Lampblack-containing waste gas treatment device for plastic granulation extruder
Through the combined treatment system of pre-wash spray tower, high-voltage electrostatic deodorization tower, VOC absorption tower and oxidation decomposition tower, the problem of difficult removal of odor in plastic extruder exhaust gas is solved, and efficient and economical exhaust gas purification effect is achieved.
Patent Information
- Application Number
- CN202422522970.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-18
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-10-18
AI Technical Summary
Existing technologies are difficult to effectively remove the foul odor generated during the plastic extrusion process. Conventional treatment process equipment occupies a large area, has high investment and high operating costs, and is unable to adapt to changes in production conditions, resulting in excessive emissions.
A combined treatment system of a pre-wash spray tower, a high-voltage electrostatic deodorization tower, a VOC absorption tower, a primary oxidation decomposition tower and a secondary oxidation decomposition tower is used to treat the waste gas through multi-stage treatment of water mist washing, electric field capture, absorption and oxidation decomposition to achieve a purification effect.
It achieves effective purification of high-temperature oil fume exhaust gas, meets national emission standards, reduces equipment footprint and operating costs, adapts to changes in production conditions, and avoids excessive emissions.
Smart Images
Figure CN223366593U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of waste gas treatment equipment, in particular to a device for treating oily fume waste gas from a plastic granulation extruder. Background Art
[0002] During the extrusion process of plastic production such as modified plastics, recycled plastics, biodegradable plastics, special engineering plastics, carbon fiber and composite materials, polypropylene resins, styrene resins and medical and health polymer materials, a large amount of high-temperature oil fume waste gas is generated. After the plastic polymer materials undergo various chemical reactions such as high-temperature melting, polymerization, and cracking, the waste gas composition is very complex and has a foul odor; the foul odor is emitted with the wind direction, resulting in many complaints from nearby residents; therefore, the waste gas needs to be treated and meet national emission standards before it can be discharged.
[0003] Currently, the treatment method commonly used is "two-stage water washing + dry filtration + activated carbon / zeolite fixed bed + RTO". Due to the high temperature, high oil smoke content, and complex volatile organic compound composition of plastic extrusion waste gas, the above conventional treatment process can treat the organic waste gas concentration to meet national emission standards, but the odor is difficult to remove, leading to complaints from surrounding residents. In addition, the equipment of the above conventional process occupies a large area, the one-time investment is very high, the operating energy consumption is high, and the adsorption materials such as activated carbon / zeolite and the heat storage body in the RTO need to be replaced regularly, resulting in high operating costs. In addition, when the waste gas concentration fluctuates significantly due to changes in production conditions, the above conventional process cannot be adjusted, and it is easy for the waste gas concentration to exceed the emission standard due to changes in production conditions. Utility Model Content
[0004] In view of the shortcomings of the existing technology, the utility model proposes a device for treating oily fume waste gas from a plastic granulation extruder, which can effectively treat the oily fume waste gas generated by the plastic granulation extruder and meet national emission standards.
[0005] To achieve the above technical solution, the utility model provides a device for treating oil fume waste gas from a plastic granulation extruder, comprising: a pre-wash spray tower, a high-voltage electrostatic deodorization tower, a VOC absorption tower, a primary oxidation and decomposition tower, a secondary oxidation and decomposition tower, a centrifugal fan and a chimney. The air outlet of the pre-wash spray tower is connected to the air inlet of the high-voltage electrostatic deodorization tower through a pipe, the air outlet of the high-voltage electrostatic deodorization tower is connected to the air inlet of the VOC absorption tower through a pipe, the air outlet of the VOC absorption tower is connected to the air inlet of the primary oxidation and decomposition tower through a pipe, the air outlet of the primary oxidation and decomposition tower is connected to the air inlet of the secondary oxidation and decomposition tower through a pipe, the centrifugal fan is installed at the air outlet of the secondary oxidation and decomposition tower, and the air exhaust port of the centrifugal fan is connected to the air outlet of the secondary oxidation and decomposition tower, and the air outlet of the centrifugal fan is connected to the chimney.
[0006] In the above technical solution, during actual operation, the oily fume exhaust gas generated by the plastic granulation extruder during production first enters the pre-wash spray tower through a pipeline. The water mist sprayed downward from the pre-wash spray tower fully contacts the high-temperature oily fume exhaust gas moving upward from the tower bottom, thereby reducing the exhaust gas temperature, washing some of the oily fume, and increasing the exhaust gas humidity. It then enters the high-voltage electrostatic deodorization tower, where the high-voltage electric field captures and intercepts the oily fume in the oily fume exhaust gas, decomposing it for effective deodorization. It then enters the VOC absorption tower, where it effectively removes harmful organic gases from the exhaust gas. It is then transported to the primary oxidation decomposition tower, where it undergoes preliminary oxidation and decomposition of organic and odorous molecules in the exhaust gas, achieving initial purification. Finally, it enters the secondary oxidation decomposition tower for deep oxidation and decomposition of organic and odorous molecules in the exhaust gas, achieving deep purification. Finally, it is exhausted out of the chimney through the suction action of a centrifugal fan. After five-stage treatment including pre-wash spray tower, high-voltage electrostatic deodorization tower, VOC absorption tower, primary oxidation decomposition tower and secondary oxidation decomposition tower, the waste gas generated by the plastic extruder, which is high-temperature, contains a large amount of oil smoke, has a complex volatile organic compound composition and is accompanied by a foul odor, is purified and meets national emission standards.
[0007] Preferably, the pre-wash spray tower includes a spray tower body, in which a first polyhedron packing layer, a second polyhedron packing layer and a third polyhedron packing layer are sequentially installed from bottom to top, a pre-wash demisting layer is installed above the third polyhedron packing layer, and pre-wash spray pipes are correspondingly installed above the first polyhedron packing layer, the second polyhedron packing layer and the third polyhedron packing layer. The pre-wash demisting layer is installed below the air outlet of the pre-wash spray tower, and a pre-wash circulating water pool is installed on the outside of the spray tower body. A pre-wash circulating water pump is installed in the pre-wash circulating water pool, and the pre-wash circulating water pump is connected to the pre-wash spray pipe by a pipe. During actual operation, the exhaust gas diffuses from the bottom of the spray tower body from bottom to top, passing through the first polyhedron packing layer, the second polyhedron packing layer and the third polyhedron packing layer in turn. At the same time, the pre-wash circulation water pump drives the pre-wash spray pipe to spray water downward. The water mist fully contacts the exhaust gas on the surface of the first polyhedron packing layer, the second polyhedron packing layer and the third polyhedron packing layer, thereby reducing the exhaust gas temperature and washing part of the oil smoke, and increasing the humidity of the exhaust gas. Finally, it is demisted by the pre-wash demisting layer and then transported to the high-voltage electrostatic deodorization tower.
[0008] Preferably, the high-voltage electrostatic deodorization tower includes a deodorization tower body, within which are mounted first and second high-voltage electrostatic plates spaced side by side. During operation, the exhaust gas after the pre-wash spray tower still contains a large amount of oil smoke, increasing the humidity of the exhaust gas. Upon entering the high-voltage electrostatic deodorization tower, the exhaust gas carries a certain amount of water vapor, thereby preventing the risk of fire during operation. The oil smoke in the exhaust gas is captured and intercepted within the high-voltage electrostatic deodorization tower by the high-voltage electric field generated by the first and second high-voltage electrostatic plates, and the oil smoke is decomposed, achieving an effective deodorization effect.
[0009] Preferably, the VOC absorption tower includes an absorption tower body, in which a first absorption filler layer, a second absorption filler layer, a third absorption filler layer and an absorption demisting layer are sequentially installed from bottom to top, wherein absorption spray pipes are correspondingly installed above the first absorption filler layer, the second absorption filler layer and the third absorption filler layer, the absorption demisting layer is installed below the air outlet of the VOC absorption tower, an absorption circulating water pool is installed on the outside of the absorption tower body, an absorption circulating water pump is installed in the absorption circulating water pool, and the absorption circulating water pump is connected to the absorption spray pipe by a pipeline. During actual operation, the waste gas treated by the high-voltage electrostatic deodorization tower diffuses upward from the bottom of the absorption tower body. The circulating liquid in the absorption circulating water pool is a configured 1% VOC absorbent solution. The circulating liquid is input into the absorption spray pipe in the tower through a corrosion-resistant absorption circulating water pump and atomized. The water mist is sprayed downward and fully contacts with the organic waste gas moving upward from the bottom of the tower in the first absorption filler layer, the second absorption filler layer, and the third absorption filler layer, decomposing and absorbing a large number of organic molecules in the waste gas. The remaining organic waste gas molecules that are difficult to absorb enter the next level of treatment equipment.
[0010] Preferably, the structure of the primary oxidation decomposition tower and the secondary oxidation decomposition tower is the same, both comprising a decomposition tower body, wherein a first oxidation packing layer, a second oxidation packing layer, a third oxidation packing layer and a decomposition demisting layer are sequentially installed in the decomposition tower body from bottom to top, wherein a decomposition spray pipe is correspondingly installed above the first oxidation packing layer, the second oxidation packing layer and the third oxidation packing layer, the decomposition demisting layer is installed below the gas outlet of the decomposition tower body, a decomposition circulating water pool is installed on the outside of the decomposition tower body, a decomposition circulating water pump is installed in the decomposition circulating water pool, and the decomposition circulating water pump is connected to the decomposition spray pipe by a pipeline. During actual operation, the circulating liquid in the decomposition circulating water pool is a configured oxidant solution with a concentration of 0.3%. The circulating liquid is input into the decomposition spray pipe in the tower through the decomposition circulating water pump for atomization, and the water mist is sprayed downward and fully contacts the exhaust gas moving upward from the bottom of the tower in the first oxidation packing layer, the second oxidation packing layer and the third oxidation packing layer, oxidizing and decomposing the organic molecules and odor molecules in the exhaust gas to achieve the purpose of purification.
[0011] The beneficial effects of the oily fume exhaust gas treatment device for a plastic pelletizing extruder provided by the utility model are as follows: The device has a rational design and compact structure, and can effectively treat the oily fume exhaust gas generated by the plastic pelletizing extruder, meeting national emission standards. During operation, the oily fume exhaust gas generated by the plastic pelletizing extruder during the production process first enters the pre-wash spray tower through a pipeline. The water mist sprayed downward from the pre-wash spray tower fully contacts the high-temperature oily fume exhaust gas moving upward from the tower bottom, thereby reducing the exhaust gas temperature, washing some of the oily fume, and increasing the exhaust gas humidity. The waste then enters the high-voltage electrostatic deodorization tower, where a high-voltage electric field captures and intercepts the oil smoke in the exhaust gas, breaking it down for effective deodorization. It then enters the VOC absorption tower, where harmful organic gases are effectively removed. The waste is then transported to the primary oxidation decomposition tower, where it undergoes preliminary oxidation and decomposition of organic and odorous molecules, achieving initial purification. Finally, it enters the secondary oxidation decomposition tower for further oxidation and decomposition, achieving deep purification. Finally, a centrifugal fan suctions the waste gas out of the chimney. After five stages of treatment—pre-wash spray tower, high-voltage electrostatic deodorization tower, VOC absorption tower, primary oxidation decomposition tower, and secondary oxidation decomposition tower—the waste gas generated by the plastic extruder, which is hot, contains a high amount of oil smoke, has a complex volatile organic compound composition, and is accompanied by a foul odor, is purified to meet national emission standards. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a structural diagram of the present utility model.
[0013] In the figure: 1. Pre-wash spray tower; 11. Spray tower body; 12. First polyhedron packing layer; 13. Second polyhedron packing layer; 14. Third polyhedron packing layer; 15. Pre-wash demisting layer; 16. Pre-wash spray pipe; 17. Pre-wash circulating water pump; 18. Pre-wash circulating water pool; 2. High-voltage electrostatic deodorization tower; 21. Deodorization tower body; 22. First high-voltage electrostatic plate; 23. Second high-voltage electrostatic plate; 3. VOC absorption tower; 31. Absorption tower body; 32. First absorption packing layer; 33. Second absorption Packing layer; 34. Third absorption packing layer; 35. Absorption demisting layer; 36. Absorption spray pipe; 37. Absorption circulating water pump; 38. Absorption circulating water pool; 4. Primary oxidation decomposition tower; 41. Decomposition tower body; 42. First oxidation packing layer; 43. Second oxidation packing layer; 44. Third oxidation packing layer; 45. Decomposition demisting layer; 46. Decomposition spray pipe; 47. Decomposition circulating water pump; 48. Decomposition circulating water pool; 5. Secondary oxidation decomposition tower; 6. Centrifugal fan; 7. Chimney; 8. Connecting pipes. DETAILED DESCRIPTION
[0014] The following is a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary persons in this field without creative work are within the scope of protection of the present invention.
[0015] Embodiment: A device for treating oily fume waste gas from a plastic granulation extruder.
[0016] Reference Figure 1 As shown, a device for treating oil fume exhaust gas from a plastic granulation extruder comprises: a pre-wash spray tower 1, a high-voltage electrostatic deodorization tower 2, a VOC absorption tower 3, a primary oxidation and decomposition tower 4, a secondary oxidation and decomposition tower 5, a centrifugal fan 6 and a chimney 7. The air outlet of the pre-wash spray tower 1 is connected to the air inlet of the high-voltage electrostatic deodorization tower 2 through a pipe 8, the air outlet of the high-voltage electrostatic deodorization tower 2 is connected to the air inlet of the VOC absorption tower 3 through a pipe, the air outlet of the VOC absorption tower 3 is connected to the air inlet of the primary oxidation and decomposition tower 4 through a pipe, the air outlet of the primary oxidation and decomposition tower 4 is connected to the air inlet of the secondary oxidation and decomposition tower 5 through a pipe, the centrifugal fan 6 is installed at the air outlet of the secondary oxidation and decomposition tower 5, and the air suction port of the centrifugal fan 6 is connected to the air outlet of the secondary oxidation and decomposition tower 5, and the air outlet of the centrifugal fan 6 is connected to the chimney 7.
[0017] Reference Figure 1 As shown, the pre-wash spray tower 1 includes a spray tower body 11, in which a first polyhedron packing layer 12 is installed, above the first polyhedron packing layer 12 is installed a second polyhedron packing layer 13, above the second polyhedron packing layer 13 is installed a third polyhedron packing layer 14, above the third polyhedron packing layer 14 is installed a pre-wash demisting layer 15, above the first polyhedron packing layer 12, the second polyhedron packing layer 13 and the third polyhedron packing layer 14 are respectively installed pre-wash spray pipes 16, the pre-wash demisting layer 15 is installed below the air outlet of the pre-wash spray tower 1, and a pre-wash circulating water pool 18 is installed on the outside of the spray tower body 11, and a pre-wash circulating water pump 17 is installed in the pre-wash circulating water pool 18, and the pre-wash circulating water pump 17 is connected to the pre-wash spray pipe 16 by a pipeline. During actual operation, the exhaust gas diffuses from the bottom of the spray tower body 11 from bottom to top, and passes through the first polyhedron packing layer 12, the second polyhedron packing layer 13 and the third polyhedron packing layer 14 in turn. At the same time, the pre-wash circulating water pump 17 drives the pre-wash spray pipe 16 to spray water downward. The water mist fully contacts the exhaust gas on the surface of the first polyhedron packing layer 12, the second polyhedron packing layer 13 and the third polyhedron packing layer 14, thereby reducing the exhaust gas temperature and washing part of the oil smoke, and increasing the humidity of the exhaust gas. Finally, it is demisted by the pre-wash demisting layer 15 and transported to the high-voltage electrostatic deodorization tower 2.
[0018] Reference Figure 1 As shown, the high-voltage electrostatic deodorization tower 2 includes a deodorization tower body 21, within which are mounted a first high-voltage electrostatic plate 22 and a second high-voltage electrostatic plate 23 spaced apart and arranged side by side. During actual operation, the exhaust gas after passing through the pre-wash spray tower 1 still contains a large amount of oil smoke, which increases the humidity of the exhaust gas. After entering the high-voltage electrostatic deodorization tower 2, the exhaust gas carries a certain amount of water vapor, which can prevent the risk of fire during operation of the high-voltage electrostatic deodorization tower. The oil smoke in the exhaust gas is captured and intercepted by the high-voltage electric field generated by the first high-voltage electrostatic plate 22 and the second high-voltage electrostatic plate 23 within the high-voltage electrostatic deodorization tower 2, and the oil smoke is decomposed, achieving an effective deodorization effect.
[0019] Reference Figure 1 As shown, the VOC absorption tower 3 includes an absorption tower body 31, in which a first absorption filler layer 32, a second absorption filler layer 33, a third absorption filler layer 34 and an absorption demisting layer 35 are sequentially installed from bottom to top, wherein absorption spray pipes 36 are correspondingly installed above the first absorption filler layer 32, the second absorption filler layer 33 and the third absorption filler layer 34, the absorption demisting layer 35 is installed below the air outlet of the VOC absorption tower 3, and an absorption circulating water pool 38 is installed on the outside of the absorption tower body 31, and an absorption circulating water pump 37 is installed in the absorption circulating water pool 38, and the absorption circulating water pump 37 is connected to the absorption spray pipe 36 through a pipeline. During actual operation, the waste gas treated by the high-voltage electrostatic deodorization tower 2 diffuses upward from the bottom of the absorption tower body 31. The circulating liquid in the absorption circulating water pool 38 is a configured VOC absorbent solution with a concentration of 1%. The circulating liquid is input into the absorption spray pipe 36 in the tower through the corrosion-resistant absorption circulating water pump 37 for atomization. The water mist is sprayed downward and fully contacts with the organic waste gas moving upward from the bottom of the tower in the first absorption filler layer 32, the second absorption filler layer 33, and the third absorption filler layer 34, decomposing and absorbing a large number of organic molecules in the waste gas. The remaining organic waste gas molecules that are difficult to absorb enter the next level of treatment equipment.
[0020] Reference Figure 1As shown, the first-level oxidation decomposition tower 4 and the second-level oxidation decomposition tower 5 have the same structure and both include a decomposition tower body 41. The first oxidation filler layer 42, the second oxidation filler layer 43, the third oxidation filler layer 44 and the decomposition demisting layer 45 are sequentially installed in the decomposition tower body 41 from bottom to top, wherein decomposition spray pipes 46 are correspondingly installed above the first oxidation filler layer 42, the second oxidation filler layer 43 and the third oxidation filler layer 44, and the decomposition demisting layer 45 is installed below the air outlet of the decomposition tower body 41. A decomposition circulating water pool 48 is installed on the outside of the decomposition tower body 41, and a decomposition circulating water pump 47 is installed in the decomposition circulating water pool 48. The decomposition circulating water pump 47 is connected to the decomposition spray pipe 46 through a pipeline. During actual operation, the circulating liquid in the decomposition circulating water pool 48 is an oxidant solution with a configured concentration of 0.3%. The circulating liquid is input into the decomposition spray pipe 46 in the tower through the decomposition circulating water pump 47 for atomization. The water mist is sprayed downward and fully contacts the exhaust gas moving upward from the bottom of the tower in the first oxidation packing layer 42, the second oxidation packing layer 43, and the third oxidation packing layer 44, oxidizing and decomposing the organic molecules and odor molecules in the exhaust gas to achieve the purpose of purification.
[0021] This device for treating oily fume waste gas from a plastic pelletizing extruder features a rational design and compact structure, effectively treating the oily fume waste gas generated by the plastic pelletizing extruder to meet national emission standards. In actual operation, the oily fume waste gas generated during the production process of the plastic pelletizing extruder first enters a pre-wash spray tower 1 through a pipeline. Water mist sprayed downward from the pre-wash spray tower 1 fully contacts the high-temperature oily fume waste gas moving upward from the tower bottom, thereby reducing the waste gas temperature, washing away some of the oily fume, and increasing the waste gas humidity. The waste gas then enters a high-voltage electrostatic deodorization tower 2, where a high-voltage electric field captures and intercepts the oily fume in the waste gas, decomposing it for effective deodorization. The waste gas then enters a VOC absorption tower 3, where harmful organic gases are effectively removed from the waste gas. The waste gas is then transported to a primary oxidation decomposition tower 4, where it undergoes preliminary oxidation and decomposition of organic and odorous molecules in the waste gas, achieving initial purification. Finally, the waste gas enters a secondary oxidation decomposition tower 5, where it undergoes further oxidation and decomposition of organic and odorous molecules in the waste gas, achieving deep purification. Finally, the waste gas is exhausted from chimney 7 by the suction action of centrifugal fan 6. After five-stage treatment in pre-wash spray tower 1, high-voltage electrostatic deodorization tower 2, VOC absorption tower 3, primary oxidation decomposition tower 4, and secondary oxidation decomposition tower 5, the waste gas generated by the plastic extruder, which is high in temperature, contains a large amount of oil smoke, has a complex volatile organic compound composition, and is accompanied by a foul odor, is purified and meets national emission standards.
[0022] The above description is only a preferred embodiment of the present invention, but the present invention should not be limited to the contents disclosed in the embodiment and the drawings. Therefore, any equivalent or modification completed without departing from the spirit disclosed in the present invention shall fall within the scope of protection of the present invention.
Claims
1. A device for treating oily fume waste gas from a plastic granulation extruder, characterized in that include: A pre-wash spray tower, a high-voltage electrostatic deodorization tower, a VOC absorption tower, a primary oxidation and decomposition tower, a secondary oxidation and decomposition tower, a centrifugal fan and a chimney, wherein the air outlet of the pre-wash spray tower is connected to the air inlet of the high-voltage electrostatic deodorization tower through a pipeline, the air outlet of the high-voltage electrostatic deodorization tower is connected to the air inlet of the VOC absorption tower through a pipeline, the air outlet of the VOC absorption tower is connected to the air inlet of the primary oxidation and decomposition tower through a pipeline, the air outlet of the primary oxidation and decomposition tower and the air inlet of the secondary oxidation and decomposition tower are connected through a pipeline, the centrifugal fan is installed at the air outlet of the secondary oxidation and decomposition tower, and the air suction port of the centrifugal fan is connected to the air outlet of the secondary oxidation and decomposition tower, and the air outlet of the centrifugal fan is connected to the chimney.
2. The device for treating oily fume waste gas from a plastic granulation extruder according to claim 1, wherein: The pre-wash spray tower includes a spray tower body, in which a first polyhedron packing layer, a second polyhedron packing layer and a third polyhedron packing layer are sequentially installed from bottom to top, a pre-wash demisting layer is installed above the third polyhedron packing layer, pre-wash spray pipes are correspondingly installed above the first polyhedron packing layer, the second polyhedron packing layer and the third polyhedron packing layer, the pre-wash demisting layer is installed below the air outlet of the pre-wash spray tower, a pre-wash circulating water pool is installed on the outside of the spray tower body, a pre-wash circulating water pump is installed in the pre-wash circulating water pool, and the pre-wash circulating water pump is connected to the pre-wash spray pipe by a pipeline.
3. The device for treating oily fume waste gas from a plastic granulation extruder according to claim 1, wherein: The high-voltage electrostatic deodorizing tower comprises a deodorizing tower body, in which a first high-voltage electrostatic plate and a second high-voltage electrostatic plate are installed in the deodorizing tower body and are arranged side by side in an upper and lower manner.
4. The device for treating oily fume waste gas from a plastic granulation extruder according to claim 1, wherein: The VOC absorption tower includes an absorption tower body, in which a first absorption filler layer, a second absorption filler layer, a third absorption filler layer and an absorption demisting layer are sequentially installed from bottom to top, wherein absorption spray pipes are correspondingly installed above the first absorption filler layer, the second absorption filler layer and the third absorption filler layer, the absorption demisting layer is installed below the air outlet of the VOC absorption tower, an absorption circulating water pool is installed on the outside of the absorption tower body, an absorption circulating water pump is installed in the absorption circulating water pool, and the absorption circulating water pump is connected to the absorption spray pipe by a pipeline.
5. The device for treating oily fume waste gas from a plastic granulation extruder according to claim 1, wherein: The first-level oxidation decomposition tower and the second-level oxidation decomposition tower have the same structure and both include a decomposition tower body. A first oxidation filler layer, a second oxidation filler layer, a third oxidation filler layer and a decomposition demisting layer are sequentially installed in the decomposition tower body from bottom to top, wherein decomposition spray pipes are correspondingly installed above the first oxidation filler layer, the second oxidation filler layer and the third oxidation filler layer, the decomposition demisting layer is installed below the air outlet of the decomposition tower body, a decomposition circulating water pool is installed on the outside of the decomposition tower body, a decomposition circulating water pump is installed in the decomposition circulating water pool, and the decomposition circulating water pump is connected to the decomposition spray pipe by a pipeline.