Equipment for treating volatile gases of dimethyl oxalate, methanol and methyl nitrite
By designing a treatment device for volatile gases such as dimethyl oxalate, methanol, and methyl nitrite, the device utilizes an alkaline neutralization reaction chamber to remove methyl nitrite and dimethyl oxalate, a methanol cooling chamber to condense methanol, and a water seal chamber for washing before discharge. This solution addresses the problem of organic emissions during the synthesis of ethylene glycol from syngas and achieves environmentally friendly waste gas treatment.
Patent Information
- Application Number
- CN202521146626.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-06
- Publication Date
- 2026-05-15
- Estimated Expiration
- 2035-06-06
AI Technical Summary
During the synthesis of ethylene glycol from syngas, organic compounds such as dimethyl oxalate, methanol, and methyl nitrite are emitted into the atmosphere, causing environmental pollution.
Design a device for treating volatile gases of dimethyl oxalate, methanol, and methyl nitrite. The device utilizes an alkaline neutralization reaction chamber to remove methyl nitrite and dimethyl oxalate, a methanol cooling chamber to condense methanol, and a water seal chamber to wash the waste gas before discharge, thereby achieving effective removal of organic matter.
It effectively removes organic matter from exhaust gas, avoiding environmental pollution. The equipment has a simple structure, low cost, and is suitable for industrial applications.
Smart Images
Figure CN224236506U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of syngas to ethylene glycol equipment, specifically relating to a device for treating volatile gases such as dimethyl oxalate, methanol, and methyl nitrite. Background Technology
[0002] The existing syngas-to-ethylene glycol process mainly consists of two parts: the first part is the oxidative carbonylation of syngas to produce dimethyl oxalate, and the second part is the hydrogenation of dimethyl oxalate to produce ethylene glycol. In the dimethyl oxalate preparation process, CO reacts with methyl nitrite in a coupling reaction to produce dimethyl oxalate and NO. After NO is separated from dimethyl oxalate, dimethyl oxalate enters a hydrogenation reactor to react with hydrogen to produce ethylene glycol, while NO enters a regeneration reactor to react with methanol and oxygen to produce methyl nitrite. Methyl nitrite is then returned to the coupling reactor as a raw material to synthesize dimethyl oxalate. Therefore, in actual production, the dimethyl oxalate product contains organic compounds such as methanol and methyl nitrite.
[0003] Because dimethyl oxalate has a melting point of 54°C, to prevent crystallization and blockage in the pipelines transporting dimethyl oxalate, the industry generally uses temperatures above 60°C for its transport. Dimethyl oxalate is highly volatile, while methanol has a boiling point of 65°C, and methyl nitrite is a gas at room temperature and pressure. Therefore, the waste gas emitted during the synthesis of ethylene glycol from syngas contains dimethyl oxalate, methanol, and methyl nitrite. If a high-point emission method is used on-site, organic matter will be released into the atmosphere, which is detrimental to the environment. Utility Model Content
[0004] The present invention aims to provide a device for treating volatile gases such as dimethyl oxalate, methanol, and methyl nitrite, in order to solve the problem of harmful environmental emissions of organic matter into the atmosphere during the synthesis of ethylene glycol from syngas.
[0005] To achieve the above objectives, the present invention provides a device for treating volatile gases of dimethyl oxalate, methanol, and methyl nitrite, comprising a treatment tank. The treatment tank has two horizontally arranged partitions that divide the internal space of the tank from bottom to top into a neutralization reaction chamber, a methanol cooling chamber, and a water seal chamber. The neutralization reaction chamber is connected to an inlet pipe and an alkali pipe, with the inlet pipe located below the alkali pipe. A drain pipe is connected to the bottom of the neutralization reaction chamber. The methanol cooling chamber is equipped with a gas cooling pipe and a finned heat exchanger. The bottom end of the gas cooling pipe is connected to the neutralization reaction chamber, and the methanol cooling chamber is connected to a top overflow pipe I. The water seal chamber is equipped with a gas flow pipe, the bottom end of which is connected to the methanol cooling chamber. Both the gas flow pipe and the gas cooling pipe include a vertical section and a curved section. The water seal chamber is connected to a top overflow pipe II. Both the top overflow pipe II and the top overflow pipe I have liquid-sealed U-shaped sections. An exhaust pipe and a liquid inlet pipe are connected to the top of the water seal chamber.
[0006] The working principle and beneficial effects of this scheme are as follows: In this scheme, the waste gas first enters the neutralization reaction chamber, where methyl nitrite and dimethyl oxalate in the waste gas react with the alkaline solution entering the neutralization reaction chamber through the alkaline solution pipe to generate oxalate, nitrite, and methanol, thereby removing methyl nitrite and dimethyl oxalate from the waste gas. The methanol then enters the methanol cooling chamber with the waste gas. Under the heat exchange of the finned heat exchanger, the temperature of the methanol cooling chamber is 30-35°C. The methanol in the waste gas loses heat and condenses into liquid in the gas cooling pipe. The liquid methanol accumulates in the methanol cooling chamber and can flow through the top overflow pipe I to the dimethyl oxalate discharge tank or methanol storage tank, thereby removing the methanol from the waste gas. Then, the waste gas enters the water seal chamber, is washed with demineralized water, and is discharged into the atmosphere through the exhaust pipe. In this way, the organic matter in the waste gas is removed, and the emission is harmless to the environment.
[0007] In summary, this solution removes methyl nitrite and dimethyl oxalate from the waste gas in the neutralization reaction chamber using alkaline solution, removes methanol from the waste gas in the methanol cooling chamber using cooling, and discharges the waste gas after water washing in the water seal chamber. This solution is harmless to the environment, has a simple structure and low manufacturing cost, and is suitable for industrial use.
[0008] Optionally, the end of the top overflow pipe II away from the water seal chamber is connected to the neutralization reaction chamber.
[0009] In this scheme, the demineralized water in the water seal chamber can enter the neutralization reaction chamber by gravity overflow, thereby flushing the salts in the neutralization reaction chamber and preventing salt precipitation from clogging the pipes.
[0010] Optionally, the bottom of the methanol cooling chamber is connected to an vent pipe I, and a valve I for controlling the opening and closing of the pipe is installed on the vent pipe I.
[0011] In this scheme, when the treatment tank is shut down, valve I is opened, and the liquid methanol in the methanol cooling chamber is drained through drain pipe I to facilitate maintenance of the treatment tank.
[0012] Optionally, the bottom of the water seal chamber is connected to a drain pipe II, and the end of the drain pipe II away from the water seal chamber is connected to the top overflow pipe II. A valve II for controlling the opening and closing of the pipeline is installed on the drain pipe II. The bottom of the liquid seal U-shaped section of the top overflow pipe II is connected to the top overflow pipe II through a connecting pipe, and a valve III for controlling the opening and closing of the pipeline is installed on the connecting pipe.
[0013] In this scheme, when the treatment tank is shut down, valves II and III are opened, and the demineralized water in the water seal chamber is drained through drain pipe II and connecting pipe to facilitate maintenance of the treatment tank.
[0014] Optionally, the neutralization reaction chamber is provided with a ring pipe, which has several air outlets. One end of the ring pipe is connected to the air inlet pipe, and the other end of the ring pipe is closed.
[0015] In this design, several vent holes on the ring pipe serve as outlets for the exhaust gas. This allows the exhaust gas to be divided into several small streams, increasing the contact area between the exhaust gas and the alkaline solution. This ensures that methyl nitrite and dimethyl oxalate in the exhaust gas fully contact and react with the alkaline solution, preventing dimethyl oxalate and methyl nitrite from entering the methanol cooling chamber.
[0016] Optionally, the air outlet is positioned at an angle downwards.
[0017] In this design, the exhaust gas has a relatively high initial velocity when it is discharged through the outlet. The downward angled design can slow down the upward velocity of the exhaust gas in the alkaline solution, thereby prolonging the residence time of the exhaust gas in the alkaline solution.
[0018] Optionally, the neutralization reaction chamber is equipped with a level gauge, the drain pipe is equipped with a pH meter and an electrically controlled valve I, and the alkali pipe is equipped with an electrically controlled valve II. The electrically controlled valve I is controlled by the level gauge, and the electrically controlled valve II is controlled by the pH meter.
[0019] In this scheme, a pH meter monitors the pH value of the liquid in the drain pipe in real time, controlling the pH value of the liquid in the neutralization reaction chamber within the range of 7 to 8. If the pH value is less than 7, the opening degree of the solenoid valve II increases, and the alkaline solution flow rate increases; if the pH value is greater than 8, the opening degree of the solenoid valve II decreases, and the alkaline solution flow rate decreases, thereby maintaining the pH value within a suitable range. Simultaneously, a level gauge monitors the liquid level in the neutralization reaction chamber in real time. When the liquid level is too high, the opening degree of the solenoid valve I increases, and the drainage volume increases; when the liquid level is too low, the opening degree of the solenoid valve I decreases, and the drainage volume decreases, thereby maintaining the liquid level within a suitable range.
[0020] Optionally, the neutralization reaction chamber is equipped with a hot water jacket.
[0021] In this scheme, a hot water jacket is used to heat the neutralization reaction chamber, so that the reaction temperature in the neutralization reaction chamber is maintained within the range of 70-75℃, thereby ensuring the reaction effect.
[0022] Optionally, the exhaust pipe passes through the neutralization reaction chamber, and heat exchange fins are provided on the outer peripheral wall of the exhaust pipe, with the heat exchange fins located inside the neutralization reaction chamber.
[0023] In this design, the waste gas after washing contains saturated water, and its temperature rises after passing through the neutralization reaction chamber. This prevents ice buildup at high points during emissions in cold winter regions (northern areas). Simultaneously, the waste gas reacting in the neutralization reaction chamber comes into contact with the heat exchange fins, lowering its temperature and reducing the amount of low-temperature water used in the methanol cooling chamber's finned heat exchanger.
[0024] Optionally, a heat insulation layer is provided on the partition between the methanol cooling chamber and the neutralization reaction chamber.
[0025] In this scheme, the temperature difference between the neutralization reaction chamber and the methanol cooling chamber is about 40°C. Therefore, a heat insulation layer is designed between the two chambers to avoid a large amount of heat exchange between them. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the structure of the dimethyl oxalate, methanol, and methyl nitrite volatile gas treatment equipment in Embodiment 1 of this utility model;
[0027] Figure 2 This is a bottom view of the annular tube in Embodiment 1 of this utility model;
[0028] Figure 3 This is a schematic diagram of the structure of the dimethyl oxalate, methanol, and methyl nitrite volatile gas treatment equipment in Embodiment 2 of this utility model. Detailed Implementation
[0029] The following detailed description illustrates the specific implementation method:
[0030] The markings in the accompanying drawings include: processing tank 1, neutralization reaction chamber 110, methanol cooling chamber 120, water seal chamber 130, partition 2, air inlet pipe 3, liquid drain pipe 4, alkali solution pipe 5, ring pipe 6, air outlet 601, hot water jacket 7, gas cooling pipe 8, finned heat exchanger 9, top overflow pipe I 10, vent pipe I 11, valve I 12, insulation layer 13, gas flow pipe 14, vertical section 1401, curved section 1402, top overflow pipe II 15, liquid seal U-shaped section 1501, exhaust pipe 16, liquid inlet pipe 17, heat exchange fins 18, rain cap 19, vent pipe II 20, valve II 21, connecting pipe 22, valve III 23, level gauge 24, pH meter 25, electric control valve I 26, electric control valve II 27, and discharge tank 28.
[0031] Example 1
[0032] This embodiment is basically as follows: Figure 1 The diagram shows a device for treating volatile gases of dimethyl oxalate, methanol, and methyl nitrite. It includes a treatment tank 1. Two horizontally arranged partitions 2 are welded inside the treatment tank 1, dividing the internal space of the treatment tank 1 from bottom to top into a neutralization reaction chamber 110, a methanol cooling chamber 120, and a water seal chamber 130. An inlet pipe 3 and a drain pipe 4 are connected to the bottom of the neutralization reaction chamber 110, and an alkali solution pipe 5 is connected to the top of the neutralization reaction chamber 110. A ring pipe 6 is provided inside the neutralization reaction chamber 110, with one end connected to the inlet pipe 3 and the other end of the ring pipe 6 closed. Figure 2As shown, the annular pipe 6 has several vent holes 601, which are angled downwards. Specifically, vent holes 601 are opened at a 45° downward angle every 50 mm on the annular pipe 6. In this way, the rising speed of the waste gas in the alkaline solution after being discharged through the vent holes 601 can be slowed down, thereby prolonging the residence time of the waste gas in the alkaline solution. The bottom of the neutralization reaction chamber 110 is conical so that the liquid inside can be discharged through the drain pipe 4. In addition, a hot water jacket 7 is provided outside the neutralization reaction chamber 110. The temperature of the heat exchange medium (water) in the hot water jacket 7 is 80°C, thereby using the hot water jacket 7 to maintain the temperature inside the neutralization reaction chamber 110 within the range of 70-75°C, thus ensuring the reaction effect.
[0033] The methanol cooling chamber 120 is equipped with a gas cooling pipe 8 and a finned heat exchanger 9. The bottom end of the gas cooling pipe 8 is connected to the neutralization reaction chamber 110. The heat exchange medium of the finned heat exchanger 9 is 7°C low-temperature water. Through heat exchange, the temperature inside the methanol cooling chamber 120 is maintained at 30-35°C. The methanol cooling chamber 120 is connected to a top overflow pipe I10, and the bottom of the methanol cooling chamber 120 is connected to a drain pipe I11. A valve I12 for controlling the opening and closing of the pipe is installed on the drain pipe I11. A heat insulation layer 13 is provided on the partition 2 between the methanol cooling chamber 120 and the neutralization reaction chamber 110. In this embodiment, the heat insulation layer 13 is made of wooden board partition and filled with rock wool.
[0034] A gas flow pipe 14 is provided inside the water seal chamber 130. The bottom end of the gas flow pipe 14 is connected to the methanol cooling chamber 120. Both the gas flow pipe 14 and the gas cooling pipe 8 include a vertical section 1401 and a curved section 1402. In this embodiment, the curved section 1402 has three bending points so that the exhaust gas travels for a longer time in the pipe. The water seal chamber 130 is connected to a top overflow pipe II 15. Both the top overflow pipe II 15 and the top overflow pipe I 10 are provided with liquid seal U-shaped sections 1501. The top of the water seal chamber 130 is connected to an exhaust pipe 16 and a liquid inlet pipe 17. The exhaust pipe 16 passes through the neutralization reaction chamber 110, and the outer peripheral wall of the exhaust pipe 16 is provided with heat exchange fins 18, which are located inside the neutralization reaction chamber 110. The top of the exhaust pipe 16 is provided with a rain cap 19 to prevent rainwater and other impurities from entering the exhaust pipe 16. The bottom of the water seal chamber 130 is connected to a drain pipe II20. The end of the drain pipe II20 away from the water seal chamber 130 is connected to the top overflow pipe II15. A valve II21 for controlling the opening and closing of the pipe is installed on the drain pipe II20. The bottom of the liquid seal U-shaped section 1501 of the top overflow pipe II15 is connected to the top overflow pipe II15 through a connecting pipe 22. A valve III23 for controlling the opening and closing of the pipe is installed on the connecting pipe 22.
[0035] In practical use, demineralized water enters the water seal chamber 130 through the inlet pipe 17, and the liquid level in the water seal chamber 130 submerges the gas outlet of the gas flow pipe 14. When the liquid level in the water seal chamber 130 rises to the inlet of the top overflow pipe II 15, the demineralized water enters the top overflow pipe II 15 and flows naturally into the neutralization reaction chamber 110 under gravity. Simultaneously, a 23wt% sodium hydroxide solution (or other alkaline solutions, such as potassium hydroxide solution, in other embodiments) enters the neutralization reaction chamber 110 through the alkaline solution pipe 5, ensuring that the alkaline solution level is higher than that of the ring pipe 6. Additionally, 7°C low-temperature water flows through the finned heat exchanger 9, carrying away heat from the methanol cooling chamber 120, thus maintaining the temperature within the methanol cooling chamber 120 at 30–35°C.
[0036] Subsequently, the waste gas (composed of dimethyl oxalate, methanol, methyl nitrite, and nitrogen) enters the ring pipe 6 through the inlet pipe 3 and is then discharged through the outlet 601. The waste gas is divided into several small streams and discharged into the alkaline solution, where it floats to the surface. During this process, methyl nitrite and dimethyl oxalate in the waste gas react with sodium hydroxide to produce sodium nitrite, sodium oxalate, and methanol. The relevant reaction equations are: 1) CH3ONO + NaOH + H2O = CH3OH + NaNO2 + H2O; 2) (COOCH3)2 + 2NaOH = Na2C2O4 + 2CH3OH. After the reaction, the generated salts are discharged along with the alkaline solution through the drain pipe 4. Furthermore, the demineralized water in the water seal chamber 130 flows into the neutralization reaction chamber 110 through the top overflow pipe II 15 to flush out the salts and prevent salt precipitation. In addition, during the reaction, 80°C water flows through the hot water jacket 7 to heat the liquid in the neutralization reaction chamber 110, maintaining the reaction temperature within the range of 70-75°C, thereby ensuring the reaction effect and completely removing methyl nitrite and dimethyl oxalate from the waste gas. During this process, the liquid seal U-shaped section 1501 on the top overflow pipe II 15 prevents the waste gas in the neutralization reaction chamber 110 from directly entering the water seal chamber 130.
[0037] After removing methyl nitrite and dimethyl oxalate, the waste gas enters gas cooling pipe 8. Since the temperature inside methanol cooling chamber 120 is 30-35°C, the waste gas loses heat within gas cooling pipe 8, and the methanol in the waste gas condenses into liquid in the middle and later sections of gas cooling pipe 8. The liquid methanol accumulates in methanol cooling chamber 120, thus removing methanol from the waste gas. When the liquid methanol level rises to the inlet port of top overflow pipe I10, the liquid methanol flows into top overflow pipe I10. In this way, excess liquid methanol in methanol cooling chamber 120 can be transported to dimethyl oxalate discharge tank 28 via top overflow pipe I10. During the above process, the liquid seal U-shaped section 1501 on top overflow pipe I10 prevents waste gas from dimethyl oxalate discharge tank 28 from entering methanol cooling chamber 120.
[0038] After methanol removal, the exhaust gas enters the gas flow pipe 14. After being washed with demineralized water in the water seal chamber 130, the exhaust gas (containing nitrogen and a small amount of saturated water) enters the exhaust pipe 16 and is discharged at its highest point. During this process, the exhaust gas passes through the neutralization reaction chamber 110 and exchanges heat with the exhaust gas in the neutralization reaction chamber 110 through the heat exchange fins 18. As a result, the temperature of the exhaust gas in the exhaust pipe 16 increases, while the temperature of the exhaust gas entering the methanol cooling chamber 120 decreases. This avoids the problem of ice forming at the highest point of the exhaust pipe 16 during the cold season in northern regions and reduces the amount of low-temperature water (7°C) used in the methanol cooling chamber 120, achieving two benefits at once.
[0039] In addition, when processing tank 1 is shut down, the neutralization reaction chamber 110 stops receiving gas and liquid, the water seal chamber 130 stops receiving liquid, and the hot water jacket 7 and finned heat exchanger 9 stop receiving media. Valve I12 on vent pipe I11 is opened, valve II21 on vent pipe II20 is opened, and valve III23 on connecting pipe 22 is opened. Liquid methanol in the methanol cooling chamber 120 is discharged through vent pipe I11 to the dimethyl oxalate discharge tank 28. After the liquid methanol is completely discharged, valve I12 is closed. Simultaneously, demineralized water in the water seal chamber 130 is discharged through vent pipe II20 and connecting pipe 22 into the neutralization reaction chamber 110, and then discharged through drain pipe 4 until the demineralized water in the water seal chamber 130 is completely discharged. This facilitates maintenance of processing tank 1. Before starting processing tank 1, valves I12, II21, and III23 are closed.
[0040] In summary, in this embodiment, methyl nitrite and dimethyl oxalate in the waste gas are removed by alkaline solution in the neutralization reaction chamber 110, methanol in the waste gas is removed by cooling in the methanol cooling chamber 120, and the waste gas is discharged after being washed with water in the water seal chamber 130. This method is harmless to the environment, and the equipment has a simple structure, low manufacturing cost, and is suitable for industrial use.
[0041] Example 2
[0042] The difference between this embodiment and Embodiment 1 is that: Figure 3 As shown, in this embodiment, a level gauge 24 is provided on the neutralization reaction chamber 110, a pH meter 25 and an electrically controlled valve I 26 are installed on the drain pipe 4, and an electrically controlled valve II 27 is installed on the alkali pipe 5. The electrically controlled valve I 26 is controlled by the level gauge 24, and the electrically controlled valve II 27 is controlled by the pH meter 25.
[0043] In this embodiment, the pH value of the liquid in the drain pipe 4 is monitored in real time by pH meter 25, and the pH value of the liquid in the drain pipe 4 is controlled within the range of 7 to 8. If the pH value is less than 7, the opening degree of the solenoid valve II 27 is increased, and the alkaline solution flow rate is increased; if the pH value is greater than 8, the opening degree of the solenoid valve II 27 is decreased, and the alkaline solution flow rate is decreased, thereby ensuring that the reaction pH value in the neutralization reaction chamber 110 is within the range of 7 to 8. At the same time, the liquid level in the neutralization reaction chamber 110 is monitored in real time by level gauge 24. When the liquid level is too high, the opening degree of solenoid valve I 26 is increased, and the drainage volume is increased; when the liquid level is too low, the opening degree of solenoid valve I 26 is decreased, and the drainage volume is decreased, thereby maintaining the liquid level in the neutralization reaction chamber 110 within a suitable height range.
[0044] The above descriptions are merely embodiments of this utility model, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness or practicality of this utility model. The specific embodiments described in the specification can be used to interpret the claims.
Claims
1. A device for treating volatile gases such as dimethyl oxalate, methanol, and methyl nitrite, comprising a treatment tank, characterized in that: The processing tank has two horizontally arranged partitions that divide the internal space of the tank from bottom to top into a neutralization reaction chamber, a methanol cooling chamber, and a water seal chamber. The neutralization reaction chamber is connected to an inlet pipe and an alkali pipe, with the inlet pipe located below the alkali pipe. A drain pipe is connected to the bottom of the neutralization reaction chamber. The methanol cooling chamber is equipped with a gas cooling pipe and a finned heat exchanger. The bottom end of the gas cooling pipe is connected to the neutralization reaction chamber, and the methanol cooling chamber is connected to a top overflow pipe I. The water seal chamber is equipped with a gas flow pipe, the bottom end of which is connected to the methanol cooling chamber. Both the gas flow pipe and the gas cooling pipe include vertical sections and curved sections. The water seal chamber is connected to a top overflow pipe II. Both the top overflow pipe II and the top overflow pipe I are equipped with liquid seal U-shaped sections. An exhaust pipe and a liquid inlet pipe are connected to the top of the water seal chamber.
2. The dimethyl oxalate, methanol, and methyl nitrite volatile gas treatment equipment according to claim 1, characterized in that: The end of the top overflow pipe II away from the water seal chamber is connected to the neutralization reaction chamber.
3. The equipment for treating dimethyl oxalate, methanol, and methyl nitrite volatile gases according to claim 1 or 2, characterized in that: The bottom of the methanol cooling chamber is connected to an vent pipe I, and a valve I for controlling the opening and closing of the pipe is installed on the vent pipe I.
4. The dimethyl oxalate, methanol, and methyl nitrite volatile gas treatment equipment according to claim 2, characterized in that: The bottom of the water seal chamber is connected to a drain pipe II. The end of the drain pipe II away from the water seal chamber is connected to the top overflow pipe II. A valve II for controlling the opening and closing of the pipeline is installed on the drain pipe II. The bottom of the liquid seal U-shaped section of the top overflow pipe II is connected to the top overflow pipe II through a connecting pipe. A valve III for controlling the opening and closing of the pipeline is installed on the connecting pipe.
5. The dimethyl oxalate, methanol, and methyl nitrite volatile gas treatment equipment according to claim 1, characterized in that: The neutralization reaction chamber is equipped with a ring pipe with several air outlets. One end of the ring pipe is connected to the air inlet pipe, and the other end of the ring pipe is closed.
6. The dimethyl oxalate, methanol, and methyl nitrite volatile gas treatment equipment according to claim 5, characterized in that: The air outlet is set at an angle downwards.
7. The equipment for treating volatile gases of dimethyl oxalate, methanol, and methyl nitrite according to claim 1, characterized in that: The neutralization reaction chamber is equipped with a level gauge, and the drain pipe is equipped with a pH meter and an electrically controlled valve I. The alkali solution pipe is equipped with an electrically controlled valve II. The electrically controlled valve I is controlled by the level gauge, and the electrically controlled valve II is controlled by the pH meter.
8. The dimethyl oxalate, methanol, and methyl nitrite volatile gas treatment equipment according to claim 1, characterized in that: The neutralization reaction chamber is equipped with a hot water jacket.
9. The equipment for treating dimethyl oxalate, methanol, and methyl nitrite volatile gases according to claim 1, characterized in that: The exhaust pipe passes through the neutralization reaction chamber, and heat exchange fins are provided on the outer peripheral wall of the exhaust pipe, which are located inside the neutralization reaction chamber.
10. The dimethyl oxalate, methanol, and methyl nitrite volatile gas treatment equipment according to claim 1, characterized in that: A heat insulation layer is provided on the partition between the methanol cooling chamber and the neutralization reaction chamber.