Flue gas circulation oxygen-rich incineration system for nitrogenous organic waste gas and / or waste liquid

Abstract

The utility model provides a flue gas circulation oxygen-rich incineration system for nitrogenous organic waste gas and / or waste liquid, which comprises an incinerator, a combustion-supporting gas burner, a waste liquid burner and / or waste gas burner are arranged on the incinerator, the combustion-supporting gas burner is connected with a gas delivery pipe through a pipeline, and the flue gas circulation oxygen-rich incineration system further comprises a waste heat boiler connected with the incinerator through a pipeline. The waste heat boiler is connected with a flue gas conveying pipeline and a low-pressure steam or high-temperature hot water recycling conveying pipeline; a gas inlet of the flue gas drying tower is communicated with a flue gas conveying pipeline, a gas outlet of the flue gas drying tower is connected with a first output pipe, the first output pipe is connected with a first three-way valve, and the first three-way valve is respectively connected with a first conveying pipe and a second conveying pipe; the oxygen supply unit is connected with a mixer through a pipeline, the mixer is connected with a first conveying pipe, and an outlet of the mixer is connected with the combustion-supporting gas burner, the waste liquid burner and / or the waste gas burner through pipelines. According to the utility model, the heat utilization rate is improved, and the flue gas denitration cost is reduced.

Description

Technical Field

[0001] This utility model relates to the fields of chemical and environmental protection technology, specifically a flue gas recirculation multi-aerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid. Background Technology

[0002] In some chemical and light industrial production processes, N,N-dimethylformamide (DMF) is widely used as a universal solvent. During the production process, a large amount of wastewater containing DMF is generated. The treatment and recovery of DMF from this wastewater containing high concentrations of DMF generates waste gas and waste liquid. These waste gases, waste liquids, and waste residues contain organic components such as dimethylamine, formic acid, and small amounts of DMF. Improper treatment and control can have a significant impact on the environment.

[0003] Currently, in the treatment of DMF-containing wastewater from synthetic leather production, the aforementioned waste gas and waste liquid are generally disposed of by incinerators. However, conventional incinerators rely on air for combustion, requiring a large excess air coefficient. This results in high nitrogen oxide content in the flue gas, large flue gas flow rate, low waste heat utilization rate, high flue gas denitrification cost, and complex subsequent flue gas treatment systems. Therefore, it is of great significance to provide a flue gas recirculation multi-aerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid with high incineration heat utilization rate and low flue gas denitrification cost to address the problems of existing incineration devices. Utility Model Content

[0004] The purpose of this invention is to overcome the aforementioned problems in the prior art and to provide a flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid. This system can solve the problems mentioned above, improve the utilization rate of incineration heat, and reduce the cost of flue gas denitrification.

[0005] This utility model provides a flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid, comprising: an incinerator, which can be designed as a vertical or horizontal incinerator depending on the material form of the nitrogen-containing organic waste gas and / or nitrogen-containing organic liquid, suitable for the incineration of organic solid waste and hazardous waste; the incinerator is a vertical structure incinerator, and the incineration temperature inside the incinerator can reach 1100℃~1300℃, and the combustion temperature inside the incinerator can be adjusted according to the characteristics of the incinerated material to ensure that the waste gas or waste liquid is fully incinerated at high temperature in the incinerator, and the system can automatically adjust the oxygen content in the recirculated flue gas; in addition, the incineration temperature can also be controlled and adjusted by adjusting the oxygen content in the recirculated flue gas, which can achieve "low nitrogen" combustion.

[0006] The incinerator also includes a waste liquid burner and / or a waste gas burner, the auxiliary combustion burner being connected to an auxiliary combustion gas supply pipe via a pipeline, the waste liquid burner being connected to a nitrogen-containing waste liquid pretreatment unit via a pipeline, and / or the waste gas burner being connected to a nitrogen-containing waste gas supply unit via a pipeline. It also includes:

[0007] The waste heat boiler is connected to the incinerator via pipelines. It is connected to flue gas conveying pipelines and waste heat recovery conveying pipelines, with the waste heat recovery conveying pipelines transporting low-pressure steam or high-temperature hot water. The high-temperature flue gas from the incinerator, after incineration of nitrogen-containing organic waste gas and / or nitrogen-containing organic waste liquid, is then processed by the waste heat boiler to generate low-pressure steam or high-temperature hot water for use in the main process. Alternatively, the incinerator and waste heat boiler can be designed as an integrated structure, making the system layout more compact and operation management more convenient.

[0008] The flue gas drying tower has a gas inlet connected to the flue gas conveying pipeline. The gas outlet of the flue gas drying tower (14) is connected to a first output pipe. The first output pipe is connected to a first three-way valve. The first three-way valve is connected to a first conveying pipe and a second conveying pipe. The second conveying pipe is connected to the flue gas re-purification device. The flue gas is cooled to below 200°C by the waste heat boiler and then enters the flue gas drying tower for dehydration.

[0009] The oxygen supply unit has an outlet connected to a mixer via a pipeline. The inlet of the mixer is connected to a first delivery pipe, and the outlet of the mixer is connected to a combustion-supporting burner via a pipeline. The outlet of the mixer is also connected to a waste liquid burner and / or a waste gas burner. Oxygen is mixed in the mixer at a controllable flow rate and then sent to the incinerator as combustion-supporting air or secondary combustion-supporting air. The oxygen supplied by the oxygen supply unit can be self-produced or supplied from purchased oxygen cylinders.

[0010] The oxygen concentration is in the range of 70% to 90%. The pipeline supplied to the mixer is equipped with an automatic flow regulating valve, which allows the oxygen concentration in the recirculated flue gas exiting the mixer to be adjusted and controlled, generally within the range of 30% to 45%, and adjusted according to the characteristics of the incinerated material and the required combustion temperature. The outlet pipe of the mixer is equipped with an oxygen content detection sensor.

[0011] In addition, the nitrogen-containing organic waste gas and / or nitrogen-containing organic waste liquid treated by the incinerator have different material forms. The flue gas purification section can be flexibly added or removed, such as dust removal, alkaline washing, water washing, reheating and other units, so that the emitted flue gas meets environmental protection standards. The CO2 separation (capture) unit in the flue gas can also be flexibly added according to the treatment scale and market demand.

[0012] Preferably, the flue gas re-purification device is connected to the induced draft fan via a pipeline, and the induced draft fan is connected to the chimney via a pipeline.

[0013] Preferably, it further includes a carbon dioxide separation unit, and a second three-way valve is connected to the first output pipe. A second output pipe and a third output pipe are connected to the second three-way valve. The second output pipe is connected to the first three-way valve, and the third output pipe is connected to the gas inlet of the carbon dioxide separation unit. The gas outlet of the carbon dioxide separation unit is connected to the second output pipe through a pipeline.

[0014] Preferably, the carbon dioxide separation unit includes at least two carbon dioxide separation devices arranged in parallel, and the gas inlet of each carbon dioxide separation device is connected to a third output pipe through a pipeline, and the gas outlet of each carbon dioxide separation device is connected to a second output pipe through a pipeline.

[0015] Preferably, an automatic regulating valve is provided on the pipeline connecting the inlet of the mixer to the oxygen supply unit.

[0016] Preferably, an oxygen content detection sensor is also provided on the pipeline connected to the outlet of the mixer.

[0017] Preferably, the nitrogen-containing waste gas conveying unit includes a waste gas buffer storage tank and a waste gas fan. The inlet of the waste gas buffer storage tank is connected to the nitrogen-containing waste gas conveying main pipe. The inlet of the waste gas fan is connected to the outlet of the waste gas buffer storage tank through a pipeline. Flame arresters are installed on the pipeline connecting the outlet of the waste gas fan to the waste gas burner, as well as on the combustion-supporting gas conveying pipeline. The pipeline containing the flame arrester connected to the waste gas fan is connected to the waste gas burner. A combustible gas alarm device can also be installed according to relevant gas regulations.

[0018] Preferably, valves are also provided on the pipelines connecting the inlet and outlet of the flame arrester.

[0019] Preferably, the nitrogen-containing waste liquid conveying unit includes a waste liquid pump and a filtration pretreatment device. The inlet of the waste liquid pump is connected to the nitrogen-containing waste liquid conveying main pipe. The outlet of the waste liquid pump is connected to a third three-way valve, which is connected to a first delivery pipe and a second delivery pipe respectively. The first delivery pipe is connected to a waste liquid burner. The second delivery pipe is connected to the first delivery pipe through the filtration pretreatment device. Valves are also provided on the first and second delivery pipes. A waste liquid storage tank is also provided between the inlet of the waste liquid pump and the nitrogen-containing waste liquid conveying main pipe.

[0020] Compared with the prior art, the beneficial effects of this utility model are:

[0021] This invention is an improved design for on-site incineration of organic nitrogen-containing waste gas and liquid in industrial production using air-assisted combustion. It uses a mixture of recirculated flue gas and oxygen as the combustion-assisted fuel. The nitrogen content in this fuel is less than that in air, and the oxygen concentration in the flue gas circulation is higher than that in air (i.e., oxy-fuel combustion). Therefore, after combustion in the incinerator, less nitrogen oxides are generated in the flue gas, and the required circulating flue gas volume is significantly lower than the air volume required for conventional combustion. Consequently, the total flue gas volume after incineration is less. Even if subsequent flue gas denitrification is required, the low nitrate content in the flue gas and the small total flue gas volume result in low denitrification costs, and may even eliminate the need for denitrification altogether. Simultaneously, the incinerator is connected to a waste heat boiler, allowing the waste gas generated during incineration to exchange heat with the boiler. This enables the recovery of waste heat from the incinerated waste gas, making the flue gas purification process more convenient and cost-effective, and the system is compact and simple.

[0022] In this invention, organic waste gas is stored in a waste gas storage tank, and organic waste liquid is sent to a filtration and preheating device for pretreatment. Both methods ensure that the output and composition fluctuations of waste gas and waste liquid will not affect the stable operation of the incineration system when production is discontinuous and unstable.

[0023] In this invention, the flue gas flow rate is reduced after being dehumidified and removed from the flue gas cooled by the waste heat boiler. The combustion air formed after recirculation and oxygen supply is more conducive to the combustion reaction. At the same time, if further purification of the flue gas is required, it is easier to configure the equipment.

[0024] This invention is applicable to various scenarios such as biomass gasification and incineration and carbon capture, and medical solid waste gasification and incineration treatment. Attached Figure Description

[0025] Figure 1 This is a diagram of a flue gas recirculation multi-aerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid according to this utility model.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Waste liquid pump; 2. Filtration pretreatment device; 3. Waste gas buffer storage tank; 4. Waste gas fan; 5. Flame arrester; 6. Oxygen generation unit or oxygen supply unit; 7. Automatic regulating valve; 8. Mixer; 9. Waste liquid burner; 10. Combustion-supporting burner; 11. Waste gas burner; 12. Incinerator; 13. Waste heat boiler; 14. Flue gas drying tower; 15. First three-way valve; 16. Carbon dioxide separation unit; 17. Second three-way valve; 18. Exhaust fan; 19. Chimney. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1The specific embodiments of this utility model are described in detail below, but it should be understood that the protection scope of this utility model is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the protection scope of this utility model.

[0029] This invention solves the problems of low incineration heat utilization and high flue gas denitrification costs in incinerators. It primarily addresses the challenges of incineration and flue gas denitrification in the treatment of nitrogen-containing organic waste gas and liquid in industrial production. This resolves the drawbacks of high incineration costs and significant environmental impact associated with the disposal of nitrogen-containing organic waste gas and liquid, while also fully recovering and utilizing the waste heat generated during incineration, achieving on-site resource utilization of waste gas and liquid and ensuring environmentally compliant flue gas emissions.

[0030] This invention effectively solves the drawbacks of incineration treatment of nitrogen-containing organic waste gas and / or nitrogen-containing organic waste liquid, such as large flue gas volume, high flue gas purification cost, and complex system configuration. For example, in the production of DMF waste gas (wastewater) in synthetic leather, the incineration of dimethylamine waste gas (wastewater) faces problems such as inconvenient incineration temperature control, high consumption of combustion fuel (gas or oil), large flue gas output, high nitrogen oxide content, low waste heat recovery and utilization rate, complex flue gas purification system, and high purification cost. It can significantly reduce the configuration and floor space of the incineration system, making the waste heat boiler more compact and improving heat exchange efficiency.

[0031] like Figure 1 As shown, this utility model provides a flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid, including: an incinerator 12, with a combustion-supporting burner 10 on the incinerator 12, and a waste liquid burner 9 and / or a waste gas burner 11 on the incinerator 12. The combustion-supporting burner 10 is connected to a combustion-supporting gas supply pipe via a pipeline, and the combustion-supporting gas supply pipe is connected to a gas supply. It can partially use natural gas or fuel oil for continuous operation. The natural gas pressure is 30 kPa, ensuring that the combustion temperature and flue gas flow rate in the incinerator 12 are relatively stable, thereby improving the heat exchange efficiency of the waste heat boiler 13. The refractory material selected for the furnace of the incinerator 12 must have excellent high-temperature resistance, erosion resistance, and corrosion resistance. The waste liquid burner 9 is connected to a nitrogen-containing waste liquid pretreatment unit via a pipeline and / or the waste gas burner 11 is connected to a nitrogen-containing waste gas supply unit via a pipeline. The system also includes:

[0032] The incinerator 12 can be designed as a vertical incinerator, horizontal incinerator, or gasifier, depending on the physical form of nitrogen-containing organic waste gas and liquid. It is suitable for incineration systems containing nitrogen-containing organic waste gas and liquid. The furnace structure of the incinerator 12 is primarily determined by the recirculated flue gas (combustion air) atmosphere and the volume, flow rate, combustion reaction time, and heat release (absolute combustion temperature, furnace water cooling, emissivity, etc.) of the waste gas and / or liquid after decomposition and combustion, determining its diameter and length. This system is designed for the incineration of waste gas and / or liquid. The incinerator is a vertical structure, and the combustion temperature is controlled within the range of 1000℃-1350℃ to ensure complete decomposition of the waste liquid. The refractory materials selected for the furnace must possess excellent high-temperature resistance, erosion resistance, and corrosion resistance; the selected materials must have high refractoriness, high strength, and improved load softening point and corrosion resistance. At this point, the combustion temperature inside the furnace can reach 1100℃~1300℃, achieving "low-NOx" combustion and ensuring that organic waste gas and nitrogen-containing organic waste liquid are fully combusted at high temperature inside incinerator 12. Furthermore, incinerator 12 can adjust the temperature and combustion atmosphere according to the scale, combustibility, and calorific value of the waste gas and / or waste liquid being treated, resulting in more complete combustion, more thorough waste gas (liquid) treatment, and low NOx emissions. x Generation amount.

[0033] The nitrogen-containing waste liquid pretreatment unit is for nitrogen-containing organic waste liquid discharged from the main process area. It may be discharged intermittently or continuously. This system is equipped with at least a waste liquid storage tank and is supplied to the incinerator by waste liquid pump 1. The intermediate pipeline is equipped with a filtration pretreatment device 2, which includes, but is not limited to, filtration, preheating, and monitoring of temperature and pressure indicators.

[0034] The waste gas collection and storage tank and conveying unit are for nitrogen-containing organic waste gas discharged from the main process area. The discharge may be intermittent or continuous. This system is equipped with at least a waste gas buffer storage tank 3, which can stably and continuously supply the waste gas to the incinerator 12, so that the system can operate smoothly. The volume of the waste gas buffer storage tank 3 can be designed to meet the incineration capacity of 2 to 5 days, or the output of 4 to 7 days of normal production discharge.

[0035] Another type of flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid includes:

[0036] Waste heat boiler 13 is connected to incinerator 12 via pipelines. Waste heat boiler 13 is connected to flue gas conveying pipelines and waste heat recovery conveying pipelines. The waste heat recovery conveying pipelines transport low-pressure steam or high-temperature hot water. The high-temperature flue gas from the incinerator 12, after incineration of nitrogen-containing organic waste gas and nitrogen-containing organic waste liquid, is then processed by waste heat boiler 13 to generate low-pressure steam or high-temperature hot water, which can be used in the main process.

[0037] The gas inlet of the flue gas drying tower 14 is connected to the flue gas conveying pipeline, and the gas outlet of the flue gas drying tower 14 is connected to a first output pipe. The first output pipe is connected to a first three-way valve 17, and the first three-way valve 17 is connected to a first conveying pipe and a second conveying pipe. The second conveying pipe is connected to the flue gas re-purification device. The incinerator 12 and the waste heat boiler 13 can also be designed as an integrated structure, making the system layout more compact and the operation and management more convenient. After the incineration flue gas passes through the flue gas drying tower 14, about 35% to 55% of the flue gas is recirculated flue gas, and the remaining flue gas does not require denitrification or only requires simple denitrification purification before being discharged.

[0038] The outlet of the oxygen supply unit 6 is connected to a mixer 8 via a pipeline. The inlet of the mixer 8 is connected to the first delivery pipe, and the outlet of the mixer 8 is connected to the combustion-supporting burner 10 via a pipeline. The outlet of the mixer 8 is also connected to the waste liquid burner 9 and / or the waste gas burner 11.

[0039] Oxygen supply unit 6 can be an oxygen generator unit 6 or other oxygen sources. Oxygen generator unit 6 is a conventional air separation unit.

[0040] The oxygen supply unit 6 requires an oxygen concentration of 70% to 90%. It can be supplied by conventional oxygen production or other means, such as from the main plant area. It needs to be equipped with an oxygen storage tank of a certain size to maintain normal supply pressure. In addition, it can also recover the oxygen-enriched air discharged from the nitrogen production unit in the plant area to realize the recovery and utilization of residual energy.

[0041] The incinerator in this invention can also be designed as a high-temperature molten state incinerator based on organic nitrogen-containing waste gas and / or organic nitrogen-containing waste liquid, with an incineration temperature of 1100℃~1500℃, which is 800℃~900℃ higher than the ash melting point temperature of organic solid waste. This allows the ash to flow out of the incinerator in a molten state. The rapidly cooled and granulated ash is a solid waste product, which is convenient for further disposal.

[0042] The combustion air fed into the incinerator 12 through the outlet of mixer 8 mainly consists of 23%–29% oxygen, 25%–40% nitrogen, 5%–15% carbon dioxide, and 20%–25% moisture and other components. This composition is significantly different from that of natural air, which contains 21% oxygen and 79% nitrogen. The combustion gas in the incinerator 12 of this system is an O2 / CO2 atmosphere obtained by oxygenating recirculated flue gas. Since natural air is not used for combustion, a large amount of N2 from the air is not introduced into the incinerator 12, resulting in less flue gas volume and a higher combustion temperature. The designed furnace volume of the incinerator 12 is smaller than that of a conventional incinerator for waste gas and waste liquid. Simultaneously, the flow rates of the flue gas waste heat boiler 13 and subsequent units related to flue gas flow are also smaller, thereby reducing the design / construction cost of the entire system and making operation and management more convenient.

[0043] The flue gas re-purification device is connected to the induced draft fan 18 via a pipeline, and the induced draft fan 18 is connected to the chimney 19 via a pipeline.

[0044] Specifically, it also includes a carbon dioxide separation unit 16. A second three-way valve 15 is connected to the first output pipe. A second output pipe and a third output pipe are connected to the second three-way valve 15. The second output pipe is connected to the first three-way valve 17, and the third output pipe is connected to the gas inlet of the carbon dioxide separation unit 16. The gas outlet of the carbon dioxide separation unit 16 is connected to the second output pipe via a pipeline. The carbon dioxide separation unit 16 is set up to reduce carbon emissions and also to reduce the carbon dioxide content in the recycled flue gas.

[0045] Specifically, the carbon dioxide separation unit 16 includes at least two carbon dioxide separation devices arranged in parallel, and the gas inlet of each carbon dioxide separation device is connected to a third output pipe through a pipeline, and the gas outlet of each carbon dioxide separation device is connected to a second output pipe through a pipeline.

[0046] Specifically, an automatic regulating valve 7 is installed on the pipeline connecting the inlet of the mixer 8 to the oxygen supply unit 6. The combustion temperature of the incinerator can be controlled and adjusted according to the characteristics of the incinerated material by adjusting the oxygen content in the recirculated flue gas.

[0047] The oxygen concentration of the oxygen supply unit 6 is in the range of 70% to 90%. The automatic regulating valve 7 makes the oxygen content concentration in the recirculated flue gas sent through the mixer 8 adjustable and controllable, generally in the range of 30% to 45%, and is adjusted according to the characteristics of the incinerated material and the required incineration temperature. The outlet pipeline of the recirculated flue gas mixer 8 is equipped with an oxygen content detection sensor.

[0048] Specifically, an oxygen content detection sensor is also installed on the pipeline connected to the outlet of the mixer 8.

[0049] Knowing the specific indicators of circulating flue gas volume and oxygen content allows for real-time control of the incinerator temperature, management of the degree of combustion cleanliness, and monitoring of the operational status of waste gas (liquid) with different components.

[0050] Specifically, the nitrogen-containing waste gas conveying unit includes a waste gas buffer storage tank 3 and a waste gas fan 4. The inlet of the waste gas buffer storage tank 3 is connected to the nitrogen-containing waste gas conveying main pipe, and the inlet of the waste gas fan 4 is connected to the outlet of the waste gas buffer storage tank 3 via a pipeline. Flame arresters 5 are installed on the pipeline connecting the outlet of the waste gas fan 4 to the waste gas burner 11, as well as on the combustion-supporting gas conveying pipeline. The pipeline containing the flame arresters 5 connected to the waste gas fan 4 is connected to the waste gas burner 11. Nitrogen-containing organic waste gas may be discharged intermittently or continuously; therefore, the waste gas buffer storage tank 3 can stably and continuously supply the incinerator 12, ensuring stable system operation. The volume of the waste gas buffer storage tank 3 can be designed to meet the incineration capacity for 2 to 5 days, or the production capacity for 4 to 7 days of normal production discharge.

[0051] Specifically, valves are also installed on the pipelines connecting the inlet and outlet of the flame arrester 5.

[0052] Specifically, the nitrogen-containing waste liquid conveying unit includes a waste liquid pump 1 and a filter preheating device 2. The inlet of the waste liquid pump 1 is connected to the nitrogen-containing waste liquid conveying main pipe, and the outlet of the waste liquid pump 1 is connected to a third three-way valve, which is connected to a first delivery pipe and a second delivery pipe respectively. The first delivery pipe is connected to a waste liquid burner 9, and the second delivery pipe is connected to the first delivery pipe through the filter preheating device 2. Valves are also provided on the first and second delivery pipes. A waste liquid storage tank is also provided between the inlet of the waste liquid pump 1 and the nitrogen-containing waste liquid conveying main pipe.

[0053] The pipeline connected to waste liquid pump 1 is equipped with components such as filtration, emergency discharge, leak detection, preheating, and temperature and pressure metering and detection in accordance with relevant fuel safety regulations.

[0054] After the flue gas is cooled to below 200°C by the waste heat boiler 13, it enters the flue gas drying tower 14. The flue gas sent out by the flue gas drying tower 14 can be sent to the CO2 separation device 16 through the second three-way valve 15, and then divided into two paths by the first three-way valve 17. Alternatively, the flue gas sent directly through the second three-way valve 15 can be divided into two paths, and the first three-way valve 17 divides it into two paths. One path is used as recirculated flue gas, and the other path is sent to the chimney 19 for discharge by the induced draft fan 18. The recirculated flue gas enters the oxygen mixing unit 8.

[0055] The high-temperature flue gas from the incinerator 12 is cooled to 110℃~145℃ after heat exchange in the waste heat boiler 13. It then enters the flue gas dehydration tower 14 to remove the moisture generated during combustion. Depending on whether CO2 capture is required, a carbon dioxide separation tower 16 is selectively installed. If CO2 capture is required, the flue gas enters the carbon dioxide separation tower 16 under the control of the flue gas bypass valve group 15. The remaining flue gas after CO2 separation is directly used as recirculated flue gas and enters the mixer 8 for oxygen distribution. If CO2 capture is not required, the flue gas is divided into two paths by the distribution regulating valve group 17. One path goes through the flue gas repurification device and is then sent to the chimney 19 for discharge by the induced draft fan 18. The other path is recirculated flue gas that enters the mixer 8 for oxygen distribution and reuse.

[0056] The high-temperature flue gas output from the incinerator 12 releases heat energy through the waste heat boiler 13, and the flue gas temperature drops to the range of 110℃~145℃. It then enters the flue gas dehydration tower 14 to remove the moisture generated during incineration. Depending on whether CO2 needs to be captured, a carbon dioxide separation unit 16 is selectively set up. If CO2 needs to be captured, it enters the carbon dioxide separation device through the second three-way valve 15. The remaining flue gas after CO2 separation is directly used as recirculated flue gas and enters the mixer 8 for oxygen distribution. If CO2 does not need to be captured, the flue gas is divided into two paths through the first three-way valve 17. One path goes through the flue gas repurification device (configured as needed, not shown in the figure) and is then sent to the chimney 19 for discharge by the induced draft fan 18. The other path is recirculated flue gas that enters the mixer 8 for oxygen distribution.

[0057] This system produces a small volume of flue gas with a relatively high temperature. It also allows for a secondary flue gas recirculation design for the incinerator 12. This involves introducing a portion of unoxygenated recirculated flue gas into an appropriate location within the furnace of the incinerator 12, where it acts as a turbulent flow and provides a small amount of oxygen to promote flame and airflow filling in the furnace. The burner of the incinerator 12 in this system is equipped with a blower to extract and deliver the recirculated flue gas into the furnace to support combustion, eliminating the need for a separate flue gas recirculation fan.

[0058] Although embodiments of the present 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 present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid, comprising: An incinerator (12) having a combustion-supporting burner (10), characterized in that the incinerator (12) also has a waste liquid burner (9) and / or a waste gas burner (11), the combustion-supporting burner (10) being connected to a combustion-supporting fuel supply pipe via a pipeline, the waste liquid burner (9) being connected to a nitrogen-containing waste liquid pretreatment unit via a pipeline and / or the waste gas burner (11) being connected to a nitrogen-containing waste gas supply unit via a pipeline, further comprising: Waste heat boiler (13) is connected to incinerator (12) via pipeline. Waste heat boiler (13) is connected to flue gas transmission pipeline and waste heat reuse transmission pipeline. The flue gas drying tower (14) has a gas inlet connected to the flue gas conveying pipeline. The gas outlet of the flue gas drying tower (14) is connected to a first output pipe. The first output pipe is connected to a first three-way valve (17). The first three-way valve (17) is connected to a first conveying pipe and a second conveying pipe. The second conveying pipe is connected to the flue gas re-purification device. The oxygen supply unit (6) has a mixer (8) connected to its outlet via a pipeline. The inlet of the mixer (8) is connected to the first delivery pipe. The outlet of the mixer (8) is connected to the combustion-supporting burner (10) via a pipeline. The outlet of the mixer (8) is also connected to the waste liquid burner (9) and / or the waste gas burner (11).

2. The flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid according to claim 1, characterized in that, The flue gas re-purification device is connected to the induced draft fan (18) via a pipeline, and the induced draft fan (18) is connected to the chimney (19) via a pipeline.

3. The flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid according to claim 1, characterized in that, It also includes a carbon dioxide separation unit (16), and a second three-way valve (15) is connected to the first output pipe. The second three-way valve (15) is connected to a second output pipe and a third output pipe. The second output pipe is connected to the first three-way valve (17), and the third output pipe is connected to the gas inlet of the carbon dioxide separation unit (16). The gas outlet of the carbon dioxide separation unit (16) is connected to the second output pipe through a pipeline.

4. The flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid according to claim 3, characterized in that, The carbon dioxide separation unit (16) includes at least two carbon dioxide separation devices arranged in parallel, and the gas inlet of each carbon dioxide separation device is connected to the third output pipe through a pipeline, and the gas outlet of each carbon dioxide separation device is connected to the second output pipe through a pipeline.

5. The flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid according to claim 1, characterized in that, An automatic regulating valve (7) is provided on the pipeline connecting the inlet of the mixer (8) to the oxygen supply unit (6).

6. A flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid according to claim 1 or 5, characterized in that, An oxygen content detection sensor is also installed on the pipeline connected to the outlet of the mixer (8).

7. The flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid according to claim 1, characterized in that, The nitrogen-containing waste gas conveying unit includes a waste gas buffer storage tank (3) and a waste gas fan (4). The inlet of the waste gas buffer storage tank (3) is connected to the nitrogen-containing waste gas conveying main pipe. The inlet of the waste gas fan (4) is connected to the outlet of the waste gas buffer storage tank (3) through a pipeline. Flame arresters (5) are provided on the pipeline connecting the outlet of the waste gas fan (4) to the waste gas burner (11) and on the combustion-supporting gas conveying pipe. The pipeline where the flame arrester (5) connected to the waste gas fan (4) is located is connected to the waste gas burner (11).

8. The flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid according to claim 7, characterized in that, Valves are also installed on the pipelines connecting the inlet and outlet of the flame arrester (5).

9. The flue gas recirculation anaerobic incineration system for nitrogen-containing organic waste gas and / or waste liquid according to claim 8, characterized in that, The nitrogen-containing waste liquid conveying unit includes a waste liquid pump (1) and a filter pretreatment device (2). The inlet of the waste liquid pump (1) is connected to the nitrogen-containing waste liquid conveying main pipe. The outlet of the waste liquid pump (1) is connected to a third three-way valve, which is connected to the first delivery pipe and the second delivery pipe respectively. The first delivery pipe is connected to the waste liquid burner (9). The second delivery pipe is connected to the first delivery pipe through the filter pretreatment device (2). Valves are also provided on the first and second delivery pipes. A waste liquid storage tank is also provided between the inlet of the waste liquid pump (1) and the nitrogen-containing waste liquid conveying main pipe.

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