A multi-tank body fluid nitrogen automatic replenishing device for a biological sample bank

Abstract

The present application relates to liquid nitrogen storage equipment technical field, disclose a kind of for biological sample library Multi-tank liquid nitrogen automatic supply device, including liquid nitrogen storage tank and for storing biological sample three groups of biological sample storage mechanism, the upper top of liquid nitrogen storage tank is provided with the liquid nitrogen discharge mechanism of the liquid nitrogen storage tank inside liquid nitrogen discharge, when the inside of biological sample storage tank is replenished with liquid nitrogen, the low liquid section of drain pipe will have part of liquid nitrogen, when electric heating ring works, the temperature of the low liquid section of drain pipe changes, and residual liquid nitrogen absorbs heat and changes into gaseous nitrogen, then solenoid valve is open, the passage between inlet pipe and drain pipe is open, and when fan works, gaseous nitrogen in the inside of drain pipe can be extracted and sent into the inside of storage tank for storage, to avoid waste when the connection between drain pipe and biological sample storage tank is disconnected, because the liquid nitrogen in the low liquid section of drain pipe contacts with external environment.

Description

Technical Field

[0001] This invention relates to the field of liquid nitrogen storage equipment technology, and more specifically, to a multi-tank automatic liquid nitrogen replenishment device for a biobank. Background Technology

[0002] Biological samples are core resources for biomedical research, clinical diagnosis, and drug development. Their long-term stable preservation depends on a continuous and reliable ultra-low temperature environment. Liquid nitrogen, with a boiling point as low as -196 degrees Celsius, is currently the most commonly used cryogenic preservation medium in biobanks. It can effectively maintain the structural integrity of bioactive substances such as cells, tissues, DNA, and proteins. In multi-tank biobanks, a centralized liquid nitrogen storage tank is usually used to replenish liquid nitrogen to multiple biological sample storage tanks through pipelines in order to maintain the low temperature state inside each storage tank.

[0003] A search revealed that Chinese patent application CN119532622A discloses a liquid nitrogen replenishment system and a Dewar flask. The liquid nitrogen replenishment system includes: a liquid nitrogen pipeline, with both ends connected to a liquid nitrogen tank and a liquid nitrogen chamber in the Dewar flask, respectively; a temperature sensor, a first vent pipe, and a replenishment valve, arranged sequentially from upstream to downstream on the liquid nitrogen pipeline; a bypass valve on the first vent pipe; a differential pressure sensor and a first connecting pipe, which connects the differential pressure sensor to the bottom of the liquid nitrogen chamber in the Dewar flask; a second vent pipe and an vent valve on the second vent pipe, which connects to the top of the liquid nitrogen chamber in the Dewar flask.

[0004] However, in existing technologies, since the drain pipe and the biological sample storage tank are usually connected in a detachable manner, operators often need to disconnect the pipe from the storage tank after replenishment in order to carry out subsequent operations or equipment maintenance. After disconnection, the liquid nitrogen remaining in the low liquid section of the drain pipe is directly exposed to the external ambient temperature environment, rapidly absorbs heat, vaporizes, and dissipates into the atmosphere. This not only causes unnecessary waste of liquid nitrogen and increases the operating cost of the sample bank, but also, if the large amount of low-temperature nitrogen gas generated by the rapid vaporization of liquid nitrogen accumulates in a closed or semi-closed space, it may lead to a decrease in local oxygen concentration, posing a potential threat to the safety of operators. Therefore, those skilled in the art provide a multi-tank liquid nitrogen automatic replenishment device for biobanks to solve the problems mentioned in the background art. Summary of the Invention

[0005] The purpose of this invention is to provide an automated liquid nitrogen replenishment device for multi-tank biobanks, thereby solving the problems mentioned in the background art.

[0006] The present invention provides the following technical solution: a multi-tank liquid nitrogen automatic replenishment device for a biobank, comprising a liquid nitrogen storage tank and three sets of biological sample storage mechanisms for storing biological samples, wherein the upper top of the liquid nitrogen storage tank is provided with a liquid nitrogen discharge mechanism for discharging liquid nitrogen from the liquid nitrogen storage tank. The outer wall of the liquid nitrogen storage tank is provided with a gas storage mechanism that converts the residual liquid nitrogen inside the pipeline into gaseous nitrogen for storage. The gas storage mechanism includes a gas storage tank fixedly connected to the outer wall of the liquid nitrogen storage tank. A fan is provided at the bottom of the gas storage tank. Gas covers are fixedly connected to both the upper and lower ends of the fan. A first circular gas pipe is provided on the outer wall of the liquid nitrogen storage tank. The gas cover located below the fan is connected to the interior of the first circular gas pipe through a pipe. The outer wall of the liquid nitrogen storage tank is provided with an exhaust mechanism to discharge excess gaseous nitrogen. The exhaust mechanism includes a second circular gas pipe disposed on the outer wall of the liquid nitrogen storage tank, and a third circular gas pipe disposed at the center of the top of the liquid nitrogen storage tank. A pressure relief pipe is fixedly connected to the exhaust end of the storage tank. The end of the pressure relief pipe communicates with the interior of the third circular gas pipe. An exhaust pipe is fixedly connected to the exhaust end of the third circular gas pipe. An exhaust hood is fixedly connected to the end of the exhaust pipe away from the third circular gas pipe.

[0007] Preferably, the liquid nitrogen discharge mechanism includes a drain device fixedly connected to the top of the liquid nitrogen storage tank. The drain device is used to discharge the liquid nitrogen inside the liquid nitrogen storage tank. A pressure gauge is installed at the top of the drain device. Three drain pipes are fixedly connected to the discharge end of the drain device. The three drain pipes are arranged in a ring array at the discharge end of the drain device. A positioning screw sleeve is threaded onto the outer wall of the end of the drain pipe. An electric heating ring for heating the drain pipe is fixedly connected to the low liquid end of the drain pipe.

[0008] Preferably, the liquid nitrogen storage tank is fixedly connected to the top end of the liquid nitrogen storage tank, the liquid inlet pipe communicates with the interior of the liquid nitrogen storage tank, the end of the liquid inlet pipe is threaded with a sealing cap, the sealing cap is used to prevent the liquid nitrogen storage tank from contacting the external environment, and the outer curved surface of the drain pipe is fixedly connected with a control valve for controlling the discharge of liquid nitrogen.

[0009] Preferably, each biological sample storage mechanism includes a biological sample storage container, the top of which is connected to a cover plate via a hinge, a support plate is fixedly connected inside the biological sample storage container, a plurality of storage boxes for storing biological sample tubes are placed on the top of the support plate, and two ultra-low temperature sensors are fixedly connected to the inner side wall of the biological sample storage container below the support plate, with the two ultra-low temperature sensors arranged in an up-down structure.

[0010] Preferably, the inlet end of the biological sample storage tank is threadedly connected to the positioning screw sleeve, and the biological sample storage tank is connected to the inside of the drain pipe through the positioning screw sleeve, so that liquid nitrogen can enter the inside of the biological sample storage tank through the drain pipe to replenish the inside of the biological sample storage tank.

[0011] Preferably, the gas storage mechanism further includes three annular arrays of inlet pipes fixedly connected to the curved surface of the first circular gas pipe. Each inlet pipe communicates with the interior of the first circular gas pipe and with the interior of the drain pipe. Each inlet pipe has an electromagnetic valve installed on its outer curved surface to control the flow of gaseous nitrogen.

[0012] Preferably, the air hood at the top of the blower is fixedly connected to the bottom of the gas storage tank via a fixing rod, the air hood at the top of the blower is connected to the inside of the gas storage tank via a pipe, the air hood at the bottom of the blower is connected to the inside of the first circular air pipe via a pipe, and a one-way valve for gas entry can be installed on the outer wall of the pipe connecting the bottom of the gas storage tank to the blower.

[0013] Preferably, the gas storage tank is internally fixedly connected to a support frame, the support frame is internally filled with adsorption filler that absorbs water vapor in gaseous nitrogen, and the inner wall of the gas storage tank is fixedly connected to four equidistant electric heating plates in a curved annular array, the electric heating plates being used to heat the gaseous nitrogen.

[0014] Preferably, the exhaust mechanism further includes three annular arrays of stamping pipes fixedly connected to the curved surface of the second circular gas pipe. The end of the stamping pipe away from the second circular gas pipe is connected to the interior of the drain pipe. A pulse valve is installed on the outer wall of the stamping pipe. The interior of the second circular gas pipe is connected to the interior of the pressure relief pipe. An electric heating ring for heating gas is fixedly sleeved on the outer curved surface of the pressure relief pipe. A pressure relief valve for controlling gas flow is fixedly connected to the outer curved surface of the pressure relief pipe. The pressure relief valve is used to prevent gaseous nitrogen from entering the interior of the pressure relief pipe.

[0015] Preferably, when the second circular gas pipe is connected to the interior of the drain pipe through the pressure pipe, gaseous nitrogen enters the interior of the drain pipe for flushing; when the pressure relief pipe and the interior of the third circular gas pipe form a gas flow, the gas entering the interior of the third circular gas pipe is discharged through the exhaust hood.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention includes a gas storage mechanism. After the liquid nitrogen inside the biological sample storage tank is replenished, some liquid nitrogen will remain in the lower liquid section of the drain pipe. At this time, do not disconnect the drain pipe from the biological sample storage tank. Then, start the fan and the electric heating ring. When the electric heating ring is working, the temperature of the lower liquid section of the drain pipe changes, and the remaining liquid nitrogen absorbs heat and turns into gaseous nitrogen. Then, the solenoid valve is in the open state, and the channel between the air inlet pipe and the drain pipe is opened. When the fan is working, it can draw out the gaseous nitrogen inside the drain pipe and send it into the gas storage tank for storage. This avoids unnecessary waste caused by the liquid nitrogen in the lower liquid section of the drain pipe coming into contact with the external environment when the connection between the drain pipe and the biological sample storage tank is disconnected. 2. This invention includes a gas storage tank and an exhaust mechanism. Due to the limited storage capacity of the gas storage tank, when gaseous nitrogen continuously enters the tank and is about to exceed its storage limit, the pressure relief valve opens and has a communication channel with the inside of the tank. When the gaseous nitrogen enters the gas hood and passes through the electric heating ring, it will be heated. The heated gaseous nitrogen then enters the third circular gas pipe and the exhaust pipe, and is finally discharged through the exhaust hood. The end of the exhaust hood is a control valve. When the control valve opens, liquid nitrogen is discharged from the liquid nitrogen storage tank and passes through the control valve. At this time, the surface temperature of the control valve drops, and a frost layer is generated. The gaseous nitrogen discharged from the exhaust hood has a certain temperature, which can remove the frost layer, thereby preventing excessive frost on the surface of the control valve from affecting its use. 3. This invention includes an exhaust mechanism. When the liquid nitrogen remaining inside the drain pipe is completely converted into gaseous nitrogen, the pressure relief valve is closed. At this time, the gaseous nitrogen will not enter the interior of the third circular gas pipe through the pressure relief pipe, but will enter the interior of the second circular gas pipe. When it is necessary to clean a drain pipe, the pulse valve is opened. At this time, the second circular gas pipe is connected to the inside of the opened pressure pipe. When the gaseous nitrogen enters the interior of the pressure pipe, it will enter the interior of the drain pipe and be discharged from its discharge end. This method can effectively clean the interior of the drain pipe and prevent dust from remaining inside the drain pipe after it is connected to the biological sample storage tank due to lack of long-term use, which would damage the internal environment of the biological sample storage tank. 4. This invention includes a gas storage tank with adsorption packing inside. When gaseous nitrogen enters the gas storage tank, it passes through the adsorption packing, and the residual water vapor inside the gaseous nitrogen is absorbed by the adsorption packing and enters the upper area of ​​the gas storage tank. An electric heating plate is installed on the inner wall of the gas storage tank to effectively heat the gaseous nitrogen. When the heated gaseous nitrogen enters the third circular gas pipe, its temperature can accelerate the melting of the frost layer on the surface of the control valve. When it enters the drain pipe, it can be purged and prevented from freezing (meaning that after the drain pipe discharges liquid nitrogen for a period of time, it can prevent the interior of the drain pipe from having frost or ice due to the transportation of liquid nitrogen). Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the liquid nitrogen storage tank in this invention; Figure 3 This is a schematic diagram of the side structure of the liquid nitrogen storage tank in this invention; Figure 4 This is a schematic diagram of the disassembled structure of the biological sample storage container in this invention; Figure 5 This is a schematic diagram of the gas storage mechanism and liquid nitrogen discharge mechanism in this invention; Figure 6 This is a schematic diagram of the exhaust mechanism in this invention; Figure 7 This is a schematic diagram of the gas storage mechanism and the exhaust mechanism in this invention; Figure 8 This is a schematic diagram of the structure of the gas storage tank in this invention.

[0018] Legend: 1. Liquid nitrogen storage tank; 2. Biological sample storage mechanism; 21. Biological sample storage tank; 22. Cover plate; 23. Support plate; 24. Storage box; 25. Ultra-low temperature sensor; 3. Gas storage mechanism; 31. Gas storage tank; 311. Electric heating plate; 312. Support frame; 313. Adsorption packing; 32. Fan; 33. Gas hood; 34. First circular gas pipe; 35. Inlet pipe; 36. Solenoid valve; 4. Liquid nitrogen discharge mechanism; 41. Drainage device; 42. Pressure gauge; 43. Drainage pipe; 431. Control valve; 44. Electric heating ring; 45. Positioning screw sleeve; 46. Inlet pipe; 47. Sealing cap; 5. Exhaust mechanism; 51. Second circular gas pipe; 52. Third circular gas pipe; 521. Exhaust pipe; 522. Exhaust hood; 53. Pressure relief pipe; 54. Pressure relief valve; 55. Stamping pipe; 56. Pulse valve. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0020] Please see Figure 1 - Figure 8 As shown, the present invention provides a technical solution: a multi-tank liquid nitrogen automatic replenishment device for a biobank, including a liquid nitrogen storage tank 1 and three sets of biological sample storage mechanisms 2 for storing biological samples. The top of the liquid nitrogen storage tank 1 is provided with a liquid nitrogen discharge mechanism 4 for discharging the liquid nitrogen inside the liquid nitrogen storage tank 1. The outer wall of the liquid nitrogen storage tank 1 is provided with a gas storage mechanism 3 for converting residual liquid nitrogen inside the pipeline into gaseous nitrogen for storage. The gas storage mechanism 3 includes a gas storage tank 31 fixedly connected to the outer wall of the liquid nitrogen storage tank 1. A fan 32 is provided at the bottom end of the gas storage tank 31. Gas covers 33 are fixedly connected to both the upper and lower ends of the fan 32. A first circular gas pipe 34 is provided on the outer wall of the liquid nitrogen storage tank 1. The gas cover 33 located below the fan 32 is connected to the interior of the first circular gas pipe 34 through a pipe. The outer wall of the liquid nitrogen storage tank 1 is provided with an exhaust mechanism 5 for discharging excess gaseous nitrogen. The exhaust mechanism 5 includes a second circular gas pipe 51 disposed on the outer wall of the liquid nitrogen storage tank 1, a third circular gas pipe 52 disposed at the center of the top of the liquid nitrogen storage tank 1, a pressure relief pipe 53 fixedly connected to the exhaust end of the gas storage tank 31, the end of the pressure relief pipe 53 communicating with the interior of the third circular gas pipe 52, an exhaust pipe 521 fixedly connected to the exhaust end of the third circular gas pipe 52, and an exhaust hood 522 fixedly connected to the end of the exhaust pipe 521 away from the third circular gas pipe 52.

[0021] It should be noted that the gas storage tank 31, together with the fan 32 and the gas hood 33, vaporizes the residual liquid nitrogen in the pipeline into gaseous nitrogen for storage, avoiding waste of cryogenic liquid nitrogen and improving the utilization rate of liquid nitrogen. The first circular gas pipe 34 is connected to the lower gas hood 33, so that the vaporization process of the residual liquid in the pipeline is completed in a closed path. The pressure relief pipe 53 guides the excess gaseous nitrogen in the gas storage tank 31 to the exhaust pipe 521 and the exhaust hood 522 through the third circular gas pipe 52 to prevent the internal pressure of the gas storage tank 31 from being too high and to ensure the safe operation of the system. The liquid nitrogen discharge mechanism 4 can stably supply liquid nitrogen to the three sets of biological sample storage mechanisms 2.

[0022] As one implementation method in this embodiment, please refer to Figure 2 , Figure 3 and Figure 6 As shown, the liquid nitrogen discharge mechanism 4 includes a drainer 41 fixedly connected to the top of the liquid nitrogen storage tank 1. The drainer 41 is used to discharge the liquid nitrogen inside the liquid nitrogen storage tank 1. A pressure gauge 42 is installed at the top of the drainer 41. Three drain pipes 43 are fixedly connected to the discharge end of the drainer 41. The three drain pipes 43 are arranged in a ring array at the discharge end of the drainer 41. A positioning screw sleeve 45 is threaded onto the outer wall of the end of the drain pipe 43. An electric heating ring 44 for heating the drain pipe 43 is fixedly connected to the low liquid end of the drain pipe 43. An inlet pipe 46 is fixedly connected to the top of the liquid nitrogen storage tank 1. The inlet pipe 46 communicates with the interior of the liquid nitrogen storage tank 1. A sealing cap 47 is threaded onto the end of the inlet pipe 46. The sealing cap 47 is used to prevent the liquid nitrogen storage tank 1 from contacting the external environment. A control valve 431 for controlling the discharge of liquid nitrogen is fixedly connected to the outer curved surface of the drain pipe 43.

[0023] It should be noted that the drain valve 41, in conjunction with the pressure gauge 42, can monitor the internal pressure of the liquid nitrogen storage tank 1 in real time. Operators can accurately determine the remaining liquid nitrogen level based on the pressure value, avoiding emptying or over-filling, thus improving management efficiency. The three drain pipes 43 are arranged in a ring array to evenly distribute liquid nitrogen to the three biological sample storage mechanisms 2, ensuring that the amount of liquid nitrogen entering each sample storage area is consistent. The positioning sleeve 45 is threaded onto the end of the drain pipe 43, facilitating flexible adjustment of the drain pipe 43 according to the interface position of different biological sample storage mechanisms 2. The insertion depth is adapted to various sample container specifications, improving the versatility of the device. The control valve 431 is set on the outer curved surface of the drain pipe 43, which can independently control the liquid nitrogen on and off of each drain pipe 43, realizing the branch liquid supply control of the three biological sample storage mechanisms 2. When a certain group does not need to be replenished, it can be shut off separately to reduce the ineffective consumption of liquid nitrogen. The inlet pipe 46, together with the sealing cap 47, can quickly connect to the inside of the liquid nitrogen storage tank 1 when liquid nitrogen is added from the outside. After the addition is completed, the sealing cap 47 effectively isolates the intrusion of external heat and reduces the daily evaporation loss of liquid nitrogen.

[0024] As one implementation method in this embodiment, please refer to Figure 2 - Figure 4 As shown, each biological sample storage mechanism 2 includes a biological sample storage tank 21. The top of the biological sample storage tank 21 is connected to a cover plate 22 via a hinge. A support plate 23 is fixedly connected inside the biological sample storage tank 21. Multiple storage boxes 24 for storing biological sample tubes are placed on the top of the support plate 23. Two ultra-low temperature sensors 25 are fixedly connected to the inner side wall of the biological sample storage tank 21 below the support plate 23. The two ultra-low temperature sensors 25 are placed in an upper and lower structure. The liquid inlet end of the biological sample storage tank 21 is threadedly connected to a positioning screw sleeve 45. The biological sample storage tank 21 is connected to the inside of the drain pipe 43 through the positioning screw sleeve 45 so that liquid nitrogen can enter the inside of the biological sample storage tank 21 through the drain pipe 43 to replenish the inside of the biological sample storage tank 21.

[0025] It should be noted that the two ultra-low temperature sensors 25 are arranged in an upper and lower structure below the support plate 23. They can simultaneously monitor the temperature distribution of the upper and lower layers inside the biological sample storage container 21, avoiding excessive temperature differences caused by liquid nitrogen density stratification. This ensures that all biological sample tubes in the storage box 24 are in a uniform ultra-low temperature environment, preventing sample degradation caused by localized heating. The support plate 23 divides the internal space of the biological sample storage container 21, and the storage box 24 is placed on it, allowing liquid nitrogen to evenly wet each storage box 24 from the bottom up. This avoids the sample tubes from directly contacting the cryogenic liquid nitrogen at the bottom of the container, which could cause localized overfreezing and cracking. The cover plate 22 is connected by a hinge, making it easy to open and close, reducing the opening time and minimizing the impact of external heat intrusion on the internal temperature. The ultra-low temperature sensor 25 can be a PT1000 (not specifically designated).

[0026] As one implementation method in this embodiment, please refer to Figure 5 - Figure 8 As shown, the gas storage mechanism 3 also includes three annular arrays of inlet pipes 35 fixedly connected to the curved surface of the first circular gas pipe 34. Each inlet pipe 35 communicates with the interior of the first circular gas pipe 34 and with the interior of the drain pipe 43. Each inlet pipe 35 has a solenoid valve 36 installed on its outer curved surface to control the flow of gaseous nitrogen. The gas cover 33 at the top of the blower 32 is fixedly connected to the bottom end of the gas storage tank 31 via a fixing rod. The gas cover 33 at the top of the blower 32 communicates with the interior of the gas storage tank 31 via a pipe. The gas cover 33 at the bottom of the blower 32 communicates with the interior of the first circular gas pipe 34 via a pipe. A one-way valve for gas entry can be installed on the outer wall of the pipe connecting the bottom end of the gas storage tank 31 to the blower 32.

[0027] It should be noted that the three air inlet pipes 35 are arranged in a ring array on the curved surface of the first circular air pipe 34 and are connected to the inside of the drain pipe 43. During the liquid nitrogen discharge process, the condensed and vaporized nitrogen generated on the outer wall of the drain pipe 43 due to the temperature difference can be recovered simultaneously, avoiding the direct loss and waste of low-temperature nitrogen and improving the utilization rate of cold energy. Each air inlet pipe 35 is independently equipped with a solenoid valve 36, which can control the recovery of each gaseous nitrogen individually. When a certain drain pipe 43 does not need to be replenished, the corresponding solenoid valve 36 is closed to prevent the recovered gaseous nitrogen from flowing back into the drain pipe 43 and causing pipeline pressure fluctuations. The top gas hood 33 of the blower 32 is connected to the inside of the gas storage tank 31, and the bottom gas hood 33 is connected to the first circular gas pipe 34, forming a forced passage for transporting gaseous nitrogen from the first circular gas pipe 34 through the blower 32 to the gas storage tank 31. This accelerates the vaporization and recovery efficiency of residual liquid nitrogen in the pipeline and shortens the vaporization waiting time. The one-way valve on the outer wall of the bottom pipe of the gas storage tank 31 ensures that gaseous nitrogen can only flow into the gas storage tank 31 in one direction, preventing the gaseous nitrogen stored in the gas storage tank 31 from flowing back into the first circular gas pipe 34 when the blower 32 stops. This ensures stable gas pressure in the gas storage tank 31 and avoids pressure backflow affecting the normal liquid supply rhythm of the liquid nitrogen discharge mechanism 4.

[0028] As one implementation method in this embodiment, please refer to Figure 8 As shown, a support frame 312 is fixedly connected inside the gas storage tank 31. The support frame 312 is filled with adsorption filler 313 that absorbs water vapor in gaseous nitrogen. Four equidistant electric heating plates 311 are fixedly connected to the inner wall of the gas storage tank 31 in a curved annular array. The electric heating plates 311 are used to heat the gaseous nitrogen.

[0029] It should be noted that the four equidistant electric heating plates 311 are fixed in a ring array on the inner wall of the gas storage tank 31. This can evenly heat the gaseous nitrogen in the gas storage tank 31, so that the trace amounts of liquid nitrogen remaining in the gaseous nitrogen can be completely vaporized. This prevents low-temperature droplets from entering the exhaust pipe with the gaseous nitrogen and causing frost blockage in the pipe, thus ensuring the smooth operation of the exhaust mechanism 5. The adsorption packing 313 filled in the support frame 312 can effectively adsorb water vapor in the gaseous nitrogen, preventing water vapor from condensing into ice crystals and blocking the pipe in the low-temperature section of the pipe. Especially at the exhaust port of the exhaust hood 522, the gaseous nitrogen dried by the adsorption packing 313 will not be affected by water vapor freezing, thus reducing the exhaust efficiency. The adsorption packing 313, together with the heating and dehumidification functions of the electric heating plates 311, makes the discharged gaseous nitrogen dry and clean, reducing the maintenance frequency of the exhaust pipe.

[0030] As one implementation method in this embodiment, please refer to Figure 3 - Figure 7 As shown, the exhaust mechanism 5 also includes three annular arrays of stamping pipes 55 fixedly connected to the curved surface of the second circular air pipe 51. The end of the stamping pipe 55 away from the second circular air pipe 51 is connected to the interior of the drain pipe 43. A pulse valve 56 is installed on the outer wall of the stamping pipe 55. The interior of the second circular air pipe 51 is connected to the interior of the pressure relief pipe 53. An electric heating ring 44 for heating gas is fixedly sleeved on the outer curved surface of the pressure relief pipe 53. A pressure relief valve 54 for controlling gas flow is fixedly connected to the outer curved surface of the pressure relief pipe 53. The pressure relief valve 54 is used to prevent gaseous nitrogen from entering the interior of the pressure relief pipe 53. When the second circular air pipe 51 is connected to the interior of the drain pipe 43 through the stamping pipe 55, gaseous nitrogen enters the interior of the drain pipe 43 for flushing. When the pressure relief pipe 53 forms a gas flow with the interior of the third circular air pipe 52, the gas entering the interior of the third circular air pipe 52 is discharged through the exhaust hood 522.

[0031] It should be noted that the three pressure tubes 55 are arranged in a ring array to connect the second circular gas tube 51 and the drain tube 43. With the help of the pulse valve 56, the inner wall of the drain tube 43 can be intermittently flushed with gaseous nitrogen. This effectively removes trace impurities and ice crystals attached to the tube wall after the residual liquid nitrogen vaporizes. It also prevents the drain tube 43 from shrinking in diameter or becoming partially blocked due to long-term use, ensuring that the liquid supply channels of the three biological sample storage mechanisms 2 are always unobstructed. The pulse valve 56 controls the flushing frequency to avoid unnecessary consumption of gaseous nitrogen caused by continuous ventilation. The pressure relief valve 54 prevents gaseous nitrogen from entering the pressure relief tube 53 in reverse, ensuring that the gaseous nitrogen in the gas storage tank 31 can only be discharged through the pressure relief tube 53 or actively discharged when the pressure in the tank exceeds the safety threshold. This maintains the pressure stabilization function of the gas storage mechanism 3. The electric heating ring 44 on the outer wall of the pressure relief tube 53 heats the gas inside the tube to prevent low-temperature gaseous nitrogen from condensing into frost on the inner wall of the pressure relief tube, ensuring that the pressure relief channel does not frost or become blocked under high-frequency pressure relief action. After the pressure relief pipe 53 is connected to the third circular gas pipe 52, gaseous nitrogen is discharged through the exhaust pipe 521 and the exhaust hood 522. The exhaust hood 522 expands the exhaust cross section, reduces the outlet flow rate, and accelerates gas diffusion to avoid the risk of oxygen deficiency caused by local accumulation of nitrogen around the tank.

[0032] Working principle: Liquid nitrogen is added into the liquid nitrogen storage tank 1 through the inlet pipe 46. After the filling is completed, the sealing cap 47 is tightened to effectively isolate external heat intrusion and reduce the daily evaporation loss of liquid nitrogen. When the biobank needs to replenish liquid nitrogen to the three sets of biosample storage institutions 2, the operator first opens the sealing cap 47 at the top of the liquid nitrogen storage tank 1. When the replenishment operation is started, the pressure gauge 42 at the top of the drainer 41 displays the internal pressure of the liquid nitrogen storage tank 1 in real time. The operator judges the remaining liquid nitrogen and decides the replenishment time accordingly. The drainer 41 discharges the liquid nitrogen inside the liquid nitrogen storage tank 1 and distributes it through the three ring array drain pipes 43. Three drain pipes 43 are threadedly connected to three sets of biological sample storage tanks 21 via positioning screw sleeves 45. Control valves 431 independently control the opening and closing of each drain pipe 43 to achieve branch liquid supply. Electric heating rings 44 continuously heat the low liquid end of drain pipe 43 to prevent liquid nitrogen from vaporizing prematurely and blocking the pipeline during long-distance transportation. When the biological sample storage tank 21 is replenished, some liquid nitrogen will inevitably remain in the low liquid section of drain pipe 43. At this time, the threaded connection between the drain pipe 43 and the biological sample storage tank 21 is kept open. The blower 32 and the electric heating ring 44 are started. The electric heating ring 44 raises the temperature of the low liquid section of the drain pipe 43. The residual liquid nitrogen absorbs heat and quickly vaporizes into gaseous nitrogen. The solenoid valve 36 is in the open state. The three air inlet pipes 35 are connected to the corresponding drain pipes 43. The top air cover 33 of the blower 32 is connected to the inside of the gas storage tank 31. The bottom air cover 33 is connected to the first circular air pipe 34. When the blower 32 is running, the gaseous nitrogen in the drain pipe 43 is drawn out through the first circular air pipe 34 and flows into the gas storage tank 31 through the air inlet pipe 35. Finally, it is sent into the gas storage tank 31 for storage. The one-way valve on the outer wall of the bottom pipe of the gas storage tank 31 ensures that the gaseous nitrogen can only flow in one direction. This prevents the gaseous nitrogen stored in the gas storage tank 31 from flowing back to the first circular air pipe 34 when the blower 32 stops, thus ensuring the stable gas pressure in the gas storage tank 31. After gaseous nitrogen enters the gas storage tank 31, it passes through the adsorption packing 313 filled in the support frame 312. The residual water vapor in the gaseous nitrogen is effectively absorbed by the adsorption packing 313, preventing the water vapor from condensing into ice crystals in the subsequent pipeline. The four equidistant electric heating plates 311 fixed in a ring array on the inner wall of the gas storage tank 31 heat the gaseous nitrogen evenly, so that the trace amount of liquid nitrogen remaining in the gaseous nitrogen is completely vaporized, eliminating the temperature dead zone inside the tank. The internal storage space of the gas storage tank 31 is limited. When the continuous injection of gaseous nitrogen is about to exceed the storage limit, the pressure relief valve 54 automatically opens. The interior of the gas storage tank 31 forms a communication channel with the pressure relief pipe 53. When the gaseous nitrogen passes through the pressure relief pipe 53, the electric heating ring 44 fixedly sleeved on the outer curved surface of the pressure relief pipe 53 heats the gas inside the pipe, preventing the low temperature gaseous nitrogen from condensing into frost on the inner wall of the pressure relief pipe 53. Heated gaseous nitrogen enters the third circular gas pipe 52, and is finally discharged through the exhaust pipe 521 and the exhaust hood 522. The exhaust hood 522 expands the exhaust cross section, reduces the outlet flow rate and local temperature, accelerates gas diffusion, and avoids the risk of oxygen deficiency caused by local accumulation of nitrogen around the tank. At the same time, the surface temperature of the control valve 431 on the outer curved surface of the drain pipe 43 drops sharply when liquid nitrogen is discharged, and frost is generated. The heated gaseous nitrogen discharged from the exhaust hood 522 has a certain temperature. When it flows near the control valve 431, it can melt and remove the frost on its surface, avoiding the accumulation of frost that causes the control valve 431 to malfunction and ensuring a continuous and stable liquid supply from the liquid nitrogen discharge mechanism 4. After the residual liquid nitrogen inside the drain pipe 43 is completely vaporized into gaseous nitrogen and recovered, the pressure relief valve 54 is closed. The gaseous nitrogen no longer enters the third circular gas pipe 52 through the pressure relief pipe 53, but instead flows into the second circular gas pipe 51. When it is necessary to clean a drain pipe 43, the corresponding pulse valve 56 is opened. The second circular gas pipe 51 is connected to the internal part of the pressure pipe 55. The gaseous nitrogen enters the drain pipe 43 through the pressure pipe 55 and is discharged from the discharge end of the drain pipe 43, realizing pulse flushing of the inner wall of the drain pipe 43. This flushing method can effectively remove the dust and ice crystal impurities remaining on the inner wall of the drain pipe 43. Since the drain pipe 43 and the biological sample storage tank 21 are connected during non-replenishment, dust may accumulate inside the drain pipe 43 due to lack of long-term use. If liquid is supplied directly, it will contaminate the internal environment of the biological sample storage tank 21. The pulse valve 56 controls the flushing frequency to avoid the ineffective consumption of gaseous nitrogen caused by continuous ventilation. While ensuring the cleanliness of the pipeline, the gas pressure balance of the gas storage mechanism 3 is maintained. The adsorption packing 313 inside the gas storage tank 31 continuously plays a drying role. After gaseous nitrogen enters the gas storage tank 31, it passes through the adsorption packing 313. Water vapor is fully absorbed and retained in the upper area of ​​the gas storage tank 31. The dried gaseous nitrogen, after being uniformly heated by four equidistant electric heating plates 311, can accelerate the melting of the frost layer on the surface of the control valve 431 when it enters the third circular gas pipe 52. When the heated gaseous nitrogen enters the interior of the drain pipe 43 through the second circular gas pipe 51 and the stamping pipe 55, it can perform hot purging to prevent freezing of the residual frost layer and ice blockage on the pipe wall of the drain pipe 43. After the drain pipe 43 discharges liquid nitrogen for a period of time, the inner wall will have residual frost layer or ice due to the continuous delivery of low temperature liquid nitrogen. Hot purging can effectively melt the frost and ice on the pipe wall, avoid the narrowing of the pipe diameter or even blockage, and ensure that the liquid nitrogen discharge mechanism 4 can continuously and stably supply liquid under long-term unattended conditions.

[0033] It should be noted that the control structures (such as valves) used in this application are all connected to an external controller to establish a signal control system. The controller enables wireless or wired connection to the control structure, thereby achieving automated control, ensuring the stability of the biological sample storage environment, and adapting to the long-term continuous replenishment needs of biological sample banks with multiple storage tanks.

[0034] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. A multi-tank liquid nitrogen automatic replenishment device for a biobank, comprising a liquid nitrogen storage tank (1) and three sets of biological sample storage mechanisms (2) for storing biological samples, characterized in that: The liquid nitrogen storage tank (1) is provided with a liquid nitrogen discharge mechanism (4) at the top of the liquid nitrogen storage tank (1) to discharge the liquid nitrogen inside the liquid nitrogen storage tank (1). The outer wall of the liquid nitrogen storage tank (1) is provided with a gas storage mechanism (3) for converting residual liquid nitrogen inside the pipe into gaseous nitrogen for storage. The gas storage mechanism (3) includes a gas storage tank (31) fixedly connected to the outer wall of the liquid nitrogen storage tank (1). A fan (32) is provided at the bottom end of the gas storage tank (31). Gas covers (33) are fixedly connected to both the upper and lower ends of the fan (32). A first circular gas pipe (34) is provided on the outer wall of the liquid nitrogen storage tank (1). The gas cover (33) located below the fan (32) is connected to the interior of the first circular gas pipe (34) through a pipe. The outer wall of the liquid nitrogen storage tank (1) is provided with an exhaust mechanism (5) for discharging excess gaseous nitrogen. The exhaust mechanism (5) includes a second circular gas pipe (51) provided on the outer wall of the liquid nitrogen storage tank (1). A third circular gas pipe (52) is provided at the center of the top of the liquid nitrogen storage tank (1). A pressure relief pipe (53) is fixedly connected to the exhaust end of the gas storage tank (31). The end of the pressure relief pipe (53) communicates with the interior of the third circular gas pipe (52). An exhaust pipe (521) is fixedly connected to the exhaust end of the third circular gas pipe (52). An exhaust hood (522) is fixedly connected to the end of the exhaust pipe (521) away from the third circular gas pipe (52).

2. The automatic liquid nitrogen replenishment device for a multi-tank biobank according to claim 1, characterized in that: The liquid nitrogen discharge mechanism (4) includes a drainer (41) fixedly connected to the top of the liquid nitrogen storage tank (1). The drainer (41) is used to discharge the liquid nitrogen inside the liquid nitrogen storage tank (1). A pressure gauge (42) is provided at the top of the drainer (41). Three drain pipes (43) are fixedly connected to the drain end of the drainer (41). The three drain pipes (43) are arranged in a ring array at the drain end of the drainer (41). A positioning screw sleeve (45) is threaded onto the outer wall of the end of the drain pipe (43). An electric heating ring (44) for heating the drain pipe (43) is fixedly connected to the low liquid end of the drain pipe (43).

3. The multi-tank liquid nitrogen automatic replenishment device for a biobank according to claim 2, characterized in that: The liquid nitrogen storage tank (1) is fixedly connected to the top end of the liquid nitrogen storage tank (1), the liquid inlet pipe (46) is connected to the interior of the liquid nitrogen storage tank (1), the end of the liquid inlet pipe (46) is threadedly connected to a sealing cap (47), the sealing cap (47) is used to prevent the liquid nitrogen storage tank (1) from contacting the external environment, and the outer curved surface of the drain pipe (43) is fixedly connected to a control valve (431) for controlling the discharge of liquid nitrogen.

4. The multi-tank liquid nitrogen automatic replenishment device for a biobank according to claim 2, characterized in that: Each biological sample storage mechanism (2) includes a biological sample storage container (21), the top of which is connected to a cover plate (22) by a hinge. A support plate (23) is fixedly connected inside the biological sample storage container (21). Multiple storage boxes (24) for storing biological sample tubes are placed on the top of the support plate (23). Two ultra-low temperature sensors (25) are fixedly connected to the inner side wall of the biological sample storage container (21) below the support plate (23). The two ultra-low temperature sensors (25) are placed in an upper and lower structure.

5. The multi-tank liquid nitrogen automatic replenishment device for a biobank according to claim 4, characterized in that: The liquid inlet of the biological sample storage tank (21) is threadedly connected to the positioning screw sleeve (45). The biological sample storage tank (21) is connected to the inside of the drain pipe (43) through the positioning screw sleeve (45) so that liquid nitrogen can enter the inside of the biological sample storage tank (21) through the drain pipe (43) to replenish the inside of the biological sample storage tank (21).

6. The multi-tank liquid nitrogen automatic replenishment device for a biobank according to claim 2, characterized in that: The gas storage mechanism (3) also includes three annular arrays of inlet pipes (35) fixedly connected to the curved surface of the first circular gas pipe (34). Each inlet pipe (35) is connected to the interior of the first circular gas pipe (34) and to the interior of the drain pipe (43). Each inlet pipe (35) is equipped with a solenoid valve (36) for controlling the flow of gaseous nitrogen on its outer curved surface.

7. The multi-tank liquid nitrogen automatic replenishment device for a biobank according to claim 6, characterized in that: The air hood (33) at the top of the blower (32) is fixedly connected to the bottom end of the gas storage tank (31) by a fixing rod. The air hood (33) at the top of the blower (32) is connected to the inside of the gas storage tank (31) through a pipe. The air hood (33) at the bottom of the blower (32) is connected to the inside of the first circular air pipe (34) through a pipe. A one-way valve for gas entry can be installed on the outer wall of the pipe connecting the bottom end of the gas storage tank (31) and the blower (32).

8. The multi-tank liquid nitrogen automatic replenishment device for a biobank according to claim 1, characterized in that: The gas storage tank (31) is fixedly connected to a support frame (312), and the support frame (312) is filled with an adsorption filler (313) that absorbs water vapor in gaseous nitrogen. The inner wall of the gas storage tank (31) is fixedly connected to four equidistant electric heating plates (311) in a circular array, and the electric heating plates (311) are used to heat gaseous nitrogen.

9. The multi-tank liquid nitrogen automatic replenishment device for a biobank according to claim 2, characterized in that: The exhaust mechanism (5) also includes three annular arrays of stamping pipes (55) fixedly connected to the curved surface of the second circular gas pipe (51). The end of the stamping pipe (55) away from the second circular gas pipe (51) is connected to the interior of the drain pipe (43). A pulse valve (56) is installed on the outer wall of the stamping pipe (55). The interior of the second circular gas pipe (51) is connected to the interior of the pressure relief pipe (53). An electric heating ring (44) for heating gas is fixedly sleeved on the outer curved surface of the pressure relief pipe (53). A pressure relief valve (54) for controlling gas flow is fixedly connected to the outer curved surface of the pressure relief pipe (53). The pressure relief valve (54) is used to prevent gaseous nitrogen from entering the interior of the pressure relief pipe (53).

10. The multi-tank liquid nitrogen automatic replenishment device for a biobank according to claim 9, characterized in that: When the second circular gas pipe (51) is connected to the inside of the drain pipe (43) through the pressure pipe (55), gaseous nitrogen enters the inside of the drain pipe (43) for flushing. When the pressure relief pipe (53) and the inside of the third circular gas pipe (52) form a gas flow, the gas entering the inside of the third circular gas pipe (52) is discharged through the exhaust hood (522).

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