A multi-mode enrichment analysis device and process for detecting xenon background in air

Abstract

The application discloses a multi-mode enrichment analysis device and process capable of detecting xenon background in air, which comprises a gas taking and enrichment unit, a pressurized adsorption, vacuum desorption and reverse desorption purification and concentration unit connected with each other through a gas flow pipeline and a refrigerator for realizing shallow low temperature. The application controls the adsorption temperature of the refrigerator to be-28 DEG C to 18 DEG C, raises the tail pressure of each xenon separation column, and increases the dynamic adsorption coefficient of each xenon separation column from 0.43 L / g under normal temperature and pressure to 1.2-3.4 L / g, thereby improving the adsorption efficiency and reducing the adsorbent loading amount of each xenon separation column under the determined gas volume. Through vacuum desorption and reverse desorption, the carrier gas volume of complete desorption can be reduced from 8-20 times the desorption volume to 3-5 times, thereby improving the desorption efficiency. The column filler loading surplus can be increased from about 30% to 50-300%, thereby greatly improving the stability and reliability of the device, and realizing self-adaption of the filler usage amount to the gas taking amount, which can meet the needs of high-sensitivity large-volume sampling monitoring and sensitive and rapid sampling monitoring.

Description

Technical Field

[0001] This invention relates to a device for monitoring radioactive xenon in the air, and in particular to a multi-mode enrichment analysis device and process for detecting background xenon in the air. The device uses filtration and membrane separation to remove impurities to obtain high-purity nitrogen, which is then subjected to multi-stage separation, purification and concentration to detect and analyze the obtained pure xenon. Background Technology

[0002] Nuclear activities at nuclear facilities such as reactors, nuclear power plants, and nuclear tests inevitably produce radioactive xenon isotopes, which may leak into the air. Monitoring characteristic radionuclides is a necessary measure to ensure the safety of nuclear activities at nuclear facilities and their environment. Radioactivity in ambient air... 133 Xe has a low background, typically only about 0.2 mBq / m 3 Xenon sampling and monitoring is highly sensitive and has been proven to be an effective means of monitoring radioactive leaks from nuclear facilities and obtaining evidence of nuclear incidents. Xenon is a rare inert gas, accounting for only 0.087 ppm in the air. Before detection, air samples need to be concentrated and enriched to remove impurities that interfere with source preparation and radioactivity measurement, resulting in a small volume of sample gas for radioactivity activity measurement and total xenon concentration analysis.

[0003] However, the existing devices and methods for enriching radioactive xenon in air have the following problems:

[0004] 1. The enrichment method employs forward adsorption and forward desorption, which severely limits the amount of adsorbent loaded in the xenon separation column. Furthermore, it cannot automatically adjust the adsorbent dosage based on the volume of the incoming raw gas. This makes the equipment unsuitable for long-term, large-volume sampling enrichment and high-frequency, rapid sampling enrichment. Consequently, the equipment struggles to adapt to different sampling volumes or monitoring frequencies, failing to achieve a seamless integration of highly sensitive sampling and monitoring of xenon in the air with rapid emergency monitoring. Additionally, the forward adsorption and forward desorption method limits the adsorbent loading, affecting the long-term stability and reliability of the device's performance indicators and increasing maintenance frequency and operating costs.

[0005] 2. In existing xenon separation and purification devices, a considerable number of pipeline components and instruments need to withstand the impact of hot and cold operating conditions, which is detrimental to maintaining the airtightness of the gas path and affects the reliability of the device performance.

[0006] 3. Since pressurized adsorption and vacuum desorption are not achieved, the adsorption and desorption efficiencies are not high enough. Therefore, the performance requirements of the adsorbent are high, the amount used is large, the equipment size is large, and the energy consumption of sampling and monitoring work is increased.

[0007] 4. The sampling and monitoring sensitivity of radioactive xenon in the air is insufficient, making it difficult to carry out routine monitoring of the background of radioactive xenon in the air. Therefore, the early warning capability for radioactive xenon leakage in nuclear accidents is insufficient.

[0008] Therefore, in order to solve the above-mentioned technical problems, the present invention proposes a multi-mode enrichment analysis device and process for detecting xenon background in air. Summary of the Invention

[0009] The purpose of this invention is to provide a multi-mode enrichment analysis device and process for detecting xenon background in air, thereby solving some of the problems existing in the prior art described in the background section.

[0010] To achieve the above objectives, this invention proposes a multi-mode enrichment analysis device for detecting xenon background in air. Its features include a gas sampling and enrichment unit, a purification and concentration unit interconnected via gas flow pipelines (forward pressurization adsorption, vacuum desorption, and reverse desorption), and a refrigerator providing a shallow low-temperature adsorption environment and protecting the pipeline components. The gas sampling and enrichment unit includes an air compressor connected to a sampling head via a pipe, a refrigerated dryer connected to the air compressor via a pipe, a three-stage gas filtration mechanism connected to the refrigerated dryer via a pipe, and several series-connected polyimide hollow fiber membrane separators connected to the three-stage gas filtration mechanism via pipes. The purification and concentration unit comprises at least three stages of progressively larger purification and concentration units, with each polyimide hollow fiber membrane separator connected to the first purification and concentration unit via a pipeline. Each purification and concentration unit is also connected to one or more gas flow pipelines, with at least one gas flow pipeline for interconnection between the purification and concentration units at each stage. Each purification and concentration unit also includes at least one unit filled with adsorbent. The xenon separation column is connected via a gas flow pipeline to a buffer mechanism consisting of several buffer tanks connected in series, used for xenon purification and concentration. The xenon separation column and buffer mechanism are also connected to a vacuum pump via the gas flow pipeline. Valves controlling the gas flow and flow rate of the gas flow pipeline, buffer mechanism, and xenon separation column are installed on the fittings of the gas flow pipeline. The fittings of the gas flow pipeline, the valves installed on the fittings, the instruments controlling the pressure and flow rate of the gas flow pipeline, buffer mechanism, and xenon separation column, and the several stages of buffer mechanism for gas purification and concentration are all placed in a refrigerator. The vacuum pump is located outside the refrigerator and connected to the xenon separation column and buffer mechanism via a gas flow pipeline. An insulation sleeve for desorption and activation of the xenon separation column is provided outside the refrigerator. The insulation sleeve and xenon separation column are also located outside the refrigerator. An online xenon concentration measurement and analysis unit is connected to the final stage purification and concentration unit via fittings. The online xenon concentration measurement and analysis unit includes a xenon storage unit. Measuring device, located The device includes a source chamber within the measuring apparatus and a thermal conductivity detector (TCD) connected to the source chamber via a pipe. The xenon storage unit is connected to the TCD via a pipe.

[0011] Preferably, the insulation sleeve includes an outer shell, which is provided with a cooling channel that can communicate with the freezer and the external environment. An inner liner is provided inside the outer shell, and an insulation layer is provided between the inner liner and the outer shell. A cavity for a xenon separation column is provided inside the inner liner, and a xenon separation column is installed in the cavity. An electric heating belt is wrapped around the xenon separation column, and a temperature sensor is attached to the xenon separation column. The temperature sensor passes through the outer shell and the inner liner and is attached to the xenon separation column.

[0012] Preferably, the cooling channel is equipped with an induced draft fan and an opener / closer for controlling the opening and closing of the cooling channel; the opener / closer is a gate driven by a motor or cylinder.

[0013] Preferably, the opening and closing device is a pneumatic valve or an electric valve.

[0014] Preferably, the three-stage purification and concentration unit includes a primary purification and concentration unit, a secondary purification and concentration unit, and a tertiary purification and concentration unit connected by gas flow pipelines; the primary purification and concentration unit includes a primary buffer mechanism consisting of one or more buffer tanks connected in series and connected to a polyimide hollow fiber membrane separator, a primary xenon separation column A and a primary xenon separation column B connected to the primary buffer mechanism, and gas flow pipelines connecting the primary xenon separation column A and the primary xenon separation column B to the secondary purification and concentration unit and the tertiary purification and concentration unit.

[0015] Preferably, the gas flow pipeline in the primary purification and concentration unit includes a membrane product gas output pipeline connecting the primary buffer mechanism to the primary xenon separation column A and the primary xenon separation column B, an adsorption pipeline connecting the primary xenon separation column A and the primary xenon separation column B, a vacuum pipeline connecting the primary xenon separation column A and the primary xenon separation column B, a low-pressure reverse desorption pipeline connecting the secondary purification and concentration unit, and an adsorption tail gas recycling pipeline connecting the primary xenon separation column A and the primary xenon separation column B to the secondary purification and concentration unit and the tertiary purification and concentration unit; the primary xenon separation column A and the primary xenon separation column B and the primary buffer mechanism are connected to pressure sensors via pipe fittings.

[0016] Preferably, the secondary purification and concentration unit includes a secondary buffer mechanism and a secondary xenon separation column connected to the primary xenon separation column A and the primary xenon separation column B via gas flow pipelines. The secondary buffer mechanism includes a first buffer group and a second buffer group, and its secondary xenon separation column is connected to the first buffer group and the second buffer group via gas flow pipelines. The secondary xenon separation column is also connected to a pressure regulator, a vacuum pump and a pressure sensor via pipe fittings. The secondary xenon separation column is connected to the tertiary purification and concentration unit via gas flow pipelines.

[0017] Preferably, the first buffer group and the second buffer group are each composed of several buffer tanks connected in series, and pressure sensors are connected to the first buffer group and the second buffer group.

[0018] Preferably, the three-stage purification and concentration unit includes a three-stage buffer mechanism consisting of several buffer tanks connected in series and a three-stage xenon separation column, a pressure regulator connected to the three-stage xenon separation column via a pipeline, and a pressure sensor connected to the three-stage buffer mechanism and the three-stage xenon separation column via a pipe fitting. The three-stage xenon separation column is connected to the three-stage buffer mechanism via a gas flow pipeline.

[0019] Preferably, the adsorption pipeline of the first-stage xenon separation column A includes a first-stage buffer mechanism, a xenon separation column A, a membrane product gas output pipeline for connecting the first-stage buffer mechanism to the xenon separation column A, a valve I connected to the membrane product gas output pipeline via a fitting, a gas delivery pipeline I connected to the first-stage xenon separation column A, a valve VI connected to the gas delivery pipeline I via a fitting, and a mass flow controller I connected to the valve VI via a fitting; the mass flow controller I is also connected to the adsorption pipeline of the first-stage xenon separation column B, and the gas delivery pipeline I is also used for connecting the first-stage xenon separation column A and a... The first-stage xenon separation column B has a low-pressure reverse desorption pipeline and an adsorption tail gas recycling pipeline that provides adsorption tail gas to the second-stage purification and concentration unit and the third-stage purification and concentration unit; the vacuum pipeline of the first-stage xenon separation column A includes a vacuum pump, a valve 28 connected to the vacuum pump through a fitting, a vacuum pipe connected to the valve 28, a valve 11011 connected to the vacuum pipe through a fitting, a valve 5 connected to the valve 11011 through a fitting, and a gas supply pipeline 1 connected to the first-stage xenon separation column A through a fitting.

[0020] Preferably, the adsorption pipeline of the first-stage xenon separation column B includes a first-stage buffer mechanism, a first-stage xenon separation column B, a membrane product gas delivery pipeline for connecting the first-stage buffer mechanism to the first-stage xenon separation column B, a valve two connected to the membrane product gas delivery pipeline via a fitting, a second gas delivery pipeline connected to the first-stage xenon separation column B, a valve seven connected to the second gas delivery pipeline via a pipeline, and a mass flow controller one connected to the second gas delivery pipeline via a pipeline. The second gas delivery pipeline is also used for the low-pressure reverse desorption pipeline of the first-stage xenon separation column A and the first-stage xenon separation column B, and for the adsorption tail gas recycling pipeline that provides adsorption tail gas to the second-stage purification and concentration unit and the third-stage purification and concentration unit. The vacuum pipeline of the first-stage xenon separation column B includes a vacuum pump, a valve twenty-eight connected to the vacuum pump via a fitting, a vacuum pipe connected to the valve twenty-eight, a valve twelve connected to the vacuum pipe via a fitting, a valve eight connected to the valve twelve via a fitting, and a connection to the second gas delivery pipeline via a fitting. The second gas delivery pipeline is connected to the first-stage xenon separation column B.

[0021] Preferably, the low-pressure reverse desorption pipeline of the primary xenon separator A includes a secondary buffer mechanism, valve thirteen connected to the secondary buffer mechanism via fittings, a membrane product gas delivery pipeline, valve two connected to the membrane product gas delivery pipeline via fittings, primary xenon separator B connected to the membrane product gas delivery pipeline, gas delivery pipeline two connected to the primary xenon separator B, valve seven connected to the gas delivery pipeline two via fittings, mass flow controller two connected to valve seven via fittings, valve nine connected to the mass flow controller two via fittings, gas delivery pipeline one connected to valve nine via fittings, primary xenon separator A connected to gas delivery pipeline one, valve three connected to the primary xenon separator A via the membrane product gas delivery pipeline via fittings, valve eleven connected to valve three via fittings, and valve eleven connected to valve thirteen via fittings.

[0022] Preferably, the low-pressure reverse desorption pipeline of the primary xenon separator B includes a secondary buffer mechanism, a valve thirteen connected to the secondary buffer mechanism via fittings, a valve membrane product gas delivery pipeline, a valve one connected to the membrane product gas delivery pipeline via fittings, a primary xenon separator A connected to the membrane product gas delivery pipeline, a gas delivery pipeline one connected to the primary xenon separator A, a valve six connected to the gas delivery pipeline one via fittings, a mass flow controller two connected to the valve six via fittings, a valve ten connected to the mass flow controller two via fittings, a gas delivery pipeline two connected to the valve ten via fittings, a primary xenon separator B connected to the gas delivery pipeline two, a valve four connected to the primary xenon separator B via the membrane product gas delivery pipeline via fittings, a valve twelfth connected to the valve four via fittings, and valves thirteen and fourteen connected via fittings.

[0023] Preferably, the adsorption tail gas recycling pipeline of the first-stage xenon separation column A includes a membrane product gas transmission pipeline, a valve 1 connected to the membrane product gas transmission pipeline via fittings, the first-stage xenon separation column A connected to the membrane product gas transmission pipeline, the first-stage xenon separation column A connected to the gas transmission pipeline 1, a valve 6 connected to the gas transmission pipeline 1, a mass flow controller 2 connected to the valve 6 via fittings, valves 15 and 20 connected to the mass flow controller 2 via fittings, and also includes a first buffer group connected to valve 15, valves 14 and 19 connected to the first buffer group via fittings, a second buffer group connected to valve 14 via fittings, a valve 21 connected to valve 20 via fittings, and a third-stage buffer mechanism connected to valve 21 via fittings.

[0024] Preferably, the adsorption tail gas recycling pipeline of the first-stage xenon separation column B includes a membrane product gas transmission pipeline, valve 2 connected to the membrane product gas transmission pipeline via fittings, the first-stage xenon separation column B connected to the membrane product gas transmission pipeline, valve 7 connected to the first-stage xenon separation column B and the gas transmission pipeline 2, valve 2 connected to the gas transmission pipeline 2, mass flow controller 2 connected to valve 7 via fittings, valve 15 and valve 20 connected to mass flow controller 2 via fittings, and also includes a first buffer group connected to valve 15, valve 14 and valve 19 connected to the first buffer group via fittings, a second buffer group connected to valve 14 via fittings, valve 21 connected to valve 20 via fittings, and a third-stage buffer mechanism connected to valve 21 via fittings.

[0025] Preferably, the gas flow pipeline in the secondary purification and concentration unit includes an adsorption pipeline for the secondary xenon separation column, a low-pressure reverse desorption pipeline, a vacuum pipeline, and a vacuum pipeline for the secondary buffer mechanism.

[0026] Preferably, the adsorption pipeline of the secondary xenon separation column includes valve 15, a first buffer group connected to valve 15 via a fitting, valve 14 connected to the first buffer group via a fitting, a second buffer group connected to valve 14 via a fitting, valve 16 connected to the second buffer group via a fitting, a secondary xenon separation column connected to valve 16 via a fitting, valve 17 connected to the secondary xenon separation column via a fitting, and a pressure regulator 1 connected to valve 17 via a fitting.

[0027] Preferably, the low-pressure reverse desorption pipeline of the secondary xenon separation column includes valve 15, a first buffer group connected to valve 15 via a fitting, valve 19 connected to the first buffer group via a fitting, a secondary xenon separation column connected to valve 19 via a fitting, valve 18 connected to the secondary xenon separation column via a fitting, valve 21 connected to valve 18 via a fitting, and a third-stage buffer mechanism connected to valve 21 via a fitting; the vacuum pipeline of the secondary xenon separation column includes a vacuum pump, valve 28 connected to the vacuum pump via a fitting, a vacuum tube connected to valve 28, valve 29 connected to the vacuum tube via a fitting, valve 18 connected to valve 29 via a fitting, and valve 18 connected to the secondary xenon separation column via a fitting; the vacuum pipeline of the secondary buffer mechanism includes a vacuum pump, valve 28 connected to the vacuum pump via a fitting, a vacuum tube connected to valve 28, valve 13 connected to the vacuum tube via a fitting, a first buffer group connected to valve 13 via a fitting, valve 14 connected to the first buffer group via a fitting, and a second buffer group connected to valve 14 via a fitting.

[0028] Preferably, the gas flow pipeline in the three-stage purification and concentration unit includes an adsorption pipeline, a vacuum pipeline, and a low-pressure reverse desorption pipeline for the three-stage xenon separation column, as well as a vacuum pipeline for the three-stage buffer mechanism; the adsorption pipeline includes valve 20, a mass flow controller 2 connected to valve 20 via a fitting, valve 21 connected to valve 20 via a fitting, a three-stage buffer mechanism connected to valve 21 via a fitting, a valve 22 connected to the three-stage buffer mechanism via a fitting, valve 22 connected to the three-stage xenon separation column, and a pressure regulator 2 connected to the three-stage xenon separation column via a fitting; The vacuum line of the three-stage xenon separator includes a vacuum pump, valve 28 connected to the vacuum pump via a fitting, valve 29 connected to valve 28 via a fitting, and valve 23 or valve 24 connected to valve 29 via a fitting. Valves 23 and 24 are connected to the three-stage xenon separator via fittings. The vacuum line of the three-stage buffer mechanism includes a vacuum pump, valve 28 connected to the vacuum pump via a fitting, valve 29 connected to valve 28 via a fitting, and valve 21 connected to valve 29 via a fitting. Valve 21 is connected to the three-stage buffer mechanism via a fitting.

[0029] Preferably, the low-pressure reverse desorption pipeline of the three-stage xenon separation column includes valve 21, valve 23 connected to valve 21 via a fitting, valve 23 connected to the three-stage xenon separation column via a fitting, valve 25 connected to the three-stage xenon separation column, and the three-stage xenon separation column of the three-stage purification and concentration unit is connected to an online xenon concentration measurement and analysis unit via valve 25 and a fitting.

[0030] Preferably, the thermal conductivity detector (TCD) and the measurement and analysis unit are... A valve 26 is installed on the pipe fitting connecting the source chamber of the measuring device, and the xenon storage unit is connected to the valve 26 via the pipe fitting.

[0031] Preferably, the online measurement and analysis unit is also connected to a vacuum pipeline, which includes a vacuum pump, a valve 30 connected to the vacuum pump via a fitting, a thermal conductivity detector (TCD) connected to valve 30 via a fitting, a valve 26 connected to the thermal conductivity detector (TCD) via a fitting, a valve 25 connected to valve 26 via a fitting, and a source chamber connected to valve 25 via a fitting.

[0032] Preferably, the first buffer group and the secondary xenon separation column are connected to a xenon storage unit via pipe fittings and valves. The first buffer group, the secondary xenon separation column, and the tertiary purification and concentration unit are connected in series via pipe fittings and several valves to form a xenon storage unit re-concentration mechanism.

[0033] Preferably, the xenon storage unit includes a vacuum line for the xenon storage unit and several file bottles, with valve 27 connected to the file bottles via fittings, and valve 27 connected to a thermal conductivity detector (TCD) via fittings.

[0034] Preferably, the vacuum piping of the xenon archive storage unit includes a vacuum pump, a valve 28 connected to the vacuum pump via a fitting, a valve 30 connected to the valve 28 via a fitting, and a valve 27 connected to the archive bottle via a fitting.

[0035] Preferably, the freezer is cooled by a compressor, and its temperature is controlled within -28℃ to 18℃.

[0036] Preferably, the adsorbent loading of each xenon separation column has a redundancy of 50% to 300%, and the adsorbent is selected from one or more combinations of coconut shell activated carbon, coal-based activated carbon, or carbon molecular sieve.

[0037] Preferably, the filtration mechanism includes a coarse filter connected between the air compressor and the refrigerated dryer via a pipe, a fine filter connected to the refrigerated dryer, and an ultrafiltration filter connected to the fine filter; the ultrafiltration filter is connected to an imide hollow fiber membrane separator via a pipe.

[0038] Preferably, the volume calculation formula for a single buffer tank of the buffer mechanism for xenon purification and concentration is as follows: The formula for calculating the total volume of a single buffer mechanism is: Where V is the volume of the pre-stage column, m is the volume of the pre-stage desorption column, n is the number of tanks connected in series, and b is the number of cleaning cycles.

[0039] Preferably, the adsorbent dosage formula for the xenon separation column in each purification and concentration unit is as follows: , For each desorption specific volume number, The value is set to 1. For the volume of each level of filled column, where The volume of the first-stage inlet gas. denoted as the dynamic adsorption coefficient of each column packing level.

[0040] This invention also proposes an enrichment analysis process for a multi-mode enrichment analysis device capable of detecting xenon background in air, characterized in that the enrichment process includes the following steps:

[0041] Gas extraction and enrichment: Air is drawn in by an air compressor, filtered by a sampling head to remove large-particle impurities, cooled by a refrigerated dryer, and filtered to remove impurities with a particle size greater than 0.01μm. Finally, it passes through several series-connected separators containing polyimide hollow fiber membranes to remove the constant components in the air, resulting in highly concentrated xenon-rich pure nitrogen membrane product gas.

[0042] In the first stage of forward pressurized adsorption, the xenon-rich pure nitrogen membrane product gas enters the first-stage buffer mechanism through a pipeline. The xenon-rich pure nitrogen membrane product gas is then fed from the first-stage buffer mechanism into the first-stage xenon separation column A or B through the adsorption pipeline of the first-stage xenon separation column A or B. The mass flow controller controls the exhaust gas pressure to perform the first-stage forward pressurized adsorption. The exhaust gas after adsorption by the adsorbent in the first-stage xenon separation column A or B is discharged through the mass flow controller in the adsorption pipeline. The first-stage xenon separation column A and the first-stage xenon separation column B work alternately. When one performs the adsorption process, the other performs the low-pressure reverse desorption process. After the first-stage adsorption is completed, the first-stage low-pressure reverse desorption process begins.

[0043] First-stage vacuum desorption reverse desorption: After the adsorption of the first-stage xenon separation column A or B is completed, the column is first vented and then evacuated using a vacuum pump and vacuum line to reduce the internal pressure. Once the pressure reaches its limit, the vacuum line is closed. The column is then heated to 120℃~220℃ using an electric heating element. Next, the secondary buffer mechanism is evacuated using a vacuum pump and vacuum line to achieve a high vacuum. Finally, the vacuum line for the secondary buffer mechanism is closed, and the first-stage xenon separation column A or B is de-vacuumed. The low-pressure reverse desorption pipeline of B is connected to the secondary buffer mechanism, and the temperature of the primary xenon A or primary xenon B is maintained for high-temperature vacuum desorption. The vacuum desorption gas and low-pressure desorption gas in the primary xenon separation column A or primary xenon separation column B are pushed to the secondary buffer mechanism through the adsorption tail gas recycling pipeline of the primary xenon separation column A or primary xenon separation column B. Then, the adsorption tail gas of the primary xenon separation column B or primary xenon separation column A is introduced into the secondary buffer mechanism through the adsorption tail gas recycling pipeline of the primary xenon separation column A or primary xenon separation column B until the pressure of the secondary buffer mechanism reaches the specified pressure value or the pressure of the secondary buffer mechanism no longer increases, thus completing the primary high-temperature vacuum desorption reverse desorption.

[0044] First-stage activation and regeneration: The first-stage xenon separation column A or B is evacuated using a vacuum pump and vacuum piping, and then heated to 250℃~350℃ using an electric heating belt. After maintaining the temperature for the set time, the heating is stopped. Then, the induced draft fan is turned on to introduce the low-temperature gas from the freezer to cool the first-stage xenon separation column A or B to the adsorption temperature, thus completing the activation and regeneration.

[0045] Secondary positive pressure adsorption: The adsorption tail gas of the primary xenon separation column A or the primary xenon separation column B is used to push the primary desorbed gas in the secondary buffer mechanism into the secondary xenon separation column for secondary adsorption and purification. The adsorption tail pressure of the secondary xenon separation column is increased by setting the exhaust pressure of the pressure regulator to perform secondary positive pressure adsorption.

[0046] Secondary vacuum desorption reverse desorption: After the secondary adsorption is completed, the secondary xenon separation column is evacuated through a vacuum pump and a vacuum line to reduce the pressure inside the column. After the secondary xenon separation column is evacuated, the secondary xenon separation column is heated to 120℃~220℃ through a heating belt. The tertiary buffer mechanism is then evacuated through a vacuum pump and a vacuum line to reach the ultimate negative pressure. After heating and maintaining the temperature for a set time, the tail gas from the primary adsorption is introduced into the low-pressure reverse desorption line of the secondary xenon separation column, pushing the secondary desorbed gas remaining in the secondary xenon separation column into the tertiary buffer mechanism until the pressure inside the tertiary buffer mechanism reaches the specified pressure value or the pressure in the tertiary buffer mechanism no longer increases, thus completing the secondary high-temperature vacuum desorption reverse desorption.

[0047] Secondary activation and regeneration: The secondary xenon separation column is evacuated through a vacuum pump and a vacuum line, and then heated to 280℃~350℃ by an electric heating belt. After maintaining the temperature for the set time, the heating is stopped. Then, the induced draft fan is turned on to introduce low-temperature gas from the freezer to cool the secondary xenon separation column to the adsorption temperature, thus completing the activation and regeneration.

[0048] After the three-stage positive pressure adsorption and the two-stage desorption are completed, the adsorption tail gas is recycled through the adsorption tail gas recycling pipeline of the first-stage xenon separation column A or the first-stage xenon separation column B. The first-stage adsorption tail gas pushes the second-stage desorbed gas stored in the three-stage buffer mechanism into the three-stage xenon separation column for three-stage purification adsorption. By setting the emission rate of pressure regulator two, the adsorption pressure of the three-stage xenon separation column is increased. The tail gas after the three-stage xenon separation column pressure adsorption is discharged through pressure regulator two in the adsorption pipeline of the three-stage xenon separation column.

[0049] Three-stage vacuum desorption reverse desorption: After the three-stage adsorption is completed, the three-stage xenon separation column is evacuated through a vacuum pump and the vacuum pumping pipeline of the three-stage xenon separation column to reduce the pressure inside the column. After the three-stage xenon separation column is evacuated, it is heated to 120℃~220℃ by an electric heating belt. The source chamber of the online measurement and analysis unit is evacuated to the ultimate vacuum through a vacuum pump and the vacuum pumping pipeline of the online measurement and analysis unit. The three-stage xenon separation column and the source chamber are connected to carry out high-temperature desorption vacuum diffusion of the three-stage xenon separation column. The temperature is maintained until the set time. The vacuum desorption gas and re-desorption gas remaining in the three-stage xenon separation column are pushed into the source chamber through the low-pressure reverse desorption pipeline of the three-stage purification and concentration unit, thus completing the three-stage high-temperature vacuum desorption reverse desorption and measurement source preparation.

[0050] Three-stage activation and regeneration: The three-stage xenon separation column is evacuated by a vacuum pump and a vacuum pipeline, and then heated to 250℃~350℃ by an electric heating belt. After maintaining the temperature for the set time, the heating is stopped. Then the induced draft fan is turned on to introduce low-temperature gas from the freezer and cool the three-stage xenon separation column to the adsorption temperature, thus completing the activation and regeneration.

[0051] Measurement and Analysis: After source preparation is completed, the radioactivity of xenon in the source chamber is measured using a radiometric measuring device; a vacuum pump is used to evacuate a certain archive bottle in the xenon storage unit. After evacuation, the sample source chamber, thermal conductivity detector (TCD), and archive bottle are connected, and the sample gas in the sample source chamber is transferred to the archive bottle for storage. After pressure equilibrium is achieved, the total xenon concentration is analyzed using the thermal conductivity detector (TCD).

[0052] Preferably, the enrichment process also includes a sample gas re-concentration process in the xenon storage unit, which includes:

[0053] Secondary adsorption and desorption of samples: First, the first buffer group is evacuated using a vacuum pump and the vacuum line of the first buffer group. After evacuation, the sample gas is transferred to the first buffer group through the pipeline by opening the valve in the designated file bottle. The adsorption tail gas is then connected to the first buffer group through the adsorption tail gas recycling pipeline of the first-stage xenon separation column A or B. The sample gas in the first buffer group is pushed into the second-stage xenon separation column for adsorption using the first-stage adsorption tail gas. The tail gas after adsorption by the adsorbent in the second-stage xenon separation column is discharged through the pressure regulator in the adsorption pipeline of the second-stage xenon separation column. After the second-stage adsorption is completed, a second-stage vacuum desorption reverse desorption process is performed. After the second-stage desorption process is completed, the sample gas is transferred to the second-stage xenon separation column. The adsorption tail gas recycling pipeline of either the first-stage xenon separation column A or the first-stage xenon separation column B uses the first-stage adsorption tail gas to push the second-stage desorption sample gas stored in the third-stage buffer mechanism into the third-stage xenon separation column for secondary purification and adsorption. After adsorption, a third-stage vacuum desorption reverse desorption is performed to complete the re-concentration of the sample gas. After re-concentration, the activity of radioactive xenon in the sample source chamber is measured by a radioactivity measuring device. Then, a vacuum pump is used to evacuate the designated archive bottle in the xenon storage unit. After evacuation, the source chamber, thermal conductivity detector (TCD), and archive bottle are connected, and the sample gas in the source chamber is transferred to the archive bottle for storage. After pressure equilibrium is achieved, the total xenon concentration after re-concentration is analyzed by the thermal conductivity detector (TCD).

[0054] The beneficial effects of this invention are as follows: By controlling the adsorption temperature at -28℃ to 18℃ using a freezer, shallow low-temperature adsorption is achieved; by increasing the tail pressure of each xenon separation column to 0.1MPa to 0.6MPa, pressurized adsorption is achieved, increasing the dynamic adsorption coefficient of each xenon separation column from 0.43L / g at room temperature and pressure to 1.2 to 3.4L / g, thus achieving self-increase in adsorption performance, thereby improving adsorption efficiency and reducing the amount of adsorbent loaded in each xenon separation column at a specified inlet volume.

[0055] By employing a multi-stage buffer mechanism consisting of several stages of reverse desorption and several buffer tanks connected in series, high-temperature vacuum desorption and reverse desorption are achieved. This reduces the volume of desorbed gas in the first, second, and third stages of purification and concentration from 8 to 20 column volumes in forward desorption to 3 to 5, thereby improving desorption efficiency. At the same time, it reduces the total amount of gas entering the next stage of adsorption and reduces the size of the device.

[0056] By adopting the reverse desorption process, the adsorbent loading redundancy of each stage of the xenon separation column can be greatly increased from the usual less than 30% to 50-300%, thereby increasing the performance stability of the device, reducing the maintenance frequency, extending the maintenance cycle, and reducing the operation and maintenance costs.

[0057] By adopting a process of shallow low-temperature pressurized adsorption and high-temperature vacuum desorption with reverse desorption, the redundant amount of adsorbent can be greatly increased, and the amount of adsorbent can be automatically matched with the gas flow rate. No matter how large the amount of raw gas is, only the corresponding amount of adsorbent needs to be adsorbed and desorbed from bottom to top. This makes the equipment suitable for large-volume sampling and monitoring, as well as high-frequency small-volume sampling and monitoring, purification and concentration, and sensitive sampling and monitoring. Therefore, it can not only be used for evidence collection of nuclear events and early warning of nuclear accidents, but also be used for nuclear emergency radioactive xenon sampling and monitoring.

[0058] In this invention, the adsorbed tail gas from either the first-stage xenon separation column A or the first-stage xenon separation column B is used as the carrier gas, eliminating the need for helium or nitrogen cylinders to provide the carrier gas. Ordinary activated carbon adsorbent can be used as the packing material for the xenon separation column for stepwise concentration, thus reducing the production cost of the device. Attached Figure Description

[0059] Appendix Figure 1 This is a schematic diagram of the process flow of the present invention;

[0060] Appendix Figure 2 This is a schematic diagram of the insulation sleeve structure in this invention;

[0061] Appendix Figure 3 This is a schematic diagram of the process flow for using a coil as a buffer mechanism in this invention;

[0062] Appendix Figure 4 This is a table showing the dynamic adsorption coefficients of activated carbon for xenon under low temperature and high pressure, based on the present invention.

[0063] Appendix Figure 5 This is a table of high-temperature vacuum desorption reverse desorption efficiency of xenon according to the present invention;

[0064] Appendix Figure 6 This is a table showing the lowest detectable activity concentration of radioactive xenon-133 in the air obtained by sampling and enriching for 24 hours using the device of this invention.

[0065] Appendix Figure 7This is the table of recovery rates for reconcentrated archival samples in this invention;

[0066] Appendix Figure 8 This is the sensitivity table for long-term continuous sampling monitoring in Embodiment 3 of the present invention;

[0067] Appendix Figure 9 This is the rapid sampling monitoring sensitivity table in Embodiment 4 of the present invention. Detailed Implementation

[0068] The following description, in conjunction with the accompanying drawings, further illustrates the multi-mode enrichment analysis device and process for detecting xenon background in air according to the present invention.

[0069] See Figure 1-9 As shown, a multi-mode enrichment analysis device for detecting xenon background in air is characterized by including a gas sampling and enrichment unit, a purification and concentration unit for forward adsorption and reverse desorption interconnected by gas flow pipelines, and a refrigerator 5. The gas sampling and enrichment unit includes an air compressor 2 connected to an air sampling head 1 via a pipe, a refrigerated dryer 3 connected to the air compressor 2 via a pipe, a three-stage gas filtration mechanism connected to the refrigerated dryer 3 via a pipe, and several series-connected polyimide hollow fiber membrane separators connected to the three-stage gas filtration mechanism via pipes. The purification and concentration unit comprises at least three stages of progressively larger purification and concentration units, with each polyimide hollow fiber membrane separator connected to the first purification and concentration unit via a pipeline. Each purification and concentration unit is also connected to one or more gas flow pipelines, with at least one gas flow pipeline for interconnection between the purification and concentration units at each stage. Each purification and concentration unit also includes at least one xenon separation column filled with adsorbent, connected to the xenon separation column via a gas flow pipeline. The pipeline connects to a multi-stage buffer mechanism consisting of several buffer tanks connected in series for xenon purification and concentration. The xenon separation column and the buffer mechanism are also connected to a vacuum pump 4 via a gas flow pipeline. Valves controlling the gas flow and flow rate of the gas flow pipeline, buffer mechanism, and xenon separation column are installed on the fittings of the gas flow pipeline. The fittings of the gas flow pipeline, the valves installed on the fittings, the instruments controlling the pressure and flow rate of the gas flow pipeline, buffer mechanism, and xenon separation column, and the multi-stage buffer mechanism for gas purification and concentration are all placed in a freezer 5. The vacuum pump 4 is located outside the freezer 5 and connected to the xenon separation column and buffer mechanism via a gas flow pipeline. A heat-insulating sleeve 6 for desorption and activation of the xenon separation column is provided outside the xenon separation column. The heat-insulating sleeve 6 and the xenon separation column are located outside the freezer 5. The online xenon concentration measurement and analysis unit is connected to the final stage purification and concentration unit via fittings. The online xenon concentration measurement and analysis unit includes a xenon storage unit. Measuring device 23, located at The xenon storage unit is connected to the thermal conductivity detector TCD25 via a pipe within the measuring device 23, which contains a source chamber 24 and is connected to the source chamber 24 via a pipe.

[0070] Furthermore, the insulation sleeve 6 includes an outer shell 61, on which a cooling channel 62 communicating with the freezer 5 is provided. An inner liner 63 is provided inside the outer shell 61, and an insulation layer 64 is provided between the inner liner 63 and the outer shell 61. A xenon separation column placement cavity 65 is provided inside the inner liner 63, and a xenon separation column is installed in the placement cavity 65. An electric heating belt 66 is wrapped around the xenon separation column, and a temperature sensor 67 is attached to the xenon separation column. The temperature sensor 67 passes through the outer shell 61 and the inner liner 63 and is attached to the xenon separation column.

[0071] Furthermore, the cooling channel 62 is equipped with an induced draft fan 68 and an opener / closer 69 for controlling the opening and closing of the cooling channel 62; the opener / closer 69 is a gate driven by a motor or cylinder.

[0072] Furthermore, the aforementioned opener / closer 69 is a pneumatic valve or an electric valve.

[0073] Furthermore, the three-stage purification and concentration unit includes a primary purification and concentration unit, a secondary purification and concentration unit, and a tertiary purification and concentration unit connected by gas flow pipelines; the primary purification and concentration unit includes a primary buffer mechanism 7 consisting of one or more buffer tanks connected in series and connected to a polyimide hollow fiber membrane separator, a primary xenon separation column A8 and a primary xenon separation column B9 connected to the primary buffer mechanism 7, and gas flow pipelines connecting the primary xenon separation column A8 and the primary xenon separation column B9 to the secondary purification and concentration unit and the tertiary purification and concentration unit.

[0074] Furthermore, the gas flow pipeline in the primary purification and concentration unit includes a membrane product gas output pipeline 10 connecting the primary buffer mechanism 7 to the primary xenon separation columns A8 and B9, an adsorption pipeline connected to the primary xenon separation columns A8 and B9, a vacuum pipeline, a low-pressure reverse desorption pipeline connected to the secondary purification and concentration unit, and an adsorption tail gas recycling pipeline connecting the primary xenon separation columns A8 and B9 to the secondary and tertiary purification and concentration units; the primary xenon separation columns A8 and B9 and the primary buffer mechanism 7 are connected to pressure sensors via pipe fittings.

[0075] Furthermore, the secondary purification and concentration unit includes a secondary buffer mechanism and a secondary xenon separation column 13 connected to the primary xenon separation column A8 and the primary xenon separation column B9 via gas flow pipelines. The secondary buffer mechanism includes a first buffer group 11 and a second buffer group 12, and its secondary xenon separation column is connected to the first buffer group 11 and the second buffer group 12 via gas flow pipelines. The secondary xenon separation column 13 is also connected to a pressure regulator 14, a vacuum pump 4 and a pressure sensor via pipe fittings. The secondary xenon separation column 13 is connected to the tertiary purification and concentration unit via gas flow pipelines.

[0076] Furthermore, the first buffer group 11 and the second buffer group 12 are each composed of several buffer tanks connected in series, and pressure sensors are connected to the first buffer group 11 and the second buffer group 12.

[0077] Furthermore, the three-stage purification and concentration unit includes a three-stage buffer mechanism 15 consisting of several buffer tanks connected in series and a three-stage xenon separation column 16, a pressure regulator 17 connected to the three-stage xenon separation column 16 via a pipeline, and a pressure sensor connected to the three-stage buffer mechanism 15 and the three-stage xenon separation column 16 via a pipe fitting. The three-stage xenon separation column 16 is connected to the three-stage buffer mechanism 15 via a gas flow pipeline.

[0078] Furthermore, the adsorption pipeline of the first-stage xenon separation column A8 includes a first-stage buffer mechanism 7, a xenon separation column A8, a membrane product gas output pipeline 10 for connecting the first-stage buffer mechanism 7 to the xenon separation column A8, a valve 01 connected to the membrane product gas output pipeline 10 via a fitting, a gas delivery pipeline 18 connected to the first-stage xenon separation column A8, a valve 06 connected to the gas delivery pipeline 18 via a fitting, and a mass flow controller 19 connected to the valve 06 via a fitting; the mass flow controller 19 is also connected to the adsorption pipeline of the first-stage xenon separation column B9, and the gas delivery pipeline 18 is also used for the first-stage xenon separation column A8. The system includes a low-pressure reverse desorption pipeline for the first-stage xenon separation column B9 and an adsorption tail gas recycling pipeline that supplies adsorption tail gas to the second-stage purification and concentration unit and the third-stage purification and concentration unit; the vacuum pipeline for the first-stage xenon separation column A8 includes a vacuum pump 4, a valve 28028 connected to the vacuum pump 4 via a fitting, a vacuum pipe 41 connected to the valve 28028, a valve 11011 connected to the vacuum pipe 41 via a fitting, a valve 505 connected to the valve 11011 via a fitting, and a gas supply pipeline 18 connected to the first-stage xenon separation column A8 via a fitting.

[0079] Furthermore, the adsorption pipeline of the first-stage xenon separation column B9 includes a first-stage buffer mechanism 7, a first-stage xenon separation column B9, a membrane product gas delivery pipeline 10 for connecting the first-stage buffer mechanism 7 to the first-stage xenon separation column B9, a valve 202 connected to the membrane product gas delivery pipeline 10 via a fitting, a second gas delivery pipeline 20 connected to the first-stage xenon separation column B9, a valve 707 connected to the second gas delivery pipeline 20 via a pipeline, and a mass flow controller 19 connected to the second gas delivery pipeline 20 via a pipeline. The second gas delivery pipeline 20 is also used for the first-stage xenon separation columns A8 and B9. The system includes a low-pressure reverse desorption pipeline and an adsorption tail gas recycling pipeline that provides adsorption tail gas to the secondary purification and concentration unit and the tertiary purification and concentration unit; the vacuum pipeline of the primary xenon separation column B9 includes a vacuum pump 4, a valve 28028 connected to the vacuum pump 4 via a fitting, a vacuum pipe 41 connected to the valve 28028, a valve 12012 connected to the vacuum pipe 41 via a fitting, a valve 808 connected to the valve 12012 via a fitting, and a gas supply pipeline 20 connected to the valve 808 via a fitting. The gas supply pipeline 20 is connected to the primary xenon separation column B9.

[0080] Furthermore, the low-pressure reverse desorption pipeline of the primary xenon separator A8 includes a secondary buffer mechanism, a valve 13013 connected to the secondary buffer mechanism via fittings, a membrane product gas delivery pipeline 10, a valve 202 connected to the membrane product gas delivery pipeline 10 via fittings, a primary xenon separator B9 connected to the membrane product gas delivery pipeline 10, a gas delivery pipeline 20 connected to the primary xenon separator B9, a valve 707 connected to the gas delivery pipeline 20 via fittings, a mass flow controller 21 connected to the valve 707 via fittings, a valve 909 connected to the mass flow controller 21 via fittings, a gas delivery pipeline 18 connected to the valve 909 via fittings, a primary xenon separator A8 connected to the gas delivery pipeline 18, a valve 303 connected to the primary xenon separator A8 via the membrane product gas delivery pipeline 10 via fittings, a valve 11011 connected to the valve 303 via fittings, and a valve 11011 connected to the valve 13013 via fittings.

[0081] Furthermore, the low-pressure reverse desorption pipeline of the primary xenon separation column B9 includes a secondary buffer mechanism, and is connected to the secondary buffer mechanism via fittings. This includes valve 13 013, valve membrane product gas delivery pipeline 10, valve 1 01 connected to membrane product gas delivery pipeline 10 via fittings, primary xenon separation column A8 connected to membrane product gas delivery pipeline 10, gas delivery pipeline 1 18 connected to primary xenon separation column A8, valve 6 06 connected to gas delivery pipeline 1 18 via fittings, mass flow controller 2 21 connected to valve 6 06 via fittings, valve 10 010 connected to mass flow controller 2 21 via fittings, gas delivery pipeline 2 20 connected to valve 10 010 via fittings, primary xenon separation column B9 connected to gas delivery pipeline 2 20, valve 4 04 connected to primary xenon separation column B9 via membrane product gas delivery pipeline 10 via fittings, valve 12 012 connected to valve 4 04 via fittings, and valves 13 013 and 14 014 connected via fittings.

[0082] Furthermore, the adsorption tail gas recycling pipeline of the first-stage xenon separation column A8 includes a membrane product gas transmission pipeline 10, a valve 01 connected to the membrane product gas transmission pipeline via fittings, the first-stage xenon separation column A8 connected to the membrane product gas transmission pipeline 10, a gas transmission pipeline 18 connected to the first-stage xenon separation column A8, a valve 06 connected to the gas transmission pipeline 18, a mass flow controller 21 connected to the valve 06 via fittings, valves 15015 and 20020 connected to the mass flow controller 21 via fittings, and also includes a first buffer group 11 connected to valve 15015, valves 14014 and 19019 connected to the first buffer group 11 via fittings, a second buffer group 12 connected to valve 14014 via fittings, a valve 21021 connected to valve 20020 via fittings, and a third-stage buffer mechanism 15 connected to valve 21021 via fittings.

[0083] Furthermore, the adsorption tail gas recycling pipeline of the first-stage xenon separation column B9 includes a membrane product gas transmission pipeline 10, a valve 202 connected to the membrane product gas transmission pipeline via fittings, the first-stage xenon separation column B9 connected to the membrane product gas transmission pipeline 10, a gas transmission pipeline 20 connected to the first-stage xenon separation column B9, a valve 707 connected to the gas transmission pipeline 20, a mass flow controller 21 connected to the valve 707 via fittings, valves 15015 and 20020 connected to the mass flow controller 21 via fittings, and also includes a first buffer group 11 connected to valve 15015, valves 14014 and 19019 connected to the first buffer group 11 via fittings, a second buffer group 12 connected to valve 14014 via fittings, a valve 21021 connected to valve 20020 via fittings, and a third-stage buffer mechanism 15 connected to valve 21021 via fittings.

[0084] Furthermore, the gas flow pipeline in the secondary purification and concentration unit includes the adsorption pipeline of the secondary xenon separation column 13, the low-pressure reverse desorption pipeline, the vacuum pipeline, and the vacuum pipeline of the secondary buffer mechanism.

[0085] Furthermore, the adsorption pipeline of the secondary xenon separation column 13 includes valve 15 015, a first buffer group 11 connected to valve 15 015 via a pipe fitting, valve 14 014 connected to the first buffer group 11 via a pipe fitting, a second buffer group 12 connected to valve 14 014 via a pipe fitting, valve 16 016 connected to the second buffer group 12 via a pipe fitting, the secondary xenon separation column 13 connected to valve 16 016 via a pipe fitting, valve 17 017 connected to the secondary xenon separation column 13 via a pipe fitting, and a pressure regulator 14 connected to valve 17 017 via a pipe fitting.

[0086] Furthermore, the low-pressure reverse desorption pipeline of the secondary xenon separation column 13 includes valve 15015, a first buffer group 11 connected to valve 15015 via a fitting, valve 19019 connected to the first buffer group 11 via a fitting, the secondary xenon separation column 13 connected to valve 19019 via a fitting, valve 18018 connected to the secondary xenon separation column 13 via a fitting, valve 21021 connected to valve 18018 via a fitting, and a tertiary buffer mechanism 15 connected to valve 21021 via a fitting; the vacuum pipeline of the secondary xenon separation column 13 includes a vacuum pump 4, a valve 28028 connected to the vacuum pump 4 via a fitting, and a valve 28028 connected to... The vacuum tube 41, valve 29 029 connected to the vacuum tube 41 via fittings, valve 18 018 connected to valve 29 029 via fittings, and valve 18 018 connected to the secondary xenon separation column 13 via fittings; the vacuum pipeline of the secondary buffer mechanism 12 includes a vacuum pump 4, valve 28 028 connected to the vacuum pump 4 via fittings, vacuum tube 41 connected to valve 28 028, valve 13 013 connected to the vacuum tube 41 via fittings, first buffer group 11 connected to valve 13 013 via fittings, valve 14 014 connected to the first buffer group 11 via fittings, and second buffer group 12 connected to valve 14 014 via fittings.

[0087] Furthermore, the gas flow pipeline in the three-stage purification and concentration unit includes an adsorption pipeline, a vacuum pipeline, and a low-pressure reverse desorption pipeline for the three-stage xenon separation column 16, as well as a vacuum pipeline for the three-stage buffer mechanism 15; the adsorption pipeline includes valve 2020, a mass flow controller 21 connected to valve 2020 via a fitting, valve 21021 connected to valve 2020 via a fitting, the three-stage buffer mechanism 15 connected to valve 21021 via a fitting, valve 22022 connected to the three-stage buffer mechanism 15 via a fitting, valve 22022 connected to the three-stage xenon separation column 16, and a pressure regulator 217 connected to the three-stage xenon separation column 16 via a fitting; the three-stage xenon separation column 16... The vacuum pumping pipeline includes a vacuum pump 4, a valve 28028 connected to the vacuum pump 4 via a fitting, a valve 29029 connected to the valve 28028 via a fitting, and a valve 23023 or a valve 24024 connected to the valve 29029 via a fitting. Valves 23023 and 24024 are connected to the three-stage xenon separation column 16 via fittings. The vacuum pumping pipeline of the three-stage buffer mechanism 15 includes a vacuum pump 4, a valve 28028 connected to the vacuum pump 4 via a fitting, a valve 29029 connected to the valve 28028 via a fitting, and a valve 21021 connected to the valve 29029 via a fitting. Valve 21021 is connected to the three-stage buffer mechanism 15 via a fitting.

[0088] Furthermore, the low-pressure reverse desorption pipeline of the three-stage xenon separation column 16 includes valve 21021, valve 23023 connected to valve 21021 via a fitting, valve 23023 connected to the three-stage xenon separation column 16 via a fitting, and valve 25025 connected to the three-stage xenon separation column 16. The three-stage xenon separation column 16 of the three-stage purification and concentration unit is connected to an online xenon concentration measurement and analysis unit via valve 25025 and a fitting.

[0089] Furthermore, the thermal conductivity detector TCD25 and the measurement and analysis unit... A valve 26026 is installed on the pipe connected to the source chamber 24 of the measuring device 23, and the xenon storage unit is connected to the valve 26026 through the pipe.

[0090] Furthermore, the online measurement and analysis unit is also connected to a vacuum pipeline. The vacuum pipeline of the online measurement and analysis unit includes a vacuum pump 4, a valve 30030 connected to the vacuum pump 4 through a pipe fitting, a thermal conductivity detector TCD25 connected to the valve 30030 through a pipe fitting, a valve 26026 connected to the valve thermal conductivity detector TCD25 through a pipe fitting, a valve 25025 connected to the valve 26026 through a pipe fitting, and a source chamber 24 connected to the valve 25025 through a pipe fitting.

[0091] Furthermore, the first buffer group 11 and the secondary xenon separation column 13 are connected to a xenon storage unit through pipe fittings and valves. The first buffer group 11, the secondary xenon separation column 13, and the tertiary purification and concentration unit are connected in series through pipe fittings and several valves to form a xenon storage unit re-concentration mechanism.

[0092] Furthermore, the xenon storage unit includes a vacuum pipeline for the xenon storage unit and several file bottles 26, and a valve 27027 connected to the file bottles 26 via a pipe fitting. The valve 27027 is connected to the thermal conductivity detector TCD25 via a pipe fitting.

[0093] Furthermore, the vacuum piping of the xenon archive storage unit includes a vacuum pump 4, a valve 28028 connected to the vacuum pump 4 via a fitting, a valve 30030 connected to the valve 28028 via a fitting, and a valve 27027 connected to the archive bottle 26 via a fitting.

[0094] Furthermore, the freezer 5 is cooled by a compressor, and its temperature is controlled within -28℃ to 18℃.

[0095] Furthermore, the adsorbent loading of each xenon separation column has a redundancy of 50% to 300%, and the adsorbent is selected from one or more combinations of coconut shell activated carbon, coal-based activated carbon, or carbon molecular sieve.

[0096] Furthermore, the filtration mechanism includes a coarse filter 31 connected between the air compressor 2 and the refrigerated dryer 3 via a pipe, a fine filter 32 connected to the refrigerated dryer 3, and an ultrafiltration filter 33 connected to the fine filter 32; the ultrafiltration filter 33 is connected to an imide hollow fiber membrane separator via a pipe.

[0097] Furthermore, the volume calculation formula for a single buffer tank of the buffer mechanism used for xenon purification and concentration is as follows: The formula for calculating the total volume of a single buffer mechanism is: Where V is the volume of the pre-stage column, m is the volume of the pre-stage desorption column, n is the number of tanks connected in series, and b is the number of cleaning cycles.

[0098] Furthermore, the formula for the amount of adsorbent used in the xenon separation column of each purification and concentration unit is as follows: , For each desorption specific volume number, The value is set to 1. For the volume of each level of filled column, where The volume of the first-stage inlet gas. denoted as the dynamic adsorption coefficient of each column packing level.

[0099] The aforementioned buffering mechanism can use a coil as the buffering mechanism, which can further improve the buffering effect.

[0100] Example 1:

[0101] Gas extraction and enrichment: Air is drawn in by air compressor 2. After large-particle impurities are filtered out by sampling head 1, the air enters air compressor 2. Air compressor 2 then transmits the gas to coarse filter 31 for filtration. After the airflow temperature is cooled by refrigerated dryer 3, it passes through fine filter 32 and ultrafine filter 33 to remove impurities with a particle size greater than 0.01μm. Finally, it passes through several series-connected polyimide hollow fiber membrane separators to remove constant components in the air, and then enters the first-stage buffer mechanism 7 to obtain highly concentrated xenon-rich pure nitrogen membrane product gas.

[0102] First-stage forward pressurized adsorption: When the first-stage xenon separation column A8 is performing adsorption, the xenon-rich pure nitrogen membrane product gas in the first-stage buffer mechanism 7 enters the first-stage xenon separation column A8 through valve 101 to adsorb xenon in the xenon-rich pure nitrogen membrane product gas. Simultaneously, valve 606 and mass flow controller 19 are opened, controlling the discharge flow rate of mass flow controller 19 to be less than the inlet flow rate of valve 101, thereby controlling the adsorption tail gas pressure, which is 0.1 MPa to 0.6 MPa, achieving pressurized adsorption in A8. After the adsorption in the first-stage xenon separation column A8 is completed, it switches to the first-stage xenon separation column B9 for adsorption via valve 202. During adsorption in the first-stage xenon separation column B9, valve 707 and mass flow controller 19 are opened, controlling the discharge flow rate of mass flow controller 19 to be less than the inlet flow rate of valve 102, thereby controlling the adsorption tail gas pressure, which is 0.1 MPa to 0.6 MPa. MPa, to achieve pressurized adsorption of the first-stage xenon separation column B9, and the two xenon separation columns alternately feed xenon-rich pure nitrogen membrane product gas for uninterrupted continuous gas adsorption.

[0103] First-stage low-pressure reverse desorption: Desorption begins immediately after adsorption is complete in the first-stage xenon separation column A8. Firstly, vacuum pump 4 is used to evacuate the first-stage xenon separation column A8 via valve 28028, vacuum line 41, valve 11011, and valve 505 until the column pressure drops to 15 kPa. Then, the vacuum line is closed. The first-stage xenon separation column A8 is then heated to 120℃~220℃ using an electric heating element and maintained for 10~90 minutes for high-temperature vacuum desorption. Next, vacuum pump 4 is used to evacuate the secondary buffer mechanism to a pressure of 2 Pa via valve 28028, vacuum line 41, valve 13013, and valve 14014, before closing vacuum line 41. Then, through valve 202, the pressure of the first-stage xenon separation column B... 9. Valve 7 (07), Mass Flow Controller 2 (21), Valve 9 (09), Gas Pipeline 1 (18), First-Stage Xenon Separator A8, Valve 3 (03), Valve 11 (011), Valve 13 (013), and Valve 14 (014) push the adsorbed exhaust gas from the first-stage xenon separator B9 into the low-pressure desorbed gas in the first-stage xenon separator A8 and into the second-stage buffer mechanism; then, turn to Valve 2 (02), First-Stage Xenon Separator B9, Valve 7 (07), Mass Flow Controller 2 (21), Valve 15 (015), and Valve 14 (014) to pass the adsorbed exhaust gas from the first-stage xenon separator B9 into the second-stage buffer mechanism until the pressure in the second-stage buffer mechanism reaches the specified pressure value or the pressure in the second-stage buffer mechanism no longer increases, then connect to the second-stage xenon separator 13 for second-stage adsorption;

[0104] After adsorption is completed in the primary xenon separator column B9, desorption begins. First, vacuum pump 4 is used to evacuate the primary xenon separator column B9 via valve 28 (028), vacuum line 41, valve 12 (012), and valve 8 (08) until the column pressure drops to 15 kPa. Then, the vacuum line is closed. The primary xenon separator column B9 is then heated to 120℃–220℃ using an electric heating element and maintained for 10–90 minutes for high-temperature vacuum desorption. Vacuum pump 4 is then used to evacuate the secondary buffer mechanism to a pressure of 2 Pa via valve 28 (028), vacuum line 41, valve 13 (013), and valve 14 (014), before closing vacuum line 41. Then, the pressure is reduced by valve 1 (01), the primary xenon separator column A8, and valve 6 (014). 06. Mass flow controller 19, valve 10 010, gas pipeline 20, primary xenon separator B9, valve 4 04, valve 12 012, valve 13 013, and valve 14 014 push the adsorbed exhaust gas from primary xenon separator A8 into the low-pressure desorbed gas in primary xenon separator B9 and into the secondary buffer mechanism; then turn valve 1 01, primary xenon separator A8, valve 6 06, mass flow controller 19, valve 15 015, and valve 14 014 to pass the adsorbed exhaust gas in primary xenon separator A8 into the secondary buffer mechanism until the pressure in the secondary buffer mechanism reaches the specified pressure value or the pressure in the secondary buffer mechanism no longer increases, then connect to secondary xenon separator 13 to perform secondary adsorption;

[0105] First-stage activation and regeneration: After the desorption of the first-stage xenon separator A8 is completed and the desorbed low-temperature desorbed gas is introduced into the second-stage buffer mechanism, the first-stage xenon separator A8 is regenerated. First, the vacuum pump 4 evacuates the first-stage xenon separator A8 through valve 28028, vacuum line 41, valve 11011, and valve 505. Then, the first-stage xenon separator A8 is heated to 250℃~350℃ by an electric heating belt and the temperature is maintained for 120~180 minutes before heating is stopped. Then, the induced draft fan 68 and the on / off switch 69 are turned on. The induced draft fan introduces the low-temperature gas in the freezer to cool the first-stage xenon separator A8 to the adsorption temperature, thus completing the activation and regeneration. The difference between the activation and regeneration of the first-stage xenon separator B9 and the first-stage xenon separator A8 is that, during vacuuming, the valves connecting the first-stage xenon separator B9 to the vacuum line are valve 12012 and valve 808.

[0106] Secondary positive pressure boosting adsorption: The adsorption tail gas from the primary xenon separation column B9 or A8 is passed into the secondary buffer mechanism, and then the low-pressure desorbed gas in the secondary buffer mechanism is pushed into the secondary xenon separation column 13. The exhaust flow rate or exhaust pressure of the pressure regulator 14 is set to be less than the flow rate or pressure of the gas entering the secondary xenon separation column 13, thereby realizing secondary positive pressure boosting adsorption; when the primary adsorption tail gas pushes the low-pressure desorbed gas in the secondary buffer mechanism into the secondary xenon separation column 13, the adsorption tail gas from the primary xenon separation column A8 passes through the gas supply pipeline 18, valve 6 06, mass flow controller 19, valve 15 015, and valve 14 014 to push the low-pressure desorbed gas in the secondary buffer mechanism through... Valve 16016 pushes the low-pressure desorbed gas in the secondary buffer mechanism into the secondary xenon separation column, or through gas pipeline 118, valve 909, valve 15015, and valve 14014, the low-pressure desorbed gas in the secondary buffer mechanism is pushed into the secondary xenon separation column through valve 16016; the adsorbed tail gas of the primary xenon separation column B9 is pushed into the secondary xenon separation column through gas pipeline 220, valve 707, mass flow controller 221, valve 15015, and valve 14014, the low-pressure desorbed gas in the secondary buffer mechanism is pushed into the secondary xenon separation column through valve 16016, or through gas pipeline 220, valve 10, valve 15015, and valve 14014, the low-pressure desorbed gas in the secondary buffer mechanism is pushed into the secondary xenon separation column through valve 16016.

[0107] Secondary low-pressure reverse desorption: After secondary adsorption is completed, vacuum pump 4 is used to evacuate the secondary xenon separation column 13 via valve 28028, vacuum line 41, valve 29029, and valve 18018, reducing the internal pressure of the secondary xenon separation column 13 to 5-20 Pa. After the vacuuming of the secondary xenon separation column 13 is completed, vacuum line 41 is closed, and the temperature of the secondary xenon separation column 13 is heated to 120℃-220℃ and maintained by a heating belt. Then, vacuum pump 4 is used to evacuate the tertiary xenon separation column 16 via vacuum line 41, valve 29029, valve 24024, and valve 22022 to achieve the desired vacuum level. Under negative pressure limit conditions, after heating and maintaining the temperature for 5-120 minutes, valves 18018 and 21021 are connected. The adsorbed tail gas from the first-stage xenon separation column A8 or B9 is pushed through valve 15015, the first buffer group 11, valve 19019, the second-stage xenon separation column 13, valve 18018, valve 24024, and valve 22022. The low-pressure desorbed gas in the second-stage xenon separation column 13 is pushed into the third-stage buffer mechanism 15 until the pressure in the third-stage buffer mechanism 15 reaches the specified pressure value or the pressure in the third-stage buffer mechanism 15 no longer increases, thus completing the second-stage low-pressure reverse desorption.

[0108] Secondary activation and regeneration: After the secondary low-pressure reverse desorption is completed, the secondary xenon separation column 13 is evacuated by vacuum pump 4 through valve 28028, vacuum pipeline 41, valve 13013, and valve 19019, and heated to 280℃~350℃ by electric heating belt, maintained for 120~180min and then heating is stopped. Then the induced draft fan and the opening and closing device are turned on. The induced draft fan introduces the low-temperature gas in the freezer to cool the secondary xenon separation column 13 to the adsorption temperature, thus completing the activation and regeneration.

[0109] Three-stage positive pressure boosting adsorption: The adsorption tail gas from the first-stage xenon separation column A8 or B9 is introduced into the third-stage buffer mechanism 15 through valves 2020 and 21021, and then the low-pressure desorbed gas in the third-stage buffer mechanism 15 is pushed into the third-stage xenon separation column 16 through valve 22022. By setting the discharge flow rate or discharge pressure of the pressure regulator 217 to be lower than the flow rate or pressure when the third-stage xenon separation column 16 is inlet, the adsorption pressure of the third-stage xenon separation column 16 is increased, and the gas is discharged through the pressure regulator 217 in the adsorption pipeline of the third-stage xenon separation column 16.

[0110] When the primary adsorption exhaust gas pushes the low-pressure desorbed gas in the tertiary buffer mechanism 15 into the tertiary xenon separation column 16, the adsorption exhaust gas of the primary xenon separation column A8 is pushed into the tertiary xenon separation column 16 via gas supply line 18, valve 606, mass flow controller 19, valve 2020, and valve 21021, or via gas supply line 18, valve 909, valve 2020, and valve 21021, and via valve 220022; the adsorption exhaust gas of the primary xenon separation column B9 is pushed into the tertiary xenon separation column 16 via gas supply line 20, valve 707, mass flow controller 21, valve 2020, and valve... The low-pressure desorbed gas in the third-stage buffer mechanism 15 is pushed into the third-stage xenon separation column 16 via valve 21021, or via gas pipeline 220, valve 10, valve 2020, and valve 21021. When the first-stage adsorption tail gas pushes the low-pressure desorbed gas in the third-stage buffer mechanism 15 into the third-stage xenon separation column 16, the adsorption tail gas passing through valve 20 can also flow through valve 22022 and then push the low-pressure desorbed gas in the third-stage buffer mechanism 15 into the third-stage xenon separation column 16 via valve 21021 and valve 23023.

[0111] Three-stage low-pressure reverse desorption: After the adsorption of the three-stage xenon separation column 16 is completed, the three-stage xenon separation column 16 is evacuated by vacuum pump 4 through valve 28028, vacuum line 41, valve 29029, and valve 23023, reducing its pressure to 2-25 Pa. The three-stage xenon separation column 16 is then heated to 120-220°C by an electric heating belt. The online measurement and analysis unit is monitored by vacuum pump 4 through valve 28028, vacuum line 41, thermal conductivity detector TCD25, and valve 26026. After the source chamber 24 of the measurement and analysis unit is evacuated to the ultimate vacuum of 2-5 Pa, the evacuation is stopped. Valve 25025 is opened to connect the three-stage xenon separation column 16 and the source chamber 24, and high-temperature desorption vacuum diffusion is carried out in the three-stage xenon separation column 16. After maintaining the temperature for 20-40 minutes, valves 21021 and 23023 are opened. The adsorption tail gas passing through valve 20 flows through valves 21021 and 23023, and the re-desorption gas and vacuum adsorption gas in the three-stage xenon separation column 16 enter the source chamber 24, completing the three-stage low-pressure reverse desorption source preparation.

[0112] Three-stage activation and regeneration: After the three-stage reverse desorption is completed, the three-stage xenon separation column 16 is evacuated by vacuum pump 4 through valves 28028, 29029, and 24024. The three-stage xenon separation column is heated to 250-350°C by electric heating belt and maintained at this temperature for 180 minutes before heating is stopped. Then, the induced draft fan and the opening and closing device are turned on. The induced draft fan introduces the low-temperature gas from the freezer to cool the three-stage xenon separation column 16 to the adsorption temperature, thus completing the activation and regeneration.

[0113] Measurement and Analysis: After the source is manufactured, through... The measuring device measures the radioactive xenon activity in source chamber 24; the vacuum pump 4 evacuates the archive bottle in the xenon storage unit via valve 28 028, vacuum line 41, valve 30 030, and valve 27 027. After evacuation, valves 27 027 and 26 026 are opened to connect source chamber 24, thermal conductivity detector TCD 25, and archive bottle, transferring the xenon gas in source chamber 24 to archive bottle for storage. After pressure equilibrium is achieved, the total xenon concentration in the sample gas is analyzed by the thermal conductivity detector TCD.

[0114] (Refer to the attached diagram) Figure 6 As can be seen, using a radioactive measuring device with a minimum detectable activity (MDA) of 6.5 mBq and a measurement time of 20,000 s, and sampling enrichment for 24 h using the device of this invention, the minimum detectable activity concentration of radioactive xenon-133 in the air is <0.1 mBq / m3.

[0115] Example 2:

[0116] This embodiment employs a sample gas re-concentration process using this device. The purpose is to enable repeated detection of xenon gas between different devices, ensuring the accuracy and reliability of the detection; it also allows for repeated confirmation of the detection effect of the sample gas measured by this device; furthermore, it enhances the accuracy and reliability of early warning capabilities for nuclear leak accidents. Specifically, the enriched and purified sample gas from this device or another device is first evacuated through vacuum pump 4 via valve 28028, vacuum pipeline 41, and valve 13013 to the first buffer group 11. After vacuuming, valve 27027 of one or more designated archive bottles is opened, allowing the sample gas to be transferred to the first buffer group through the pipeline. The sample gas in the first buffer group 11 is then pushed through the adsorption tail gas in the first-stage xenon separation column A8 or B9 into the second-stage xenon separation column 13 for adsorption. The adsorbed tail gas is discharged through pressure regulator 14. After the second-stage adsorption is completed, a second-stage low-pressure reverse desorption process is performed. After the second-stage low-pressure reverse desorption process is completed, the sample gas in the third-stage xenon separation column 16 is pushed through the adsorption tail gas recycling pipeline of the first-stage xenon separation column A8 or B9 into the third-stage xenon separation column 16 for secondary purification adsorption using the first-stage adsorption tail gas. After the adsorption is completed, a third-stage low-pressure reverse desorption process is performed to complete the re-concentration of the sample gas. After the re-concentration is completed, the sample gas is then discharged through the pressure regulator 14. The activity of radioactive xenon in the sample source chamber 24 is measured by the measuring device; then, the designated archive bottle in the xenon storage unit is evacuated by the vacuum pump 4. After the evacuation is completed, the source chamber 24, the thermal conductivity detector TCD25 and the archive bottle are connected, and the sample gas in the source chamber 24 is transferred to the archive bottle for storage. After the pressure is balanced, the total concentration of xenon after re-concentration is analyzed by the thermal conductivity detector TCD25.

[0117] (Refer to the attached diagram) Figure 7 The results show that the total recovery rate of the gas reconcentration of the archive sample is greater than 92%.

[0118] Example 3:

[0119] Routine sampling and monitoring of xenon in the air:

[0120] Using the method described in Example 1 above, gas was extracted from the first-stage xenon separation column A8 and the first-stage xenon separation column B9 for 4 hours, and continuous sampling and monitoring were performed with one sample per 24 hours. Gas was continuously extracted and pre-enriched using a polyimide hollow fiber membrane separator. The first-stage xenon separation columns A8 and B9 were alternately regenerated by adsorption / desorption. When the first-stage xenon separation column A8 was adsorbing, the first-stage xenon separation column B9 was desorbed for 40 minutes, activated for 160 minutes, and cooled for 40 minutes. When the first-stage xenon separation column B9 was adsorbing, the first-stage xenon separation column A8 was desorbed for 40 minutes, activated for 160 minutes, and cooled for 40 minutes. After the second-stage buffer mechanism received the first-stage desorbed gas, it was used to perform adsorption for 40 minutes, desorption for 40 minutes, activation for 120 minutes, and cooling for 40 minutes.

[0121] In the first 5 cycles of a certain sample, after the three-stage buffer mechanism 15 receives the second-stage desorbed gas, it is adsorbed for 40 minutes using the three-stage xenon separation column 16; in the 6th cycle, after the three-stage buffer mechanism 15 receives the second-stage desorbed gas, it is adsorbed for 40 minutes, desorbed for 60 minutes, activated for 100 minutes, and cooled for 40 minutes using the three-stage xenon separation column 16.

[0122] Twenty minutes before receiving the sample gas in source chamber 24, the radioactivity measurement of the previous sample is completed. The previous sample gas is transferred to a file bottle for storage, and the total xenon concentration is analyzed online using a thermal conductivity detector TCD25. Based on the stable xenon background in the air, the effective sampling volume is calculated. Combined with the measured net activity of radioactive 133Xe, the activity concentration of 133Xe in the air or the minimum detectable activity concentration (MDC) is calculated.

[0123] Combined with appendix Figure 8 It can be seen that under the conventional sampling and monitoring mode of 24-hour continuous gas sampling, pure xenon ~7mL can be collected, which is equivalent to a minimum detection limit of less than 0.09mBq / m3, and can be used for background xenon in the air;

[0124] Example 4:

[0125] High-frequency rapid sampling monitoring: High-frequency rapid sampling monitoring uses a certain volume of air intake for nuclear accident emergency monitoring, thereby enabling rapid nuclear accident detection in a short period of time.

[0126] Using the gas extraction and enrichment operation steps in Example 1 above, the polyimide hollow fiber membrane separator was pre-enriched by extracting gas using the membrane separation operating parameters that maximize xenon production within 2 hours. The single-cycle adsorption time of the first-stage xenon separation column A8 or the first-stage xenon separation column B9 was 2 hours. After each cycle of first-stage adsorption, first-stage desorption, second-stage adsorption, second-stage desorption, and third-stage adsorption were performed. The third-stage desorption was then used to generate the source, and measurements and analyses were performed.

[0127] The first-stage xenon separation columns A8 and B9 alternately perform adsorption of xenon-rich pure nitrogen membrane product gas and desorption regeneration of the separation columns; while adsorption occurs in the first-stage xenon separation column A8, desorption, activation, and cooling occur in the first-stage xenon separation column B9; while adsorption occurs in the first-stage xenon separation column B9, desorption, activation, and cooling occur in the first-stage xenon separation column A8; a secondary buffer mechanism receives the first-stage vacuum desorption gas and low-pressure desorption gas, flowing along valve 2, first-stage xenon separation column B9, valve 7, mass flow controller 2, valve 9, first-stage xenon separation column A8, valve 3, valve 11011, valve 13013, and first buffer group 11. The process involves adsorption via valve 18 (018), secondary xenon separation column 13, valve 17, and pressure regulator 14, followed by adsorption via primary xenon separation column B9, desorption via primary xenon separation column A8, and secondary adsorption via valve 1 (01), primary xenon separation column A8, valve 6 (06), mass flow controller 2 (21), valve 10 (010), primary xenon separation column B9, valve 4 (04), valve 12 (012), valve 13 (013), first buffer group 11, valve 18 (018), secondary xenon separation column 13, valve 17, and pressure regulator 1, followed by adsorption via primary xenon separation column A8, desorption via primary xenon separation column B9, and secondary adsorption via secondary adsorption.

[0128] Then, through valve 15 015, first buffer group 11, valve 19 019, secondary xenon separation column 13, valve 18 018, valve 24 024, tertiary xenon separation column 16, and pressure controller two-way carrier gas, secondary desorption and tertiary adsorption are carried out. After the secondary desorption is completed, the tertiary xenon separation column 16 is cooled to the adsorption temperature.

[0129] Vacuum pump 4 is used to evacuate source chamber 24 to a high vacuum through valve 28 (028), vacuum line 41, thermal conductivity detector TCD 25, valve 26 (026), and source chamber gas path. The three-stage xenon separation column 16 is heated to the desorption temperature for three-stage vacuum desorption. The pressure controller 2 is set, and then valves 21 (021) and 23 (023) are opened to vent the three-stage xenon separation column 16, completing the source preparation. The temperature is raised to 350°C for vacuum activation, and the three-stage xenon separation column is cooled to the adsorption temperature for the next sample gas to undergo three-stage adsorption.

[0130] Use two The measuring device continuously receives three stages of desorbed gas to measure radioactive xenon activity. Twenty minutes before receiving the next sample gas in source chamber 24, the radioactive activity measurement of the previous sample gas is completed, and the sample is transferred to a storage bottle for preservation. The total xenon concentration is analyzed using a thermal conductivity detector (TCD25). Based on the stable xenon background in the air, the effective sampling volume is calculated. Combined with the measured net activity of radioactive 133Xe, the concentration of 133Xe activity in the air or the minimum detectable activity concentration (MDC) is calculated.

[0131] After continuously sampling and monitoring 40 to 80 samples, the adsorption columns at each stage are vacuum activated and then cooled to the adsorption temperature to complete the regeneration.

[0132] Combined with appendix Figure 9 As can be seen, high-frequency rapid sampling monitoring at 12 times / day can collect 0.53-0.64 mL of pure xenon, with a detection limit of 7-6 mBq / m3.

[0133] In any of the embodiments 1-4 above, the redundancy of the adsorbent filling in each stage of the xenon separation column can be 50% to 80%, 80% to 100%, 100% to 150%, 150% to 180%, 180% to 200%, 200% to 225%, 225% to 260%, 260% to 280%, or 280% to 300%.

[0134] The scope of protection of this invention is not limited to the above embodiments and their variations. Conventional modifications and substitutions made by those skilled in the art based on the content of these embodiments are all within the scope of protection of this invention.

Claims

1. A multi-mode enrichment analysis device for detecting xenon background in air, characterized by including gas sampling. The gas enrichment unit includes a purification and concentration unit with forward adsorption and reverse desorption interconnected by gas flow pipelines, and a refrigerator (5). The gas sampling and enrichment unit includes an air compressor (2) connected to an air sampling head (1) via a pipe, a refrigerated dryer (3) connected to the air compressor (2) via a pipe, a three-stage gas filtration mechanism connected to the refrigerated dryer (3) via a pipe, and several series-connected polyimide hollow fiber membrane separators connected to the filtration mechanism via pipes. The purification and concentration unit consists of at least three stages of progressive purification and concentration units, and polyimide... The amine hollow fiber membrane separator is connected to the initial purification and concentration unit via pipelines. Each purification and concentration unit is also connected to one or more gas flow pipelines, with at least one gas flow pipeline for interconnection between the purification and concentration units. Each purification and concentration unit also has at least one xenon separation column filled with adsorbent, which is connected to the xenon separation column via a gas flow pipeline to a buffer mechanism consisting of several buffer tanks connected in series or several coils connected in series for xenon purification and concentration. The xenon separation column and the buffer mechanism are also connected to a vacuum pump via gas flow pipelines. (4); Valves for controlling the opening and closing of the gas flow pipeline and instruments for controlling the pressure and flow of the gas flow pipeline, buffer mechanism and xenon separation column are installed on the fittings of the gas flow pipeline. The fittings of the gas flow pipeline, the valves installed on the fittings of the gas flow pipeline, the instruments for controlling the pressure and flow of the gas flow pipeline, buffer mechanism and xenon separation column and several stages of buffer mechanism for gas purification and concentration are all placed in the refrigerator (5). The vacuum pump (4) is placed outside the refrigerator (5) and connected to the xenon separation column and buffer mechanism through the gas flow pipeline. A [missing information - likely a device or mechanism] is provided outside the xenon separation column. A heat-insulating sleeve (6) for desorption and activation of the xenon separation column is placed outside the refrigerator (5). The xenon concentration online measurement and analysis unit is connected to the final primary purification and concentration unit through a pipe. The xenon concentration online measurement and analysis unit includes a xenon storage unit, a β-γ coincidence measurement device (23), a source chamber (24) located in the β-γ coincidence measurement device (23), and a thermal conductivity detector (TCD) (25) connected to the source chamber (24) through a pipe. The xenon storage unit is connected to the thermal conductivity detector (TCD) (25) through a pipe.

2. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 1, characterized in that: The insulation sleeve (6) includes an outer shell (61), on which a cooling channel (62) communicating with the freezer (5) is provided. An inner liner (63) is provided inside the outer shell (61), and an insulation layer (64) is provided between the inner liner (63) and the outer shell (61). A xenon separation column placement cavity (65) is provided inside the inner liner (63), and a xenon separation column is installed in the placement cavity (65). An electric heating belt (66) is wrapped around the xenon separation column. A temperature sensor (67) is also attached to the xenon separation column. The temperature sensor (67) passes through the outer shell (61) and the inner liner (63) and is attached to the xenon separation column. The cooling channel (62) and the placement cavity (65) communicate to form a cooling air duct for the xenon separation column.

3. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 2, characterized in that: The cooling channel (62) is equipped with an induced draft fan (68) and an opener (69) for controlling the opening and closing of the cooling channel (62); the opener (69) is a gate driven by a motor or cylinder.

4. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 3, characterized in that: The aforementioned opener (69) is a pneumatic valve or an electric valve.

5. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 1, characterized in that: The purification and concentration unit includes a primary purification and concentration unit, a secondary purification and concentration unit, and a tertiary purification and concentration unit connected by a gas flow pipeline; the primary purification and concentration unit includes a primary buffer mechanism (7) consisting of one or more buffer tanks connected in series and connected to a polyimide hollow fiber membrane separator, a primary xenon separation column A (8) and a primary xenon separation column B (9) connected to the primary buffer mechanism (7), and a gas flow pipeline connecting the primary xenon separation column A (8) and the primary xenon separation column B (9) to the secondary purification and concentration unit and the tertiary purification and concentration unit.

6. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 5, characterized in that: The gas flow pipeline in the primary purification and concentration unit includes a membrane product gas output pipeline (10) for connecting the primary buffer mechanism (7) to the primary xenon separation column A (8) and the primary xenon separation column B (9), an adsorption pipeline connected to the primary xenon separation column A (8) and the primary xenon separation column B (9), a vacuum pipeline, a low-pressure reverse desorption pipeline connected to the secondary purification and concentration unit, and an adsorption tail gas recycling pipeline connecting the primary xenon separation column A (8) and the primary xenon separation column B (9) to the secondary purification and concentration unit and the tertiary purification and concentration unit; the primary xenon separation column A (8) and the primary xenon separation column B (9) and the primary buffer mechanism (7) are connected to pressure sensors through pipe fittings.

7. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 5, characterized in that: The secondary purification and concentration unit includes a secondary buffer mechanism and a secondary xenon separation column (13) connected to the primary xenon separation column A (8) and the primary xenon separation column B (9) via a gas flow pipeline. The secondary buffer mechanism includes a first buffer group (11) and a second buffer group (12). Its secondary xenon separation column is connected to the first buffer group (11) and the second buffer group (12) via a gas flow pipeline. The secondary xenon separation column (13) is also connected to a pressure regulator (14), a vacuum pump (4) and a pressure sensor via a pipe. The secondary xenon separation column (13) is connected to the tertiary purification and concentration unit via a gas flow pipeline.

8. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 7, characterized in that: The first buffer group (11) and the second buffer group (12) are each composed of several buffer tanks connected in series, and pressure sensors are connected to the first buffer group (11) and the second buffer group (12).

9. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 5, characterized in that: The three-stage purification and concentration unit includes a three-stage buffer mechanism (15) consisting of several buffer tanks connected in series and a three-stage xenon separation column (16), a pressure regulator (17) connected to the three-stage xenon separation column (16) through a pipeline, and a pressure sensor connected to the three-stage buffer mechanism (15) and the three-stage xenon separation column (16) through a pipe fitting. The three-stage xenon separation column (16) is connected to the three-stage buffer mechanism (15) through a gas flow pipeline.

10. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 6, characterized in that: The adsorption pipeline of the first-stage xenon separation column A (8) includes a first-stage buffer mechanism (7), a first-stage xenon separation column A (8), a membrane product gas output pipeline (10) for connecting the first-stage buffer mechanism (7) and the first-stage xenon separation column A (8), a valve (01) connected to the membrane product gas output pipeline (10) via a fitting, a gas delivery pipeline (18) connected to the first-stage xenon separation column A (8), a valve (06) connected to the gas delivery pipeline (18) via a fitting, and a mass flow controller (19) connected to the valve (06) via a fitting; the mass flow controller (19) is also connected to the adsorption pipeline of the first-stage xenon separation column B (9), and the gas delivery pipeline (18) is also used for the adsorption pipeline of the first-stage xenon separation column A (8). (8) and the low-pressure reverse desorption pipeline of the first-stage xenon separation column B (9) and the adsorption tail gas recycling pipeline that provides adsorption tail gas to the second-stage purification and concentration unit and the third-stage purification and concentration unit; the vacuum pipeline of the first-stage xenon separation column A (8) includes a vacuum pump (4), a valve twenty-eight (028) connected to the vacuum pump (4) through a fitting, a vacuum pipe (41) connected to the valve twenty-eight (028), a valve eleven (011) connected to the vacuum pipe (41) through a fitting, a valve five (05) connected to the valve eleven (011) through a fitting, and a gas supply pipeline one (18) connected to the first-stage xenon separation column A (8).

11. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 6, characterized in that: The adsorption pipeline of the first-stage xenon separation column B (9) includes a first-stage buffer mechanism (7), a first-stage xenon separation column B (9), a membrane product gas output pipeline (10) for connecting the first-stage buffer mechanism (7) and the first-stage xenon separation column B (9), a valve two (02) connected to the membrane product gas output pipeline (10) via a fitting, a gas delivery pipeline two (20) connected to the first-stage xenon separation column B (9), a valve seven (07) connected to the gas delivery pipeline two (20) via a pipeline, and a mass flow controller one (19) connected to the gas delivery pipeline two (20) via a pipeline. The gas delivery pipeline two (20) is also used for the first-stage xenon separation column A (8) and the first-stage xenon separation column B (9). 9) The low-pressure reverse desorption pipeline and the adsorption tail gas recycling pipeline that provides adsorption tail gas to the secondary purification and concentration unit and the tertiary purification and concentration unit; the vacuum pipeline of the first-stage xenon separation column B (9) includes a vacuum pump (4), a valve twenty-eight (028) connected to the vacuum pump (4) through a fitting, a vacuum pipe (41) connected to the valve twenty-eight (028), a valve twelve (012) connected to the vacuum pipe (41) through a fitting, a valve eight (08) connected to the valve twelve (012) through a fitting, and a gas supply pipeline two (20) connected to the valve eight (08) through a fitting. The gas supply pipeline two (20) is connected to the first-stage xenon separation column B (9).

12. A multi-mode enrichment analysis device for detecting xenon background in air as described in claim 6 or 11, characterized in that: The low-pressure reverse desorption pipeline of the primary xenon separation column A (8) includes a secondary buffer mechanism, a valve thirteen (013) connected to the secondary buffer mechanism via a fitting, a membrane product gas output pipeline (10), a valve two (02) connected to the membrane product gas output pipeline (10) via a fitting, a primary xenon separation column B (9) connected to the membrane product gas output pipeline (10), a gas delivery pipeline two (20) connected to the primary xenon separation column B (9), a valve seven (07) connected to the gas delivery pipeline two (20) via a fitting, and a valve seven (07) connected via a fitting. Mass flow controller 2 (21), valve 9 (09) connected to mass flow controller 2 (21) via fittings, gas pipeline 1 (18) connected to valve 9 (09) via fittings, first-stage xenon separator A (8) connected to gas pipeline 1 (18), valve 3 (03) connected to first-stage xenon separator A (8) via membrane product gas output pipeline (10) via fittings, valve 11 (011) connected to valve 3 (03) via fittings, and valve 11 (011) and valve 13 (013) connected via fittings.

13. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 6, characterized in that: The low-pressure reverse desorption pipeline of the primary xenon separation column B (9) includes a secondary buffer mechanism, a valve thirteen (013) connected to the secondary buffer mechanism via a fitting, a membrane product gas output pipeline (10), a valve one (01) connected to the membrane product gas output pipeline (10) via a fitting, a primary xenon separation column A (8) connected to the membrane product gas output pipeline (10), a gas delivery pipeline one (18) connected to the primary xenon separation column A (8), a valve six (06) connected to the gas delivery pipeline one (18) via a fitting, and a mass flow meter connected to the valve six (06) via a fitting. The flow controller 2 (21), the valve 10 (010) connected to the flow controller 2 (21) via a pipe fitting, the gas pipeline 2 (20) connected to the valve 10 (010) via a pipe fitting, the first-stage xenon separator B (9) connected to the gas pipeline 2 (20), the valve 4 (04) connected to the first-stage xenon separator B (9) via the membrane product gas output pipeline (10) via a pipe fitting, the valve 12 (012) connected to the valve 4 (04) via a pipe fitting, the valve 12 (012), the valve 13 (013) and the valve 14 (014) are connected via pipe fittings.

14. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 6, characterized in that: The adsorption tail gas recycling pipeline of the first-stage xenon separator A (8) includes a membrane product gas output pipeline (10), a valve one (01) connected to the membrane product gas output pipeline via fittings, the first-stage xenon separator A (8) connected to the membrane product gas output pipeline (10), a gas transmission pipeline one (18) connected to the first-stage xenon separator A (8), a valve six (06) connected to the gas transmission pipeline one (18), a mass flow controller two (21) connected to the valve six (06) via fittings, and a mass flow controller two (21) connected to the mass flow controller two (21). The system includes valve 15 (015) and valve 20 (020) connected by pipe fittings, as well as a first buffer group (11) connected to valve 15 (015), valve 14 (014) and valve 19 (019) connected to the first buffer group (11) by pipe fittings, a second buffer group (12) connected to valve 14 (014) by pipe fittings, valve 21 (021) connected to valve 20 (020) by pipe fittings, and a third-level buffer mechanism (15) connected to valve 21 (021) by pipe fittings.

15. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 6, characterized in that: The adsorption tail gas recycling pipeline of the first-stage xenon separation column B (9) includes a membrane product gas output pipeline (10), a valve two (02) connected to the membrane product gas output pipeline via a fitting, the first-stage xenon separation column B (9) connected to the membrane product gas output pipeline (10), a gas transmission pipeline two (20) connected to the first-stage xenon separation column B (9), a valve seven (07) connected to the gas transmission pipeline two (20), a mass flow controller two (21) connected to the valve seven (07) via a fitting, and a mass flow controller two (21) connected to the mass flow controller two (21). The system includes valve 15 (015) and valve 20 (020) connected by pipe fittings, as well as a first buffer group (11) connected to valve 15 (015), valve 14 (014) and valve 19 (019) connected to the first buffer group (11) by pipe fittings, a second buffer group (12) connected to valve 14 (014) by pipe fittings, valve 21 (021) connected to valve 20 (020) by pipe fittings, and a third-level buffer mechanism (15) connected to valve 21 (021) by pipe fittings.

16. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 7, characterized in that: The gas flow pipeline in the secondary purification and concentration unit includes the adsorption pipeline of the secondary xenon separation column (13), the low-pressure reverse desorption pipeline and the vacuum pipeline, as well as the vacuum pipeline of the secondary buffer mechanism.

17. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 16, characterized in that: The adsorption pipeline of the secondary xenon separation column (13) includes valve 15 (015), a first buffer group (11) connected to valve 15 (015) via a pipe fitting, valve 14 (014) connected to the first buffer group (11) via a pipe fitting, a second buffer group (12) connected to valve 14 (014) via a pipe fitting, valve 16 (016) connected to the second buffer group (12) via a pipe fitting, the secondary xenon separation column (13) connected to valve 16 (016) via a pipe fitting, valve 17 (017) connected to the secondary xenon separation column (13) via a pipe fitting, and pressure regulator 1 (14) connected to valve 17 (017) via a pipe fitting.

18. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 16, characterized in that: The low-pressure reverse desorption pipeline of the secondary xenon separation column (13) includes valve 15 (015), a first buffer group (11) connected to valve 15 (015) via a pipe fitting, valve 19 (019) connected to the first buffer group (11) via a pipe fitting, the secondary xenon separation column (13) connected to valve 19 (019) via a pipe fitting, valve 18 (018) connected to the secondary xenon separation column (13) via a pipe fitting, valve 21 (021) connected to valve 18 (018) via a pipe fitting, and a tertiary buffer mechanism (15) connected to valve 21 (021) via a pipe fitting; the vacuum pipeline of the secondary xenon separation column (13) includes a vacuum pump (4), valve 28 (028) connected to the vacuum pump (4) via a pipe fitting, and a pump connected to valve 28 (028) via a pipe fitting. Vacuum tube (41), valve 29 (029) connected to vacuum tube (41) via fitting, valve 18 (018) connected to valve 29 (029) via fitting, and valve 18 (018) connected to secondary xenon separation column (13) via fitting; the vacuum pipeline of the secondary buffer mechanism includes vacuum pump (4), valve 28 (028) connected to vacuum pump (4) via fitting, vacuum tube (41) connected to valve 28 (028), valve 13 (013) connected to vacuum tube (41) via fitting, first buffer group (11) connected to valve 13 (013) via fitting, valve 14 (014) connected to first buffer group (11) via fitting, and second buffer group (12) connected to valve 14 (014) via fitting.

19. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 9, characterized in that: The gas flow pipeline in the three-stage purification and concentration unit includes the adsorption pipeline, vacuum pipeline, and low-pressure reverse desorption pipeline of the three-stage xenon separation column (16) and the vacuum pipeline of the three-stage buffer mechanism (15); the adsorption pipeline includes valve 20 (020), mass flow controller 2 (21) connected to valve 20 (020) through a fitting, valve 21 (021) connected to valve 20 (020) through a fitting, the three-stage buffer mechanism (15) connected to valve 21 (021) through a fitting, valve 22 (022) connected to the three-stage buffer mechanism (15) through a fitting, valve 22 (022) connected to the three-stage xenon separation column (16) through a fitting, and pressure regulator 2 (17) connected to the three-stage xenon separation column (16) through a fitting; the vacuum pipeline of the three-stage xenon separation column (16) includes Vacuum pump (4), valve 28 (028) connected to vacuum pump (4) via fittings, valve 29 (029) connected to valve 28 (028) via fittings, valve 23 (023) or valve 24 (024) connected to valve 29 (029) via fittings, valve 23 (023) and valve 24 (024) are connected to the three-stage xenon separation column (16) via fittings; the vacuum pump (4) of the three-stage buffer mechanism (15), valve 28 (028) connected to vacuum pump (4) via fittings, valve 29 (029) connected to valve 28 (028) via fittings, valve 21 (021) connected to valve 29 (029) via fittings, valve 21 (021) is connected to the three-stage buffer mechanism (15) via fittings.

20. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 19, characterized in that: The low-pressure reverse desorption pipeline of the three-stage xenon separation column (16) includes valve twenty-one (021), valve twenty-three (023) connected to valve twenty-one (021) through a fitting, valve twenty-three (023) connected to the three-stage xenon separation column (16) through a fitting, and valve twenty-five (025) connected to the three-stage xenon separation column (16) of the three-stage purification and concentration unit. The three-stage xenon separation column (16) of the three-stage purification and concentration unit is connected to an online xenon concentration measurement and analysis unit through valve twenty-five (025) using a fitting.

21. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 1, characterized in that: A valve 26 (026) is installed on the pipe connecting the source chamber (24) of the thermal conductivity detector TCD (25) and the β-g coincidence measurement device (23) of the measurement and analysis unit. The xenon storage unit is connected to the valve 26 (026) through the pipe.

22. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 21, characterized in that: The online measurement and analysis unit is also connected to a vacuum pipeline. The vacuum pipeline of the online measurement and analysis unit includes a vacuum pump (4), a valve 30 (030) connected to the vacuum pump (4) through a pipe fitting, a thermal conductivity detector TCD (25) connected to the valve 30 (030) through a pipe fitting, a valve 26 (026) connected to the valve thermal conductivity detector TCD (25) through a pipe fitting, a valve 25 (025) connected to the valve 26 (026) through a pipe fitting, and a source chamber (24) connected to the valve 25 (025) through a pipe fitting.

23. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 7, characterized in that: The first buffer group (11) and the secondary xenon separation column (13) are connected to a xenon storage unit through pipe fittings and valves. The first buffer group (11), the secondary xenon separation column (13) and the tertiary purification and concentration unit are connected in series through pipe fittings and several valves to form a xenon storage unit re-concentration mechanism.

24. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 23, characterized in that: The xenon storage unit includes a vacuum line for the xenon storage unit and several file bottles (26), and a valve twenty-seven (027) connected to the file bottles (26) via a pipe fitting. The valve twenty-seven (027) is connected to the thermal conductivity detector TCD (25) via a pipe fitting.

25. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 24, characterized in that: The vacuum line of the xenon archive storage unit includes a vacuum pump (4), a valve 28 (028) connected to the vacuum pump (4) via a fitting, a valve 30 (030) connected to the valve 28 (028) via a fitting, and a valve 27 (027) connected to the archive bottle (26) via a fitting.

26. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 1, characterized in that: The freezer (5) is cooled by an air compressor, and its temperature is controlled within -28℃ to 18℃.

27. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 1, characterized in that: The adsorbent loading of each xenon separation column has a redundancy of 50% to 300%, and the adsorbent is selected from one or more combinations of coconut shell activated carbon, coal-based activated carbon, or carbon molecular sieve.

28. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 9, characterized in that: The adsorbent filling amount in the three-stage xenon separation column (16) is 20% to 300% redundant.

29. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 1, characterized in that: The filtration mechanism includes a coarse filter (31) connected between the air compressor (2) and the refrigerated dryer (3) via a pipe, a fine filter (32) connected to the refrigerated dryer (3), and an ultrafiltration filter (33) connected to the fine filter (32); the ultrafiltration filter (33) is connected to an imide hollow fiber membrane separator via a pipe.

30. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 1, characterized in that: The volume calculation formula for a single buffer tank of the buffer mechanism used for xenon purification and concentration is as follows: ; The formula for calculating the total volume of a single buffer mechanism is: Where V is the volume of the pre-stage column, m is the volume of the pre-stage desorption column, n is the number of tanks connected in series, and b is the number of cleaning cycles.

31. The multi-mode enrichment analysis device for detecting xenon background in air as described in claim 1, characterized in that: The formula for the amount of adsorbent used in the xenon separation column of each purification and concentration unit is as follows: , For each desorption specific volume number, where Set to 1. For the volume of each level of filled column, where The volume of the first-stage inlet gas. denoted as the dynamic adsorption coefficient of each level of column packing.

32. The enrichment process of a multi-mode enrichment analysis device for detecting xenon background in air as described in any one of claims 1-31, characterized in that, The enrichment process includes the following steps: Gas extraction and enrichment: Air is drawn in by an air compressor, filtered by a sampling head to remove large-particle impurities, cooled by a refrigerated dryer, and filtered to remove impurities with a particle size greater than 0.01μm. Finally, it passes through several series-connected separators containing polyimide hollow fiber membranes to remove the constant components in the air, resulting in highly concentrated xenon-rich pure nitrogen membrane product gas. In the first stage of forward pressurized adsorption, the xenon-rich pure nitrogen membrane product gas enters the first-stage buffer mechanism through a pipeline. The xenon-rich pure nitrogen membrane product gas is then fed from the first-stage buffer mechanism into the first-stage xenon separation column A or B through the adsorption pipeline of the first-stage xenon separation column A or B. The mass flow controller controls the exhaust gas pressure to perform the first-stage forward pressurized adsorption. The exhaust gas after adsorption by the adsorbent in the first-stage xenon separation column A or B is discharged through the mass flow controller in the adsorption pipeline. The first-stage xenon separation column A and the first-stage xenon separation column B work alternately. When one performs the adsorption process, the other performs the low-pressure reverse desorption process. After the first-stage adsorption is completed, the first-stage low-pressure reverse desorption process begins. First-stage low-pressure reverse desorption: After the adsorption of the first-stage xenon separation column A or B is completed, the column is first vented and then evacuated using a vacuum pump and vacuum line to reduce the internal pressure. Once the internal pressure reaches its limit, the vacuum line of the first-stage xenon separation column A or B is closed. The column is then heated to 120℃~220℃ using an electric heating element. Next, the vacuum pump is used to evacuate the second-stage buffer mechanism through the vacuum line, reducing the pressure to its limit. Finally, the vacuum line of the second-stage buffer mechanism is closed, and the pressure of the first-stage xenon separation column A or B is reduced to its limit. The low-pressure reverse desorption pipeline of separation column B is connected to the secondary buffer mechanism, and the temperature of the primary xenon separation column A or primary xenon separation column B is maintained for 10-90 minutes for high-temperature vacuum desorption. The vacuum desorption gas and low-pressure desorption gas in the primary xenon separation column A or primary xenon separation column B are pushed to the secondary buffer mechanism through the adsorption tail gas recycling pipeline of the primary xenon separation column A or primary xenon separation column B. Then, the adsorption tail gas of the primary xenon separation column B or primary xenon separation column A is introduced into the secondary buffer mechanism through the adsorption tail gas recycling pipeline of the primary xenon separation column A or primary xenon separation column B until the pressure of the secondary buffer mechanism reaches the specified pressure value or the pressure of the secondary buffer mechanism no longer increases. First-stage activation and regeneration: Vacuum is drawn from the first-stage xenon separation column A or B using a vacuum pump and vacuum piping. The first-stage xenon separation column A or B is then heated to 250℃~350℃ using an electric heating belt. After maintaining the temperature for a certain period of time, the heating is stopped. Then, the induced draft fan is turned on to introduce the low-temperature gas from the freezer to cool the first-stage xenon separation column A or B to the adsorption temperature, thus completing the activation and regeneration. The second-stage forward pressurization adsorption uses the adsorption tail gas recovery pipeline of the first-stage xenon separation column A or the first-stage xenon separation column B to push the first-stage desorbed gas in the second-stage buffer mechanism into the second-stage xenon separation column for secondary adsorption and purification. By setting the exhaust pressure of pressure regulator one, the adsorption tail pressure of the second-stage xenon separation column is increased to perform second-stage forward pressurization adsorption. Secondary low-pressure reverse desorption: After the secondary adsorption is completed, the secondary xenon separation column is evacuated through a vacuum pump and a vacuum line to reduce the pressure inside the column. After the secondary xenon separation column is evacuated, the secondary xenon separation column is heated to 120℃~220℃ through a heating belt. The tertiary buffer mechanism is then evacuated through a vacuum pump and a vacuum line to reach the ultimate negative pressure. After maintaining the temperature for a certain period of time, the tail gas from the primary adsorption is introduced into the low-pressure reverse desorption line of the secondary xenon separation column, pushing the secondary desorbed gas remaining in the secondary xenon separation column into the tertiary buffer mechanism until the pressure in the tertiary buffer mechanism reaches the specified pressure value or the pressure in the tertiary buffer mechanism no longer increases, thus completing the secondary low-pressure reverse desorption. Secondary activation and regeneration: The secondary xenon separation column is evacuated through a vacuum pump and a vacuum line, and then heated to 280℃~350℃ by an electric heating belt. After maintaining the temperature for a certain period of time, the heating is stopped. Then, the induced draft fan is turned on to introduce low-temperature gas from the freezer to cool the secondary xenon separation column to the adsorption temperature, thus completing the activation and regeneration. After the three-stage positive pressure adsorption and the two-stage desorption are completed, the adsorption tail gas is recycled through the adsorption tail gas recycling pipeline of the first-stage xenon separation column A or the first-stage xenon separation column B. The first-stage adsorption tail gas pushes the second-stage desorbed gas stored in the three-stage buffer mechanism into the three-stage xenon separation column for three-stage purification adsorption. By setting the emission rate of pressure regulator two, the adsorption pressure of the three-stage xenon separation column is increased. The tail gas after the three-stage xenon separation column pressure adsorption is discharged through pressure regulator two in the adsorption pipeline of the three-stage xenon separation column. Three-stage low-pressure reverse desorption: After the three-stage adsorption is completed, the three-stage xenon separation column is evacuated through a vacuum pump and the vacuum line of the three-stage xenon separation column to reduce the pressure inside the column. After the three-stage xenon separation column is evacuated, it is heated to 120℃~220℃ by an electric heating belt. The source chamber of the online measurement and analysis unit is evacuated to the ultimate vacuum through a vacuum pump and the vacuum line of the online measurement and analysis unit. The three-stage xenon separation column and the source chamber are connected to carry out high-temperature desorption vacuum diffusion of the three-stage xenon separation column. After maintaining the temperature for a certain time, the vacuum desorption gas and re-desorption gas remaining in the three-stage xenon separation column are pushed into the source chamber through the low-pressure reverse desorption line of the three-stage purification and concentration unit, thus completing the three-stage low-pressure reverse desorption source preparation. Three-stage activation and regeneration: The three-stage xenon separation column is evacuated by a vacuum pump and a vacuum pipeline, and then heated to 250℃~350℃ by an electric heating belt. After maintaining the temperature for 180 minutes, the heating is stopped. Then, the induced draft fan is turned on to introduce low-temperature gas from the freezer to cool the three-stage xenon separation column to the adsorption temperature, thus completing the activation and regeneration. Measurement and Analysis: After source preparation is completed, the radioactive xenon activity in the source chamber is measured using a β-γ coincidence measurement device; the archive bottle in the xenon storage unit is evacuated using a vacuum pump. After evacuation, the source chamber, thermal conductivity detector (TCD), and archive bottle are connected, and the sample gas in the source chamber is transferred to the archive bottle for storage. After pressure equilibrium is achieved, the total xenon concentration is analyzed using a thermal conductivity detector (TCD).

33. The enrichment process of a multi-mode enrichment analysis device for detecting xenon background in air as described in claim 32, characterized in that, It also includes a sample gas re-concentration process in the xenon storage unit, which includes: Secondary adsorption and desorption of samples: First, the first buffer group is evacuated using a vacuum pump and the vacuum line of the first buffer group. After evacuation, the sample gas is transferred to the first buffer group through the pipeline by opening the valve in the designated file bottle. The adsorption tail gas is then connected to the first buffer group through the adsorption tail gas recycling pipeline of the first-stage xenon separation column A or B. The sample gas in the first buffer group is pushed into the second-stage xenon separation column for adsorption using the first-stage adsorption tail gas. The tail gas after adsorption by the adsorbent in the second-stage xenon separation column is discharged through the pressure regulator in the adsorption pipeline of the second-stage xenon separation column. After the second-stage adsorption is completed, a second-stage low-pressure reverse desorption process is performed. After the second-stage low-pressure reverse desorption process is completed, the sample gas is transferred to the second-stage xenon separation column. The adsorption tail gas recycling pipeline of either the first-stage xenon separation column A or the first-stage xenon separation column B uses the first-stage adsorption tail gas to push the second-stage desorption sample gas stored in the third-stage buffer mechanism into the third-stage xenon separation column for secondary purification and adsorption. After adsorption, a third-stage low-pressure reverse desorption is performed to complete the re-concentration of the sample gas. After re-concentration, the activity of radioactive xenon in the sample source chamber is measured by a β-γ coincidence measurement device. Then, a vacuum pump is used to evacuate the designated archive bottle in the xenon storage unit. After evacuation, the source chamber, thermal conductivity detector (TCD), and archive bottle are connected, and the sample gas in the source chamber is transferred to the archive bottle for storage. After pressure equilibrium, the total xenon concentration after re-concentration is analyzed by the thermal conductivity detector (TCD).

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