Sintering flue gas circulation method

Abstract

The present invention discloses a sintering flue gas circulation method and a sintering flue gas circulation system, which solves the current problem of low internal circulation rate of sintering flue gas, ensures that the circulating flue gas is completely absorbed by the material surface of the sintering trolley, and significantly reduces the total amount of sintering flue gas discharged externally. Among them, the sintering flue gas circulation method includes the following steps: collecting the sintering flue gas in the wind box at the rear of the sintering machine; performing a preset treatment on the sintering flue gas to increase the specific gravity of the sintering flue gas; and sending the sintering flue gas after the preset treatment into the sintering machine. The sintering flue gas circulation method provided by the present invention performs a preset treatment on the sintering flue gas to reduce the volume of the sintering flue gas and increase the specific gravity of the sintering flue gas. While the volume of the sintering flue gas is reduced, the density of the flue gas is increased, which is conducive to the absorption of the flue gas by the material surface; it can significantly improve the absorption rate of the sintering flue gas, reduce the total amount of sintering flue gas discharged externally, and reduce the operating load of the flue gas desulfurization and denitrification system equipment.

Description

Technical Field

[0001] The invention relates to the technical field of sintering process of iron and steel metallurgy, and in particular to a sintering flue gas circulation method and a sintering flue gas circulation system. Background Art

[0002] The sintering process is the main source of energy consumption and pollutant emissions in steel production. During the sintering process, fuel combustion and mineral chemical reactions under high temperature conditions will produce a large amount of waste gas. The waste gas contains SO2, NOx, CO, CO2, dioxins, dust and other pollutants, which pollute the atmospheric environment. In recent years, in order to control environmental pollution, the country has continuously improved the emission standards of atmospheric pollutants in the steel sintering and pelletizing industries. Some new technologies that are conducive to environmental protection, energy conservation and emission reduction have also been developed and applied. The sintering flue gas circulation process is one of them. The basic principle of sintering flue gas circulation is to return part of the sintering waste gas to the sintering trolley, continue to use the residual oxygen and waste heat in the waste gas to participate in the sintering reaction process, and ultimately reduce the amount of flue gas discharged into the atmosphere. The Ministry of Ecology and Environment and other five ministries have encouraged the implementation of flue gas circulation as a process technology.

[0003] However, the existing production generally has the problem of low flue gas circulation rate. The actual flue gas circulation rate is only about 10%, which is far from the designed circulation rate (20%~30%). Therefore, it is necessary to further research, develop and improve this technology to improve its environmental protection and emission reduction effect. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a sintering flue gas circulation method and a sintering flue gas circulation system to solve the technical problem of low flue gas circulation rate commonly existing in existing production.

[0005] The technical solution adopted to achieve the purpose of the present invention is a sintering flue gas circulation method, comprising the following steps:

[0006] Collect the sintering flue gas in the wind box at the tail of the sintering machine;

[0007] Pre-processing the sintering fume to increase the specific gravity of the sintering fume;

[0008] The sintering flue gas after the preset treatment is sent into the sintering machine.

[0009] Furthermore, the collecting of sintering flue gas in the tail wind box of the sintering machine specifically includes: collecting the sintering flue gas in the tail wind box of the sintering machine, wherein the temperature of the sintering flue gas is greater than 300° C. and the oxygen content is greater than 18%.

[0010] Furthermore, the preset treatment of the sintering flue gas specifically includes: passing the sintering flue gas into a heat exchange device for heat exchange treatment, and the temperature of the sintering flue gas after the heat exchange is less than 170°C.

[0011] Furthermore, before the sintering flue gas is subjected to a preset treatment, or before the sintering flue gas after the preset treatment is fed into the sintering machine, the sintering flue gas circulation method further comprises: performing dust removal treatment on the sintering flue gas.

[0012] Furthermore, the sintering fume is subjected to dust removal treatment, specifically comprising: passing the sintering fume into a dust removal device to reduce the dust concentration of the sintering fume to 200 mg / m 3 the following.

[0013] Furthermore, the sending of the sintering flue gas after the preset treatment into the sintering machine specifically includes sending the sintering flue gas after the preset treatment into a hot air hood of the sintering machine through a circulating fan.

[0014] Based on the same inventive concept, the present invention also provides a sintering flue gas circulation system for implementing the above-mentioned sintering flue gas circulation method; the sintering flue gas circulation system includes a sintering machine and a circulation component; the sintering machine includes a tail bellows, a sintering machine body and a hot air hood, the tail bellows connects the sintering machine body and the circulation component, and the hot air hood is arranged above the sintering machine body; the circulation component includes a flue gas treatment device and a pipeline, the flue gas treatment device is used to perform preset treatment on the sintering flue gas to increase the specific gravity of the sintering flue gas, and the flue gas treatment device is connected to the tail bellows and the hot air hood through the pipeline.

[0015] Furthermore, the flue gas treatment device is a heat exchange device; the circulation component also includes a dust removal device and a circulation fan, the heat exchange device, the dust removal device, and the circulation fan are connected through the pipeline to form a flue gas treatment passage, the inlet of the flue gas treatment passage is connected to the tail bellows, and the outlet of the flue gas treatment passage is connected to the hot air hood.

[0016] Furthermore, the circulation component also includes an air supply regulating valve, the heat exchange equipment, the dust removal equipment and the circulation fan are connected in sequence through the pipeline, and the air supply regulating valve is installed on the pipeline between the circulation fan and the hot air hood.

[0017] Furthermore, a wheel walking mechanism is provided on the hot air hood; the heat exchange equipment is a waste heat boiler; the sintering machine also includes a front bellows and a sintering flue, the front bellows and the tail bellows are arranged in sequence along the length direction of the sintering machine, the sintering flue is connected with the circulation component and the tail bellows, a blind plate is provided in the sintering flue, the blind plate separates the selected flue gas of the tail bellows and the flue gas of the front bellows, the tail bellows and the front bellows are connected with the sintering flue through pipes, and regulating valves are provided on the pipes.

[0018] It can be seen from the above technical scheme that the sintering fume circulation method provided by the present invention comprises the following steps: collecting the sintering fume in the wind box at the rear of the sintering machine; pre-treating the sintering fume to reduce the volume of the sintering fume and increase the specific gravity of the sintering fume; and finally sending the sintering fume after the preset treatment into the sintering machine. The sintering fume circulation method provided by the present invention can effectively solve the current problem of low internal circulation rate of sintering fume, ensure that the circulating fume is completely absorbed by the material surface of the sintering trolley, and significantly reduce the total amount of sintering fume discharged externally.

[0019] Research has found that at the tail of the sintering machine, the sintering process is close to the end, so the oxygen content of the flue gas in the last few bellows is relatively high. This part of the flue gas is collected and sent to the sintering material layer to participate in combustion, which can reduce the total amount of exhaust flue gas. The sintering flue gas circulation method provided by the present invention collects the sintering flue gas from the bellows at the tail of the sintering machine. By utilizing the high oxygen content of this part of the sintering flue gas, the flue gas can be recycled and utilized, achieving the technical effect of energy saving and consumption reduction.

[0020] Due to the sintering flue gas circulation method provided by the present invention, the collected sintering flue gas comes from the wind box at the rear of the sintering machine, and the temperature of this part of the flue gas is relatively high, which causes its volume expansion, reduces its specific gravity, and is difficult to be inhaled by the material surface. In the present invention, the sintering flue gas is pre-processed to reduce the volume of the sintering flue gas and increase its specific gravity. The volume of the sintering flue gas is reduced while the density of the flue gas is increased, which is conducive to the absorption of the flue gas by the material surface; at the same time, it plays a role in heat preservation of the material layer, improving the quality of sintered ore, and reducing fuel consumption, which can significantly improve the absorption rate of the sintering flue gas, and at the same time improve the circulation rate of the sintering flue gas, reduce the total amount of sintering flue gas discharged, and reduce the operating load of the flue gas desulfurization and denitrification system equipment.

[0021] The sintering flue gas circulation system provided by the present invention is used to implement the above-mentioned sintering flue gas circulation method. The sintering flue gas circulation system includes a sintering machine and a circulation component; the sintering machine includes a tail bellows, a sintering machine body and a hot air hood, the bellows connects the sintering machine body and the circulation component, the hot air hood is arranged above the sintering machine body, and the sintering flue gas that meets the circulation requirements is re-introduced into the sintering machine for combustion through the circulation component. The circulation component includes a flue gas treatment device and a pipeline, and the flue gas treatment device is used to perform preset treatment on the sintering flue gas to increase the specific gravity and density of the sintering flue gas, which is conducive to the sintering flue gas being re-absorbed by the material surface. The flue gas treatment device is connected to the tail bellows and the hot air hood through a pipeline, thereby realizing the internal circulation of the sintering flue gas inside the sintering machine, and improving the absorption rate and circulation rate of the sintering flue gas through preset treatment.

[0022] The sintering flue gas circulation system provided by the present invention uses heat exchange equipment to heat and cool the sintering flue gas in the wind box at the rear of the sintering machine. According to the ideal gas state equation, the volume of the flue gas can be reduced and the density of the flue gas can be increased, which is conducive to the absorption of the flue gas by the material surface; at the same time, it plays a role in heat preservation of the material layer, improving the quality of sintered ore, and reducing fuel consumption. The device can increase the flue gas circulation rate from 10% to 20%~30%, reduce the total amount of sintering flue gas discharged, and reduce the operating load of the flue gas desulfurization and denitrification system equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A flow chart of the sintering flue gas circulation method provided in Example 1 of the present invention;

[0024] Figure 2 This is a schematic structural diagram of the sintering flue gas circulation system provided in Example 2 of the present invention.

[0025] Description of the drawings: 1-rear bellows; 2-sintering machine body; 3-waste heat boiler; 4-multi-tube dust collector; 5-circulating fan; 6-hot air hood; 7-front bellows; 8-igniter, 9-head star wheel; 10-rear star wheel; 11-sintering flue; 12-blind plate; 13-regulating valve; 14-air supply regulating valve. DETAILED DESCRIPTION

[0026] In order to enable technicians in the technical field to which the present application belongs to understand the present application more clearly, the technical solution of the present application is described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0027] In view of the problem of low circulation rate in the prior art, the present invention provides a sintering fume circulation method and a sintering fume circulation system to ensure that the circulating fume is completely absorbed by the sintering trolley material surface, significantly reducing the total amount of sintering fume discharged. The content of the present invention is described in detail through two embodiments below:

[0028] Example 1

[0029] This embodiment provides a sintering flue gas circulation method, which sends the sintering flue gas that meets the recycling requirements to the sintering material layer after preset treatment to participate in combustion, so as to improve the circulation rate and absorption rate of the sintering flue gas. Figure 1 The sintering flue gas circulation method provided in this embodiment comprises the following steps:

[0030] (1) Collect the sintering flue gas in the wind box at the tail end of the sintering machine.

[0031] Research has found that at the tail of the sintering machine, the sintering process is close to the end, so the oxygen content of the flue gas in the last few bellows is relatively high. This part of the flue gas is collected and sent to the sintering material layer to participate in combustion, which can reduce the total amount of exhaust flue gas. In this embodiment, the sintering flue gas in the bellows at the tail of the sintering machine is collected, and the temperature of the collected sintering flue gas is greater than 300°C and the oxygen content is greater than 18%. By collecting the sintering flue gas from the bellows at the tail of the sintering machine and utilizing the high oxygen content of this part of the sintering flue gas, the flue gas can be recycled and internally circulated, achieving the technical effect of energy saving and consumption reduction.

[0032] (2) Pre-treat the sintering flue gas to reduce the volume of the sintering flue gas and increase the specific gravity of the sintering flue gas.

[0033] In order to reduce the volume of sintering fume and increase the specific gravity of sintering fume, the preset treatment of sintering fume may specifically be air compression, heat exchange treatment, etc. The present invention does not limit the specific content of the preset treatment, as long as the purpose of reducing the volume of sintering fume and increasing the specific gravity of sintering fume can be achieved.

[0034] Specifically, in order to reduce the volume of sintering flue gas, increase the specific gravity of sintering flue gas, and utilize the heat energy of sintering flue gas as much as possible to achieve the effect of energy saving and consumption reduction, in this embodiment, the sintering flue gas is pre-processed, specifically including: passing the sintering flue gas into the heat exchange equipment for heat exchange treatment, and the temperature of the sintering flue gas after heat exchange is less than 170°C. The heat exchange equipment is used to heat and cool the sintering flue gas in the wind box at the tail end of the sintering machine. According to the ideal gas state equation, the volume of the flue gas can be reduced and the density of the flue gas can be increased, which is conducive to the absorption of the flue gas by the material surface, playing a role in heat preservation of the material layer, improving the quality of sintered ore, and reducing fuel consumption. The heat exchange treatment can increase the flue gas circulation rate from 10% to 20%~30%, reduce the total amount of sintering flue gas discharged, and reduce the operating load of the flue gas desulfurization and denitrification system equipment. At the same time, the waste heat in the high-temperature flue gas at the end of the sintering is recovered by the heat exchange equipment, and the steam recovery amount is 20-30kg / t, which saves energy and reduces consumption.

[0035] This embodiment does not specifically limit the selected heat exchange equipment. For example, the heat exchange equipment can be a partition heat exchanger, a hybrid heat exchanger, a heat storage heat exchanger (direct contact between hot and cold fluids), an indirect heat exchanger with a liquid heat carrier, etc., as long as it can reduce the specific gravity of the sintering flue gas. In this embodiment, the heat exchange equipment is preferably a waste heat boiler, which is a combination of a heat exchanger and a steam drum. While exchanging heat with the sintering flue gas, it generates low-pressure steam and effectively recycles the waste heat of the sintering flue gas for power generation or heating.

[0036] (3) Sending the sintering flue gas after preset treatment into the sintering machine.

[0037] In this embodiment, the sintering fume after preset treatment is sent to the hot air hood of the sintering machine by the circulating fan. The circulating fan sends the sintering fume to the hot air hood on the upper part of the sintering machine trolley according to the set material surface wind speed, and the trolley material surface air volume and air pressure can be adjusted according to production conditions to obtain a reasonable material surface wind speed.

[0038] In order to effectively avoid the influence of dust on sintering materials, the flue gas circulation method provided by the present invention further includes: dust removal treatment of the sintering flue gas before the sintering flue gas is subjected to preset treatment, or before the sintering flue gas after preset treatment is fed into the sintering machine.

[0039] In this embodiment, the sintering flue gas is subjected to dust removal treatment, specifically including passing the sintering flue gas into a dust removal device to reduce the dust concentration of the sintering flue gas to 200 mg / m 3 The present embodiment does not specifically limit the dust removal equipment, and bag dust collectors, cyclone dust collectors, silo top dust collectors, boiler dust collectors, cyclone dust collectors, mine dust collectors, wet dust collectors, etc. may be selected. In the present embodiment, the dust removal equipment is preferably a multi-tube dust collector.

[0040] In the sintering flue gas circulation method provided by the present invention, the collected sintering flue gas comes from the wind box at the rear of the sintering machine, and the temperature of this part of the flue gas is relatively high, which causes its volume expansion and specific gravity to decrease, making it difficult to be inhaled by the material surface. Therefore, in the present invention, the sintering flue gas is pre-processed to reduce the volume of the sintering flue gas and increase the specific gravity of the sintering flue gas. The volume of the sintering flue gas is reduced while the density of the flue gas is increased, which is conducive to the absorption of the flue gas by the material surface; at the same time, it plays a role in heat preservation of the material layer, improving the quality of sintered ore, and reducing fuel consumption, which can significantly improve the absorption rate of the sintering flue gas, and at the same time improve the circulation rate of the sintering flue gas, reduce the total amount of sintering flue gas discharged, and reduce the operating load of the flue gas desulfurization and denitrification system equipment.

[0041] Example 2

[0042] Based on the same inventive concept, this embodiment provides a sintering fume circulation system for implementing the sintering fume circulation method in the above embodiment 1. Figure 2 The sintering flue gas circulation system includes a sintering machine and a circulation component; the sintering machine includes a tail bellows 1, a sintering machine body 2 and a hot air hood 6, the tail bellows 1 is connected to the sintering machine body 2 and the circulation component, and the hot air hood 6 is arranged above the sintering machine body 2; the circulation component includes a flue gas treatment device and a pipeline, the flue gas treatment device is used to perform preset treatment on the sintering flue gas to increase the specific gravity of the sintering flue gas, and the flue gas treatment device is connected to the tail bellows 1 and the hot air hood 6 through a pipeline.

[0043] The present embodiment does not make any specific limitation on the flue gas treatment device, as long as the technical effect of reducing the specific gravity of sintering flue gas can be achieved, for example, the flue gas treatment device can be a gas compression device. In the present embodiment, in order to reduce the specific gravity of sintering flue gas while recovering the heat energy of sintering flue gas, the flue gas treatment device is preferably a heat exchange device. The circulation component also includes a dust removal device and a circulation fan 5. The heat exchange device, the dust removal device, and the circulation fan 5 are connected by a pipeline to form a flue gas treatment passage. The inlet of the flue gas treatment passage is connected to the tail bellows 1, and the outlet of the flue gas treatment passage is connected to the hot air hood 6. The present embodiment does not make any specific limitation on the setting order of the heat exchange device, the dust removal device, and the circulation fan 5. The setting order can be changed according to different needs, as long as the temperature and specific gravity of the sintering flue gas can be reduced, and the sintering flue gas introduced into the sintering machine after the preset treatment meets the requirements, and the circulation rate and absorption rate requirements can be met.

[0044] In order to reduce the specific gravity of sintering flue gas and recover the heat energy of sintering flue gas, in this embodiment, the heat exchange device is preferably a waste heat boiler 3. Further, in order to make full use of the waste heat of sintering flue gas and avoid the loss of waste heat of flue gas, the sintering flue gas circulation system provided by the present invention is connected with the hot air hood 6, but the order of setting the heat exchange device and the dust removal device is not limited. Since heat exchange first is conducive to increasing the recovered heat energy, in this embodiment, preferably, the heat exchange device, the dust removal device and the circulation fan 5 are connected in sequence through pipelines.

[0045] In order to facilitate the adjustment of the speed at which the sintering flue gas enters the sintering machine, in this embodiment, the circulation component further includes an air supply regulating valve 14, which is installed on the pipeline between the circulation fan 5 and the hot air hood 6. The circulation fan 5 is designed to be variable frequency speed regulation, and the air supply regulating valve 14 is arranged on the branch pipe of the hot air hood 6, which can adjust the air volume and air pressure of the material surface of the trolley according to the production situation, obtain a reasonable material surface wind speed, ensure that the circulating flue gas is completely absorbed by the material surface, and achieve a flue gas circulation rate of 20% to 30%.

[0046] The hot air hood 6 is arranged above the sintering machine body 2. In order to change the position of the hot air hood 6 according to needs, in this embodiment, a wheel travel mechanism is arranged on the hot air hood 6.

[0047] The sintering machine also includes a front wind box 7 and a flue gas desulfurization and denitration treatment device. The front wind box 7 and the rear wind box 1 are sequentially arranged along the length direction of the sintering machine to collect the flue gas generated by sintering. However, the oxygen content of the sintering flue gas from the front wind box 7 does not meet the requirements for recycling, so it is treated by the flue gas desulfurization and denitration treatment device for subsequent discharge.

[0048] The sintering fume circulation system provided by the present invention comprises a sintering machine further comprising a sintering fume duct 11 , wherein the sintering fume duct 11 is connected with the circulation component and the tail wind box 1 , so as to realize the circulation of the sintering fume in the tail wind box 1 .

[0049] In this embodiment, the flue gas from the front bellows 7 and the rear bellows 1 converge into the same sintering flue 11. In order to isolate the rear sintering flue gas for circulating treatment and the front sintering flue gas for desulfurization and denitrification treatment, a blind plate 12 is provided in the sintering flue 11 in this embodiment. The blind plate 12 separates the flue gas from the selected rear bellows 1 and the flue gas from the front bellows 7.

[0050] In order to adjust the speed at which the sintering flue gas enters the circulation component and the flue gas desulfurization and denitrification treatment device, in this embodiment, a regulating valve 13 is provided on the connecting pipe between the sintering flue 11 and each wind box.

[0051] In the sintering fume circulation system provided by the present invention, the sintering machine further includes an igniter 8 for starting sintering. The igniter 8 is arranged above the sintering machine and in the direction from the front wind box 7 to the rear wind box 1. The igniter 8 is arranged before the hot air hood 6. The treated sintering fume passes through the hot air hood 6 into the sintering machine body 2. Since this part of the sintering fume has a high oxygen content, it is conducive to combustion and is easily absorbed by the sintering material surface.

[0052] In this embodiment, the sintering machine further comprises a head star wheel 9 and a tail star wheel 10 for driving. The head star wheel 9 and the tail star wheel 10 are respectively arranged at the head and the tail of the sintering machine to drive the sintering machine to run on the track.

[0053] The sintering flue gas circulation system provided by the present invention utilizes heat exchange equipment to cool down the sintering flue gas in the wind box 1 at the tail end of the sintering machine. According to the ideal gas state equation, the volume of the flue gas can be reduced and the density of the flue gas can be increased, which is conducive to the absorption of the flue gas by the material surface; at the same time, it plays a role in heat preservation of the material layer, improving the quality of sintered ore, and reducing fuel consumption. The device can increase the flue gas circulation rate from 10% to 20%~30%, reduce the total amount of sintering flue gas discharged, and reduce the operating load of the flue gas desulfurization and denitrification system equipment. At the same time, the waste heat in the high-temperature flue gas at the tail end of the sintering is recovered through the waste heat boiler 3, and the steam recovery amount is 20-30kg / t, which saves energy and reduces consumption.

[0054] The working principle and use method of the sintering flue gas circulation system in this embodiment are as follows:

[0055] At the end of the sintering machine, the sintering flue gas in the tail wind box 1 has a high temperature (300-400°C) and an oxygen content of >18%, which meets the requirements for re-entering the sintering material layer for combustion support (recycling). Specific implementation route: The flue gas enters the sintering flue 11 from the tail wind box 1 of the sintering machine, and the high-temperature flue gas in the sintering flue 11 enters the waste heat boiler 3. In the waste heat boiler 3, the high-temperature sintering flue gas and water undergo gas-water heat exchange to generate steam, and the temperature of the high-temperature sintering flue gas is reduced to 150°C, and the volume is reduced; the low-temperature sintering flue gas is dedusted by the multi-tube dust collector 4, and the dust concentration of the treated sintering flue gas is reduced to 200mg / m 3 Next, the sintering fume is passed through the circulating fan 5 into the hot air hood 6 and finally sucked into the material layer.

[0056] Through the above embodiments, the present invention has the following beneficial effects or advantages:

[0057] 1) The sintering flue gas circulation method provided by the present invention performs preset treatment on the sintering flue gas to reduce the volume of the sintering flue gas and increase the specific gravity of the sintering flue gas. The volume of the sintering flue gas is reduced while the density of the flue gas is increased, which is conducive to the absorption of the flue gas by the material surface; at the same time, it plays a role in heat preservation of the material layer, improving the quality of sintered ore, and reducing fuel consumption, and can significantly improve the absorption rate of the sintering flue gas. At the same time, it improves the circulation rate of the sintering flue gas, reduces the total amount of sintering flue gas discharged, and reduces the operating load of the flue gas desulfurization and denitrification system equipment.

[0058] 2) The sintering flue gas circulation system provided by the present invention utilizes heat exchange equipment to cool down the sintering flue gas (temperature 350°C, oxygen content above 18%) in the wind box at the rear end of the sintering machine. According to the ideal gas state equation, the volume of the flue gas can be reduced and the density of the flue gas can be increased, which is beneficial for the flue gas to be absorbed by the material surface. The device can increase the flue gas circulation rate from 10% to 20%~30%, and at the same time, recover the waste heat in the high-temperature flue gas at the rear end of the sintering machine through the heat exchange equipment, thereby saving energy and reducing consumption.

[0059] 3) The sintering flue gas circulation system provided by the present invention can recover the waste heat in the high-temperature flue gas at the end of sintering through the waste heat boiler, and the steam recovery amount is 20-30kg / t.

[0060] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0061] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A sintering flue gas circulation method, characterized in that: The steps include: Separating the tail wind box and the front wind box of the sintering machine, collecting the sintering flue gas in the tail wind box of the sintering machine, wherein the temperature of the sintering flue gas is greater than 300° C. and the oxygen content is greater than 18%; The sintering flue gas is pre-processed according to an ideal gas state equation, and the sintering flue gas is passed into a heat exchange device for heat exchange treatment, and the temperature of the sintering flue gas after the heat exchange is less than 170° C., so as to increase the specific gravity of the sintering flue gas; Sending the sintering flue gas after preset treatment into the sintering machine; The sintering machine includes a front bellows, a rear bellows, a sintering machine body, a hot air hood and a sintering flue. The rear bellows is connected to the sintering machine body and a circulation component, and the hot air hood is arranged above the sintering machine body; the circulation component includes a flue gas treatment device and a pipeline, the flue gas treatment device is used to perform preset treatment on the sintering flue gas to increase the specific gravity of the sintering flue gas, and the flue gas treatment device is connected to the rear bellows and the hot air hood through the pipeline; the front bellows and the rear bellows are arranged in sequence along the length direction of the sintering machine, and the sintering flue is connected to the circulation component and the rear bellows. A blind plate is arranged in the sintering flue, and the blind plate separates the flue gas of the selected rear bellows and the flue gas of the front bellows. The rear bellows and the front bellows are both connected to the sintering flue through a pipeline, and a regulating valve is arranged on the pipeline.

2. The sintering flue gas circulation method according to claim 1, characterized in that: Before performing a preset treatment on the sintering flue gas, or before feeding the sintering flue gas after the preset treatment into the sintering machine, the sintering flue gas circulation method further comprises: performing a dust removal treatment on the sintering flue gas.

3. The sintering flue gas circulation method according to claim 2, characterized in that: The dust removal treatment of the sintering flue gas specifically includes passing the sintering flue gas into a dust removal device to reduce the dust concentration of the sintering flue gas to 200 mg / m 3 the following.

4. The sintering flue gas circulation method according to claim 1, characterized in that: The sending the sintering flue gas after the preset treatment into the sintering machine specifically includes sending the sintering flue gas after the preset treatment into the hot air hood of the sintering machine through a circulating fan.

5. The sintering flue gas circulation method according to claim 1, characterized in that: The flue gas treatment device is a heat exchange device; the circulation component also includes a dust removal device and a circulation fan. The heat exchange device, the dust removal device, and the circulation fan are connected through the pipeline to form a flue gas treatment passage. The inlet of the flue gas treatment passage is connected to the tail bellows, and the outlet of the flue gas treatment passage is connected to the hot air hood.

6. The sintering flue gas circulation method according to claim 5, characterized in that: The circulation component also includes an air supply regulating valve. The heat exchange device, the dust removal device and the circulation fan are connected in sequence through the pipeline. The air supply regulating valve is installed on the pipeline between the circulation fan and the hot air hood.

7. The sintering flue gas circulation method according to claim 6, characterized in that: The hot air hood is provided with a wheel travel mechanism; the heat exchange equipment is a waste heat boiler.

Images