many homologous compounds with different relative molecular masses.

[0028] Fiber-forming polymers: Synthetic high-molecular polymers capable of being made into fibers. They must not only possess the ability to form fibers, but also be completely soluble in a suitable solvent to form a viscous, concentrated solution; or melt at elevated temperatures to transform into a viscous flow state without decomposition, in order to facilitate solution spinning or melt spinning.

[0029] Low molecular weight polymers: polymers with a low average molecular weight.

[0030] Flocculent matter: Small, loose aggregates of material suspended in or settled from a liquid.

[0031] Storage equipment: refers to equipment used for storing various liquid raw materials, semi-finished products, or finished products. In this invention, it refers to equipment for storing coagulation baths.

[0032] Coagulation bath: In the manufacture of chemical fibers, this is the bath in which the spinning colloidal solution is coagulated or undergoes a chemical change as it passes through the spinneret to form fibers. The coagulation bath plays a crucial role in the manufacturing process of chemical fibers. It is not only the medium for coagulating the spinning colloidal solution but also a key factor in initiating the chemical change. This process involves the combined effects of physical and chemical processes, including the chemical reaction between the polymer and the coagulant, as well as the diffusion of the solvent from the raw solution into the coagulation bath and the diffusion of the coagulant from the raw solution into the raw solution. Process parameters such as the composition, temperature, concentration, flow rate, filament length, tension, and solution height of the coagulation bath directly affect the spinning formation and fiber quality. For example, in the manufacture of viscose fibers, a commonly used coagulation bath is an aqueous solution prepared from sulfuric acid and sodium sulfate, where sodium sulfate acts as a coagulant, while sulfuric acid promotes the decomposition of sodium xanthate, thereby forming regenerated cellulose.

[0033] Furthermore, the coagulation bath process is also used in the preparation of certain fibers, such as meta-aramid fibers. The use of a coagulation bath ensures that the spinning solution coagulates into fibers under specific conditions. This method involves not only the properties of the spinning solution but also the precise proportions of the components in the coagulation bath and temperature control to ensure that the fiber quality and performance meet the expected standards.

[0034] The coagulation bath is not only a crucial step in the manufacturing process of chemical fibers, but also an important means of ensuring fiber quality and performance. By precisely controlling the composition and process parameters of the coagulation bath, high-quality chemical fibers can be produced.

[0035] Dispersed phase: A mixture formed by the distribution of particles (molecules, ions, or molecular aggregates, etc.) of one (or more) substances in another substance. Examples include solutions, colloids, suspensions, and emulsions. In a dispersion system, the substance dispersed into particles is called the "dispersed phase" or "dispersed medium"; the substance in which the particles can be dispersed is called the "dispersant" or "dispersion medium".

[0036] Continuous phase: This usually refers to the substance in a dispersion system in which other substances are dispersed. For example, in a rubber mixture system, when one rubber or polymer surrounds another rubber or polymer, the surrounded rubber or polymer is called the dispersed phase, while the other rubber or polymer is called the continuous phase.

[0037] Laminar flow: This is a flow state of fluids that occurs in layers. When a fluid flows at low speed inside a pipe, it exhibits laminar flow, with its particles moving smoothly in a straight line parallel to the pipe axis. The fluid velocity is highest at the center of the pipe and lowest near the wall. The ratio of the average velocity to the maximum velocity inside the pipe is equal to 0.5.

[0038] Reynolds number: A dimensionless number used to characterize fluid flow. It can be used to distinguish between laminar and turbulent flow, and also to determine the resistance experienced by an object flowing in a fluid. Physically, the Reynolds number represents the ratio of the magnitude of inertial forces to viscous forces. When the Reynolds number is small, the influence of viscous forces on the flow field is greater than that of inertia, and the fluid flow is stable, i.e., laminar flow. Conversely, if the Reynolds number is large, the influence of inertia on the flow field is greater than that of viscous forces, and the fluid flow is less stable, easily forming a turbulent and irregular flow field.

[0039] Dynamic viscosity coefficient: also known as dynamic viscosity, absolute viscosity, or simple viscosity, is a physical quantity that measures the viscosity of a fluid. It is defined as the ratio of stress to strain rate, and numerically equal to the internal friction generated by the fluid interaction between two flat plates with an area of ​​1㎡ and a distance of 1m, moving relative to each other at a speed of 1m / s.

[0040] 2. The reference numerals in the accompanying drawings of the instruction manual include: 1. Discharge valve; 2. Sight glass; 3. Orifice; 4. Lower tube sheet; 5. Rectifier tube; 6. Upper tube sheet; 7. Distribution plate; 8. Exhaust valve; 9. Inlet pipe; 10. Container; 11. Liquid collection ring; 12. Drain pipe; 13. Storage device; 14. Filter.

[0041] The basic embodiments are as follows: A method for improving the filtration effect of a spinning coagulation bath includes a filtration step: filtering the coagulation bath in the storage device 13 using a filter 14, and returning the filtered coagulation bath to the storage device 13 for storage, such as... Figure 3 As shown; A pre-precipitation step is included before the filtration step: the coagulation bath undergoes pre-precipitation before filtration. During the pre-precipitation process, the coagulation bath is pressurized and fed into container 10 using a transfer pump. Container 10, as... Figure 1 As shown. The coagulation bath is first evenly distributed by the distribution plate 7 and then enters the rectifier tube 5. The coagulation bath flows faster in the rectifier tube 5 in the container 10 and maintains the flow of the coagulation bath in a stable laminar flow state. The impurities of the dispersed phase in the coagulation bath move towards the bottom of the container 10, and the continuous phase bath liquid flows out from the liquid collection ring 11 opened in the side wall of the container 10 halfway. The coagulation bath flowing out from the side wall of the container 10 undergoes a filtration step.

[0042] In order to ensure that the coagulation bath maintains a stable laminar flow state when flowing in the rectifier tube, this embodiment selects the diameter of the rectifier tube 5 and the flow velocity of the coagulation bath in the rectifier tube 5. Specifically, the diameter d of the rectifier tube 5 and the flow velocity v of the coagulation bath in the rectifier tube 5 are selected to satisfy Re=ρvd / μ and Re≤2000, where Re is the Reynolds coefficient, ρ is the density of the coagulation bath, and μ is the dynamic viscosity coefficient of the coagulation bath.

[0043] During the pre-sedimentation process, the precipitate accumulated inside container 10 is also discharged from the bottom of container 10. Specifically, during the pre-sedimentation process, the accumulation of precipitate inside container 10 is observed through the observation hole with a sight glass 2 provided at the bottom of the liquid receiving ring 11. When there is a large amount of accumulated precipitate, the discharge valve 1 at the bottom of container 10 is opened to discharge the precipitate.

[0044] This embodiment also provides an apparatus for improving the filtration effect of a spinning coagulation bath, including a pre-precipitation container 10. A coagulation bath inlet and an exhaust valve 8 are provided at the top of the container 10. The inlet is connected to a liquid inlet pipe 9, which is connected to a storage device 13 for the coagulation bath. Inside the container 10, from top to bottom, there are a distribution plate 7, an upper tube plate 6, a rectifier tube 5, and a lower tube plate 4. Multiple rectifier tubes 5 are provided and are evenly arranged. The two ends of the rectifier tubes 5 are fixed to the upper tube plate 6 and the lower tube plate 4, respectively. The upper tube plate 6 and the lower tube plate 4 are fixed inside the container 10.

[0045] Multiple small holes 3 are formed around the lower side wall of container 10, and liquid collection rings 11 are provided outside the small holes 3. The liquid collection rings 11 are evenly distributed around the circumference of container 10. Drain pipes 12 are connected to both ends of the liquid collection rings 11. The output end of the drain pipes 12 is connected to the equipment in the subsequent process. In this embodiment, the subsequent process is a filtration step, so the output end of the drain pipes 12 is connected to the filtration equipment.

[0046] An observation hole is provided at the bottom of the container 10, and a sight glass 2 is installed inside the observation hole. An outlet is also provided at the bottom of the container 10, and a discharge valve 1 is connected to the outlet.

[0047] This embodiment also provides an application of a method for improving the filtration effect of the spinning coagulation bath in wet spinning.

[0048] The specific implementation process is as follows: In this embodiment, an alkaline sodium sulfate aqueous solution is used as the coagulation bath. The coagulation bath temperature is 45℃, and the filtration flow rate is 5.5m³ / h. 3 The filter 14 has a cleaning cycle of 15-20 days per hour. To extend its service life, a pre-sedimentation container 10 is provided. The container 10 is made of 304 stainless steel. The diameter of the distribution plate 7 matches the diameter of the container 10. The rectifier tube 5 is a stainless steel tube with an inner diameter of Ф30mm. The spacing between two adjacent rectifier tubes 5 is 1.5 to 3 times the diameter of the rectifier tube 5. The arrangement is as follows: Figure 2As shown. In this embodiment, 33 rectifier tubes 5 are provided, and the spacing between two adjacent rectifier tubes 5 is 1.5 times the diameter of the rectifier tube 5. The flow velocity of the coagulation bath in the rectifier tubes 5 is 0.0656 m / s, and the Reynolds coefficient Re = 1508, which meets the conditions for laminar flow. In other embodiments, the diameter and flow velocity of the rectifier tubes 5 can be selected from other parameters. Since the density and viscosity of a given coagulation bath are fixed, the selection of the diameter and flow velocity of the rectifier tubes 5 only needs to satisfy Re = ρvd / μ and Re ≤ 2000.

[0049] The pre-sediment container 10 is installed between the outlet of the transfer pump and the filter 14. After it is put into use, the cleaning cycle of the filter 14 becomes 2 to 3 months, which greatly reduces the labor intensity and the discharge of cleaning wastewater. The container 10 is discharged about once a week.

[0050] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for improving the filtration effect of a spinning coagulation bath, comprising the following filtration steps: filtering the coagulation bath in a storage device, and returning the filtered coagulation bath to the storage device for storage; Its features are: A pre-precipitation step is also set before the filtration step: the coagulation bath is pre-precipitated before filtration. During the pre-precipitation process, the coagulation bath is sent into the container and the impurities of the dispersed phase in the coagulation bath are kept moving towards the bottom of the container. The continuous phase of the bath liquid flows out from the side wall of the container halfway. The coagulation bath flowing out from the side wall of the container is used for the filtration step.

2. The method for improving the filtration effect of the spinning coagulation bath according to claim 1, characterized in that: In the pre-precipitation step, the coagulation bath flows in the rectifier tube in the container, and the flow of the coagulation bath is kept in a stable laminar flow state.

3. The method for improving the filtration effect of the spinning coagulation bath according to claim 2, characterized in that: The diameter of the rectifier tube and the flow velocity of the coagulation bath within the rectifier tube are selected to ensure that the coagulation bath can maintain a stable laminar flow state within the rectifier tube.

4. The method for improving the filtration effect of the spinning coagulation bath according to claim 3, characterized in that: After entering the container and before entering the rectifier tubes, the coagulation bath is first distributed by the distribution plate, so that the distributed coagulation bath can flow evenly into each rectifier tube.

5. The method for improving the filtration effect of the spinning coagulation bath according to claim 4, characterized in that: The coagulation bath is also added to the flow in the rectifier tubes while flowing evenly into each rectifier tube.

6. The method for improving the filtration effect of a spinning coagulation bath according to any one of claims 1-5, characterized in that: The continuous phase of the bath liquid flows out along the liquid collection ring opened on the side wall of the container halfway through.

7. The method for improving the filtration effect of the spinning coagulation bath according to claim 6, characterized in that: In the pre-precipitation step, the precipitate accumulated in the container is also drained from the bottom of the container.

8. The method for improving the filtration effect of the spinning coagulation bath according to claim 7, characterized in that: In the pre-precipitation step, the coagulation bath is pressurized by a transfer pump and then enters the container.

9. An apparatus for improving the filtration effect of a spinning coagulation bath, characterized in that: The container includes a pre-precipitation container, wherein the container is provided with a pre-precipitation structure, and the pre-precipitation structure performs a pre-precipitation operation on the coagulation bath using the method described in claims 1-8 for improving the filtration effect of the spinning coagulation bath.

10. The application of the method for improving the filtration effect of the spinning coagulation bath according to any one of claims 1-8 in wet spinning forming.

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