An ultrafiltration centrifuge tube

Abstract

This utility model provides an ultrafiltration centrifuge tube, including an inner tube and an outer tube. The outer edge of the inner tube's opening overlaps the inner edge of the outer tube's opening. The gap between the outer wall of the inner tube and the inner wall of the outer tube forms a filtration cavity. The outer tube's port is provided with a cap. The upper end of the inner tube has a liquid storage cavity, and the lower end has a filtration cavity. A wedge-shaped block is provided in the filtration cavity. The inner tube has a first filtration surface and a second filtration surface arranged opposite each other on both sides of the filtration cavity. Both the first and second filtration surfaces are provided with filter membranes. The wedge-shaped block is located between the first and second filtration surfaces, dividing the filtration cavity into the first and second filtration cavities. The filter membrane is an ultrafiltration membrane, and the wedge-shaped block is wedge-shaped.

Description

Technical Field

[0001] This utility model relates to the field of filter devices, and in particular to an ultrafiltration centrifuge tube. Background Technology

[0002] In the life sciences, membrane separation has become a highly efficient separation method, gradually replacing traditional methods such as chemical precipitation, dialysis, and lyophilization. Ultrafiltration centrifuge tubes are commonly used membrane separation tools in laboratories, primarily for the concentration, desalting, buffer replacement, or purification of biological macromolecules. Ultrafiltration centrifuge tubes utilize the pore size of the ultrafiltration membrane, employing centrifugal force to drive the solution through the membrane for selective retention. Large molecules such as proteins are retained in the upper layer, forming the retention solution, while smaller molecules such as salts and water are filtered out to the lower layer, yielding the filtrate. In use, the sample solution to be processed is injected into the upper layer of the ultrafiltration centrifuge tube, and the appropriate centrifugal force and time are set. After centrifugation, the upper layer of the ultrafiltration centrifuge tube contains the retention solution concentrated with the target macromolecules, while the lower layer is the filtrate composed of the filtered-out smaller molecules and the solvent.

[0003] Ultrafiltration centrifuge tubes are classified into two types based on the placement of the filter membrane in their main structure: one type has the filter membrane placed horizontally, and the other has the filter membrane placed vertically. Due to structural limitations, horizontally placed membranes typically have a smaller membrane area and are prone to concentration polarization, leading to increasingly slower filtration speeds and reduced filtration efficiency. Therefore, most commercially available ultrafiltration centrifuge tubes use a near-vertical vertical placement of the filter membrane. Centrifuge tubes with vertically placed membranes have a larger membrane area, reduce membrane fouling caused by concentration polarization, and have a faster filtration speed than the former.

[0004] However, vertical placement of the filter membrane also has its drawbacks: during centrifugation, as the upper layer of liquid gradually concentrates and decreases, when the liquid decreases to a certain extent due to the continuous filtration of small molecules and solvents to the lower layer, the membrane surface at the top of the centrifuge tube can no longer be completely wetted by the remaining liquid and is exposed. As a result, the membrane surface wetted by the remaining liquid decreases, the filtration area gradually decreases, the filtration speed also decreases, the filtration speed slows down in the later stages, resulting in a long overall filtration time, and it can also lead to concentration polarization and membrane fouling.

[0005] In the existing technology, some ultrafiltration centrifuge tubes with improved new structures have emerged to improve these defects of vertical filter membranes. Although they have improved the filtration area and filtration efficiency to a certain extent, these patents on the market have very limited improvement in filtration speed, the overall filtration time is still very long, and they cannot solve the membrane fouling problem caused by concentration polarization. Utility Model Content

[0006] Therefore, it is necessary to provide an ultrafiltration centrifuge tube.

[0007] To solve the above-mentioned technical problems, this utility model provides an ultrafiltration centrifuge tube, including an inner tube, an outer tube sleeved around the inner tube, the outer edge of the inner tube opening overlapping the inner edge of the outer tube opening, a filtration cavity formed by the gap between the outer wall of the inner tube and the inner wall of the outer tube, a cap provided at the end of the outer tube, a liquid storage cavity at the upper end of the inner tube and a filtration cavity at the lower end, a wedge block provided in the filtration cavity, a first filtration surface and a second filtration surface arranged opposite each other on both sides of the inner tube in the filtration cavity, both the first filtration surface and the second filtration surface being provided with a filter membrane, the wedge block being located between the first filtration surface and the second filtration surface, the wedge block dividing the filtration cavity into a first filtration cavity and a second filtration cavity, and the filter membrane being an ultrafiltration membrane.

[0008] Preferably, the wedge-shaped block has corresponding first and second sides, which are respectively opposite to the two opposing filter membranes.

[0009] Preferably, the wedge-shaped block has a liquid collection groove, the opening of which faces the side where the inner tube is located, and the first filter chamber and the second filter chamber are respectively connected to the liquid collection groove.

[0010] Preferably, the shape of the liquid collection tank gradually decreases from top to bottom, so that the shape of the liquid collection tank matches the shape of the pipette tip.

[0011] Preferably, the top of the wedge block is flush with the top of the filter membrane; or, the top of the wedge block is located below the top of the filter membrane, and the distance between the top of the wedge block and the top of the filter membrane is 0-15mm.

[0012] Preferably, the two filter membranes arranged opposite each other are mirror-symmetrical, the first side is parallel to the first filter surface, the second side is parallel to the second filter surface, and the gap width of the first filter cavity and the second filter cavity is 0.05-1.5mm.

[0013] Preferably, the gap width between the first filter chamber and the second filter chamber is 0.1-0.4 mm.

[0014] Preferably, the membrane surface where the filter membrane is located has an angle with the vertical direction, and the value of the angle is in the range of 1-10°.

[0015] Preferably, the wedge block is detachably installed inside the inner tube, and the shape and size of the wedge block match the shape and size of the filter cavity, so that the two sides of the wedge block are respectively aligned and fitted into the two ends of the filter cavity.

[0016] Preferably, the inner wall of the inner tube is provided with limiting grooves on both sides opposite to each other, the limiting grooves are arranged in the vertical direction, and the two sides of the wedge block are respectively embedded in the limiting grooves, the two sides of the wedge block are interference fit with the limiting grooves.

[0017] The beneficial effects of this utility model are as follows: This application improves the inner tube structure by adding wedge blocks, thereby increasing liquid disturbance on the membrane surface and enhancing membrane turbulence, which greatly improves the utilization of membrane area in the concentration process, reduces membrane fouling, increases filtration speed, and shortens the separation and concentration time. Attached Figure Description

[0018] The above and other objects, features, and advantages of this invention will become clearer through a more detailed description of the preferred embodiments shown in the accompanying drawings. The same reference numerals indicate the same parts throughout the drawings, and the drawings are not intentionally drawn to scale with actual dimensions; the focus is on illustrating the gist of this invention.

[0019] Figure 1 This is a perspective view of the central tube with an embedded core in Embodiment 1 of the present invention;

[0020] Figure 2 This is a front view of the central tube with an embedded core in Embodiment 1 of the present invention;

[0021] Figure 3 for Figure 2 Cross-sectional view of the central tube at point AA;

[0022] Figure 4 for Figure 2 Cross-sectional view of the central tube at the FF point;

[0023] Figure 5 This is a side view of the central tube with an embedded core in Embodiment 1 of the present invention;

[0024] Figure 6 for Figure 5 Cross-sectional view at point BB;

[0025] Figure 7 This is a top view of the central tube in Embodiment 1 of the present invention;

[0026] Figure 8 This is a cross-sectional view of the inner tube according to Embodiment 1 of the present invention;

[0027] Figure 9 This is a perspective view of the inner tube according to Embodiment 1 of the present invention;

[0028] Figure 10 This is a schematic diagram of the outer tube from the front view in Embodiment 1 of the present invention;

[0029] Figure 11This is a schematic diagram of the structure of the wedge block according to a preferred embodiment of the present invention;

[0030] In the figure: outer tube 8; inner tube 1; filter chamber 4; first filter surface 31; second filter surface 32; first filter chamber 71; second filter chamber 72; wedge block 6; plane 60 corresponding to the first or second side; membrane filter 5; filter membrane 51; filter 53; liquid collection tank 13; central tube 14; filter welding area 12. Detailed Implementation

[0031] To facilitate understanding of this utility model, a more comprehensive description of this utility model will be given below with reference to the accompanying drawings.

[0032] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to and integrated with the other component, or there may be an intervening component present. The terms "mounted," "one end," "the other end," and similar expressions used in this document are for illustrative purposes only.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] refer to Figures 1-11This utility model provides an ultrafiltration centrifuge tube, including an inner tube and an outer tube. The outer edge of the inner tube's opening overlaps the inner edge of the outer tube's opening. The gap between the outer wall of the inner tube and the inner wall of the outer tube forms a filtration cavity. A cap is provided at the end of the outer tube. The upper end of the inner tube has a liquid storage cavity, and the lower end has a filtration cavity. A wedge-shaped block is provided in the filtration cavity. A first filtration surface and a second filtration surface are arranged opposite each other on both sides of the inner tube in the filtration cavity. Both the first and second filtration surfaces are provided with filter membranes. The wedge-shaped block is located between the first and second filtration surfaces, dividing the filtration cavity into the first and second filtration cavities. Preferably, the filter membrane is a non-woven fabric-supported ultrafiltration membrane. It should be noted that the liquid storage cavity is a cylindrical cavity, which is relatively long and narrow. The first filtration cavity 71 and the second filtration cavity 72 are the gaps between the filter membrane 51 and the wedge-shaped block 6. Preferably, all structures in the inner tube 1 are arranged in a centrally symmetrical manner. Furthermore, in membrane separation methods, if the centrifugation time is too long when forming the ultrafiltration centrifuge tube assembly, the local sealing performance requirements for the ultrafiltration membrane and the ultrafiltration centrifuge tube assembly are higher. Poor sealing will cause leakage, seriously affecting the separation effect and data reliability. This application innovates the structural design of the filter centrifuge tube by adding a wedge block 6, making full use of the membrane area, improving its filtration speed, and shortening the concentration time. The surface of the wedge block 6 is polished to prevent protein adsorption on the material surface. The centrifuge tube of this utility model has the following advantages: more efficient use of membrane area and faster filtration speed; shortened centrifugation filtration time and better prevention of protein aggregation during centrifugation; better membrane surface flow rate and stronger membrane surface scouring ability to prevent membrane fouling.

[0035] In a preferred embodiment, the wedge block has corresponding first and second sides, which are respectively opposite to two oppositely arranged filter membranes.

[0036] In a preferred embodiment, a liquid collection groove is provided on the wedge block, with the groove opening facing the side where the inner tube port is located. The first and second filter chambers are respectively connected to the liquid collection groove. More preferably, the liquid collection groove 13 extends from top to bottom through the wedge block 6, and is vertically positioned at the center of the wedge block 6. The groove opening of the liquid collection groove 13 is the liquid collection port. The liquid collection port is pre-reserved on the wedge block, and has a certain taper from top to bottom, facilitating the extraction of the concentrate using a pipette after centrifugation.

[0037] In a preferred embodiment, the shape of the liquid collection tank gradually decreases from top to bottom, so that the shape of the liquid collection tank matches the shape of the pipette tip.

[0038] In a preferred embodiment, the top of the wedge block is flush with the top of the filter membrane; or, the top of the wedge block is located below the top of the filter membrane, and the distance between the top of the wedge block and the top of the filter membrane is 0-15 mm.

[0039] In a preferred embodiment, the two opposing filter membranes are mirror-symmetrical, with the first side parallel to the first filter surface and the second side parallel to the second filter surface. The gap width between the first and second filter chambers is 0.05-1.5 mm. The two sides of the wedge block 6 are parallel to the membrane surface of the filter membrane 51 and maintain a certain distance; the 0.05-1.5 mm gap width ensures sufficient contact between the liquid and the membrane surface. A liquid collection port is provided in the middle of the wedge block 6 to facilitate the insertion of a pipette to remove the concentrate after centrifugation. Optionally, the filter plate has several liquid outlets. Liquid permeating through the membrane surface collects at the outlet holes and flows out into the outer tube 8 for collection. It should be noted that the gap width of the first filter chamber refers to the distance between the first side and the first filter surface, and the gap width of the second filter chamber refers to the distance between the second side and the second filter surface.

[0040] In a preferred embodiment, the gap width between the first and second filter chambers is 0.1-0.4 mm. This gap width ensures that the liquid can fully contact the membrane surface.

[0041] In a preferred embodiment, the membrane surface where the filter membrane is located has an angle with the vertical direction, and the angle ranges from 1 to 10°.

[0042] In a preferred embodiment, the wedge block 6 is integrally formed with the inner tube 1; alternatively, the wedge block is detachably installed inside the inner tube, and the shape and size of the wedge block match the shape and size of the filter chamber, so that the two sides of the wedge block are respectively aligned and fitted into the two ends of the filter chamber. The shape of the wedge block 6, especially the shape of the two ends of the wedge block 6, is modeled after the inner cavity structure of the inner tube 1, and the wedge block 6 reduces the dead volume of the filtration area. The wedge block 6 can be a separate unit; after the central tube 14 is manufactured, the wedge block 6 is inserted to form the inner tube 1, which is then inserted into the outer tube 8, and the tube cap is screwed on to complete the production of a single centrifuge tube product. Optionally, the material of the wedge block 6 is the same as the material of the inner tube 1, and the material of the inner tube 1 is any one or more of polystyrene, polystyrene-butadiene copolymer, polystyrene-butadiene-acrylonitrile copolymer, polycarbonate, polypropylene, etc.

[0043] In a preferred embodiment, limiting grooves are provided on both sides of the inner wall of the inner tube, the limiting grooves are arranged in the vertical direction, and the two sides of the wedge block are respectively embedded in the limiting grooves, with the two sides of the wedge block and the limiting grooves being interference fit.

[0044] Preferably, when the wedge block 6 and the central tube 14 are detachably installed, the inner tube 1 includes the central tube 14, the wedge block 66, and the membrane filter 5. Two filter openings are arranged opposite each other at the lower end of the central tube. The filter 5 is fixed to the two oppositely arranged filter openings by welding and embedding to form a first filter surface and a second filter surface. The first and second filter surfaces are mirror-symmetrical and both have filter holes. An outer tube 8 is fitted over the inner tube 1. The ends of the inner tube 1 and the outer tube 8 are capped. The inner tube 1 has a liquid storage chamber, which consists of an upper storage chamber and a lower filter chamber. A gap filtration chamber is formed between the outer wall of the central tube and the inner wall of the outer tube 8. The filter holes connect the liquid storage chamber and the gap filtration chamber, and the filter membrane covers the filter holes. The filter membrane 51 is an ultrafiltration membrane. In this design, a filter membrane is welded to the inner side of the filter element 53, forming a membrane-coated filter element 5. An annular filter element welding area 12 is located on the outer side of the central tube 14 around the filter perforation. The membrane-coated filter element 5 is embedded in the filter perforation, so that its periphery covers the filter element welding area 12, and the membrane-coated filter element 5 is fixed by welding. A stepped surface is formed around the periphery of the filter element, abutting against the filter element welding area 12, and the stepped surface and the filter element welding area 12 are fixed by welding. The welding method includes one of the following: hot melt welding, high-frequency welding, ultrasonic welding, and laser welding.

[0045] When the wedge block 6 and the central tube 14 are integrally formed, the manufacturing of the ultrafiltration centrifuge tube includes the following steps: manufacturing a central tube and a filter plate integrally formed with the wedge block, such that the shape and size of the filter plate matches the filter perforation; covering the inner side of the filter plate with a filter membrane and fixing it by welding to obtain a membrane-coated filter plate 5; embedding the membrane-coated filter plate 5 into the filter perforation, so that the periphery of the membrane-coated filter plate 5 covers the filter plate welding area 12, and fixing the membrane-coated filter plate 5 by welding to obtain the inner tube 1 of the ultrafiltration centrifuge tube. The inner tube 1 is subjected to an airtightness test. If the airtightness is qualified, it is assembled with the outer tube 8 and the tube cap to obtain the ultrafiltration centrifuge tube.

[0046] The inner tube structure of this utility model is reasonable, and the ultrafiltration tube with wedge blocks in the inner tube has a faster filtration speed. The centrifugation speed of the ultrafiltration tube with wedge blocks in the inner tube of this utility model is greatly improved.

[0047] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0048] In the description of this specification, the references to terms such as "preferred embodiment," "another embodiment," "other embodiment," or "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0049] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An ultrafiltration centrifuge tube characterized by, The device includes an inner tube, which is fitted with an outer tube. The outer edge of the inner tube's opening overlaps the inner edge of the outer tube's opening. The gap between the outer wall of the inner tube and the inner wall of the outer tube forms a filtration cavity. The outer tube has a cap at its port. The upper end of the inner tube has a liquid storage cavity, and the lower end has a filtration cavity. A wedge-shaped block is disposed within the filtration cavity. The inner tube has a first filtration surface and a second filtration surface arranged opposite each other on both sides of the filtration cavity. Both the first and second filtration surfaces are provided with filter membranes. The wedge-shaped block is located between the first and second filtration surfaces, dividing the filtration cavity into the first and second filtration cavities. The filter membrane is an ultrafiltration membrane.

2. The centrifuge tube of claim 1, wherein, The wedge-shaped block has corresponding first and second sides, which are respectively opposite to the two filter membranes arranged opposite to each other.

3. The centrifuge tube of claim 1, wherein, The wedge-shaped block is provided with a liquid collection groove, the opening of which faces the side where the port of the inner tube is located. The first filter chamber and the second filter chamber are respectively connected to the liquid collection groove.

4. The centrifuge tube of claim 3, wherein, The shape of the liquid collection tank gradually decreases from top to bottom, so that the shape of the liquid collection tank matches the shape of the pipette tip.

5. The centrifuge tube of claim 1, wherein, The top of the wedge block is flush with the top of the filter membrane; or, the top of the wedge block is located below the top of the filter membrane, and the distance between the top of the wedge block and the top of the filter membrane is 0-15mm.

6. The centrifuge tube of claim 2, wherein, The two filter membranes are arranged opposite each other and are mirror symmetrical. The first side is parallel to the first filter surface, and the second side is parallel to the second filter surface. The gap width of the first filter cavity and the second filter cavity is 0.05-1.5mm.

7. The centrifuge tube of claim 6, wherein, The gap width between the first filter chamber and the second filter chamber is 0.1-0.4 mm.

8. The centrifuge tube of claim 1, wherein, The membrane surface where the filter membrane is located has an angle with the vertical direction, and the value of the angle ranges from 1 to 10°.

9. The centrifuge tube of claim 1, wherein, The wedge block is detachably installed inside the inner tube. The shape and size of the wedge block match the shape and size of the filter cavity, so that the two sides of the wedge block are respectively aligned and fitted into the two ends of the filter cavity.

10. The centrifuge tube of claim 9, wherein, The inner wall of the inner tube has two opposing limiting grooves on its inner side. The limiting grooves are arranged in a vertical direction. The two sides of the wedge block are respectively embedded in the limiting grooves. The two sides of the wedge block are interference-fitted with the limiting grooves.

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