Continuous preparation method and preparation system of nanofiltration membrane

Abstract

The invention discloses a nanofiltration membrane continuous preparation method and a preparation system.The preparation method comprises the steps that a moving carrier membrane is evenly coated with a polymer solution, a membrane layer with the set thickness is formed, the carrier membrane is a polyester membrane or a polyether sulfone membrane, and the membrane layer is a membrane layer with the set thickness; the polymer solution is polysulfone, polyimide, polyacrylate or a mixture thereof; carrying out suction filtration on the membrane layer, and removing the solvent to form a nanofiltration membrane with a predetermined pore structure; the nanofiltration membrane is dried and coiled, and movement of the carrier membrane is achieved through traction of a nanofiltration membrane coiling mechanism. According to the preparation method and the preparation system, continuous automatic production of the nanofiltration membrane can be realized, related parameters in the production process can be automatically adjusted according to data detected in real time, the production efficiency is improved, the production cost is reduced, and the product quality consistency can be ensured.

Description

Technical Field

[0001] The invention relates to the technical field of nanofiltration membrane preparation, and specifically provides a nanofiltration membrane continuous preparation method and a preparation system. Background Art

[0002] Under the background of existing technology, the preparation of nanofiltration membranes faces many challenges. First, traditional preparation methods often rely on intermittent, manual process flows, which not only limits production efficiency, but also increases production costs. Due to the lack of continuous and automated production lines, these methods are difficult to meet the needs of large-scale industrial production; secondly, due to human factors and imprecise process control during the operation, the quality of the produced nanofiltration membranes is significantly inconsistent. This quality fluctuation problem affects the performance stability of the nanofiltration membranes and limits their wide application in water treatment, food processing, biomedicine and other fields. This makes the commercial application of nanofiltration membranes restricted by economic benefits, and there is an urgent need for a new method that can improve production efficiency, reduce costs and ensure product quality consistency.

[0003] Therefore, proposing a new nanofiltration membrane preparation method to reduce preparation costs, improve production efficiency, and ensure product quality consistency has become an urgent problem to be solved. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a continuous preparation method and system for nanofiltration membranes to solve the problems of high cost, low efficiency, and poor product quality consistency in traditional preparation methods.

[0005] In one aspect, the present invention provides a method for continuously preparing a nanofiltration membrane, comprising: uniformly coating a polymer solution on a moving carrier membrane to form a membrane layer of a set thickness, wherein the carrier membrane is a polyester film or a polyethersulfone film, and the polymer solution is polysulfone, polyimide, polyacrylate or a mixture thereof;

[0006] The membrane layer is filtered to remove the solvent, thereby forming a nanofiltration membrane with a predetermined pore structure;

[0007] The nanofiltration membrane is dried and rolled up, wherein the movement of the carrier membrane is achieved by traction of a nanofiltration membrane rolling mechanism.

[0008] Preferably, the method for continuously preparing nanofiltration membranes further comprises the step of adjusting the supply rate of the polymer solution in real time according to the target coating thickness.

[0009] Further preferably, the method for continuous preparation of nanofiltration membranes also includes the step of detecting the filtration pressure in real time and making precise adjustments.

[0010] Further preferably, the drying is multi-stage drying or progressive drying.

[0011] Further preferably, the method for continuous preparation of nanofiltration membrane also includes the step of adjusting the winding speed and tension according to the characteristics of the nanofiltration membrane.

[0012] The present invention also provides a nanofiltration membrane continuous preparation system, comprising: a coating device, a filtration device, a drying device and a winding device arranged in sequence;

[0013] The coating device is used to evenly coat the polymer solution on the moving carrier film to form a film layer of a set thickness, wherein the carrier film is a polyester film or a polyethersulfone film, and the polymer solution is polysulfone, polyimide, polyacrylate or a mixture thereof;

[0014] The suction filtration device is used to filter the membrane layer to remove the solvent and form a nanofiltration membrane with a predetermined pore structure;

[0015] The drying device and the winding device are used for drying and winding the nanofiltration membrane respectively, wherein the movement of the carrier membrane is achieved by traction of the nanofiltration membrane winding mechanism.

[0016] Preferably, the coating device is a coating machine, and the coating machine is connected to a polymer solution supply system, and the polymer solution supply system adjusts the supply speed of the polymer solution in real time according to the target coating thickness.

[0017] Further preferably, the filtration device comprises a filtration pressure detection unit and a filtration pressure adjustment unit, and the filtration pressure adjustment unit is used for accurately adjusting the filtration pressure according to the filtration pressure detected by the filtration pressure detection unit.

[0018] Further preferably, the drying device comprises a plurality of independent drying units, each of which has a temperature and humidity regulating unit for adjusting the drying temperature and humidity.

[0019] Further preferably, the winding device comprises a tension detection unit and a winding speed adjustment unit, the tension detection unit is used to detect the tension of the nanofiltration membrane, and the winding speed adjustment unit is used to adjust the winding speed according to the tension.

[0020] The continuous preparation method and system of nanofiltration membrane provided by the present invention can realize the continuous preparation of nanofiltration membrane. First, a polymer solution is coated on a carrier membrane to form a membrane layer of a set thickness. Then, suction filtration is performed to form a nanofiltration membrane with a predetermined pore structure. Then, drying and winding are performed in sequence to obtain the prepared nanofiltration membrane. The preparation method can realize the continuous automated production of nanofiltration membrane. The relevant parameters in the production process can be automatically adjusted according to the real-time detection data, thereby improving the production efficiency, reducing the production cost, and ensuring the consistency of product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments:

[0022] Figure 1 A flow chart of the method for continuous preparation of nanofiltration membrane provided by the present invention;

[0023] Figure 2 This is a structural block diagram of the nanofiltration membrane continuous preparation system provided by the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further explained below in conjunction with specific implementation schemes, but the present invention is not limited thereto.

[0025] like Figure 1 As shown, the present invention provides a method for continuously preparing a nanofiltration membrane, comprising:

[0026] S1: uniformly coating a polymer solution on a moving carrier film to form a film layer of a set thickness, wherein the carrier film is a polyester film or a polyethersulfone film, and the polymer solution is polysulfone, polyimide, polyacrylate or a mixture thereof;

[0027] S2: filtering the membrane layer to remove the solvent, thereby forming a nanofiltration membrane with a predetermined pore structure;

[0028] S3: drying and rolling up the nanofiltration membrane, wherein the movement of the carrier membrane is achieved by traction of a nanofiltration membrane rolling mechanism.

[0029] The continuous preparation method of nanofiltration membrane can realize the continuous preparation of nanofiltration membrane. First, a polymer solution is coated on a carrier membrane to form a membrane layer of a set thickness. Then, suction filtration is performed to form a nanofiltration membrane with a predetermined pore structure. Then, drying and winding are performed in sequence to obtain a prepared nanofiltration membrane. The preparation method can realize the continuous automated production of nanofiltration membranes. The relevant parameters in the production process can be automatically adjusted according to the real-time detection data, thereby improving production efficiency, reducing production costs, and ensuring product quality consistency.

[0030] As an improvement of the technical solution, the continuous preparation method of the nanofiltration membrane also includes a step of adjusting the supply speed of the polymer solution in real time according to the target coating thickness. In order to achieve the target coating thickness, the coating thickness needs to be detected in real time. The coating thickness can be monitored in real time using a high-precision displacement sensor or a laser rangefinder. The target coating thickness is set at 0.1 to 2 mm.

[0031] As an improvement of the technical solution, the continuous preparation method of nanofiltration membrane also includes the steps of real-time detection of the filtration pressure and precise adjustment. By precisely controlling the filtration pressure, the consistency of the pore structure (size, distribution) formed by the nanofiltration membrane can be ensured, wherein the adjustable range of the filtration pressure is between 0.1 and 5 bars.

[0032] As an improvement of the technical solution, the drying is multi-stage drying or progressive drying, and the drying temperature range is set at 40 to 120 degrees Celsius to optimize the drying effect and prevent damage to the nanofiltration membrane. At the same time, the drying humidity is controlled between 30% and 90% RH, which can effectively remove residual solvents and moisture in the nanofiltration membrane. Drying can adopt multiple drying units. When passing through each drying unit, the nanofiltration membrane undergoes a gradual heating process from mild to strong, and at the same time, through a gradually lowering humidity environment to optimize the removal efficiency of solvents and moisture.

[0033] As an improvement of the technical solution, the continuous preparation method of the nanofiltration membrane also includes the step of adjusting the winding speed and tension according to the characteristics of the nanofiltration membrane. The winding speed and tension are adjusted according to the characteristics of the nanofiltration membrane (such as thickness and elasticity), the winding speed can be adjusted in the range of 0.1 to 5 m / min, and the tension can be adjusted in the range of 5 to 50 N. The above range can ensure that the nanofiltration membrane will not be deformed or damaged during the winding process.

[0034] like Figure 2 As shown, the present invention also provides a nanofiltration membrane continuous preparation system, comprising: a coating device, a filtration device, a drying device and a winding device arranged in sequence;

[0035] The coating device is used to evenly coat the polymer solution on the moving carrier film to form a film layer of a set thickness, wherein the carrier film is a polyester film or a polyethersulfone film, and the polymer solution is polysulfone, polyimide, polyacrylate or a mixture thereof;

[0036] The suction filtration device is used to filter the membrane layer to remove the solvent and form a nanofiltration membrane with a predetermined pore structure;

[0037] The drying device and the winding device are used for drying and winding the nanofiltration membrane respectively, wherein the movement of the carrier membrane is achieved by traction of the nanofiltration membrane winding mechanism.

[0038] The nanofiltration membrane continuous preparation system can realize the continuous preparation of nanofiltration membranes. The polymer solution can be evenly coated on the carrier membrane through the coating device to form a membrane layer of a set thickness. The nanofiltration membrane with a predetermined pore structure can be formed through the suction filtration device. The nanofiltration membrane can be dried and rolled up through the drying device and the winding device to finally obtain the prepared nanofiltration membrane. The preparation system can realize the continuous and automated production of nanofiltration membranes. The relevant parameters in the production process can be automatically adjusted according to the real-time detection data, which improves the production efficiency, reduces the production cost, and ensures the consistency of product quality.

[0039] As an improvement of the technical solution, the coating device is a coating machine, which is connected to a polymer solution supply system, and the polymer solution supply system adjusts the supply speed of the polymer solution in real time according to the target coating thickness. In order to achieve the target coating thickness, the coating thickness needs to be detected in real time. The coating thickness can be monitored in real time using a high-precision displacement sensor or a laser rangefinder, and the target coating thickness is set at 0.1 to 2 mm.

[0040] As an improvement of the technical solution, the filtration device includes a filtration pressure detection unit and a filtration pressure regulating unit, and the filtration pressure regulating unit is used to accurately adjust the filtration pressure according to the filtration pressure detected by the filtration pressure detection unit, wherein the consistency of the pore structure (size, distribution) formed by the nanofiltration membrane can be ensured by accurately controlling the filtration pressure, and the adjustable range of the filtration pressure is between 0.1 and 5 bars.

[0041] As an improvement of the technical solution, the drying device includes a plurality of independent drying units, each of which has a temperature and humidity adjustment unit for adjusting the drying temperature and humidity. When the nanofiltration membrane passes through each drying unit, it undergoes a gradual temperature increase process from mild to strong, and at the same time, it passes through a gradually reduced humidity environment to optimize the removal efficiency of solvents and water. Preferably, the drying temperature range is set at 40 to 120 degrees Celsius to optimize the drying effect and prevent damage to the nanofiltration membrane. At the same time, the drying humidity is controlled between 30% and 90% RH, which can effectively remove residual solvents and water in the nanofiltration membrane.

[0042] As an improvement of the technical solution, the winding device includes a tension detection unit and a winding speed adjustment unit, wherein the tension detection unit is used to detect the tension of the nanofiltration membrane, and the winding speed adjustment unit is used to adjust the winding speed according to the tension to achieve the set tension and winding speed. The winding speed and tension are adjusted according to the characteristics of the nanofiltration membrane (such as thickness and elasticity). Preferably, the winding speed is adjustable in the range of 0.1 to 5 m / min, and the tension is adjustable in the range of 5 to 50 N. The above range can ensure that the nanofiltration membrane will not be deformed or damaged during the winding process.

[0043] The embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for continuous preparation of nanofiltration membrane, characterized in that: include: Uniformly coating a polymer solution on a moving carrier film to form a film layer of a set thickness, wherein the carrier film is a polyester film or a polyethersulfone film, and the polymer solution is polysulfone, polyimide, polyacrylate or a mixture thereof; The membrane layer is filtered to remove the solvent, thereby forming a nanofiltration membrane with a predetermined pore structure; The nanofiltration membrane is dried and rolled up, wherein the movement of the carrier membrane is achieved by traction of a nanofiltration membrane rolling mechanism.

2. The method for continuous preparation of nanofiltration membrane according to claim 1, characterized in that: The method further includes adjusting the supply speed of the polymer solution in real time according to the target coating thickness.

3. The method for continuous preparation of nanofiltration membrane according to claim 1, characterized in that: The method also includes the steps of detecting the filtration pressure in real time and making precise adjustments.

4. The method for continuous preparation of nanofiltration membrane according to claim 1, characterized in that: The drying is multi-stage drying or progressive drying.

5. The method for continuous preparation of nanofiltration membrane according to claim 1, characterized in that: The method also includes the step of adjusting the winding speed and tension according to the characteristics of the nanofiltration membrane.

6. A nanofiltration membrane continuous preparation system, characterized in that: include: The coating device, filtration device, drying device and winding device are arranged in sequence; The coating device is used to evenly coat the polymer solution on the moving carrier film to form a film layer of a set thickness, wherein the carrier film is a polyester film or a polyethersulfone film, and the polymer solution is polysulfone, polyimide, polyacrylate or a mixture thereof; The suction filtration device is used to filter the membrane layer to remove the solvent and form a nanofiltration membrane with a predetermined pore structure; The drying device and the winding device are used for drying and winding the nanofiltration membrane respectively, wherein the movement of the carrier membrane is achieved by traction of the nanofiltration membrane winding mechanism.

7. The nanofiltration membrane continuous preparation system according to claim 6, characterized in that: The coating device is a coating machine, and the coating machine is connected to a polymer solution supply system. The polymer solution supply system adjusts the supply speed of the polymer solution in real time according to a target coating thickness.

8. The nanofiltration membrane continuous preparation system according to claim 6, characterized in that: The suction filtration device comprises a suction filtration pressure detection unit and a suction filtration pressure adjustment unit, and the suction filtration pressure adjustment unit is used to accurately adjust the suction filtration pressure according to the suction filtration pressure detected by the suction filtration pressure detection unit.

9. The nanofiltration membrane continuous preparation system according to claim 6, characterized in that: The drying device comprises a plurality of independent drying units, each of which has a temperature and humidity regulating unit for adjusting the drying temperature and humidity.

10. The nanofiltration membrane continuous preparation system according to claim 6, characterized in that: The winding device comprises a tension detection unit and a winding speed adjustment unit, wherein the tension detection unit is used to detect the tension of the nanofiltration membrane, and the winding speed adjustment unit is used to adjust the winding speed according to the tension.

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