Odor purification system and process with additional water washing tower

Abstract

The application discloses a peculiar smell purification system and process with a water washing tower, and belongs to the technical field of peculiar smell purification treatment of industrial waste water, and comprises an alkali washing tower, a water washing tower and an induced draft fan, the exhaust port of the alkali washing tower is communicated with the air inlet of the water washing tower through a first pipeline, and the exhaust port of the water washing tower is communicated with the air inlet of the induced draft fan through a second pipeline; the alkali washing tower is used as a primary purification unit for removing hydrogen sulfide in peculiar smell gas, and the water washing tower is used as a secondary purification unit for removing methanol in the gas treated by the alkali washing tower; the two-stage grading purification structure with the alkali washing tower and the water washing tower in series is arranged, hydrogen sulfide is removed by the alkali washing tower first, and then methanol is removed by the water washing tower, the two purification functions that cannot be simultaneously realized by a single washing tower are distributed to two-stage tower bodies and completed respectively, the technical problem that hydrogen sulfide and methanol cannot be simultaneously removed by the single washing tower is solved in a targeted manner, and all pollutant indexes of the discharge port can meet environmental protection requirements.

Description

Technical Field

[0001] This invention belongs to the field of industrial wastewater odor purification and treatment technology, specifically relating to an odor purification system and process with the addition of a water washing tower. Background Technology

[0002] Chemical production processes generate wastewater containing pollutants such as hydrogen sulfide, methanol, formaldehyde, and VOCs, producing odorous gases that must be treated by specialized odor purification equipment before being discharged in compliance with standards. Existing chemical wastewater odor purification equipment typically includes a plant scrubbing tower, which uses plant-based scrubbing liquid to spray and wash the odorous gases, removing some of the pollutants. In actual operation, this plant scrubbing tower can be used as an alkaline scrubbing tower or a water scrubbing tower, depending on process requirements, to remove characteristic pollutants such as hydrogen sulfide or methanol from the odorous gases.

[0003] However, existing odor purification devices have significant technical shortcomings in actual operation. Actual testing has verified that when the plant scrubbing tower is used as an alkaline scrubbing tower, the hydrogen sulfide emission level meets the standard, but the methanol emission level fails to meet the standard; when used as a water scrubbing tower, the methanol emission level meets the standard, but the hydrogen sulfide emission level fails to meet the standard. It is impossible to simultaneously meet the emission standards for both hydrogen sulfide and methanol. A single scrubbing tower structure can only effectively remove one type of pollutant, making it difficult to consider the different purification characteristics of hydrogen sulfide and methanol, posing a risk of exceeding emission standards. Furthermore, the physicochemical properties of different pollutants differ significantly. Hydrogen sulfide is best removed through alkaline washing neutralization, while methanol is better removed through water washing absorption. A single scrubbing tower cannot simultaneously match the optimal purification process conditions for both pollutants, necessitating optimization and modification of the existing odor purification system. Summary of the Invention

[0004] To address the problems mentioned in the background section, this invention provides an odor purification system with an added water washing tower, featuring the synergistic removal of hydrogen sulfide and methanol to achieve the required standards.

[0005] The present invention also provides an odor purification process by adding a water washing tower.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an odor purification system with an added water washing tower, comprising an alkaline washing tower, a water washing tower, and an induced draft fan. The exhaust port of the alkaline washing tower is connected to the air inlet of the water washing tower via a first pipeline, and the exhaust port of the water washing tower is connected to the air inlet of the induced draft fan via a second pipeline. The alkaline washing tower serves as a primary purification unit for removing hydrogen sulfide from odor gases, and the water washing tower serves as a secondary purification unit for removing methanol from the gas treated by the alkaline washing tower. The induced draft fan is used to transport the purified gas to the exhaust port, forming a two-stage purification structure of alkaline washing and water washing.

[0007] Furthermore, the alkaline washing tower is modified from a plant washing tower to utilize existing equipment resources and reduce modification costs. The odor purification system is designed to have a processing capacity of 20,000 m³ / h.

[0008] Furthermore, the water washing tower is a 9m³ carbon steel tower that has been modified from an existing tower. The tower body is equipped with an anti-corrosion layer and a spraying device. The anti-corrosion layer is used to prevent the inner wall of the tower from being corroded, and the spraying device is used to spray circulating water into the tower to absorb methanol in the gas.

[0009] Furthermore, the water washing tower is equipped with a circulation pump, which is connected to the spray device of the water washing tower through a circulation pipeline. The circulation pump is used to provide circulating power for the spray purification of the water washing tower.

[0010] Furthermore, two circulation pumps are provided, which serve as backups for each other to ensure continuous system operation in the event of a failure of one circulation pump.

[0011] Furthermore, both the first and second pipelines are DN800 fiberglass pipelines. Manholes and valves are installed on both the first and second pipelines. The manholes are used for internal inspection and maintenance of the pipelines, and the valves are used to control the on / off state of the pipelines and regulate the gas flow.

[0012] Furthermore, the water washing tower is connected to an inlet pipeline and an outlet pipeline, and valves are installed on the inlet and outlet pipelines. The inlet pipeline is used to supply circulating water to the water washing tower, and the outlet pipeline is used to discharge the circulating water in the water washing tower. The valves are used to control the supply and discharge of circulating water. The inlet pipeline is a DN100 stainless steel pipeline, and the outlet pipeline is a DN80 stainless steel pipeline.

[0013] Furthermore, a pressure gauge with a range of 0-1.6 MPa is installed on the body of the water washing tower to monitor the pressure parameters of the water washing tower and related pipelines in real time.

[0014] Furthermore, the first pipeline and / or the second pipeline are provided with fiberglass elbows and manhole bolt connectors. The fiberglass elbows are used to change the direction of the pipeline, and the manhole bolt connectors are used to seal and fix the manhole.

[0015] Furthermore, an odor purification process that adds a water washing tower includes the following steps: S1: Primary Alkali Washing Purification: The chemical odor gases containing hydrogen sulfide, methanol, formaldehyde, and ammonia are collected and sent into the alkali washing tower, which is a modified plant scrubbing tower, at a flow rate of 20,000 m³ / h. The alkaline solution sprayed inside the tower comes into full countercurrent contact with the odor gases, and hydrogen sulfide is removed from the gas phase through acid-base neutralization reaction, controlling the hydrogen sulfide concentration at the outlet of the alkali washing tower to below 5.0 mg / m³. The pre-purified gas after treatment by the alkali washing tower is discharged from the top exhaust port and then transported to the inlet of the water washing tower through the first pipeline, which is sealed by fiberglass elbows, manhole bolt connections, maintenance manholes, and control valves. The valves control the gas flow rate in the pipeline in real time, and the manholes are reserved for regular maintenance of the pipeline. S2: Secondary Water Washing and Purification: The gas after the primary alkaline wash enters a 9m³ recycled carbon steel water washing tower from bottom to top. The inner wall of the water washing tower is fully covered with an anti-corrosion layer to isolate corrosive media. Two parallel circulating pumps, acting as backups for each other, continuously draw circulating water from the bottom of the water washing tower through a circulation pipeline and deliver it to the spray device at the top of the tower for downward spraying. This creates a counter-current gas-liquid contact with the upward-flowing gas, relying on the physical property that methanol is easily soluble in water to absorb residual methanol in the gas phase, thus stabilizing the methanol concentration at the outlet of the water washing tower below 80mg / m³. The water washing tower is equipped with a water inlet. Both the inlet and outlet water pipelines are equipped with valves. The valves are used to periodically open the inlet water pipeline to replenish fresh circulating water and open the outlet water pipeline to discharge methanol-rich wastewater, thus maintaining the quality of the water washing circulating water. The water washing tower is equipped with a pressure gauge with a range of 0-1.6MPa to monitor the gas phase pressure inside the tower and the downstream pipeline in real time. It provides timely warnings when the pressure is abnormal, ensuring the stable operation of the water washing unit. The gas purified by the water washing tower flows out from the exhaust port at the top of the tower and enters a second pipeline, which is also equipped with manholes, valves, FRP elbows, and manhole bolt connections. S3: Compliant Emissions: The clean gas after secondary water washing is transported to the inlet of the induced draft fan via the second pipeline. The induced draft fan provides negative pressure for the entire system, pressurizing and transporting the purified gas to the high-altitude exhaust outlet. The final exhaust gas simultaneously meets multiple environmental limits: hydrogen sulfide < 5.0 mg / m³, methanol < 80 mg / m³, formaldehyde < 20 mg / m³, and ammonia < 30 mg / m³, achieving synergistic compliance of multiple pollutants. Throughout the system, the flow rate of gas and water can be adjusted through valves on each pipeline. Pipeline manholes and tower interfaces can be regularly inspected and cleaned. The standby circulating pump can automatically switch to operation when the running pump fails, ensuring uninterrupted continuous operation of the entire purification process.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention employs a two-stage purification structure with an alkaline scrubbing tower and a water scrubbing tower connected in series. First, the alkaline scrubbing tower removes hydrogen sulfide, and then the water scrubbing tower removes methanol. This distributes the two purification functions, which cannot be achieved simultaneously by a single scrubbing tower, to two separate towers, thus specifically solving the technical problem that existing single scrubbing towers cannot simultaneously remove hydrogen sulfide and methanol, ensuring that all pollutant indicators at the emission outlet meet environmental protection requirements.

[0017] 2. This invention sets a graded purification sequence for hydrogen sulfide and methanol, first using alkali washing to remove hydrogen sulfide and then using water washing to remove methanol. This matches the different purification characteristics of hydrogen sulfide being suitable for alkali washing and methanol being suitable for water washing, avoiding mutual interference between the two in the same washing tower, and achieving synergistic and efficient removal of hydrogen sulfide and methanol.

[0018] 3. This invention utilizes existing carbon steel towers to transform them into water washing towers and applies internal anti-corrosion and spraying treatments, making full use of existing equipment resources on site. While ensuring purification effects, it significantly reduces equipment modification costs, shortens the construction cycle, and has minimal impact on the original production process.

[0019] 4. This invention monitors the pressure parameters of the water washing tower and related pipelines in real time by installing a pressure gauge with a range of 0-1.6MPa on the water washing tower body. When abnormal pressure fluctuations occur, an early warning can be issued in time. At the same time, manholes are installed on key pipelines to facilitate regular inspection and maintenance, ensuring the stability and safety of the system in long-term operation. Attached Figure Description

[0020] Figure 1 This is a system flowchart of the present invention; Figure 2 This is a flowchart of the process flow of the present invention; Figure 3 This is a system principle block diagram of the present invention; In the diagram: 1. Alkali washing tower; 2. Water washing tower; 21. Anti-corrosion layer; 22. Spraying device; 3. Exhaust fan; 4. First pipeline; 5. Second pipeline; 6. Circulating pump; 7. Circulating pipeline; 8. Manhole; 9. Valve; 10. Inlet pipeline; 11. Outlet pipeline; 12. Pressure gauge; 13. Fiberglass elbow; 14. Manhole bolt connector. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figure 1-3The present invention provides the following technical solution: an odor purification system with an added water washing tower, comprising an alkaline washing tower 1, a water washing tower 2, and an induced draft fan 3. The exhaust port of the alkaline washing tower 1 is connected to the air inlet of the water washing tower 2 through a first pipeline 4, and the exhaust port of the water washing tower 2 is connected to the air inlet of the induced draft fan 3 through a second pipeline 5. The alkaline washing tower 1 serves as a primary purification unit for removing hydrogen sulfide from odor gases, the water washing tower 2 serves as a secondary purification unit for removing methanol from the gas treated by the alkaline washing tower 1, and the induced draft fan 3 is used to transport the purified gas to the exhaust port, forming a two-stage purification structure of alkaline washing and water washing. See Figure 1-3 Alkali scrubbing tower 1 was modified from the original plant scrubbing tower. The original unit was designed to process 20,000 m³ / h, collecting and treating odorous gases containing pollutants such as hydrogen sulfide, methanol, formaldehyde, and VOCs generated by various units. The original plant scrubbing tower was modified by adjusting the process and put into use as an alkaline scrubbing tower. See Figure 1-3 The water washing tower 2 is a newly added purification unit. It is a 9m³ carbon steel tower that has been modified from an old tower. The inside of the tower is treated with anti-corrosion and is equipped with a spray device 22. The anti-corrosion layer 21 covers the inner wall surface of the tower to prevent the corrosive components in the circulating water and gas from eroding the tower. The spray device 22 is set at the top inside the tower to spray the circulating water evenly into the inner cavity of the tower, so that the gas and liquid can fully contact each other to absorb methanol in the gas. See Figure 1-3 The water washing tower 2 is equipped with a circulation pump 6. The inlet of the circulation pump 6 is connected to the bottom of the water washing tower 2 through the circulation pipeline 7, and the outlet of the circulation pump 6 is connected to the spray device 22 of the water washing tower 2 through the circulation pipeline 7. After the circulation pump 6 is started, it will pump out the water accumulated at the bottom of the water washing tower 2 and transport it to the spray device 22 to realize the continuous spraying of circulating water and provide continuous spraying power for water washing and de-alcoholization. See Figure 1-3 Two circulating pumps 6 are installed. The two circulating pumps 6 are connected in parallel and serve as backups for each other. During normal operation, one pump is in operation and the other is in hot standby. When the operating pump fails, it automatically switches to the backup pump to ensure that the spraying and purification of the water washing tower 2 is uninterrupted and that the system operates continuously and stably. See Figure 1-3Alkali washing tower 1 and water washing tower 2 are connected by a DN800 fiberglass pipeline as the first pipeline 4, and water washing tower 2 and induced draft fan 3 are connected by a DN800 fiberglass pipeline as the second pipeline 5. Utilizing the corrosion resistance, light weight, and smooth inner wall of fiberglass, the pipeline ensures that the humid odor gas is transported in a closed loop without leakage. Manholes 8 and valves 9 are respectively installed on the first pipeline 4 and the second pipeline 5. The manholes 8 are installed in the middle or at the corner of the pipeline for workers to enter the pipeline for inspection, cleaning and maintenance. The valves 9 are installed near the inlet and outlet of the pipeline to control the opening and closing of the pipeline or to adjust the gas flow during system debugging. See Figure 1-3 The water washing tower 2 is connected to an inlet water pipeline 10 and an outlet water pipeline 11. The inlet water pipeline 10 is used to replenish the water washing tower 2 with fresh circulating water, and the outlet water pipeline 11 is used to periodically discharge the circulating water containing methanol at the bottom of the water washing tower 2 to maintain water quality. A valve 9 is installed on the inlet water pipeline 10 to control the start and stop of water replenishment and the flow rate, and a valve 9 is installed on the outlet water pipeline 11 to control the timing and volume of drainage. The inlet water pipeline 10 is made of DN100 stainless steel, and the outlet water pipeline 11 is made of DN80 stainless steel. See Figure 1-3 Pressure gauge 12 is installed on the tower body of water washing tower 2. Pressure gauge 12 is installed at the top gas phase space or outlet pipeline of water washing tower 2. The range is 0-1.6MPa. It is used to monitor the pressure parameters inside water washing tower 2 and outlet pipeline in real time. When abnormal pressure fluctuation occurs, an early warning is issued in time to remind the operator to check and deal with it, and ensure that the system operates stably within the safe pressure range. See Figure 1-3 The first pipeline 4 and the second pipeline 5 are respectively equipped with fiberglass elbows 13 and manhole bolt connectors 14. The fiberglass elbows 13 are used to make bends when the pipeline needs to change direction. The manhole bolt connectors 14 are used to fasten the manhole cover and the manhole seat with bolts. Together with the sealing gasket, the manhole 8 is reliably sealed to prevent odorous gases from leaking from the manhole 8 during operation. Furthermore, the present invention provides an odor purification process that incorporates a water washing tower, comprising the following steps: S1: Primary Alkali Washing Purification: The chemical odor gas containing hydrogen sulfide, methanol, formaldehyde, and ammonia to be treated is collected and sent into the alkali washing tower 1, which is modified from the original plant washing tower, at an air volume of 20,000 m³ / h. The alkaline solution sprayed inside the tower comes into full contact with the odor gas in a countercurrent flow. Hydrogen sulfide in the gas phase is removed in a directional manner through an acid-base neutralization reaction, and the hydrogen sulfide concentration at the outlet of alkali washing tower 1 is controlled below 5.0 mg / m³. The preliminarily purified gas after treatment by alkali washing tower 1 is discharged from the top exhaust port and transported in a closed manner to the air inlet of water washing tower 2 through the first pipeline 4, which is connected to the fiberglass elbow 13, manhole bolt connector 14, maintenance manhole 8, and control valve 9. Valve 9 controls the gas flow rate in the pipeline in real time, and manhole 8 is reserved for regular maintenance of the pipeline. S2: Secondary water washing purification: The gas after primary alkaline washing enters the 9m³ recycled carbon steel water washing tower 2 from bottom to top. The inner wall of the water washing tower 2 is fully covered with an anti-corrosion layer 21 to isolate corrosive media. Two parallel circulating pumps 6, acting as backups for each other, continuously draw circulating water from the bottom of the water washing tower 2 through the circulating pipeline 7 and deliver it to the spray device 22 at the top of the tower for downward spraying. This creates a counter-current gas-liquid contact with the upward-flowing gas, relying on the physical property that methanol is easily soluble in water to absorb residual methanol in the gas phase, thus stabilizing the methanol concentration at the outlet of the water washing tower 2 below 80mg / m³. The water washing tower 2 is equipped with a water inlet pipeline 10 and... The outlet pipeline 11 is equipped with valves 9. Valves 9 are used to periodically open the inlet pipeline 10 to replenish fresh circulating water and open the outlet pipeline 11 to discharge methanol-rich wastewater, thus maintaining the quality of the water washing circulating water. The water washing tower 2 is equipped with a pressure gauge 12 with a range of 0-1.6MPa to monitor the gas phase pressure inside the tower and the downstream pipeline in real time. It provides timely warnings when the pressure is abnormal, ensuring the stable operation of the water washing unit. The gas purified by the water washing tower 2 flows out from the exhaust port at the top of the tower and enters the second pipeline 5, which is also equipped with a manhole 8, valves 9, fiberglass elbows 13, and manhole bolt connectors 14. S3: Compliant Emissions: The clean gas after secondary water washing is transported to the air inlet of the induced draft fan 3 via the second pipeline 5. The induced draft fan 3 provides negative pressure for the entire system, pressurizing and transporting the purified gas to the high-altitude emission outlet. The final exhaust gas simultaneously meets multiple environmental protection limits: hydrogen sulfide < 5.0 mg / m³, methanol < 80 mg / m³, formaldehyde < 20 mg / m³, and ammonia < 30 mg / m³, achieving synergistic compliance of multiple pollutants. Throughout the system, the flow rate of gas and water can be adjusted via valves 9 on each pipeline. The pipeline manholes 8 and various interfaces on the tower can be regularly inspected and cleaned. The standby circulating pump 6 can be automatically switched on and put into operation when the operating pump fails, ensuring uninterrupted continuous operation of the entire purification process.

[0023] The working principle and usage process of this invention are as follows: When using this invention, the odor purification device is started. The odor gas from the chemical wastewater to be treated (20,000 m³ / h) first enters from the bottom of the alkaline washing tower 1. Inside the tower, it comes into countercurrent contact with the alkaline solution. The hydrogen sulfide is neutralized and absorbed by the alkaline solution, and the hydrogen sulfide concentration at the outlet drops to below 5.0 mg / m³. The gas discharged from the top of the alkaline washing tower 1 enters the bottom of the water washing tower 2 through the first pipeline 4 (DN800 fiberglass). The gas passes through the inner cavity of the water washing tower 2 from bottom to top. The circulating pump 6 transports the circulating water at the bottom of the tower to the spray device 22 for spraying from top to bottom. The gas and liquid phases come into full contact, and the methanol is absorbed by the circulating water, reducing the methanol concentration at the outlet to below 80 mg / m³. The purified gas enters the induced draft fan 3 through the second pipeline 5 (DN800 fiberglass). After being pressurized by the induced draft fan 3, it is transported to the discharge port for discharge. The formaldehyde, ammonia, and other pollutants in the discharged gas simultaneously meet the environmental protection requirements. During operation, pressure gauge 12 monitors the system pressure in real time, valve 9 is used for on / off control of various pipelines and flow regulation, and manhole 8 is used for regular inspection and maintenance. The entire system achieves staged and coordinated removal of hydrogen sulfide and methanol, completely solving the problem that hydrogen sulfide and methanol could not meet the standards simultaneously when the original single scrubbing tower was put into operation.

[0024] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An odor purification system with an added water washing tower, characterized in that: The system includes an alkaline scrubbing tower (1), a water scrubbing tower (2), and an induced draft fan (3). The exhaust port of the alkaline scrubbing tower (1) is connected to the air inlet of the water scrubbing tower (2) through a first pipeline (4), and the exhaust port of the water scrubbing tower (2) is connected to the air inlet of the induced draft fan (3) through a second pipeline (5). The alkaline scrubbing tower (1) serves as a primary purification unit to remove hydrogen sulfide from odorous gases, and the water scrubbing tower (2) serves as a secondary purification unit to remove methanol from the gas treated by the alkaline scrubbing tower (1). The induced draft fan (3) is used to transport the purified gas to the exhaust port, forming a two-stage purification structure of alkaline scrubbing and water scrubbing.

2. The odor purification system with an added water washing tower according to claim 1, characterized in that: The alkaline washing tower (1) is modified from the plant washing tower to utilize existing equipment resources and reduce modification costs.

3. The odor purification system with an added water washing tower according to claim 1, characterized in that: The water washing tower (2) is equipped with an anti-corrosion layer (21) and a spray device (22) inside the tower body. The anti-corrosion layer (21) is attached to and covers the entire inner wall surface of the water washing tower (2) to prevent corrosive components in the circulating water and gas from eroding the inner wall of the tower body. The spray device (22) is located inside the tower body of the water washing tower (2) and inside the anti-corrosion layer (21). It is used to spray the circulating water from top to bottom into the inner cavity of the tower body so that the gas and liquid can fully contact each other to absorb methanol in the gas.

4. An odor purification system with an added water washing tower according to claim 3, characterized in that: The water washing tower (2) is equipped with a circulation pump (6). The inlet of the circulation pump (6) is connected to the bottom circulating water outlet of the water washing tower (2) through the circulation pipeline (7). The outlet of the circulation pump (6) is connected to the spray device (22) of the water washing tower (2) through the circulation pipeline (7). After the circulation pump (6) is started, it draws out the circulating water at the bottom of the water washing tower (2) and delivers it to the spray device (22). The circulating water sprayed by the spray device (22) flows downward through the packing in the tower and then flows back to the bottom of the water washing tower (2). The circulation pump (6) is used to provide circulating power for the spray purification of the water washing tower (2).

5. An odor purification system with an added water washing tower according to claim 4, characterized in that: Two circulating pumps (6) are provided, and the two circulating pumps (6) are connected in parallel and serve as backups for each other, so as to ensure the continuous operation of the system when one circulating pump (6) fails.

6. An odor purification system with an added water washing tower according to claim 1, characterized in that: Manholes (8) and valves (9) are provided on the first pipeline (4) and the second pipeline (5). The manholes (8) are used for inspection and maintenance inside the pipeline, and the valves (9) are used to control the opening and closing of the pipeline and regulate the gas flow.

7. An odor purification system with an added water washing tower according to claim 1, characterized in that: The water washing tower (2) is connected to an inlet pipe (10) and an outlet pipe (11). Both the inlet pipe (10) and the outlet pipe (11) are equipped with valves (9). The inlet pipe (10) is used to supply circulating water to the water washing tower (2), and the outlet pipe (11) is used to discharge the circulating water in the water washing tower (2). The valve (9) is used to control the supply and discharge of circulating water.

8. An odor purification system with an added water washing tower according to claim 1, characterized in that: A pressure gauge (12) is installed on the body of the water washing tower (2). The pressure gauge (12) is used to monitor the pressure parameters of the water washing tower (2) and related pipelines in real time.

9. An odor purification system with an added water washing tower according to claim 6, characterized in that: The first pipeline (4) and the second pipeline (5) are provided with fiberglass elbows (13) and manhole bolt connectors (14). The fiberglass elbows (13) are used to change the direction of the pipeline, and the manhole bolt connectors (14) are used to seal and fix the manhole (8).

10. An odor purification process for an odor purification system with an added water washing tower according to any one of claims 1-9, characterized in that: Includes the following steps: S1: Primary alkaline washing purification: After collecting the chemical odor gas containing hydrogen sulfide, methanol, formaldehyde and ammonia to be treated, it is sent into the alkaline washing tower (1) which is transformed from the original plant washing tower at an air volume of 20000 m³ / h. The alkaline solution sprayed in the tower is in full countercurrent contact with the odor gas. Hydrogen sulfide in the gas phase is removed in a directional manner through acid-base neutralization reaction. The hydrogen sulfide concentration at the outlet of the alkaline washing tower (1) is controlled below 5.0 mg / m³. The pre-purified gas after treatment by the alkaline washing tower (1) is discharged from the top exhaust port and transported to the air inlet of the water washing tower (2) through the first pipeline (4) of the fiberglass elbow (13), manhole bolt connector (14), maintenance manhole (8) and control valve (9). The valve (9) controls the gas transport flow rate in the pipeline in real time. The manhole (8) is reserved for the pipeline to be inspected regularly. S2: Secondary water washing purification: The gas after primary alkaline washing enters the 9m³ water washing tower (2) modified from old carbon steel from bottom to top. The inner wall of the water washing tower (2) is fully covered with an anti-corrosion layer (21) to isolate the corrosive medium. Two parallel circulating pumps (6) continuously draw circulating water from the bottom of the water washing tower (2) through the circulating pipeline (7) and deliver it to the spray device (22) at the top of the tower to spray downwards. It forms a counter-current gas-liquid contact with the upward gas and absorbs the residual methanol in the gas phase by relying on the physical property that methanol is easily soluble in water. The methanol concentration at the outlet of the water washing tower (2) is stably controlled below 80mg / m³. The water washing tower (2) is equipped with an inlet water pipeline (10) and an outlet water pipeline (10). Pipeline (11) is equipped with valves (9). The inlet pipeline (10) is opened at regular intervals through valves (9) to replenish fresh circulating water and the outlet pipeline (11) is opened to discharge methanol-rich wastewater, thus maintaining the quality of the water washing circulating water. The water washing tower (2) is equipped with a pressure gauge (12) with a range of 0-1.6MPa. The pressure of the gas phase inside the tower and the pipeline at the back end is monitored in real time throughout the process. When the pressure is abnormal, an early warning is given in time to ensure the stable operation of the water washing unit. The gas purified by the water washing tower (2) flows out from the exhaust port at the top of the tower and enters the second pipeline (5), which is also equipped with a manhole (8), valves (9), fiberglass elbows (13), and manhole bolt connectors (14). S3: Standardized Emission: The clean gas after secondary water washing is transported to the air inlet of the induced draft fan (3) through the second pipeline (5). The induced draft fan (3) provides negative pressure for the entire system and pressurizes the purified gas to the high-altitude emission outlet. Finally, the exhaust gas meets multiple environmental protection limits: hydrogen sulfide < 5.0 mg / m³, methanol < 80 mg / m³, formaldehyde < 20 mg / m³, ammonia < 30 mg / m³, achieving coordinated standard emission of multiple pollutants. The flow rate of gas and water can be adjusted through the valves (9) of each pipeline throughout the system. The pipeline manholes (8) and tower interfaces can be regularly inspected and cleaned. The standby circulating pump (6) can be automatically switched to use when the running pump fails, ensuring the uninterrupted continuous operation of the entire purification process.

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