Concentration adjusting system for preparing electronic-grade hydrofluoric acid

Abstract

The utility model discloses a concentration allocation system for preparing electronic-grade hydrofluoric acid. The concentration allocation system comprises a mixing tank, a pure water input pipe arranged above the mixing tank, a hydrofluoric acid input pipe and an output pipe positioned below the mixing tank, a first control valve is arranged in the pure water input pipe, and a second control valve is arranged in the hydrofluoric acid input pipe; the plurality of delivery pipes are uniformly arranged around the axis of the mixing tank, and the heights of the adjacent delivery pipes are staggered; a concentration detection module is arranged in the delivery pipe; according to the utility model, the control module, the judgment module and the plurality of control valves are matched with the plurality of concentration detection modules to monitor and adjust the concentration of mixed liquid in real time, and liquid circulation and vortex are formed by utilizing the pump and the obliquely mounted spray pipe, so that the mixing efficiency is improved, the accuracy and stability of hydrofluoric acid concentration are ensured, and the electronic-grade requirement is met; and manual intervention and personal errors are reduced.

Description

Technical Field

[0001] The utility model relates to a concentration mixing system for preparing electronic-grade hydrofluoric acid, belonging to the technical field of hydrofluoric acid dilution. Background Art

[0002] Electronic-grade hydrofluoric acid (HF) is a high-purity form of hydrofluoric acid used in cleaning and etching processes for semiconductors, microelectronics, and other high-tech applications. Unlike industrial-grade HF, electronic-grade HF has extremely strict impurity controls to avoid damage to delicate electronic components.

[0003] The production of electronic-grade hydrofluoric acid requires high-precision purification methods to remove metal ions, organic matter, and other impurities from the raw materials. These methods may include distillation, ion exchange, filtration, and chemical treatment to ultimately produce a product of extremely high purity.

[0004] The concentration of electronic-grade hydrofluoric acid cleaning fluids is typically carefully controlled. This concentration range may vary depending on the specific application and process requirements, but is generally between 0.1% and 10%. The specific concentration depends on the cleaning or etching purpose to ensure effective contaminant removal without damaging the material.

[0005] Since hydrofluoric acid concentration can fluctuate due to factors such as raw material purity, environmental factors, and operational errors, manual monitoring and adjustment are prone to human error. Furthermore, the concentration ratio of electronic-grade hydrofluoric acid cleaning fluids requires high precision, making it difficult to stabilize the concentration of the final product within the predetermined range. Utility Model Content

[0006] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a concentration adjustment system for preparing electronic grade hydrofluoric acid to solve the problems of the existing technology.

[0007] In order to achieve the above purpose, the present invention is implemented through the following technical solutions:

[0008] A concentration preparation system for preparing electronic-grade hydrofluoric acid comprises: a mixing tank, a pure water inlet pipe and a hydrofluoric acid inlet pipe arranged above the mixing tank, and an output pipe located below the mixing tank;

[0009] A first control valve is provided in the pure water input pipe, and a second control valve is provided in the hydrofluoric acid input pipe;

[0010] A plurality of outlet pipes are evenly arranged around the axis of the mixing tank, and adjacent outlet pipes are staggered in height;

[0011] A concentration detection module is provided in the outlet pipe;

[0012] a control module, the control module being electrically connected to the first control valve, the second control valve, the concentration detection module, and the pump;

[0013] The mixed liquid at different heights in the mixing tank is extracted by the cooperation of the plurality of the outlet pipes and the concentration detection module, and the concentration of the hydrofluoric acid liquid in the mixed liquid is detected and fed back to the control module;

[0014] Wherein, when the difference between any two detection values ​​of the plurality of concentration detection modules is within a first preset value range, the control module determines the hydrofluoric acid liquid concentration of the liquid in the mixing tank;

[0015] It also includes a judgment module, which cooperates with the control module to:

[0016] When the concentration of the hydrofluoric acid liquid is lower than a second preset value range, the hydrofluoric acid liquid is input through the cooperation of the control module and the second control valve;

[0017] When the concentration of the hydrofluoric acid liquid is higher than a second preset value range, pure water is input through the cooperation of the control module and the first control valve;

[0018] When the concentration of the hydrofluoric acid liquid is within a second preset value range, the mixed liquid is output through the output pipe.

[0019] As a further improvement, it also includes an inlet pipe arranged above the side of the mixing tank, and a pump connecting the inlet pipe and several outlet pipes. Through the cooperation of the pump and the inlet pipe, the liquids in the several outlet pipes are collected and re-introduced into the mixing tank.

[0020] As a further improvement, the inlet pipe is further provided with a nozzle inclined toward the interior of the mixing tank, and the angle between the nozzle and the ground is in the range of 60°-70°.

[0021] As a further improvement, the nozzle aperture decreases along the water flow direction, and the ratio of the nozzle aperture at the water flow input end to the nozzle aperture at the water flow output end is 3:1.

[0022] As a further improvement, the outlet tubes are provided in three groups, and the height interval between two adjacent outlet tubes is at least 10 cm.

[0023] As a further improvement, one side of the outlet pipe is provided with a connection hole communicating with the interior;

[0024] The concentration detection module includes a detection head threadedly connected to the connection hole, and a sealing ring is sleeved on the outer ring of the detection head toward the outer side of the outlet pipe.

[0025] As a further improvement, the first preset value range is 0.001 to 0.005, and the second preset value range is 0.01 to 0.1H□O□.

[0026] As a further improvement, it also includes a cooling module arranged outside the inlet pipe, the cooling module is electrically connected to the control module, and the temperature of the liquid inside the inlet pipe is reduced by the cooling module.

[0027] The beneficial effects of the utility model are:

[0028] By incorporating a control module, a judgment module, and multiple control valves, this new device reduces manual intervention and human error. The concentration detection module, in conjunction with the device, monitors and adjusts the concentration of the mixed solution in real time, ensuring a highly efficient and stable preparation process. Multiple concentration detection modules and evenly spaced outlet pipes ensure uniform concentration of the mixed solution at different heights, providing more accurate concentration data. This ensures accurate and stable concentration of electronic-grade hydrofluoric acid, meeting the stringent requirements of high-performance semiconductor and microelectronic products.

[0029] Because hydrofluoric acid is corrosive, a stirring mechanism isn't included. However, to ensure efficient mixing, a new inlet pipe, located above the mixing tank, and a pump connecting the inlet pipe to several outlet pipes are added. The pump collects the liquid from the outlet pipes and redirects it into the mixing tank. This inlet pipe and pump arrangement allows for circulating mixing of the liquid. Simultaneously, the pump pressurizes the liquid, boosting its pressure and outputting it through the inlet pipe. This water flow impacts the interior of the mixing tank, creating a vortex within the liquid and accelerating mixing.

[0030] To further ensure the mixing efficiency, the inlet pipe is also installed with a nozzle tilted toward the inside of the mixing tank, and the angle between the nozzle and the ground is in the range of 60°-70°. The diameter of the nozzle decreases along the direction of water flow, and the ratio of the nozzle diameter at the water flow input end to the nozzle diameter at the water flow output end is 3:1. When the liquid passes through the gradually shrinking nozzle, the flow rate will increase significantly, and the sprayed liquid will have greater kinetic energy. High kinetic energy liquid jet can mix more effectively with the liquid in the tank and improve mixing efficiency. In a chemical mixing tank, high kinetic energy jet can break the liquid interface faster and achieve rapid and uniform mixing.

[0031] To collect samples at different heights, multiple sets of outlet tubes, each located at different heights (at least 10 cm apart), can be used to obtain liquid samples from different layers within the mixing tank. This provides a comprehensive view of the liquid concentration distribution within the mixing tank, rather than just a single layer. By collecting samples and performing concentration tests at different heights, more comprehensive test data can be obtained. This comprehensive data more accurately reflects the overall concentration of the liquid within the mixing tank than single-point test data.

[0032] By setting up a control module, a judgment module, and multiple control valves in conjunction with multiple concentration detection modules, the concentration of the mixed liquid can be monitored and adjusted in real time. A pump and an inclined nozzle are used to form liquid circulation and vortexes to improve mixing efficiency, ensure the accurate and stable concentration of hydrofluoric acid, meet electronic grade requirements, and reduce manual intervention and human errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 The utility model is a schematic diagram of the connection modules of a concentration preparation system for preparing electronic grade hydrofluoric acid.

[0035] Figure 2 The utility model is a schematic diagram of the three-dimensional structure of a hydrofluoric acid preparation tank of a concentration preparation system for preparing electronic-grade hydrofluoric acid.

[0036] Figure 3 The utility model is a partial cross-sectional structural diagram of a hydrofluoric acid preparation tank of a concentration preparation system for preparing electronic-grade hydrofluoric acid.

[0037] Figure 4 The utility model is a schematic diagram of a partially enlarged side view of a hydrofluoric acid mixing tank of a concentration mixing system for preparing electronic-grade hydrofluoric acid.

[0038] 1. Mixing tank; 12. Pure water inlet pipe; 13. Hydrofluoric acid inlet pipe; 14. Output pipe; 121. First control valve; 131. Second control valve; 141. Third control valve; 15. Export pipe; 16. Import pipe; 2. Concentration detection module; 3. Control module; 4. Judgment module; 5. Pump; 161. Nozzle; 21. Detection head; 22. Sealing ring; 6. Cooling module; 61. Heat exchanger. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the utility model for which protection is sought, but merely represents the selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] In the description of this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically specified.

[0041] Since hydrofluoric acid concentration can fluctuate due to factors such as raw material purity, environmental factors, and operational errors, manual monitoring and adjustment are prone to human error. Furthermore, the concentration ratio of electronic-grade hydrofluoric acid cleaning fluids requires high precision, making it difficult to stabilize the concentration of the final product within the predetermined range.

[0042] Reference Figure 1-4 As shown, a concentration preparation system for preparing electronic grade hydrofluoric acid comprises:

[0043] A mixing tank 1, a pure water inlet pipe 12 and a hydrofluoric acid inlet pipe 13 provided above the mixing tank 1, and an outlet pipe 14 located below the mixing tank 1;

[0044] The pure water inlet pipe 12 is provided with a first control valve 121, and the hydrofluoric acid inlet pipe 13 is provided with a second control valve 131;

[0045] A plurality of outlet pipes 15 are evenly arranged around the axis of the mixing tank 1, and adjacent outlet pipes 15 are staggered in height;

[0046] A concentration detection module 2 is provided in the outlet pipe 15;

[0047] A control module 3, wherein the control module 3 is electrically connected to the first control valve 121, the second control valve 131, the concentration detection module 2, and the pump 5;

[0048] The mixed liquid at different heights in the mixing tank 1 is extracted through the cooperation of the plurality of the outlet pipes 15 and the concentration detection module 2, and the concentration of the hydrofluoric acid liquid in the mixed liquid is detected and fed back to the control module 3;

[0049] When the difference between any two detection values ​​of the plurality of concentration detection modules 2 is within a first preset value range, the control module 3 determines the hydrofluoric acid liquid concentration of the liquid in the mixing tank 1;

[0050] The system further includes a judgment module 4, which cooperates with the control module 3 to:

[0051] When the concentration of the hydrofluoric acid liquid is lower than the second preset value range, the hydrofluoric acid liquid is input through the cooperation of the control module 3 and the second control valve 131;

[0052] When the concentration of the hydrofluoric acid liquid is higher than the second preset value range, pure water is input through the cooperation of the control module 3 and the first control valve 121;

[0053] When the concentration of the hydrofluoric acid liquid is within the second preset value range, the mixed liquid is output through the output pipe 14 .

[0054] Start the control system, including the control module 3, the concentration detection module 2 and the pump 5. Input pure water and hydrofluoric acid through the pure water input pipe 12 and the hydrofluoric acid input pipe 13 respectively.

[0055] The concentration detection module 2 cooperates with the multiple outlet pipes 15 to extract the mixed liquid from different heights of the mixing tank 1 and detect the hydrofluoric acid concentration of the mixed liquid in real time.

[0056] The detection data of the multiple concentration detection modules 2 are calculated by the control module 3 . When the difference between any two detection values ​​is within a first preset value interval, the control module 3 determines the concentration of the liquid hydrofluoric acid in the mixing tank 1 .

[0057] When the concentration of the hydrofluoric acid liquid is lower than the second preset value range, the judgment module 4 controls the second control valve 131 through the control module 3 to increase the input of hydrofluoric acid.

[0058] When the concentration of the hydrofluoric acid liquid is higher than the second preset value range, the judgment module 4 controls the first control valve 121 through the control module 3 to increase the input of pure water.

[0059] When the concentration of the hydrofluoric acid liquid is within the second preset value range, the control module 3 opens the output pipe 14 to output the mixed liquid.

[0060] By setting up the control module 3, the judgment module 4, and multiple control valves, manual intervention is reduced and human errors are reduced. The concentration detection module 2 is used to monitor and adjust the concentration of the mixed solution in real time to ensure the efficiency and stability of the preparation process.

[0061] Multiple concentration detection modules 2 and evenly spaced outlet pipes 15 ensure uniform concentration of the mixed solution at different heights, providing more accurate concentration data. This ensures accurate and stable concentration of electronic-grade hydrofluoric acid, meeting the stringent requirements of high-performance semiconductor and microelectronic products.

[0062] The coordination between the judgment module 4 and the control module 3 enables the system to automatically and continuously monitor and adjust the ratio of hydrofluoric acid to pure water, outputting a stable concentration. The solidified software logic reduces the possibility of sudden failures or misoperations, improving system reliability.

[0063] Reduce material waste and product rejection rates due to concentration fluctuations, thereby reducing production costs. Improve operational efficiency and product quality stability, and reduce labor and maintenance costs.

[0064] The output of the output pipe 14 is controlled by a third solenoid valve, and the third solenoid valve is electrically connected to the control module 3 .

[0065] Since hydrofluoric acid liquid is corrosive, a stirring mechanism is not provided. However, it is necessary to ensure the efficiency of mixing. Therefore, an inlet pipe 16 is provided above the side of the mixing tank 1, and a pump 5 connecting the inlet pipe 16 with several outlet pipes 15. Through the cooperation of the pump 5 and the inlet pipe 16, the liquids in the several outlet pipes 15 are collected and re-introduced into the mixing tank 1.

[0066] By adding an inlet pipe 16 disposed above the side of the mixing tank 1 and a pump 5 for connecting the inlet pipe 16 with a plurality of outlet pipes 15, the pump 5 collects the liquid in the outlet pipes 15 and reintroduces it into the mixing tank 1. The inlet pipe 16 and the pump 5 enable circulation and mixing of the liquid. At the same time, the pump 5 pressurizes the liquid so that it is output through the inlet pipe 16 at a higher pressure. The water flow impacts the interior of the mixing tank 1, causing the liquid inside the mixing tank 1 to form a vortex, accelerating mixing.

[0067] Furthermore, even if there are local concentration differences within the mixing tank 1, this process allows the mixed liquid at different heights to be re-extracted and re-injected, ensuring that the liquid is fully mixed within the tank and improving mixing uniformity. The recirculation system remixes the liquids at different heights within the mixing tank 1, potentially with different concentrations, eliminating concentration gradients caused by sedimentation or stratification.

[0068] In order to improve the corrosion resistance of the pump body, in addition to being made of anti-corrosion materials, the pump 5 adopts a corrosion-resistant magnetic suction pump to minimize the mechanical structure in contact with the hydrofluoric acid liquid.

[0069] To further ensure mixing efficiency, the inlet pipe 16 is further inclined toward the interior of the mixing tank 1, with a nozzle 161 positioned at an angle of 60°-70° to the ground. The nozzle 161's diameter decreases along the water flow direction, with a 3:1 ratio between the nozzle 161 at the water input end and the nozzle 161 at the water output end.

[0070] Fluid mechanics research shows that an angle of 60°-70° can generate sufficient shear force to promote mixing, can be close to the landing point of hydrofluoric acid, can quickly disperse the hydrofluoric acid, and will not splash pure hydrofluoric acid onto the wall of the mixing tank 1.

[0071] This angle range is commonly used in many industrial mixing equipment designs, based on years of industry practice and experience. Experimental verification shows that an angle of 60°-70° achieves optimal liquid mixing under given conditions (pressure, flow rate, etc.).

[0072] Referring to existing successful cases, such as large-scale mixing devices in the chemical and pharmaceutical fields, the angle between the nozzle 161 and the ground is mostly in the range of 60°-70°.

[0073] Computational fluid dynamics (CFD) simulation was used to verify the injection effects at different angles, and ultimately confirmed that this angle range was optimal.

[0074] Optimizing the spray angle makes the flow path of the liquid in the mixing tank more reasonable, which helps to improve the mixing efficiency.

[0075] The appropriate spray angle reduces the direct impact of the liquid on the tank wall, extending the service life of the equipment. The optimized angle reduces the risk of high-pressure liquid rebound and splashing, improving the safety of the operation process.

[0076] According to the basic principles of fluid dynamics, when a liquid passes through a gradually narrowing pipe, its flow rate increases. This is based on Bernoulli's equation, which states that the pressure and velocity of a liquid are mutually complementary during flow. Therefore, the diameter of nozzle 161 is arranged to decrease along the direction of the water flow, with the ratio of the diameter of nozzle 161 at the water flow input end to the diameter of nozzle 161 at the water flow output end being 3:1.

[0077] By adjusting the nozzle 161's diameter from large to small, the pressure and flow rate of the liquid can be adjusted, ensuring that the ejected liquid has sufficient kinetic energy for effective mixing. By reducing the diameter, the flow rate of the liquid can be controlled. Experimental and simulation studies have shown that a 3:1 ratio can effectively increase the speed and impact of the liquid spray, thereby improving the mixing effect. This ratio can ensure an increase in flow rate while reducing turbulence and turbulence caused by sudden changes, maintaining the stability of the jet flow.

[0078] In actual engineering applications, the 3:1 ratio has been verified many times, proving that this ratio has high adaptability and reliability in a variety of fluids and conditions.

[0079] As the liquid passes through the tapering nozzle 161, its flow rate increases significantly, and the ejected liquid possesses greater kinetic energy. This high-kinetic-energy liquid jet mixes more effectively with the liquid within the tank, improving mixing efficiency. In chemical mixing tanks, this high-kinetic-energy jet can more quickly break down the liquid interface, achieving rapid and uniform mixing.

[0080] To sample different layers at different heights, multiple groups of outlet pipes 15 are provided, each located at different heights (at least 10 cm apart), so that liquid samples can be obtained from different layers within the mixing tank 1. This allows for a comprehensive reflection of the liquid concentration distribution within the mixing tank 1, rather than just data from a single layer.

[0081] Since the liquid inside the mixing tank 1 may have laminar flow or sedimentation, a sample taken from a single layer may not be representative. Sampling at different heights can detect and eliminate potential local concentration differences.

[0082] By taking samples at different heights and performing concentration tests, more comprehensive test data can be obtained. These comprehensive data can more accurately reflect the concentration of the entire liquid in the mixing tank 1 than single-point test data.

[0083] Multi-point sampling at least at intervals of 10 cm in height can smooth detection fluctuations to a certain extent and improve the stability and reliability of concentration detection data.

[0084] A connection hole communicating with the interior is provided on one side of the outlet pipe 15 ; the concentration detection module 2 includes a detection head 21 threadedly connected to the connection hole, and a sealing ring 22 is sleeved on the outer ring of the detection head 21 toward the outside of the outlet pipe 15 .

[0085] The outer ring of the detection head 21 is made of corrosion-resistant stainless steel and has threads, which can be matched with the internal threads of the connecting hole for installation. At the same time, due to the flexible material characteristics of the sealing ring 22, it is easily corroded, but in order to enhance the sealing performance, it is set on the outside for sealing.

[0086] The detection head 21 for detecting the concentration of hydrofluoric acid can use an ion selective electrode to detect fluoride ions (F - ) and the concentration of hydrofluoric acid is determined by measuring the potential difference.

[0087] The photometric detector is based on the optical absorption properties of hydrofluoric acid and determines the concentration by measuring the intensity of light absorption at a specific wavelength.

[0088] The conductivity detector indirectly estimates the concentration of hydrofluoric acid by measuring the change in the conductivity of the solution.

[0089] In this embodiment, a conductivity detector is used to detect the concentration of hydrofluoric acid.

[0090] To ensure the accuracy and reliability of the data, the first preset value range is 0.001 to 0.005, and the second preset value range is 0.01 to 0.1 H□O2.

[0091] By using multiple concentration detection modules 2, data errors caused by failure or abnormality of a single detector can be reduced.

[0092] When the difference between the detection values ​​of the multiple detection modules is within a small interval (the first preset value interval is 0.001 to 0.005), it means that these detection values ​​are relatively consistent, and the concentration measurement can be considered reliable.

[0093] When the exact concentration of the hydrofluoric acid liquid is lower than the second preset value range (0.01-0.1), the system inputs the hydrofluoric acid liquid through the second control valve 131 to increase the concentration to ensure that the set standard is met.

[0094] When the concentration of the hydrofluoric acid liquid is detected to be higher than the second preset value range (0.01-0.1), the system inputs pure water through the first control valve 121 to dilute it, thereby reducing the concentration to prevent excessive concentration from causing safety hazards or process problems.

[0095] When the concentration is within the second preset value range (0.01 to 0.1), the system outputs the mixed solution through the output pipe 14 to ensure that the hydrofluoric acid concentration of the output solution is within the expected range.

[0096] The range of 0.01 to 0.1 corresponds to the hydrofluoric acid concentration range of 1% to 10%. The concentration is selected based on the required precision of the electronic instrument. In this embodiment, the second preset value is 0.05 to 0.06.

[0097] Since hydrofluoric acid is corrosive, its corrosive effect can be effectively suppressed by lowering the temperature. Therefore, a cooling module 6 is also included, which is arranged outside the inlet pipe 16. The cooling module 6 is electrically connected to the control module 3, and the temperature of the liquid inside the inlet pipe 16 is lowered by the cooling module 6.

[0098] During the reaction, excessively high temperatures can cause the reaction to accelerate, making it difficult to control and even leading to side reactions that can affect product quality. Cooling the input pure water / mixed liquid to a low temperature before entering the reactor allows for rapid dispersion of the hydrofluoric acid liquid. This continuous cooling stabilizes its physical properties, ensuring the stability and controllability of the entire process. This allows for more precise control of reaction rates and conditions, improving product purity and yield, and enhancing the energy efficiency of the entire production system.

[0099] The heat exchanger 61 in the cooling assembly can be a double-tube plate heat exchanger. The double-tube plate heat exchanger is a common heat exchange device. Liquid flows in the inner and outer layers of the pipes and performs heat exchange through the pipe walls.

[0100] The inner tube is generally made of corrosion-resistant materials such as polytetrafluoroethylene (PTFE), high-alloy steel, etc. The heat exchange efficiency is improved by increasing the heat transfer area, such as fin design.

[0101] Spiral plate heat exchangers utilize spiral channels to improve heat exchange efficiency. They can also be made of corrosion-resistant materials as needed, making them suitable for handling corrosive liquids. The spiral structure increases fluid turbulence and promotes heat transfer.

[0102] Compact structure, saving installation space.

[0103] Shell-and-tube heat exchangers feature a shell containing multiple heat transfer tubes. Liquid flows within the tubes or within the shell, exchanging heat through the tube walls. They can handle high pressure and high temperature conditions. They are easy to replace and maintain, and can be made of a variety of corrosion-resistant materials to meet specific needs.

[0104] Plate heat exchangers, composed of multiple layers of baffles, exchange heat through fluid flow through channels between the plates, making them suitable for both efficient cooling and heating. The plate design provides a large surface area, significantly improving heat exchange efficiency. The number of plates can be adjusted to increase or decrease the heat transfer area. Their small footprint makes them suitable for applications with limited space.

[0105] In this embodiment, a spiral heat exchanger is used to cover the inlet pipe 16 to cool the pure water / mixed liquid in the pipe.

[0106] It should be noted that the device structure and drawings of the present invention mainly describe the principle of the present invention. In terms of the technology of the design principle, the settings of the device's power mechanism, power supply system, and control system are not fully described. However, those skilled in the art can clearly understand the details of its power mechanism, power supply system, and control system on the premise that they understand the principle of the above-mentioned utility model. The control method of the application document is automatic control through a controller, and the control circuit of the controller can be implemented by simple programming by those skilled in the art.

[0107] The standard parts used can be purchased from the market and can be customized according to the description in the specification and drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the existing technology. The machinery, parts and equipment all adopt conventional models in the existing technology, and the components known to technical personnel in this field, their structures and principles can be known to these technical personnel through technical manuals or through conventional experimental methods.

[0108] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A concentration preparation system for preparing electronic grade hydrofluoric acid, characterized in that: include: A mixing tank (1), a pure water inlet pipe (12), a hydrofluoric acid inlet pipe (13) arranged above the mixing tank (1), and an output pipe (14) located below the mixing tank (1); A first control valve (121) is provided in the pure water input pipe (12), and a second control valve (131) is provided in the hydrofluoric acid input pipe (13); A plurality of outlet pipes (15) are evenly arranged around the axis of the mixing tank (1), and adjacent outlet pipes (15) are arranged with height staggered positions; A concentration detection module (2) is provided in the outlet pipe (15); A control module (3), wherein the control module (3) is electrically connected to the first control valve (121), the second control valve (131), the concentration detection module (2), and the pump (5); The mixed liquid at different heights in the mixing tank (1) is extracted by the cooperation of the plurality of the outlet pipes (15) and the concentration detection module (2), and the concentration of the hydrofluoric acid liquid in the mixed liquid is detected and fed back to the control module (3); When the difference between any two detection values ​​of the plurality of concentration detection modules (2) is within a first preset value interval, the control module (3) determines the hydrofluoric acid liquid concentration of the liquid in the mixing tank (1); It also includes a judgment module (4), which cooperates with the control module (3): When the concentration of the hydrofluoric acid liquid is lower than a second preset value range, the hydrofluoric acid liquid is input through the cooperation of the control module (3) and the second control valve (131); When the concentration of the hydrofluoric acid liquid is higher than a second preset value range, pure water is input through the control module (3) in cooperation with the first control valve (121); When the concentration of the hydrofluoric acid liquid is within a second preset value range, the mixed liquid is output through the output pipe (14).

2. The concentration adjustment system for preparing electronic-grade hydrofluoric acid according to claim 1, wherein: The invention also includes an inlet pipe (16) arranged on the upper side of the mixing tank (1), and a pump (5) connecting the inlet pipe (16) and a plurality of outlet pipes (15). Through the cooperation of the pump (5) and the inlet pipe (16), the liquids in the plurality of outlet pipes (15) are collected and reintroduced into the mixing tank (1).

3. A concentration adjustment system for preparing electronic-grade hydrofluoric acid according to claim 2, characterized in that: The inlet pipe (16) is further provided with a nozzle (161) which is tilted toward the interior of the mixing tank (1), and the angle between the nozzle (161) and the ground is in the range of 60°-70°.

4. The concentration adjustment system for preparing electronic-grade hydrofluoric acid according to claim 3, wherein: The nozzle (161) has a diameter that decreases along the water flow direction, and the ratio of the nozzle (161) diameter at the water flow input end to the nozzle (161) diameter at the water flow output end is 3:

1.

5. The concentration adjustment system for preparing electronic-grade hydrofluoric acid according to claim 1, wherein: The outlet pipes (15) are provided in three groups, and the height of two adjacent outlet pipes (15) is at least 10 cm apart.

6. The concentration adjustment system for preparing electronic-grade hydrofluoric acid according to claim 5, characterized in that: One side of the outlet pipe (15) is provided with a connection hole communicating with the interior; The concentration detection module (2) comprises a detection head (21) threadedly connected to the connection hole, and a sealing ring (22) is sleeved on the outer ring of the detection head (21) toward the outside of the outlet pipe (15).

7. The concentration adjustment system for preparing electronic-grade hydrofluoric acid according to claim 1, wherein: The first preset value range is 0.001 to 0.005, and the second preset value range is 0.01 to 0.

1.

8. The concentration adjustment system for preparing electronic-grade hydrofluoric acid according to claim 2, wherein: It also includes a cooling module (6) arranged outside the inlet pipe (16), the cooling module (6) being electrically connected to the control module (3), and the temperature of the liquid inside the inlet pipe (16) being reduced by the cooling module (6).

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