Rectification device for producing anhydrous hydrofluoric acid
By using an integrated distillation unit, combining a reflux spiral tube and distillation components, continuous distillation and waste heat recovery of anhydrous hydrofluoric acid are achieved, solving the problems of low production efficiency and high energy consumption in existing technologies, and improving product purity and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-27
- Publication Date
- 2026-04-03
AI Technical Summary
Existing anhydrous hydrofluoric acid preparation equipment requires multiple independent distillation columns connected in series, resulting in low production efficiency, inability to recover steam waste heat, high energy consumption, and unstable product purity.
An integrated distillation apparatus is employed, which combines a liquid pump, a reflux spiral tube, and distillation components to achieve heat exchange and waste heat recovery during the distillation process. By utilizing the vapor liquefaction and solution heating within the reflux spiral tube, continuous distillation and multiple distillations are achieved, thereby reducing condensation energy consumption.
It improves the production efficiency of anhydrous hydrofluoric acid, reduces energy consumption, enhances the stability of product purity, simplifies the operation process, and reduces material loss.
Smart Images
Figure CN121775469A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of hydrofluoric acid production equipment technology, and in particular to a distillation apparatus for the production of anhydrous hydrofluoric acid. Background Technology
[0002] Anhydrous hydrofluoric acid is a key basic raw material in the chemical industry. Its purity level directly determines its application scenarios. In ordinary industrial production scenarios, anhydrous hydrofluoric acid only needs to be distilled and dehydrated once to achieve the required purity. However, with the rapid development of industries such as semiconductors and high-end fine chemical synthesis, the market demand for high-purity anhydrous hydrofluoric acid continues to expand. These high-purity products need to remove trace amounts of water and impurities, so distillation has become the core step in its purification process.
[0003] Currently, the industry generally adopts a multi-stage distillation process when preparing high-purity anhydrous hydrofluoric acid. The corresponding existing production equipment is mostly a series system of multiple independent distillation columns. Each distillation column needs to be equipped with a heating module, condensation module, feed pipeline and discharge temporary storage device. The material needs to pass through each distillation column in sequence to complete multiple separation operations, and gradually achieve deep removal of moisture and impurities.
[0004] However, existing anhydrous hydrofluoric acid preparation equipment and supporting processes have complex problems. On the one hand, connecting multiple independent devices requires additional auxiliary components such as material conveying pipelines and switching valves, which not only increases the overall footprint and hardware investment cost of the equipment, but also requires setting temperature, pressure and other control parameters for each distillation column individually. The operation process is cumbersome and requires a high level of professional expertise from personnel. On the other hand, the material needs to be transferred multiple times between multiple devices, which affects the purity stability of high-purity products and increases the material loss rate. At the same time, the waste heat of the steam after distillation cannot be recovered, resulting in high energy consumption in the condensation process, ultimately making it difficult to improve production efficiency. Summary of the Invention
[0005] This application aims to propose a distillation apparatus for the production of anhydrous hydrofluoric acid, which at least solves the technical problems in the related technology that the preparation of anhydrous hydrofluoric acid requires multiple transfers between multiple devices, resulting in low production efficiency and the inability to recover the waste heat of the steam after distillation, thus increasing the energy consumption of the equipment.
[0006] In a first aspect, this application provides a distillation apparatus for the production of anhydrous hydrofluoric acid, comprising: Base; A liquid storage tank is disposed on the base. The liquid storage tank has a liquid storage cavity. A main shaft is provided through the liquid storage cavity along a first direction. The main shaft is provided with threaded sections with opposite directions at intervals along the axial direction. A first sleeve and a second sleeve are respectively provided on the upper and lower inner end faces of the liquid storage cavity. A reflux spiral tube is provided in the liquid storage chamber. The reflux spiral tube is provided with a nut seat that is threadedly connected to the threaded section. One end of the reflux spiral tube is provided with a first straight tube section extending into the first tube sleeve, and the other end is provided with a second straight tube section extending into the second tube sleeve and open at both ends. A distillation assembly is mounted on the liquid storage tank, and the vapor output end of the distillation assembly is connected to one end of the first sleeve. A liquid pump, wherein the inlet end of the liquid pump is provided with a main pipe extending into the liquid storage chamber, and the outlet end is connected to the distillation assembly. The end face of the main pipe is provided with an auxiliary pipe extending into the second straight pipe section. The bottom end of the auxiliary pipe is closed and the side end face is provided with a through hole facing the connection port of the reflux spiral tube and the second straight pipe section. The second straight pipe section is provided with a connecting rod, the other end of which is sleeved on the main pipe and connected to a sealing plug adapted to the bottom port of the main pipe. The sealing plug can move in the first direction to switch the on / off state of the bottom port.
[0007] In some embodiments, the first straight pipe section and the first sleeve, and a portion of the second straight pipe section and the second sleeve are axially slidably connected, and a sealing member is provided at the connection between the first straight pipe section and the first sleeve, and the second straight pipe section and the second sleeve, the sealing member being used to seal the sliding fit gap between the straight pipe section and the sleeve.
[0008] In some embodiments, the reflux spiral tube is arranged circumferentially around the main shaft, and the adjacent ends of the two threaded sections are respectively provided with reversing grooves. When the main shaft rotates clockwise, the two nut seats move towards each other in the first direction to drive the reflux spiral tube to compress in the first direction. When the main shaft rotates counterclockwise, the two nut seats move in opposite directions in the first direction to drive the reflux spiral tube to expand in the first direction. The reversing groove is used to limit the maximum compression of the reflux spiral tube and enables the threaded connection between the nut seat and the threaded section to switch to a relative rotational connection.
[0009] In some embodiments, a flow-dispersing member is sleeved on the main shaft between the two threaded segments, and the projected outer contour of the flow-dispersing member along the first direction is located between the return spiral tubes.
[0010] In some embodiments, at least one limiting member is provided at one end of the connecting rod near the main tube, the limiting member extends away from the connecting rod to the bottom port of the main tube and is connected to a sealing plug, the sealing plug being coaxially disposed with the main tube.
[0011] In some embodiments, a plurality of annular heat dissipation fins are fitted onto the return spiral tube, and the plurality of heat dissipation fins are spaced apart along the length direction of the return spiral tube.
[0012] In some embodiments, the distillation assembly includes a heating tank and a steam filter disposed on the heating tank. The lower end face of the steam filter is connected to the heating tank via a pipe, and the upper end face is connected to the end of the first sleeve opposite to the reflux spiral tube via a pipe.
[0013] In some embodiments, the steam filter includes a housing with a cavity and a filter element disposed within the cavity. The filter element is provided with a rotating shaft extending outside the housing and being drivenly connected to the main shaft. The two ends of the filter screen holes of the filter element face the upper and lower end faces of the cavity, respectively. When the main shaft rotates, it drives the filter element to switch the filtration area.
[0014] In some embodiments, the distillation apparatus further includes a liquid cooling tank disposed at the bottom end face of the liquid storage tank, wherein a drain pipe is disposed inside the liquid cooling tank, one end of which extends to be connected to the second sleeve and the other end of which extends to the outside of the liquid cooling tank.
[0015] In some embodiments, the liquid storage tank is circumferentially surrounded by a vacuum chamber for thermal insulation.
[0016] Compared with the prior art, the technical solutions provided by the above embodiments of this application have at least the following beneficial effects or advantages: The distillation apparatus provided in this application, during the distillation process, firstly, a liquid pump delivers the hydrofluoric acid solution to be filtered from the storage tank to the heating tank of the distillation assembly. Once the heating tank of the distillation assembly is filled with a preset amount of hydrofluoric acid solution, the liquid pump stops operating, and simultaneously drives the main shaft to rotate. Due to the double-threaded section of the main shaft, the reflux spiral tube is driven to contract axially. Simultaneously, the second straight tube section and the sealing plug move upwards, causing the second straight tube section to switch from being connected to the second sleeve to being connected to the auxiliary tube. At the same time, the bottom port of the main tube is sealed by the sealing plug. During the distillation process of the distillation assembly, vapor is delivered to the reflux spiral tube. Since the reflux spiral tube is immersed in the hydrofluoric acid solution in the storage tank, heat exchange is achieved, allowing the reflux spiral tube to... The vapor inside is liquefied, and the temperature of the solution in the storage tank rises, which improves the cooling effect and recovers waste heat. After the hydrofluoric acid solution in the distillation component is distilled, the auxiliary pipe is connected and the main pipe is blocked. The liquid pump can transport the distilled hydrofluoric acid solution to the distillation component for multiple distillations. When anhydrous hydrofluoric acid is obtained, the main shaft is reversed, so that the second straight pipe section is connected to the second sleeve, and the bottom port of the main pipe is connected to the storage tank, so that the anhydrous hydrofluoric acid is discharged through the second sleeve. The liquid pump continues to draw hydrofluoric acid solution from the storage tank for further distillation. The device achieves continuous distillation in the preparation of anhydrous hydrofluoric acid and can recover the waste heat of vapor and liquid after distillation, reducing the energy consumption of the equipment condensation process and improving the production efficiency of anhydrous hydrofluoric acid.
[0017] Additional aspects and advantages of this application 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 this application. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a schematic diagram of the distillation apparatus according to an embodiment of this application; Figure 2 This is a first-view structural schematic diagram of a partial cross-section of a distillation apparatus according to an embodiment of this application; Figure 3 This is a second-view structural schematic diagram of a partial cross-section of a distillation apparatus according to an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the reflux spiral tube according to an embodiment of this application; Figure 5 This is a cross-sectional view of the threaded section connection according to an embodiment of this application; Figure 6This is a cross-sectional view of the first sleeve connection according to an embodiment of this application; Figure 7 This is a structural schematic diagram of the first straight pipe section and the auxiliary pipe section according to an embodiment of this application; Figure 8 This is a schematic diagram of the structure of a steam filter according to an embodiment of this application.
[0020] Figure label: 100. Distillation apparatus; 10. Base; 20. Liquid storage tank; 201. Liquid outlet; 202. Liquid inlet; 21. Liquid storage chamber; 22. Main shaft; 221. First threaded section; 222. Second threaded section; 223. Reversing spindle; 23. First sleeve; 24. Second sleeve; 25. Vacuum chamber; 26. Turbulence-inducing component; 30. Return spiral tube; 301. Heat dissipation fins; 31. Nut seat; 32. First straight pipe section; 33. Second straight pipe section; 331. Connecting rod; 332. Limiting rod; 3321. Guide hole; 333. Guide rod; 334. Sealing plug; 34. Sealing component; 40. Distillation assembly; 41. Heating tank; 411. Impurity discharge pipe; 42. Steam filter; 421. Shell; 422. Filter element; 4221. Rotating shaft; 4222. Filter sieve holes; 50. Liquid pump; 51. Main pipe; 52. Auxiliary pipe; 521. Through hole; 60. Liquid cooling tank; 61. Drain pipe; 62. Flange interface; A. First direction. Detailed Implementation
[0021] The embodiments of this application are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. It should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.
[0022] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.
[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0024] Please see Figures 1 to 4 As shown in Figure 7, this embodiment provides a distillation apparatus for the production of anhydrous hydrofluoric acid. The distillation apparatus 100 may include a base 10, a storage tank 20, a reflux spiral tube 30, a distillation assembly 40, and a liquid pump 50. For ease of description, the height direction of the storage tank 20 is defined as the first direction A. The storage tank 20 is mounted on the base 10 and has a storage cavity 21 for storing the hydrofluoric acid solution to be distilled. The storage cavity 21 can be cylindrical. A main shaft 22 extends through the storage cavity 21 along the first direction A. The main shaft 22 is axially divided... The liquid storage chamber 21 is provided with a first threaded section 221 and a second threaded section 222 with opposite screw directions. At the same time, the upper and lower inner end faces of the liquid storage chamber 21 are respectively provided with a first sleeve 23 and a second sleeve 24. The first sleeve 23 and the second sleeve 24 can be staggered in the first direction A. The return spiral tube 30 is provided in the liquid storage chamber 21. The return spiral tube 30 is provided with a nut seat 31 that is threadedly connected to the threaded section. One end of the return spiral tube 30 is provided with a first straight tube section 32 extending into the first sleeve 23, and the other end is provided with a second straight tube section 33 extending into the second sleeve 24 and open at both ends. For further information, please refer to [link / reference]. Figure 3 The distillation assembly 40 is mounted on the storage tank 20. The distillation assembly 40 is used to distill the hydrofluoric acid solution to be distilled. The vapor output end of the distillation assembly 40 is connected to one end of the first sleeve 23. The inlet end of the liquid pump 50 is provided with a main pipe 51 extending into the storage chamber 21, and the outlet end is connected to the distillation assembly 40. The liquid pump 50 is used to transport the hydrofluoric acid solution to be distilled in the storage chamber 21 to the distillation assembly 40. The end face of the main pipe 51 is provided with an auxiliary pipe 52 extending into the second straight pipe section 33. The bottom end of the auxiliary pipe 52 is closed and the side end face is provided with a through hole 521 facing the connection port of the reflux spiral pipe 30 and the second straight pipe section 33. The second straight pipe section 33 is provided with a connecting rod 331. The other end of the connecting rod 331 is sleeved on the main pipe 51 and connected to a sealing plug 334 adapted to the bottom port of the main pipe 51. The sealing plug 334 can move in the first direction A to switch the on / off state of the bottom port.
[0025] It should be noted that one end of the main shaft 22 can penetrate through the storage tank 20 and extend into the distillation tank of the distillation assembly 40. A turbine can be installed on the main shaft 22, and a motor can be installed on the top of the storage tank 20. The output shaft of the motor is equipped with a worm gear connected to the turbine, thereby driving the rotation of the main shaft 22. Two nut seats 31 are spaced apart on the reflux spiral tube 30. The two nut seats 31 can be located at the two ends of the reflux spiral tube 30 near the first sleeve 23 and the second sleeve 24, respectively. The first sleeve 23, the second sleeve 24, the first straight pipe section 32, and the second straight pipe section 33 are arranged along the first direction A in length direction. The first sleeve 23 and the first straight pipe section 32 are slidably connected in the vertical direction, and the second sleeve 24 and the second straight pipe section 33 are also slidably connected in the vertical direction. That is, during the compression or expansion process of the return spiral pipe 30 driven by the main shaft 22, the first sleeve 23 and the first straight pipe section 32, and the second sleeve 24 and the second straight pipe section 33 remain connected at all times, and the connection points are isolated from the liquid storage chamber 21. It should also be noted that the length direction of the connection between the main pipe 51 and the auxiliary pipe 52 and the second straight pipe is arranged along the first direction A. The bottom port of the main pipe 51 can extend to the bottom near the liquid storage chamber 21 to avoid leaving too much hydrofluoric acid solution to be distilled in the liquid storage chamber 21 after distillation. The reflux spiral tube 30 has a certain elasticity. During the contraction and expansion of the reflux spiral tube 30, the upper and lower ends of the second straight pipe section 33 are slidably connected to the second sleeve 24 and the auxiliary pipe 52, respectively. At the same time, the second straight pipe section 33 drives the connecting rod 331 to move along the first direction A during the movement, thereby driving the sealing plug 334 to move up and down.
[0026] In the distillation apparatus 100 of this embodiment, during the distillation process, firstly, the hydrofluoric acid solution to be filtered in the storage tank 20 is transported to the heating tank 41 of the distillation assembly 40 by the liquid pump 50. After the heating tank 41 of the distillation assembly 40 is filled with a preset amount of hydrofluoric acid solution, the liquid pump 50 stops operating and drives the main shaft 22 to rotate. Due to the double-threaded section of the main shaft 22, the reflux spiral tube 30 is driven to contract axially. At the same time, the second straight tube section 33 and the sealing plug 334 move upward, so that the second straight tube section 33 switches from being connected to the second sleeve 24 to being connected to the auxiliary tube 52. Meanwhile, the bottom port of the main tube 51 is blocked by the sealing plug 334. During the distillation process of the distillation assembly 40, the vapor from the distillation assembly 40 is transported to the reflux spiral tube 30. Since the reflux spiral tube 30 is immersed in the hydrofluoric acid solution in the storage tank 20, heat exchange can be achieved, causing the vapor in the reflux spiral tube 30 to be liquefied. Simultaneously, the temperature of the solution in the storage tank 20 rises. Of course, it should be understood that due to the large volume of the storage tank 20, the temperature rise of the hydrofluoric acid solution inside the tank is only a small increase. However, since the temperature of the hydrofluoric acid solution to be distilled rises, it means that when the hydrofluoric acid solution to be distilled is transported to the distillation assembly 40, it can change from a liquid state to a gas state more quickly, which improves the cooling effect and realizes waste heat recovery.
[0027] After the hydrofluoric acid solution in the distillation assembly 40 is distilled, because the auxiliary pipe 52 is connected and the main pipe 51 is blocked, the liquid pump 50 can transport the distilled hydrofluoric acid solution from the reflux spiral pipe 30 to the distillation assembly 40 for multiple distillations, thereby achieving the production of anhydrous hydrofluoric acid on the same equipment. After the anhydrous hydrofluoric acid is produced, the main shaft 22 is controlled to rotate in reverse (opposite to the initial rotation direction), causing the second straight pipe section 33 to move upward, thereby connecting the reflux spiral pipe 30 and the second straight pipe section 33 to the second sleeve 24. The main pipe 51 is connected to the storage tank 20 and separated from the auxiliary pipe 52. The bottom port of the main pipe 51 is connected to the storage tank 20, so that anhydrous hydrofluoric acid can be discharged and collected through the second sleeve 24. The liquid pump 50 continues to draw hydrofluoric acid solution from the storage tank 20 for further distillation, thereby realizing the continuous production of anhydrous hydrofluoric acid in a cycle. Due to the setting of the reflux spiral pipe 30, the residual heat of vapor and liquid after distillation is absorbed by the hydrofluoric acid solution to be distilled. The subsequent cooling of anhydrous hydrofluoric acid can reduce the energy consumption of the condensation process and improve the production efficiency of anhydrous hydrofluoric acid.
[0028] Meanwhile, after multiple distillations, the main shaft 22 drives the reflux spiral tube 30 to extend. In the extended state, the spacing between adjacent spiral sections of the reflux spiral tube 30 increases significantly, which reduces the adhesion area and residual probability of anhydrous hydrofluoric acid solution on the tube wall. At the same time, the increase in the spiral inclination increases the component of gravity on the anhydrous hydrofluoric acid solution along the first direction A, effectively reducing the path resistance during solution flow. This allows the solution to form a smooth flow channel under the natural drive of gravity, accelerating the discharge rate of the distilled solution, shortening the single production cycle, and improving overall production efficiency.
[0029] Please see Figure 2 and Figure 3 Optionally, the storage tank 20 may be provided with an inlet 202 near the top, which communicates with the storage chamber 21, and an outlet 201 near the bottom, which also communicates with the storage chamber 21. The inlet 202 is provided to temporarily store the hydrofluoric acid solution to be distilled, and the outlet 201 is provided to discharge the remaining solution containing more impurities in the storage chamber 21 in a timely manner after each distillation. The storage tank 20 is circumferentially surrounded by a vacuum chamber 25 for heat insulation, which surrounds the storage chamber 21.
[0030] This configuration, by evacuating the vacuum chamber 25 to eliminate the conductive medium inside, effectively blocks heat exchange between the inside and outside of the storage tank 20, forming a thermal barrier. This prevents changes in the external ambient temperature from affecting the temperature of the material inside the storage tank 20, while also reducing heat loss from the material inside the storage tank 20 and maintaining the temperature stability of the hydrofluoric acid solution to be distilled inside the storage tank 20. This ensures precise control of temperature parameters during the distillation process. Furthermore, the surrounding design of the vacuum chamber 25 achieves uniform thermal insulation throughout the circumference, preventing localized thermal insulation failure and further ensuring the operational stability of the distillation unit 100.
[0031] Continue reading Figure 2 In some embodiments, a flow-dispersing member 26 is sleeved on the main shaft 22 between two threaded sections. The outer contour of the flow-dispersing member 26 along the first direction A is located between the return spiral tubes 30. The flow-dispersing member 26 can be multiple bent rods set on the main shaft 22 and located within the surrounding range of the return spiral tubes 30. Since the temperature of the distilled hydrofluoric acid solution in the return spiral tubes 30 is high, the temperature of the solution around the return spiral tubes 30 in the storage chamber 21 is relatively high. By rotating the flow-dispersing member 26 driven by the main shaft 22, the temperature of the hydrofluoric acid solution to be distilled around the return spiral tubes 30 can be made more uniform. At the same time, the waste heat recovery efficiency of the distilled hydrofluoric acid solution in the return spiral tubes 30 is improved.
[0032] Continue reading Figure 3 In some embodiments, a plurality of annular heat dissipation fins 301 are fitted onto the reflux spiral tube 30. The plurality of heat dissipation fins 301 are spaced apart along the length of the reflux spiral tube 30. The annular heat dissipation fins 301 can increase the heat dissipation area of the reflux spiral tube 30 and accelerate the heat exchange between the reflux spiral tube 30 and the surrounding environment in the liquid storage chamber 21. When anhydrous hydrofluoric acid vapor flows in the reflux spiral tube 30, the heat dissipation fins 301 can quickly remove the heat of the vapor, promote the vapor to condense into liquid, enhance the condensation efficiency in the distillation process, and improve production efficiency. The spaced arrangement of the heat dissipation fins 301 not only ensures the heat dissipation effect, but also does not hinder the contraction and expansion of the reflux spiral tube 30, and at the same time, no additional cooling power is required, thus reducing energy consumption.
[0033] Continue reading Figure 3 Optionally, the distillation apparatus 100 also includes a liquid cooling tank 60 disposed at the bottom end of the storage tank 20. The liquid cooling tank 60 is provided with a drain pipe 61 extending at one end to connect with the second sleeve 24 and at the other end to the outside of the liquid cooling tank 60. Specifically, the drain pipe 61 is spirally arranged inside the liquid cooling tank 60 to discharge the anhydrous hydrofluoric acid obtained by the distillation of the reflux spiral tube 30 in a timely manner. The liquid cooling tank 60 provides a cooling environment for the drain pipe 61. When the liquid anhydrous hydrofluoric acid after distillation is discharged through the drain pipe 61, the liquid cooling tank 60 can quickly remove the residual heat of the liquid anhydrous hydrofluoric acid, so that the material temperature drops to a range suitable for storage or subsequent processing. The liquid cooling tank 60 can be provided with two flange interfaces 62, which can be used to connect to equipment that provides circulating coolant, thereby continuously providing cooling.
[0034] Please see Figure 4 and Figure 5 In some embodiments, the return spiral tube 30 is arranged in a circumferential spiral around the main shaft 22, and the adjacent ends of the two threaded sections are respectively provided with reversing grooves 223. When the main shaft 22 rotates clockwise, the two nut seats 31 move towards each other along the first direction A to drive the return spiral tube 30 to compress along the first direction A. When the main shaft 22 rotates counterclockwise, the two nut seats 31 move in opposite directions along the first direction A to drive the return spiral tube 30 to expand along the first direction A. The reversing grooves 223 are used to limit the maximum compression of the return spiral tube 30 and can switch the threaded connection between the nut seat 31 and the threaded section to a relative rotational connection.
[0035] Specifically, by utilizing the threaded transmission relationship between the main shaft 22 and the nut seat 31, the rotational motion of the main shaft 22 is converted into the axial linear motion of the nut seat 31, thereby driving the spirally wound reflux spiral tube 30 to contract or expand. The reversing groove 223 prevents the nut seat 31 from moving excessively through mechanical limiting, avoiding damage to the reflux spiral tube 30 due to excessive compression. At the same time, when the ultimate compression state is reached, the nut seat 31 disengages from the threaded section and rotates relative to it, forming an overload protection mechanism. After the reflux spiral tube 30 contracts, the connection between the second straight tube section 33 and the second sleeve 24 is switched to the connection with the auxiliary tube 52. Meanwhile, after the reflux spiral tube 30 is compressed, it does not affect the continued clockwise rotation of the main shaft 22, thus facilitating subsequent continuous distillation. When the main shaft 22 rotates counterclockwise, the nut seat 31 disengages from the reversing groove 223 and is threadedly connected to the threaded section.
[0036] During the distillation process, since hydrofluoric acid has a different boiling point than other impurities in the solution, the distillation of hydrofluoric acid can be achieved by controlling the temperature of the distillation assembly 40 during distillation. After the distillation assembly 40 completes the first distillation of the solution, the waste liquid in the distillation assembly 40 needs to be discharged first, and then the hydrofluoric acid liquid in the reflux spiral tube 30 is transported to the distillation assembly 40 for a second distillation by the liquid pump 50. This cycle is repeated to improve the purity of the distilled hydrofluoric acid solution.
[0037] Of course, it should be understood that in this embodiment, the main shaft 22 can also rotate counterclockwise to control the compression of the return spiral tube 30 and rotate clockwise to control the expansion of the return spiral tube 30, but it needs to be compatible with the thread direction of the two threaded sections.
[0038] Please see Figure 4 and Figure 6 In some embodiments, the first straight pipe section 32 is axially slidably connected to the first sleeve 23, and a portion of the second straight pipe section 33 is axially slidably connected to the second sleeve 24. A sealing member 34 is provided at the connection between the first straight pipe section 32 and the first sleeve 23, and the second straight pipe section 33 and the second sleeve 24. The sealing member 34 is used to seal the sliding fit gap between the straight pipe section and the sleeve. The sealing member 34 can be a rubber ring provided at the end of the first straight pipe section 32 and the end of the second straight pipe section 33. The axial sliding connection design can adapt to the expansion and contraction deformation requirements of the return spiral pipe 30, ensuring that the straight pipe section and the sleeve always maintain a stable assembly relationship during the contraction or expansion of the return spiral pipe 30, avoiding connection failure due to structural deformation. The sealing member 34 fills the sliding fit gap to build a two-way sealing barrier, which can effectively block the leakage of hydrofluoric acid solution and its vapor in the pipe. On the other hand, it can prevent the hydrofluoric acid solution to be distilled in the storage chamber 21 from entering the pipe, avoiding impurities from contaminating the material and affecting the purity of the product.
[0039] Please see Figure 4 and Figure 7In some embodiments, at least one limiting member is provided at the end of the connecting rod 331 near the main pipe 51, arranged along the first direction A. The end of the limiting member opposite to the connecting rod 331 extends to the bottom port protruding from the main pipe 51 and is connected to a sealing plug 334. The sealing plug 334 is arranged coaxially with the main pipe 51. Specifically, the connecting rod 331 is arranged perpendicular to the first direction A, and the other end is sleeved on the main pipe 51 and can slide up and down along the main pipe 51. The limiting member includes a limiting rod 332 and a guide rod 333. One end of the rod 332 is connected to the bottom end face of the connecting rod 331. At the same time, the limiting rod 332 is provided with a guide hole 3321. One end of the guide rod 333 is provided with a slider, which extends into the guide hole 3321. When the limiting rod 332 is driven to slide upward by the connecting rod 331, the guide rod 333 has a transition period. During this transition period, the guide rod 333 does not move. When the slider touches the bottom end of the guide hole 3321, the guide rod 333 is driven to move the sealing plug 334 upward.
[0040] It should be understood that the setting and assembly relationship of the limiting rod 332 and the guide rod 333 are mainly used to realize the synchronous switching of the second straight pipe section 33 with the second sleeve and auxiliary pipe 52. Furthermore, the limiting rod 332 is arranged along the first direction A to provide precise guidance for the movement of the sealing plug 334, ensuring that the sealing plug 334 always remains coaxial with the main pipe 51, and avoiding deviation or jamming during the movement. The sealing plug 334 realizes the on-off control of the main pipe 51 channel by adapting to the bottom port of the main pipe 51. Moreover, the linkage relationship between the connecting rod 331 and the return spiral pipe 30 makes the on-off action of the sealing plug 334 synchronously adapted to the extension and retraction of the return spiral pipe 30. The coaxial setting and limiting guide design improve the sealing reliability of the sealing plug 334 and avoid sealing failure due to deviation.
[0041] Please see Figure 8 In some embodiments, the distillation assembly 40 includes a heating tank 41 and a steam filter 42 disposed on the heating tank 41. The bottom end of the steam filter 42 is connected to the heating tank 41 through a pipeline, and the top end is connected to the end of the first sleeve 23 away from the reflux spiral tube 30 through a pipeline. Specifically, a discharge pipe 411 can be provided at the bottom of the heating tank 41. The discharge pipe 411 is used to discharge the impurity solution in the heating tank 41 after each distillation. The heating of the heating tank 41 can be achieved by a set heating element. The heating tank 41 provides the heat required for the material to be distilled. When the steam flows through the steam filter 42, it can intercept the trace droplets and other impurities carried in the steam, so that the hydrofluoric acid vapor can enter the subsequent reflux spiral tube 30 for further separation.
[0042] With this configuration, the steam filter 42 can remove visible impurities from the steam in advance, preventing impurities from adhering to the inner wall of the return spiral tube 30 or blocking the flow channel, ensuring the mass transfer efficiency of the return spiral tube 30, and improving the purity and stability of the final product; the integrated pipeline connection between the heating tank 41 and the steam filter simplifies the equipment structure, reduces the risk of leakage and heat loss during steam transportation, and improves the system's sealing performance.
[0043] Continue reading Figure 2 and Figure 8 In some embodiments, the steam filter 42 includes a housing 421 with a cavity and a filter element 422 disposed within the cavity. The filter element 422 is provided with a rotating shaft 4221 extending outside the housing 421 and drivenly connected to the main shaft 22. The two ends of the filter screen holes 4222 of the filter element 422 face the upper and lower end faces of the cavity, respectively. When the main shaft 22 rotates, it drives the filter element 422 to switch the filtration zones. Specifically, the main shaft 22 can pass through the heating tank 41 and be connected to the rotating shaft 4221 through gear transmission. The rotating shaft 4221 drives the filter element 422 to rotate synchronously, so that the different filtration zones of the filter element 422 can switch. Aligning the alternating zones with the steam flow path prevents a single filtration area from being subjected to prolonged steam scouring and impurity accumulation. Simultaneously, the filter screen holes 4222 of filter element 422 face the upper and lower end faces of the cavity, ensuring that steam can fully contact the filter medium as it flows through the filter element 422, improving the interception effect. The dynamic switching of filtration zones effectively slows down the clogging rate of filter element 422, reducing the frequency of downtime for filter element 422 replacement and improving production continuity. Sufficient filtration contact combined with dynamic switching ensures filtration efficiency while preventing increased steam flow resistance due to impurity accumulation, further guaranteeing product purity and production efficiency.
[0044] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the invention.
[0045] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.
[0046] Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The reference to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily indicate the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0047] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.
Claims
1. A distillation apparatus for the production of anhydrous hydrofluoric acid, characterized in that, include: Base; A liquid storage tank is disposed on the base. The liquid storage tank has a liquid storage cavity. A main shaft is provided through the liquid storage cavity along a first direction. The main shaft is provided with threaded sections with opposite directions at intervals along the axial direction. A first sleeve and a second sleeve are respectively provided on the upper and lower inner end faces of the liquid storage cavity. A reflux spiral tube is provided in the liquid storage chamber. The reflux spiral tube is provided with a nut seat that is threadedly connected to the threaded section. One end of the reflux spiral tube is provided with a first straight tube section extending into the first tube sleeve, and the other end is provided with a second straight tube section extending into the second tube sleeve and open at both ends. A distillation assembly is mounted on the liquid storage tank, and the vapor output end of the distillation assembly is connected to one end of the first sleeve. A liquid pump, wherein the inlet end of the liquid pump is provided with a main pipe extending into the liquid storage chamber, and the outlet end is connected to the distillation assembly. The end face of the main pipe is provided with an auxiliary pipe extending into the second straight pipe section. The bottom end of the auxiliary pipe is closed and the side end face is provided with a through hole facing the connection port of the reflux spiral tube and the second straight pipe section. The second straight pipe section is provided with a connecting rod, the other end of which is sleeved on the main pipe and connected to a sealing plug adapted to the bottom port of the main pipe. The sealing plug can move in the first direction to switch the on / off state of the bottom port.
2. The distillation apparatus for anhydrous hydrofluoric acid production according to claim 1, characterized in that, The first straight pipe section and the first pipe sleeve, and a portion of the second straight pipe section and the second pipe sleeve are axially slidably connected, and a sealing member is provided at the connection between the first straight pipe section and the first pipe sleeve, and the second straight pipe section and the second pipe sleeve. The sealing member is used to seal the sliding fit gap between the straight pipe section and the pipe sleeve.
3. The distillation apparatus for anhydrous hydrofluoric acid production according to claim 2, characterized in that, The return spiral tube is spirally arranged around the main shaft in a circumferential direction. The adjacent ends of the two threaded sections are respectively provided with reversing grooves. When the main shaft rotates clockwise, the two nut seats move towards each other in the first direction to drive the return spiral tube to compress in the first direction. When the main shaft rotates counterclockwise, the two nut seats move in opposite directions in the first direction to drive the return spiral tube to expand in the first direction. The reversing groove is used to limit the maximum compression of the return spiral tube and can switch the threaded connection between the nut seat and the threaded section to a relative rotational connection.
4. The distillation apparatus for anhydrous hydrofluoric acid production according to claim 3, characterized in that, A flow-dispersing component is sleeved on the main shaft between the two threaded sections, and the outer contour of the flow-dispersing component along the first direction is located between the return spiral tubes.
5. The distillation apparatus for producing anhydrous hydrofluoric acid according to any one of claims 1-4, characterized in that, At least one limiting member is provided at the end of the connecting rod near the main tube, which is arranged along the first direction. The limiting member extends away from the connecting rod to the bottom port of the main tube and is connected to a sealing plug. The sealing plug is arranged coaxially with the main tube.
6. The distillation apparatus for producing anhydrous hydrofluoric acid according to any one of claims 1-4, characterized in that, The return spiral tube is fitted with a plurality of annular heat dissipation fins, which are spaced apart along the length of the return spiral tube.
7. The distillation apparatus for producing anhydrous hydrofluoric acid according to claim 1, characterized in that, The distillation assembly includes a heating tank and a steam filter disposed on the heating tank. The bottom end of the steam filter is connected to the heating tank through a pipe, and the top end of the steam filter is connected to the end of the first sleeve away from the reflux spiral tube through a pipe.
8. The distillation apparatus for producing anhydrous hydrofluoric acid according to claim 7, characterized in that, The steam filter includes a housing with a cavity and a filter element disposed within the cavity. The filter element is provided with a rotating shaft extending outside the housing and being drivenly connected to the main shaft. The two ends of the filter screen holes of the filter element face the upper and lower end faces of the cavity, respectively. When the main shaft rotates, it drives the filter element to switch the filtration area.
9. The distillation apparatus for anhydrous hydrofluoric acid production according to claim 1, characterized in that, The distillation apparatus further includes a liquid cooling tank disposed at the bottom end of the liquid storage tank, wherein a drain pipe is disposed inside the liquid cooling tank, one end of which extends to connect with the second sleeve and the other end of which extends outside the liquid cooling tank.
10. The distillation apparatus for producing anhydrous hydrofluoric acid according to claim 1, characterized in that, The storage tank is surrounded by a vacuum chamber for heat insulation.