Tubular membrane repairing system and repairing method and application thereof

Abstract

The invention belongs to the technical field of tubular membrane repairing, and particularly relates to a tubular membrane repairing system and a repairing method and application thereof. The tubular membrane repairing system comprises a gas source unit, a repairing unit, an auxiliary unit and a tail gas treatment unit, the gas source unit, the auxiliary unit and the tail gas treatment unit are respectively connected with the repairing unit. The system is simple in structure and low in cost. The integrity and the separation characteristic of the tubular membrane repaired by adopting the system are remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of tubular membrane repair, and in particular relates to a tubular membrane repair system and a repair method and application thereof. Background Art

[0002] Tubular membrane is a special membrane separation material with a porous tubular structure and high specific surface area and permeability. Tubular membrane is widely used in water treatment, drinking water purification, sewage treatment, desalination, concentration, pigment separation and other fields. The size of the hollow tubular membrane can vary according to the specific application requirements. The outer diameter of the tubular membrane is usually between a few microns and tens of microns, and the inner diameter is between hundreds of nanometers and a few microns. The membrane wall thickness is usually between tens of nanometers and hundreds of nanometers.

[0003] During the preparation and use of tubular membranes, defects will always occur due to factors such as preparation process, material failure, processing damage and use environment. These defects have low selectivity for the separation phase, reducing the separation efficiency of the tubular membrane. In addition, the diameter of the tubular membrane is small, and these defects will lead to uneven structure, which in turn makes the mechanical properties of the membrane vary greatly, and it is easy to rupture or fail. In addition, the tubular membrane with uneven structure will also lead to unstable permeability and separation effect of the membrane, affecting the use effect. In this regard, the method of repairing the tubular membrane is adopted to repair these defects, so as to improve the permeability and separation effect of the tubular membrane.

[0004] The traditional method of repairing tubular membranes is to use chemicals to repair the damaged parts. For example, specific solvents or adhesives can be used to fill or connect the damaged areas. However, the traditional repair method requires specific repair materials and conditions, and the operation is complicated and requires high operator skills. The repaired tubular membrane often cannot be completely restored to its original state, which may cause the separation performance to decline or become unstable. The repair of tubular membranes requires professional technology and equipment support, which requires high operator skills and cannot be widely used. Summary of the invention

[0005] To solve the above problems, the present invention proposes a tubular membrane repair system and a repair method and application thereof, wherein the system has a simple structure and low cost, and the integrity and separation characteristics of the tubular membrane repaired by the system are significantly improved.

[0006] One of the purposes of the present invention is to provide a tubular membrane repair system, comprising:

[0007] Gas source unit, repair unit, auxiliary unit and tail gas treatment unit;

[0008] The gas source unit, the auxiliary unit and the tail gas treatment unit are respectively connected to the repair unit;

[0009] The repair unit comprises a shell and a porous disk; the porous disk comprises a first porous disk and a second porous disk; the first porous disk and the second porous disk are respectively arranged at two ends of the shell;

[0010] One end of the shell is set as an air outlet end, and the other end is set as an air inlet end. The side wall of the shell is provided with a first air port and a second air port.

[0011] The present invention provides a tubular membrane repair system, wherein the gas source unit provides the repair unit with gas and inert cleaning gas required for repairing the tubular membrane; the repair unit provides a place for repairing the tubular membrane, wherein the first porous disk and the second porous disk support the tubular membrane; the auxiliary unit assists the repair unit in repairing the tubular membrane. The system has a simple structure and low cost.

[0012] In some possible implementations, the gas source unit includes a repair gas source and an inert cleaning gas source;

[0013] The repair gas source is connected to the gas inlet end, the inert cleaning gas source is connected to the first gas port, and the tail gas treatment unit is connected to the second gas port and the gas outlet end respectively.

[0014] In some other possible implementations, the gas source unit includes a repair gas source and an inert cleaning gas source;

[0015] The inert cleaning gas source is connected to the gas inlet end, the repair gas source is connected to the first gas port, and the tail gas treatment unit is connected to the second gas port and the gas outlet end respectively.

[0016] The second object of the present invention is to provide a method for repairing a tubular membrane using the tubular membrane repair system provided by the present invention, comprising the following steps:

[0017] S1. Pre-repair: Under the premise of introducing an inert cleaning gas into the repair unit, introduce a first gas treatment into the repair unit containing the tubular membrane to be repaired and then introduce a second gas treatment;

[0018] In the first gas treatment / second gas treatment step, the first gas / second gas is introduced into the membrane surface of the tubular membrane to be repaired, and the inert cleaning gas is introduced into the carrier surface of the tubular membrane to be repaired to remove the residual first gas / residual second gas that has seeped out of the carrier surface of the tubular membrane to be repaired;

[0019] When the content of the first retentate gas is less than 50 ppm and maintains a dynamic equilibrium, the second gas is introduced; when the content of the second retentate gas is less than 50 ppm and maintains a dynamic equilibrium, a pre-repaired tubular membrane is obtained;

[0020] The first gas includes SO 2 and NO2 The second gas comprises a mixture of water vapor and clean air.

[0021] S2. Strengthening and calcining the pre-repaired tubular membrane to obtain a repaired tubular membrane.

[0022] The present invention provides a method for repairing a tubular membrane. The first gas passes through the surface of the tubular membrane and penetrates into the repair point of the membrane layer. 2 and NO 2 Stable sulfur-nitrogen compounds are synthesized at the repair point; the second gas passes through the tubular membrane surface and reacts with the sulfur-nitrogen compounds to form a more stable reaction complex; the excess SO in the tubular membrane is removed in an enhanced manner 2 and NO 2 , high-temperature calcination causes the reaction complex to undergo a bonding reaction with the groups of the tubular membrane itself, and the reaction complex that has not undergone a repair reaction is removed by calcination, so that the chemical bonds at the defects of the tubular membrane are connected and repaired as complete as before, and the repair is more stable. The overall structure of the repaired tubular membrane is more stable, the heat resistance and corrosion resistance of the tubular membrane are higher, the ability to resist airflow impact is stronger, and the service life of the tubular membrane is improved. In short, the method of the embodiment of the present invention is a non-destructive repair with simple steps, easy implementation, and low cost. It is conducive to the large-scale application of tubular membranes and has high practical value.

[0023] In some possible implementations, in the first gas, SO 2 and NO 2 The volume ratio is (0.1~10):1.

[0024] In some possible implementations, during the first gas processing, the pressure difference between the two sides of the tubular membrane is 0.05 MPa to 5 MPa.

[0025] In some possible implementations, the first gas is treated with the tubular membrane for 3 hours to 24 hours.

[0026] In some possible implementations, during the second gas treatment, the pressure difference between the two sides of the membrane is 0.01 MPa to 5 MPa.

[0027] In some possible implementations, the high temperature calcination step includes: heating to 350°C to 700°C at a heating rate of 0.1°C / min to 5°C / min, and calcining at 350°C to 700°C for 6h to 60h;

[0028] After calcination, the temperature is lowered to 20°C to 25°C at a cooling rate of 0.1°C / min to 5°C / min.

[0029] The third object of the present invention is to provide an application of the tubular membrane repair system provided by the present invention in the field of tubular membrane repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1a It is a schematic diagram of the structure of a tubular membrane system in an embodiment of the present invention;

[0031] Figure 1b It is a schematic diagram of the cross-sectional structure of the repair unit after being equipped with a tubular membrane in an embodiment of the present invention;

[0032] Figure 1c It is a schematic diagram of the longitudinal cross-section structure of the repair unit after being equipped with a tubular membrane in an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the structure of the tubular membrane repair system in Example 1 of the present invention;

[0034] Figure 3 This is a schematic diagram of the structure of the tubular membrane repair system in Example 2 of the present invention.

[0035] Description of reference numerals: 1-gas source unit: 100-sulfur dioxide gas source, 101-nitrogen dioxide gas source, 102-water vapor gas source, 11-inert cleaning gas source;

[0036] 2- Patching Unit:

[0037] 20-shell, 200-air outlet, 201-air inlet, 202-first air port, 203-second air port;

[0038] 210-first porous disk, 211-second porous disk;

[0039] 3- auxiliary unit, 301- gas analyzer, 302- flow meter;

[0040] 4- tail gas treatment unit;

[0041] 5- Tubular membrane. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the embodiment of this application will be described in more detail below in conjunction with the drawings in the embodiment of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of this application, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain this application, and should not be construed as limitations on this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of this application are described in detail below in conjunction with the drawings.

[0043] The term "tubular membrane" means that the tubular membrane is mainly composed of two parts: the membrane shell and the membrane tube. The core components are composed of a supporting carrier layer and a membrane filtration layer. The shape is mainly circular or quasi-circular. Common diameters of tubular membranes include 4mm, 6mm, 8mm, 10mm, 12mm, 24mm and other models.

[0044] Tubular membrane is a membrane separation device composed of multiple tubular membrane units. Its main feature is that the membrane material is made into a tubular form to form a pipeline structure with a certain length. Each tubular membrane element usually has a hollow channel inside, and the liquid or gas passes through the membrane surface for separation. The structure of the tubular membrane can be divided into two parts: the membrane layer and the tubular carrier. The membrane layer is the core part of the tubular membrane, usually a thin film material (such as polymer, ceramic or stainless steel, etc.), which has selective permeability and is used to achieve the separation of substances. The membrane layer generally has a microporous structure that allows specific molecules or ions to pass through and blocks other substances. The membrane layer is usually wrapped or covered in a layer of tubular carrier. The function of the carrier is to provide support, ensure the shape of the membrane and allow the fluid to flow in the tube.

[0045]

Tubular membrane repair system

[0046] One of the purposes of the embodiments of the present invention is to provide a tubular membrane repair system, such as Figure 1a As shown, including:

[0047] Gas source unit 1, repair unit 2, auxiliary unit 3 and tail gas treatment unit 4;

[0048] The gas source unit 1, the auxiliary unit 3 and the tail gas treatment unit 4 are respectively connected to the repair unit 2;

[0049] The repair unit 2 includes a housing 20 and a porous disk 21; Figure 1b and Figure 1c As shown, the porous disk includes a first porous disk 210 and a second porous disk 211; the first porous disk 210 and the second porous disk 211 are respectively arranged at two ends inside the housing 20;

[0050] One end of the shell 20 is set as an air outlet end 200, and the other end is an air inlet end 201. The side wall of the shell 20 is provided with a first air port 202 and a second air port 203.

[0051] In the tubular membrane repair system provided by the embodiment of the present invention, the gas source unit 1 provides the gas required for repairing the tubular membrane to the repair unit 2; the repair unit 2 provides a place for repairing the tubular membrane, wherein the first porous disk 210 and the second porous disk 211 receive the tubular membrane; the auxiliary unit 3 assists the repair unit 2 in cleaning and repairing the tubular membrane. The system has a simple structure and low cost.

[0052] In some embodiments, the holes on the first porous disk 210 and the second porous disk 211 are symmetrically arranged. In this case, the tubular membrane can be stably supported between the first porous disk 210 and the second porous disk 211.

[0053] In some embodiments, the gas source unit 1 includes a repair gas source and an inert cleaning gas source 11;

[0054] The repair gas source is connected to the gas inlet 201, the inert cleaning gas source 11 is connected to the first gas port 202, and the tail gas treatment unit 4 is connected to the second gas port 203 and the gas outlet 200 respectively. In this case, the system is used to repair a tubular membrane with an inner layer of a membrane layer and an outer layer of a carrier layer (i.e., the membrane layer is located on the inner wall of the tubular membrane). The repair gas (SO 2 、NO 2 and water vapor) enters the hollow part of the tubular membrane from the air inlet end 201, penetrates into and fills the defects of the membrane layer, passes through the carrier layer of the tubular membrane, and is discharged from the second gas port 203 by the inert cleaning gas, and enters the exhaust gas treatment unit 4. When the repair is completed, the repair gas can no longer seep out of the carrier layer of the tubular membrane and can only return by the original route; therefore, when the repair gas content in the inert cleaning gas is below 50ppm and maintains dynamic equilibrium, it means that the repair is completed.

[0055] In other embodiments, the gas source unit 1 includes a repair gas source and an inert cleaning gas source 11;

[0056] The inert cleaning gas source 11 is connected to the gas inlet 201, the repair gas source is connected to the first gas port 202, and the tail gas treatment unit 4 is connected to the gas outlet 200. In this case, the system is used to repair a tubular membrane with a film layer as the outer layer and a carrier layer as the inner layer (i.e., the film layer is located on the outer wall of the tubular membrane). The repair gas provided by the gas source unit enters the shell 20 from the first gas port 202, and passes through the hollow part of the membrane layer--carrier layer--tubular membrane, and is carried by the inert cleaning gas and discharged from the gas outlet 200 to enter the tail gas treatment unit 4. When the repair is completed, the repair gas can no longer penetrate into the hollow part from the carrier layer of the tubular membrane and can only return along the original route; therefore, when the repair gas content in the inert cleaning gas is below 50ppm and maintains a dynamic balance, it means that the repair is completed.

[0057] In some embodiments, the repair gas source includes a sulfur dioxide source 100, a nitrogen dioxide source 101, and a water vapor source 102. In this case, sulfur dioxide, nitrogen dioxide, and water vapor work together to repair defects of the tubular membrane.

[0058] In some embodiments, the inert cleaning gas source 11 is a nitrogen gas source 110 or an argon gas source.

[0059] In some embodiments, the auxiliary unit 3 includes: at least one of a gas heater, an ultrasonic generator, a microwave transmitter, a sensor, a gas analyzer 301, and a flow meter 302. In this case, the auxiliary unit 3 can provide heat, ultrasonic and other functions for the shell, so that the system can clean the tubular membrane before repairing, eliminating the need for additional manual cleaning steps. It should be noted that the gas heater, ultrasonic generator, microwave generator, sensor, gas analyzer, and flow meter in the auxiliary unit are all existing instruments and do not need to be specifically limited in this application. However, as an example, the sensor may include: at least one of a temperature sensor, a pH sensor, a pressure sensor, a humidity sensor, a flow sensor, and a concentration sensor. The sensor can detect data such as temperature, humidity, pH value, pressure, gas flow, gas concentration, etc. when cleaning or repairing the tubular membrane to determine the end point of cleaning or repairing.

[0060] In some embodiments, the tail gas treatment unit 4 includes but is not limited to at least one of solid adsorption (fixed adsorption bed, mobile adsorption bed, fluidized adsorption bed, etc.), liquid absorption (lime water adsorption tower, NaOH solution), catalytic reduction (SCR, SNCR, etc.), and biological method (biological desulfurization, etc.) to treat excess SO in the adsorption repair unit. 2 and NO 2 .

[0061] [A method for repairing tubular membrane]

[0062] A second object of the embodiment of the present invention is to provide a method for repairing a tubular membrane using the tubular membrane repair system provided by the embodiment of the present invention, comprising the following steps:

[0063] S1. Pre-repair: Under the premise of introducing an inert cleaning gas into the repair unit, introduce a first gas treatment into the repair unit containing the tubular membrane to be repaired and then introduce a second gas treatment;

[0064] In the first gas treatment / second gas treatment step, the first gas / second gas is introduced into the membrane surface of the tubular membrane to be repaired, and the inert cleaning gas is introduced into the carrier surface of the tubular membrane to be repaired to remove the seepage gas to be repaired.

[0065] The retentate first gas / retentate second gas on the surface of the tube-filling membrane carrier;

[0066] When the content of the first retentate gas is less than 50 ppm and maintains a dynamic equilibrium, the second gas is introduced; when the content of the second retentate gas is less than 50 ppm and maintains a dynamic equilibrium, a pre-repaired tubular membrane is obtained;

[0067] The first gas includes SO 2 and NO 2 The second gas comprises a mixture of water vapor and clean air.

[0068] S2. Strengthening and calcining the pre-repaired tubular membrane to obtain a repaired tubular membrane.

[0069] The tubular membrane repair method provided by the embodiment of the present invention comprises the following steps: a first gas passes through the tubular membrane surface and penetrates into the membrane layer repair point, wherein the SO 2 and NO 2 Stable sulfur-nitrogen compounds are synthesized at the repair point; the second gas passes through the tubular membrane surface and reacts with the sulfur-nitrogen compounds to form a more stable reaction complex; strengthening to consolidate and stabilize the reaction complex while removing excess SO from the tubular membrane surface 2 and NO 2 , high-temperature calcination causes the reaction complex to undergo a bonding reaction with the groups at the defects of the tubular membrane itself, and the unreacted complex and adsorbed gas are removed by calcination, so that the chemical bonds at the defects of the tubular membrane are connected and repaired as complete as before, and the repair is more stable. The overall structure of the repaired tubular membrane is more stable, the heat resistance and corrosion resistance of the tubular membrane are higher, the ability to resist airflow impact is stronger, and the service life of the tubular membrane is improved. In short, the method of the embodiment of the present invention is a non-destructive repair with simple steps, easy implementation, and low cost. It is conducive to the large-scale use of tubular membranes and has high practical value. It should be noted that the content of the residual first gas / residual second gas is detected by the auxiliary unit collecting the gas from the exhaust gas treatment unit, and the detection method is a conventional technology in the field, such as a flue gas analyzer, a dew point meter, a hygrometer, NO x Analyzer, SO 2 Analyzers, etc., are not particularly limited in the embodiments of the present application.

[0070] The reaction complex refers to a complex formed by the coordination of electron pairs of sulfur dioxide molecules, nitrogen dioxide molecules and water molecules at membrane defects.

[0071] The defects of tubular membranes refer to the pinholes, cracks and crystal boundaries formed on the membrane layer during the synthesis and use of the membrane.

[0072] Clean air refers to air that does not contain moisture (or the moisture is negligible), dust or other solid particles.

[0073] In some embodiments, in the above step S1, SO 2 and NO 2 The volume ratio of SO is (0.1-10):1, which can be 0.1:1, 0.5:1, 1:1, 2:1, 3:1, 7:1, 10:1, etc., which are typical but non-limiting volume ratios, or a range between any two volume ratios. In this case, SO 2 and NO 2 Hydrogen bonds form stable sulfur-nitrogen compounds in the membrane layers of the tubular membrane.

[0074] In some embodiments, in the above step S1, an air source unit is used, and other external air sources may also be used.

[0075] In some embodiments, in the above step S1, before the first gas is introduced, the tubular membrane to be repaired is first cleaned, including the steps of water washing, ultrasonic cleaning and drying. In this case, water washing removes suspended matter on the membrane surface, ultrasonic cleaning removes microscopic impurities on the membrane surface, and drying removes crystal water in the membrane that affects the repair effect.

[0076] In some specific embodiments, the water washing time is 5 minutes to 10 minutes. In the exemplary examples, it can be a typical but non-limiting time such as 5 minutes, 8 minutes, 10 minutes, or a range between any two times.

[0077] In some specific embodiments, the ultrasonic cleaning time is 10s to 100s. In the exemplary examples, it can be 10s, 30s, 50s, 80s, 100s, etc., which are typical but non-limiting times, or a range between any two times.

[0078] In some specific embodiments, the drying temperature is 100° C. to 200° C. In exemplary embodiments, it can be a typical but non-limiting temperature such as 100° C., 150° C., 200° C., or a range between any two temperatures.

[0079] In some specific embodiments, the drying time is more than 6 hours.

[0080] In some specific embodiments, a tubular membrane is cleaned using a tubular membrane repair system, the steps comprising:

[0081] Step 1: Water enters the repair unit (depending on the position of the membrane surface) from the air inlet or the first air port (second air port), flushes the tubular membrane surface for 5 to 10 minutes, and is discharged from the air outlet or the second air port (first air port).

[0082] Step 2: Submerge the surface of the tubular membrane in water and use the ultrasonic generator in the auxiliary unit to clean the tubular membrane for 10s to 100s.

[0083] Step 3, using the gas heater in the auxiliary unit to heat the nitrogen or air provided in the gas source unit to 100°C to 200°C, and the heated nitrogen or air enters the repair unit to take away the crystal water on the membrane surface to dry the tubular membrane.

[0084] In the embodiment of the present application, the temperature, humidity, pressure, etc. in the repair unit are detected by the auxiliary unit, and the connection between the auxiliary unit and the repair unit is a common method in the art, and is not specifically described in the embodiment of the present application. For example, the temperature is measured by thermocouples, thermal resistors, etc.; the pressure is measured by pressure gauges and pressure sensors, etc.; the humidity is measured by dew point meters and hygrometers, etc.

[0085] In some embodiments, during the first gas treatment in step S1, the pressure difference between the two sides of the tubular membrane is 0.05 MPa to 5 MPa. In the exemplary embodiment, the pressure difference may be 0.05 MPa, 0.1 MPa, 1 MPa, 3 MPa, 5 MPa, etc., which are typical but non-limiting pressure differences, or a range between any two pressure differences. In this case, the first gas can reach the defect (repair point) of the tubular membrane and form a repair point of sulfur-nitrogen compounds without deforming the tubular membrane.

[0086] The two sides of the film refer to the part of the film attached to the carrier that contacts the carrier as one side and the other side of the film away from the side.

[0087] In some embodiments, in the above step S1, the time for the first gas to treat the tubular membrane is 3 hours to 24 hours. In the exemplary embodiment, it can be 3 hours, 8 hours, 12 hours, 16 hours, 24 hours, etc., which are typical but not limiting times, or a range between any two times. In some embodiments, the flow rate of the first gas is 1 mL / (cm 2 ·min)~40mL / (cm 2 ·min), in the example, it can be 1mL / (cm 2 ·min)、2mL / (cm 2 ·min)、3mL / (cm 2 ·min)、5mL / (cm 2 ·min)、10mL / (cm 2 ·min)、20mL / (cm 2 ·min)、40mL / (cm 2 min) or a range between any two flow rates.

[0088] Flow rate unit mL / (cm 2 ·min), refers to every cm 2 The volume of gas required per minute on the membrane surface.

[0089] In some embodiments, when the second gas is processed, the pressure difference between the two sides of the membrane is 0.01 MPa to 5 MPa. In the exemplary embodiment, it can be 0.01 MPa, 0.1 MPa, 5 MPa1 MPa, 3 MPa, 5 MPa, etc., which are typical but non-limiting pressure differences or a range between any two pressure differences. In this case, the second gas reaches the repair point and reacts with the sulfur-nitrogen compound at the repair point to form a reaction complex without deforming the tubular membrane.

[0090] In some embodiments, the flow rate of the second gas is 1 mL / (cm 2 ·min)~40mL / (cm 2 ·min), in the example, it can be 1mL / (cm 2 ·min)、2mL / (cm 2 ·min)、3mL / (cm 2 ·min)、5mL / (cm 2 ·min)、10mL / (cm 2 ·min)、20mL / (cm 2 ·min)、40mL / (cm 2 min) or a range between any two flow rates.

[0091] In some embodiments, the relative humidity of water vapor in the second gas is 1% to 100%. In this case, sufficient water vapor molecules can enter the defects to react.

[0092] In some embodiments, the temperature of the second gas is -10° C. to 40° C. In this case, the repair precursor can be generated more stably and exist in the defects of the tubular film.

[0093] In some embodiments, the second gas treatment time is more than 6 hours. In this case, the water vapor in the second gas can fully react with the compounds in all the repair points to stabilize the repair points.

[0094] In some embodiments, the structure of the tubular membrane to be repaired is that the inner layer is a carrier layer and the outer layer is a membrane layer, or the inner layer is a membrane layer and the outer layer is a carrier layer.

[0095] In some embodiments, the tubular membrane to be repaired includes a hollow fiber membrane, and the material of the membrane in the hollow fiber membrane includes at least one of a zeolite molecular sieve membrane, a metal organic framework membrane, a covalent organic framework membrane, a mixed matrix membrane, a polymer membrane, and a carbon membrane. It should be noted that the material of the membrane is a commonly used material in the art and is not particularly limited in this application, but as an example, the inorganic molecular sieve membrane may be SSZ-13, ZSM-5, SAPO-34, NaA, etc., the polymer membrane may be polyethersulfone (PES), polyimide (PI), polyetheretherketone (PEEK), polypropylene (PP), etc., the carbon membrane may be an amorphous carbon membrane, a porous carbon membrane, a carbon nanotube (CNT) membrane, a carbon fiber membrane, etc., and the covalent organic framework membrane may be TpPa-1, COF-5, COK-69, COF-NH 2 , COF-10, etc. The mixed matrix membrane can be MOF / polyimide membrane, carbon nanotube (CNT) / polymer membrane, aluminum oxide (Al 2 O 3 ) / polymer membrane, silicon-based / polymer membrane, etc. The material of the carrier is also conventional in the art and is not particularly limited in this application, but as an example, the material of the carrier in the hollow fiber membrane can be ceramic, metal carrier, polymer carrier, carbon material carrier and porous glass carrier, etc.

[0096] In some embodiments, in the above step S2, the strengthening step includes: flushing the membrane surface of the tubular membrane with water at a flow rate of 0.02 m / s to 3 m / s until the pH value of the water is above 6.5. In this case, while strengthening and stabilizing the reaction complex at the defect, the residual attached compounds on the membrane surface are removed.

[0097] In some embodiments, during the strengthening step, the temperature of the water is between 1°C and 30°C.

[0098] In some embodiments, in the strengthening step, when the inner wall of the tubular membrane is the membrane surface, water enters the repair unit from the air inlet end for flushing;

[0099] When the outer wall of the tubular membrane is the membrane surface, water enters the repair unit from the first air port for flushing.

[0100] In some embodiments, in the above step S2, the high temperature calcination step comprises: heating the strengthened tubular membrane to 350°C to 700°C at a heating rate of 0.1°C / min to 5°C / min, and calcining at 350°C to 700°C for 6h to 60h;

[0101] After calcination, the temperature is lowered to 20°C to 25°C (normal temperature) at a cooling rate of 0.1°C / min to 5°C / min.

[0102] In the above-mentioned high-temperature calcination step, heating to 350°C to 700°C at a heating rate of 0.1°C / min to 5°C / min and then calcining for 6h to 60h can allow the reaction complex of the tubular membrane to react and bond with the groups at the defective boundaries of the tubular membrane, so that the chemical bonds at the defects of the tubular membrane are connected and repaired as complete as before, and the repair is more stable.

[0103] In some embodiments, in the above step S2, an auxiliary unit is used to directly perform the strengthening step and the calcining step in the repairing unit.

[0104] In some specific embodiments, a method for repairing a tubular membrane by a tubular membrane repair system is provided, the steps of which are as follows:

[0105] S10. Select a tubular membrane structure to be repaired whose inner layer is a carrier layer and the outer layer is a membrane layer.

[0106] S20. Install the tubular membrane to be repaired between the first porous disk and the second porous disk.

[0107] S30. Cleaning the tubular membrane to be repaired, including the steps of water washing, ultrasonic cleaning and drying.

[0108] S40. Under the condition that the inert cleaning gas is continuously introduced into the repair unit through the gas inlet, the first gas enters the repair unit from the first gas port and is discharged from the second gas port. The first gas seeping out from the inner carrier surface is mixed with the inert cleaning gas and discharged from the gas outlet. When the residual first gas content is less than 50 ppm and maintains a dynamic balance, the second gas is introduced;

[0109] The second gas enters the repair unit from the first gas port and is discharged from the second gas port. The second gas seeping from the inner carrier surface is mixed with the inert cleaning gas and discharged from the gas outlet. When the residual second gas content is below 50 ppm and maintains dynamic equilibrium, a pre-repaired tubular membrane is obtained.

[0110] S50. Strengthening and calcining the pre-repaired tubular membrane to obtain a repaired tubular membrane.

[0111] The inner carrier surface refers to the side of the inner carrier facing away from the membrane layer.

[0112] In some specific embodiments, a method for repairing a tubular membrane by a tubular membrane repair system is provided, the steps of which are as follows:

[0113] S11. Select a tubular membrane structure to be repaired whose outer layer is a carrier layer and whose inner layer is a membrane layer.

[0114] S21. Install the tubular membrane to be repaired between the first porous disk and the second porous disk.

[0115] S31. Cleaning the tubular membrane to be repaired, including the steps of water washing, ultrasonic cleaning and drying.

[0116] S41. Under the condition that the inert cleaning gas is continuously introduced into the repair unit through the first gas port, the first gas is introduced into the repair unit from the gas inlet end and discharged from the gas outlet end, the first gas seeping out from the outer carrier surface is mixed with the inert cleaning gas and discharged from the second gas port, and when the residual first gas content is less than 50 ppm and maintains a dynamic equilibrium, the second gas is introduced;

[0117] The second gas enters the repair unit from the gas inlet end and is discharged from the gas outlet end. The second gas seeping from the outer carrier surface is mixed with the inert cleaning gas and discharged from the second gas port. When the residual second gas content is below 50 ppm and maintains dynamic equilibrium, a pre-repaired tubular membrane is obtained.

[0118] S51. Strengthening and calcining the pre-repaired tubular membrane to obtain a repaired tubular membrane.

[0119] The outer carrier surface refers to the side of the outer carrier facing away from the membrane layer.

[0120] The following is further described in conjunction with specific embodiments.

[0121] Example 1

[0122] Example 1 proposes a tubular membrane repair system, such as Figure 2 As shown, it is composed of a gas source unit, a repair unit, an auxiliary unit (gas analyzer 301, a flow detector 302, a gas flow meter MFC) and an exhaust gas treatment unit 4;

[0123] The gas source unit provides a first gas (a mixture of a sulfur dioxide gas source 100 and a nitrogen dioxide gas source 101), a second gas (a mixture of a water vapor gas source 102 and clean air), and nitrogen (an inert cleaning gas source 11);

[0124] The repair unit is composed of a housing 20, a first porous disk 210 and a second porous disk 211; the first porous disk 210 and the second porous disk 211 are respectively arranged at two ends of the housing 20;

[0125] One end of the housing 20 is set as an air outlet end 200, and the other end is an air inlet end 201;

[0126] The outer wall of the shell 20 is provided with a first air port 202 and a second air port 203, and the first air port 202 and the second air port 203 are respectively located on the outer wall of the side of the shell 20;

[0127] The repair gas source (first gas, second gas) is connected to the gas inlet end, the inert cleaning gas source 11 is connected to the first gas port 202, and the tail gas treatment unit 4 is connected to the second gas port 203 and the gas outlet end 200 respectively.

[0128] Embodiment 1 also provides a method for repairing a tubular membrane using the tubular membrane repair system provided in this embodiment, the steps are as follows:

[0129] (1) The tubular membrane structure to be repaired is selected to have an outer layer as a carrier layer and an inner layer as a membrane layer; the material of the membrane in the tubular membrane to be repaired is CHA, and the carrier material is ceramic (α-Al 2 O 3 ).

[0130] (2) Install the tubular membrane to be repaired between the first porous disk and the second porous disk.

[0131] (3) Nitrogen is continuously introduced into the repair unit through the first gas port, and the following pre-repair is performed:

[0132] ① Sulfur-nitrogen compounds: The first gas including sulfur dioxide and nitrogen dioxide is introduced into the hollow part of the tubular membrane from the gas inlet end to infiltrate and fill the defects of the membrane layer, and then discharged from the gas outlet end. A small amount of the first gas infiltrating from the outer carrier surface is mixed with nitrogen and discharged from the second gas port to enter the tail gas treatment unit; when the content of sulfur dioxide and nitrogen dioxide in the inert cleaning gas is below 50ppm and maintains a dynamic balance, it indicates that the defects are filled and the second gas is introduced; wherein, NO 2 and SO 2 The volume ratio is 1:1, and the flow rate is 10mL / (cm 2 ·min).

[0133] ② Reaction complex: The second gas is passed into the hollow part of the tubular membrane from the air inlet end to infiltrate and react with the sulfur-nitrogen compounds at the defects of the membrane layer to form a more stable reaction complex, which is discharged from the air outlet end. A small amount of the first gas that infiltrates from the outer carrier surface is mixed with nitrogen and discharged from the second gas port to enter the exhaust gas treatment unit; when the second gas content in the nitrogen is below 50 ppm and maintains a dynamic equilibrium, it indicates that the sulfur-nitrogen compounds at the defects have completely reacted to form a reaction complex, and a pre-repaired tubular membrane is obtained; the relative humidity of water vapor in the second gas is 50%.

[0134] (4) Water enters the repair unit from the air inlet end at a flow rate of 0.1 m / s to flush the membrane surface of the pre-repaired tubular membrane. The water temperature is 5°C until the pH value of the water is above 6.5.

[0135] (5) heating to 450°C at a heating rate of 0.5°C / min and calcining at 450°C for 6 h;

[0136] After calcination, the temperature was lowered to 20°C to 25°C (normal temperature) at a cooling rate of 0.5°C / min to obtain a repaired tubular membrane.

[0137] Example 2

[0138] Example 2 proposes a tubular membrane repair system, which has a structure substantially the same as that of Example 1, except that:

[0139] like Figure 3 As shown, the inert cleaning gas source 11 (nitrogen) is connected to the air inlet 201, the repair gas source (sulfur dioxide source 100, nitrogen dioxide source 101, water vapor source 102) is connected to the first air port 202, and the tail gas treatment unit 4 is connected to the second air port 203 and the air outlet 200.

[0140] Example 2 also provides a method for repairing a tubular membrane using the tubular membrane repair system provided in this embodiment. The steps are basically the same as those in Example 1, except that:

[0141] In step (1), the tubular membrane structure to be repaired is selected to have an outer layer as a membrane layer and an inner layer as a carrier layer; the material of the membrane in the tubular membrane to be repaired is CHA, and the carrier material is ceramic (α-Al 2 O 3 ).

[0142] In step (3), nitrogen is continuously introduced into the repair unit through the air inlet, and the following pre-repair is performed:

[0143] ① Sulfur-nitrogen compounds: The first gas including sulfur dioxide and nitrogen dioxide is introduced into the repair unit through the first gas port, and most of it is discharged from the second gas port. A small amount of the first gas passes through the hollow part of the membrane layer-the carrier layer-the tubular membrane, and is mixed with nitrogen and then discharged from the gas outlet and enters the tail gas treatment unit; when the content of sulfur dioxide and nitrogen dioxide in the nitrogen is below 50ppm and maintains a dynamic balance, it means that the defect is filled and the second gas is introduced.

[0144] ② Sulfur-nitrogen compounds: The second gas is introduced into the repair unit from the first gas port, and most of it is discharged from the second gas port. A small amount of the second gas passes through the hollow part of the membrane layer-the carrier layer-the tubular membrane, and is mixed with nitrogen and then discharged from the gas outlet and enters the tail gas treatment unit; when the water vapor content in the nitrogen is below 50ppm and maintains a dynamic equilibrium, it indicates that the sulfur-nitrogen compounds at the defect are completely reacted to form a reaction complex, and a pre-repaired tubular membrane is obtained.

[0145] In step (4), water enters the repair unit from the first air port at a flow rate of 0.1 m / s to flush the membrane surface of the pre-repaired tubular membrane. The water temperature is 5° C. until the pH value of the water is above 6.5.

[0146] Example 3

[0147] Example 3 proposes a tubular membrane repair system, the structure of which is the same as that of Example 1.

[0148] Example 3 also provides a method for repairing a tubular membrane using the tubular membrane repair system provided in this embodiment. The steps are basically the same as those in Example 1, except that:

[0149] In step (3), NO 2 and SO 2 The volume ratio is 0.5:1; the flow rate of the first gas is 2mL / (cm 2 ·min); the relative humidity of water vapor in the second gas is 30%.

[0150] In step (4), water flows into the repair unit from the air inlet end at a speed of 1 m / s to flush the membrane surface of the pre-repaired tubular membrane at a water temperature of 20° C. until the pH value of the water is above 6.5.

[0151] Example 4

[0152] Example 4 proposes a tubular membrane repair system, the structure of which is the same as that of Example 1.

[0153] Example 4 also provides a method for repairing a tubular membrane using the tubular membrane repair system provided in this embodiment. The steps are basically the same as those in Example 1, except that:

[0154] In step (3), NO 2 and SO 2 The volume ratio is 1:4; in step (2), the flow rate of the first gas is 20 mL / (cm 2 ·min); the relative humidity of water vapor in the second gas is 50%.

[0155] In step (4), water flows into the repair unit from the air inlet end at a speed of 2 m / s to flush the membrane surface of the pre-repaired tubular membrane at a water temperature of 25° C. until the pH value of the water is above 6.5.

[0156] Example 5

[0157] Example 5 proposes a tubular membrane repair system, the structure of which is the same as that of Example 1.

[0158] Example 5 also provides a method for repairing a tubular membrane using the tubular membrane repair system provided in this embodiment. The steps are basically the same as those in Example 1, except that:

[0159] In step (4), water flows into the repair unit from the air inlet end at a speed of 3 m / s to flush the membrane surface of the pre-repaired tubular membrane at a water temperature of 30° C. until the pH value of the water is above 6.5.

[0160] In step (5), the calcination temperature is 350°C; the heating rate is 0.25°C / min, the cooling rate is 0.25°C / min; and the calcination time is 20h.

[0161] Example 6

[0162] Example 6 proposes a tubular membrane repair system, the structure of which is the same as that of Example 1.

[0163] Example 6 also provides a method for repairing a tubular membrane using the tubular membrane repair system provided in this embodiment. The steps are basically the same as those in Example 1, except that:

[0164] In step (4), water flows into the repair unit from the air inlet end at a speed of 0.01 m / s to flush the membrane surface of the pre-repaired tubular membrane at a water temperature of 1° C. until the pH value of the water is above 6.5.

[0165] In step (5), the calcination temperature is 600°C; the heating rate is 2°C / min, the cooling rate is 2°C / min; and the calcination time is 8h.

[0166] Example 7

[0167] Example 7 proposes a tubular membrane repair system, the structure of which is the same as that of Example 1.

[0168] Example 7 also provides a method for repairing a tubular membrane using the tubular membrane repair system provided in this embodiment. The steps are basically the same as those in Example 1, except that:

[0169] In step (4), water flows into the repair unit from the air inlet end at a speed of 0.5 m / s to flush the membrane surface of the pre-repaired tubular membrane at a water temperature of 10° C. until the pH value of the water is above 6.5.

[0170] In step (5), the calcination temperature is 700°C; the heating rate is 5°C / min, the cooling rate is 3°C / min; and the calcination time is 6h.

[0171] Comparative Example 1

[0172] Comparative Example 1 proposes a method for repairing a tubular membrane, and the steps are basically the same as those of Example 1, except that:

[0173] In step (3), after the first gas is introduced, a pre-repaired tubular membrane is obtained (ie, the second gas is not introduced).

[0174] Comparative Example 2

[0175] Comparative Example 2 proposes a method for repairing a tubular membrane, and the steps are basically the same as those of Example 1, except that:

[0176] In step (3), the first gas is SO 2 .

[0177] Comparative Example 3

[0178] Comparative Example 3 proposes a method for repairing a tubular membrane, the steps of which are basically the same as those of Example 1, except that:

[0179] In step (3), the first gas is NO 2 .

[0180] Comparative Example 4

[0181] Comparative Example 4 proposes a method for repairing a tubular membrane, the steps of which are basically the same as those of Example 1, except that:

[0182] This method does not involve strengthening in step (4) and calcining in step (5).

[0183] In order to verify the advancement of the tubular membrane repair system and repair method of the embodiment of the present invention, the tubular membranes of the embodiment and the comparative example before and after repair were subjected to CO 2 / N 2 The separation performance test results are shown in Table 1. The test steps are as follows:

[0184] The volume ratio of CO was 1:1 2 / N 2 The mixed gas was introduced into the inlet end of the membrane at a gas flow rate of 80 mL / min. The mixed gas was fully heat exchanged in the water bath to 25°C. The back pressure valve was used at the residual end to control the opening of the gas when passing through, and the pressure at the inlet end was controlled to be maintained at 100 kPa. The gas flow rate was tested at the permeation end using a soap bubble flowmeter, and the CO 2 Concentration analyzer detects CO 2 concentration, thus obtaining the permeate end CO 2 / N 2 The volume ratio and CO 2 The permeability of the tubular membrane for CO 2 / N 2 Separation performance. The tubular membranes before and after repair were subjected to CO 2 / N 2 Gas separation test experiment, so as to change the separation performance of tubular membrane before and after repair and CO 2 permeability changes.

[0185] Table 1

[0186]

[0187] From Table 1 above, at least the following conclusions can be drawn:

[0188] (1) The method for repairing a tubular membrane proposed in an embodiment of the present invention firstly passes a repairing gas into the surface of the tubular membrane, and the gas molecules generate a leak repairing compound at the defects of the tubular membrane. Then, the repairing compound is calcined at high temperature to react and bond with the defects to form a stable repaired tubular membrane. The CO2 / N 2 The separation performance is significantly improved, that is, the separation performance of the separation system is improved. The method has simple steps and low cost, and can effectively improve the separation performance of the tubular membrane, extend the working life of the tubular membrane, and thus improve the economic benefits of the tubular membrane separation technology.

[0189] (2) The method for repairing a tubular membrane proposed in the embodiment of the present invention can be used to repair defects of tubular membranes of different membrane types and carrier types, and has great application potential.

[0190] (3) The CO of the repaired tubular membrane of Comparative Example 1 2 / N 2 The separation performance (8.17 before repair and 13.18 after repair) shows that when only the first gas is used for repair, a more stable reaction complex cannot be generated at the defect, which makes the CO of the repaired molecular sieve (tubular membrane) 2 / N 2 The separation performance (13.18) is low.

[0191] (4) From Examples 1 to 7 and Comparative Examples 2 to 3, it can be seen that the first gas contains SO 2 with NO 2 , and when the second gas contains moisture, the tubular membrane can be repaired well.

[0192] (5) From Examples 1 to 7 and Comparative Example 4, it can be seen that strengthening can consolidate the formed reaction complex and remove excess SO in the tubular membrane. 2 and NO 2 High-temperature calcination causes the reaction complex to undergo a bonding reaction with the groups of the tubular membrane itself. The reaction complex is removed by calcination, so that the chemical bonds at the defects of the tubular membrane are connected and repaired as complete as before, and the repair is more stable.

[0193] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A tubular membrane repair system, characterized in that: include: Gas source unit, repair unit, auxiliary unit and tail gas treatment unit; The gas source unit, the auxiliary unit and the tail gas treatment unit are respectively connected to the repair unit; The repair unit comprises a shell and a porous disk; the porous disk comprises a first porous disk and a second porous disk; the first porous disk and the second porous disk are respectively arranged at two ends of the shell; One end of the shell is an air outlet end, and the other end is an air inlet end. The side wall of the shell is provided with a first air port and a second air port, and the first air port and the second air port are respectively located on the side outer wall of the shell.

2. The tubular membrane repair system according to claim 1, characterized in that: The gas source unit includes a repair gas source and an inert cleaning gas source; The repair gas source is connected to the gas inlet end, the inert cleaning gas source is connected to the first gas port, and the tail gas treatment unit is connected to the second gas port and the gas outlet end respectively.

3. The tubular membrane repair system according to claim 1, characterized in that: The gas source unit includes a repair gas source and an inert cleaning gas source; The inert cleaning gas source is connected to the gas inlet end, the repair gas source is connected to the first gas port, and the tail gas treatment unit is connected to the second gas port and the gas outlet end respectively.

4. A method for repairing a tubular membrane using a tubular membrane repair system according to any one of claims 1 to 3, characterized in that: The steps include: S1. Pre-repair: Under the premise of introducing an inert cleaning gas into the repair unit, introduce a first gas treatment into the repair unit containing the tubular membrane to be repaired and then introduce a second gas treatment; In the first gas treatment / second gas treatment step, the first gas / second gas is introduced into the membrane surface of the tubular membrane to be repaired, and the inert cleaning gas is introduced into the carrier surface of the tubular membrane to be repaired to remove the residual first gas / residual second gas that has seeped out of the carrier surface of the tubular membrane to be repaired; When the content of the first retentate gas is less than 50 ppm and maintains a dynamic equilibrium, the second gas is introduced; when the content of the second retentate gas is less than 50 ppm and maintains a dynamic equilibrium, a pre-repaired tubular membrane is obtained; The first gas includes a mixture of SO2 and NO2, and the second gas includes a mixture of water vapor and clean air; S2. Strengthening and calcining the pre-repaired tubular membrane to obtain a repaired tubular membrane.

5. The method for repairing a tubular membrane by a tubular membrane repair system according to claim 4, characterized in that: In the first gas, the volume ratio of SO2 to NO2 is (0.1-10):

1.

6. The method for repairing a tubular membrane by a tubular membrane repair system according to claim 4, characterized in that: During the first gas treatment, the pressure difference between the two sides of the tubular membrane is 0.05 MPa to 5 MPa; and / or, the first gas treatment tubular membrane time is 3h to 24h; and / or, the flow rate of the first gas is 1 to 40 mL / (cm 2 ·min).

7. The method for repairing a tubular membrane by a tubular membrane repair system according to claim 6, characterized in that: During the second gas treatment, the pressure difference between the two sides of the membrane is 0.01MPa to 5MPa; And / or, the flow rate of the second gas is 1 to 40 mL / (cm 2 ·min).

8. The method for repairing a tubular membrane by a tubular membrane repair system according to claim 7, characterized in that: The relative humidity of water vapor in the second gas is 1% to 100%.

9. The method for repairing a tubular membrane according to any one of claims 4 to 8, characterized in that: The strengthening step includes: flushing the membrane surface of the tubular membrane at a water flow rate of 0.02 m / s to 3 m / s until the pH value of the water is above 6.5; And / or, the high temperature calcination step comprises: heating to 350°C to 700°C at a heating rate of 0.1°C / min to 5°C / min, and calcining at 350°C to 700°C for 6h to 60h; After calcination, the temperature is lowered to 20°C to 25°C at a cooling rate of 0.1°C / min to 5°C / min.

10. Use of the tubular membrane repair system according to any one of claims 1 to 3 in the field of tubular membrane repair.

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