Method and system for multi-element upgrading and collaborative sintering of annular cooling waste gas

Abstract

The invention discloses a method and a system for multi-element upgrading and collaborative sintering of annular cooling waste gas. Ring cooling waste gas is shunted according to a proportion and then is converted into oxygen-supplementing steam-enriching hot air, oxygen-enriching hot air and oxygen-supplementing gas-enriching hot air which can be directly used for a sintering process after being subjected to oxygen-supplementing heat-supplementing, oxygen-enriching heat-supplementing, oxygen-supplementing heat-supplementing gas-enriching, stepped heat exchange and selective steam supplementing respectively; and in the conversion process, waste heat is efficiently utilized to obtain high-quality steam for power generation, industrial hot water for internal use and the like. The waste heat recovery of the sintering ring cooling medium-temperature and low-temperature waste gas is realized at low cost and high efficiency, the discharge amount of the waste gas is obviously reduced, the sintering working condition is greatly enhanced, and the quality of a sintered ore product is obviously improved.

Description

Technical Field

[0001] The present invention relates to metallurgical sintering technology, and in particular to a method and system for multi-element quality-improving and coordinated sintering of annularly cooled waste gas, belonging to the technical field of metallurgical sintering. Background Art

[0002] During the sintering process, the temperature of the sinter cake after it is unloaded from the sintering machine can reach 700-800°C. The physical sensible heat it carries is the most important component of the sintering waste heat resource. During the air cooling process, the sinter temperature drops below 150°C, generating a large amount of hot air. Generally, the temperature of the cooling exhaust gas varies from different parts of the sintering ring cooler, gradually decreasing from the receiving end to the discharge end. It is generally divided into three sections: a high-temperature zone above 250°C, a medium-temperature zone between 150°C and 250°C, and a low-temperature zone below 150°C.

[0003] In actual production, many companies have built supporting sintering waste heat recovery systems to utilize the high-temperature cooling exhaust gas from the ring cooler for waste heat power generation. However, due to the low temperature of the cooling exhaust gas from the medium and low temperature sections, the boiler heat exchange can only produce low-parameter steam, resulting in low waste heat utilization efficiency and high utilization costs. Some companies even discharge the medium and low temperature exhaust gas directly through the chimney, which is both wasteful and polluting. In addition, some companies return part of the flue gas from the ring cooler to the upper sealed cover of the sintering machine for hot air sintering to improve the heat utilization rate of the ring cooler exhaust gas. The goal is to reduce ring cooler flue gas emissions while reducing sintering fuel consumption and improving sintered ore quality. For example, patent document CN108731486 A proposes a system and method for recycling medium- and low-temperature waste gas from an annular cooler. A fume hood is installed above the sintering machine and connected to the hood above the annular cooler. This system converts the medium- and low-temperature waste gas from the annular cooler, which is between 80°C and 250°C, from being discharged directly into the atmosphere, into a system that directly recycles it into the sintering bed. This replaces the air the sintering machine normally draws from the surrounding atmosphere for sintering raw materials and auxiliary fuels, fully utilizing the sensible heat in the medium- and low-temperature waste gas and eliminating the environmental pollution caused by direct discharge of dust-laden waste gas. Patent document CN106931792 B proposes a method and apparatus for the comprehensive utilization of annular cooler waste gas. The medium-temperature waste gas, between 150°C and 220°C, is used for ORC low-temperature power generation through heat exchange. The recycled waste gas is then returned to the sintering process for hot-air sintering, or mixed with low-temperature cooling waste gas below 150°C to a temperature of approximately 100°C, which is then returned to the sintering car for hot-air sintering.

[0004] In the existing technology, directly using the cooling exhaust gas from the medium and low temperature sections for boiler heat exchange can only produce low-parameter steam, and the waste heat preheating efficiency is low and the utilization cost is high. Returning the medium and low temperature exhaust gas to the sintering process instead of air can utilize the waste heat of the exhaust gas to a certain extent from an energy perspective. However, since the temperature of the cooling exhaust gas is much higher than that of air, the gas volume expands, resulting in an oxygen concentration lower than that of normal temperature air (about 310 mg / L), and the higher the temperature, the lower the oxygen concentration, resulting in a reduction in the amount of oxygen drawn into the sintering material layer, which is not conducive to fuel combustion and affects the quality of the sintered minerals. Therefore, the exhaust gas must generally be cooled to about 100°C before being introduced into the sintering process before being returned to the sintering process, resulting in a low efficiency in utilizing the waste heat of the exhaust gas during the sintering process. Summary of the Invention

[0005] In response to the problems in the prior art of low efficiency and high cost in directly recovering waste heat from medium and low-temperature waste gas in sintering ring cooling, and the low waste heat utilization efficiency caused by the need to lower the temperature before returning to sintering, the present invention provides a method and system for multi-element quality improvement and coordinated sintering of ring cooling waste gas. According to the actual sintering working conditions, the ring cooling waste gas is divided proportionally and then subjected to oxygen supplementation and heat supplementation, oxygen enrichment and heat supplementation, oxygen supplementation and heat supplementation and gas enrichment, cascade heat exchange, and selective steam supplementation, and then converted into oxygen-supplemented steam-rich (water vapor) hot air, oxygen-enriched hot air, and oxygen-supplemented gas-rich (gas) hot air that can be directly used in the sintering process. In the conversion process, the waste heat is efficiently utilized to obtain high-quality steam for power generation and industrial hot water for internal use. That is, the method achieves low-cost and high-efficiency waste heat recovery from medium and low-temperature waste gas in sintering ring cooling, significantly reduces waste gas emissions, greatly enhances sintering working conditions, and significantly improves the quality of sintered ore products.

[0006] In order to achieve the above technical objectives, the technical solutions adopted by the present invention are as follows:

[0007] According to a first embodiment of the present invention, a method for multi-element upgrading and synergistic sintering of annularly cooled exhaust gas is provided:

[0008] A method for multi-element quality improvement and coordinated sintering of annularly cooled waste gas, the method comprising:

[0009] S1) The annular cooling exhaust gas is split and oxygen-supplemented and heat-supplemented, oxygen-enriched and heat-supplemented, and oxygen-supplemented and heat-enriched to obtain oxygen-supplemented high-temperature exhaust gas, oxygen-enriched high-temperature exhaust gas, and oxygen-supplemented and air-enriched high-temperature exhaust gas.

[0010] S1) The oxygen-supplemented high-temperature exhaust gas is subjected to cascade heat exchange and steam supplementation in sequence to obtain oxygen-supplemented steam-rich hot air, and the oxygen-rich high-temperature exhaust gas and the oxygen-supplemented gas-rich high-temperature exhaust gas are subjected to cascade heat exchange to obtain oxygen-rich hot air and oxygen-supplemented gas-rich hot air respectively.

[0011] S3) delivering the oxygen-enriched steam hot air to the material surface of the rear section of sintering for steam-enriched sintering, delivering the oxygen-enriched hot air to the material surface of the middle section of sintering for oxygen-enriched sintering, and delivering the oxygen-enriched gas hot air to the material surface of the front section of sintering for gas-enriched sintering.

[0012] Preferably, the ring cooling waste gas is a mixture of medium-temperature ring cooling waste gas and low-temperature ring cooling waste gas. Alternatively, the ring cooling waste gas is medium-temperature ring cooling waste gas generated by using low-temperature ring cooling waste gas as the cooling medium in the medium-temperature section of the ring cooling.

[0013] Preferably, the temperature of the annular cooling exhaust gas is less than 250°C, preferably 120-240°C, more preferably 140-200°C.

[0014] Preferably, the oxygen and heat supplementation is to use the ring cooling exhaust gas as a combustion-supporting gas for oxygen supplementation combustion, so that the temperature of the oxygen supplementation high-temperature exhaust gas obtained after combustion is increased to 400-550°C, and the oxygen concentration content is 145-190 mg / L.

[0015] Preferably, the oxygen-enriched heat supplement is to use the annular cooling exhaust gas as a combustion-supporting gas for oxygen-enriched combustion, so that the temperature of the oxygen-enriched high-temperature exhaust gas obtained after combustion is increased to 400-550°C, and the oxygen concentration content is 160-260 mg / L.

[0016] Preferably, the oxygen-supplemented heat-supplemented rich gas is specifically prepared by using the annular cooling exhaust gas as the supporting combustion gas for oxygen-enriched combustion, so that the temperature of the oxygen-supplemented rich high-temperature exhaust gas obtained after combustion is increased to 400-550°C, the oxygen concentration content is 145-190 mg / L, and the gas volume content is 0.5-0.6%.

[0017] Preferably, the cascade heat exchange comprises the following steps: first, hot water is used to perform indirect heat exchange with the oxygen-supplemented high-temperature exhaust gas, the oxygen-enriched high-temperature exhaust gas, and the oxygen-enriched high-temperature exhaust gas to obtain high-parameter steam and the oxygen-supplemented medium-temperature exhaust gas, the oxygen-enriched medium-temperature exhaust gas, and the oxygen-enriched medium-temperature exhaust gas; then, cold water is used to perform indirect heat exchange with the oxygen-supplemented medium-temperature exhaust gas, the oxygen-enriched medium-temperature exhaust gas, and the oxygen-enriched medium-temperature exhaust gas to obtain hot water and the oxygen-supplemented low-temperature exhaust gas, the oxygen-enriched hot air, and the oxygen-enriched hot air. Water mist is sprayed into the oxygen-supplemented low-temperature exhaust gas to perform steam supplementation to obtain the oxygen-supplemented steam-enriched hot air.

[0018] Preferably, the temperature of the oxygen-enriched steam hot air is 120-140°C, the oxygen concentration is 310-330 mg / L, and the water vapor content is 2.5-4.8 wt%. The temperature of the oxygen-enriched hot air is 140-160°C, the oxygen concentration is 330-420 mg / L. The temperature of the oxygen-enriched gas hot air is 140-160°C, the oxygen concentration is 315-335 mg / L, and the gas volume content is 0.5-0.6%. The temperature of the high-parameter steam is not less than 390°C, and the pressure is not less than 1.5 MPa.

[0019] Preferably, the air volume distribution ratio of the annular cooling exhaust gas diversion for oxygen and heat supplementation, oxygen enrichment and heat supplementation, and oxygen and heat supplementation and enriched gas is 25-50%: 20-50%: 10-30%.

[0020] Preferably, the material surface in the front section of sintering is the 1 / 25 to 5 / 25 material surface after the ignition furnace of the sintering machine, the material surface in the middle section of sintering is the 6 / 25 to 15 / 25 material surface after the ignition furnace of the sintering machine, and the material surface in the rear section of sintering is the 16 / 25 to 23 / 25 material surface after the ignition furnace of the sintering machine.

[0021] According to a second embodiment of the present invention, a system for multi-element upgrading and sintering of annularly cooled exhaust gas is provided:

[0022] A system for multi-element upgrading of annularly cooled waste gas for coordinated sintering, or a system for the method according to any one of claims 1 to 4, comprising a sintering machine, an annular cooler, and an integrated waste gas diversion and upgrading device. The inner cavity of the integrated waste gas diversion and upgrading device is divided into three mutually incommunicative vertical chambers by a partition wall, which are respectively denoted as a steam-rich stripping chamber, an oxygen-rich stripping chamber, and a gas-rich stripping chamber. Independent air inlet valves are provided at the air inlets at the bottom of each of the steam-rich stripping chamber, the oxygen-rich stripping chamber, and the gas-rich stripping chamber. The steam-rich stripping chamber, the oxygen-rich stripping chamber, and the gas-rich stripping chamber all include, from bottom to top, a heat supplementation and upgrading zone, a high-temperature heat exchange zone, and a low-temperature heat exchange zone, which are connected in series in sequence. A water mist steam supplementation zone is also provided at the top of the steam-rich stripping chamber. The top air outlet of the steam-rich stripping chamber is connected to the air inlet of the rear section wind hood above the sintering machine through an oxygen-rich steam hot air delivery pipeline. The top air outlet of the oxygen-enriched upgrading chamber is connected to the air inlet of the middle section hood above the sintering machine via an oxygen-enriched hot air delivery duct. The top air outlet of the gas-enriched upgrading chamber is connected to the air inlet of the front section hood above the sintering machine via an oxygen-enriched hot air delivery duct. The exhaust gas outlet of the ring cooler is connected to the bottom air inlet of the integrated exhaust gas diversion and upgrading device via an exhaust gas delivery duct.

[0023] Preferably, the front and rear ends of the front section hood are respectively located at the front end of the 1 / 25 section of the material surface and the rear end of the 5 / 25 section of the material surface behind the ignition furnace of the sintering machine. The front and rear ends of the middle section hood are respectively located at the front end of the 6 / 25 section of the material surface and the rear end of the 15 / 25 section of the material surface behind the ignition furnace of the sintering machine. The front and rear ends of the rear section hood are respectively located at the front end of the 16 / 25 section of the material surface and the 23 / 25 section of the material surface behind the ignition furnace of the sintering machine.

[0024] Preferably, independent burners are provided in the supplementary heat and upgrading zones of the steam-rich stripping chamber, the oxygen-rich stripping chamber and the gas-rich stripping chamber, and the air inlet ends of the three burners are independently connected to the gas delivery pipeline and the oxygen delivery pipeline.

[0025] Preferably, the gas delivery pipelines are connected to the plant gas network, and the oxygen delivery pipelines are connected to the plant oxygen network. Preferably, a natural gas supplementary pipeline is also independently provided in the heat supplement and quality upgrading area of ​​the gas-enriched upgrading chamber.

[0026] Preferably, a high-parameter steam superheater, a high-parameter steam evaporator, a high-parameter economizer, a deoxygenation evaporator, and a low-parameter economizer are independently arranged in order from bottom to top in the high-temperature heat exchange zone of each of the steam-rich stripping chamber, the oxygen-rich stripping chamber, and the gas-rich stripping chamber. A steam drum, a deaerator, a desalted water pipeline network, and a steam power generation mechanism are also arranged outside the high-temperature heat exchange zone. One end of each high-parameter steam superheater is connected to the steam power generation mechanism via a pipe valve group, and the other end is connected to the steam drum via a pipeline. Both ends of all high-parameter steam evaporators are connected to the steam drum via a pipeline. One end of each high-parameter economizer is connected to the deaerator via a pipeline, and the other end is connected to the steam drum via a pipeline. Both ends of all deoxygenation evaporators are connected to the deaerator via a pipeline. One end of each low-parameter economizer is connected to the desalted water pipeline network via a pipeline, and the other end is connected to the deaerator via a pipeline.

[0027] Preferably, an industrial water heater is independently installed in the low-temperature heat exchange zone of each of the steam-rich stripping chamber, the oxygen-rich stripping chamber, and the gas-rich stripping chamber. An industrial water network and hot water utilization pipeline are installed outside the low-temperature heat exchange zone. The water inlet of each industrial water heater is connected to the industrial water network, and the water outlet is connected to the hot water utilization pipeline.

[0028] Preferably, a water mist nozzle is provided in the water mist supplementary steam area of ​​the rich steam stripping cavity, and the water inlet end of the water mist nozzle is connected to one end of the low parameter economizer close to the deaerator.

[0029] Preferably, the low-temperature exhaust gas outlet of the low-temperature section of the ring cooler and the medium-temperature exhaust gas outlet of the medium-temperature section of the ring cooler are both connected to the bottom air inlet of the integrated exhaust gas diversion and upgrading device through an exhaust gas conveying pipeline. Alternatively, the low-temperature exhaust gas outlet of the low-temperature section of the ring cooler is first connected to the cooling air inlet of the medium-temperature section through a circulating air duct, and then the medium-temperature exhaust gas outlet of the medium-temperature section of the ring cooler is further connected to the bottom air inlet of the integrated exhaust gas diversion and upgrading device through an exhaust gas conveying pipeline.

[0030] In the present invention, the volume of each of the steam-rich stripping chamber, the oxygen-rich stripping chamber and the gas-rich stripping chamber is 0.1-800m 3 , preferably 1-500m 3 , more preferably 3-300m 3The integrated waste gas diversion and upgrading device has a height of 1-500m, preferably 2-300m, and more preferably 3-100m. All gas or liquid transport pipelines are independently equipped with flow control regulating valves. The steam-rich stripping chamber, oxygen-rich stripping chamber, and gas-rich stripping chamber may have the same or different horizontal widths or horizontal inner diameters.

[0031] In the present invention, after the annular cooling waste gas (mainly the annular cooling medium-temperature waste gas and the annular cooling low-temperature waste gas) is diverted according to the working conditions (for example, the distribution volume ratio is 25-50%: 20-50%: 10-30%), oxygen and heat supplementation, oxygen-enriched heat supplementation, oxygen and heat-enriched gas supplementation, cascade heat exchange and selective steam supplementation (mainly water mist spraying to supplement water vapor for this part of the waste gas after oxygen and heat supplementation and cascade heat exchange) are carried out respectively, multiple streams of annular cooling waste gas are converted into hot waste gas of different compositions such as oxygen-enriched steam hot air, oxygen-enriched hot air, oxygen-enriched gas hot air, etc., and returned to the sintering rear, middle and front material surface wind hoods respectively, thereby realizing the sintering production coupled with various advanced technologies such as hot air sintering, oxygen-enriched sintering, and steam-enriched sintering at the same time, thereby significantly improving the sintering product quality and pollutant process control level.

[0032] In the present invention, the low-temperature exhaust gas from the low-temperature section of the ring cooling can be used as the cooling medium for the medium-temperature section of the ring cooling through the circulating air duct, and the material can be cooled and heat-exchanged upward to obtain the medium-temperature exhaust gas, which can then be sent to the hot air selective generating device for quality improvement and conversion. That is, by recycling the low-temperature exhaust gas, on the one hand, the direct discharge of the low-temperature exhaust gas can be completely avoided, and the temperature of the medium-temperature exhaust gas originally at a temperature of 150°C to 250°C can be increased to 200°C to 300°C, thereby achieving the enrichment of the sensible heat of the material and facilitating the efficient recovery of subsequent heat. On the other hand, by fully or partially replacing the cold air entering the medium-temperature section of the ring cooling, the total amount of cold air used for cooling by the ring cooler is significantly reduced, and thus the output of hot exhaust gas is significantly reduced, and ultimately the heat discharged with the exhaust gas is also significantly reduced.

[0033] In the present invention, although the temperature of the ring-cooled medium-temperature exhaust gas can be increased compared with the exhaust gas temperature of the traditional process by circulating the ring-cooled low-temperature exhaust gas as the cooling air of the ring-cooled medium-temperature section, there is still a disadvantage that the wind temperature is relatively low and the waste heat utilization efficiency is relatively low when it is directly utilized (that is, it is difficult to obtain high-parameter steam by heat exchange with industrial hot water and it cannot be directly used for sintering). Therefore, the present invention first diverts the medium-temperature exhaust gas (or the mixed exhaust gas of the ring-cooled medium and low-temperature exhaust gases) according to the air volume requirements of the sintering conditions for simultaneous gas-rich sintering, oxygen-rich sintering, and steam-rich sintering, and then transports the diverted ring-cooled exhaust gas into the steam-rich stripping chamber, the oxygen-rich stripping chamber, and the gas-rich stripping chamber respectively. The quality improvement cavity is processed with oxygen supplementation and heat supplementation, oxygen enrichment and heat supplementation, oxygen supplementation and heat supplementation and gas enrichment, etc., wherein the heat supplementation process is to transport gas and oxygen for combustion, and the gas generally uses low-value combustible gas (such as blast furnace gas, converter gas and other low-value gas that is easy to obtain in steel plants, which can achieve self-sufficiency and also make this part of low-value gas fully recycled and utilized; high-value fuel or gas can also be used when necessary, but the relative cost will be higher). By oxygen supplementation or oxygen-enriched combustion, on the one hand, it is beneficial to promote the full combustion of low-value combustible gas, thereby increasing the flue gas temperature, and on the other hand, it can increase the oxygen concentration in the flue gas, that is, the oxygen concentration can be increased while supplementing heat to the annular cooling exhaust gas. Generally, after oxygen supplementation and heat supplementation, this part of the annular cooling waste gas is transformed into oxygen-supplemented high-temperature waste gas with a temperature of more than 400°C and an oxygen concentration of more than 145 mg / L. After oxygen enrichment and heat supplementation, this part of the annular cooling waste gas is transformed into oxygen-enriched high-temperature waste gas with a temperature of more than 400°C and an oxygen concentration of more than 160 mg / L. After oxygen supplementation and heat supplementation and gas enrichment, this part of the annular cooling waste gas is transformed into oxygen-supplemented enriched high-temperature waste gas with a temperature of more than 400°C, an oxygen concentration of more than 145 mg / L, and a fuel gas volume content of more than 0.5%. In other words, through oxygen supplementation and heat supplementation, oxygen enrichment and heat supplementation, oxygen supplementation and heat supplementation and gas enrichment, the annular cooling medium and low-temperature waste gas that is difficult to directly utilize is transformed into high-temperature waste gas that is easy to directly utilize (oxygen supplemented high-temperature waste gas, oxygen-enriched high-temperature waste gas, and oxygen-supplemented enriched high-temperature waste gas), and at the same time, the efficient recovery and utilization of low-value combustible gas in the factory area is also achieved.

[0034] In the present invention, a step-by-step heat exchange method is adopted to achieve efficient recovery and utilization of high-temperature exhaust gas (oxygen-supplemented high-temperature exhaust gas, oxygen-enriched high-temperature exhaust gas, and oxygen-supplemented gas-enriched high-temperature exhaust gas). That is, the high-temperature exhaust gas passes through the high-temperature heat exchange zone and the low-temperature heat exchange zone in turn for two indirect heat exchanges and then enters the atomization and steam addition chamber to selectively perform or not perform atomization and steam supplementation, thereby generating high-quality steam, industrial hot water, and oxygen-supplemented steam-enriched hot air, oxygen-enriched hot air, and oxygen-supplemented gas-enriched hot air that can be directly reused for sintering. Specifically: first, the high-temperature exhaust gas is heat exchanged with industrial hot water in the high-temperature heat exchange zone to produce high-parameter steam with a pressure of ≥1.5MPa and a temperature of ≥390℃ for power generation, and the exhaust gas temperature at the outlet of the high-temperature heat exchange zone is reduced to 160℃~200℃ (medium-temperature exhaust gas, including oxygen-supplemented medium-temperature exhaust gas, oxygen-enriched medium-temperature exhaust gas and oxygen-supplemented gas-enriched medium-temperature exhaust gas); then the medium-temperature exhaust gas is heat exchanged with normal temperature water (industrial water) in the low-temperature heat exchange zone to produce industrial hot water with a temperature of ≥90℃. The industrial hot water can be reused in the high-temperature heat exchange zone to exchange heat with the high-temperature exhaust gas to produce high-parameter steam or use In the sintering production process, the temperature of the exhaust gas at the outlet of the low-temperature heat exchange zone is reduced to 130-160°C (low-temperature exhaust gas, including oxygen-supplemented low-temperature exhaust gas, oxygen-enriched hot air, and oxygen-supplemented gas-enriched hot air); finally, the oxygen-supplemented low-temperature exhaust gas is atomized and sprayed with water for heat exchange cooling in the water mist and steam supply zone to further reduce the exhaust gas temperature. At the same time, the atomized water absorbs heat and vaporizes into water vapor, ultimately generating oxygen-supplemented steam-enriched hot air with a temperature of 120-140°C, an oxygen concentration of 310mg / L-330mg / L, and a water vapor concentration of approximately 2.5%-4.8%, which can be directly reused for sintering. In other words, the present invention achieves efficient step-by-step utilization of high-temperature exhaust gas through a cascade heat exchange method, and obtains multiple-stage products that can be directly recycled internally, achieving complete absorption and utilization of high-temperature exhaust gas without exhaust gas emissions.

[0035] In the present invention, oxygen-supplemented, gas-enriched hot air, oxygen-enriched hot air, and oxygen-supplemented, steam-enriched hot air are respectively delivered to the front, middle, and back sections of the sintering machine through a circulating gas pipeline, replacing ambient air and entering the sintering material layer to promote the sintering reaction. The front section refers to the section between the 1 / 25 and 5 / 25 sections of the material surface between the ignition point and the end point; the middle section refers to the section between the 6 / 25 and 15 / 25 sections of the material surface between the ignition point and the end point; and the back section refers to the section between the 16 / 25 and 23 / 25 sections of the material surface between the ignition point and the end point. The oxygen-supplemented gas-enriched hot air is directly returned to the material surface of the front section of sintering for gas injection sintering, which increases the sintering temperature and promotes uniform heat sintering; the oxygen-enriched hot air is directly returned to the material surface of the middle section of sintering for oxygen-enriched hot air sintering, which increases the upper limit of the hot air allowable temperature and realizes oxygen-enriched sintering, further optimizes the sintering reaction process in the middle end of sintering, and improves the quality indicators of sintered minerals; and the oxygen-supplemented steam-enriched hot air is directly returned to the material surface of the rear section of sintering for steam injection sintering, which optimizes the sintering reaction process in the middle and back ends of sintering and improves the quality of sintered minerals.

[0036] In the present invention, burners are installed in the supplementary heating and upgrading zones at the bottom of each of the steam-rich stripping chamber, the oxygen-rich stripping chamber, and the gas-rich stripping chamber to increase the temperature, oxygen concentration, and fuel gas concentration of the medium- and low-temperature exhaust gases from the annular cooling process. It should be noted that when supplementary heating and combustion are applied to the annular cooling exhaust gas in the steam-rich stripping chamber, the amount of oxygen added is such that the oxygen content of the hot air entering the sintering process is no less than the oxygen concentration of ambient air. When supplementary heating and combustion are applied to the annular cooling exhaust gas in the oxygen-rich stripping chamber, the amount of oxygen added is such that the oxygen content of the hot air entering the sintering process is higher than the oxygen concentration of ambient air. When supplementary heating and combustion are applied to the annular cooling exhaust gas in the gas-rich stripping chamber, the amount of oxygen added is such that the oxygen content of the hot air entering the sintering process is no less than the oxygen concentration of ambient air, and the amount of fuel gas added is such that the fuel gas content of the hot air entering the sintering process exceeds that of ambient air by approximately 0.5-0.6% by volume. It should be noted that the burners in each supplementary heating and upgrading zone are independent supplementary heating burners and supplementary oxygen nozzles, and are independently controlled.

[0037] In the present invention, a high-parameter steam superheater, a high-parameter steam evaporator, a high-parameter economizer, a deoxygenation evaporator and a low-parameter economizer are arranged in sequence from bottom to top in the high-temperature heat exchange zone of the steam-rich stripping chamber, the oxygen-rich stripping chamber and the gas-rich stripping chamber, and a steam drum, a deaerator, a desalted water pipeline network and a steam power generation mechanism are arranged on the outside thereof. The high-temperature exhaust gas from the supplementary heat upgrading zone is indirectly heat exchanged with the industrial hot water sent into the high-temperature heat exchange zone. The industrial hot water absorbs the heat carried by the high-temperature exhaust gas and is converted into high-parameter steam for power generation; the high-temperature exhaust gas is converted into medium-temperature exhaust gas and enters the low-temperature heat exchange zone upward.

[0038] In the present invention, industrial water heaters are installed within the low-temperature heat exchange zones of the steam-rich stripping chamber, the oxygen-rich stripping chamber, and the gas-rich stripping chamber. These industrial water heaters are connected to an external industrial water network. The industrial water network delivers industrial cold water (at ambient temperature) to the industrial water heaters for indirect heat exchange with the medium-temperature exhaust gas from the high-temperature heat exchange zone. The industrial cold water absorbs heat to produce industrial hot water, which is then supplied to the high-temperature heat exchange zone and the sintering production process. After heat exchange and cooling, the medium-temperature exhaust gas is converted into oxygen-supplemented low-temperature exhaust gas, oxygen-enriched hot air, and oxygen-enriched hot air. The oxygen-supplemented low-temperature exhaust gas then flows upward into the water mist steam supply zone.

[0039] In the present invention, a water mist nozzle is installed in the water mist steam replenishment area. The oxygen-supplemented low-temperature exhaust gas from the low-temperature heat exchange area is sprayed with water mist through the water mist nozzle, which reduces the exhaust gas temperature and increases the water vapor concentration in the exhaust gas, thereby generating oxygen-supplemented steam-enriched hot air that can be directly reused in sintering (the oxygen-enriched hot air and oxygen-supplemented steam-enriched hot air are discharged directly into the sintering process without the water mist steam replenishment process).

[0040] In the present invention, the method and system of the present invention adopt technical means such as cascade utilization of comprehensive sintering ring cooling low-temperature waste gas, simultaneous heat and oxygen supplementation for waste gas to improve quality, cascade heat exchange, and selective steam supplementation to eliminate direct emission of low-temperature waste gas, and adopt low-value coal gas combustion in steel plant areas to supplement heat and coordinate oxygen supplementation or oxygen-enriched combustion to increase the temperature of medium and low-temperature waste gas to meet the production requirements of high-parameter steam while significantly increasing the oxygen content in the waste gas. After heat exchange to produce high-quality steam and industrial hot water, selective water mist spraying is adopted to further control the flue gas temperature, and at the same time achieve the purpose of containing a certain amount of water vapor in the waste gas. By taking the above technical measures, firstly, the recovery of waste heat from medium and low temperature exhaust gas in sintering ring cooling is transformed from direct emission or recovery of low parameter steam to recovery of high parameter steam, and the quality and efficiency of waste heat recovery are improved; secondly, oxygen, fuel gas and selective water vapor are added to the medium and low temperature exhaust gas while replenishing heat, so as to increase the oxygen concentration in the exhaust gas finally returned to sintering (≥310 mg / L of oxygen concentration in normal temperature air), so that the oxygen content of the exhaust gas entering sintering can still meet the needs of sintering reaction when the temperature is greater than 120℃, eliminating the negative impact of thin oxygen at high temperature on the sintering process, and improving the sintering process. The utilization rate of waste heat from exhaust gas is improved; thirdly, oxygen-supplemented steam-rich hot air is transported to the material surface in the rear section of sintering for steam-rich sintering, oxygen-rich hot air is transported to the material surface in the middle section of sintering for oxygen-rich sintering, and oxygen-supplemented gas-rich hot air is transported to the material surface in the front section of sintering for gas-rich sintering. Compared with ordinary air, which contains both fuel gas and excess oxygen as well as some steam, the existing "fuel gas injection sintering technology", "oxygen-enriched sintering technology" and "material surface injection water steam technology" are coupled together to superimpose the improvement effect on sintering. When the exhaust gas is used to replace air for sintering, the quality indicators of sintered minerals can be significantly improved and pollutant emissions can be reduced.

[0041] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0042] 1: The method and system provided by the present invention realize the recovery of waste heat from medium and low temperature exhaust gas in sintering ring cooling, which is transformed from direct emission or recovery of low parameter steam to recovery of high parameter steam, with zero exhaust gas emission, thus significantly improving the quality and efficiency of waste heat recovery; at the same time, oxygen and gas are added to the medium and low temperature exhaust gas while replenishing heat, thereby increasing the oxygen concentration and fuel gas content in the exhaust gas finally returned to sintering. When the exhaust gas temperature is greater than 120°C, the oxygen content of the exhaust gas entering the sintering material layer can still meet the reaction requirements, thereby eliminating the negative impact of thin oxygen at high temperature on the sintering process, and improving the utilization rate of waste heat from the exhaust gas in the sintering process.

[0043] 2: The method and system provided by the present invention integrate the units of heat supplement, oxygen supplement, oxygen enrichment, gas supplement and steam supplement into one, with strong adjustability. It takes advantage of the positive effects of technical means such as cascade utilization of low-temperature exhaust gas from sintering ring cooling, synchronous heat supplement and quality improvement of medium-temperature exhaust gas, cascade heat exchange and oxygen enrichment, gas enrichment and steam enrichment, etc., to greatly improve the waste heat utilization efficiency of low-temperature exhaust gas from the ring cooler and reduce exhaust gas emissions.

[0044] 3: The oxygen-supplemented gas-enriched hot air, oxygen-enriched hot air, and oxygen-supplemented steam-enriched hot air generated by the method and system of the present invention are returned to different material surfaces for sintering to respectively perform oxygen-supplemented gas injection sintering, oxygen-enriched hot air sintering, and oxygen-supplemented steam injection sintering. Compared with the existing separate gas injection sintering, hot air sintering, and steam injection sintering, they have better sintering production quality improvement and pollutant control effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The process flow chart of the method of the present invention is shown in FIG.

[0046] Figure 2 Schematic diagram of the structure of the system of the present invention.

[0047] Figure 3 This is a cross-sectional diagram of the integrated exhaust gas diversion and upgrading device of the present invention. Figure 1 .

[0048] Figure 4 This is a cross-sectional diagram of the integrated exhaust gas diversion and upgrading device of the present invention. Figure 2 .

[0049] Reference numerals: 1: sintering machine; 101: front section air hood; 102: middle section air hood; 103: rear section air hood; 2: annular cooler; 201: exhaust gas conveying pipeline; 3: integrated exhaust gas diversion and upgrading device; 31: steam-enriched stripping chamber; 32: oxygen-enriched stripping chamber; 33: gas-enriched stripping chamber; 301: partition wall; 302: air inlet valve; 303: oxygen-supplemented steam-enriched hot air conveying pipeline; 304: oxygen-enriched hot air conveying pipeline; 305: oxygen-supplemented gas-enriched hot air conveying pipeline; 4: heat supplementation and upgrading area; 401: burner; 402: gas conveying pipeline; 403: Oxygen delivery pipeline; 404: Natural gas supplementary pipeline; 5: High-temperature heat exchange area; 501: High-parameter steam superheater; 502: High-parameter steam evaporator; 503: High-parameter economizer; 504: Deaerator evaporator; 505: Low-parameter economizer; 506: Steam drum; 507: Deaerator; 508: Demineralized water pipeline network; 509: Steam power generation mechanism; 6: Low-temperature heat exchange area; 601: Industrial water heater; 602: Industrial water pipeline network; 603: Hot water utilization pipeline; 7: Water mist steam supply area; 701: Water mist nozzle. DETAILED DESCRIPTION

[0050] The technical solutions of the present invention are illustrated below with examples, and the scope of protection requested by the present invention includes but is not limited to the following embodiments.

[0051] A system for multi-element upgrading and coordinated sintering of annularly cooled waste gas, the system comprising a sintering machine 1, an annular cooler 2 and an integrated waste gas diversion and upgrading device 3. The inner cavity of the integrated waste gas diversion and upgrading device 3 is divided into three mutually incommunicative vertical chambers by a partition wall 301, which are respectively denoted as a steam-rich stripping chamber 31, an oxygen-rich stripping chamber 32 and a gas-rich stripping chamber 33. An independent air inlet valve 302 is provided at the air inlet at the bottom of each of the steam-rich stripping chamber 31, the oxygen-rich stripping chamber 32 and the gas-rich stripping chamber 33. The steam-rich stripping chamber 31, the oxygen-rich stripping chamber 32 and the gas-rich stripping chamber 33 all comprise, from bottom to top, a heat supplementation and upgrading zone 4, a high-temperature heat exchange zone 5 and a low-temperature heat exchange zone 6, which are connected in series in sequence. A water mist steam supplementation zone 7 is also provided at the top of the steam-rich stripping chamber 31. The top air outlet of the steam-enriched stripping chamber 31 is connected to the air inlet of the rear section hood 103 above the sintering machine 1 via the oxygen-enriched steam hot air delivery pipe 303. The top air outlet of the oxygen-enriched stripping chamber 32 is connected to the air inlet of the middle section hood 102 above the sintering machine 1 via the oxygen-enriched hot air delivery pipe 304. The top air outlet of the gas-enriched stripping chamber 33 is connected to the air inlet of the front section hood 101 above the sintering machine 1 via the oxygen-enriched gas hot air delivery pipe 305. The exhaust gas outlet of the ring cooler 2 is connected to the bottom air inlet of the integrated exhaust gas diversion and upgrading device 3 via the exhaust gas delivery pipe 201.

[0052] Preferably, the front and rear ends of the front hood 101 are respectively located at the front end of the 1 / 25 section of the material surface and the rear end of the 5 / 25 section of the material surface behind the ignition furnace of the sintering machine. The front and rear ends of the middle hood 102 are respectively located at the front end of the 6 / 25 section of the material surface and the rear end of the 15 / 25 section of the material surface behind the ignition furnace of the sintering machine. The front and rear ends of the rear hood 103 are respectively located at the front end of the 16 / 25 section of the material surface and the 23 / 25 section of the material surface behind the ignition furnace of the sintering machine.

[0053] Preferably, an independent burner 401 is provided in each of the supplementary heat and upgrading zones 4 of the steam-rich upgrading chamber 31, the oxygen-rich upgrading chamber 32 and the gas-rich upgrading chamber 33, and the air inlet ends of the three burners 401 are independently connected to a gas delivery pipeline 402 and an oxygen delivery pipeline 403.

[0054] Preferably, the gas delivery pipelines 402 are all connected to the plant gas network, and the oxygen delivery pipelines 403 are all connected to the plant oxygen network. Preferably, a natural gas supplementary pipeline 404 is also independently provided in the heat supplementation and upgrading zone 4 of the gas-enriched upgrading chamber 33.

[0055] Preferably, a high-parameter steam superheater 501, a high-parameter steam evaporator 502, a high-parameter economizer 503, a deaerator 504, and a low-parameter economizer 505 are independently arranged in order from bottom to top within the high-temperature heat exchange zone 5 of each of the steam-rich stripping chamber 31, the oxygen-rich stripping chamber 32, and the gas-rich stripping chamber 33. A steam drum 506, a deaerator 507, a desalted water pipe network 508, and a steam power generation mechanism 509 are also provided outside the high-temperature heat exchange zone 5. One end of each high-parameter steam superheater 501 is connected to the steam power generation mechanism 509 via a pipe-valve group, and their other ends are connected to the steam drum 506 via a pipeline. Both ends of all high-parameter steam evaporators 502 are connected to the steam drum 506 via a pipeline. One end of each high-parameter economizer 503 is connected to the deaerator 507 via a pipeline, and their other ends are connected to the steam drum 506 via a pipeline. Both ends of all deaerators 504 are connected to the deaerator 507 through pipelines. One end of all low-parameter economizers 505 is connected to the desalted water network 508 through pipelines, and the other ends of all low-parameter economizers 505 are connected to the deaerator 507 through pipelines.

[0056] Preferably, an industrial water heater 601 is independently installed in the low-temperature heat exchange zone 6 of each of the steam-rich stripping chamber 31, the oxygen-rich stripping chamber 32, and the gas-rich stripping chamber 33. An industrial water network 602 and a hot water utilization pipeline 603 are installed outside the low-temperature heat exchange zone 6. The water inlet of each industrial water heater 601 is connected to the industrial water network 602, and their water outlet is connected to the hot water utilization pipeline 603.

[0057] Preferably, a water mist nozzle 701 is provided in the water mist supplementary steam zone 7 of the rich steam stripping chamber 31 , and the water inlet end of the water mist nozzle 701 is connected to one end of the low-parameter economizer 506 close to the deaerator 507 .

[0058] Preferably, the low-temperature exhaust gas outlet of the low-temperature section of the ring cooler 2 and the medium-temperature exhaust gas outlet of the medium-temperature section are both connected to the bottom air inlet of the integrated exhaust gas diversion and upgrading device 3 through the exhaust gas conveying pipe 201. Alternatively, the low-temperature exhaust gas outlet of the low-temperature section of the ring cooler 2 is first connected to the cooling air inlet of the medium-temperature section through the circulating air duct, and then the medium-temperature exhaust gas outlet of the medium-temperature section of the ring cooler 2 is further connected to the bottom air inlet of the integrated exhaust gas diversion and upgrading device 3 through the exhaust gas conveying pipe 201.

[0059] Example 1

[0060] like Figure 2-4As shown, a system for multi-element upgrading and coordinated sintering of annularly cooled waste gas is provided, which includes a sintering machine 1, an annular cooler 2, and an integrated waste gas diversion and upgrading device 3. The inner cavity of the integrated waste gas diversion and upgrading device 3 is divided into three mutually incommunicative vertical chambers by a partition wall 301, which are respectively denoted as a steam-rich stripping chamber 31, an oxygen-rich stripping chamber 32, and a gas-rich stripping chamber 33. An independent air inlet valve 302 is provided at the air inlet at the bottom of each of the steam-rich stripping chamber 31, the oxygen-rich stripping chamber 32, and the gas-rich stripping chamber 33. The steam-rich stripping chamber 31, the oxygen-rich stripping chamber 32, and the gas-rich stripping chamber 33 all include, from bottom to top, a heat supplementation and upgrading zone 4, a high-temperature heat exchange zone 5, and a low-temperature heat exchange zone 6, which are connected in series in sequence. A water mist steam supplementation zone 7 is also provided at the top of the steam-rich stripping chamber 31. The top air outlet of the steam-enriched stripping chamber 31 is connected to the air inlet of the rear section hood 103 above the sintering machine 1 via the oxygen-enriched steam hot air delivery pipe 303. The top air outlet of the oxygen-enriched stripping chamber 32 is connected to the air inlet of the middle section hood 102 above the sintering machine 1 via the oxygen-enriched hot air delivery pipe 304. The top air outlet of the gas-enriched stripping chamber 33 is connected to the air inlet of the front section hood 101 above the sintering machine 1 via the oxygen-enriched gas hot air delivery pipe 305. The exhaust gas outlet of the ring cooler 2 is connected to the bottom air inlet of the integrated exhaust gas diversion and upgrading device 3 via the exhaust gas delivery pipe 201.

[0061] Example 2

[0062] Example 1 was repeated, except that the front and rear ends of the front hood 101 were located at the front end of the 1 / 25 section of the charge surface and the rear end of the 5 / 25 section of the charge surface, respectively, behind the ignition furnace of the sintering machine. The front and rear ends of the middle hood 102 were located at the front end of the 6 / 25 section of the charge surface and the rear end of the 15 / 25 section of the charge surface, respectively, behind the ignition furnace of the sintering machine. The front and rear ends of the rear hood 103 were located at the front end of the 16 / 25 section of the charge surface and the rear end of the 23 / 25 section of the charge surface, respectively, behind the ignition furnace of the sintering machine.

[0063] Example 3

[0064] Example 2 is repeated, except that independent burners 401 are provided in the supplementary heat upgrading zone 4 of each of the steam-rich stripping chamber 31, the oxygen-rich stripping chamber 32 and the gas-rich stripping chamber 33, and the air inlet ends of the three burners 401 are independently connected to the gas delivery pipeline 402 and the oxygen delivery pipeline 403.

[0065] Example 4

[0066] Example 3 is repeated, except that the gas transmission pipelines 402 are all connected to the factory gas network, and the oxygen transmission pipelines 403 are all connected to the factory oxygen network.

[0067] Example 5

[0068] The fourth embodiment is repeated except that a natural gas supplementary pipeline 404 is independently provided in the heat supplementation and upgrading zone 4 of the rich gas upgrading chamber 33 .

[0069] Example 6

[0070] Example 5 was repeated, except that a high-parameter steam superheater 501, a high-parameter steam evaporator 502, a high-parameter economizer 503, a deaerator 504, and a low-parameter economizer 505 were independently installed in the high-temperature heat exchange zone 5 of each of the steam-rich stripping chamber 31, the oxygen-rich stripping chamber 32, and the gas-rich stripping chamber 33, from bottom to top. A steam drum 506, a deaerator 507, a desalted water pipe network 508, and a steam power generation mechanism 509 were also installed outside the high-temperature heat exchange zone 5. One end of each high-parameter steam superheater 501 was connected to the steam power generation mechanism 509 via a pipe valve group, and their other ends were connected to the steam drum 506 via a pipeline. Both ends of all high-parameter steam evaporators 502 were connected to the steam drum 506 via a pipeline. One end of each high-parameter economizer 503 was connected to the deaerator 507 via a pipeline, and their other ends were connected to the steam drum 506 via a pipeline. Both ends of all deaerators 504 are connected to the deaerator 507 through pipelines. One end of all low-parameter economizers 505 is connected to the desalted water network 508 through pipelines, and the other ends of all low-parameter economizers 505 are connected to the deaerator 507 through pipelines.

[0071] Example 7

[0072] Example 6 was repeated, except that an industrial water heater 601 was independently installed in the low-temperature heat exchange zone 6 of each of the steam-rich stripping chamber 31, the oxygen-rich stripping chamber 32, and the gas-rich stripping chamber 33. An industrial water network 602 and a hot water utilization pipeline 603 were installed outside the low-temperature heat exchange zone 6. The water inlets of all industrial water heaters 601 were connected to the industrial water network 602, and their water outlets were connected to the hot water utilization pipeline 603.

[0073] Example 8

[0074] Example 7 is repeated, except that a water mist nozzle 701 is provided in the water mist supplementary steam zone 7 of the rich steam stripping chamber 31 , and the water inlet end of the water mist nozzle 701 is connected to one end of the low parameter economizer 506 close to the deaerator 507 .

[0075] Example 9

[0076] Example 8 is repeated, except that the low-temperature exhaust gas outlet of the low-temperature section of the ring cooler 2 and the medium-temperature exhaust gas outlet of the medium-temperature section are both connected to the bottom air inlet of the integrated exhaust gas diversion and upgrading device 3 through the exhaust gas conveying pipe 201.

[0077] Example 10

[0078] Repeat Example 9, except that the low-temperature exhaust gas outlet of the low-temperature section of the ring cooler 2 is first connected to the cooling air inlet of its medium-temperature section through the circulating air duct, and then the medium-temperature exhaust gas outlet of the medium-temperature section of the ring cooler 2 is connected to the bottom air inlet of the integrated exhaust gas diversion and quality improvement device 3 through the exhaust gas conveying pipe 201.

[0079] Example 11

[0080] The system described in Example 10 was used for collaborative sintering:

[0081] The initial temperature of the annular cooling exhaust gas is about 159°C, and then it is divided into three exhaust gases in a volume ratio of 40%:35%:25%. The three exhaust gases are respectively transported to different heat supplement and quality improvement zones and transported with different oxygen and fuel gas for combustion. The exhaust gas accounting for 40% is heated to 492°C and the oxygen content is about 167mg / L after oxygen supplement and heat supplement combustion. The exhaust gas accounting for 35% is heated to 505°C and the oxygen content is about 203mg / L after oxygen-enriched heat supplement combustion. The exhaust gas accounting for 25% is heated to 496°C and the oxygen content is about 169mg / L after oxygen supplement and heat supplement combustion. The fuel gas volume content is about 0.55%; then the three exhaust gases are sequentially passed through the high-temperature heat exchange zone and the low-temperature heat exchange zone for cascade heat exchange treatment. , and then 40% of the waste gas is treated with water mist steam supplementation, wherein: 40% of the waste gas is further converted into oxygen-supplemented steam-rich hot air with a temperature of about 129°C, an oxygen content of about 318mg / L, and a water vapor content of about 3.7%; 35% of the waste gas is further converted into oxygen-rich hot air with a temperature of about 145°C, an oxygen content of about 377mg / L; 25% of the waste gas is further converted into oxygen-supplemented gas-rich hot air with a temperature of about 142°C, an oxygen content of about 314mg / L, and a fuel gas volume content of about 0.57%; the oxygen-supplemented steam-rich hot air is transported to the rear section of the sintering material surface for steam-rich sintering, the oxygen-rich hot air is transported to the middle section of the sintering material surface for oxygen-rich sintering, and the oxygen-supplemented gas-rich hot air is transported to the front section of the sintering material surface for gas-rich sintering. During the cascade heat exchange process, a flow rate of about 50m 3 / h, high-parameter steam with a pressure of about 1.8MPa and a temperature of about 417℃, and hot water with a flow rate of about 50t / h and a temperature of about 90℃. Compared with the conventional process, the annular cooling waste gas is directly utilized, and the temperature of the hot air returned to the sintering material surface is increased by about 29-45℃. The overall waste heat utilization rate of the annular cooling waste gas is increased by about 26%, the sintering ore return rate is reduced by about 1.4%, the sintering ore drum strength is increased by about 1.7%, and the utilization coefficient is increased by about 0.037t / m 2 ·h -1 , solid fuel consumption decreased by 2.1kg / t.

[0082] Example 12

[0083] Example 11 was repeated, except that the initial distribution volume ratio of the ring cooling waste gas was 30%:50%:20%. After quality improvement and utilization, the waste gas was returned to the sintering material surface for utilization. Compared with the conventional process, the ring cooling waste gas was directly utilized, and at the same time, the temperature of the hot air returned to the sintering material surface was increased by about 26 to 43°C, the overall waste heat utilization rate of the ring cooling waste gas was increased by about 25%, the sintered ore return rate was reduced by about 1.5%, the sintered ore drum strength was increased by about 1.6%, and the utilization coefficient was increased by about 0.039 t / m 2 ·h -1 , solid fuel consumption decreased by 1.9kg / t.

[0084] Comparative Example 1

[0085] Conventional processes are used for cooling sintered ore. The exhaust gas from the low-temperature cooling section of the ring cooler (about 142°C) is directly discharged, and the exhaust gas from the medium-temperature cooling section of the ring cooler (about 219°C) is heat exchanged with waste heat boilers and industrial water, generating low-parameter steam with a flow rate of about 11.5t / h, a pressure of about 0.4MPa, and a temperature of about 180°C, and hot water with a flow rate of about 50t / h and a temperature of about 90°C. This low-pressure steam cannot be fully utilized in the plant, and its heat utilization efficiency is low.

[0086] Comparative Example 2

[0087] Conventional processes are used for cooling sintered ore. The exhaust gas from the low-temperature cooling section of the ring cooler (about 142°C) is directly discharged, and the exhaust gas from the medium-temperature cooling section of the ring cooler (about 219°C) is returned to the sintering ignition section and the sintering material surface. Due to the high temperature of the exhaust gas, obvious volume expansion, and thin oxygen content (about 188 mg / L), the amount of oxygen absorbed into the sintering material layer per unit time is low, and the quality of the sintered ore is reduced. In order to ensure the sintering quality, a large amount of cold air must be added to reduce the exhaust gas temperature, resulting in the inability to fully utilize the cooling exhaust gas and its heat.

Claims

1. A method for multi-element quality improvement and synergistic sintering of annularly cooled exhaust gas, characterized by: The method includes: S1) splitting the annular cooling exhaust gas and performing oxygen supplementation and heat supplementation, oxygen enrichment and heat supplementation, and oxygen supplementation and heat enrichment to obtain oxygen-supplemented high-temperature exhaust gas, oxygen-enriched high-temperature exhaust gas, and oxygen-supplemented and enriched high-temperature exhaust gas; S1) performing cascade heat exchange and steam supplementation on the oxygen-supplemented high-temperature exhaust gas in sequence to obtain oxygen-supplemented steam-rich hot air, and performing cascade heat exchange on the oxygen-rich high-temperature exhaust gas and the oxygen-supplemented gas-rich high-temperature exhaust gas to obtain oxygen-rich hot air and oxygen-supplemented gas-rich hot air respectively; S3) delivering the oxygen-enriched steam hot air to the material surface of the rear section of sintering for steam-enriched sintering, delivering the oxygen-enriched hot air to the material surface of the middle section of sintering for oxygen-enriched sintering, and delivering the oxygen-enriched gas hot air to the material surface of the front section of sintering for gas-enriched sintering.

2. The method according to claim 1, wherein: The ring cooling waste gas is a mixture of sintering ring cooling medium temperature waste gas and sintering ring cooling low temperature waste gas; or, the ring cooling waste gas is sintering ring cooling medium temperature waste gas generated after the sintering ring cooling low temperature waste gas is used as the cooling medium of the sintering ring cooling medium temperature section; Preferably, the temperature of the annular cooling exhaust gas is less than 250°C, preferably 120-240°C, more preferably 140-200°C.

3. The method according to claim 1 or 2, characterized in that: The oxygen and heat supplementation is specifically to use the ring cooling exhaust gas as the supporting combustion gas for oxygen supplementation combustion, so that the temperature of the oxygen supplemented high temperature exhaust gas obtained after combustion is increased to 400-550°C and the oxygen concentration content is 145-190 mg / L; and / or The oxygen-enriched heat supplementation is specifically to use the annular cooling exhaust gas as the supporting combustion gas for oxygen-enriched combustion, so that the temperature of the oxygen-enriched high-temperature exhaust gas obtained after combustion is increased to 400-550°C and the oxygen concentration is 160-260 mg / L; and / or The oxygen-supplemented heat-supplemented rich gas is specifically prepared by using the annular cooling exhaust gas as the supporting combustion gas for oxygen-enriched combustion, and then the gas is excessive, so that the temperature of the oxygen-supplemented rich high-temperature exhaust gas obtained after combustion is increased to 400-550°C, the oxygen concentration content is 145-190 mg / L, and the gas volume content is 0.5-0.6%.

4. The method according to any one of claims 1 to 3, characterized in that: The cascade heat exchange is specifically as follows: first, hot water is used to perform indirect heat exchange with the oxygen-supplemented high-temperature exhaust gas, the oxygen-enriched high-temperature exhaust gas, and the oxygen-enriched gas-supplemented high-temperature exhaust gas to obtain high-parameter steam and the oxygen-supplemented medium-temperature exhaust gas, the oxygen-enriched medium-temperature exhaust gas, and the oxygen-supplemented rich gas medium-temperature exhaust gas; then, cold water is used to perform indirect heat exchange with the oxygen-supplemented medium-temperature exhaust gas, the oxygen-enriched medium-temperature exhaust gas, and the oxygen-supplemented rich gas medium-temperature exhaust gas to obtain hot water and the oxygen-supplemented low-temperature exhaust gas, the oxygen-enriched hot air, and the oxygen-supplemented rich gas hot air; water mist is sprayed into the oxygen-supplemented low-temperature exhaust gas to perform steam supplementation to obtain the oxygen-supplemented steam-enriched hot air; Preferably, the temperature of the oxygen-supplemented steam-rich hot air is 120-140°C, the oxygen concentration is 310-330 mg / L, and the water vapor content is 2.5-4.8 wt%; the temperature of the oxygen-enriched hot air is 140-160°C, the oxygen concentration is 330-420 mg / L; the temperature of the oxygen-supplemented gas-enriched hot air is 140-160°C, the oxygen concentration is 315-335 mg / L, and the fuel gas volume content is 0.5-0.6%; the temperature of the high-parameter steam is not lower than 390°C, and the pressure is not lower than 1.5 MPa.

5. The method according to any one of claims 1 to 4, characterized in that: The volume ratio of the air volume distribution of the ring cooling exhaust gas diversion for oxygen supplementation and heat supplementation, oxygen enrichment and heat supplementation, and oxygen supplementation and heat supplementation and enriched gas is 25-50%: 20-50%: 10-30%; and / or The material surface in the front section of sintering is the 1 / 25 to 5 / 25 material surface after the ignition furnace of the sintering machine, the material surface in the middle section of sintering is the 6 / 25 to 15 / 25 material surface after the ignition furnace of the sintering machine, and the material surface in the back section of sintering is the 16 / 25 to 23 / 25 material surface after the ignition furnace of the sintering machine.

6. A system for multi-element upgrading and synergistic sintering of annularly cooled exhaust gas or a system for the method according to any one of claims 1 to 5, characterized in that: The system comprises a sintering machine (1), an annular cooler (2) and an integrated waste gas diversion and upgrading device (3); the inner cavity of the integrated waste gas diversion and upgrading device (3) is divided into three mutually incommunicative vertical chambers by a partition wall (301), which are respectively recorded as a steam-rich stripping chamber (31), an oxygen-rich stripping chamber (32) and a gas-rich stripping chamber (33); an independent air inlet valve (302) is provided at the air inlet at the bottom of each of the steam-rich stripping chamber (31), the oxygen-rich stripping chamber (32) and the gas-rich stripping chamber (33); the steam-rich stripping chamber (31), the oxygen-rich stripping chamber (32) and the gas-rich stripping chamber (33) all comprise, from bottom to top, a heat supplementation and upgrading zone (4), a high-temperature heat exchange zone (5) and a low-temperature heat exchange zone (6) which are sequentially connected in series, The top of the chamber (31) is also provided with a water mist steam supply area (7); the top air outlet of the steam-enriched stripping chamber (31) is connected to the air inlet of the rear section wind hood (103) above the sintering machine (1) through the oxygen-enriched steam hot air delivery pipe (303); the top air outlet of the oxygen-enriched stripping chamber (32) is connected to the air inlet of the middle section wind hood (102) above the sintering machine (1) through the oxygen-enriched hot air delivery pipe (304); the top air outlet of the gas-enriched stripping chamber (33) is connected to the air inlet of the front section wind hood (101) above the sintering machine (1) through the oxygen-enriched gas hot air delivery pipe (305); the exhaust gas outlet of the ring cooler (2) is connected to the bottom air inlet of the integrated exhaust gas diversion and upgrading device (3) through the exhaust gas delivery pipe (201); Preferably, the front and rear ends of the front section hood (101) are respectively located at the front end of the 1 / 25 section material surface and the rear end of the 5 / 25 section material surface behind the ignition furnace of the sintering machine; the front and rear ends of the middle section hood (102) are respectively located at the front end of the 6 / 25 section material surface and the rear end of the 15 / 25 section material surface behind the ignition furnace of the sintering machine; and the front and rear ends of the rear section hood (103) are respectively located at the front end of the 16 / 25 section material surface and the 23 / 25 section material surface behind the ignition furnace of the sintering machine.

7. The system according to claim 6, characterized in that: Independent burners (401) are provided in the supplementary heat and upgrading zones (4) of the steam-rich stripping chamber (31), the oxygen-rich stripping chamber (32), and the gas-rich stripping chamber (33), and the gas inlet ends of the three burners (401) are independently connected to a gas delivery pipeline (402) and an oxygen delivery pipeline (403); Preferably, the gas transmission pipelines (402) are all connected to the plant area gas network, and the oxygen transmission pipelines (403) are all connected to the plant area oxygen network; preferably, a natural gas supplementary pipeline (404) is also independently provided in the heat supplement and upgrading zone (4) of the rich gas upgrading chamber (33).

8. The system according to claim 6 or 7, characterized in that: A high-parameter steam superheater (501), a high-parameter steam evaporator (502), a high-parameter economizer (503), a deaerator (504) and a low-parameter economizer (505) are independently arranged in order from bottom to top in the high-temperature heat exchange zone (5) of each of the steam-rich stripping chamber (31), the oxygen-rich stripping chamber (32) and the gas-rich stripping chamber (33); a steam drum (506), a deaerator (507), a desalted water pipe network (508) and a steam power generation mechanism (509) are also arranged outside the high-temperature heat exchange zone (5); one end of each high-parameter steam superheater (501) is connected to the steam power generation mechanism (509) through a pipe valve group. are connected to each other, and their other ends are connected to the steam drum (506) through pipelines; both ends of all high-parameter steam evaporators (502) are connected to the steam drum (506) through pipelines; one end of all high-parameter economizers (503) are connected to the deaerator (507) through pipelines, and their other ends are connected to the steam drum (506) through pipelines; both ends of all deaeration evaporators (504) are connected to the deaerator (507) through pipelines; one end of all low-parameter economizers (505) are connected to the desalted water network (508) through pipelines, and their other ends are connected to the deaerator (507) through pipelines.

9. The system according to any one of claims 6 to 8, characterized in that: Industrial water heaters (601) are independently provided in the low-temperature heat exchange zones (6) of the steam-rich stripping chamber (31), the oxygen-rich stripping chamber (32), and the gas-rich stripping chamber (33), and industrial water pipe networks (602) and hot water utilization pipes (603) are provided outside the low-temperature heat exchange zones (6); the water inlets of all the industrial water heaters (601) are connected to the industrial water pipe networks (602), and their water outlets are connected to the hot water utilization pipes (603).

10. The system according to any one of claims 6 to 9, characterized in that: A water mist nozzle (701) is provided in the water mist supplementary steam zone (7) of the rich steam stripping chamber (31), and the water inlet end of the water mist nozzle (701) is connected to one end of the low parameter economizer (506) close to the deaerator (507); and / or The low-temperature exhaust gas outlet of the low-temperature section of the ring cooler (2) and the medium-temperature exhaust gas outlet of the medium-temperature section are both connected to the bottom air inlet of the integrated exhaust gas diversion and quality improvement device (3) through the exhaust gas conveying pipe (201); or, the low-temperature exhaust gas outlet of the low-temperature section of the ring cooler (2) is first connected to the cooling air inlet of the medium-temperature section through the circulating air duct, and then the medium-temperature exhaust gas outlet of the medium-temperature section of the ring cooler (2) is connected to the bottom air inlet of the integrated exhaust gas diversion and quality improvement device (3) through the exhaust gas conveying pipe (201).

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