Flash evaporation equipment and hydrogen fluoride recovery device

Abstract

The utility model discloses flash evaporation equipment and a hydrogen fluoride recovery device, and relates to the technical field of chemical equipment. The flash evaporation equipment is used for recycling hydrogen fluoride and comprises a flash evaporation tank, a heating structure, a first driving structure and a negative pressure generator, the flash evaporation tank is provided with a liquid inlet, a first communicating port, a second communicating port and a flash evaporation exhaust port, the first communicating port is located at the bottom of the flash evaporation tank, and the second communicating port and the flash evaporation exhaust port are both located in the upper portion of the flash evaporation tank; the heating structure is arranged outside the flash tank, the first driving structure is connected between the flash tank and the heating structure in series and is used for driving a medium in the flash tank to flow through the heating structure from the first end to the second end, a negative pressure runner is arranged in the negative pressure generator and is provided with a first inlet and an outlet, the first inlet is connected with a flash exhaust port, and the second inlet is connected with a second outlet. Therefore, the negative pressure flow channel can extract gas in the flash tank, negative pressure is generated in the flash tank, and the gas is sent out through the outlet. Therefore, the working temperature of the flash tank can be reduced, and the operation reliability is improved.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, and in particular to a hydrogen fluoride recovery device. Background Technology

[0002] In related technologies, sulfuric acid decomposition is a commonly used process for producing anhydrous hydrogen fluoride. Fluorosilicic acid is heated and decomposed into hydrogen fluoride and silicon tetrafluoride in a decomposition tower. Most of the hydrogen fluoride dissolves in sulfuric acid in the tower, and the hydrogen fluoride is recovered by evaporating the fluorinated sulfuric acid. Currently, most industries using fluorinated sulfuric acid employ falling film evaporation or flash evaporation processes. These processes operate at high temperatures, requiring temperatures such as 170°C to recover 90% of the hydrogen fluoride. Under these conditions, it is extremely difficult for the evaporation system equipment to operate safely and reliably for extended periods. Therefore, flash evaporation equipment for evaporating fluorinated sulfuric acid requires further improvement. Utility Model Content

[0003] This utility model aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, one objective of this invention is to provide a flash evaporation device that can reduce the operating temperature and improve operational reliability.

[0005] Another objective of this invention is to provide a hydrogen fluoride recovery device having the aforementioned flash evaporation equipment.

[0006] According to a first aspect of the present invention, a flash evaporation device is used to recover hydrogen fluoride and includes: a flash tank, the flash tank having an inlet, a first connecting port, a second connecting port, and a flash exhaust port, the inlet being used to introduce fluorinated sulfuric acid into the flash tank, the first connecting port being located at the bottom of the flash tank, and the second connecting port and the flash exhaust port being located at the top of the flash tank; a heating structure, the heating structure being disposed outside the flash tank, a first end of the heating structure being connected to the first connecting port, and a second end of the heating structure being connected to the second connecting port; a first driving structure, the first driving structure being connected in series between the flash tank and the heating structure, and being used to drive the medium in the flash tank to flow through the heating structure from the first end toward the second end; and a negative pressure generator, the negative pressure generator having a negative pressure channel having a first inlet and an outlet, the first inlet being connected to the flash exhaust port, so that the negative pressure channel can draw gas from the flash tank to create a negative pressure in the flash tank and send the gas out through the outlet.

[0007] In some embodiments, the negative pressure generator is configured such that the pressure P' generated in the flash tank satisfies: -0.06MPa≤P'≤-0.01MPa; and / or, the negative pressure generator is configured such that the working pressure P of its negative pressure zone and the pressure P' generated in the flash tank satisfy: P≤2×P'.

[0008] In some embodiments, the negative pressure generator is a vacuum pump.

[0009] In some embodiments, the flash evaporation device further includes a storage tank for storing washing media, the negative pressure generator includes a venturi ejector and a second drive structure, the negative pressure channel also has a second inlet connected to the storage tank, and the second drive structure is connected in series between the storage tank and the second inlet for driving the washing media in the storage tank to flow to the second inlet.

[0010] In some embodiments, the heating structure is configured as a block-hole silicon carbide heat exchanger.

[0011] A hydrogen fluoride recovery device according to a second aspect of the present invention includes: a first scrubbing tower and a flash evaporation device according to the first aspect of the present invention, wherein the first scrubbing tower is connected to the outlet and is used to store the scrubbing medium.

[0012] The hydrogen fluoride recovery device according to the embodiments of this utility model, by employing the above-mentioned flash evaporation equipment, helps to improve the operational stability of the device.

[0013] In some embodiments, the negative pressure generator includes a Venturi ejector and a second drive structure, the negative pressure channel further having a second inlet connected to the first washing tower, and the second drive structure connected in series between the first washing tower and the second inlet for driving the washing medium in the first washing tower to flow to the second inlet.

[0014] In some embodiments, the hydrogen fluoride recovery device further includes: a third drive structure, the inlet of which is connected to the first scrubbing tower, and the outlet of which is adapted to be connected to a decomposition tower for decomposing fluorosilicic acid.

[0015] In some embodiments, the first scrubbing tower further has a first exhaust port, and the hydrogen fluoride recovery device further includes: a first spray structure and a fourth drive structure, the inlet of the fourth drive structure being connected to the bottom of the first scrubbing tower, the outlet of the fourth drive structure being connected to the first spray structure, the first spray structure being disposed inside the first scrubbing tower and used to spray the gas flowing toward the first exhaust port.

[0016] In some embodiments, the hydrogen fluoride recovery device further includes: a second washing tower to an nth washing tower, the mth washing tower having an mth exhaust port and correspondingly provided with an mth medium driving element and an mth spray structure, the mth medium driving element connecting the mth washing tower and the (m-1)th exhaust port, and used to drive the gas sprayed by the (m-1)th spray structure in the (m-1)th washing tower to the mth washing tower for washing, n≥2 and is a positive integer, 2≤m≤n, m is a positive integer, and the structure of the mth medium driving element is the same as or different from the structure of the negative pressure generator.

[0017] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a hydrogen fluoride recovery device in some embodiments of this utility model.

[0019] Figure 2 This is a partial schematic diagram of a hydrogen fluoride recovery device in some other embodiments of this utility model.

[0020] Figure label:

[0021] Hydrogen fluoride recovery device 100, flash tank 10, first connecting port 11, second connecting port 12, first exhaust port 13, liquid inlet 14, heating structure 20, first drive structure 30, negative pressure generator 40, venturi ejector 41, second inlet 411, first inlet 412, outlet 413, second drive structure 42, first washing assembly 50, first washing tower 51, first inlet 511, second drain port 512, third drain port 513, second exhaust port 514, first tower section 515, second tower section 516, first spray structure 52, spray unit 521, fourth drive structure 53, third drive structure 54, second washing assembly 60, flash evaporation equipment 70. Detailed Implementation

[0022] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0023] In related technologies, fluorosilicic acid is decomposed into hydrogen fluoride by sulfuric acid decomposition. Fluorosilicic acid is heated and decomposed into hydrogen fluoride and silicon tetrafluoride in the decomposition tower. Most of the hydrogen fluoride dissolves in sulfuric acid in the decomposition tower. Therefore, it is necessary to achieve flash evaporation of hydrogen fluoride by evaporating fluorine-containing sulfuric acid. However, the operating temperature required for evaporating fluorine-containing sulfuric acid at atmospheric pressure is relatively high. For example, it is necessary to reach 170°C to recover 90% of the hydrogen fluoride. This makes it extremely difficult for the equipment required for hydrogen fluoride recovery to operate safely and reliably for a long period of time, which greatly affects the reliability of the recovery equipment.

[0024] Therefore, this utility model proposes a flash evaporation device 70, which can reduce the operating temperature and improve the reliability of operation.

[0025] like Figure 1 and Figure 2 In some embodiments of this utility model, the flash evaporation device 70 includes a flash evaporation tank 10, a heating structure 20, a first driving structure 30, and a negative pressure generator 40.

[0026] The flash tank 10 is provided with a liquid inlet 14, a first connecting port 11, a second connecting port 12, and a flash exhaust port 13. The liquid inlet 14 is used to introduce fluorinated sulfuric acid into the flash tank 10. The heating structure 20 is located outside the flash tank 10, and the first end of the heating structure 20 is connected to the first connecting port 11, and the second end of the heating structure 20 is connected to the second connecting port 12. The heating structure 20 is used to heat the medium flowing through the heating structure 20. The first driving structure 30 is connected in series with the heating structure 20, and the first driving structure 30 is used to drive the medium in the flash tank 10 to flow towards the heating structure 20. In other words, the first driving structure 30 is connected in series between the flash tank 10 and the heating structure 20, and the first driving structure 30 is used to drive the medium in the flash tank 10 to flow from the first end to the second end through the heating structure 20. The first connecting port 11 can be formed as a first drain port, and the second connecting port 12 can be formed as a return port. It is understood that the first driving structure 30 can be connected in series between the first connecting port 11 and the heating structure 20, or the first driving structure 30 can be connected in series between the second connecting port 12 and the heating structure 20.

[0027] The negative pressure generator 40 has a negative pressure flow channel with a first inlet 412 and an outlet 413. The first inlet 412 is connected to the flash exhaust port 13 so that the negative pressure generator 40 can draw gas from the flash tank 10 to create negative pressure in the flash tank 10 and send the gas out through the outlet 413 to achieve flash evaporation. This setting can reduce the operating temperature of the flash tank 10 and improve the reliability of operation.

[0028] Working principle of flash evaporator 70:

[0029] When the flash evaporator 70 is in use, other equipment introduces fluorinated sulfuric acid into the flash tank 10 through the inlet 14. For example, the inlet 14 is connected to the decomposition tower so that the fluorinated sulfuric acid in the decomposition tower can be discharged into the flash tank 10 through the inlet 14. The first connecting port 11 and the second connecting port 12 of the flash tank 10 are respectively connected to the heating structure 20, so that the flash tank 10 and the heating structure 20 are connected to form a circulation loop. The first driving structure 30 can drive the fluorinated sulfuric acid to circulate between the flash tank 10 and the heating structure 20. The fluorinated sulfuric acid in the flash tank 10 flows out through the first connecting port 11 and flows back to the flash tank 10 through the second connecting port 12 after flowing through the heating structure 20. The fluorinated sulfuric acid is heated by the heating structure 20 and flashes in the flash tank 10 to evaporate hydrogen fluoride gas. During this process, the negative pressure generator 40 draws water from the flash tank 10. The gas inside the flash tank 10 reduces the pressure, creating a negative pressure state (negative pressure is a gas pressure state below normal atmospheric pressure, which is one atmosphere). This lowers the boiling point of the fluorinated sulfuric acid, allowing it to evaporate into hydrogen fluoride gas at a lower temperature (e.g., 140°C or below). This hydrogen fluoride gas is then discharged from the flash tank 10 through the flash exhaust port 13 under the action of the negative pressure generator 40. Thus, the negative pressure generator 40 reduces the operating temperature of the flash evaporation equipment 70, which helps lower the requirements for the high-temperature resistance of the materials used in the flash evaporation equipment 70 (e.g., flash tank 10, heating structure 20, first drive structure 30). It also reduces the power consumption of the heating structure 20, eliminating the need to heat the fluorinated sulfuric acid to a high temperature, and improves the operational reliability of the flash evaporation equipment 70.

[0030] Furthermore, since the heating structure 20 is located outside the flash tank 10, there is no need to allocate space inside the flash tank 10 for the heating structure 20, which is beneficial for the flash tank 10 to provide a larger storage space for the medium. The first connecting port 11 is located at the bottom of the flash tank 10, and the second connecting port 12 and the flash exhaust port 13 are both located at the top of the flash tank 10. Therefore, the second connecting port 12 and the flash exhaust port 13 are both located above the middle of the flash tank 10. For example, the flash exhaust port 13 is located at the top of the flash tank 10. In the circulation loop formed between the flash tank 10 and the heating structure 20, the material is drawn from the bottom of the flash tube 10, heated, and then returned to the flash tank 10 from the top. When the material flows into the flash tank 10 from the top, the high-temperature fluid, due to its lower density, "floats" above the original liquid phase inside the tank, forming a top-down flow gradient. During this process, the material slowly descends under gravity, and because the pressure inside the tank is lower than the pressure on the heating side, the hydrogen fluoride gradually vaporizes, forming a gas-liquid counter-current contact (gas phase rises, liquid phase falls). This helps to prolong the gas-liquid contact time, making vaporization more complete and improving the recovery efficiency. Furthermore, the top return material does not require a complex distributor or stirring device inside the tank. The second connecting port 12 can be located above the liquid surface inside the flash tank 10, which helps to reduce the resistance components inside the tank, reduce the pressure drop of the gas phase flow, and maintain the low-pressure environment required for flash evaporation. Moreover, the lifting height from bottom extraction to top return material is usually less than the height of the flash tank 10, and the material is mainly liquid (high density, low head requirement). Compared with top extraction (which may require pumping a gas-liquid mixture, resulting in high head and low efficiency), the power consumption of the first drive structure 30 can be reduced.

[0031] Optionally, a draining drive can be connected to the first connection port 11. The first connection port 11 can be selectively connected to the first drive structure 30 and the draining drive. When it is necessary to evaporate fluorinated sulfuric acid, the first connection port 11 can be connected to the first drive structure 30. When it is necessary to discharge the sulfuric acid in the evaporation tube, the first connection port 11 can be connected to the draining drive.

[0032] In some embodiments of this utility model, the negative pressure generator 40 is configured such that the pressure P' generated in the flash tank 10 satisfies: -0.06MPa≤P'≤-0.01MPa, so as to reliably realize the flash evaporation of the medium in the flash tank 10 at a lower temperature. For example, if the flash tank 10 contains fluorinated sulfuric acid, the heating structure 20 can heat the fluorinated sulfuric acid to 140°C or below to realize flash evaporation; and / or, the negative pressure generator 40 is configured such that the working pressure P of its negative pressure zone and the pressure P' generated in the flash tank 10 satisfy: P≤2×P', so that while the heating structure 20 heats the medium to realize flash evaporation, the negative pressure generator 40 can still generate a reliable negative pressure in the flash tank 10. Moreover, the above configuration can be applied to more types of pipe arrangements between the heating structure 20 and the flash tank 10, and can also be applied to more types of flash tanks 10 with different volumes, different flash evaporation capacities, etc., which is beneficial to improving the applicability of the flash evaporation equipment 70.

[0033] For example, P' can be -0.01MPa, -0.02MPa, -0.03MPa, -0.04MPa, -0.05MPa, -0.06MPa, etc.; P can be 2×P', 2.2×P', 2.5×P', 2.7×P', 3×P', 3.5×P', or 4×P', etc.

[0034] In some embodiments of this utility model, the negative pressure generator 40 is configured such that the working pressure P of its negative pressure zone satisfies: P≤-0.04MPa. It can be understood that the negative pressure generator 40 generates negative pressure in its negative pressure zone and generates negative pressure inside the flash tank 10 through the flash exhaust port 13 of the flash tank 10, thereby reducing the boiling point of fluorinated sulfuric acid. Therefore, in order to keep the pressure value inside the flash tank 10 stable below atmospheric pressure, the working pressure P of the negative pressure zone of the negative pressure generator 40 needs to satisfy: P≤-0.04MPa, so as to reduce the working temperature of the flash equipment 70 and improve the operational stability of the flash equipment 70.

[0035] In some embodiments, the negative pressure generator 40 is a vacuum pump. For example, a vacuum pump can extract gas from the flash tank 10 to achieve a specific vacuum level within the flash tank 10. This application does not limit the specific type of vacuum pump. For instance, the outlet 413 of the vacuum pump is adapted to connect to the first scrubbing tower 51, and the vacuum pump is used to drive the gas in the flash tank 10 to the first scrubbing tower 51 to create a negative pressure within the flash tank 10. This reduces the evaporation temperature of the fluorinated sulfuric acid within the flash tank 10 and improves the operational stability of the flash evaporation equipment 70.

[0036] Even better, the lining of the vacuum pump is made of a high-temperature and corrosion-resistant material, such as silicon carbide.

[0037] In some embodiments, the flash evaporation device 10 further includes a storage tank for storing a washing medium. The negative pressure generator 40 includes a Venturi ejector 41 and a second drive structure 42. The negative pressure flow channel also has a second inlet 411 connected to the storage tank. The second drive structure 42 is connected in series between the storage tank and the second inlet 411, and is used to drive the washing medium in the storage tank to flow towards the second inlet 411. At this time, the negative pressure generator 40 generates negative pressure within the flash evaporation tank 10 using the washing medium from the storage tank. The washing medium mixes with hydrogen fluoride, and the washing medium can wash the hydrogen fluoride. The mixture is then discharged through 413.

[0038] For example, the flash evaporator 100 can be connected to the first scrubbing tower 51 to wash the hydrogen fluoride flashed out by the flash evaporator 100. The first scrubbing tower 51 has a first inlet 511 and a second outlet 512. The negative pressure generator 40 includes a Venturi ejector 41 and a second drive structure 42. The Venturi ejector 41 has a second inlet 411, a first inlet 412, and an outlet 413. The first inlet 412 is a low-pressure inlet, and the second inlet 411 is a high-pressure inlet. The first inlet 412 is connected to the flash exhaust port 13. The outlet 413 is connected to the first inlet 511; the flash evaporator 10 also includes a storage tank for storing the washing medium, a second inlet 411 connected to the storage tank, and a second drive structure 42 connected in series between the storage tank and the second inlet 411, and the second drive structure 42 is used to drive the washing medium in the storage tank to flow to the second inlet 411; in this way, a negative pressure can be generated in the flash evaporator 10 by means of the flow of the washing medium, and the hydrogen fluoride gas can also be pre-washed by the Venturi injector 41 to improve the recovery efficiency of hydrogen fluoride.

[0039] Specifically, the second inlet 411 of the Venturi ejector 41 is connected to the storage tank, and the outlet 413 is connected to the first inlet 511 of the first scrubbing tower 51. The second drive structure 42 drives the washing medium to flow from the storage tank to the first scrubbing tower 51, thereby forming a negative pressure zone in the Venturi ejector 41. The negative pressure zone is connected to the first inlet 412 of the Venturi ejector 41 to generate a negative pressure in the flash tank 10, which facilitates the evaporation of hydrogen fluoride gas from fluorinated sulfuric acid at a lower temperature. The Venturi ejector 41 can also draw the hydrogen fluoride gas in the flash tank 10 into its negative pressure zone and mix the hydrogen fluoride gas with the washing medium for preliminary washing. The mixed medium is then discharged to the first scrubbing tower 51 through the outlet 413. In this way, the hydrogen fluoride gas can be pre-washed by the Venturi ejector 41 before entering the first scrubbing tower 51, thereby improving the recovery efficiency of hydrogen fluoride.

[0040] In some embodiments of this utility model, the heating structure 20 is configured as a block-hole silicon carbide heat exchanger. It can be understood that, compared with the tube-type heating structure 20, the block-hole heating structure 20 has higher structural strength, can withstand greater impact, and improves the working stability of the flash evaporation equipment 70. Furthermore, the inner lining of the heating structure 20 can be made of silicon carbide, which gives the heating structure 20 good corrosion resistance and high temperature resistance, making it easier to heat fluorinated sulfuric acid.

[0041] The hydrogen fluoride recovery device 100 according to the second aspect of the present invention includes a first washing tower 51 and a flash evaporation device 70 according to the first aspect of the present invention. The first washing tower 51 is connected to an outlet 413 and is used to store washing media.

[0042] For example, the first scrubbing tower 51 is provided with a first inlet 511, which is connected to the outlet 413 of the negative pressure generator 40. The first scrubbing tower 51 is used to scrub the gas discharged from the negative pressure generator 40. It is understood that the hydrogen fluoride gas evaporated from the fluorinated sulfuric acid in the flash tank 10 carries some impurities. The hydrogen fluoride gas needs to be discharged into the scrubbing tower through the first inlet 511 to scrub the hydrogen fluoride gas, so as to improve the recovery efficiency of hydrogen fluoride.

[0043] For example, the hydrogen fluoride gas evaporated through flash tank 10 usually contains some moisture. Sulfuric acid can be used as the washing medium in the first scrubbing tower 51 to remove the moisture from the hydrogen fluoride gas. It should be understood that the hydrogen fluoride gas is evaporated by heating fluorinated sulfuric acid. Therefore, the temperature of the hydrogen fluoride gas entering the first scrubbing tower 51 is relatively high, and it is not easy to redissolve in sulfuric acid. Therefore, sulfuric acid can be used as the washing medium. Moreover, the sulfuric acid after washing can be easily recycled and reused to decompose the fluorosilicic acid in the tower to continue producing hydrogen fluoride, reducing waste and improving utilization rate.

[0044] The hydrogen fluoride recovery device 100 according to the present invention, by employing the flash evaporation equipment 70 described above, helps to improve the operational stability of the device.

[0045] Regarding the negative pressure generating principle of the negative pressure generator 40, the negative pressure generator 40 may include an ejector or a vacuum pump, etc.; for example, the negative pressure generator 40 includes a Venturi ejector 41. In this case, the negative pressure generator 40 can utilize the Venturi effect, that is, by rapidly flowing fluid through the negative pressure generator 40, negative pressure is generated within the flash tank 10. In the following description, the negative pressure generator 40 including a Venturi ejector 41 is used as an example. After reading the following scheme, those skilled in the art will easily understand that the negative pressure generator 40 is an embodiment of other structures that can generate negative pressure within the flash tank 10. The present invention specifically provides the following embodiments for description:

[0046] Implementation Method 1

[0047] The negative pressure generator 40 generates negative pressure in the flash tank 10 by means of the washing medium inside the first washing tower 51.

[0048] Specifically, such as Figure 1 and Figure 2 The first scrubbing tower 51 also has a second drain port 512. The negative pressure generator 40 includes a Venturi injector 41 and a second drive structure 42. The negative pressure flow channel has a second inlet 411, a first inlet 412, and an outlet 413. The first inlet 412 is connected to the flash exhaust port 13, the outlet 413 is connected to the first scrubbing tower 51, the second inlet 411 is connected to the first scrubbing tower 51, and the second drive structure 42 is connected in series between the first scrubbing tower 51 and the second inlet 411. The second drive structure 42 is used to drive the scrubbing medium in the first scrubbing tower 51 to flow to the second inlet 411. For example, the outlet 413 is connected to the first inlet 511 of the first scrubbing tower 51, the second inlet 411 is connected to the second drain port 512 of the first scrubbing tower 51, and the second drive structure 42 is connected in series between the second drain port 512 and the second inlet 411. In this way, negative pressure can be generated in the flash tank 10 by means of the flow of the scrubbing medium, and hydrogen fluoride gas can be pre-washed to improve the recovery efficiency of hydrogen fluoride.

[0049] Specifically, the second inlet 411 and outlet 413 of the Venturi ejector 41 are respectively connected to the second drain port 512 and the first inlet 511 of the first scrubbing tower 51, so that the Venturi ejector 41 and the first scrubbing tower 51 are connected to form a circulation loop. The second drive structure 42 drives the scrubbing medium to circulate between the first scrubbing tower 51 and the Venturi ejector 41, thereby forming a negative pressure zone in the negative pressure channel. The negative pressure channel is connected to the first inlet 412 of the Venturi ejector 41 to generate negative pressure in the flash tank 10, which facilitates the evaporation of hydrogen fluoride gas from fluorinated sulfuric acid at a lower temperature. The Venturi ejector 41 can also draw the hydrogen fluoride gas in the flash tank 10 into its negative pressure zone and mix the hydrogen fluoride gas with the scrubbing medium for preliminary scrubbing. The mixed medium is then discharged to the first scrubbing tower 51 through the outlet 413. In this way, the hydrogen fluoride gas can be pre-washed by the Venturi ejector 41 before entering the first scrubbing tower 51, thereby improving the recovery efficiency of hydrogen fluoride.

[0050] Implementation Method 2

[0051] The negative pressure generator 40 generates negative pressure in the flash tank 10 by means of the washing medium introduced into the first washing tower 51 from the storage tank.

[0052] In some other embodiments of this utility model, the first scrubbing tower 51 also has a second drain port 512, and the negative pressure generator 40 includes a Venturi injector 41 and a second drive structure 42. The Venturi injector 41 has a second inlet 411, a first inlet 412 and an outlet 413. The first inlet 412 is connected to the flash exhaust port 13, and the outlet 413 is connected to the first inlet 511. The hydrogen fluoride recovery device 100 also includes a storage tank for storing the washing medium. The second inlet 411 is connected to the storage tank, and the second drive structure 42 is connected in series between the storage tank and the second inlet 411. The second drive structure 42 is used to drive the washing medium in the storage tank to flow to the second inlet 411. In this way, a negative pressure can be generated in the flash tank 10 by means of the flow of the washing medium, and the hydrogen fluoride gas can also be pre-washed by the Venturi injector 41 to improve the recovery efficiency of hydrogen fluoride.

[0053] Specifically, the second inlet 411 and outlet 413 of the Venturi ejector 41 are connected to the storage tank and the first inlet 511 of the first scrubbing tower 51, respectively. The second drive structure 42 drives the scrubbing medium to flow from the storage tank to the first scrubbing tower 51, thereby forming a negative pressure zone in the Venturi ejector 41. The negative pressure zone is connected to the first inlet 412 of the Venturi ejector 41 to generate a negative pressure in the flash tank 10, which facilitates the evaporation of hydrogen fluoride gas from fluorinated sulfuric acid at a lower temperature. The Venturi ejector 41 can also draw the hydrogen fluoride gas in the flash tank 10 into its negative pressure zone and mix the hydrogen fluoride gas with the scrubbing medium for preliminary scrubbing. The mixed medium is then discharged to the first scrubbing tower 51 through the outlet 413. In this way, the hydrogen fluoride gas can be pre-washed by the Venturi ejector 41 before entering the first scrubbing tower 51, thereby improving the recovery efficiency of hydrogen fluoride.

[0054] As can be seen, in Embodiments 1 and 2 above, regardless of whether the washing medium driven by the second driving structure 42 to the Venturi injector 41 originates from the first washing tower 51 or the storage tank, pre-washing can be performed by the Venturi injector 41 before the hydrogen fluoride flows to the first washing tower 51. It is understood that other types of injectors can also be used to perform pre-washing before the hydrogen fluoride flows to the first washing tower 51.

[0055] In some embodiments of this utility model, the working pressure P of the negative pressure zone inside the Venturi injector 41 satisfies: -0.09MPa≤P≤-0.04MPa. It can be understood that if the working pressure P of the negative pressure zone inside the Venturi injector 41 is greater than -0.04MPa, it is easy to limit the specifications of the flash tank 10 matched with the Venturi injector 41, resulting in limited use of the hydrogen fluoride recovery device 100. If the working pressure of the negative pressure zone inside the Venturi injector 41 is less than -0.09MPa, the requirements for the Venturi injector 41 are too high, which is easy to exceed the working load of the Venturi injector 41, causing the Venturi injector 41 to be in a state of extreme operation for a long time and the operation is unstable. Therefore, the working pressure P in the negative pressure zone inside the Venturi injector 41 can satisfy: -0.09MPa≤P≤-0.04MPa. In this way, a negative pressure can be generated in the flash tank 10 while ensuring the stable operation of the Venturi injector 41, which facilitates the reduction of the evaporation temperature of the fluorinated sulfuric acid and thus improves the working stability of the hydrogen fluoride recovery device 100.

[0056] like Figure 1 and Figure 2 In some embodiments of this utility model, the hydrogen fluoride recovery device 100 further includes a third drive structure 54. The inlet of the third drive structure 54 is connected to the first washing tower 51, and the outlet of the third drive structure 54 is adapted to be connected to a decomposition tower for decomposing fluorosilicic acid, so that the third drive structure 54 is used to drive the washing medium in the first washing tower 51 to flow to the decomposition tower; in this way, waste can be reduced and the recycling rate of the washing medium can be improved.

[0057] It is understandable that fluorosilicic acid is decomposed into hydrogen fluoride in a decomposition tower via sulfuric acid decomposition. Most of the hydrogen fluoride produced is dissolved in sulfuric acid. Therefore, it is necessary to evaporate the fluorinated sulfuric acid to evaporate the hydrogen fluoride and wash the hydrogen fluoride to achieve hydrogen fluoride recovery. In conjunction with the above, sulfuric acid can be used as the washing medium in the first washing tower 51 to wash the hydrogen fluoride gas. After washing, it can be refluxed back into the decomposition tower under the drive of the third driving structure 54 to achieve the purpose of recycling the washing medium.

[0058] As an example, when the hydrogen fluoride recovery device 100 is in use, the outlet of the third drive structure 54 is connected to the decomposition tower, which can produce hydrogen fluoride by decomposing fluorosilicic acid using the sulfuric acid method. The flash tank 10 is provided with an inlet 14, which is connected to the decomposition tower so that the fluorinated sulfuric acid in the decomposition tower can be discharged to the flash tank 10 through the inlet 14. In this way, a cycle is formed between the hydrogen fluoride recovery device 100 and the decomposition tower.

[0059] In addition, exemplarily, fluorosilicic acid reacts with 95% sulfuric acid in the decomposition tower to produce hydrogen fluoride, while the Venturi injector 41 generates negative pressure through the flow of 98% sulfuric acid to drive the hydrogen fluoride gas in the flash tank 10 to the first scrubbing tower 51. In the Venturi injector 41, the 98% sulfuric acid washes the hydrogen fluoride gas, absorbing the moisture in the hydrogen fluoride gas and converting it into 95% sulfuric acid. Similarly, in the first scrubbing tower 51, 98% sulfuric acid is used to wash the hydrogen fluoride gas, absorbing the moisture in the hydrogen fluoride gas and converting it into 95% sulfuric acid. Finally, under the action of the third driving structure 54, the 95% sulfuric acid in the first scrubbing tower 51 can be returned to the decomposition tower. In this way, the washing medium can be recycled and reused, reducing waste.

[0060] like Figure 1 and Figure 2 In some embodiments of this utility model, the first scrubbing tower 51 further includes a first exhaust port 514, and the hydrogen fluoride recovery device 100 further includes a first spray structure 52 and a fourth drive structure 53. The inlet of the fourth drive structure 53 is connected to the bottom of the first scrubbing tower 51, and the outlet of the fourth drive structure 53 is connected to the first spray structure 52. The fourth drive structure 53 is used to drive the scrubbing medium in the first scrubbing tower 51 to flow towards the first spray structure 52. The first spray structure 52 is located inside the first scrubbing tower 51 and is used to spray the gas flowing towards the first exhaust port 514. In this way, impurities in the hydrogen fluoride gas can be removed, achieving the purpose of recovering the hydrogen fluoride gas. For example, the first scrubbing tower 51 also includes a third drain port 513, and the fourth drive structure 53 is connected between the third drain port 513 and the first spray structure 52.

[0061] For example, the hydrogen fluoride gas evaporated from the fluorinated sulfuric acid carries some moisture. Therefore, sulfuric acid can be introduced into the first scrubbing tower 51 as a scrubbing medium to wash the hydrogen fluoride gas and reduce the moisture in the hydrogen fluoride gas. The first scrubbing tower 51 is provided with a first spray structure 52 and a fourth drive structure 53. The fourth drive structure 53 drives the scrubbing medium in the first scrubbing tower 51 to flow to the first spray structure 52. The first spray structure 52 sprays and washes the gas flowing to the first exhaust port 514, thereby removing the moisture from the hydrogen fluoride gas.

[0062] like Figure 1 and Figure 2In some embodiments of this utility model, the first scrubbing tower 51 includes a first tower section 515 and a second tower section 516. The first tower section 515 is located above the second tower section 516, and the cross-sectional area of ​​the first tower section 515 is smaller than that of the second tower section 516. A first exhaust port 514 is formed at the top of the first tower section 515, and a first spray structure 52 is located in the first tower section 515, below the first exhaust port 514. It can be understood that the second tower section 516 can be used to provide a storage space for sulfuric acid, and the first tower section 515 can be used to reduce the flow area of ​​hydrogen fluoride gas, so as to facilitate the first spray structure 52 to spray and wash the hydrogen fluoride gas, thereby improving the removal effect of impurities.

[0063] Furthermore, the first spray structure 52 may include a plurality of spray units 521 arranged at intervals from top to bottom (e.g., Figure 1 The first spray structure 52 includes two spray units 521 arranged vertically and horizontally, each spray unit 521 including at least one spiral nozzle; thus, through the multiple spray units 521 arranged vertically, multi-stage spraying of hydrogen fluoride gas can be achieved to further improve the impurity removal effect of hydrogen fluoride gas; and the coverage area of ​​the spray liquid sprayed by the spray unit 521 is not less than the cross-sectional area of ​​the tower section where the spray unit 521 is located, so as to ensure the spraying effect of the spray unit 521 on hydrogen fluoride gas.

[0064] like Figure 2 In some embodiments of this utility model, it can be understood that the hydrogen fluoride recovery device 100 further includes a second washing tower 60 to an nth washing tower, the mth washing tower having an mth exhaust port, and the mth washing tower being provided with a corresponding mth medium driving component. The mth medium driving component connects the mth washing tower and the (m-1)th exhaust port, and the mth medium driving component is used to drive the gas in the (m-1)th washing tower to the mth washing tower for washing, where n≥2 and is a positive integer, 2≤m≤n, and m is a positive integer; thus, the hydrogen fluoride gas can be washed multiple times through multiple washing towers to improve the recovery efficiency of the hydrogen fluoride gas.

[0065] Furthermore, the m-th scrubbing tower is also provided with a corresponding m-th spray structure. The m-th spray structure is located inside the m-th scrubbing tower, and the m-th medium driving unit is used to drive the gas sprayed by the (m-1)-th spray structure in the (m-1)-th scrubbing tower to be discharged to the m-th scrubbing tower for scrubbing.

[0066] It is understood that in this embodiment of the application, the hydrogen fluoride recovery device 100 includes a first washing assembly 50, which includes a first washing tower 51; further, the first washing assembly 50 includes a first washing tower 51, a first spray structure 52, and a fourth driving structure 53. Therefore, the hydrogen fluoride recovery device 100 may also include a second to an nth washing assembly, the mth washing assembly including an mth washing tower and an mth medium driving element; further, the mth washing assembly also includes an mth spray structure, and the mth medium driving element is used to drive the gas sprayed by the (m-1)th spray structure in the (m-1)th washing tower to the mth washing tower for washing. In addition, the structure of the mth medium driving element may be the same as or different from the structure of the negative pressure generator 40.

[0067] For example, m is set to 2, but m can also be 3, 4, or more than 4; for ease of explanation, the present invention provides the following embodiments:

[0068] Example 1

[0069] m=2, the structure of the mth washing component is the same as the structure of the first washing component 50:

[0070] The first washing assembly 50 includes a first washing tower 51, a first spray structure 52, and a fourth drive structure 53. The first spray structure 52 is disposed inside the first washing tower 51. The fourth drive structure 53 connects the first washing tower 51 and the first spray structure 52 and drives the washing medium in the first washing tower 51 to flow to the first spray structure 52. The first spray structure 52 is used to spray the gas in the first washing tower 51. Optionally, the first washing assembly 50 also includes a third drive structure 54. The third drive structure 54 is connected to the first washing tower 51 and drives the washing medium in the first washing tower 51 to flow back to the decomposition tower for recycling.

[0071] The second washing assembly 60 includes a second washing tower, a second spray structure, and a fifth driving structure. The second spray structure is disposed inside the second washing tower. The fifth driving structure is connected to the second washing tower and the second spray structure, and drives the washing medium inside the second washing tower to flow to the second spray structure. The second spray structure is used to spray the gas inside the second washing tower. Optionally, the second washing assembly 60 also includes a sixth driving structure, which is connected to the second washing tower and drives the washing medium inside the second washing tower to flow back to the decomposition tower for recycling.

[0072] The first scrubbing tower 51 has a first inlet 511 and a first exhaust port 514. The first inlet 511 is connected to the flash exhaust port 13 of the flash tank 10. The second scrubbing tower has a second inlet and a second exhaust port. The second inlet is connected to the first exhaust port 514 of the first scrubbing tower 51. A second medium driving element is connected between the second inlet and the first exhaust port 514. A negative pressure generator 40 is connected between the first inlet 511 and the flash exhaust port 13. The negative pressure generator 40 can generate a negative pressure in the flash tank 10 to reduce the evaporation temperature of the fluorinated sulfuric acid. The hydrogen fluoride gas discharged from the flash tank 10 can be washed by the first scrubbing tower 51 and the second scrubbing tower, which greatly improves the recovery and utilization of hydrogen fluoride gas.

[0073] In the above configuration, the negative pressure generator 40 is a vacuum pump, which drives the gas in the flash tank 10 to flow into the first scrubbing tower 51 to generate negative pressure in the flash tank 10; or, the negative pressure generator 40 may include a Venturi ejector 41 and a second drive structure 42, which causes the washing medium to flow rapidly through the Venturi ejector 41 to generate negative pressure in the flash tank 10 and pre-wash the hydrogen fluoride gas, thereby improving the recovery effect of the hydrogen fluoride gas.

[0074] Of course, the m-th medium driving component is a vacuum pump; or, the m-th medium driving component includes a Venturi injector and a driving structure, through which the washing medium flows rapidly through the Venturi injector to generate negative pressure in the pipeline between the (m-1)-th washing component and the m-th washing component, and pre-washes the hydrogen fluoride gas to improve the recovery effect of the hydrogen fluoride gas.

[0075] Example 2

[0076] m=2, the structure of the m-th washing component is the same as that of the first washing component 50, and the structure of the m-th media drive component is the same as that of the negative pressure generator 40:

[0077] The first washing assembly 50 includes a first washing tower 51, a first spray structure 52, and a fourth driving structure 53. The first spray structure 52 is disposed inside the first washing tower 51. The fourth driving structure 53 connects the first washing tower 51 and the first spray structure 52 and drives the washing medium inside the first washing tower 51 to flow to the first spray structure 52. The first spray structure 52 is used to spray the gas inside the first washing tower 51. Exemplarily, the first washing assembly 50 also includes a third driving structure 54. The third driving structure 54 is connected to the first washing tower 51 and drives the washing medium inside the first washing tower 51 to flow back to the decomposition tower for recycling.

[0078] The second washing assembly 60 includes a second washing tower, a second spray structure, and a fifth driving structure. The second spray structure is disposed inside the second washing tower. The fifth driving structure is connected to the second washing tower and the second spray structure, and drives the washing medium inside the second washing tower to flow to the second spray structure. The second spray structure is used to spray the gas inside the second washing tower. Exemplarily, the second washing assembly 60 also includes a sixth driving structure, which is connected to the second washing tower and drives the washing medium inside the second washing tower to flow back to the decomposition tower for recycling.

[0079] The first scrubbing tower 51 has a first inlet 511 and a first exhaust port 514. The first inlet 511 is connected to the flash exhaust port 13 of the flash tank 10. The second scrubbing tower has a second inlet and a second exhaust port. The second inlet is connected to the first exhaust port 514 of the first scrubbing tower 51. A first negative pressure generator (i.e., the negative pressure generator 40 mentioned above) is connected between the first inlet 511 and the flash exhaust port 13, and a second negative pressure generator is connected between the second inlet and the first exhaust port 514. The first and second negative pressure generators can generate negative pressure in the flash tank 10 to reduce the evaporation temperature of the fluorinated sulfuric acid. The hydrogen fluoride gas discharged from the flash tank 10 can be washed by the first scrubbing tower 51 and the second scrubbing tower, which greatly improves the recovery and utilization of hydrogen fluoride gas.

[0080] For example, both the first negative pressure generator and the second negative pressure generator are vacuum pumps; or, the first negative pressure generator may include a first Venturi ejector (the Venturi ejector 41 mentioned above) and a first medium driving structure (the second driving structure 42 mentioned above), through which the washing medium is rapidly flowed through the first Venturi ejector to generate negative pressure in the flash tank 10 and pre-wash the hydrogen fluoride gas, thereby improving the recovery effect of the hydrogen fluoride gas; wherein, the first inlet 412 and the outlet 413 of the first Venturi ejector are respectively connected to the first washing tower 51, and the second inlet 411 of the first Venturi ejector is connected to the flash tank 10.

[0081] Similarly, the second negative pressure generator may include a second Venturi ejector and a second medium driving structure. The second medium driving structure enables the washing medium to flow rapidly through the second Venturi ejector and pre-wash the hydrogen fluoride gas, thereby improving the recovery effect of the hydrogen fluoride gas. The first inlet 412 and outlet 413 of the second Venturi ejector are respectively connected to the second washing tower, and the height inlet of the second Venturi ejector is connected to the first exhaust port 514 of the first washing tower 51.

[0082] It is understood that the structure of the m-th washing component may be the same as or different from the structure of the first washing component 50.

[0083] It's important to understand that sulfuric acid decomposition is a common process for producing anhydrous hydrogen fluoride. Fluorosilicic acid decomposes into hydrogen fluoride and silicon tetrafluoride in the decomposition tower upon heating. Most of the hydrogen fluoride dissolves in sulfuric acid in the tower, and is then recovered through evaporation of the fluorinated sulfuric acid and a washing process with hydrogen fluoride. The evaporation of fluorinated sulfuric acid in the industry mostly uses falling film evaporation or atmospheric flash evaporation processes. These processes operate at high temperatures, requiring 170°C to recover 90% of the hydrogen fluoride. Under these conditions, it is extremely difficult for the evaporation system equipment to operate safely and reliably for extended periods. Simultaneously, the washing of the evaporated hydrogen fluoride often involves multi-stage packed towers in series, resulting in a complex process and significant equipment investment.

[0084] Therefore, the hydrogen fluoride recovery device 100 according to the present invention relates to the evaporation of fluorinated sulfuric acid and the washing process of hydrogen fluoride in the process of producing anhydrous hydrogen fluoride from fluorosilicic acid. The device includes a heating structure 20, a flash tank 10, a forced circulation pump (i.e., a first drive structure 30), a Venturi ejector 41, an ejector circulation pump (i.e., a second drive structure 42), a washing tower, and a washing tower circulation pump (i.e., a fourth drive structure 53).

[0085] The heating structure 20 uses a block-hole silicon carbide heat exchanger and uses 0.5MPa steam to heat the fluorinated sulfuric acid to 140℃.

[0086] The flash tank 10 is made of carbon steel using a PFA molding process. The internal pressure P' is -10KPa and the internal temperature T is 140℃. Fluorine-containing sulfuric acid is flashed inside.

[0087] The forced circulation pump is a high-temperature magnetic pump lined with PFA (Polyfluoroalkoxy, soluble polytetrafluoroethylene) to continuously circulate fluorinated sulfuric acid in the heating structure 20 and the flash tank 10.

[0088] The Venturi injector is manufactured using a carbon steel molding PFA process. It creates negative pressure in the flash tank 10 while simultaneously mixing the evaporated hydrogen fluoride and sulfuric acid before introducing them into the scrubbing tower. The main structure of the Venturi includes a nozzle, a suction chamber, a mixing chamber, and a diffusion chamber. The nozzle is made of pressureless sintered silicon carbide, while the other materials are manufactured using a carbon steel molding PFA process. Sulfuric acid from the injection circulation pump is ejected from the nozzle at a pressure of 0.4MPa-0.5MPa and a temperature of 140℃. Under the high-speed injection of sulfuric acid, a vacuum is created in the suction chamber, reaching a negative pressure of -0.08MPa. This negative pressure draws the HF (hydrogen fluoride) evaporated from the flash tank 10 into the suction chamber of the Venturi. The HF then enters the mixing chamber along with the injected sulfuric acid. In the mixing chamber, the HF and sulfuric acid are thoroughly mixed and washed, achieving the initial washing function. After mixing, the HF and sulfuric acid enter the diffusion chamber, where the pressure is maintained at approximately 0.4MPa-0.5MPa and the temperature at 140℃, before finally entering the scrubbing tower.

[0089] The ejector circulation pump and the scrubbing tower circulation pump are PFA-lined high-temperature magnetic pumps. The circulating medium is 98% sulfuric acid at a temperature of 140°C, and they circulate in the ejector and scrubbing tower respectively.

[0090] The scrubbing tower is manufactured using a carbon steel molding PFA process and employs a single packed tower with a double-layer spray structure. The packing material is Pall rings and PTFE (filled with polytetrafluoroethylene resin). Hydrogen fluoride, after being mixed and washed by the Venturi injector, enters from the bottom of the scrubbing tower for further spray washing.

[0091] Therefore, the hydrogen fluoride recovery device 100 of this utility model can reduce the evaporation temperature of fluorinated sulfuric acid by creating a vacuum through venturi injection, thereby improving the safety and stability of the system; in addition, the HF is initially mixed and washed by venturi injection, which reduces the load on the washing tower and the number of washing towers.

[0092] In the description of this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0093] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0094] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0095] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0096] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A flash evaporation apparatus, characterized by, The flash evaporation equipment is used to recover hydrogen fluoride and includes: A flash tank is provided with a liquid inlet, a first connecting port, a second connecting port and a flash exhaust port. The liquid inlet is used to introduce fluorinated sulfuric acid into the flash tank. The first connecting port is located at the bottom of the flash tank, and the second connecting port and the flash exhaust port are both located at the top of the flash tank. A heating structure is provided outside the flash tank, with a first end of the heating structure connected to the first communication port and a second end of the heating structure connected to the second communication port. A first driving structure is connected in series between the flash tank and the heating structure, and is used to drive the medium in the flash tank to flow through the heating structure from the first end toward the second end; A negative pressure generator has a negative pressure flow channel with a first inlet and an outlet. The first inlet is connected to the flash exhaust port so that the negative pressure flow channel can draw gas from the flash tank to create negative pressure in the flash tank and send the gas out through the outlet.

2. The flash evaporation equipment according to claim 1, characterized in that, The negative pressure generator is configured to generate a pressure P' within the flash tank that satisfies: -0.06 MPa ≤ P' ≤ -0.01 MPa; and / or, The negative pressure generator is configured such that the working pressure P of its negative pressure zone and the pressure P' generated in the flash tank satisfy: P≤2×P'.

3. The flash apparatus according to claim 1, wherein The negative pressure generator is a vacuum pump.

4. The flash apparatus according to claim 3, wherein It also includes a liquid storage tank for storing washing media, the negative pressure generator includes a venturi ejector and a second drive structure, the negative pressure channel also has a second inlet, the second inlet is connected to the liquid storage tank, and the second drive structure is connected in series between the liquid storage tank and the second inlet and is used to drive the washing media in the liquid storage tank to flow to the second inlet.

5. The flash apparatus according to claim 1, wherein The heating structure is a block-hole silicon carbide heat exchanger.

6. A hydrogen fluoride recovery apparatus characterized by comprising: include: The first washing tower and the flash evaporation device according to any one of claims 1-5, wherein the first washing tower is connected to the outlet and is used to store the washing medium.

7. The hydrogen fluoride recovery device of claim 6, wherein, The negative pressure generator includes a Venturi ejector and a second drive structure. The negative pressure channel also has a second inlet, which is connected to the first washing tower. The second drive structure is connected in series between the first washing tower and the second inlet and is used to drive the washing medium in the first washing tower to flow to the second inlet.

8. The hydrogen fluoride recovery device of claim 6, wherein, Also includes: A third drive structure, wherein the inlet of the third drive structure is connected to the first washing tower, and the outlet of the third drive structure is adapted to be connected to a decomposition tower for decomposing fluorosilicic acid.

9. The hydrogen fluoride recovery device of claim 6, wherein, The first scrubbing tower also has a first exhaust port, and the hydrogen fluoride recovery device further includes: A first spray structure and a fourth drive structure are provided. The inlet of the fourth drive structure is connected to the bottom of the first scrubbing tower, and the outlet of the fourth drive structure is connected to the first spray structure. The first spray structure is located inside the first scrubbing tower and is used to spray the gas flowing toward the first exhaust port.

10. The hydrogen fluoride recovery device according to any one of claims 6 to 9, characterized in that, The hydrogen fluoride recovery device also includes: The second to the nth washing towers, the mth washing tower has the mth exhaust port, and is correspondingly provided with the mth medium driving component and the mth spray structure. The mth medium driving component connects the mth washing tower and the (m-1)th exhaust port, and is used to drive the gas sprayed by the (m-1)th spray structure in the (m-1)th washing tower to the mth washing tower for washing. n≥2 and is a positive integer, 2≤m≤n, m is a positive integer, and the structure of the mth medium driving component is the same as or different from the structure of the negative pressure generator.

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