Liquid nitrogen sample freezing device

Abstract

The application belongs to the technical field of sample freezing, and discloses a liquid nitrogen sample freezing device, which comprises a liquid nitrogen tank body, a basket hung in the liquid nitrogen tank body, and a cover plate arranged on the top of the liquid nitrogen tank body, and further comprises a receiving assembly which is sleeved on the top of the liquid nitrogen tank body and is used for storing and taking samples and plugging the opening on the top of the liquid nitrogen tank body. The basket is moved into the storage tube by pushing the basket hanging rod along the rectangular slot, the sealing tube is rotated by 180 degrees to form a cylinder with the storage tube, the basket is located in the cylinder, and the storage tube is in an open state, so that the basket can be taken out. In this process, the opening on the top of the liquid nitrogen tank body is plugged by the storage tube, the sealing tube and the fixing assembly, so that the opening on the top of the liquid nitrogen tank body is always in a closed state during the storage and taking process of the basket, thereby reducing the opening on the top of the liquid nitrogen tank body and further reducing the volatilization of liquid nitrogen.

Description

Technical Field

[0001] This invention belongs to the field of sample freezing technology, specifically a liquid nitrogen sample freezing device. Background Technology

[0002] Liquid nitrogen is a liquid obtained by freezing inert, colorless, non-corrosive, and non-flammable nitrogen gas at extremely low temperatures. Liquid nitrogen tanks can preserve biological samples at extremely low temperatures, preventing damage from temperature changes. This makes liquid nitrogen tanks widely used in medicine, biology, agriculture, and the food industry for preserving biological samples such as cells, tissues, enzymes, bacteria, and other microorganisms. Currently, liquid nitrogen tanks have an opening near the center of the top, through which a basket is placed. The basket has evenly arranged drawers, each containing evenly arranged compartments for storing biological samples. To retrieve a sample, the opening must be opened, keeping the tank constantly open, which leads to significant evaporation of liquid nitrogen. Therefore, a liquid nitrogen sample freezing device is proposed. Summary of the Invention

[0003] To address the problems mentioned in the background section, this invention provides a liquid nitrogen sample freezing device, which solves the problem that existing liquid nitrogen tanks require opening to retrieve biological samples from the corresponding basket, resulting in a large amount of liquid nitrogen evaporating during the process.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a liquid nitrogen sample freezing device, comprising a liquid nitrogen tank body, a basket suspended inside the liquid nitrogen tank body, a cover plate disposed on the top of the liquid nitrogen tank body, and further comprising... A receiving component is sleeved on the top of the liquid nitrogen tank body for storing and retrieving samples and for sealing the opening at the top of the liquid nitrogen tank body; A sealing assembly, which is fitted inside the receiving assembly, and is located between the receiving assembly and the sealing assembly during basket storage and retrieval; A fixing component is connected to the bottom of the receiving component for fixing the receiving component and the sealing component. The receiving component, the sealing component and the fixing component are all made of stainless steel. The receiving component includes a fixing frame fixed to the top of the liquid nitrogen tank body for hanging the basket. The fixing frame is fitted with a fixing cylinder inside. A fixing ring is fixed to the top of the fixing cylinder. A first connecting rod is connected to the inner wall of the fixing cylinder. One end of the first connecting rod is connected to a storage tube located inside the fixing cylinder. The sealing assembly includes a sealing tube sleeved between the fixed cylinder and the receiving tube. The lower ends of the receiving tube and the sealing tube have cross-sections that are two "C" shapes, and the lower end of the sealing tube is sleeved outside the receiving tube. The sealing tube is rotated 180 degrees and combined with the lower end of the receiving tube to form a cylinder. The upper ends of the fixed cylinder, the receiving tube and the sealing tube are all provided with rectangular slots.

[0005] Preferably, the top annular array of the fixing frame has six grooves for placing the basket hanging rod, the bottom annular array of the fixing ring has six limiting blocks, the top annular array of the fixing frame has six limiting grooves corresponding to the limiting blocks, the six limiting grooves are located between two adjacent grooves, and the width of the six limiting grooves is the same as that of the rectangular slot.

[0006] Preferably, the six limiting blocks are located in the six grooves, with one of the grooves being opposite to the rectangular slot.

[0007] Preferably, the basket is attached to the inside of the liquid nitrogen tank body. After lifting the fixing ring and rotating it 30 degrees, it moves downward. At this time, the six limiting blocks are respectively located in the six grooves.

[0008] Preferably, the basket is pushed into the storage tube, the basket hanging rod is located in the rectangular slot, the sealing tube is rotated 180 degrees and combined with the storage tube to form a cylinder, and the lower end of the basket is located between the sealing tube and the storage tube.

[0009] Preferably, the sealing assembly further includes spring telescopic rods hinged to the inner wall of the sealing tube and arranged symmetrically, with sealing plugs hinged to the opposite ends of the two spring telescopic rods, and an arc-shaped groove for the first connecting rod to slide on the outer circumferential surface of the sealing plug, and the sealing plug is made of low-temperature resistant rubber material; The sealing plug extends and stretches two spring telescopic rods, pushing the basket so that the hanging rod enters the rectangular slot and the basket enters the storage tube.

[0010] Preferably, the fixing component includes a fixing tube connected to the bottom of the receiving tube via a second connecting rod, a limit ring fixedly installed at the bottom of the fixing tube, a guide groove for the second connecting rod to slide at the bottom of the sealing tube, a drain pipe connected to the bottom of the sealing tube, and the fixing tube sleeved outside the drain pipe. The fixed tube is internally fitted with a limiting rod, and the drain tube is externally threaded with a transmission ring. The transmission ring slides outside the limiting rod. Six pushing blocks are installed in an outer annular array on the outer side of the transmission ring. The fixed tube has six movable slots in an outer annular array. A sealing support block is fitted inside the movable slot. The inner wall of the sealing support block and the pushing block are both trapezoidal. The sealing support block is in contact with the outer inclined side of the pushing block. A movable ring is fitted outside the drain tube. A spring connects the movable ring and the sealing support block. The outer end of the movable ring is T-shaped.

[0011] Preferably, during the rotation of the sealing tube by 180 degrees, the drain tube rotates, the receiving tube is in the open state, and under the action of the external thread, the transmission ring and the pushing block are located at the upper end of the drain tube, and the sealing support block will be located inside the fixed tube.

[0012] Preferably, the bottom of the receiving tube is provided with a first semi-circular hole, the top of the drain tube is provided with a second semi-circular hole, and the inside of the drain tube is provided with a spiral blade. The sealing tube is rotated 180 degrees, and the first semicircular hole coincides with the second semicircular hole.

[0013] Preferably, the storage tube and the basket and fixing assembly move upward, the six sealing support blocks are respectively opposite to the six limiting grooves, the reverse rotation of the sealing tube drives the drain tube to rotate in the opposite direction, so that the transmission ring and the push block move downward, and respectively push out the sealing support blocks and engage in the limiting grooves.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention involves pushing the basket hanging rod along a rectangular slot to move the basket into the storage tube. The sealing tube rotates 180 degrees to form a cylinder with the storage tube, and the basket is located inside the cylinder. At this point, the receiving component, sealing component, and the basket inside can be pulled upwards until the basket is detached from the liquid nitrogen tank body. The sealing tube rotates 180 degrees in the opposite direction, causing the fixing component to fix the positions of the receiving component and the sealing component. At the same time, the storage tube is in the open state, and the basket can be taken out. During this process, the top of the liquid nitrogen tank body is sealed by the storage tube, sealing tube, and fixing component, so that the opening at the top of the liquid nitrogen tank body is always closed during the storage and retrieval of the basket, thereby reducing the opening at the top of the liquid nitrogen tank body and thus reducing liquid nitrogen evaporation. This invention utilizes a basket positioned between a receiving tube and a sealing tube, with a sealing support block located inside a fixed tube. Pulling upwards detaches the receiving assembly, sealing assembly, basket, and fixed assembly from the liquid nitrogen tank body. Reverse rotation of the sealing tube causes the drain pipe to rotate in the opposite direction. Under the action of external threads, the transmission ring and the pushing block move downwards along the limiting rod. Since the pushing block contacts the inclined edge of the sealing support block, the downward movement of the pushing block pushes out the sealing support block, which then engages in the limiting groove. The "T"-shaped overlap at the top of the sealing support block with the top of the fixed frame secures the positions of the receiving assembly and the sealing assembly, thus facilitating the storage and retrieval of samples inside the basket. This invention allows for storage and retrieval of samples by placing the basket between the sealing tube and the receiving tube. During storage, the basket does not contact the inner wall of the liquid nitrogen tank body, thus preventing damage to the inner wall of the liquid nitrogen tank body during storage and retrieval, which would affect the liquid nitrogen storage capacity of the tank body and improve its service life. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall appearance and structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 This is a schematic diagram of the structure of the receiving component, sealing component, fixing component and liquid nitrogen tank body of the present invention; Figure 4 This is a schematic diagram of the external structure of the receiving component and the sealing component of the present invention; Figure 5 This is a schematic diagram of the mating structure of the receiving component and the sealing component of the present invention; Figure 6 This is an exploded structural diagram of the receiving component and sealing component of the present invention; Figure 7 This is an exploded structural diagram of the sealing component, receiving component, and fixing component of the present invention; Figure 8 This is a schematic diagram of the structure of the sealing plug, spring telescopic rod, and sealing tube of the present invention. Figure 9 This is a schematic diagram of the external structure of the fixing frame, limiting block and fixing ring of the present invention; Figure 10 This is a schematic diagram of the internal structure of the fixing component of the present invention; Figure 11 This is a schematic diagram of the exploded structure of the fixing component of the present invention; Figure 12This is a schematic diagram of the assembly structure of the fixing component, the liquid nitrogen tank body, and the fixing frame of the present invention. In the diagram: 1. Liquid nitrogen tank body; 2. Cover plate; 3. Receiving component; 31. Fixing cylinder; 32. Fixing ring; 33. Limiting block; 34. Storage tube; 35. First connecting rod; 36. Fixing frame; 37. Second connecting rod; 4. Sealing component; 41. Sealing tube; 42. Sealing plug; 43. Spring telescopic rod; 44. Guide groove; 45. Drain pipe; 5. Basket; 6. Fixing component; 61. Fixing tube; 62. Limiting ring; 63. Transmission ring; 64. Pushing block; 65. Limiting rod; 66. Sealing support block; 67. Spring; 68. Movable ring; 69. Spiral blade. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] like Figures 1 to 12 As shown, the present invention provides a liquid nitrogen sample freezing device, including a liquid nitrogen tank body 1, a basket 5 suspended inside the liquid nitrogen tank body 1, a cover plate 2 disposed on the top of the liquid nitrogen tank body 1, and further comprising... Component 3 is fitted onto the top of the liquid nitrogen tank body 1 for storing and retrieving samples and for sealing the opening at the top of the liquid nitrogen tank body 1; The sealing component 4 is fitted inside the receiving component 3, and the basket 5 is located between the receiving component 3 and the sealing component 4 during storage and retrieval. The fixing component 6 is connected to the bottom of the receiving component 3 to fix the receiving component 3 and the sealing component 4. The receiving component 3, the sealing component 4 and the fixing component 6 are all made of stainless steel. The receiving component 3 includes a fixing frame 36 fixed to the top of the liquid nitrogen tank body 1 for hanging the basket 5. The fixing frame 36 is fitted with a fixing cylinder 31. A fixing ring 32 is fixed to the top of the fixing cylinder 31. A first connecting rod 35 is connected to the inner wall of the fixing cylinder 31. One end of the first connecting rod 35 is connected to a storage tube 34 located inside the fixing cylinder 31. The sealing assembly 4 includes a sealing tube 41 sleeved between the fixed cylinder 31 and the receiving tube 34. The lower ends of the receiving tube 34 and the sealing tube 41 have two "C" shapes in cross-section, and the lower end of the sealing tube 41 is sleeved outside the receiving tube 34. The sealing tube 41 is rotated 180 degrees and combined with the lower end of the receiving tube 34 to form a cylinder. The upper ends of the fixed cylinder 31, the receiving tube 34 and the sealing tube 41 are all provided with rectangular slots. The top annular array of the fixing frame 36 has six grooves for placing the hanging rod of the basket 5. The bottom annular array of the fixing ring 32 has six limiting blocks 33. The top annular array of the fixing frame 36 has six limiting slots corresponding to the limiting blocks 33. The six limiting slots are located between two adjacent grooves, and the width of the six limiting slots is the same as that of the rectangular slot opening. The six limiting blocks 33 are located in the six grooves, at which point one of the grooves is opposite to the rectangular slot. The basket 5 is pushed into the storage tube 34, the hanging rod of the basket 5 is located in the rectangular groove, the sealing tube 41 is rotated 180 degrees and combined with the storage tube 34 to form a cylinder, and the lower end of the basket 5 is located between the sealing tube 41 and the storage tube 34.

[0018] When it is necessary to remove the sample from the basket 5 attached to the top opening of the liquid nitrogen tank body 1, pull up the receiving component 3, sealing component 4, and fixing component 6, as follows. Figure 6 and 7 As shown, the initial position of the limiting block 33 is engaged in the limiting groove. The limiting block 33 moves upward and disengages from the limiting groove and rotates 30 degrees to release. At this time, the limiting blocks 33 are engaged in the grooves respectively. The limiting groove where the basket 5 to be taken out is located is connected to the rectangular slots opened on the outside of the sealing tube 41 and the storage tube 34. The hanging rod of the basket 5 can be pushed to move along the rectangular slots, so that the basket 5 enters the storage tube 34. The sealing tube 41 rotates 180 degrees to form a cylinder with the storage tube 34, and the basket 5 is located inside the cylinder. At this time, the receiving component 3, the sealing component 4, and the internal components can be pulled upward. The basket 5 is moved upward until it is detached from the liquid nitrogen tank body 1. The sealing tube 41 rotates 180 degrees in the opposite direction, which drives the fixing component 6 to fix the position of the receiving component 3 and the sealing component 4. At the same time, the storage tube 34 is in the open state, so the basket 5 can be taken out. By reversing the above steps, the basket 5 and the internal sample can be placed inside the liquid nitrogen tank body 1. Thus, the storage tube 34, the sealing tube 41 and the fixing component 6 keep the top opening of the liquid nitrogen tank body 1 sealed during the storage and retrieval of the basket 5, reducing the opening at the top of the liquid nitrogen tank body 1 and thus reducing the evaporation of liquid nitrogen.

[0019] like Figure 4 - Figure 6 , Figure 9 As shown, the basket 5 is attached to the inside of the liquid nitrogen tank body 1. After lifting the fixing ring 32 and rotating it 30 degrees, it moves down. At this time, the six limiting blocks 33 are respectively located in the six grooves.

[0020] By placing the basket 5 inside the receiving tube 34 and fixing the basket 5 between the receiving tube 34 and the sealing tube 41 by rotating the sealing tube 41 in the opposite direction, the receiving component 3 and the sealing component 4 can be moved down into the liquid nitrogen tank body 1. At this time, the limiting blocks 33 are respectively engaged in the grooves. By rotating the sealing tube 41 in the opposite direction, the basket 5 can be pushed away from the receiving tube 34 in the opposite direction. The hanging rod of the basket 5 can be hung on the top of the limiting groove, and the receiving component 3 and the sealing component 4 can be pulled up. The limiting block 33 moves up and rotates thirty degrees to release, so that the limiting block 33 is engaged in the limiting groove, sealing the limiting groove and reducing the evaporation of liquid nitrogen inside.

[0021] like Figure 8 As shown, the sealing assembly 4 also includes spring telescopic rods 43 that are hinged to the inner wall of the sealing tube 41 and arranged symmetrically. The two spring telescopic rods 43 are hinged to the opposite ends of a sealing plug 42. The outer circumferential surface of the sealing plug 42 is provided with an arc-shaped groove for the first connecting rod 35 to slide. The sealing plug 42 is made of low-temperature resistant rubber material. The sealing plug 42 extends upwards, pulling the two spring telescopic rods 43, pushing the basket 5 so that the hanging rod enters the rectangular slot, and the basket 5 enters the storage tube 34.

[0022] By pulling the sealing plug 42 upward, the two spring telescopic rods 43 are stretched respectively, and the sealing plug 42 is disengaged from the rectangular slot. At this time, the hanging rod of the basket 5 can enter the rectangular slot for storage and retrieval. After the hanging rod of the basket 5 is disengaged from the rectangular slot, the sealing plug 42 is released. Under the action of the two spring telescopic rods 43, the sealing plug 42 enters the rectangular slot to seal it, thereby sealing the inside of the liquid nitrogen tank body 1.

[0023] like Figure 3 , Figure 10 - Figure 12 As shown, the fixing component 6 includes a fixing tube 61 connected to the bottom of the receiving tube 34 via a second connecting rod 37. A limit ring 62 is fixedly installed at the bottom of the fixing tube 61. A guide groove 44 for sliding of the second connecting rod 37 is provided at the bottom of the sealing tube 41. A drain pipe 45 is connected to the bottom of the sealing tube 41. The fixing tube 61 is sleeved on the outside of the drain pipe 45. The fixed tube 61 is internally fixed with a limit rod 65. The external thread of the drain tube 45 is fitted with a transmission ring 63. The transmission ring 63 slides outside the limit rod 65. The external annular array of the transmission ring 63 is equipped with six push blocks 64. The external annular array of the fixed tube 61 has six movable slots. The movable slots are fitted with sealing support blocks 66. The inner wall of the sealing support block 66 and the push block 64 are both trapezoidal. The sealing support block 66 is in contact with the outer inclined edge of the push block 64. The external drain tube 45 is fitted with a movable ring 68. A spring 67 is connected between the movable ring 68 and the sealing support block 66. The outer end of the movable ring 68 is T-shaped. During the rotation of the sealing tube 41 by 180 degrees, the drain tube 45 is rotated, the receiving tube 34 is in the open state, and the transmission ring 63 and the push block 64 are located at the upper end of the drain tube 45 under the action of the external thread, and the sealing support block 66 will be located inside the fixed tube 61. The storage tube 34 drives the basket 5 and the fixing component 6 to move upward. The six sealing support blocks 66 are respectively kept opposite to the six limiting grooves. The reverse rotation of the sealing tube 41 drives the drain tube 45 to rotate in the opposite direction, causing the transmission ring 63 and the push block 64 to move downward, respectively pushing out the sealing support blocks 66 and engaging them in the limiting grooves.

[0024] By pushing the basket 5 into the storage tube 34, the sealing tube 41 rotates 180 degrees, fixing the basket 5 inside the cylinder between the storage tube 34 and the sealing tube 41. During the rotation of the sealing tube 41, the drain tube 45 rotates, causing the transmission ring 63 to be positioned at the upper end of the drain tube 45. The sealing support block 66, under the action of the spring 67, is positioned inside the fixing tube 61. At this point, the receiving assembly 3, sealing assembly 4, fixing assembly 6, and basket 5 can be pulled upwards. Figure 3 As shown, the reverse rotating sealing tube 41 drives the drain tube 45 to rotate in the opposite direction. Under the action of the external thread, the transmission ring 63 and the push block 64 move down along the limit rod 65. Since the push block 64 is in contact with the inclined side of the sealing support block 66, the sealing support block 66 is pushed out by the downward movement of the push block 64. The sealing support blocks 66 are respectively engaged in the limit groove, and the position of the receiving component 3 and the sealing component 4 is fixed by the "T" shaped overlap of the top of the sealing support block 66 on the top of the fixing frame 36. At the same time, the storage tube 34 is in the open state, so the basket 5 can be taken out.

[0025] like Figure 7 , Figure 10 - Figure 12 As shown, the bottom of the receiving tube 34 is provided with a first semi-circular hole, the top of the drain tube 45 is provided with a second semi-circular hole, and a spiral blade 69 is provided inside the drain tube 45. The sealing tube 41 is rotated 180 degrees, and the first semicircular hole coincides with the second semicircular hole.

[0026] As the basket 5 moves between the receiving tube 34 and the sealing tube 41, the sealing tube 41 rotates 180 degrees, connecting the first semicircular hole with the second semicircular hole. During the upward pulling of the receiving component 3, the sealing component 4, the basket 5, and the fixing component 6, the liquid nitrogen gradually detaches from the liquid nitrogen inside the liquid nitrogen tank body 1. The liquid nitrogen between the receiving tube 34 and the sealing tube 41 can then be discharged into the liquid nitrogen tank body 1 through the drain pipe 45 along the spiral blade 69. At the same time, when the receiving component 3 and the sealing component 4 are moved out of the liquid nitrogen tank body 1, the sealing tube 41 is rotated in the opposite direction. At this time, the first semicircular hole and the second semicircular hole are not overlapping, thus sealing the drain pipe 45 and the inside of the liquid nitrogen tank body 1 to prevent liquid nitrogen from evaporating.

[0027] Working principle and usage process of this invention: By removing the cover plate 2, the lower end of the sealing tube 41 is rotated 180 degrees to form a cylinder with the receiving tube 34. The rotation of the sealing tube 41 drives the drain tube 45 to rotate. At this time, the transmission ring 63 is located at the upper end of the drain tube 45. The sealing support block 66 is located inside the fixed tube 61 under the action of the spring 67. The receiving component 3, the sealing component 4 and the fixed component 6 can be pulled upward. After the limiting ring 62 contacts the top of the inner wall of the liquid nitrogen tank body 1, the sealing tube 41 is rotated in the opposite direction to drive the drain tube 45 to rotate in the opposite direction. Under the action of the external thread, the transmission ring 63 moves down to push out the sealing support block 66 and engage it in the limiting groove of the inner wall of the fixed frame 36 to seal the top opening of the liquid nitrogen tank body 1. The reverse rotation of the sealing tube 41 makes the receiving tube 34 open, and the sealing tube 41 and the rectangular groove of the receiving tube 34 coincide. The basket 5 containing the sample can be placed inside the receiving tube 34, and the hanging rod of the basket 5 is located in the rectangular groove. By rotating the sealing tube 41 by 180 degrees, the sealing tube 41 and the lower end of the receiving tube 34 form a cylinder with the basket 5 located inside it. At the same time, the transmission ring 63 and the pushing block 64 move up to the upper end of the drain pipe 45. Under the action of the spring 67, the sealing support block 66 retracts into the fixed tube 61. At this time, the sealing tube 41, the receiving tube 34, the fixed component 6 and the basket 5 can descend and enter the liquid nitrogen tank body 1. The receiving tube 34 and the sealing tube 41 are moved into the liquid nitrogen tank body 1. The limiting block 33 is engaged in the corresponding groove. The sealing tube 41 can be rotated in the opposite direction, and the receiving tube 34 is in the open state. The basket 5 hanging rod is pushed in the opposite direction to move into the rectangular slot and is engaged in the limiting groove. At this time, the receiving component 3 can be pulled up, and the limiting block 33 is released by rotating 30 degrees away from the groove, so that the limiting block 33 is engaged in the six limiting grooves. Thus, the limiting grooves are sealed by the limiting block 33. By reversing the above steps, the basket 5 can be taken out. During the storage and retrieval of the basket 5, the top of the liquid nitrogen tank body 1 is kept completely open to reduce the evaporation of liquid nitrogen.

[0028] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A liquid nitrogen sample freezing device, comprising a liquid nitrogen tank body (1), a basket (5) suspended inside the liquid nitrogen tank body (1), and a cover plate (2) disposed on the top of the liquid nitrogen tank body (1), characterized in that: It also includes, The receiving component (3) is sleeved on the top of the liquid nitrogen tank body (1) for storing and retrieving samples and sealing the top opening of the liquid nitrogen tank body (1); A sealing component (4) is fitted inside the receiving component (3), and the basket (5) is located between the receiving component (3) and the sealing component (4) during storage and retrieval. Fixing component (6), which is connected to the bottom of the receiving component (3) for fixing the receiving component (3) and the sealing component (4), wherein the receiving component (3), the sealing component (4) and the fixing component (6) are all made of stainless steel; The receiving component (3) includes a fixing frame (36) fixed to the top of the liquid nitrogen tank body (1) for hanging the basket (5). The fixing frame (36) is fitted with a fixing cylinder (31). The top of the fixing cylinder (31) is fixed with a fixing ring (32). The inner wall of the fixing cylinder (31) is connected to a first connecting rod (35). One end of the first connecting rod (35) is connected to a storage tube (34) located inside the fixing cylinder (31). The sealing assembly (4) includes a sealing tube (41) sleeved between the fixed cylinder (31) and the receiving tube (34). The lower ends of the receiving tube (34) and the sealing tube (41) have two "C" shapes in cross-section, and the lower end of the sealing tube (41) is sleeved outside the receiving tube (34). The sealing tube (41) is rotated 180 degrees and combined with the lower end of the receiving tube (34) to form a cylinder. The upper ends of the fixed cylinder (31), the receiving tube (34) and the sealing tube (41) are all provided with rectangular slots. The top annular array of the fixing frame (36) has six grooves for placing the hanging rod of the basket (5), the bottom annular array of the fixing ring (32) has six limiting blocks (33), the top annular array of the fixing frame (36) has six limiting slots corresponding to the limiting blocks (33), the six limiting slots are located between two adjacent grooves, and the width of the six limiting slots is the same as that of the rectangular slot. The six limiting blocks (33) are located in the six grooves, with one of the grooves being opposite to the rectangular slot. The basket (5) is attached to the inside of the liquid nitrogen tank body (1). After lifting the fixing ring (32) and rotating it thirty degrees, it moves down. At this time, the six limiting blocks (33) are respectively located in the six grooves. The basket (5) is pushed into the storage tube (34), the hanging rod of the basket (5) is located in the rectangular slot, the sealing tube (41) is rotated 180 degrees and combined with the storage tube (34) to form a cylinder, and the lower end of the basket (5) is located between the sealing tube (41) and the storage tube (34).

2. The liquid nitrogen sample freezing device according to claim 1, characterized in that: The sealing assembly (4) further includes spring telescopic rods (43) hinged to the inner wall of the sealing tube (41) and arranged symmetrically. The two spring telescopic rods (43) are hinged to each other with sealing plugs (42). The outer circumferential surface of the sealing plug (42) is provided with an arc-shaped groove for the first connecting rod (35) to slide. The sealing plug (42) is made of low-temperature resistant rubber material. The sealing plug (42) stretches the two spring telescopic rods (43) upwards, pushing the basket (5) so that the hanging rod enters the rectangular slot and the basket (5) enters the storage tube (34).

3. The liquid nitrogen sample freezing device according to claim 2, characterized in that: The fixing component (6) includes a fixing tube (61) connected to the bottom of the receiving tube (34) via a second connecting rod (37). A limit ring (62) is fixedly installed at the bottom of the fixing tube (61). A guide groove (44) for sliding of the second connecting rod (37) is provided at the bottom of the sealing tube (41). A drain pipe (45) is connected to the bottom of the sealing tube (41). The fixing tube (61) is sleeved on the outside of the drain pipe (45). The fixed tube (61) is internally fitted with a limiting rod (65), and the external thread of the drain tube (45) is fitted with a transmission ring (63). The transmission ring (63) slides outside the limiting rod (65). The external annular array of the transmission ring (63) is equipped with six pushing blocks (64). The external annular array of the fixed tube (61) is provided with six movable slots. The movable slots are fitted with sealing support blocks (66). The inner wall of the sealing support block (66) and the pushing block (64) are both trapezoidal. The sealing support block (66) is in contact with the outer inclined side of the pushing block (64). The external drain tube (45) is fitted with a movable ring (68). A spring (67) is connected between the movable ring (68) and the sealing support block (66). The outer end of the movable ring (68) is T-shaped.

4. The liquid nitrogen sample freezing device according to claim 3, characterized in that: During the rotation of the sealing tube (41) by 180 degrees, the drain tube (45) is rotated, the receiving tube (34) is in the open state, and under the action of the external thread, the transmission ring (63) and the push block (64) are located at the upper end of the drain tube (45), and the sealing support block (66) will be located inside the fixed tube (61).

5. The liquid nitrogen sample freezing device according to claim 4, characterized in that: The bottom of the receiving tube (34) is provided with a first semi-circular hole, the top of the drain tube (45) is provided with a second semi-circular hole, and the inside of the drain tube (45) is provided with a spiral blade (69). The sealing tube (41) is rotated 180 degrees, and the first semicircular hole coincides with the second semicircular hole.

6. The liquid nitrogen sample freezing device according to claim 5, characterized in that: The storage tube (34) drives the basket (5) and the fixing component (6) to move upward. The six sealing support blocks (66) are respectively opposite to the six limiting grooves. The reverse rotation of the sealing tube (41) drives the drain tube (45) to rotate in the opposite direction, so that the transmission ring (63) and the push block (64) move downward, respectively pushing out the sealing support blocks (66) and engaging them in the limiting grooves.

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