A low temperature biological sample transport tank

Abstract

The present application relates to the field of low temperature biological preservation technology, and particularly relates to a low temperature biological sample transportation storage tank, which comprises an inner tank body provided with a vacuum interlayer and a double-layer structure, an inner tank body is internally provided with a placing rack for fixing biological sample storage equipment, and further comprises an outer tank body provided outside the inner tank body and provided with a heat preservation layer between the inner tank body and the outer tank body; a placing pipe is provided on the inner tank body and used for leading to the inside of the inner tank body. A normally closed sealing mechanism is arranged at the bottom of the placing pipe, the opening operation of the mechanism is driven by a gear and a rack, and a cooling mechanism is synchronously driven. When the disadvantageous operation of opening the placing pipe to access the sample occurs, the higher temperature nitrogen gas in the upper part of the gas phase zone can be automatically drawn back into the liquid nitrogen to be cooled and condensed, the temperature of the gas phase zone is effectively reduced, and the thermal shock of the sample exposure is reduced. Meanwhile, the gaseous nitrogen gas is pressed back into the liquid nitrogen, the partial liquefaction of the gaseous nitrogen gas is promoted, and the loss of the liquid nitrogen caused by the opening operation is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of low-temperature biological preservation technology, and in particular to a low-temperature biological sample transport tank. BACKGROUND

[0002] Low-temperature biological samples, such as cells, tissues, embryos, and stem cells, need to be stored and transported in an extremely low-temperature environment to maintain their biological activity. Liquid nitrogen biological tanks are key equipment for completing this task, which uses a high-vacuum interlayer and thermal insulation materials to minimize the transfer of external heat, allowing the internal liquid nitrogen to slowly evaporate to maintain a low-temperature environment. In the prior art, conventional low-temperature biological sample transport tanks are mainly divided into two categories: liquid nitrogen wet transport tanks and dry transport tanks. Liquid nitrogen wet transport tanks store liquid nitrogen inside, and samples can be directly immersed in liquid nitrogen or stored in the low-temperature vapor phase zone.

[0003] However, the existing liquid nitrogen wet transport tank still has some deficiencies in practical application. First, in terms of sample access operations, the placement tube or opening of the existing tank is directly exposed to the gas phase zone inside the tank when it is opened. Due to the physical properties of hot air rising and cold air sinking, a significant temperature stratification is formed in the tank, i.e., the temperature of the gas phase zone gradually changes from much higher than -196℃ to close to the liquid nitrogen temperature from top to bottom. When accessing the sample, the higher-temperature gas near the placement tube will exchange heat with the sample, causing the sample to experience irreversible temperature fluctuations, which can easily cause ice crystal recrystallization, solution effect, and other damage, seriously threatening the survival rate of the sample. At the same time, this operation process also causes a large amount of cold loss and environmental heat influx, exacerbating the inefficient consumption of liquid nitrogen.

[0004] Therefore, a low-temperature biological sample transport tank is proposed to solve the above-mentioned problems. SUMMARY

[0005] Technical problems solved

[0006] To solve the above-mentioned shortcomings of the prior art, the present application provides a low-temperature biological sample transport tank, which can solve the problems of large cold loss, uneven gas phase zone temperature, and unreliable liquid nitrogen residual quantity monitoring of conventional liquid nitrogen tanks in the prior art during sample access. The technical purpose of actively maintaining a low-temperature environment, recovering cold, and achieving mechanical recording of a safe state is achieved without external energy.

[0007] Technical solutions

[0008] To achieve the above purpose, the present application is implemented by the following technical solutions:

[0009] The application provides a low-temperature biological sample transportation storage tank, which comprises an inner tank body and an outer tank body sleeved outside the inner tank body, and a heat preservation layer is formed between the inner tank body and the outer tank body, the inner tank body is a double-layer structure and is provided with a vacuum interlayer, a placing rack (10) for fixing equipment for storing biological samples is further arranged in the inner tank body (1), a placing pipe communicating with the inside of the inner tank body is arranged on the inner tank body, a sealing mechanism is arranged in the placing pipe to isolate the gas phase area of the inner tank body in a non-operation state, a cooling mechanism communicating with the inside of the inner tank body is arranged on the surface of the placing pipe, when the sealing mechanism is driven to open due to the putting in or taking out of biological samples, the gas in the inner tank body is drawn into and backflows to the liquid phase area of the inner tank body through the mechanical action generated by the driving, so that the cooling and the cold energy recovery are realized.

[0010] Further, the sealing mechanism comprises a torsion spring shaft rotatably connected to the lower part of the placing pipe and capable of generating a closing torsion, and a sealing plate arranged on the torsion spring shaft, a first spring and a pressing plate matched with the first spring are arranged in the placing pipe, and the first spring acts on the pressing plate to assist the sealing plate to keep a horizontal sealing state.

[0011] Further, the cooling mechanism is provided with a fixing block on the surface of the placing pipe, the fixing block is connected with a gas suction pipe extending into the liquid phase area of the inner tank body, a piston assembly is slidably arranged in the gas suction pipe, so that the gas suction pipe is divided into upper and lower chambers, the gas suction pipe is provided with a suction port communicating with the lower chamber and an air inlet one-way valve allowing only gas to enter, and the gas suction pipe is provided with an exhaust branch pipe communicating with the upper chamber and extending into the liquid phase area.

[0012] Further, the piston assembly comprises a piston block slidably sealed in the gas suction pipe and a connecting rod connected to the piston block.

[0013] Further, the torsion spring shaft and the piston assembly are connected through a transmission mechanism, the transmission mechanism comprises a gear and a rack which are engaged with each other, the rack is arranged on the upper end of the connecting rod, and the gear is arranged on the torsion spring shaft.

[0014] Further, the outlet end of the exhaust branch pipe extends away from the placing rack from top to bottom.

[0015] Further, the pipe wall of the placing pipe is provided with a communication port communicating with the heat preservation layer, and the sealing mechanism is pushed open when the internal pressure of the inner tank body exceeds a predetermined value, so that the excess gas is discharged to the heat preservation layer through the placing pipe and the communication port.

[0016] Further, an indicating mechanism for indicating the residual amount of liquid nitrogen in the inner tank body is arranged on the outer tank body, and the indicating mechanism communicates with the heat preservation layer.

[0017] Further, the indicating mechanism comprises a vertical pipe communicated with the heat preservation layer, a second spring arranged in the vertical pipe and compressed under the action of air pressure, and a sliding block arranged in the second spring, the sliding block being movable to a preset position under the action of air pressure and recorded.

[0018] Further, the indicating mechanism further comprises a locking assembly for locking the position of the sliding block when the sliding block moves to the preset position to record the peak air pressure reached, which comprises a side pipe connected to the vertical pipe and communicated therewith, and a limiting block elastically and slidingly arranged in the side pipe, the surface of the sliding block being provided with a limiting hole matched with the limiting block.

[0019] Advantages

[0020] Compared with the prior art, the technical scheme provided by the application has the following advantages:

[0021] The application sets a normally closed sealing mechanism composed of a torsion spring shaft and a sealing plate at the bottom of the placing tube, the opening action of the mechanism is transmitted by a gear and a rack, and a cooling mechanism composed of a piston and a one-way valve is synchronously driven. When the disadvantageous operation of opening the placing tube to access the sample occurs, the higher temperature nitrogen gas in the upper part of the gas phase zone can be automatically drawn back into the liquid nitrogen for cooling and condensation, the temperature of the gas phase zone is effectively reduced, and the thermal shock of the sample is reduced. At the same time, the gas phase nitrogen gas is pressed back into the liquid nitrogen, which promotes the partial re-liquefaction of the liquid nitrogen, reduces the loss of liquid nitrogen evaporation caused by the opening operation, and improves the economy.

[0022] In addition, a vertical pipe communicated with the heat preservation layer is arranged, and a sliding block slidable with air pressure is arranged in the vertical pipe, and a mechanical locking assembly composed of a side pipe, a limiting block and a limiting hole is further arranged, the highest position reached by the sliding block can be locked, the lowest liquid level of the liquid nitrogen consumed in the transportation is recorded, an irreversible black box type historical alarm is provided, and misjudgment caused by air pressure fluctuation is avoided. The structure uses a pure mechanical structure, does not need electricity, has strong anti-interference ability, and provides intuitive and reliable physical evidence for sample transportation safety.

[0023] In addition, the sealing mechanism itself is used as a pressure relief valve, when the pressure in the inner tank body is too high, the gas can push open the sealing plate, the excess gas is discharged into the heat preservation layer through the communication port on the wall of the placing tube, a passive and automatic safety pressure relief path is provided, the danger caused by the excessive pressure in the tank is prevented, and the safety of the equipment is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only show some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative effort based on these drawings.

[0025] Figure 1 Fig. 1 is a cutaway schematic view of the internal structure of the storage tank in the embodiment of the present application;

[0026] Figure 2 Fig. 2 is a schematic view of the external structure of the storage tank in the embodiment of the present application;

[0027] Figure 3 Fig. 3 is a schematic view of the structure of the sealing mechanism in the embodiment of the present application;

[0028] Figure 4 Fig. 4 is a schematic view of the structure of the cooling mechanism in the embodiment of the present application;

[0029] Figure 5 Fig. 5 is a schematic view of the cooperation of the sealing mechanism and the cooling mechanism in the embodiment of the present application;

[0030] Figure 6 Fig. 6 is a schematic view of the installation of the exhaust branch pipe in the embodiment of the present application;

[0031] Figure 7 Fig. 7 is a schematic view of the structure of the indicating mechanism in the embodiment of the present application;

[0032] Figure 8 Fig. 8 is a schematic view of the principle of the indicating mechanism in the embodiment of the present application.

[0033] The reference numerals in the drawings represent: 1, inner tank body; 2, outer tank body; 3, heat preservation layer; 4, vacuum interlayer; 5, placing pipe; 6, communication port; 7, sealing mechanism; 701, torsion spring shaft; 702, sealing plate; 703, sealing gasket; 704, first spring; 705, pressing plate; 8, cooling mechanism; 801, fixed block; 802, suction pipe; 803, piston block; 804, connecting rod; 805, rack; 806, gear; 807, air inlet one-way valve; 808, air suction port; 809, exhaust branch pipe; 810, exhaust one-way valve; 9, indicating mechanism; 901, vertical pipe; 902, second spring; 903, sliding block; 904, side pipe; 905, third spring; 906, limiting block; 907, limiting hole; 10, placing rack. DETAILED DESCRIPTION

[0034] The application will be further described below in connection with the drawings and embodiments. It should be understood that the specific embodiments described herein are intended to be merely exemplary of the application and that the intention is to cover any and all modifications and alternatives of the application. It is also to be understood that, unless otherwise specified, reference to a particular implementation or implementation means that a particular feature, structure, or characteristic is included in at least one implementation of the present application. Furthermore, it is to be understood that the description and drawings herein are intended to be illustrative only and that the application is not limited in scope to the precise embodiments described herein.

[0035] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "upper", "above" and "on" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0037] In the description of the present application, the terms "upper", "lower", "left", "right", and other orientation or position relationships are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0038] The present application will be further described below in connection with the embodiments.

[0039] Embodiment:

[0040] Please refer to the accompanying Figures 1-8 The present application provides a low-temperature biological sample transportation storage tank, which comprises an inner tank body 1 for storing liquid nitrogen, and the standard boiling point of the liquid nitrogen is-196 DEG C. The liquid nitrogen in the tank will absorb heat from the external environment and vaporize, which will absorb a large amount of heat, so that the temperature of the remaining liquid nitrogen in the inner tank body 1 and the space in the inner tank body 1 is maintained at a level close to-196 DEG C. Thus, all biological and chemical activities in the sample are greatly inhibited, so that the sample enters a dormant state and is effectively stored for a long time.

[0041] The inner tank body 1 is internally provided with a rack 10 for fixing the biological sample storage device, thereby preventing the biological sample from being broken due to collision, vibration and jolt during transportation. The inner tank body 1 is provided with a double-layer structure, and a vacuum interlayer 4 is arranged between the two layers and is vacuumized. The vacuum environment eliminates the main medium of convection heat transfer and conduction heat transfer, thereby greatly reducing the rate of heat transfer from the outside to the inner tank body 1.

[0042] The surface of the inner tank body 1 is further provided with a placing pipe 5 which is located above the rack 10. The biological sample storage device can be fixed on the rack 10 through the placing pipe 5, thereby realizing the fixation of the biological sample storage device. Meanwhile, the surface of the placing pipe 5 is provided with a sealing cover for sealing the upper opening of the placing pipe 5, thereby avoiding the leakage of liquid nitrogen.

[0043] However, the difference is that the placing pipe 5 is internally provided with a sealing mechanism 7 for sealing the lower opening of the placing pipe 5. During the transportation of the tank, even if the vacuum interlayer 4 arranged on the inner tank body 1 greatly slows down the rate of heat transfer, it cannot be reduced to zero. These incoming heat will be absorbed by the liquid nitrogen in the tank, causing a part of the liquid nitrogen to boil and gasify into nitrogen gas. In this process, the low-temperature nitrogen gas initially gathers above the liquid nitrogen; since nitrogen gas is lighter than liquid nitrogen, it will form a clear gas phase zone.

[0044] The temperature of this gas phase zone is not uniform at -196℃, but gradually increases from the liquid surface upwards. Meanwhile, the thermal conductivity of the gas itself is poor, and it cannot achieve rapid heat balance through convection like liquid, resulting in a higher temperature inside the inner tank body 1 at the placing pipe 5. If there is no sealing mechanism 7, the low-temperature nitrogen gas in the inner tank body 1 will enter the placing pipe 5, causing the nitrogen gas to be more easily affected by the heat outside the placing pipe 5, thereby increasing the temperature inside the placing pipe 5 and increasing the consumption of liquid nitrogen. When the biological sample is placed into the inner tank body 1 through the placing pipe 5, it will inevitably pass through the placing pipe 5, thereby causing the temperature fluctuation to cause serious and irreversible damage to the biological sample. Through the arrangement of the sealing mechanism 7, the time for the placing pipe 5 to communicate with the internal gas phase zone is greatly shortened, ensuring that the sample is always in a lower-temperature microenvironment formed by liquid nitrogen vapor during storage, greatly reducing the amplitude and time of the sample experiencing temperature fluctuations, thereby directly ensuring the activity and preservation quality of the sample.

[0045] By avoiding the placing pipe 5 from becoming a gap for heat exchange, it helps to maintain the relative stability of the temperature distribution inside the entire inner tank body 1, especially in the gas phase zone. Through the arrangement of the sealing mechanism 7, the gas phase zone in the inner tank body 1 will be maintained below the lower opening of the placing pipe 5, which can avoid the higher-temperature nitrogen gas from gathering upwards.

[0046] Specifically, the sealing mechanism 7 includes a torsion spring shaft 701 rotatably connected below the placement tube 5, and the surface of the torsion spring shaft 701 is provided with a sealing plate 702. Two groups of sealing plates 702 symmetrically distributed are installed below the placement tube 5, and the two groups of sealing plates 702 have a tendency to rotate upward under the action of the torsion spring inside the torsion spring shaft 701.

[0047] Meanwhile, the inside of the placement tube 5 is connected with a pressing plate 705 through a first spring 704, and the pressing plate 705 is in contact with the surface of the sealing plate 702 under the elastic force of the first spring 704, and limits the sealing plate 702 to continue to rotate upward. Further, under the action of the first spring 704 and the torsion spring inside the torsion spring shaft 701, the two groups of sealing plates 702 are rotated to a horizontal state, which just seals the opening below the placement tube 5, thereby avoiding the escape of nitrogen. Meanwhile, the surface of the two groups of sealing plates 702 is provided with a sealing gasket 703, thereby sealing the butt joint gap of the two groups of sealing plates 702, effectively preventing the escape of nitrogen.

[0048] When the equipment for storing biological samples needs to be put into the inner tank 1, after opening the lid above the inner tank 1, the equipment for storing biological samples can be directly inserted into the placement tube 5, and when the equipment is in contact with the surface of the sealing plate 702 under the action of the insertion force, it will push the sealing plate 702 to rotate against the force of the torsion spring inside the torsion spring shaft 701, and then the sealing plate 702 will rotate downward and open the opening below the placement tube 5, until the equipment for storing biological samples is inserted into the placement rack 10 for fixation, and then the sealing plate 702 is reset under the action of the torsion spring inside the torsion spring shaft 701, thereby realizing the resealing of the opening below the placement tube 5.

[0049] In the traditional storage tank, the sample needs to be completely opened, and the tank opening will be exposed for a long time, resulting in a large amount of hot air entering and low-temperature nitrogen escaping. The present scheme changes a large opening exposure into a temporary opening of only a sample equipment cross-sectional area size, greatly reducing the exchange interface and time. When the sealing plate 702 rotates downward and opens, since the inner tank 1 is filled with low-temperature nitrogen with a density greater than air in the gas phase zone, a low-temperature nitrogen flow will be formed to flow out from the opening.

[0050] This gas flow can effectively block the entry of external hot air and form a dynamic low-temperature air curtain barrier at the opening. This greatly reduces the total amount of heat invasion during each sample access. For application scenarios that require frequent sample access, the long-term cumulative effect can significantly reduce the daily consumption of liquid nitrogen, thereby prolonging the single charging maintenance time of the storage tank and reducing the operating cost and liquid supplement frequency.

[0051] It is worth mentioning that the surface of the placing tube 5 is also provided with a cooling mechanism 8. When the biological sample storage device is placed into the inner tank 1, the placing tube 5 is opened, causing heat to enter the inner tank 1 through the placing tube 5, thereby increasing the consumption of liquid nitrogen in the inner tank 1. When the biological sample storage device enters the inner tank 1, the sealing mechanism 7 is controlled to move, and the cooling mechanism 8 uses the mechanical force generated by the rotation of the sealing mechanism 7 to draw the nitrogen gas in the gas phase zone into the liquid nitrogen below. Through forced circulation, it breaks the natural temperature stratification in the gas phase zone, making the temperature distribution of the entire gas phase zone more uniform and closer to the liquid nitrogen temperature as a whole, thereby reducing the temperature of the gas phase zone.

[0052] At the same time, the nitrogen gas will condense into liquid nitrogen again after entering the liquid nitrogen below, thereby effectively reducing the consumption of liquid nitrogen in the inner tank 1. By recovering part of the heat and liquefying it again, the additional consumption of liquid nitrogen due to the opening operation is directly compensated, thereby prolonging the effective preservation time of the storage tank during transportation and improving the overall energy efficiency.

[0053] Specifically, the cooling mechanism 8 includes a fixed block 801 installed on the surface of the placing tube 5, and the surface of the fixed block 801 is provided with a suction pipe 802, the lower end of which is inserted into the liquid nitrogen. The inside of the suction pipe 802 is slidably provided with a piston block 803, the upper end of which is connected with a connecting rod 804, the upper end of which penetrates to the outside of the fixed block 801 and is connected with a rack 805. The cooling mechanism 8 further includes a gear 806 connected to the torsion spring shaft 701, and the gear 806 and the rack 805 are engagedly connected.

[0054] At the same time, the inside of the fixed block 801 is provided with an air inlet one-way valve 807, which is located below the piston block 803 and can only allow the medium below the air inlet one-way valve 807 to enter the suction pipe 802. The surface of the fixed block 801 below the air inlet one-way valve 807 is provided with uniformly distributed air suction ports 808, and the surface of the fixed block 801 is connected with an exhaust branch pipe 809, the connection between the exhaust branch pipe 809 and the fixed block 801 is located above the air inlet one-way valve 807 and is provided with an exhaust one-way valve 810, which can only allow the medium in the suction pipe 802 to enter the exhaust branch pipe 809. More specifically:

[0055] When the biological sample storage device is placed into the inner tank 1, it will push the sealing plate 702 connected to the torsion spring shaft 701 to rotate, such as Figures 3-4As shown, take the left sealing plate 702 as an example. The sealing plate 702 will rotate counterclockwise and open the placing tube 5; when the sealing plate 702 rotates, the synchronous belt 806 drives the gear 806 to rotate counterclockwise, and then controls the gear 806 to mesh with the rack 805 to slide upward. Then the connecting rod 804 pulls the piston block 803 to slide upward in the suction tube 802, so that the negative pressure is formed in the suction tube 802, and the nitrogen in the gas phase zone is sucked into the suction tube 802 through the air inlet one-way valve 807.

[0056] When the equipment for storing biological samples is inserted, the sealing plate 702 is reset under the elastic force of the torsional spring in the torsional spring shaft 701, which drives the gear 806 to rotate clockwise, and then engages the rack 805 to drive the connecting rod 804 to slide downward, and the nitrogen sucked into the suction tube 802 is extruded by the piston block 803, so that the nitrogen in the suction tube 802 enters the exhaust branch pipe 809 through the exhaust one-way valve 810, and the lower end of the exhaust branch pipe 809 is inserted below the liquid nitrogen, so that the inhaled nitrogen is extruded into the liquid nitrogen.

[0057] And when the nitrogen flows in the exhaust branch pipe 809, it is affected by the external liquid nitrogen and absorbs heat to cool the nitrogen, so that the nitrogen is recondensed into liquid nitrogen, directly increasing the amount of liquid nitrogen and offsetting part of the daily consumption.

[0058] The suction ports 808 evenly arranged on the lower surface of the suction tube 802 ensure that the suction ports 808 above the liquid level in the inner tank body 1 can work normally regardless of the fluctuation of the liquid level, and the nitrogen in the gas phase zone can always be sucked into the suction tube 802.

[0059] Thus, it is ensured that the cooling mechanism 8 can continuously and stably play its designed function throughout the entire use cycle of the tank. And by ensuring that the nitrogen in the gas phase zone is always extracted, the hottest gas in the gas phase zone is continuously circulated to the cold end, which effectively promotes the balance of the temperature field in the tank and maximizes the effect of active cooling and reducing liquid nitrogen evaporation.

[0060] The exhaust branch pipe 809 is distributed from top to bottom in a right-inward and outward manner, so that the nitrogen can be transported away from the fixed biological samples in the placing rack 10 in the exhaust branch pipe 809.

[0061] By avoiding the direct impact of warm air flow on the biological samples, the local and rapid vaporization of liquid nitrogen around the sample tube is effectively prevented, and the high stability of the thermal environment of the samples is ensured.

[0062] It is worth noting that the outer tank body 2 is also installed outside the inner tank body 1, and the heat preservation layer 3 is arranged between the inner tank body 1 and the outer tank body 2.

[0063] When the biological sample is placed in the inner tank 1, and as the transportation time changes, the liquid nitrogen in the inner tank 1 is converted into nitrogen gas, which increases the air pressure in the inner tank 1. If the pressure accumulates without limit, exceeding the pressure limit of the inner tank 1 and its seal, it can cause the tank to rupture or explode, not only completely destroying all biological samples, but also causing serious personal injury to the operator.

[0064] When the air pressure in the inner tank 1 increases, it pushes the sealing plate 702 upwards, further causing the sealing plate 702 to overcome the elastic force of the first spring 704 under the action of the elastic force and pressure of the torsional spring in the torsional spring shaft 701, and to push the pressing plate 705 to slide upwards to extrude the first spring 704, thereby opening the gap between the two sets of sealing plates 702 and releasing the pressure in the inner tank 1. The surface of the placement tube 5 is provided with a communication port 6 that communicates with the insulation layer 3, and when the nitrogen gas in the inner tank 1 enters the placement tube 5, the nitrogen gas enters the insulation layer 3 through the communication port 6 due to the sealing of the lid above the placement tube 5 under the action of air pressure.

[0065] Until the pressure in the inner tank 1 and the elastic force of the torsional spring in the torsional spring shaft 701 are less than the elastic force of the first spring 704, the sealing plate 702 will be resealed in the inner tank 1 under the action of the elastic force of the first spring 704. By controlling the pressure within a safe range, the temperature is prevented from fluctuating sharply due to sudden pressure rise or drop. The gradual and automatic pressure relief process helps to maintain the long-term stability of the ultra-low temperature environment in the tank, providing the best preservation conditions for the samples.

[0066] It should be noted that the surface of the outer tank 2 is also connected to an indicating mechanism 9, which communicates with the insulation layer 3.

[0067] When the liquid nitrogen in the inner tank 1 is consumed, it is converted into nitrogen gas and continues to pressurize the insulation layer 3. Therefore, the higher the air pressure, the less the amount of liquid nitrogen, and the lower the liquid level. When the liquid level drops to a certain extent, the sample container that was originally immersed in liquid nitrogen or in the ideal low-temperature vapor zone is exposed to a much higher temperature upper gas phase zone, which in turn affects the biological sample.

[0068] The indicating mechanism 9 is a mechanical, external power-free liquid nitrogen level monitoring and early warning system. It indirectly reflects the consumption of liquid nitrogen by monitoring the pressure changes in the insulation layer 3 that communicates with the inner tank 1, and can provide the operator with an intuitive liquid nitrogen level warning before the sample is exposed to dangerous high temperatures.

[0069] The indicating mechanism 9 includes a vertical pipe 901 connected to the surface of the outer tank 2, which communicates with the insulation layer 3; the vertical pipe 901 is arranged in a vertical manner and has a sliding block 903 slidably installed inside by a second spring 902.

[0070] When the air pressure in the insulation layer 3 gradually increases, it will push the sliding block 903 and overcome the elastic force of the second spring 902 and slide upward. The vertical pipe 901 is set to be transparent and has a scale on the surface. The distance of the sliding block 903 sliding upward can be used to determine the remaining amount of liquid nitrogen in the inner tank body 1, thereby more effectively monitoring the low-temperature storage of biological samples and avoiding temperature fluctuations caused by frequent opening of the placement tube 5.

[0071] The surface of the vertical pipe 901 is also connected with a side pipe 904 in communication. The side pipe 904 is connected with a limiting block 906 slidingly through a third spring 905. The surface of the sliding block 903 is provided with a limiting hole 907 matched with the limiting block 906. The limiting block 906 always abuts against the surface of the sliding block 903 under the elastic force of the third spring 905.

[0072] When the liquid nitrogen is consumed to a certain extent, the sliding block 903 slides upward under the action of air pressure, and after the limiting hole 907 moves to one side of the limiting block 906, the limiting block 906 will be inserted into the limiting hole 907 under the elastic force of the third spring 905, so that the sliding block 903 cannot be reset under the elastic force of the side pipe 904. Even if the internal air pressure of the insulation layer 3 decreases due to the decrease of ambient temperature, the tank is supplemented with liquid nitrogen, etc., the sliding block 903 cannot fall back under the action of the second spring 902. Because the reset force of the second spring 902 is much smaller than the force of the third spring 905 for keeping the limiting block 906 in the locking position.

[0073] The position of the sliding block 903 is permanently locked at the highest point it has ever reached. This means that the amount of liquid nitrogen in the tank has been consumed to a low level corresponding to the air pressure. This provides a clear warning that the sample may have been exposed to a dangerous high-temperature gas-phase environment, even if the current pressure has decreased. This is crucial for assessing the safety of the sample during the entire transportation or storage period. And the entire recording process does not depend on any power, electronic sensors or complex programs. It is completely driven by air pressure changes and spring mechanical force, simple structure, strong anti-interference ability, very suitable for long-term stable work in harsh environments such as low temperature and vibration, and almost no maintenance is required.

[0074] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit it; although the foregoing embodiments of the present application have been described in detail, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the protection scope of the technical solutions of the embodiments of the present application.

Claims

1. A cryogenic biological sample transport storage tank, comprising an inner tank (1) and an outer tank (2) sleeved thereon, with an insulation layer (3) formed between the inner and outer tanks, wherein the inner tank (1) has a double-layer structure and is provided with a vacuum interlayer (4), and the inner tank (1) is also provided with a rack (10) for fixing the equipment for storing biological samples, characterized in that, The inner tank (1) is provided with a placement tube (5) that connects to its interior. The placement tube (5) is provided with a sealing mechanism (7) to isolate the gas phase region of the inner tank (1) in the non-operating state. A cooling mechanism (8) that connects to the interior of the inner tank (1) is provided on the surface of the placement tube (5). When the sealing mechanism (7) is driven to open due to the insertion or removal of biological samples, the mechanical action generated by the drive will draw the gas in the inner tank (1) into the liquid phase region of the inner tank (1) and return it to the liquid phase region of the inner tank (1), thereby achieving cooling and cold energy recovery. The wall of the placement tube (5) is provided with a communication port (6) that communicates with the insulation layer (3). The sealing mechanism (7) is opened when the gas pressure inside the inner tank (1) exceeds a predetermined value, so that the excess gas is released into the insulation layer (3) through the placement tube (5) and the communication port (6). The outer tank (2) is equipped with an indicator mechanism (9) for indicating the remaining liquid nitrogen in the inner tank (1), and the indicator mechanism (9) is connected to the insulation layer (3); The indicating mechanism (9) includes a vertical tube (901) connected to the insulation layer (3), a second spring (902) disposed in the vertical tube (901) and compressible under air pressure, and a slider (903) slidably disposed by the second spring (902). The slider (903) can move to a preset position under air pressure and be recorded. The indicating mechanism (9) further includes a locking component, which is used to lock the position of the slider (903) when the slider (903) moves to a preset position to record the peak air pressure reached. The locking component includes a side tube (904) connected to and communicating with the vertical tube (901) and a limiting block (906) elastically slidably disposed in the side tube (904). The surface of the slider (903) is provided with a limiting hole (907) that is adapted to the limiting block (906).

2. The cryogenic biological sample transport tank according to claim 1, characterized in that, The sealing mechanism (7) includes a torsion spring shaft (701) rotatably connected to the lower part of the placement tube (5) and capable of generating a closing torque, and a sealing plate (702) provided on the torsion spring shaft (701). The placement tube (5) is provided with a first spring (704) and a pressure plate (705) cooperating with the first spring (704). The first spring (704) acts on the pressure plate (705) to assist the sealing plate (702) in maintaining a horizontal sealing state.

3. A cryogenic biological sample transport tank according to claim 2, characterized in that, The cooling mechanism (8) has a fixing block (801) on the surface of the placement tube (5). The fixing block (801) is connected to a suction pipe (802) that extends into the liquid phase zone of the inner tank (1). A piston assembly is slidably arranged inside the suction pipe (802), which can divide the suction pipe (802) into upper and lower chambers. The suction pipe (802) is provided with an air intake port (808) that communicates with the lower chamber and an air intake check valve (807) that only allows gas to enter. The suction pipe (802) is also provided with an exhaust branch pipe (809) that communicates with the upper chamber and extends into the liquid phase zone.

4. A cryogenic biological sample transport tank according to claim 3, characterized in that, The piston assembly includes a piston block (803) that is slidably sealed within a suction pipe (802) and a connecting rod (804) connected to the piston block (803).

5. A cryogenic biological sample transport tank according to claim 4, characterized in that, The torsion spring shaft (701) is connected to the piston assembly via a transmission mechanism, which includes a meshing gear (806) and a rack (805). The rack (805) is located on the upper end of the connecting rod (804), and the gear (806) is located on the torsion spring shaft (701).

6. A cryogenic biological sample transport tank according to claim 4, characterized in that, The outlet end of the exhaust branch pipe (809) extends from top to bottom in a direction away from the placement rack (10).

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