Split thin film filter

Abstract

The utility model relates to a kind of split type membrane filter, including filter piece and sample container;Sample container is formed with container cavity in it, and container nozzle is provided on sample container, and container nozzle is used for sample liquid to enter and exit container cavity;Filter piece is provided with filter cavity in it, and the bottom of filter piece is provided with water outlet hole communicated with filter cavity, filter membrane is provided in filter cavity, and filter membrane is used to filter liquid from filter cavity to water outlet hole;Interface is provided on filter piece and is communicated with filter cavity, and interface is suitable for detachably connected with container nozzle;When container nozzle is connected with interface, sample container is connected with filter piece as a whole, and container cavity is communicated with filter cavity by the channel formed by the connection of container nozzle and interface.The utility model can sample and transport sample liquid by sample container, and it is beneficial to the popularization of membrane filtration method.The utility model reduces the restriction to the size of filter piece, which helps to reduce the manufacturing cost, storage cost and transportation cost of filter piece.

Description

Technical Field

[0001] This utility model relates to the field of microbial limit detection technology, specifically to a split-type membrane filter. Background Technology

[0002] Membrane filtration is suitable for detecting microbial limits in sample solutions, such as beverages, pharmaceuticals, biological agents, biological reagents, hospital treatment water, and disinfectants. One method of membrane filtration involves placing the sample solution in a filter element (e.g., a vacuum filter cup) containing a membrane designed to intercept microorganisms. The membrane is sealed tightly to prevent leakage. Positive or negative pressure is used to expel liquid from the filter element, trapping microorganisms on the membrane. The membrane is then placed flat on an agar medium and incubated. The number of colonies (CFU) growing on the membrane is counted to determine if the microbial limits are exceeded.

[0003] While using filter elements to filter sample solutions is widely used, it presents the following technical challenges:

[0004] The filter element needs to form a chamber for holding the test sample liquid, which results in a large size of the filter element, especially in the height direction. Firstly, more material is needed to manufacture the filter element, resulting in higher material costs. Secondly, the large size of the filter element will occupy a large storage space during transportation, resulting in higher logistics costs.

[0005] Due to the high price of filter components, there is a risk of complete loss of the filter components during use and circulation, especially when used by front-line sampling personnel. The high management costs also limit the application of filter components and hinder the popularization of membrane filtration.

[0006] Using filters for sampling places high demands on operators and also on the transport of the filters containing sample solutions, which limits the application of filters and hinders the widespread adoption of membrane filtration. Utility Model Content

[0007] The purpose of this invention is to provide a split-type membrane filter to alleviate or eliminate at least one of the aforementioned technical problems.

[0008] The present invention provides a split-type membrane filter, comprising a filter element and a sample container separately disposed relative to the filter element; the sample container has a container cavity formed therein, and a container nozzle is provided on the sample container for allowing sample liquid to enter and exit the container cavity.

[0009] The filter element has a filter chamber inside, and the bottom of the filter element has a water outlet hole communicating with the filter chamber. The filter chamber has a filter membrane inside, and the filter membrane is used to filter the liquid flowing from the filter chamber to the water outlet hole.

[0010] The filter element is provided with an interface communicating with the filter cavity, and the interface is adapted to be detachably connected to the container nozzle; when the container nozzle is connected to the interface, the sample container and the filter element are integrated into a whole, and the container cavity and the filter cavity are connected through a channel formed by the connection between the container nozzle and the interface.

[0011] Optionally, the sample container is configured such that the volume of the container cavity can vary with changes in the pressure inside the container cavity.

[0012] Optionally, the wall of the container cavity is flexible, so that the volume of the container cavity can change with the pressure inside the container cavity.

[0013] Optionally, the sample container is a sample bag.

[0014] Optionally, the sample bag includes a bag body with a rigid spout and a bag cap detachably connected to the rigid spout, the bag cap being used to open and close the rigid spout.

[0015] Optionally, the wall of the container cavity is a rigid body, and the wall of the container cavity is provided with an air vent with an air filter.

[0016] Optionally, the interface is located on top of the filter element.

[0017] Optionally, the height of the filter chamber is from 0.1 mm to 100 mm.

[0018] This invention allows for the sampling and transport of sample liquids via a sample container, facilitating the widespread adoption of membrane filtration methods. Furthermore, this invention reduces limitations on the size of the filter element, helping to lower manufacturing, storage, and transportation costs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the split-type membrane filter described in some embodiments;

[0020] Figure 2 This is a partially enlarged schematic diagram of the filter element described in some embodiments;

[0021] Figure 3 This is a schematic diagram illustrating the operation of the microbial limit detection method described in some embodiments.

[0022] In the diagram: 1—Filter element; 2—Sample bag; 3—Sample solution;

[0023] 11—Cup holder; 12—Side wall; 13—Top wall; 14—Filter chamber; 15—Interface; 16—Filter membrane; 17—Water outlet; 18—Connecting cylinder;

[0024] 21—Bag body; 22—Bag lid. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings.

[0026] The embodiments of this utility model will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be understood that the preferred embodiments are only for illustrating this utility model and not for limiting the scope of protection of this utility model.

[0027] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0028] like Figure 1 The illustrated split-type membrane filter includes a filter element 1 and a sample container separately disposed relative to the filter element 1. The sample container has a container cavity and a container nozzle for allowing sample liquid 3 to enter and exit the container cavity. The filter element 1 has a filter chamber 14, and the bottom of the filter element 1 has a water outlet 17 communicating with the filter chamber. The filter chamber 14 has a filter membrane 16 for filtering the liquid flowing from the filter chamber 14 to the water outlet 17. The filter element 1 has an interface 15 communicating with its filter chamber 14, and the interface 15 is adapted to be detachably connected to the container nozzle. When the container nozzle is connected to the interface 15, the sample container and the filter element 1 are integrated, and the container cavity and the filter chamber 14 are connected through a channel formed by the connection between the container nozzle and the interface 15.

[0029] Using the above technical solution, a sample container can be used to collect and hold the sample solution 3 at the sampling site. At the testing site, the sample container containing the sample solution 3 is connected to the filter element 1 to filter the sample solution 3. The filter membrane 16 is used to intercept microorganisms in the sample solution 3, and the water outlet 17 is used to drain the water in the sample solution 3.

[0030] Using the aforementioned split-type membrane filter, sample containers can be used for sampling and transporting samples, eliminating the need to bring filter element 1 to the sampling site. This reduces the possibility of filter element 1 being lost. Moreover, the cost of sample containers is usually much lower than that of filter element 1, reducing the limitations on the application of filter element 1. Since the high-cost component does not leave the laboratory, only the low-cost sample containers are distributed to various clinical departments, reducing the cost of loss and facilitating sample collection, transport, and the popularization of membrane filtration methods.

[0031] By employing the aforementioned split-type membrane filter, since the sample container provides a cavity for holding the sample liquid 3, the volume requirement for the sample cup filtration cavity 14 is smaller, allowing for a smaller size of the filter element 1. On one hand, this reduces the material used in the filter element 1, lowering material costs; on the other hand, the smaller size of the filter element 1 requires less storage space, helping to reduce storage and transportation costs.

[0032] In practical implementation, the use of the aforementioned split-type membrane filter significantly reduces the limitation on the height of the filter chamber 14 of the filter element 1. The height of the filter chamber 14 can be set from 0.1mm to 100mm. For example: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, ..., 1mm, 2mm, 3mm ..., 100mm. In practical implementation, the height of the filter chamber 14 can be set to any height between 0.1mm and 100mm as needed.

[0033] In some embodiments, the sample container is configured such that the volume of the container cavity can change with the pressure inside the container cavity. Using this design, during the filtration process where the sample container containing the sample solution 3 is placed on the filter element 1, the pressure-adjustable volume of the container cavity allows the sample solution 3 to be smoothly transferred from the container cavity to the filter chamber 14 of the filter element 1 under negative pressure. Furthermore, this sample container can typically be contracted to reduce storage space requirements, thereby lowering storage and transportation costs.

[0034] In existing technologies, to ensure smooth filtration, a vent is typically provided on the lid of the filter element 1, and an air filter for filtering air is installed at the vent. By setting a container cavity whose volume can change with pressure, the vent is not required on the lid of the filter element 1, which simplifies the structure of the filter element 1 and reduces its cost.

[0035] In some embodiments, the walls of the container cavity are flexible, allowing the volume of the container cavity to change with variations in internal pressure. Specifically, by making the walls of the container cavity deformable and flexible, a container cavity whose volume can change with internal pressure can be formed. Specifically, the flexible material can be made of flexible material, or it can be formed by combining a flexible material with a deformable structure. The deformable structure can be, but is not limited to, corrugated structures or thin-walled structures, and the flexible material can be, but is not limited to, plastics or rubber.

[0036] The wall of the container cavity is preferably soft, but it can also be made hard when necessary. When the wall of the container cavity is made hard, in order to balance the air pressure and allow the sample liquid 3 in the container cavity to flow smoothly into the filter cavity 14 of the filter element 1, the wall of the container cavity is provided with an air vent with an air filter.

[0037] As a specific example, the sample container is sample bag 2. Sample bag 2 can be a commercially available product, and it is easy to manufacture, inexpensive, and readily achievable. Sample bag 2 meets the requirement that the volume of the container cavity can change with the pressure inside the cavity.

[0038] In practice, sample bag 2 typically includes a bag body 21, a spout connected to the bag body 21, and a cap 22 for opening and closing the spout. The inner cavity of the bag body 21 is the container cavity. Compared to sample cups, sample bag 2 requires less operator skill and has lower transport requirements, facilitating the widespread adoption of membrane filtration methods.

[0039] In some embodiments, the sample bag 2 includes a bag body 21 with a rigid spout and a bag cap 22 detachably connected to the rigid spout. The bag cap 22 is used to open and close the rigid spout. The rigid spout facilitates direct connection between the spout and the interface 15. In a specific implementation, the rigid spout has external threads, and the bag cap 22 has internal threads that mate with the external threads. The bag cap 22 and the rigid spout are detachably connected via a threaded connection.

[0040] In some embodiments, a detachable connection structure is provided between the interface 15 and the container nozzle, which is suitable for direct connection between the interface 15 and the container nozzle. By directly connecting the container nozzle to the interface 15, the sample liquid 3 can enter the filter chamber 14 of the sample cup through the container nozzle and the interface 15, eliminating the need for tubing to connect the sample container and the filter element 1. This helps reduce testing costs and allows more sample liquid 3 from the sample container to enter the filter element 1. In specific implementations, the detachable connection structure can adopt, but is not limited to, a threaded connection structure, a snap-fit ​​structure, or a quick-connect coupling structure.

[0041] In practical implementation, to better connect the container nozzle, a connector for detachable connection to the container nozzle is provided at interface 15. The connector can be integrally formed on the top wall 13 of the cup body with the cup body of filter element 1.

[0042] In practical implementation, since the filter element 1 and the sample container adopt a separate design, the filter element 1 can be packaged independently. This means that a sealing element is not required at the interface 15 of the filter element 1. For example, the filter element 1 can be sealed in a separate packaging bag, and can be directly taken out and used after opening the bag. Obviously, a removable sealing element can also be installed at the interface 15 of the filter element 1 when needed.

[0043] In some embodiments, the bottom of the filter element 1 is provided with a water outlet 17 communicating with the filter chamber 14. A filter membrane 16 is provided inside the filter chamber 14, and the filter membrane 16 is used to filter the liquid flowing from the filter chamber 14 to the water outlet 17. The filter membrane 16 is used to intercept microorganisms in the sample solution 3, and the water outlet 17 is used to drain water from the sample solution 3.

[0044] In specific implementation, the filter element 1 includes a cup body and a cup seat 11. The cup body has a top wall 13 and a side wall 12, which together form a space with a lower opening. The cup body and the cup seat 11 form a filter chamber 14. A water outlet 17 is disposed on the cup seat 11. A filter membrane 16 is clamped between the cup body and the cup seat 11, and an interface 15 is disposed on the top wall 13 of the cup body. Using the above technical solution, the filter membrane 16 is clamped between the cup body and the cup seat 11 to prevent leakage, and it features easy installation and removal of the filter membrane 16. A pressure ring is provided inside the cup body, and the periphery of the filter membrane 16 is pressed downward and sealed by the pressure ring to prevent leakage.

[0045] In some embodiments, the interface 15 is disposed on the top of the filter element 1. The interface 15 is disposed on the top wall 13 of the cup body to facilitate the downward flow of the sample liquid 3 in the sample container into the filter chamber 14 of the filter element 1.

[0046] In specific implementation, the cup body, cup seat 11, the connection structure between the two and the sealing structure between the two can be implemented with reference to the filter element 1 or the suction cup in the prior art.

[0047] In practical implementation, the cup body of this application can adopt a one-piece molded structure. For example, a one-piece molded transparent plastic cup body.

[0048] In some embodiments, the cup holder 11 is provided with a structure for detachable connection with a filtration device. The filtration device offers the advantage of simple operation. The cup holder 11 is provided with a downwardly extending connecting cylinder 18, and the water outlet 17 communicates with the connecting cylinder 18. The connecting cylinder 18 is used to connect to and seal with the filtration device. Existing products can be selected for the filtration device, such as the fully automatic membrane filtration machine described in Chinese patent application CN201720853552.6.

[0049] This utility model also provides a method for detecting microbial limits, using any of the split-type membrane filters described above. The method for detecting microbial limits includes the following steps:

[0050] Collect the sample, add the sample to the sample container to form sample solution 3, and seal the sample container;

[0051] The sample container containing sample solution 3 was transported to the testing site;

[0052] The container nozzle of the sample container is connected to the interface 15 of the filter element 1, so that the container cavity of the sample container is connected to the filter cavity 14 of the filter element 1.

[0053] Perform a vacuum filtration operation on filter element 1 or squeeze the sample container. The sample liquid 3 in the sample container gradually transfers to the filter chamber 14 of filter element 1. The sample liquid 3 in the filter chamber 14 of filter element 1 is filtered until the sample liquid 3 in the sample container and the sample liquid 3 in the filter element 1 are filtered out.

[0054] Open filter element 1 and remove the filter membrane for incubation.

[0055] It should be noted that when the sample contains little or no liquid, liquid can be added to the sample container to form sample solution 3.

[0056] In practice, the filtration operation of filter element 1 can be performed using a filtration device that is compatible with filter element 1.

[0057] The sample container described above can be a sample bag 2. By squeezing the sample bag 2, the sample liquid 3 in the sample container is gradually transferred to the filter chamber 14 of the filter element 1, and the sample liquid 3 in the filter chamber 14 of the filter element 1 is filtered. The experiment is conducted by squeezing the sample bag 2, which is easy to implement, has low requirements, and is low in cost.

[0058] The characteristics of the microbial limit detection method described above have been explained in the introduction to the split-type membrane filter, which can be referred to, and will not be repeated here.

[0059] This invention separates the two functions of a conventional vacuum filtration cup widely used in the prior art, facilitating cost reduction and ease of use. The container and filtration functions are designed to be separable, allowing for the separation of sample collection, transportation, and filtration operations. This clear division of labor and separation of the two stages significantly reduces costs, primarily affecting the filtration component. Only the container is involved in sample collection and transportation, greatly reducing losses during transit. It avoids the greater losses associated with conventional filtration components during transit. Risk is mitigated through the low-cost container component. This also facilitates the collection and centralized transport of samples after collection, such as samples collected by third-party testing companies and during epidemic outbreaks.

[0060] The above embodiments are merely preferred embodiments provided to fully illustrate the present utility model, and the protection scope of the present utility model is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present utility model are all within the protection scope of the present utility model. In the description of this specification, the reference to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., means that a specific feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of the present utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0061] In the description of this utility model, it should be understood that the terms "upper" and "lower," etc., indicate the orientation based on the attached... Figure 1 The coordinate system in the diagram represents the orientation only for the convenience of describing the present invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

Claims

1. A split-type membrane filter, characterized in that, The sample container includes a filter element and a sample container separately disposed relative to the filter element; the sample container has a container cavity formed inside the sample container and a container nozzle is provided on the sample container for allowing sample liquid to enter and exit the container cavity. The filter element has a filter chamber inside, and the bottom of the filter element has a water outlet hole communicating with the filter chamber. The filter chamber has a filter membrane inside, and the filter membrane is used to filter the liquid flowing from the filter chamber to the water outlet hole. The filter element is provided with an interface communicating with the filter cavity, and the interface is adapted to be detachably connected to the container nozzle; when the container nozzle is connected to the interface, the sample container and the filter element are integrated into a whole, and the container cavity and the filter cavity are connected through a channel formed by the connection between the container nozzle and the interface.

2. The split-type membrane filter according to claim 1, characterized in that, The sample container is configured such that the volume of the container cavity can change with the pressure inside the container cavity.

3. The split-type membrane filter according to claim 2, characterized in that, The walls of the container cavity are made of soft material so that the volume of the container cavity can change with the pressure inside the container cavity.

4. The split-type membrane filter according to claim 3, characterized in that, The sample container is a sample bag.

5. The split-type membrane filter according to claim 4, characterized in that, The sample bag includes a bag body with a rigid spout and a bag cap detachably connected to the rigid spout, the bag cap being used to open and close the rigid spout.

6. The split-type membrane filter according to claim 1, characterized in that, The wall of the container cavity is a rigid body, and the wall of the container cavity is provided with an air vent with an air filter.

7. The split-type membrane filter according to claim 1, characterized in that, The interface is located on top of the filter element.

8. The split-type membrane filter according to claim 1, characterized in that, The height of the filter chamber is from 0.1 mm to 100 mm.

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