An ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration

Abstract

The present invention relates to the field of liquid nitrogen refrigeration technology, and specifically to an ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration, comprising a liquid nitrogen tank and a constant temperature tank, wherein the interior of the constant temperature tank is provided with an inner box, the outer surface of the constant temperature tank is provided with an outer ring body, the outer surface of the outer ring body is provided with an exhaust assembly, the outer surface of the constant temperature tank is provided with an exhaust assembly, the end of the exhaust assembly away from the constant temperature tank is provided with a nitrogen tank, a docking pipe is provided between the liquid nitrogen tank and the constant temperature tank, and the outer surface of the docking pipe is provided with a docking assembly. Compared with the prior art, the present application connects the constant temperature tank and the outer ring body by providing an exhaust assembly, utilizes a motor to drive the turntable to rotate and drive the shift block to pull the strip plate up and down, and the strip plate drives the first one-way valve to move up and down to squeeze or stretch the upper and lower parts of the bellows, so that the nitrogen in the constant temperature tank is filled with the outer ring body, thereby achieving the effect of cooling the outer surface of the constant temperature tank, reducing the vaporization rate of the liquid nitrogen, and achieving the effect of energy saving.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid nitrogen refrigeration, and in particular to an ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration. Background Art

[0002] Liquid nitrogen refrigeration equipment is a device that uses the ultra-low temperature characteristics of liquid nitrogen for refrigeration. Liquid nitrogen has an extremely low boiling point of -196°C and can quickly absorb heat under normal pressure, thereby achieving rapid freezing. Liquid nitrogen refrigeration equipment contains a constant temperature device, which is a device that can provide a stable and reliable ultra-low temperature environment. Combining the refrigeration capacity of liquid nitrogen with a precise constant temperature control system, it can meet the high requirements of ultra-low temperature environments in scientific research, production and other fields.

[0003] In the prior art, a Chinese patent document with publication number CN113941385B proposes a temperature control device based on ultra-low temperature precision constant temperature device and temperature control method of liquid nitrogen refrigeration, which includes a tank body and a shell, a guide tube is arranged in the tank body, and the upper and lower ends of the guide tube have vents, an air circulation mechanism includes a circulation fan, which is installed on the inner side of the lower edge of the guide tube, an air heating mechanism includes a temperature sensor and an annular heating belt, a measuring end of the temperature sensor is arranged in the guide tube, and the annular heating belt is arranged between the outer side of the guide tube and the inner side of the tank body, a liquid nitrogen injection mechanism includes a fast liquid nitrogen diffusion ring, a slow liquid nitrogen diffusion ring, an ultra-low temperature relay and a liquid nitrogen tank, liquid nitrogen is input into the insulation tank through the double liquid nitrogen diffusion rings to cool down, and a fast liquid nitrogen is injected into the insulation tank. The diffusion ring realizes rapid cooling of the initial section, and the slow liquid nitrogen diffusion ring provides a cooling source for the temperature control of the constant section. It can quickly and evenly release liquid nitrogen to the constant temperature device without causing the temperature field inside the constant temperature device to get out of control, and can quickly generate a constant and uniform temperature field. However, the thermal insulation layer on the outer layer of the device simply relies on thermal insulation for insulation, and the insulation effect is limited, resulting in liquid nitrogen in a continuous volatilization state, resulting in a large amount of liquid nitrogen consumption. When the liquid nitrogen temperature reaches the boiling point, it will vaporize into nitrogen. At this time, the nitrogen temperature is also at a low state. The existing device directly recovers the nitrogen and cannot utilize it. Therefore, the present application provides an ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration to meet the needs of utilizing nitrogen and improving the insulation effect. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to propose an ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration to solve the problem that the insulation layer has poor insulation effect and nitrogen cannot be utilized.

[0005] Based on the above objectives, the present invention provides an ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration, comprising a liquid nitrogen tank and a constant temperature tank, wherein an inner box is provided inside the constant temperature tank, an outer ring body is provided on the outer surface of the constant temperature tank, a vacuum assembly is provided on the outer surface of the outer ring body, an exhaust assembly is provided on the outer surface of the constant temperature tank, a nitrogen tank is provided on the end of the exhaust assembly away from the constant temperature tank, a docking pipe is provided between the liquid nitrogen tank and the constant temperature tank, and a docking assembly is provided on the outer surface of the docking pipe;

[0006] The gas extraction component is connected to the thermostatic tank and the outer ring body, and the exhaust component is connected to the outer ring body and the nitrogen tank. The exhaust component and the gas extraction component are used together to extract nitrogen;

[0007] The air extraction assembly includes a protective box fixedly connected to the outer surface of the outer ring body, a motor is provided on the outer surface of the protective box, a turntable is fixedly connected to the driving end of the motor, a shift block is fixedly connected to the outer surface of the turntable, an upper pipe is provided at the top of the protective box, a lower pipe is provided at the bottom of the protective box, a bellows is provided between the upper and lower pipes, and a first one-way valve is provided in the middle of the bellows;

[0008] The exhaust assembly includes an air collecting pipe fixedly connected to the upper part of the outer surface of the outer ring body, and one end of the air collecting pipe away from the outer ring body is fixedly connected to the top of the nitrogen tank. A sphere is provided inside the air collecting pipe, and a through hole is opened through the middle part of the outer surface of the sphere. The bottom end of the sphere is fixedly connected to a transmission rod, and the bottom end of the transmission rod is inserted into the interior of the lower pipe. The bottom end of the transmission rod is fixedly connected to a central shaft, and fan plates are distributed circumferentially on the outer surface of the central shaft.

[0009] Preferably, a strip plate is fixedly connected to the outer surface of the first one-way valve, a strip groove is formed on a side of the strip plate away from the first one-way valve, and the shift block slides inside the strip groove.

[0010] Preferably, a second one-way valve is provided at both the upper and lower ends of the bellows, the upper pipe is connected to the upper end of the bellows through the second one-way valve, and the end of the upper pipe away from the bellows is fixed to the upper outer surface of the thermostatic tank, and the lower pipe is connected to the lower end of the bellows through the second one-way valve, and the end of the lower pipe away from the bellows is fixed to the lower outer surface of the outer ring body.

[0011] Preferably, the docking assembly includes a docking tube sleeved on the outer surface of the connecting tube, a rotating shaft is movably provided in the middle of the docking tube, an inner rod is fixedly connected to the inside of the rotating shaft, a threaded rod is fixedly connected to the end of the inner rod, a threaded sleeve is threadedly sleeved on the outer surface of the threaded rod, a push rod is hinged on the outer surface of the threaded sleeve, and an arc block is hinged on the end of the push rod away from the threaded sleeve.

[0012] Preferably, there are two threaded rods and they are symmetrically arranged at both ends of the inner rod. The threaded rod is arranged in a T shape. The inner wall of the arc block is fixedly connected with a positioning rod. The end of the positioning rod away from the arc block is movably inserted into the end of the threaded rod.

[0013] Preferably, an extension rod is fixedly connected to the outer surface of the threaded sleeve, and a sliding groove is provided on the inner wall of the butt joint tube, and the extension rod slides inside the sliding groove.

[0014] Preferably, both ends of the butt joint pipe are provided with mounting grooves, and the ends of the connecting pipe are clamped in the mounting grooves.

[0015] Beneficial effects of the present invention:

[0016] 1. This ultra-low temperature precision constant temperature device connects the constant temperature tank and the outer ring body by setting an exhaust component. The motor drives the turntable to rotate and drives the shift block to pull the strip plate up and down. The strip plate drives the first one-way valve to move up and down to squeeze or stretch the upper and lower parts of the bellows. Under the action of the second one-way valve, the nitrogen in the constant temperature tank is pumped into the lower pipe and then flows into the outer ring body, so that the nitrogen fills the outer ring body, thereby achieving the effect of cooling the outer surface of the constant temperature tank, reducing the vaporization rate of liquid nitrogen, reducing the consumption of liquid nitrogen, and achieving the effect of energy saving.

[0017] 2. This ultra-low temperature precision constant temperature device is connected to the vacuum component by arranging an exhaust component. When the nitrogen flows in the lower pipe, it will impact the fan plate, push the fan plate to drive the central axis to rotate, and then drive the sphere to rotate through the transmission rod. The nitrogen in the outer ring body will flow into the gas collecting pipe through the through hole under the action of pressure, and then be collected in the nitrogen tank. Because the rotation of the sphere is indirect under the action of the vacuum component, it can not only collect the nitrogen, but also block the nitrogen, avoid the continuous removal of nitrogen, and increase the retention time of nitrogen in the outer ring body. Then, the temperature conversion effect of nitrogen can be used to improve the thermal insulation effect of the outer ring body.

[0018] 3. This ultra-low temperature precision constant temperature device connects the connecting pipe by setting a docking assembly. The ends of the docking pipe are both clamped in the installation groove. The rotating shaft drives the inner rod to rotate. Under the action of the threaded rod and the threaded sleeve, and the limitation of the positioning rod, the extension rod and the slide groove, the driving push rod pushes the arc block to expand outward. The arc block is squeezed on the inner wall of the docking pipe, so that the joint between the docking pipe and the connecting pipe is pressed tightly, reducing the risk of leakage and improving the safety performance of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of the air extraction component of the present invention;

[0022] Figure 3 This is a schematic diagram of the internal structure of the protective box of the present invention;

[0023] Figure 4 This is a schematic diagram of the exhaust assembly structure of the present invention;

[0024] Figure 5 This is a schematic diagram of the docking assembly structure of the present invention;

[0025] Figure 6 It is a schematic diagram of the internal structure of the butt joint pipe of the present invention.

[0026] The following are marked in the figure:

[0027] 1. Liquid nitrogen tank; 2. Constant temperature tank; 3. Inner box; 4. Outer ring; 5. Pumping assembly; 501. Protective box; 502. Motor; 503. Turntable; 504. Dial block; 505. Strip plate; 506. First one-way valve; 507. Upper pipe; 508. Lower pipe; 509. Bellows; 510. Second one-way valve; 511. Strip groove; 6. Nitrogen tank; 7. Exhaust assembly; 701. Collector Air pipe; 702, sphere; 703, through hole; 704, transmission rod; 705, center axis; 706, fan plate; 8, connecting pipe; 9, docking assembly; 901, docking tube; 902, rotating shaft; 903, inner rod; 904, threaded rod; 905, threaded sleeve; 906, push rod; 907, arc block; 908, positioning rod; 909, mounting groove; 910, extension rod; 911, slide groove. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0029] It should be noted that, unless otherwise defined, the technical or scientific terms used in the present invention should have the usual meanings understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0030] like Figures 1 to 6 As shown, an ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration includes a liquid nitrogen tank 1 and a constant temperature tank 2, an inner box 3 is provided inside the constant temperature tank 2, an outer ring body 4 is provided on the outer surface of the constant temperature tank 2, a gas extraction component 5 is provided on the outer surface of the constant temperature tank 2, an exhaust component 7 is provided, and a nitrogen tank 6 is provided on the end of the exhaust component 7 away from the constant temperature tank 2. A docking pipe 901 is provided between the liquid nitrogen tank 1 and the constant temperature tank 2, and a docking component 9 is provided on the outer surface of the docking pipe 901. The gas extraction component 5 connects the constant temperature tank 2 and the outer ring body 4, and the exhaust component 7 connects the outer ring body 4 and the nitrogen tank 6. The exhaust component 7 and the gas extraction component 5 are used in conjunction with each other to extract nitrogen.

[0031] Nitrogen is extracted by the exhaust component 5 and discharged into the outer ring body 4, so that the nitrogen fills the outer ring body 4, thereby achieving the effect of cooling the outer surface of the constant temperature tank 2, reusing the low temperature of the nitrogen, reducing the gasification rate of liquid nitrogen, reducing the consumption of liquid nitrogen, and achieving the effect of energy saving. In addition, the nitrogen in the outer ring body 4 is recovered by the exhaust component 7 and stored in the nitrogen tank 6. A docking device is provided at the joint of the connecting pipe 8 between the liquid nitrogen tank 1 and the constant temperature tank 2 to improve the sealing effect of the docking, avoid leakage, and improve the safety performance of the device.

[0032] like Figure 2 and Figure 3As shown, the air extraction component 5 includes a protective box 501 fixedly connected to the outer surface of the outer ring body 4, the outer surface of the protective box 501 is provided with a motor 502, the driving end of the motor 502 is fixedly connected to a turntable 503, the outer surface of the turntable 503 is fixedly connected to a dial block 504, the top of the protective box 501 is provided with an upper pipe 507, the bottom of the protective box 501 is provided with a lower pipe 508, a bellows 509 is provided between the upper pipe 507 and the lower pipe 508, the middle of the bellows 509 is provided with a first one-way valve 506, the outer surface of the first one-way valve 506 is fixedly connected to a strip plate 5 05, a strip groove 511 is formed on the side of the strip plate 505 away from the first one-way valve 506, and the shift block 504 slides inside the strip groove 511. Second one-way valves 510 are provided at both the upper and lower ends of the bellows 509. The upper pipe 507 is connected to the upper end of the bellows 509 through the second one-way valve 510. The end of the upper pipe 507 away from the bellows 509 is fixed to the upper outer surface of the thermostatic tank 2. The lower pipe 508 is connected to the lower end of the bellows 509 through the second one-way valve 510. The end of the lower pipe 508 away from the bellows 509 is fixed to the lower outer surface of the outer ring body 4;

[0033] The motor 502 drives the turntable 503 to rotate. During the rotation of the turntable 503, the shift block 504 is driven to make a circular motion around the center of the turntable 503. Since the shift block 504 is placed in the strip groove 511 on the outer surface of the strip plate 505, the shift block 504 drives the strip plate 505 and the first one-way valve 506 to make a reciprocating motion up and down during the movement. During the downward movement of the first one-way valve 506, the upper half of the bellows 509 is stretched, and the nitrogen is forced from the upper pipe 507 through the second one-way valve 510 into the upper half of the bellows 509, and at the same time, the lower half of the bellows 509 is squeezed, so that the lower half of the bellows 509 can be stretched. 9 flows into the lower pipe 508 from the second one-way valve 510. As the turntable 503 rotates, the first one-way valve 506 stretches the lower bellows 509 and squeezes the upper bellows 509 during its upward movement, so that the nitrogen in the upper bellows 509 can be pressed into the lower bellows 509 through the first one-way valve 506. This reciprocating process can realize the nitrogen in the thermostatic tank 2 being drawn into the lower pipe 508 and then flowing into the outer ring body 4, so that the nitrogen fills the outer ring body 4, thereby achieving the effect of cooling the outer surface of the thermostatic tank 2, reducing the vaporization rate of liquid nitrogen, reducing the consumption of liquid nitrogen, and achieving the effect of energy saving.

[0034] like Figure 1 、 Figure 2 and Figure 4As shown, the exhaust assembly 7 includes an air collecting pipe 701 fixedly connected to the upper portion of the outer surface of the outer ring body 4. The end of the air collecting pipe 701 away from the outer ring body 4 is fixedly connected to the top of the nitrogen tank 6. A sphere 702 is provided inside the air collecting pipe 701. A through hole 703 is formed in the middle of the outer surface of the sphere 702. The bottom end of the sphere 702 is fixedly connected to a transmission rod 704. The bottom end of the transmission rod 704 extends into the interior of the lower pipe 508. The bottom end of the transmission rod 704 is fixedly connected to a central shaft 705. The outer surface of the central shaft 705 is circumferentially distributed with fan plates 706.

[0035] When the nitrogen flows in the lower pipe 508, it will impact the fan plate 706, push the fan plate 706 to drive the central axis 705 to rotate, and then drive the sphere 702 to rotate through the transmission rod 704. The outer surface of the sphere 702 is penetrated by a through hole 703. When the through hole 703 is connected to the gas collecting pipe 701, the nitrogen in the outer ring body 4 will flow into the gas collecting pipe 701 through the through hole 703 under the action of pressure, and then be collected in the nitrogen tank 6. Due to the action of the vacuum component 5, the nitrogen flows into the lower pipe 508 indirectly, and the rotation of the sphere 702 is also indirect, which can not only realize the collection of nitrogen, but also realize the blocking of nitrogen, avoid the continuous removal of nitrogen, and increase the retention time of nitrogen in the outer ring body 4. Then, the temperature conversion effect of nitrogen can be used to improve the thermal insulation effect of the outer ring body 4.

[0036] like Figure 5 and Figure 6 As shown, the docking assembly 9 includes a docking tube 901 sleeved on the outer surface of the connecting tube 8, a rotating shaft 902 is movably provided in the middle of the docking tube 901, an inner rod 903 is fixedly connected to the interior of the rotating shaft 902, and a threaded rod 904 is fixedly connected to the end of the inner rod 903. The outer surface of the threaded rod 904 is threadedly sleeved with a threaded sleeve 905, and the outer surface of the threaded sleeve 905 is hinged with a push rod 906. The end of the push rod 906 away from the threaded sleeve 905 is hinged with an arc block 907. The threaded rod 904 is provided with two and symmetrically arranged At both ends of the inner rod 903, the threaded rod 904 is set in a T shape, the inner wall of the arc block 907 is fixedly connected to a positioning rod 908, and the end of the positioning rod 908 away from the arc block 907 is movably inserted into the end of the threaded rod 904. The outer surface of the threaded sleeve 905 is fixedly connected to an extension rod 910. The inner wall of the butt joint 901 is provided with a sliding groove 911, and the extension rod 910 slides inside the sliding groove 911. Both ends of the butt joint 901 are provided with mounting grooves 909, and the end of the connecting pipe 8 is clamped inside the mounting groove 909;

[0037] The rotating shaft 902 drives the inner rod 903 to rotate, and the rotation of the inner rod 903 drives the threaded rod 904 to rotate. The outer surface of the threaded rod 904 is sleeved with a threaded sleeve 905, and the extension rod 910 on the outer surface of the threaded sleeve 905 is limited in the slide groove 911, and then the rotation of the threaded rod 904 drives the threaded sleeve 905 to move along the threaded rod 904. The outer surface of the threaded sleeve 905 is hinged with an arc block 907 through the push rod 906, and the inner wall of the arc block 907 is inserted into the end round block of the threaded rod 904 through the positioning rod 908, and then the movement of the threaded sleeve 905 pushes the arc block 907 to expand outward, so that the arc block 907 is squeezed on the inner wall of the docking tube 901, so that the connection between the docking tube 901 and the connecting pipe 8 is pressed tightly, reducing the risk of leakage and improving the safety performance of the device.

[0038] The technical solution provided by the present invention is to put the items that need to be refrigerated into the inner box 3, and the liquid nitrogen tank 1 transports liquid nitrogen to the constant temperature tank 2 through the connecting pipe 8 to achieve the effect of constant temperature refrigeration. The liquid nitrogen placed in the constant temperature tank 2 will gasify when the temperature rises, and the nitrogen is extracted by the exhaust component 5 and discharged into the outer ring body 4, so that the nitrogen fills the outer ring body 4, achieving the effect of cooling the outer surface of the constant temperature tank 2, and reusing the low temperature of the nitrogen, thereby reducing the gasification speed of the liquid nitrogen and reducing the consumption of liquid nitrogen, thereby achieving the effect of energy saving. In addition, the nitrogen in the outer ring body 4 is recovered and stored in the nitrogen tank 6 through the exhaust component 7. The joint of the connecting pipe 8 between the liquid nitrogen tank 1 and the constant temperature tank 2 is provided with a docking device to improve the sealing effect of the docking, avoid the occurrence of leakage, and improve the safety performance of the device. Specifically, the motor 502 drives the turntable 503 to rotate. During the rotation of the turntable 503, the dial block 504 will be driven to make a circular motion around the center of the turntable 503. Since the dial block 504 is placed in the strip groove 511 on the outer surface of the strip plate 505 The first one-way valve 506 is moved downwards, and the upper portion of the bellows 509 is stretched during the downward movement of the first one-way valve 506. The nitrogen is then forced from the upper pipe 507 through the second one-way valve 510 into the upper bellows 509. At the same time, the lower bellows 509 is squeezed, and the nitrogen in the lower bellows 509 is forced from the second one-way valve 510 into the lower pipe 508. As the turntable 503 rotates, the first one-way valve 506 is stretched downwards, and the upper portion of the bellows 509 is stretched downwards. During the upward movement of the one-way valve 506, the lower half bellows 509 is stretched and the upper half bellows 509 is squeezed, so that the nitrogen in the upper half bellows 509 can be pressed into the lower half bellows 509 through the first one-way valve 506. In this way, the nitrogen in the thermostatic tank 2 is pumped into the lower pipe 508 and then flows into the outer ring body 4, so that the nitrogen fills the outer ring body 4, thereby achieving the effect of cooling the outer surface of the thermostatic tank 2, reducing the vaporization speed of liquid nitrogen, reducing the consumption of liquid nitrogen, and achieving the effect of energy saving;

[0039] When the nitrogen flows in the lower pipe 508, it will impact the fan plate 706, pushing the fan plate 706 to drive the central shaft 705 to rotate, and then drive the ball 702 to rotate through the transmission rod 704. The outer surface of the ball 702 is penetrated by a through hole 703. When the through hole 703 is connected to the gas collecting pipe 701, the nitrogen in the outer ring body 4 will flow into the gas collecting pipe 701 through the through hole 703 under the action of pressure, and then be collected in the nitrogen tank 6. Because the nitrogen flows into the lower pipe 508 indirectly under the action of the exhaust component 5, the rotation of the ball 702 is also indirect, which can not only realize the collection of nitrogen, but also realize the blocking of nitrogen, avoid the continuous removal of nitrogen, and increase the retention time of nitrogen in the outer ring body 4. Then, through the temperature conversion effect of nitrogen, the heat preservation effect of the outer ring body 4 is improved;

[0040] The outer surface of the threaded rod 904 is sleeved with a threaded sleeve 905, and the extension rod 910 on the outer surface of the threaded sleeve 905 is limited in the sliding groove 911. Then, the rotation of the threaded rod 904 drives the threaded sleeve 905 to move along the threaded rod 904. The outer surface of the threaded sleeve 905 is hinged with an arc block 907 through the push rod 906, and the inner wall of the arc block 907 is inserted into the end round block of the threaded rod 904 through the positioning rod 908. Then, the movement of the threaded sleeve 905 pushes the arc block 907 to expand outward, so that the arc block 907 is squeezed on the inner wall of the connecting tube 901, so that the connection between the connecting tube 901 and the connecting tube 8 is tightly pressed, reducing the risk of leakage and improving the safety performance of the device.

[0041] It should be understood by those skilled in the art that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0042] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration, characterized in that: include: A liquid nitrogen tank (1) and a constant temperature tank (2), wherein an inner box (3) is provided inside the constant temperature tank (2), an outer ring body (4) is provided on the outer surface of the constant temperature tank (2), an exhaust assembly (5) is provided on the outer surface of the outer ring body (4), an exhaust assembly (7) is provided on the outer surface of the constant temperature tank (2), a nitrogen tank (6) is provided at one end of the exhaust assembly (7) away from the constant temperature tank (2), a butt joint (901) is provided between the liquid nitrogen tank (1) and the constant temperature tank (2), and a butt joint assembly (9) is provided on the outer surface of the butt joint (901); The exhaust assembly (5) is connected to the constant temperature tank (2) and the outer ring body (4), the exhaust assembly (7) is connected to the outer ring body (4) and the nitrogen tank (6), and the exhaust assembly (7) and the exhaust assembly (5) are used in conjunction with each other to extract nitrogen; The air extraction assembly (5) comprises a protective box (501) fixedly connected to the outer surface of the outer ring body (4); a motor (502) is provided on the outer surface of the protective box (501); a driving end of the motor (502) is fixedly connected to a turntable (503); a shift block (504) is fixedly connected to the outer surface of the turntable (503); an upper pipe (507) is provided at the top end of the protective box (501); a lower pipe (508) is provided at the bottom end of the protective box (501); a bellows (509) is provided between the upper pipe (507) and the lower pipe (508); and a first one-way valve (506) is provided in the middle of the bellows (509); The exhaust assembly (7) includes an air collecting pipe (701) fixedly connected to the upper portion of the outer surface of the outer ring body (4), one end of the air collecting pipe (701) away from the outer ring body (4) is fixedly connected to the top of the nitrogen tank (6), a sphere (702) is provided inside the air collecting pipe (701), a through hole (703) is provided through the middle portion of the outer surface of the sphere (702), a transmission rod (704) is fixedly connected to the bottom end of the sphere (702), the bottom end of the transmission rod (704) is inserted into the interior of the lower pipe (508), the bottom end of the transmission rod (704) is fixedly connected to the central shaft (705), and fan plates (706) are distributed circumferentially on the outer surface of the central shaft (705); When the nitrogen flows in the lower pipe (508), it will impact the fan plate (706), push the fan plate (706) to drive the central shaft (705) to rotate, and then drive the sphere (702) to rotate through the transmission rod (704). When the through hole (703) on the outer surface of the sphere (702) is connected to the gas collecting pipe (701), the nitrogen in the outer ring body (4) will flow into the gas collecting pipe (701) through the through hole (703) under the action of pressure, and then be collected in the nitrogen tank (6).

2. The ultra-low temperature precision constant temperature device according to claim 1, characterized in that: A strip plate (505) is fixedly connected to the outer surface of the first one-way valve (506), a strip groove (511) is provided on a side of the strip plate (505) away from the first one-way valve (506), and the shift block (504) slides inside the strip groove (511).

3. The ultra-low temperature precision constant temperature device according to claim 2, characterized in that: The upper and lower ends of the bellows (509) are both provided with second one-way valves (510), the upper pipe (507) is connected to the upper end of the bellows (509) via the second one-way valve (510), and the end of the upper pipe (507) away from the bellows (509) is fixed to the upper part of the outer surface of the thermostatic tank (2), and the lower pipe (508) is connected to the lower end of the bellows (509) via the second one-way valve (510), and the end of the lower pipe (508) away from the bellows (509) is fixed to the lower part of the outer surface of the outer ring body (4).

4. The ultra-low temperature precision constant temperature device according to claim 3, characterized in that: The docking assembly (9) comprises a docking tube (901) sleeved on the outer surface of the connecting tube (8); a rotating shaft (902) is movably provided in the middle of the docking tube (901); an inner rod (903) is fixedly connected to the interior of the rotating shaft (902); a threaded rod (904) is fixedly connected to the end of the inner rod (903); a threaded sleeve (905) is threadedly sleeved on the outer surface of the threaded rod (904); a push rod (906) is hingedly connected to the outer surface of the threaded sleeve (905); and an arc block (907) is hingedly connected to the end of the push rod (906) away from the threaded sleeve (905).

5. The ultra-low temperature precision constant temperature device according to claim 4, characterized in that: Two threaded rods (904) are provided and symmetrically arranged at both ends of the inner rod (903). The threaded rods (904) are arranged in a T-shape. A positioning rod (908) is fixedly connected to the inner wall of the arc block (907). The end of the positioning rod (908) away from the arc block (907) is movably inserted into the end of the threaded rod (904).

6. The ultra-low temperature precision constant temperature device according to claim 5, characterized in that: An extension rod (910) is fixedly connected to the outer surface of the threaded sleeve (905), and a sliding groove (911) is provided on the inner wall of the butt joint tube (901), and the extension rod (910) slides inside the sliding groove (911).

7. The ultra-low temperature precision constant temperature device according to claim 6, characterized in that: Both ends of the butt-jointing pipe (901) are provided with mounting grooves (909), and the ends of the connecting pipe (8) are clamped inside the mounting grooves (909).

Images