A dead volume reduction type feed liquid recovery fitting for a three-stage filtration system

Abstract

The utility model discloses a dead volume reduction type feed liquid recovery accessory for three-stage filtering system belongs to liquid filtering equipment technical field. Mainly includes the main part, and the main part is hollow's cylindrical shape, and the inside of main part is slidably provided with movable seal, and the main part inner diameter is adapted with movable seal, and movable seal is one -way air -permeable type structure, one end of main part is connected with inlet pipe and discharge pipe, the other end of main part is connected with the snorkel, the inner wall of main part is through the honing treatment, and the roughness Ra is less than or equal to 0.8mu m, and the main part inner diameter is with movable seal cooperation gap 0.01~0.03mm, movable seal is cylindrical, and movable seal center is provided with micro - spring formula one - way pressure valve, and the both ends of movable seal are equipped with PTFE guide ring. A dead volume reduction type feed liquid recovery accessory for three-stage filtering system of the application solves the collaborative problem of "sealing liquid discharge" and "ventilation emptying".

Description

Technical Field

[0001] This utility model relates to the field of liquid filtration equipment technology, and more specifically, it relates to a dead volume reduction liquid recovery accessory for a three-stage filtration system. Background Technology

[0002] In biopharmaceuticals, fine chemicals, and other fields, a three-stage filtration system (typically consisting of coarse filtration, fine filtration, and a terminal filter) is crucial for ensuring the purity of the feed solution. Filters that have reached their load capacity (such as terminal sterilization filters) need to be replaced periodically. In existing technologies, dead volumes (typically 10ml-1L) exist at the filter-to-pipeline connection points and within the filter itself. When replacing the filter, the feed solution within the dead volume cannot be effectively recovered, leading to the loss of valuable feed solutions (such as monoclonal antibodies and high-concentration drug solutions). Furthermore, traditional emptying methods have the following drawbacks: Manual purging defects: When compressed air or gas pumped in by a peristaltic pump is introduced through the main pipeline to vent the filter, the filter membrane is prone to bursting due to uncontrolled pressure (most filters have a pressure resistance of ≤0.3MPa). Furthermore, if the air is not purified, it may carry microorganisms / particles and contaminate the residual liquid. Natural drainage defects: It relies on the natural dripping of liquid by gravity, resulting in incomplete drainage, a dead volume loss rate of over 10%, and a long time consumption (5-10 minutes), which affects filtration efficiency. Conflict between sealing and ventilation: Existing piston-type drain accessories can only achieve sealed draining, and cannot simultaneously meet the requirements of "sealing during draining and ventilation during emptying", resulting in residual liquid in the filter not being blown away. In summary, existing technologies lack a filter replacement accessory that can simultaneously achieve "low dead volume, pollution prevention, and ease of operation," and there is an urgent need to solve these problems through structural improvements.

[0003] Therefore, it is necessary to provide a dead volume reduction liquid recovery accessory for a three-stage filtration system to solve the above problems. Utility Model Content

[0004] Based on the aforementioned problems in the existing technology, the purpose of this application is to provide a dead volume reduction liquid recovery accessory for a three-stage filtration system, which solves the problem of coordinating "sealed drainage" and "ventilated drainage".

[0005] The technical solution adopted by this application to solve its technical problem is: a dead volume reduction type liquid recovery accessory for a three-stage filtration system, including a main body, the main body being a hollow cylinder, a movable seal being slidably disposed inside the main body, the inner diameter of the main body being adapted to the movable seal, the movable seal being a one-way permeable structure, one end of the main body being connected to an inlet pipe and an outlet pipe, and the other end of the main body being connected to a vent pipe.

[0006] Furthermore, the inner wall of the main body is honed, with a roughness Ra≤0.8μm.

[0007] Furthermore, the clearance between the inner diameter of the main body and the movable seal is 0.01-0.03 mm.

[0008] Furthermore, the movable seal is cylindrical, and a miniature spring-type one-way pressure valve is provided at the center of the movable seal. PTFE guide rings are fitted at both ends of the movable seal.

[0009] Furthermore, the movable seal is annular, and a PTFE breathable membrane is fixed to the left end face of the movable seal by ultrasonic welding.

[0010] Furthermore, the vent pipe is connected to an external air source, and a two-stage gas filter is connected in series between the vent pipe and the external air source. The first stage is a 5μm particle filter, and the second stage is a 0.22μm sterilization filter.

[0011] Furthermore, a pressure reducing and stabilizing valve is integrated between the two-stage gas filter and the vent pipe.

[0012] The beneficial effects of this utility model are: 1. Significantly reduced dead volume loss: Through the design of "the left end of the liquid inlet and outlet is aligned with the end of the seal's stroke" and "the seal moves along the wall", combined with the ventilation and venting function, the residual liquid is ≤0.5mL, which is more than 90% less than the traditional method, making it especially suitable for the recovery of valuable liquids. 2. Excellent anti-pollution performance: The right end integrates two-stage gas filtration, combined with corrosion-resistant and non-leaching materials such as 316L stainless steel and PTFE, which meet FDA 21 CFR Part 177 and GMP requirements to avoid contamination of liquid materials; 3. Safe and convenient operation: The pressure reducing and stabilizing valve controls the maximum ventilation pressure to ≤0.2MPa to prevent filter damage; the three-way switching valve enables quick switching between "main filtration" and "parts recycling" without disconnecting the pipeline, and the residual liquid recovery time during filter replacement is ≤5 minutes; 4. High adaptability: The movable seal provides two implementation methods, which are suitable for low viscosity liquids and high viscosity liquids respectively; the sanitary quick-connect fitting is suitable for existing three-stage filtration system pipelines without the need to modify the main system. Attached Figure Description

[0013] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments and descriptions of this utility model are used to explain this utility model and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is an overall schematic diagram of a dead volume reduction type liquid recovery accessory for a three-stage filtration system according to this application; In the diagram: 1. Main body; 2. Movable seal; 3. Inlet pipe; 4. Outlet pipe; 5. Vent pipe. Detailed Implementation

[0014] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0015] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0016] In this utility model, unless otherwise stated, the orientations used, such as "up" and "down", usually refer to the direction shown in the accompanying drawings, or to the vertical, perpendicular, or gravitational direction; similarly, for ease of understanding and description, "left" and "right" usually refer to the left and right shown in the accompanying drawings; "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not used to limit this utility model.

[0017] like Figure 1 As shown, this application provides a dead volume reduction type liquid recovery accessory for a three-stage filtration system, including a body 1. The body 1 is a hollow cylinder made of 316L stainless steel or high borosilicate glass, and the inner wall of the body 1 is honed (roughness Ra≤0.8μm). The axial length of the cylindrical body is 80-150mm, and the inner diameter is 20-30mm, ensuring that the sealing stroke meets the dead volume coverage requirements.

[0018] A movable seal 2 is slidably mounted inside the main body 1, and the inner diameter of the main body 1 is adapted to the movable seal 2 (fitting clearance 0.01-0.03mm). The movable seal 2 is a one-way ventilated structure, and the following two structures are optional: 1. The movable seal 2 is made of perfluororubber with a Shore hardness of 70-80 HA and is cylindrical. A miniature spring-loaded one-way pressure valve is located at the center of the movable seal 2, with a threshold pressure set at 0.1-0.2 MPa (0.3 MPa lower than the filter's withstand pressure), and the valve port faces left. PTFE guide rings, 2-3 mm thick, are fitted at both ends of the movable seal 2. These PTFE guide rings ensure that the seal moves along its axis without uneven wear.

[0019] 2. The movable seal 2 is made of EPDM material and is ring-shaped. A PTFE breathable membrane (0.22μm pore size, sterilization grade) is fixed to the left end face of the movable seal 2 by ultrasonic welding. The PTFE breathable membrane covers 80% of the area of ​​the movable seal 2, ensuring that gas can only pass through the membrane from the right end to the left end, and liquid cannot pass through.

[0020] One end of the main body 1 is connected to the inlet pipe 3 and the outlet pipe 4.

[0021] The other end of the main body 1 is connected to a vent pipe 5. Vent pipe 5 is connected to an external air source, and a two-stage gas filter is connected in series between vent pipe 5 and the external air source: the first stage is a 5μm particulate filter (polypropylene material), and the second stage is a 0.22μm sterilizing filter (PTFE material), ensuring the cleanliness of the incoming gas. A pressure reducing and regulating valve is integrated between the two-stage gas filters and vent pipe 5. The pressure reducing and regulating valve has a range of 0-0.5MPa and the output pressure can be manually set (default 0.2MPa) to prevent overpressure damage to the filter.

[0022] The position of the seal can be monitored by setting a magnetostrictive sensor on the left end of the outer wall of the main body 1, or by setting a transparent observation window made of high borosilicate glass in the middle of the main body 1.

[0023] During use, it is equipped with a three-way switching valve. One end is connected to the main inlet of the three-stage filtration system via a sanitary quick-connect fitting (such as Tri-Clamp 1 / 2"), the other end is connected to the inlet of the target filter, and the other end serves as a sample port (sampling valve optional).

[0024] A one-way check valve is integrated on the pipeline connecting the three-way switching valve and the filter, with the flow direction being "cylindrical body → filter" to prevent gas from flowing back into the main pipeline.

[0025] Normal filtration stage: The three-way switching valve is switched to "main line mode", and the liquid enters the filter directly from the main line of the three-stage filtration system. The movable seal 2 is at the right end of the main body 1 (initial position). This type of dead volume reduction liquid recovery accessory for the three-stage filtration system does not participate in the flow guidance. Filter replacement preparation stage: When the filter reaches its load (monitored by differential pressure gauge, differential pressure ≥ 0.1MPa), switch the three-way switching valve to "accessory mode", the main liquid supply line is closed, and this dead volume reduction type liquid recovery accessory for three-stage filtration system forms a closed loop with the filter; Seal drainage stage: Turn on the external air source (clean compressed air), after being purified by two-stage filters and stabilized by pressure reducing and stabilizing valve (0.2MPa), it is introduced into the right end of the main body 1 through the air pipe 5; the gas pushes the movable seal 2 to move to the left along the inner wall of the main body 1, squeezing the residual protein solution inside the main body 1 and the filter, and the solution is discharged into the clean container through the recovery port of the three-way switching valve at the left end. During the venting and purging phase: When the movable seal 2 moves to the left end of the main body 1 (the magnetostrictive sensor outputs a positioning signal), the gas pressure at the right end rises to the threshold of the one-way pressure valve (0.15MPa). The miniature spring-type one-way pressure valve is opened, and the gas passes through the left end of the movable seal 2 and is blown into the filter through the one-way check valve to thoroughly clean the residual liquid inside the filter (lasting 10-15 seconds). Reset and filter replacement: Turn off the gas supply, reverse the flow of a small amount of nitrogen (0.05MPa) to push the movable seal 2 back to the right end; disconnect the filter connection, replace the filter with a new one, switch the three-way switching valve back to "main mode" to restore normal filtration.

[0026] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. Significantly reduced dead volume loss: Through the design of "the left end of the liquid inlet and outlet is aligned with the end of the seal's stroke" and "the seal moves along the wall", combined with the ventilation and venting function, the liquid residue is ≤0.5mL, which is more than 90% less than the traditional method (0.5-5mL residue), making it especially suitable for the recovery of valuable liquids. 2. Excellent anti-contamination performance: The right end integrates two-stage gas filtration (particle + sterilization), combined with corrosion-resistant and non-leaching materials such as 316L stainless steel and PTFE, which meet FDA 21 CFR Part 177 and GMP requirements to avoid contamination of liquid materials; 3. Safe and convenient operation: The pressure reducing and stabilizing valve controls the maximum ventilation pressure to ≤0.2MPa to prevent filter damage; the three-way switching valve enables quick switching between "main filtration" and "parts recycling" without disconnecting the pipeline, and the residual liquid recovery time during filter replacement is ≤5 minutes; 4. High adaptability: The movable seal provides two implementation methods, which are adapted to low viscosity liquids (buffer solutions) and high viscosity liquids (protein solutions) respectively; the sanitary quick-connect fitting is compatible with existing three-stage filtration system pipelines (such as 1 / 2" and 3 / 4" interfaces), without the need to modify the main system. The following are performance tests: Dead volume test: The feed solution was simulated using a 10% bovine serum albumin solution (viscosity 3 cP), and the residual volume after recovery was 0.3 mL; Sealing test: No leakage was observed in the seals after 30 minutes of continuous pressure at 0.2 MPa. Compatibility test: The accessories were soaked in 10% bovine serum albumin solution for 24 hours, and HPLC analysis showed no protein denaturation or leaching of impurities.

[0027] Obviously, the embodiments described above are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0028] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0030] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

[0031] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A dead volume reduction type liquid recovery accessory for a three-stage filtration system, characterized in that: Includes a main body (1), which is a hollow cylinder. A movable seal (2) is slidably disposed inside the main body (1). The inner diameter of the main body (1) is adapted to the movable seal (2). The movable seal (2) is a one-way breathable structure. One end of the main body (1) is connected to an inlet pipe (3) and an outlet pipe (4). The other end of the main body (1) is connected to a vent pipe (5).

2. The dead volume reduction type liquid recovery accessory for a three-stage filtration system according to claim 1, characterized in that: The inner wall of the main body (1) is honed, and the roughness Ra≤0.8μm.

3. The dead volume reduction type liquid recovery accessory for a three-stage filtration system according to claim 1, characterized in that: The inner diameter of the main body (1) and the movable seal (2) have a clearance of 0.01-0.03 mm.

4. A dead volume reduction type liquid recovery accessory for a three-stage filtration system according to claim 1, characterized in that: The movable seal (2) is cylindrical, and a miniature spring-type one-way pressure valve is provided in the center of the movable seal (2). PTFE guide rings are fitted at both ends of the movable seal (2).

5. A dead volume reduction type liquid recovery accessory for a three-stage filtration system according to claim 1, characterized in that: The movable seal (2) is annular, and a PTFE breathable membrane is fixed to the left end face of the movable seal (2) by ultrasonic welding.

6. A dead volume reduction type liquid recovery accessory for a three-stage filtration system according to claim 1, characterized in that: The ventilation pipe (5) is connected to an external air source. A two-stage gas filter is connected in series between the ventilation pipe (5) and the external air source. The first stage is a 5μm particle filter and the second stage is a 0.22μm sterilization filter.

7. A dead volume reduction type liquid recovery accessory for a three-stage filtration system according to claim 6, characterized in that: A pressure reducing and stabilizing valve is integrated between the two-stage gas filter and the vent pipe (5).

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