Low-temperature adsorption neon removal device

Abstract

The utility model discloses a low-temperature adsorption neon removal device which comprises a gas supply unit, a flash evaporation unit, a purification unit and a Dewar container which are connected in sequence, the flash evaporation unit comprises a liquid-air separation cylinder, the liquid-air separation cylinder is located in the Dewar container, a cold medium is injected into the Dewar container, and the boiling point of the cold medium is lower than that of impurity gas. The purification unit comprises at least two groups of adsorption cylinders connected in parallel, each group of adsorption cylinders comprises at least one adsorption cylinder, and an exhaust pipeline of the liquid-air separation cylinder is connected to the upstream of the adsorption cylinder. According to the device, a gas supply unit provides feed gas to enter a heat exchanger, then the feed gas comes out of the top of a liquid-air separation cylinder of a flash evaporation unit and enters a purification unit, the purification unit comprises two groups of adsorption cylinders, a purifier is formed by connecting at least one adsorption cylinder in series, and under the condition of a temperature zone of a cold medium, the cold medium is injected into a Dewar container; and the boiling point of the cold medium is lower than that of the impurity gas, so that the impurity gas can be separated, and the adsorption barrel can realize continuous operation of the device through two processes of adsorption and regeneration.

Description

Technical Field

[0001] This utility model relates to the field of gas separation technology, and more specifically to a low-temperature adsorption denemonene removal device. Background Technology

[0002] Helium is considered the "golden gas" among gases. Helium resources are primarily derived from natural gas, which contains 1% to 8% helium. Due to its low content, extraction is difficult and costly, and it also contains many impurities. Therefore, there is an urgent need to research new methods to separate helium from other impurities in natural gas beforehand. Since neon and helium have similar boiling points and separation coefficients, the key challenge lies in developing the technical process for separating helium and neon. Using a low-temperature adsorption process to remove neon from helium has proven effective, resulting in higher purity helium after separation. Utility Model Content

[0003] The technical problem to be solved by this invention is how to remove neon impurities from helium and improve the purity of helium after separation.

[0004] This utility model solves the above-mentioned technical problems through the following technical means: a low-temperature adsorption and de-neon device, comprising a gas supply unit, a flash evaporation unit, a purification unit, and a Dewar container connected in sequence. The flash evaporation unit includes a liquid-air separation cylinder located inside the Dewar container, which is filled with a cold medium. The boiling point of the cold medium is lower than that of the impurity gas. The purification unit includes at least two sets of adsorption cylinders connected in parallel, each set of adsorption cylinders including at least one adsorption cylinder. The exhaust pipe of the liquid-air separation cylinder is connected upstream of the adsorption cylinder.

[0005] As a preferred technical solution, it also includes a heat exchange unit, which includes a heat exchanger. The heat exchange unit is located downstream of the gas supply unit and upstream of the purification unit. The product gas pipeline is connected downstream of the adsorption cylinder. The gas supply unit includes a raw material gas pipeline, which exchanges heat with the product gas pipeline through the heat exchanger.

[0006] As a preferred technical solution, each set of adsorption cylinders includes two adsorption cylinders connected in series.

[0007] As a preferred technical solution, each set of adsorption cylinders includes three adsorption cylinders connected in series.

[0008] As a preferred technical solution, the Dewar container includes an inner cylinder and an outer cylinder disposed outside the inner cylinder, with a vacuum cavity formed between the inner cylinder and the outer cylinder.

[0009] As a preferred technical solution, the adsorption cylinder and heat exchanger are located inside the Dewar container.

[0010] As a preferred technical solution, a heat recovery unit is also included, which includes a water bath reheater connected downstream of the purification unit.

[0011] As a preferred technical solution, the gas supply unit, flash evaporation unit, purification unit, and regeneration unit are all connected to a temperature detection device, a pressure detection device, a purity detection device, and a liquid level detection device, which are respectively a thermocouple, a pressure sensor, a helium purity analyzer, and a liquid level gauge.

[0012] As a preferred technical solution, a flow meter is installed on the product's gas pipeline.

[0013] As a preferred technical solution, the liquid-air separation cylinder includes liquid-air separation cylinder A and / or liquid-air separation cylinder B.

[0014] The beneficial effects of this utility model are as follows:

[0015] (1) In this utility model, the gas supply unit provides raw gas into the heat exchanger, and then it comes out from the top of the liquid-air separation cylinder of the flash evaporation unit and enters the purification unit. The purification unit includes two sets of adsorption cylinders. The purifier is composed of at least one adsorption cylinder connected in series. Under the temperature zone of the cold medium, the Dewar container is filled with cold medium. The boiling point of the cold medium is lower than the boiling point of the impurity gas, so that the impurity gas can be separated. The adsorption cylinder goes through two processes of adsorption and regeneration, and the continuous operation of the device can also be realized.

[0016] (2) In this utility model, the raw material gas and product gas enter the flash evaporation unit after heat exchange through the heat exchanger, which improves the utilization rate of cold energy.

[0017] (3) In this utility model, for larger processing volumes in actual production, the number of purification units can be increased to four, five or more, and for smaller processing volumes, the number of purification units can be reduced to two or one. Gas separation can be achieved under low temperature and medium-high pressure conditions, thus improving the applicability of the device. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall block diagram provided in Embodiment 1 of this utility model;

[0019] Figure 2 This is a schematic diagram of the overall structure of the device provided in Embodiment 1 of this utility model;

[0020] Figure 3 This is a schematic diagram of the overall structure of the device provided in Embodiment 2 of this utility model;

[0021] Figure 4 This is a schematic diagram of the overall structure of the device provided in Embodiment 3 of this utility model;

[0022] Reference numerals: 101, Gas supply unit; 102, Heat exchange unit; 103, Flash evaporation unit; 104, Purification unit; 105, Regeneration unit; 106, Control unit; 1, Heat exchanger A; 2, Heat exchanger B; 3, Liquid-air separator A; 4, Liquid-air separator B; 5, Adsorption cylinder A1; 6, Adsorption cylinder B1; 7, Adsorption cylinder A2; 8, Adsorption cylinder B2; 9, Adsorption cylinder A3; 10, Adsorption cylinder B3; 11, Water bath regenerator. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below in conjunction with the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] Example 1

[0025] See Figure 1 A low-temperature adsorption-de-neon device includes a gas supply unit 101, a heat exchange unit 102, a flash evaporation unit 103, a purification unit 104, a regeneration unit 105, and a control unit 106. The gas supply unit 101, heat exchange unit 102, flash evaporation unit 103, purification unit 104, and regeneration unit 105 are sequentially connected via pipelines and are all electrically or communicatively connected to the control unit 106. The control unit 106 is a controller. The gas supply unit 101 includes a raw material gas pipeline, and the raw material gas in the raw material gas pipeline is subjected to certain pressure, temperature, and flow... Under certain conditions, the raw material gas, composed of helium, nitrogen, oxygen, neon, and other components, can have its temperature, pressure, flow rate, and composition varied depending on the operating conditions. The gas supply unit 101, heat exchange unit 102, flash evaporation unit 103, purification unit 104, and regeneration unit 105 are all equipped with temperature detection devices, pressure detection devices, purity detection devices, and liquid level detection devices. In this embodiment, the temperature detection device is a thermocouple, the pressure detection device is a pressure sensor, the purity detection device is a helium purity analyzer, and the liquid level detection device is a liquid level gauge.

[0026] See Figure 2 The heat exchange unit 102 includes at least one set of heat exchangers and a Dewar container (not shown in the figure). In this embodiment, two sets are used as an example, namely heat exchanger A 1 and heat exchanger B 2. One set is working and the other is regenerating. Both heat exchanger A 1 and heat exchanger B 2 are placed in the Dewar container. The Dewar container is kept cold by internal vacuum insulation. The upper flange of the Dewar container is equipped with a safety valve, a pressure detection device, and an inlet and outlet gas connection pipe. The inlet and outlet gas connection pipe is equipped with a valve. The valve is electrically or communicatively connected to the control unit 106.

[0027] The flash evaporation unit 103 includes at least one set of liquid-air separation cylinders and a Dewar container. In this embodiment, two sets are used as an example, namely liquid-air separation cylinder A 3 and liquid-air separation cylinder B 4. One set is in operation and the other is regenerating. Of course, it can also be liquid-air separation cylinder A 3 or liquid-air separation cylinder B 4. Liquid-air separation cylinder A 3 and liquid-air separation cylinder B 4 can be used together or as two sets. Liquid-air separation cylinder A 3 and liquid-air separation cylinder B 4 are both placed inside the Dewar container. The Dewar container adopts a combination of inner and outer cylinders. The inner and outer cylinders of the Dewar container are kept cold by vacuum insulation. Liquid nitrogen / or liquid argon and other media are added to the inner cylinder of the Dewar container to provide cooling. The upper flange of the Dewar container is equipped with a safety valve and a pressure detection device. Sampling tubes are installed inside liquid-air separation cylinder A 3 and liquid-air separation cylinder B 4. The sampling tubes are connected to an external analysis device for purity monitoring. The connecting pipes on the liquid-air separation cylinder are equipped with a safety valve and a pressure detection device. Heating coils and temperature detection devices are installed on the outside of the liquid-air separation cylinder.

[0028] The purification unit 104 includes adsorption cylinders A1 (5), B1 (6), A2 (7), B2 (8), A3 (9), and B3 (10). Adsorption cylinders A1 (5), A2 (7), and A3 (9) form one group connected in series, while adsorption cylinders B1 (6), B2 (8), and B3 (10) form another group connected in series. One group operates while the other regenerates. The number of adsorption cylinder groups can be set to 2, 3, or more, and the number of adsorption cylinders in each group can be adjusted. In this embodiment, three cylinders per group are used as an example. All adsorption cylinders are placed inside a Dewar container. The Dewar container uses a combination of inner and outer cylinders, with vacuum insulation between the inner and outer cylinders for cooling. Liquid nitrogen or liquid argon is added to the inner cylinder of the Dewar container to provide cooling. A safety valve and pressure detection device are installed on the flange of the Dewar container. The adsorption cylinders are connected to a vacuum pump.

[0029] The downstream of the purification unit 104 is connected to the product gas pipeline. The product gas pipeline exchanges heat with the raw material gas pipeline through the heat exchanger of the heat exchange unit 102. The Dewar container is also connected to an external nitrogen water bath vaporizer and a nitrogen vacuum pump to achieve negative pressure liquid nitrogen purification. A flow meter is also connected to the product gas pipeline. The flow meter can detect the pure helium output. Combined with the purity analyzer, the helium recovery rate can be obtained.

[0030] The regenerating unit 105 is a water bath regenerator 11. The water bath regenerator 11 is existing technology and is a combination structure of heat exchange coil, electric heater and water bath. The heat exchange coil is placed inside the water bath, the electric heater is placed at the bottom of the water bath, a temperature detection device is installed inside the water bath, and a liquid level detection device is installed outside the water bath.

[0031] Working principle: The raw material gas from the gas supply unit 101 enters the heat exchange unit 102. The raw material gas and product gas exchange heat in the heat exchanger, which pre-cools the raw material gas and warms the product gas. The raw material gas, after being pre-cooled by the heat exchange unit 102, passes through the liquid-air separator. Under the temperature range of the cold medium such as liquid nitrogen or liquid argon, impurity gases with boiling points higher than liquid nitrogen or liquid argon are condensed into liquids and remain at the bottom of the separator under a certain partial pressure. Impurity gases with boiling points lower than liquid nitrogen or liquid argon are not condensed under a certain partial pressure. The purified helium and other process gases flow out through the top of the separator and enter the purification unit 104. The purity of the helium in 3 / 4 of the liquid-air separator is monitored by an external purity monitoring device and a liquid level monitoring device. The valve on the drain pipe connected to the bottom of the liquid-air separator is opened to discharge the condensed impurity liquid. The process gas purified by the flash evaporation unit 103 enters the adsorption cylinder. Under the temperature range of cold media such as liquid nitrogen or liquid argon, a small amount of impurity gas such as neon in the process gas is removed by the principle of low temperature medium pressure / high pressure physical adsorption in the purification unit 104. The purity of helium is further purified to 99.999%, which meets the requirements of the national standard BB / T4844-2011, and the neon content of a single component is <4ppm. Under normal operating conditions, the maximum neon content is 0.5ppm-1ppm. After the product helium comes out of the purification unit 104, it returns to the heat exchange unit 102 to exchange heat with the raw material gas, so that the product helium is warmed up. However, the temperature does not reach the room temperature supply condition, so it needs to be further returned to room temperature in the heat recovery unit 105 before being supplied to the downstream.

[0032] The specific adsorption and regeneration processes are as follows:

[0033] Adsorption: The raw gas is adsorbed and separated in the adsorption cylinder under a certain working pressure and in the liquid nitrogen temperature zone (-196℃). The high-purity helium produced is reheated and the pure helium gas is collected, thus completing the purpose of gas adsorption separation and purification. The low-temperature adsorption process utilizes the different adsorption forces of different adsorbates on the adsorbent to achieve gas separation. Compared with other separation technologies such as room temperature adsorption and membrane separation, it has the advantages of good separation effect, high product purity, stable equipment operation, and automated operation.

[0034] The regeneration process includes depressurization, liquid nitrogen / liquid argon discharge, heating, vacuuming, backfilling, and precooling.

[0035] Depressurization: After the adsorbent is saturated, the depressurization process begins. The outlet of the adsorption cylinder is connected to the heat recovery unit 105. After the depressurized gas is heated by the heat recovery unit, it is returned to the low-pressure end for storage. The depressurization is stopped when the pressure is reduced to below 1 bar.g.

[0036] Liquid nitrogen / liquid argon discharge: After depressurization is completed, the liquid nitrogen in the Dewar container needs to be discharged so that the adsorption cylinder can be warmed up. The liquid nitrogen or liquid argon can be directly discharged into the liquid nitrogen or liquid argon pit or recovered to the on-site liquid nitrogen or liquid argon tank through the liquid nitrogen or liquid argon pump.

[0037] Heating: The heating process involves heating the adsorption cylinder. Hot nitrogen is used to purge and heat the adsorption cylinder until the temperature reaches 60°C. An external heating coil is used to heat the outside of the adsorption cylinder until it reaches 100°C or higher.

[0038] Vacuuming: When the temperature of the adsorption cylinder is heated to above 100℃, the vacuum pump is used to start the vacuuming process, and the vacuuming is controlled by time.

[0039] Backfilling: Use product helium for backfilling until a slight positive pressure is reached. Continue backfilling during the pre-cooling stage to maintain a slight positive pressure in the adsorption cylinder, in preparation for the next adsorption operation.

[0040] Pre-cooling: After backfilling is completed, the Dewar container needs to be filled with liquid nitrogen / liquid argon, which is automatically controlled by the level gauge. The filling valve will be closed when the set liquid level is reached.

[0041] The regeneration process is complete.

[0042] In this embodiment, the purification unit 104 utilizes two sets of three purifiers (adsorption cartridges) each to separate and purify helium, neon, and other impurities. This results in a smaller footprint and lower investment for the same processing capacity. For larger processing volumes, the number of purifiers in a single purification unit can be increased to four, five, or more; for smaller processing volumes, the number of purifiers can be reduced to two or one. Gas separation can be achieved under low temperature and medium-high pressure conditions, featuring miniaturization, low energy consumption, high reliability, full automation, and low maintenance costs.

[0043] Example 2

[0044] See Figure 3 The difference between this embodiment and embodiment 1 is that in this embodiment, the adsorption cylinder in the purification unit 104 is set to two groups, with two adsorption cylinders in each group, and the liquid-air separation cylinder in the flash evaporation unit 103 is one, with the two groups of adsorption cylinders sharing one liquid-air separation cylinder.

[0045] Example 3

[0046] See Figure 4 The difference between this embodiment and embodiment 1 is that in this embodiment, the adsorption cylinder in the purification unit 104 is set to two groups, with one adsorption cylinder in each group, and the liquid-air separation cylinder in the flash evaporation unit 103 is one, with the two groups of adsorption cylinders sharing one liquid-air separation cylinder.

[0047] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A low temperature adsorptive neon removal device, characterized by comprising: The device comprises a gas supply unit, a flash unit, a purification unit and a Dewar vessel connected in sequence, the flash unit comprises a liquid-air separation cylinder, the liquid-air separation cylinder is located in the Dewar vessel, the Dewar vessel is filled with a cold medium, the boiling point of the cold medium is lower than that of the impurity gas, the purification unit comprises at least two groups of parallelly connected adsorption cylinders, each group of adsorption cylinders comprises at least one adsorption cylinder, and the exhaust pipeline of the liquid-air separation cylinder is connected upstream of the adsorption cylinder.

2. A cryosorptive neon-removal apparatus according to claim 1, wherein The device further comprises a heat exchange unit, the heat exchange unit comprises a heat exchanger, the heat exchange unit is located downstream of the gas supply unit, upstream of the purification unit and downstream of the adsorption cylinder, the product gas pipeline is connected downstream of the adsorption cylinder, the gas supply unit comprises a raw gas pipeline, and the raw gas pipeline exchanges heat with the product gas pipeline through the heat exchanger.

3. A cryosorptive neon-removal apparatus according to claim 1, wherein Each group of adsorption cylinders comprises two adsorption cylinders connected in sequence.

4. A cryosorptive neon-removal apparatus according to claim 1, wherein Each group of adsorption cylinders comprises three adsorption cylinders connected in sequence.

5. A low temperature adsorption neon removal device according to claim 1, wherein The Dewar vessel comprises an inner cylinder and an outer cylinder arranged outside the inner cylinder, and a vacuum cavity is formed between the inner cylinder and the outer cylinder.

6. A cryosorptive neon-removal apparatus according to claim 2, wherein The adsorption cylinder and the heat exchanger are located in the Dewar vessel.

7. A low-temperature adsorption neon-removal apparatus according to claim 1 or 2, characterized by The device further comprises a heat recovery unit, the heat recovery unit comprises a water bath heat recovery device, and the water bath heat recovery device is connected downstream of the purification unit.

8. A cryoadsorption de-lanium device according to claim 7, characterized in that The gas supply unit, the flash unit, the purification unit and the heat recovery unit are all connected with temperature detection devices, pressure detection devices, purity detection devices and liquid level detection devices, and the temperature detection devices, the pressure detection devices, the purity detection devices and the liquid level detection devices are thermocouples, pressure sensors, helium purity analyzers and liquid level meters respectively.

9. A low-temperature adsorption neon-removal apparatus according to claim 2, wherein A flow meter is arranged on the product gas pipeline.

10. A low temperature adsorption neon removal device according to claim 1, wherein The liquid-air separation cylinder comprises an A liquid-air separation cylinder and / or a B liquid-air separation cylinder.

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