Pressure balancing device of hollow fiber filter

Abstract

The utility model relates to a pressure balancing device of a hollow fiber filter, which adopts the scheme that the pressure balancing device comprises a tube shell, a liquid outlet joint arranged at the top of the tube shell and a hollow fiber membrane arranged in the tube shell, a one-way valve is arranged in a liquid outlet of the liquid outlet joint, a liquid outlet pipe capable of axially moving is arranged in the one-way valve in a penetrating manner, and a side edge small hole is formed in the side wall of the liquid outlet pipe. During suction filtration, the liquid outlet pipe is inserted into the liquid outlet to open the one-way valve, and the hollow fiber membrane is communicated with a vacuum source; after suction filtration is completed, the liquid outlet pipe is pulled out until the side small hole is separated from the sealing range of the one-way valve, so that the outer side of the hollow fiber membrane is communicated with external air, and internal and external air pressures are quickly balanced; and the one-way valve closes and seals the liquid outlet when being completely pulled out. According to the utility model, the built-in one-way valve is matched with the liquid outlet pipe, so that pressure balance operation and pipeline disassembly are integrated, the volume of an inner cavity of the filter is remarkably reduced, the problems that a traditional external valve is complicated to operate and the amount of eluent is difficult to control are solved, and the elution efficiency and the detection precision of a biological sample are improved.

Description

Technical Field

[0001] This utility model relates to the field of hollow fiber filtration technology, specifically a pressure balancing device for hollow fiber filters, which is particularly suitable for the efficient elution of biological samples in liquid microbial enrichment devices, solving the problems of pressure balance inside and outside the hollow fiber membrane and precise control of the eluent. Background Technology

[0002] Hollow fiber filters, with their tangential filtration technology, are widely used in water treatment, biopharmaceuticals, food and beverage, infectious disease monitoring, and food safety testing. Their core principle utilizes the pore size difference of hollow fiber membranes to trap large molecular biological samples (such as bacteria, viruses, and blood cells) inside the membrane fibers, while smaller molecules like water molecules permeate the membrane wall and escape, thus achieving rapid liquid concentration and sample enrichment. In the subsequent biological sample elution process, the sample adhering to the inner wall of the membrane fibers needs to be washed off using an eluent (such as wet foam). Maintaining pressure balance inside and outside the hollow fiber membrane fibers is a crucial prerequisite at this stage.

[0003] Currently, traditional pressure balancing methods typically rely on external three-way directional valves or similar devices: after filtration, the directional valve connects the negative pressure space outside the hollow fiber membrane to the outside air to release the vacuum. However, this approach has significant drawbacks:

[0004] 1. Cumbersome operation: It requires additional reversing steps, increases the cost of manual intervention, and may cause incomplete pressure balance due to operational errors, affecting the washing efficiency;

[0005] 2. Complex piping structure: External valves require extended connecting pipes, which increases the internal cavity volume from the hollow fiber filter outlet to the sealing section, making it difficult to accurately control the amount of eluent, thus affecting the accuracy of subsequent testing;

[0006] 3. Insufficient sealing and reliability: The connection of multiple components is prone to leakage risk, and the response speed of external valves is slow, making it impossible to achieve rapid pressure balance.

[0007] While the existing patent CN115060571A relates to bioparticle concentration technology, it does not offer a specific solution to the pressure balance problem during hollow fiber filter elution, particularly failing to disclose the design of the integration of the built-in pressure balancing device with the pipeline structure. Therefore, there is an urgent need for a compact, easy-to-operate pressure balancing device that can precisely control the elution process, addressing the problems of complex operation and low elution efficiency inherent in traditional solutions. Utility Model Content

[0008] The purpose of this invention is to address the aforementioned problems in the prior art by providing a pressure balancing device for a hollow fiber filter. By integrating a one-way valve and a movable outlet pipe structure into the outlet connector of the hollow fiber filter, the pressure balancing operation and pipeline disassembly process are integrated into a single design, effectively overcoming the shortcomings of the prior art and providing an innovative solution for the efficient enrichment and elution of biological samples.

[0009] To achieve the above-mentioned application objectives, the present invention adopts the following technical solution: a pressure balancing device for a hollow fiber filter includes a tube shell and a liquid outlet connector disposed at the top of the tube shell. The liquid outlet connector is provided with a liquid outlet. A hollow fiber membrane is disposed inside the tube shell. A one-way valve is disposed inside the liquid outlet. A liquid outlet pipe that can move axially is disposed inside the one-way valve. A side hole is opened on the side wall of the liquid outlet pipe as an air outlet.

[0010] When the outlet tube is inserted into the outlet port, the one-way valve is opened to connect the hollow fiber membrane with the vacuum source; when the outlet tube is pulled outward until the side hole is out of the sealing range of the one-way valve, the hollow fiber membrane is connected to the outside air to balance the internal and external air pressure.

[0011] Furthermore, the outlet pipe and the outlet port of the outlet connector slide and seal together, the one-way valve is a sleeve made of elastic material, its inner wall is in close contact with the outer wall of the outlet pipe and sealed, and one end of the one-way valve is fixed on the inner wall of the outlet connector.

[0012] Furthermore, the top of the liquid outlet connector is provided with an eluent rinsing port, which is connected to the inner side of the hollow fiber membrane and is used to spray eluent onto the inner wall of the hollow fiber membrane.

[0013] Furthermore, the one-way valve is located near the outlet opening of the tubing.

[0014] Furthermore, the liquid outlet pipe is connected to the vacuum source via a connecting pipe, and a small hole on the side is located at the end of the liquid outlet pipe near the shell.

[0015] Furthermore, when the outlet tube is completely pulled out of the outlet, the one-way valve closes to block the hollow fiber membrane from communicating with the outside world, and the outlet of the outlet connector is in a sealed state.

[0016] Furthermore, the outlet has a groove for installing a one-way valve, and the end of the one-way valve away from the opening of the outlet has a protruding edge that mates with the groove.

[0017] Furthermore, the outer wall of the end of the outlet pipe facing the check valve has a chamfer.

[0018] Furthermore, the one-way valve is a cylindrical structure made of elastic silicone or rubber, with its inner diameter matching the outer diameter of the outlet pipe. When the outlet pipe is inserted, the one-way valve expands and opens; when the outlet pipe is pulled out, the one-way valve contracts and tightly adheres to the inner wall of the outlet connector to achieve a seal.

[0019] Furthermore, the side holes of the liquid outlet tube are multiple evenly distributed through holes.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. By axially moving the outlet pipe, the system can simultaneously switch between three states: "vacuum filtration and connection to the vacuum source", "pressure balance and air conduction", and "elution and sealing of the outlet". This combines the separate steps of "disassembling the pipeline" and "operating the three-way valve to balance the pressure" in the traditional solution into one, eliminating the need for additional reversing operations, significantly simplifying the operation process, and reducing the cost of manual intervention and the risk of misoperation.

[0022] 2. By placing the one-way valve close to the opening in the tubing, the pipeline extension required by traditional external three-way valves is avoided, significantly reducing the volume of the internal cavity formed by the tubing and the outlet connector. Experimental results have shown that a smaller cavity volume significantly improves the accuracy of eluent dosage control, preventing volume deviations caused by residual eluent or negative pressure adsorption within the cavity, thereby improving the accuracy of subsequent biological sample testing.

[0023] 3. The outlet pipe and the inner wall of the one-way valve always maintain a sliding seal, which reduces the risk of leakage compared to the multi-port connection of traditional external valves. It is especially suitable for scenarios with extremely high sealing requirements, such as aseptic testing.

[0024] 4. It eliminates the need for complex components such as external three-way valves and additional pipelines. The core function is achieved through the built-in cooperation of the liquid outlet pipe and the check valve, reducing component costs and assembly difficulty. At the same time, it reduces the overall size of the filter, making it suitable for the compact design requirements of portable POCT (point-of-care testing) devices. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of this utility model;

[0026] Figure 2 This is a magnified view of the outlet pipe being fully inserted into the check valve.

[0027] Figure 3 This is a magnified view of a portion of the process of pulling out the check valve from the outlet tube;

[0028] Figure 4 This is a schematic diagram of the structure during elution;

[0029] Figure 5 This is a magnified view of a section where the outlet tube is completely pulled out of the check valve during elution.

[0030] Figure 6 This is a schematic diagram of the internal space of the one-way valve of this utility model;

[0031] Figure 7 This is a schematic diagram of the internal space of a three-way directional valve used in existing technology.

[0032] In the diagram, 1 is the liquid outlet connector; 2 is the tube shell; 3 is the hollow fiber membrane; 4 is the one-way valve; 5 is the liquid outlet pipe; 6 is the connecting pipe; 7 is the vacuum source; 8 is the three-way reversing valve; 11 is the eluent flushing port; 12 is the liquid outlet; 21 is the liquid inlet; and 51 is the side hole. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model are within the protection scope of the present utility model.

[0034] Those skilled in the art should understand that in the disclosure of this utility model, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on this utility model.

[0035] like Figure 1-6 As shown, the pressure balancing device of this hollow fiber filter includes a shell 2 and an outlet connector 1 located at the top of the shell 2. The outlet connector 1 has an outlet port 12 on its side (or top, not limited). A hollow fiber membrane 3 is located inside the shell 2, and an inlet port 21 is located at the bottom. A one-way valve 4 is installed inside the outlet port 12. An axially movable outlet pipe 5 passes through the one-way valve 4. A small side hole 51 is opened on the side wall of the outlet pipe 5 as an air outlet (this side hole 51 can be multiple holes or a single hole). The outlet pipe 5 and the outlet port 12 of the outlet connector 1 are slidably sealed together. The one-way valve 4 is a sleeve made of elastic material, and its inner wall is sealed against the outer wall of the outlet pipe 5. One end of the one-way valve 4 is fixed to the inner wall of the outlet connector 1. An eluent rinsing port 11 is located at the top of the outlet connector 1. The eluent rinsing port 11 communicates with the inner side of the hollow fiber membrane 3 and is used to spray eluent onto the inner wall of the hollow fiber membrane 3.

[0036] Preferably, the one-way valve 4 is a cylindrical structure made of elastic silicone or rubber, with its inner diameter matching the outer diameter of the outlet pipe 5. When the outlet pipe 5 is inserted, the one-way valve 4 expands and opens; when the outlet pipe 5 is pulled out, the one-way valve 4 contracts and seals tightly against the inner wall of the outlet connector 1. To facilitate the insertion of the outlet pipe 5, the cross-section of the one-way valve 4 is "V"-shaped, and the end of the outlet pipe 5 is chamfered. The outer wall of the end of the outlet pipe 5 facing the one-way valve 4 is chamfered. The outlet 12 has a groove for installing the one-way valve 4 inside, and the end of the one-way valve 4 away from the opening of the outlet 12 has a protruding edge that mates with the groove.

[0037] In this embodiment, during the liquid filtration process, the positional relationship between the outlet pipe 5, the outlet connector 1, and the one-way valve 4 is as follows: Figure 1 As shown, at this time, the outlet pipe 5 is inserted into the outlet port 12 of the outlet connector 1, and simultaneously passes through the one-way valve 4. Opening the one-way valve 4 ensures that the outlet port 12 is connected to the inside of the tube shell 2 and the outside of the hollow fiber membrane 3. Through the connecting pipe 6, a vacuum source 7 is connected, allowing the sample to be drawn in from the inlet port 21, filtered through the hollow fiber membrane 3, and the biological sample retained inside the hollow fiber membrane 3. The remaining liquid is discharged through the outlet port 12. (See enlarged view) Figure 2 As can be seen, an air vent is provided on the outlet pipe 5. In this state, the side hole is sealed by the one-way valve 4, which does not affect normal filtration. The outlet connector 1 is used to connect to the eluent tank to wash off the biological sample attached to the inner wall of the hollow fiber membrane 3 after filtration is completed.

[0038] Pressure balancing operation: After completing the filtration operation, pressure balancing is required to ensure that the biological sample on the inner wall of the hollow fiber membrane 3 is fully eluted. Otherwise, since the outlet 12 is connected to the vacuum source 7 and is under negative pressure, when the eluent enters from the eluent rinsing port 11, the biological sample will be drawn in by the negative pressure, resulting in a low elution rate. The eluent itself may also be drawn out of the hollow fiber membrane 3 by the negative pressure, resulting in a small overall eluent volume. Therefore, the operation at this time is to slowly remove the outlet tube 5. During this process, the one-way valve 4 will slowly contract due to the loss of its internal support, while always maintaining a tight seal with the outlet tube 5. When the side hole 51 on the outlet tube 5 is removed from the one-way valve 4, the space between the inside of the tube shell 2 and the outside of the hollow fiber membrane 3 is connected to the outside air, and pressure balancing can be achieved in a short time. The relative positions of the outlet tube 5, the outlet connector 1, and the one-way valve 4 are as follows: Figure 3 As shown.

[0039] Elution Steps: As the outlet tube 5 continues to move outward, the one-way valve 4 slowly closes. At this point, the internal pressure of the hollow fiber tube (hollow fiber membrane 3) is the same as the external air pressure, and the one-way valve 4 is fully closed. The internal pressure of the hollow fiber filter returns to normal, and the outlet connector 1 is partially closed. The eluent can then be released. The eluent flows in from the eluent flushing port 11 and forms wet foam upon release, which fully contacts the inner wall of the hollow fiber membrane 3. The biological sample adhering to the inner wall of the hollow fiber membrane 3 is fully eluted by the tangential force generated during the wet foam ejection process and flows out from the inlet 21. The key factors in this process are ensuring that there is no negative pressure inside the tube shell 2 and outside the hollow fiber membrane 3, and ensuring the outlet is sealed. The relative positions of the components in this state are as follows: Figure 4 and Figure 5 As shown.

[0040] Meanwhile, since the one-way valve 4 can be built-in, it can be placed very close to the opening of the shell 2, greatly reducing the volume of the internal cavity formed by the shell 2 and the outlet connector 1. Traditional designs generally rely on components such as the three-way reversing valve 8, which are all located outside the outlet connector 1, inevitably increasing the internal cavity volume. Through multiple experiments, it has been verified that a smaller internal cavity volume is more conducive to ensuring quantitative control of the eluent, thereby improving subsequent detection accuracy. The internal space of this design compared to traditional designs is as follows: Figure 6 and Figure 7 As shown.

[0041] The parts of this utility model not described in detail are existing technologies, therefore they are not described in detail here.

[0042] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0043] Although this document uses a considerable amount of technical terminology, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any additional limitation would contradict the spirit of this utility model.

[0044] This utility model is not limited to the above-described preferred embodiment. Anyone can derive other forms of products under the guidance of this utility model. However, regardless of any changes made to their shape or structure, any technical solution that is the same as or similar to this utility model falls within the protection scope of this utility model.

Claims

1. A pressure balancing device for a hollow fiber filter, comprising a housing (2) and a liquid outlet connector (1) disposed at the top of the housing (2), wherein the liquid outlet connector (1) is provided with a liquid outlet (12), and a hollow fiber membrane (3) is disposed inside the housing (2), characterized in that, A one-way valve (4) is provided inside the liquid outlet (12), and a liquid outlet pipe (5) that can move along the axial direction is provided inside the one-way valve (4). A side hole (51) is provided on the side wall of the liquid outlet pipe (5) as an air outlet. When the liquid outlet pipe (5) is inserted into the liquid outlet, the one-way valve (4) is opened to connect the hollow fiber membrane (3) with the vacuum source (7); when the liquid outlet pipe (5) is pulled outward until the side hole is out of the sealing range of the one-way valve (4), the hollow fiber membrane (3) is connected to the outside air to balance the internal and external air pressure.

2. The pressure balancing device for a hollow fiber filter according to claim 1, characterized in that, The liquid outlet pipe (5) is slidably sealed to the liquid outlet port (12) of the liquid outlet connector (1). The one-way valve (4) is a sleeve made of elastic material, and its inner wall is sealed to the outer wall of the liquid outlet pipe (5). One end of the one-way valve (4) is fixed to the inner wall of the liquid outlet connector (1).

3. The pressure balancing device for a hollow fiber filter according to claim 1, characterized in that, The liquid outlet connector (1) is provided with an eluent rinsing port (11) at the top. The eluent rinsing port (11) is connected to the inner side of the hollow fiber membrane (3) and is used to spray eluent onto the inner wall of the hollow fiber membrane (3).

4. The pressure balancing device for a hollow fiber filter according to claim 1, characterized in that, The one-way valve (4) is located near the opening of the outlet (12) of the casing (2).

5. The pressure balancing device for a hollow fiber filter according to claim 1, characterized in that, The liquid outlet pipe (5) is connected to the vacuum source (7) through the connecting pipe (6), and the side hole is located at one end of the liquid outlet pipe (5) near the shell (2).

6. The pressure balancing device for a hollow fiber filter according to claim 1, characterized in that, When the liquid outlet tube (5) is completely pulled out of the liquid outlet (12), the one-way valve (4) closes to block the hollow fiber membrane (3) from communicating with the outside world, and the liquid outlet (12) of the liquid outlet connector (1) is in a sealed state.

7. The pressure balancing device for a hollow fiber filter according to claim 1, characterized in that, The outlet (12) has a groove for mounting the one-way valve (4), and the one-way valve (4) has a protruding edge that mates with the groove at one end away from the opening of the outlet (12).

8. A pressure balancing device for a hollow fiber filter according to any one of claims 1-7, characterized in that, The outer wall of the end of the outlet pipe (5) facing the one-way valve (4) is chamfered.

9. A pressure balancing device for a hollow fiber filter according to any one of claims 1-7, characterized in that, The one-way valve (4) is a cylindrical structure made of elastic silicone or rubber, and its inner diameter is adapted to the outer diameter of the liquid outlet pipe (5). When the liquid outlet pipe (5) is inserted, the one-way valve (4) expands and opens. When the liquid outlet pipe (5) is pulled out, the one-way valve (4) contracts and tightly adheres to the inner wall of the liquid outlet connector (1) to achieve a seal.

10. A pressure balancing device for a hollow fiber filter according to any one of claims 1-7, characterized in that, The side holes (51) of the liquid outlet pipe (5) are multiple evenly distributed through holes.

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