Organic nitrogen oxide waste gas treatment device and treatment method thereof

Abstract

The invention relates to the technical field of nitrogen oxide waste gas treatment, and discloses an organic nitrogen oxide waste gas treatment device and a treatment method thereof.The upper end of a heat exchanger is provided with a waste gas inlet, the heat exchanger is provided with a cooling waste gas branch pipe and a liquid storage tank, and the heat exchanger communicates with the liquid storage tank and communicates with a rotational flow plate tower through the cooling waste gas branch pipe; a rotational flow liquid collecting part, a rotational flow plate assembly, a first spraying assembly and a rotational flow waste gas branch pipe are connected in the rotational flow plate tower, and the rotational flow plate tower is communicated to a bottom gas inlet of the packed tower through the rotational flow waste gas branch pipe; the packed tower is provided with a packing liquid collecting part, packing is arranged in the packed tower, the packed tower is provided with a second spraying assembly and a packing waste gas branch pipe, and the packed tower is communicated to the gas inlet of the catalytic oxidation furnace through the packing waste gas branch pipe; and the catalytic oxidation furnace is communicated with the fan. According to the organic nitrogen oxide waste gas treatment device and the treatment method thereof, the problem that high-temperature and high-humidity dust-containing organic nitrogen oxide waste gas is difficult to efficiently, safely and continuously treat in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nitrogen oxide waste gas treatment, and particularly relates to an organic nitrogen oxide waste gas treatment device and a treatment method thereof. BACKGROUND

[0002] At present, in the production process of chemical industry, pharmaceutical industry, new material industry and the like, high-temperature and high-humidity waste gas containing organic matter, nitrogen oxide (such as NO and NO2), acid gas (such as nitric acid vapor) and dust is often generated. Such waste gas usually has the characteristics of strong corrosiveness, flammability and explosiveness, complex composition and great difficulty in treatment, and if directly discharged, will seriously pollute the environment and exist safety hazards.

[0003] At present, the treatment of such waste gas is mostly single or simple combination process. For example, some enterprises use alkali liquor spray tower to absorb acid gas, but when the waste gas contains a large amount of dust, the spray system is easy to be blocked, resulting in unstable operation; another scheme is to directly send high-temperature waste gas into a catalytic oxidation furnace or a regenerative incineration device (RTO) for high-temperature decomposition, but due to the high temperature (up to 180℃ or above) and high humidity of the waste gas, not only energy is wasted, but also the catalyst is easy to be deactivated, the equipment is easy to be corroded and even safety accidents are easy to occur. In addition, the high-temperature water vapor entering the rear-end oxidation equipment is condensed, which may cause internal water accumulation, short circuit or structural damage of the equipment.

[0004] The high-temperature waste gas enters the absorption or oxidation system without being fully cooled and dedusted, so that the absorption efficiency is low and the service life of the equipment is shortened. At the same time, most systems do not consider the sealing safety under negative pressure condition, and under the negative pressure effect of the fan induced draft, external air may be sucked into the pipeline containing organic flammable gas to form an explosive mixture, which brings major safety risks. SUMMARY

[0005] The present application aims to at least solve one of the problems in the prior art. The present application provides an organic nitrogen oxide waste gas treatment device and a treatment method thereof, to solve the problem that the organic nitrogen oxide waste gas with high temperature, high humidity, dust, corrosiveness and potential explosion risk is difficult to be efficiently, safely and continuously treated in the prior art.

[0006] In order to achieve the above-mentioned purpose, the present application provides an organic nitrogen oxide waste gas treatment device, comprising a heat exchanger, a cyclone plate tower, a packed tower, a catalytic oxidation furnace and a fan which are sequentially communicated. The upper end of the heat exchanger is provided with a waste gas inlet, the lower end of the heat exchanger is respectively provided with a cooling waste gas branch pipe and a liquid storage tank, the lower end of the heat exchanger is communicated with the liquid storage tank for discharging condensate, and the gas outlet of the heat exchanger is communicated with the bottom gas inlet of the cyclone plate tower through the cooling waste gas branch pipe. The cyclone plate tower is connected with a cyclone liquid collecting part, a cyclone plate assembly, a first spraying assembly and a cyclone exhaust branch pipe, the cyclone plate assembly is arranged below the first spraying assembly, the first spraying assembly is used for spraying lye into the cyclone plate tower, and a top gas outlet of the cyclone plate tower is communicated to a bottom gas inlet of the filler tower through the cyclone exhaust branch pipe; The filler tower is provided with a filler liquid collecting part, and is provided with fillers, a second spraying assembly and a filler exhaust branch pipe, the second spraying assembly is used for spraying lye into the filler tower, and a top gas outlet of the filler tower is communicated to a gas inlet of the catalytic oxidation furnace through the filler exhaust branch pipe. The gas outlet of the catalytic oxidation furnace is communicated to the air inlet of the fan.

[0007] As a preferred solution, the heat exchanger comprises a shell, a first support plate, a second support plate and a plurality of heat exchange pipes. The first support plate and the second support plate are fixedly connected in the shell and are arranged in an axial direction, thereby separating the shell into a gas buffer cavity at an upper portion, a cooling cavity at a middle portion and an exhaust cavity at a lower portion. The first support plate is provided with a plurality of first through holes, and the second support plate is provided with a plurality of second through holes. Both ends of each heat exchange pipe are sealingly connected to the first support plate and the second support plate, wherein the upper end of the heat exchange pipe is communicated to the gas buffer cavity through the corresponding first through hole, and the lower end is communicated to the exhaust cavity through the corresponding second through hole. The shell is provided with the exhaust inlet, a cooling medium inlet and a cooling medium outlet, wherein the exhaust inlet is communicated to the gas buffer cavity, the cooling medium inlet and the cooling medium outlet are respectively communicated to the cooling cavity, the cooling medium flows through the outer wall of the heat exchange pipe to cool the exhaust gas in the pipe, and one end of the cooling exhaust branch pipe is communicated to the exhaust cavity.

[0008] As a preferred solution, the heat exchanger further comprises a third spraying assembly, the third spraying assembly is installed on the shell and located in the gas buffer cavity, and the spraying port of the third spraying assembly is arranged to open towards the upper end of the heat exchange pipe.

[0009] As a preferred solution, the liquid storage tank is connected with a stirring assembly, the stirring assembly comprises a stirring driving member and a stirring paddle, and the stirring driving member is in transmission connection with the stirring paddle.

[0010] As a preferred embodiment, the system also includes a pump body, wherein the liquid storage tank is connected to a cooling drain pipe, the vortex liquid collecting section is connected to a vortex drain pipe, the packing liquid collecting section is connected to a packing drain pipe, and the cooling drain pipe, the vortex drain pipe, and the packing drain pipe are respectively connected to the pump body.

[0011] As a preferred embodiment, the swirl plate tower is provided with multiple swirl plate assemblies and the first spray assembly, and the swirl plate assemblies and the first spray assembly are arranged alternately and at intervals along the height direction of the tower.

[0012] As a preferred embodiment, the swirl plate assembly includes multiple blades, an outer ring arranged coaxially, and a fixing part. The fixing part is located below the outer ring. The blades are inclined and the multiple blades are spaced apart circumferentially along the outer ring. One end of each blade is connected to the inner wall of the outer ring, and the other end is connected to the fixing part.

[0013] As a preferred embodiment, the packed tower is provided with a plurality of packing zones spaced apart along the height direction, the packing is filled in the packing zones, and the second spray assembly is located above all the packing zones.

[0014] As a preferred embodiment, a funnel is provided between the heat exchanger and the liquid storage tank. The upper end of the funnel is connected to the bottom of the heat exchanger, and a liquid seal pipe is provided at the lower end of the funnel. The outlet end of the liquid seal pipe is inserted below the liquid level in the liquid storage tank.

[0015] A method for treating organic nitrogen oxide waste gas, comprising the following steps using the aforementioned organic nitrogen oxide waste gas treatment device: S1. Organic nitrogen oxide waste gas is introduced from the waste gas inlet at the top of the heat exchanger and cooled in the heat exchanger, so that the water vapor in the waste gas is condensed and introduced into the storage tank together with the dust. S2. The cooled exhaust gas enters the bottom of the cyclone plate tower through the cooling exhaust gas branch pipe. During the upward process in the cyclone plate tower, the acidic gas and nitrogen oxides are absorbed by the alkaline solution sprayed by the first spray component, and the dust settles into the cyclone collection section. S3. The exhaust gas is discharged from the top of the cyclone plate tower through the cyclone exhaust gas branch pipe and enters the bottom of the packed tower. Inside the packed tower, it passes through the packing area and is further absorbed by the alkaline solution sprayed by the second spray assembly. The waste liquid is collected in the packing liquid collection section. S4. The waste gas enters the catalytic oxidation furnace through the filler waste gas branch pipe for high-temperature oxidation treatment; S5. The treated exhaust gas is drawn into the chimney by the blower; The waste liquid in the storage tank, the vortex liquid collection section and the packing liquid collection section is discharged and transported to the wastewater treatment system.

[0016] This invention discloses an organic nitrogen oxide waste gas treatment device and method. Compared with existing technologies, its advantages lie in the following: it comprises a heat exchanger, a cyclone plate tower, a packed tower, a catalytic oxidation furnace, and a blower connected in sequence, forming a closed, negative pressure-driven integrated treatment process. The waste gas first enters through the waste gas inlet at the top of the heat exchanger. Inside the heat exchanger, the waste gas is cooled, causing a large amount of water vapor to condense and settle along with dust. The condensate is discharged into a storage tank through a cooling waste gas branch pipe at the bottom of the heat exchanger, while the cooled gas is introduced to the bottom of the cyclone plate tower through the cooling waste gas branch pipe. Inside the cyclone plate tower, liquid from the first spray assembly is sprayed from the top, while the gas enters from the bottom of the cyclone plate tower and is forced to rotate and rise as it passes through the cyclone plate assembly. Under the centrifugal force of the cyclone plate assembly, droplets and dust particles entrained in the airflow are thrown against the tower wall and flow down with the liquid to the cyclone collection section. Simultaneously, the absorbent liquid from the first spray assembly is also cut into fine droplets, increasing the gas-liquid contact area. After preliminary purification, the gas enters the bottom of the packed tower through the cyclone exhaust branch pipe, passes through the packing, and is deeply absorbed by the alkaline solution sprayed by the second spray component at the top, resulting in the collection of residual pollutants. The waste liquid is collected in the packing liquid collection section. Subsequently, the gas with higher purity enters the catalytic oxidation furnace through the packing exhaust branch pipe, where trace organic matter and combustible gases are oxidized into carbon dioxide and water at high temperature. Finally, the exhaust gas is induced into the chimney by the terminal fan. Through heat exchanger cooling and dust removal, two-stage absorption by the cyclone plate tower and the packed tower, and deep oxidation by the catalytic oxidation furnace, damage to the catalytic oxidation furnace equipment caused by high temperature and humidity is avoided, dust blockage of the packing is prevented, absorption efficiency is improved, and the installation of the fan ensures negative pressure operation of the entire system. Combined with the waste liquid collection structure, intrinsic safety is guaranteed, thereby achieving efficient, stable, continuous, and safe treatment of organic nitrogen oxide waste gas under complex operating conditions. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention.

[0018] Figure 2 This is an embodiment of the present invention. Figure 1 A magnified structural diagram of point A in the diagram.

[0019] Figure 3 This is an embodiment of the present invention. Figure 1 A magnified structural diagram of point B in the diagram.

[0020] Figure 4 This is a schematic diagram of the structure of the liquid storage tank according to an embodiment of the present invention.

[0021] Figure 5 This is a side view of the swirl plate assembly according to an embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of the structure of the swirl plate assembly according to an embodiment of the present invention.

[0023] In the picture: 10. Heat exchanger; 11. Exhaust gas inlet; 12. Cooling exhaust gas branch pipe; 13. Liquid storage tank; 14. Stirring assembly; 15. Stirring drive component; 16. Stirring paddle; 17. Funnel; 18. Liquid seal pipe; 19. Cooling drain pipe; 20. Swirl drain pipe; 21. Packing drain pipe; 22. Pump body; 23. Shell; 24. First support plate; 25. First through hole; 26. Second support plate; 27. Second through hole; 28. Heat exchange tube; 29. ​​Gas buffer chamber; 30. Cooling chamber; 31. Cooling medium inlet; 32. Cooling medium outlet; 33. Exhaust chamber; 34. Third spray assembly; 40. Cyclone plate tower; 41. Cyclone liquid collection section; 42. Cyclone plate assembly; 43. Blade; 44. Outer ring; 45. Fixing part; 46. First spray assembly; 47. Cyclone exhaust gas branch pipe; 50. Packed tower; 51. Packed liquid collection section; 52. Packing; 53. Second spray assembly; 54. Packed exhaust gas branch pipe; 55. Packing area; 60. Catalytic oxidation furnace; 70. Fan; Detailed Implementation

[0024] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0025] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0026] In the description of this invention, it should be understood that the terms "connected," "linked," and "fixed," etc., used in this invention should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or a welded connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] like Figure 1As shown, a preferred embodiment of the present invention provides an organic nitrogen oxide waste gas treatment device, which includes a heat exchanger 10, a cyclone plate tower 40, a packed tower 50, a catalytic oxidation furnace 60 and a blower 70 connected in sequence. The upper end of the heat exchanger 10 is provided with a waste gas inlet 11, and the lower end of the heat exchanger 10 is provided with a cooling waste gas branch pipe 12 and a liquid storage tank 13. The lower end of the heat exchanger 10 is connected to the liquid storage tank 13 for discharging condensate, and the gas outlet of the heat exchanger 10 is connected to the bottom air inlet of the cyclone plate tower 40 through the cooling waste gas branch pipe 12. The cyclone plate tower 40 is internally connected to a cyclone liquid collection section 41, a cyclone plate assembly 42, a first spray assembly 46, and a cyclone exhaust gas branch pipe 47. The cyclone plate assembly 42 is located below the first spray assembly 46. The first spray assembly 46 is used to spray alkaline solution into the cyclone plate tower 40. The top gas outlet of the cyclone plate tower 40 is connected to the bottom gas inlet of the packed tower 50 through the cyclone exhaust gas branch pipe 47. The bottom of the packed tower 50 is provided with a packing liquid collection section 51, the packed tower 50 is provided with packing 52, the packed tower 50 is provided with a second spray assembly 53 and a packing exhaust gas branch pipe 54. The second spray assembly 53 is used to spray alkaline solution into the packed tower 50, and the top gas outlet of the packed tower 50 is connected to the gas inlet of the catalytic oxidation furnace 60 through the packing exhaust gas branch pipe 54. The gas outlet of the catalytic oxidation furnace 60 is connected to the air inlet of the blower 70.

[0028] The organic nitrogen oxide waste gas treatment device and method of the present invention include a heat exchanger 10, a cyclone plate tower 40, a packed tower 50, a catalytic oxidation furnace 60, and a blower 70 connected in sequence, forming a closed, negative pressure driven integrated treatment process. Waste gas first enters through the waste gas inlet 11 at the upper end of the heat exchanger 10. Inside the heat exchanger 10, the waste gas is cooled, causing a large amount of water vapor to condense and settle along with dust. The condensate is discharged into the storage tank 13 through the cooling waste gas branch pipe 12 at the lower end of the heat exchanger 10, while the cooled gas is introduced to the bottom of the cyclone plate tower 40 through the cooling waste gas branch pipe 12. Inside the cyclone plate tower 40, liquid from the first spray assembly 46 is sprayed from the top, and gas enters from the bottom of the cyclone plate tower 40, being forced to rotate and rise as it passes through the cyclone plate assembly 42. Under the centrifugal force of the cyclone plate assembly 42, droplets and dust particles entrained in the airflow are thrown against the tower wall and flow down with the liquid to the cyclone collection section 41. Simultaneously, the absorbent liquid in the first spray assembly 46 is also cut into fine droplets, increasing the gas-liquid contact area. The pre-purified gas enters the bottom of the packed tower 50 through the cyclone exhaust branch pipe 47, passes through the packing 52, and is deeply absorbed by the alkaline solution sprayed by the second spray assembly 53 at the top, with the waste liquid collected in the packing liquid collection section 51. Subsequently, the gas with higher purity enters the catalytic oxidizer 60 through the packing exhaust branch pipe 54, where trace organic matter and combustible gases are oxidized into carbon dioxide and water at high temperature. Finally, the exhaust gas is induced into the chimney by the terminal fan 70. Through the cooling and dust removal of the heat exchanger 10, the two-stage absorption of the cyclone plate tower 40 and the packed tower 50, and the deep oxidation of the catalytic oxidizer 60, damage to the catalytic oxidizer 60 equipment due to high temperature and humidity is avoided, dust blockage of the packing 52 is prevented, absorption efficiency is improved, and the setting of the fan 70 enables the entire system to operate under negative pressure. Combined with the waste liquid collection structure, inherent safety is ensured, thereby achieving efficient, stable, continuous, and safe treatment of organic nitrogen oxide waste gas under complex operating conditions.

[0029] It should be noted that a liquid film refers to a thin layer of liquid that spreads on the packing 52, trays, cyclone plates, or other contact surfaces due to gravity, spraying, or airflow. The liquid film has a large specific surface area and is the primary site for mass transfer (such as absorption and reaction) between the gas and liquid phases. Specifically, in the cyclone plate tower 40, the first spray assembly 46 sprays alkaline solution downwards; the alkaline solution falls onto the surface of the blades 43, forming a liquid film flowing along the surface of the blades 43 under the action of gravity and rotating airflow; the exhaust gas comes into full contact with the liquid film as it passes through the cyclone plate, and the acidic gases are absorbed by the alkaline solution in the liquid film and undergo a neutralization reaction; simultaneously, dust particles are captured by impacting the liquid film due to inertia or centrifugal force and flow with the liquid film into the cyclone collection section 41 at the bottom of the cyclone plate tower 40. In the packed tower 50, the second spray assembly 53 sprays alkaline solution onto the packing 52. The liquid wets and spreads on the surface of the packing 52, forming a continuous or semi-continuous liquid film. The exhaust gas passes through the packing 52 from bottom to top and comes into countercurrent contact with the liquid film. Residual pollutants diffuse into the liquid film and are absorbed. The high specific surface area of ​​the packing 52 makes the liquid film distribution more uniform and the contact more sufficient, thereby achieving efficient fine absorption.

[0030] As one embodiment, such as Figure 1 As shown, packing 52 is inert packing 52.

[0031] As one embodiment, such as Figure 1 As shown, the packing 52 filling the packed tower 50 is one or more combinations of multifaceted hollow spheres, Raschig rings, and Pall rings. Preferably, the multifaceted hollow sphere packing 52 made of polypropylene has the advantages of large specific surface area, high porosity, strong corrosion resistance and not easy to clog, and is suitable for the fine absorption process of humid and dusty waste gas.

[0032] In one embodiment, the exhaust gas temperature is between 160°C and 200°C. Preferably, the exhaust gas temperature is 180°C, and it mainly originates from the tail gas of the nitration reaction.

[0033] As one embodiment, such as Figure 1 As shown, the exhaust gas is cooled to 30°C–50°C in heat exchanger 10.

[0034] As one embodiment, such as Figure 1 As shown, fan 70 is a centrifugal fan 70.

[0035] As one embodiment, the cooling exhaust pipe 12 is connected to a temperature sensor, and the data collected by the temperature sensor is fed back to the control system, which improves the automation level, operational reliability and safety of the whole device.

[0036] Furthermore, such as Figures 2-3 As shown, the heat exchanger 10 includes a shell 23, a first support plate 24, a second support plate 26, and a plurality of heat exchange tubes 28; The first support plate 24 and the second support plate 26 are fixedly connected inside the housing 23 and are arranged at intervals along the axial direction, thereby dividing the housing 23 to form a gas buffer chamber 29 in the upper part, a cooling chamber 30 in the middle part and an exhaust chamber 33 in the lower part. The first support plate 24 is provided with a plurality of first through holes 25, and the second support plate 26 is provided with a plurality of second through holes 27; Both ends of each heat exchange tube 28 are sealed and connected to the first support plate 24 and the second support plate 26 respectively. The upper end of the heat exchange tube 28 is connected to the gas buffer chamber 29 through the corresponding first through hole 25, and the lower end is connected to the exhaust chamber 33 through the corresponding second through hole 27. The shell 23 is provided with an exhaust gas inlet 11, a cooling medium inlet 31, and a cooling medium outlet 32. The exhaust gas inlet 11 is connected to the gas buffer chamber 29, and the cooling medium inlet 31 and the cooling medium outlet 32 ​​are respectively connected to the cooling chamber 30. This allows the cooling medium to flow through the outer wall of the heat exchange tube 28 to cool the exhaust gas inside the heat exchange tube 28. One end of the cooling exhaust gas branch pipe 12 is connected to the exhaust chamber 33. By constructing the heat exchanger 10 internally as a gas buffer chamber 29, a cooling chamber 30, and an exhaust chamber 33 formed by the first support plate 24 and the second support plate 26 arranged axially at intervals, and by sealing both ends of multiple heat exchange tubes 28 to the first support plate 24 and the second support plate 26 respectively and connecting the buffer chamber and the exhaust chamber 33, the orderly distribution and uniform flow of exhaust gas during the heat exchange process are achieved. High-temperature exhaust gas enters the gas buffer chamber 29 through the exhaust gas inlet 11 at the upper end of the shell 23 and is evenly distributed to the upper ends of each heat exchange tube 28, avoiding local airflow short-circuiting or deflection. The cooling medium enters the cooling chamber 30 through the cooling medium inlet 31, forming a stable flow on the outer wall of the heat exchange tube 28, efficiently removing heat from the exhaust gas inside the tube. The cooled exhaust gas is collected in the lower exhaust chamber 33 and uniformly discharged to the swirl plate tower 40 through the cooling exhaust gas branch pipe 12. The three-chamber partition structure not only improves the heat exchange area utilization and heat exchange efficiency, rapidly and evenly cooling the exhaust gas at about 180°C to 30–50°C, but also enhances the structural stability of the equipment under high temperature and corrosive conditions by rigidly fixing the heat exchange tube 28 through the first support plate 24 and the second support plate 26, preventing leakage of the heat exchange tube 28 due to vibration or thermal stress deformation. Meanwhile, the gas buffer chamber 29 buffers the intake fluctuations, making the system run more smoothly and providing stable operating conditions for the subsequent dust removal and absorption units, thereby improving the overall processing efficiency and long-term operational reliability of the device.

[0037] As one embodiment, the heat exchanger 10 is made of a corrosion-resistant metal material, which prevents the generation of static electricity.

[0038] Furthermore, such as Figure 2As shown, the heat exchanger 10 also includes a third spray assembly 34, which is installed in the housing 23 and located in the gas buffer chamber 29. The spray nozzles of the third spray assembly 34 are positioned facing the upper opening of the heat exchange tubes 28. By installing the third spray assembly 34 in the gas buffer chamber 29 of the heat exchanger 10 and positioning its spray nozzles facing the upper opening of each heat exchange tube 28, directional online cleaning of the inside of the heat exchange tubes 28 is achieved. During the operation of the device, nitric acid vapor and metal dust carried by the high-temperature exhaust gas are easily condensed and deposited at the inlet of the heat exchange tubes 28, forming a dense scale layer, which leads to a reduction in the flow cross-section or even blockage. The third spray assembly 34 sprays high-pressure water or cleaning fluid onto the upper end of the heat exchange tubes 28 at preset times. The water flow washes downward along the inner side of the tube wall, peeling off the deposits inside the heat exchange tubes 28 and carrying them into the lower exhaust chamber 33, and finally discharges them into the storage tank 13 through the cooling exhaust gas branch pipe 12. The inclusion of the third spray assembly 34 avoids the need for shutdown and disassembly of the heat exchanger 10 due to blockage of the heat exchange tube 28, thus improving the continuous operation capability and ease of maintenance of the unit. Simultaneously, since the flushing operation is completed within the gas buffer chamber 29, it does not affect the sealing of the main airflow channel. Furthermore, its combination with the three-chamber partition structure prevents flushing water from entering the cooling chamber 30, thus avoiding thermal shock or media contamination. This not only solves the technical problem of easy blockage of the heat exchanger 10 in the treatment of dusty, high-humidity nitrogen oxide waste gas, but also ensures the long-term, efficient, and stable operation of the front-end cooling unit, providing a reliable operating basis for subsequent cyclone dust removal and catalytic oxidation.

[0039] As one embodiment, such as Figure 2 As shown, the third spray assembly 34 is a high-pressure nozzle. The third spray assembly 34 is activated periodically to use high-pressure water flow to flush away the dust inside the heat exchange tubes 28, ensuring unobstructed flow inside the heat exchange tubes.

[0040] Furthermore, such as Figure 4 As shown, a stirring assembly 14 is connected inside the storage tank 13. The stirring assembly 14 includes a stirring drive 15 and a stirring paddle 16, which are connected in a driving connection. By installing the stirring assembly 14 inside the storage tank 13, the problem of solid particle deposition, caking, and even pump blockage 22 caused by gravity settling of dust-laden condensate during storage is solved. The condensate from the heat exchanger 10 contains high concentrations of nitrates, metal oxides, and organic dust. If left to stand, the particles quickly settle to the bottom of the tank and form a dense sludge layer, which not only reduces the effective volume but also easily causes blockage of subsequent drainage pipes or centrifugal pump impellers, affecting the continuous operation of the system. The stirring assembly 14 continuously or intermittently agitates the waste liquid in the tank, ensuring that solid particles are uniformly suspended in the liquid phase, maintaining the fluidity of the waste liquid, and ensuring that it can be stably transported to the wastewater treatment system. At the same time, if a trace amount of alkaline spray return liquid is mixed in, the stirring action can also promote local acid-base neutralization and reduce localized accumulation of corrosive substances.

[0041] As one embodiment, the liquid storage tank 13 is made of a corrosion-resistant material.

[0042] Furthermore, such as Figure 1 As shown, the system also includes a pump body 22, a storage tank 13 connected to a cooling drain pipe 19, a vortex collecting section 41 connected to a vortex drain pipe 20, and a packing collecting section 51 connected to a packing 52 drain pipe 21. The cooling drain pipe 19, the vortex drain pipe 20, and the packing 52 drain pipe 21 are all connected to the pump body 22. The acidic and dusty condensate from the heat exchanger 10, the alkaline and dusty primary absorption waste liquid from the vortex plate tower 40, and the alkaline and low-dust fine treatment waste liquid from the packed tower 50, although slightly different in composition, can all be transported to the wastewater treatment station on demand or in shifts via the shared pump body 22. This avoids the equipment redundancy, increased footprint, and control complexity caused by configuring a separate pump for each collecting unit. At the same time, the unified drain path simplifies the pipeline layout, reduces the risk of leakage, and improves the system's sealing performance and intrinsic safety.

[0043] As one embodiment, the pump body 22 is a centrifugal pump.

[0044] Furthermore, such as Figure 1 As shown, the cyclone plate tower 40 is equipped with multiple cyclone plate assemblies 42 and a first spray assembly 46, which are arranged alternately along the height of the tower. By setting multiple cyclone plate assemblies 42 and first spray assembly 46 in the cyclone plate tower 40 and arranging them alternately along the height of the tower, the gas-liquid mass transfer efficiency and dust collection capacity are improved. As the exhaust gas rises from the bottom of the cyclone plate tower 40, it is forced to rotate each time it passes through a cyclone plate assembly 42, generating a centrifugal separation effect, causing the entrained dust particles to be thrown towards the tower wall and fall with the liquid film; while the first spray assembly 46, located immediately above it, sprays fresh alkaline solution in a timely manner, forming a new active liquid film on the surface of the next cyclone plate, which not only replenishes the absorbent concentration, but also allows acidic gases such as NO2 and HNO3 vapors that were not completely removed in the previous stage to be absorbed again. The multi-stage alternating structure combining swirling flow and spraying avoids the problems of liquid film drying, absorption saturation, or airflow short-circuiting caused by traditional single-spray layers, resulting in more sufficient gas-liquid contact and a more thorough reaction. Simultaneously, the multi-stage swirling flow extends the residence time of the exhaust gas within the tower, enhancing turbulent mixing and further improving overall purification efficiency.

[0045] As one embodiment, the cyclone plate tower 40 is made of corrosion-resistant metal.

[0046] Furthermore, such as Figures 5-6As shown, the cyclone plate assembly 42 includes multiple blades 43, an outer ring 44 arranged coaxially, and a fixing part 45. The fixing part 45 is located below the outer ring 44. The blades 43 are inclined and spaced apart circumferentially along the outer ring 44. One end of each blade 43 is connected to the inner wall of the outer ring 44, and the other end is connected to the fixing part 45. The inclined blades 43 apply tangential force to the rising exhaust gas, forcing the airflow to spiral upward along the tower wall of the cyclone plate tower 40, enhancing the centrifugal effect, and effectively throwing dust particles towards the tower wall and causing them to fall with the liquid film to the cyclone collection part 41. The uniform circumferential distribution of the blades 43 ensures that the airflow is subjected to balanced force across the entire tower cross-section, avoiding local eddies or flow deviations, and improving the uniformity of treatment. At the same time, the upper and lower double support structure formed by the outer ring 44 and the fixing part 45 ensures that the blades 43 maintain geometric stability during operation, preventing deformation or loosening and ensuring the reliability of the cyclone effect. In addition, the blades 43, together with the flushing effect of the alkaline spray above, prevent dust from accumulating and forming scale on the plate surface, thus solving the technical problems of traditional tower plates being prone to clogging and requiring frequent shutdowns for cleaning.

[0047] Furthermore, such as Figure 1 As shown, the packed tower 50 has multiple packed zones 55 spaced apart along the height direction. Packing material 52 fills the packed zones 55, and the second spray assembly 53 is located above all the packed zones 55. By setting multiple packed zones 55 spaced apart along the height direction in the packed tower 50 and placing the second spray assembly 53 above all the packed zones 55, the internal structure is simplified while ensuring absorption efficiency. After the alkaline solution is evenly sprayed by the top second spray assembly 53, it flows sequentially through each packed zone under the action of gravity, forming a continuous liquid film on the surface of the multifaceted hollow spheres, realizing the stepwise absorption of residual nitrogen oxides and acidic gases. The space between the packed zones 55 serves as a buffer and redistribution zone for airflow, eliminating airflow deviation and channeling phenomena caused by uneven packing or local blockage, making the waste gas more evenly distributed in the packed tower 50 and improving the gas-liquid contact efficiency.

[0048] As one embodiment, the packed tower 50 is made of corrosion-resistant metal.

[0049] Furthermore, such as Figure 4As shown, a funnel 17 is provided between the heat exchanger 10 and the storage tank 13. The upper end of the funnel 17 is connected to the bottom of the heat exchanger 10, and a liquid seal pipe 18 is provided at the lower end of the funnel 17. The outlet end of the liquid seal pipe 18 is inserted below the liquid surface in the storage tank 13. Since the entire device is operated by the terminal fan 70, the system is always under negative pressure. If the heat exchanger 10 and the storage tank 13 are directly open, external air can easily be drawn into the waste gas flow containing organic matter and nitrogen oxides. This would not only dilute the waste gas concentration and reduce the catalytic oxidation efficiency, but could also form an explosive mixture, posing a serious safety hazard. The liquid seal structure utilizes the static pressure of the waste liquid in the storage tank 13 to block external air from entering the heat exchanger 10 and other channels in reverse along the drain path, ensuring that the system remains sealed under negative pressure conditions. At the same time, the funnel 17 facilitates the collection of condensate, preventing airflow disturbance from causing liquid seal damage; the insertion of the liquid seal pipe 18 into the liquid surface also prevents air bubbles from being carried away or splashed during waste liquid discharge.

[0050] A method for treating organic nitrogen oxide waste gas, such as Figure 1 As shown, the treatment of organic nitrogen oxide waste gas by the organic nitrogen oxide waste gas treatment device includes the following steps: S1. Organic nitrogen oxide waste gas is introduced into the waste gas inlet 11 at the top of the heat exchanger 10. The waste gas is cooled in the heat exchanger 10, causing the water vapor in the waste gas to condense and be introduced into the liquid storage tank 13 together with the dust. In this step, the high temperature waste gas is cooled in the heat exchanger 10 and the gas-liquid-solid preliminary separation is achieved simultaneously. This avoids the high temperature and high humidity gas from directly entering the downstream equipment, prevents the moisture evaporation imbalance of the packed tower 50 and the thermal shock of the catalytic oxidation furnace 60, and creates a stable operating condition for subsequent deep treatment.

[0051] S2. The cooled exhaust gas enters the bottom of the cyclone plate tower 40 through the cooling exhaust gas branch pipe 12. During the upward process in the cyclone plate tower 40, the acidic gas and nitrogen oxides are absorbed by the alkaline solution sprayed by the first spray component 46, and the dust settles to the cyclone collection section 41. S3. The exhaust gas is discharged from the top of the cyclone plate tower 40 through the cyclone exhaust gas branch pipe 47 and enters the bottom of the packed tower 50. It passes through the packing zone 55 in the packed tower 50 and is further absorbed by the alkaline solution sprayed by the second spray assembly 53. The waste liquid is collected in the packing liquid collection section 51. First, the cyclone plate tower 40 removes most of the dust and acidic components, and then the packed tower 50 performs deep purification of the remaining pollutants. This not only solves the problem of easy clogging of traditional spray towers, but also ensures a high removal rate of nitrogen oxides and acidic gases, and the concentration of pollutants in the outlet gas is lower than the emission standard.

[0052] S4. The exhaust gas enters the catalytic oxidation furnace 60 through the filler exhaust gas branch pipe 54 for high-temperature oxidation treatment. Since the dust, moisture and corrosive components have been greatly reduced, the catalyst activity is protected, the equipment life is extended, and the exhaust gas is converted into CO2 and H2O to achieve harmless emission.

[0053] Among them, the reaction in the catalytic oxidation furnace 60 is CxHy+(4x+y) / 4O2→xCO2+y / 2H2O. This reaction is carried out at high temperature (usually ≥760℃) to completely oxidize non-methane total hydrocarbons into carbon dioxide and water. 2CO+O2→2CO2. This reaction is carried out at high temperature to oxidize carbon monoxide into carbon dioxide and water.

[0054] S5. The treated exhaust gas is induced to flow into the chimney by the fan 70; the fan 70 induced to flow the exhaust gas keeps the whole system under negative pressure, ensuring that the exhaust gas flows stably along the preset path and improving the coordination efficiency of each treatment unit.

[0055] The waste liquid in the storage tank 13, the vortex collection section 41, and the packing collection section 51 is discharged and transported to the wastewater treatment system. The waste liquid in the storage tank 13, the vortex collection section 41, and the packing collection section 51 is collected separately and discharged uniformly, which facilitates automated control and centralized wastewater treatment, avoids cross-contamination or sediment blockage, and ensures long-term continuous and stable operation of the device.

[0056] As one embodiment, the catalytic oxidation furnace 60 is equipped with an electric heating or gas heating system to maintain the reaction temperature ≥760°C and ensure complete oxidation of organic matter.

[0057] In summary, this invention provides an organic nitrogen oxide waste gas treatment device and method, comprising a heat exchanger 10, a cyclone plate tower 40, a packed tower 50, a catalytic oxidation furnace 60, and a blower 70 connected in sequence, forming a closed, negative pressure driven integrated treatment process. The waste gas first enters through the waste gas inlet 11 at the upper end of the heat exchanger 10. Inside the heat exchanger 10, the waste gas is cooled, causing a large amount of water vapor to condense and settle along with dust. The condensate is discharged into a storage tank 13 through a cooling waste gas branch pipe 12 at the lower end of the heat exchanger 10, while the cooled gas is introduced to the bottom of the cyclone plate tower 40 through the cooling waste gas branch pipe 12. Inside the cyclone plate tower 40, liquid from the first spray assembly 46 is sprayed from the top, and the gas enters from the bottom of the cyclone plate tower 40, being forced to rotate and rise as it passes through the cyclone plate assembly 42. Under the centrifugal force of the cyclone plate assembly 42, droplets and dust particles entrained in the airflow are thrown towards the tower wall and flow down with the liquid to the cyclone collection section 41. At the same time, the absorbent liquid of the first spray assembly 46 is also cut into fine droplets, increasing the gas-liquid contact area. The preliminarily purified gas enters the bottom of the packed tower 50 through the cyclone exhaust gas branch pipe 47, passes through the packing 52, and is deeply absorbed by the alkaline solution sprayed by the second spray assembly 53 at the top, and the waste liquid is collected in the packing collection section 51; then, the gas with higher purity enters the catalytic oxidation furnace 60 through the packing exhaust gas branch pipe 54, where trace organic matter and combustible gases are oxidized into carbon dioxide and water at high temperature; finally, the exhaust gas is drawn into the chimney by the terminal fan 70. By using heat exchanger 10 for cooling and dust removal, cyclone plate tower 40 and packed tower 50 for two-stage absorption, and catalytic oxidation furnace 60 for deep oxidation, the damage to the catalytic oxidation furnace 60 equipment caused by high temperature and high humidity is avoided, dust blockage of packing 52 is prevented, absorption efficiency is improved, and the setting of fan 70 enables the entire system to operate under negative pressure. Combined with the waste liquid collection structure, intrinsic safety is ensured, thereby achieving efficient, stable, continuous and safe treatment of organic nitrogen oxide waste gas under complex working conditions.

[0058] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several improvements and substitutions without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. An organic nitrogen oxide waste gas treatment device, characterized in that: It includes a heat exchanger, a cyclone plate tower, a packed tower, a catalytic oxidation furnace, and a blower connected in sequence; The heat exchanger is provided with an exhaust gas inlet at its upper end and a cooling exhaust gas branch pipe and a liquid storage tank at its lower end. The lower end of the heat exchanger is connected to the liquid storage tank for discharging condensate, and the gas outlet of the heat exchanger is connected to the bottom air inlet of the cyclone plate tower through the cooling exhaust gas branch pipe. The cyclone plate tower is connected to a cyclone liquid collection section, a cyclone plate assembly, a first spray assembly, and a cyclone exhaust gas branch pipe. The cyclone plate assembly is located below the first spray assembly. The first spray assembly is used to spray alkaline solution into the cyclone plate tower. The top gas outlet of the cyclone plate tower is connected to the bottom gas inlet of the packed tower through the cyclone exhaust gas branch pipe. The bottom of the packed tower is provided with a packing liquid collection section, the packed tower is provided with packing, the packed tower is provided with a second spray assembly and a packing exhaust gas branch pipe, the second spray assembly is used to spray alkaline solution into the packed tower, and the top gas outlet of the packed tower is connected to the gas inlet of the catalytic oxidation furnace through the packing exhaust gas branch pipe. The gas outlet of the catalytic oxidation furnace is connected to the air inlet of the blower.

2. The organic nitrogen oxide waste gas treatment device according to claim 1, characterized in that: The heat exchanger includes a shell, a first support plate, a second support plate, and multiple heat exchange tubes; The first support plate and the second support plate are fixedly connected to the housing and are arranged at intervals along the axial direction, thereby dividing the housing to form a gas buffer chamber at the top, a cooling chamber in the middle and an exhaust chamber at the bottom. The first support plate is provided with a plurality of first through holes, and the second support plate is provided with a plurality of second through holes; Both ends of each heat exchange tube are respectively sealed and connected to the first support plate and the second support plate. The upper end of each heat exchange tube is connected to the gas buffer chamber through the corresponding first through hole, and the lower end is connected to the exhaust chamber through the corresponding second through hole. The housing is provided with an exhaust gas inlet, a cooling medium inlet, and a cooling medium outlet. The exhaust gas inlet is connected to the gas buffer chamber, and the cooling medium inlet and the cooling medium outlet are respectively connected to the cooling chamber. The cooling medium is used to flow through the outer wall of the heat exchange tube to cool the exhaust gas inside the tube. One end of the cooling exhaust gas branch pipe is connected to the exhaust chamber.

3. The organic nitrogen oxide waste gas treatment device according to claim 2, characterized in that: The heat exchanger also includes a third spray assembly, which is installed in the housing and located in the gas buffer chamber, with the spray nozzle of the third spray assembly facing the upper opening of the heat exchange tube.

4. The organic nitrogen oxide waste gas treatment device according to claim 1, characterized in that: The storage tank is connected to a stirring assembly, which includes a stirring drive and a stirring paddle, and the stirring drive is connected to the stirring paddle in a driving connection.

5. The organic nitrogen oxide waste gas treatment device according to claim 1, characterized in that: It also includes a pump body, the liquid storage tank is connected to a cooling drain pipe, the vortex liquid collecting part is connected to a vortex drain pipe, the packing liquid collecting part is connected to a packing drain pipe, and the cooling drain pipe, the vortex drain pipe and the packing drain pipe are respectively connected to the pump body.

6. The organic nitrogen oxide waste gas treatment device according to claim 1, characterized in that: The swirl plate tower is equipped with multiple swirl plate assemblies and the first spray assembly, which are arranged alternately at intervals along the height of the tower.

7. The organic nitrogen oxide waste gas treatment device according to claim 1, characterized in that: The swirl plate assembly includes multiple blades, an outer ring arranged coaxially, and a fixing part. The fixing part is located below the outer ring. The blades are inclined and the multiple blades are spaced apart along the circumference of the outer ring. One end of each blade is connected to the inner wall of the outer ring, and the other end is connected to the fixing part.

8. The organic nitrogen oxide waste gas treatment device according to claim 1, characterized in that: The packed tower is provided with multiple packing zones spaced apart along the height direction, the packing is filled in the packing zones, and the second spray assembly is located above all the packing zones.

9. The organic nitrogen oxide waste gas treatment device according to claim 1, characterized in that: A funnel is provided between the heat exchanger and the liquid storage tank. The upper end of the funnel is connected to the bottom of the heat exchanger, and a liquid seal pipe is provided at the lower end of the funnel. The outlet end of the liquid seal pipe is inserted below the liquid level in the liquid storage tank.

10. A method for treating organic nitrogen oxide waste gas, characterized in that: The treatment of organic nitrogen oxide waste gas by the organic nitrogen oxide waste gas treatment device according to any one of claims 1-9 includes the following steps: S1. Organic nitrogen oxide waste gas is introduced from the waste gas inlet at the top of the heat exchanger and cooled in the heat exchanger, so that the water vapor in the waste gas is condensed and introduced into the storage tank together with the dust. S2. The cooled exhaust gas enters the bottom of the cyclone plate tower through the cooling exhaust gas branch pipe. During the upward process in the cyclone plate tower, the acidic gas and nitrogen oxides are absorbed by the alkaline solution sprayed by the first spray component, and the dust settles into the cyclone collection section. S3. The exhaust gas is discharged from the top of the cyclone plate tower through the cyclone exhaust gas branch pipe and enters the bottom of the packed tower. Inside the packed tower, it passes through the packing area and is further absorbed by the alkaline solution sprayed by the second spray assembly. The waste liquid is collected in the packing liquid collection section. S4. The waste gas enters the catalytic oxidation furnace through the filler waste gas branch pipe for high-temperature oxidation treatment; S5. The treated exhaust gas is drawn into the chimney by the blower; The waste liquid in the storage tank, the vortex liquid collection section and the packing liquid collection section is discharged and transported to the wastewater treatment system.

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