Hollow fiber composite membrane module leak detection device and method

Abstract

The invention belongs to the technical field of gas separation membranes, and particularly relates to a leak detection device and method for a hollow fiber composite membrane module. The leak detection device comprises a shell, a plurality of composite membrane filaments are arranged in the shell, and each composite membrane filament comprises a composite membrane base material and a composite membrane coating; the two ends of the shell, the shell and the composite membrane filaments and the multiple composite membrane filaments are sealed through sealants; the two ends of each composite membrane wire are communicated with the atmosphere, the sealant at one end of the shell and the end faces of the multiple composite membrane wires form a first membrane assembly end face, the sealant at the other end of the shell and the end faces of the multiple composite membrane wires form a second membrane assembly end face, and the first membrane assembly end face and the second membrane assembly end face are evenly coated with a solution type leak detection agent; a first membrane module shell side joint is arranged on the shell and is connected with a negative pressure device. According to the leakage detection device and method for the hollow fiber composite membrane module, the leakage point membrane filaments of the hollow fiber composite membrane are detected in the mode that the end faces of the membrane filaments are covered with a layer of solution type leakage detection agent and negative pressure is pumped out of the outer side of the membrane filament base material, and the leakage point membrane filaments of the hollow fiber composite membrane can be simply, efficiently and safely detected.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of gas separation membrane, and particularly relates to a kind of hollow fiber composite membrane module leak detection device and method. BACKGROUND

[0002] Hollow fiber membrane module is widely used in the field of gas separation, water treatment and other fields due to its high packing density. In recent years, with the development of gas separation membrane materials, a layer of composite membrane is coated on the surface of hollow fiber membrane to form hollow fiber composite membrane, which further improves the separation performance of the membrane module. After the preparation of hollow fiber composite membrane module, due to the inconsistency of the uniformity of the coating, some membrane filaments have leakage points, and the integrity detection of hollow fiber composite membrane module is the core link to detect leakage points, eliminate defects and ensure the performance of membrane module.

[0003] The existing leak detection technology (such as pressure decay method, bubble observation method) is designed for traditional membrane materials, which is difficult to meet the detection needs of ultra-thin composite membrane with high precision, high sensitivity and without damaging the structure of composite membrane. For example, Chinese invention patent CN109758910B coats a layer of leak detection agent on the end of the membrane filament, and introduces gas with pressure outside the membrane filament. Due to the positive pressure of the gas, the leak detection agent on the membrane filament with leakage point will fall off, thereby locking the membrane filament with leakage point, but this method needs to pressurize the outside of the internal pressure type composite membrane, which can easily reduce the bonding degree of the composite membrane structure and the membrane substrate, cause the coating of the internal pressure type composite membrane to fall off, and further cause the hollow fiber membrane module to leak gas in a large area, and the solid leak detection agent used is easy to enter the surface of the composite membrane coating, further forming new defects of the membrane. SUMMARY

[0004] In order to solve the above problems existing in the prior art, the purpose of the present application is to provide a kind of hollow fiber composite membrane module leak detection device and method, adopt a layer of solution type leak detection agent to cover the end face of membrane filament, the way of extracting negative pressure outside the membrane filament substrate detects the membrane filament with leakage point of hollow fiber composite membrane, can simply, efficiently, safely detect the membrane filament with leakage point of hollow fiber composite membrane.

[0005] The technical scheme adopted by the present application is as follows: A kind of hollow fiber composite membrane module leak detection device, including shell, a plurality of composite membrane filaments are arranged in the shell, the composite membrane filament includes composite membrane substrate and composite membrane coating;The sealing glue is sealed between the shell and the composite membrane filament, and between the plurality of composite membrane filaments at both ends of the shell;The ends of the composite membrane filament are communicated with the atmosphere, the sealing glue of one end of the shell and the end face of the plurality of composite membrane filaments form the first membrane module end face, and the sealing glue of the other end of the shell and the end face of the plurality of composite membrane filaments form the second membrane module end face, the solution type leak detection agent is uniformly coated on the first membrane module end face and the second membrane module end face;First membrane module shell side joint is arranged on the shell, and the negative pressure device is connected to the first membrane module shell side joint.

[0006] The negative pressure device of the present application establishes a negative pressure environment on the outer surface of the composite membrane wire through the membrane module shell side joint, so that a differential pressure is formed between the inner and outer sides of the composite membrane wire, thereby breaking the liquid film. The first membrane module end face and the second membrane module end face are marked at the corresponding positions of the liquid film breaking position using a marker pen, and the membrane wire with a leak point can be detected.

[0007] The present application does not damage the membrane wire during leak detection, and the leak point membrane wire detection effect is obvious. The hollow fiber composite membrane leak point membrane wire can be simply, efficiently and safely detected. The present application uses a negative pressure method to detect the hollow fiber composite membrane, solves the problem that the composite membrane coating is easily detached during positive pressure detection, and the detection method is simple and easy to operate. The leak detection agent used in the present application is a water-soluble liquid film and a foam agent, which is easy to obtain and has no negative impact on the membrane wire, and has the advantages of low cost, safety and high efficiency.

[0008] As a preferred scheme of the present application, one end of the shell is connected with a first membrane module head, and the first membrane module head is in communication with the inner side of the composite membrane wire.

[0009] As a preferred scheme of the present application, the other end of the shell is connected with a second membrane module head, and the second membrane module head is in communication with the inner side of the composite membrane wire.

[0010] As a preferred scheme of the present application, the axis of the shell is parallel to the axis of the composite membrane wire; and during leak detection, the shell is placed horizontally or inclinedly.

[0011] As a preferred scheme of the present application, the composite membrane substrate is a porous material, the pore size of the composite membrane substrate is 1 nm to 1 μm, and the gas permeability of air is 100,000 to 1,500,000 GPU.

[0012] As a preferred scheme of the present application, the material of the composite membrane substrate is a polymer or an inorganic ceramic.

[0013] As a preferred scheme of the present application, the composite membrane coating is a functional layer with a separation function formed on the inner surface of the composite membrane substrate by solution coating, and the gas permeability of air is 100 GPU.

[0014] As a preferred scheme of the present application, the shell is further provided with a first membrane module shell side joint.

[0015] As a preferred scheme of the present application, the solution type leak detection agent is a water solution or foam formed by sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, fatty acid salt or sodium lauroyl amino acid.

[0016] A hollow fiber composite membrane module leak detection method, comprising the following steps: S1: uniformly coating a solution type leak detection agent on the first membrane module end face and the second membrane module end face; S2: the negative pressure device is communicated with the shell through the first membrane module shell side joint; S3: the negative pressure device is started to establish a negative pressure environment on the outer surface of the composite membrane wire; S4: the solution type leak detection agent is broken at the leak point position of the composite membrane wire; S5: the solution type leak detection agent is marked by using a marker pen, and the membrane wire leak detection of the membrane module is realized.

[0017] The beneficial effects of the present application are: The negative pressure device of the present application establishes a negative pressure environment on the outer surface of the composite membrane wire through the membrane module shell side joint, so that a differential pressure is formed between the inner and outer sides of the composite membrane wire, thereby breaking the liquid film. The liquid film breaking position corresponding to the positions of the first membrane module end face and the second membrane module end face is marked by using a marker pen, and the membrane wire with a leak point can be detected.

[0018] The present application does not damage the membrane wire during leak detection, and the leak point membrane wire detection effect is obvious. The hollow fiber composite membrane leak point membrane wire can be simply, efficiently and safely detected. The present application adopts a negative pressure method to detect the hollow fiber composite membrane, solves the problem that the composite membrane coating is easily detached during positive pressure detection, and the detection method is simple and easy to operate. The leak detection agent used in the present application is a water-soluble liquid film and a foaming agent, which is easy to obtain and has no negative impact on the membrane wire, and has the advantages of low cost, safety and high efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic diagram of the present application; Figure 2 is a structural schematic diagram of the composite membrane wire; Figure 3 is a schematic diagram of the end face of the membrane module before leak detection; Figure 4 is a schematic diagram of the end face of the membrane module after coating the solution type leak detection agent; Figure 5 is a schematic diagram of the leak point position of the end face of the membrane module; Figure 6 is a structural schematic diagram of the hollow fiber membrane module.

[0020] In the figure: 1-first membrane module head; 2-second membrane module head; 3-second membrane module shell side joint; 4-first membrane module shell side joint; 5-sealing glue; 6-composite membrane wire; 7-solution type leak detection agent; 8-negative pressure device; 101-first membrane module end face; 102-second membrane module end face; 601-composite membrane substrate; 602-composite membrane coating. DETAILED DESCRIPTION

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the invention can be combined with each other.

[0023] like Figure 1 and Figure 2 As shown, the hollow fiber composite membrane module leak detection device of this embodiment includes a housing, in which a plurality of composite membrane fibers 6 are disposed. The composite membrane fibers 6 include a composite membrane substrate 601 and a composite membrane coating 602. At both ends of the housing, the housing and the composite membrane fibers 6, as well as the plurality of composite membrane fibers 6, are sealed with sealant 5. Both ends of the composite membrane fibers 6 are in communication with the atmosphere. The sealant 5 at one end of the housing and the end face of the plurality of composite membrane fibers 6 form a first membrane module end face 101, and the sealant 5 at the other end of the housing and the end face of the plurality of composite membrane fibers 6 form a second membrane module end face 102. A solution-type leak detection agent 7 is uniformly coated on the first membrane module end face 101 and the second membrane module end face 102. A first membrane module shell-side connector 4 is provided on the housing, and a negative pressure device 8 is connected to the first membrane module shell-side connector 4.

[0024] The negative pressure device 8 of the present invention establishes a negative pressure environment on the outer surface of the composite membrane fiber 6 through the membrane module shell-side connector, creating a differential pressure between the inner and outer sides of the composite membrane fiber 6, thereby causing the liquid membrane to rupture. By marking the liquid membrane rupture location at the corresponding positions on the first membrane module end face 101 and the second membrane module end face 102 with a marker pen, the membrane fiber with leakage can be detected.

[0025] This invention does not damage the membrane fibers during leak detection, and the detection effect on leaking membrane fibers is obvious. It can simply, efficiently, and safely detect leaking membrane fibers in hollow fiber composite membranes. This invention uses a negative pressure method to detect hollow fiber composite membranes, solving the problem that the 602 coating on the composite membrane is easily peeled off during positive pressure detection. The detection method is simple and easy to operate. The leak detection agents used in this invention are water-soluble liquid membranes and foaming agents, which are readily available materials and have no negative impact on the membrane fibers. It has the advantages of low cost, safety, and high efficiency.

[0026] like Figure 6As shown, the hollow fiber composite membrane module includes a shell, a first membrane module end cap 1, a second membrane module end cap 2, a first membrane module shell-side connector 4, a second membrane module shell-side connector 3, sealant 5, and composite membrane fibers 6. The composite membrane fibers 6 are separated and fixed by the sealant 5 to ensure a good seal between the composite membrane fibers 6. The first membrane module end cap 1 and the second membrane module end cap 2 are connected to the inner side of the composite membrane fibers 6, and the first membrane module shell-side connector 4 and the second membrane module shell-side connector 3 are connected to the outer side of the composite membrane fibers 6.

[0027] The composite membrane fiber 6 consists of two parts: a composite membrane substrate 601 and a composite membrane coating 602. The composite membrane substrate 601 is made of porous materials, including polymers and inorganic ceramics. In the composite membrane structure, the pore size of the composite membrane substrate 601 is generally 1 nm to 1 μm, with good air permeability. The gas permeability (based on air) can reach 10,000 to 1,500,000 GPU, but it has no gas selectivity and only serves to mechanically support the composite membrane coating 602. The composite membrane coating 602 is a functional layer with special separation function formed on the inner surface of the composite membrane substrate 601 through solution coating. Its gas permeability (based on air) is around 100 GPU, which is much lower than that of the composite membrane substrate 601. The resistance R2 of gas passing through the composite membrane coating 602 is much greater than the resistance R1 of gas passing through the composite membrane substrate 601.

[0028] After the composite membrane coating 602 is coated on the composite membrane substrate 601 to form the composite membrane fiber 6, due to the coating operation process and the influence of the membrane composite substrate 601, the composite membrane coating 602 may not completely cover the surface of the composite membrane substrate 601, thus forming defects, forming air leakage points, and reducing the overall separation performance of the hollow fiber composite membrane module.

[0029] During the leak detection process of the hollow fiber composite membrane module, the first membrane module end cap 1 is removed, exposing the first membrane module end face 101 to the atmosphere. The second membrane module end cap 2 is also removed, exposing the second membrane module end face 102 to the atmosphere. The second membrane module shell-side connector 3 is then sealed, and the first membrane module shell-side connector 4 is connected to the negative pressure device 8. Figure 1 As shown. A solution-type leak detector 7 is uniformly coated on the surfaces of the first membrane module end face 101 and the second membrane module end face 102. The solution-type leak detector 7 includes an aqueous solution or foam (foam diameter ≤1mm) formed from sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), fatty acid salts (such as sodium stearate), sodium lauroyl sarcosinate, etc. Negative pressure device 8 establishes a negative pressure environment on the outer surface of the composite membrane fiber 6 through the shell-side connector 4 of the first membrane module, controlling the vacuum degree to 2-90kPa, so that a differential pressure of 2-90kPa is formed between the inner and outer sides of the composite membrane fiber 6.

[0030] like Figures 3-5As shown, at the leak point of the composite membrane fiber 6, due to the differential pressure between the inner and outer sides of the composite membrane fiber 6, and because the resistance R2 of gas permeation through the composite membrane coating 602 is much greater than the resistance R1 of gas permeation through the composite membrane substrate 601, the gas inside the composite membrane fiber 6 will quickly flow to the outside through the leak point, causing the pressure inside the composite membrane fiber 6 to decrease, thereby causing the solution-type leak detection agent 7 to rupture. Marking the corresponding location with a marker pen achieves membrane fiber leak detection of the membrane module. During the leak detection process, the membrane module can be placed arbitrarily within the horizontal angle range of 0° (horizontal) to 90° (vertical), preferably 0° (horizontal placement) or 45° (tilted placement).

[0031] The leak detection method for hollow fiber composite membrane modules in this embodiment includes the following steps: S1: A solution-type leak detection agent 7 is uniformly coated on the end face 101 of the first membrane module and the end face 102 of the second membrane module; S2: The negative pressure device 8 is connected to the housing through the first membrane module housing-side connector 4; S3: Start the negative pressure device 8 to establish a negative pressure environment on the outer surface of the composite membrane fiber 6, control the vacuum degree to 2-90 kPa, and make a differential pressure of 2-90 kPa between the inner and outer sides of the composite membrane fiber 6. S4: At the leak point of composite membrane fiber 6, the solution-type leak detection agent 7 ruptures; S5: Use a marker pen to mark the location of the rupture in the solution-type leak detector 7 to achieve leak detection of the membrane fibers in the membrane module.

[0032] Example 1: Place the hollow fiber membrane module horizontally (at a 0° angle to the horizontal), remove the first membrane module end cap 1, exposing the first membrane module end face 101 to the atmosphere, and remove the second membrane module end cap 2, exposing the second membrane module end cap 2 to the atmosphere. Seal the second membrane module shell-side connector 3, and connect the first membrane module shell-side connector 4 to the negative pressure device 8. Figure 1 As shown. A solution-type leak detection agent 7 (sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), fatty acid salts (such as sodium stearate), sodium lauroyl sarcosinate, aqueous solution or foam (foam diameter ≤ 1 mm)) is uniformly coated on the surfaces of the first membrane module end face 101 and the second membrane module end face 102. Figure 1 As shown. The negative pressure device 8 establishes a negative pressure environment on the outer surface of the composite membrane fiber 6 through the first membrane module shell-side connector 4, controls the vacuum degree to 2 kPa, and creates a 2 kPa differential pressure between the inner and outer sides of the composite membrane fiber 6, thereby causing the liquid membrane to rupture. By using a marker pen to mark the liquid membrane rupture positions at the corresponding positions on the end face 101 of the first membrane module and the end face 102 of the second membrane module, the membrane fiber with leakage can be detected.

[0033] Example 2 The hollow fiber membrane module is placed at an angle of 45° to the horizontal. The first membrane module end cap 1 is removed, opening the first membrane module end face 101 to the atmosphere. The second membrane module end cap 2 is removed, opening the second membrane module end face 102 to the atmosphere. The second membrane module shell-side connector 3 is sealed, and the first membrane module shell-side connector 4 is connected to the negative pressure device 8. Figure 1 As shown. A solution-type leak detection agent 7 (sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), fatty acid salts (such as sodium stearate), sodium lauroyl sarcosinate, aqueous solution or foam (foam diameter ≤ 1 mm)) is uniformly coated on the surfaces of the first membrane module end face 101 and the second membrane module end face 102. Figure 1 As shown. The negative pressure device 8 establishes a negative pressure environment on the outer surface of the composite membrane fiber 6 through the first membrane module shell-side connector 4, controls the vacuum degree to 2 kPa, and creates a 2 kPa differential pressure between the inner and outer sides of the composite membrane fiber 6, thereby causing the liquid membrane to rupture. By using a marker pen to mark the liquid membrane rupture positions at the corresponding positions on the end face 101 of the first membrane module and the end face 102 of the second membrane module, the membrane fiber with leakage can be detected.

[0034] Example 3 Place the hollow fiber membrane module vertically (at a 90° angle to the horizontal), remove the first membrane module end cap 1, opening the first membrane module end face 101 to the atmosphere, and remove the second membrane module end cap 2, opening the second membrane module end face 102 to the atmosphere. Seal the second membrane module shell-side connector 3, and connect the first membrane module shell-side connector 4 to the negative pressure device 8. Figure 1 As shown. A solution-type leak detection agent 7 (sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), fatty acid salts (such as sodium stearate), sodium lauroyl sarcosinate, aqueous solution or foam (foam diameter ≤ 1 mm)) is uniformly coated on the surfaces of the first membrane module end face 101 and the second membrane module end face 102. Figure 1 As shown. The negative pressure device 8 establishes a negative pressure environment on the outer surface of the composite membrane fiber 6 through the first membrane module shell-side connector 4, controls the vacuum degree to 2 kPa, and creates a 2 kPa differential pressure between the inner and outer sides of the composite membrane fiber 6, thereby causing the liquid membrane to rupture. By using a marker pen to mark the liquid membrane rupture positions at the corresponding positions on the end face 101 of the first membrane module and the end face 102 of the second membrane module, the membrane fiber with leakage can be detected.

[0035] Example 4 Place the hollow fiber membrane module horizontally (at a 0° angle to the horizontal), remove the first membrane module end cap 1, opening the first membrane module end face 101 to the atmosphere, and remove the second membrane module end cap 2, opening the second membrane module end face 102 to the atmosphere. Seal the second membrane module shell-side connector 3, and connect the first membrane module shell-side connector 4 to the negative pressure device 8. Figure 1As shown. A solution-type leak detection agent 7 (sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), fatty acid salts (such as sodium stearate), sodium lauroyl sarcosinate, aqueous solution or foam (foam diameter ≤ 1 mm)) is uniformly coated on the surfaces of the first membrane module end face 101 and the second membrane module end face 102. Figure 1 As shown. The negative pressure device 8 establishes a negative pressure environment on the outer surface of the composite membrane fiber 6 through the first membrane module shell-side connector 4, controlling the vacuum degree to 90 kPa, so that a differential pressure of 90 kPa is formed between the inner and outer sides of the composite membrane fiber 6, thereby causing the liquid membrane to rupture. By using a marker pen to mark the liquid membrane rupture position at the corresponding position on the end face 101 of the first membrane module and the end face 102 of the second membrane module, the membrane fiber with leakage can be detected.

[0036] Example 5 Place the hollow fiber membrane module horizontally (at a 0° angle to the horizontal), remove the first membrane module end cap 1, opening the first membrane module end face 101 to the atmosphere, and remove the second membrane module end cap 2, opening the second membrane module end face 102 to the atmosphere. Seal the second membrane module shell-side connector 3, and connect the first membrane module shell-side connector 4 to the negative pressure device 8. Figure 1 As shown. A solution-type leak detection agent 7 (sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), fatty acid salts (such as sodium stearate), sodium lauroyl sarcosinate, aqueous solution or foam (foam diameter ≤ 1 mm)) is uniformly coated on the surfaces of the first membrane module end face 101 and the second membrane module end face 102. Figure 1 As shown. The negative pressure device 8 establishes a negative pressure environment on the outer surface of the composite membrane fiber 6 through the first membrane module shell-side connector 4, controlling the vacuum degree to 20 kPa, so that a differential pressure of 20 kPa is formed between the inner and outer sides of the composite membrane fiber 6, thereby causing the liquid membrane to rupture. By using a marker pen to mark the liquid membrane rupture position at the corresponding position on the end face 101 of the first membrane module and the end face 102 of the second membrane module, the membrane fiber with leakage can be detected.

[0037] Control group 1: Place the hollow fiber membrane module horizontally (at a 0° angle to the horizontal). Remove the end cap 1 of the first membrane module, exposing end face 101 to the atmosphere. Remove the end cap 2 of the second membrane module, exposing end face 102 to the atmosphere. Seal the shell-side connector 3 of the second membrane module and connect the shell-side connector 4 of the first membrane module to compressed air. Use a scraper to evenly press calcium carbonate powder (leak detection agent) onto the end faces 101 and 102 of the first and second membrane modules to be tested. Scrape off excess calcium carbonate powder to expose the end faces 101 and 102. Inject compressed air into the shell-side connector 4 of the first membrane module, and then use a repair pin to seal any detached composite membrane fibers 6. After repair, blow away any remaining calcium carbonate powder with compressed air to complete the inspection and repair operation.

[0038] Table 1. Summary of the comparison results between Examples 1-4 and Control Example 1:

[0039] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A leak detection device for hollow fiber composite membrane modules, characterized in that: The device includes a housing, within which are disposed a plurality of composite membrane filaments (6). Each composite membrane filament (6) comprises a composite membrane substrate (601) and a composite membrane coating (602). At both ends of the housing, the housing and the composite membrane filaments (6), as well as the plurality of composite membrane filaments (6), are sealed with sealant (5). Both ends of the composite membrane filaments (6) are in communication with the atmosphere. The sealant (5) at one end of the housing and the end face of the plurality of composite membrane filaments (6) form a first membrane assembly end face (101), and the sealant (5) at the other end of the housing and the end face of the plurality of composite membrane filaments (6) form a second membrane assembly end face (102). A solution-type leak detection agent (7) is uniformly coated on the first membrane assembly end face (101) and the second membrane assembly end face (102). A first membrane assembly shell-side connector (4) is disposed on the housing, and a negative pressure device (8) is connected to the first membrane assembly shell-side connector (4).

2. The leak detection device for a hollow fiber composite membrane module according to claim 1, characterized in that: One end of the housing is connected to a first membrane assembly end cap (1), and the first membrane assembly end cap (1) is connected to the inner side of the composite membrane filament (6).

3. The leak detection device for a hollow fiber composite membrane module according to claim 2, characterized in that: The other end of the housing is connected to a second membrane assembly end cap (2), which is connected to the inner side of the composite membrane filament (6).

4. The leak detection device for a hollow fiber composite membrane module according to claim 1, characterized in that: The axis of the housing is parallel to the axis of the composite membrane fiber (6); during leak detection, the housing is placed horizontally or at an angle.

5. The leak detection device for a hollow fiber composite membrane module according to claim 1, characterized in that: The composite membrane substrate (601) is a porous material with a pore size of 1 nm to 1 μm and a gas permeability of 10,000 to 1,500,000 GPUs in terms of air.

6. The leak detection device for a hollow fiber composite membrane module according to claim 5, characterized in that: The composite film substrate (601) is made of polymer or inorganic ceramic.

7. The leak detection device for a hollow fiber composite membrane module according to claim 1, characterized in that: The composite membrane coating (602) is a functional layer with a separation function formed on the inner surface of the composite membrane substrate (601) by solution coating, and the gas permeability is 100 GPU in terms of air.

8. The leak detection device for a hollow fiber composite membrane module according to claim 1, characterized in that: The housing is also provided with a first membrane assembly shell-side connector (4).

9. A leak detection device for a hollow fiber composite membrane module according to claim 1, characterized in that: The solution-type leak detector (7) is an aqueous solution or foam formed from sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, fatty acid salt or sodium lauroyl sarcosinate.

10. A method for leak detection of hollow fiber composite membrane modules, using the leak detection device for hollow fiber composite membrane modules according to any one of claims 1 to 9, characterized in that: Includes the following steps: S1: A solution-type leak detection agent (7) is uniformly coated on the end face (101) of the first membrane module and the end face (102) of the second membrane module. S2: The negative pressure device (8) is connected to the housing through the first membrane module housing side connector (4); S3: Activate the negative pressure device (8) to establish a negative pressure environment on the outer surface of the composite membrane fiber (6); S4: At the leak point of the composite membrane fiber (6), the solution-type leak detection agent (7) ruptures; S5: Use a marker pen to mark the location of the rupture in the solution-type leak detector (7) to achieve leak detection of the membrane fibers of the membrane module.

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