Rectification-free argon recovery system

Abstract

The utility model relates to the technical field of purification, in particular to a rectification-free argon recovery system which comprises a first heat exchanger, a carbon and oxygen removal furnace, a second heat exchanger, a precooler, a drying device, a third heat exchanger, a nitrogen removal furnace, a fourth heat exchanger, a compressor, a first electric heater and a second electric heater, an outlet end of the compressor is connected with a first inlet end pipeline of the first heat exchanger, a first outlet end of the first heat exchanger is connected with an inlet end pipeline of the first electric heater, an outlet end of the first electric heater is connected with an inlet end pipeline of the carbon and oxygen removing furnace, and an outlet end of the carbon and oxygen removing furnace is connected with a second inlet end pipeline of the first heat exchanger. A second outlet end of the first heat exchanger is connected with an inlet end pipeline of the second heat exchanger; the low-flow hydrogen-free argon recovery device is beneficial for increasing the cost performance of low-flow hydrogen-free argon recovery and reducing equipment which is easy to fail, such as a cold box and an air compressor, so that the equipment investment and the maintenance cost are reduced, and the extraction rate, the stability and the safety of the device are increased.

Description

Technical Field

[0001] The utility model relates to the technical field of purification, in particular to a non-distillation argon recovery system. Background Art

[0002] With the rapid development of photovoltaic power generation, the demand for monocrystalline silicon, one of the primary raw materials for silicon-based solar cell modules, has skyrocketed. Typical monocrystalline silicon is refined from raw silicon ingots using the Czochralski method at temperatures exceeding 1400°C. To ensure the quality of the monocrystalline silicon, large quantities of high-purity argon are used for atmosphere purging. This purge removes various volatile impurities and air components, including oxygen, nitrogen, carbon monoxide, moisture, carbon dioxide, and methane, generated from the crucible during the refining process. Cryogenic argon recovery involves removing oxygen, nitrogen, carbon monoxide, moisture, carbon dioxide, and methane from the raw gas before it enters the cold box, where it is distilled to produce 5N argon.

[0003] The traditional distillation process uses a complex series of steps to improve the purity of low-purity, high-flow contaminated argon. First, the contaminated argon is fed into a compressor for pressurization. It then passes through a preheater and an electric heater to raise the temperature. Once the temperature reaches a certain level, the gas enters a decarbonization furnace, where it comes into contact with a copper-based catalyst, causing a redox reaction between CO and O₂, effectively removing excess carbon monoxide or oxygen.

[0004] After this reaction, the gas is cooled in a shell-and-tube heat exchanger to lower its temperature and prepare it for further processing. The gas is then sent to a pre-cooler to remove moisture through cooling. To further purify the gas, it passes through a drying unit to remove any remaining moisture and carbon dioxide. The final step is a cold box, where the nitrogen component of the argon is removed through cryogenic separation.

[0005] However, this traditional distillation process is not very cost-effective when dealing with high-purity, small-flow argon. Specifically, this method has several significant disadvantages: Fluctuation of raw gas composition: If the composition of the raw gas is unstable, the stability and extraction efficiency of the entire recovery process will be seriously affected. Cold box cooling capacity replenishment demand: In order to maintain the low-temperature environment required for distillation, additional liquid argon is usually required to be added to the cold box to provide cooling capacity. High cost: The manufacture of the cold box not only requires an extremely high level of process, but also requires supporting air compressors and purification equipment, which significantly increases the overall cost of installation and operation, resulting in the process being not cost-effective.

[0006] To overcome the above shortcomings and provide a more efficient and economical option, especially when processing high-purity and low-flow argon, this process is designed with greater emphasis on economic benefits and ease of operation, especially when extreme cryogenic conditions are not required. Utility Model Content

[0007] The purpose of this utility model is to provide a non-distillation argon recovery system to address the shortcomings of the existing technology.

[0008] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0009] The utility model provides a non-distillation argon recovery system, comprising: a first heat exchanger, a carbon and oxygen removal furnace, a second heat exchanger, a precooler, a drying device, a third heat exchanger, a nitrogen removal furnace, a fourth heat exchanger, a compressor, a first electric heater, and a second electric heater;

[0010] Wherein, the outlet end of the compressor is connected to the first inlet end pipeline of the first heat exchanger, the first outlet end of the first heat exchanger is connected to the inlet end pipeline of the first electric heater, the outlet end of the first electric heater is connected to the inlet end pipeline of the carbon removal furnace, the outlet end of the carbon removal furnace is connected to the second inlet end pipeline of the first heat exchanger, the second outlet end of the first heat exchanger is connected to the inlet end pipeline of the second heat exchanger, the outlet end of the second heat exchanger is connected to the inlet end pipeline of the precooler, the outlet end of the precooler is connected to the inlet end pipeline of the drying device, the outlet end of the drying device is connected to the first inlet end pipeline of the third heat exchanger, the first outlet end of the third heat exchanger is connected to the inlet end pipeline of the second electric heater, the outlet end of the second electric heater is connected to the inlet end pipeline of the denitrification furnace, the outlet end of the denitrification furnace is connected to the second inlet end pipeline of the third heat exchanger, and the second outlet end of the third heat exchanger is connected to the inlet end pipeline of the fourth heat exchanger;

[0011] Wherein, lithium metal is arranged inside the nitrogen removal furnace.

[0012] Furthermore, it also includes: a precision filter, the inlet end of the precision filter is connected to the outlet end pipeline of the fourth heat exchanger.

[0013] Furthermore, a buffer tank is fixedly connected to the connecting pipeline between the precision filter and the fourth heat exchanger.

[0014] Furthermore, the cooling medium of the second heat exchanger is circulating water.

[0015] Furthermore, the cooling medium of the fourth heat exchanger is circulating water.

[0016] Furthermore, a copper-based catalyst is provided inside the carbon and oxygen removal furnace.

[0017] Furthermore, the first heat exchanger, the second heat exchanger, and the fourth heat exchanger are all shell and tube heat exchangers.

[0018] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0019] The utility model is beneficial to improving the cost-effectiveness of small-flow hydrogen-free argon recovery, reducing equipment prone to failure such as cold boxes and air compressors, thereby reducing equipment investment and maintenance costs, and increasing the extraction rate, stability and safety of the device;

[0020] The design of the utility model focuses more on economic benefits and ease of operation, and is particularly suitable for situations where extreme low temperature conditions are not required. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the process structure of the utility model;

[0022] The accompanying drawings of the present invention are as follows:

[0023] First heat exchanger, 1; carbon and oxygen removal furnace, 2; second heat exchanger, 3; precooler, 4; drying device, 5; third heat exchanger, 6; nitrogen removal furnace, 7; fourth heat exchanger, 8; compressor, 9; first electric heater, 10; second electric heater, 11; precision filter, 12. DETAILED DESCRIPTION

[0024] The specific implementation of the present utility model will be described in detail below.

[0025] Unless otherwise defined, the technical or scientific terms used in the claims and the specification shall have the common meanings understood by persons having ordinary skills in the technical field to which the present invention belongs.

[0026] The words "include" or similar used in the description and claims of this utility model patent application mean that the items before "include" include the items listed after "include" or their equivalents, and do not exclude other items.

[0027] The numerical values ​​mentioned in the present invention include all numerical values ​​increasing from low to high. For example, if a component or a physical quantity is said to be from 1 to 100, 10 to 90 is more preferred, and 20 to 80 is the most preferred, it is intended to express that the numerical values ​​of 5 to 95, 14 to 76, 23 to 67, 32 to 58, 41 to 49, etc. have been clearly listed in this specification; for numerical values ​​less than 1, 0.0001, 0.001, 0.01 or 0.1 are considered to be more appropriate units. The above examples are for illustrative purposes only. In fact, all numerical combinations between the lowest value and the highest value listed are considered to be clearly listed in this specification in a similar manner. Example

[0028] This embodiment provides a non-distillation argon recovery system, comprising: a first heat exchanger 1, a carbon and oxygen removal furnace 2, a second heat exchanger 3, a precooler 4, a drying device 5, a third heat exchanger 6, a nitrogen removal furnace 7, a fourth heat exchanger 8, a compressor 9, a first electric heater 10, and a second electric heater 11;

[0029] The outlet of the compressor 9 is connected to the first inlet pipeline of the first heat exchanger 1, the first outlet of the first heat exchanger 1 is connected to the inlet pipeline of the first electric heater 10, the outlet of the first electric heater 10 is connected to the inlet pipeline of the carbon removal furnace 2, the outlet of the carbon removal furnace 2 is connected to the second inlet pipeline of the first heat exchanger 1, the second outlet of the first heat exchanger 1 is connected to the inlet pipeline of the second heat exchanger 3, the outlet of the second heat exchanger 3 is connected to the inlet pipeline of the precooler 4. The outlet of the precooler 4 is connected to the inlet pipeline of the drying device 5, the outlet of the drying device 5 is connected to the first inlet pipeline of the third heat exchanger 6, the first outlet of the third heat exchanger 6 is connected to the inlet pipeline of the second electric heater 11, the outlet of the second electric heater 11 is connected to the inlet pipeline of the denitrification furnace 7, the outlet of the denitrification furnace 7 is connected to the second inlet pipeline of the third heat exchanger 6, and the second outlet of the third heat exchanger 6 is connected to the inlet pipeline of the fourth heat exchanger 8;

[0030] Wherein, lithium metal is provided inside the nitrogen removal furnace 7, and copper-based catalyst is provided inside the carbon and oxygen removal furnace 2;

[0031] Wherein, the cooling medium of the second heat exchanger 3 is circulating water, and the cooling medium of the fourth heat exchanger 8 is circulating water;

[0032] Wherein, the first heat exchanger 1, the second heat exchanger 3, and the fourth heat exchanger 8 are all shell and tube heat exchangers;

[0033] Wherein: a precision filter 12, the inlet end of the precision filter 12 is connected to the outlet end pipeline of the fourth heat exchanger 8;

[0034] Wherein, a buffer tank is fixedly connected to the connecting pipeline between the precision filter 12 and the fourth heat exchanger 8 .

[0035] During use, the nitrogen-containing contaminated argon gas coming out of the drying device 5 enters the cold medium inlet of the third heat exchanger 6, where it is preheated to about 240°C. The contaminated argon gas then passes through the second electric heater 11, causing the temperature of the contaminated argon gas to reach about 300°C when entering the denitrification furnace. At this time, under high temperature and high pressure, the contaminated argon gas enters the denitrification furnace 7, where the nitrogen-containing contaminated argon gas reacts violently with the lithium metal inside the denitrification furnace 7 to generate lithium nitride solid. When the lithium metal comes into contact with the nitrogen, the lithium atoms first lose electrons to form lithium ions (Li + At the same time, nitrogen molecules are reduced to form nitrogen ions (N 3- ), these ions combine with each other to form lithium nitride crystals, and the reaction can be carried out at room temperature and normal pressure, and the reaction rate will be faster at high temperature and high pressure; the remaining argon gas after being treated by the denitrification furnace 7 comes out of the denitrification furnace 7, enters the hot medium inlet of the third heat exchanger 6 to exchange heat with the cold medium, and the argon gas after heat exchange enters the fourth heat exchanger 8, and uses circulating water as a cooling medium to reduce the argon gas to about 40°C. Finally, it passes through auxiliary equipment such as the product buffer tank and the precision filter 12 to filter out the entrained lithium and lithium nitride powder to obtain pure argon gas.

[0036] In summary, this utility model is beneficial in improving the cost-effectiveness of low-flow hydrogen-free argon recovery, reducing the need for equipment prone to failure, such as cold boxes and air compressors, thereby reducing equipment investment and maintenance costs, and increasing the extraction rate, stability, and safety of the device. The design of this utility model focuses on economic benefits and ease of operation, making it particularly suitable for applications where extreme low-temperature conditions are not required.

[0037] The above description is only a preferred embodiment of the present invention and does not limit the implementation method and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A non-distillation argon recovery system, characterized in that: include: A first heat exchanger (1), a carbon removal furnace (2), a second heat exchanger (3), a precooler (4), a drying device (5), a third heat exchanger (6), a nitrogen removal furnace (7), a fourth heat exchanger (8), a compressor (9), a first electric heater (10), and a second electric heater (11); The outlet of the compressor (9) is connected to the first inlet pipeline of the first heat exchanger (1), the first outlet of the first heat exchanger (1) is connected to the inlet pipeline of the first electric heater (10), the outlet of the first electric heater (10) is connected to the inlet pipeline of the carbon removal furnace (2), the outlet of the carbon removal furnace (2) is connected to the second inlet pipeline of the first heat exchanger (1), the second outlet of the first heat exchanger (1) is connected to the inlet pipeline of the second heat exchanger (3), the outlet of the second heat exchanger (3) is connected to the inlet pipeline of the precooler (4). The outlet of the precooler (4) is connected to the inlet pipeline of the drying device (5), the outlet of the drying device (5) is connected to the first inlet pipeline of the third heat exchanger (6), the first outlet of the third heat exchanger (6) is connected to the inlet pipeline of the second electric heater (11), the outlet of the second electric heater (11) is connected to the inlet pipeline of the denitrification furnace (7), the outlet of the denitrification furnace (7) is connected to the second inlet pipeline of the third heat exchanger (6), and the second outlet of the third heat exchanger (6) is connected to the inlet pipeline of the fourth heat exchanger (8); Wherein, lithium metal is arranged inside the nitrogen removal furnace (7).

2. The non-distillation argon recovery system according to claim 1, characterized in that: Also includes: A precision filter (12), wherein the inlet end of the precision filter (12) is connected to the outlet end pipeline of the fourth heat exchanger (8).

3. The non-rectified argon recovery system according to claim 2, characterized in that: A buffer tank is fixedly connected to the connecting pipeline between the precision filter (12) and the fourth heat exchanger (8).

4. The non-distillation argon recovery system according to claim 1, characterized in that: The cooling medium of the second heat exchanger (3) is circulating water.

5. The non-distillation argon recovery system according to claim 1, characterized in that: The cooling medium of the fourth heat exchanger (8) is circulating water.

6. The non-distillation argon recovery system according to claim 1, characterized in that: A copper-based catalyst is provided inside the carbon removal furnace (2).

7. The non-distillation argon recovery system according to claim 1, characterized in that: The first heat exchanger (1), the second heat exchanger (3), and the fourth heat exchanger (8) are all shell and tube heat exchangers.

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