A membrane filtration device and filtration method for heparin sodium production

Abstract

The application discloses a membrane filtering device and filtering method for heparin sodium production in the technical field of filtering for heparin sodium production, which comprises a shell, an outer wall of the shell is provided with a feeding pipe, a concentrated liquid outlet pipe and a permeated liquid outlet pipe, and an inner wall of the shell is provided with symmetrical support plates, first through holes are formed in the support plates, and a liquid collecting cavity is formed between the support plates and the shell; a membrane filtering assembly, which comprises a hollow fiber membrane bundle and a driving mechanism; and a cross-flow disturbing piece; wherein when the hollow fiber membrane bundle rotates, the cross-flow disturbing piece and the surface of the hollow fiber membrane bundle produce relative motion and periodically change the local flow direction and flow rate of fluid in the vicinity of the cross-flow disturbing piece. The membrane filtering device produces relative motion between the cross-flow disturbing piece and the surface of the hollow fiber membrane bundle, directly produces high shear force on the membrane surface, can effectively strip and prevent the adhesion of pollutants and gel layers, periodically changes the local flow direction and flow rate of fluid, strongly interferes with and thins the concentration difference polarization boundary layer, and significantly delays the rising speed of the transmembrane pressure difference.

Description

Technical Field

[0001] This invention relates to the field of filtration technology for heparin sodium production, and particularly to a membrane filtration device and filtration method for heparin sodium production. Background Technology

[0002] In the production of biochemical products such as heparin sodium, membrane filtration is a key purification process used to remove impurities such as proteins, viruses, and pyrogens, and to desalinate and concentrate the target product. Currently, hollow fiber membrane modules are commonly used in industry for cross-flow filtration. These modules typically encapsulate a large number of hollow fiber membrane filaments in a static shell. The feed liquid flows in the shell side (outer side of the membrane filaments). Under pressure, small molecules pass through the membrane wall and enter the inner lumen of the membrane filaments (tube side) to become permeate, while large molecules and impurities are retained to form concentrate.

[0003] However, in practical applications, especially when processing complex, high-viscosity feed solutions such as crude heparin sodium extract, which are prone to forming gel layers, large molecular impurities (such as proteins and polysaccharides) and colloidal particles in the feed solution are easily adsorbed and deposited on the membrane surface, forming a dense fouling layer. This leads to a rapid decrease in membrane flux and a reduction in separation efficiency, which is the primary problem limiting the efficient and continuous operation of membrane technology. Secondly, severe membrane fouling affects the stability and selectivity of membrane separation, making it difficult to guarantee product yield and batch-to-batch consistency. Therefore, improvements are needed. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the present invention provides a membrane filtration device and filtration method for heparin sodium production, so as to solve the problems mentioned in the background art.

[0005] The object of this invention is achieved as follows: a membrane filtration device for heparin sodium production, comprising:

[0006] The shell has an outer wall with a feed pipe, a concentrate outlet pipe and a permeate outlet pipe, and an inner wall with symmetrical support plates. A first through hole is provided on the support plate, and a liquid collection cavity is formed between the support plate and the shell.

[0007] A membrane filtration assembly is disposed between adjacent support plates and includes a hollow fiber membrane bundle that can rotate about its own axis and a drive mechanism for driving the hollow fiber membrane bundle to rotate.

[0008] Cross-flow disturbance plates are located between adjacent support plates and are arranged around the hollow fiber membrane bundle;

[0009] When the hollow fiber membrane bundle rotates, the cross-flow disturbance plate and the surface of the hollow fiber membrane bundle generate relative motion and periodically change the local flow direction and velocity of the fluid in the vicinity.

[0010] Preferably, the hollow fiber membrane bundle includes a central tube, end caps fixed at both ends of the central tube, and multiple hollow fiber membrane filaments fixed on the end caps. The liquid collecting end of the hollow fiber membrane bundle is connected to the permeate outlet pipe through a rotary joint. A second through hole is provided on the central tube, and the end caps are rotatably connected to the support plate.

[0011] Preferably, the drive mechanism includes a motor located outside the housing and a transmission shaft fixed to the output end of the motor, with the transmission shaft fixedly connected to one of the end covers.

[0012] Preferably, both ends of the crossflow disturbance plate have arc-shaped guide surfaces.

[0013] Preferably, the cross-flow disturbance plate has multiple flow guiding channels, with the liquid inlet end of the flow guiding channel close to the feed pipe and the liquid outlet end of the flow guiding channel aligned with the hollow fiber membrane bundle.

[0014] Preferably, the end of the flow channel near the feed pipe is gradually expanding, and the end of the flow channel near the hollow fiber membrane bundle is gradually contracting.

[0015] Preferably, the crossflow disturbance sheet has a comb-like structure on the side near the hollow fiber membrane bundle.

[0016] Preferably, both the crossflow disturbance plate and the comb-like structure have an anti-stick coating on their surfaces, and the comb-like structure is an integral flexible tooth made of flexible material.

[0017] Preferably, the comb-like structure includes a pointed cone near the feed pipe, a rounded top near the permeate outlet pipe, and a flat top located between the pointed cone and the rounded top, wherein the density of the pointed cone is greater than that of the flat top, and the density of the flat top is greater than that of the rounded top.

[0018] The present invention also provides a method for a membrane filtration device for heparin sodium production, comprising the following steps:

[0019] Drive the hollow fiber membrane bundle to rotate at a set speed;

[0020] The crude heparin sodium solution is pumped into the housing through the feed pipe, and the feed pressure and cross-flow velocity are controlled.

[0021] When the feed liquid flows between the rotating hollow fiber membrane bundle and the fixed cross-flow disturbance plate, it is subjected to the shearing action of periodic disturbance. The filtered permeate is collected in the inner cavity of the central tube and discharged from the permeate outlet pipe, while the concentrate is discharged from the concentrate outlet pipe.

[0022] When the transmembrane pressure difference rises to a set threshold, the system switches to cleaning mode to perform online backflushing or chemical cleaning while maintaining the rotation of the hollow fiber membrane bundle.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. When the hollow fiber membrane bundle rotates under the drive mechanism, the surface of the hollow fiber membrane filaments and the cross-flow disturbance plate generate continuous relative motion. This not only generates high shear force directly on the membrane surface, which can effectively peel off and prevent the adhesion of pollutants and gel layers, but also periodically changes the flow direction and velocity of the local fluid, strongly disturbs and thins the concentration polarization boundary layer, significantly slows down the rise rate of transmembrane pressure difference, and enables the device to maintain a stable high-flux filtration state for a longer period of time, thereby greatly improving the extraction efficiency of heparin sodium and reducing the cost of frequent cleaning or replacement of membrane modules.

[0024] 2. The flow channel adopts a streamlined design that expands at the front and narrows at the back. This design can smoothly receive the fluid from the feed pipe, reducing impact, and accelerate and concentrate the liquid feed to the surface of the hollow fiber membrane bundle, forming a directional scouring effect. At the same time, the comb-like structure of the cross-flow disturbance plate on the side of the hollow fiber membrane bundle, especially its density gradient of pointed cones, flat tops, and rounded tops, can further divide and disturb the laminar flow between the membrane fibers, creating more micro-turbulence. This multi-scale, gradient disturbance combination ensures the uniform distribution and efficient renewal of the liquid feed on the surface of the hollow fiber membrane bundle, enhances the mass transfer process of the target substance from the bulk solution to the membrane surface, and improves the separation selectivity.

[0025] 3. The hollow fiber membrane bundle is rotatably connected to the support plate through end caps at both ends, and achieves sealed liquid collection under dynamic filtration through a rotary joint. The structure is compact and the sealing is reliable. The cross-flow disturbance plate and the comb-shaped structure use anti-stick coating and flexible materials to ensure efficient disturbance while avoiding mechanical damage to the hollow fiber membrane filaments. In addition, the drive mechanism is located outside the shell, which is convenient for inspection and maintenance. This design enables the device to maintain high separation performance, good operational stability and maintenance convenience in the long-term and continuous production of heparin sodium, thereby reducing the overall operating cost. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a membrane filtration device for heparin sodium production in one embodiment.

[0028] Figure 2 This is a partial cross-sectional view of a membrane filtration device for heparin sodium production in one embodiment.

[0029] Figure 3 for Figure 2 A magnified schematic diagram of the structure at point A in the diagram.

[0030] Figure 4 for Figure 2 Enlarged schematic diagram of the structure at point B in the diagram.

[0031] Figure 5 This is a schematic diagram of a hollow fiber membrane bundle structure in one embodiment.

[0032] Figure 6 This is a partial structural diagram of a membrane filtration device for heparin sodium production in one embodiment.

[0033] Figure 7 This is a schematic diagram of the crossflow disturbance plate structure in one embodiment.

[0034] Figure 8 This is a schematic diagram of a membrane filtration method for producing heparin sodium in one embodiment.

[0035] Figure label:

[0036] 100. Shell; 110. Feed pipe; 120. Concentrate outlet pipe; 130. Permeate outlet pipe; 140. Support plate; 150. First through hole; 160. Collection chamber; 170. Rotary joint; 200. Membrane filter assembly; 210. Hollow fiber membrane bundle; 211. Central tube; 212. End cap; 213. Hollow fiber membrane filament; 214. Second through hole; 220. Drive mechanism; 221. Motor; 222. Drive shaft; 300. Crossflow disturbance plate; 310. Guide surface; 320. Flow guiding channel; 330. Comb-shaped structure; 331. Conical part; 332. Flat top; 333. Round top. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] like Figures 1-7 As shown, a membrane filtration device for heparin sodium production includes a housing 100, a membrane filtration assembly 200, and a cross-flow disturbance plate 300.

[0039] Please refer to Figure 2 and Figure 3The outer wall of the shell 100 has a feed pipe 110, a concentrate outlet pipe 120 and a permeate outlet pipe 130, and the inner wall of the shell 100 has symmetrical support plates 140. The support plates 140 have a first through hole 150, and a liquid collection cavity 160 is formed between the support plates 140 and the shell 100.

[0040] The membrane filter assembly 200 is disposed between adjacent support plates 140, and the membrane filter assembly 200 includes a hollow fiber membrane bundle 210 that can rotate about its own axis and a drive mechanism 220 that drives the hollow fiber membrane bundle 210 to rotate.

[0041] The crossflow disturbance plate 300 is located between adjacent support plates 140 and is arranged around the hollow fiber membrane bundle 210.

[0042] When the hollow fiber membrane bundle 210 rotates, the cross-flow disturbance plate 300 and the surface of the hollow fiber membrane bundle 210 generate relative motion and periodically change the local flow direction and velocity of the fluid in the vicinity.

[0043] The hollow fiber membrane bundle 210 is rotated by the drive mechanism 220. At the same time, the cross-flow disturbance plate 300 and the surface of the hollow fiber membrane bundle 210 generate relative motion, which periodically changes the flow direction and velocity of the fluid near the surface of the hollow fiber membrane bundle 210, enhances the shearing effect, effectively reduces the contamination and concentration polarization of the hollow fiber membrane bundle 210, and improves the filtration efficiency of heparin sodium solution and the service life of the hollow fiber membrane bundle 210.

[0044] For details, please refer to Figure 4 , Figure 5 and Figure 6 The hollow fiber membrane bundle 210 includes a central tube 211, end caps 212 fixed at both ends of the central tube 211, and multiple hollow fiber membrane filaments 213 fixed on the end caps 212. The liquid collecting end of the hollow fiber membrane bundle 210 is connected to the permeate outlet pipe 130 through a rotary joint 170. A second through hole 214 is provided on the central tube 211, and the end caps 212 are rotatably connected to the support plate 140.

[0045] The hollow fiber membrane bundle 210 is connected to the permeate outlet pipe 130 through the rotary joint 170 to achieve dynamic filtration. The second through hole 214 on the central tube 211 facilitates the collection and discharge of permeate. The structure is compact and ensures a continuous and stable filtration process.

[0046] Please refer to Figure 1 and Figure 2The drive mechanism 220 is a motor 221 located outside the housing 100 and a transmission shaft 222 fixed to the output end of the motor 221. The transmission shaft 222 is fixedly connected to one of the end caps 212. The motor 221 directly drives the end cap 212 through the transmission shaft 222, thereby driving the hollow fiber membrane bundle 210 to rotate. The transmission structure is simple and reliable, easy to control the speed, and adaptable to the needs of different filtration conditions.

[0047] Please refer to Figure 7 Both ends of the crossflow disturbance plate 300 have arc-shaped guide surfaces 310. The arc-shaped guide surfaces 310 can guide the fluid to flow smoothly to the membrane filter assembly 200, reduce flow resistance, and make the fluid distribution more uniform.

[0048] The cross-flow disturbance plate 300 has multiple flow guiding channels 320. The liquid inlet end of the flow guiding channel 320 is close to the feed pipe 110, and the liquid outlet end of the flow guiding channel 320 is aligned with the hollow fiber membrane bundle 210. The flow guiding channel 320 directs part of the feed liquid to the surface of the hollow fiber membrane bundle 210, increases the shear force of the fluid near the surface of the hollow fiber membrane bundle 210, and further enhances the anti-fouling ability.

[0049] The flow channel 320 is gradually expanding at the end near the feed pipe 110 and gradually contracting at the end near the hollow fiber membrane bundle 210. The gradually expanding inlet reduces the impact of the feed, and the gradually contracting outlet accelerates the fluid and concentrates it on the surface of the hollow fiber membrane bundle 210, forming a highly efficient scouring process and reducing the deposition of pollutants on the membrane surface.

[0050] The cross-flow disturbance plate 300 has a comb-like structure 330 on the side near the hollow fiber membrane bundle 210. The comb-like structure 330 further divides and disturbs the fluid boundary layer around the hollow fiber membrane filaments 213, enhances local turbulence, improves mass transfer efficiency, and prevents membrane pore blockage.

[0051] Both the cross-flow disturbance plate 300 and the comb-shaped structure 330 have an anti-stick coating to reduce the adhesion of pollutants. The anti-stick coating is a fluoropolymer coating, a modified fluoropolymer coating, or an organosilicon coating. The comb-shaped structure 330 is an integral flexible tooth made of a flexible material, such as polyvinylidene fluoride, polytetrafluoroethylene, ultra-high molecular weight polyethylene, thermoplastic polyurethane elastomer, or silicone rubber. The flexible tooth structure avoids scratching or abrading the hollow fiber membrane filaments 213, and protects the surface of the hollow fiber membrane bundle 210 while disturbing it, thus extending the life of the membrane filter assembly 200.

[0052] For details, please refer to Figure 7The comb-like structure 330 includes a pointed cone 331 near the feed pipe 110, a rounded top 333 near the permeate outlet pipe 130, and a flat top 332 located between the pointed cone 331 and the rounded top 333. The density of the pointed cone 331 is greater than that of the flat top 332, and the density of the flat top 332 is greater than that of the rounded top 333.

[0053] The high-density pointed cone 331 comb teeth near the feed pipe 110 form a tight fence, which finely divides the fluid and generates more micro-vortices. The sharp tooth tips of the pointed cone 331 are conducive to concentrating shear force. In addition, the short and thick teeth of the pointed cone 331 near the feed pipe 110 have high strength and are suitable for dealing with the impact of large particles. The low-density rounded top 333 comb teeth near the liquid outlet pipe 130 reduce the obstruction to high-viscosity fluids. The smooth tooth tips of the rounded top 333 reduce the shedding of vortices and make the flow more stable. In addition, the slender teeth of the rounded top 333 near the liquid outlet pipe 130 are prone to slight vibration under the action of fluid, forming a dynamic and gentle cleaning effect.

[0054] The comparative experimental data report on membrane filtration devices for heparin sodium production is as follows:

[0055] I. Experimental Design and Test Groups

[0056] 1. Test solution: crude heparin sodium extract from the same batch (solid content approximately 1.5%, viscosity approximately 8.5 cP at 25°C).

[0057] 2. Core membrane module: All groups use hollow fiber membrane bundles 210 with the same material, area (10 m²), and molecular weight cutoff.

[0058] 3. Operating conditions: constant flow filtration mode, initial flux set at 40 LMH (liters / square meter / hour); temperature 25°C; concentrate circulation.

[0059] 4. Cleaning procedure: When the transmembrane pressure difference rises to 3 times the initial value, perform the standard in-situ cleaning procedure (first alkaline washing, then rinsing with clean water).

[0060] 5. Set up four sets of testing devices.

[0061] Option A (Rotating Membrane Only): Only the hollow fiber membrane bundle 210 is driven to rotate (speed set to 300 rpm), without crossflow disturbance plate 300.

[0062] Option B (fixed disturbance only): Install fixed crossflow disturbance plate 300 (basic type without flow channel 320 and comb structure 330), but the hollow fiber membrane bundle 210 does not rotate.

[0063] Option C (simple combination): It has both a rotating hollow fiber membrane bundle 210 (rotation speed set at 300 rpm) and a fixed disturbance plate (basic type), but the disturbance plate is a smooth flat plate and does not have the flow channel 320 and comb-shaped structure 330 in this invention.

[0064] Scheme D of the present invention: a scheme combining a rotating hollow fiber membrane bundle 210 (rotation speed set at 300 rpm), a cross-flow disturbance plate 300 with a flow guiding channel 320 and a comb-shaped structure 330.

[0065] II. Comparison of Key Performance Indicators

[0066] 1. Filtration flux attenuation and antifouling performance

[0067] Test: Within the same operating time (4 hours), the decay of standardized flux and the rate of increase of transmembrane pressure difference were recorded for each group. The results are shown in the table below:

[0068]

[0069] Data analysis: Single technologies (Schemes A and B) showed severe flux decay (approximately 40%) after 4 hours, with a rapid increase in transmembrane pressure, indicating limited antifouling capabilities. The simple combination (Scheme C) outperformed the single technologies, demonstrating a preliminary synergistic effect between rotation and perturbation, but the improvement was limited. The proposed solution (Scheme D) exhibited the best antifouling performance, with the highest flux retention rate (85%) and the slowest rate of increase in transmembrane pressure, and the difference from the simple combination of Scheme C was statistically significant (p<0.05). This proves that the optimized cross-flow perturbation plate 300 structure (flow channel 320 and comb-like structure 330) in this invention produced a synergistic antifouling effect that surpasses conventional superposition.

[0070] 2. Cleaning efficiency and membrane flux recovery rate

[0071] Test: After triggering the cleaning conditions (transmembrane pressure difference reaching 3 times the initial value), standard in-situ cleaning was performed, and the membrane flux recovery rate after cleaning was measured. The results are shown in the table below:

[0072]

[0073] Data analysis: The flux recovery rate of Scheme D in this invention is close to 100%, which is significantly higher than that of other groups. This indicates that its unique flow field design not only delays fouling, but also makes the pollutants loose and easy to fall off on the membrane surface, rather than a dense and firm filter cake layer. This greatly improves the cleaning efficiency and reduces the consumption of chemical cleaning agents and the risk of membrane damage.

[0074] 3. Key indicators of operational economy: effective filtration time and cleaning cycle

[0075] Test: Record the effective operating time from the start of filtration to the point where cleaning is required (transmembrane pressure difference reaches 3 times the initial value) to evaluate the cleaning cycle. The results are shown in the table below:

[0076]

[0077] Data analysis: Solution D of this invention extends the effective operating time (cleaning cycle) by nearly 100% (96%), and still achieves a 50% improvement compared to the second-best simple combination C, with a highly significant difference (p<0.001). This directly translates into fewer downtime cleaning times, higher equipment utilization, and lower unit output operating costs, demonstrating significant commercial application value.

[0078] In summary, Solution D of this invention is not a simple superposition of rotation (Solution A) and disturbance (Solution B) technologies (Solution C). It is a composite design that optimizes the inflow distribution through the flow guide channel 320 and generates micro-vortices through the comb-shaped structure 330. This design, combined with the rotational shear force field, produces a strong hydrodynamic synergy. In terms of core indicators such as flux maintenance, contamination control, cleaning and recovery, and operating cycle, it is significantly superior to any single technology or simple combination solution. This solution is designed specifically for the characteristics of heparin sodium material, and experimental data fully demonstrate its powerful practicality in solving membrane fouling problems, improving production efficiency, and enhancing economic benefits in this specific application scenario.

[0079] like Figure 8 As shown, the present invention also provides a method for a membrane filtration device for heparin sodium production, comprising the following steps:

[0080] In step S410, the hollow fiber membrane bundle 210 is driven to rotate at a set speed.

[0081] In step S420, the crude heparin sodium solution is pumped into the housing 100 through the feed pipe 110, and the feed pressure and cross-flow velocity are controlled.

[0082] In step S430, when the feed liquid flows between the rotating hollow fiber membrane bundle 210 and the fixed cross-flow disturbance plate 300, it is subjected to the shearing action of periodic disturbance. The filtered permeate is collected in the inner cavity of the central tube 211 and discharged from the permeate outlet pipe 130, while the concentrate is discharged from the concentrate outlet pipe 120.

[0083] Step S440: When the transmembrane pressure difference rises to a set threshold, while maintaining the rotation of the hollow fiber membrane bundle 210, switch to cleaning mode to perform online backflushing or chemical cleaning.

[0084] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A membrane filtration device for heparin sodium production, characterized in that, include: The shell (100) has an outer wall with a feed pipe (110), a concentrate outlet pipe (120) and a permeate outlet pipe (130), and an inner wall with symmetrical support plates (140). A first through hole (150) is provided on the support plate (140), and a liquid collection cavity (160) is formed between the support plate (140) and the shell (100). The membrane filtration assembly (200) is disposed between adjacent support plates (140) and includes a hollow fiber membrane bundle (210) that can rotate about its own axis and a drive mechanism (220) for driving the hollow fiber membrane bundle (210) to rotate. Cross-flow disturbance plate (300) is located between adjacent support plates (140) and is arranged around the hollow fiber membrane bundle (210); When the hollow fiber membrane bundle (210) rotates, the cross-flow disturbance plate (300) and the surface of the hollow fiber membrane bundle (210) generate relative motion and periodically change the local flow direction and velocity of the fluid in the vicinity. The cross-flow disturbance plate (300) has a comb-like structure (330) on the side near the hollow fiber membrane bundle (210). The comb-like structure (330) includes a pointed cone (331) near the feed pipe (110), a rounded top (333) near the permeate outlet pipe (130), and a flat top (332) located between the pointed cone (331) and the rounded top (333). The density of the pointed cone (331) is greater than that of the flat top (332), and the density of the flat top (332) is greater than that of the rounded top (333).

2. The membrane filtration device for heparin sodium production according to claim 1, characterized in that, The hollow fiber membrane bundle (210) includes a central tube (211), end caps (212) fixed at both ends of the central tube (211), and multiple hollow fiber membrane filaments (213) fixed on the end caps (212). The liquid collecting end of the hollow fiber membrane bundle (210) is connected to the permeate outlet pipe (130) through a rotary joint (170). A second through hole (214) is provided on the central tube (211), and the end cap (212) is rotatably connected to the support plate (140).

3. The membrane filtration device for heparin sodium production according to claim 2, characterized in that, The drive mechanism (220) is a motor (221) located outside the housing (100) and a transmission shaft (222) fixed to the output end of the motor (221). The transmission shaft (222) is fixedly connected to one of the end caps (212).

4. The membrane filtration device for heparin sodium production according to claim 1, characterized in that, Both ends of the crossflow disturbance plate (300) have arc-shaped guide surfaces (310).

5. A membrane filtration device for heparin sodium production according to claim 4, characterized in that, The cross-flow disturbance plate (300) has multiple flow guiding channels (320), the liquid inlet end of the flow guiding channel (320) is close to the feed pipe (110), and the liquid outlet end of the flow guiding channel (320) is aligned with the hollow fiber membrane bundle (210).

6. A membrane filtration device for heparin sodium production according to claim 5, characterized in that, The flow channel (320) is gradually expanding at one end near the feed pipe (110), and gradually contracting at the other end near the hollow fiber membrane bundle (210).

7. A membrane filtration device for heparin sodium production according to claim 1, characterized in that, The surfaces of the crossflow disturbance plate (300) and the comb-shaped structure (330) are both coated with an anti-stick coating, and the comb-shaped structure (330) is an integral flexible tooth made of flexible material.

8. A filtration method for a membrane filtration apparatus for heparin sodium production according to any one of claims 1-7, characterized in that, Includes the following steps: Drive the hollow fiber membrane bundle (210) to rotate at a set speed; The crude heparin sodium solution is pumped into the housing (100) through the feed pipe (110), and the feed pressure and cross-flow velocity are controlled. When the feed liquid flows between the rotating hollow fiber membrane bundle (210) and the fixed cross-flow disturbance plate (300), it is subjected to the shearing action of periodic disturbance. The filtered permeate is collected in the inner cavity of the central tube (211) and discharged from the permeate outlet pipe (130), while the concentrate is discharged from the concentrate outlet pipe (120). When the transmembrane pressure difference rises to the set threshold, the hollow fiber membrane bundle (210) is kept rotating, and the cleaning mode is switched to perform online backflushing or chemical cleaning.

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