Liquid nitrogen tank

Abstract

The invention discloses a liquid nitrogen tank which comprises a temporary storage unit which comprises a blocking block inserted in a liquid nitrogen tank body and used for sealing a tank opening, and a temporary storage cavity arranged in the blocking block and used for temporarily storing a material storage barrel taken out of a liquid nitrogen storage cavity; the sealing assembly comprises a second adjusting assembly rotationally arranged in the blocking block and used for blocking the lower portion of the temporary storage cavity, and a first adjusting assembly arranged in the second adjusting assembly and used for blocking the upper portion of the temporary storage cavity; the positioning unit is arranged on the upper portion of the plugging assembly and used for locking and positioning the first adjusting assembly and the second adjusting assembly. The temporary storage cavity is arranged for transition in the process that the liquid nitrogen storage cavity is taken out of the material storage barrel, and the upper opening and the lower opening of the temporary storage cavity are opened and closed in sections, so that the volatilization loss of the liquid nitrogen is reduced, the heating speed of a sample is slowed down, and the accuracy of an experimental result of the sample is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid nitrogen tanks, and specifically to a liquid nitrogen tank. Background Art

[0002] Liquid nitrogen tanks are extremely widely used in the field of long-term cryogenic storage of biological samples. They can provide a stable and extremely low-temperature preservation environment for cells, tissues, blood samples, etc., ensuring that the activity and integrity of biological samples can be maintained for a long time.

[0003] However, during the process of opening the lid to take samples with this traditional liquid nitrogen tube, it may be necessary to take different samples multiple times in a short period. The operator needs to frequently open the lid of the liquid nitrogen tank in a low-temperature environment, which increases the volatilization loss of liquid nitrogen, easily causes hot air from the outside to rush into the tank, disturbs the originally stable cooling atmosphere inside the tank, and exacerbates the loss of liquid nitrogen.

[0004] In addition, due to the huge difference between the external environmental temperature and the ultra-low temperature environment inside the liquid nitrogen tank, once the sample leaves the liquid nitrogen tank, it will quickly start to heat up, resulting in the occurrence of the freeze-thaw process. Frequent and rapid freeze-thaw is extremely damaging to the quality and activity of biological samples, can damage cell structures and denature biomolecules, thus seriously affecting the accuracy and reliability of experimental results. In fields such as medical research and biopharmaceutical R & D that involve precious biological samples or have extremely high requirements for samples, this kind of influence may cause irreparable losses.

[0005] The above content is only used to assist in understanding the technical solution of the present invention, and does not represent an admission that the above content is the closest prior art. Summary of the Invention

[0006] The purpose of the present invention is to provide a liquid nitrogen tank to solve the problems in the prior art that the lid of the liquid nitrogen tank lacks a transitional storage device, and the sample is prone to freeze-thaw phenomenon due to rapid temperature rise after leaving the liquid nitrogen tank. In addition, frequent opening of the lid of the liquid nitrogen tank increases the volatilization loss of liquid nitrogen.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A liquid nitrogen tank, comprising:

[0009] A temporary storage unit, including a plug block inserted inside the liquid nitrogen tank body for closing the tank opening, and a temporary storage cavity provided inside the plug block for temporarily storing the storage cylinder taken out from the liquid nitrogen storage cavity;

[0010] A sealing component, including a second adjustment component rotatably provided inside the plug block for blocking the lower part of the temporary storage cavity, and a first adjustment component provided inside the second adjustment component for blocking the upper part of the temporary storage cavity;

[0011] The positioning unit is arranged on the upper part of the plugging assembly and is used to lock and position the first adjusting assembly and the second adjusting assembly.

[0012] Furthermore, the plug is cylindrical, and the outer diameter of the plug is adapted to the inner diameter of the tank opening;

[0013] A plurality of groups of the temporary storage cavities are arranged in the plug at equal angles;

[0014] The lower sealing cavity is arranged at the lower part inside the plug and is used to accommodate the second adjusting assembly;

[0015] The upper sealing cavity is arranged at the upper part inside the plug and is used to accommodate the first adjusting assembly.

[0016] Furthermore, the second adjusting assembly includes:

[0017] The rotating shaft is rotatably connected inside the plug and is on the same axis as the plug;

[0018] The second rotating rod is fixedly connected to the outer side of the upper part of the rotating shaft and is used to rotate and adjust the rotating shaft;

[0019] The lower baffle is fixedly connected to the outer side of the rotating shaft and is located inside the lower sealing cavity. The lower baffle corresponds to the temporary storage cavity one by one and is used to close the lower part of the temporary storage cavity.

[0020] Furthermore, the first adjusting assembly includes:

[0021] The rotating sleeve is rotatably sleeved on the outer side of the rotating shaft. A limiting groove is arranged on the outer side of the rotating shaft and inside the rotating sleeve. The outer diameter of the limiting groove is adapted to the inner diameter of the rotating sleeve and is used to limit the up and down movement of the rotating sleeve;

[0022] The first rotating rod is fixedly connected to the outer side of the upper part of the rotating sleeve and is used to rotate and adjust the rotating sleeve;

[0023] The upper baffle is fixedly connected to the outer side of the rotating sleeve and is located inside the upper sealing cavity. The upper baffle corresponds to the temporary storage cavity one by one and is used to seal the upper part of the temporary storage cavity.

[0024] Furthermore, the positioning unit includes:

[0025] The cover plate is slidably sleeved on the outer side of the first rotating rod and is used to cover the tank opening. A hole for passing through the first rotating rod is arranged inside the cover plate and on the outer side of the first rotating rod;

[0026] The lifting rod is fixedly connected to the upper end of the cover plate and is used to lift the cover plate.

[0027] Furthermore, a guiding hole is arranged on one side of the lifting rod located inside the closing unit;

[0028] A pin for locking and positioning the rotating sleeve and the rotating shaft is slidably inserted into the guiding hole.

[0029] A jack corresponding to the pin is provided in the rotating sleeve.

[0030] A clamping groove corresponding to the pin is provided in the rotating shaft.

[0031] Further, a second hook is fixedly connected to the upper end of the plug near the edge.

[0032] A first limiting groove is provided inside the upper end of the tank opening for accommodating and limiting the second hook.

[0033] Further, a reserved groove is provided on the outer side of the plug, and the reserved groove communicates with the temporary storage cavity.

[0034] A lifting rod is inserted into the reserved groove.

[0035] The lifting rod is fixedly connected to the upper end of the material storage cylinder, and the outer diameter of the material storage cylinder is adapted to the inner diameter of the temporary storage cavity.

[0036] A first hook is fixedly connected to the upper end of the lifting rod for hanging on the upper end of the tank opening to limit the material storage cylinder.

[0037] A second limiting groove for limiting the first hook is provided at the upper end of the tank opening.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] 1. By rotating the second adjustment component, the lower opening of the temporary storage cavity is opened, the material storage cylinder is lifted upward into the temporary storage cavity, the lower opening of the temporary storage cavity is closed, and the first adjustment component is rotated to open the upper opening of the temporary storage cavity. At this time, the material storage cylinder is taken out from the upper opening of the temporary storage cavity. By providing a temporary storage cavity for transition during the process of taking out the material storage cylinder from the liquid nitrogen storage cavity and segmentally opening and closing the upper and lower openings of the temporary storage cavity, the volatilization loss of liquid nitrogen is reduced, the heating rate of the sample is slowed down, and the accuracy of the experimental results of the sample is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0041] Figure 2 It is a schematic diagram of the internal structure of the liquid nitrogen tank body of the present invention;

[0042] Figure 3 It is in the present invention Figure 2 The enlarged view at A;

[0043] Figure 4 It is a schematic diagram of the structure of the temporary storage unit of the present invention;

[0044] Figure 5 This is a schematic diagram of the cover plate of the present invention being lifted upward along the rotating sleeve.

[0045] Figure 6 This is a matching relationship diagram of the tank opening and the plug block of the present invention.

[0046] Figure 7 This is a matching relationship diagram of the upper sealing cavity and the upper baffle of the present invention.

[0047] Figure 8 This is a matching relationship diagram of the lower sealing cavity and the lower baffle of the present invention.

[0048] Figure 9 This is a matching relationship diagram of the first adjusting component and the second adjusting component of the present invention.

[0049] Reference numerals: 100, liquid nitrogen tank body; 1001, tank opening; 1002, first limiting groove; 1003, second limiting groove; 101, liquid nitrogen storage cavity; 102, lifting rod; 1021, storage cylinder; 1022, first hook; 1, temporary storage unit; 11, plug block; 111, reserved groove; 112, second hook; 12, temporary storage cavity; 13, lower sealing cavity; 14, upper sealing cavity; 2, closing unit; 21, first adjusting component; 211, rotating sleeve; 212, first rotating rod; 213, jack; 214, upper baffle; 22, second adjusting component; 221, rotating shaft; 2211, clamping groove; 222, second rotating rod; 223, limiting groove; 224, lower baffle; 225, limiting disc; 3, positioning unit; 31, cover plate; 32, export port; 33, lifting rod; 331, guiding hole; 332, pin. Detailed implementation manners

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0051] Please refer to Figures 1-9 , the present invention provides a technical solution:

[0052] A liquid nitrogen tank, comprising:

[0053] A temporary storage unit 1, including a plug block 11 inserted inside the liquid nitrogen tank body 100 for closing the tank opening 1001, and a temporary storage cavity 12 provided inside the plug block 11 for temporarily storing the storage cylinder 1021 taken out from the liquid nitrogen storage cavity 101;

[0054] The sealing component includes a second adjusting component 22 rotatably arranged inside the plug 11 for sealing the lower part of the temporary storage cavity 12, and a first adjusting component 21 arranged inside the second adjusting component 22 for sealing the upper part of the temporary storage cavity 12;

[0055] The positioning unit 3 is arranged on the upper part of the sealing component and is used for locking and positioning the first adjusting component 21 and the second adjusting component 22.

[0056] It should be noted that: initially, both the first adjusting component 21 and the second adjusting component 22 seal the temporary storage cavity 12. During the process of taking out the storage cylinder 1021 from the liquid nitrogen storage cavity 101, adjust the positioning unit 3 so that the positioning unit 3 stops locking the first adjusting component 21 and the second adjusting component 22, rotate the second adjusting component 22 to open the lower opening of the temporary storage cavity 12, lift the storage cylinder 1021 upward into the temporary storage cavity 12, close the lower opening of the temporary storage cavity 12, and rotate the first adjusting component 21 to open the upper opening of the temporary storage cavity 12. At this time, take out the storage cylinder 1021 from the upper opening of the temporary storage cavity 12. By setting the temporary storage cavity 12 for transition during the process of taking out the storage cylinder 1021 from the liquid nitrogen storage cavity 101 and opening and closing the upper and lower openings of the temporary storage cavity 12 in segments, the volatilization loss of liquid nitrogen is reduced, the heating rate of the sample is slowed down, and the accuracy of the experimental results of the sample is ensured.

[0057] As an improvement, as Figures 2-4 shown, the plug 11 is cylindrical, and the outer diameter of the plug 11 is adapted to the inner diameter of the tank mouth 1001;

[0058] A plurality of groups of the temporary storage cavities 12 are arranged in the plug 11 at equal angles;

[0059] The lower sealing cavity 13 is arranged at the lower part inside the plug 11 and is used for accommodating the second adjusting component 22;

[0060] The upper sealing cavity 14 is arranged at the upper part inside the plug 11 and is used for accommodating the first adjusting component 21.

[0061] Furthermore, as Figures 2-4 shown, the second adjusting component 22 includes:

[0062] The rotating shaft 221 is rotatably connected inside the plug 11 and is on the same axis as the plug 11;

[0063] The second rotating rod 222 is fixedly connected to the outer side of the upper part of the rotating shaft 221 and is used for rotating and adjusting the rotating shaft 221;

[0064] The lower baffle 224 is fixedly connected to the outside of the rotating shaft 221 and is located inside the lower sealing cavity 13. The lower baffle 224 corresponds to the temporary storage cavity 12 one by one and is used to seal the lower part of the temporary storage cavity 12.

[0065] The lower end of the rotating shaft 221 is fixedly connected with a limiting disk 225. The limiting disk 225 is rotatably connected with the reserved groove 111. The diameter of the limiting disk 225 is larger than that of the rotating shaft 221 and is used to limit the rotating shaft 221.

[0066] Furthermore, as Figures 3-4 , Figures 7-9 shown, the first adjusting assembly 21 includes:

[0067] A rotating sleeve 211 is rotatably sleeved on the outside of the rotating shaft 221. A limiting groove 223 is arranged on the outside of the rotating shaft 221 and inside the rotating sleeve 211. The outer diameter of the limiting groove 223 is adapted to the inner diameter of the rotating sleeve 211 and is used to limit the up and down position of the rotating sleeve 211.

[0068] A first rotating rod 212 is fixedly connected to the outside of the upper part of the rotating sleeve 211 and is used to adjust the rotation of the rotating sleeve 211.

[0069] An upper baffle 214 is fixedly connected to the outside of the rotating sleeve 211 and is located inside the upper sealing cavity 14. The upper baffle 214 corresponds to the temporary storage cavity 12 one by one and is used to seal the upper part of the temporary storage cavity 12.

[0070] Among them, as Figures 2-5 shown, the positioning unit 3 includes:

[0071] A cover plate 31 is slidably sleeved on the outside of the first rotating rod 212 and is used to cover the tank opening 1001. A hole for passing through the first rotating rod 212 is arranged inside the cover plate 31 and on the outside of the first rotating rod 212.

[0072] A lifting rod 33 is fixedly connected to the upper end of the cover plate 31 and is used to lift the cover plate 31.

[0073] A lead-out port 32 corresponding to the first hook 1022 is arranged on the outside of the cover plate 31 and is used to lead out the first hook 1022 from the second limiting groove 1003.

[0074] In addition, a guiding hole 331 is arranged on one side of the lifting rod 33 located inside the closing unit 2;

[0075] A plug pin 332 for locking and positioning the rotating sleeve 211 and the rotating shaft 221 is slidably inserted into the guiding hole 331;

[0076] A jack 213 corresponding to the plug pin 332 is arranged inside the rotating sleeve 211;

[0077] A clamping groove 2211 corresponding to the bolt 332 is provided in the rotating shaft 221.

[0078] As an improvement, as Figure 6 shown, a second hook 112 is fixedly connected to the upper end of the blocking block 11 near the edge;

[0079] A first limiting groove 1002 is provided inside the upper end of the can mouth 1001 for accommodating and limiting the second hook 112.

[0080] Furthermore, a reserved groove 111 is provided on the outer side of the blocking block 11, and the reserved groove 111 communicates with the temporary storage cavity 12;

[0081] A lifting rod 102 is inserted into the reserved groove 111;

[0082] The lifting rod 102 is fixedly connected to the upper end of the material storage cylinder 1021, and the outer diameter of the material storage cylinder 1021 is adapted to the inner diameter of the temporary storage cavity 12;

[0083] A first hook 1022 is fixedly connected to the upper end of the lifting rod 102 for hanging on the upper end of the can mouth 1001 to limit the material storage cylinder 1021;

[0084] A second limiting groove 1003 for limiting the first hook 1022 is provided at the upper end of the can mouth 1001.

[0085] It should be added that sealing materials are provided in the gaps between the reserved groove 111 and the lifting rod 102, and between the lifting rod 102 and the upper baffle 214 and the lower baffle 224 to prevent the liquid nitrogen in the liquid nitrogen storage cavity 101 from volatilizing from the gaps between the reserved groove 111 and the lifting rod 102, and between the lifting rod 102 and the upper baffle 214 and the lower baffle 224. Among them, the sealing materials are not shown in the figure.

[0086] It should be noted that: in the specific implementation process of the present invention, as Figure 2 , Figure 4 shown, initially, the bolt 332 is inserted into the jacks 213 and the clamping groove 2211 in sequence through the guiding hole 331 to limit the angles of the rotating shaft 221 and the rotating sleeve 211, and the lower baffle 224 closes the lower opening of the temporary storage cavity 12, and the upper baffle 214 closes the upper opening of the temporary storage cavity 12;

[0087] As Figures 3-5As shown, when it is necessary to take out the storage cylinder 1021 from inside the liquid nitrogen storage cavity 101, first pull out the bolt 332 from the clamping groove 2211 and the jack 213, and pull up the lifting rod 33. The lifting rod 33 drives the cover plate 31 to move upward along the rotating sleeve 211, so that the cover plate 31 is separated from the upper end of the tank opening 1001. Subsequently, rotate the second rotating rod 222. The second rotating rod 222 drives the lower baffle 224 to rotate along the lower sealing cavity 13 through the rotating shaft 221, so that the lower opening of the temporary storage cavity 12 is opened. Pull up the first hook 1022 upward, pass through the export port 32 and drive the storage cylinder 1021 to move upward through the lifting rod 102, so that the storage cylinder 1021 is taken from the liquid nitrogen storage cavity 101 to the temporary storage cavity 12. Reverse-rotate the second rotating rod 222. The second rotating rod 222 drives the lower baffle 224 to close the lower opening of the temporary storage cavity 12 again through the rotating shaft 221. At this time, the storage cylinder 1021 is located in the temporary storage cavity 12 and between the upper baffle 214 and the lower baffle 224. Finally, rotate the first rotating rod 212. The first rotating rod 212 drives the rotating sleeve 211 to rotate in the limit groove 223, and the rotating sleeve 211 drives the upper baffle 214 to rotate in the upper sealing cavity 14, so that the upper opening of the temporary storage cavity 12 is opened. Pull up the lifting rod 102 again. The lifting rod 102 drives the storage cylinder 1021 to be taken out through the upper opening of the temporary storage cavity 12. During the whole sampling process, the sample inside the storage cylinder 1021 is first transferred from the liquid nitrogen storage cavity 101 and then temporarily stored in the temporary storage cavity 12, and then the storage cylinder 1021 is transferred out of the temporary storage cavity 12, avoiding the damage to the quality and activity of the sample due to the rapid temperature rise of the sample directly transferred from the liquid nitrogen storage cavity 101 to the liquid nitrogen tank body 100, and improving the accuracy of the experimental results;

[0088] As Figures 2-5 , Figures 7-9 shown, in the process of taking out the storage cylinder 1021 from the liquid nitrogen tank body 100, the present invention adopts a segmented taking-out method, that is, first keep the upper opening of the temporary storage cavity 12 closed and the lower opening open, transfer the storage cylinder 1021 from the liquid nitrogen storage cavity 101 to the temporary storage cavity 12, then open the upper opening of the temporary storage cavity 12, close the lower opening, and transfer the storage cylinder 1021 out of the temporary storage cavity 12. By adopting such a material-taking method, it can be ensured that the liquid nitrogen storage cavity 101 in the liquid nitrogen tank body 100 is in a continuously closed state, greatly reducing the volatilization loss of liquid nitrogen caused by frequent opening of the tank cover;

[0089] As Figure 2As shown, in addition, compared with directly opening the can lid in the prior art, which makes the liquid nitrogen storage cavity 101 completely open, in the present invention, during the process of moving the cover plate 31 upward along the rotating sleeve 211 to open the can mouth 1001 and taking out the storage cylinder 1021 from the liquid nitrogen storage cavity 101, the blocking block 11 is always inside the can mouth 1001, thereby further reducing the loss of liquid nitrogen in the liquid nitrogen storage cavity 101;

[0090] As Figure 3 As shown, after the sampling work is completed, move the cover plate 31 downward along the rotating sleeve 211 to close the upper end of the can mouth 1001 again, and then rotate the first rotating rod 212 and the second rotating rod 222 respectively, so that the lower baffle 224 blocks the lower opening of the temporary storage cavity 12, and the upper baffle 214 blocks the upper opening of the temporary storage cavity 12. At this time, the card slot 2211 and the jack 213 are coaxial, and push the pin 332 into the jack 213 and the card slot 2211 again along the guide hole 331 to complete the locking and positioning of the rotating shaft 221 and the rotating sleeve 211, so as to avoid the lower baffle 224 and the upper baffle 214 from shifting during the subsequent transfer of the liquid nitrogen tank body 100.

[0091] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0092] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A liquid nitrogen tank, characterized in that: include: The temporary storage unit (1) comprises a block (11) inserted into the interior of a liquid nitrogen tank body (100) for sealing a tank opening (1001), and a temporary storage chamber (12) provided inside the block (11) for temporarily storing a storage cylinder (1021) taken out of a liquid nitrogen storage chamber (101); The sealing component comprises a second adjusting component (22) rotatably arranged inside the blocking block (11) for sealing the lower part of the temporary storage chamber (12), and a first adjusting component (21) arranged inside the second adjusting component (22) for sealing the upper part of the temporary storage chamber (12); The positioning unit (3) is arranged on the upper part of the blocking component and is used to lock and position the first adjustment component (21) and the second adjustment component (22).

2. A liquid nitrogen tank according to claim 1, characterized in that: The blocking block (11) is cylindrical, and the outer diameter of the blocking block (11) is adapted to the inner diameter of the tank mouth (1001); The temporary storage chambers (12) are provided in multiple groups at equal angles inside the blocking block (11); A lower sealing cavity (13) is arranged at a lower position inside the blocking block (11) and is used to accommodate the second adjustment component (22); The upper sealing cavity (14) is arranged at the upper part of the interior of the blocking block (11) and is used to accommodate the first adjustment component (21).

3. A liquid nitrogen tank according to claim 2, characterized in that: The second adjustment component (22) comprises: A rotating shaft (221) is rotatably connected inside the block (11) and is on the same axis as the block (11); A second rotating rod (222) is fixedly connected to the outer side of the upper part of the rotating shaft (221) and is used for rotating and adjusting the rotating shaft (221); The lower baffle (224) is fixedly connected to the outside of the rotating shaft (221) and is located inside the lower sealing chamber (13). The lower baffle (224) corresponds to the temporary storage chamber (12) one by one and is used to seal the lower part of the temporary storage chamber (12).

4. A liquid nitrogen tank according to claim 3, characterized in that: The first adjustment component (21) comprises: A rotating sleeve (211), the rotating sleeve being arranged outside the rotating shaft (221), a limiting groove (223) being arranged outside the rotating shaft (221) and inside the rotating sleeve (211), the outer diameter of the limiting groove (223) being matched with the inner diameter of the rotating sleeve (211), and being used for limiting the upper and lower positions of the rotating sleeve (211); A first rotating rod (212) is fixedly connected to the outer side of the upper portion of the rotating sleeve (211) and is used for rotating and adjusting the rotating sleeve (211); An upper baffle (214) is fixedly connected to the outside of the rotating sleeve (211) and is located inside the upper sealing cavity (14); the upper baffle (214) corresponds to the temporary storage cavity (12) one by one and is used to seal the upper part of the temporary storage cavity (12).

5. A liquid nitrogen tank according to claim 4, characterized in that: The positioning unit (3) comprises: A cover plate (31) is slidably sleeved on the outside of the first rotating rod (212) and is used to seal the can mouth (1001); a hole for penetrating the first rotating rod (212) is provided inside the cover plate (31) and on the outside of the first rotating rod (212); A lifting rod (33) is fixedly connected to the upper end of the cover plate (31) and is used to lift the cover plate (31).

6. A liquid nitrogen tank according to claim 5, characterized in that: A guide hole (331) is provided on one side of the lifting rod (33) located inside the closed unit (2); A latch (332) for locking and positioning the rotating sleeve (211) and the rotating shaft (221) is slidably inserted into the guide hole (331); The rotating sleeve (211) is provided with a plug hole (213) corresponding to the plug pin (332); A slot (2211) corresponding to the latch pin (332) is provided in the rotating shaft (221).

7. A liquid nitrogen tank according to claim 1, characterized in that: A second hook (112) is fixedly connected to the upper end of the blocking block (11) near the edge; A first limiting groove (1002) is provided on the inner side of the upper end of the tank mouth (1001) for accommodating and limiting the second hook (112).

8. A liquid nitrogen tank according to claim 1, characterized in that: A reserved groove (111) is provided on the outer side of the blocking block (11), and the reserved groove (111) is communicated with the temporary storage cavity (12); A lifting rod (102) is inserted into the reserved groove (111); The lifting rod (102) is fixedly connected to the upper end of the material storage barrel (1021), and the outer diameter of the material storage barrel (1021) is adapted to the inner diameter of the temporary storage chamber (12); The upper end of the lifting rod (102) is fixedly connected with a first hook (1022) for being hung on the upper end of the tank mouth (1001) to limit the position of the material storage barrel (1021); The upper end of the tank mouth (1001) is provided with a second limiting groove (1003) for limiting the first hook (1022).

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