Helium recovery device and helium recovery method

Abstract

The invention discloses a helium recovery device and a helium recovery method. The device comprises a recovery box, a recovery pipe, a first pressure detector and a second pressure detector, wherein the first pressure detector and the second pressure detector are used for detecting the internal air pressure of the recovery pipe and the recovery box respectively; the recycling pipe is made of a PFA (Polyfluoroalkoxy) material, and the wall of the recycling pipe is provided with molecular pores of 0.25-0.26 nm; the recycling pipe comprises a recycling pipe part, an inlet end connected with a gas source and an outlet end connected with a tail gas treatment device, the recycling pipe part is arranged in the recycling box, and when the difference between the air pressure in the recycling pipe and the air pressure in the recycling box is 30 psi-100 psi, the recycling pipe expands, and helium molecules flow into the recycling box through molecular pores. The helium recovery method is performed using a helium recovery device. Molecular pores are enlarged by controlling the pressure difference, helium molecules flow into the recycling box from the inside of the recycling pipe through the molecular pores, and helium recycling is achieved. The device is simple in structure, the purity of the recovered helium is high, purification treatment is not needed, and the recovery efficiency is improved.

Description

Technical Field

[0001] The invention relates to a waste gas collection device, and in particular to a helium recovery device and a helium recovery method. Background Art

[0002] The self-igniting liquid supply system is a supply system used in some special occasions or equipment. This type of system can automatically provide flammable liquid under certain conditions to ensure the normal operation of the equipment. This type of system is used in specific industrial processes, such as metal smelting or chemical production. The self-igniting liquid supply system is used to maintain high temperature or provide necessary chemical reactants. The self-igniting liquid supply system includes a liquid supply pipeline, a supply tank as the source of the supply liquid, and a source liquid tank as the source of the supply tank liquid replenishment. After the source liquid tank is empty, it is necessary to use a purge gas to purge the liquid supply pipeline before replacing a new full tank of liquid access equipment. The supply tank also needs to be purged with a purge gas when it is installed for the first time, or it needs to be purged with a purge gas before it can be removed when the supply tank is removed. At the same time, different types of purge gases are required to be used to purge different liquids in the liquid pipeline: the purge gas in contact with the liquid and the ordinary clean purge gas of the liquid pipeline are different types of purge gases.

[0003] In the existing self-igniting liquid supply system, different types of purge gases are mixed and collected or discharged after purging. Purge gas generally uses an inert gas with high stability, and nitrogen and helium are the preferred gases for purge gas. The domestic demand for helium accounts for about 14% of the world's total, while its own resource reserves account for only about 2% of the world's total, and China's helium production capacity is only about 0.63% of the world's total, far from meeting domestic demand. Every year, China needs to import a large amount of helium from overseas, and the import volume of helium accounts for 95% of the total consumption, while the proportion of domestic helium is only 5%. That is, recycling helium and avoiding helium waste is an important problem that needs to be solved urgently. Summary of the invention

[0004] In view of the above problems, the present invention proposes a helium recovery device and a helium recovery method.

[0005] The technical solution adopted by the present invention is as follows: The present application provides a helium recovery device, comprising a recovery box, a recovery pipe, a first pressure detector, a second pressure detector and a helium storage device; The recovery box is a sealed gas recovery box, the recovery pipe includes a recovery pipe part and an inlet end and an outlet end arranged at both ends of the recovery pipe part, the recovery pipe part is placed in the recovery box and is used for helium recovery, the inlet end is arranged outside the recovery box and is used to connect with a mixed gas source containing helium, and the outlet end is arranged outside the recovery box and is used to connect with an exhaust gas treatment device; The recovery tube is made of PFA material, and the tube wall of the recovery tube has molecular pores, and the radial size of the molecular pores in the natural state is 0.25nm~0.26nm; The first pressure detector is used to detect the air pressure in the recovery pipe, and the second pressure detector is used to detect the air pressure inside the recovery box; When the pressure difference between the recovery tube and the recovery box is 30 psi to 100 psi, the recovery tube expands, the radial size of the molecular pores of the recovery tube becomes 0.26 nm to 0.28 nm, and the helium molecules in the recovery tube flow into the recovery box through the molecular pores of the recovery tube; The helium storage device includes a first pipeline, a first gas compressor, a first valve and a helium storage tank. The helium storage tank is connected to the recovery tank through the first pipeline and the first gas compressor. The first valve is arranged on the first pipeline. The first gas compressor is used to compress the helium collected in the recovery tank and then draw it into the helium storage tank, so that the air pressure in the recovery pipe and the air pressure inside the recovery tank maintain a pressure difference.

[0006] Among the commonly used gas molecules, the molecular diameter of helium molecules is 0.26nm, the molecular diameter of hydrogen molecules is 0.289nm, the molecular diameter of nitrogen molecules is 0.346nm, the molecular diameter of oxygen molecules is 0.346nm, and the molecular diameter of argon molecules is 0.34nm, which are all smaller than the molecular diameter of helium molecules. By controlling the air pressure in the recovery pipe and the air pressure inside the recovery box, and controlling the air pressure in the recovery pipe to 20psi~100psi and the air pressure inside the recovery box to be less than -10psi, the molecular pores are slightly enlarged (greater than or equal to 0.26nm and not more than 0.28nm) under the action of the pressure difference, and the helium molecules flow from the high-pressure recovery pipe to the low-pressure recovery box through the molecular pores (the other gas molecules cannot pass), thereby realizing the recovery of helium and reducing the waste of helium.

[0007] At the same time, compared with the existing helium recovery devices and helium recovery methods, the helium recovery device provided by the present application has a simple structure, the recovered helium has high purity, and no purification treatment is required, that is, the helium recovery efficiency is greatly improved.

[0008] PFA is a kind of plastic, also known as fusible polytetrafluoroethylene, which is a copolymer of a small amount of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene. PFA tube, full name fusible polytetrafluoroethylene tube, is a special pipe made of perfluorinated polymer material with excellent chemical resistance and high temperature stability.

[0009] Furthermore, the recovery tube portion is a spiral tube structure, and the tube wall thickness of the recovery tube portion is 50 μm to 2000 μm.

[0010] Furthermore, the material of the recovery tube is PFA451.

[0011] Furthermore, the air pressure in the recovery pipe is 20psi~100psi, and the air pressure inside the recovery box is less than or equal to -10psi.

[0012] Furthermore, the pressure difference between the air pressure in the recovery tube and the air pressure inside the recovery box is preferably 45 psi to 80 psi, and the radial size of the molecular pores of the recovery tube is preferably 0.26 nm to 0.27 nm.

[0013] Furthermore, a second pressure detector is arranged at a pipe portion of the first pipeline located in the recovery tank.

[0014] Furthermore, a third pressure detector is included, which is connected to the helium storage tank and is used to detect the air pressure inside the helium storage tank.

[0015] Furthermore, it also includes a second gas compressor, a second valve, a third valve, a second pipeline and a third pipeline. One end of the second pipeline is connected to the inlet end of the recovery pipe, and the other end is used to connect to a mixed gas source containing helium; The third pipeline is connected to the outlet end of the recovery pipe; The second valve and the third valve are respectively arranged on the second pipeline and the third pipeline. In actual use, the second valve can also be arranged at the inlet end of the recovery pipe; The second gas compressor is arranged on the second pipeline and is located on a side of the second valve away from the recovery tank.

[0016] Furthermore, it also includes a helium concentration detector and a vacuum device, wherein the helium concentration detector is arranged on the third pipeline and is located on the side of the third valve close to the recovery box; The vacuum device is used to perform vacuum treatment on the interior of the recovery box.

[0017] Furthermore, it also includes a secondary recovery pipeline, one end of which is connected to a side of the third pipeline away from the outlet end, and the other end of which is used to be connected to the second pipeline; When the helium concentration detector detects that the helium concentration in the third pipeline exceeds the set value, the secondary recovery pipeline is opened to perform secondary recovery of helium, thereby further improving the recovery degree of helium and reducing the waste of helium.

[0018] Furthermore, the recovery box is a constant temperature box and can perform temperature control.

[0019] Furthermore, at least a hollow sleeve is provided on the outer sleeve of the recovery pipe in the recovery box, and the inner diameter of the sleeve is slightly larger than the outer diameter of the recovery pipe, so as to prevent the recovery pipe from bursting due to excessive expansion.

[0020] In actual use, the recovery pipe may burst under high pressure, and a pipe sleeve can be provided to support the recovery pipe to prevent bursting. The pipe sleeve can be a metal pipe sleeve or a plastic pipe sleeve, and the outer wall of the pipe sleeve exposed in the recovery box is provided with an anti-corrosion coating to prevent corrosion. Alternatively, when the wall thickness of the recovery pipe is less than 500 μm, the gas separation speed will be significantly accelerated, but in order to avoid the recovery pipe from bursting under high pressure, a pipe sleeve can be provided to support the recovery pipe to prevent bursting.

[0021] The present application also provides a helium recovery device, comprising a collection pipe, a recovery pipe, a first pressure detector, a second pressure detector and a helium storage device; The recovery pipe includes a recovery pipe portion and an inlet end and an outlet end provided at both ends of the recovery pipe portion, wherein the inlet end is used to be connected to a mixed gas source containing helium, and the outlet end is used to be connected to an exhaust gas treatment device; The recovery tube is made of PFA material, and the tube wall of the recovery tube has molecular pores, and the radial size of the molecular pores in the natural state is 0.25nm~0.26nm; The collecting pipe is fitted onto the recovery pipe portion of the recovery pipe, the inner wall of the collecting pipe is provided with a guide groove and a supporting convex wall, the outer wall of the recovery pipe portion is exposed in the guide groove, the supporting convex wall is located at the outer wall of the recovery pipe, and the inner diameter of the collecting pipe where the most convex point of the supporting convex wall is located is slightly larger than the outer diameter of the recovery pipe portion, and the supporting convex wall is used to prevent the recovery pipe portion from bursting; The first pressure detector is used to detect the air pressure in the recovery pipe, and the second pressure detector is used to detect the air pressure inside the guide groove; When the pressure difference between the recovery pipe and the guide groove is 30psi-100psi, the recovery pipe expands, the radial size of the molecular pores of the recovery pipe becomes 0.26nm-0.28nm, and the helium molecules in the recovery pipe flow into the guide groove through the molecular pores of the recovery pipe; The helium storage device includes a first pipeline, a first gas compressor, a first valve and a helium storage tank. The helium storage tank is connected to the guide groove through the first pipeline. The first gas compressor and the first valve are respectively arranged on the first pipeline. The first gas compressor is used to compress the helium collected by the guide groove and then draw it into the helium storage tank, so that the air pressure in the recovery pipe and the air pressure in the guide groove maintain a pressure difference.

[0022] The collection pipe is arranged outside the recovery pipe part of the recovery pipe to collect gas and support the recovery pipe at the same time to prevent the recovery pipe from bursting under pressure. This type of helium recovery device has a simple structure and a small size, which is easy to install in the self-igniting liquid supply system.

[0023] Furthermore, the inner wall of the collecting pipe is provided with an anti-corrosion coating, and the collecting pipe is preferably a metal structure.

[0024] Furthermore, the guide grooves include a plurality of guide grooves, which are arranged at intervals along the axial direction of the collection tube, and the groove bodies of the guide grooves form supporting convex walls. Alternatively, the guide grooves are spirally arranged on the inner wall of the collection tube. The guide grooves can simultaneously realize the collection and diversion functions of helium.

[0025] Furthermore, a temperature control element for controlling the temperature in the guide groove is also provided on the outside of the collecting pipe.

[0026] Furthermore, it also includes a second gas compressor, a second valve, a third valve, a second pipeline and a third pipeline. One end of the second pipeline is connected to the inlet end of the recovery pipe, and the other end is used to connect to a mixed gas source containing helium; The third pipeline is connected to the outlet end of the recovery pipe; The second valve and the third valve are respectively arranged on the second pipeline and the third pipeline; The second gas compressor is arranged on the second pipeline and is located on the side of the second valve away from the recovery tank; It also includes a helium concentration detector and a vacuum device, wherein the helium concentration detector is arranged on the third pipeline and is located on the side of the third valve close to the recovery box; The vacuum device is used to perform vacuum treatment on the interior of the recovery box.

[0027] Further, the first valve is arranged on a side close to the first gas compressor and close to the helium storage tank.

[0028] The present application also provides a helium recovery method, comprising the following steps: Providing a helium recovery device, wherein the helium recovery device is a helium recovery device as described above; Performing vacuum treatment on the recovery box or the diversion trough; A mixed gas containing helium is introduced into the recovery pipe, and the pressure difference between the recovery pipe and the recovery box or the pressure difference between the recovery pipe and the guide groove is controlled to be 30psi-100psi, so that the recovery pipe is expanded, and the radial size of the molecular pores of the recovery pipe becomes 0.26nm-0.28nm, and the helium is filtered from the recovery pipe through the molecular pores to the recovery box or the guide groove under the action of the pressure difference; The helium collected in the recovery box or the diversion trough is compressed and pumped into the helium storage tank, so that the air pressure in the recovery pipe and the air pressure inside the recovery box or the diversion trough maintain a pressure difference; The helium concentration at the outlet of the recovery pipe is detected. When the helium concentration is lower than the first value, the mixed gas is subjected to tail gas treatment or discharged. When the helium concentration is higher than the first value, the mixed gas is connected to the inlet again for secondary recovery of helium.

[0029] Furthermore, the mixed gas also includes nitrogen; When recovering helium, the temperature inside the recovery box or the guide groove is controlled to be 10 degrees Celsius to 35 degrees Celsius, preferably 25 degrees Celsius; The air pressure in the recovery pipe is 20psi~100psi, and the air pressure inside the recovery box or the guide groove is less than or equal to -10psi.

[0030] When the air pressure inside the recovery box or the diversion trough is less than or equal to -10psi, and the air pressure inside the recovery pipe is lower than 20psi, it is not easy for helium molecules to be filtered into the recovery box or the diversion trough through the molecular pores; when the air pressure inside the recovery box or the diversion trough is less than or equal to -10psi, and the air pressure inside the recovery pipe is higher than 80psi, it is easy to introduce small molecular impurity gases in the mixed gas into the recovery box or the diversion trough; when the air pressure inside the recovery box or the diversion trough is less than or equal to -10psi, and the air pressure inside the recovery pipe is 40psi~80psi, most of the helium molecules can be filtered into the recovery box or the diversion trough through the molecular pores; when the air pressure inside the recovery pipe is 70psi~80psi, the helium recovery rate and effect are optimal.

[0031] The beneficial effects of the present invention are: (1) The helium recovery device provided in the present application uses a PFA recovery tube, combined with the air pressure in the recovery tube and the air pressure inside the recovery box or the guide groove. When the air pressure in the recovery tube is 20psi~100psi and the air pressure inside the recovery box is less than -10psi, the molecular pores are slightly enlarged (0.26nm~0.28nm) under the action of the pressure difference, and the helium molecules flow from the high-pressure recovery tube to the low-pressure recovery box or the guide groove through the molecular pores (the other gas molecules cannot pass through), thereby realizing the recovery of helium.

[0032] (2) Compared with the existing helium recovery devices and helium recovery methods, the helium recovery device provided by the present application has a simple structure and the recovered helium has a high purity and does not require purification treatment, that is, the helium recovery efficiency is greatly improved.

[0033] (3) The collection pipe is arranged outside the recovery pipe part of the recovery pipe to collect gas and support the recovery pipe at the same time, so as to prevent the recovery pipe from bursting under pressure. This type of helium recovery device has a simple structure and a small size, and is easy to install in the self-igniting liquid supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic structural diagram of a helium recovery device according to an embodiment of the present invention; Figure 2 1 is a schematic flow chart of a helium recovery method according to an embodiment of the present invention; Figure 3 It is a schematic diagram of the cross-section structure of the collecting tube and the recovery tube in the helium recovery device of Example 2 of the present invention.

[0035] The reference numerals in the figures are: 1. Recovery box; 2. Recovery pipe; 201. Recovery pipe part; 202. Inlet end; 203. Outlet end; 3. First pressure detector; 4. Second pressure detector; 5. First pipeline; 6. First valve; 7. Helium storage tank; 8. First gas compressor; 9. Third pressure detector; 10. Second gas compressor; 11. Second valve; 12. Third valve; 13. Second pipeline; 14. Third pipeline; 15. Helium concentration detector; 16. Collection pipe; 161. Guide groove; 162. Support convex wall. DETAILED DESCRIPTION

[0036] The present invention is described in detail below in conjunction with the accompanying drawings.

[0037] Example 1 like Figure 1 As shown, the present application provides a helium recovery device, including a recovery box 1, a recovery pipe 2, a first pressure detector 3, a second pressure detector 4 and a helium storage device; The recovery box 1 is a sealed gas recovery box, and the recovery pipe 2 includes a recovery pipe portion 201 and an inlet end 202 and an outlet end 203 arranged at both ends of the recovery pipe portion 201. The recovery pipe portion 201 is placed in the recovery box 1 and is used for helium recovery. The inlet end 202 is arranged outside the recovery box 1 and is used to be connected to a mixed gas source containing helium. The outlet end 203 is arranged outside the recovery box 1 and is used to be connected to an exhaust gas treatment device. The recovery tube 2 is a PFA tube, and the tube wall of the recovery tube 2 has molecular pores. The radial size of the molecular pores in the natural state is 0.25nm~0.26nm; The first pressure detector 3 is used to detect the air pressure in the recovery pipe 2 (the first pressure detector 3 can be arranged in the recovery pipe 2), and the second pressure detector 4 is used to detect the air pressure inside the recovery box 1; When the pressure difference between the recovery tube 2 and the recovery box 1 is 30 psi to 100 psi, the recovery tube 2 expands, the radial size of the molecular pores of the recovery tube 2 becomes 0.26 nm to 0.28 nm, and the helium molecules in the recovery tube portion 201 flow through the molecular pores of the recovery tube 2 to the inside of the recovery box 1; The helium storage device includes a first pipeline 5, a first gas compressor 8, a first valve 6 and a helium storage tank 7. The helium storage tank 7 is connected to the recovery tank 1 through the first pipeline 5 and the first gas compressor 8. The first valve 6 is arranged on the first pipeline 5. The first gas compressor 8 is used to compress the helium collected in the recovery tank 1 and draw it into the helium storage tank 7, so that the air pressure in the recovery pipe 2 and the air pressure inside the recovery tank 1 maintain a pressure difference.

[0038] Among the commonly used gas molecules, the molecular diameter of helium molecules is 0.26nm, the molecular diameter of hydrogen molecules is 0.289nm, the molecular diameter of nitrogen molecules is 0.346nm, the molecular diameter of oxygen molecules is 0.346nm, and the molecular diameter of argon molecules is 0.34nm, which are all smaller than the molecular diameter of helium molecules. By controlling the air pressure in the recovery pipe 2 and the air pressure inside the recovery box 1, and controlling the air pressure in the recovery pipe 2 to be 20psi~100psi and the air pressure inside the recovery box 1 to be less than -10psi, the molecular pores are slightly enlarged (greater than or equal to 0.26nm and not more than 0.28nm) under the action of the pressure difference, and the helium molecules flow from the high-pressure recovery pipe 2 to the low-pressure recovery box 1 through the molecular pores (the other gas molecules cannot pass through), thereby realizing the recovery of helium and reducing the waste of helium.

[0039] At the same time, compared with the existing helium recovery devices and helium recovery methods, the helium recovery device provided by the present application has a simple structure, the recovered helium has high purity, and no purification treatment is required, that is, the helium recovery efficiency is greatly improved.

[0040] PFA is a kind of plastic, also known as fusible polytetrafluoroethylene, which is a copolymer of a small amount of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene. PFA tube, full name fusible polytetrafluoroethylene tube, is a special pipe made of perfluorinated polymer material with excellent chemical resistance and high temperature stability.

[0041] In this embodiment, the recovery tube 201 is a spiral tube structure, which can increase the tube length to facilitate helium recovery. The tube wall thickness of the recovery tube 201 is 1000 μm.

[0042] In this embodiment, the material of the recovery pipe 2 is PFA451.

[0043] In this embodiment, the air pressure in the recovery pipe 2 is 20 psi to 100 psi, and the air pressure inside the recovery box 1 is less than or equal to -10 psi.

[0044] In other embodiments, the air pressure difference between the recovery tube 2 and the recovery box 1 is preferably 45 psi to 80 psi, and the radial size of the molecular pores of the recovery tube 2 is preferably 0.26 nm to 0.27 nm.

[0045] In this embodiment, the second pressure detector 4 is disposed at the pipe portion of the first pipeline 5 located at the recovery box 1 .

[0046] In this embodiment, a third pressure detector 9 is further included. The third pressure detector 9 is connected to the helium storage tank 7 and is used to detect the air pressure inside the helium storage tank 7 .

[0047] In this embodiment, the second gas compressor 10, the second valve 11, the third valve 12, the second pipeline 13 and the third pipeline 14 are also included. One end of the second pipeline 13 is connected to the inlet end 202 of the recovery pipe 2, and the other end is used to connect to the mixed gas source containing helium; The third pipeline 14 is connected to the outlet end 203 of the recovery pipe 2; The second valve 11 and the third valve 12 are respectively arranged on the second pipeline 13 and the third pipeline 14. In actual use, the second valve 11 can also be arranged at the inlet end 202 of the recovery pipe 2; The second gas compressor 10 is disposed on the second pipeline 13 and is located on a side of the second valve 11 away from the recovery tank 1 .

[0048] In this embodiment, a helium concentration detector 15 and a vacuum device (not shown) are also included. The helium concentration detector 15 is arranged on the third pipeline 14 and is located on the side of the third valve 12 close to the recovery box 1; The vacuum device is used to perform vacuum treatment on the inside of the recovery box 1 .

[0049] In this embodiment, a secondary recovery pipeline is also included, one end of which is connected to the side of the third pipeline 14 away from the outlet end 203, and the other end is used to connect to the second pipeline 13; When the helium concentration detector 15 detects that the helium concentration in the third pipeline 14 exceeds the set value, the secondary recovery pipeline is opened to perform secondary recovery of helium, thereby further improving the recovery degree of helium and reducing the waste of helium.

[0050] In this embodiment, the recovery box 1 is a constant temperature box and can perform temperature control.

[0051] In this embodiment, at least the recovery tube 2 located in the recovery box 1 is covered with a hollow tube sleeve (not shown in the figure). The inner diameter of the tube sleeve is slightly larger than the outer diameter of the recovery tube 2 and is used to prevent the recovery tube 2 from bursting due to excessive expansion.

[0052] In actual use, the recovery pipe 2 may burst under high pressure. Setting a pipe sleeve can provide support for the recovery pipe 2 to prevent bursting. The pipe sleeve can be a metal pipe sleeve or a high-strength plastic pipe sleeve. The outer wall of the pipe sleeve exposed in the recovery box 1 is provided with an anti-corrosion coating to prevent corrosion.

[0053] like Figure 1 , Figure 2 and Figure 3 As shown, the present application also provides a helium recovery method, comprising the following steps: S1. Providing a helium recovery device, the helium recovery device being a helium recovery device as described above; S2. Vacuum the recycling box 1; S3. Close the first valve 6 and the third valve 12, open the second valve 11, introduce a mixed gas containing helium into the recovery pipe 2, and control the air pressure difference between the recovery pipe 2 and the recovery box 1 to be 30psi~100psi, that is, control the air pressure in the recovery pipe 2 to be 20psi~100psi (displayed by the first pressure detector 3), control the air pressure inside the recovery box 1 to be less than -10psi (displayed by the second pressure detector 4), close the first valve 6, the second valve 11, and the third valve 12, control the temperature inside the recovery box 1 to be 25 degrees Celsius, so that the recovery pipe 2 expands, and the radial size of the molecular pores of the recovery pipe 2 becomes 0.26nm~0.28nm, and the helium is filtered from the recovery pipe 2 through the molecular pores to the inside of the recovery box 1 under the action of suitable temperature and pressure difference (from high pressure to low pressure); S4. The helium collected in the recovery tank 1 is compressed and pumped into the helium storage tank 7, so that the air pressure in the recovery pipe 2 and the air pressure inside the recovery tank 1 maintain a pressure difference; S5. Detect the helium concentration at the outlet end 203 of the recovery pipe 2. When the helium concentration is lower than the first value, the mixed gas is subjected to tail gas treatment or discharged. When the helium concentration is higher than the first value, the mixed gas is reconnected to the inlet end 202 for secondary recovery of helium.

[0054] In other embodiments, the mixed gas also includes nitrogen; When recovering helium, the temperature inside the recovery box 1 is controlled at 30 degrees Celsius; The air pressure in the recovery pipe 2 is 20psi~100psi, and the air pressure inside the recovery box 1 is less than or equal to -10psi.

[0055] Example 2 like Figure 1 and Figure 3 As shown, the difference between this embodiment and embodiment 1 is that the recovery box structure is replaced by a collection pipe structure: In this embodiment, the helium recovery device includes a collection pipe 16, a recovery pipe 2, a first pressure detector 3, a second pressure detector 4 and a helium storage device; The recovery pipe 2 includes a recovery pipe portion 201 and an inlet end 202 and an outlet end 203 arranged at both ends of the recovery pipe portion 201. The inlet end 202 is used to connect to a mixed gas source containing helium, and the outlet end 203 is used to connect to an exhaust gas treatment device. The recovery tube 2 is a PFA tube, and the tube wall of the recovery tube 2 has molecular pores. The radial size of the molecular pores in the natural state is 0.25nm~0.26nm; The collecting pipe 16 is disposed on the recovery pipe portion 201 of the recovery pipe 2. The inner wall of the collecting pipe 16 is provided with a guide groove 161 and a supporting convex wall 162. The outer wall of the recovery pipe portion 201 is exposed in the guide groove 161. The supporting convex wall 162 is located at the outer wall of the recovery pipe 2. The inner diameter of the collecting pipe where the most convex point of the supporting convex wall 162 is located is slightly larger than the outer diameter of the recovery pipe portion 201. When the recovery pipe portion 201 expands, the supporting convex wall 162 is used to support and prevent the recovery pipe 2 from bursting. The first pressure detector 3 is used to detect the air pressure in the recovery pipe 2, and the second pressure detector 4 is used to detect the air pressure inside the guide groove 161; When the pressure difference between the recovery pipe 2 and the guide groove 161 is 30 psi to 100 psi, the recovery pipe 2 expands, the radial size of the molecular pores of the recovery pipe 2 becomes 0.26 nm to 0.28 nm, and the helium molecules in the recovery pipe portion 201 flow into the guide groove 161 through the molecular pores of the recovery pipe 2; The helium storage device includes a first pipeline 5, a first gas compressor 8, a first valve 6 and a helium storage tank 7. The helium storage tank 7 is connected to the guide groove 161 through the first pipeline 5. The first gas compressor 8 and the first valve 6 are respectively arranged on the first pipeline 5. The first gas compressor 8 is used to compress the helium collected in the guide groove 161 and draw it into the helium storage tank 7, so that the air pressure in the recovery pipe 2 and the air pressure in the guide groove 161 maintain an air pressure difference.

[0056] The collection pipe 16 is arranged outside the recovery pipe portion 201 of the recovery pipe 2 to collect gas and support the recovery pipe 2 to prevent the recovery pipe 2 from bursting under pressure. This type of helium recovery device has a simple structure and a small size, and is easy to install in a self-igniting liquid supply system.

[0057] In this embodiment, the guide groove 161 includes a plurality of guide grooves 161, which are arranged at intervals along the axial direction of the collecting tube 16, and the groove body of the guide groove 161 forms a supporting convex wall 162. Alternatively, the guide groove 161 is spirally arranged on the inner wall of the collecting tube 16. The guide groove 161 can simultaneously realize the collection function and the diversion function of helium.

[0058] In this embodiment, a temperature control element for controlling the temperature in the guide groove 161 is further disposed on the outside of the collecting pipe 16 .

[0059] In this embodiment, the second gas compressor 10, the second valve 11, the third valve 12, the second pipeline 13 and the third pipeline 14 are also included. One end of the second pipeline 13 is connected to the inlet end 202 of the recovery pipe 2, and the other end is used to connect to the mixed gas source containing helium; The third pipeline 14 is connected to the outlet end 203 of the recovery pipe 2; The second valve 11 and the third valve 12 are respectively arranged on the second pipeline 13 and the third pipeline 14; The second gas compressor 10 is disposed on the second pipeline 13 and is located on the side of the second valve 11 away from the recovery tank 1; It also includes a helium concentration detector 15 and a vacuum device (not shown in the figure). The helium concentration detector 15 is arranged on the third pipeline 14 and is located on the side of the third valve 12 close to the recovery box 1; The vacuum device is used to perform vacuum treatment on the inside of the recovery box 1 .

[0060] In this embodiment, the first valve 6 is disposed on a side close to the first gas compressor 8 and close to the helium storage tank 7 .

[0061] In this embodiment, the recovery pipe portion 201 of the recovery pipe 2 is a straight pipe.

[0062] The above description is only a preferred embodiment of the present invention, and does not limit the patent protection scope of the present invention. Any equivalent structural transformation made by using the contents of the present invention and the drawings, directly or indirectly used in other related technical fields, is also included in the protection scope of the present invention.

Claims

1. A helium recovery device, characterized in that: It includes a recovery box, a recovery pipe, a first pressure detector, a second pressure detector and a helium storage device; The recovery box is a sealed gas recovery box, the recovery pipe includes a recovery pipe part and an inlet end and an outlet end arranged at both ends of the recovery pipe part, the recovery pipe part is placed in the recovery box and is used for helium recovery, the inlet end is arranged outside the recovery box and is used to connect with a mixed gas source containing helium, and the outlet end is arranged outside the recovery box and is used to connect with an exhaust gas treatment device; The recovery tube is made of PFA material, and the tube wall of the recovery tube has molecular pores, and the radial size of the molecular pores in the natural state is 0.25nm~0.26nm; The first pressure detector is used to detect the air pressure in the recovery pipe, and the second pressure detector is used to detect the air pressure inside the recovery box; When the pressure difference between the recovery tube and the recovery box is 30 psi to 100 psi, the recovery tube expands, and the helium molecules in the recovery tube flow into the recovery box through the molecular pores of the recovery tube; The helium storage device includes a first pipeline, a first gas compressor, a first valve and a helium storage tank. The helium storage tank is connected to the recovery tank through the first pipeline and the first gas compressor. The first valve is arranged on the first pipeline. The first gas compressor is used to compress the helium collected in the recovery tank and then draw it into the helium storage tank, so that the air pressure in the recovery pipe and the air pressure inside the recovery tank maintain a pressure difference.

2. A helium recovery device as claimed in claim 1, characterized in that: The recovery pipe part is a spiral pipe structure, and the pipe wall thickness of the recovery pipe part is 50 μm to 2000 μm.

3. A helium recovery device according to claim 1, characterized in that: The air pressure in the recovery pipe is 20 psi to 100 psi, and the air pressure inside the recovery box is less than or equal to -10 psi; The recovery box is a constant temperature box and can perform temperature control.

4. A helium recovery device as claimed in claim 1, characterized in that: It also includes a second gas compressor, a second valve, a third valve, a second pipeline and a third pipeline, One end of the second pipeline is connected to the inlet end of the recovery pipe, and the other end is used to connect to a mixed gas source containing helium; The third pipeline is connected to the outlet end of the recovery pipe; The second valve and the third valve are respectively arranged on the second pipeline and the third pipeline; The second gas compressor is arranged on the second pipeline and is located on the side of the second valve away from the recovery tank; It also includes a helium concentration detector and a vacuum device, wherein the helium concentration detector is arranged on the third pipeline and is located on the side of the third valve close to the recovery box; The vacuum device is used to perform vacuum treatment on the interior of the recovery box.

5. A helium recovery device as claimed in claim 4, characterized in that: It also includes a secondary recovery pipeline, one end of which is connected to a side of the third pipeline away from the outlet end, and the other end of which is used to be connected to the second pipeline; When the helium concentration detector detects that the concentration of helium in the third pipeline exceeds a set value, the secondary recovery pipeline is opened to perform secondary recovery of helium.

6. A helium recovery device as claimed in claim 1, characterized in that: At least a hollow pipe sleeve is provided on the outer sleeve of the recovery pipe in the recovery box, and the inner diameter of the pipe sleeve is slightly larger than the outer diameter of the recovery pipe, so as to prevent the recovery pipe from bursting due to excessive expansion.

7. A helium recovery device, characterized in that: It includes a collecting pipe, a recovery pipe, a first pressure detector, a second pressure detector and a helium storage device; The recovery pipe includes a recovery pipe portion and an inlet end and an outlet end provided at both ends of the recovery pipe portion, wherein the inlet end is used to be connected to a mixed gas source containing helium, and the outlet end is used to be connected to an exhaust gas treatment device; The recovery tube is made of PFA material, and the tube wall of the recovery tube has molecular pores, and the radial size of the molecular pores in the natural state is 0.25nm~0.26nm; The collecting pipe is fitted onto the recovery pipe portion of the recovery pipe, the inner wall of the collecting pipe is provided with a guide groove and a supporting convex wall, the outer wall of the recovery pipe portion is exposed in the guide groove, the supporting convex wall is located at the outer wall of the recovery pipe, and the inner diameter of the collecting pipe where the most convex point of the supporting convex wall is located is slightly larger than the outer diameter of the recovery pipe portion, and the supporting convex wall is used to prevent the recovery pipe portion from bursting; The first pressure detector is used to detect the air pressure in the recovery pipe, and the second pressure detector is used to detect the air pressure inside the guide groove; When the pressure difference between the recovery pipe and the guide groove is 30 psi to 100 psi, the recovery pipe expands, and the helium molecules in the recovery pipe flow into the guide groove through the molecular pores of the recovery pipe; The helium storage device includes a first pipeline, a first gas compressor, a first valve and a helium storage tank. The helium storage tank is connected to the guide groove through the first pipeline. The first gas compressor and the first valve are respectively arranged on the first pipeline. The first gas compressor is used to compress the helium collected by the guide groove and then draw it into the helium storage tank, so that the air pressure in the recovery pipe and the air pressure in the guide groove maintain a pressure difference.

8. A helium recovery method, characterized in that: The steps include: A helium recovery device is provided, wherein the helium recovery device is a helium recovery device according to any one of claims 1 to 7; Vacuum the recovery bin or diversion trough; A mixed gas containing helium is introduced into the recovery pipe, and the pressure difference between the recovery pipe and the recovery box or the pressure difference between the recovery pipe and the guide groove is controlled to be 30psi to 100psi, so that the recovery pipe expands, and the helium is filtered from the recovery pipe through the molecular pores to the recovery box or the guide groove under the action of the pressure difference; The helium collected in the recovery box or diversion trough is compressed and pumped into the helium storage tank, so that the air pressure in the recovery pipe and the air pressure inside the recovery box maintain a pressure difference.

9. A helium recovery method according to claim 8, characterized in that: It also includes detecting the helium concentration at the outlet end of the recovery pipe. When the helium concentration is lower than a first value, the mixed gas is subjected to tail gas treatment or discharged. When the helium concentration is higher than the first value, the mixed gas is reconnected to the inlet end for secondary recovery of the helium.

10. A helium recovery method according to claim 8, characterized in that: The mixed gas also includes nitrogen; When recovering helium, the temperature inside the recovery box or diversion trough is controlled at 10 degrees Celsius to 35 degrees Celsius; The air pressure in the recovery pipe is 20psi~100psi, and the air pressure inside the recovery box or the guide groove is less than or equal to -10psi.

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