Sintering machine energy-saving system and method based on circular cooler tail section hot air recycling coupling oxygen-enriched combustion

Abstract

The invention relates to the technical field of ferrous metallurgy sintering processes, in particular to a sintering machine energy-saving system and method based on circular cooler tail section hot air recycling coupling oxygen-enriched combustion, and the sintering machine energy-saving system comprises a low-temperature hot air recycling unit, an oxygen-enriched mixing unit, a discharge detection unit and an intelligent regulation and control unit. Low-temperature hot air at the tail section of an annular cooler is taken and introduced into a closed hood of a sintering machine mineral aggregate layer through the suction force of an induced draft fan, the oxygen enrichment degree of the hot air in the closed hood is increased, and the uniform oxygen-enriched hot air passes through the sintering mineral aggregate layer and is combusted and completely reacted with the solid fuel-coke powder in the sintering mineral aggregate layer through negative pressure driving of an air bellow below the material level. The method has the beneficial effects that the reaction speed is high, the theoretical combustion temperature is high, CO emission is reduced while sintering of the sintered ore is assisted, energy is saved, and the yield is increased.

Description

Technical Field

[0001] This invention relates to the field of sintering technology in iron and steel metallurgy, and in particular to an energy-saving system and method for sintering machines based on hot air recycling coupled with oxygen-enriched combustion in the tail section of an annular cooler. Background Technology

[0002] Currently, the steel industry is still in a period of deep adjustment, with overcapacity and the pressure of green transformation coexisting, and market competition becoming increasingly fierce; cost reduction and efficiency improvement have become the foundation for enterprises to survive.

[0003] Sintering accounts for 12% of the total energy consumption in steel production, but its carbon emissions account for as much as 15%. In terms of environmental emissions, the sintering system is not only a major emitter of nitrogen oxides and sulfides, but CO escape from the flue gas of the sintering machine is also the most serious emission source among all steel production processes. Furthermore, from the perspective of waste heat utilization, the low-temperature hot air at the tail end of the annular cooler in traditional sintering production processes is directly discharged, resulting in a very low waste heat utilization rate (<30%). Under the current context of striving for ultimate energy efficiency throughout the entire steel production process, this is far from meeting policy requirements.

[0004] The CO content in the flue gas emitted from sintering machine systems varies due to the involvement of multiple factors and their different formation mechanisms. Research and analysis indicate that combustion reaction factors are the most significant influencing factor. Conventional combustion processes often have shortcomings, namely local oxygen deficiency, resulting in incomplete combustion. Low flame temperatures also contribute to incomplete combustion, leading to the emission of combustible materials as soot and a large escape of CO, wasting energy and causing air pollution. Survey results show that if CO emission concentration is reduced at the source using only sintering flue gas recirculation (with the circulating hot and cold air in an oxygen-deficient condition and an oxygen content of 17-18%), steam injection onto the material surface, or hydrogen or natural gas, the CO emission concentration in sintering flue gas can generally only be reduced to around 6000 mg / m³. While catalytic oxidation treatment can meet the standards, it is a tail-end treatment with high investment and operating costs. Although terminal CO incineration and waste heat recovery for steam generation may meet emission concentration standards, the energy conversion efficiency is significantly reduced. The thermal energy of CO, as a combustible material, is not released within the system but is emitted for secondary conversion, which is not advisable.

[0005] Through technological research and engineering trials, the application of oxygen-enriched sintering (oxygen-enriched material surface) technology will further demonstrate its advantages in reducing pollution and carbon emissions, as well as reducing costs and increasing efficiency. Moreover, its synergy with the utilization of waste heat from the surrounding cooling exhaust gas will more effectively help reduce CO emissions, enabling the CO emission concentration of sintering flue gas to reach the standard of 2800 mg / m³ or less. Therefore, there is an urgent need for an energy-saving system and method that efficiently utilizes the surrounding cooling exhaust gas to achieve oxygen-enriched sintering. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention provides an energy-saving system and method for sintering machines based on the reuse of hot air from the tail section of an annular cooler coupled with oxygen-enriched combustion. Low-temperature hot air from the tail section of the annular cooler is drawn into the sealed hood of the sintering machine's ore layer by the suction force of an induced draft fan. By increasing the oxygen enrichment of the hot air inside the sealed hood, driven by the negative pressure of the air box under the material surface, the uniform oxygen-enriched hot air passes through the sintering ore layer and reacts completely with the solid fuel—coke powder. The reaction speed is fast, the theoretical combustion temperature is high, which helps the sintering of the ore while reducing CO emissions, thus saving energy and increasing production.

[0007] To achieve the above objectives, the present invention employs the following technical solution: An energy-saving system for a sintering machine based on hot air recycling coupled with oxygen-enriched combustion at the tail end of an annular cooler includes a low-temperature hot air recovery unit, an oxygen-enriched mixing unit, an emission detection unit, and an intelligent control unit. The low-temperature hot air recovery unit includes a low-temperature hot air duct system, through which low-temperature hot air from the tail end of the annular cooler is delivered to a closed hood at the material surface of the sintering machine. The low-temperature hot air duct system includes a hot air duct, a hot air manifold, and transition air guides. One end of the hot air duct is connected to the air collection hood at the tail end of the annular cooler, and the other end of the hot air duct is connected to the hot air manifold at the material surface of the sintering machine. The hot air manifold is sequentially connected to multiple transition air guides into the closed hood. Oxygen-enriched mixing unit: Staged oxygen supply is adopted. The first stage oxygen supply is achieved by evenly distributing oxygen injection holes radially around the hot air duct, with the oxygen volume concentration controlled within the range of 22% to 23%. The second stage oxygen supply is achieved by mixing oxygen with the low-temperature hot air from the tail of the annular cooler through a jet oxygen gun installed in the transition air guide duct, with the oxygen volume concentration controlled within the range of 24% to 28%. Emissions detection unit: An oxygen concentration analyzer is installed in the low-temperature hot air duct system and enclosed enclosure to monitor oxygen concentration; Intelligent control unit: dynamically controls the air volume, temperature, and oxygen injection of the low-temperature hot air in the cooling tail section, and dynamically adjusts the frequency of the induced draft fan.

[0008] Furthermore, an exhaust fan and a dust collector are installed on the hot air duct.

[0009] Furthermore, the induced draft fan has an air volume of 50,000 to 100,000 Nm³ / h and an air pressure of ≥5,000 Pa; the dust content at the dust collector outlet is ≤50 mg / Nm³, and the dust removal efficiency is ≥85%.

[0010] Furthermore, the oxygen injection port for the primary oxygen supply is located on the hot air duct before the induced draft fan.

[0011] Furthermore, the multiple transition air ducts are respectively connected to the sealed cover of the 6# air box after the machine head is ignited and the 3rd air box before the sintering endpoint.

[0012] Furthermore, the secondary oxygen supply in multiple transition ducts adopts sequential gradient oxygen supply, with the oxygen volume concentration decreasing from the head to the tail of the machine.

[0013] Furthermore, the emission detection unit also includes residual oxygen concentration monitors and CO concentration monitors installed on the corresponding wind box risers of the sintering machine to detect the residual oxygen concentration and CO concentration in the flue gas, respectively; and NOx concentration monitors and CO concentration monitors installed on the main exhaust flue of the sintering machine to detect the NOx emission and the CO concentration in the final flue gas emission, respectively.

[0014] Furthermore, a flow meter and a hot air regulating valve are sequentially installed on the aforementioned low-temperature hot air duct system.

[0015] Furthermore, the temperature of the hot air in the aforementioned low-temperature hot air duct system is generally 80–160°C.

[0016] An oxygen-enriched sintering method based on an energy-saving sintering machine system using hot air reuse coupled with oxygen-enriched combustion at the tail end of an annular cooler, the oxygen-enriched sintering method comprising the following: S1. The low-temperature hot air recovery unit collects the low-temperature hot air that is discharged from the tail section of the ring cooler and enters the air collection hood of the tail section of the ring cooler. The air collection hood is connected to the hot air pipe and is sent into the hot air collection pipe outside the material surface enclosure of the sintering machine trolley by the suction of the induced draft fan. The hot air collection pipe is connected to multiple transition air guide pipes to send low-temperature hot air into the enclosure for hot air sintering. S2. Oxygen medium is transported through the oxygen source pipeline and oxygen is supplied in stages through the oxygen-enriched mixing unit. The first stage oxygen supply is set on the hot air pipeline; the second stage oxygen supply is achieved by inserting a jet oxygen gun on the transition air duct and sending the oxygen-enriched hot air after staged oxygen mixing into the material surface enclosure of the sintering machine trolley. S3. The oxygen concentration detected in the oxygen concentration analyzer inside the sealed enclosure is controlled by the intelligent control unit to control the oxygen supply of the secondary oxygen supply jet oxygen gun, so that the oxygen is enriched in a gradient from ignition to the end of sintering production, forming a hot air oxygen-enriched sintering process. S4. Through the oxygen concentration analyzer, CO concentration detector, NOx concentration detector and residual oxygen detector set in the emission detection unit, oxygen-enriched sintering information is obtained in real time, and the sintering hot air oxygen-enriched sintering process is dynamically controlled by the intelligent control unit.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1) Improve combustion efficiency and reduce energy consumption Increased oxygen concentration: Oxygen-enriched air enhances the combustion kinetics of fuel, promotes complete combustion, reduces CO escape emissions caused by incomplete combustion, and reduces solid fuel consumption by about 5% to 10%.

[0018] Waste heat utilization of annular cooling preheating air: Low-temperature hot air waste heat has low power generation efficiency, but it can be used for hot air sintering to achieve the ultimate utilization of low-temperature waste heat. It can directly provide physical heat to the sintering material layer, reduce dependence on fuel chemical heat, and reduce overall energy consumption by 10%. Combined with oxygen-enriched combustion to provide physical heat to the sintering material layer, it helps to reduce the consumption of solid fuel, and the overall energy consumption can be reduced by 5% to 10%.

[0019] 2) Optimize sinter quality Homogenization in the high-temperature zone: Oxygen-enriched combustion raises the temperature of the high-temperature zone of the sintering zone by 50-100°C, and hot air sintering helps to extend the high-temperature holding time by providing continuous heating, thereby improving fuel utilization and reducing solid fuel consumption; it also promotes the development of calcium ferrite minerals, increases the content of calcium ferrite and binder phase in the sinter, and improves the phase structure, drum strength, and low-temperature reducibility of the sinter. The drum strength of the sinter can be increased by 2%-3%, the FeO content can be reduced by 1%-2%, and the reducibility can be improved by 5%-10%.

[0020] Microstructure densification: The molten liquid phase is generated more fully, the porosity is reduced by 2% to 5%, the mineral crystallinity is improved, and the wear resistance is enhanced.

[0021] 3) Enhance process efficiency and production capacity: Increased vertical sintering speed: Oxygen enrichment accelerates the migration rate of the combustion front, and hot air reduces the excessively wet zone at the bottom of the material layer, increasing the sintering speed by 5% to 15% and the hourly output by 5% to 8%.

[0022] Equipment utilization rate optimization: shorten sintering cycle, reduce process fluctuations, and improve equipment utilization.

[0023] 4) Significant environmental benefits: Emission reduction effect: Complete combustion and improved reaction efficiency promote CO burnout, and improved combustion efficiency reduces CO emissions by 20% to 30%; oxygen-enriched air reduces N2 content, and high temperature but low nitrogen content inhibits the formation of thermal NOx, and sulfide emissions are reduced simultaneously, reducing environmental pressure and truly achieving energy saving, emission reduction, pollution reduction, carbon reduction and low cost production effects.

[0024] Solid waste reduction: The rate of ore return decreases by 3% to 5%, dust generation is reduced, and environmental protection costs are lowered.

[0025] 5) Enhanced flexibility in process control: Coordinated control of oxygen concentration and air temperature: The oxygen enrichment rate (23%~30%) and hot air temperature (80~160℃) can be dynamically adjusted according to the characteristics of raw materials, making it more adaptable to complex minerals.

[0026] Low-carbon adaptability: It provides a high-temperature oxidation environment for low-carbon technologies such as hydrogen-based sintering and biomass fuels, and promotes the integrated application of new technologies. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a sintering machine energy-saving system based on hot air recycling coupled with oxygen-enriched combustion at the tail end of an annular cooler, as described in this invention.

[0028] Figure 2 This is a P&ID diagram of the oxygen-enriched sintering oxygen supply process described in this invention.

[0029] In the diagram: 1. Air collection hood; 2. Hot air duct; 3. Cyclone dust collector; 4. Hot air regulating valve; 5. Exhaust fan; 6. Oxygen source pipeline; 7. Oxygen regulating valve; 8. Oxygen flow meter; 9. Oxygen-specific valve assembly; 10. Oxygen injection port; 11. Flow meter; 12. Hot air manifold; 13. Transition air duct; 14. Oxygen jet lance; 15. Oxygen concentration analyzer; 16. Enclosed hood; 17. CO concentration detector; 18. NOx concentration detector; 19. Residual oxygen detector; 20. Intelligent control unit. Detailed Implementation

[0030] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings: like Figures 1-2 As shown, a sintering machine energy-saving system based on hot air recycling coupled with oxygen-enriched combustion in the tail section of an annular cooler includes a low-temperature hot air recovery unit, an oxygen-enriched mixing unit, an emission detection unit, and an intelligent control unit 20.

[0031] Low-temperature hot air recovery unit: includes a low-temperature hot air duct system connecting the air collecting hood 1 at the tail end of the annular cooler and the sealed cover 16 at the material surface of the sintering machine trolley. The low-temperature hot air duct system includes a hot air duct 2, a hot air manifold 12, and transition air guide pipes. One end of the hot air duct 2 is connected to the air collecting hood 1 at the tail end of the annular cooler, and the other end of the hot air duct 2 is connected to the hot air manifold 12 at the material surface of the sintering machine. The hot air manifold 12 is sequentially connected to multiple transition air guide pipes into the sealed cover 16. An induced draft fan 5 and a cyclone dust collector 3 are installed on the hot air duct 2 to deliver purified hot air to the enclosed hood 16 on the sintering machine material surface. The induced draft fan 5 has an air volume of 50,000 to 100,000 Nm³ / h and an air pressure ≥5000 Pa. The dust content at the outlet of the cyclone dust collector 3 is ≤50 mg / Nm³, and the dust removal efficiency is ≥85%. Multiple transition air guide pipes 13 are connected to the enclosed hood 16 of the third air box before the sintering endpoint, from the 6# air box after the machine head ignition. A flow meter 11 and a hot air regulating valve 4 are sequentially installed on the low-temperature hot air duct system, which, together with the oxygen regulating valve 7 and oxygen flow meter 8 installed on the oxygen enrichment mixing unit, dynamically adjust the oxygen supply. The hot air temperature in the low-temperature hot air duct system is generally 80–160℃.

[0032] Oxygen-enriched mixing unit: Staged oxygen supply is adopted. The low-temperature hot air duct system injects primary oxygen supply radially into the hot air duct 2 before the induced draft fan 5, with the oxygen volume concentration controlled within the range of 22% to 23%. Then, secondary oxygen supply is provided by a jet oxygen gun 14 installed on the transition duct 13 of the low-temperature hot air duct system. The secondary oxygen supply in multiple transition ducts 13 adopts sequential gradient oxygen supply, with the oxygen volume concentration supplied from high to low in the direction from the head to the tail of the machine. In conjunction with the oxygen concentration monitored by the oxygen concentration analyzer 15, the oxygen volume concentration is controlled within the range of 24% to 28%.

[0033] Emission detection unit: An oxygen concentration analyzer 15 is installed in the low-temperature hot air duct system; an oxygen concentration analyzer 15 is installed at the top of the enclosure 16 on the material surface of the sintering machine trolley for final oxygen concentration analysis and monitoring after secondary oxygen supply; a residual oxygen concentration monitor 19 and a CO concentration monitor 17 are installed on the corresponding air box risers of the sintering machine to detect the residual oxygen concentration and the CO concentration in the flue gas, respectively; a NOx concentration monitor 18 and a CO concentration monitor 17 are installed on the main exhaust flue of the sintering machine to detect NOx emissions and the CO concentration in the final flue gas emissions, respectively; these online monitoring results, along with oxygen content, are connected to the intelligent control unit.

[0034] Intelligent Control Unit 20: In conjunction with the sintering production process control system, it dynamically controls the air volume, temperature, and oxygen injection of the low-temperature hot air in the annular cooling tail section based on the detected residual oxygen concentration, CO concentration and NOx emission values ​​in the flue gas, and parameters such as the sintering temperature, pressure, and flow rate of the hot air in the sintering machine material layer. It also dynamically adjusts the input set value of the induced draft fan 5 frequency or the rated air volume of the annular cooling tail section blower to ensure that the oxygen injection amount matches the oxygen-enriched gradient required along the sintering process by utilizing the low-temperature hot air for waste heat utilization. This ensures that the solid fuel is completely burned and the heat energy is fully utilized during the sintering process, improves the quality of sintered ore, reduces solid fuel consumption, lowers the CO escape concentration from incomplete combustion, and retains the heat energy from the CO combustion reaction within the system.

[0035] like Figure 1-2 As shown, an oxygen-enriched sintering method for an energy-saving sintering machine system based on hot air recycling coupled with oxygen-enriched combustion in the tail section of an annular cooler includes the following steps: S1. The low-temperature hot air discharged from the tail section of the annular cooler is collected in the air intake hood 1, connected to the hot air duct 2, and sent into the sealed cover 16 of the sintering machine trolley material surface by the suction force of the induced draft fan 5 for hot air sintering. A cyclone dust collector 3 is designed on the low-temperature hot air duct for the purification of the regenerated hot air, and a hot air regulating valve 4 and a hot air flow meter 11 are installed to upload real-time data to the intelligent control unit 20.

[0036] S2. The oxygen source pipeline 6 is laid and the oxygen medium is set to be transported through the oxygen-specific valve group 9. The oxygen regulating valve 7 and oxygen flow meter 8 are installed on the pipeline, and the real-time data of oxygen supply is uploaded to the intelligent control unit 20. The staged oxygen supply process includes the first stage oxygen supply before the induced draft fan 5 and the second stage oxygen supply through the transition duct. The first stage oxygen supply is achieved by evenly distributing radial oxygen injection holes 10 on the hot air pipeline before the induced draft fan 5. The second stage oxygen supply is achieved by inserting a jet oxygen gun 14 into the transition duct 13, and sending the oxygen-enriched hot air after staged oxygen mixing into the closed hood 16. The closed hood 16 is equipped with an oxygen concentration analyzer 15.

[0037] S3. Based on the oxygen concentration detected by the oxygen concentration analyzer inside the sealed enclosure 16, the oxygen supply of the secondary oxygen supply jet lance 14 is controlled by the intelligent control unit 20, so that the oxygen is gradually enriched along the sintering process from ignition to the sintering endpoint, forming a hot air oxygen-enriched sintering process. Since the oxygen content of the hot air from the annular cooler is insufficient, with a maximum of 18%, local gradient oxygen enhancement is required to assist the hot air sintering process. The uniformly oxygen-enriched hot air inside the sealed enclosure 16 enters the sintering ore layer through the negative pressure of the air box under the sintering machine trolley for a penetrating, uniform, and complete combustion reaction, improving the quality and performance of the sintered ore and reducing solid fuel consumption.

[0038] S4. By installing an online oxygen concentration analyzer 15, a CO concentration detector 17, a NOx concentration detector 18, and a residual oxygen detector 19, real-time oxygen-enriched sintering feedback information is obtained. Combined with dynamic control of oxygen enrichment, hot air temperature, flow rate, and pressure, and linkage with the sintering production automatic control system, the optimal and maximum quality effect, energy saving, and emission reduction benefits are achieved. It can be said that energy saving and production increase are achieved simultaneously, with ultra-low CO emissions and extreme energy efficiency in the sintering process.

[0039] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A sintering machine energy-saving system based on hot air recycling coupled with oxygen-enriched combustion in the tail section of an annular cooler, comprising a low-temperature hot air recovery unit, an oxygen-enriched mixing unit, an emission detection unit, and an intelligent control unit, characterized in that, The low-temperature hot air recovery unit includes a low-temperature hot air pipeline system, through which low-temperature hot air from the tail of the annular cooler is delivered to the enclosed hood of the sintering machine material surface. The low-temperature hot air pipeline system includes a hot air duct, a hot air manifold, and transition air guides. One end of the hot air duct is connected to the air collection hood of the tail section of the annular cooler, and the other end of the hot air duct is connected to the hot air manifold at the material surface of the sintering machine. The hot air manifold is sequentially connected to multiple transition air guides into the enclosed hood. Oxygen-enriched mixing unit: Staged oxygen supply is adopted. The first stage oxygen supply is achieved by evenly distributing oxygen injection holes radially around the hot air duct, with the oxygen volume concentration controlled within the range of 22% to 23%. The second stage oxygen supply is achieved by mixing oxygen with the low-temperature hot air from the tail of the annular cooler through a jet oxygen gun installed in the transition air guide duct, with the oxygen volume concentration controlled within the range of 24% to 28%. Emissions detection unit: An oxygen concentration analyzer is installed in the low-temperature hot air duct system and enclosed enclosure to monitor oxygen concentration; Intelligent control unit: dynamically controls the air volume, temperature, and oxygen injection of the low-temperature hot air in the cooling tail section, and dynamically adjusts the frequency of the induced draft fan.

2. The sintering machine energy-saving system based on hot air reuse coupled with oxygen-enriched combustion in the tail section of an annular cooler as described in claim 1, characterized in that, An induced draft fan and a dust collector are installed on the hot air duct.

3. The sintering machine energy-saving system based on hot air reuse coupled with oxygen-enriched combustion in the tail section of the annular cooler as described in claim 2, characterized in that, The induced draft fan has an air volume of 5 to 100,000 Nm³ / h and an air pressure of ≥5000 Pa; the dust content at the dust collector outlet is ≤50 mg / Nm³ and the dust removal efficiency is ≥85%.

4. The sintering machine energy-saving system based on hot air reuse coupled with oxygen-enriched combustion in the tail section of an annular cooler as described in claim 1, characterized in that, The oxygen injection port for primary oxygen supply is located on the hot air duct before the induced draft fan.

5. The sintering machine energy-saving system based on hot air reuse coupled with oxygen-enriched combustion in the tail section of an annular cooler according to claim 1, characterized in that, The multiple transition air ducts are connected to the sealed cover of the third air box before the sintering endpoint, which is connected to the 6# air box after the machine head is ignited.

6. The sintering machine energy-saving system based on hot air reuse coupled with oxygen-enriched combustion in the tail section of the annular cooler according to claim 1, characterized in that, The secondary oxygen supply in multiple transition air ducts adopts sequential gradient oxygen supply, with the oxygen volume concentration decreasing from the head to the tail of the machine.

7. The sintering machine energy-saving system based on hot air reuse coupled with oxygen-enriched combustion in the tail section of an annular cooler according to claim 1, characterized in that, The emission detection unit also includes residual oxygen concentration monitors and CO concentration monitors installed on the corresponding wind box risers of the sintering machine to detect the residual oxygen concentration and CO concentration in the flue gas, respectively; and NOx concentration monitors and CO concentration monitors installed on the main exhaust flue of the sintering machine to detect the NOx emission and the CO concentration in the final flue gas emission, respectively.

8. The sintering machine energy-saving system based on hot air reuse coupled with oxygen-enriched combustion in the tail section of an annular cooler according to claim 1, characterized in that, A flow meter and a hot air regulating valve are sequentially installed on the aforementioned low-temperature hot air duct system.

9. A sintering machine energy-saving system based on hot air reuse coupled with oxygen-enriched combustion in the tail section of an annular cooler, as described in claim 1, is characterized in that... The temperature of the hot air in the low-temperature hot air duct system is generally 80-160℃.

10. The oxygen-enriched sintering method of a sintering machine energy-saving system based on hot air reuse coupled with oxygen-enriched combustion in the tail section of an annular cooler, as described in claim 1, is characterized in that... The oxygen-enriched sintering method includes the following: S1. The low-temperature hot air recovery unit collects the low-temperature hot air that is emptied from the tail section of the ring cooler and enters the air collection hood of the tail section of the ring cooler. The air collection hood is connected to the hot air pipe and is sent into the hot air collection pipe outside the material surface enclosure of the sintering machine trolley by the suction of the induced draft fan. The hot air collection pipe is connected to multiple transition air guide pipes to send low-temperature hot air into the enclosure for hot air sintering. S2. Oxygen medium is transported through the oxygen source pipeline and oxygen is supplied in stages through the oxygen-enriched mixing unit. The first stage oxygen supply is set on the hot air pipeline; the second stage oxygen supply is achieved by inserting a jet oxygen gun on the transition air duct and sending the oxygen-enriched hot air after staged oxygen mixing into the material surface enclosure of the sintering machine trolley. S3. The oxygen concentration detected in the oxygen concentration analyzer inside the sealed enclosure is controlled by the intelligent control unit to control the oxygen supply of the secondary oxygen supply jet lance, so that the oxygen is enriched in a gradient from ignition to the end of sintering production, forming a hot air oxygen-enriched sintering process. S4. Through the oxygen concentration analyzer, CO concentration detector, NOx concentration detector and residual oxygen detector set in the emission detection unit, oxygen-enriched sintering information is obtained in real time, and the sintering hot air oxygen-enriched sintering process is dynamically controlled by the intelligent control unit.

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