A system for treating high-concentration organic exhaust gas in the storage, loading and unloading process

Abstract

The application discloses a kind of storage, handling link high concentration organic waste gas processing system, it is related to the field of organic matter containing waste gas treatment technology, including low-temperature solvent absorption system, activated carbon adsorption and desorption system and high-temperature oxidation treatment system, low-temperature solvent absorption system, activated carbon adsorption and desorption system and high-temperature oxidation treatment system are sequentially connected in series through waste gas delivery pipeline;The low-temperature solvent absorption system can absorb the organic matter in waste gas by low-temperature solvent, the activated carbon adsorption and desorption system can intermittently adsorb the organic matter in waste gas by activated carbon, and the activated carbon of the activated carbon adsorption and desorption system is desorbed in the interval between two adsorption actions.The application uses the technical means of low-temperature solvent combined with activated carbon to remove organic matter, replaces the low-temperature condensation link in conventional oil gas recovery process, and the whole system is more energy-saving and low in operating cost.

Description

Technical Field

[0001] This application relates to the field of organic waste gas treatment technology, and in particular to a treatment system for high-concentration organic waste gas during storage and loading / unloading. Background Technology

[0002] For high-concentration organic waste gases generated during storage, loading, and unloading processes in industries such as petrochemicals, coal chemicals, and new energy anode materials, the current conventional treatment methods employ oil and gas recovery processes such as low-temperature condensation, condensation + adsorption, and membrane separation. In existing technologies, the low-temperature condensation process requires reducing the temperature of the organic waste gas to approximately -70°C through two or three stages of condensation. This process consumes a significant amount of energy, resulting in high operating costs. Summary of the Invention

[0003] In order to reduce the operating cost of treating high-concentration organic waste gas, this application provides a treatment system for high-concentration organic waste gas in the storage and loading / unloading process.

[0004] The high-concentration organic waste gas treatment system provided in this application adopts the following technical solution:

[0005] A system for treating high-concentration organic waste gas during storage and loading / unloading includes a low-temperature solvent absorption system, an activated carbon adsorption and desorption system, and a high-temperature oxidation system. These systems are connected in series via a waste gas delivery pipeline. The low-temperature solvent absorption system absorbs organic matter from the waste gas using a low-temperature solvent. The activated carbon adsorption and desorption system intermittently adsorbs organic matter from the waste gas using activated carbon, with the activated carbon in the system desorbing organic matter during the interval between two adsorption cycles.

[0006] By adopting the above technical solution, the waste gas generated during storage and loading / unloading sequentially passes through a low-temperature solvent absorption system, a gas-liquid separator, an activated carbon adsorption and desorption system, and a high-temperature oxidation treatment system. The low-temperature solvent absorption system first adsorbs high-molecular-weight, high-boiling-point organic compounds from the waste gas. Then, the activated carbon adsorption and desorption system further filters and reduces the concentration of organic compounds in the waste gas. After the concentration of organic compounds in the waste gas is reduced to a certain level, it is then subjected to high-temperature oxidation treatment by the high-temperature oxidation treatment system. This technical solution utilizes the low-temperature solvent to absorb the concentrated organic matter, resulting in lower operating costs. Simultaneously, solvent absorption is highly adaptable to gas composition, capable of absorbing high-molecular-weight organic compounds, and is less prone to activated carbon clogging problems. The activated carbon adsorption and desorption process has a large adsorption capacity, which can further reduce the waste gas concentration, improving the overall system's resistance to operating condition fluctuations. The technical means of removing organic matter using low-temperature solvents combined with activated carbon replaces the low-temperature condensation stage in conventional oil and gas recovery processes, making the entire system more energy-efficient and with lower operating costs.

[0007] Optionally, the cryogenic solvent absorption system includes a solvent storage container, a lean oil pump, a lean oil cooling heat exchanger, a refrigeration unit, and an absorption tower; the solvent storage container, the lean oil pump, the lean oil cooling heat exchanger, and the absorption tower are sequentially connected through a solvent delivery pipeline to form a circulation loop, and the refrigeration unit is used to cool the solvent passing through the lean oil cooling heat exchanger.

[0008] By adopting the above technical solution, when the low-temperature solvent absorption system is running, the solvent in the solvent storage container is pumped by the lean oil pump and flows to the top of the absorption tower after passing through the lean oil cooling heat exchanger. The lean oil cooling heat exchanger cools the solvent. The high-concentration organic waste gas enters from the bottom of the absorption tower and comes into countercurrent contact with the low-temperature absorption solvent sprayed from the top of the absorption tower on the surface of the packing material, and a mass transfer process occurs. The high-concentration organic matter dissolves into the low-temperature solvent.

[0009] Optionally, the cryogenic solvent absorption system further includes a rich oil pump and a lean-rich oil heat exchanger. The lean-rich oil heat exchanger is connected in series between the lean oil pump and the lean oil cooling heat exchanger. The rich oil pump is used to pump the solvent returning from the absorption tower, and the solvent returning from the absorption tower serves as the cooling medium for the lean-rich oil heat exchanger.

[0010] By adopting the above technical solution, the solvent pumped by the lean oil pump first passes through the lean-rich oil heat exchanger and then enters the lean oil cooling heat exchanger. The solvent that has absorbed organic matter in the absorption tower, under the pumping action of the rich oil pump, flows back to the solvent storage container after passing through the rich oil heat exchanger. The solvent returning from the absorption tower serves as the cooling medium for the lean-rich oil heat exchanger, pre-cooling the solvent at the front end of the lean oil cooling heat exchanger, which helps to improve the cooling efficiency of the solvent and reduce the energy consumption of solvent cooling.

[0011] Optionally, the absorption tower is equipped with a circulating air pump, the outlet end of which is connected to the lower part of the absorption tower, and the inlet end of which is connected to the top of the absorption tower.

[0012] By adopting the above technical solution, the circulating gas pump can increase the circulation flow rate of the waste gas in the absorption tower, thereby enabling more sufficient contact between the waste gas and the low-temperature solvent, which is beneficial to improving the mass transfer efficiency between the waste gas and the low-temperature solvent.

[0013] Optionally, the activated carbon adsorption and desorption system includes an adsorption tank, a vacuum pump, and a switching valve. The adsorption tank is filled with activated carbon, and there are two adsorption tanks. The two adsorption tanks operate alternately, and the switching valve is used to connect the two adsorption tanks to the corresponding vacuum pump and the waste gas delivery pipeline, respectively.

[0014] By employing the above technical solution, the waste gas, after being absorbed by a low-temperature solvent, enters the adsorption tank. During its passage through activated carbon, the organic matter in the waste gas is adsorbed into the microporous structure inside the activated carbon, thus purifying the waste gas. After the first adsorption tank adsorbs for a certain period, the system switches to the second adsorption tank. The first adsorption tank then enters a desorption state, and a vacuum pump is used to evacuate the inside of the adsorption tank, causing the organic matter adsorbed into the microporous structure of the activated carbon to vaporize and escape, thus regenerating the activated carbon. After the second adsorption tank adsorbs for a certain period, the system switches back to the first adsorption tank, and the second adsorption tank enters a desorption state, and this cycle repeats continuously.

[0015] Optionally, the adsorption tank is equipped with a nitrogen pipe for supplying nitrogen to the adsorption tank.

[0016] By adopting the above technical solution, during the process of using a vacuum pump to remove the organic matter adsorbed by activated carbon, nitrogen gas is introduced into the adsorption tank through a nitrogen pipe, so that a continuous airflow is formed in the adsorption tank, thereby enabling the organic matter adsorbed by activated carbon to be fully desorbed.

[0017] Optionally, the airflow direction of the adsorption tank is generally along the height direction of the adsorption tank, the activated carbon in the adsorption tank is arranged in layers, the upper and lower layers of activated carbon are separated by a separator, one side of the separator is provided with a notch, and the notches of adjacent upper and lower separators are staggered along the circumference of the adsorption tank.

[0018] By adopting the above technical solution, the waste gas in the adsorption tank flows sequentially through each activated carbon layer along the height direction of the adsorption tank. When the waste gas flows between adjacent activated carbon layers, it needs to pass through the gaps of the separator. Since the gaps of adjacent separators are staggered along the circumference of the adsorption tank, it is beneficial to extend the path of the waste gas in the adsorption tank, thereby increasing the effective residence time of the waste gas in the adsorption tank and thus improving the filtration efficiency of activated carbon in the waste gas.

[0019] Optionally, the air inlet pipe of the adsorption tank includes a main air inlet pipe and a bypass pipe. The main air inlet pipe is connected to the end wall of the adsorption tank, and the bypass pipe is connected to the side wall of the adsorption tank. The port of the bypass pipe connected to the adsorption tank is inclined toward the port of the main air inlet pipe connected to the adsorption tank.

[0020] By adopting the above technical solution, the waste gas enters the adsorption tank through the main inlet pipe and the bypass pipe. Since the port of the bypass pipe connected to the adsorption tank is tilted towards the port of the main inlet pipe connected to the adsorption tank, the waste gas entering the adsorption tank through the main inlet pipe and the waste gas entering the adsorption tank through the bypass pipe interfere with each other, so that the waste gas in the adsorption tank is dispersed as much as possible, which is conducive to more sufficient contact between the waste gas and the activated carbon.

[0021] Optionally, the high-temperature oxidation treatment system includes a regenerative oxidizer, the front end of which is equipped with a lower explosive limit analyzer for combustible gases, and the front end of which is equipped with an exhaust duct.

[0022] By adopting the above technical solution, the waste gas, after being adsorbed by activated carbon, can be sent to a regenerative thermal oxidizer for high-temperature oxidation treatment if the concentration measured by the lower explosive limit analyzer is within safe limits. If the waste gas concentration exceeds the safe limits, dilution gas is supplied to the front end of the analyzer via an exhaust pipe to reduce the concentration of organic matter in the waste gas. The regenerative thermal oxidizer can achieve a treatment efficiency of over 99.5%, controlling the final non-methane total hydrocarbon emission index to below 20 mg / m³, achieving ultra-low emissions from tank farms and loading / unloading operations.

[0023] Optionally, a gas-liquid separator is also included, which is connected in series between the cryogenic solvent absorption system and the activated carbon adsorption and desorption system.

[0024] By adopting the above technical solution, the gas-liquid separator can separate solvent droplets in the waste gas, reduce the amount of solvent droplets entering the inner side of the adsorption tank and wetting the activated carbon, so that the activated carbon in the adsorption tank can fully play its role in adsorbing organic matter.

[0025] In summary, this application includes at least one of the following beneficial technical effects:

[0026] 1. The technical solution of this application utilizes low-temperature solvent adsorption to reduce the concentration of organic matter. Solvent adsorption is highly adaptable to gas composition, capable of absorbing large molecular weight organic matter, and is less prone to activated carbon clogging. The activated carbon adsorption-desorption process has a large adsorption capacity, which can further reduce the concentration of waste gas and improve the overall system's resistance to operating condition fluctuations. The technical means of removing organic matter using low-temperature solvents combined with activated carbon has low operating costs.

[0027] 2. During the process of using a vacuum pump to remove the organic matter adsorbed by activated carbon, nitrogen gas is introduced into the adsorption tank through a nitrogen pipe to create a continuous airflow inside the adsorption tank, thereby enabling the organic matter adsorbed by the activated carbon to be fully desorbed. Attached Figure Description

[0028] Figure 1 This is a process flow diagram showing the usage status of the high-concentration organic waste gas treatment system in the storage and loading / unloading stages of Example 1.

[0029] Figure 2 This is a schematic diagram of the activated carbon adsorption and desorption system in Example 1 under one of its operating states.

[0030] Figure 3This is a schematic diagram of the activated carbon adsorption and desorption system in Example 1 under another working state.

[0031] Figure 4 This is a schematic diagram of the absorption tower in Example 2.

[0032] Figure 5 This is a schematic diagram of the adsorption tank in Example 3.

[0033] Figure 6 This is a schematic diagram of the steam trap in Example 4.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Low-temperature solvent absorption system; 11. Solvent storage container; 12. Lean oil pump; 13. Rich oil pump; 14. Lean oil cooling heat exchanger; 15. Lean and rich oil heat exchanger; 16. Refrigeration unit; 17. Absorption tower; 18. Circulating air pump; 19. Baffle; 2. Gas-liquid separator; 3. Activated carbon adsorption and desorption system; 31. Adsorption tank; 311. Separator; 3111. Notch; 312. Main air inlet pipe; 313. Bypass pipe; 32. Vacuum pump; 33. Switching valve; 34. Nitrogen pipe; 4. High-temperature oxidation treatment system; 41. Regenerative oxidizer; 42. Combustible gas lower explosion limit analyzer; 43. Exhaust duct; 5. Drain valve; 51. Shell; 52. Float; 53. Magnet. Detailed Implementation

[0036] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0037] Example 1

[0038] This application discloses a system for treating high-concentration organic waste gas during storage and loading / unloading processes. (Refer to...) Figure 1 The high-concentration organic waste gas treatment system for storage and loading / unloading includes a low-temperature solvent absorption system 1, a gas-liquid separator 2, an activated carbon adsorption and desorption system 3, and a high-temperature oxidation treatment system 4. The low-temperature solvent absorption system 1, the gas-liquid separator 2, the activated carbon adsorption and desorption system 3, and the high-temperature oxidation treatment system 4 are connected in series through waste gas transmission pipelines.

[0039] The waste gas generated during storage and loading / unloading processes sequentially passes through a low-temperature solvent absorption system 1, a gas-liquid separator 2, an activated carbon adsorption and desorption system 3, and a high-temperature oxidation treatment system 4. The low-temperature solvent absorption system 1 first adsorbs high-molecular-weight, high-boiling-point organic compounds from the waste gas. Then, the activated carbon adsorption and desorption system 3 further filters and reduces the concentration of organic compounds in the waste gas. After the concentration of organic compounds in the waste gas is reduced to a certain level, it is then subjected to high-temperature oxidation treatment by the high-temperature oxidation treatment system 4.

[0040] The cryogenic solvent absorption system 1 includes a solvent storage container 11, a lean oil pump 12, a rich oil pump 13, a lean oil cooling heat exchanger 14, a lean and rich oil heat exchanger 15, a refrigeration unit 16, and an absorption tower 17. The solvent storage container 11, the lean oil pump 12, the lean and rich oil heat exchanger 15, the lean oil cooling heat exchanger 14, the absorption tower 17, and the rich oil pump 13 are sequentially connected through solvent delivery pipelines to form a circulation loop. The solvent in the cryogenic solvent absorption system 1 is gasoline, diesel, or wash oil, etc.

[0041] The refrigeration unit 16 is used to cool the solvent that has passed through the lean oil cooling heat exchanger 14; the lean and rich oil heat exchanger 15 is connected in series between the lean oil pump 12 and the lean oil cooling heat exchanger 14; the rich oil pump 13 is used to pump the solvent returning from the absorption tower 17; the solvent returning from the absorption tower 17 passes through the lean and rich oil heat exchanger 15; the solvent passes through the lean and rich oil heat exchanger 15 both when flowing into and out of the absorption tower 17; the solvent remains separated from the other during the two processes of passing through the lean and rich oil heat exchanger 15; the solvent returning from the absorption tower 17 serves as the cooling medium for the lean and rich oil heat exchanger 15.

[0042] When the low-temperature solvent absorption system 1 is running, the solvent in the solvent storage container 11 is pumped by the lean oil pump 12 and flows sequentially through the lean-rich oil heat exchanger 15 and the lean oil cooling heat exchanger 14 to the top of the absorption tower 17. The lean-rich oil heat exchanger 15 and the lean oil cooling heat exchanger 14 cool the solvent sequentially, reducing the solvent temperature to 10-15℃. The high-concentration organic waste gas enters from the bottom of the absorption tower 17 and comes into countercurrent contact with the low-temperature absorption solvent sprayed from the top of the absorption tower 17 on the packing surface, resulting in a mass transfer process. The high-concentration organic matter dissolves into the low-temperature solvent. The solvent that has absorbed organic matter in the absorption tower 17 is pumped by the rich oil pump 13 and flows back to the solvent storage container 11 after passing through the rich oil heat exchanger.

[0043] Reference Figure 1 , Figure 2 and Figure 3 The activated carbon adsorption and desorption system 3 includes an adsorption tank 31, a vacuum pump 32, and a switching valve 33. The adsorption tank 31 is filled with activated carbon, which is columnar coal-based activated carbon granules. There are two adsorption tanks 31. Waste gas flows in from the bottom of the adsorption tank 31 and flows out from the top of the adsorption tank 31. The two adsorption tanks 31 operate alternately. In this embodiment, the switching valve 33 is a four-way ball valve. The air inlet pipes of the two adsorption tanks 31 are respectively connected to the two opposite ports of the four-way ball valve. The other two ports of the four-way ball valve are respectively used to connect to the waste gas delivery pipeline and the vacuum pump 32. The switching valve 33 is used to connect the two adsorption tanks 31 to the corresponding vacuum pump 32 and the waste gas delivery pipeline.

[0044] After being absorbed by a low-temperature solvent, the waste gas enters adsorption tank 31. As it passes through activated carbon, the organic matter in the waste gas is adsorbed into the microporous structure of the activated carbon, thus purifying the waste gas. After 20 minutes of adsorption in the first adsorption tank 31, the process switches to the second adsorption tank 31. The first adsorption tank 31 then enters desorption mode. A vacuum pump 32 is used to evacuate the inside of the adsorption tank 31, raising the pressure to approximately 5 kPa within 15 minutes and maintaining this pressure. This causes the organic matter adsorbed into the microporous structure of the activated carbon to vaporize and escape, regenerating the activated carbon and restoring its adsorption capacity. After 20 minutes of adsorption in the second adsorption tank 31, the process switches back to the first adsorption tank 31, which then enters desorption mode. This cycle repeats continuously. The desorbed organic waste gas from adsorption tank 31, along with the highly concentrated organic waste gas, is fed into the bottom of the adsorption tower.

[0045] Reference Figure 1 The adsorption tank 31 is equipped with a nitrogen pipe 34, which connects the two adsorption tanks 31 and is connected to a nitrogen supply device. When the adsorption tank 31 enters the desorption state, the nitrogen pipe 34 supplies nitrogen to the adsorption tank 31 in the desorption state, so that a continuous airflow is formed in the adsorption tank 31, allowing the activated carbon in the adsorption tank 31 to be fully desorbed and regenerated.

[0046] In this embodiment, the activated carbon in the adsorption tank 31 is desorbed and regenerated by vacuuming combined with nitrogen supply. In another embodiment, the desorption and regeneration of activated carbon can be replaced by supplying compressed air or nitrogen.

[0047] The high-temperature oxidation treatment system 4 includes a regenerative thermal oxidizer 41 (RTO). A combustible gas lower explosion limit analyzer 42 is installed at the front end of the RTO. An exhaust pipe 43 is installed at the front end of the combustible gas lower explosion limit analyzer 42. The exhaust pipe 43 is used to introduce the flue gas treated by the RTO into the front end of the combustible gas lower explosion limit analyzer 42. The combustible gas lower explosion limit analyzer 42 is installed at the front end of the RTO. There are three sets of combustible gas lower explosion limit analyzers 42, which are controlled by a three-zone two-logic (3OO2) control. The combustible gas lower explosion limit analyzer 42 detects the concentration of exhaust gas in real time.

[0048] When the gas concentration purified by adsorption tank 31 is <25% LEL, the waste gas can be safely introduced into regenerative thermal oxidizer 41 for high-temperature oxidation treatment. The NMHC emission index of the oxidized waste gas can reach below 20 mg / m³. When the waste gas concentration is detected to be >25% LEL, the waste gas is diluted using the flue gas discharged from regenerative thermal oxidizer 41 to reduce the waste gas concentration to below 25% LEL before being introduced into regenerative thermal oxidizer 41 for oxidation treatment. If the waste gas concentration after dilution is still higher than 25% LEL, the system is switched to the emergency emission system to ensure the safe operation of regenerative thermal oxidizer 41.

[0049] The implementation principle of a high-concentration organic waste gas treatment system in the storage and loading / unloading process according to an embodiment of this application is as follows: the solvent stored in the solvent storage container 11 is cooled to a suitable temperature range by the lean oil pump 12 and the lean oil cooler; the cooled solvent is sprayed down from the top of the absorption tower 17; the high-concentration organic waste gas enters from the bottom of the absorption tower 17, and the low-temperature absorption solvent sprayed down from the top of the absorption tower 17 comes into countercurrent contact with the packing surface of the absorption tower 17, and a mass transfer process occurs, in which the high molecular weight and high boiling point organic compounds in the high-concentration organic waste gas dissolve into the low-temperature solvent; after absorbing the organic compounds, the solvent in the absorption tower 17 returns to the solvent storage container 11.

[0050] The waste gas absorbed by the absorption tower 17 is discharged from the top of the tower and sent to the subsequent activated carbon adsorption and desorption system 3. The activated carbon in the adsorption tank 31 will further absorb the organic matter in the waste gas, so that the concentration of organic matter in the waste gas will be further reduced. The two adsorption tanks 31 operate alternately. The activated carbon in the adsorption tank 31 that has adsorbed organic matter is regenerated by vacuum pump 32. After the waste gas is adsorbed by the activated carbon, if the waste gas meets the safe concentration as measured by the combustible gas lower explosion limit analyzer 42, it can be sent to the regenerative oxidizer 41 for high-temperature oxidation treatment. If the waste gas exceeds the safe concentration as measured by the combustible gas lower explosion limit analyzer 42, the flue gas from the combustion in the regenerative oxidizer 41 is transported to the front end of the combustible gas lower explosion limit analyzer 42 for dilution using the air supply device.

[0051] The technical solution presented in this application utilizes low-temperature solvent adsorption to reduce the concentration of organic matter, resulting in lower operating costs. Furthermore, solvent adsorption is highly adaptable to gas composition, capable of absorbing large molecular weight organic matter and minimizing activated carbon clogging issues. The activated carbon adsorption-desorption process boasts a large adsorption capacity, further reducing the concentration of waste gas and improving the overall system's resilience to operating condition fluctuations. This technology, combining low-temperature solvents with activated carbon for organic matter removal, replaces the low-temperature condensation stage in conventional oil and gas recovery processes, making the entire system more energy-efficient and reducing operating costs.

[0052] Example 2

[0053] Reference Figure 4The difference between this embodiment and embodiment 1 is that the absorption tower 17 is equipped with a circulating air pump 18. The outlet end of the circulating air pump 18 is connected to the lower part of the absorption tower 17, and the inlet end of the circulating air pump 18 is connected to the top of the absorption tower 17. The circulating air pump 18 can promote the flow rate of the waste gas in the absorption tower 17, so that the waste gas and the low temperature solvent can be in more sufficient contact.

[0054] The inner wall of the absorption tower 17 is equipped with a baffle 19, which is used to shield the port of the inlet pipe of the circulating air pump 18. A gap is left between the baffle 19 and the port of the inlet pipe of the circulating air pump 18. When the waste gas in the absorption tower 17 flows towards the inlet port of the circulating air pump 18, it comes into contact with the baffle 19, so that the baffle 19 can intercept some of the solvent droplets carried in the waste gas, which helps to keep the waste gas entering the circulating air pump 18 as dry as possible.

[0055] Example 3

[0056] Reference Figure 5 The difference between this embodiment and embodiment 1 is that the activated carbon in the adsorption tank 31 is arranged in layers, and the upper and lower layers of activated carbon are separated by a separator 311. The separator 311 is filter cotton or non-woven fabric. A notch 3111 is provided on one side of the separator 311, and the notches 3111 of the upper and lower adjacent separators 311 are staggered along the circumference of the adsorption tank 31.

[0057] The waste gas in the adsorption tank 31 flows sequentially through each activated carbon layer along the height direction of the adsorption tank 31. When the waste gas flows between adjacent activated carbon layers, it needs to pass through the gaps 3111 of the separator 311. Since the gaps 3111 of the adjacent separator 311 are staggered along the circumference of the adsorption tank 31, it is beneficial to extend the path of the waste gas in the adsorption tank 31, thereby increasing the effective residence time of the waste gas in the adsorption tank 31, and thus improving the filtration efficiency of the activated carbon in the waste gas.

[0058] In this embodiment, the air inlet pipe of the adsorption tank 31 includes a main air inlet pipe 312 and a bypass pipe 313. The main air inlet pipe 312 is connected to the end wall of the adsorption tank 31, and the bypass pipe 313 is connected to the side wall of the adsorption tank 31. The port of the bypass pipe 313 connected to the adsorption tank 31 is inclined towards the port of the main air inlet pipe 312 connected to the adsorption tank 31. The waste gas enters the adsorption tank 31 through the main air inlet pipe 312 and the bypass pipe 313. Since the port of the bypass pipe 313 connected to the adsorption tank 31 is inclined towards the port of the main air inlet pipe 312 connected to the adsorption tank 31, the waste gas entering the adsorption tank 31 through the main air inlet pipe 312 and the waste gas entering the adsorption tank 31 through the bypass pipe 313 interfere with each other, so that the waste gas in the adsorption tank 31 is dispersed as much as possible, which is conducive to more sufficient contact between the waste gas and the activated carbon.

[0059] Example 4

[0060] Reference Figure 6 The difference between this embodiment and embodiment 1 is that the gas-liquid separator 2 is provided with a drain valve 5 for intermittently discharging liquid solvent. The drain valve 5 is a float-type drain valve 52, which includes a housing 51 and a float 52. The float 52 is made of ferritic or martensitic stainless steel. A magnet 53 is provided on the top of the housing 51. The magnet 53 is located inside the housing 51 and is used to apply an upward magnetic attraction force to the float 52. This magnetic attraction force is less than the weight of the float 52.

[0061] When the float 52 is located at the bottom of the housing 51 of the steam trap 5, the float 52 is outside the magnetic attraction range of the magnet 53. When the solvent level in the housing 51 reaches the corresponding drainage level of the steam trap 5, the magnet 53 exerts a magnetic attraction on the float 52. The magnetic attraction force of the magnet 53 on the float 52 can compensate for the insufficient buoyancy of the solvent on the float 52.

[0062] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A system for treating high-concentration organic waste gas during storage and loading / unloading processes, characterized in that, The system includes a low-temperature solvent absorption system (1), an activated carbon adsorption and desorption system (3), and a high-temperature oxidation treatment system (4). The low-temperature solvent absorption system (1), the activated carbon adsorption and desorption system (3), and the high-temperature oxidation treatment system (4) are connected in series through a waste gas conveying pipeline. The low-temperature solvent absorption system (1) can absorb organic matter in the waste gas through a low-temperature solvent. The activated carbon adsorption and desorption system (3) can adsorb organic matter in the waste gas through activated carbon intermittently. The activated carbon in the activated carbon adsorption and desorption system (3) desorbs organic matter during the interval between two adsorption actions. The low-temperature solvent absorption system (1) includes a solvent storage container (11), a lean oil pump (12), a lean oil cooling heat exchanger (14), a refrigeration unit (16), and an absorption tower (17); the solvent storage container (11), the lean oil pump (12), the lean oil cooling heat exchanger (14), and the absorption tower (17) are sequentially connected through a solvent delivery pipeline to form a circulation loop; the refrigeration unit (16) is used to cool the solvent passing through the lean oil cooling heat exchanger (14); The activated carbon adsorption and desorption system (3) includes an adsorption tank (31), a vacuum pump (32), and a switching valve (33). The adsorption tank (31) is filled with activated carbon. There are two adsorption tanks (31), and the two adsorption tanks (31) operate alternately. The switching valve (33) is used to connect the two adsorption tanks (31) to the vacuum pump (32) and the corresponding waste gas conveying pipeline, respectively. The air inlet pipe of the adsorption tank (31) includes an air inlet main pipe (312) and a bypass pipe (313). The air inlet main pipe (312) is connected to the end wall of the adsorption tank (31), and the bypass pipe (313) is connected to the side wall of the adsorption tank (31). The port of the bypass pipe (313) connected to the adsorption tank (31) is inclined toward the port of the air inlet main pipe (312) connected to the adsorption tank (31). It also includes a gas-liquid separator (2), which is connected in series between the low-temperature solvent absorption system (1) and the activated carbon adsorption and desorption system (3); the gas-liquid separator (2) is provided with a condensate drain valve (5) for intermittently discharging liquid solvent. The condensate drain valve (5) is a float-type condensate drain valve, which includes a housing (51) and a float (52). The float (52) is made of ferritic or martensitic stainless steel. A magnet (53) is provided on the top of the housing (51). The magnet (53) is located inside the housing (51). The magnet (53) is used to apply an upward magnetic attraction force to the float (52), which is less than the weight of the float (52).

2. The system for treating high-concentration organic waste gas during storage and loading / unloading as described in claim 1, characterized in that: The low-temperature solvent absorption system (1) also includes a rich oil pump (13) and a lean oil heat exchanger (15). The lean oil heat exchanger (15) is connected in series between the lean oil pump (12) and the lean oil cooling heat exchanger (14). The rich oil pump (13) is used to pump the solvent returning from the absorption tower (17). The solvent returning from the absorption tower (17) serves as the cooling medium for the lean oil heat exchanger (15).

3. The system for treating high-concentration organic waste gas during storage and loading / unloading as described in claim 1, characterized in that: The absorption tower (17) is equipped with a circulating air pump (18), the outlet end of which is connected to the lower part of the absorption tower (17), and the inlet end of which is connected to the top of the absorption tower (17).

4. The system for treating high-concentration organic waste gas during storage and loading / unloading as described in claim 1, characterized in that: The adsorption tank (31) is equipped with a nitrogen pipe (34) for supplying nitrogen to the adsorption tank (31).

5. The system for treating high-concentration organic waste gas during storage and loading / unloading as described in claim 1, characterized in that: The airflow direction of the adsorption tank (31) is generally along the height direction of the adsorption tank (31). The activated carbon in the adsorption tank (31) is arranged in layers, and the upper and lower layers of activated carbon are separated by a separator (311). A notch (3111) is provided on one side of the separator (311), and the notches (3111) of the upper and lower adjacent separators (311) are staggered along the circumference of the adsorption tank (31).

6. The system for treating high-concentration organic waste gas during storage and loading / unloading as described in claim 1, characterized in that: The high-temperature oxidation treatment system (4) includes a regenerative oxidizer (41), and a combustible gas lower explosion limit analyzer (42) is provided at the front end of the regenerative oxidizer (41), and an exhaust pipe (43) is provided at the front end of the combustible gas lower explosion limit analyzer (42).

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