A built-in helium impurity adsorption device and an adsorption method

Abstract

The application provides an embedded helium impurity adsorption device, a filtering unit is located in a sealed cavity, an outlet of the filtering unit is communicated with an exhaust port, a flow guide is inherent in the sealed cavity, helium enters the sealed cavity through an air inlet, is uniformly dispersed around the filtering unit through the flow guide, enters from an inlet of the filtering unit, and is discharged from an outlet of the filtering unit; a gap in the sealed cavity is filled with a filtering medium; the filtering unit comprises a plurality of filters connected in series, according to a helium flow direction, a first filter is provided with a helium inlet at one end opposite to the air inlet of the sealed cavity, and a helium outlet is arranged at an end of a last filter facing the exhaust port of the sealed cavity; the rest of the connection nodes are located at adjacent sides of the filters. The application arranges the filtering unit in an outer cylinder, fills the gap with the filtering medium, carries out primary filtering and adsorption on the helium through the gap, carries out secondary filtering and adsorption on the helium through the filtering unit, and improves the adsorption efficiency and precision. In the case of the same filtering path, the application has a more compact structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of helium gas purification, in particular to an internal helium impurity adsorption device and an adsorption method. BACKGROUND

[0002] Helium is a rare gas, non-renewable, with characteristics of stable chemical properties, extremely low boiling point, etc., and is widely used in aerospace, nuclear industry high temperature gas cooled reactor, low temperature superconducting research, optoelectronic product production, refrigeration, semiconductor, medical treatment, leak detection, deep sea diving, high precision welding, etc. It is an important strategic material for the development of national security and high-tech industries.

[0003] Helium content on earth is very small, and the source of helium extraction is mainly extracted from natural gas. The extracted helium is not very high in purity, and the scientific research, medical industry and other industries have higher requirements for the purity of helium. Usually, low-temperature adsorption method and low-temperature freezing method are used for purification. The low-temperature adsorption method uses a low-temperature purifier to pass impure helium into an adsorption cylinder containing liquid nitrogen to remove impurities such as oxygen and nitrogen by the adsorption characteristics of activated carbon and other adsorbents at low temperature. When the gas adsorbent is in contact, the phenomenon of containing and adsorbing gas occurs on the surface and inside of the solid, and the porous particles can selectively adsorb one or more components in the gas stream, so as to achieve the purpose of removing impurities. When the activated carbon is in the liquid nitrogen, the activated carbon has strong adsorption effect on nitrogen and oxygen in helium. Therefore, the low-temperature adsorption cylinder is the core component of the low-temperature purifier, and is an important factor to determine the efficiency of the low-temperature purifier. The publication number CN207980782U introduces a multi-zone reciprocating high-efficiency adsorption device, which uses a partition plate to divide the outer cylinder into multiple sealed chambers, increases the helium travel, but the actual operation is difficult, the angle between the adjacent partition plates is small, the welding difficulty is large, and there may be situations such as welding leakage and welding separation, which reduces the helium travel and reduces the adsorption effect. SUMMARY

[0004] The technical problem to be solved by the present application is how to simplify the structure of the adsorption device, reduce the volume and prolong the adsorption path.

[0005] The present application solves the above technical problems by the following technical means:

[0006] An internal helium impurity adsorption device, comprising an outer cylinder, a filter unit; the outer cylinder has a sealed cavity, the sealed cavity is provided with an air inlet and an air outlet; the filter unit is located in the sealed cavity, the outlet of the filter unit is communicated with the air outlet, and a flow guide is inherent in the sealed cavity; helium enters the sealed cavity through the air inlet, is uniformly dispersed around the filter unit through the flow guide, enters from the inlet of the filter unit, and is discharged from the outlet of the filter unit; the space in the sealed cavity is filled with filter medium;

[0007] The filter unit comprises a plurality of filters connected in series, and the first filter is provided with a helium inlet at one end opposite to the air inlet of the sealed cavity, and the last filter is provided with a helium outlet facing the air outlet of the sealed cavity; the remaining nodes connected in series are located at the adjacent sides of the filters.

[0008] The application achieves first filtration and adsorption of helium through the gap and second filtration and adsorption through the filter unit, thereby improving the adsorption efficiency and precision. In the case of the same filtration path, the application has a more compact structure and a more reasonable design, so that a larger adsorption function is realized in a smaller volume. In particular, the nodes connected in series of the filters are designed on the sides of the filters, thereby reducing the pipes at both ends of the filters and reducing the height.

[0009] Further, the peripheral size of the filter unit is the same as the size of the sealed cavity.

[0010] Further, the sealed cavity is cylindrical or cubic.

[0011] Further, the filter is cylindrical, and the maximum size of the filter unit surrounded by the plurality of filters is equal to the size of the sealed cavity.

[0012] Further, the filter unit comprises seven filters, and the first filter is located in the middle, and the remaining six filters are arranged around the first filter.

[0013] Further, a filter medium layer is laid on the bottom of the sealed cavity, and the inlet side of the filter unit is placed towards the filter medium layer.

[0014] Further, a reinforcing rib is fixed in the sealed cavity, the reinforcing rib passes through the gap between the filters, and both ends are fixed with the two ends of the sealed cavity.

[0015] Further, the reinforcing rib passes through the flow guide, and the flow guide is fixed with the reinforcing rib.

[0016] Further, the flow guide is a plate structure, the outer edge size of which is smaller than the size of the sealed cavity, and the flow guide is located in the middle of the air inlet of the sealed cavity and the air inlet surface of the flow guide.

[0017] Corresponding to the above device, the application also provides an adsorption method, comprising the following steps: soaking the entire adsorption device in liquid nitrogen, conducting cold energy through the reinforcing rib to cool the internal activated carbon, thereby improving the adsorption effect. Injecting helium into the air inlet, the helium is uniformly dispersed and slowed down by the flow guide plate, the helium flows downward from the activated carbon of the gap of the sealing ring, enters the inlet of the first filter, and flows through all the filters in a snakelike manner, and finally is discharged from the outlet of the last filter.

[0018] The application has the advantages that:

[0019] The present application achieves first filtering and adsorption of helium through the gap and second filtering and adsorption through the filter unit, improves the adsorption efficiency and precision, and has a more compact structure and a more reasonable design to realize greater adsorption function in a smaller volume.

[0020] The filter unit is directly placed in the sealing cavity without shaking, the welding points are reduced, and the assembly process is simplified.

[0021] The inlet of the filter unit is designed at the center position, the flow guide member is matched to disperse and guide the helium, the activated carbon at each position in the sealing cavity plays a role, and the filtering efficiency is provided.

[0022] The reinforcing ribs provide support for the upper cover, minimize the thickness of the upper cover, and reduce the overall weight. Meanwhile, the reinforcing ribs can also act as a heat conduction medium to cool the activated carbon in the sealing cavity under the liquid nitrogen environment, improve the adsorption precision, and achieve multiple purposes at once. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The figure is a schematic diagram of the overall structure of the device in the embodiment of the present application;

[0024] Figure 2 The figure is a schematic diagram of the structure of the device after hiding the upper cover in the embodiment of the present application;

[0025] Figure 3 The figure is a schematic diagram of the structure of the device hiding the upper cover and the outer cylinder sidewall in the embodiment of the present application. DETAILED DESCRIPTION

[0026] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] The built-in helium impurity adsorption device described in the embodiment, as shown in Figure 1 , Figure 2 , Figure 3 The figure is a schematic diagram of the structure of the device in the embodiment of the present application;

[0028] The filtering unit 2 is located in the sealed cavity, and the outlet of the filtering unit 2 is communicated with the exhaust port 13. The filtering unit 2 is inherently provided with the flow guide 3 in the sealed cavity. The helium supply device supplies helium. The helium enters the sealed cavity through the air inlet 12, is uniformly dispersed around the filtering unit 2 through the flow guide 3, enters the filtering unit 2 from the inlet of the filtering unit 2, and is discharged from the outlet of the filtering unit 2. The space in the sealed cavity is filled with the filtering medium. In this embodiment, the filtering medium is activated carbon. In this embodiment, a filter screen is installed at the bottom of the air inlet 12 and a certain distance away from the flow guide 3. The filter screen can disperse the helium flow and has a dispersion and buffering effect. Similarly, a filter screen is also installed at the outlet of the terminal filter 21.

[0029] The filtering unit 2 includes a plurality of filters 21 connected in series. In this embodiment, the filtering unit 2 includes seven filters 21, which are all cylindrical. According to the direction of the helium flow, the first filter 21 is located in the middle, and the remaining six filters 21 are arranged around the first filter 21. The end of the first filter 21 opposite to the air inlet 12 of the sealed cavity is the helium inlet. The terminal filter 21 is provided with the helium outlet 22 facing the exhaust port 13 of the sealed cavity. The pipeline of the helium outlet 22 penetrates out through the exhaust port 13. The remaining nodes connected in series are located on the adjacent sides of the filters 21. Correspondingly, the sealed cavity is cylindrical in this embodiment. The peripheral size of the filtering unit 2 surrounded by the seven filters 21 is the same as the size of the sealed cavity, so that the filtering unit 2 does not shake when placed in the sealed cavity. The gap after the seven filters 21 are enclosed and the remaining gap of the sealed cavity are both filled with activated carbon (not shown in the figure). Of course, the sealed cavity can also be a cubic cavity. The arrayed filters 21 adapt to the sealed cavity. The size and shape only need to meet the requirement that the filters 21 do not shake. The external shape of the outer cylinder 1 can be consistent with the sealed cavity, such as a cylinder or a cube. The external shape of the outer cylinder 1 can also be inconsistent with the sealed cavity. The shape and size of the outer cylinder 1 can be designed according to the current application space.

[0030] In order to improve the filtering effect, a filtering medium layer (not shown in the figure) is laid at the bottom of the sealed cavity. The inlet side of the filtering unit 2 is placed towards the filtering medium layer.

[0031] In this embodiment, the sealed cavity is fixed with the reinforcing rib 14. The reinforcing rib 14 can be made of a material with high thermal conductivity, such as an aluminum rod. The reinforcing rib 14 penetrates through the gap between the filters 21, is welded or screw-connected to the bottom of the sealed cavity at one end, penetrates through the hole of the upper cover 11 at the other end, and is screw-fixed through the sealing nut.

[0032] In the embodiment, the flow guide 3 is a plate structure, the outer edge size of which is smaller than the size of the sealing cavity, and a hole is formed in the position corresponding to the reinforcing rib 14 on the flow guide plate. The reinforcing rib 14 can be welded to fix the flow guide plate after passing through the flow guide plate. Alternatively, a limiting pin (not shown in the figure) can be welded on the reinforcing rib 14, and the flow guide plate is limited to a set height by the limiting pin after passing through the reinforcing rib 14. In order to uniformly guide the flow, the flow guide 3 is centrally located in the sealing cavity, and the air inlet 12 is centrally located on the air-facing surface of the flow guide 3.

[0033] In the embodiment, a temperature sensor 5 such as a thermocouple is also fixed in the sealing cavity. The temperature sensor can be clamped between the activated carbon filled in the sealing cavity. Generally, three temperature sensors 5 are placed and uniformly distributed in the sealing cavity. The data transmission line of the temperature sensor 5 passes out of the upper cover 11 (not shown in the figure).

[0034] The assembly method of the adsorption device in the embodiment is as follows. The bottom of the reinforcing rib 14 is welded to the bottom of the sealing cavity, and the position of the reinforcing rib 14 is calculated to prevent the filter 21 from being unable to be placed. The side walls of the plurality of filters 21 are connected in series by node connection, and generally, the welding method is used to make the filters 21 closely close to each other to reduce the overall volume. Then, a layer of activated carbon is laid on the bottom of the sealing cavity, and the assembled filter unit 2 is placed on the activated carbon. The reinforcing rib 14 passes out of the gap between the filters 21, at this time, the filter unit 2 is closely abutted with the side wall of the sealing cavity and will not shake, and the activated carbon is used to fill all the gaps between the filter unit 2 and the sealing cavity. Then, the flow guide plate is installed, the outlet 22 pipeline of the last filter 21 passes out of the corresponding hole on the flow guide plate, and finally, the upper cover 11 is installed. The outlet 22 pipeline and the reinforcing rib 14 pass out of the corresponding holes of the upper cover 11, the reinforcing rib 14 can be welded or screwed with the upper cover 11, and finally, the sealing property of the outer cylinder 1 can be ensured.

[0035] In operation, the entire adsorption device is immersed in liquid nitrogen, the internal activated carbon is cooled by the reinforcing rib 14 to conduct cold energy, so as to improve the adsorption effect. Helium is injected into the air inlet 12, the helium is uniformly dispersed and slowed down by the flow guide plate, the helium flows downward from the activated carbon of the sealing ring gap, enters the inlet of the first filter 21, and flows through all the filters 21 in a snakelike manner, and finally is discharged from the outlet 22 of the last filter 21.

[0036] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalent features. The modification or replacement does not change the essence of the corresponding technical solutions, and does not deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A built-in helium impurity adsorption device, characterized in that, The system includes an outer cylinder (1) and a filter unit (2). The outer cylinder (1) has a sealed cavity with an air inlet (12) and an exhaust outlet (13). The filter unit (2) is located inside the sealed cavity, and its outlet (22) is connected to the exhaust outlet (13). A flow guide (3) is provided inside the sealed cavity. Helium enters the sealed cavity through the air inlet (12), is evenly dispersed around the filter unit (2) by the flow guide (3), enters from the inlet of the filter unit (2), and exits from the outlet (22) of the filter unit (2). The gaps inside the sealed cavity are filled with filter media. The filter unit (2) includes multiple filters (21) connected in series. According to the direction of helium flow, the first filter (21) has a helium inlet at the end opposite to the air inlet (12) of the sealed cavity, and the end filter (21) has a helium outlet (22) facing the exhaust port (13) of the sealed cavity; the remaining connected nodes are all located on the adjacent side of the filter (21).

2. The built-in helium impurity adsorption device according to claim 1, characterized in that, The outer dimensions of the filter unit (2) are the same as the dimensions of the sealed cavity.

3. A built-in helium impurity adsorption device according to claim 1 or 2, characterized in that, The sealed cavity is cylindrical or cubic.

4. The built-in helium impurity adsorption device according to claim 3, characterized in that, The filter (21) is cylindrical, and the maximum size of the filter unit (2) formed by multiple filters (21) is equal to the size of the sealed cavity.

5. The built-in helium impurity adsorption device according to claim 4, characterized in that, The filter unit (2) includes 7 filters (21), with the first filter (21) located in the middle and the remaining 6 filters (21) arranged around the first filter (21).

6. The built-in helium impurity adsorption device according to claim 5, characterized in that, The bottom of the sealed cavity is covered with a filter medium layer, and the inlet side of the filter unit (2) is placed facing the filter medium layer.

7. The built-in helium impurity adsorption device according to claim 4, characterized in that, A reinforcing rib (14) is fixed inside the sealed cavity. The reinforcing rib (14) passes through the gap between the filters (21) and is fixed at both ends to the two ends of the sealed cavity.

8. The built-in helium impurity adsorption device according to claim 7, characterized in that, The reinforcing rib (14) passes through the guide member (3), and the guide member (3) is fixed to the reinforcing rib (14).

9. The built-in helium impurity adsorption device according to claim 8, characterized in that, The guide (3) is a plate-shaped structure with an outer edge dimension smaller than the sealing cavity dimension. The guide (3) is centrally located at the air inlet (12) of the sealing cavity, which is centrally located on the air-facing side of the guide (3).

10. The adsorption method of the built-in helium impurity adsorption device according to any one of claims 1 to 9, characterized in that, The process includes the following steps: immersing the entire adsorption device in liquid nitrogen, using reinforcing ribs (14) to conduct heat and cool the internal activated carbon, thereby improving the adsorption effect. Helium is injected into the inlet (12), where it is evenly dispersed and slowed by the guide plate. The helium flows downwards through the activated carbon in the sealing ring gaps, entering from the inlet of the first filter (21), flowing in a serpentine pattern through all filters (21), and finally exiting from the outlet (22) of the end filter (21).

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