Electron grade nitric acid rectification device and preparation method

Abstract

The present application relates to nitric acid production technical field, especially to a kind of electronic grade nitric acid rectification device and preparation method.The electronic grade nitric acid rectification device, from upstream to downstream, includes: liquid inlet pipeline, first heat exchanger, second heat exchanger, reflux device, rectifying kettle, first packing tower, first cooling system, second packing tower, second cooling system and liquid outlet pipeline;The bottom of the first packing tower is communicated with the top of reflux device;The lower portion of the first packing tower is communicated with the top of rectifying kettle;The top of the first packing tower is provided with reflux pipeline, and the outlet end of the reflux pipeline is respectively communicated with the top of the second heat exchanger and the middle part of reflux device;The second cooling system includes first tube heat exchanger and multiple pressure stabilizing pipelines.The electronic grade nitric acid rectification device of the present application optimizes structure, stabilizes system pressure during continuous production, thereby improves the rectification purity of nitric acid, and improves the heat recovery rate.

Description

Technical Field

[0001] This invention relates to the field of nitric acid production technology, and in particular to an electronic-grade nitric acid distillation apparatus and preparation method. Background Technology

[0002] Electronic-grade nitric acid, as an indispensable key chemical material in microelectronic precision processing, plays a vital role in many high-tech fields. It is mainly used in the cleaning and etching processes of silicon wafers and chips used in electronic-grade polysilicon, liquid crystal display devices, integrated circuits, and very large-scale integrated circuits. In the semiconductor manufacturing field, electronic-grade nitric acid can effectively remove oxides and organic impurities from the surface of silicon wafers, ensuring the cleanliness of subsequent wafer processing and playing a crucial role in improving chip yield, electrical performance, and reliability.

[0003] However, the preparation of electronic-grade nitric acid faces numerous challenges. Due to the extremely high purity requirements, the impurity content must be controlled within 10%. -9 The concentration of nitric acid at the ppb (parts per billion) level poses a severe challenge to the preparation process. Furthermore, the preparation of electronic-grade nitric acid requires distillation, a process that consumes a significant amount of energy, which contradicts current energy conservation and environmental protection principles.

[0004] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide an electronic-grade nitric acid distillation apparatus and preparation method, aiming to provide a distillation apparatus that can continuously produce electronic-grade nitric acid and reduce energy consumption in the distillation process.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of this invention provides an electronic-grade nitric acid distillation apparatus, comprising, from upstream to downstream:

[0008] Liquid inlet pipe, primary heat exchanger, secondary heat exchanger, reflux device, distillation kettle, first packed tower, primary cooling system, second packed tower, secondary cooling system and liquid outlet pipe;

[0009] A steam heating pipe is provided on the outside of the distillation vessel;

[0010] The primary heat exchanger includes a first heat exchange pipe and a second heat exchange pipe; the first heat exchange pipe is connected to the outlet of the steam heating pipe of the distillation vessel; the two ends of the second heat exchange pipe are respectively connected to the liquid inlet pipe and the secondary heat exchanger.

[0011] The secondary heat exchanger includes a first shell and a third heat exchange pipe disposed within the first shell; both ends of the third heat exchange pipe are respectively connected to a second heat exchange pipe and a reflux device; the bottom of the first shell is connected to a recovery pipe.

[0012] The top of the reflux device is connected to the bottom of the first packed tower, and its bottom is connected to the bottom of the distillation vessel;

[0013] The top of the distillation vessel is connected to the bottom of the first packed column;

[0014] The upper part of the first packed tower is connected to a reflux pipe, and the outlet end of the reflux pipe is connected to the top of the first shell and the middle part of the reflux device, respectively.

[0015] The top of the first packed tower is connected to the inlet of the primary cooling system; the outlet of the primary cooling system is connected to the top of the second packed tower; the bottom of the second packed tower is connected to the inlet of the secondary cooling system; and the outlet of the secondary cooling system is connected to the liquid outlet pipe.

[0016] The lower part of the second packed tower is connected to an air duct, which is used to remove nitrogen oxides;

[0017] The secondary cooling system includes a first shell-and-tube heat exchanger and multiple pressure-stabilizing pipes; the bottom of the multiple pressure-stabilizing pipes is connected to the top of the shell of the first shell-and-tube heat exchanger; the top of the multiple pressure-stabilizing pipes is connected to the lower part of the second packed tower; the tubes of the first shell-and-tube heat exchanger are connected to cold water pipes.

[0018] The electronic-grade nitric acid distillation apparatus, wherein the first packed column includes a pressure stabilizing pipe section, a first packing section, and an exhaust section arranged sequentially from bottom to top; the diameter of the pressure stabilizing pipe section is larger than the diameter of the packed column section; the side of the pressure stabilizing pipe section is connected to the top of the distillation vessel; and the bottom of the pressure stabilizing pipe section is connected to the reflux device.

[0019] The electronic-grade nitric acid distillation apparatus, wherein the second packed tower comprises a top pipe section, a second packed section, and a bottom pipe section arranged sequentially from top to bottom; the top of multiple pressure-stabilizing pipes is connected to the middle of the bottom pipe section; the bottom of the bottom pipe section is connected to the inlet end of the secondary cooling system; and the side of the bottom pipe section is connected to the air pipe.

[0020] In the aforementioned electronic-grade nitric acid distillation apparatus, the temperature of the second packed tower is 90–100°C.

[0021] The electronic-grade nitric acid distillation apparatus, wherein the primary cooling system includes at least one second shell-and-tube heat exchanger.

[0022] The electronic-grade nitric acid distillation apparatus, wherein the primary cooling system comprises multiple third-shell heat exchangers arranged in parallel.

[0023] In the aforementioned electronic-grade nitric acid distillation apparatus, the first packed tower and the second packed tower are arranged vertically, and the nitric acid inlet and outlet of the primary cooling system are respectively connected to the top of the first packed tower and the second packed tower.

[0024] A second aspect of the present invention provides a method for preparing electronic-grade nitric acid, which uses the electronic-grade nitric acid distillation apparatus described above to distill nitric acid.

[0025] Beneficial effects: This invention provides an electronic-grade nitric acid distillation apparatus. By installing a reflux pipe at the first packed tower, the apparatus not only heats the low-temperature nitric acid using reflux nitric acid but also balances the gas pressure in the first packed tower, ensuring that the nitric acid-containing mixed gas passes through the first packed tower at a stable rate, thus guaranteeing effective impurity removal. Furthermore, this invention also includes multiple pressure-stabilizing pipes in the secondary cooling system to ensure stable bottom pressure in the second packed tower, thereby stabilizing the air whitening effect and the impurity removal effect of the second packed tower. Attached Figure Description

[0026] Figure 1 Schematic diagram of an electronic-grade nitric acid distillation unit Figure 1 .

[0027] Figure 2 Schematic diagram of an electronic-grade nitric acid distillation unit Figure 2 .

[0028] Explanation of main component symbols: 1-Inlet pipe, 2-First-stage heat exchanger, 3-Second-stage heat exchanger, 4-Reflux device, 5-Distillation kettle, 6-First packed tower, 7-First-stage cooling system, 8-Second-stage packed tower, 9-Second-stage cooling system, 10-Outlet pipe, 11-Air pipe, 12-Steam heating pipe, 13-Pressure stabilizing pipe, 14-Reflux pipe, 21-First heat exchange pipe, 22-Second heat exchange pipe, 31-First shell, 32-Third heat exchange pipe, 61-Pressure stabilizing section, 62-First packed section, 63-Exhaust section, 81-Top pipe section, 82-Second packed section, 83-Bottom pipe section, 71-Second shell-and-tube heat exchanger, 72-Third shell-and-tube heat exchanger, 141-Vertical pipe, 142-Horizontal pipe, 811-Exhaust pipe, 15-Cold water pipe. Detailed Implementation

[0029] This invention provides an electronic-grade nitric acid distillation apparatus and preparation method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0030] In the description of this invention, it should be understood that the terms "upper," "lower," "left," and "right," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or a specific orientational structure and operation. Therefore, they should not be construed as limitations on the invention. Furthermore, "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "multiple" means two or more.

[0031] Please see Figure 1 The first aspect of the present invention provides an electronic-grade nitric acid distillation apparatus, comprising, from upstream to downstream:

[0032] Liquid inlet pipe 1, primary heat exchanger 2, secondary heat exchanger 3, reflux device 4, distillation kettle 5, first packed tower 6, primary cooling system 7, second packed tower 8, secondary cooling system 9 and liquid outlet pipe 10;

[0033] A steam heating pipe 12 is provided on the outside of the distillation vessel 5;

[0034] The primary heat exchanger 2 includes a first heat exchange pipe and a second heat exchange pipe; the first heat exchange pipe is connected to the outlet of the steam heating pipe 12 of the distillation kettle 5; the two ends of the second heat exchange pipe are respectively connected to the liquid inlet pipe and the secondary heat exchanger; the primary heat exchanger 2 is used to preheat nitric acid with the steam after distillation.

[0035] The secondary heat exchanger 3 includes a first shell 31 and a third heat exchange pipe 32 disposed within the first shell 31; the two ends of the third heat exchange pipe 32 are respectively connected to the second heat exchange pipe and the reflux device 4; the bottom of the first shell 31 is connected to the recovery pipe; the secondary heat exchanger 3 is used to preheat low-temperature nitric acid using the reflux nitric acid from the first packed tower 6.

[0036] The top of the reflux device 4 is connected to the bottom of the first packed tower 6, and its bottom is connected to the bottom of the distillation vessel 5.

[0037] The top of the distillation vessel 5 is connected to the bottom of the first packed tower 6;

[0038] The upper part of the first packed tower 6 is connected to a reflux pipe 14, and the outlet end of the reflux pipe 14 is connected to the top of the first shell 31 and the middle part of the reflux device 4 respectively.

[0039] The top of the first packed tower 6 is connected to the inlet end of the primary cooling system 7; the outlet end of the primary cooling system 7 is connected to the top of the second packed tower 8.

[0040] The bottom of the second packed tower 8 is connected to the inlet end of the secondary cooling system 9; the outlet end of the secondary cooling system 9 is connected to the liquid outlet pipe 10.

[0041] The lower part of the second packed tower 8 is connected to an air pipe 11, which is used to remove nitrogen oxides;

[0042] The secondary cooling system 9 includes a first shell-and-tube heat exchanger and multiple pressure-stabilizing pipes 13. The bottom of the multiple pressure-stabilizing pipes 13 is connected to the top of the shell of the first shell-and-tube heat exchanger; the top of the multiple pressure-stabilizing pipes 13 is connected to the lower part of the second packed tower 8; the tubes of the first shell-and-tube heat exchanger are connected to a chilled water pipe 15. The pressure-stabilizing pipes 13 are used to discharge gas from the first shell-and-tube heat exchanger.

[0043] The raw material used in this invention is industrial-grade nitric acid. After the raw nitric acid passes through the inlet pipe 1, it undergoes primary heating in the primary heat exchanger 2. The primary heat exchanger 2 uses water vapor flowing out of the distillation kettle 5 for heating, which can recover some heat and reduce waste. After preliminary preheating, the raw nitric acid enters the secondary heat exchanger 3. The top of the secondary heat exchanger 3 is connected to the return pipe 14. The high-temperature gas-liquid mixture in the return pipe 14 is used to perform secondary heating on the raw nitric acid, which can further recover heat.

[0044] The raw material nitric acid, after being further preheated by the secondary heat exchanger 3, enters the reflux device 4, and then enters the distillation kettle 5. The gas-liquid mixture formed by heating in the distillation kettle 5 enters the bottom of the first packed tower 6 through the top of the distillation kettle 5. At this time, the gas-liquid mixture moves upward along the first packed tower 6, and some of the condensed liquid moves to the reflux device 4 below, returning to the distillation kettle 5.

[0045] The top of the reflux pipe 14 is connected to the top of the first packed tower 6, and the outlet end of the lower part of the reflux pipe 14 is connected to the top of the secondary heat exchanger 3 and the middle part of the reflux device 4, respectively. This connects the top of the first packed tower 6, the secondary heat exchanger 3 and the reflux device 4, balances the pressure at the top of the first packed tower 6, and avoids excessive local pressure causing excessive flow rate fluctuations, which would lead to unstable pressure when nitric acid passes through the first packed tower 6 and affect the removal effect of metal impurities.

[0046] Specifically, the first packed column 6 is filled with glass Raschig rings. During the nitric acid purification process, when nitric acid vapor and liquid flow in the distillation column, they can fully contact the surface of the Raschig ring packing, increasing the contact area between the gas and liquid phases and providing more space for mass and heat transfer. Nitric acid vapor flows upward from the bottom of the column, while liquid (such as refluxed nitric acid liquid) flows downward from the top, forming a countercurrent contact. This countercurrent contact allows a large concentration difference to be maintained between the gas and liquid phases. According to the principle of mass transfer, the concentration difference is the driving force for mass transfer, thereby promoting the separation of volatile and non-volatile components in nitric acid. If the pressure in the system is unstable, it will disrupt the phase equilibrium between the gas and liquid phases, causing the liquid phase containing more impurities to move downstream. The reflux pipe 14 can effectively avoid the problem of excessive pressure fluctuations. If liquid phase overflows from the packed section, it can be returned to the reflux device 4 through the reflux pipe 14, preventing it from entering the downstream primary cooling system 7.

[0047] After the gas-liquid mixture leaves the first packed tower 6, it enters the primary cooling system 7 for initial cooling to bring the temperature to a suitable level for bleaching. Then, it enters the second packed tower 8 from the top, where it is bleached by the air and exits from the bottom of the second packed tower 8 into the secondary cooling system 9 for complete liquefaction.

[0048] In the above process, the multiple pressure stabilizing pipes 13 set in the secondary cooling system 9 of the present invention also play a role in stabilizing the pressure. In the continuous production process, the mixing of gas and liquid often leads to unstable pressure in the pipes. The pressure change of the upper and lower parts of the second packed tower 8 will affect the air blowing effect and the passing speed of the nitric acid gas-liquid mixture, thereby affecting the impurity removal effect of the second packed tower 8.

[0049] Specifically, multiple tubes in the first shell-and-tube heat exchanger are connected to a cold water pipe 15. Nitric acid solution flows through the shell of the first shell-and-tube heat exchanger, where it is cooled by the cold water. To ensure heat exchange efficiency, the multiple tubes in the first shell-and-tube heat exchanger are closely spaced, which easily leads to the accumulation of air bubbles, affecting heat exchange. Specifically, multiple pressure-stabilizing pipes 13 are arranged sequentially along the length of the first shell-and-tube heat exchanger. When large air bubbles accumulate in the middle or rear of the first shell-and-tube heat exchanger, they can be discharged through the pressure-stabilizing pipes 13, preventing the accumulation of air bubbles from affecting the liquid flow and cooling liquefaction effect in the first shell-and-tube heat exchanger. If air bubbles accumulate in the first shell-and-tube heat exchanger, some tubes will not be able to achieve sufficient heat exchange, thus affecting the liquefaction and discharge of nitric acid. When discharge is obstructed, the upstream pressure increases. This leads to a series of chain reactions, resulting in incomplete separation of impurities.

[0050] The electronic-grade nitric acid distillation apparatus of this invention is a continuous production device with a sealed connection in the middle. If there is a gas-liquid mixture downstream causing poor flow, it will also affect the upstream. The flow rate of the downstream second packed tower 8 is simultaneously affected by air input, upstream pressure, and downstream pressure. Therefore, only by maintaining stable pressure in all key upstream and downstream components can the impurity removal effect be ensured and the purity of nitric acid be guaranteed.

[0051] Specifically, the reflux pipe 14 includes a vertical pipe 141 and a horizontal pipe 142. The vertical pipe 141 connects the top of the first packed tower 6 and the reflux device 4, and the horizontal pipe 142 connects the middle of the vertical pipe 141 and the first shell 31. When there is liquid reflux, the liquid mainly enters the reflux device 4 along the vertical pipe 141, with a small amount entering the first shell 31. The high-temperature gas enters the first shell 31 through the horizontal pipe 142 and exchanges heat with the low-temperature nitric acid in the third heat exchange pipe 32.

[0052] Please see Figure 2 In one embodiment, the first packed tower 6 includes a pressure-stabilizing pipe section 61, a first packing section 62, and an exhaust section 63 arranged sequentially from bottom to top. The diameter of the pressure-stabilizing pipe section 61 is larger than the diameter of the packed tower section. The side of the pressure-stabilizing pipe section 61 is connected to the top of the distillation vessel 5. The bottom of the pressure-stabilizing pipe section 61 is connected to the reflux device 4. The pressure-stabilizing pipe section 61 connects the distillation vessel 5 and the reflux device 4 below. The larger diameter of the pressure-stabilizing pipe section 61 acts as a buffer, preventing the impurity removal effect of the first packing section 62 from being affected by excessive pressure of the gas-liquid mixture from the distillation vessel 5. Combined with the function of the reflux pipe 14, the pressure stabilization effect in the region of the first packed tower 6 can be further improved.

[0053] Please see Figure 2 In one embodiment, the second packed tower 8 includes a top pipe section 81, a second packed section 82, and a bottom pipe section 83 arranged sequentially from top to bottom; the top of multiple pressure stabilizing pipes 13 is connected to the middle of the bottom pipe section 83; the bottom of the bottom pipe section 83 is connected to the inlet end of the secondary cooling system 9; and the side of the bottom pipe section 83 is connected to the air pipe 11.

[0054] Preferably, the temperature of the second packed tower 8 is 90–100°C. Within this temperature range, it is more conducive to the separation of nitrogen oxides from the nitric acid solution. According to the gas-liquid mass transfer theory, when purified air is introduced into the nitric acid solution containing nitrogen oxides, the gas and liquid phases come into full contact. Since the partial pressure of nitrogen oxides in the gas phase is lower than the equilibrium partial pressure of nitrogen oxides in the nitric acid solution, the nitrogen oxides in the nitric acid solution diffuse into the gas phase in the second packed tower 8, thereby achieving the separation purpose. Specifically, the second packed section 82 is also filled with glass Raschig rings, and during the air blowing process, heat exchange can also be carried out on the nitric acid solution through the air, reducing the requirements on the secondary cooling system 9.

[0055] Specifically, an exhaust pipe 811 is provided in the middle of the top pipe section 81 of the second packed tower 8, and an air outlet is provided on the exhaust pipe 811. The nitric acid solution cooled by the primary cooling system 7 flows downward along the tower wall, while air and nitrogen oxides flow upward from the second packed section 82 and are discharged from the exhaust pipe 811 of the top pipe section 81.

[0056] Please see Figure 1 In one embodiment, the primary cooling system 7 includes at least one second shell-and-tube heat exchanger 71.

[0057] Please see Figure 2 In a preferred embodiment, the primary cooling system 7 includes multiple third-shell tube heat exchangers 72 arranged in parallel. The tubes of a shell-and-tube heat exchanger are closely spaced, making them prone to gas accumulation and unstable flow rates. This embodiment, however, by arranging multiple third-shell tube heat exchangers 72 in parallel, allows for multiple downstream pathways, maintaining relatively stable overall pressure. Furthermore, arranging multiple third-shell tube heat exchangers 72 in parallel allows for the installation of more heat exchangers within a limited length space, meeting cooling requirements.

[0058] Please see Figure 1 Specifically, the first packed tower 6 and the second packed tower 8 are arranged vertically, and the nitric acid inlet and outlet of the primary cooling system 7 are respectively connected to the top of the first packed tower 6 and the second packed tower 8.

[0059] The second aspect of the present invention provides a method for preparing electronic-grade nitric acid, which uses the electronic-grade nitric acid distillation apparatus described above to distill nitric acid, and finally obtains nitric acid with impurities at the level of only 10 ppb, achieving electronic-grade purity.

[0060] In summary, the electronic-grade nitric acid distillation apparatus of the present invention optimizes the upstream, midstream, and downstream structures, ensuring stable pressure in key impurity removal structures within the distillation apparatus at different stages, and preventing a decrease in the impurity removal efficiency of the first packed tower 6 and the second packed tower 8 due to excessive pressure fluctuations.

[0061] Example

[0062] A method for preparing electronic-grade nitric acid, comprising distilling nitric acid using an electronic-grade nitric acid distillation apparatus as described below;

[0063] The electronic-grade nitric acid distillation unit comprises, from upstream to downstream:

[0064] The system comprises an inlet pipe 1, a primary heat exchanger 2, a secondary heat exchanger 3, a reflux device 4, a distillation kettle 5, a first packed tower 6, a primary cooling system 7, a second packed tower 8, a secondary cooling system 9, and an outlet pipe 10. The bottom of the first packed tower 6 is connected to the top of the reflux device 4. The lower part of the first packed tower 6 is connected to the top of the distillation kettle 5. A steam heating pipe 12 is installed on the outside of the distillation kettle 5. The primary heat exchanger 2 is used to preheat nitric acid using the steam from distillation. A reflux pipe 14 is installed at the top of the first packed tower 6. The outlet end of pipe 14 is connected to the top of the secondary heat exchanger 3 and the middle of the reflux device 4, respectively; the secondary heat exchanger 3 is used to preheat low-temperature nitric acid using the reflux nitric acid from the first packed tower 6; the lower part of the second packed tower 8 is connected to an air pipe 11, which is used to remove nitrogen oxides; the secondary cooling system 9 includes a first shell-and-tube heat exchanger and multiple pressure-stabilizing pipes 13; the multiple pressure-stabilizing pipes 13 are connected to the top of the shell of the first shell-and-tube heat exchanger; the top of the multiple pressure-stabilizing pipes 13 are connected to the lower part of the second packed tower 8;

[0065] The primary heat exchanger 2 includes a first heat exchange pipe 21 and a second heat exchange pipe 22; the first heat exchange pipe 21 is connected to the outlet of the steam heating pipe 12 of the distillation vessel 5; the two ends of the second heat exchange pipe 22 are respectively connected to the liquid inlet pipe 1 and the secondary heat exchanger 3.

[0066] The secondary heat exchanger 3 includes a first housing 31 and a third heat exchange pipe 32 disposed within the first housing 31; the two ends of the third heat exchange pipe 32 are respectively connected to the second heat exchange pipe 22 and the reflux device 4; the top of the first housing 31 is connected to the reflux pipe 14, and its bottom is connected to the recovery pipe.

[0067] The first packed tower 6 includes a pressure stabilizing pipe section 61, a first packing section 62, and an exhaust section 63 arranged sequentially from bottom to top; the diameter of the pressure stabilizing pipe section 61 is larger than the diameter of the packed tower section; the side of the pressure stabilizing pipe section 61 is connected to the top of the distillation kettle 5; the bottom of the pressure stabilizing pipe section 61 is connected to the reflux device 4.

[0068] The second packed tower 8 includes a top pipe section 81, a second packed section 82, and a bottom pipe section 83 arranged sequentially from top to bottom; the top of multiple pressure stabilizing pipes 13 is connected to the middle of the bottom pipe section 83; the bottom of the bottom pipe section 83 is connected to the inlet end of the secondary cooling system 9; and the side of the bottom pipe section 83 is connected to the air pipe 11.

[0069] The primary cooling system 7 consists of three parallel-connected third-shell tube heat exchangers 72;

[0070] During continuous preparation, the temperature of the distillation vessel is controlled at 100–120°C;

[0071] The temperature of the mobile phase inside the second packed tower 8 is controlled to be 90-100℃.

[0072] Table 1 shows the test results of electronic-grade nitric acid obtained by the electronic-grade nitric acid distillation apparatus in Example 1. As can be seen from the results in Table 1, all indicators of the obtained electronic-grade nitric acid meet the product requirements.

[0073] Table 1

[0074]

[0075] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. An apparatus for distilling electronic grade nitric acid, characterized by comprising: From upstream to downstream, it comprises: a liquid inlet pipeline, a first heat exchanger, a second heat exchanger, a reflux device, a rectifying kettle, a first packed tower, a first cooling system, a second packed tower, a second cooling system and a liquid outlet pipeline; a water vapor heating pipeline is arranged outside the rectifying kettle; the first heat exchanger comprises a first heat exchange pipeline and a second heat exchange pipeline; the first heat exchange pipeline is communicated with the water vapor heating pipeline outlet of the rectifying kettle; the two ends of the second heat exchange pipeline are respectively communicated with the liquid inlet pipeline and the second heat exchanger; the second heat exchanger comprises a first shell and a third heat exchange pipeline arranged in the first shell; the two ends of the third heat exchange pipeline are respectively communicated with the second heat exchange pipeline and the reflux device; the bottom of the first shell is communicated with a recovery pipeline; the top of the reflux device is communicated with the bottom of the first packed tower, and the bottom of the reflux device is communicated with the bottom of the rectifying kettle; the top of the rectifying kettle is communicated with the lower part of the first packed tower; the upper part of the first packed tower is communicated with a reflux pipeline; the outlet end of the reflux pipeline is respectively communicated with the top of the first shell and the middle part of the reflux device; the top of the first packed tower is communicated with the inlet end of the first cooling system; the outlet end of the first cooling system is communicated with the top of the second packed tower; the bottom of the second packed tower is communicated with the inlet end of the second cooling system; the outlet end of the second cooling system is communicated with the liquid outlet pipeline; an air pipeline is arranged in the lower part of the second packed tower; the air pipeline is used to provide purified air to the second packed tower; when the purified air is introduced into the nitric acid solution containing nitrogen oxides, the gas-liquid phases are fully contacted; since the partial pressure of nitrogen oxides in the gas phase is lower than the equilibrium partial pressure of nitrogen oxides in the nitric acid solution, the nitrogen oxides in the nitric acid solution will diffuse to the gas phase to remove the nitrogen oxides; the second cooling system comprises a first shell-and-tube heat exchanger and a plurality of pressure stabilizing pipelines; the bottom of the plurality of pressure stabilizing pipelines is communicated with the top of the shell of the first shell-and-tube heat exchanger; the top of the plurality of pressure stabilizing pipelines is communicated with the lower part of the second packed tower; the tubes of the first shell-and-tube heat exchanger are communicated with a cold water pipeline.

2. The electronic grade nitric acid rectification apparatus according to claim 1, wherein The first packed tower comprises a pressure stabilizing pipeline segment, a first packed tower segment and an exhaust segment arranged in sequence from bottom to top; the pipe diameter of the pressure stabilizing pipeline segment is greater than the pipe diameter of the packed tower segment; the side of the pressure stabilizing pipeline segment is communicated with the top of the rectifying kettle; the bottom of the pressure stabilizing pipeline segment is communicated with the reflux device.

3. The electronic grade nitric acid rectification apparatus according to claim 1, wherein The second packed tower comprises a top pipeline segment, a second packed tower segment and a bottom pipeline segment arranged in sequence from top to bottom; the top of the plurality of pressure stabilizing pipelines is communicated with the middle part of the bottom pipeline segment; the bottom of the bottom pipeline segment is communicated with the inlet end of the second cooling system; the side of the bottom pipeline segment is communicated with the air pipeline.

4. The electronic grade nitric acid rectification apparatus according to claim 3, wherein The temperature of the second packed tower is 90-100℃.

5. The electronic grade nitric acid rectification apparatus according to claim 1, wherein The first cooling system comprises at least one second shell-and-tube heat exchanger.

6. The electronic grade nitric acid rectification apparatus according to claim 1, wherein The first cooling system comprises a plurality of third shell-and-tube heat exchangers arranged in parallel.

7. A process for the production of electronic grade nitric acid, characterized in that, The electronic grade nitric acid rectification device is used for rectifying nitric acid.

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