Micron-sized liquid nitrogen generator and manufacturing method

Abstract

The invention discloses a micron-sized liquid nitrogen generator and a manufacturing method, which comprises the following steps: a supply mixing mechanism precools and mixes liquid nitrogen and nitrogen and disperses the liquid nitrogen and the nitrogen into liquid nitrogen bubbles, a shearing and refining mechanism shears and refines the liquid nitrogen bubbles, and a quality monitoring mechanism monitors the particle size of the liquid nitrogen bubbles and adjusts and controls the shearing and refining mechanism to work. The sample storage tank receives the liquid nitrogen bubbles sheared by the shearing and refining mechanism, and the sample storage tank can store samples through the liquid nitrogen bubbles. The device has the beneficial effects that raw materials can be supplied by arranging the supplying and mixing mechanism, nitrogen can be precooled and mixed with liquid nitrogen, and large liquid nitrogen bubbles can be cut and crushed by utilizing the shearing and refining mechanism to finally form 1-100 [mu] m micron-sized liquid nitrogen bubbles; the quality monitoring mechanism adjusts and controls the shearing and refining mechanism according to a result of detecting the particle size of the bubbles; 1-100 [mu] m micron-sized liquid nitrogen bubbles can be received through the sample storage tank, and the sample is stored at low temperature through the sample storage tank.

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. 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, even in the instantaneously cooled area, the target sample tube or single rack cannot be uniformly sprayed, 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 produce 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 produce liquid nitrogen bubbles and 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 solutions: a micron-level liquid nitrogen generator, comprising a supply mixing mechanism, a shear refining mechanism, a quality monitoring mechanism and a sample storage tank; the shear refining mechanism is in communication with the supply mixing mechanism and the sample storage tank, and the quality monitoring mechanism is arranged on the shear refining mechanism. The supply mixing mechanism mixes and disperses liquid nitrogen and nitrogen gas into liquid nitrogen bubbles, the shearing and refining mechanism 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, and the sample storage tank can receive the liquid nitrogen bubbles after being sheared by the shearing and refining mechanism and store the sample through the liquid nitrogen bubbles.

[0008] As a preferred scheme of the micron-level liquid nitrogen generator, the shearing and refining mechanism comprises a two-stage mechanical shearer and a three-stage micro-pore shearer; the two-stage mechanical shearer can shear and break the liquid nitrogen bubbles delivered by the mixing mechanism; and the three-stage micro-pore shearer can shear the broken liquid nitrogen bubbles to a target particle size.

[0009] As a preferred scheme of the micron-level liquid nitrogen generator, the quality monitoring mechanism comprises a particle image analyzer and a PLC control system; the particle image analyzer can monitor the particle size of the sheared liquid nitrogen bubbles in real time, and the PLC control system controls the shearing particle size of the two-stage mechanical shearer according to the detection result of the particle image analyzer.

[0010] As a preferred scheme of the micron-level liquid nitrogen generator, the supply mixing mechanism comprises a supply assembly, a pre-cooler and a mixer; the supply assembly can deliver liquid nitrogen and nitrogen gas to the mixer, the pre-cooler can pre-cool the nitrogen gas, and the mixer can mix and disperse the liquid nitrogen and the nitrogen gas into liquid nitrogen bubbles.

[0011] As a preferred scheme of the micron-level liquid nitrogen generator, the supply assembly comprises a main liquid nitrogen storage tank and a nitrogen gas buffer tank, the main liquid nitrogen storage tank and the nitrogen gas buffer tank are respectively communicated with the pre-cooler through pipelines, the main liquid nitrogen storage tank can deliver liquid nitrogen, and the nitrogen gas buffer tank can deliver nitrogen gas.

[0012] As a preferred scheme of the micron-level liquid nitrogen generator, the two-stage mechanical shearer comprises a cylindrical structure, a rotor and a stator are arranged in the cylindrical structure, and the rotor and the stator are coaxially arranged; the rotor is in a blade type structure, the rotor can rotate on the stator, a shearing gap is arranged between the rotor and the stator, and the rotor is driven by a driving member; fluid inlets and outlets are arranged at both ends of the cylindrical structure.

[0013] As a preferred scheme of the micron-level liquid nitrogen generator, the three-stage micro-pore shearer comprises a filter screen, and the filter screen is arranged in multiple layers, and the pore diameters of the multiple layers of the filter screen are successively reduced.

[0014] As a preferred scheme of the micron-level liquid nitrogen generator, the cylindrical structure further comprises a gap adjusting member, the gap adjusting member is connected with the stator, the gap adjusting member can drive the stator to move, and the gap adjusting member can adjust the gap between the rotor and the stator. The cylindrical structure is provided with an observation window on one side.

[0015] As a preferred scheme of the microscale liquid nitrogen generator, the rotor comprises a transmission shaft and blade cutters; the transmission shaft is connected with a driving member, the driving member can drive the transmission shaft to rotate circumferentially, and a plurality of groups of blade cutters are circumferentially, horizontally and / or vertically arranged on the transmission shaft; the plurality of groups of blade cutters can cooperate with the stator to shear the liquid nitrogen bubbles.

[0016] As a preferred scheme of the microscale liquid nitrogen generator, the stator comprises a stator fixed frame, a plurality of groups of support frames are arranged on the stator fixed frame, a plurality of groups of stator cutters are arranged on the support frames, and the stator cutters can cooperate with the blade cutters to shear the liquid nitrogen bubbles. The stator fixed frame is further provided with a plurality of groups of optical axes, the optical axes can limit the stator fixed frame, and the gap adjusting member can drive the stator fixed frame to move along the optical axes.

[0017] As a preferred scheme of the microscale liquid nitrogen generator, the driving member is further provided with a sealing member on one side, and the sealing member is sealingly connected with the cylindrical structure.

[0018] The microscale liquid nitrogen generator has the following advantages: the raw materials can be supplied through the supply mixing mechanism, and the nitrogen gas can be pre-cooled; the pre-cooled nitrogen gas is mixed with the liquid nitrogen to preliminarily form larger liquid nitrogen bubbles; the larger liquid nitrogen bubbles are cut and broken by the shearing and refining mechanism to finally form 1-100 mu microscale liquid nitrogen bubbles; the quality monitoring mechanism can monitor whether the liquid nitrogen bubbles cut by the shearing and refining mechanism meet the requirements in real time, and the shearing and refining mechanism can be adjusted and controlled according to the results of the bubble particle size detection; the sample storage tank can receive the 1-100 mu microscale liquid nitrogen bubbles, and the uniform consistency of the liquid nitrogen bubbles is realized; the sample storage tank can store the samples at low temperature, and the sample storage tank is internally provided with a multi-channel distribution device, which can uniformly spray the microscale liquid nitrogen bubbles onto the sample holder to uniformly wrap the samples; the shearing and refining mechanism can break the larger bubbles to the micron level, avoiding the problem that the larger liquid nitrogen bubbles sprayed by the spraying device cannot uniformly wrap the samples during programmed cooling, thereby reducing the stability of the samples; the device sprays the micron-sized liquid nitrogen particles on the sample plate holder, so that the sample is more fully wrapped, the cooling is more balanced, the liquid nitrogen consumption is reduced, a small amount of liquid nitrogen can realize the cooling and storage functions of the biological samples; the inventor first proposed the liquid nitrogen bubble spraying method, and the sample tube is wrapped and cooled by the micron-sized liquid nitrogen bubbles, which solves the problems of the previous liquid nitrogen spraying mechanism and avoids the problem of uneven cooling.

[0019] 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; 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 detected by a 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.

[0020] As a preferred embodiment of the method for manufacturing the micron-scale liquid nitrogen generator of the present invention, 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.

[0021] In a preferred embodiment of the method for manufacturing the micron-scale liquid nitrogen generator of the present invention, S11 includes: 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.

[0022] In a preferred embodiment of the method for manufacturing the micron-scale liquid nitrogen generator of the present invention, 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.

[0023] In a preferred embodiment of the method for manufacturing the micron-scale liquid nitrogen generator of the present invention, S2 includes: 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.

[0024] In a preferred embodiment of the method for manufacturing the micron-scale liquid nitrogen generator of the present invention, S2 further includes: S22: The shearing and refining mechanism further comprises a three-stage micro-hole shearer, and the 10-50 mu m liquid nitrogen bubbles broken by the two-stage mechanical shearer are further broken by the three-stage micro-hole shearer, so as to form 1-100 mu m micron-level liquid nitrogen bubbles.

[0025] As a preferred scheme of the method for manufacturing the micron-level liquid nitrogen generator, in S3, the method comprises: S31: The quality monitoring mechanism comprises a particle image analyzer and a PLC control system; the particle image analyzer can monitor the 1-500 mu m liquid nitrogen bubbles in real time and feed back to the PLC control system; when the particle size of the liquid nitrogen bubbles deviates too much, the PLC control system can adjust and control the rotating speed of the two-stage mechanical shearer or the pressure of the three-stage micro-hole shearer.

[0026] The method for manufacturing the micron-level liquid nitrogen generator has the following advantages: the main liquid nitrogen tank and the nitrogen buffer tank are used to deliver liquid nitrogen and nitrogen to the mixer, the nitrogen is pre-cooled by the pre-cooler, the temperature difference vaporization when the nitrogen contacts with the liquid nitrogen is reduced, the liquid nitrogen and the nitrogen are preliminarily mixed by the mixer, and 100-500 mu m liquid nitrogen bubbles are formed; the 100-500 mu m liquid nitrogen bubbles are broken by the shearing and refining mechanism for multiple times, and 10-50 mu m liquid nitrogen bubbles are finally formed; the particle size of the liquid nitrogen bubbles broken by the shearing and refining mechanism is detected by the quality monitoring mechanism, and the state and power of the shearing and refining mechanism are adjusted and controlled in real time; the sample storage tank is used to receive and store the liquid nitrogen bubbles with the target particle size, and the uniformity of the liquid nitrogen is realized; the shearing and refining mechanism can break the larger bubbles to micron level; the currently used storage device cannot uniformly wrap the sample with the large liquid nitrogen bubbles when the program is cooled, the sample is not uniformly cooled, and the stability of the sample is poor; the method for manufacturing the micron-level liquid nitrogen generator can break the larger bubble particles and finally form 10-50 mu m uniform liquid nitrogen bubbles, so that the sample tube is uniformly wrapped and uniformly cooled, and the stability of the sample is good; the method can spray the micron-level small particle liquid nitrogen on the sample plate rack, so that the sample is more fully wrapped, the cooling is more balanced, the consumption of the liquid nitrogen is reduced, and a small amount of liquid nitrogen can realize the cooling and storage of the biological sample. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative labor. Among them: Fig. 1 Flow chart of the manufacturing method of the micron-level liquid nitrogen generator.

[0028] Fig. 2 Overall schematic diagram of the micron-level liquid nitrogen generator.

[0029] Fig. 3 Internal schematic diagram of the secondary mechanical shear of the micron-level liquid nitrogen generator.

[0030] Fig. 4 Enlarged internal schematic diagram of the secondary mechanical shear of the micron-level liquid nitrogen generator.

[0031] Fig. 5 Enlarged partial view of the tertiary micro-hole shear of the micron-level liquid nitrogen generator.

[0032] Fig. 6 Enlarged internal schematic diagram of the secondary mechanical shear of the micron-level liquid nitrogen generator from another perspective.

[0033] The figure legend: supply mixing mechanism, 1; shear refining mechanism, 2; sample storage tank, 3; secondary mechanical shear, 21; tertiary micro-hole shear, 22; rotor, 212; stator, 213; cylindrical structure, 211; gap adjusting piece, 214; driving piece, 215; filter screen, 221; supply assembly, 11; pre-cooler, 12; mixer, 13; main liquid nitrogen storage tank, 111; nitrogen buffer tank, 112; transmission shaft, 2121; blade cutting edge, 2122; stator fixed frame, 2131; support frame, 2132; stator cutting edge, 2133; optical axis, 2134; sealing piece, 216; threaded rod, 2141; magnetic coupling sheet, 2142; servo motor, 2143; DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objectives, features and advantages of the present application more apparent and comprehensible, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0035] In the following description, a lot of specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the spirit of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0036] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is separate or alternative to other embodiments. Example 1

[0037] Referring to Figs. 1-6 For the first embodiment of the present application, the embodiment provides a micron-level liquid nitrogen generator, which comprises a supply mixing mechanism 1, a shearing refining mechanism 2, a quality monitoring mechanism, and a sample storage tank 3; the shearing refining mechanism 2 is in communication with the supply mixing mechanism 1 and the sample storage tank 3 respectively, and the quality monitoring mechanism is arranged on the shearing refining mechanism 2; The supply mixing mechanism 1 pre-cools and mixes liquid nitrogen and nitrogen gas and disperses them into liquid nitrogen bubbles, the shearing 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 refining mechanism 2, and the sample storage tank 3 can receive the liquid nitrogen bubbles after shearing by the shearing refining mechanism 2, and the sample storage tank 3 can store samples through the liquid nitrogen bubbles.

[0038] Further, the shearing refining mechanism 2 comprises a two-stage mechanical shearing device 21 and a three-stage micro-pore shearing device 22; the two-stage mechanical shearing device 21 can shear and break the liquid nitrogen bubbles conveyed from the mixing mechanism; and the three-stage micro-pore shearing device 22 can shear the broken liquid nitrogen bubbles to a target particle size.

[0039] Further, the two-stage mechanical shearing device 21 comprises a cylindrical structure 211, a rotor 212 and a stator 213 arranged in the cylindrical structure 211, and the rotor 212 and the stator 213 are coaxially arranged; the rotor 212 is of a blade type structure, the rotor 212 can rotate on the stator 213, a shearing gap is arranged between the rotor 212 and the stator 213, and the rotor 212 is driven by a driving member 215; and fluid inlets and outlets are arranged at both ends of the cylindrical structure 211.

[0040] Preferably, a gap adjusting member 214 is further arranged in the cylindrical structure 211, the gap adjusting member 214 is connected with the stator 213, the gap adjusting member 214 can drive the stator 213 to move, and the gap adjusting member 214 can adjust the gap between the rotor 212 and the stator 213.

[0041] Preferably, the gap adjusting member 214 can adjust the gap in the form of a threaded rod.

[0042] Preferably, the stator 213 is supported and fixed outside by an optical axis, and the optical axis is connected with the inside of the cylindrical structure 211.

[0043] Further, a gap adjusting member is further arranged in the cylindrical structure, the gap adjusting member is connected with the stator, the gap adjusting member can drive the stator to move, and the gap adjusting member can adjust the gap between the rotor and the stator; Preferably, the gap adjusting piece 214 comprises a threaded rod 2141, a magnetic coupling piece 2142 and a servo motor 2143; micron-level movement can be achieved. The gap adjusting piece 214 is threadedly connected with the stator fixed frame 2131, and the stator fixed frame 2131 is moved by rotating the gap adjusting piece 214, so that the stator fixed frame 2131 drives the support frame 2132 and the stator cutting blade 2133 to move, thereby adjusting the gap between the stator cutting blade 2133 and the blade cutting blade 2122 and controlling the size of the sheared liquid nitrogen bubbles.

[0044] The cylindrical structure is further provided with an observation window on one side, and the observation window can observe the inside of the cylindrical structure.

[0045] Further, the rotor comprises a transmission shaft 2121 and a blade cutting blade 2122; the transmission shaft 2121 is connected with a driving piece, the driving piece can drive the transmission shaft 2121 to rotate circumferentially, and a plurality of groups of blade cutting blades 2122 are arranged circumferentially, horizontally and / or vertically on the transmission shaft 2121, which can cooperate with the stator to shear the liquid nitrogen bubbles.

[0046] Further, the stator 213 comprises a stator fixed frame 2131, a plurality of support frames 2132 are arranged on the stator fixed frame 2131, and a plurality of groups of stator cutting blades 2133 are arranged on the support frames 2132, which can cooperate with the blade cutting blade 2122 to shear the liquid nitrogen bubbles. The stator fixed frame 2131 is further provided with a plurality of groups of optical axes 2134, which can limit the stator fixed frame 2131, and the gap adjusting piece can drive the stator fixed frame 2131 to move along the optical axis 2134.

[0047] Preferably, the optical axis 2134 is arranged in multiple groups, which can avoid the circumferential rotation of the stator fixed frame 2131, and can make the stator fixed frame 2131 only move along the direction of the optical axis 2134 when the gap needs to be adjusted.

[0048] Further, the driving piece is further provided with a sealing piece 216 on one side, which is sealingly connected with the cylindrical structure to ensure that there is no leakage.

[0049] Preferably, the three-stage micro-pore shear cutter 22 is arranged on one side of the cylindrical structure 211, and after the liquid nitrogen bubbles are cut by the two-stage mechanical shear cutter 21, the cut liquid nitrogen bubbles enter the three-stage micro-pore shear cutter 22 for cutting, so as to generate 1-100 micron liquid nitrogen bubbles.

[0050] Preferably, the rotor 212 is a multi-blade structure, such as with 4-6 shear blades, made of low-temperature-resistant and wear-resistant 316L stainless steel, with sharp edges to enhance the shearing effect, and connected to the driving motor through a rotating shaft.

[0051] Preferably, the stator 213 is coaxially arranged with the rotor 212, with a tooth-shaped or groove-shaped structure on the inner side to match the blades of the rotor 212, also made of 316L stainless steel, and forms an adjustable shearing gap of 0.1-0.3mm between the stator 213 and the rotor 212.

[0052] Preferably, the cylindrical structure 211 encloses the rotor 212 and the stator 213 to provide a closed flow space for the gas-liquid fluid, with fluid inlets and outlets at both ends, and is made of 316L stainless steel to adapt to low-temperature environments.

[0053] Preferably, the driving member 215 provides power for the rotor 212, using a servo motor that is adapted to low-temperature working conditions, can stably output a rotational speed of 2500-3500RPM, and can adjust the rotational speed according to the instructions of the PLC control system, thereby controlling the shearing effect.

[0054] It should be noted that the secondary mechanical shear 21 utilizes the shearing action between the high-speed rotating rotor 212 and the stator 213 to physically break and refine the liquid nitrogen bubbles in the gas-liquid mixture. After the larger liquid nitrogen bubbles are preliminarily dispersed by the mixer 13, the gas-liquid fluid with a size of 100-500μm enters the shear, and the rotor 212 rotates at a high speed of 2500-3500RPM, driving the fluid to form strong turbulent flow. The shearing gap between the rotor 212 and the stator 213 can be adjusted within the range of 0.1-0.3mm to produce shearing, collision, and grinding effects on the bubbles, thereby breaking the larger liquid nitrogen bubbles into smaller bubbles of 10-50μm, laying the foundation for further refinement by the subsequent tertiary micropore shear 22.

[0055] Further, the tertiary micropore shear 22 includes a filter screen 221, and the filter screen 221 is arranged in multiple layers, with the pore sizes of the multiple layers of filter screens 221 gradually decreasing.

[0056] Preferably, the filter screen 221 is a multi-layered metal filter screen with gradually changing pore sizes made of 316L stainless steel, with pore sizes of 100μm→50μm→10μm, a porosity of 40%, and a working pressure of 0.6-0.9MPa, ultimately achieving the generation of micron-level liquid nitrogen bubbles of 1-100μm.

[0057] Further, the quality monitoring mechanism comprises a particle image analyzer and a PLC control system; the particle image analyzer can monitor the particle size of the sheared liquid nitrogen gas bubbles in the secondary mechanical shear cutter 21 in real time, and the PLC control system controls the shearing particle size of the secondary mechanical shear cutter 21 according to the detection result of the particle image analyzer.

[0058] Preferably, the particle image analyzer is of PIA-300 type, which can monitor the particle size distribution of the liquid nitrogen gas bubbles in real time, the measurement range is 1-500 μm, and the data sampling frequency is 1 time / s. Preferably, the PLC control system is based on a PLC of S7-1200 type, which realizes closed-loop control, and when the particle size deviation exceeds ±20%, the rotation speed of the secondary mechanical shear cutter 21 or the working pressure of the micro-porous shear cutter is automatically adjusted.

[0059] Further, the supply mixing mechanism 1 comprises a supply assembly 11, a pre-cooler 12 and a mixer 13; the supply assembly 11 can deliver liquid nitrogen and nitrogen gas to the mixer 13, the pre-cooler 12 can pre-cool the nitrogen gas, and the mixer 13 can mix and disperse the liquid nitrogen and the nitrogen gas into liquid nitrogen gas bubbles.

[0060] Preferably, the coaxial jet structure is adopted, the liquid nitrogen is sprayed out through a central nozzle with a hole diameter of 0.8 mm, the pre-cooled nitrogen gas forms a surrounding gas flow through an annular channel with a gap of 0.5 mm, and the initial dispersion degree of the initial gas-liquid mixing is 100-500 μm.

[0061] Preferably, the pre-cooler 12 is of a spiral pipe structure, has a heat exchange area of 0.3 m2, and pre-cools the nitrogen gas to -170--180℃, so as to reduce the temperature difference vaporization when the nitrogen gas contacts with the liquid nitrogen. Further, the supply assembly 11 comprises a main liquid nitrogen storage tank 111 and a nitrogen gas buffer tank 112, the main liquid nitrogen storage tank 111 and the nitrogen gas buffer tank 112 are respectively communicated with the pre-cooler 12 through pipelines, the main liquid nitrogen storage tank 111 can deliver liquid nitrogen, and the nitrogen gas buffer tank 112 can deliver nitrogen gas.

[0062] Preferably, the main liquid nitrogen storage tank 111 is of a double-layer vacuum heat insulation structure, is made of 316L stainless steel, has a volume of 30-50 L, a working temperature of -196℃, and is equipped with a low-temperature electromagnetic valve of V-LN2-01 type with a flow control accuracy of ±0.5%. Preferably, the nitrogen gas buffer tank 112 is of a high-pressure inert gas storage structure, is made of 304 stainless steel, has a working pressure of 0.8-1.2 MPa, a volume of 10-20 L, and is equipped with a pressure reducing regulating valve with an adjusting accuracy of ±0.02 MPa, which is used to provide inert dispersion gas.

[0063] Preferably, the sample storage tank 3 is a biological sample storage tank; it is a double-layer vacuum insulation structure, made of 316L stainless steel, with a volume of 100-200L, a working temperature of -196℃, and a temperature uniformity of ±1℃; The multi-channel distribution device inside the biological sample storage tank 3: matrix distribution of 12 spray ports, aperture 0.3mm, uniform delivery of micron-sized liquid nitrogen bubbles to the sample holder, 10-15 layers of sample holder, each layer carrying 50-100 sample tubes; 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 <1s, and an oxygen concentration monitor with an alarm threshold of 19.5%vol.

[0064] Workflow: Raw material pretreatment: the main liquid nitrogen storage tank 111 delivers liquid nitrogen through a low-temperature electromagnetic valve, while the nitrogen buffer tank 112 outputs nitrogen gas which is pre-cooled to -170~-180℃ through a low-temperature heat exchanger, and the flow ratio of nitrogen gas to liquid nitrogen is controlled at 3:1~8:1; Preliminary mixing: the pre-cooled nitrogen gas and liquid nitrogen form a gas-liquid two-phase flow in the mixer 13, and are preliminarily dispersed into liquid nitrogen bubbles of 100-500μm; Multi-stage refinement: the mixed fluid enters a two-stage mechanical shear device 21 in sequence to refine to 10-50μm, and a three-stage micro-porous shear device 22 to finally refine to 1-100μm; Quality monitoring: a particle image analyzer monitors the bubble particle size in real time, and a PLC control system dynamically adjusts the parameters to ensure the stability of the micron-sized liquid nitrogen bubbles; Sample storage: qualified micron-sized liquid nitrogen bubbles are injected into the sample storage tank 3 through the multi-channel distribution device, uniformly covering the samples, and achieving ultra-low temperature preservation.

[0065] In summary, the present application provides a raw material supply mechanism 1 that can supply raw materials and pre-cool nitrogen gas, mix the pre-cooled nitrogen gas with liquid nitrogen to preliminarily form larger liquid nitrogen bubbles, a shear refinement mechanism 2 that can cut and break the larger liquid nitrogen bubbles to finally form 1-100μm micron-sized liquid nitrogen bubbles, a quality monitoring mechanism that monitors whether the liquid nitrogen bubbles cut by the shear refinement mechanism 2 meet the requirements in real time and adjusts and controls the shear refinement mechanism 2 according to the results of the bubble particle size detection, and a sample storage tank 3 that can receive 1-100μm micron-sized liquid nitrogen bubbles and store samples at low temperature. Example 2

[0066] Reference Figs. 1-6For the second embodiment of the application, based on the basis of embodiment 1, further comprising the manufacturing method of micron-level liquid nitrogen generator, comprising S1: through the supply mixing mechanism 1, liquid nitrogen and nitrogen supply, and the supply mixing mechanism 1 can be pre-cooled to liquid nitrogen and nitrogen mixing; S2: through the shear refining mechanism 2, the liquid nitrogen bubble delivered by the supply mixing mechanism 1 is received, and the liquid nitrogen bubble is physically broken; S3: the particle size of the liquid nitrogen bubble can be monitored by the quality monitoring mechanism, and the shear refining mechanism 2 can be controlled according to the particle size deviation result; S4: the liquid nitrogen bubble of the target particle size can be received and stored by the sample storage tank 3.

[0067] Further, S1 includes; S11: the mixing mechanism includes a supply assembly 11 and a mixer 13; the mixer 13 is respectively delivered by the supply assembly 11 to mix liquid nitrogen and nitrogen; the flow ratio of nitrogen to liquid nitrogen is controlled at 3:1~8:1; S12: the mixing mechanism further comprises a pre-cooler 12, which can pre-cool the nitrogen to-170~-180°, so as to reduce the temperature difference vaporization when the nitrogen contacts with the liquid nitrogen.

[0068] Preferably, the pre-cooler 12: the nitrogen is pre-cooled to-170~-180℃, so as to reduce the temperature difference vaporization when the nitrogen contacts with the liquid nitrogen.

[0069] Preferably, the mixer 13 realizes the preliminary mixing of liquid nitrogen and pre-cooled nitrogen, and forms 100-500μm liquid nitrogen bubbles.

[0070] Preferably, the sample storage tank 3 includes a biological sample storage tank 3: a double-layer vacuum insulation structure, a material 316L stainless steel, a volume 100-200L, a working temperature-196℃, and a temperature uniformity±1℃; Multi-channel distribution device: matrix distribution 12 spray ports, aperture 0.3mm, uniform delivery of micron-level liquid nitrogen bubbles to sample holder, sample holder layer 10-15 layers, each layer bearing capacity 50-100 sample tubes; Safety protection module: equipped with pressure safety valve opening pressure 1.8MPa, low temperature leakage sensor response time<1s, oxygen concentration monitor alarm threshold 19.5%vol.

[0071] Further, S11 includes: S111: the supply assembly 11 includes a main liquid nitrogen tank 111 and a nitrogen buffer tank 112, the main liquid nitrogen tank 111 and the nitrogen buffer tank 112 are respectively communicated with the mixer 13 through the pipeline, and the valve control member is arranged on the pipeline to control the pipeline.

[0072] Preferably, the main liquid nitrogen storage tank 111 stores liquid nitrogen, and the flow of liquid nitrogen is controlled by a valve and a cryogenic solenoid valve.

[0073] The nitrogen buffer tank 112 stores nitrogen, and the flow of nitrogen is controlled by a cryogenic solenoid valve.

[0074] Further, S11 further includes: S112: The liquid nitrogen is sprayed inside the mixer 13, the inside of the mixer 13 is provided with an annular channel, and the annular channel is provided with an annular opening, the nitrogen is released in the annular channel of the mixer 13, so that the liquid nitrogen and the nitrogen are preliminarily mixed and form 100-500μm liquid nitrogen bubbles.

[0075] Further, S2 includes: S21: The shearing and refining mechanism 2 includes a secondary mechanical shearing device 21, which receives the liquid nitrogen bubbles delivered by the mixer 13; and the secondary mechanical shearing device 21 is used to cut and form 10-50μm liquid nitrogen bubbles.

[0076] Preferably, the secondary mechanical shearing device 21 uses the shearing action between the high-speed rotating rotor 212 and the stator 213 to physically break and refine the liquid nitrogen bubbles mixed with gas. After the liquid nitrogen bubbles containing larger bubbles are preliminarily dispersed by the primary mixer 13, the gas-liquid fluid with a size of 100-500μm enters the shearing device, the rotor 212 rotates at a high speed of 2500-3500RPM to form a strong turbulent flow. The shearing gap between the rotor 212 and the stator 213 can be adjusted within the range of 0.1-0.3mm to produce shearing, collision and grinding effects on the bubbles, thereby breaking the larger liquid nitrogen bubbles into smaller bubbles with a size of 10-50μm, laying a foundation for further refinement by the tertiary micro-porous shearing device 22.

[0077] Further, S2 further includes: S22: The shearing and refining mechanism 2 further includes a tertiary micro-porous shearing device 22, which further shears and breaks the 10-50μm liquid nitrogen bubbles broken by the secondary mechanical shearing device 21, to form 1-100μm micron-sized liquid nitrogen bubbles.

[0078] Preferably, the tertiary micro-porous shearing device 22 is made of 316L stainless steel, the pore size is 100μm→50μm→10μm, the porosity is 40%, and the working pressure is 0.6-0.9MPa, finally realizing the generation of 1-100μm micron-sized liquid nitrogen bubbles.

[0079] Further, S3 includes: S31: The quality monitoring mechanism comprises a particle image analyzer and a PLC control system; the particle image analyzer can monitor the liquid nitrogen bubbles with a particle size of 1-500 mu m in real time and feed back 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 rotating speed of the secondary mechanical shear cutter 21 or the pressure of the tertiary micro-porous shear cutter 22.

[0080] Further, the particle image analyzer: real-time monitoring of liquid nitrogen bubble particle size distribution, measurement range 1-500 mu m, data sampling frequency 1 time / second; The PLC control system: based on PLC realizes closed-loop control, when the particle size deviation exceeds ± 20%, automatically adjusts the rotating speed of the secondary mechanical shear cutter 21 or the working pressure of the micro-porous shear cutter.

[0081] Workflow: Raw material pretreatment: the main liquid nitrogen storage tank 111 delivers liquid nitrogen through a low-temperature electromagnetic valve, and the nitrogen buffer tank 112 outputs nitrogen which is pre-cooled to -170~ -180 DEG C through a low-temperature heat exchanger; the flow ratio of nitrogen to liquid nitrogen is controlled at 3:1~8:1; Preliminary mixing: the pre-cooled nitrogen and liquid nitrogen form a gas-liquid two-phase flow in the mixer 13 and are preliminarily dispersed into liquid nitrogen bubbles with a particle size of 100-500 mu m; Multi-stage refinement: the mixed fluid enters the secondary mechanical shear cutter 21 in turn to be refined to 10-50 mu m, and the tertiary micro-porous shear cutter 22 is finally refined to 1-100 mu m; Quality monitoring: the particle image analyzer monitors the bubble particle size in real time, and the PLC control system dynamically adjusts the parameters to ensure the stability of the micron-sized liquid nitrogen bubbles; Sample storage: the qualified micron-sized liquid nitrogen bubbles are injected into the sample storage tank 3 through the multi-channel distribution device to uniformly cover the sample and realize ultra-low temperature preservation.

[0082] In summary, the main liquid nitrogen storage tank 111 and the nitrogen buffer tank 112 deliver liquid nitrogen and nitrogen to the mixer 13, the nitrogen can be pre-cooled through the pre-cooler 12 to reduce the temperature difference vaporization when the nitrogen contacts with the liquid nitrogen, the liquid nitrogen and the nitrogen are preliminarily mixed in the mixer 13 to form liquid nitrogen bubbles with a particle size of 100-500 mu m; the liquid nitrogen bubbles with a particle size of 100-500 mu m are sheared and broken multiple times through the shearing and refining mechanism 2 to finally form liquid nitrogen bubbles with a particle size of 10-50 mu m; 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 liquid nitrogen bubbles with a target particle size are received and stored through the sample storage tank 3 to realize the uniformity of the liquid nitrogen.

[0083] It is important to note that the construction and arrangement of the application shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review the present disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. For example, elements shown as integrally formed can be constructed of multiple parts or elements, the position of elements can be reversed or otherwise varied, and the nature or number of elements or positions can be altered or varied. Thus, the foregoing description is by way of example only, and is not intended to be limiting. The application is limited only as defined in the following claims and equivalents thereto. The sequence of any process or method steps, or the order in which they are carried out, can be altered or re-ordered without departing from the scope of the application. Any "articles of manufacture" or "manufacturing" as described herein are intended to encompass structures constructed of a multitude of different physical elements or components. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and also cover structures yet to be invented which perform the recited function but operate in a different manner. Other substitutions, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the application as expressed in the appended claims.

[0084] Also, to provide a concise description of the exemplary embodiments, not all features of an actual implementation can be described (that is, those related to the best mode for carrying out the present application, or those which are not necessary for an understanding of the present application).

[0085] It should be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions can be made. Such development efforts might be complex and time-consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0086] It should be noted that the above-mentioned embodiments are only used to illustrate the technical solutions of the present application but not to limit the present application, and although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalent replaced without departing from the spirit and scope of the present application, and all should be included in the scope of the claims of the present application.

Claims

1. A micron-scale liquid nitrogen generator, characterized in that: It includes a supply mixing mechanism, a shearing and refining mechanism, a quality monitoring mechanism, and a sample storage tank; the shearing and refining mechanism is connected to both the supply mixing mechanism and the sample storage tank, and the quality monitoring mechanism is mounted on the shearing and refining mechanism; 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.

2. The micron-scale liquid nitrogen generator as described in claim 1, characterized in that: 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.

3. The micron-scale liquid nitrogen generator as described in claim 2, 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.

4. The micron-scale liquid nitrogen generator as described in claim 1, characterized in that: 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.

5. The micron-scale liquid nitrogen generator as described in claim 4, 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.

6. The micron-scale liquid nitrogen generator as described in claim 2, characterized in that: 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.

7. The micron-scale liquid nitrogen generator as described in claim 6, characterized in that: 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.

8. The micron-scale liquid nitrogen generator as described in claim 7, 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.

9. The micron-scale liquid nitrogen generator as described in claim 8, 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.

10. The micron-scale liquid nitrogen generator as described in claim 6, 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.

11. The micron-scale liquid nitrogen generator as described in claim 2, characterized in that: The three-stage microporous shear includes a filter screen, and the filter screen is configured as multiple layers, with the pore size of each layer decreasing sequentially.

12. A method for manufacturing a micron-scale liquid nitrogen generator, characterized in that: It also includes the micron-scale liquid nitrogen generator according to any one of claims 1 to 11; and further includes 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.

13. The method for manufacturing a micron-scale liquid nitrogen generator as described in claim 12, 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.

14. The method for manufacturing a micron-scale liquid nitrogen generator as described in claim 13, 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.

15. The method for manufacturing a micron-scale liquid nitrogen generator as described in claim 14, 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.

16. The method for manufacturing a micron-scale liquid nitrogen generator as described in claim 13, 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.

17. The method for manufacturing a micron-scale liquid nitrogen generator as described in claim 16, 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.

18. The method for manufacturing a micron-scale liquid nitrogen generator as described in claim 17, 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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