Rare gas rectification extraction refining device and extraction method
By employing multi-stage cryogenic distillation and flash evaporation processes and synergistic control methods, the problem of substandard purity in rare gas extraction devices has been solved, enabling the separation and purification of high-purity krypton and xenon to meet the needs of the semiconductor and microelectronics industries.
Patent Information
- Application Number
- CN202511565026.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-30
- Publication Date
- 2026-01-06
AI Technical Summary
Existing rare gas extraction devices suffer from problems such as insufficient purity and unsatisfactory operating results, especially in the separation and purification of high-purity rare gases, which is difficult to meet the needs of the semiconductor and microelectronics industries.
A multi-stage series cryogenic distillation and flash evaporation process is adopted, combined with the coordinated control of temperature, pressure and composition. Krypton and xenon are efficiently separated through a rare gas distillation extraction and refining device, and multi-stage separation and purification are carried out using heaters and condensers.
It significantly improves the purity of krypton and xenon to 99.999% and 99.9995% respectively, while ensuring the safety and operational reliability of the device, adapting to fluctuations in feed composition, and achieving efficient rare gas extraction.
Smart Images
Figure CN121274591A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of cryogenic equipment technology, specifically relating to a rare gas distillation extraction and purification device and extraction method. Background Technology
[0002] Rare gases, primarily including helium, neon, krypton, and xenon, are scarce resources with high added value, thus earning them the nickname "golden gases" in the industry. With China's high-quality economic development, rare gases are increasingly widely used in industries such as precision equipment manufacturing, biomedicine, aerospace, nuclear energy, semiconductors, and quantum computing, especially in the field of electronic specialty gases. Electronic specialty gases are indispensable fundamental raw materials for industries such as integrated circuits, optoelectronics, and microelectronics, particularly in the manufacturing of very large-scale integrated circuits, liquid crystal display devices, and semiconductor materials. Their purity directly affects the quality, integration, specific technical indicators, and yield of optoelectronic and microelectronic components, as well as the accuracy of circuits and devices.
[0003] With the development of semiconductor and microelectronics technologies towards high performance and high integration, and the high-quality development of related industries, higher requirements have been placed on the purity of rare gases, making the separation and purification of rare gases increasingly critical. Initially, only a few countries internationally, such as the United States, Germany, and Russia, were capable of manufacturing rare gas refining and extraction equipment. However, the high cost of imported complete sets of equipment limited the development of devices for extracting neon, helium, krypton, and xenon. Among these imported devices, the highest extraction capacity for lean krypton and xenon was only 210 Nm³. 3 / h, crude neon-helium extraction capacity is only 15 Nm 3 As the rare gas market continues to expand, some domestic steel mills have begun importing rare gas extraction equipment from abroad, attempting to develop the rare gas industry by leveraging their existing large-scale air separation facilities. However, due to foreign technological monopolies, the operational performance of these devices is not ideal, and the product quality falls far short of international standards.
[0004] Neon, krypton, and xenon are primarily extracted from the air through gas liquefaction and fractionation methods in air separation devices. However, the volumetric concentrations of neon, helium, krypton, and xenon in the air are extremely low, at 18 ppm, 5.2 ppm, 1.14 ppm, and 0.086 ppm, respectively, making the extraction of these rare gases from traditional air separation devices technically challenging. Therefore, there is an urgent need to develop advanced equipment for the purification and refining of high-purity rare gases. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of the prior art and to provide a rare gas distillation extraction and purification apparatus and extraction method.
[0006] The specific technical solution adopted in this invention is as follows:
[0007] In a first aspect, the present invention provides a rare gas distillation extraction and purification apparatus, comprising a first distillation system, a second distillation system, a flash evaporation system, a fourth distillation system, and a fifth distillation system connected in series; each distillation system is provided with a heater, a distillation column, and a condenser from bottom to top; the flash evaporation system is provided with a third heater, a flash tank, and a third condenser from bottom to top.
[0008] The first distillation column in the middle of the first distillation system receives a krypton-xenon mixture from the upstream demethanizing unit; the first condenser at the top of the first distillation system receives liquid nitrogen and nitrogen gas from the outside as a cold source; the liquid phase outlet of the first distillation column is connected to the second distillation column in the middle of the second distillation system through a pipeline; the nitrogen gas outlet at the top of the first distillation system is connected to the fifth condenser at the top of the fifth distillation system through a pipeline.
[0009] The krypton outlet at the top of the second distillation column in the second distillation system is connected to the second condenser; the krypton outlet at the top of the second condenser is connected to the flash tank in the flash system via a pipeline; the liquid phase outlet at the bottom of the second condenser is connected to the fourth distillation column in the fourth distillation system via a pipeline.
[0010] The gas phase outlet at the top of the flash tank is divided into two branches, one branch enters the third condenser, and the other branch returns to the inlet of the flash tank; the liquid phase outlet at the bottom of the flash tank is connected to the third heater at the bottom of the flash system; the product liquid krypton outlet of the third heater is connected to the external filling system through a pipeline.
[0011] The vapor outlet at the top of the fourth distillation column in the middle of the fourth distillation system is connected to the fourth condenser at the top; the vapor outlet at the top of the fourth condenser is connected to the fifth distillation column in the middle of the fifth distillation system through a pipeline; the liquid outlet at the bottom of the fourth distillation column is vented through a pipeline to the fourth heater at the bottom of the fourth distillation system.
[0012] The vapor outlet at the top of the fifth distillation column is connected to the fifth condenser. The outlet of the fifth condenser is divided into two branches: one branch flows back to the fifth distillation column, and the other branch is led out to vent. The liquid outlet at the bottom of the fifth distillation column is connected to the fifth heater at the bottom of the fifth distillation system through a pipeline. The product liquid xenon outlet of the fifth heater is connected to the external filling system through a pipeline.
[0013] Preferably, the shell-side inlet of the first condenser receives nitrogen and liquid nitrogen as a cold source; the shell-side inlets of the second, third, fourth, and fifth condensers receive nitrogen as a cold source.
[0014] Preferably, the top and bottom of the distillation column in each distillation system are connected to the condenser and heater via flanges or welding, respectively; each distillation system is designed with a vacuum to meet the requirements for mechanical strength and high-vacuum helium mass spectrometry leak detection.
[0015] Preferably, the first, second, fourth, and fifth distillation columns are all equipped with metal packing and a distributor for uniformly distributing gas and liquid phases, as well as support members for supporting the metal packing and clamping members for fixing the metal packing.
[0016] Furthermore, the notch angle of the toothed design at the bottom of the distributor is 45°~60°, and the height of the tooth is set to 2~5 mm.
[0017] Furthermore, the spacing between the grid bars of the support member is set to 20~30 mm; the spacing between the grid bars of the clamping member is set to 30~50 mm.
[0018] Preferably, the heater and condenser in each distillation system are connected to the component analysis control device, the temperature control device, and the liquid level control device; the distillation columns are connected to the component analysis control device, the temperature control device, and the pressure control device.
[0019] Secondly, the present invention provides a method for extracting rare gases using the rare gas distillation and purification apparatus described in the first aspect, the specific steps of which are as follows:
[0020] S1: The krypton-xenon mixture from the upstream demethanizing unit enters the first distillation column in the middle of the first distillation system; the first condenser receives liquid nitrogen from the liquid nitrogen storage tank and nitrogen from the nitrogen generator as a cold source; the first heater at the bottom provides heat to generate rising steam; in the first distillation column, the krypton-xenon mixture undergoes initial separation, wherein the low-boiling-point components are condensed by the first condenser and the gas phase is returned to the demethanizing unit through a pipeline, while the liquid phase is returned to the first distillation column for further distillation; the krypton-xenon concentrate at the bottom of the first distillation column enters the second distillation column in the middle of the second distillation system; the nitrogen after heat exchange at the top of the first condenser enters the fifth condenser at the top of the fifth distillation system through a pipeline;
[0021] S2: The second heater at the bottom of the second distillation system provides heat to generate rising steam; the krypton-xenon concentrate from the first distillation column is separated into krypton and xenon in the second distillation column, wherein the low-boiling-point krypton gas enters the flash tank in the middle of the flash evaporation system after passing through the second condenser; the crude xenon liquid at the bottom of the second distillation column enters the fourth distillation column in the middle of the fourth distillation system.
[0022] S3: Krypton gas from the second condenser enters the flash tank for separation; the third heater at the bottom provides heat to generate rising steam; the krypton gas at the top of the flash tank enters the third condenser at the top for condensation, part of which is condensed into liquid krypton product and connected to the external filling system, while the uncondensed gas is released into the air.
[0023] S4: The crude xenon liquid from the second distillation column is distilled in the fourth distillation column. The light component xenon gas enters the fourth condenser at the top for heat exchange and then enters the fifth distillation column of the fifth distillation system. The heavy component is evaporated by the fourth heater at the bottom and then vented.
[0024] S5: Xenon gas from the fourth condenser is further distilled in the fifth distillation column. The light component krypton rises into the fifth condenser, is vented after heat exchange, and the heavy component xenon is obtained after passing through the bottom fifth heater to obtain product xenon, which is connected to the external filling system.
[0025] Preferably, the operating temperature of the first heater, second heater, third heater, fourth heater and fifth heater is controlled at -165℃ to -100℃, and the operating pressure is controlled at 0.14 to 0.48 MPa.
[0026] Preferably, the temperature range of the cold source introduced into the condenser is controlled between -190℃ and -180℃, and the pressure range is controlled between 0.40 and 0.50 MPa.
[0027] Compared with the prior art, the present invention has the following advantages:
[0028] (1) This invention employs a multi-stage series cryogenic distillation and flash evaporation process to fully utilize the difference in boiling points between krypton and xenon components for efficient separation. This process not only significantly increases the concentration of krypton in the intermediate product, laying a solid foundation for subsequent refining, but also flexibly adapts to fluctuations in the feed components. The entire system is tightly coupled, has strong anti-interference capabilities, and can ultimately stably produce krypton products with a purity of up to 99.999% and xenon products with a purity of 99.9995%.
[0029] (2) This invention integrates coordinated control of temperature, pressure, and composition (online monitoring) to precisely regulate the operating conditions of key processes such as distillation and flash evaporation. This constructs a multi-layered safety protection system, effectively preventing risks such as equipment overpressure, local overheating, or process malfunctions, and greatly improving the safety and reliability of the entire unit's operation.
[0030] (3) The device provided by the present invention is equipped with a dedicated heating and vaporization device, which can safely and completely convert the residual liquid into a gas phase and then lead it to the venting system, thereby realizing the harmless treatment of the residue. Attached Figure Description
[0031] Figure 1A schematic diagram of the process for the rare gas distillation extraction and purification apparatus provided by the present invention;
[0032] Figure 2 This is a schematic diagram of the distillation system provided by the present invention;
[0033] Figure 3 A schematic diagram of the distributor provided by the present invention;
[0034] Figure 4 This is a schematic diagram of the flash tank provided by the present invention;
[0035] Figure 5 A cross-sectional view of the perforated sealing device provided by the present invention;
[0036] Figure 6 A cross-sectional view of a threaded pipe provided for this invention;
[0037] Figure 7 A cross-sectional view of the stepped sleeve provided by the present invention;
[0038] Figure 8 A cross-sectional view of the threaded sealing device provided by the present invention;
[0039] In the diagram: First distillation system 1, Second distillation system 2, Flash distillation system 3, Fourth distillation system 4, Fifth distillation system 5, First heater 1-1, First distillation column 1-2, First condenser 1-3, Second heater 2-1, Second distillation column 2-2, Second condenser 2-3, Third heater 3-1, Flash tank 3-2, Third condenser 3-3, Fourth heater 4-1, Fourth distillation column 4-2, Fourth condenser 4-3, Fifth heater 5-1, Fifth distillation column 5-2, Fifth condenser 5-3, Metal packing 6, Support component 7, Clamping component 8, Demethane removal unit 9. Detailed Implementation
[0040] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly, provided that there is no mutual conflict.
[0041] In the description of this invention, it should be understood that the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.
[0042] In the description of this invention, it should be understood that the terms "low temperature" and "high temperature" refer to high or low temperatures relative to the temperature of the same medium in the same passage, and should not be construed as indicating or implying relative importance or implicitly specifying the temperature value of the indicated technical feature. Similarly, the terms "high pressure" and "low pressure" refer to high or low pressure relative to the pressure of the same medium in the same passage, and should not be construed as indicating or implying relative importance or implicitly specifying the pressure value of the indicated technical feature.
[0043] like Figure 1 As shown, this invention provides a rare gas distillation extraction and purification apparatus, which includes a first distillation system 1, a second distillation system 2, a flash evaporation system 3, a fourth distillation system 4, and a fifth distillation system 5 connected in series. Each of the first distillation system 1, second distillation system 2, fourth distillation system 4, and fifth distillation system 5 has a heater, a distillation column, and a condenser arranged from bottom to top. The flash evaporation system 3 has a third heater 3-1, a flash tank 3-2, and a third condenser 3-3 arranged from bottom to top. The specific connection methods of each component in each system are as follows:
[0044] In the apparatus provided by this invention, the first distillation column 1-2 in the middle of the first distillation system 1 receives a krypton-xenon mixture from the upstream demethanizing unit 9 as feed gas. If the upstream feed gas is insufficient, it can also be connected to a gas cylinder to obtain a krypton-xenon mixture as a supplementary feed gas. The first condenser 1-3 at the top of the first distillation system 1 receives liquid nitrogen and nitrogen gas from the outside as a cold source. The condenser is used to provide sufficient cooling capacity so that the xenon gas vaporized in the heater can be cooled into liquid xenon near its boiling point. It should be noted that the temperature at the heater is controlled at -165℃ to -100℃, and the operating pressure is controlled at 0.14 to 0.48 MPa. At this temperature, the nitrogen gas is higher than the krypton-xenon mixture and can be used as a heat source for the heater or the column bottom.
[0045] The first heater 1-1 at the bottom of the first distillation system 1 provides heat to generate rising steam in the first distillation column 1-2. In the first distillation system 1, due to the different boiling points and concentrations of the volatile component krypton and the non-volatile component xenon, mass transfer and separation occur through contact with the metal packing. The krypton-xenon mixture undergoes initial separation to obtain a krypton-xenon concentrate. The liquid outlet of the first distillation column 1-2 is connected via a pipe to the second distillation column 2-2 in the middle of the second distillation system 2. The nitrogen outlet at the top of the first distillation system 1 is connected via a pipe to the fifth condenser 5-3 at the top of the fifth distillation system 5.
[0046] In the apparatus provided by this invention, the second distillation column 2-2 in the middle of the second distillation system 2 receives krypton-xenon concentrate from the first distillation column 1-2, and performs preliminary separation of krypton and xenon within the second distillation column 2-2, separating them into krypton gas and crude xenon liquid. The second heater 2-1 at the bottom of the second distillation system 2 provides heat, generating rising steam in the second distillation column 2-2. The krypton gas outlet at the top of the second distillation column 2-2 is connected to the second condenser 2-3. The krypton gas outlet at the top of the second condenser 2-3 is connected via a pipe to the flash tank 3-2 in the flash evaporation system 3. The liquid phase outlet at the bottom of the second condenser 2-3 is connected via a pipe to the fourth distillation column 4-2 in the middle of the fourth distillation system 4; this liquid phase is crude xenon liquid.
[0047] In the apparatus provided by this invention, krypton gas from the second condenser 2-3 enters the flash tank 3-2 in the middle of the third distillation system 3 for further purification. The gas phase outlet at the top of the flash tank 3-2 splits into two branches: one branch enters the third condenser 3-3, and the other branch returns to the inlet of the flash tank 3-2. The liquid phase outlet at the bottom of the flash tank 3-2 is connected to the third heater 3-1 at the bottom of the flash system 3. The liquid krypton from the bottom of the flash tank 3-2 is heated by the third heater 3-1 to obtain product liquid krypton, which is then connected to an external filling system through a pipeline.
[0048] The flash evaporator provided by this invention, such as Figure 4 As shown, the diameter of the flash tank is larger than that of the condenser at the top and the tower connected at the bottom, providing sufficient lateral separation space and necessary longitudinal residence time for the gas and liquid phases inside the tank, so as to ensure that the krypton gas and liquid krypton achieve efficient and stable natural separation under the action of gravity.
[0049] In the apparatus provided by this invention, the fourth distillation column 4-2 in the middle of the fourth distillation system 4 receives crude xenon liquid from the bottom of the second condenser 2-3 and purifies it. The lighter xenon components rise into the top fourth condenser 4-3, while the heavier components flow downwards to the bottom fourth heater 4-1. The xenon gas entering the fourth condenser 4-3 undergoes heat exchange and then enters the fifth distillation column 5-2 of the fifth distillation system 5. The heavier components are evaporated by the bottom fourth heater 4-1 and then vented.
[0050] In the apparatus provided by this invention, xenon gas from the fourth condenser 4-3 enters the fifth distillation column 5-2 for further purification and separation of lighter xenon components. The lighter xenon components rise and enter the top fifth condenser 5-3. The outlet of the fifth condenser 5-3 splits into two branches: one branch carries the condensed liquid xenon back to the fifth distillation column 5-2, and the other branch carries the uncondensed xenon gas, which is then vented. Because the liquid xenon is heavier, it flows downwards to the bottom fifth heater 5-1. After being heated by the bottom fifth heater 5-1, the liquid xenon yields product liquid xenon, which is connected to the external filling system.
[0051] It should be noted that in this invention, the shell-side inlet of the first condenser 1-3 receives nitrogen and liquid nitrogen as a cold source. The shell-side inlets of the second condenser 2-3, the third condenser 3-3, the fourth condenser 4-3, and the fifth condenser 5-3 receive nitrogen as a cold source.
[0052] Figure 2 A schematic diagram of the overall structure of the first distillation system 1 is shown. The distillation column is located in the middle, with its top connected to the condenser via flange or welding, and its bottom connected to the heater via flange or welding. This invention does not limit the connection method; those skilled in the art can configure it according to specific circumstances. Each distillation system employs a vacuum design to ensure effective cryogenic distillation.
[0053] The distillation column is equipped with metal packing 6 and a distributor for equalizing gas and liquid. This invention does not limit the specific form of the metal packing; those skilled in the art can select it according to specific operating conditions. As a preferred embodiment of this invention, the packing can be selected as follows: Figure 3 The distributor shown has a toothed design at the bottom with a notch angle of 45° to 60° and a tooth height of 2 to 5 mm.
[0054] like Figure 2 As shown, the device also includes a support member 7 for supporting the metal packing 6 and a clamping member 8 for fixing the metal packing 6. Preferably, the grid bar spacing of the support member 7 is set to 20~30 mm. The grid bar spacing of the clamping member 8 is set to 30~50 mm.
[0055] Each distillation system's heater and condenser are equipped with component analysis control, temperature control, and level control devices. The distillation column itself is equipped with these same devices. The component analysis control enables both online and offline analysis, effectively monitoring the levels of harmful impurities such as carbon dioxide and nitrous oxide, and analyzing trace impurities in the sample gas, including hydrocarbons, fluorides, oxygen, krypton, and xenon. The level control device precisely controls the liquid level within the system, ensuring continuous and normal operation. The temperature and pressure controls effectively regulate temperature and pressure, ensuring smooth heat exchange and distillation processes.
[0056] It should be noted that during equipment manufacturing, various process holes need to be made in distillation columns or condensers for internal welding, polishing, or cleaning. These holes must be permanently and securely sealed before delivery to ensure absolute sealing of the unit under cryogenic, continuous pressure conditions and prevent any leakage. This invention uses either perforated or non-perforated sealing devices to seal these process holes. The perforated sealing device includes, for example... Figure 5As shown, one end of the perforated sealing device is fixedly welded to the process hole for sealing. Its center has a flat plate with standard threads, which can be screwed into the M20 threaded hole with a solid plug or bolt to achieve a seal. The non-perforated sealing device, on the other hand, is a completely solid flat plate, directly welded to the process hole.
[0057] It should be noted that in cryogenic separation devices, directly welding an external threaded connector to the equipment and then screwing on an internal threaded connector can lead to differences in shrinkage rates and amounts due to variations in the materials and wall thicknesses of the two types of threads. This difference can cause the thread engagement to loosen, creating a potentially fatal leakage path. Therefore, a threaded pipe is required, specifically... Figure 6 As shown. The threaded pipe is a short pipe closed at one end, with a groove structure inside and threads on the groove wall. The closed end is fixed to the equipment body by welding, and the other end is threaded to the external pipeline through the internal groove.
[0058] To precisely connect the pipes between two independent devices, the present invention employs the following... Figure 7 The stepped sleeve shown is provided. Both ends of the stepped sleeve have grooved structures, providing an "insertion-type" positioning reference for connecting pipes from two different towers.
[0059] Figure 8 This is a cross-sectional view of the threaded sealing device provided by the present invention. The threaded sealing device is a long tube closed at one end, typically installed at the feed inlet of a distillation column. The closed end can be connected to the column body by welding. The inner wall of this end has a groove structure, and the groove wall has threads to achieve threaded connection with external pipelines. A distribution hole is provided on the other end to achieve effective distribution of the feed liquid. Discharge holes are provided symmetrically at the distribution holes to balance the fluid flow.
[0060] Example 1
[0061] This embodiment provides a method for extracting rare gases from a krypton-xenon mixture by distillation, the specific steps of which are as follows:
[0062] S1: The krypton-xenon mixture from the upstream demethanizing unit 9 enters the first distillation column 1-2 in the middle of the first distillation system 1, with a pressure of 0.48 MPa and a temperature of -165°C. The first condenser 1-3 receives liquid nitrogen from the liquid nitrogen storage tank and nitrogen from the nitrogen generator as a cold source, with nitrogen conditions of 0.5 MPa and -185°C. The first heater 1-1 at the bottom provides heat to generate rising steam. In the first distillation column 1-2, the krypton-xenon mixture undergoes initial separation, with the low-boiling-point components condensed in the first condenser 1-3, the vapor phase returning to the demethanizing unit 9 via a pipeline, and the liquid phase returning to the first distillation column 1-2 for further distillation. The krypton-xenon concentrate at the bottom of the first distillation column 1-2 enters the second distillation column 2-2 in the middle of the second distillation system 2. The nitrogen gas after heat exchange at the top of the first condenser 1-3 enters the fifth condenser 5-3 at the top of the fifth distillation system 5 via a pipeline. The krypton-xenon concentrate after preliminary treatment by the first distillation system 1 has a pressure of 0.48 MPa and a temperature of -165℃.
[0063] S2: The second heater 2-1 at the bottom of the second distillation system 2 provides heat to generate rising steam. The krypton-xenon concentrate from the first distillation column 1-2 undergoes krypton-xenon separation in the second distillation column 2-2, where the low-boiling-point krypton gas passes through the second condenser 2-3 and enters the flash tank 3-2 in the middle of the flash system 3. The crude xenon liquid at the bottom of the second distillation column 2-2 enters the fourth distillation column 4-2 in the middle of the fourth distillation system 4.
[0064] S3: Krypton gas from the second condenser 2-3 enters the flash tank 3-2 for separation. The third heater 3-1 at the bottom provides heat to generate rising steam. The krypton gas at the top of the flash tank 3-2 enters the third condenser 3-3 at the top for condensation. Part of the condensed product liquid krypton is connected to the external filling system, while the uncondensed gas is vented. The resulting product liquid krypton has a pressure of 0.37 MPa, a temperature of -134℃, and a purity of 99.999%.
[0065] S4: The crude xenon liquid from the second distillation column 2-2 is distilled in the fourth distillation column 4-2. The light component xenon gas enters the fourth condenser 4-3 at the top for heat exchange and then enters the fifth distillation column 5-2 of the fifth distillation system 5. The heavy component is evaporated by the fourth heater 4-1 at the bottom and then vented.
[0066] S5: Xenon gas from the fourth condenser 4-3 is further refined in the fifth distillation column 5-2. The light component, krypton, rises into the fifth condenser 5-3, where it is vented after heat exchange. The heavy component, xenon, passes through the bottom fifth heater 5-1 to obtain product xenon, which is connected to the external filling system. The resulting liquid xenon product has a pressure of 0.14 MPa, a temperature of -102°C, and a purity of 99.9995%.
[0067] In the apparatus provided by this invention, during distillation, rising xenon gas and descending liquid xenon come into contact on the trays, resulting in partial condensation and partial vaporization, producing equilibrium xenon gas. Because the concentration of krypton, a volatile component, in the liquid xenon in contact with the metal packing is higher than that in the next layer of metal packing, the concentration of krypton in the resulting equilibrium gas is also higher than that of the xenon gas from the next layer of metal packing. Thus, the krypton content in the rising xenon continuously increases, while the krypton content in the descending liquid xenon continuously decreases. After passing through the entire apparatus, the liquid xenon undergoes multiple concentrations and is finally drawn from the bottom of the column, yielding high-purity liquid xenon (non-volatile component) and gaseous krypton (volatile component). The final high-purity krypton product has a purity of not less than 99.999%, a nitrogen content of not more than 2 ppm, a xenon content of not more than 2 ppm, and the content of other components of not more than 6 ppm. The final high-purity xenon product has a purity of not less than 99.9995%, a nitrogen content of not more than 1.5 ppm, a krypton content of not more than 1 ppm, and the content of other components of not more than 2.7 ppm.
[0068] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, all technical solutions obtained through equivalent substitution or transformation fall within the protection scope of the present invention.
Claims
1. A rare gas rectification extraction refining apparatus characterized by comprising: The system comprises a first rectification system (1), a second rectification system (2), a flash system (3), a fourth rectification system (4) and a fifth rectification system (5) connected in series; a heater, a rectification tower and a condenser are arranged from bottom to top in each rectification system; a third heater (3-1), a flash tank (3-2) and a third condenser (3-3) are arranged from bottom to top in the flash system (3); The first rectification tower (1-2) in the middle of the first rectification system (1) receives the krypton-xenon mixed gas from the upstream demethanizing device (9); the first condenser (1-3) at the top of the first rectification system (1) receives liquid nitrogen and nitrogen gas from the outside as a cold source; the liquid phase outlet of the first rectification tower (1-2) is communicated with the second rectification tower (2-2) in the middle of the second rectification system (2) through a pipeline; the nitrogen gas outlet at the top of the first rectification system (1) is communicated with the fifth condenser (5-3) at the top of the fifth rectification system (5) through a pipeline; The krypton gas outlet at the top of the second rectification tower (2-2) in the middle of the second rectification system (2) is communicated with the second condenser (2-3); the krypton gas outlet at the top of the second condenser (2-3) is communicated with the flash tank (3-2) in the flash system (3) through a pipeline; the liquid phase outlet at the bottom of the second condenser (2-3) is communicated with the fourth rectification tower (4-2) in the middle of the fourth rectification system (4) through a pipeline; The gas phase outlet at the top of the flash tank (3-2) is divided into two branches, one branch enters the third condenser (3-3), and the other branch returns to the inlet of the flash tank (3-2); the liquid phase outlet at the bottom of the flash tank (3-2) is communicated with the third heater (3-1) at the bottom of the flash system (3); the product liquid krypton outlet of the third heater (3-1) is communicated with the outside filling system through a pipeline; The gas phase outlet at the top of the fourth rectification tower (4-2) in the middle of the fourth rectification system (4) is communicated with the fourth condenser (4-3) at the top; the gas phase outlet at the top of the fourth condenser (4-3) is communicated with the fifth rectification tower (5-2) in the middle of the fifth rectification system (5) through a pipeline; the liquid phase outlet at the bottom of the fourth rectification tower (4-2) is vented after passing through the fourth heater (4-1) at the bottom of the fourth rectification system (2) through a pipeline; The gas phase outlet at the top of the fifth rectification tower (5-2) is communicated with the fifth condenser (5-3), and the outlet of the fifth condenser (5-3) is divided into two branches, one branch returns to the fifth rectification tower (5-2), and the other branch is vented; the liquid phase outlet at the bottom of the fifth rectification tower (5-2) is communicated with the fifth heater (5-1) at the bottom of the fifth rectification system (2) through a pipeline; the product liquid xenon outlet of the fifth heater (5-1) is communicated with the outside filling system through a pipeline.
2. The rare gas rectification extraction refining apparatus according to claim 1, characterized by The shell inlet of the first condenser (1-3) receives nitrogen gas and liquid nitrogen as a cold source; the shell inlets of the second condenser (2-3), the third condenser (3-3), the fourth condenser (4-3) and the fifth condenser (5-3) receive nitrogen gas and also receive liquid nitrogen as a cold source.
3. The rare gas rectification extraction refining apparatus according to claim 1, characterized by The top and bottom of the rectifying column in each rectifying system are connected with the condenser and the heater by flange connection or welding respectively; vacuum design is adopted in each rectifying system.
4. The rare gas rectification extraction refining apparatus according to claim 1, characterized by The first rectifying column (1-2), the second rectifying column (2-2), the fourth rectifying column (4-2) and the fifth rectifying column (5-2) are provided with metal fillers (6) and distributors for dividing gas and liquid, and are further provided with support members (7) for supporting the metal fillers (6) and pressing members (8) for fixing the metal fillers (6).
5. The rare gas rectification extraction refining apparatus according to claim 4, characterized by The gap angle of the tooth-shaped design at the bottom of the distributor is 45°-60°, and the height of the tooth shape is 2-5 mm.
6. The rare gas rectification extraction refining apparatus according to claim 4, characterized by The grid bar spacing of the support member (7) is 20-30 mm, and the grid bar spacing of the pressing member (8) is 30-50 mm.
7. The rare gas rectification extraction refining apparatus according to claim 1, characterized by The heater and the condenser in each rectifying system are connected with the component analysis control device, the temperature control device and the liquid level control device; the rectifying column is connected with the component analysis control device, the temperature control device and the pressure control device.
8. A rare gas extraction method using the rare gas extraction and refining apparatus according to any one of claims 1 to 7, characterized by, The specific steps are as follows: S1: The krypton-xenon mixed gas from the upstream demethanizing device (9) enters the first rectifying column (1-2) in the middle of the first rectifying system (1); the first condenser (1-3) receives liquid nitrogen from a liquid nitrogen storage tank and nitrogen gas from a nitrogen making device as a cold source; the first heater (1-1) at the bottom provides heat to generate rising steam; in the first rectifying column (1-2), the krypton-xenon mixed gas is preliminarily separated, wherein the low-boiling-point components are condensed after passing through the first condenser (1-3) and the gas phase returns to the demethanizing device (9) through a pipeline, and the liquid phase returns to the first rectifying column (1-2) for further rectification; the krypton-xenon concentrate at the bottom of the first rectifying column (1-2) enters the second rectifying column (2-2) in the middle of the second rectifying system (2); the nitrogen gas after heat exchange at the top of the first condenser (1-3) enters the fifth condenser (5-3) at the top of the fifth rectifying system (5) through a pipeline; S2: The second heater (2-1) at the bottom of the second rectifying system (2) provides heat to generate rising steam; the krypton-xenon concentrate from the first rectifying column (1-2) is separated into krypton and xenon in the second rectifying column (2-2), wherein the krypton gas with low boiling point enters the flash tank (3-2) in the middle of the flash system (3) after passing through the second condenser (2-3); the crude xenon liquid at the bottom of the second rectifying column (2-2) enters the fourth rectifying column (4-2) in the middle of the fourth rectifying system (4); S3: The krypton gas from the second condenser (2-3) enters the flash tank (3-2) for separation; the third heater (3-1) at the bottom provides heat to generate rising steam; the krypton gas at the top of the flash tank (3-2) enters the third condenser (3-3) at the top for condensation, and part of the condensed product liquid krypton is connected with an external filling system, and the uncondensed gas is vented; S4: The crude xenon liquid from the second rectifying column (2-2) is rectified in the fourth rectifying column (4-2), wherein the xenon gas with light components enters the fourth condenser (4-3) at the top for heat exchange and then enters the fifth rectifying column (5-2) of the fifth rectifying system (5), and the heavy components are evaporated after passing through the fourth heater (4-1) at the bottom and are vented; S5: The xenon from the fourth condenser (4-3) is further rectified in the fifth rectifying column (5-2), wherein the light component krypton rises into the fifth condenser (5-3) and is vented after heat exchange; the heavy component xenon is connected to the outside filling system after the bottom fifth heater (5-1).
9. The rare gas extraction method according to claim 8, characterized by, The operating temperature of the first heater (1-1), the second heater (2-1), the third heater (3-1), the fourth heater (4-1) and the fifth heater (5-1) is controlled at -165℃ to -100℃, and the operating pressure is controlled at 0.14 to 0.48 MPa.
10. The rare gas extraction method according to claim 8, characterized by, The temperature range of the cold source entering the condenser is controlled at -190℃ to -180℃, and the pressure range is controlled at 0.40 to 0.50 MPa.