Dewar flask upper end face sealing structure for physical adsorption instrument

Abstract

The invention discloses a Dewar flask upper end face sealing structure for a physical adsorption instrument, which comprises triangular cake structures capable of being spliced into a cylinder, each triangular cake structure is provided with an upper functional layer, a middle functional layer and a lower functional layer, the upper functional layer is a weight applying layer, the middle functional layer is an anti-leakage layer, the lower functional layer is a porous fixed supporting layer, and the sections of triangular cakes are the same. And two radiuses corresponding to the central angles of the fan-shaped structures of the upper functional layer, the middle functional layer and the lower functional layer are respectively provided with an inward semicircular gap. The blocking structure between the Dewar flask and the sample tube for the physical adsorption instrument is simple in structure, during working, low-temperature nitrogen volatilized and released from the Dewar flask condenses gas water in air in gaps into ice, the gaps are automatically filled with the ice, the periphery of the outer side of the sample tube can be blocked, loss of liquid nitrogen in a liquid nitrogen container is effectively reduced, and the service life of the sample tube is prolonged. The sustainable testing time after one-time liquid nitrogen adding is prolonged, and the testing effect is guaranteed.

Description

Technical Field

[0001] This invention relates to an auxiliary device for a physical adsorption instrument, specifically a sealing structure for the upper end face of a Dewar flask used in a physical adsorption instrument, belonging to the technical field of materials testing devices. Background Technology

[0002] A physical adsorption analyzer is an analytical instrument that measures parameters such as specific surface area, pore size distribution, and pore volume of materials based on the static volumetric isothermal adsorption principle.

[0003] Currently, conventional physical adsorption analyzers involve pouring liquid nitrogen into a container below the sample tube, or using a Dewar flask filled with liquid nitrogen, and then directly immersing the sample tube in the liquid nitrogen for analysis. After the test, the remaining liquid nitrogen is poured back into the liquid nitrogen container. During this process, because the container or Dewar flask is not capped, some liquid nitrogen inevitably evaporates and leaks. The low temperature of the evaporating nitrogen gas, upon contact with air molecules, causes water to freeze and settle at the bottom of the Dewar flask. Excessive ice crystal deposition affects the boiling point of the liquid nitrogen, thus impacting the accuracy of the data. Therefore, a significant amount of liquid nitrogen is wasted per test. If the test duration is long or the number of tests is high, it may be necessary to increase the amount of liquid nitrogen poured and the number of pours, resulting in significant waste, increased testing costs, and a reduction in the quality and reliability of the collected isothermal adsorption data. Summary of the Invention

[0004] The purpose of this invention is to provide a sealing structure for the upper end face of a Dewar flask for a physical adsorption instrument. This structure is mainly used to block the sample tube after it enters the Dewar flask during the operation of the physical adsorption instrument, thereby reducing the loss of liquid nitrogen.

[0005] This invention is implemented as follows:

[0006] A sealing structure for the upper end face of a Dewar flask used in a physical adsorption instrument includes triangular disc structures that can be assembled into a cylinder. Each triangular disc structure has three functional layers: an upper functional layer is a weighting layer, a middle functional layer is a leak-proof layer, and a lower functional layer is a porous fixing support layer. Each triangular disc has the same cross-section, which is a fan-shaped structure. The two radii corresponding to the central angles of the fan-shaped structures of the upper, middle, and lower functional layers are all provided with inward semi-circular notches.

[0007] A further step is:

[0008] The number of triangular discs is at least two, for example, two, three, four, six, etc., and the number of triangular discs can be adjusted according to the number of sample tubes entering the Dewar flask. Regardless of the number of triangular discs, they will eventually be pieced together to form a complete cylinder.

[0009] A further step is:

[0010] The middle functional layer is a frame structure without a top or bottom surface, including a frame shell filled with aerogel or cotton. Due to the softness of the aerogel or cotton, it can maintain close contact with the sample tube, effectively slowing down the evaporation of liquid nitrogen through sealing. At the same time, the cotton or aerogel can absorb ice in the gaps, which is then heated and melted into water instead of dripping to the bottom of the bottle.

[0011] A further step is:

[0012] The lower functional layer has a fan-shaped arc bottom with a downwardly protruding baffle. During use, the baffle contacts the side wall of the liquid nitrogen container, which helps to position and fix the sample tube blocking structure.

[0013] A further step is:

[0014] Heating mechanisms are provided at the center and radius of the fan-shaped surface of the functional layer to heat the sample tube after the test is completed, preventing the three triangular disc structures of the cover from freezing with the sample tube and facilitating the removal of the sample tube blockage structure and sample tube.

[0015] A further step is:

[0016] The notch in the middle functional layer has an open via structure at the contact point with the sample tube.

[0017] A further step is:

[0018] The upper functional layer has recessed and protruding ribs on its fan-shaped surface. These ribs are coupled and matched with the additional layer of the upper functional layer to achieve a better sealing effect.

[0019] A further step is:

[0020] The semi-circular notch can slide along the radius of the fan-shaped surface, thus ensuring effective sealing even when different brands or sample tubes are used and their positions vary.

[0021] A further step is:

[0022] The semi-circular notch can slide along the radius of the sector surface, and the sliding is carried out by a sliding mechanism. One type of sliding mechanism consists of a pulley, which drives the portion including the semi-circular notch to slide along the radial edge of the sector. The sliding mechanism is embedded inside the sector surface of the upper functional layer.

[0023] A further step is:

[0024] The semi-circular notch can be extended into the fan-shaped surface when necessary to accommodate different brands and sample tube sizes, thus achieving the corresponding sealing effect.

[0025] A further step is:

[0026] Above the upper functional layer is an additional layer, also fan-shaped, with a long groove. This additional layer can rotate around the center of the fan. In use, by rotating the additional layer, the connection between the upper functional layers of two adjacent triangular disc structures can be blocked, further reducing the evaporation and emission of liquid nitrogen.

[0027] A further step is:

[0028] An elastic pinch section is provided on one side of the arc edge of the middle functional layer, and an elastomer is provided inside the elastic pinch section. In use, by pinching the two sides of the elastic pinch section, the middle functional layer can be compressed inward as a whole, which makes it easy to place and install on top of the Dewar flask. In addition, due to the design of the elastomer, the elastomer automatically rebounds when the elastic pinch section is released, so that the middle functional layer can make better and tighter contact with the sample tube.

[0029] This invention is applicable to physical adsorption instruments with three sample tubes arranged in a triangular pattern. Under the guidance of this invention, those skilled in the art can design corresponding cap structures for the upper end of the Dewar flask for different configurations with one, two, four, or six sample tubes. These different sealing structures for the upper end of the Dewar flask have an overall structure similar to that of this invention. For example, for two sample tubes, two triangular disc structures that can be joined to form a circle can be designed, each with a semi-circular cross-section; for four sample tubes, four triangular disc structures that can be joined to form a circle can be designed, each with a sector-shaped cross-section with a 90° central angle. All of these are within the scope of protection of this invention.

[0030] This invention employs a simple physical adsorption instrument with a sealing structure on the upper end of the Dewar flask. This structure effectively blocks the upper end of the Dewar flask and the area around the outside of the sample tube, thereby reducing the loss of liquid nitrogen in the liquid nitrogen container, extending the testing time, and ensuring the testing results. Attached Figure Description

[0031] Figure 1 This is a top view schematic diagram of the sealing structure of the upper end face of the Dewar flask of a physical adsorption apparatus according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of a triangular disc structure according to an embodiment of the present invention;

[0033] Figure 3 This is a top view of the upper functional layer of an embodiment of the present invention;

[0034] Figure 4 This is a top view of the upper functional layer of an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the upper functional layer and additional layers according to an embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the middle functional layer structure according to an embodiment of the present invention;

[0037] Figure 7 This is a top view schematic diagram of the sealing structure of the upper end face of the Dewar flask of the physical adsorption instrument according to another embodiment of the present invention;

[0038] Figure 8 This is a top view schematic diagram of the sealing structure of the upper end face of the Dewar flask of the physical adsorption instrument according to another embodiment of the present invention;

[0039] Figure 9 This is a top view schematic diagram of the sealing structure of the upper end face of the Dewar flask of the physical adsorption instrument according to another embodiment of the present invention;

[0040] Figure 10 This is a top view schematic diagram of the sealing structure of the upper end face of the Dewar flask of the physical adsorption instrument according to another embodiment of the present invention. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0042] As attached Figure 1 As shown, a sealing structure for the upper end face of a Dewar flask used in a physical adsorption instrument includes three triangular disc structures 1 that can be spliced ​​into a circle. Each triangular disc structure has three layers: the upper functional layer 2 is a weighting layer, the middle functional layer 3 is a leak-proof layer, and the lower functional layer 4 is a porous fixing support layer. Each triangular disc has the same cross-section, which is a fan-shaped structure. The central angle of the fan-shaped structure of the upper, middle, and lower functional layers is 120°, and there are inward semi-circular notches 5 on the two radii corresponding to the central angle.

[0043] As an optimized embodiment, the middle functional layer 2 is a frame structure, including a plastic frame shell filled with aerogel or cotton. Due to the softness of the aerogel or cotton, it can maintain close contact with the sample tube, thus slowing down the evaporation of liquid nitrogen. The notch in the middle functional layer, where it contacts the sample tube, has an open, perforated structure. During use, the aerogel or cotton can partially overflow from the semi-circular notch 5, thereby better encapsulating the sample tube.

[0044] As an optimized embodiment, the bottom of the fan-shaped arc of the lower functional layer 3 is provided with a downwardly protruding baffle 6, which, during use, contacts the side wall of the liquid nitrogen container to position and fix the sample tube blockage structure. The protruding baffle 6 may occupy the entire length of the arc of the lower functional layer or only a portion of it.

[0045] As an optimized embodiment, a heating mechanism (not shown in the figure) is provided at the center and radius of the sector surface of the upper functional layer. This mechanism is used to heat the sample tube after testing to prevent the three triangular disc structures of the sample tube blockage structure from freezing to the sample tube, thus facilitating the removal of the blockage structure and the sample tube. The heating mechanism can use conventional heating wires or other mechanisms without affecting the normal operation of this embodiment.

[0046] As an optimized embodiment, the upper functional layer has recessed ribs 7 and protruding ribs 8 on its fan-shaped surface. The ribs achieve a better sealing effect.

[0047] As an optimized embodiment, the semi-circular notch can, if necessary, extend its depth into the fan-shaped surface to form a long, groove-shaped extension groove 9, as shown in the attached figure. Figure 3 As shown, this allows for effective use even when the position of the sample tube needs adjustment, achieving the corresponding sealing effect.

[0048] As an optimized embodiment, the semi-circular notch can slide along the radius of the sector surface, and the sliding is carried out by a sliding mechanism. (See attached diagram) Figure 4 As shown, one type of sliding mechanism 10 is illustrated. The sliding mechanism consists of pulleys that drive a portion including a semi-circular notch to slide along the radial side of a sector. Specifically, on the upper functional layer's sector surface, the left sliding mechanism consists of four pulleys, and the right sliding mechanism consists of two pulleys. The sliding mechanisms are embedded within the upper functional layer's sector surface.

[0049] As an optimized embodiment, as shown in the appendix Figure 5 As shown, an additional layer 11 is provided above the upper functional layer 2. The additional layer is also fan-shaped and has a long groove 12. The additional layer can rotate around the center of the fan shape. In use, by rotating the additional layer, the connection between the upper functional layers of two adjacent triangular disc structures can be blocked, further reducing the emission of liquid nitrogen.

[0050] Furthermore, in conjunction with the aforementioned rib design, this embodiment utilizes the ribs to increase the path for liquid nitrogen flow above the upper functional layer 2 and below the additional layer, thereby achieving a better sealing effect.

[0051] As an optimized embodiment, as shown in the appendix Figure 6 As shown, an elastic pinching part 13 is provided on one side of the arc edge of the middle functional layer 3. An elastomer 14 is provided inside the elastic pinching part 13. When in use, by pinching the two sides of the elastic pinching part 13, the middle functional layer can be compressed inward as a whole, so that it can be easily placed and installed on top of the Dewar flask. Moreover, due to the design of the elastomer, when the elastic pinching part is released, the elastomer automatically rebounds, so that the middle functional layer 3 can better contact the sample tube.

[0052] As an optimized embodiment, as shown in the appendix Figure 7 As shown, a sealing structure for the upper end face of a Dewar flask for a physical adsorption instrument includes four triangular disc structures 1 that can be spliced ​​into a circle. Each triangular disc structure is the same as in other embodiments, except that the central angle of the fan-shaped structure of the upper functional layer, middle functional layer and lower functional layer is 90°, which is suitable for cases where there are four sample tubes.

[0053] As an optimized embodiment, as shown in the appendix Figure 8 As shown, a sealing structure for the upper end face of a Dewar flask for a physical adsorption instrument includes two triangular disc structures 1 that can be spliced ​​into a circle. Each triangular disc structure is the same as in other embodiments, except that the central angle of the fan-shaped structure of the upper functional layer, middle functional layer and lower functional layer is 180°, which is suitable for cases where there are two sample tubes.

[0054] As an optimized embodiment, as shown in the appendix Figure 9 As shown, a sealing structure for the upper end face of a Dewar flask used in a physical adsorption instrument includes two triangular disc structures 1 that can be joined together to form a circle. Each triangular disc structure is the same as in other embodiments, except that the central angle of the fan-shaped structures of the upper, middle, and lower functional layers is 180°, and there is only one semi-circular notch located directly at the center. This is suitable for cases where there is only one sample tube.

[0055] As an optimized embodiment, as shown in the appendix Figure 10 As shown, a sealing structure for the upper end face of a Dewar flask for a physical adsorption instrument includes six triangular disc structures 1 that can be assembled into a circle. Each triangular disc structure is the same as in other embodiments, except that the central angle of the fan-shaped structure of the upper functional layer, middle functional layer, and lower functional layer is 60°, which is suitable for cases where the number of sample tubes is six.

[0056] Although the present invention has been described herein with reference to illustrative embodiments, the above embodiments are merely preferred embodiments of the present invention, and the implementation of the present invention is not limited to the above embodiments. It should be understood that those skilled in the art can devise many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. A sealing structure for the upper end face of a Dewar flask used in a physical adsorption apparatus, characterized in that: It includes triangular disc structures that can be assembled into cylinders. Each triangular disc structure has three functional layers: the upper functional layer is the weight-bearing layer, the middle functional layer is the leak-proof layer, and the lower functional layer is the porous fixing support layer. Each triangular disc has the same cross-section, which is a fan-shaped structure. The two radii corresponding to the central angles of the fan-shaped structures of the upper, middle, and lower functional layers are all provided with inward semi-circular notches.

2. The sealing structure of the upper end face of the Dewar flask for a physical adsorption instrument according to claim 1, characterized in that: The number of triangular disc structures is at least two.

3. The sealing structure of the upper end face of the Dewar flask for a physical adsorption instrument according to claim 1, characterized in that: The middle functional layer is a frame structure, including a frame shell, the inside of which is filled with aerogel or cotton.

4. The sealing structure of the upper end face of the Dewar flask for a physical adsorption instrument according to claim 1, characterized in that: The bottom of the fan-shaped arc of the lower functional layer is provided with a downwardly protruding baffle.

5. The sealing structure of the upper end face of the Dewar flask for a physical adsorption instrument according to claim 1, characterized in that: Heating mechanisms are provided at the center and radius of the sector-shaped surface of the middle functional layer.

6. The sealing structure of the upper end face of the Dewar flask for a physical adsorption apparatus according to claim 5, characterized in that: The notch in the middle functional layer has an open via structure at the contact point with the sample tube.

7. The sealing structure of the upper end face of the Dewar flask for a physical adsorption instrument according to claim 1, characterized in that: The semi-circular notch can slide along the radius of the sector surface via a sliding mechanism.

8. The sealing structure of the upper end face of the Dewar flask for a physical adsorption instrument according to claim 7, characterized in that: The depth of the semi-circular notch extends into the fan-shaped surface, so that it can be used effectively even when the position of the sample tube is adjusted, achieving the corresponding sealing effect.

9. The sealing structure of the upper end face of the Dewar flask for a physical adsorption instrument according to claim 1, characterized in that: Above the upper functional layer is an additional layer, which is also fan-shaped and has a long groove. The additional layer can rotate around the center of the fan shape.

10. The sealing structure of the upper end face of a Dewar flask for a physical adsorption instrument according to claim 1, characterized in that: An elastic kneading part is provided on one side of the arc edge of the middle functional layer, and an elastic body is provided inside the elastic kneading part.

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