Device for removing CO by coupling sintering flue gas CO removal system with flue gas circulation technology

Abstract

The utility model discloses a device for removing CO by coupling a sintering flue gas CO removal system with a flue gas circulation technology. The device comprises a plurality of front-section main flue bellow branch pipe flues, a plurality of middle-section flue bellow branch pipe flues and a plurality of tail-section flue bellow branch pipe flues, a plurality of front-section main flue bellows branch pipe flues are sequentially connected with a front-section main flue, a main dust remover, a desulfurizing tower, a cold side of a GGH heat exchanger, a heat exchanger, a CO removal denitration tower, a hot side of the GGH heat exchanger, a main induced draft fan and a chimney; the plurality of middle-section flue bellows branch pipe flues are sequentially connected with a middle-section low-temperature high-CO flue, a first dust remover, a first fan, an annular cooler and a second dust remover; the multiple tail section flue bellows branch pipe flue tail sections are sequentially connected with a high-temperature low-CO flue, a second draught fan, a second dust remover, a heat exchanger, a third draught fan, a flue gas dehumidifier and a flue gas circulation sealing cover. By coupling sintering flue gas circulation, sensible heat utilization of the circular cooler and a catalytic oxidation method, CO is efficiently removed, coal gas in a plant is saved, and the treatment cost of the sintering flue gas is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of energy conservation and environmental protection technology, and relates to the removal of carbon monoxide, specifically to a device for removing CO by coupling a sintering flue gas CO removal system with flue gas recirculation technology. Background Technology

[0002] In recent years, driven by ultra-low emission and other environmental protection policies, air pollution prevention and control efforts have been continuously deepened across the country, and conventional pollutants such as SO2 and nitrogen oxides have been effectively controlled. In the next stage, with the continuous strengthening of environmental governance, some unconventional pollutants such as CO may become the focus of control. Currently, the steel industry is one of the main sources of CO emissions, with sintering machine heads accounting for 22% of total CO emissions from steel plants, reaching concentrations of up to 16,000 mg / Nm³. 3 Much greater than SO2 and NO x This refers to the total emissions of pollutants such as carbon dioxide (CO). Furthermore, CO is toxic to humans, binding with hemoglobin to form carboxyhemoglobin, causing hemoglobin to lose its oxygen-carrying capacity, leading to tissue hypoxia, and in severe cases, death. Therefore, CO emission reduction in sintering flue gas is imperative in the future.

[0003] Currently, pollution control for CO emission reduction in sintering flue gas, both domestically and internationally, mainly relies on process reduction and end-of-pipe treatment. Process reduction technologies focus on improving fossil fuel combustion conditions to reduce CO production; end-of-pipe treatment technologies separate CO or oxidize it into CO2 through physical / chemical methods. Sintering process control technologies such as sintering machine flue gas recirculation, surface media spraying, and oxygen-enriched combustion are effective measures for CO emission reduction. After treatment, CO emissions from sintering flue gas can be controlled within a certain concentration, but overall, the emission reduction effect is limited, and it may be difficult to meet actual needs in the future as environmental standards gradually become more stringent. End-of-pipe treatment is the ultimate guarantee for CO emission reduction. The main technologies include catalytic oxidation, solvent absorption, and adsorbent adsorption. Among these, catalytic oxidation can be used in conjunction with current steel flue gas desulfurization and denitrification technologies, demonstrating strong feasibility in industrial practice.

[0004] In the future, a greener, more economical and effective way to reduce CO emissions from sintering flue gas is to develop a technology system that combines source and process emission reduction with end-of-pipe treatment. For example, by combining process emission reduction technologies such as sintering machine flue gas recirculation and oxygen-enriched combustion with end-of-pipe treatment technologies such as catalytic oxidation, the effect of deep and efficient removal of CO from sintering flue gas can be achieved.

[0005] Currently, commercially available and mature SCR catalysts are mainly designed for medium-to-high temperature (>280℃) denitrification conditions. However, the flue gas temperature generated in actual sintering production is relatively low (generally around 120℃), and the temperature is even lower when the sintering flue gas enters the SCR reactor after dust removal and desulfurization processes. In this case, an external heating device is needed to heat the flue gas to increase its temperature to meet the SCR denitrification temperature requirements. For example, steel plants often use blast furnace gas to heat the flue gas before sending it into the SCR reactor.

[0006] Since CO catalytic oxidation is an exothermic reaction, the complete oxidation of 1 mol of CO into CO2 releases 283 kJ of heat. Existing technologies often incorporate a CO catalytic oxidation process between traditional desulfurization and denitrification steps. This process oxidizes CO in flue gas into CO2 while simultaneously using the released heat to heat the flue gas, reducing or even completely replacing the large amount of coal gas consumed by flue gas heating devices.

[0007] Chinese patent CN212236736U discloses a combined removal device for carbon monoxide and nitrogen oxides in sintering flue gas. The device is equipped with a heating system, a carbon monoxide catalytic reaction system, an ammonia injection system and a low-temperature SCR denitrification reaction system in sequence according to the flue gas flow direction. It uses the heat released during the CO reaction to generate CO2 to raise the temperature of the sintering flue gas by about 15 to 75°C.

[0008] Chinese patent CN111482071A discloses a synergistic purification system and process for multiple pollutants in sintering flue gas and waste heat utilization. It adopts a technical solution of high-efficiency bag filter + high-efficiency dust removal wet desulfurization device + catalytic denitrification, CO removal and waste heat utilization integrated device. It uses the heat released by CO catalytic combustion to heat the flue gas, which can recover energy and reduce coal gas consumption.

[0009] However, the CO concentration in the sintering flue gas flues significantly and frequently. When the CO concentration is low, the heat released by the catalytic oxidation of CO raises the flue gas temperature, but it is still insufficient to meet the temperature requirements for denitrification. Therefore, to ensure the long-term stable operation of the denitrification system while minimizing gas consumption, a supplementary heating device and intelligent regulation and control measures need to be added during the design process. This presents problems such as cumbersome control, difficulty in implementation, high operational difficulty, and high cost.

[0010] Meanwhile, in order to save energy, reduce emissions, and decrease pollutant emissions, existing steel plants have generally begun to adopt sintering flue gas recirculation technology. However, current sintering flue gas CO removal systems are not fully integrated with flue gas recirculation technology in their design. In addition, the sintered hot ore produced by the sintering machine is at a high temperature and contains a large amount of sensible heat, but most current sintering flue gas CO removal systems are not effectively integrated with the utilization of this sensible heat from the annular cooler. Summary of the Invention

[0011] To address the shortcomings of existing technologies, this utility model proposes a device for CO removal from sintering flue gas coupled with flue gas recirculation technology, in order to solve the technical problem that the sensible heat of the annular cooler in the existing sintering flue gas CO removal and flue gas recirculation technology cannot be effectively combined.

[0012] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0013] A device for removing CO from sintering flue gas using a coupled flue gas recirculation technology includes a sintering machine. Multiple air box branch flues are arranged below the sintering machine. The multiple air box branch flues are divided into multiple front main flue air box branch flues, multiple middle flue air box branch flues, and multiple tail flue air box branch flues.

[0014] The multiple front-end main flue gas ducts and branch flue gas ducts are respectively connected to the front-end main flue gas duct, the front-end main flue gas duct is connected to the main dust collector, the main dust collector is connected to the desulfurization tower, the desulfurization tower is connected to the cold-side feed port of the GGH heat exchanger, the cold-side discharge port of the GGH heat exchanger is connected to the tube-side input end of the heat exchanger, the tube-side output end of the heat exchanger is connected to the CO and denitrification tower, the CO and denitrification tower is connected to the hot-side feed port of the GGH heat exchanger, the hot-side discharge port of the GGH heat exchanger is connected to the main induced draft fan, and the main induced draft fan is connected to the chimney.

[0015] The multiple intermediate flue gas ducts and branch pipes are respectively connected to the intermediate low-temperature high-CO flue gas duct, the intermediate low-temperature high-CO flue gas duct is connected to the first dust collector, the first dust collector is connected to the first fan, the first fan is connected to the annular cooler, and the annular cooler is connected to the second dust collector.

[0016] The multiple tail section flue box branch pipes are respectively connected to the tail section high temperature and low CO flue. The tail section high temperature and low CO flue is connected to the second fan. The second fan is also connected to the second dust collector. The second dust collector is connected to the shell side input end of the heat exchanger. The shell side output end of the heat exchanger is connected to the third fan. The third fan is connected to the flue gas dehumidifier. The flue gas dehumidifier is connected to the flue gas circulation sealing cover. The flue gas circulation sealing cover is located above the sintering machine.

[0017] This utility model also has the following technical features:

[0018] The main flue and the main dust collector, the main dust collector and the desulfurization tower, the desulfurization tower and the cold side inlet of the GGH heat exchanger, and the cold side outlet of the GGH heat exchanger and the tube side inlet of the heat exchanger are all connected sequentially through the main flue pipe.

[0019] The tube-side output end of the heat exchanger is sequentially connected to the CO removal and denitrification tower, the CO removal and denitrification tower is connected to the hot-side feed inlet of the GGH heat exchanger, the hot-side discharge outlet of the GGH heat exchanger is connected to the main induced draft fan, and the main induced draft fan is connected to the chimney via the front-end heat exchange main flue pipe.

[0020] The intermediate low-temperature high-CO flue is sequentially connected to the first dust collector, the first dust collector to the first fan, the first fan to the annular cooler, and the annular cooler to the second dust collector via intermediate flue pipes.

[0021] The tail section high-temperature low-CO flue is connected to the second fan and the second dust collector in sequence through the tail section flue pipe.

[0022] The shell-side input end of the second dust collector and heat exchanger, the shell-side output end of the heat exchanger and the third fan, the third fan and the flue gas dehumidifier, and the flue gas dehumidifier and the flue gas circulation sealing cover are all connected sequentially through a recovery flue pipe.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects:

[0024] (I) The CO removal device for sintering flue gas using a coupled flue gas recirculation technology proposed in this utility model first introduces the flue gas from the mid-section wind box branch flue, which has the characteristics of low-temperature, high-CO flue gas, into the annular cooler. Utilizing the catalytic effect of natural iron oxides in the sintering hot ore, CO is oxidized to CO2, thereby significantly reducing the CO concentration. Second, through internal recirculation of the sintering flue gas, the oxidation-reduction reaction during the sintering combustion process is utilized to further reduce the CO in the flue gas. Finally, a catalytic oxidation method is used at the end to control the CO emission concentration at 500 mg / Nm³. 3 the following.

[0025] (II) The CO removal device of the sintering flue gas CO removal system coupled with flue gas circulation technology proposed in this utility model exchanges heat between the flue gas in the front section of the main flue before denitrification, the flue gas in the middle section of the flue after being heated by the ring cooler, and the flue gas in the tail section of the flue with high temperature characteristics. This raises the temperature of the flue gas in the front section of the main flue. In addition, the heat released by the catalytic oxidation of CO itself can meet the optimal temperature requirements for denitrification. There is no need to use an external heating device to heat the flue gas, which can save a lot of coal gas in the plant area.

[0026] (III) The CO removal device for sintering flue gas coupled with flue gas recirculation technology proposed in this utility model can reduce the total amount of flue gas emitted by 30% to 40% through sintering flue gas recirculation, thereby reducing the production and operation load of the flue gas desulfurization and denitrification system. Simultaneously, in the annular cooler, NO in the sintering flue gas... xIn sintered ore, natural iron oxides such as calcium ferrite can be reduced from CO to N2 through efficient catalysis, thereby effectively controlling NO. x Both CO emission concentration and total emissions should be reduced, as should NO emission concentration and total emissions. x And the cost of CO2 treatment. Attached Figure Description

[0027] Figure 1 A schematic diagram of the process for removing CO from sintering flue gas using a coupled flue gas recirculation technology.

[0028] Figure 2 This is a diagram showing the characteristics of flue gas emissions from the branch pipe of the sintering air box.

[0029] The labels in the diagram represent the following: 1-Sintering machine, 2-Blowbox branch flue, 3-Front section main flue, 4-Main dust collector, 5-Desulfurization tower, 6-GGH heat exchanger, 7-Heat exchanger, 8-CO removal and denitrification tower, 9-Main induced draft fan, 10-Chimney, 11-Middle section low temperature high CO flue, 12-First dust collector, 13-First fan, 14-Annular cooler, 15-Second dust collector, 16-Tail section high temperature low CO flue, 17-Second fan, 18-Third fan, 19-Flue gas dehumidifier, 20-Flue gas circulation sealing cover, 21-Front section main flue pipe, 22-Middle section flue pipe, 23-Tail section flue pipe, 24-Recovery flue pipe, 25-Front section heat exchange main flue pipe.

[0030] 201 - Front section main flue wind box branch pipe flue, 202 - Middle section flue wind box branch pipe flue, 203 - Tail section flue wind box branch pipe flue.

[0031] The specific content of this utility model will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, all equipment and materials in this utility model are based on existing technologies.

[0033] In this invention, the various devices are mainly connected by pipelines, and each pipeline is equipped with valves as needed, which are opened or closed according to process requirements. All valves in this invention are commonly used valves in the prior art.

[0034] Following the above technical solution, the following are specific embodiments of this utility model. It should be noted that this utility model is not limited to the following specific embodiments, and all equivalent modifications made based on the technical solution of this application fall within the protection scope of this utility model.

[0035] Example:

[0036] This embodiment provides a device for CO removal from sintering flue gas using a coupled flue gas recirculation technology, including a sintering machine 1, such as... Figure 1 As shown, multiple air box branch flues 2 are provided below the sintering machine 1. The multiple air box branch flues 2 are divided into multiple front section main flue air box branch flues 201, multiple middle section flue air box branch flues 202 and multiple tail section flue air box branch flues 203.

[0037] like Figure 1 As shown, multiple front-end main flue branch pipes 201 are connected to the front-end main flue 3, the front-end main flue 3 is connected to the main dust collector 4, the main dust collector 4 is connected to the desulfurization tower 5, the desulfurization tower 5 is connected to the cold-side feed port of the GGH heat exchanger 6, the cold-side discharge port of the GGH heat exchanger 6 is connected to the tube-side input end of the heat exchanger 7, the tube-side output end of the heat exchanger 7 is connected to the CO removal and denitrification tower 8, the CO removal and denitrification tower 8 is connected to the hot feed port side of the GGH heat exchanger 6, the hot-side discharge port of the GGH heat exchanger 6 is connected to the main induced draft fan 9, and the main induced draft fan 9 is connected to the chimney 10.

[0038] like Figure 1 As shown, multiple intermediate flue box branch flues 202 are connected to intermediate low-temperature high-CO flue 11, intermediate low-temperature high-CO flue 11 is connected to the first dust collector 12, the first dust collector 12 is connected to the first fan 13, the first fan 13 is connected to the annular cooler 14, and the annular cooler 14 is connected to the second dust collector 15.

[0039] like Figure 1 As shown, multiple tail section flue box branch pipe flues 203 are connected to the tail section high temperature low CO flue 16, the tail section high temperature low CO flue 16 is connected to the second fan 17, the second fan 17 is also connected to the second dust collector 15, the second dust collector 15 is connected to the shell side input end of the heat exchanger 7, the shell side output end of the heat exchanger 7 is connected to the third fan 18, the third fan 18 is connected to the flue gas dehumidifier 19, the flue gas dehumidifier 19 is connected to the flue gas circulation sealing cover 20, and the flue gas circulation sealing cover 20 is located above the sintering machine 1.

[0040] As a preferred embodiment of this invention, such as Figure 1 As shown, the main flue 3 is connected to the main dust collector 4, the main dust collector 4 to the desulfurization tower 5, the desulfurization tower 5 to the cold side inlet of the GGH heat exchanger 6, and the cold side outlet of the GGH heat exchanger 6 to the tube side inlet of the heat exchanger 7, all through the main flue duct 21.

[0041] As a preferred embodiment of this invention, such as Figure 1As shown, the tube-side output end of heat exchanger 7 is connected to CO removal and denitrification tower 8, the CO removal and denitrification tower 8 is connected to the hot-side feed port of GGH heat exchanger 6, the hot-side discharge port of GGH heat exchanger 6 is connected to the main induced draft fan 9, and the main induced draft fan 9 is connected to the chimney 10, all in sequence through the front-end heat exchange main flue pipe 25.

[0042] As a preferred embodiment of this invention, such as Figure 1 As shown, the intermediate low-temperature high-CO flue 11 is connected to the first dust collector 12, the first dust collector 12 is connected to the first fan 13, the first fan 13 is connected to the annular cooler 14, and the annular cooler 14 is connected to the second dust collector 15 through the intermediate flue duct 22.

[0043] As a preferred embodiment of this invention, such as Figure 1 As shown, the tail section high-temperature low-CO flue 16 is connected to the second fan 17 and the second dust collector 15 in sequence through the tail section flue duct 23.

[0044] As a preferred embodiment of this invention, such as Figure 1 As shown, the second dust collector 15 is connected to the shell-side input end of the heat exchanger 7, the shell-side output end of the heat exchanger 7 is connected to the third fan 18, the third fan 18 is connected to the flue gas dehumidifier 19, and the flue gas dehumidifier 19 is connected to the flue gas circulation sealing cover 20 through the recovery flue pipe 24 in sequence.

[0045] In this embodiment, the preferred embodiment is as follows: Figure 1 As shown, sections 1 to 7 are branch flues 201 of the main flue gas duct, producing low-temperature, low-CO flue gas with an average temperature between 90-100℃ and an average CO concentration of...

[0046] 4000-5000mg / Nm 3 Between; Nos. 8 and 17 are branch flues of the middle flue box, duct 202, producing low-temperature, high-CO flue gas, with an average temperature between 75-85℃ and an average CO concentration between 15000-16000 mg / Nm³. 3 Between; Nos. 18 and 25 are branch pipes of the tail flue, producing high-temperature, low-CO flue gas with an average temperature between 380-400℃ and an average CO concentration between 1000-1500 mg / Nm³. 3 between.

[0047] In this preferred embodiment, the low-temperature, low-CO flue gas is introduced into the front main flue pipe 21 and the front heat exchange main flue pipe 25 by the front main flue pipe 201 for dust removal, desulfurization, CO removal and denitrification and other flue gas purification devices before being discharged in compliance with standards.

[0048] In this preferred embodiment, the middle flue gas duct branch pipe flue 202 first removes dust from the low-temperature, high-CO flue gas before introducing it into the annular cooler 14. The low-temperature, high-CO flue gas absorbs a large amount of sensible heat from the sintering hot ore, significantly increasing the flue gas temperature to over 350°C. Simultaneously, the high concentration of CO in the flue gas undergoes a series of reactions under the influence of the iron-based components in the sintering hot ore layer to generate CO2, releasing chemical heat to further increase the flue gas temperature.

[0049] In this preferred embodiment, the high-temperature, low-CO flue gas in the tail flue fan branch pipe flue 203 merges with the flue gas in the middle flue pipe 22 after heating, and is then removed from dust in the second dust collector 15. It then exchanges heat with the flue gas in the front main flue pipe 21 before denitrification, raising the temperature of the flue gas in the front main flue pipe 21 to meet the temperature requirements for subsequent CO and NOx removal. Simultaneously, the flue gas recovered from the heat exchange in the flue pipe 24 is then dehumidified, oxygenated, and circulated back into the sintering machine 1, where the oxidation-reduction reaction during sintering combustion further treats the CO in the flue gas.

[0050] In this embodiment, preferably, the main dust collector 4, the first dust collector 12, and the second dust collector 15 are all multi-tube dust collectors or electrostatic dust collectors.

[0051] In this embodiment, the desulfurization tower 5 preferably adopts any one of dry desulfurization, semi-dry desulfurization, or wet desulfurization. In this embodiment, semi-dry desulfurization is adopted.

[0052] In this embodiment, the heat exchanger 7 is preferably a plate heat exchanger or a tubular heat exchanger.

[0053] In this preferred embodiment, the CO removal and denitrification tower 8 is sequentially provided with a CO removal catalyst layer and a NO removal catalyst layer. x The catalytic layer is used to remove CO and NO from the heated sintering flue gas. x The reaction is as follows: The CO removal catalyst is honeycomb type, and the suitable reaction temperature is between 250-350℃; the NO removal catalyst is honeycomb type. x The catalyst is plate-type, and the medium-high temperature SCR denitrification process is adopted, with a suitable reaction temperature >280℃.

[0054] In this embodiment, the preferred embodiment is that the GGH heat exchanger 6 is used to exchange heat between the desulfurized flue gas and the high-temperature flue gas after CO and nitrification in the main flue duct 21.

[0055] In this preferred embodiment, the flue gas dehumidifier 19 controls the water content of the flue gas to be below 5%, and controls the oxygen content of the flue gas to be maintained above 18% by performing oxygen replenishment operation on the recovery flue duct 24.

[0056] In this embodiment, the working process of the CO removal device coupled with flue gas recirculation technology in the sintering flue gas CO removal system is as follows:

[0057] Multiple air box branch flues 2 are provided below the sintering machine 1. Based on the differences in flue gas emission characteristics (temperature and CO concentration, etc.) of each branch flue, such as... Figure 2 As shown, from front to back, it is divided into the front section main flue wind box branch pipe flue 201, the middle section flue wind box branch pipe flue 202, and the rear section flue wind box branch pipe flue 203.

[0058] The flue gas temperature in the middle section of the flue gas duct branch pipe 202 is around 80℃, and the CO concentration is 15500 mg / Nm³. 3 After reducing the dust content using the first dust collector 12, the dust is introduced into the sintering hot ore in the ring cooler 14 (around 850°C). The high concentration of CO in the flue gas undergoes a series of reactions under the action of the iron-based components in the sintering hot ore layer: (1) reduction of iron oxides. When the reaction temperature is greater than 570°C, the iron oxides follow the principle of stepwise reduction, and the reduction order is Fe2O3→Fe3O4→FeO. Therefore, the main reaction in the sintering hot ore is 3Fe2O3+CO=

[0059] 2Fe3O4+CO2 and Fe3O4+CO=3FeO+CO2; (2) Reduce nitrogen oxides. Under the catalytic action of iron oxides such as calcium ferrite, NO+CO=N2+CO2 can occur. Through the above series of reactions, the CO concentration in flue gas can be reduced to 5000mg / Nm3. 3 The following methods simultaneously improve sintering reduction degree and reduce NO x Concentration. After absorbing a large amount of sensible heat from the sintering hot minerals and the chemical heat from the reaction, the temperature of the flue gas rises significantly to over 380°C, and then merges with the high-temperature flue gas in the tail flue duct 23.

[0060] The flue gas temperature in the tail section flue duct 23 is around 390℃, and the CO concentration is 1400mg / Nm³. 3 The flue gas, after merging with the flue gas in the middle section flue duct 22 after heating, passes through the second dust collector 15 for dust removal, reducing wear on the downstream heat exchange device.

[0061] The flue gas temperature in the main flue duct 3 is around 95℃, and the CO concentration is 4500 mg / Nm³. 3The flue gas first undergoes dust removal via the main dust collector 4, followed by semi-dry desulfurization, resulting in a flue gas temperature of approximately 85°C. After desulfurization, the flue gas passes through the GGH heat exchanger 6, exchanging heat with the denitrified flue gas to raise the temperature of the flue gas in the front main flue duct 3 to over 220°C. The flue gas in the front main flue duct 21 then merges with the treated flue gas in the tail flue duct 23 and the middle flue duct 22 for further heat exchange, raising the flue gas temperature to over 280°C, meeting the temperature requirements of SCR (Selective Catalytic Reduction). The CO catalytic oxidation layer and the SCR denitrification catalytic layer are placed in the same tower. The flue gas in the front main flue duct 21 first undergoes CO catalytic oxidation, controlling the CO concentration in the flue gas to 500 mg / Nm³. 3 Furthermore, by simultaneously raising the flue gas temperature to above 300℃, the SCR denitrification reaction can be further facilitated. Finally, the sintering flue gas is discharged into the atmosphere from the hot side of the GGH heat exchanger 6 through the chimney 10 under the action of the main induced draft fan 9.

[0062] The flue gas in the heat exchange recovery flue duct 24 is dehumidified and oxygenated to control its moisture content below 5%, avoiding excessive moisture content in the sintering flue gas caused by repeated flue gas circulation, which would affect the sintering effect and hinder the rise in flue gas temperature. The oxygen content is maintained above 18% to prevent fluctuations in oxygen content from affecting the quality of the sintered ore. The dehumidified and oxygenated flue gas is then introduced into the flue gas circulation sealing hood 20 for circulation. During the sintering combustion process, CO in the flue gas is oxidized, further reducing the CO concentration. Simultaneously, during the flue gas circulation sintering process, organic pollutants such as dioxins, polycyclic aromatic hydrocarbons (PAHs), and volatile organic compounds (VOCs) in the exhaust gas are thermally decomposed as they pass through the high-temperature sintering zone.

[0063] This device, which removes CO by coupling a sintering flue gas CO removal system with flue gas recirculation technology, achieves deep and efficient removal of CO from sintering flue gas, controlling the CO emission concentration to 500 mg / Nm³. 3 The following. Simultaneously, it saves a large amount of coal gas consumed by the original flue gas reheating device, reducing total flue gas emissions and NO. x This reduces CO emission concentration and lowers end-of-pipe treatment costs.

Claims

1. A device for removing CO from sintering flue gas by coupling a flue gas circulation technology to a sintering flue gas CO removal system, comprising a sintering machine (1), characterized in that, The sintering machine (1) is provided below with a plurality of wind box branch flues (2), which are divided into a plurality of front section main flue wind box branch flues (201), a plurality of middle section flue wind box branch flues (202) and a plurality of tail section flue wind box branch flues (203); The plurality of front section main flue wind box branch flues (201) are respectively connected with the front section main flue (3), the front section main flue (3) is connected with the main dust remover (4), the main dust remover (4) is connected with the desulfurization tower (5), the desulfurization tower (5) is connected with the cold side inlet of the GGH heat exchanger (6), the cold side outlet of the GGH heat exchanger (6) is connected with the tube side input end of the heat exchanger (7), the tube side output end of the heat exchanger (7) is connected with the CO and denitration tower (8), the CO and denitration tower (8) is connected with the hot side inlet of the GGH heat exchanger (6), the hot side outlet of the GGH heat exchanger (6) is connected with the main induced draft fan (9), and the main induced draft fan (9) is connected with the chimney (10); The plurality of middle section flue wind box branch flues (202) are respectively connected with the middle section low-temperature high-CO flue (11), the middle section low-temperature high-CO flue (11) is connected with the first dust remover (12), the first dust remover (12) is connected with the first fan (13), the first fan (13) is connected with the ring cooler (14), and the ring cooler (14) is connected with the second dust remover (15); The plurality of tail section flue wind box branch flues (203) are respectively connected with the tail section high-temperature low-CO flue (16), the tail section high-temperature low-CO flue (16) is connected with the second fan (17), the second fan (17) is also connected with the second dust remover (15), the second dust remover (15) is connected with the shell side input end of the heat exchanger (7), the shell side output end of the heat exchanger (7) is connected with the third fan (18), the third fan (18) is connected with the flue gas dehumidifier (19), the flue gas dehumidifier (19) is connected with the flue gas circulating sealing cover (20), and the flue gas circulating sealing cover (20) is located above the sintering machine (1).

2. The apparatus for removing CO from the flue gas of a sintering plant coupled with the flue gas recycling technology for removing CO according to claim 1, wherein, The front section main flue (3) and the main dust remover (4), the main dust remover (4) and the desulfurization tower (5), the desulfurization tower (5) and the cold side inlet of the GGH heat exchanger (6), and the cold side outlet of the GGH heat exchanger (6) and the tube side input end of the heat exchanger (7) are sequentially connected through the front section main flue pipeline (21); The tube side output end of the heat exchanger (7) and the CO and denitration tower (8), the CO and denitration tower (8) and the hot side inlet of the GGH heat exchanger (6), the hot side outlet of the GGH heat exchanger (6) and the main induced draft fan (9), and the main induced draft fan (9) and the chimney (10) are sequentially connected through the front section heat exchange main flue pipeline (25).

3. The apparatus for removing CO from flue gas by coupling a flue gas recycling technology with a sintering flue gas CO removal system according to claim 1, wherein, The middle section low-temperature high-CO flue (11) and the first dust remover (12), the first dust remover (12) and the first fan (13), the first fan (13) and the ring cooler (14), and the ring cooler (14) and the second dust remover (15) are sequentially connected through the middle section flue pipeline (22).

4. The apparatus for removing CO from flue gas by coupling a flue gas recycling technology with a sintering flue gas CO removal system according to claim 1, wherein, The tail section high-temperature low-CO flue (16) is connected with the second fan (17) and the second fan (17) is connected with the second dust collector (15) through the tail section flue pipeline (23) in sequence.

5. The apparatus for removing CO from flue gas by coupling a flue gas recycling technology with a sintering flue gas CO removal system according to claim 1, wherein, The second dust collector (15) is connected with the shell side input end of the heat exchanger (7), the shell side output end of the heat exchanger (7) is connected with the third fan (18), the third fan (18) is connected with the flue gas dehumidifier (19), and the flue gas dehumidifier (19) is connected with the flue gas circulating sealing cover (20) through the recovery flue pipeline (24) in sequence.

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