A type of mass spectrometer for accelerators 14 C-measured atmospheric sample CO2 enrichment and purification system

Abstract

This utility model discloses a method for accelerator mass spectrometry. 14 This invention relates to a CO2 enrichment and purification system for atmospheric samples measured by C, and pertains to the fields of atmospheric chemistry and isotope geochemistry. It includes an atmospheric sample supply unit connected to a first valve, which in turn connects to a second valve. The second valve connects to an enrichment and purification unit, which is connected to a quantification unit via a third valve. The quantification unit is connected to a collection unit via a fourth valve, and the collection unit is connected to a vacuum control unit. The atmospheric sample supply unit is also connected to the vacuum control unit via a separate pipeline. This invention employs multi-stage cryogenic cooling of the atmospheric sample to separate gaseous CO2 from the sample, and uses a cryogenic collection method to obtain pure CO2 gas.

Description

Technical Field

[0001] This invention relates to the fields of atmospheric chemistry and isotope geochemistry, and in particular to a method for accelerator mass spectrometry. 14 CO2 enrichment and purification system for atmospheric samples measured by C. Background Technology

[0002] The significant increase in the concentration of greenhouse gases such as CO2 emitted from anthropogenic sources is the main cause of global warming since the mid-20th century. The combustion of fossil fuels such as coal, oil, and natural gas is the most important anthropogenic source of atmospheric CO2 emissions. Accurately distinguishing and quantifying CO2 emissions from fossil sources is crucial for assessing the effectiveness of carbon reduction achieved through energy structure adjustments. Radioactive carbon isotopes ( 14 C) has a half-life of 5730 years. This is due to the fact that fossil fuels... 14 Carbon has decayed and been depleted; therefore, the CO2 emitted from the combustion of fossil fuels contributes to atmospheric CO2 levels. 14 C content ( 14 The decrease in CO2. Based on this, atmospheric CO2 was analyzed using an accelerator mass spectrometer. 14 High-precision measurement of CO2 content can accurately quantify the fossil (anthropogenic) contribution of CO2 in the atmosphere.

[0003] 14 The natural abundance of C is extremely low, only 1.2 × 10⁻⁶. -12 Therefore, in using accelerator mass spectrometry to determine atmospheric... 14 Before processing CO2, atmospheric samples require enrichment and purification. However, accelerator mass spectrometry (AMS) is primarily used in archaeology and geology. Although it has been increasingly applied to atmospheric science in recent years, there is currently a lack of commercially available equipment for CO2 enrichment and purification in atmospheric samples. This significantly limits the widespread application of AMS technology in atmospheric science, particularly in the study of atmospheric fossil-source CO2. Existing domestic patents also lack devices for CO2 enrichment and purification in atmospheric samples. On the other hand, some patents involve purification devices for CO2 generated from the combustion / reaction of solid samples (including organic and inorganic samples). These designs are primarily for high-concentration, small-volume CO2 samples, which are insufficient to meet the needs of low-concentration, large-volume atmospheric samples. Furthermore, they suffer from limitations such as a single sample introduction pathway and low enrichment and purification efficiency. Utility Model Content

[0004] The purpose of this invention is to provide a mass spectrometer for accelerators. 14The CO2 enrichment and purification system for atmospheric samples measured by C addresses the problems of existing technologies. Based on the principle that different gaseous substances in the atmosphere have different liquefaction or sublimation points at low temperatures, the system performs multi-stage low-temperature cooling on the atmospheric samples to separate CO2 gaseous elements from the atmospheric samples, and further uses low-temperature collection to obtain pure CO2 gas.

[0005] To achieve the above objectives, this utility model provides the following solution:

[0006] This invention provides a method for accelerator mass spectrometry. 14 A CO2 enrichment and purification system for atmospheric samples, measured by C, includes an atmospheric sample supply unit. The outlet of the atmospheric sample supply unit is connected to the inlet of a first valve. The outlet of the first valve is connected to the inlet of a second valve. The outlet of the second valve is connected to the inlet of an enrichment and purification unit. The outlet of the enrichment and purification unit is connected to the inlet of a third valve. The outlet of the third valve is connected to the inlet of a quantitative unit. The outlet of the quantitative unit is connected to the inlet of a fourth valve. The outlet of the fourth valve is connected to the inlet of a collection unit. The outlet of the collection unit is connected to a system with a unique... The vacuum control unit with airflow interruption function has an air inlet; the air outlet of the atmospheric sample supply unit is also connected to the air inlet of the sixth valve, and the air outlet of the sixth valve is connected to the air inlet of the vacuum control unit; the atmospheric sample supply unit includes at least one sample bottle, at least one gas delivery pipe and at least one gas delivery valve, the sample bottle, the gas delivery pipe and the gas delivery valve are arranged in a group, the air outlet of the sample bottle is connected to the air inlet of the gas delivery pipe, the air outlet of the gas delivery pipe is connected to the air inlet of the gas delivery valve, and the air outlet of the gas delivery valve serves as the air outlet of the atmospheric sample supply unit.

[0007] In one embodiment, the atmospheric sample supply unit includes 1 to 12 sample bottles, 1 to 12 gas delivery pipes, and 1 to 12 gas delivery valves. Each group includes one sample bottle, one gas delivery pipe, and one gas delivery valve. The outlet end of the gas delivery valve is connected to the same outlet pipe, and the outlet end of the outlet pipe serves as the outlet end of the atmospheric sample supply unit.

[0008] In one embodiment, the enrichment and purification unit includes at least two collectors connected in series. The inlet of the first collector in series serves as the inlet of the enrichment and purification unit, and the outlet of the last collector in series serves as the outlet of the enrichment and purification unit. A flow meter is installed at the inlet of the enrichment and purification unit. When there are two collectors, the cooling device for the first collector in series is an ethanol-liquid nitrogen cold trap cup, and the cooling device for the second collector in series is a liquid nitrogen cold trap cup. When there are more than two collectors, the cooling devices for the first and last collectors in series are ethanol-liquid nitrogen cold trap cups, and the cooling devices for the other collectors in series are liquid nitrogen cold trap cups.

[0009] In one embodiment, there are four collectors, including a primary collector, a secondary collector, a tertiary collector, and a quaternary collector, which are connected in series. There are four cold trap cups, including a primary ethanol-liquid nitrogen cold trap cup for holding the primary collector, a primary liquid nitrogen cold trap cup for holding the secondary collector, a secondary liquid nitrogen cold trap cup for holding the tertiary collector, and a secondary ethanol-liquid nitrogen cold trap cup for holding the quaternary collector. A collection valve is provided between the primary collector and the secondary collector.

[0010] In one embodiment, the metering unit includes a main pipe, the air inlet of the main pipe being the air inlet of the metering unit, the air outlet of the main pipe being the air outlet of the metering unit, the air inlet of the pressure gauge being connected to the main pipe, and the air inlet of the metering tube being connected to the main pipe; it also includes a metering unit cold trap cup for holding the metering tube.

[0011] In one embodiment, the collection unit includes a collection pipe, with the inlet end of the collection pipe serving as the air inlet end of the collection unit and the outlet end of the collection pipe serving as the air outlet end of the collection unit. The collection unit further includes at least one test sample collection tube and at least one backup sample collection tube, the number of which is the same. The air inlet end of the test sample collection tube is connected to the collection pipe, and a test sample collection valve is provided between the test sample collection tube and the collection pipe. The air inlet end of the backup sample collection tube is connected to the collection pipe, and a backup sample collection valve is provided between the backup sample collection tube and the collection pipe. The collection unit also includes a cold trap cup for holding the test sample collection tube and the backup sample collection tube.

[0012] In one embodiment, the number of test sample collection tubes is 1 to 12, and the number of backup sample collection tubes is 1 to 12.

[0013] In one embodiment, the vacuum control unit includes a first vacuum gauge, a second vacuum gauge, a molecular pump, and a primary pump. The outlet of the collection unit is connected to the inlet of a fifth valve and the inlet of a seventh valve, respectively. The outlet of the fifth valve is connected to the inlet of the first vacuum gauge. The outlet of the first vacuum gauge is connected to the inlet of a ninth valve. The outlet of the second vacuum gauge is connected to the inlet of the primary pump. The outlet of the primary pump is connected to the inlet of an eighth valve. The outlet of the eighth valve is connected to the inlet of the molecular pump.

[0014] In one embodiment, the outlet of the collection unit, the inlet of the fifth valve, and the inlet of the seventh valve are connected by a three-way pipe; the outlet of the seventh valve, the inlet of the second vacuum gauge, and the outlet of the sixth valve are connected by a three-way pipe; and the outlet of the eighth valve, the outlet of the ninth valve, and the inlet of the molecular pump are connected by a three-way pipe.

[0015] In one embodiment, the outlet of the first valve, the inlet of the second valve, and the inlet of the sixth valve are connected by a T-junction.

[0016] The present invention achieves the following technical advantages over the prior art:

[0017] This invention provides a method for accelerator mass spectrometry. 14The CO2 enrichment and purification system for atmospheric samples measured by C is based on the principle that different gaseous substances in the atmosphere have different liquefaction or sublimation points at low temperatures. It performs multi-stage low-temperature cooling on the atmospheric samples to separate gaseous CO2 from the samples, and further uses low-temperature collection to obtain pure dry ice. In this invention, atmospheric sample bottles are used to hold atmospheric samples collected from different areas. The vacuum control unit is used to extract gas from the system, creating a near-vacuum environment within the system to ensure the flow of atmospheric samples. The vacuum control unit is also used to discharge separated water vapor and other non-CO2 gases. The enrichment and purification unit uses temperature zone control to separate the dry ice formed by CO2 sublimation from the ice crystals formed by water vapor sublimation. The dry ice is then reduced back to CO2 gas, completing the CO2 enrichment and purification. During this process, gaseous substances that will not liquefy or sublimate are extracted and separated. The quantitative unit first converts CO2 gas into dry ice at low temperatures, maintaining a low-pressure state within the quantitative unit so that CO2 gas can continuously enter the unit. After collection, the inlet and outlet of the quantitative unit are sealed, and the unit is allowed to return to room temperature, allowing all the dry ice to be converted into CO2 gas. The amount of carbon in the collected CO2 is calculated by measuring the gas pressure. Then, the quantitative unit and the collection unit are connected. The collection unit is kept at a low temperature, and the CO2 gas entering the collection unit is captured and converted into dry ice. The pressure inside the collection unit remains lower than that inside the quantitative unit, allowing the CO2 gas to diffuse continuously. Quantitative collection of CO2 is achieved by monitoring changes in the pressure gauge reading. After collection, the collection unit is returned to room temperature, allowing the dry ice to convert back into CO2 gas for subsequent analysis. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a system structure without a cold trap cup, a metering unit cold trap cup, and a collection unit cold trap cup in an embodiment of this utility model;

[0020] Figure 2 This is a schematic diagram of a system structure for setting a cold trap cup in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of a system structure with a quantitative unit cold trap cup in an embodiment of the present invention;

[0022] Figure 4This is a schematic diagram of a system structure with a cold trap cup for collecting units according to an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the structure of a collector according to an embodiment of the present utility model;

[0024] Figure 6 This is a half-sectional structural diagram of a cold trap cup, a quantitative unit cold trap cup, or a collection unit cold trap cup in an embodiment of this utility model.

[0025] Among them, 1. Atmospheric sample supply unit; 101. Sample bottle; 102. Gas delivery pipe; 103. Gas delivery valve;

[0026] 2. First valve;

[0027] 3. Second valve;

[0028] 4. Enrichment and purification unit; 401. Flow meter; 402. Primary collector; 403. Secondary collector; 404. Tertiary collector; 405. Quaternary collector; 406. Primary ethanol-liquid nitrogen cold trap cup; 407. Primary liquid nitrogen cold trap cup; 408. Secondary liquid nitrogen cold trap cup; 409. Secondary ethanol-liquid nitrogen cold trap cup; 410. Collection valve; 411. Isolation tube; 412. Threaded part;

[0029] 5. Third valve;

[0030] 6. Metering unit; 601. Main pipe; 602. Pressure gauge; 603. Metering tube; 604. Metering unit cold trap cup;

[0031] 7. Fourth valve;

[0032] 8. Collection unit; 801. Test sample collection tube; 802. Backup sample collection tube; 803. Test sample collection valve; 804. Backup sample collection valve; 805. Collection unit cold trap cup;

[0033] 9. Fifth valve;

[0034] 10. First vacuum gauge;

[0035] 11. Molecular pump;

[0036] 12. The sixth valve;

[0037] 13. Second vacuum gauge;

[0038] 14. Primary pump;

[0039] 15. Seventh valve;

[0040] 16. Eighth valve;

[0041] 17. Cup body;

[0042] 18. Internal cavity;

[0043] 19. Ninth valve;

[0044] 20. Vacuum control unit. Detailed Implementation

[0045] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0046] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the implementation of this utility model and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this utility model, should still fall within the scope of the technical content disclosed herein. In the description of this utility model, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are merely for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Therefore, features specified with "first," "second," etc., may explicitly or implicitly include one or more of those features. In the description of this utility model, unless otherwise stated, "multiple" means two or more.

[0047] It should also be noted that in the embodiments of this application, the same reference numerals are used to denote the same component or the same part.

[0048] The purpose of this invention is to provide a mass spectrometer for accelerators. 14The CO2 enrichment and purification system for atmospheric samples measured by C addresses the problems of existing technologies. Based on the principle that different gaseous substances in the atmosphere have different liquefaction or sublimation points at low temperatures, the system performs multi-stage low-temperature cooling on the atmospheric samples to separate CO2 gaseous elements from the atmospheric samples, and further uses low-temperature collection to obtain pure dry ice elements.

[0049] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] like Figures 1-6 As shown, this utility model provides a method for accelerator mass spectrometry. 14 The atmospheric sample CO2 enrichment and purification system for measurement includes an atmospheric sample supply unit 1. The outlet of the atmospheric sample supply unit 1 is connected to the inlet of a first valve 2. The outlet of the first valve 2 is connected to the inlet of a second valve 3. The outlet of the second valve 3 is connected to the inlet of an enrichment and purification unit 4. The outlet of the enrichment and purification unit 4 is connected to the inlet of a third valve 5. The outlet of the third valve 5 is connected to the inlet of a quantitative unit 6. The outlet of the quantitative unit 6 is connected to the inlet of a fourth valve 7. The outlet of the fourth valve 7 is connected to the inlet of a collection unit 8. The outlet of the collection unit 8 is connected to the inlet of a vacuum control unit 20 with independent airflow control function. The outlet of the atmospheric sample supply unit 1 is also connected to the inlet of a sixth valve 12, and the outlet of the sixth valve 12 is connected to the inlet of the vacuum control unit 20. The atmospheric sample supply unit 1 includes at least one sample bottle 101, at least one gas supply pipe 102, and at least one gas supply valve 103. The sample bottle 101, gas supply pipe 102, and gas supply valve 103 are arranged in a group. The outlet of the sample bottle 101 is connected to the inlet of the gas supply pipe 102, and the outlet of the gas supply pipe 102 is connected to the inlet of the gas supply valve 103. The outlet of the gas supply valve 103 serves as the outlet of the atmospheric sample supply unit 1.

[0051] Working principle:

[0052] This utility model provides a mass spectrometer for accelerators. 14The atmospheric sample CO2 enrichment and purification system measured by C utilizes the principle that different gaseous substances in the atmosphere have different liquefaction or sublimation points at low temperatures. It performs multi-stage low-temperature cooling on the atmospheric sample to separate elemental CO2 from the sample, and further uses low-temperature collection to obtain pure dry ice. The atmospheric sample released from the atmospheric sample supply unit 1 first enters the enrichment and purification unit 4, where elemental CO2 is separated. Then, the elemental CO2 enters the quantification unit 6 to determine the enrichment amount. Next, the elemental CO2 enters the collection unit 8 for collection. After collection, the collection unit 8 returns to room temperature, allowing the dry ice to convert into CO2 gas for subsequent analysis. The vacuum control unit 20 is used to extract gas from the system, creating a near-vacuum environment within the system to ensure the flow of the atmospheric sample. The vacuum control unit 20 also removes separated water vapor and other non-CO2 gases.

[0053] This utility model includes the following steps:

[0054] ①System evacuation

[0055] Without loading sample vial 101 and ensuring the gas inlet of gas supply pipe 102 is sealed, open gas supply valve 103, first valve 2, second valve 3, third valve 5, fourth valve 7, and sixth valve 12, and activate vacuum control unit 20 to begin evacuating the gas inside the system until the vacuum level measurement value of vacuum control unit 20 drops to 5*10. -3 millibar.

[0056] ② Loading samples

[0057] The sample vial 101 is loaded onto the gas supply pipe 102. This loading process will disrupt the original seal of the gas supply pipe 102, allowing air to enter. To prevent air from re-entering the main system pipeline, it is necessary to close the first valve 2 and the second valve 3 after step ①, then load the sample vial 101, ensuring the vial opening is not open, and disconnect the vacuum control unit 20 from the collection unit 8 to prevent gas backflow. After completing the above operations, slowly open the first valve 2. The vacuum control unit 20 will then directly evacuate the atmospheric sample supply unit 1. The vacuum measurement value of the vacuum control unit 20 should not exceed 5*10⁻⁶. -3 millibar.

[0058] ③ Enrichment and purification

[0059] Based on step ②, adjust the opening and closing states of each valve to ensure that only the atmospheric sample supply unit 1, enrichment and purification unit 4, quantification unit 6, collection unit 8, and vacuum control unit 20 are sequentially connected. It is important to note that only one sample bottle 101 is supplied with gas during each collection process until all atmospheric sample in that bottle is exhausted and collected. The atmospheric sample supply unit 1 provides the sample to the enrichment and purification unit 4. The enrichment and purification unit 4 employs temperature zone control to separate the dry ice formed by CO2 gas sublimation from the ice formed by water vapor sublimation. The dry ice is then reduced back to elemental CO2 gas, completing the enrichment and purification of CO2.

[0060] Before reducing dry ice to elemental CO2, the vacuum control unit 20 is kept connected to the enrichment and purification unit 4, and the gas components that cannot be liquefied or sublimated are extracted from the enrichment and purification unit 4. The method of gradually reducing dry ice to CO2 gas is to keep the CO2 collector at room temperature, and close the collection valve 410 and the third valve 5 just before the reduction begins to prevent the obtained elemental CO2 gas from being extracted.

[0061] ④ Quantitative measurement

[0062] Before collecting elemental CO2 gas, based on step ③, first close the fourth valve 7, then open the third valve 5. During CO2 gas collection, the temperature of the collecting device in the quantitative unit 6 is below the sublimation point of CO2 gas, resulting in dry ice. Because the gas in the collecting device of the quantitative unit 6 is continuously converted into a solid state, the gas pressure in the collecting device of the quantitative unit 6 is low, allowing CO2 gas in the enrichment and purification unit 4 to spontaneously flow into the quantitative unit 6. After collection is complete, close the third valve 5. At this point, the quantitative unit 6 is an independent sealed structure, keeping the collecting device of the quantitative unit 6 at room temperature until the dry ice is completely converted into gas and the temperature returns to room temperature. Measure the pressure of the captured CO2 gas at room temperature, and calculate the carbon content of the CO2 based on the measurement results.

[0063] After closing the third valve 5, the seventh valve 15 can be closed and the sixth valve 12 can be opened. At the same time, the ice that is still in solid state in the enrichment and purification unit 4 is converted into water vapor, which can be extracted from the air inlet of the enrichment and purification unit 4 by the vacuum control unit 20.

[0064] ⑤ Collect CO2

[0065] Based on step ④, the valve opening and closing status is adjusted so that the metering unit 6 and the collecting unit 8 form an internally connected, sealed environment. Elemental CO2 gas from the metering unit 6 enters the collecting unit 8. Since the temperature of the collecting unit 8 is below the sublimation point of CO2 gas, the elemental CO2 gas entering the collecting unit 8 is converted into dry ice. Because the gas in the collecting unit 8 is continuously converted into a solid state, the gas pressure in the collecting unit 8 is low, allowing the CO2 gas in the metering unit 6 to spontaneously flow into the collecting unit 8. After collection is complete, the collecting unit 8 returns to room temperature, causing the dry ice to convert back into CO2.

[0066] After CO2 is lost from the quantitative unit 6, the gas pressure in its collection device will decrease. The volume of gas lost (carbon content) can be determined by the pressure reduction value.

[0067] ⑥ Determine the system status

[0068] When the vacuum level measurement value of the second vacuum gauge 13 of the vacuum control unit 20 decreases to 5*10 -2 When the concentration reaches millibars, it can be determined that the water vapor emission in enrichment and purification unit 4 has met the requirements, and step ① can be repeated.

[0069] In one embodiment, the gas flow rate of the atmospheric sample is monitored by flow meter 401 at a flow rate of 250 ml per minute.

[0070] In one embodiment, the atmospheric sample supply unit 1 includes 1 to 12 sample bottles 101, 1 to 12 gas supply pipes 102, and 1 to 12 gas supply valves 103. Each group includes one sample bottle 101, one gas supply pipe 102, and one gas supply valve 103. The outlet end of the gas supply valve 103 is connected to the same outlet pipe, and the outlet end of the outlet pipe serves as the outlet end of the atmospheric sample supply unit 1. Preferably, each sample bottle 101 is supplied with gas independently, and the gas supply is switched to other sample bottles 101 after the atmospheric sample in one sample bottle 101 has been collected. Preferably, the number of sample bottles 101, gas supply pipes 102, and gas supply valves 103 are all 5.

[0071] In one embodiment, the enrichment and purification unit 4 includes at least two collectors connected in series. The inlet end of the first collector connected in series serves as the inlet end of the enrichment and purification unit 4, and the outlet end of the last collector connected in series serves as the outlet end of the enrichment and purification unit 4. A flow meter 401 is installed at the inlet end of the enrichment and purification unit 4. When there are two collectors, the cooling device for the first collector connected in series is an ethanol-liquid nitrogen cold trap cup, and the cooling device for the second collector connected in series is a liquid nitrogen cold trap cup. When there are more than two collectors, the cooling devices for the first and last collectors connected in series are ethanol-liquid nitrogen cold trap cups, and the cooling devices for the other collectors connected in series are liquid nitrogen cold trap cups.

[0072] In one embodiment, there are four collectors, including a primary collector 402, a secondary collector 403, a tertiary collector 404, and a quaternary collector 405, which are connected in series. There are also four cold trap cups, including a primary ethanol-liquid nitrogen cold trap cup 406 for holding the primary collector 402, a primary liquid nitrogen cold trap cup 407 for holding the secondary collector 403, a secondary liquid nitrogen cold trap cup 408 for holding the tertiary collector 404, and a secondary ethanol-liquid nitrogen cold trap cup 409 for holding the quaternary collector 405. A collection valve 410 is provided between the primary collector 402 and the secondary collector 403. The primary ethanol-liquid nitrogen cold trap cup 406 and the secondary ethanol-liquid nitrogen cold trap cup 409 contain a mixture of ethanol and liquid nitrogen at a temperature of approximately -80 degrees Celsius. These cups are used to capture other atmospheric components, primarily water vapor. The primary liquid nitrogen cold trap cup 407 and the secondary liquid nitrogen cold trap cup 408 contain liquid nitrogen at a temperature of approximately -196 degrees Celsius and are used to capture CO2. The collection valve 410 isolates the primary collector 402 from the secondary collector 403. Since the primary collector 402 is in direct contact with the original atmospheric sample and can capture a large amount of water vapor, the collection valve 410 can be closed to isolate the primary collector 402 from the water vapor present during the reduction of the captured dry ice to CO2.

[0073] In one embodiment, the collecting pipe includes an isolation pipe 411 and a threaded portion 412. The isolation pipe 411 is disposed outside the threaded portion 412 for protection. The threaded portion 412 has a coiled thread structure. The air inlet and outlet of the threaded portion 412 are the air inlet and outlet of the collecting pipe. The threaded portion 412 can extend the gas flow distance within a limited arrangement length.

[0074] In one embodiment, the metering unit 6 includes a main pipe 601, the air inlet of the main pipe 601 is the air inlet of the metering unit 6, the air outlet of the main pipe 601 is the air outlet of the metering unit 6, the air inlet of the pressure gauge 602 is connected to the main pipe 601, the air inlet of the metering tube 603 is connected to the main pipe 601, and also includes a metering unit cold trap cup 604 for holding the metering tube 603.

[0075] In one embodiment, liquid nitrogen is contained within the metering unit cold trap cup 604.

[0076] In one embodiment, the collection unit 8 includes a collection pipe, with the inlet end of the collection pipe serving as the air inlet end of the collection unit 8 and the outlet end of the collection pipe serving as the air outlet end of the collection unit 8. The collection unit 8 also includes at least one test sample collection tube 801 and at least one backup sample collection tube 802, with the number of test sample collection tubes 801 and backup sample collection tubes 802 being the same. The air inlet end of the test sample collection tube 801 is connected to the collection pipe, and a test sample collection valve 803 is provided between the test sample collection tube 801 and the collection pipe. The air inlet end of the backup sample collection tube 802 is connected to the collection pipe, and a backup sample collection valve 804 is provided between the backup sample collection tube 802 and the collection pipe. The collection unit 8 also includes a collection unit cold trap cup 805 for holding the test sample collection tube 801 and the backup sample collection tube 802. The test sample collection tube 801 and the backup sample collection tube 802 are used in pairs, with only one set used per collection. The test sample collection tube 801 needs to collect CO2 equivalent to 1 milligram of carbon, and the corresponding backup sample collection tube 802 should also collect CO2 equivalent to 1 milligram of carbon. However, if the quantitative unit 6 cannot provide enough CO2 after the test sample collection tube 801 has collected CO2, then the corresponding backup sample collection tube 802 can collect all the collectable CO2. After collection, the openings of the test sample collection tube 801 and the backup sample collection tube 802 are sealed. Preferably, the openings are sealed with a flame seal.

[0077] In one embodiment, the number of test sample collection tubes 801 is 1 to 12, and the number of backup sample collection tubes 802 is 1 to 12. Preferably, the number of both test sample collection tubes 801 and backup sample collection tubes 802 is 5.

[0078] In one embodiment, the cold trap cup 805 of the collection unit contains liquid nitrogen.

[0079] In one embodiment, the cold trap cup, the metering unit cold trap cup 604, or the collecting unit cold trap cup 805 is a cup body 17 with an inner cavity 18.

[0080] In one embodiment, the vacuum control unit 20 includes a first vacuum gauge 10, a second vacuum gauge 13, a molecular pump 11, and a primary pump 14. The outlet of the collection unit 8 is connected to the inlet of the fifth valve 9 and the inlet of the seventh valve 15, respectively. The outlet of the fifth valve 9 is connected to the inlet of the first vacuum gauge 10, and the outlet of the first vacuum gauge 10 is connected to the inlet of the ninth valve 19. The outlet of the second vacuum gauge 13 is connected to the inlet of the primary pump 14, and the outlet of the primary pump 14 is connected to the inlet of the eighth valve 16. The outlet of the eighth valve 16 is connected to the inlet of the molecular pump 11. The molecular pump 11 can operate independently or simultaneously with the primary pump 14. The primary pump 14 is located at the inlet of the molecular pump 11 to protect it. When the pumped gas flow contains large molecular gases such as nitrogen or water vapor, the airflow can be controlled by the on / off states of the eighth valve 16 and the ninth valve 19 to pass through the primary pump 14 first and then through the molecular pump 11, thus preventing water droplets from damaging the molecular pump 11. The first vacuum gauge 10 and the second vacuum gauge 13 can independently measure the vacuum level, and can ensure accurate measurement results regardless of which pipeline is used for evacuation.

[0081] In one embodiment, the outlet of the collection unit 8, the inlet of the fifth valve 9, and the inlet of the seventh valve 15 are connected by a three-way pipe; the outlet of the seventh valve 15, the inlet of the second vacuum gauge 13, and the outlet of the sixth valve 12 are connected by a three-way pipe; and the outlet of the eighth valve 16, the outlet of the ninth valve 19, and the inlet of the molecular pump 11 are connected by a three-way pipe.

[0082] In one embodiment, the molecular pump 11 may be a turbomolecular pump.

[0083] In one embodiment, the primary pump 14 may be an oil-free diaphragm vacuum pump.

[0084] In one embodiment, the outlet of the first valve 2, the inlet of the second valve 3, and the inlet of the sixth valve 12 are connected by a three-way pipe.

[0085] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "connected," and "connected" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integrated connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to connections within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0086] If this utility model discloses or relates to mutually fixed and connected parts or structural components, then, unless otherwise stated, fixed connection can be understood as: a fixed connection that can be detached (e.g., a connection using bolts or screws), or a fixed connection that cannot be detached (e.g., riveting, welding). Of course, mutually fixed connection can also be replaced by an integral structure (e.g., manufactured by integral molding using a casting process) (except where it is obviously impossible to use an integral molding process).

[0087] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in this utility model above include states or shapes that are similar to, close to, or approximate with them.

[0088] Any component provided by this utility model can be assembled from multiple individual components, or it can be a single component manufactured by a one-piece molding process.

[0089] Any adaptive changes made according to actual needs are within the protection scope of this utility model.

[0090] It should be noted that, for those skilled in the art, it is obvious that this utility model is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this utility model is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0091] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A system for accelerator mass spectrometry 14 A system for atmospheric sample CO2 enrichment purification measured by C, characterized by: It includes an atmospheric sample supply unit (1), the outlet of which is connected to the inlet of a first valve (2), the outlet of which is connected to the inlet of a second valve (3), the outlet of which is connected to the inlet of an enrichment and purification unit (4), the outlet of which is connected to the inlet of a third valve (5), the outlet of which is connected to the inlet of a quantitative unit (6), the outlet of which is connected to the inlet of a fourth valve (7), the outlet of which is connected to the inlet of a collection unit (8), and the outlet of which is connected to the inlet of a vacuum control unit (20) with independent airflow control function. The outlet of the atmospheric sample supply unit (1) is also connected to the inlet of the sixth valve (12), and the outlet of the sixth valve (12) is connected to the inlet of the vacuum control unit (20). The atmospheric sample supply unit (1) includes at least one sample bottle (101), at least one gas supply pipe (102), and at least one gas supply valve (103). The sample bottle (101), the gas supply pipe (102), and the gas supply valve (103) are arranged in a group. The outlet of the sample bottle (101) is connected to the inlet of the gas supply pipe (102), the outlet of the gas supply pipe (102) is connected to the inlet of the gas supply valve (103), and the outlet of the gas supply valve (103) serves as the outlet of the atmospheric sample supply unit (1).

2. The system for accelerator mass spectrometry of claim 1, wherein: 14 A system for atmospheric sample CO2 enrichment purification measured by C, characterized in that: The atmospheric sample supply unit (1) includes 1 to 12 sample bottles (101), 1 to 12 gas supply pipes (102), and 1 to 12 gas supply valves (103). Each group includes one sample bottle (101), one gas supply pipe (102), and one gas supply valve (103). The outlet end of the gas supply valve (103) is connected to the same outlet pipe, and the outlet end of the outlet pipe serves as the outlet end of the atmospheric sample supply unit (1).

3. The system for accelerator mass spectrometry of claim 1, wherein: 14 A system for purifying atmospheric sample CO2 enrichment measured by C, characterized in that: The enrichment and purification unit (4) includes at least two collectors connected in series. The inlet end of the first collector connected in series serves as the inlet end of the enrichment and purification unit (4), and the outlet end of the last collector connected in series serves as the outlet end of the enrichment and purification unit (4). A flow meter (401) is installed at the inlet end of the enrichment and purification unit (4). When there are two collectors, the cooling device for the first collector connected in series is an ethanol-liquid nitrogen cold trap cup, and the cooling device for the second collector connected in series is a liquid nitrogen cold trap cup. When there are more than two collectors, the first and last collectors connected in series are cooled by ethanol-liquid nitrogen cold trap cups, and the other collectors connected in series are cooled by liquid nitrogen cold trap cups.

4. The system for accelerator mass spectrometry of claim 3, wherein: 14 A system for purifying atmospheric sample CO2 enrichment measured by C, characterized in that: The collectors are four in number, including a primary collector (402), a secondary collector (403), a tertiary collector (404), and a quaternary collector (405), which are connected in series. The cold trap cups are four in total, including a primary ethanol-liquid nitrogen cold trap cup (406) for holding the primary collector (402), a primary liquid nitrogen cold trap cup (407) for holding the secondary collector (403), a secondary liquid nitrogen cold trap cup (408) for holding the tertiary collector (404), and a secondary ethanol-liquid nitrogen cold trap cup (409) for holding the quaternary collector (405). A collection valve (410) is provided between the primary collector (402) and the secondary collector (403).

5. The system for accelerator mass spectrometry of claim 1, wherein the system is configured to perform the method of claim 1. 14 A system for atmospheric sample CO2 enrichment purification measured by C, characterized in that: The metering unit (6) includes a main pipe (601), the air inlet of the main pipe (601) is the air inlet of the metering unit (6), the air outlet of the main pipe (601) is the air outlet of the metering unit (6), the air inlet of the pressure gauge (602) is connected to the main pipe (601), and the air inlet of the metering tube (603) is connected to the main pipe (601). It also includes a metering unit cold trap cup (604) for holding the metering tube (603).

6. The system for accelerator mass spectrometry of claim 1, wherein: 14 A system for purifying atmospheric sample CO2 enrichment measured by C, characterized in that: The collection unit (8) includes a collection pipe, the air inlet end of the collection pipe is the air inlet end of the collection unit (8), and the air outlet end of the collection pipe is the air outlet end of the collection unit (8). The collection unit (8) further includes at least one test sample collection tube (801) and at least one backup sample collection tube (802), the number of test sample collection tubes (801) and backup sample collection tubes (802) is the same, the air inlet end of the test sample collection tube (801) is connected to the collection pipe, a test sample collection valve (803) is provided between the test sample collection tube (801) and the collection pipe, the air inlet end of the backup sample collection tube (802) is connected to the collection pipe, and a backup sample collection valve (804) is provided between the backup sample collection tube (802) and the collection pipe; The collection unit (8) also includes a collection unit cold trap cup (805) for holding the test sample collection tube (801) and the backup sample collection tube (802).

7. The system for accelerator mass spectrometry of claim 6, wherein: 14 A system for purifying atmospheric sample CO2 enrichment measured by C, characterized in that: The number of test sample collection tubes (801) is 1 to 12, and the number of backup sample collection tubes (802) is 1 to 12.

8. The system for accelerator mass spectrometry of claim 1, wherein: 14 A system for purifying atmospheric sample CO2 enrichment measured by C, characterized in that: The vacuum control unit (20) includes a first vacuum gauge (10), a second vacuum gauge (13), a molecular pump (11), and a primary pump (14). The outlet of the collection unit (8) is connected to the inlet of the fifth valve (9) and the inlet of the seventh valve (15), respectively. The outlet of the fifth valve (9) is connected to the inlet of the first vacuum gauge (10). The outlet of the first vacuum gauge (10) is connected to the inlet of the ninth valve (19). The outlet of the second vacuum gauge (13) is connected to the inlet of the primary pump (14). The outlet of the primary pump (14) is connected to the inlet of the eighth valve (16). The outlet of the eighth valve (16) is connected to the inlet of the molecular pump (11).

9. The system for accelerator mass spectrometry of claim 8, wherein the system is configured to perform the method of claim 1. 14 A system for atmospheric sample CO2 enrichment purification measured by C, characterized in that: The air outlet of the collection unit (8), the air inlet of the fifth valve (9) and the air inlet of the seventh valve (15) are connected by a three-way pipe. The outlet of the seventh valve (15), the inlet of the second vacuum gauge (13), and the outlet of the sixth valve (12) are connected by a three-way pipe. The outlet of the eighth valve (16), the outlet of the ninth valve (19), and the inlet of the molecular pump (11) are connected by a three-way pipe.

10. The system for accelerator mass spectrometry of claim 1, wherein: 14 A system for purifying atmospheric sample CO2 enrichment measured by C, characterized in that: The outlet of the first valve (2), the inlet of the second valve (3), and the inlet of the sixth valve (12) are connected by a three-way pipe.

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