Electronic-grade hydrofluoric acid production system

Abstract

The utility model discloses an electronic-grade hydrofluoric acid production system, industrial hydrofluoric acid is input into the system to obtain high-purity electronic-grade hydrofluoric acid, and the system comprises a graphite evaporator, a rectifying tower and a condenser, the graphite evaporator is provided with a feeding pipeline and a condensed water outlet, and the feeding pipeline is used for inputting industrial hydrofluoric acid into the graphite evaporator; a steam pipeline is further arranged on the graphite evaporator, the other end of the steam pipeline is connected with the rectifying tower, the steam pipeline is used for conveying gas heated by the graphite evaporator into the rectifying tower, and the rectifying tower is used for rectifying and separating hydrofluoric acid gas produced by the graphite evaporator; industrial hydrofluoric acid is added into the graphite evaporator to be heated to obtain hydrofluoric acid, then the hydrofluoric acid is fed into the rectifying tower with a certain height to be distilled, backflow is conducted in proportion, the product quality meets the requirement, and continuous production can be achieved through combination of the graphite evaporator and the rectifying tower; liquid hydrofluoric acid is used as a raw material, high risk of anhydrous hydrogen fluoride gas is avoided, and safety of the system is improved.

Description

Technical Field

[0001] This utility model belongs to the field of electronic hydrofluoric acid production technology, and specifically relates to an electronic-grade hydrofluoric acid production system. Background Technology

[0002] Electronic-grade hydrofluoric acid is a high-purity hydrofluoric acid primarily used in microelectronics, solar photovoltaics, and liquid crystal displays (LCDs). In integrated circuit manufacturing, electronic-grade hydrofluoric acid is used for cleaning and etching semiconductor surfaces. In the solar photovoltaic industry, it is mainly used for cleaning and etching silicon wafer surfaces, serving as a key material in the first process step (cleaning and texturing) from silicon ingot to wafer to solar cell. In the LCD industry, it is used for cleaning glass substrates and as an etchant for silicon nitride and silicon dioxide. Furthermore, electronic-grade hydrofluoric acid can be broadly categorized into semiconductor-grade and photovoltaic-grade hydrofluoric acid based on its downstream applications. Semiconductor-grade hydrofluoric acid is mainly used in integrated circuits, LCDs, and semiconductors, while photovoltaic-grade hydrofluoric acid is primarily used in photovoltaic solar cells.

[0003] The current method for producing electronic-grade hydrofluoric acid typically involves absorbing anhydrous hydrogen fluoride gas with pure water to obtain the desired electronic-grade product. However, anhydrous hydrogen fluoride gas is highly hazardous; transportation is dangerous and difficult; it easily reaches major hazard sources, making management challenging. Utility Model Content

[0004] The purpose of this invention is to provide an electronic-grade hydrofluoric acid production system to address the aforementioned problems. This system aims to improve the low purity of the electronic-grade hydrofluoric acid obtained in existing electronic-grade hydrofluoric acid production methods, which suffer from the high risk, transportation difficulties, high costs, and management challenges associated with anhydrous hydrogen fluoride gas.

[0005] The technical solution adopted in this utility model is as follows: an electronic-grade hydrofluoric acid production system, in which industrial hydrofluoric acid is input into the system to obtain high-purity electronic-grade hydrofluoric acid. The system includes a graphite evaporator, a distillation column, and a condenser. The graphite evaporator is provided with a feed pipe and a condensate outlet. The feed pipe is used to input industrial hydrofluoric acid into the graphite evaporator. The graphite evaporator is also provided with a steam pipe, the other end of which is connected to the distillation column. The steam pipe is used to transport the gas heated by the graphite evaporator to the distillation column. The distillation column is used to distill and separate the hydrofluoric acid gas produced by the graphite evaporator. A condenser tube is connected to the top output end of the distillation column. The other end of the condenser tube is connected to the condenser. The condenser is used to condense the hydrofluoric acid gas coming out from the top of the distillation column and adjust the reflux ratio of the condensate.

[0006] Due to the above structure, industrial hydrofluoric acid is added to a graphite evaporator and heated to produce hydrofluoric acid, which is then sent to a distillation column of a certain height for distillation and refluxed in proportion to ensure that the product quality meets the requirements. The combination of graphite evaporator and distillation column enables continuous production, and the graphite heater has low cost.

[0007] Furthermore, in order to improve the purity of the product, the system also includes a U-shaped cooler and a finished product container. The input end of the U-shaped cooler is connected to the output end of the condenser, and the output end of the U-shaped cooler is connected to the finished product container. The U-shaped cooler is provided with an exhaust gas outlet. Cooling water inlet and cooling water outlet are respectively provided at both ends of the U-shaped cooler.

[0008] Furthermore, in order to reduce environmental pollution during the production process, the finished product barrel is equipped with an exhaust gas treatment pipe, which is connected to an exhaust gas absorption tower, which is used to absorb and treat the exhaust gas.

[0009] Furthermore, in order to improve the applicability of the system and the purity of electronic-grade hydrofluoric acid, the distillation column is provided with a certain height, and the distillation column is a high-fluorine-lined distillation column.

[0010] Furthermore, in order to further improve the corrosion resistance of the distillation column and increase the purity of the product, the distillation column is equipped with packing material, which is high-purity PFA material.

[0011] Furthermore, in order to improve the automation level of the production system, the feed pipe is located on the upper side of the graphite evaporator, and the condensate outlet is located on the lower side of the graphite evaporator.

[0012] Furthermore, the condenser tube is provided with a condensation channel and a reflux channel. The condensation channel conveys the material from the distillation column to the condenser, and the reflux channel conveys the material from the condenser to the distillation column.

[0013] Furthermore, in order to monitor the production status of the production system in real time, the system is also equipped with a reflux flow meter and a finished product flow meter. The reflux flow meter is connected to the distillation column and is used to calculate the gas flow rate flowing out of the distillation column. The finished product flow meter is connected to the U-shaped cooler and the finished product tank and is used to calculate the flow rate of the finished product output by the U-shaped cooler.

[0014] Furthermore, in order to save costs and reduce raw material waste, the system is also equipped with a gas-liquid separator. The input end of the gas-liquid separator is connected to the output end of the condenser, and the output end of the gas-liquid separator is connected to the distillation column and the U-shaped cooler respectively. The gas-liquid separator is used to separate the condensed hydrofluoric acid into reflux liquid and product liquid.

[0015] Furthermore, in order to further reduce the impact of the equipment of the production system on the purity of the finished product, valves are installed on the feed pipe, steam pipe and exhaust gas treatment pipe, and the valves are lined with high-purity PFA material.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0017] 1. By adding industrial hydrofluoric acid to a graphite evaporator and heating it to produce hydrofluoric acid, which is then sent to a distillation column of a certain height for distillation and refluxed in proportion, the product quality meets the requirements. The combination of graphite evaporator and distillation column enables continuous production, and the graphite heater has low cost.

[0018] 2. Using liquid hydrofluoric acid as a raw material avoids the high risk of anhydrous hydrogen fluoride gas and improves the safety of the system.

[0019] 3. The evaporator uses a graphite heater, the distillation column packing is high-purity PFA, and the pipes and valves are lined with high-purity PFA to reduce corrosion and costs, thereby optimizing materials, reducing environmental pollution, and improving yield.

[0020] 4. Install exhaust emission devices and condensation systems to effectively control pollutant emissions and protect the environment. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall system structure of this utility model;

[0023] Figure 2 This is a schematic diagram of the connection structure between the graphite evaporator and the distillation column of this utility model;

[0024] Figure 3 This is a schematic diagram of the connection structure between the U-shaped cooler and the finished product tank of this utility model.

[0025] The markings in the diagram are: 1. Graphite evaporator; 2. Distillation column; 3. Steam pipe; 4. Condenser; 5. U-shaped cooler; 6. Finished product container; 7. Gas-liquid separator; 8. Reflux flow meter; 9. Finished product flow meter; 10. Condenser tube. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings.

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0028] like Figure 1 As shown, an electronic-grade hydrofluoric acid production system heats industrial hydrofluoric acid through a graphite evaporator 1, then feeds it into a distillation column 2 of a certain height for distillation separation to improve product purity. The hydrofluoric acid vapor exiting from the top of the distillation column 2 is condensed in a condenser 4, with a portion flowing back into the distillation column 2 to adjust the reflux ratio. After being cooled by a U-shaped cooler, it reaches the finished product container 6, finally yielding high-purity electronic-grade hydrofluoric acid.

[0029] Industrial hydrofluoric acid is heated in a graphite evaporator 1 to produce hydrofluoric acid, which is then sent to a distillation column 2 of a certain height for distillation and refluxed in proportion to ensure the product quality meets requirements. The combination of graphite evaporator 1 and distillation column 2 enables continuous production, and the graphite heater is low-cost. A tail gas emission device (not shown in the figure) and a condensation system are also installed to effectively control pollutant emissions and protect the environment.

[0030] Its raw material is liquid hydrofluoric acid. Compared with anhydrous hydrogen fluoride gas, liquid hydrofluoric acid is easier to transport and has a lower risk factor, thus improving the safety of the system to a certain extent.

[0031] Example 1

[0032] like Figure 2 As shown, in one embodiment of the present invention, the system includes a graphite evaporator 1, a distillation column 2, and a condenser 4;

[0033] The graphite evaporator 1 is equipped with a feed pipe and a condensate outlet. The feed pipe is used to input industrial hydrofluoric acid into the graphite evaporator 1; the steam condensate is output from the system through the condensate outlet. The raw material input into the feed pipe is liquid hydrofluoric acid, which can avoid the high risk of anhydrous hydrogen fluoride gas and improve the safety of the system.

[0034] The graphite evaporator 1 is also equipped with a steam pipe 3, the other end of which is connected to the distillation column 2. The steam pipe 3 is used to transport the steam heated by the graphite evaporator 1 to the distillation column 2, which is used to distill and separate the hydrofluoric acid gas produced by the graphite evaporator 1.

[0035] The top output end of the distillation column 2 is connected to a condenser tube, the other end of which is connected to a condenser 4. The condenser 4 is used to condense the hydrofluoric acid gas exiting from the top of the distillation column 2 and adjust the reflux ratio of the condensate. The distillation column 2 has a certain height and also receives liquid refluxed from the condenser 4.

[0036] The combination of graphite evaporator 1 and distillation column 2 enables continuous production of the system. Furthermore, the use of graphite as the heater reduces costs and helps control system production costs to a certain extent.

[0037] Example 2

[0038] like Figure 3 As shown, another embodiment of the present invention includes a U-shaped cooler 5 and a finished product barrel 6. The input end of the U-shaped cooler 5 is connected to the output end of the condenser 4, and the output end of the U-shaped cooler 5 is connected to the finished product barrel 6. The U-shaped cooler 5 is provided with an exhaust gas outlet. Cooling water inlet and cooling water outlet are respectively provided at both ends of the U-shaped cooler 5.

[0039] The exhaust outlet discharges the gas generated during the cooling process. If the gas is harmful, it will be further treated to prevent environmental pollution. If the gas is harmless, it will be discharged.

[0040] U-shaped cooler 5 is used to further cool the remaining tail gas or product after distillation. The steam is condensed into liquid by condenser 4 and enters U-shaped cooler 5. Cooling water is injected into U-shaped cooler 5 through cooling water inlet to cool the steam and generate finished product. Finished product enters finished product tank 6 and cooling water is discharged from U-shaped cooler 5 through cooling water outlet.

[0041] The above-mentioned apparatus generates electronic-grade hydrofluoric acid, which can improve product quality and reduce system costs.

[0042] Example 3

[0043] like Figure 3 As shown, in order to reduce the pollution rate of the system, another embodiment of this utility model is that the finished product barrel 6 is provided with a tail gas treatment pipe, which is connected to a tail gas absorption tower, and the tail gas absorption tower is used to absorb and treat the tail gas.

[0044] Electronic-grade hydrofluoric acid is highly corrosive, and its vapor is irritating; contact with skin can cause severe burns that are difficult to heal. Therefore, the production process of electronic-grade hydrofluoric acid is complex, requiring the treatment of the exhaust gases generated during production to prevent environmental pollution and harm to operators.

[0045] The treatment process of its exhaust gas absorption tower generally includes the following:

[0046] Preliminary treatment: The exhaust gas first enters the dust collector and scrubbing tower for dust removal and cooling, which helps to remove large particulate matter and some water-soluble pollutants from the exhaust gas.

[0047] Sodium hydroxide solution absorption: The pre-treated tail gas enters the sodium hydroxide absorption tower, where most of the HF is absorbed by the sodium hydroxide solution; this not only helps remove HF, but also partially absorbs other acidic gases in the tail gas.

[0048] Water scrubbing tower treatment: The tail gas absorbed by the sodium hydroxide solution will sequentially enter the first and second water scrubbing towers. In the water scrubbing towers, the tail gas will further contact with water to generate compounds such as fluorosilicic acid, thereby removing the remaining acidic gases in the tail gas.

[0049] Advanced purification: The exhaust gas treated by the water scrubbing tower may still need to be further purified by devices such as dry filters and activated carbon adsorption to ensure that the concentration of pollutants in the exhaust gas meets emission standards. Dry filters can remove fine particulate matter and residual moisture from the exhaust gas, while activated carbon adsorption can adsorb VOCs and other residual pollutants in the exhaust gas.

[0050] Emissions: If the exhaust gas treated as described above meets national and local emission standards, it can be discharged through an exhaust stack. During the emission process, it should be ensured that the height of the exhaust stack and the emission rate comply with relevant regulations to avoid adverse impacts on the surrounding environment.

[0051] Example 4

[0052] In order to improve the purity of the finished product, another embodiment of this utility model is that the distillation column 2 is a high-fluorine-lined distillation column, that is, a distillation column whose interior is lined with fluorine material. It combines the advantages of metal materials and fluorine materials (such as polytetrafluoroethylene PTFE), and has significant application value in the chemical industry.

[0053] The advantages of a high-fluorine-lined distillation column are: strong corrosion resistance; efficient separation and purification; strong adaptability; the extremely low surface energy of fluorine materials makes it difficult for materials to adhere to the column wall, thus ensuring the purity of the product; and the fluorine lining effectively isolates corrosion, resulting in lower maintenance costs.

[0054] Example 5

[0055] like Figure 1 As shown, in order to monitor the flow rate of the output substances of each component in real time, another embodiment of this utility model is that the system is also equipped with a reflux flow meter 8 and a finished product flow meter 9. The reflux flow meter 8 is connected to the distillation column 2 and is used to calculate the flow rate of the gas flowing out of the distillation column 2. The finished product flow meter 9 is connected to the U-shaped cooler 5 and the finished product tank 6 and is used to calculate the flow rate of the finished product output by the U-shaped cooler 5.

[0056] In order to adjust the flow rate of each input or output material in the production process in real time according to the actual situation, it is necessary to monitor the flow rate of each step, thereby enabling real-time control of production data.

[0057] Example 6

[0058] like Figure 2 As shown, in order to reduce the pollution rate of the system, another embodiment of this utility model is that the system is further provided with a gas-liquid separator 7. The input end of the gas-liquid separator 7 is connected to the output end of the condenser 4, and the output end of the gas-liquid separator 7 is connected to the distillation column 2 and the U-shaped cooler 5 respectively. The gas-liquid separator 7 is used to separate the condensed hydrofluoric acid into reflux liquid and product liquid. The reflux liquid enters the top of the distillation column 2, and the product liquid is sent to the finished product flow meter 9 for flow rate calculation, and then sent to the finished product tank 6 for temporary storage.

[0059] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A system for producing electronic-grade hydrofluoric acid, wherein industrial hydrofluoric acid is input into the system to obtain high-purity electronic-grade hydrofluoric acid, characterized in that, The system includes a graphite evaporator, a distillation column, and a condenser; The graphite evaporator is equipped with a feed pipe and a condensate outlet. The feed pipe is used to input industrial hydrofluoric acid into the graphite evaporator. The graphite evaporator is also equipped with a steam pipe, the other end of which is connected to a distillation column. The steam pipe is used to transport the gas heated by the graphite evaporator to the distillation column, which is used to distill and separate the hydrofluoric acid gas produced by the graphite evaporator. The top output end of the distillation column is connected to a condenser tube, and the other end of the condenser tube is connected to a condenser. The condenser is used to condense the hydrofluoric acid gas coming out from the top of the distillation column and adjust the reflux ratio of the condensate.

2. The electronic-grade hydrofluoric acid production system according to claim 1, characterized in that, The system also includes a U-shaped cooler and a finished product container. The input end of the U-shaped cooler is connected to the output end of the condenser, and the output end of the U-shaped cooler is connected to the finished product container. The U-shaped cooler is provided with an exhaust gas outlet. Cooling water inlet and cooling water outlet are respectively provided at both ends of the U-shaped cooler.

3. The electronic-grade hydrofluoric acid production system according to claim 2, characterized in that, The finished product barrel is equipped with an exhaust gas treatment pipe, which is connected to an exhaust gas absorption tower, which is used to absorb and treat the exhaust gas.

4. The electronic-grade hydrofluoric acid production system according to claim 1, characterized in that, The distillation column has a certain height and is a high-fluorine-lined distillation column.

5. The electronic-grade hydrofluoric acid production system according to claim 4, characterized in that, The distillation column is equipped with packing material, which is high-purity PFA material.

6. The electronic-grade hydrofluoric acid production system according to claim 2, characterized in that, The feed pipe is located on the upper side of the graphite evaporator, and the condensate outlet is located on the lower side of the graphite evaporator.

7. The electronic-grade hydrofluoric acid production system according to claim 1, characterized in that, The condenser tube is provided with a condensation channel and a reflux channel. The condensation channel conveys the material from the distillation column to the condenser, and the reflux channel conveys the material from the condenser to the distillation column.

8. The electronic-grade hydrofluoric acid production system according to claim 2, characterized in that, The system is also equipped with a reflux flow meter and a product flow meter. The reflux flow meter is connected to the distillation column and is used to calculate the gas flow rate flowing out of the distillation column. The product flow meter is connected to the U-shaped cooler and the product tank and is used to calculate the flow rate of the product output from the U-shaped cooler.

9. The electronic-grade hydrofluoric acid production system according to claim 2, characterized in that, The system is also equipped with a gas-liquid separator, the input end of which is connected to the output end of the condenser, and the output end of which is connected to the distillation column and the U-shaped cooler respectively; the gas-liquid separator is used to separate the condensed hydrofluoric acid into reflux liquid and product liquid.

10. The electronic-grade hydrofluoric acid production system according to claim 3, characterized in that, Valves are installed on the feed pipe, steam pipe and exhaust gas treatment pipe, and the valves are lined with high-purity PFA material.

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