Recovery system for hydrogen fluoride and uranium hexafluoride in fluorinated tail gas

Abstract

The invention discloses a recovery system for hydrogen fluoride and uranium hexafluoride in fluorinated tail gas, the recovery system comprises at least one set of recovery subsystem, the recovery subsystem comprises a heat exchanger, refrigeration equipment and a storage tank, to-be-treated process tail gas is introduced into the heat exchanger for heat exchange, hydrogen fluoride contained in the process tail gas is condensed into a liquid state, and uranium hexafluoride in the liquid state is recycled; uranium hexafluoride contained in the process tail gas is condensed into a solid state, the solid state is reserved in the heat exchanger, and then residual gas is output; the storage tank is positioned below the heat exchanger and is communicated with the heat exchanger through a self-flowing pipe, and the condensed liquid hydrogen fluoride flows into the storage tank; the device further comprises a heating component and a uranium hexafluoride output pipe, the heating component heats and gasifies uranium hexafluoride in the heat exchanger, and uranium hexafluoride is output through the uranium hexafluoride output pipe. According to the invention, hydrogen fluoride and uranium hexafluoride in the process tail gas can be recovered before the process tail gas enters the leaching tower to be treated, so that the production cost is saved, and meanwhile, the output of waste liquid can be greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of exhaust gas recovery technology, and in particular to a system for recovering hydrogen fluoride and uranium hexafluoride from fluorinated exhaust gas. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] The main components of fluorinated tail gas include uranium hexafluoride, fluorine, hydrogen fluoride (HF), nitrogen, and oxygen. It must be treated by a fluorinated tail gas treatment system to meet emission standards before being discharged.

[0004] In existing fluorination tail gas treatment processes, hydrogen fluoride in the process tail gas is usually treated by a scrubbing tower, and the resulting fluorine-containing waste liquid is discharged after being treated by a defluorination system to meet standards. This method generates a large amount of fluorine-containing waste liquid. If hydrogen fluoride (HF) and uranium hexafluoride in the process tail gas can be recovered and reused, it can not only save production costs, but also greatly reduce the amount of waste liquid generated. Therefore, this application proposes a system for recovering hydrogen fluoride and uranium hexafluoride from fluorination tail gas. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings mentioned above by providing a system for recovering hydrogen fluoride and uranium hexafluoride from fluorinated tail gas.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A system for recovering hydrogen fluoride and uranium hexafluoride from fluorinated tail gas includes at least one recovery subsystem. The recovery subsystem includes a heat exchanger, a refrigeration device, and a storage tank. The process tail gas to be treated is passed into the heat exchanger for heat exchange and then output. The refrigeration equipment is used to introduce a cold medium into the heat exchanger, condensing the hydrogen fluoride contained in the process tail gas into a liquid state and the uranium hexafluoride contained in the process tail gas into a solid state, which are then retained in the heat exchanger. The storage tank is located below the heat exchanger and is connected to the heat exchanger via a gravity flow pipe. The liquid hydrogen fluoride condenses into liquid form and flows into the storage tank via the gravity flow pipe. The gravity flow pipe is equipped with a first valve body for controlling its on / off state. It also includes a heating element and a uranium hexafluoride output pipe. The heating element is used to heat and vaporize the uranium hexafluoride in the heat exchanger and output the vaporized uranium hexafluoride through the uranium hexafluoride output pipe, wherein the uranium hexafluoride output pipe is provided with a second valve body for controlling its on and off.

[0007] Furthermore, the amount of solid uranium hexafluoride collected inside the heat exchanger is determined by detecting the weight of the heat exchanger.

[0008] Furthermore, the heat exchanger is a shell-and-tube heat exchanger, the cold medium flows through the tube side of the heat exchanger, and the process exhaust gas flows through the shell side of the heat exchanger. The top of the heat exchanger is provided with a first exhaust gas port and a second exhaust gas port. The process exhaust gas to be treated enters the heat exchanger through the first exhaust gas port and then exits from the second exhaust gas port. The connection port between the gravity flow pipe and the heat exchanger is located on the upper part of one side of the heat exchanger and below the second exhaust gas interface, allowing liquid hydrogen fluoride to flow out by overflow.

[0009] Furthermore, the bottom surface inside the heat exchanger is tilted, and the connection port between the gravity flow pipe and the heat exchanger and the second exhaust gas port are both located at the higher end of the tilted position, while the first exhaust gas port is located at the lower end of the tilted position. The heating components are concentrated at the lower end of the tilted position.

[0010] Furthermore, by tilting the heat exchanger, the bottom surface inside the heat exchanger is tilted.

[0011] Furthermore, the recovery subsystem is provided in two sets. Each recovery subsystem has an inlet branch pipe and an outlet branch pipe connected to its heat exchanger. Each inlet branch pipe is connected to a common inlet main pipe, and each outlet branch pipe is connected to a common outlet main pipe. Each inlet branch pipe is equipped with a third valve body, and each outlet branch pipe is equipped with a fourth valve body, which are used to control the opening and closing of the corresponding inlet branch pipe and outlet branch pipe, respectively. The two recovery subsystems serve as backups for each other. When uranium hexafluoride in one of the heat exchangers needs to be output, the corresponding recovery subsystem stops operating and closes the first and fourth valves, while keeping the second valve closed and the third valve open. Simultaneously, the other recovery subsystem operates, sequentially heating and vaporizing the residual hydrogen fluoride and uranium hexafluoride in the heat exchanger of the corresponding recovery subsystem. The vaporized hydrogen fluoride is fed into the heat exchanger of the other recovery subsystem through the inlet branch pipe and the inlet main pipe. After the residual hydrogen fluoride has vaporized, uranium hexafluoride is vaporized and fed into the heat exchanger of the other recovery subsystem for a predetermined time. Then, the third valve of the corresponding recovery subsystem is closed, and the second valve is opened and closed, allowing uranium hexafluoride to be output through the uranium hexafluoride output pipe.

[0012] Furthermore, the uranium hexafluoride output tubes on each recovery subsystem are connected to a common output main pipe. Each uranium hexafluoride output tube and the output main pipe are equipped with heating elements for heat preservation and to keep the uranium hexafluoride in a gaseous state.

[0013] Furthermore, it also includes a main infusion pipe, which is connected to multiple branch infusion pipes, each branch infusion pipe corresponding to a recovery subsystem, with one end of each branch infusion pipe extending into the bottom of the corresponding storage tank; wherein, each branch infusion pipe is equipped with a fifth valve body for controlling the opening and closing of the corresponding branch infusion pipe; It also includes a main pressure delivery pipe and multiple branch pressure delivery pipes. One end of each branch pressure delivery pipe is connected to the main pressure delivery pipe, and the other end is connected to the corresponding storage tank. Compressed gas enters each branch pressure delivery pipe through the main pressure delivery pipe and is fed into the corresponding storage tank. The liquid inside the storage tank is fed through the corresponding delivery branch pipe into the main delivery pipe and then output through the pressure delivery method. Each branch pressure delivery pipe is equipped with a sixth valve body to control the opening and closing of the corresponding branch pressure delivery pipe.

[0014] Furthermore, each recycling subsystem is also equipped with an exhaust pipe, one end of which is connected to the top of the storage tank and the other end is connected to the main exhaust pipe. The exhaust pipe is equipped with a seventh valve body for controlling the opening and closing of the exhaust pipe.

[0015] Furthermore, each recovery subsystem has a short-circuit branch pipe connected between the inlet branch pipe and the outlet branch pipe, and an eighth valve body is installed on the short-circuit branch pipe, which is used to control the opening and closing of the short-circuit branch pipe.

[0016] The beneficial effects of this invention are reflected in: This invention can recover and reuse hydrogen fluoride and uranium hexafluoride in the process tail gas before it enters the scrubbing tower for treatment, thereby saving production costs and greatly reducing the amount of waste liquid generated. Attached Figure Description

[0017] Figure 1 This is an overall flowchart of the recycling system described in this invention; Figure 2 This is a flowchart of the recycling subsystem described in this invention.

[0018] In the picture: 1. Heat exchanger; 11. Inlet branch pipe; 111. Third valve body; 12. Outlet branch pipe; 121. Fourth valve body; 13. Uranium hexafluoride outlet pipe; 131. Second valve body; 2. Refrigeration equipment; 3. Storage tank; 31. Gravity flow pipe; 311. First valve body; 32. Exhaust pipe; 321. Seventh valve body; 4. Main intake manifold; 5. Main exhaust pipe; 6. Output main pipe; 7. Main infusion line; 71. Branch infusion line; 711. Fifth valve body; 8. Pressure delivery main pipe; 81. Pressure delivery branch pipe; 811. Sixth valve body; 9. Short-circuit branch pipe; 91. Eighth valve body. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1-2 The present invention discloses a recovery system for hydrogen fluoride and uranium hexafluoride in fluorinated tail gas, including at least one recovery subsystem. The recovery subsystem includes a heat exchanger 1, a refrigeration device 2 and a storage tank 3. The process tail gas to be treated is passed into the heat exchanger 1 for heat exchange and then output. The refrigeration device 2 is used to introduce a cold medium into the heat exchanger 1, condensing the hydrogen fluoride contained in the process tail gas in the heat exchanger 1 into a liquid state (the boiling point of hydrogen fluoride is 19.52℃ and the melting point is -84℃), and condensing the uranium hexafluoride contained in the process tail gas into a solid state (the boiling point of uranium hexafluoride is 56.5℃ and the melting point is 64.8℃. Under normal pressure, uranium hexafluoride will not directly liquefy, but will directly sublimate from a solid state into a gaseous state), and leaving it in the heat exchanger 1; The storage tank 3 is located below the heat exchanger 1. The storage tank 3 is connected to the heat exchanger 1 through a gravity flow pipe 31. The liquid hydrogen fluoride condenses into liquid form and flows into the storage tank 3 through the gravity flow pipe 31. The gravity flow pipe 31 is equipped with a first valve body 311 for controlling its opening and closing. It also includes a heating element (not shown in the figure) and a uranium hexafluoride output pipe 13. The heating element is used to heat and vaporize the uranium hexafluoride in the heat exchanger 1 and output the vaporized uranium hexafluoride through the uranium hexafluoride output pipe 13. The uranium hexafluoride output pipe 13 is provided with a second valve body 131 for controlling its on and off.

[0021] In practice, initially, the first valve body 311 is open and the second valve body 131 is closed. Before the process tail gas enters the scrubbing tower for treatment, the process tail gas first passes through heat exchanger 1 to condense the hydrogen fluoride and uranium hexafluoride into liquid and solid states, respectively. Then, the liquid hydrogen fluoride is collected through storage tank 3. When the solid uranium hexafluoride in heat exchanger 1 reaches a certain amount, the flow of process tail gas into heat exchanger 1 is stopped. Then, the refrigeration equipment 2 is shut down, and the other connecting pipes of heat exchanger 1 are closed, leaving only the uranium hexafluoride output pipe 13 connected to heat exchanger 1. (At this time, the second valve body 131 is open and the first valve body 311 is closed.) Then, the heating component is started to heat and vaporize uranium hexafluoride and output it through the uranium hexafluoride output pipe 13 (usually output to another cooling device to be re-condensed into a solid and then collected uniformly, or returned to the fluorination tail gas treatment process through the uranium hexafluoride output pipe 13 to participate in the treatment of fluorination tail gas again). After the output is completed, the uranium hexafluoride output pipe 13 is closed, and then the next round of condensation and recovery operation is carried out (at this time, the first valve body 311 is open and the second valve body 131 is closed).

[0022] This application enables the recovery and reuse of hydrogen fluoride and uranium hexafluoride in the process tail gas before it enters the scrubbing tower for treatment, thereby saving production costs and greatly reducing the amount of waste liquid generated.

[0023] Preferably, the heating element can heat the uranium hexafluoride inside the heat exchanger 1 by wrapping an electric heating belt around the outside of the heat exchanger 1 or by setting a steam tracing pipe.

[0024] Preferably, the refrigeration equipment 2 is a refrigeration unit, connected to the heat exchanger 1 via a pipeline, providing the heat exchanger 1 with a refrigerant at approximately -80°C to better and faster liquefy and solidify hydrogen fluoride and uranium hexafluoride. A solenoid valve is installed on the pipeline connecting the refrigeration equipment 2 to the heat exchanger 1 to control the flow of the refrigerant.

[0025] In one embodiment, the amount of solid uranium hexafluoride collected in the heat exchanger 1 is determined by detecting the weight of the heat exchanger 1.

[0026] In practice, the heat exchanger 1 is connected to various devices and pipelines via flexible hoses, and an electronic scale is installed at the bottom of the heat exchanger 1 to monitor the amount of uranium hexafluoride collected.

[0027] In one embodiment, the heat exchanger 1 is a shell-and-tube heat exchanger 1. The cold medium flows through the tube side of the heat exchanger 1, and the process exhaust gas flows through the shell side of the heat exchanger 1. The top of the heat exchanger 1 is provided with a first exhaust gas port and a second exhaust gas port. The process exhaust gas to be treated enters the heat exchanger 1 through the first exhaust gas port and then exits from the second exhaust gas port. The connection port of the gravity flow pipe 31 to the heat exchanger 1 is located on the upper part of one side of the heat exchanger 1 and below the second exhaust gas port, so that the liquid hydrogen fluoride flows out by overflow.

[0028] In practice, since the density of solid uranium hexafluoride is about 5 times that of liquid hydrogen fluoride, by raising the connection point between the gravity flow pipe 31 and the heat exchanger 1, the liquid hydrogen fluoride flows out by overflow, and the solid uranium hexafluoride will be deposited in the heat exchanger 1. This can effectively prevent the solid uranium hexafluoride from flowing into the storage tank 3 along with the liquid hydrogen fluoride, thus ensuring the purity of the hydrogen fluoride in the storage tank 3.

[0029] It should be noted that a shell-and-tube heat exchanger typically includes components such as a shell, heat transfer tube bundles, and tube sheets. The shell is mostly cylindrical, containing the tube bundles, with both ends of the tube bundles fixed to the tube sheets. The two fluids exchanging heat are called tube-side fluid (i.e., the tube side of the heat exchanger mentioned above) and shell-side fluid (i.e., the shell side of the heat exchanger mentioned above). This is existing technology and will not be elaborated upon here.

[0030] In one embodiment, the bottom surface inside the heat exchanger 1 is inclined. The connection port of the gravity flow pipe 31 to the heat exchanger 1 and the second exhaust gas port are both located at the higher end of the inclined posture, while the first exhaust gas port is located at the lower end. The heating components are concentrated at the lower end of the inclined posture. With this design, in the early stage of uranium hexafluoride solidification, multiple small solid uranium hexafluoride particles will gather in one place and then condense into larger solid uranium hexafluoride particles (i.e., uranium hexafluoride easily solidifies into a clump and gathers in one place). This makes it less likely for small uranium hexafluoride particles to move with the liquid hydrogen fluoride, and it also facilitates concentrated heating and vaporization of solid uranium hexafluoride, reducing heat loss and thus reducing energy consumption.

[0031] Preferably, the bottom surface inside the heat exchanger 1 is tilted by placing the heat exchanger 1 at an angle; of course, the bottom surface inside the heat exchanger 1 can also be made in a tilted manner.

[0032] In one embodiment, the recovery subsystem is provided in two sets. Each heat exchanger 1 of the recovery subsystem is connected to an inlet branch pipe 11 and an outlet branch pipe 12. Each inlet branch pipe 11 is connected to a common inlet main pipe 4, and each outlet branch pipe 12 is connected to a common outlet main pipe 5. The process exhaust gas to be treated enters the corresponding heat exchanger 1 through the inlet main pipe 4 and the corresponding inlet branch pipe 11, and flows into the outlet main pipe 5 through the corresponding outlet branch pipe 12 for output. Each inlet branch pipe 11 is provided with a third valve body 111, and each outlet branch pipe 12 is provided with a fourth valve body 121, which are used to control the opening and closing of the corresponding inlet branch pipe 11 and outlet branch pipe 12, respectively. The two recovery subsystems serve as backups for each other. When uranium hexafluoride in one of the heat exchangers 1 needs to be output, the corresponding recovery subsystem stops operating and closes the first valve 311 and the fourth valve 121 on that recovery subsystem, while keeping the second valve 131 closed and the third valve 111 open. At the same time, the other recovery subsystem is in operation. The residual hydrogen fluoride and uranium hexafluoride in the heat exchanger 1 of the corresponding recovery subsystem are heated and vaporized sequentially. The vaporized hydrogen fluoride is fed into the heat exchanger 1 of the other recovery subsystem through the inlet branch pipe 11 and the inlet main pipe 4. After the residual hydrogen fluoride has been vaporized, the uranium hexafluoride is vaporized and fed into the heat exchanger 1 of the other recovery subsystem for a predetermined time. Then, the third valve 111 on the corresponding recovery subsystem is closed, and the second valve 131 is opened and closed. The uranium hexafluoride is output through the uranium hexafluoride output pipe 13.

[0033] In specific implementation, when heating the residual hydrogen fluoride and uranium hexafluoride in heat exchanger 1, a first-stage heating (temperature between 20-50℃) is performed to vaporize the residual hydrogen fluoride in heat exchanger 1, and the vapor is then fed into heat exchanger 1 in another recovery subsystem through inlet branch pipe 11 and inlet main pipe 4. Subsequently, a second-stage heating (temperature above 60℃) is performed to vaporize the uranium hexafluoride remaining in heat exchanger 1 and feed it into heat exchanger 1 in another recovery subsystem for a predetermined time (5-10 seconds, mainly used to vent the gaseous hydrogen fluoride in heat exchanger 1). Then, the third valve body 111 on the corresponding recovery subsystem is closed, and the second valve body 131 is opened and closed. Uranium hexafluoride is then output through uranium hexafluoride output pipe 13, making the uranium hexafluoride output from uranium hexafluoride output pipe 13 relatively pure. Meanwhile, the two backup recovery subsystems can ensure the continuous collection of hydrogen fluoride and uranium hexafluoride contained in the process tail gas even if one of the recovery subsystems fails, is under maintenance, or is outputting the collected hydrogen fluoride and uranium hexafluoride.

[0034] In one embodiment, the uranium hexafluoride output pipes 13 of each recovery subsystem are connected to a common output manifold 6. Each uranium hexafluoride output pipe 13 and the output manifold 6 are equipped with heating elements for heat preservation, keeping the uranium hexafluoride in a gaseous state at all times. This design can prevent uranium hexafluoride from condensing and clogging the pipes.

[0035] Preferably, the heating element can be heated by steam tracing (i.e., steam tracing pipe) or electric tracing (i.e., wrapping electric tracing tape).

[0036] In one embodiment, the system also includes a main infusion pipe 7, which is connected to multiple infusion branch pipes 71. Each infusion branch pipe 71 corresponds to a recovery subsystem. One end of each infusion branch pipe 71 extends into the bottom of the corresponding storage tank 3. Each infusion branch pipe 71 is provided with a fifth valve body 711 for controlling the opening and closing of the corresponding infusion branch pipe 71. It also includes a main pressure pipe 8 and multiple pressure branch pipes 81. One end of each pressure branch pipe 81 is connected to the main pressure pipe 8, and the other end is connected to the corresponding storage tank 3. Compressed gas enters each pressure branch pipe 81 through the main pressure pipe 8 and is input into the corresponding storage tank 3. The liquid inside the storage tank 3 is fed into the main infusion pipe 7 through the corresponding infusion branch pipe 71 and then output through the pressure. Each pressure branch pipe 81 is equipped with a sixth valve body 811, which is used to control the opening and closing of the corresponding pressure branch pipe 81.

[0037] In practice, a level gauge is installed on the storage tank 3, or an electronic scale is installed at the bottom of the storage tank 3. The amount of liquid collected in the storage tank 3 is determined by the level gauge or weighing method. When the specified amount is reached, the corresponding recovery subsystem stops operating and closes the corresponding first valve body 311. Then, the corresponding fifth valve body 711 and sixth valve body 811 are opened. Compressed gas enters the corresponding storage tank 3 through the pressure delivery main pipe 8 and pressure delivery branch pipe 81, increasing the gas pressure inside the storage tank 3. Under this pressure, the liquid inside the storage tank 3 enters the corresponding liquid delivery branch pipe 71 and flows into the liquid delivery main pipe 7 for final output. This method is simple and controllable and is suitable for recovery systems with multiple recovery subsystems. The liquid output from the storage tank 3 can be centrally stored or re-poured into the fluorination tail gas treatment process to participate in the treatment of fluorination tail gas again.

[0038] Preferably, to prevent liquid hydrogen fluoride from vaporizing, cold insulation measures (e.g., covering with insulating foam) are taken for the main infusion pipe 7 and the branch infusion pipe 71.

[0039] Preferably, the compressed gas is a low-temperature inert gas; more preferably, low-temperature nitrogen is selected as the compressed gas.

[0040] In one embodiment, each recycling subsystem is further provided with an exhaust pipe 32, one end of which is connected to the top of the storage tank 3 and the other end is connected to the main exhaust pipe 5. The exhaust pipe 32 is provided with a seventh valve body 321 for controlling the opening and closing of the exhaust pipe 32.

[0041] In practice, while liquid is being introduced into storage tank 3, the seventh valve 321 opens, allowing gas inside storage tank 3 to enter the main exhaust pipe 5 through the exhaust pipe 32 and eventually be discharged together. When liquid is being discharged from storage tank 3, the seventh valve 321 is closed.

[0042] In one embodiment, each recovery subsystem has a short-circuit branch pipe 9 connecting the inlet branch pipe 11 and the outlet branch pipe 12, and an eighth valve body 91 is installed on the short-circuit branch pipe 9 to control the opening and closing of the short-circuit branch pipe 9. This design allows the eighth valve body 91 to be opened when the corresponding heat exchanger 1 is damaged and no other recovery subsystem is available or is in an inoperable state, enabling the process exhaust gas to be treated to directly enter the outlet main pipe 5 for output, ensuring the normal operation of the pre-fluorinated exhaust gas treatment process.

[0043] Preferably, the first valve body 311, the second valve body 131, the third valve body 111, the fourth valve body 121, the fifth valve body 711, the sixth valve body 811, the seventh valve body 321, and the eighth valve body 91 may each have a solenoid valve, and a controller (not shown in the figure) is provided to electrically connect to it to control the opening and closing of the corresponding valve body. The refrigeration equipment 2 and the heating component can also be connected to the controller for control, so as to realize the automatic control of the entire equipment. Since the control part is common knowledge to those skilled in the art, it will not be described in detail here.

[0044] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0045] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0046] Additionally, "multiple" refers to two or more.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A system for recovering hydrogen fluoride, uranium hexafluoride from a fluorinated tail gas, characterized by, The recovery subsystem comprises a heat exchanger (1), a refrigeration device (2) and a storage tank (3), the process tail gas to be treated is introduced into the heat exchanger (1) to exchange heat, and then is output; The refrigeration device (2) is used for introducing a refrigerant medium into the heat exchanger (1) to condense hydrogen fluoride contained in the process tail gas in the heat exchanger (1) into liquid state and condense uranium hexafluoride contained in the process tail gas into solid state and remain in the heat exchanger (1); The storage tank (3) is located below the heat exchanger (1), and the storage tank (3) is communicated with the heat exchanger (1) through a self-flow pipe (31), the liquid hydrogen fluoride condensed into liquid state is self-flowed to the storage tank (3) through the self-flow pipe (31); wherein the self-flow pipe (31) is provided with a first valve body (311) for controlling the opening and closing thereof; The recovery subsystem further comprises a heating component and a uranium hexafluoride output pipe (13), the heating component is used for heating and gasifying the uranium hexafluoride in the heat exchanger (1) and outputting the gasified uranium hexafluoride through the uranium hexafluoride output pipe (13), wherein the uranium hexafluoride output pipe (13) is provided with a second valve body (131) for controlling the opening and closing thereof.

2. The system for recovering hydrogen fluoride, uranium hexafluoride from a fluorinated tail gas according to claim 1, characterized in that, The collection amount of the solid uranium hexafluoride in the heat exchanger (1) is determined by detecting the weight of the heat exchanger (1).

3. The system for recovering hydrogen fluoride, uranium hexafluoride from a fluorinated tail gas according to claim 1 or 2, characterized in that, The heat exchanger (1) is a shell-and-tube heat exchanger (1), the refrigerant medium passes through the tube side of the heat exchanger (1), the process tail gas passes through the shell side of the heat exchanger (1), the top of the heat exchanger (1) is provided with a first tail gas interface and a second tail gas interface, the process tail gas to be treated is introduced into the heat exchanger (1) through the first tail gas interface and then is output from the second tail gas interface; The connection port of the self-flow pipe (31) connected with the heat exchanger (1) is located at the upper part of one side of the heat exchanger (1) and is below the second tail gas interface, so that the liquid hydrogen fluoride flows out in the form of overflow.

4. The system for recovering hydrogen fluoride, uranium hexafluoride from a fluorinated tail gas according to claim 3, characterized in that, The bottom surface inside the heat exchanger (1) is in an inclined posture, the connection port of the self-flow pipe (31) connected with the heat exchanger (1) and the second tail gas interface are located at the higher end in the inclined posture, the first tail gas interface is located at the lower end in the inclined posture, and the heating component is concentratedly arranged at the lower end in the inclined posture.

5. The system for recovering hydrogen fluoride, uranium hexafluoride from a fluorinated tail gas according to claim 4, characterized in that, The bottom surface inside the heat exchanger (1) is in an inclined posture by tilting the heat exchanger (1).

6. The system for recovering hydrogen fluoride, uranium hexafluoride from a fluorinated tail gas according to claim 1 or 2, characterized in that, The recovery subsystem is provided with two sets, the heat exchanger (1) of each recovery subsystem is respectively communicated with an air inlet branch pipe (11) and an air outlet branch pipe (12), the air inlet branch pipes (11) are collectively communicated with an air inlet main pipe (4), and the air outlet branch pipes (12) are collectively communicated with an air outlet main pipe (5); wherein the air inlet branch pipes (11) are provided with third valve bodies (111), and the air outlet branch pipes (12) are provided with fourth valve bodies (121), which are respectively used for controlling the opening and closing of the corresponding air inlet branch pipe (11) and air outlet branch pipe (12). The two recovery subsystems are standby for each other, when the uranium hexafluoride in one heat exchanger (1) needs to be output, the corresponding recovery subsystem stops running, the first valve body (311) and the fourth valve body (121) on the recovery subsystem are closed, the second valve body (131) is kept closed, the third valve body (111) is opened, and the other recovery subsystem is in working state, then the residual hydrogen fluoride and uranium hexafluoride in the heat exchanger (1) of the corresponding recovery subsystem are sequentially heated and gasified, the gasified hydrogen fluoride is input into the heat exchanger (1) of the other recovery subsystem through the gas inlet branch pipe (11) and the gas inlet main pipe (4), after the residual hydrogen fluoride is gasified, the uranium hexafluoride is gasified and input into the heat exchanger (1) of the other recovery subsystem for a predetermined time, then the third valve body (111) on the corresponding recovery subsystem is closed, the second valve body (131) is opened, and the uranium hexafluoride is output through the uranium hexafluoride output pipe (13).

7. The system for recovering hydrogen fluoride, uranium hexafluoride from a fluorinated tail gas according to claim 1 or 2, characterized in that, The uranium hexafluoride output pipes (13) on the recovery subsystems are connected to an output main pipe (6) in common, heating components are arranged on the uranium hexafluoride output pipes (13) and the output main pipe (6) for heat preservation and heating, so that the uranium hexafluoride is always in a gaseous state.

8. The system for recovering hydrogen fluoride, uranium hexafluoride from a fluorinated tail gas according to claim 1 or 2, characterized in that, The liquid delivery main pipe (7) is connected with a plurality of liquid delivery branch pipes (71), each liquid delivery branch pipe (71) corresponds to one recovery subsystem, one end of the liquid delivery branch pipe (71) extends into the tank bottom of the corresponding storage tank (3), and a fifth valve body (711) is arranged on each liquid delivery branch pipe (71) for controlling the opening and closing of the corresponding liquid delivery branch pipe (71). The compression main pipe (8) and a plurality of compression branch pipes (81) are further arranged, one end of each compression branch pipe (81) is connected with the compression main pipe (8), the other end is connected with the corresponding storage tank (3), compressed gas enters each compression branch pipe (81) through the compression main pipe (8) and is input into the corresponding storage tank (3), the liquid in the storage tank (3) is output into the liquid delivery main pipe (7) through the corresponding liquid delivery branch pipe (71) by compression, and a sixth valve body (811) is arranged on each compression branch pipe (81) for controlling the opening and closing of the corresponding compression branch pipe (81).

9. The system for recovering hydrogen fluoride, uranium hexafluoride from a fluorinated tail gas according to claim 6, wherein An exhaust pipe (32) is further arranged in each recovery subsystem, one end of the exhaust pipe (32) is connected with the top of the storage tank (3), the other end is connected with the gas outlet main pipe (5), and a seventh valve body (321) is arranged on the exhaust pipe (32) for controlling the opening and closing of the exhaust pipe (32).

10. The system for recovering hydrogen fluoride, uranium hexafluoride from a fluorinated tail gas according to claim 6, wherein A short circuit branch pipe (9) is connected between the gas inlet branch pipe (11) and the gas outlet branch pipe (12) in each recovery subsystem, and an eighth valve body (91) is arranged on the short circuit branch pipe (9) for controlling the opening and closing of the short circuit branch pipe (9).

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