Nitrogen oxide quantitative conveying device

Abstract

The invention relates to the technical field of nitrogen oxide treatment, and provides a nitrogen oxide quantitative conveying device which comprises a quantitative unit and an input unit, the quantitative unit comprises a first container, a mixing container, a first pipeline and a first pressure adjusting assembly, and the first container is used for containing liquid nitrogen tetroxide; the first pipeline is communicated with the first container and the mixing container; the first pressure regulating assembly is arranged on the first pipeline; the input unit comprises a second container, a second pipeline and a second pressure adjusting assembly, the second container is used for containing driving gas, the second pipeline is communicated with the second container and the first container, and the second pressure adjusting assembly is arranged on the second pipeline. The second pressure regulating assembly maintains the constant input pressure of the driving gas, the first pressure regulating assembly maintains the constant output pressure of the liquid nitrogen tetroxide, the first pressure regulating assembly and the second pressure regulating assembly jointly maintain the constant flow of the liquid nitrogen tetroxide, and quantitative output is achieved in combination with the conveying time of the liquid nitrogen tetroxide.

Description

Technical Field

[0001] This application relates to the field of nitrogen oxide treatment technology, and in particular to a nitrogen oxide quantitative delivery device. Background Technology

[0002] In spent fuel reprocessing, it is necessary to destroy the reducing agent contained in the fuel feed and to oxidize and adjust the valence state of the metals contained therein. The destruction of the reducing agent and the oxidation and adjustment of the metal valence state are redox chemical reactions, involving quantitative issues. It is necessary to control the amount of oxidant added to avoid insufficient oxidant, incomplete destruction of the reducing agent, and insufficient metal oxidation. Currently, the engineering application of nitrogen oxides as oxidants in reprocessing plants is not yet widespread. There is a need for a system capable of quantitatively delivering nitrogen oxides, which has a promising market application for the oxidation and valence adjustment of fuel feed using nitrogen oxides in reprocessing plants. Summary of the Invention

[0003] This application provides a nitrogen oxide quantitative delivery device. A second pressure regulating component maintains a constant input pressure of the driving gas, and a first pressure regulating component maintains a constant output pressure of liquid nitrogen tetroxide. Together, they maintain a constant flow rate of liquid nitrogen tetroxide. Combined with the delivery time of liquid nitrogen tetroxide, quantitative output is achieved.

[0004] The technical solution of this application embodiment is implemented as follows: This application provides a nitrogen oxide quantitative delivery device, the nitrogen oxide quantitative delivery device comprising: The quantitative unit includes a first container, a mixing container, a first pipeline, and a first pressure regulating component. The first container is used to hold liquid nitrogen tetroxide, the first pipeline connects the first container and the mixing container, and the first pressure regulating component is disposed on the first pipeline. The input unit includes a second container, a second pipeline, and a second pressure regulating component. The second container is used to hold driving gas, the second pipeline connects the second container and the first container, and the second pressure regulating component is disposed on the second pipeline.

[0005] In some embodiments, the nitrogen oxide metering device includes a weighing mechanism for obtaining the total mass of the first container and the liquid nitrogen tetroxide inside; and / or, The nitrogen oxide quantitative delivery device includes a mass flow meter, which is installed in the first pipeline and is used to obtain the mass flow rate of dinitrogen tetroxide flowing in the first pipeline.

[0006] In some embodiments, the first voltage regulating component includes: A first pressure regulating valve is provided in the first pipeline and located between the first container and the mixing container; A first one-way valve is disposed in the first pipeline and located between the first pressure regulating valve and the mixing container. The first one-way valve is used to restrict the unidirectional flow of nitrogen tetroxide into the mixing container.

[0007] In some embodiments, the second voltage regulating component includes: A second pressure regulating valve is installed in the second pipeline and located between the second container and the first container; A second check valve is provided in the second pipeline and located between the second pressure regulating valve and the first container. The second check valve is used to restrict the unidirectional flow of the driving gas in the second pipeline to the first container.

[0008] In some embodiments, the first conduit includes a connecting pipe, the lower port of which is disposed inside the first container and located at the bottom of the first container, and the upper port of which is disposed outside the first container.

[0009] In some embodiments, the nitrogen oxide metering device includes a first switching valve disposed in the first pipeline and located between the first pressure regulating assembly and the first container; and / or, The nitrogen oxide metering device includes a second switching valve, which is disposed in the second pipeline and located between the second pressure regulating component and the first container.

[0010] In some embodiments, the nitrogen oxide metering device includes: A liquid supply unit is connected to the first container, and the liquid supply unit is used to inject the liquid nitrogen tetroxide into the first container.

[0011] In some embodiments, the nitrogen oxide metering device includes: A gas supply unit is connected to the second container, and the gas supply unit is used to inject the driving gas into the second container.

[0012] In some embodiments, the metering unit includes a heating element disposed in the mixing container.

[0013] In some embodiments, the nitrogen oxide metering device includes: A carrier gas unit is connected to the mixing container and is used to input carrier gas into the mixing container.

[0014] The basic principle of the nitrogen oxide quantitative conveying device of this application for quantitative conveying is roughly as follows: the driving gas in the second container, after being stabilized by the second pressure regulating component, enters the first container through the second pipeline. The pressure of the driving gas acts on the surface of the liquid nitrogen tetroxide in the first container, forming the driving force to propel the flow of liquid nitrogen tetroxide. The pressure difference between the input pressure and the output pressure of the first container is kept constant by the first pressure regulating component and the second pressure regulating component. Because the pressure difference is constant, the output flow rate of liquid nitrogen tetroxide to the mixing container through the first pipeline is constant. By controlling the conveying time, the target output mass of liquid nitrogen tetroxide can be calculated and obtained, thus achieving quantitative output. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a nitrogen oxide quantitative delivery device provided in some embodiments of this application; Figure 2 This is a schematic diagram of a partial structure of a nitrogen oxide quantitative delivery device provided in some embodiments of this application.

[0016] Explanation of reference numerals in the attached figures 1. Quantitative unit; 11. First container; 111. Discharge pipe; 12. Mixing container; 12a. Carrier gas inlet; 12b. Mixed gas outlet; 121. Drain pipe; 13. First pipeline; 131. Connecting pipe; 132. Inlet pipe; 133. First node; 14. First pressure regulating assembly; 141. First pressure regulating valve; 142. First check valve; 15. Heating element; 16. Base; 2. Input unit; 21. Second container; 22. Second pipeline; 23. Second pressure regulator Components; 231, Second pressure regulating valve; 232, Second check valve; 3, Weighing mechanism; 4, Mass flow meter; 5, First switching valve; 6, Second switching valve; 7, Liquid supply unit; 8, Gas supply unit; 9, Carrier gas unit; 91, Compressed air pump; 92, Carrier gas pipeline; 10, Oxidation column; 20, Nozzle; 30, Oxidation pipeline; 40, Online analysis device; 50, Gas replenishment unit; 51, Gas replenishment pipeline; 52, Third pressure regulating valve; 53, Gas flow meter; 54, Third check valve. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, embodiments of the technical solutions of this application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of this application more clearly, and are therefore merely examples and should not be used to limit the scope of protection of this application.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0019] In the description of the embodiments of this application, the technical terms "first", "second", etc. are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0020] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that combinations can be made in any suitable manner without contradiction; for example, different combinations of specific technical features / embodiments can form different implementations. To avoid unnecessary repetition, the various possible combinations of specific technical features / embodiments in this application will not be described separately.

[0021] It should be noted that in this application, "multiple" includes two or more.

[0022] Please see Figure 1 and Figure 2 This application provides a nitrogen oxide quantitative delivery device, which includes a quantitative unit 1 and an input unit 2. The quantitative unit 1 includes a first container 11, a mixing container 12, a first pipeline 13, and a first pressure regulating component 14. The first container 11 is used to hold liquid nitrogen tetroxide, the first pipeline 13 connects the first container 11 and the mixing container 12, and the first pressure regulating component 14 is disposed in the first pipeline 13. The input unit 2 includes a second container 21, a second pipeline 22, and a second pressure regulating component 23. The second container 21 is used to hold driving gas, the second pipeline 22 connects the second container 21 and the first container 11, and the second pressure regulating component 23 is disposed in the second pipeline 22.

[0023] Nitrogen oxides (NOx) at room temperature X Nitrogen tetroxide is primarily a mixture of liquid and gaseous nitrogen dioxide. In other words, it is a nitrogen oxide, existing as an equilibrium mixture. Its composition depends on temperature and pressure. Nitrogen tetroxide has a boiling point of 21.15°C and a density (at 20°C) of 1.446 g / cm³. 3 (grams per cubic centimeter). Nitrogen tetroxide and nitrogen dioxide are strong oxidizing agents and undergo violent redox reactions when in contact with reducing agents such as amines and hydrazines. Therefore, it is necessary to control the stoichiometry of nitrogen oxides.

[0024] The second pressure regulating component 23 is used to regulate the input pressure of the driving gas, providing a stable power source for the flow of liquid nitrogen tetroxide in the first container 11. The first pressure regulating component 14 is used to regulate the output pressure of the liquid nitrogen tetroxide. The second pressure regulating component 23 works in conjunction with the first pressure regulating component 14 to regulate the pressure difference between the input and output pressures, so that the pressure in the second container 21 is maintained above a preset range higher than that in the first container 11, and the pressure in the first container 11 is maintained above a preset range higher than that in the mixing container 12. In other words, the pressure in the second container 21 is greater than the pressure in the first container 11, and the pressure in the first container 11 is greater than the pressure in the mixing container 12.

[0025] The basic principle of the nitrogen oxide quantitative conveying device of this application for quantitative conveying is roughly as follows: the driving gas in the second container 21, after being stabilized by the second pressure regulating component 23, enters the first container 11 through the second pipeline 22. The pressure of the driving gas acts on the surface of the liquid nitrogen tetroxide in the first container 11, forming the driving force to propel the flow of liquid nitrogen tetroxide. The pressure difference between the input pressure and the output pressure of the first container 11 is kept constant by the first pressure regulating component 14 and the second pressure regulating component 23. Because the pressure difference is constant, the output flow rate of liquid nitrogen tetroxide to the mixing container 12 through the first pipeline 13 is constant. By controlling the conveying time, the target output mass of liquid nitrogen tetroxide can be calculated and obtained, thus achieving quantitative output.

[0026] The pressure difference in the first container 11 affects the output flow rate of liquid nitrogen tetroxide (N2O4), that is, the volume of liquid nitrogen tetroxide flowing through the first pipeline 13 per unit time. The greater the pressure difference in the first container 11, the stronger the driving force for the flow of liquid nitrogen tetroxide, and the greater the output flow rate; conversely, the smaller the pressure difference, the weaker the driving force, and the smaller the output flow rate. The first pressure regulating component 14 and the second pressure regulating component 23 can adjust the flow rate of liquid nitrogen tetroxide by adjusting the pressure difference.

[0027] The driving gas does not react with nitrogen tetroxide. The driving gas includes, but is not limited to, nitrogen or inert gases.

[0028] The pressure in the mixing container 12 is lower than that in the first container 11. After the liquid nitrogen tetroxide enters the mixing container 12, it exists mainly as a balanced gas mixture of nitrogen tetroxide and nitrogen dioxide (NO2) due to the reversible equilibrium between nitrogen tetroxide and nitrogen dioxide. In other words, there are multiple forms of nitrogen oxides in the mixing container 12.

[0029] In some embodiments, the nitrogen tetroxide in the first container 11 is kept in a liquid state, which can be achieved by controlling the temperature and pressure inside the first container 11.

[0030] For example, the temperature inside the first container 11 is lower than the saturation temperature (vaporization temperature) of nitrogen tetroxide at the corresponding pressure, but higher than its freezing point (approximately -11.2°C). The vaporization temperature of nitrogen tetroxide increases with increasing pressure; for example, its vaporization temperature at 0.1 MPa is approximately 21.15°C. If the pressure inside the first container 11 rises to 0.3 MPa, the corresponding vaporization temperature will also increase. In this case, the temperature of the first container 11 needs to be controlled below the vaporization temperature corresponding to that pressure to prevent the vaporization of liquid nitrogen tetroxide. The pressure inside the first container 11 must be higher than the saturated vapor pressure of nitrogen tetroxide at the corresponding temperature. At a given temperature, the saturated vapor pressure is the minimum pressure required for liquid nitrogen tetroxide to remain in the liquid phase. A pressure higher than this value can suppress the vaporization process of liquid nitrogen tetroxide. The driving gas input pressure can be adjusted by the second pressure regulating component 23 to keep the pressure inside the first container 11 stably above the saturated vapor pressure.

[0031] The nitrogen oxide quantitative delivery device provided in this application embodiment includes a second pressure regulating component 23 for adjusting the input pressure of the driving gas, providing a stable power foundation for the flow of liquid nitrogen tetroxide in the first container 11. A first pressure regulating component 14 is used to adjust the output pressure of the liquid nitrogen tetroxide. The second pressure regulating component 23 cooperates with the first pressure regulating component 14 to adjust the pressure difference between the input and output pressures, maintaining the pressure in the second container 21 at a preset range higher than that in the first container 11, and maintaining the pressure in the first container 11 at a preset range higher than that in the mixing container 12. The driving gas in the second container 21 is sent into the first container 11 through the second pipeline 22, applying a compressive force to the liquid nitrogen tetroxide. Under the action of the pressure difference, the liquid nitrogen tetroxide flows to the mixing container 12 through the first pipeline 13. The second pressure regulating component 23 maintains a constant input pressure of the driving gas, and the first pressure regulating component 14 maintains a constant output pressure of the liquid nitrogen tetroxide. Both components together maintain a constant flow rate of the liquid nitrogen tetroxide. Combined with the delivery time of the liquid nitrogen tetroxide, quantitative output is achieved.

[0032] In some embodiments, the nitrogen oxide metering device includes a cooling element that can be disposed in the first container 11 for regulating the temperature of the first container 11. Exemplarily, the cooling element can be disposed within the first container 11. Exemplarily, the cooling element can have a generally layered structure and can cover the outer surface of the first container 11. The cooling element can lower the temperature inside the first container 11, thereby maintaining the nitrogen tetroxide in the first container 11 in a liquid state.

[0033] The nitrogen oxide metering device provided in this application embodiment can be used to use nitrogen oxides in the mixing container 12 for the oxidation treatment of liquid F.

[0034] In some embodiments, the nitrogen oxide metering device can deliver nitrogen oxides to the oxidation column 10, and the F liquid enters the oxidation column 10. The nitrogen oxides and the F liquid undergo an oxidation-reduction reaction in the oxidation column 10, destroying the reducing agent in the F liquid and oxidizing the metal ions in the F liquid.

[0035] F-feed solution typically refers to an aqueous waste liquid rich in fission products, but from which uranium and plutonium have been extracted into the organic phase after the extraction process. F-feed solution contains reducing agents such as hydroxylamine and hydrazine, as well as metal ions.

[0036] F feedstock can include 2AF feedstock and OF feedstock in the nuclear fuel reprocessing process. 2AF feedstock is the plutonium purification recycling feedstock in the Purex process. OF feedstock is the feedstock (OF) before plutonium precipitation in the Purex process. For example, in the Purex process, the plutonium crude product feedstock (1BP feedstock) is converted to the plutonium purification recycling feedstock (2AF feedstock), and the plutonium product feedstock (2BP feedstock) is converted to the feedstock (OF feedstock) before plutonium precipitation.

[0037] In related technologies, during the extraction and purification stage of spent fuel reprocessing metal-containing feed solutions, sodium nitrite is used as an oxidant to destroy reducing agents such as hydroxylamine and hydrazine in the F feed solution, thereby oxidizing and adjusting the valence of metal ions in the F feed solution. The sodium salt ultimately enters the intermediate-term waste liquid, causing the intermediate-term waste liquid to have excessively high salt content, thus reducing its evaporation and concentration ratio.

[0038] This application uses nitrogen oxides as a salt-free reagent to oxidize and adjust the value of feed liquid F, avoiding the influence of sodium salt on the evaporation and denitrification of the intermediate-level waste liquid. This can increase the evaporation and concentration ratio of the intermediate-level waste liquid, implement the principle of minimizing waste as much as possible, and thus avoid affecting the overall operating capacity of the reprocessing plant.

[0039] In some embodiments, during the salt-free valence adjustment process of the F-feed solution, the amount of nitrogen oxides added is controlled to ensure an excess of 1.1 to 1.3 times. This can essentially completely destroy the reducing agents such as hydrazine and hydroxylamine contained in the F-feed solution, and also adjust the metals in the F-feed solution to a suitable valence state to meet the requirements of the next processing step for the metal valence state.

[0040] In some embodiments, please refer to Figure 1 The nitrogen oxide quantitative delivery device includes a weighing mechanism 3, which is used to obtain the total mass of the first container 11 and the liquid dinitrogen tetroxide inside.

[0041] The total mass of the first container 11 and the liquid nitrogen tetroxide inside refers to the sum of the mass of the first container 11 and the mass of the liquid nitrogen tetroxide inside.

[0042] The weighing mechanism 3 acquires the total mass of the first container 11 and the internal liquid nitrogen tetroxide in real time or periodically, and the output mass of nitrogen tetroxide can be obtained by the mass difference. For example, before the conveying begins, the initial total mass M1 of the first container 11 and the internal liquid nitrogen tetroxide is recorded; during or after the conveying process, the real-time total mass M2 of the first container 11 and the internal liquid nitrogen tetroxide is recorded; the mass difference M1-M2 is the actual output mass of nitrogen tetroxide. By comparing this actual output mass with a preset target output mass, the output mass of nitrogen tetroxide can be verified.

[0043] In this embodiment, the weighing mechanism 3 is unaffected by pressure fluctuations and can accurately reflect the actual output quality; at the same time, it can provide timely warnings of abnormalities such as pipeline leakage and delivery stagnation by measuring the rate of change of the quality difference; and it can also be adapted to output quality verification under various working conditions such as intermittent and continuous operation.

[0044] In some embodiments, please refer to Figure 1 The nitrogen oxide quantitative delivery device includes a mass flow meter 4, which is installed in the first pipeline 13 and is used to obtain the mass flow rate of dinitrogen tetroxide flowing in the first pipeline 13.

[0045] The mass flow meter 4 can achieve real-time dynamic verification of the output quality of nitrogen tetroxide by directly measuring the mass flow rate of nitrogen tetroxide flowing through the first pipeline 13 per unit time. For example, the mass flow meter 4 outputs a real-time mass flow rate signal. By integrating the real-time mass flow rate over time, the actual output quality of nitrogen tetroxide within any time period can be obtained. By comparing this with the preset target output quality, the output quality of nitrogen tetroxide can be verified.

[0046] The unit of the mass flow meter 4 can be kg / s (kilograms per second) or g / min (grams per minute), etc., and this application does not limit it.

[0047] In this embodiment, the mass flow meter 4 can quickly capture instantaneous flow fluctuations and provide data support for real-time system control, thereby avoiding the accumulation of deviations to a certain extent; it can reflect the delivery status in the first pipeline 13 to assist in fault location and reduce maintenance costs, while continuously outputting data to form a complete chain, providing a basis for subsequent accuracy traceability and system optimization.

[0048] In some embodiments, the nitrogen oxide metering device may employ a weighing mechanism 3 or a mass flow meter 4. The weighing mechanism 3 or the mass flow meter 4 is used to verify whether the actual output mass meets the preset target output mass.

[0049] In some embodiments, the nitrogen oxide quantitative delivery device can employ a weighing mechanism 3 and a mass flow meter 4. This design allows the real-time data from the mass flow meter 4 to dynamically correct minor deviations during the delivery process, while the total mass of the weighing mechanism 3 can perform final calibration of the cumulative integral result of the mass flow meter 4, correcting any potential systematic errors and improving overall verification accuracy. Cross-comparison of the two data points, such as ensuring the mass difference of the weighing mechanism 3 is essentially consistent with the cumulative integral value of the mass flow meter 4, further enhances the accuracy of anomaly identification, effectively distinguishing between deviations caused by pipeline leaks, equipment malfunctions, or measurement errors, providing dual assurance for stable operation.

[0050] In some embodiments, the first container 11 may be placed on top of the weighing mechanism 3.

[0051] The type of weighing mechanism 3 is not limited; for example, the weighing mechanism 3 can be an electronic scale.

[0052] For example, the weighing range of the electronic scale can be from 0 kg to 500 kg; the accuracy can be 20 g.

[0053] The mass flow meter 4 can be designed to resist nitrogen tetroxide corrosion, and the mass flow rate can be from 0 g / min to 50 g / min; the accuracy can be one-thousandth, for example, an accuracy of 0.1% to 0.2%.

[0054] In some embodiments, please refer to Figure 1 The first pressure regulating component 14 includes a first pressure regulating valve 141 and a first one-way valve 142. The first pressure regulating valve 141 is disposed in the first pipeline 13 and located between the first container 11 and the mixing container 12. The first one-way valve 142 is disposed in the first pipeline 13 and located between the first pressure regulating valve 141 and the mixing container 12. The first one-way valve 142 is used to restrict the unidirectional flow of nitrogen tetroxide into the mixing container 12.

[0055] The first pressure regulating valve 141 is used to regulate the delivery pressure of nitrogen tetroxide in the first pipeline 13, with the goal of stabilizing the pressure of liquid nitrogen tetroxide before it enters the mixing container 12 within a preset range. For example, the output pressure can be stabilized within a preset range suitable for the feed into the mixing container 12 by changing the valve opening of the first pressure regulating valve 141; simultaneously, the change in valve opening can synchronously change the fluid flow cross-sectional area, thereby regulating the flow rate of nitrogen tetroxide per unit time.

[0056] The delivery pressure of the first pipeline 13 can be smoothly adjusted by the first pressure regulating valve 141 to avoid negative pressure or sudden pressure drop in the first pipeline 13 due to sudden changes in valve opening, and to prevent the driving gas above the liquid surface in the first container 11 from being sucked back into the first pipeline 13.

[0057] The first one-way valve 142 is used to restrict the one-way flow of nitrogen tetroxide, allowing nitrogen tetroxide to flow only from the first container 11 to the mixing container 12, which can effectively block the backflow of fluid in the mixing container 12 to the first pressure regulating valve 141 and the first container 11.

[0058] The type of the first pressure regulating valve 141 is not limited. For example, the first pressure regulating valve 141 can be a pressure reducing valve. The pressure reducing valve has an internal pressure sensing element (such as a diaphragm or piston) and an adjusting spring, with a preset, suitable outlet pressure threshold. When fluctuations in inlet pressure or flow rate cause the outlet pressure to exceed the threshold, the fluid pressure pushes the sensing element to compress the adjusting spring, causing the valve orifice to close slightly, enhancing the throttling effect and reducing the outlet pressure. When the outlet pressure is below the threshold, the adjusting spring force pushes the valve orifice to open wider, weakening the throttling effect and increasing the outlet pressure. Through this cycle of pressure feedback and adaptive valve orifice adjustment, the outlet pressure is continuously stabilized within the preset range.

[0059] The type of the first check valve 142 is not limited. For example, the first check valve 142 can be a spring-loaded check valve, which relies on the cooperation between the valve core and the return spring to achieve opening and closing. For example, the first check valve 142 can be a ball valve, which achieves rapid opening and closing through the rolling of the ball.

[0060] In some embodiments, please refer to Figure 1 The second pressure regulating component 23 includes a second pressure regulating valve 231 and a second one-way valve 232. The second pressure regulating valve 231 is disposed in the second pipeline 22 and located between the second container 21 and the first container 11. The second one-way valve 232 is disposed in the second pipeline 22 and located between the second pressure regulating valve 231 and the first container 11. The second one-way valve 232 is used to restrict the unidirectional flow of the driving gas in the second pipeline 22 to the first container 11.

[0061] The second pressure regulating valve 231 is used to regulate the delivery pressure of the driving gas in the second pipeline 22. The goal is to stabilize the pressure of the driving gas before it enters the first container 11 within a preset range. By regulating the driving gas pressure, it provides suitable power for the flow of liquid nitrogen tetroxide in the first container 11, and avoids affecting the delivery stability due to excessively high or low driving gas pressure.

[0062] The input pressure of the driving gas is controlled by the second pressure regulating component 23, so that the pressure in the first container 11 is within the range that drives the liquid nitrogen tetroxide to flow but does not cause violent turbulence. This avoids the high-pressure driving gas from impacting the liquid surface and forming gas-liquid entrainment. It can also maintain a stable pressure level in the first container 11 that is greater than the pressure in the mixing container 12, ensuring that the flow direction is the delivery of liquid nitrogen tetroxide to the mixing container 12, rather than the driving gas entering the first pipeline 13.

[0063] The second one-way valve 232 restricts the one-way flow of the driving gas, allowing the driving gas to flow only from the second pressure regulating valve 231 side to the first container 11 side, and blocking the backflow of liquid nitrogen tetroxide in the first container 11 to the second pressure regulating valve 231 and the second container 21 side.

[0064] The type of the second pressure regulating valve 231 is not limited. For example, the second pressure regulating valve 231 can be a pressure reducing valve. The pressure reducing valve has an internal pressure sensing element (such as a diaphragm or piston) and an adjusting spring, with a preset, suitable outlet pressure threshold. When fluctuations in inlet pressure or flow rate cause the outlet pressure to exceed the threshold, the fluid pressure pushes the sensing element to compress the adjusting spring, causing the valve orifice to close slightly, enhancing the throttling effect and reducing the outlet pressure. When the outlet pressure is below the threshold, the adjusting spring force pushes the valve orifice to open wider, weakening the throttling effect and increasing the outlet pressure. Through this cycle of pressure feedback and adaptive valve orifice adjustment, the outlet pressure is continuously stabilized within the preset range.

[0065] The type of the second check valve 232 is not limited. For example, the second check valve 232 can be a spring-loaded check valve, which relies on the cooperation between the valve core and the return spring to achieve opening and closing. For example, the second check valve 232 can be a ball valve, which achieves rapid opening and closing through the rolling of the ball.

[0066] In some embodiments, the second pressure regulating valve 231 is interlocked with the mass flow meter 4. When the mass flow meter 4 is below the set value, the input pressure of the driving gas is increased, and the flow rate of liquid nitrogen tetroxide is increased; when the mass flow meter 4 is above the set value, the input pressure of the driving gas is decreased, and the flow rate of liquid nitrogen tetroxide is reduced.

[0067] In some embodiments, please refer to Figure 1 The first pipeline 13 includes a connecting pipe 131, the lower port of which is located inside the first container 11 and at the bottom of the first container 11, and the upper port of which is located outside the first container 11.

[0068] Specifically, the lower port of the connecting pipe 131 can be lower than the lowest liquid level of liquid nitrogen tetroxide in the first container 11. The lower port of the connecting pipe 131 is kept below the liquid level of liquid nitrogen tetroxide in the first container 11, and the lower port of the connecting pipe 131 is always immersed in liquid nitrogen tetroxide to avoid the intake of driving gas due to the lower port of the connecting pipe 131 being exposed above the liquid surface.

[0069] In this embodiment, the lower port of the connecting pipe 131 is located at the bottom of the first container 11, and there is a relatively small gap between the lower port of the connecting pipe 131 and the bottom wall of the first container 11. After the driving gas is introduced into the first container 11, the driving gas mainly accumulates above the liquid surface. The connecting pipe 131 can reduce the mixing of driving gas into the connecting pipe 131 by taking material from the bottom, and can also maximize the extraction of liquid nitrogen tetroxide in the first container 11, thereby improving the material utilization rate.

[0070] In some embodiments, the connections of the first container 11, the connecting pipe 131, and the first pipeline 13 are all sealed to prevent the driving gas from seeping into the connecting pipe 131 through the sealing gap. This also helps to prevent the liquid nitrogen tetroxide from leaking and causing the liquid level to drop too quickly, thus exposing the lower end of the connecting pipe 131 to the gas environment.

[0071] In some embodiments, please refer to Figure 1 The nitrogen oxide quantitative delivery device includes a first switching valve 5, which is disposed in the first pipeline 13 and located between the first pressure regulating component 14 and the first container 11.

[0072] For example, the first switching valve 5 can be connected in series with the connecting pipe 131.

[0073] In this embodiment, the first switching valve 5 is connected in series at the end of the first pipeline 13 near the first container 11, and can selectively open or close the first pipeline 13. When the first switching valve 5 is opened, the liquid nitrogen tetroxide in the first container 11 can flow through the first switching valve 5 to the first pressure regulating component 14 under the action of pressure difference, and then enter the mixing container 12; when it is necessary to stop the delivery, the first switching valve 5 is closed, which can directly cut off the delivery path of nitrogen tetroxide. The first switching valve 5 can also be closed when it is necessary to inspect, maintain or replace parts of the pipeline on the first pressure regulating component 14 or the mixing container 12 side, or when an abnormality occurs on the mixing container 12 side.

[0074] The first switching valve 5 can use existing valve components, and this application does not restrict this.

[0075] In some embodiments, please refer to Figure 1 The nitrogen oxide metering device includes a second switching valve 6, which is disposed in the second pipeline 22 and located between the second pressure regulating component 23 and the first container 11.

[0076] The first switching valve 5 is connected in series at one end of the second pipeline 22 near the first container 11. It can selectively open or close the second pipeline 22 to control the supply of driving gas to the first container 11. When the second switching valve 6 is open, the driving gas is stably input into the first container 11 after being regulated by the second pressure regulating component 23 to establish a pressure gradient that drives the flow of nitrogen tetroxide. When the second switching valve 6 is closed, the supply of driving gas is cut off, which avoids the driving gas from unexpectedly entering the first container 11 and causing pressure imbalance due to the poor sealing of the second pressure regulating component 23. It can also achieve safe isolation between the first container 11 and the second pipeline 22 during system maintenance, debugging of the second pressure regulating component 23, or abnormal operating conditions, reducing the risk of driving gas backflow or external impurities intrusion and improving operational safety.

[0077] In some embodiments, please refer to Figure 1 The nitrogen oxide quantitative delivery device includes a liquid supply unit 7, which is connected to a first container 11. The liquid supply unit 7 is used to inject liquid nitrogen tetroxide into the first container 11.

[0078] In this embodiment, the liquid supply unit 7 can continuously and stably replenish the first container 11 with liquid nitrogen tetroxide, so that the first container 11 can maintain a sufficient amount of liquid nitrogen tetroxide to meet the quantitative delivery requirements and avoid delivery interruption due to material depletion.

[0079] In some embodiments, the liquid supply unit 7 may include a nitrogen tetroxide raw material tank, a liquid supply pipeline, a liquid supply pump, and a liquid supply valve; the nitrogen tetroxide raw material tank is used to store a sufficient amount of liquid nitrogen tetroxide, one end of the liquid supply pipeline is connected to the bottom outlet of the nitrogen tetroxide raw material tank, and the other end is connected to the inlet of the first container 11, the liquid supply pump is connected in series with the liquid supply pipeline, and the liquid supply pump is driven by power to pump the liquid nitrogen tetroxide in the nitrogen tetroxide raw material tank into the first container 11, and the liquid supply valve is set at one end of the liquid supply pipeline near the first container 11 to control the opening and closing of the liquid supply pipeline and prevent the material in the first container 11 from flowing back or the liquid supply from being excessive.

[0080] In some embodiments, the feed inlet of the first container 11 may be formed at the top of the first container 11.

[0081] In some embodiments, please refer to Figure 1 The nitrogen oxide metering device includes a gas supply unit 8, which is connected to a second container 21. The gas supply unit 8 is used to inject driving gas into the second container 21.

[0082] In this embodiment, the gas supply unit 8 can continuously and stably replenish the driving gas to the second container 21, so that the gas pressure in the second container 21 always meets the pressure gradient requirements, providing a reliable power source for the quantitative delivery of liquid nitrogen tetroxide.

[0083] In some embodiments, the gas supply unit 8 may include a driving gas raw material tank, a gas supply pipeline, a gas supply pump, and a gas supply valve; the driving gas raw material tank is used to store driving gas; one end of the gas supply pipeline is connected to the outlet of the driving gas raw material tank, and the other end is connected to the inlet of the second container 21; the gas supply pump is connected in series with the gas supply pipeline, and the gas supply pump pumps the driving gas in the driving gas raw material tank into the second container 21 by power drive; the gas supply valve is set at one end of the gas supply pipeline near the second container 21, and is used to control the opening and closing of the gas supply pipeline to prevent gas backflow in the second container 21 or excessive gas supply that could cause pressure to exceed the standard.

[0084] In some embodiments, a second flow meter is provided on the second pipeline 22, which is used to measure the flow rate of the driving gas in the second pipeline 22.

[0085] In some embodiments, the temperature of the mixing container 12 is higher than that of the first container 11. This promotes the full vaporization of the nitrogen tetroxide entering the mixing container 12.

[0086] In some embodiments, please refer to Figure 2 The metering unit 1 includes a heating element 15, which is disposed in the mixing container 12. The heating element 15 is used to heat the nitrogen tetroxide in the mixing container 12 to vaporize it.

[0087] In some embodiments, the heating element 15 may be disposed inside the mixing container 12. In this way, the heating element 15 can directly transfer heat to the nitrogen oxides.

[0088] In some embodiments, the heating element 15 may be disposed on the exterior of the mixing container 12. Exemplarily, the heating element 15 may have a generally layered structure, and the heating element 15 may cover the outer surface of the mixing container 12. In this way, heat can be transferred to the nitrogen oxides through the heat exchange container.

[0089] The type of heating element 15 is not limited. For example, the heating element 15 can convert electrical energy into heat energy. The heating element 15 includes, but is not limited to, a resistance heating structure.

[0090] In some embodiments, please refer to Figure 1 and Figure 2 The nitrogen oxide metering device includes a carrier gas unit 9, which is connected to a mixing container 12. The carrier gas unit 9 is used to input carrier gas into the mixing container 12.

[0091] The nitrogen oxides in the carrier gas-carrier mixing container 12 enter the next process. For example, the nitrogen oxides in the carrier gas-carrier mixing container 12 enter the oxidation column 10.

[0092] In this embodiment, the carrier gas unit 9 introduces a carrier gas with a stable flow rate and pressure into the mixing container 12. The carrier gas mixes with the vaporized nitrogen oxides in the mixing container 12. The mixed gas flows into the oxidation column 10 by the pressure of the carrier gas itself (for example, the outlet pressure of the mixing container 12 can be higher than the inlet pressure of the oxidation column 10), thereby realizing the directional delivery of nitrogen oxides and the stable feeding of subsequent oxidation-reduction processes.

[0093] The type of carrier gas is not limited. For example, the carrier gas includes, but is not limited to, inert gas or air. For example, gaseous nitrogen dioxide in the mixing container 12 is transported by compressed air at 0.3 MPa. The volume ratio of gaseous nitrogen dioxide is 30% to 50%. The compressed air carrier can complete the long-distance transportation of gaseous nitrogen dioxide to each seasoning process point for oxidation and valence adjustment reaction.

[0094] In some embodiments, please refer to Figure 2 The carrier gas unit 9 includes a compressed air pump 91, a carrier gas on / off valve, a carrier gas pressure regulating valve, and a carrier gas pipeline 92. The carrier gas pipeline 92 connects the carrier gas inlet 12a of the mixing container 12 and the compressed air pump 91. The carrier gas on / off valve is located at one end of the carrier gas pipeline 92 near the carrier gas inlet 12a and is used to control the start and stop of carrier gas delivery. The carrier gas pressure regulating valve is located on the carrier gas pipeline 92 and is used to regulate the pressure of the carrier gas pipeline 92.

[0095] In some embodiments, a third flow meter is provided on the carrier gas line 92 to measure the flow rate of the carrier gas in the carrier gas line 92.

[0096] In some embodiments, please refer to Figure 2 The mixing container 12 has a carrier gas inlet 12a and a mixed gas outlet 12b at opposite ends in the horizontal direction. After the carrier gas enters from one end, it can fully flush and entrain the vaporized nitrogen oxides in the mixing container 12, reducing the risk of material retention caused by local dead air flow; it also helps the carrier gas and nitrogen oxides to form a uniform turbulent mixing state in the mixing container 12, improving the concentration consistency of the mixed gas.

[0097] In some embodiments, please refer to Figure 2 The nitrogen oxide metering device includes a nozzle 20, and a first pipeline 13 includes an inlet pipe 132. The lower end of the inlet pipe 132 passes through the upper wall of the mixing container 12 and is inserted into the mixing container 12. The nozzle 20 is connected to the lower end of the inlet pipe 132, and the nozzle 20 forms multiple spray outlets. Liquid nitrogen tetroxide enters the mixing container 12 through the multiple spray outlets.

[0098] In some embodiments, the nitrogen oxide metering device includes a third switching valve, which may be connected in series at the end of the first pipeline 13 near the mixing container 12. Exemplarily, the third switching valve is connected in series at the location of the inlet pipe 132 outside the mixing container 12. The third switching valve can control the on / off state of the end of the first pipeline 13 near the mixing container 12.

[0099] In some embodiments, please refer to Figure 1 and Figure 2 The nitrogen oxide quantitative delivery device includes an oxidation pipeline 30 and an online analysis device 40. The oxidation pipeline 30 connects the mixed gas outlet 12b and the oxidation column 10, and the online analysis device 40 is installed in the oxidation pipeline 30. The online analysis device 40 is used to analyze the concentration of nitrogen oxides in the mixed gas within the oxidation pipeline 30.

[0100] In some embodiments, the nitrogen oxide metering device includes a fourth switching valve, which may be connected in series at one end of the oxidation line 30 near the mixed gas outlet 12b. The fourth switching valve can control the on / off state of the oxidation line 30.

[0101] In some embodiments, please refer to Figure 2 A drain pipe 121 is installed at the lowest part of the mixing container 12, and a drain valve is installed on the drain pipe 121. The drain pipe 121 is connected to the inside of the mixing container 12 and is used to drain any residual liquid nitrogen tetroxide or other substances in the mixing container 12. The drain valve controls the opening and closing of the drain pipe 121.

[0102] In some embodiments, a first pressure gauge and a first thermometer are provided on the first container 11. The first pressure gauge is used to measure the pressure inside the first container 11, and the first thermometer is used to measure the temperature inside the first container 11.

[0103] The range of the first pressure gauge is unlimited; for example, it can be 1.0 MPa.

[0104] In some embodiments, a second pressure gauge and a second thermometer are provided on the second container 21. The second pressure gauge is used to measure the pressure inside the second container 21, and the second thermometer is used to measure the temperature inside the second container 21.

[0105] The range of the second pressure gauge is unlimited; for example, it can be 1.0 MPa.

[0106] In some embodiments, a third pressure gauge and a third thermometer are provided on the mixing container 12. The third pressure gauge is used to measure the pressure inside the mixing container 12, and the third thermometer is used to measure the temperature inside the mixing container 12.

[0107] The range of the third pressure gauge is unlimited; for example, it can be 1.0 MPa.

[0108] In some embodiments, the third thermometer is a temperature indicator controller. The heating element 15 is electrically connected to the temperature indicator controller. The temperature indicator controller can control the start and stop of the heating element 15 according to the set temperature, so that the temperature in the mixing container 12 is within the target temperature range.

[0109] In some embodiments, the first container 11, the second container 21, and the mixing container 12 can all be made of stainless steel, for example, 304 stainless steel, which has good resistance to nitrogen tetroxide corrosion.

[0110] In some embodiments, please refer to Figure 1 A discharge pipe 111 is installed at the lowest part of the first container 11, and a discharge valve is installed on the discharge pipe 111. The discharge pipe 111 is connected to the inside of the first container 11 and is used to discharge any residual liquid nitrogen tetroxide or other substances in the first container 11. The discharge valve controls the opening and closing of the discharge pipe 111.

[0111] In some embodiments, please refer to Figure 1 The metering unit 1 includes a base 16, which forms an upward-opening placement groove. A first container 11 is disposed in the placement groove, and the first container 11 is spaced apart from the lower surface of the placement groove. The first container 11 is fixedly connected to the base 16, and the base 16 can provide support for the first container 11. The first container 11 is spaced apart from the lower surface of the placement groove to avoid the discharge pipe 111 and the discharge valve.

[0112] The base 16 and the first container 11 can be connected by non-detachable means such as welding, or by detachable means such as screw connection.

[0113] It is understandable that when the first container 11 is fixed to the base 16, the base 16 and the first container 11 can be placed together on the weighing mechanism 3.

[0114] In some embodiments, please refer to Figure 1 The first pipeline 13 has a first node 133, which is located downstream of the mass flow meter 4. The nitrogen oxide quantitative delivery device includes a gas replenishment unit 50, which includes a gas replenishment pipeline 51, a third pressure regulating valve 52, a gas flow meter 53, and a third check valve 54. The gas replenishment pipeline 51 connects the second container 21 and the first node 133. The third pressure regulating valve 52, the gas flow meter 53, and the third check valve 54 are sequentially connected in series in the gas replenishment pipeline 51 along the flow direction of the gas in the gas replenishment pipeline 51.

[0115] The third pressure regulating valve 52 is used to regulate the delivery pressure of the driving gas in the gas supply line 51.

[0116] The gas flow meter 53 is used to monitor the instantaneous and cumulative flow of the driving gas in the gas supply pipeline 51 in real time, providing data support for the regulation of the gas supply.

[0117] The third one-way valve 54 is located between the gas flow meter 53 and the first node 133. The function of the third one-way valve 54 is to restrict the driving gas to flow into the first pipeline 13 only from the gas supply pipeline 51, and to block the backflow of liquid nitrogen tetroxide in the first pipeline 13 to the gas supply pipeline 51, so as to prevent contamination of the gas supply unit 50 or cause pressure imbalance.

[0118] In this embodiment, the driving gas in the second container 21 is supplied to the first node 133 of the first pipeline 13 through the gas supply pipeline 51. The pressure fluctuation during the delivery of nitrogen tetroxide in the first pipeline 13 is compensated by the regulation of the gas supply flow rate and pressure.

[0119] The specifications of the gas flow meter 53 are not limited. For example, the flow rate of the gas flow meter 53 can be 0 L / min to 20 L / min (liters per minute).

[0120] The volume of the first container 11 can be designed according to requirements. For example, the volume of the first container 11 is 180L.

[0121] The specifications of the second pipeline 22, the second switching valve 6, the second pressure regulating valve 231, the air supply pipeline 51, and the carrier gas pipeline 92 are not limited. For example, the specification can be DN10.

[0122] The specifications of the first pipeline 13, the first switch valve 5, the first pressure regulating valve 141, the connecting pipe 131, the liquid supply pipeline and the liquid supply valve are not limited. For example, the specification can be DN15.

[0123] This application provides an operation method for a nitrogen oxide quantitative conveying device, the operation method including: Step S1: Turn on the liquid supply unit 7, and transfer liquid nitrogen tetroxide from the nitrogen tetroxide raw material tank, such as a transfer tank or a dedicated pipeline, to the first container 11; the first container 11 has a cooling function to maintain the temperature inside the first container 11 at about 5°C, and record the reading of the weighing mechanism 3, such as an electronic scale.

[0124] Step S2: Turn on the gas supply unit 8 to deliver a certain amount of driving gas, such as nitrogen, into the second container 21. The pressure of the second container 21 is maintained at 0.2 MPa to 0.5 MPa. Step S3: Open the second pressure reducing valve and the second one-way valve 232 to inject a driving gas, such as nitrogen, at a pressure of 0.2 to 0.5 MPa into the first container 11. A quantitative gas extrusion method is used, i.e., the driving gas, such as nitrogen, is quantitatively supplied from the top of the first container 11 (maintained at a constant temperature of 5°C). The incoming driving gas can quantitatively expel the liquid nitrogen tetroxide from the lower port of the connecting pipe 131 within the first container 11. During the extrusion of liquid nitrogen tetroxide, the changes in the electronic scale and the reading of the mass flow meter 4 are recorded to calculate the flow rate of the liquid nitrogen tetroxide.

[0125] Step S4: Liquid nitrogen tetroxide is extruded and conveyed into the mixing container 12. The mixing container 12 has a heating function and is heated to about 60°C to 70°C. The liquid nitrogen tetroxide vaporizes into gaseous nitrogen dioxide in the mixing container.

[0126] Step S5: Turn on the carrier gas unit 9 and blow compressed air into the mixing container 12 through the carrier gas unit 9. The blowing pressure is about 0.3MPa. The amount of compressed air blown in is based on the volume ratio of gaseous nitrogen dioxide after blowing in 30% to 50%. The gaseous nitrogen dioxide with a volume ratio of 30% to 50% is transported to each seasoning process section, such as the oxidation column 10, for oxidation and valence adjustment by the compressed air carrier.

[0127] In some embodiments, the airtightness of the first container 11 can be tested. Exemplarily, the driving gas can be nitrogen, with a pressure range of 2 bar to 5 bar, and the operating pressure range of the first pressure reducing valve is also 2 bar to 5 bar. First, the second switch valve 6 of the first container 11 is opened, while the other valves are closed. Then, the pressure is adjusted to 0.3 MPa by the second pressure reducing valve, allowing compressed nitrogen to enter the first container 11, resulting in a pressure of 0.2 MPa within the first container 11. Leaks are checked at the joints and flanges using soapy water, and any leaks are tightened. If the pressure inside the first container 11 remains unchanged for one hour, the airtightness of the first container 11 meets the requirements.

[0128] In some embodiments, the airtightness of the first pipeline 13 can be tested. For example, when the first switch valve 5 is opened and the pressure is greater than 0.1 MPa, nitrogen gas passes through the mass flow meter 4 and opens the first one-way valve 142. When the pressure is lower than 0.1 MPa, the first one-way valve 142 cannot be opened. If the first pipeline 13 is leak-tested with soapy water and no leakage is found, it indicates that the airtightness of the first pipeline 13 meets the requirements.

[0129] In some embodiments, the airtightness of the carrier gas line 92 can be checked. For example, the third flow meter is turned on, the carrier gas pressure regulating valve is adjusted to 0.2 MPa, and the carrier gas line 92 is checked for leaks using soapy water. For instance, if a serious leak is found at the threaded connection to the third flow meter, it is retightened, the third flow meter is adjusted to 600 ml / min, and an airtightness check is performed. If the line does not leak, it indicates that the airtightness of the carrier gas line 92 meets the requirements.

[0130] In some embodiments, the overall system airtightness can be checked by ensuring that both the second pipeline 22 and the carrier gas pipeline 92 are in a continuous state, adjusting the pressure of the second pressure regulating valve 231 to 0.3 MPa, adjusting the pressure of the carrier gas pressure regulating valve to 0.2 MPa, adjusting the pressure of the first container 11 to 0.207 MPa, and closing the second switch valve 6. After maintaining the system pressure for 24 hours, if the pressure on the first pressure gauge does not decrease, it indicates that the overall system airtightness is qualified.

[0131] In some embodiments, the quantitative delivery device for nitrogen oxides provided in this application is used to conduct a quantitative delivery test of liquid dinitrogen tetroxide. Liquid dinitrogen tetroxide is injected into the first container 11, the electronic scale reading is recorded, and the mass of injected liquid dinitrogen tetroxide is measured to be 5200g. The second pressure regulating valve 231 is adjusted to a pressure of 0.3MPa, and compressed nitrogen gas enters the first container 11. The first pressure gauge in the first container 11 slowly rises, and the pressure in the first container 11 reaches 0.2MPa. The first switch valve 5 is opened, and the mass flow meter 4 on the first pipeline 13 displays a value, indicating that liquid dinitrogen tetroxide is flowing out. The readings of the electronic scale and the mass flow meter 4 are recorded, and the mass data of the liquid dinitrogen tetroxide flowing out is obtained. The second pressure regulating valve 231 is stepped up (~5kPa), and the readings of the electronic scale and the data of the mass flow meter 4 are recorded at different times and pressures. The flow rate of liquid dinitrogen tetroxide is checked by mass change and flow meter reading. The recorded data is shown in Table 1 below.

[0132] Table 1

[0133] As shown in Table 1, when the pressure of the second pressure regulating valve 231 is 0.3 MPa, adjusting the pressure of the first pressure regulating valve 141 to 0.11 MPa results in a reading of 8.012 g / min for mass flow meter 4. After 5 minutes of operation, the fluid mass is 40.06 g. The reading of the electronic scale decreases from 5200 g to 5160 g, which matches the data from mass flow meter 4. With a pressure increase of approximately 5 kPa every 5 minutes, the decrease in the electronic scale reading matches the flow rate of mass flow meter 4.

[0134] As can be seen from the above quantitative delivery experiment of liquid nitrogen tetroxide, the nitrogen oxide quantitative delivery device of this application can meet the quantitative delivery requirements of liquid nitrogen tetroxide.

[0135] In some embodiments, the heating temperature of the mixing container 12 is set to 75°C. A metered amount of liquid dinitrogen tetroxide enters the mixing container 12 through a nozzle 20, dispersing the liquid on the inner surface of the container. The mixture is then heated to 75°C by a heating element 15 located outside the container. Based on the amount of liquid dinitrogen tetroxide vaporized, compressed air is blown into the mixing container 12 at a ratio of 30% nitrogen dioxide and 70% air (i.e., a nitrogen dioxide volume ratio of 30%). The vaporization conditions for liquid dinitrogen tetroxide are calculated as a pressure of 0.3 MPa and a temperature of 60°C (333 K). The amount of dinitrogen tetroxide added is 422 g, and the calculated volume of vaporized nitrogen dioxide is 145 L. The flow rate of the third flow meter is controlled at 11.2 L / min, and the air added over 30 minutes is 338 L. The vaporized nitrogen dioxide enters the online analysis device 40 to detect the concentration of the mixed gas. The concentration percentage of nitrogen dioxide is 30.5%, realizing the vaporization and quantitative delivery of dinitrogen tetroxide.

[0136] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way.

Claims

1. A nitrogen oxide quantitative conveying device, characterized in that, The nitrogen oxide quantitative delivery device includes: The quantitative unit includes a first container, a mixing container, a first pipeline, and a first pressure regulating component. The first container is used to hold liquid nitrogen tetroxide, the first pipeline connects the first container and the mixing container, and the first pressure regulating component is disposed on the first pipeline. The input unit includes a second container, a second pipeline, and a second pressure regulating component. The second container is used to hold driving gas, the second pipeline connects the second container and the first container, and the second pressure regulating component is disposed on the second pipeline.

2. The nitrogen oxide metering device according to claim 1, characterized in that, The nitrogen oxide quantitative delivery device includes a weighing mechanism for obtaining the total mass of the first container and the liquid nitrogen tetroxide inside; and / or, The nitrogen oxide quantitative delivery device includes a mass flow meter, which is installed in the first pipeline and is used to obtain the mass flow rate of dinitrogen tetroxide flowing in the first pipeline.

3. The nitrogen oxide quantitative conveying device according to claim 1, characterized in that, The first voltage regulating component includes: A first pressure regulating valve is provided in the first pipeline and located between the first container and the mixing container; A first one-way valve is disposed in the first pipeline and located between the first pressure regulating valve and the mixing container. The first one-way valve is used to restrict the unidirectional flow of nitrogen tetroxide into the mixing container.

4. The nitrogen oxide metering device according to claim 1, characterized in that, The second voltage regulating component includes: A second pressure regulating valve is installed in the second pipeline and located between the second container and the first container; A second check valve is provided in the second pipeline and located between the second pressure regulating valve and the first container. The second check valve is used to restrict the unidirectional flow of the driving gas in the second pipeline to the first container.

5. The nitrogen oxide quantitative conveying device according to claim 1, characterized in that, The first pipeline includes a connecting pipe, the lower port of which is located inside the first container and at the bottom of the first container, and the upper port of which is located outside the first container.

6. The nitrogen oxide metering device according to any one of claims 1 to 5, characterized in that, The nitrogen oxide metering device includes a first switching valve, which is disposed in the first pipeline and located between the first pressure regulating component and the first container; and / or, The nitrogen oxide metering device includes a second switching valve, which is disposed in the second pipeline and located between the second pressure regulating component and the first container.

7. The nitrogen oxide metering device according to any one of claims 1 to 5, characterized in that, The nitrogen oxide quantitative delivery device includes: A liquid supply unit is connected to the first container, and the liquid supply unit is used to inject the liquid nitrogen tetroxide into the first container.

8. The nitrogen oxide metering device according to any one of claims 1 to 5, characterized in that, The nitrogen oxide quantitative delivery device includes: A gas supply unit is connected to the second container, and the gas supply unit is used to inject the driving gas into the second container.

9. The nitrogen oxide metering device according to any one of claims 1 to 5, characterized in that, The metering unit includes a heating element disposed in the mixing container.

10. The nitrogen oxide metering device according to any one of claims 1 to 5, characterized in that, The nitrogen oxide quantitative delivery device includes: A carrier gas unit is connected to the mixing container and is used to input carrier gas into the mixing container.

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