Low-carbon sintering flue gas circulation system and purification process for multi-pollutant collaborative treatment

Abstract

The present application relates to the technical field of metallurgical energy saving and carbon reduction, and proposes a low-carbon sintering flue gas circulating system and purification process for collaborative treatment of multiple pollutants, which is used for grading treatment of sintering flue gas, and comprises a sintering chamber, a high-sulfur air duct and a low-sulfur air duct, a first flue gas treatment system, and a sintering cavity and a flue gas injection port of the sintering chamber, wherein the sintering cavity is connected to the high-sulfur air duct or the low-sulfur air duct, the low-sulfur air duct is connected to the flue gas injection port, and the high-sulfur air duct is connected to the first flue gas treatment system. Through the above technical scheme, the problem of high energy consumption in the prior art for treating the flue gas generated after sintering of sinter is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of metallurgical energy conservation and carbon reduction, and in particular to a low-carbon sintering flue gas circulation system and purification process for coordinated multi-pollutant control. Background Art

[0002] In industries involving sintering ore, such as steel production, the sintering process produces large amounts of sulfur-containing waste gas. Conventional flue gas treatment technologies face numerous challenges when dealing with this type of sintering flue gas, the most prominent of which is excessive energy consumption.

[0003] In previous processes, sintering flue gas was typically not carefully classified and treated, but rather uniformly. All sulfur-containing flue gas was treated equally, requiring a complex and energy-intensive treatment process, which resulted in high operating costs for the entire flue gas treatment system.

[0004] With increasingly stringent environmental regulations, emission limits on various pollutants in sintering flue gas are tightening, further exacerbating the difficulties faced by traditional processes. Not only does this require more energy to remove pollutants, but the treatment results are often unsatisfactory, making it difficult to simultaneously meet low emission requirements for pollutants such as sulfur oxides, nitrogen oxides, and dust. Summary of the Invention

[0005] The present invention proposes a low-carbon sintering flue gas circulation system and purification process for coordinated multi-pollutant treatment, which solves the problem of high energy consumption in the related art for treating the flue gas generated after sintering of sintered ore.

[0006] The technical solutions of the present invention are as follows:

[0007] The low-carbon sintering flue gas circulation system with coordinated multi-pollutant treatment is used to grade the sintering flue gas, including:

[0008] A sintering chamber, comprising a sintering cavity and a flue gas injection port;

[0009] A high-sulfur air duct and a low-sulfur air duct, the sintering chamber leads to the high-sulfur air duct and the low-sulfur air duct, and the low-sulfur air duct leads to the flue gas injection port;

[0010] The first flue gas treatment system, the high-sulfur air duct leads to the first flue gas treatment system.

[0011] Optionally, it also includes:

[0012] a second flue gas treatment system, wherein the low-sulfur air duct is connected to the flue gas injection port via the second flue gas treatment system, and the second flue gas treatment system comprises a first fan, a first electrostatic precipitator, and a dehydrator, wherein the first fan, the first electrostatic precipitator, and the dehydrator are connected in sequence;

[0013] The first flue gas treatment system includes a second fan, a second electrostatic precipitator, a first desulfurization device, an annular cooler, a bag filter and a denitrification device, wherein the second fan, the second electrostatic precipitator, the first desulfurization device, the annular cooler, the bag filter and the denitrification device are connected in sequence.

[0014] Optionally, it further includes an exhaust device, the first flue gas treatment system leads to the exhaust device, and further includes:

[0015] a first regulating valve, located between the first electrostatic precipitator and the dehydrator, the first electrostatic precipitator leading to the dehydrator via the first regulating valve, the first regulating valve also leading to the discharge device, the first regulating valve being used to regulate the flow of the low-sulfur flue gas entering the dehydrator;

[0016] The second desulfurization device is arranged on the low-sulfur air duct and is located between the first regulating valve and the discharge device, and is used for desulfurizing the excess low-sulfur flue gas discharged by the first regulating valve.

[0017] Optionally, the ring cooler has a low-temperature part and a high-temperature part, the low-temperature part is arranged between the first desulfurization device and the bag filter, and the high-temperature part is arranged in parallel with the low-temperature part, and further includes:

[0018] a second regulating valve, the second regulating valve being connected in series with the high-temperature portion and being located between the first desulfurization device and the high-temperature portion;

[0019] A heat exchanger is connected in series with the high-temperature portion and is located between the high-temperature portion and the bag filter.

[0020] Optionally, the bag dust collector includes:

[0021] a housing, the housing having an air inlet and an air outlet, the air inlet being connected to the heat exchanger, the air outlet being connected to the denitration device, and the housing having a maintenance port;

[0022] a mounting plate, the mounting plate being rotatably disposed within the housing, the mounting plate dividing the interior of the housing into a first cavity and a second cavity, the air inlet being connected to the first cavity, the air outlet and the maintenance port both being connected to the second cavity, the mounting plate having a plurality of mounting holes, and upon rotation of the mounting plate, the plurality of mounting holes being sequentially moved circumferentially to below the maintenance port;

[0023] There are a plurality of filter bags, each of which is arranged in the mounting hole, and the gas to be processed passes from the first cavity through the filter bags into the second cavity.

[0024] Optionally, the bag dust collector further includes:

[0025] a knocking rod, one end of which is swingably disposed on the inner wall of the first cavity;

[0026] a reset elastic member, wherein two ends of the reset elastic member act on the knocking rod and the inner wall of the first cavity respectively, and are used to provide a force for the other end of the knocking rod to approach the axis of the mounting plate;

[0027] After the mounting plate rotates, the other end of the knocking rod knocks a plurality of the filter bags in sequence.

[0028] Optionally, the plurality of filter bags have different lengths, and the lengths of the plurality of filter bags decrease gradually along the axis of the mounting plate.

[0029] There are a number of knocking rods, which are arranged longitudinally, and the knocking rods from top to bottom knock on the filter bags from short to long in sequence.

[0030] Optionally, the bag dust collector further includes:

[0031] a cover plate, the cover plate being rotatably disposed on the housing and being used to close the maintenance opening after the cover plate is rotated;

[0032] a rotating shaft, the rotating shaft being rotatably disposed in the second cavity, one end of the rotating shaft being connected to the mounting plate, and the other end extending out of the second cavity;

[0033] A driving member is arranged on the housing, and an output end of the driving member is connected to the rotating shaft for driving the mounting plate to rotate.

[0034] Optionally, the cover plate has a through hole, and the rotating shaft passes through the through hole;

[0035] The inner wall of the through hole has a plurality of clamping grooves, and the plurality of clamping grooves are evenly distributed around the circumference of the axis of the rotating shaft. The connection between the clamping groove and the inner wall of the through hole has a transition surface, and the transition surface is an arc surface;

[0036] The rotating shaft has a sliding groove;

[0037] The top of the housing has a first limiting column and a second limiting column. When the cover plate abuts against the first limiting column, the cover plate closes the maintenance opening. When the cover plate abuts against the second limiting column, the cover plate opens the maintenance opening. The bag dust collector also includes:

[0038] A sliding driving rod, wherein the sliding driving rod is slidably arranged in the sliding groove;

[0039] A second elastic member is arranged in the sliding groove, and two ends of the second elastic member act on the sliding driving rod and the sliding groove respectively, so as to provide a force for the sliding driving rod to approach the clamping groove.

[0040] The low-carbon sintering flue gas purification process for multi-pollutant collaborative treatment uses a low-carbon sintering flue gas circulation system for multi-pollutant collaborative treatment.

[0041] The working principle and beneficial effects of the present application are as follows:

[0042] In the present application, sulfur-containing waste gas is generated in the sintering process, and part of the sulfur-containing waste gas can be reused. The purpose of this system is to recycle the flue gas with a SO2 concentration below 50 mg / m3. The principle is that flue gas with a sulfur content below 50 mg / m3 will not significantly increase the sulfur content of sintered ore, which can ensure the product quality of sintered ore. The flue gas is divided into high-sulfur flue gas and low-sulfur flue gas. Flue gas with a SO2 concentration below 50 mg / m3 is defined as low-sulfur flue gas, and flue gas with a sulfur content above 50 mg / m3 is high-sulfur flue gas. This classification management enables different types of flue gas to be reasonably treated, thereby reducing the impact on the product quality of sintered ore. For low-sulfur flue gas, through reasonable design of the bend and flow rate control, it is smoothly conveyed to the flue gas injection port, so that the low-sulfur flue gas is coupled with the injected air, significantly increasing the air temperature and effectively reducing the solid fuel consumption. At the same time, high-sulfur flue gas flows into the desulfurization system, and after wet desulfurization, the flue gas needs to be preheated due to its low temperature. We pass the high-sulfur flue gas (after desulfurization) into the high-temperature section of the circular cooler, and use the temperature of the sintered ore to re-increase the flue gas temperature, achieving effective preheating. In the preheating process, CO in the flue gas is catalytically reacted with calcium ferrite in the sintered ore, and NO X is reduced, which prepares for the subsequent SCR denitration process. Although this process reduces the waste heat power generation of the circular cooler, the system overall energy consumption is significantly reduced due to the reduction of the required energy consumption for SCR temperature rise and the total amount of NO X to be removed. Through the above optimization design, the present application not only improves the energy efficiency of the sintering process, but also effectively reduces environmental pollution, which has significant economic and ecological benefits. BRIEF DESCRIPTION OF DRAWINGS

[0043] The above-mentioned features, technical characteristics, advantages and implementation modes of the present application will be further described in the following preferred embodiments in a clear and understandable manner combined with the accompanying drawings.

[0044] Figure 1 The structure flowchart of the present application is shown in the figure;

[0045] Figure 2 The structure schematic diagram of the bag-type dust collector of the present application is shown in the figure;

[0046] Figure 3 Schematic diagram of the internal structure of the bag filter of the present invention;

[0047] Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle;

[0048] Figure 5 This is a schematic diagram of the internal structure of the bag dust collector of the present invention from another angle;

[0049] Figure 6 For the present invention Figure 5 Enlarged view of point B in the middle;

[0050] Figure 7 For the present invention Figure 2 Enlarged view of point C in the middle;

[0051] Figure 8 For the present invention Figure 7 Enlarged view of point D in the middle.

[0052] In the figure: 1, sintering chamber, 2, high sulfur air duct, 3, low sulfur air duct, 101, sintering chamber, 102, flue gas injection port, 4, discharge device, 301, first fan, 302, first electrostatic precipitator, 303, dehydrator, 201, second electrostatic precipitator, 202, first desulfurization device, 203, ring cooler, 204, bag filter, 205, denitrification device, 304, first regulating valve, 305, second desulfurization device, 2031, low temperature part, 2032, high temperature part, 206, second regulating valve, 207, heat exchanger, 208, second fan, 5 , shell, 501, air inlet, 502, air outlet, 503, maintenance port, 6, mounting plate, 504, first cavity, 505, second cavity, 601, mounting hole, 7, filter bag, 801, knocking rod, 802, reset elastic member, 9, cover plate, 10, rotating shaft, 11, driving member, 901, through hole, 902, snap-in groove, 903, transition surface, 1001, slide groove, 507, first limiting column, 506, second limiting column, 12, sliding drive rod, 13, first area, 14, second area, 15, third area, 16, fourth area. DETAILED DESCRIPTION

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific embodiments of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings and other embodiments can be obtained based on these drawings without inventive work.

[0054] To simplify the drawings, only portions relevant to the invention are schematically depicted in each figure; they do not represent the actual structure of the product. Furthermore, to simplify the drawings and facilitate understanding, in some figures, only one component with the same structure or function is schematically depicted or labeled. In this document, "one" not only means "only one" but also "more than one," and "several" includes "two" and "more than two."

[0055] It should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0056] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0057] Reference Figures 1 to 8 , which is the first embodiment of the present invention, proposes a low-carbon sintering flue gas circulation system for coordinated control of multiple pollutants, which is used for graded treatment of sintering flue gas, including a sintering chamber 1, the sintering chamber 1 has a sintering cavity 101 and a flue gas injection port 102; a high-sulfur air duct 2 and a low-sulfur air duct 3, the sintering cavity 101 leads to the high-sulfur air duct 2 and the low-sulfur air duct 3, the low-sulfur air duct 3 leads to the flue gas injection port 102; a first flue gas treatment system, the high-sulfur air duct 2 leads to the first flue gas treatment system.

[0058] In this embodiment, in order to solve the problem of high energy consumption in the treatment of flue gas generated after sintering of sintered ore in related technologies, the sintering chamber 1 is made of alloy steel that is resistant to high temperatures and has good chemical stability, and its internal sintering cavity 101 is a rectangular structure. Sulfur-containing waste gas will be generated during the sintering process, and some of the sulfur-containing waste gas can be reused. The purpose of this system is to recycle flue gas with a SO2 concentration below 50 mg / m³. Therefore, flue gas with a SO2 concentration below 50 mg / m³ is defined as low-sulfur flue gas, and vice versa as high-sulfur flue gas. This data can be changed accordingly according to process requirements.

[0059] Multiple flue gas injection ports 102 are evenly distributed on the top of the sintering chamber 101 to ensure smooth exhaust of flue gas. High-precision SO2 concentration sensors are installed at key locations in the air duct. Based on advanced optical detection technology, they accurately monitor the SO2 concentration in the flue gas in real time.

[0060] During the combustion of sintered ore, the sintered ore will continue to move in the sintering chamber 1 and will continue to generate sulfur-containing exhaust gas. When the sintered ore just enters the sintering chamber 101, the sulfur content of the exhaust gas generated by sintering is higher than 50 mg / m³. This is the first area 13, which is connected to the high-sulfur air duct 2. As the sintered ore gradually moves, the sulfur content in the generated flue gas is less than 50 mg / m³. 3 This is the second area 14, which is connected to the low-sulfur air duct 3. As the sintering time increases, the reaction will gradually become more intense, and the sulfur content in the generated exhaust gas will be higher than 50 mg / m 3 This area is the third area 15, which is connected to the high-sulfur air duct 2. When the sintered ore moves to the discharge port, the reaction is basically completed, and the sulfur content in the sintering exhaust gas is again lower than 50 mg / m 3 This is the fourth area 16 , and the fourth area 16 is connected to the low-sulfur air duct 3 .

[0061] Concentration less than 50 mg / m 3 The low-sulfur flue gas is smoothly transported to the flue gas injection port 102 through the low-sulfur air duct 3 by using reasonable bend and flow rate control design, and is coupled with the injected air to increase the injection temperature; the high-sulfur flue gas is first wet desulfurized and then preheated in the first and second stages of the ring cooler. During the preheating process, the CO and NO in the sintered ore are X This process not only reduces the total amount of SCR denitrification but also avoids the flue gas heating step before denitrification. While saving the cost of low-sulfur flue gas treatment, by precisely controlling parameters such as sintering temperature, time, and atmosphere, the catalytically active components such as calcium ferrite within the sintered ore are fully activated during the formation process, ensuring that these natural catalysts perform optimally in the subsequent synergistic removal of carbon monoxide and nitrogen oxides.

[0062] The advantage is that the flue gas is divided into high-sulfur flue gas and low-sulfur flue gas, where the flue gas with a SO2 concentration below 50 mg / m³ is defined as low-sulfur flue gas, and the flue gas above 50 mg / m³ is high-sulfur flue gas. This classification management enables different types of flue gas to be treated reasonably, thereby reducing the impact on the quality of sintered ore products. For low-sulfur flue gas, it is smoothly transported to the flue gas injection port through reasonable bend and flow rate control design, so that the low-sulfur flue gas is coupled with the injection air, which significantly increases the wind temperature and effectively reduces solid fuel consumption. At the same time, the high-sulfur flue gas flows into the desulfurization system. After wet desulfurization, the flue gas temperature is relatively low, so it needs to be preheated in advance. We pass the high-sulfur flue gas (after desulfurization) into the high-temperature section of the ring cooler, and use the temperature of the sintered ore to raise the flue gas temperature again to achieve effective preheating. During the preheating process, the CO in the flue gas reacts with the calcium ferrite in the sintered ore to catalyze the reaction, and NO XThe CO2 can be reduced in synergy with that of CO2, thus preparing for the subsequent SCR denitrification process. Although this process reduces the waste heat power generation of the ring cooler, it reduces the SCR heating energy consumption and the required NO removal. X Through the above optimization design, the present invention not only improves the energy efficiency of the sintering process, but also effectively reduces environmental pollution, with significant economic and ecological benefits.

[0063] Furthermore, it also includes a second flue gas treatment system, the low-sulfur air duct 3 is connected to the flue gas injection port 102 through the second flue gas treatment system, the second flue gas treatment system includes a first fan 301, a first electrostatic precipitator 302 and a dehydrator 303, and the first fan 301, the first electrostatic precipitator 302 and the dehydrator 303 are connected in sequence; the first flue gas treatment system includes a second fan 208, a second electrostatic precipitator 201, a first desulfurization device 202, an annular cooler 203, a bag-type dust collector 204 and a denitrification device 205, and the second fan 208, the second electrostatic precipitator 201, the first desulfurization device 202, the annular cooler 203, the bag-type dust collector 204 and the denitrification device 205 are connected in sequence,

[0064] In this embodiment, in the second flue gas treatment system, the first fan 301 utilizes a high-efficiency centrifugal fan, whose impeller has undergone special wear- and corrosion-resistant treatment and is connected to the low-sulfur air duct 3 to ensure stable extraction of low-sulfur flue gas. The first electrostatic precipitator 302 utilizes an advanced plate-type electrostatic precipitator with optimized plate spacing, effectively adsorbing dust particles from the low-sulfur flue gas. The dehydrator 303 utilizes a cyclone-type dehydrator 303, internally equipped with spiral guide vanes and a separation structure to effectively separate water from the flue gas under centrifugal force. In the first flue gas treatment system, the second fan 208 utilizes a high-power axial flow fan to provide power for the high-sulfur flue gas. The second electrostatic precipitator 201 utilizes tubular electrostatic precipitator technology, with the tube diameter and length designed based on the flue gas flow rate and dust characteristics to enhance dust removal effectiveness. The first desulfurization unit 202 utilizes the proven limestone-gypsum wet desulfurization process. The desulfurization tower is filled with a highly active desulfurizer and equipped with a spray and stirring system to ensure adequate desulfurization. The ring cooler 203 utilizes a multi-stage structure, with precise cooling capacity and temperature control in each section. Its low-temperature section 2031 and high-temperature section 2032 are tightly connected to upstream and downstream equipment via independent, high-temperature-resistant piping. During the cooling process, catalytically active components such as calcium ferrite on the sintered ore surface are utilized to create favorable conditions for the synergistic removal of carbon monoxide and nitrogen oxides. The bag filter 204 utilizes high-quality, high-temperature, and corrosion-resistant filter bags 7. The filter area is designed based on the flue gas processing volume to ensure excellent filtration results. The denitrification unit 205 utilizes highly efficient selective catalytic reduction (SCR) technology, equipped with a high-performance vanadium-titanium catalyst, and precise temperature and flow control to ensure denitrification efficiency.

[0065] The advantage lies in the separate treatment systems designed for low-sulfur and high-sulfur flue gases, each highly adapted to their respective flue gas characteristics. The secondary flue gas treatment system effectively purifies low-sulfur flue gas, ensuring its subsequent utilization or compliance with emission standards. The primary flue gas treatment system comprehensively treats high-sulfur flue gas, with each link working closely together. In particular, the annular cooler 203 utilizes the catalytic properties of sintered ore to promote the coordinated removal of pollutants, significantly improving the overall system's removal efficiency for multiple pollutants. Furthermore, the optimized selection and design of each device enhances system reliability and stability, reducing equipment failure rates and maintenance costs.

[0066] Furthermore, it also includes an emission device 4. The first flue gas treatment system leads to the emission device 4. It also includes a first regulating valve 304, which is located between the first electrostatic precipitator 302 and the dehydrator 303. The first electrostatic precipitator 302 leads to the dehydrator 303 through the first regulating valve 304. The first regulating valve 304 also leads to the emission device 4. The first regulating valve 304 is used to adjust the flow rate of the low-sulfur flue gas entering the dehydrator 303; a second desulfurization device 305. The second desulfurization device 305 is arranged on the low-sulfur air duct 3, between the first regulating valve 304 and the emission device 4, and is used to desulfurize the excess low-sulfur flue gas discharged from the first regulating valve 304.

[0067] In this embodiment, the exhaust device 4 utilizes a chimney of suitable height and sturdy structure, coated internally with multiple layers of high-efficiency anti-corrosion coating to ensure long-term resistance to flue gas corrosion. Advanced flue gas flow sensors and highly sensitive pollutant concentration analyzers are precisely installed at the bottom, enabling real-time and accurate monitoring of key flue gas indicators. The first regulating valve 304 utilizes an electric regulating valve with high-precision control capabilities. Its electric actuator responds quickly and operates stably, seamlessly connecting to the monitoring instruments at the bottom via a reliable automated control system. During system operation, when low-sulfur flue gas from the first electrostatic precipitator 302 enters this stage, the flow sensor and concentration analyzer continuously monitor the flue gas status and transmit the data to the control system in real time. If the flue gas flow rate or composition flue gas ... The second desulfurization unit 305 utilizes a highly efficient spray-drying desulfurization process. A specially designed, high-speed rotating atomizing nozzle is installed within the desulfurization tower, evenly dispersing the desulfurizer into tiny droplets that thoroughly mix and contact the flue gas, ensuring efficient desulfurization. Its processing capacity has been rigorously designed to adequately handle potential excess low-sulfur flue gas. Throughout the process, the natural catalytic activity of the sintered ore is fully utilized to further enhance the synergistic removal of carbon monoxide and nitrogen oxides, optimizing the overall purification efficiency of the system.

[0068] The advantage is that the first regulating valve 304 plays a key hub role in the entire flue gas treatment process. By precisely controlling the flow of low-sulfur flue gas entering the dehydrator 303, the dehydrator 303 is ensured to always operate under optimal conditions, effectively avoiding equipment blockage, corrosion, or poor treatment results caused by excessive flow or abnormal composition. This significantly improves the operating efficiency and service life of the dehydrator 303 and reduces equipment maintenance costs. At the same time, excess low-sulfur flue gas is properly directed to the second desulfurization device 305 for secondary treatment, ensuring that all low-sulfur flue gas is properly treated, greatly reducing untreated or incompletely treated flue gas emissions, reducing environmental pollution risks, and improving the environmental performance and reliability of the system.

[0069] Furthermore, the ring cooler 203 has a low-temperature part 2031 and a high-temperature part 2032. The low-temperature part 2031 is arranged between the first desulfurization device 202 and the bag dust collector 204, and the high-temperature part 2032 is arranged in parallel with the low-temperature part 2031. It also includes a second regulating valve 206. The second regulating valve 206 is connected in series with the high-temperature part 2032 and is located between the first desulfurization device 202 and the high-temperature part 2032; the heat exchanger 207 is connected in series with the high-temperature part 2032 and is located between the high-temperature part 2032 and the bag dust collector 204.

[0070] In this embodiment, the ring cooler 203 employs a segmented design, divided into a low-temperature section 2031 and a high-temperature section 2032. The second regulating valve 206 utilizes a highly sensitive pneumatic regulating valve. Through real-time monitoring and feedback from precise pressure and temperature sensors, it precisely regulates the flue gas flow entering the high-temperature section 2032. The heat exchanger 207 utilizes a high-efficiency plate structure with well-designed flow guide grooves between the plates to ensure sufficient contact and heat exchange between the flue gas and the cooling medium during flow.

[0071] When the system is started, high-sulfur flue gas, containing a large amount of impurities and heat energy, is extracted by the second fan 208 and transported to the second electrostatic precipitator 201. The dedusted flue gas enters the first desulfurization device 202 for wet desulfurization, which significantly reduces the sulfur content of the flue gas. Simultaneously, this process dissipates heat, significantly lowering the flue gas temperature.

[0072] The cooled, high-sulfur flue gas then enters the high-temperature section 2032 of the ring cooler 203. While the flue gas flushes the sintered ore in this section, cooling it, the flue gas temperature rises again due to heat exchange. This elevated temperature eliminates the need for further heating during denitration, creating optimal temperature conditions for the denitration reaction. This allows the denitration catalyst to fully activate, reacting with nitrogen oxides in the flue gas through a series of complex and efficient chemical reactions, converting harmful nitrogen oxides into harmless nitrogen and water, completing the flue gas denitration process.

[0073] The advantage is that high-sulfur flue gas flows into the desulfurization system. After wet desulfurization, the flue gas temperature is relatively low, so it needs to be preheated in advance. We pass the high-sulfur flue gas (after desulfurization) into the high-temperature section of the ring cooler, and use the temperature of the sintered ore to raise the flue gas temperature again, thus achieving effective preheating. During the preheating process, the CO in the flue gas reacts with the calcium ferrite in the sintered ore to catalyze the reaction, and NO X The CO2 can be reduced in synergy with that of CO2, thus preparing for the subsequent SCR denitrification process. Although this process reduces the waste heat power generation of the ring cooler, it reduces the SCR heating energy consumption and the required NO removal. X Through the above optimization design, the present invention not only improves the energy efficiency of the sintering process, but also effectively reduces environmental pollution, with significant economic and ecological benefits.

[0074] Furthermore, the bag dust collector 204 includes a shell 5, which has an air inlet 501 and an air outlet 502. The air inlet 501 is connected to the heat exchanger 207, and the air outlet 502 is connected to the denitrification device 205. The shell 5 has a maintenance port 503; the mounting plate 6 is rotatably arranged in the shell 5, and the mounting plate 6 divides the interior of the shell 5 into a first cavity 504 and a second cavity 505. The air inlet 501 is connected to the first cavity 504, and the air outlet 502 and the maintenance port 503 are both connected to the second cavity 505. The mounting plate 6 has a plurality of mounting holes 601. After the mounting plate 6 rotates, the plurality of mounting holes 601 move circumferentially in sequence to below the maintenance port 503; there are a plurality of filter bags 7, and the filter bags 7 are arranged in the mounting holes 601. The gas to be treated enters the second cavity 505 from the first cavity 504 through the filter bags 7.

[0075] In this embodiment, the shell 5 of the bag filter 204 is made of carbon steel with moderate thickness, and has reinforcing ribs welded inside to enhance the overall strength. The positions and sizes of the air inlet 501 and the air outlet 502 are precisely designed to ensure that the smoke can flow in and out smoothly and is evenly distributed. The maintenance port 503 is set in a position that is convenient for operation, and the size is sufficient for personnel to carry out maintenance. The mounting plate 6 is made of a lightweight and sturdy aluminum alloy material, and is installed in the shell 5 through a central axis and high-precision bearings to ensure that it can rotate flexibly. There are multiple mounting holes 601 evenly distributed on the mounting plate 6, and their diameters are closely matched with the size of the filter bag 7 to ensure that the filter bag 7 is firmly installed and well sealed. The filter bag 7 is made of high-quality polytetrafluoroethylene fiber material, which has excellent high temperature resistance, corrosion resistance and filtering performance. It is customized according to the specifications of the mounting hole 601 and is tightly installed in the mounting hole 601.

[0076] An advanced dust concentration monitoring device is installed within the air outlet 502 of the bag filter 204. This device, utilizing the principle of laser scattering, accurately and in real time measures the dust concentration in the exhaust gas. Furthermore, a pressure sensor is installed within the first chamber 504 to monitor pressure changes as the flue gas passes through the filter bags 7. Damage to the filter bags 7 can cause a sharp increase in dust concentration in the flue gas, or abnormal pressure fluctuations. If the monitoring data exceeds the preset normal range, the control system will immediately issue an alarm.

[0077] A miniature radio frequency identification (RFID) tag is mounted on the top of each filter bag 7, each with a unique code. A set of RFID readers is located within the first cavity 504. While the device is operating, these readers continuously scan each tag. If an abnormal dust concentration or pressure is detected in a specific area, the damaged filter bag 7 can be quickly located by comparing the corresponding RFID tag code.

[0078] When damage is detected on individual filter bags 7 through the aforementioned method, the drive mechanism activates, driving the mounting plate 6 to rotate. The mounting plate 6 rotates smoothly around its central axis. As the mounting plate 6 rotates, the mounting hole 601 containing the damaged bag gradually moves below the maintenance port 503, precisely positioning it for quick replacement by maintenance personnel.

[0079] The advantage lies in real-time monitoring of dust concentration and pressure changes, combined with radio frequency identification technology to accurately locate damaged bags. Damage to filter bags 7 can be promptly detected and addressed, preventing the release of large amounts of dust due to filtration failure. The ability to rotate the mounting plate 6 to move the bag below the maintenance port 503 after a damaged bag is detected significantly streamlines the maintenance process. Compared to the traditional method of removing the entire outer casing to locate and replace damaged bags, this design saves significant maintenance time, improves equipment availability, and reduces production interruptions caused by maintenance.

[0080] Furthermore, the bag dust collector 204 also includes a knocking rod 801, one end of which is swingably set on the inner wall of the first cavity 504; the two ends of the reset elastic member 802 act on the knocking rod 801 and the inner wall of the first cavity 504 respectively, for providing a force for the other end of the knocking rod 801 to approach the axis of the mounting plate 6; after the mounting plate 6 rotates, the other end of the knocking rod 801 knocks several filter bags 7 in turn.

[0081] In this embodiment, one end of the knocking rod 801 is swing-connected with the inner wall of the first cavity 504 through a high-strength nitriding shaft. The reset elastic member 802 is a spiral spring with stable performance. The spring is tightly fixed at both ends of the knocking rod 801 and the specific position of the inner wall of the first cavity 504. During the operation of the equipment, when the mounting plate 6 rotates, the mounting hole 601 drives the filter cloth bag 7 to move in an orderly manner. At this time, the knocking rod 801 will abut against the filter cloth bags 7 in turn, and under the elastic force of the reset elastic member 802, the knocking rod 801 can accurately knock each filter cloth bag 7 in turn.

[0082] The combination of the knocking rod 801 and the reset elastic member 802 provides the filter cloth bag 7 with an efficient automatic dust cleaning function. When some filter cloth bags 7 are damaged, the remaining filter cloth bags 7 can be cleaned at the same time of maintenance, effectively preventing the excessive accumulation of dust on the surface of the cloth bag, avoiding the problems of rapid increase of filtration resistance and significant decrease of filtration efficiency caused by dust accumulation. This not only maintains the stable operation of the bag-type dust collector 204 and ensures good filtration effect, but also significantly reduces the workload and cost of manual dust cleaning.

[0083] Further, the lengths of the filter cloth bags 7 are different, the lengths of the filter cloth bags 7 decrease along the axis of the mounting plate 6 towards the periphery; the number of the knocking rods 801 is several, and the knocking rods 801 are arranged longitudinally, and the knocking rods 801 from top to bottom knock the filter cloth bags 7 from short to long in turn.

[0084] In this embodiment, the lengths of the filter cloth bags 7 are designed to decrease along the axis of the mounting plate 6 towards the periphery, and the shortest filter cloth bag 7 is located at the outermost side. The lengths are optimized and determined according to the actual flue gas flow distribution and dust deposition law, and the longest filter cloth bag 7 is located at the center position. The number and longitudinal arrangement of the knocking rods 801 are matched with the filter cloth bags 7, and the lengths of the knocking rods 801 are customized according to the positions of the corresponding filter cloth bags 7. During the dust cleaning process, with the uniform rotation of the mounting plate 6, the filter cloth bags 7 with different lengths pass through the corresponding knocking rods 801 in turn. The knocking rods 801 can apply knocking force to the filter cloth bags 7 with different lengths, so that the dust attached to the surface of the filter cloth bags 7 can be fully removed.

[0085] The differentiated design of the lengths of the filter cloth bags 7 and the layout of the knocking rods 801 matched therewith greatly optimize the dust cleaning effect. This avoids the problems of incomplete dust cleaning or excessive dust cleaning of some cloth bags that may be caused by the traditional unified dust cleaning method. This improves the overall performance and stability of the bag-type dust collector 204, effectively reduces the energy consumption of the equipment operation, and further reduces the equipment maintenance cost.

[0086] Furthermore, the bag dust collector 204 also includes a cover plate 9, which is rotatably set on the shell 5, and is used to close the maintenance port 503 after rotation; the rotating shaft 10 is rotatably set in the second cavity 505, one end of the rotating shaft 10 is connected to the mounting plate 6, and the other end extends out of the second cavity 505; the driving member 11 is set on the shell 5, and the output end of the driving member 11 is connected to the rotating shaft 10, which is used to drive the mounting plate 6 to rotate.

[0087] In this embodiment, the cover plate 9 is rotatably connected to the top of the housing 5. Rotation of the cover plate 9 opens or closes the maintenance access 503. The drive element 11 utilizes a reduction motor with appropriate power and precisely adjustable speed. It is mounted at a specific location on the housing 5 and tightly connected to the rotating shaft 10 via a high-strength coupling. When the equipment requires maintenance, the operator activates the drive element 11 through the control system. The output shaft of the drive element 11 slowly rotates the rotating shaft 10, causing the mounting plate 6 to rotate at a predetermined speed and direction. The mounting plate 6 is then moved to position the filter bag 7 requiring maintenance below the maintenance access 503.

[0088] Furthermore, the cover plate 9 has a through hole 901, and the rotating shaft 10 passes through the through hole 901; the inner wall of the through hole 901 has a plurality of snap-fit ​​grooves 902, and the plurality of snap-fit ​​grooves 902 are evenly distributed around the circumference of the axis of the rotating shaft 10, and the connection between the snap-fit ​​grooves 902 and the inner wall of the through hole 901 has a transition surface 903, and the transition surface 903 is an arc surface; the rotating shaft 10 has a slide groove 1001; the top of the housing 5 has a first limiting column 507 and a second limiting column 506, and the cover plate 9 and the first limiting column 507 are fixed to each other. 07 After abutting, the cover plate 9 closes the maintenance port 503. After the cover plate 9 abuts against the second limiting column 506, the cover plate 9 opens the maintenance port 503. The bag dust collector 204 also includes a sliding drive rod 12, which is slidably set in the slide groove 1001; the second elastic member is set in the slide groove 1001, and the two ends of the second elastic member act on the sliding drive rod 12 and the slide groove 1001 respectively, for providing a force for the sliding drive rod 12 to approach the clamping groove 902.

[0089] In this embodiment, the cover plate 9 rotates horizontally at the top of the shell 5, and opens or closes the maintenance port 503 after rotation. One end of the rotating shaft 10 is connected to the output shaft of the driving member 11 through a coupling, and the other end precisely passes through the through hole 901 of the cover plate 9 and keeps rotating in the second cavity 505. On the inner wall of the through hole 901 of the cover plate 9, a plurality of snap-in grooves 902 are evenly distributed, and the arc surface between these snap-in grooves 902 and the inner wall of the through hole 901 serves as a transition surface 903. A corresponding slide groove 1001 is provided on the rotating shaft 10 to match the sliding drive rod 12, and the sliding drive rod 12 is precisely placed in the slide groove 1001. The second elastic member adopts a disc spring with stable performance and is installed in the slide groove 1001, which continuously provides a stable thrust to the sliding drive rod 12 in the direction of the snap-in groove 902, ensuring that the sliding drive rod 12 is tightly fitted with the snap-in groove 902.

[0090] When the system detects that a filter bag 7 requires maintenance, the drive member 11 starts operating, driving the rotating shaft 10 to begin rotating. Because the sliding drive rod 12 is tightly abutted against the engaging groove 902 by the action of the second elastic member, the rotation of the rotating shaft 10 can effectively drive the cover plate 9 to rotate synchronously. As the rotation continues, when a side edge of the cover plate 9 abuts the second limiting post 506, the cover plate 9 stops rotating. While the rotating shaft 10 continues to rotate, one end of the sliding drive rod 12 follows the guidance of the transition surface 903, overcomes the elastic force of the second elastic member, and smoothly slides out of the current engaging groove 902. Under the push of the second elastic member, it quickly enters the next engaging groove 902. Because the position of the cover plate 9 has been restricted by the second limiting post 506 and cannot continue to rotate, the rotating shaft 10 will idle relative to the cover plate 9 in the through hole 901. During this period, the mounting plate 6 continues to rotate driven by the rotating shaft 10, accurately moving the mounting hole 601 with the damaged filter bag 7 to directly below the maintenance opening 503, providing convenient operating space for maintenance personnel. After the maintenance work is completed, the driving member 11 rotates in the opposite direction, and the rotating shaft 10 drives the cover plate 9 to rotate horizontally in the opposite direction. When the cover plate 9 abuts the first limit column 507, it indicates that the cover plate 9 has completely closed the maintenance opening 503. At this time, the sliding driving rod 12 will once again accurately snap into the corresponding snap-in groove 902, ensuring that the cover plate 9 is fixed and the equipment returns to normal operation.

[0091] The low-carbon sintering flue gas purification process with coordinated multi-pollutant control uses a low-carbon sintering flue gas circulation system with coordinated multi-pollutant control.

[0092] By setting up high sulfur and low sulfur air ducts 3 and using a high-precision SO2 concentration sensor based on electrochemical detection technology to classify the flue gas generated in the sintering chamber 1. When the SO2 concentration in the flue gas is lower than 50mg / m 3 When the concentration of sulfur in the flue gas is 0.17777%, the low-sulfur flue gas is transported to the injection port through the low-sulfur air duct 3; while the high-sulfur flue gas with a concentration higher than this enters the subsequent treatment process. The low-sulfur flue gas is drawn into the second flue gas treatment system by the first centrifugal fan 301 with a specially treated impeller. It first enters the plate-type first electrostatic precipitator 302 with an optimized plate design for dust removal, and then enters the cyclone dehydrator 303 with a special structure. During this process, the intelligent electric first regulating valve 304 accurately controls the flue gas flow entering the dehydrator 303 based on the data fed back by the monitor in the discharge device 4 that uses ultrasonic flow measurement and spectral analysis of concentration. The excess is transported to the spray-drying second desulfurization device 305 equipped with a high-efficiency nozzle and good airflow distribution for further desulfurization.

[0093] Deep treatment and synergistic reaction of high-sulfur flue gas. The high-sulfur flue gas enters the first flue gas treatment system under the suction action of the high-power and pressure-adjustable axial flow second fan 208. It first passes through the tubular second electrostatic precipitator 201 with optimized pipe diameter and length to remove dust, and then enters the first desulfurization device 202 that uses a limestone-gypsum wet method, has a highly active desulfurizer, and an advanced spray stirring system for desulfurization. The desulfurized flue gas enters the ring cooler 203 with a multi-stage design and excellent cooling pipe performance, and uses the catalytic components on the surface of the sintered ore to remove carbon monoxide and nitrogen oxides. During this process, the pneumatic second control valve 206, equipped with high-precision pressure and temperature sensors and with a sensitive response, accurately adjusts the amount of flue gas entering the high-temperature section 2032 of the ring cooler 203 according to the temperature and pressure changes in the system. At the same time, the plate-type heat exchanger 207 with high-quality heat exchange plates and guide grooves recovers the heat of the high-temperature flue gas to preheat other media or process links, and cools the flue gas before transporting it to the bag filter 204, and then to the denitrification device 205, and finally discharged from the emission device 4.

[0094] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A low-carbon sintering flue gas circulation system for coordinated multi-pollutant treatment, used for graded treatment of sintering flue gas, characterized by: include: A sintering chamber (1), the sintering chamber (1) having a sintering cavity (101) and a flue gas injection port (102); A high-sulfur air duct (2) and a low-sulfur air duct (3), the sintering chamber (101) leads to the high-sulfur air duct (2) and the low-sulfur air duct (3), and the low-sulfur air duct (3) leads to the flue gas injection port (102); a first flue gas treatment system, wherein the high-sulfur air duct (2) leads to the first flue gas treatment system; the first flue gas treatment system comprises a second fan (208), a second electrostatic precipitator (201), a first desulfurization device (202), a ring cooler (203), a bag filter (204), and a denitrification device (205) connected in sequence; The ring cooler (203) comprises a low-temperature portion (2031) and a high-temperature portion (2032), wherein the low-temperature portion (2031) is arranged between the first desulfurization device (202) and the bag filter (204), and the high-temperature portion (2032) is arranged in parallel with the low-temperature portion (2031), and further comprises: a second regulating valve (206), the second regulating valve (206) being connected in series with the high-temperature portion (2032) and being located between the first desulfurization device (202) and the high-temperature portion (2032); a heat exchanger (207), the heat exchanger (207) being connected in series with the high-temperature portion (2032) and being located between the high-temperature portion (2032) and the bag filter (204); Wherein, the bag dust collector (204) comprises: A housing (5), the housing (5) having an air inlet (501) and an air outlet (502), the air inlet (501) being connected to the heat exchanger (207), the air outlet (502) being connected to the denitration device (205), and the housing (5) having a maintenance port (503); a mounting plate (6), the mounting plate (6) being rotatably disposed in the shell (5), the mounting plate (6) dividing the interior of the shell (5) into a first cavity (504) and a second cavity (505), the air inlet (501) being connected to the first cavity (504), the air outlet (502) and the maintenance port (503) both being connected to the second cavity (505), the mounting plate (6) having a plurality of mounting holes (601), and after the mounting plate (6) is rotated, the plurality of mounting holes (601) are sequentially moved circumferentially to below the maintenance port (503); Filter bags (7), the number of the filter bags (7) being several, the filter bags (7) being arranged in the mounting hole (601), and the gas to be treated passing from the first cavity (504) through the filter bags (7) into the second cavity (505); a knocking rod (801), one end of which is swingably disposed on the inner wall of the first cavity (504); a reset elastic member (802), wherein two ends of the reset elastic member (802) act on the knocking rod (801) and the inner wall of the first cavity (504) respectively, and are used to provide a force for the other end of the knocking rod (801) to approach the axis of the mounting plate (6); After the mounting plate (6) rotates, the other end of the knocking rod (801) knocks on a plurality of the filter bags (7) in sequence; The lengths of the plurality of filter bags (7) are different, and the lengths of the plurality of filter bags (7) decrease gradually along the axis of the mounting plate (6); There are a number of knocking rods (801), and the knocking rods (801) are arranged longitudinally. The knocking rods (801) from top to bottom knock the filter bags (7) from short to long in sequence.

2. The low-carbon sintering flue gas circulation system for coordinated multi-pollutant treatment according to claim 1 is characterized in that: Also includes: A second flue gas treatment system, wherein the low-sulfur air duct (3) is connected to the flue gas blowing port (102) via the second flue gas treatment system, and the second flue gas treatment system comprises a first fan (301), a first electrostatic precipitator (302) and a dehydrator (303), and the first fan (301), the first electrostatic precipitator (302) and the dehydrator (303) are connected in sequence.

3. The low-carbon sintering flue gas circulation system for coordinated multi-pollutant treatment according to claim 2 is characterized in that: It also includes an exhaust device (4), the first flue gas treatment system leads to the exhaust device (4), and further includes: a first regulating valve (304) located between the first electrostatic precipitator (302) and the dehydrator (303); the first electrostatic precipitator (302) leads to the dehydrator (303) via the first regulating valve (304); the first regulating valve (304) also leads to the discharge device (4); the first regulating valve (304) is used to regulate the flow of low-sulfur flue gas entering the dehydrator (303); A second desulfurization device (305) is provided on the low-sulfur air duct (3), located between the first regulating valve (304) and the discharge device (4), and is used for desulfurizing the excess low-sulfur flue gas discharged from the first regulating valve (304).

4. The low-carbon sintering flue gas circulation system for coordinated multi-pollutant treatment according to claim 1 is characterized in that: The bag dust collector (204) further comprises: a cover plate (9), the cover plate (9) being rotatably disposed on the housing (5), and the cover plate (9) being used to close the maintenance opening (503) after being rotated; a rotating shaft (10), the rotating shaft (10) being rotatably disposed in the second cavity (505), one end of the rotating shaft (10) being connected to the mounting plate (6), and the other end extending out of the second cavity (505); A driving member (11), the driving member (11) is arranged on the housing (5), and an output end of the driving member (11) is connected to the rotating shaft (10) and is used to drive the mounting plate (6) to rotate.

5. The low-carbon sintering flue gas circulation system for coordinated multi-pollutant treatment according to claim 4 is characterized in that: The cover plate (9) has a through hole (901), and the rotating shaft (10) passes through the through hole (901); The inner wall of the through hole (901) has a plurality of snap-fit ​​grooves (902), and the plurality of snap-fit ​​grooves (902) are evenly distributed around the axis of the rotating shaft (10). A transition surface (903) is provided at the connection between the snap-fit ​​grooves (902) and the inner wall of the through hole (901), and the transition surface (903) is an arc surface. The rotating shaft (10) has a sliding groove (1001); The top of the shell (5) has a first limiting column (507) and a second limiting column (506); after the cover plate (9) abuts against the first limiting column (507), the cover plate (9) closes the maintenance opening (503); after the cover plate (9) abuts against the second limiting column (506), the cover plate (9) opens the maintenance opening (503); the bag dust collector (204) further comprises: A sliding driving rod (12), wherein the sliding driving rod (12) is slidably arranged in the sliding groove (1001); A second elastic member, wherein the second elastic member is arranged in the slide groove (1001), and two ends of the second elastic member act on the sliding driving rod (12) and the slide groove (1001) respectively, and are used to provide a force for the sliding driving rod (12) to approach the clamping groove (902).

6. A low-carbon sintering flue gas purification process for coordinated multi-pollutant treatment, using the low-carbon sintering flue gas circulation system for coordinated multi-pollutant treatment according to any one of claims 1 to 5, characterized in that: S1. Low-sulfur flue gas treatment: The low-sulfur flue gas is drawn into the second flue gas treatment system by the first fan (301), and is sequentially passed through the first electrostatic precipitator (302) for dust removal and the dehydrator (303) for dehydration. During this process, the first regulating valve (304) controls the flue gas flow entering the dehydrator (303) based on monitoring data, and the excess is sent to the second desulfurization device (305) for desulfurization, and then discharged from the discharge device (4). S2. High-sulfur flue gas treatment: The high-sulfur flue gas is drawn into the first flue gas treatment system through the second fan (208); the flue gas is first dedusted by the second electrostatic precipitator (201), and then enters the first desulfurization device (202) for desulfurization; the flue gas after desulfurization enters the multi-stage ring cooler (203), during which the second regulating valve (206) adjusts the amount of flue gas entering the high-temperature part (2032) of the ring cooler (203); the flue gas is finally filtered by the bag filter (204) and denitrated by the denitrification device (205), and then discharged from the emission device (4).

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