Hollow fiber membrane product drying apparatus

Abstract

The utility model discloses a hollow fiber membrane product drying device, including autoclave, be provided with support in autoclave, and support is connected with liquid CO2 storage tank through first pipeline, be provided with first high -pressure pump on first pipeline, and the bottom of autoclave is connected with liquid CO2 storage tank through second pipeline, and support is connected with waste liquid collector through third pipeline, the utility model discloses the hollow fiber membrane product of wet membrane detection is placed in autoclave to be fixed on the support. The product should be placed horizontally or vertically, avoid distortion and extrusion. Through the replacement of water molecules in the pore of hollow fiber membrane product by supercritical CO2 in liquid CO2 storage tank, then drying, fundamentally eliminate capillary force in the drying process, because the membrane hole becomes small due to thermal expansion and contraction, maximum limit keeps the original appearance of membrane hole, thereby prevent hollow fiber membrane from being damaged in the drying process, improve product performance.

Description

Technical Field

[0001] This utility model belongs to the field of medical devices, and more specifically, relates to a drying device for hollow fiber membrane products. Background Technology

[0002] Membrane separation technology refers to the selective separation of a mixture of molecules of different particle sizes at the molecular level when passing through a membrane. In the field of blood purification, membrane separation technology is one of the key technologies in modern medicine. The performance of its core component—the hollow fiber membrane—directly determines the treatment efficiency and safety. Before leaving the factory, membrane separation products must undergo multiple tests to ensure safety and performance, including tests on dialysis membrane pore size, permeability, clearance rate, membrane integrity, and blood compatibility. Some testing methods require wet membrane treatment.

[0003] However, in traditional membrane separation product manufacturing processes, the drying process after wet membrane gas detection typically involves direct drying, a step with serious technical flaws. When conventional hot air, microwave, or vacuum drying is used, the purified water in the molecular to micron-level pores inside the membrane evaporates directly, generating enormous capillary forces at the gas-liquid interface. This powerful contractile force irreversibly compresses and destroys the delicate and fragile porous structure formed in the wet state, leading to pore collapse or micro-collapse, decreased porosity, and loss of specific surface area. Consequently, this results in a significant reduction in water flux and unsatisfactory solute removal rates. Utility Model Content

[0004] The main purpose of this invention is to provide a hollow fiber membrane product drying device to prevent damage to the hollow fiber membrane during the drying process and improve product performance.

[0005] According to a first aspect of the present invention, a hollow fiber membrane product drying device is provided, including an autoclave, a support is provided inside the autoclave, the support is connected to a liquid CO2 storage tank through a first pipeline, a first high-pressure pump is provided on the first pipeline, the bottom of the autoclave is connected to the liquid CO2 storage tank through a second pipeline, and the support is connected to a waste liquid collector through a third pipeline.

[0006] The hollow fiber membrane product drying device according to the first aspect of the present invention further includes an anhydrous ethanol storage tank, which is connected to the support via a fourth pipeline.

[0007] According to the hollow fiber membrane product drying device of the first aspect of the present invention, a third valve is provided on the fourth pipeline.

[0008] According to the hollow fiber membrane product drying device of the first aspect of the present invention, a shut-off valve and a pressure reducing valve are provided on the third pipeline. The shut-off valve is located at one end near the support, and the pressure reducing valve is located at one end near the waste liquid collector.

[0009] According to the hollow fiber membrane product drying device of the first aspect embodiment of the present invention, a concentration monitor or a moisture analyzer is further provided on the third pipeline, and the concentration monitor or moisture analyzer is located between the shut-off valve and the support.

[0010] According to the hollow fiber membrane product drying device of the first aspect of the present invention, a gas-liquid separator is provided on the third pipeline, and the gas-liquid separator is disposed between the support and the waste liquid collector.

[0011] According to the hollow fiber membrane product drying device of the first aspect of the present invention, the gas-liquid separator is connected to the gas purification dryer through a fifth pipeline.

[0012] According to the hollow fiber membrane product drying device of the first aspect of the present invention, the gas purification dryer is connected to the liquid CO2 storage tank through a sixth pipeline, and a second high-pressure pump is provided on the sixth pipeline.

[0013] According to the hollow fiber membrane product drying apparatus of the first aspect of the present invention, the high-pressure autoclave is further provided with a temperature control device.

[0014] According to the hollow fiber membrane product drying device of the first aspect of the present invention, a first valve is provided on the first pipeline and a second valve is provided on the second pipeline.

[0015] One of the above-described technical solutions of this utility model has at least one of the following advantages or beneficial effects: This invention involves placing the hollow fiber membrane product, obtained after wet membrane testing, into an autoclave and fixing it on a support. The product should be placed horizontally or vertically to avoid twisting and compression. Supercritical CO2 from a liquid CO2 storage tank replaces the water molecules within the pores of the hollow fiber membrane product, followed by drying. This fundamentally eliminates capillary forces during the drying process, preventing the pores from shrinking due to thermal expansion and contraction, thus maximizing the preservation of the original pore morphology and preventing damage to the hollow fiber membrane during drying, thereby improving product performance. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a schematic diagram of the hollow fiber membrane product drying device in the first embodiment of this utility model. Detailed Implementation

[0017] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0018] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0019] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" and "second" may explicitly or implicitly include one or more features.

[0021] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection or a movable connection, a detachable connection or a non-detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection or a connection that can communicate with each other; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two elements, an indirect connection, or an interaction between two elements.

[0022] The following disclosure provides many different implementation methods or examples for different solutions to implement this utility model.

[0023] Reference Figure 1As shown, a hollow fiber membrane product drying device is provided, including an autoclave 1, a support 10 is provided inside the autoclave 1, the support 10 is connected to a liquid CO2 storage tank 2 through a first pipeline 13, a first high-pressure pump 4 is provided on the first pipeline 13, the bottom of the autoclave 1 is connected to the liquid CO2 storage tank 2 through a second pipeline 14, and the support 10 is connected to a waste liquid collector 3 through a third pipeline 15.

[0024] In some embodiments of this utility model, an anhydrous ethanol storage tank 5 is also included, which is connected to the support 10 via a fourth pipeline 16.

[0025] Furthermore, a third valve 21 is installed on the fourth pipeline 16.

[0026] In some embodiments of this utility model, a shut-off valve 6 and a pressure reducing valve 7 are provided on the third pipeline 15. The shut-off valve 6 is located at one end near the support 10, and the pressure reducing valve 7 is located at one end near the waste liquid collector 3.

[0027] Furthermore, a concentration monitor 12 or a moisture analyzer is also installed on the third pipeline 15, which is located between the shut-off valve 6 and the bracket 10.

[0028] In some embodiments of this utility model, a gas-liquid separator 8 is provided on the third pipeline 15, and the gas-liquid separator 8 is located between the support 10 and the waste liquid collector 3.

[0029] Furthermore, the gas-liquid separator 8 is connected to the gas purification dryer 9 via the fifth pipeline 17.

[0030] In some embodiments of this utility model, the gas purification dryer 9 is connected to the liquid CO2 storage tank 2 through a sixth pipeline 18, and a second high-pressure pump 11 is provided on the sixth pipeline 18.

[0031] In some embodiments of this utility model, the high-pressure reactor 1 is also equipped with a temperature control device.

[0032] In some embodiments of this utility model, a first valve 19 is provided on the first pipeline 13, and a second valve 20 is provided on the second pipeline 14.

[0033] In this embodiment, water molecules in the pores of the hollow fiber membrane product are replaced by supercritical CO2 and then dried, which fundamentally eliminates capillary forces during the drying process. Due to thermal expansion and contraction, the membrane pores become smaller, thus preserving the original morphology of the membrane pores to the maximum extent and preventing damage to the hollow fiber membrane during the drying process, thereby reducing product performance.

[0034] Example 1: A dialyzer drying process (to completely dry the product): 1. Place the hollow fiber membrane product obtained after wet membrane testing into the autoclave 1 of this drying apparatus, and securely mount it on the dedicated support 10 inside the autoclave 1. The product should be placed horizontally or vertically, avoiding twisting and compression. Pump anhydrous ethanol into the product from one port and out from the other port using an external solvent circulation system. Maintain a low, steady flow rate and circulate for 30-60 minutes. Ensure that the ethanol fully penetrates into the finest pores of each membrane fiber, displacing water molecules.

[0035] 2. Discharge and recover the outflowing ethanol-water mixture. Connect the product port to a continuous flow pipeline using a tooling. One end of this pipeline is connected to a liquid CO2 storage tank 2 for liquid CO2 supply, and the other end is connected to a waste liquid recovery system outside the autoclave 1. The waste liquid recovery system includes a waste liquid collector 3, a gas-liquid separator 8, and a gas purification dryer 9.

[0036] 3. Start the refrigeration system and cool the autoclave 1 to 0℃~10℃ using the temperature control device. Pump liquid CO2 into the autoclave 1 from the bottom until the autoclave is full and the product is completely submerged. Start the first high-pressure pump 4 and continuously pump liquid CO2 into the product at a constant and low flow rate of 0.5-1L / min. At the same time, adjust the outlet valve (including the shut-off valve 6 and the pressure reducing valve 7) to continuously discharge the waste CO2-ethanol mixture carrying ethanol from the autoclave 1 and direct it into the waste liquid collector 3. This process continues for 10-30 minutes to ensure that the ethanol inside the product is completely replaced. Install an online concentration monitor 12 (such as a near-infrared NIR sensor) on the third outlet pipeline 15 to monitor the ethanol content in the outflowing CO2 in real time.

[0037] 4. When the ethanol concentration is below the preset threshold of 1-10 ppm, the displacement endpoint is considered reached. Close all valves to stop the flow of liquid CO2. Start the heating system and slowly increase the internal temperature and pressure of autoclave 1 using the temperature control device. Stabilize the system at 40-50℃ and 10-15 MPa. Maintain this state for 10-30 minutes. Under these supercritical conditions, CO2 has extremely high diffusivity and extremely low viscosity, allowing it to penetrate even the smallest pores, dissolving and carrying away the last trace amount of residual ethanol.

[0038] While maintaining the temperature, depressurize at an extremely slow rate using the precision back pressure valve on autoclave 1. The depressurization rate is controlled at 0.5-1.0 MPa / min. Once the pressure has dropped to atmospheric pressure and the temperature has cooled to room temperature, open the autoclave lid. Disassemble the tooling connectors and remove the completely dried hollow fiber membrane product.

[0039] Example 2: A dialyzer drying process (suitable for products with specific moisture content requirements): 1. Place the hollow fiber membrane product obtained after wet membrane testing into the autoclave 1 of this supercritical drying apparatus, and securely install it on the special support 10 inside the autoclave 1. The product should be placed horizontally or vertically to avoid twisting and compression. Use compressed dry air at a temperature of 10℃~25℃ and a low flow rate to purge the inside of the product and remove the moisture inside the blood chamber channels.

[0040] 2. Start the heating system and slowly increase the temperature and pressure inside the reactor using the temperature control device. Stabilize the system at 40-50℃ and 10-15MPa. Continuously pump a measured amount of dry supercritical / liquid CO2 into the system.

[0041] 3. An online moisture analyzer (such as a laser or NIR spectrometer) needs to be installed at the outlet to monitor the water content in the outflowing CO2 in real time. When the monitoring data, calculated by the model, indicates that the residual water content in the product has reached the target value, rinsing should be stopped immediately.

[0042] 4. After reaching the target moisture content, while maintaining the temperature, release the pressure at an extremely slow rate through the precision back pressure valve on autoclave 1. The pressure release rate should be controlled at 0.5-1.0 MPa / min. Once the pressure has dropped to atmospheric pressure and the temperature has cooled to room temperature, open the autoclave lid. Disassemble the tooling connectors and remove the dried hollow fiber membrane product.

[0043] The product prepared by the drying device of this application has significantly improved blood compatibility and significantly reduced the probability of platelets adhering to the fiber surface; supercritical CO2 has a good extraction effect and the content of PVP, a leachable substance in the product fiber, is also reduced.

[0044] The above is a further detailed description of this utility model and should not be considered as a limitation on the specific implementation of this utility model. For those skilled in the art, simple deductions or substitutions without departing from the concept of this utility model are all within the protection scope of this utility model.

Claims

1. A hollow fiber membrane product drying device, comprising an autoclave (1), characterized in that, The autoclave (1) is equipped with a support (10), which is connected to the liquid CO2 storage tank (2) through a first pipeline (13). A first high-pressure pump (4) is installed on the first pipeline (13). The bottom of the autoclave (1) is connected to the liquid CO2 storage tank (2) through a second pipeline (14). The support (10) is connected to the waste liquid collector (3) through a third pipeline (15).

2. The hollow fiber membrane product drying apparatus according to claim 1, characterized in that, It also includes an anhydrous ethanol storage tank (5), which is connected to the support (10) via a fourth pipeline (16).

3. The hollow fiber membrane product drying apparatus according to claim 2, characterized in that, The fourth pipeline (16) is equipped with a third valve (21).

4. The hollow fiber membrane product drying apparatus according to claim 1, characterized in that, The third pipeline (15) is equipped with a shut-off valve (6) and a pressure reducing valve (7). The shut-off valve (6) is located at one end near the support (10), and the pressure reducing valve (7) is located at one end near the waste liquid collector (3).

5. The hollow fiber membrane product drying apparatus according to claim 4, characterized in that, A concentration monitor (12) or a moisture analyzer is also installed on the third pipeline (15), and the concentration monitor (12) or moisture analyzer is located between the shut-off valve (6) and the bracket (10).

6. The hollow fiber membrane product drying apparatus according to claim 1, characterized in that, A gas-liquid separator (8) is provided on the third pipeline (15), and the gas-liquid separator (8) is located between the support (10) and the waste liquid collector (3).

7. The hollow fiber membrane product drying apparatus according to claim 6, characterized in that, The gas-liquid separator (8) is connected to the gas purification dryer (9) via the fifth pipeline (17).

8. The hollow fiber membrane product drying apparatus according to claim 7, characterized in that, The gas purification dryer (9) is connected to the liquid CO2 storage tank (2) through the sixth pipeline (18), and the sixth pipeline (18) is equipped with a second high-pressure pump (11).

9. The hollow fiber membrane product drying apparatus according to claim 1, characterized in that, The high-pressure autoclave (1) is also equipped with a temperature control device.

10. The hollow fiber membrane product drying apparatus according to claim 1, characterized in that, The first pipeline (13) is provided with a first valve (19), and the second pipeline (14) is provided with a second valve (20).

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