Electronic-grade purification and rectification equipment for preparing hydrofluoric acid

Abstract

The invention discloses electronic-grade purification and rectification equipment for preparing hydrofluoric acid, and relates to the technical field of rectification equipment. Comprising a tower body, a connecting cylinder and a tower kettle, a plurality of groups of tower plates are arranged in the tower body, a stirring heating element is arranged in the tower kettle and comprises a heating shaft, a heating pipe and a temperature sensing element, the heating shaft is provided with a lifting plate through a lifting assembly, the lifting plate is provided with a heating plate and a cleaning plate, and the heating shaft and the lifting plate are both provided with magnetic driving units. The magnetic driving unit is matched with the lifting assembly to realize spiral movement of the lifting plate, multi-dimensional disturbance of materials by the heating plate, heating of the materials from inside by the heating shaft and the heating plate through electromagnetic induction, heating of the materials from outside by the heating pipe, simultaneous heating of the outside and the inside of the materials, uniform heating of the materials, and improvement of rectification purification efficiency and product purity.

Description

Technical Field

[0001] This invention relates to the field of distillation equipment technology, specifically to an electronic-grade purification distillation device for the preparation of hydrofluoric acid. Background Technology

[0002] Electronic-grade hydrofluoric acid, as a key semiconductor material, requires extremely high purity and necessitates purification through efficient distillation. Existing distillation equipment suffers from uneven heating, insufficient material mixing, and easy scaling in the distillation vessel, leading to low reaction efficiency and insufficient product purity. Traditional heating methods have high thermal resistance, and stirring is mostly unidirectional, resulting in poor mass transfer; scaling further reduces heat transfer efficiency, affecting the long-term stable operation of the equipment. As the semiconductor industry's purity requirements for hydrofluoric acid have increased to PPT level, traditional equipment struggles to overcome the purity bottleneck, and its high energy consumption and frequent shutdowns for cleaning exacerbate production costs. Summary of the Invention

[0003] The purpose of this invention is to provide an electronic-grade purification and distillation apparatus for the preparation of hydrofluoric acid, so as to solve the problems raised in the prior art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an electronic-grade purification distillation device for the preparation of hydrofluoric acid, comprising a column body, a connecting cylinder and a column reboiler arranged in sequence, wherein multiple sets of column plates are arranged in sequence in the column body, a discharge end is provided on the column body, a feed end and a discharge end are provided on the column reboiler, and a stirring and heating element is provided in the column reboiler; The stirring heating element includes a heating shaft located in the middle of the column, a heating pipe embedded in the column, and a temperature sensing element located on the column. The heating shaft is equipped with a lifting plate via a lifting assembly. A heating plate and a cleaning plate are sequentially installed on the lifting plate. Both the heating shaft and the lifting plate are equipped with magnetic drive units.

[0005] The lifting assembly includes a lifting groove disposed on the heating shaft and a lifting shaft disposed in the middle of the lifting plate. The lifting shaft and the lifting groove are slidably connected, and the lifting groove is spirally distributed.

[0006] The magnetic drive unit on the heating shaft is a first coil, and the magnetic drive unit on the lifting plate is a permanent magnet. Each turn of the first coil is electrically connected to the control system through a wire, so that the control system can flexibly energize the first coil with different numbers of turns according to the temperature data of the temperature sensing element to achieve temperature adjustment at different positions. The temperature sensing element is a temperature sensor.

[0007] Multiple sets of extension shafts are provided on the outer side of the lifting plate. The multiple sets of extension shafts are horizontally arranged. Multiple sets of heating plates are provided. The heating plate is eccentrically provided with a rotating groove. The two ends of the rotating groove are mounted on the extension shaft through bearings. The heating plate is sleeved on the extension shaft through the rotating groove and the bearings. A torsion spring is connected between the heating plate and the extension shaft. The torsion spring is located in the rotating groove.

[0008] The outer side of the lifting plate is provided with multiple sets of extension shafts, which are inclined. The heating plate is provided with multiple sets, and the middle of the heating plate is provided with a rotating groove. The heating plate is sleeved on the extension shaft through the rotating groove. A first magnet is provided at the end of the extension shaft away from the heating shaft, and a second magnet is provided on the heating plate, with the first magnet and the second magnet facing each other.

[0009] The heating plate is twisted.

[0010] The cleaning plate is mounted on the extension shaft, and one side of the cleaning plate is in contact with the reboiler.

[0011] The heating shaft is hollow inside, and a heat-conducting medium is provided inside the heating shaft.

[0012] The inlet and outlet of the heating tube are both connected to an external heat source delivery system.

[0013] The outer sides of the first magnet, second magnet, extension shaft, heating plate, lifting plate, heating shaft, lifting shaft, and cleaning plate are all made of corrosion-resistant material; the column body is equipped with or connected to conventional general configurations for material distillation (the above structures are not shown in the figure) to ensure normal distillation processing.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. Internal and external synergistic heating improves heating efficiency and uniformity. The heating shaft and heating plate are made of metal. An alternating magnetic field is generated by the first coil, which cuts the magnetic field lines to generate eddy currents, achieving internal heating. Heating tubes are embedded in the tower, and heat is provided by an external heat source delivery system for external heating. Temperature sensing elements provide real-time temperature feedback, and the control system dynamically adjusts the heating power. Breaking through the traditional single heating mode, internal and external synergistic heating significantly reduces thermal resistance and temperature gradient. Electromagnetic induction internal heating acts directly on the inside of the material, resulting in faster heating response. Combined with external heating, it ensures overall temperature uniformity. Compared with traditional equipment, heating efficiency is significantly improved, avoiding local overheating or incomplete reaction, providing a stable temperature environment for efficient distillation of hydrofluoric acid, while reducing energy consumption and meeting energy-saving requirements.

[0015] 2. Three-dimensional spiral stirring enhances material mixing and mass transfer. A magnetic drive unit moves the lifting plate up and down, and the lifting groove and shaft of the lifting assembly work together to create a spiral motion. The heating plate employs a torsion design, using a torsion spring or magnet to rotate or slide, forming a multi-dimensional stirring trajectory. This eliminates traditional unidirectional stirring; the combination of spiral motion and multi-dimensional disturbance from the heating plate breaks down material flow stratification, making it particularly suitable for high-viscosity systems. It significantly increases the gas-liquid contact area and mass transfer efficiency, effectively avoiding incomplete local reactions and promoting the complete reaction of calcium fluoride and concentrated sulfuric acid to form hydrofluoric acid, laying the foundation for subsequent distillation and purification and improving product yield.

[0016] 3. Real-time anti-scaling, ensuring long-term stable operation of the equipment. The cleaning plate is installed on the extension shaft of the lifting plate, with one side closely attached to the inner wall of the tower. As the lifting plate spirals, it drives the cleaning plate to scrape along the inner wall simultaneously, removing deposits and scale generated during the reaction process in real time. No shutdown is required for cleaning, achieving real-time anti-scaling during operation and preventing scale from affecting heat transfer efficiency and tower volume. Compared to traditional methods of periodic disassembly and cleaning, this reduces downtime, lowers maintenance costs and labor intensity, while ensuring the cleanliness of heat transfer surfaces, maintaining long-term stable operation of the equipment, extending its service life, and ensuring the continuity and stability of electronic-grade hydrofluoric acid production. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the tower reactor in this invention; Figure 3 This is a schematic diagram of the heating tube structure in this invention; Figure 4 yes Figure 3 Schematic diagram of the structure of region A in the middle; Figure 5 This is a structural schematic diagram of Embodiment 1; Figure 6 This is a structural schematic diagram of Embodiment 2; Figure 7 This is a schematic diagram of the lifting plate in this invention.

[0018] In the diagram: 1. Tower body; 101. Discharge end; 11. Tower plate; 2. Connecting cylinder; 3. Tower kettle; 301. Feed end; 302. Discharge end; 31. Heating shaft; 32. Heating tube; 33. Lifting assembly; 331. Lifting groove; 332. Lifting shaft; 34. Lifting plate; 35. Heating plate; 36. Cleaning plate; 37. Magnetic drive unit. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example: Figures 1-7 As shown, the present invention provides a technical solution for an electronic-grade purification distillation device for hydrofluoric acid preparation, comprising a column body 1, a connecting cylinder 2, and a column kettle 3 arranged sequentially. Multiple sets of trays 11 are arranged sequentially inside the column body 1. A discharge end 101 is provided on the column body 1. A feed end 301 and a discharge end 302 are provided on the column kettle 3. A stirring and heating element is provided inside the column kettle 3. The stirring and heating element includes a heating shaft 31 located in the middle of the column kettle 3, a heating tube 32 embedded in the column kettle 3, and a temperature sensing element located on the column kettle 3. The heating shaft 31 is hollow inside and contains a heat-conducting medium. The inlet and outlet of the heating tube 32 are connected to an external heat source delivery system (not shown in the figure). A lifting plate 34 is installed on the heating shaft 31 via a lifting assembly 33. A heating plate 35 and a cleaning plate 36 are sequentially installed on the lifting plate 34. Magnetic drive units 37 are provided on both the heating shaft 31 and the lifting plate 34.

[0021] The distillation equipment achieves gas-liquid mass transfer and separation through multiple sets of trays 11 within the column body 1, thereby realizing the distillation process. The reboiler 3 receives materials (such as calcium fluoride and concentrated sulfuric acid) from the feed end 301. The stirring and heating element heats the reactants from the outside through the heating tube 32, and also drives the heating plate 35 to stir the materials through the heating shaft 31 and the lifting plate 34, making the reaction uniform and enhancing heat transfer. The temperature sensing element monitors the temperature in real time, and the control system flexibly adjusts the heating power according to the temperature data from the temperature sensing element. The lifting plate 34 is lifted and rotated by the magnetic drive unit 37, which drives the cleaning plate 36 to scrape the inner wall of the reboiler 3 to prevent scaling. The distilled product is output from the discharge end 101, and the residual liquid is discharged from the discharge end 302.

[0022] The lifting assembly 33 includes a lifting groove 331 disposed on the heating shaft 31 and a lifting shaft 332 disposed in the middle of the lifting plate 34. The lifting shaft 332 and the lifting groove 331 are slidably connected, and the lifting groove 331 is spirally distributed.

[0023] The lifting groove 331 in the lifting assembly 33 is a spiral track, and the lifting shaft 332 slides along the lifting groove 331. When the two sets of magnetic drive units 37 cooperate to drive the lifting plate 34 to move up and down, the lifting shaft 332 moves along the spiral groove, forcing the lifting plate 34 to rotate at the same time, realizing spiral lifting and enhancing the three-dimensional mixing effect of stirring.

[0024] The magnetic drive unit 37 on the heating shaft 31 is the first coil, and the magnetic drive unit 37 on the lifting plate 34 is a permanent magnet. Each turn of the first coil is electrically connected to the control system through a wire.

[0025] When alternating current is applied to the first coil, it generates an alternating magnetic field, which interacts with the permanent magnet on the lifting plate 34, producing alternating attractive and repulsive forces, driving the lifting plate 34 to move continuously up and down. Combined with the lifting assembly 33, the lifting plate 34 switches to a spiral lifting motion. At the same time, the alternating magnetic field causes the metal heating shaft 31 and heating plate 35 to cut the magnetic field lines, generating eddy current heating (electromagnetic induction heating), directly heating the material from the inside; the heating tube 32 provides auxiliary heating from the outside, achieving coordinated heating from both inside and outside, improving energy efficiency and reaction uniformity.

[0026] During the distillation process, the control system supplies alternating current to the first coil, causing it to continuously generate an alternating magnetic field. This alternating magnetic field alternately attracts and repels the permanent magnet. Under the influence of these forces, the permanent magnet drives the lifting plate 34 to move up and down continuously. Since the lifting plate 34 is mounted on the heating shaft 31 via the lifting assembly 33, it rotates spirally during its up-and-down movement. The lifting plate 34 drives the heating plate 35 to continuously stir the calcium fluoride and concentrated sulfuric acid in the reboiler 3. Because the heating plate 35 and the heating shaft 31 are made of metal, they cut magnetic field lines within the alternating magnetic field of the first coil, thereby generating heat. The heating plate 35 and the heating shaft 31 heat the calcium fluoride and concentrated sulfuric acid from the inside, while the control system simultaneously heats the calcium fluoride and concentrated sulfuric acid from the outside via the heating tube 32.

[0027] The heating shaft 31 and the heating plate 35 are internally made of metal, and both the heating shaft 31 and the heating plate 35 are within the magnetic field of the first coil.

[0028] The heating shaft 31 and heating plate 35 are made of metal, allowing them to be placed in the alternating magnetic field of the first coil. Eddy currents are generated through electromagnetic induction, converting electrical energy into heat energy, achieving direct internal heating, and reducing thermal resistance and temperature gradient.

[0029] The heating plate 35 is twisted. The twisted design of the heating plate 35 can generate multidimensional fluid disturbance when rotating or sliding, breaking the flow stratification, improving the material contact area and heat transfer efficiency, and is especially suitable for high viscosity or easy-to-deposit systems.

[0030] The cleaning plate 36 is mounted on the extension shaft, with one side of the cleaning plate 3 in contact with the inner wall of the tower 3. When the lifting plate 34 moves spirally, the cleaning plate 36 scrapes along the inner wall, removing deposits or scale, maintaining the cleanliness of the heat transfer surface, and ensuring long-term operating efficiency.

[0031] Example 1: As shown in the attached document Figure 5 As shown, multiple sets of extension shafts are provided on the outer side of the lifting plate 34. The multiple sets of extension shafts are horizontally arranged. Multiple sets of heating plates 35 are provided. A rotating groove is eccentrically arranged on the heating plate 35. The two ends of the rotating groove are mounted on the extension shaft through bearings. The heating plate 35 is sleeved on the extension shaft through the rotating groove and the bearings. A torsion spring is connected between the heating plate 35 and the extension shaft. The torsion spring is located in the rotating groove.

[0032] When the extension shaft is set horizontally, the magnetic drive unit 37 on the heating shaft 31 and the lifting plate 34 cooperates to drive the lifting plate 34 to spiral up or spiral down. The lifting plate 34 drives multiple sets of extension shafts to follow the movement, so that the extension shaft drives the heating plate 35 to spiral up or spiral down. At this time, the heating plate 35 stirs the calcium fluoride and concentrated sulfuric acid. When the resistance of calcium fluoride and concentrated sulfuric acid to the heating plate 35 is greater than the elastic force of the torsion spring, the resistance of calcium fluoride and concentrated sulfuric acid drives the heating plate 35 to rotate in the forward direction on the extension shaft, and the heating plate 35 compresses the torsion spring at the same time. When the resistance of calcium fluoride and concentrated sulfuric acid to the heating plate 35 is less than the spring force of the torsion spring, the resistance of calcium fluoride and concentrated sulfuric acid will not be able to drive the heating plate 35 to rotate in the forward direction on the extension shaft. At this time, the torsion spring will push the heating plate 35 to rotate in the reverse direction. The heating plate 35 rotates on the extension shaft by utilizing the resistance of calcium fluoride and concentrated sulfuric acid, as well as in conjunction with the torsion spring, thereby enhancing the mixing and heating effect of calcium fluoride and concentrated sulfuric acid and improving the distillation effect.

[0033] The resistance from calcium fluoride and concentrated sulfuric acid enables the heating plate 35 to rotate on the extension shaft, enhancing fluid shearing and mixing, and improving mass transfer and heating uniformity.

[0034] Example 2: As shown in the attached document Figure 6 As shown, multiple sets of extension shafts are provided on the outer side of the lifting plate 34. The multiple sets of extension shafts are inclined. Multiple sets of heating plates 35 are provided. A rotating groove is provided in the middle of the heating plate 35. The heating plate 35 is sleeved on the extension shaft through the rotating groove. A first magnet is provided at the end of the extension shaft away from the heating shaft 31, and a second magnet is provided on the heating plate 35, with the first magnet and the second magnet facing each other.

[0035] When the extension shaft is inclined, the magnetic drive unit 37 on the heating shaft 31 and the lifting plate 34 cooperates to drive the lifting plate 34 to spiral up or down. The lifting plate 34 drives multiple sets of extension shafts to follow the movement, so that the extension shafts drive the heating plate 35 to spiral up or down. At this time, the heating plate 35 stirs and heats the calcium fluoride and concentrated sulfuric acid. During the spiraling up or down process of the heating plate 35, the first magnet and the second magnet generate a repulsive force, and the heating plate 35 is also affected by centrifugal force. When the centrifugal force of the heating plate 35 is greater than the repulsive force, the heating plate 35 slides forward on the extension shaft to move away from the heating shaft 31; When the centrifugal force of the heating plate 35 is less than the repulsive force, the heating plate 35 slides in the opposite direction on the extension shaft to approach the heating shaft 31.

[0036] Working principle: Raw materials (such as calcium fluoride and concentrated sulfuric acid) enter the reactor 3 through the feed end 301. After the equipment is started, the stirring and heating elements begin to work. On one hand, the external heat source delivery system circulates heat medium to the heating pipes 32 embedded in the wall of the reactor 3, heating the material inside the reactor from the outside. On the other hand, the control system supplies alternating current to the first coil (magnetic drive unit 37) set on the heating shaft 31, causing it to generate an alternating magnetic field. This alternating magnetic field interacts with the permanent magnet (magnetic drive unit 37) fixed on the lifting plate 34, generating alternating attraction and repulsion forces, thereby driving the lifting plate 34 to make continuous up-and-down reciprocating motion along the heating shaft 31. Because the lifting plate 34 is slidably connected to the spirally distributed lifting grooves 331 on the heating shaft 31 via the lifting shaft 332 on it, the vertical linear motion of the lifting plate 34 is converted into a composite motion of spiral upward and spiral downward. The lifting plate 34 drives the heating plate 35 and cleaning plate 36 installed on its outer side to perform this three-dimensional spiral motion together; During the three-dimensional spiral motion of the heating plate 35, the heating plate 35 powerfully stirs the calcium fluoride and concentrated sulfuric acid materials in the reboiler 3, breaking up the flow stratification and greatly enhancing the material mixing and mass transfer process. Simultaneously, because the heating shaft 31 and the metal heating plate 35 are in the alternating magnetic field of the first coil, they generate eddy currents (electromagnetic induction heating) by cutting magnetic field lines, thus directly converting electrical energy into heat energy. This provides efficient and uniform direct heating from within the material, forming a synergistic heating mode with the external heating of the heating tube 32, significantly improving energy efficiency and temperature uniformity. The control system monitors the temperature in real time through temperature sensing elements and dynamically adjusts the heating power.

[0037] As the lifting plate 34 spirals, the cleaning plate 36, which is in close contact with the inner wall of the tower vessel 3 on one side, continuously scrapes the inner wall, effectively removing any substances that may adhere or scale, maintaining the long-term cleanliness and efficiency of the heat transfer surface. Furthermore, depending on the embodiment, the heating plate 35 can also be designed to have adaptive movement capabilities. In Embodiment 1, the heating plate 35 is hinged to the extension shaft by a torsion spring, and periodic forward and reverse rotation is achieved by utilizing the balance between fluid resistance and elastic force. In Embodiment 2, the repulsive force between the first magnet at the end of the inclined extension shaft and the second magnet on the heating plate 35 interacts with the centrifugal force generated by the helical motion, driving the heating plate 35 to slide along the shaft. These designs further enhance the shearing and mixing effects of the fluid.

[0038] The gaseous mixture generated by the heating reaction in the reboiler 3 rises into the column body 1. Through gas-liquid mass transfer and separation via the multi-stage trays 11 within the column body 1, distillation purification is achieved. The high-purity product vapor is finally condensed and collected from the discharge end 101 at the top of the column body 1, while the reaction residue is periodically discharged from the discharge end 302 at the bottom of the reboiler 3. The entire system, through integrated stirring, internal and external synergistic heating, adaptive mixing, and self-cleaning functions, achieves efficient, uniform, and stable purification and distillation of electronic-grade hydrofluoric acid feedstock.

[0039] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An electronic-grade purification and distillation apparatus for the preparation of hydrofluoric acid, characterized in that: The tower includes a tower body (1), a connecting cylinder (2), and a tower kettle (3) arranged in sequence. Multiple sets of tower plates (11) are arranged in sequence inside the tower body (1). A discharge end (101) is provided on the tower body (1). A feed end (301) and a discharge end (302) are provided on the tower kettle (3). A stirring and heating element is provided inside the tower kettle (3). The stirring heating element includes a heating shaft (31) located in the middle of the tower (3), a heating tube (32) embedded in the tower (3), and a temperature sensing element located on the tower (3). The heating shaft (31) is equipped with a lifting plate (34) via a lifting assembly (33). A heating plate (35) and a cleaning plate (36) are sequentially installed on the lifting plate (34). A magnetic drive unit (37) is provided on both the heating shaft (31) and the lifting plate (34).

2. The electronic-grade purification and distillation apparatus for hydrofluoric acid preparation according to claim 1, characterized in that: The lifting assembly (33) includes a lifting groove (331) disposed on the heating shaft (31) and a lifting shaft (332) disposed in the middle of the lifting plate (34). The lifting shaft (332) and the lifting groove (331) are slidably connected, and the lifting groove (331) is spirally distributed.

3. The electronic-grade purification and distillation apparatus for hydrofluoric acid preparation according to claim 1, characterized in that: The magnetic drive unit (37) on the heating shaft (31) is a first coil, and the magnetic drive unit (37) on the lifting plate (34) is a permanent magnet. Each turn of the first coil is electrically connected to the control system through a wire.

4. The electronic-grade purification and distillation apparatus for preparing hydrofluoric acid according to claim 3, characterized in that: The heating shaft (31) and heating plate (35) are internally made of metal material, and both the heating shaft (31) and heating plate (35) are within the magnetic field of the first coil.

5. The electronic-grade purification and distillation apparatus for hydrofluoric acid preparation according to claim 1, characterized in that: The lifting plate (34) is provided with multiple sets of extension shafts on its outer side. The multiple sets of extension shafts are horizontally arranged. The heating plate (35) is provided with multiple sets. The heating plate (35) is eccentrically provided with a rotating groove. The two ends of the rotating groove are mounted on the extension shaft through bearings. The heating plate (35) is sleeved on the extension shaft through the rotating groove and the bearing. A torsion spring is connected between the heating plate (35) and the extension shaft. The torsion spring is located in the rotating groove.

6. The electronic-grade purification and distillation apparatus for hydrofluoric acid preparation according to claim 1, characterized in that: The lifting plate (34) is provided with multiple sets of extension shafts on its outer side. The multiple sets of extension shafts are inclined. The heating plate (35) is provided with multiple sets. The heating plate (35) is provided with a rotating groove in the middle. The heating plate (35) is sleeved on the extension shaft through the rotating groove. A first magnet is provided at the end of the extension shaft away from the heating shaft (31), and a second magnet is provided on the heating plate (35), with the first magnet and the second magnet facing each other.

7. An electronic-grade purification and distillation apparatus for the preparation of hydrofluoric acid according to any one of claims 5 or 6, characterized in that: The heating plate (35) is twisted.

8. The electronic-grade purification and distillation apparatus for preparing hydrofluoric acid according to claim 7, characterized in that: The cleaning plate (36) is disposed on the extension shaft, and one side of the cleaning plate (36) is in contact with the tower (3).

9. The electronic-grade purification and distillation apparatus for preparing hydrofluoric acid according to claim 1, characterized in that: The heating shaft (31) is hollow inside, and a heat-conducting medium is provided inside the heating shaft (31).

10. The electronic-grade purification and distillation apparatus for preparing hydrofluoric acid according to claim 1, characterized in that: The inlet and outlet of the heating tube (32) are both connected to an external heat source delivery system.

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