Micron-sized liquid nitrogen generator and manufacturing method

Abstract

The application discloses a micron-level liquid nitrogen generator and a manufacturing method thereof. The micron-level liquid nitrogen generator comprises a supply mixing mechanism, a shearing refining mechanism and a quality monitoring mechanism. The supply mixing mechanism is used for pre-cooling and mixing liquid nitrogen and nitrogen gas and dispersing the liquid nitrogen and nitrogen gas into liquid nitrogen bubbles. The shearing refining mechanism is used for shearing and refining the liquid nitrogen bubbles. The quality monitoring mechanism is used for monitoring the particle size of the liquid nitrogen bubbles and adjusting and controlling the shearing refining mechanism. A sample storage tank is used for receiving the liquid nitrogen bubbles after being sheared by the shearing refining mechanism. The sample storage tank can store samples through the liquid nitrogen bubbles. The micron-level liquid nitrogen generator has the advantages that the supply mixing mechanism can supply raw materials, the nitrogen gas can be pre-cooled and mixed with the liquid nitrogen, the shearing refining mechanism can cut and break the larger liquid nitrogen bubbles to form 1-100 micron-level liquid nitrogen bubbles, the quality monitoring mechanism can adjust and control the shearing refining mechanism according to the detection result of the bubble particle size, the sample storage tank can receive the 1-100 micron-level liquid nitrogen bubbles, and the sample storage tank can store samples at low temperature.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sample storage, in particular to a micron-level liquid nitrogen generator and a manufacturing method thereof. BACKGROUND

[0002] The sample in the low-temperature storage tank of the currently used sample storage device is sprayed and cooled by a spraying mechanism when being cooled, and the target is cooled by liquid nitrogen. However, the existing spraying method is relatively rough and direct, which not only impacts the target during cooling, but also causes some areas to be instantaneously cooled, while other areas that have not been fully contacted with liquid nitrogen are still in a non-cooled or weakly affected state. Moreover, the existing spraying method cannot make the target sample tube or single rack be evenly sprayed even in the instantaneously cooled area, that is, the target tube or single rack cannot be truly and evenly cooled, and the entire environment cannot be evenly cooled, resulting in poor stability of the sample and large nitrogen consumption.

[0003] Therefore, the inventor designs a device that can generate micron-level liquid nitrogen bubbles. SUMMARY

[0004] This section aims to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, abstract and title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0005] In view of the above or existing problems in the prior art, the present application is proposed.

[0006] Therefore, the purpose of the present application is to provide a micron-level liquid nitrogen generator that can generate liquid nitrogen bubbles, shear and break larger liquid nitrogen bubbles, and ultimately form 1-100 μm micron-level liquid nitrogen bubbles. The low-temperature storage tank uses a multi-channel distribution device to spray 1-100 μm micron-level liquid nitrogen bubbles on the sample tube, and uses the liquid nitrogen bubbles to wrap the sample tube, thereby achieving uniform cooling of the sample tube and saving the use of liquid nitrogen.

[0007] To solve the above technical problems, the present application provides the following technical solution: a micron-level liquid nitrogen generator, comprising a supply mixing mechanism, a shearing and refining mechanism, a quality monitoring mechanism, and a sample storage tank; the shearing and refining mechanism is in communication with the supply mixing mechanism and the sample storage tank, and the quality monitoring mechanism is arranged on the shearing and refining mechanism.

[0008] The supply mixing mechanism pre-cools and mixes liquid nitrogen and nitrogen gas, dispersing them into liquid nitrogen bubbles. The shearing and refining mechanism shears and refines the liquid nitrogen bubbles. The quality monitoring mechanism monitors the particle size of the liquid nitrogen bubbles and adjusts and controls the operation of the shearing and refining mechanism. The sample storage tank receives the liquid nitrogen bubbles sheared by the shearing and refining mechanism and stores the sample through the liquid nitrogen bubbles.

[0009] As a preferred embodiment of the micron-level liquid nitrogen generator of the present invention, the shearing and refining mechanism includes a two-stage mechanical shear and a three-stage microporous shear; the two-stage mechanical shear can shear and break up the liquid nitrogen bubbles delivered by the mixing mechanism; the three-stage microporous shear can shear the broken liquid nitrogen bubbles to the target particle size.

[0010] In a preferred embodiment of the micron-level liquid nitrogen generator of the present invention, the quality monitoring mechanism includes a particle image analyzer and a PLC control system; the particle image analyzer can monitor the particle size of the shearing liquid nitrogen bubbles of the secondary mechanical shearer in real time, and the PLC control system controls the shearing particle size of the secondary mechanical shearer based on the detection results of the particle image analyzer.

[0011] As a preferred embodiment of the micron-level liquid nitrogen generator of the present invention, the supply and mixing mechanism includes a supply component, a precooler, and a mixer; the supply component can supply liquid nitrogen and nitrogen gas into the mixer, the precooler can precool the nitrogen gas, and the mixer can mix the liquid nitrogen and gaseous nitrogen and disperse them into liquid nitrogen bubbles.

[0012] As a preferred embodiment of the micron-level liquid nitrogen generator of the present invention, the supply component includes a main liquid nitrogen storage tank and a nitrogen buffer tank. The main liquid nitrogen storage tank and the nitrogen buffer tank are respectively connected to a precooler through pipelines. The main liquid nitrogen storage tank can transport liquid nitrogen, and the nitrogen buffer tank can transport nitrogen.

[0013] As a preferred embodiment of the micron-level liquid nitrogen generator of the present invention, the secondary mechanical shear includes a cylindrical structure, in which a rotor and a stator are disposed, and the rotor and stator are coaxially arranged; the rotor is a blade structure, and the rotor can rotate on the stator, and a shearing gap is provided between the rotor and the stator, and the rotor is driven by a driving component; fluid inlet and outlet are provided at both ends of the cylindrical structure.

[0014] As a preferred embodiment of the micron-level liquid nitrogen generator of the present invention, the three-stage microporous shearer includes a filter screen, and the filter screen is configured as multiple layers, with the pore size of the multiple filter screens decreasing sequentially.

[0015] As a preferred embodiment of the micron-level liquid nitrogen generator of the present invention, a gap adjustment component is further provided inside the cylindrical structure. The gap adjustment component is connected to the stator, and the gap adjustment component can drive the stator to move. The gap adjustment component can adjust the gap between the rotor and the stator.

[0016] An observation window is also provided on one side of the cylindrical structure, allowing observation of the interior of the cylindrical structure.

[0017] As a preferred embodiment of the micron-level liquid nitrogen generator of the present invention, the rotor includes a drive shaft and blade cutting edges; the drive shaft is connected to a drive component, which can drive the drive shaft to rotate circumferentially; multiple sets of blade cutting edges are arranged circumferentially and / or horizontally and / or vertically on the drive shaft; the multiple sets of blade cutting edges can cooperate with the stator to shear liquid nitrogen bubbles.

[0018] As a preferred embodiment of the micron-level liquid nitrogen generator of the present invention, the stator includes a stator fixing frame, a plurality of support frames are provided on the stator fixing frame, a plurality of stator cutting blades are provided on the support frames, and the stator cutting blades and blade cutting blades can cooperate to shear the liquid nitrogen bubbles.

[0019] The stator fixing frame is also equipped with multiple optical axes, which can limit the movement of the stator fixing frame, and the gap adjustment component can drive the stator fixing frame to move along the optical axes.

[0020] In a preferred embodiment of the micron-level liquid nitrogen generator of the present invention, a sealing element is also provided on one side of the driving component, and the sealing element is sealed to the cylindrical structure.

[0021] The beneficial effects of the micron-sized liquid nitrogen generator of the present invention are as follows: A supply and mixing mechanism can supply raw materials and pre-cool nitrogen gas. The pre-cooled nitrogen gas mixes with liquid nitrogen to initially form larger liquid nitrogen bubbles. A shearing and refining mechanism can then cut and break these larger bubbles to ultimately form 1-100 μm micron-sized liquid nitrogen bubbles. Furthermore, a quality monitoring mechanism monitors in real time whether the liquid nitrogen bubbles cut by the shearing and refining mechanism meet the specifications, and adjusts and controls the shearing and refining mechanism based on the detected bubble size. A sample storage tank can receive 1-100 μm micron-sized liquid nitrogen bubbles, achieving uniformity and consistency. The sample storage tank allows for low-temperature sample storage, and it is equipped with a multi-channel distribution device. This invention uses a shearing and refining mechanism to uniformly spray micron-sized liquid nitrogen bubbles onto a sample holder, thus uniformly encapsulating the samples. This method avoids the problem of larger liquid nitrogen bubbles failing to uniformly encapsulate the samples during programmed cooling, which can lead to poor sample stability. The device sprays micron-sized liquid nitrogen particles onto the sample holder, ensuring more thorough sample encapsulation. This results in more even cooling and reduced liquid nitrogen consumption, allowing for the cooling and storage of biological samples with only a small amount of liquid nitrogen. The inventors first proposed using liquid nitrogen bubbles for spraying, and by using micron-sized liquid nitrogen bubbles to encapsulate and cool the sample tubes, they overcame the drawbacks of previous liquid nitrogen spraying methods, ensuring uniform cooling.

[0022] The inventors also provide a method for manufacturing a micron-sized liquid nitrogen generator, which can quickly generate liquid nitrogen bubbles in the 1-100μm range; specifically, it includes: S1: supplying liquid nitrogen and nitrogen gas through a supply mixing mechanism, and the supply mixing mechanism can pre-cool and mix the liquid nitrogen and nitrogen gas;

[0023] S2: The liquid nitrogen bubbles supplied to the mixing mechanism are received by the shearing and refining mechanism, and the liquid nitrogen bubbles are physically broken up.

[0024] S3: The particle size of liquid nitrogen bubbles can be detected by a quality monitoring agency, and the shearing and refining mechanism can be controlled and adjusted according to the particle size deviation results;

[0025] S4: Liquid nitrogen bubbles of the target particle size can be received and stored through the sample storage tank.

[0026] As a preferred embodiment of the method for manufacturing the micron-scale liquid nitrogen generator of the present invention, S1 includes:

[0027] S11: The mixing mechanism includes a supply component and a mixer; the supply component supplies liquid nitrogen and nitrogen gas to the mixer for mixing; the flow ratio of nitrogen gas to liquid nitrogen is controlled at 3:1 to 8:1.

[0028] S12: The mixing mechanism also includes a precooler, which can precool nitrogen to -170~-180° to reduce the temperature difference vaporization when nitrogen comes into contact with liquid nitrogen.

[0029] In a preferred embodiment of the method for manufacturing the micron-scale liquid nitrogen generator of the present invention, S11 includes:

[0030] S111: The supply components include a main liquid nitrogen storage tank and a nitrogen buffer tank. The main liquid nitrogen storage tank and the nitrogen buffer tank are connected to the mixer through pipelines. Valves are installed on the pipelines to control the on / off of the pipelines.

[0031] In a preferred embodiment of the method for manufacturing the micron-scale liquid nitrogen generator of the present invention, S11 further includes:

[0032] S112: Liquid nitrogen is injected into the mixer, which has an annular channel with an annular opening. Nitrogen is released annularly inside the mixer, allowing liquid nitrogen and nitrogen gas to be initially mixed and form liquid nitrogen bubbles of 100-500μm.

[0033] In a preferred embodiment of the method for manufacturing the micron-scale liquid nitrogen generator of the present invention, S2 includes:

[0034] S21: The shearing and refining mechanism includes a two-stage mechanical shear, which receives liquid nitrogen bubbles from the mixer; the two-stage mechanical shear cuts the liquid nitrogen bubbles and forms liquid nitrogen bubbles of 10-50μm.

[0035] In a preferred embodiment of the method for manufacturing the micron-scale liquid nitrogen generator of the present invention, S2 further includes:

[0036] S22: The shearing and refining mechanism also includes a three-stage microporous shearer, which further shears and breaks down the 10-50μm liquid nitrogen bubbles after they have been sheared and broken by the two-stage mechanical shearer, thereby forming 1-100μm micron-sized liquid nitrogen bubbles.

[0037] In a preferred embodiment of the method for manufacturing the micron-scale liquid nitrogen generator of the present invention, S3 includes:

[0038] S31: The quality monitoring mechanism includes a particle image analyzer and a PLC control system; the particle image analyzer can monitor 1-500μm liquid nitrogen bubbles in real time and feed the feedback to the PLC control system. When the particle size deviation of the liquid nitrogen bubbles is too large, the PLC control system can adjust and control the speed of the secondary mechanical shear or the pressure of the tertiary microporous shear.

[0039] The beneficial effects of the method for manufacturing a micron-sized liquid nitrogen generator according to the present invention are as follows: The present invention delivers liquid nitrogen and nitrogen gas into a mixer through a main liquid nitrogen storage tank and a nitrogen buffer tank. A precooler precools the nitrogen gas, reducing the temperature difference that causes vaporization when nitrogen gas comes into contact with liquid nitrogen. The mixer initially mixes the liquid nitrogen and nitrogen gas, forming liquid nitrogen bubbles of 100-500 μm. A shearing and refining mechanism repeatedly shears and breaks up the 100-500 μm liquid nitrogen bubbles, ultimately forming liquid nitrogen bubbles of 10-50 μm. A quality monitoring mechanism detects the particle size of the liquid nitrogen bubbles broken by the shearing and refining mechanism and adjusts the state and power of the shearing and refining mechanism in real time. A sample storage tank receives and stores liquid nitrogen bubbles of the target particle size, achieving uniformity of liquid nitrogen. The present invention, through shearing... The fine-cutting mechanism can break larger air bubbles down to the micron level. Currently used storage devices, during programmed cooling, suffer from uneven sample cooling and poor sample stability because the large liquid nitrogen bubbles cannot uniformly coat the sample. The micron-sized liquid nitrogen generator of this invention can break down larger air bubble particles and ultimately form uniform liquid nitrogen bubbles of 10-50 μm, thereby achieving uniform coating of the sample tube and uniform cooling, while also improving sample stability. This method can spray micron-sized liquid nitrogen particles onto the sample holder, making the sample more fully coated, resulting in more even cooling and reduced liquid nitrogen consumption. A small amount of liquid nitrogen is sufficient for cooling and storing biological samples. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0041] Fig. 1 This is a schematic diagram of the process for manufacturing a micron-sized liquid nitrogen generator.

[0042] Fig. 2 This is a schematic diagram of a micron-scale liquid nitrogen generator.

[0043] Fig. 3 This is a schematic diagram of the internal structure of the secondary mechanical shear in a micron-level liquid nitrogen generator.

[0044] Fig. 4 This is an enlarged schematic diagram of the internal structure of the secondary mechanical shear in a micron-scale liquid nitrogen generator.

[0045] Fig. 5 This is a magnified view of a three-stage microporous shearing device in a micron-scale liquid nitrogen generator.

[0046] Fig. 6 This is a magnified schematic diagram of the interior of the secondary mechanical shear of a micron-sized liquid nitrogen generator from another perspective.

[0047] Reference numerals: 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 10; 1 ...1; 12; 13; 11; 11; 11; 12; 11; 11; 12; 13; 14; 15; 16; 17; 18; 19; 10; 11; 12; 13; 19; 10; 11; 12; 13; 11; 12; 13; 13; 14; 15; 16; 19; 10; 11; 12; 13; 19; 10; 11; 11; 12; 13; 11; 12; 13; 19; 10; 11; 11; 12; 13; 19; 10; 11; 11; 12; 19; 10; 11; 19; 10; 11; 19; 10; 11; 19; 10; 19; 10; 19; 10; 19; 10; 19; 19; 10; 19; 19; 10; 19; 19; 10; 19; 19; 10; 19; 19; 10; 19; 19; 10; 19; 19; 1 Detailed Implementation

[0048] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0049] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0050] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments. Example 1

[0051] Reference Figs. 1-6 This is the first embodiment of the present invention. This embodiment provides a micron-level liquid nitrogen generator, which includes a supply and mixing mechanism 1, a shearing and refining mechanism 2, a quality monitoring mechanism, and a sample storage tank 3. The shearing and refining mechanism 2 is connected to the supply and mixing mechanism 1 and the sample storage tank 3 respectively, and the quality monitoring mechanism is disposed on the shearing and refining mechanism 2.

[0052] The supply mixing mechanism 1 pre-cools and mixes liquid nitrogen and nitrogen gas and disperses them into liquid nitrogen bubbles. The shearing and refining mechanism 2 can shear and refine the liquid nitrogen bubbles. The quality monitoring mechanism can monitor the particle size of the liquid nitrogen bubbles and adjust and control the operation of the shearing and refining mechanism 2. The sample storage tank 3 can receive the liquid nitrogen bubbles sheared by the shearing and refining mechanism 2. The sample storage tank 3 can store samples through the liquid nitrogen bubbles.

[0053] Furthermore, the shearing and refining mechanism 2 includes a secondary mechanical shearer 21 and a tertiary microporous shearer 22; the secondary mechanical shearer 21 can shear and break up the liquid nitrogen bubbles conveyed by the mixing mechanism; the tertiary microporous shearer 22 can shear the broken liquid nitrogen bubbles to the target particle size.

[0054] Furthermore, the secondary mechanical shear 21 includes a cylindrical structure 211, within which a rotor 212 and a stator 213 are disposed, and the rotor 212 and the stator 213 are coaxially disposed; the rotor 212 has a blade structure, and the rotor 212 can rotate on the stator 213, and a shearing gap is provided between the rotor 212 and the stator 213, and the rotor 212 is driven by a driving component 215; fluid inlet and outlet are provided at both ends of the cylindrical structure 211.

[0055] Preferably, a gap adjusting member 214 is also provided inside the cylindrical structure 211. The gap adjusting member 214 is connected to the stator 213. The gap adjusting member 214 can drive the stator 213 to move. The gap adjusting member 214 can adjust the gap between the rotor 212 and the stator 213.

[0056] Preferably, the clearance adjustment element 214 can be adjusted by means of a threaded rod.

[0057] Preferably, the stator 213 is supported and fixed on the outside by an optical axis, which is connected to the inside of the cylindrical structure 211.

[0058] Furthermore, a gap adjusting component is also provided inside the cylindrical structure. The gap adjusting component is connected to the stator, and the gap adjusting component can drive the stator to move. The gap adjusting component can adjust the gap between the rotor and the stator.

[0059] Preferably, the gap adjustment component 214 includes a threaded rod 2141, a magnetic coupling plate 2142, and a servo motor 2143; micron-level movement can be achieved. The gap adjustment component 214 is threadedly connected to the stator fixing frame 2131. By rotating the gap adjustment component 214, the stator fixing frame 2131 can be moved. The stator fixing frame 2131 then moves the support frame 2132 and the stator cutting edge 2133, thereby adjusting the gap between the stator cutting edge 2133 and the blade cutting edge 2122, thus controlling the size of the liquid nitrogen bubbles being sheared.

[0060] An observation window is also provided on one side of the cylindrical structure, which allows observation of the interior of the cylindrical structure.

[0061] Furthermore, the rotor includes a drive shaft 2121 and blade cutting edges 2122; the drive shaft 2121 is connected to a drive component, the drive component can drive the drive shaft 2121 to rotate circumferentially, and the drive shaft 2121 is provided with multiple sets of blade cutting edges 2122 circumferentially and / or horizontally and / or vertically, the multiple sets of blade cutting edges 2122 can cooperate with the stator to shear liquid nitrogen bubbles.

[0062] Furthermore, the stator 213 includes a stator fixing frame 2131, on which multiple sets of support frames 2132 are provided, and on which multiple sets of stator cutting blades 2133 are provided, and the stator cutting blades 2133 and the blade cutting blades 2122 can cooperate to shear liquid nitrogen bubbles.

[0063] The stator fixing frame 2131 is also provided with multiple optical axes 2134, which can limit the stator fixing frame 2131, and the gap adjusting member can drive the stator fixing frame 2131 to move along the optical axis 2134.

[0064] Preferably, the optical axis 2134 is set in multiple groups, which can prevent the stator fixing frame 2131 from rotating in a circular manner, and can ensure that the stator fixing frame 2131 can only move along the direction of the optical axis 2134 when the gap needs to be adjusted.

[0065] Furthermore, a sealing element 216 is provided on one side of the drive component, and the sealing element 216 is sealed to the cylindrical structure to ensure that there is no leakage.

[0066] Preferably, the three-stage microporous shearer 22 is disposed on one side of the cylindrical structure 211. After the two-stage mechanical shearer 21 cuts the liquid nitrogen bubbles, the cut liquid nitrogen bubbles enter the three-stage microporous shearer 22 for further cutting, thereby achieving the generation of 1-100μm micron-sized liquid nitrogen bubbles.

[0067] Preferably, the rotor 212 has a multi-blade structure, such as having 4 to 6 shearing blades, made of low-temperature resistant and wear-resistant 316L stainless steel, with sharpened blade edges to enhance the shearing effect, and the center is connected to the drive motor through a rotating shaft, rotating at high speed with the motor.

[0068] Preferably, the stator 213 is coaxially arranged with the rotor 212, and has a toothed or slotted structure on the inner side that cooperates with the blades of the rotor 212. It is also made of 316L stainless steel. An adjustable shear gap of 0.1-0.3mm is formed between the stator 213 and the rotor 212.

[0069] Preferably, the cylindrical structure 211 encloses the rotor 212 and the stator 213, providing a closed flow space for gas-liquid fluids. The cylindrical structure 211 has fluid inlets and outlets at both ends and is made of 316L stainless steel to adapt to low-temperature environments.

[0070] Preferably, the drive unit 215 provides power to the rotor 212, and adopts a servo motor adapted to low temperature working conditions, which can stably output a speed of 2500-3500RPM, and can adjust the speed according to the instructions of the PLC control system, thereby controlling the shearing effect.

[0071] It should be noted that the secondary mechanical shearer 21 utilizes the shearing action between the high-speed rotating rotor 212 and stator 213 to physically break up and refine the liquid nitrogen bubbles in the gas-liquid mixture. After the larger liquid nitrogen bubbles are initially dispersed by the mixer 13, the gas-liquid fluid with a size of 100-500 μm enters the shearer. The rotor 212 rotates at a high speed of 2500-3500 RPM, causing the fluid to form strong turbulence. The shearing gap between the rotor 212 and the stator 213 can be adjusted within the range of 0.1-0.3 mm, which produces shearing, collision, and grinding effects on the bubbles, thereby breaking up the larger liquid nitrogen bubbles into smaller bubbles of 10-50 μm, laying the foundation for further refinement by the subsequent tertiary microporous shearer 22.

[0072] Furthermore, the three-stage microporous shearing device 22 includes a filter screen 221, and the filter screen 221 is configured as multiple layers, with the pore size of the multiple filter screens 221 decreasing sequentially.

[0073] Preferably, filter 221 is a multi-layered gradient pore size metal filter made of 316L stainless steel, with pore sizes of 100μm→50μm→10μm, a porosity of 40%, and an operating pressure of 0.6-0.9MPa, ultimately achieving the generation of 1-100μm micron-level liquid nitrogen bubbles.

[0074] Furthermore, the quality monitoring mechanism includes a particle image analyzer and a PLC control system; the particle image analyzer can monitor the particle size of the liquid nitrogen bubbles being sheared by the secondary mechanical shearer 21 in real time, and the PLC control system controls the shearing particle size of the secondary mechanical shearer 21 based on the detection results of the particle image analyzer.

[0075] Preferably, the particle image analyzer model is PIA-300: it monitors the particle size distribution of liquid nitrogen bubbles in real time, with a measurement range of 1-500μm and a data sampling frequency of 1 time / second;

[0076] Preferably, the PLC control system is based on the S7-1200 PLC to achieve closed-loop control. When the particle size deviation exceeds ±20%, the speed of the secondary mechanical shear 21 or the working pressure of the micro-hole shear is automatically adjusted.

[0077] Furthermore, the supply mixing mechanism 1 includes a supply component 11, a precooler 12, and a mixer 13; the supply component 11 can supply liquid nitrogen and nitrogen gas into the mixer 13, the precooler 12 can precool the nitrogen gas, and the mixer 13 can mix the liquid nitrogen and gaseous nitrogen and disperse them into liquid nitrogen bubbles.

[0078] Preferably, the coaxial jet structure allows liquid nitrogen to be ejected through a central nozzle with an orifice diameter of 0.8 mm, while pre-cooled nitrogen gas forms a surrounding airflow through an annular channel with a gap of 0.5 mm, achieving initial gas-liquid mixing and an initial dispersion of 100-500 μm.

[0079] Preferably, the precooler 12 has a spiral tube structure with a heat exchange area of ​​0.3㎡, which precools the nitrogen to -170~-180℃, reducing the temperature difference vaporization when in contact with liquid nitrogen;

[0080] Furthermore, the supply component 11 includes a main liquid nitrogen storage tank 111 and a nitrogen buffer tank 112. The main liquid nitrogen storage tank 111 and the nitrogen buffer tank 112 are connected to the precooler 12 through pipelines. The main liquid nitrogen storage tank 111 can transport liquid nitrogen, and the nitrogen buffer tank 112 can transport nitrogen.

[0081] Preferably, the main liquid nitrogen storage tank 111 has a double-layer vacuum insulation structure, is made of 316L stainless steel, has a volume of 30-50L, an operating temperature of -196℃, and is equipped with a cryogenic solenoid valve (model: V-LN2-01) with a flow control accuracy of ±0.5%.

[0082] Preferably, the nitrogen buffer tank 112 is a high-pressure inert gas storage structure made of 304 stainless steel, with a working pressure of 0.8-1.2MPa and a volume of 10-20L. It is equipped with a pressure reducing valve with an adjustment accuracy of ±0.02MPa and is used to provide inert dispersion gas.

[0083] Preferably, sample storage container 3 is a biological sample storage container; it has a double-layer vacuum insulation structure, is made of 316L stainless steel, has a volume of 100-200L, an operating temperature of -196℃, and a temperature uniformity of ±1℃.

[0084] The biological sample storage container 3 has an internal multi-channel distribution device: 12 injection nozzles are distributed in a matrix, with an aperture of 0.3 mm, which uniformly delivers micron-sized liquid nitrogen bubbles to the sample rack. The sample rack has 10-15 layers, and each layer can hold 50-100 sample tubes.

[0085] Safety protection module: equipped with a pressure safety valve with an opening pressure of 1.8MPa, a low-temperature leakage sensor with a response time of <1 second, and an oxygen concentration monitor with an alarm threshold of 19.5% vol.

[0086] Workflow:

[0087] Raw material pretreatment: The main liquid nitrogen storage tank 111 delivers liquid nitrogen through a cryogenic solenoid valve, while the nitrogen buffer tank 112 outputs nitrogen gas which is pre-cooled to -170~-180℃ by a cryogenic heat exchanger. The flow ratio of nitrogen gas to liquid nitrogen is controlled at 3:1~8:1.

[0088] Preliminary mixing: Pre-cooled nitrogen and liquid nitrogen form a gas-liquid two-phase flow in mixer 13, and are initially dispersed into liquid nitrogen bubbles of 100-500μm;

[0089] Multi-stage refinement: The mixed fluid is sequentially refined to 10-50μm by a two-stage mechanical shear 21 and finally to 1-100μm by a three-stage microporous shear 22;

[0090] Quality monitoring: The particle image analyzer monitors the bubble size in real time, and the PLC control system dynamically adjusts the parameters to ensure the stability of micron-sized liquid nitrogen bubbles;

[0091] Sample storage: Qualified micron-sized liquid nitrogen bubbles are injected into sample storage tank 3 through a multi-channel dispensing device to evenly cover the sample and achieve ultra-low temperature preservation.

[0092] In summary, this invention provides a supply and mixing mechanism 1 for supplying raw materials and pre-cooling nitrogen. The pre-cooled nitrogen is then mixed with liquid nitrogen to initially form larger liquid nitrogen bubbles. The shearing and refining mechanism 2 cuts and breaks these larger liquid nitrogen bubbles, ultimately forming 1-100 μm micron-sized liquid nitrogen bubbles. Furthermore, a quality monitoring mechanism monitors in real time whether the liquid nitrogen bubbles cut by the shearing and refining mechanism 2 meet the specifications, and adjusts and controls the shearing and refining mechanism 2 based on the detected bubble particle size. The sample storage tank 3 can receive the 1-100 μm micron-sized liquid nitrogen bubbles and allows for low-temperature storage of samples. Example 2

[0093] Reference Figs. 1-6 This is the second embodiment of the present invention. Based on embodiment 1, it also includes a method for manufacturing a micron-level liquid nitrogen generator, including S1: supplying liquid nitrogen and nitrogen gas through a supply mixing mechanism 1, and the supply mixing mechanism 1 can pre-cool and mix the liquid nitrogen and nitrogen gas.

[0094] S2: The liquid nitrogen bubbles supplied by the mixing mechanism 1 are received by the shearing and refining mechanism 2, and the liquid nitrogen bubbles are physically broken up.

[0095] S3: The particle size of liquid nitrogen bubbles can be monitored by the quality monitoring agency, and the shearing and refining mechanism 2 can be controlled and adjusted according to the particle size deviation results;

[0096] S4: Liquid nitrogen bubbles of the target particle size can be received and stored through sample storage tank 3.

[0097] Furthermore, S1 includes;

[0098] S11: The mixing mechanism includes a supply component 11 and a mixer 13; liquid nitrogen and nitrogen gas are respectively supplied to the mixer 13 through the supply component 11 for mixing; the flow ratio of nitrogen gas to liquid nitrogen is controlled at 3:1 to 8:1.

[0099] S12: The mixing mechanism also includes a precooler 12, which can precool nitrogen to -170~-180° to reduce the temperature difference vaporization when nitrogen comes into contact with liquid nitrogen.

[0100] Preferably, the precooler 12 precools the nitrogen gas to -170~-180℃ to reduce the temperature difference vaporization when it comes into contact with liquid nitrogen.

[0101] Preferably, the mixer 13 achieves preliminary mixing of liquid nitrogen and pre-cooled nitrogen gas to form liquid nitrogen bubbles of 100-500 μm.

[0102] Preferably, the sample storage container 3 includes a biological sample storage container 3: a double-layer vacuum insulation structure, made of 316L stainless steel, with a volume of 100-200L, an operating temperature of -196℃, and a temperature uniformity of ±1℃.

[0103] Multi-channel distribution device: 12 injection nozzles are distributed in a matrix, with an aperture of 0.3mm, to uniformly deliver micron-sized liquid nitrogen bubbles to the sample rack. The sample rack has 10-15 layers, and each layer can hold 50-100 sample tubes.

[0104] Safety protection module: equipped with a pressure safety valve with an opening pressure of 1.8MPa, a low-temperature leakage sensor with a response time of <1 second, and an oxygen concentration monitor with an alarm threshold of 19.5% vol.

[0105] Furthermore, S11 includes:

[0106] S111: The supply component 11 includes a main liquid nitrogen storage tank 111 and a nitrogen buffer tank 112. The main liquid nitrogen storage tank 111 and the nitrogen buffer tank 112 are respectively connected to the mixer 13 through pipelines. A valve control component is installed on the pipeline, and the pipeline can be controlled to open or close through the valve control component.

[0107] Preferably, the main liquid nitrogen storage tank 111 stores liquid nitrogen and controls the flow of liquid nitrogen through valves and cryogenic solenoid valves.

[0108] Nitrogen buffer tank 112: Stores nitrogen and controls the flow of nitrogen through a cryogenic solenoid valve.

[0109] Furthermore, S11 also includes:

[0110] S112: Liquid nitrogen is injected into the mixer 13. The mixer 13 has an annular channel with an annular opening. Nitrogen gas is released annularly inside the mixer 13, so that liquid nitrogen and nitrogen gas are initially mixed and form liquid nitrogen bubbles of 100-500μm.

[0111] Furthermore, S2 includes:

[0112] S21: The shearing and refining mechanism 2 includes a secondary mechanical shear 21, which receives liquid nitrogen bubbles delivered by the mixer 13; the secondary mechanical shear 21 is used to cut the liquid nitrogen bubbles and form liquid nitrogen bubbles of 10-50μm.

[0113] Preferably, the secondary mechanical shearer 21 uses the shearing action between the high-speed rotating rotor 212 and stator 213 to physically break up and refine the liquid nitrogen bubbles in the gas-liquid mixture. After the larger liquid nitrogen bubbles are initially dispersed by the primary mixer 13, the gas-liquid fluid with a size of 100-500 μm enters the shearer. The rotor 212 rotates at a high speed of 2500-3500 RPM, causing the fluid to form strong turbulence. The shearing gap between the rotor 212 and the stator 213 can be adjusted within the range of 0.1-0.3 mm to produce shearing, collision, and grinding effects on the bubbles, thereby breaking up the larger liquid nitrogen bubbles into smaller bubbles of 10-50 μm, laying the foundation for further refinement by the subsequent tertiary microporous shearer 22.

[0114] Furthermore, S2 also includes:

[0115] S22: The shearing and refining mechanism 2 also includes a three-stage microporous shearer 22, which further shears and breaks down the 10-50μm liquid nitrogen bubbles after being sheared and broken by the two-stage mechanical shearer 21, thereby forming 1-100μm micron-sized liquid nitrogen bubbles.

[0116] Preferably, the three-stage microporous shearing device 22 is made of 316L stainless steel with multi-layered gradient pore size metal filter screen 221, with pore sizes of 100μm→50μm→10μm, porosity of 40%, and working pressure of 0.6-0.9MPa, ultimately achieving the generation of 1-100μm micron-level liquid nitrogen bubbles.

[0117] Furthermore, S3 includes:

[0118] S31: The quality monitoring mechanism includes a particle image analyzer and a PLC control system; the particle image analyzer can monitor 1-500μm liquid nitrogen bubbles in real time and feed the feedback to the PLC control system. When the particle size deviation of the liquid nitrogen bubbles is too large, the PLC control system can adjust and control the rotation speed of the secondary mechanical shear 21 or the pressure of the tertiary microporous shear 22.

[0119] Furthermore, the particle image analyzer can monitor the particle size distribution of liquid nitrogen bubbles in real time, with a measurement range of 1-500μm and a data sampling frequency of 1 time / second.

[0120] PLC control system: Based on PLC, closed-loop control is implemented. When the particle size deviation exceeds ±20%, the speed of the secondary mechanical shear 21 or the working pressure of the micro-hole shear is automatically adjusted.

[0121] Workflow:

[0122] Raw material pretreatment: The main liquid nitrogen storage tank 111 delivers liquid nitrogen through a cryogenic solenoid valve, while the nitrogen buffer tank 112 outputs nitrogen gas which is pre-cooled to -170~-180℃ by a cryogenic heat exchanger. The flow ratio of nitrogen gas to liquid nitrogen is controlled at 3:1~8:1.

[0123] Preliminary mixing: Pre-cooled nitrogen and liquid nitrogen form a gas-liquid two-phase flow in mixer 13, and are initially dispersed into liquid nitrogen bubbles of 100-500μm;

[0124] Multi-stage refinement: The mixed fluid is sequentially refined to 10-50μm by a two-stage mechanical shear 21 and finally to 1-100μm by a three-stage microporous shear 22;

[0125] Quality monitoring: The particle image analyzer monitors the bubble size in real time, and the PLC control system dynamically adjusts the parameters to ensure the stability of micron-sized liquid nitrogen bubbles;

[0126] Sample storage: Qualified micron-sized liquid nitrogen bubbles are injected into sample storage tank 3 through a multi-channel dispensing device to evenly cover the sample and achieve ultra-low temperature preservation.

[0127] In summary, this invention delivers liquid nitrogen and nitrogen gas into the mixer 13 via the main liquid nitrogen storage tank 111 and the nitrogen buffer tank 112. The nitrogen gas is pre-cooled by the precooler 12 to reduce the temperature difference vaporization when the nitrogen gas comes into contact with the liquid nitrogen. The mixer 13 performs preliminary mixing of the liquid nitrogen and nitrogen gas, forming liquid nitrogen bubbles of 100-500 μm. The shearing and refining mechanism 2 can repeatedly shear and break the 100-500 μm liquid nitrogen bubbles, ultimately forming liquid nitrogen bubbles of 10-50 μm. The particle size of the liquid nitrogen bubbles broken by the shearing and refining mechanism 2 is detected by the quality monitoring mechanism, and the state and power of the shearing and refining mechanism 2 are adjusted and controlled in real time. The sample storage tank 3 can receive and store liquid nitrogen bubbles of the target particle size, achieving uniformity of liquid nitrogen.

[0128] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape, and proportions of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of the invention. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structurally equivalent but also equivalent in structure. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0129] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the invention as currently considered, or those features that are not relevant to implementing the invention) may be omitted.

[0130] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0131] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A micron-scale liquid nitrogen generator, characterized in that: Includes a mixing mechanism, a shearing and refining mechanism, and a quality monitoring system. The apparatus includes a shearing and refining mechanism and a sample storage tank; the shearing and refining mechanism is connected to the supply and mixing mechanism and the sample storage tank respectively, and the quality monitoring mechanism is installed on the shearing and refining mechanism; The supply mixing mechanism pre-cools and mixes liquid nitrogen and nitrogen gas and disperses them into liquid nitrogen bubbles. The shearing and refining mechanism shears and refines the liquid nitrogen bubbles. The quality monitoring mechanism monitors the particle size of the liquid nitrogen bubbles and adjusts and controls the operation of the shearing and refining mechanism. The sample storage tank receives the liquid nitrogen bubbles sheared by the shearing and refining mechanism and stores the sample through the liquid nitrogen bubbles. The shearing and refining mechanism includes a two-stage mechanical shear and a three-stage microporous shear; the two-stage mechanical shear can shear and break up the liquid nitrogen bubbles fed by the mixing mechanism; the three-stage microporous shear can shear the broken liquid nitrogen bubbles to the target particle size. The supply and mixing mechanism includes a supply component, a precooler, and a mixer; the supply component can supply liquid nitrogen and nitrogen gas into the mixer, the precooler can precool the nitrogen gas, and the mixer can mix the liquid nitrogen and gaseous nitrogen and disperse them into liquid nitrogen bubbles. The secondary mechanical shear includes a cylindrical structure, within which a rotor and a stator are disposed, the rotor and stator being coaxially arranged; the rotor can rotate within the cylindrical structure, the rotor being driven by a driving component, and the rotor and stator can shear liquid nitrogen bubbles; The cylindrical structure is also provided with a gap adjusting component, which is connected to the stator. The gap adjusting component can drive the stator to move and can adjust the gap between the rotor and the stator. An observation window is also provided on one side of the cylindrical structure, which allows observation of the interior of the cylindrical structure.

2. The micron-scale liquid nitrogen generator as described in claim 1, characterized in that: The quality monitoring mechanism includes a particle image analyzer and a PLC control system; the particle image analyzer can monitor the particle size of the shearing liquid nitrogen bubbles in the secondary mechanical shearer in real time, and the PLC control system controls the shearing particle size of the secondary mechanical shearer based on the detection results of the particle image analyzer.

3. The micron-scale liquid nitrogen generator as described in claim 1, characterized in that: The supply components include a main liquid nitrogen storage tank and a nitrogen buffer tank. The main liquid nitrogen storage tank and the nitrogen buffer tank are connected to the precooler through pipelines. The main liquid nitrogen storage tank can supply liquid nitrogen, and the nitrogen buffer tank can supply nitrogen gas.

4. The micron-scale liquid nitrogen generator as described in claim 3, characterized in that: The rotor includes a drive shaft and blade cutting edges; the drive shaft is connected to a drive component, which can drive the drive shaft to rotate circumferentially; multiple sets of blade cutting edges are arranged circumferentially and / or horizontally and / or vertically on the drive shaft; the multiple sets of blade cutting edges can cooperate with the stator to shear liquid nitrogen bubbles.

5. The micron-scale liquid nitrogen generator as described in claim 4, characterized in that: The stator includes a stator fixing frame, on which multiple sets of support frames are provided, and on which multiple sets of stator cutting blades are provided, the stator cutting blades and blade cutting blades can cooperate to shear liquid nitrogen bubbles; The stator fixing frame is also provided with multiple optical axes, which can limit the position of the stator fixing frame, and the gap adjustment component can drive the stator fixing frame to move along the optical axes.

6. The micron-scale liquid nitrogen generator as described in claim 1, characterized in that: A sealing element is also provided on one side of the driving component, and the sealing element is sealed to the cylindrical structure.

7. The micron-scale liquid nitrogen generator as described in claim 1, characterized in that: The three-stage microporous shearing device includes a filter. The filter screen is multi-layered, with the pore size decreasing sequentially across the multiple layers.

8. A method for manufacturing a micron-scale liquid nitrogen generator, characterized in that: The method further includes: using a micron-scale liquid nitrogen generator as described in any one of claims 1 to 7 to create liquid nitrogen bubbles in the 1-100 μm range; and using the following method: S1: Liquid nitrogen and nitrogen are supplied through a supply mixing mechanism, which can pre-cool and mix the liquid nitrogen and nitrogen. S2: The liquid nitrogen bubbles supplied to the mixing mechanism are received by the shearing and refining mechanism, and the liquid nitrogen bubbles are physically broken up. S3: The particle size of liquid nitrogen bubbles can be monitored by the quality monitoring agency, and the shearing and refining mechanism can be controlled and adjusted according to the particle size deviation results. S4: Liquid nitrogen bubbles of the target particle size can be received and stored through the sample storage tank.

9. The method for manufacturing a micron-scale liquid nitrogen generator as described in claim 8, characterized in that: S1 includes; S11: The mixing mechanism includes a supply component and a mixer; the supply component supplies liquid nitrogen and nitrogen gas to the mixer for mixing; the flow ratio of nitrogen gas to liquid nitrogen is controlled at 3:1 to 8:

1. S12: The mixing mechanism also includes a precooler, which can precool nitrogen to -170~-180℃ to reduce the temperature difference vaporization when nitrogen comes into contact with liquid nitrogen.

10. The method for manufacturing a micron-scale liquid nitrogen generator as described in claim 9, characterized in that: S11 includes: S111: The supply component includes a main liquid nitrogen storage tank and a nitrogen buffer tank. The main liquid nitrogen storage tank and the nitrogen buffer tank are respectively connected to the mixer through pipelines. Valve control components are installed on the pipelines, and the pipelines can be controlled to open or close.

11. The method for manufacturing a micron-scale liquid nitrogen generator as described in claim 10, characterized in that: S11 further includes: S112: Liquid nitrogen is injected into the mixer, which has an annular channel with an annular opening. Nitrogen is released annularly inside the mixer, allowing liquid nitrogen and nitrogen gas to be initially mixed and form liquid nitrogen bubbles of 100-500μm.

12. The method for manufacturing a micron-scale liquid nitrogen generator as described in claim 10, characterized in that: S2 includes: S21: The shearing and refining mechanism includes a two-stage mechanical shear, which receives liquid nitrogen bubbles from the mixer; and uses the two-stage mechanical shear to cut the liquid nitrogen bubbles and form liquid nitrogen bubbles of 10-50μm.

13. The method for manufacturing a micron-scale liquid nitrogen generator as described in claim 12, characterized in that: S2 further includes: S22: The shearing and refining mechanism also includes a three-stage microporous shear, which further shears and breaks down the 10-50μm liquid nitrogen bubbles after they have been sheared and broken by the two-stage mechanical shear, thereby forming 1-100μm micron-sized liquid nitrogen bubbles.

14. The method for manufacturing a micron-scale liquid nitrogen generator as described in claim 13, characterized in that: S3 includes: S31: The quality monitoring mechanism includes a particle image analyzer and a PLC control system; the particle image analyzer can monitor 1-500μm liquid nitrogen bubbles in real time and feed the feedback to the PLC control system. When the particle size deviation of the liquid nitrogen bubbles is too large, the PLC control system can adjust and control the rotation speed of the secondary mechanical shear or the pressure of the tertiary microporous shear.

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