Helium recovery device and helium recovery method

Abstract

The present application discloses a helium recovery device and a helium recovery method. The device includes a recovery tank, a recovery pipe, a first pressure detector for detecting the internal air pressure of the recovery pipe, and a second pressure detector for detecting the internal air pressure of the recovery tank. The recovery pipe is made of PFA material, and the pipe wall has molecular pores with a size of 0.25 nm to 0.26 nm. The recovery pipe includes a recovery pipe section, an inlet end connected to a gas source, and an outlet end connected to a tail gas treatment device. The recovery pipe section is placed inside the recovery tank. When the air pressure difference between the inside of the recovery pipe and the inside of the recovery tank is 30 psi to 100 psi, the recovery pipe expands, and helium molecules flow into the recovery tank through the molecular pores. The helium recovery method is carried out using the helium recovery device. By controlling the pressure difference, the molecular pores become larger, and helium molecules flow from the inside of the recovery pipe into the recovery tank through the molecular pores, realizing the recovery of helium. The device has a simple structure, high purity of the recovered helium, does not require purification treatment, and improves the recovery efficiency.

Description

Technical Field

[0001] The present invention relates to an exhaust gas collection device, and particularly 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 certain special occasions or equipment. Such systems can automatically supply combustible liquids under specific conditions to ensure the normal operation of the equipment. This type of system is applied in specific industrial processes, such as metal smelting or chemical production, where the self-igniting liquid supply system is used to maintain high temperatures or provide necessary chemical reactants. The self-igniting liquid supply system includes a liquid supply pipeline, a supply tank as the source of the supplied liquid, and a source liquid tank as the source for replenishing the liquid in the supply tank. After the source liquid tank is emptied, the liquid supply pipeline needs to be purged with a purging gas before a new full tank of liquid can be connected to the equipment. When the supply tank is initially installed and used, the liquid supply pipeline also needs to be purged with a purging gas, or when the supply tank is removed, it also needs to be purged with a purging gas before it can be removed. At the same time, different types of purging gases are required to purge the liquid pipeline when different liquids are input: the purging gas in contact with the liquid and the ordinary cleaning purging gas for the liquid pipeline are different types of purging gases.

[0003] In the existing self-igniting liquid supply system, different types of purging gases after purging are mixed and collected or discharged. The purging gas is generally an inert gas with high stability, and nitrogen and helium are preferred gases as purging gases. That is, the demand for helium is relatively large, and the proportion of domestic helium in the world is also small. Therefore, recovering 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 provides a helium recovery device and a helium recovery method.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The present application provides a helium recovery device, including a recovery box, a recovery pipe, a first pressure detector, a second pressure detector, and a helium storage device;

[0007] The recovery box is a sealed gas recovery box. 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. The recovery pipe portion is disposed inside the recovery box and is used for helium recovery. The inlet end penetrates through the recovery box and is used to connect to a mixed gas source containing helium, and the outlet end penetrates through the recovery box and is used to connect to a tail gas treatment device;

[0008] The recovery pipe is made of PFA material, and the pipe wall of the recovery pipe has molecular pores. The radial dimension of the molecular pores in the natural state is 0.25 nm to 0.26 nm;

[0009] 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 tank;

[0010] When the air pressure difference between the inside of the recovery pipe and the inside of the recovery tank is 30 psi to 100 psi, the recovery pipe expands, the radial dimension of the molecular pores of the recovery pipe becomes 0.26 nm to 0.28 nm, and the helium molecules inside the recovery pipe flow into the inside of the recovery tank through the molecular pores of the recovery pipe;

[0011] 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 communicated with 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 by the recovery tank and pump it into the helium storage tank, so as to keep the air pressure difference between the inside of the recovery pipe and the inside of the recovery tank.

[0012] Among common gas molecules, the molecular diameter of helium molecules is 0.26 nm, the molecular diameter of hydrogen molecules is 0.289 nm, the molecular diameter of nitrogen molecules is 0.346 nm, the molecular diameter of oxygen molecules is 0.346 nm, and the molecular diameter of argon molecules is 0.34 nm, all of which are smaller than the molecular diameter of helium molecules. By controlling the air pressure inside the recovery pipe and the air pressure inside the recovery tank, and controlling the air pressure inside the recovery pipe to be 20 psi to 100 psi and the air pressure inside the recovery tank to be less than -10 psi, the molecular pores slightly expand under the action of the pressure difference (greater than or equal to 0.26 nm and not exceeding 0.28 nm), and helium molecules flow from the high-pressure recovery pipe into the low-pressure recovery tank through the molecular pores (the rest of the gas molecules cannot pass through), thereby realizing the recovery of helium and reducing the waste of helium.

[0013] At the same time, compared with the existing helium recovery device and helium recovery method, the helium recovery device provided by this application has a simple structure and high purity of the recovered helium, and no purification treatment is required, that is, the recovery efficiency of helium is greatly improved.

[0014] PFA is a kind of plastic, also known as soluble polytetrafluoroethylene, which is a copolymer of a small amount of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene. The PFA pipe, also known as the soluble polytetrafluoroethylene pipe, is a special pipe made of perfluorinated polymer material, with excellent chemical resistance and high-temperature stability.

[0015] Further, the recovery pipe part is of a spiral pipe structure, and the wall thickness of the recovery pipe part is 50 μm to 2000 μm.

[0016] Further, the material of the recovery pipe is PFA451.

[0017] Further, the air pressure in the recovery pipe is 20 psi to 100 psi, and the air pressure inside the recovery tank is less than or equal to -10 psi.

[0018] Further, the air pressure difference between the air pressure in the recovery pipe and the air pressure inside the recovery tank is preferably 45 psi to 80 psi, and the radial dimension of the molecular pores of the recovery pipe is preferably 0.26 nm to 0.27 nm.

[0019] Further, the second pressure detector is arranged at the pipe part position of the first pipeline located in the recovery tank.

[0020] Further, it further includes a third pressure detector, which is connected to the helium storage tank and is used to detect the air pressure inside the helium storage tank.

[0021] Further, it further includes a second gas compressor, a second valve, a third valve, a second pipeline and a third pipeline.

[0022] One end of the second pipeline is communicated with the inlet end of the recovery pipe, and the other end is used to be connected to a mixed gas source containing helium.

[0023] The third pipeline is communicated with the outlet end of the recovery pipe.

[0024] 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.

[0025] 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.

[0026] Further, it further includes a helium concentration detector and a vacuum device. The helium concentration detector is arranged on the third pipeline and is located on the side of the third valve close to the recovery tank.

[0027] The vacuum device is used to evacuate the inside of the recovery tank.

[0028] Further, it further includes a secondary recovery pipeline. One end of the secondary recovery pipeline is connected to the side of the third pipeline away from the outlet end, and the other end is used to be communicated to the second pipeline.

[0029] When the helium concentration detector detects that the concentration of helium in the third pipeline exceeds the set value, the secondary recovery pipeline is opened for secondary recovery of helium, further improving the recovery degree of helium and reducing the waste of helium.

[0030] Further, the recovery tank is a constant temperature tank and can perform temperature regulation.

[0031] Further, at least the recovery pipe located inside the recovery box is sleeved with a hollow pipe sleeve, and the inner diameter of the pipe sleeve is slightly larger than the outer diameter of the recovery pipe, which is used to prevent the recovery pipe from bursting due to excessive expansion.

[0032] During actual use, the recovery pipe may burst under the action of large pressure. The pipe sleeve can provide support for the recovery pipe to prevent bursting. The pipe sleeve can be a metal pipe sleeve or a plastic pipe sleeve. The outer wall of the pipe sleeve exposed inside the recovery box is provided with an anti-corrosion coating to prevent corrosion. Or, when the wall thickness of the recovery pipe part is less than 500 μm, the gas separation speed will be significantly accelerated. However, in order to avoid the recovery pipe from bursting under the action of large pressure, the pipe sleeve can provide support for the recovery pipe to prevent bursting.

[0033] The present application also provides a helium recovery device, including a collection pipe, a recovery pipe, a first pressure detector, a second pressure detector, and a helium storage device;

[0034] The recovery pipe includes a recovery pipe part and an inlet end and an outlet end provided at both ends of the recovery pipe part. The inlet end is used to connect to a mixed gas source containing helium, and the outlet end is used to connect to an exhaust gas treatment device;

[0035] The recovery pipe is a PFA material pipe, and the pipe wall of the recovery pipe has molecular pores. The radial size of the molecular pores in the natural state is 0.25 nm to 0.26 nm;

[0036] The collection pipe is sleeved on the recovery pipe part of the recovery pipe. The inner wall of the collection pipe is provided with a diversion groove and a support convex wall. The outer wall of the recovery pipe part is exposed in the diversion groove. The support convex wall is located at the outer wall position of the recovery pipe, and the inner diameter of the collection pipe where the most convex point of the support convex wall is located is slightly larger than the outer diameter of the recovery pipe part. The support convex wall is used to prevent the recovery pipe part from bursting;

[0037] The first pressure detector is used to detect the air pressure inside the recovery pipe, and the second pressure detector is used to detect the air pressure inside the diversion groove;

[0038] When the air pressure difference between the inside of the recovery pipe and the inside of the diversion groove is 30 psi to 100 psi, the recovery pipe expands, and the radial size of the molecular pores of the recovery pipe becomes 0.26 nm to 0.28 nm. The helium molecules inside the recovery pipe part flow into the diversion groove through the molecular pores of the recovery pipe;

[0039] 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 diversion 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 diversion groove and pump it into the helium storage tank, so as to maintain a pressure difference between the pressure in the recovery pipe and the pressure in the diversion groove.

[0040] Setting a collection pipe outside the recovery pipe part of the recovery pipe can simultaneously achieve the collection of gas and the support function for the recovery pipe, so as to prevent the recovery pipe from bursting under pressure. This type of helium recovery device has a simple structure and a small volume, and is convenient to install in the spontaneous combustion liquid supply system.

[0041] Furthermore, an anti-corrosion coating is provided on the inner wall of the collection pipe, and the collection pipe is preferably made of a metal structure.

[0042] Furthermore, there are multiple diversion grooves. The multiple diversion grooves are arranged at intervals along the axial direction of the collection pipe, and the groove body of the diversion groove forms a supporting convex wall. Or, the diversion groove is arranged spirally on the inner wall of the collection pipe. The diversion groove can simultaneously achieve the collection function of helium and the diversion function of helium.

[0043] Furthermore, a temperature control element for controlling the temperature inside the diversion groove is also provided outside the collection pipe.

[0044] Furthermore, it also includes a second gas compressor, a second valve, a third valve, a second pipeline, and a third pipeline.

[0045] 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.

[0046] The third pipeline is connected to the outlet end of the recovery pipe.

[0047] The second valve and the third valve are respectively arranged on the second pipeline and the third pipeline.

[0048] The second gas compressor is arranged on the second pipeline and is located on the side of the second valve away from the recovery box.

[0049] It also includes a helium concentration detector and a vacuum device. 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.

[0050] The vacuum device is used to evacuate the inside of the recovery box.

[0051] Furthermore, the first valve is arranged on the side of the first gas compressor close to the helium storage tank.

[0052] This application also provides a helium recovery method, which includes the following steps:

[0053] Provide a helium recovery device, and the helium recovery device is one of the above-mentioned helium recovery devices;

[0054] Perform a vacuum treatment on the recovery tank or the diversion trough;

[0055] Introduce a mixed gas containing helium into the recovery pipe, and control the pressure difference between the inside of the recovery pipe and the inside of the recovery tank or the pressure difference between the inside of the recovery pipe and the diversion trough to be 30 psi to 100 psi, so that the recovery pipe expands, and the radial dimension of the molecular pores of the recovery pipe becomes 0.26 nm to 0.28 nm. Helium is filtered from the inside of the recovery pipe through the molecular pores into the recovery tank or the inside of the diversion trough under the action of the pressure difference;

[0056] Compress the helium collected in the recovery tank or the diversion trough and pump it into the helium storage tank to keep the pressure difference between the pressure inside the recovery pipe and the pressure inside the recovery tank or the diversion trough;

[0057] Detect the helium concentration at the outlet end of the recovery pipe. When the helium concentration is lower than the first value, perform tail gas treatment or discharge on the mixed gas. When the helium concentration is higher than the first value, reconnect the mixed gas to the inlet end for secondary recovery of helium.

[0058] Further, the mixed gas also includes nitrogen;

[0059] When recovering helium, the temperature inside the recovery tank or the diversion trough is controlled to be 10 degrees Celsius to 35 degrees Celsius, preferably 25 degrees Celsius;

[0060] The pressure inside the recovery pipe is 20 psi to 100 psi, and the pressure inside the recovery tank or the diversion trough is less than or equal to -10 psi.

[0061] When the pressure inside the recovery tank or the diversion trough is less than or equal to -10 psi and the pressure inside the recovery pipe is lower than 20 psi, helium molecules are not easily filtered into the recovery tank or the diversion trough through the molecular pores; when the pressure inside the recovery tank or the diversion trough is less than or equal to -10 psi and the pressure inside the recovery pipe is higher than 80 psi, small molecule impurity gases in the mixed gas are easily introduced into the recovery tank or the diversion trough; when the pressure inside the recovery tank or the diversion trough is less than or equal to -10 psi and the pressure inside the recovery pipe is 40 psi to 80 psi, most helium molecules can be filtered into the recovery tank or the diversion trough through the molecular pores; when the pressure inside the recovery pipe is 70 psi to 80 psi, the helium recovery rate and effect are optimal.

[0062] The beneficial effects of the present invention are:

[0063] (1)The helium recovery device provided by this application uses a PFA recovery pipe. According to the air pressure settings inside the recovery pipe and inside the recovery tank or the diversion trough, when the air pressure inside the recovery pipe is 20 psi to 100 psi and the air pressure inside the recovery tank is less than -10 psi, the molecular pores slightly expand (0.26 nm to 0.28 nm) under the action of the pressure difference. Helium molecules flow from the high-pressure recovery pipe into the low-pressure recovery tank or the inside of the diversion trough through the molecular pores (other gas molecules cannot pass through), thereby achieving the recovery of helium.

[0064] (2)Compared with the existing helium recovery devices and helium recovery methods, the helium recovery device provided by this application has a simple structure and high purity of the recovered helium, and does not require purification treatment, that is, the helium recovery efficiency is greatly improved.

[0065] (3)Setting a collection pipe outside the recovery pipe part of the recovery pipe can simultaneously achieve gas collection and support for the recovery pipe to prevent the recovery pipe from bursting under pressure. This type of helium recovery device has a simple structure and small volume, and is convenient to install in the spontaneous combustion liquid supply system. Description of the Drawings

[0066] Figure 1 is a schematic structural diagram of the helium recovery device according to an embodiment of the present invention;

[0067] Figure 2 is a schematic flow chart of the helium recovery method according to an embodiment of the present invention;

[0068] Figure 3 is a schematic cross-sectional structure diagram of the collection pipe and the recovery pipe in the helium recovery device according to Embodiment 2 of the present invention.

[0069] Each reference numeral in the figure is as follows:

[0070] 1, recovery tank; 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, diversion trough; 162, support convex wall. Detailed Embodiments

[0071] The present invention will be described in detail below with reference to the accompanying drawings.

[0072] Embodiment 1

[0073] As Figure 1As shown in the figure, the present application provides a helium recovery device, which includes a recovery tank 1, a recovery pipe 2, a first pressure detector 3, a second pressure detector 4, and a helium storage device;

[0074] The recovery tank 1 is a sealed gas recovery tank. The recovery pipe 2 includes a recovery pipe part 201 and an inlet end 202 and an outlet end 203 provided at both ends of the recovery pipe part 201. The recovery pipe part 201 is placed inside the recovery tank 1 and is used for helium recovery. The inlet end 202 penetrates through the recovery tank 1 and is used to connect to a mixed gas source containing helium, and the outlet end 203 penetrates through the recovery tank 1 and is used to connect to an exhaust gas treatment device;

[0075] The recovery pipe 2 is a PFA material pipe, and the pipe wall of the recovery pipe 2 has molecular pores. When in a natural state, the radial size of the molecular pores is 0.25nm to 0.26nm;

[0076] The first pressure detector 3 is used to detect the air pressure inside the recovery pipe 2 (the first pressure detector 3 can be arranged inside the recovery pipe 2), and the second pressure detector 4 is used to detect the air pressure inside the recovery tank 1;

[0077] When the air pressure difference between the inside of the recovery pipe 2 and the inside of the recovery tank 1 is 30psi to 100psi, the recovery pipe 2 expands, and the radial size of the molecular pores of the recovery pipe 2 becomes 0.26nm to 0.28nm. The helium molecules inside the recovery pipe part 201 flow into the inside of the recovery tank 1 through the molecular pores of the recovery pipe 2;

[0078] 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 by the recovery tank 1 and pump it into the helium storage tank 7, so as to keep the air pressure difference between the inside of the recovery pipe 2 and the inside of the recovery tank 1.

[0079] Among common 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, all of which are smaller than the molecular diameter of helium molecules. By controlling the air pressure inside the recovery pipe 2 and the air pressure inside the recovery tank 1, and controlling the air pressure inside the recovery pipe 2 to be 20psi to 100psi and the air pressure inside the recovery tank 1 to be less than -10psi, the molecular pores slightly expand under the action of the pressure difference (greater than or equal to 0.26nm and not exceeding 0.28nm), and the helium molecules flow from the high-pressure recovery pipe 2 to the low-pressure inside of the recovery tank 1 through the molecular pores (the rest of the gas molecules cannot pass through), thereby realizing the recovery of helium and reducing the waste of helium.

[0080] Meanwhile, compared with the existing helium recovery devices and methods, the helium recovery device provided by this application has a simple structure, high purity of the recovered helium, and does not require purification treatment, that is, the helium recovery efficiency is greatly improved.

[0081] PFA is a kind of plastic, also known as soluble polytetrafluoroethylene, which is a copolymer of a small amount of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene. The PFA tube, fully called soluble polytetrafluoroethylene tube, is a special pipe made of perfluorinated polymer material, with excellent chemical resistance and high-temperature stability.

[0082] In this embodiment, the recovery pipe part 201 is of a spiral pipe structure. The spiral pipe structure can increase the pipe length, facilitating the promotion of helium recovery. The wall thickness of the recovery pipe part 201 is 1000 μm.

[0083] In this embodiment, the material of the recovery pipe 2 is PFA451.

[0084] In this embodiment, the air pressure inside 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.

[0085] In other embodiments, the air pressure difference between the inside of the recovery pipe 2 and the inside of the recovery box 1 is preferably 45 psi to 80 psi, and the radial size of the molecular pores of the recovery pipe 2 is preferably 0.26 nm to 0.27 nm.

[0086] In this embodiment, the second pressure detector 4 is arranged at the pipe part position of the first pipeline 5 located in the recovery box 1.

[0087] In this embodiment, it further includes a third pressure detector 9. 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.

[0088] In this embodiment, it further includes a second gas compressor 10, a second valve 11, a third valve 12, a second pipeline 13 and a third pipeline 14.

[0089] One end of the second pipeline 13 is communicated with the inlet end 202 of the recovery pipe 2, and the other end is used to be connected to a mixed gas source containing helium.

[0090] The third pipeline 14 is communicated with the outlet end 203 of the recovery pipe 2.

[0091] 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.

[0092] The second gas compressor 10 is arranged on the second pipeline 13 and is located on the side of the second valve 11 away from the recovery box 1.

[0093] In this embodiment, it further 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 tank 1;

[0094] The vacuum device is used to evacuate the inside of the recovery tank 1.

[0095] In this embodiment, it further includes a secondary recovery pipeline. One end of the secondary recovery pipeline is connected to the side of the third pipeline 14 away from the outlet end 203, and the other end is used to communicate with the second pipeline 13;

[0096] 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 for secondary recovery of helium, further improving the recovery degree of helium and reducing the waste of helium.

[0097] In this embodiment, the recovery tank 1 is a constant temperature tank and can be temperature-controlled.

[0098] In this embodiment, at least a hollow pipe sleeve (not shown in the figure) is sleeved outside the recovery pipe 2 located in the recovery tank 1. The inner diameter of the pipe sleeve is slightly larger than the outer diameter of the recovery pipe 2 and is used to prevent the recovery pipe 2 from bursting due to excessive expansion.

[0099] In actual use, the recovery pipe 2 may burst under the action of large pressure. Setting the 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. Anti-corrosion coatings are provided on the outer walls of the pipe sleeve exposed in the recovery tank 1 to prevent corrosion.

[0100] As Figure 1 、 Figure 2 and Figure 3 shown, the present application also provides a helium recovery method, including the following steps:

[0101] S1. Provide a helium recovery device, and the helium recovery device is the above-mentioned helium recovery device;

[0102] S2. Evacuate the recovery tank 1;

[0103] S3. Close the first valve 6 and the third valve 12, open the second valve 11, introduce the mixed gas containing helium into the recovery pipe 2, and control the air pressure difference between the inside of the recovery pipe 2 and the inside of the recovery tank 1 to be 30 psi to 100 psi, that is, control the air pressure inside the recovery pipe 2 to be 20 psi to 100 psi (displayed by the first pressure detector 3), control the air pressure inside the recovery tank 1 to be less than -10 psi (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 tank 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 0.26 nm to 0.28 nm. Under the action of suitable temperature and pressure difference (from high pressure to low pressure), helium is filtered from the inside of the recovery pipe 2 through the molecular pores into the inside of the recovery tank 1;

[0104] S4. Compress the helium collected in the recovery tank 1 and pump it into the helium storage tank 7 to keep the air pressure difference between the inside of the recovery pipe 2 and the inside of the recovery tank 1;

[0105] 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, treat the tail gas of the mixed gas or discharge it. When the helium concentration is higher than the first value, reconnect the mixed gas to the inlet end 202 for secondary recovery of helium.

[0106] In other embodiments, the mixed gas further includes nitrogen;

[0107] When recovering helium, the temperature inside the recovery tank 1 is controlled to be 30 degrees Celsius;

[0108] The air pressure inside the recovery pipe 2 is 20 psi to 100 psi, and the air pressure inside the recovery tank 1 is less than or equal to -10 psi.

[0109] Embodiment 2

[0110] As Figure 1 and Figure 3 shown, the difference between this embodiment and Embodiment 1 is that the structure of the recovery tank is replaced with the structure of the collection pipe:

[0111] 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;

[0112] The recovery pipe 2 includes a recovery pipe portion 201 and an inlet end 202 and an outlet end 203 provided 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 a tail gas treatment device;

[0113] The recovery pipe 2 is a PFA material pipe. The pipe wall of the recovery pipe 2 has molecular pores. When in the natural state, the radial dimension of the molecular pores is 0.25 nm to 0.26 nm;

[0114] The collection pipe 16 is sleeved on the recovery pipe part 201 of the recovery pipe 2. The inner wall of the collection pipe 16 is provided with a diversion groove 161 and a support convex wall 162. The outer wall of the recovery pipe part 201 is exposed in the diversion groove 161. The support convex wall 162 is located at the outer wall position of the recovery pipe 2. The inner diameter of the collection pipe where the most convex point of the support convex wall 162 is located is slightly larger than the outer diameter of the recovery pipe part 201. When the recovery pipe part 201 expands, the support convex wall 162 is used to support and prevent the recovery pipe 2 from bursting;

[0115] The first pressure detector 3 is used to detect the air pressure inside the recovery pipe 2, and the second pressure detector 4 is used to detect the air pressure inside the diversion groove 161;

[0116] When the air pressure difference between the inside of the recovery pipe 2 and the inside of the diversion groove 161 is 30 psi to 100 psi, the recovery pipe 2 expands, and the radial dimension of the molecular pores of the recovery pipe 2 becomes 0.26 nm to 0.28 nm. The helium molecules inside the recovery pipe part 201 flow into the diversion groove 161 through the molecular pores of the recovery pipe 2;

[0117] 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 communicated with the diversion 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 by the diversion groove 161 and pump it into the helium storage tank 7, so as to keep the air pressure difference between the inside of the recovery pipe 2 and the air pressure of the diversion groove 161.

[0118] Arranging the collection pipe 16 outside the recovery pipe part 201 of the recovery pipe 2 can simultaneously realize the collection of gas and the support function for 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 volume, and is convenient to install in the spontaneous combustion liquid supply system.

[0119] In this embodiment, there are multiple diversion grooves 161. The multiple diversion grooves 161 are arranged at intervals along the axial direction of the collection pipe 16. The groove body of the diversion groove 161 forms the support convex wall 162. Alternatively, the diversion groove 161 is arranged in a spiral shape on the inner wall of the collection pipe 16. The diversion groove 161 can simultaneously realize the collection function of helium and the diversion function of helium.

[0120] In this embodiment, a temperature control element for controlling the temperature inside the diversion groove 161 is further arranged outside the collection pipe 16.

[0121] In this embodiment, it further includes a second gas compressor 10, a second valve 11, a third valve 12, a second pipeline 13 and a third pipeline 14.

[0122] One end of the second pipeline 13 is communicated with the inlet end 202 of the recovery pipe 2, and the other end is used to be connected with a mixed gas source containing helium.

[0123] The third pipeline 14 is communicated with the outlet end 203 of the recovery pipe 2.

[0124] The second valve 11 and the third valve 12 are respectively arranged on the second pipeline 13 and the third pipeline 14.

[0125] The second gas compressor 10 is arranged on the second pipeline 13 and is located on the side of the second valve 11 away from the recovery tank 1.

[0126] It further 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 tank 1.

[0127] The vacuum device is used to evacuate the interior of the recovery tank 1.

[0128] In this embodiment, the first valve 6 is arranged on the side of the first gas compressor 8 close to the helium storage tank 7.

[0129] In this embodiment, the recovery pipe portion 201 of the recovery pipe 2 is a straight pipe.

[0130] The above are only the preferred embodiments of the present invention, and thus do not limit the patent protection scope of the present invention. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention, directly or indirectly applied in other related technical fields, shall be included in the protection scope of the present invention by the same token.

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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