Integrated air-cooled liquid nitrogen generator of GM refrigerator technology

Abstract

The invention discloses an integrated air-cooled liquid nitrogen generator of a GM refrigerating machine technology, and relates to the field of liquid nitrogen generators, the integrated air-cooled liquid nitrogen generator comprises a rack, and two air compressors, a radiating pipe, an air adsorption tower, a nitrogen storage tank, a Dewar tank, a GM refrigerating cold head, a helium compressor, a numerical control component cabinet and an electrical component cabinet are arranged in the rack; a first supporting plate and a second supporting plate are installed in the rack, the air compressors and the heat dissipation pipe are both arranged at the bottom of the second supporting plate, the two air compressors and the heat dissipation pipe are both installed on the rack, and the output ends of the two air compressors are both connected with the input end of the heat dissipation pipe. The integrated structural design is adopted, the equipment size is reduced, and the device adapts to the narrow space of a laboratory; the problem of nitrogen separation interruption when an adsorbent is saturated is solved through alternate work of the two air adsorption towers, and continuous supply of liquid nitrogen is guaranteed; a traditional water cooling system is replaced with full air cooling heat dissipation, the water leakage risk is avoided, operation noise is reduced, and the mute requirement of a laboratory is met.

Description

Technical Field

[0001] This invention relates to the field of liquid nitrogen generators, and particularly to an integrated air-cooled liquid nitrogen generator based on GM refrigeration technology. Background Technology

[0002] Nitrogen refers to liquid nitrogen gas. Liquid nitrogen is an inert, colorless, odorless, non-corrosive, and non-flammable liquid. Its vaporization at extremely low temperatures absorbs a large amount of heat, which can cause frostbite upon contact. Nitrogen constitutes the majority of the atmosphere (78.03% by volume, 75.5% by weight). At normal pressure, nitrogen's boiling point is -196.56℃. One cubic meter of liquid ammonia can expand to 696 cubic meters of pure gaseous nitrogen (21℃). With pressure, liquid nitrogen can be obtained at even higher temperatures. In industry, liquid nitrogen is obtained through air fractionation. The air is first purified and then liquefied under pressure and cooling, separating components based on their different boiling points. Instantaneous contact with liquid nitrogen is harmless to human skin; frostbite only occurs after more than two seconds and is irreversible.

[0003] Currently, when using liquid nitrogen in laboratories, liquid nitrogen generators are generally quite large, while the laboratory space itself is limited. Therefore, the liquid nitrogen used in laboratories is mostly purchased. If the size of the liquid nitrogen generator is reduced and placed in the laboratory for use, the existing technology for preparing liquid nitrogen mostly separates nitrogen from the air by adsorbing oxygen from the air. However, after the oxygen adsorption device becomes saturated, the adsorbed oxygen needs to be released. During the release process, nitrogen cannot be separated, resulting in the inability to produce liquid nitrogen during this period. This would cause a shortage of liquid nitrogen, thus affecting the experiment.

[0004] Existing liquid nitrogen generators generally rely on water cooling systems. During operation, they mostly use built-in water circulation to cool the gas and equipment. However, due to the presence of built-in water circulation, an external chiller needs to be deployed to complete the cooling work of the water circulation inside the equipment. This poses a risk of water leakage and generates significant noise (>80dB), which does not meet the requirements for quiet operation in laboratories.

[0005] Therefore, it is imperative to invent an integrated air-cooled liquid nitrogen generator to solve the problems mentioned above, such as the impact of intermittent nitrogen supply on experimental continuity, the increase in equipment size and maintenance costs due to water cooling systems, and the damage to the laboratory environment caused by external components. Summary of the Invention

[0006] The purpose of this invention is to provide an integrated air-cooled liquid nitrogen generator for GM refrigeration technology, which achieves continuous nitrogen production through alternating adsorption in two towers, and uses an integrated air-cooling system to replace water cooling, thus solving the problems of nitrogen supply interruption, large size and high noise in traditional equipment.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an integrated air-cooled liquid nitrogen generator for GM refrigeration process, comprising a frame, wherein the frame is provided with two air compressors, heat dissipation pipes, an air adsorption tower, a nitrogen storage tank, a Dewar flask, a GM refrigeration cold head, a helium compressor, a CNC component cabinet and an electrical component cabinet; The frame is equipped with a first support plate and a second support plate. The air compressor and the heat dissipation pipe are both located at the bottom of the second support plate. Both air compressors and the heat dissipation pipe are mounted on the frame. The output ends of both air compressors are connected to the input ends of the heat dissipation pipe. The output ends of the heat dissipation pipe are connected to the air adsorption tower through pipes. The air adsorption tower, nitrogen storage tank, CNC component cabinet and electrical component cabinet are all installed on the first support plate, the Dewar can is installed on the second support plate, the air adsorption tower is connected to the nitrogen storage tank through a pipe, the top of the Dewar can is fixedly connected to a nitrogen injection check valve, the nitrogen storage tank is connected to the nitrogen injection check valve through a pipe, and the GM refrigeration cold head is installed on the top of the Dewar can. The helium compressor is located at the bottom of the first support plate and is mounted on the frame. The output end of the helium compressor is connected to the input end of the GM cooling head through a metal hose. The output end of the GM cooling head is connected to the input end of the helium compressor through a metal hose. The side wall of the frame is equipped with a liquid nitrogen outlet door plate, the top of the Dewar canister is fixedly connected with a liquid nitrogen discharge pipe, and the surface of the liquid nitrogen outlet door plate is provided with a liquid nitrogen outlet corresponding to the liquid nitrogen discharge pipe. A side panel is installed on the other side of the frame. The surface of the side panel has an air outlet corresponding to the helium compressor. A front side door panel is installed on the front side of the frame via a hinge. The surface of the front side door panel has an air inlet corresponding to the helium compressor. A door lock is provided on the surface of the front side door panel. A drain outlet is provided on the surface of the side panel.

[0008] Preferably, omnidirectional casters are installed at the four bottom corners of the frame.

[0009] Preferably, lifting rings are fixedly connected to the top four corners of the frame.

[0010] Preferably, the top of the frame is equipped with a left top plate and a right top plate, the top of the left top plate is provided with a first heat dissipation vent, and a top fan is installed in the first heat dissipation vent.

[0011] Preferably, the bottom of the liquid nitrogen outlet door panel is provided with an installation door panel, and the surface of the installation door panel has two second heat dissipation vents, and a bottom fan is installed in the second heat dissipation vents.

[0012] Preferably, a four-way pipe is fixedly connected to the top of the Dewar jar, a level gauge is connected to the top of the four-way pipe, a venting valve is connected to the left side of the four-way pipe, a three-way pipe is connected to the right side of the four-way pipe, and a first safety valve and a second safety valve are respectively connected to the other two ends of the three-way pipe.

[0013] Preferably, the surface of the CNC component cabinet is provided with a CNC operation screen, and a green start button, a red stop button, a buzzer and an emergency stop button are provided below the CNC operation screen.

[0014] Preferably, there are two air adsorption towers, namely tower A and tower B.

[0015] The technical effects and advantages of this invention are as follows: By using an air-cooled cooling device for heat exchange and cooling, compared to the traditional water-cooled cooling device which requires water circulation, the air-cooled cooling device avoids the risk of water leakage because it does not have a circulating water path. Furthermore, by eliminating the need for an external chiller, the overall equipment volume is reduced by 33%, making it more suitable for laboratory installation conditions. The device's air filtration system adopts a dual-tower alternating operation mode, with PLC-controlled solenoid valves switching the airflow path, ensuring that the equipment produces nitrogen without interruption and increasing the equipment's operating efficiency. Attached Figure Description

[0016] Figure 1 This is a front view structural diagram of the present invention; Figure 2 This is a schematic diagram of the rear structure of the present invention; Figure 3 For the present invention Figure 2 A schematic diagram of the side view structure; Figure 4 For the present invention Figure 1 A schematic diagram of the door panel removal structure; Figure 5 For the present invention Figure 4 A schematic diagram of the side view structure; Figure 6 This is a schematic diagram of the structure of the Dewar jar of the present invention; Figure 7 This is a schematic diagram of the frame structure of the present invention; Figure 8 For the present invention Figure 2 A magnified structural diagram of part A; Figure 9 For the present invention Figure 6 A schematic diagram of the enlarged structure of part B; Figure 10 This is a schematic diagram of the process structure of the present invention.

[0017] In the diagram: 1. Frame; 2. Air compressor; 3. Heat sink; 4. Air adsorption tower; 5. Nitrogen storage tank; 6. Dewar flask; 7. GM cooling head; 8. Helium compressor; 9. CNC component cabinet; 10. Electrical component cabinet; 11. First support plate; 12. Second support plate; 13. Nitrogen injection check valve; 14. Liquid nitrogen outlet door; 15. Liquid nitrogen discharge pipe; 16. Liquid nitrogen outlet; 17. Side plate; 18. Air outlet; 19. Front and side door; 20. Air inlet. 21. Door lock; 22. Drain outlet; 23. Universal caster wheel; 24. Lifting ring; 25. Left side top panel; 26. Right side top panel; 27. Buzzer; 28. Top fan; 29. ​​Door panel installation; 30. Emergency stop button; 31. Bottom fan; 32. Four-way pipe; 33. Level gauge; 34. CNC operation screen; 35. Green start button; 36. Red stop button; 37. Drain valve; 38. Three-way pipe; 39. First safety valve; 40. Second safety valve. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] This invention provides, for example Figure 1-10 The integrated air-cooled liquid nitrogen generator of GM refrigeration process shown includes a frame 1, which contains two air compressors 2, heat dissipation pipes 3, air adsorption towers 4, nitrogen storage tanks 5, Dewar canisters 6, GM refrigeration cold heads 7, helium compressors 8, CNC component cabinets 9 and electrical component cabinets 10. The frame 1 is equipped with a first support plate 11 and a second support plate 12. The air compressor 2 and the heat dissipation pipe 3 are both located at the bottom of the second support plate 12. The two air compressors 2 and the heat dissipation pipe 3 are both installed on the frame 1. The output ends of the two air compressors 2 are connected to the input ends of the heat dissipation pipe 3. The output ends of the heat dissipation pipe 3 are connected to the air adsorption tower 4 through a pipe. An air-water separator is installed on the pipe connecting the heat dissipation pipe 3 and the air adsorption tower 4. The air-water separator is connected to the drain outlet 22 through a pipe. Air adsorption tower 4, nitrogen storage tank 5, CNC component cabinet 9 and electrical component cabinet 10 are all installed on the first support plate 11. Dewar 6 is installed on the second support plate 12. Dewar 6 is used to store liquid nitrogen. Air adsorption tower 4 is connected to nitrogen storage tank 5 through a pipe. After the carbon molecular sieve in air adsorption tower 4 adsorbs oxygen in the air, it discharges high-purity nitrogen to nitrogen storage tank 5 for temporary storage. A nitrogen injection check valve 13 is fixedly connected to the top of Dewar 6. Nitrogen storage tank 5 is connected to nitrogen injection check valve 13 through a pipe. A filter is installed on the pipe connecting nitrogen storage tank 5 and nitrogen injection check valve 13. GM cooling head 7 is installed on the top of Dewar 6. GM cooling head 7 is used to realize the nitrogen liquefaction process. The helium compressor 8 is located at the bottom of the first support plate 11 and is mounted on the frame 1. The output end of the helium compressor 8 is connected to the input end of the GM cooling head 7 through a metal hose. The output end of the GM cooling head 7 is connected to the input end of the helium compressor 8 through a metal hose, forming a helium circulation loop to provide power for the cooling operation of the GM cooling head 7. A liquid nitrogen outlet door plate 14 is installed on the side wall of the frame 1, and a liquid nitrogen discharge pipe 15 is fixedly connected to the top of the Dewar tank 6. A liquid nitrogen outlet 16 corresponding to the liquid nitrogen discharge pipe 15 is opened on the surface of the liquid nitrogen outlet door plate 14 for receiving liquid nitrogen in the Dewar tank 6. A side panel 17 is installed on the other side of the frame 1. The surface of the side panel 17 has an air outlet 18 corresponding to the helium compressor 8. A front side door panel 19 is installed on the front side of the frame 1 via a hinge. The surface of the front side door panel 19 has an air inlet 20 corresponding to the helium compressor 8 to complete the circulation of air between the inside and outside of the helium compressor 8. A door lock 21 is provided on the surface of the front side door panel 19. A drain outlet 22 is provided on the surface of the side panel 17. The air compressor 2 compresses the air, which enters the heat dissipation pipe 3 to cool the high-pressure gas discharged by the air compressor 2, and then enters the air adsorption tower 4. In the air adsorption tower 4, oxygen is adsorbed by carbon molecular sieve. After the adsorption is saturated, high-purity nitrogen is discharged into the nitrogen storage tank 5. The high-purity nitrogen in the nitrogen storage tank 5 is then transported to the Dewar canister 6. The nitrogen is liquefied and stored in the Dewar canister 6 by the operation of the GM refrigeration head 7.

[0020] Universal casters 23 are installed at the four corners of the bottom of the frame 1.

[0021] Lifting rings 24 are fixedly connected to the top four corners of the frame 1.

[0022] The top of the rack 1 is equipped with a left top plate 25 and a right top plate 26. The top of the left top plate 25 has a first heat dissipation vent, and a top fan 28 is installed in the first heat dissipation vent to exhaust the hot air inside the rack 1 and improve the overall heat dissipation effect.

[0023] The bottom of the liquid nitrogen outlet door panel 14 is provided with a mounting door panel 29. Two second heat dissipation vents are opened on the surface of the mounting door panel 29, and a bottom fan 31 is installed in the second heat dissipation vents to complete the heat exchange between the air compressor 2 and the heat dissipation pipe 3.

[0024] A four-way pipe 32 is fixedly connected to the top of the Dewar 6. A level gauge 33 is connected to the top of the four-way pipe 32. A venting valve 37 is connected to the left side of the four-way pipe 32, and a three-way pipe 38 is connected to the right side of the four-way pipe 32. The other two ends of the three-way pipe 38 are respectively connected to a first safety valve 39 and a second safety valve 40. The level gauge 33 can detect the amount of liquid nitrogen in the Dewar 6. The venting valve 37 can empty the liquid nitrogen in the Dewar 6. The first safety valve 39 and the second safety valve 40 can release pressure when the pressure in the Dewar 6 reaches a certain threshold. When the first threshold is reached, the first safety valve 39 starts to release pressure. When the second threshold is reached, both the first safety valve 39 and the second safety valve 40 start to release pressure.

[0025] The surface of the CNC component cabinet 9 is equipped with a CNC operation screen 34. Below the CNC operation screen 34 are a green start button 35, a red stop button 36, a buzzer 27, and an emergency stop button 30. The green start button 35 is used to start the equipment, the red stop button 36 is used to stop the equipment normally, the emergency stop button 30 is used to stop the machine quickly in an emergency, and the buzzer 27 is used for fault warning. Together, they complete the control function of the equipment.

[0026] There are two air adsorption towers 4, namely tower A and tower B.

[0027] Except for the metal flexible pipe connected to the helium compressor 9, all other pipes used in this device are gas-filled plastic flexible pipes.

[0028] Working principle of this invention: The equipment operating parameters are set through the CNC operation screen 34, and the equipment is started by pressing the green start button 35. The two air compressors 2 start working, compressing the air and sending it to the heat dissipation pipe 3. The bottom fan 31 starts to accelerate the air circulation and cool the high-pressure gas in the heat dissipation pipe 3. The cooled gas enters the air adsorption tower 4 through the pipeline. At this time, tower A works first, adsorbing oxygen in the air through the internal carbon molecular sieve. The separated high-purity nitrogen is transported to the nitrogen storage tank 5 through the pipeline for temporary storage. When the carbon molecular sieve in tower A becomes saturated with adsorbed oxygen, the equipment automatically switches to tower B to continue nitrogen separation. At the same time, tower A begins to release the adsorbed oxygen and regenerate, thus enabling continuous nitrogen separation. High-purity nitrogen in nitrogen storage tank 5 is transported to Dewar 6 through pipelines and nitrogen injection check valve 13. Helium compressor 8 starts and provides power to GM cooling head 7 through helium circulation loop. GM cooling head 7 liquefies the nitrogen in Dewar 6 into liquid nitrogen and stores it. During equipment operation, the top fan 28 starts to exhaust the hot air inside the frame 1, achieving overall heat dissipation; when liquid nitrogen needs to be connected, it can be connected through the liquid nitrogen outlet 16 and the liquid nitrogen discharge pipe 15; when the Dewar canister 6 needs to be cleaned, the venting valve 37 is opened, and the liquid nitrogen in the Dewar canister 6 is completely emptied through the venting valve 37 before maintenance. When the equipment malfunctions, the buzzer 27 will sound an alarm. The staff can troubleshoot according to the prompts on the CNC operation screen 34. In case of emergency, the emergency stop button 30 can be pressed to stop the machine quickly. After the work is completed, the red stop button 36 can be pressed to stop the equipment.

[0029] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An integrated air-cooled liquid nitrogen generator based on GM refrigeration technology, comprising a frame, characterized in that: The rack is equipped with two air compressors, heat dissipation pipes, air adsorption tower, nitrogen storage tank, Dewar canister, GM refrigeration cold head, helium compressor, CNC component cabinet and electrical component cabinet; The frame is equipped with a first support plate and a second support plate. The air compressor and the heat dissipation pipe are both located at the bottom of the second support plate. Both air compressors and the heat dissipation pipe are mounted on the frame. The output ends of both air compressors are connected to the input ends of the heat dissipation pipe. The output ends of the heat dissipation pipe are connected to the air adsorption tower through pipes. The air adsorption tower, nitrogen storage tank, CNC component cabinet and electrical component cabinet are all installed on the first support plate, the Dewar can is installed on the second support plate, the air adsorption tower is connected to the nitrogen storage tank through a pipe, the top of the Dewar can is fixedly connected to a nitrogen injection check valve, the nitrogen storage tank is connected to the nitrogen injection check valve through a pipe, and the GM refrigeration cold head is installed on the top of the Dewar can. The helium compressor is located at the bottom of the first support plate and is mounted on the frame. The output end of the helium compressor is connected to the input end of the GM cooling head through a metal hose. The output end of the GM cooling head is connected to the input end of the helium compressor through a metal hose. The side wall of the frame is equipped with a liquid nitrogen outlet door plate, the top of the Dewar canister is fixedly connected with a liquid nitrogen discharge pipe, and the surface of the liquid nitrogen outlet door plate is provided with a liquid nitrogen outlet corresponding to the liquid nitrogen discharge pipe. A side panel is installed on the other side of the frame. The surface of the side panel has an air outlet corresponding to the helium compressor. A front side door panel is installed on the front side of the frame via a hinge. The surface of the front side door panel has an air inlet corresponding to the helium compressor. A door lock is provided on the surface of the front side door panel. A drain outlet is provided on the surface of the side panel.

2. The integrated air-cooled liquid nitrogen generator according to claim 1, characterized in that: The frame is equipped with universal casters at all four corners of its bottom.

3. The integrated air-cooled liquid nitrogen generator according to claim 2, characterized in that: The top four corners of the frame are all fixedly connected with lifting rings.

4. The integrated air-cooled liquid nitrogen generator according to claim 3, characterized in that: The top of the frame is equipped with a left top plate and a right top plate. The top of the left top plate has a first heat dissipation vent, and a top fan is installed inside the first heat dissipation vent.

5. An integrated air-cooled liquid nitrogen generator according to claim 4, characterized in that: The bottom of the liquid nitrogen outlet door is provided with an installation door plate, and the surface of the installation door plate has two second heat dissipation vents, and a bottom fan is installed in the second heat dissipation vents.

6. The integrated air-cooled liquid nitrogen generator according to claim 5, characterized in that: The top of the Dewar can is fixedly connected to a four-way pipe, the top of the four-way pipe is connected to a level gauge, the left side of the four-way pipe is connected to a vent valve, the right side of the four-way pipe is connected to a three-way pipe, and the other two ends of the three-way pipe are respectively connected to a first safety valve and a second safety valve.

7. An integrated air-cooled liquid nitrogen generator according to claim 6, characterized in that: The surface of the CNC component cabinet is equipped with a CNC operation screen, and below the CNC operation screen are a green start button, a red stop button, a buzzer, and an emergency stop button.

8. An integrated air-cooled liquid nitrogen generator according to claim 7, characterized in that: There are two air adsorption towers, namely Tower A and Tower B.

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