Method and system for treating dioxin in desulfurization sintering flue gas

Abstract

The invention discloses a desulfurization sintering flue gas dioxin treatment method and system, and relates to the technical field of sintering flue gas dioxin treatment. A flue gas inlet of a fixed bed activated carbon adsorption tower is connected with a tubular heat exchanger through a connecting pipeline, and an electric air mixing valve is mounted at the connecting pipeline; the lower end of the lower part of the adsorption tower is a gas inlet outer hopper, the upper part is fixedly provided with a filler inner hopper, the periphery of the upper end of the filler inner hopper is in close contact with the inner wall of the lower part, the lower end is provided with an activated carbon discharge port and penetrates out of the lower end of the gas inlet outer hopper, and a flue gas inlet is formed in one side below the filler inner hopper; the lower end of the middle part of the adsorption tower is directly communicated with the lower part, the upper end and the upper part are separated through a uniform distributor, and a flue gas outlet is formed in one side of the upper part of the middle part; the upper part of the adsorption tower is used for supplementing and adding filler downwards through an activated carbon feeding hole; the filling inner hopper is higher than the upper end; the device is simple in structure, easy in filler replacement, flexible in arrangement and suitable for removing dioxin pollutants in the flue gas of the sintering machine of the iron and steel enterprise.

Description

Technical Field

[0001] The invention relates to the technical field of dioxin treatment in sintering flue gas, and in particular to a method and system for treating dioxin in desulfurized sintering flue gas. Background Art

[0002] Dioxin is a general term for a class of organic compounds, including more than 200 substances, of which 17 are internationally recognized as toxic. Its generation mechanism is complex and difficult to control. In industrial processes, if the raw materials contain organic carbon, chlorine and oxidized non-ferrous metals, dioxins may be generated at high temperatures. Its main generation pathway is that organic precursors are converted into dioxins during the cooling process; another is that organic matter decomposes and recombine into dioxins during the incineration process. Due to the high toxicity of dioxins and their wide range of existence, dioxins have become a difficult problem that needs to be solved urgently in the waste incineration industry, the steel industry, etc.

[0003] At present, the dioxin emission standard in most countries is 0.1ngTEQ / m 3 Among them, the EU is revising the new emission standard, which is expected to be 0.05ngTEQ / m 3 In many large cities and suburbs in Japan, the standard is far lower than 0.1ngTEQ / m 3 ; Singapore currently implements 0.1ngTEQ / m 3 The future goal is to be much lower than 0.1ngTEQ / m 3 ; The current emission standard in the United States is 0.059ngTEQ / m 3 From the overall trend, the international emission standard of dioxins tends to be 0.05ngTEQ / m 3 And below. The ever-increasing emission standards have put forward higher requirements for the control of dioxins, which is a huge challenge to the existing technology.

[0004] my country's current standards "Emission Standards of Air Pollutants from Iron and Steel Sintering and Pelletizing Industries" (GB 28662-2012) and "Emission Standards of Air Pollutants from Steelmaking Industries" (GB 28664-2012) stipulate the emission standards of dioxins in the flue gas of sintering machines, pelletizing equipment, electric furnaces, converters, etc. in the steel industry. The emission limit of dioxins is 0.5ng TEQ / Nm 3 .

[0005] At present, domestic and foreign domestic waste incineration, medical waste incineration, chemical plant waste incineration and other fields have been widely used in the end-of-pipe treatment of dioxins in flue gas, but the iron and steel industry, especially the dioxin treatment of sintering machine flue gas, is still in the initial stage of research and development. As the flue gas emission standards of steel enterprises become increasingly stringent, the dioxin emission indicators in sintering flue gas will be strictly evaluated in the future.

[0006] Activated carbon injection technology is widely used internationally to treat dioxins. The principle of pollution control is to inject activated carbon powder into the gas and use activated carbon to adsorb dioxins in the exhaust gas. The overall difficulty of activated carbon technology is relatively low and its popularity is high, but it also has certain limitations: First, the emission of dioxins is unstable, and its concentration is difficult to be effectively predicted, and the amount of activated carbon used cannot be accurately estimated during injection. In practice, a fixed amount is often used for injection. If the injection amount is reduced or stopped due to improper operation of the device, dioxins will exceed the standard and the emission control is not accurate enough; second, the essence of activated carbon technology is to adsorb dioxins from the exhaust gas to the solid and mix them into the by-products of sintering flue gas desulfurization, causing secondary pollution to the desulfurization by-products. Third, the injection process of activated carbon has high requirements for the overall reliability of the equipment and the operating level of the personnel, and the practical effect is easily affected and lacks stability. On the other hand, the technology of dioxin online monitoring equipment at home and abroad is not mature enough, and it is impossible to effectively detect dioxins online in real time, resulting in the inability to control emissions normally. Considering the future emission reduction trend, the activated carbon injection adsorption technology for removing dioxins will face many challenges in practical application.

[0007] Up to now, there is basically no special dioxin treatment technology for sintering flue gas in China, and sintering flue gas treatment projects using wet or semi-dry desulfurization processes have basically not started to set up dioxin treatment facilities. In other fields in China, such as domestic waste incineration, cement kiln coordinated incineration and hazardous waste treatment, activated carbon powder spraying and bag filter dust collection technology are still widely used to treat dioxins. However, powder spraying technology is not suitable for wet or semi-dry desulfurization technology because it will produce a large amount of desulfurization ash (or desulfurization gypsum) doped with waste activated carbon powder. If the form of activated carbon adsorption filling box commonly used in other small gas volume fields is adopted, there are many problems such as huge equipment size and excessive activated carbon loading, which is not suitable for direct application to sintering flue gas purification projects with large flue gas volumes. Therefore, a desulfurization sintering flue gas dioxin treatment method and system are urgently needed to solve this problem. Summary of the invention

[0008] The object of the present invention is to provide a method and system for treating dioxins in desulfurized sintering flue gas to solve the problems mentioned in the above background technology.

[0009] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a desulfurization sintering flue gas dioxin treatment system, comprising a fixed bed activated carbon adsorption tower, which is provided with a flue gas inlet and a flue gas outlet, the flue gas inlet is connected to a tubular heat exchanger through a connecting pipe, and an electric air mixing valve is also installed at the connecting pipe for emergency cooling; the fixed bed activated carbon adsorption tower is divided into three parts: upper, middle and lower, wherein the lower part is used for air intake and adsorption, the lower end of the lower part is an air intake outer bucket with a coarse upper part and a thin lower part, and the upper part of the lower part is fixed with a filler inner bucket full of air holes, which is filled with granular activated carbon filler, and the upper end outer periphery of the filler inner bucket is connected to the lower part The fixed-bed activated carbon adsorption tower is in close contact with the inner wall, an activated carbon unloading port is opened at the lower end and passes through the lower end of the air inlet outer hopper, a flue gas inlet is opened on the lower side of the filler inner hopper, the middle part of the fixed-bed activated carbon adsorption tower is a straight cylindrical section of the adsorption tower, the lower end of which is directly connected with the lower part, and the upper end of which is separated from the upper part by a uniform distributor, an activated carbon feeding port is provided in the middle of the uniform distributor and is connected with the upper part, a flue gas outlet is opened on the upper side of the middle part, and the upper part of the fixed-bed activated carbon adsorption tower is used to supplement the filler downward through the activated carbon feeding port; the filler inner hopper is filled with granular activated carbon filler, and the loading height is higher than the upper end of the filler inner hopper.

[0010] Preferably, multiple fixed-bed activated carbon adsorption towers are arranged according to the flue gas treatment capacity, and the connecting pipe is provided with several gas outlet ends. The flue gas inlet of any fixed-bed activated carbon adsorption tower is connected to one gas outlet end of the connecting pipe or the flue gas outlet of another fixed-bed activated carbon adsorption tower.

[0011] Preferably, in the lower part of the fixed bed activated carbon adsorption tower, a porous plate is fixedly provided between the flue gas inlet and the filler inner bucket, which is used to reinforce the filler inner bucket containing the filler, and a plurality of air distribution holes are opened on it for rectifying and evenly flowing the flue gas; a plurality of guide plates are fixedly provided between the porous plate and the air inlet outer bucket to guide the flue gas to be evenly distributed.

[0012] Preferably, an activated carbon feeding port gate valve is installed in the activated carbon feeding port to control the opening when feeding is required, and to separate the upper part and the middle part of the fixed bed activated carbon adsorption tower when feeding is not required; the lower end of the activated carbon discharging port is connected to an electric discharging device for discharging granular activated carbon filler.

[0013] Preferably, a loading electric hoist and a hoisting track are installed at the upper end of the upper part of the fixed bed activated carbon adsorption tower, which are used to lift the packaged granular activated carbon filler to above the activated carbon feeding port.

[0014] Preferably, the uniform distributor includes a conical distribution surface, and its center line is collinear with the center line of the activated carbon feeding port and the center line of the filler inner bucket.

[0015] Preferably, the flue gas inlet and the flue gas outlet are respectively arranged on opposite sides of the fixed bed activated carbon adsorption tower.

[0016] Preferably, a top canopy is fixedly provided at the upper end of the fixed bed activated carbon adsorption tower, and a bottom support frame of the adsorption tower is fixedly provided at the lower end.

[0017] Another technical solution provided by the present invention: a method for treating dioxins in desulfurized sintering flue gas, which adopts the above-mentioned treatment system and includes the following specific contents: connecting the air inlet end of the tubular heat exchanger to the air outlet end of the bag dust collector of the desulfurization system of the sintering machine through the air inlet flue, and connecting the flue gas outlet to the desulfurization fan and chimney of the desulfurization system of the sintering machine through the air outlet flue, completing the gas path connection, so that the flue gas after desulfurization and dust removal passes through the treatment system; controlling the temperature of the sintering flue gas entering the fixed bed activated carbon adsorption tower to be no higher than 70°C through the tubular heat exchanger and the electric mixing valve; discharging a portion of the old granular activated carbon filler located at the lower end of the filler inner bucket through the activated carbon unloading port at regular intervals, and adding the same amount of new filler to the upper end surface of the filler inner bucket from the activated carbon feeding port, so that the uppermost end is always the filler with the strongest adsorption force.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. A method and system for treating dioxins in desulfurized sintering flue gas of the present invention adopts a form in which the upper and lower inner buckets of the filler have inlets and outlets respectively to pass through the area where the flue gas is located, so as to facilitate the replacement of the filler. Since the filler extends to the lower part of the straight cylinder section, it is ensured that the flue gas must pass through a large amount of filler. In this case, the flue gas will always pass through the old filler at the lower part first, and then pass through the new filler at the top layer. In this way, only a part of the filler can be replaced each time, and a higher frequency of discharge and replenishment can be performed. The old filler is first used to contact dioxins with a higher concentration, and then the new filler with stronger adsorption capacity is used to treat the flue gas with a lower dioxin content. In this way, the utilization rate of the filler added each time can be improved, and it is also easier to keep the device's removal capacity for dioxins in the flue gas relatively consistent, and there is no need to stop production for replacing the filler.

[0020] 2. The desulfurization sintering flue gas dioxin treatment method and system of the present invention can be independently arranged after the desulfurization and dust removal device, semi-dry desulfurization device and other purification process equipment. After purification, it is still dry flue gas. The system does not need corrosion protection and has no "white smoke". It avoids the pollution of activated carbon powder to by-products such as desulfurization ash and will not affect the original purification process.

[0021] 3. A method and system for treating dioxins in desulfurized sintering flue gas of the present invention can be composed of two or more fixed-bed activated carbon adsorption towers according to different flue gas volumes. It is applicable to a wide range of flue gas volumes and is theoretically not limited by the scale of flue gas volumes. The structural design of the adsorption tower is flexible, and it has obvious advantages in site layout and online switching control. The overall system resistance of the adsorption tower is small, and no transmission equipment is required inside the activated carbon adsorption tower. It has a low failure rate and low energy consumption. No on-duty is required during normal operation of the equipment, and the workload of personnel inspection and maintenance is extremely small.

[0022] 4. The desulfurization sintering flue gas dioxin treatment method and system of the present invention has a simple structure, reliable technical process, high freedom, easy to realize industrial design parameterization, conducive to industrial mass production, greatly reduces the difficulty of dioxin removal facility design, and greatly saves the engineering project design and installation cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the top view of the structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the main structure of the present invention;

[0025] Figure 3 It is a schematic diagram of the internal structure of the fixed bed activated carbon adsorption tower of the present invention;

[0026] Figure 4 It is a schematic structural diagram of an embodiment of the porous plate of the present invention.

[0027] In the figure: 1. Air inlet flue; 2. Tubular heat exchanger; 3. Electric air mixing valve; 4. Fixed bed activated carbon adsorption tower; 5. Air outlet flue; 6. Flue gas inlet; 7. Air inlet outer bucket; 8. Perforated plate; 9. Filling inner bucket; 10. Straight section of adsorption tower; 11. Uniform distributor; 12. Flue gas outlet; 13. Activated carbon feeding port; 14. Activated carbon feeding port plug valve; 15. Activated carbon unloading port; 16. Electric unloader; 17. Top canopy; 18. Electric hoist for loading; 19. Hoisting track; 20. Bottom support frame of adsorption tower; 21. Granular activated carbon filler. DETAILED DESCRIPTION

[0028] See also Figures 1 to 4A method and system for treating dioxins in flue gas from desulfurization sintering, comprising a fixed bed activated carbon adsorption tower 4, which is provided with a flue gas inlet 6 and a flue gas outlet 12, the flue gas inlet 6 is connected to a tubular heat exchanger 2 through a connecting pipe, and an electric air mixing valve 3 is also installed at the connecting pipe for emergency cooling; the fixed bed activated carbon adsorption tower 4 is divided into three parts: upper, middle and lower, wherein the lower part is used for air intake and adsorption, the lower end of the lower part is an air intake outer bucket 7 with a coarse upper part and a thin lower part, the upper part of the lower part is fixed with a filler inner bucket 9 full of pores, which is filled with granular activated carbon filler 21, and the upper end periphery of the filler inner bucket 9 is in close contact with the inner wall of the lower part, The lower end is provided with an activated carbon discharge port 15 and passes through the lower end of the air inlet outer bucket 7. The flue gas inlet 6 is provided on one side below the filler inner bucket 9. The middle part of the fixed bed activated carbon adsorption tower 4 is an adsorption tower straight cylinder section 10, the lower end of which is directly connected to the lower part, and the upper end of which is separated from the upper part by a uniform distributor 11. The middle part of the uniform distributor 11 is provided with an activated carbon feeding port 13 connected to the upper part, and the flue gas outlet 12 is provided on one side of the upper part of the middle part (in order to make the utilization of the fillers in various places in the filler inner bucket 9 more uniform, the flue gas inlet 6 and the flue gas outlet 12 are preferably respectively arranged on the opposite sides of the fixed bed activated carbon adsorption tower 4, see Figure 3 ), the upper part of the fixed bed activated carbon adsorption tower 4 is used to add fillers downward through the activated carbon feeding port 13; the filler inner bucket 9 is filled with granular activated carbon fillers 21, and the filling height is higher than the upper end of the filler inner bucket 9. Since the filler extends to the lower part of the adsorption tower straight section 10, it is ensured that the flue gas must pass through a large amount of fillers. In this case, the flue gas will always pass through the old fillers at the bottom first, and then pass through the new fillers on the top layer at the end. In this way, only a part of the fillers can be replaced each time, and a higher frequency of discharge and replenishment can be performed. The old fillers are first used to contact dioxins with a higher concentration, and then the new fillers with stronger adsorption capacity are used to treat flue gas with a lower dioxin content. In this way, the utilization rate of the fillers added each time can be improved, and it is also easier to keep the device's removal capacity for dioxins in flue gas relatively consistent.

[0029] According to the different amounts of sintering flue gas to be treated, the fixed-bed activated carbon adsorption tower 4 can be composed of multiple combinations. The interior of the combined adsorption tower can be designed to be through-type or to be designed to be independently partitioned, and the configuration is flexible and changeable. Specifically, in a preferred embodiment, a plurality of fixed-bed activated carbon adsorption towers 4 are provided, and a connecting pipe is provided with a plurality of gas outlet ends. The flue gas inlet 6 of any fixed-bed activated carbon adsorption tower 4 is connected to a gas outlet end of the connecting pipe or a flue gas outlet 12 of another fixed-bed activated carbon adsorption tower 4. Of course, a combination of two or three sets of multiple fixed-bed activated carbon adsorption towers 4 can also be provided to facilitate maintenance or switching in case of failure.

[0030] In the lower part of the fixed bed activated carbon adsorption tower 4, a porous plate 8 can be further fixedly provided between the flue gas inlet 6 and the filler inner bucket 9, which is used to reinforce the filler inner bucket 9 filled with fillers, and at the same time, a plurality of gas distribution holes are opened on it for rectifying and equalizing the flow of flue gas; similarly, in order to make the flue gas distribution more uniform, a number of guide plates can be fixedly provided between the porous plate 8 and the air inlet outer bucket 7 to guide the flue gas to be evenly distributed. The direction, form, quantity, etc. of the guide plates are all well-known technologies in various gas transportation fields, so they will not be repeated here.

[0031] An activated carbon feeding port plug valve 14 may be further installed in the activated carbon feeding port 13 to control the opening when feeding is required, and to separate the upper part and the middle part of the fixed bed activated carbon adsorption tower 4 when feeding is not required; the lower end of the activated carbon discharging port 15 may be further connected to an electric discharger 16 for discharging granular activated carbon filler 21. Specifically, the electric discharger 16 is equipped with an active motor, which can not only avoid discharge blockage compared to natural discharge, but also simply control the discharge speed of the filler by controlling the rotation speed, which is a more convenient control method.

[0032] like Figure 3 As shown, optionally, a loading electric hoist 18 and a lifting rail 19 are installed at the upper end of the upper part of the fixed bed activated carbon adsorption tower 4, which are used to lift the granular activated carbon filler 21 packaged in ton bags or other forms to above the activated carbon feeding port 13. The specific installation positions of the loading electric hoist 18 and the lifting rail 19 are relatively arbitrary. Generally speaking, for reference, the lifting rail 19 can be made to pass directly above the activated carbon feeding port 13 to facilitate the replenishment of fillers, but it can also be used if the position is not directly opposite. Therefore, it can be set according to actual needs, as long as the packaged filler can be lifted above the activated carbon feeding port 13 to facilitate downward feeding. The specific feeding method can be to align the outlet of the packaging bag with the activated carbon feeding port 13, or to set a chute, funnel, etc.

[0033] In addition, the uniform distributor 11 mentioned above can adopt a relatively common structure on the market. For specific reference, please refer to Figure 3 , including a conical distribution surface, and its center line is collinear with the center line of the activated carbon feeding port 13 and the center line of the filling inner bucket 9, in order to allow the fallen filler to be more evenly distributed on the upper end surface of the filling inner bucket 9 below.

[0034] Finally, if it is set outdoors, it is best to have a top canopy 17 fixed on the upper end of the fixed bed activated carbon adsorption tower 4; in addition, the lower end of the fixed bed activated carbon adsorption tower 4 generally needs to be fixed with an adsorption tower bottom support frame 20, which can be made in the form of a steel structure frame or a reinforced concrete frame, and can be equipped with necessary ladders, guardrails and maintenance platforms, etc. Of course, other forms of fixing can also be used, such as the outer periphery of the junction of the middle part and the upper part is fixed to the steel structure foundation by welding, and an operating platform is set on the outer side of the upper part, etc., which can be specifically set according to needs.

[0035] The method for treating dioxins in desulfurized sintering flue gas by using the treatment system of the present invention is as follows: the air inlet end of the tubular heat exchanger 2 is connected to the air outlet end of the bag filter of the desulfurization system of the sintering machine through the air inlet flue 1, and the flue gas outlet 12 is connected to the desulfurization fan and chimney of the desulfurization system of the sintering machine through the air outlet flue 5, so as to complete the gas path connection and allow the flue gas after desulfurization and dust removal to pass through the treatment system; the temperature of the sintering flue gas entering the fixed bed activated carbon adsorption tower 4 is controlled to be no higher than 70°C by the tubular heat exchanger 2 and the electric mixing valve 3; at regular intervals, a portion of the old granular activated carbon filler 21 located at the lower end of the filler inner bucket 9 is discharged through the activated carbon unloading port 15, and the same amount of new filler is added to the upper end surface of the filler inner bucket 9 from the activated carbon feeding port 13 to keep the upper end always as the filler with the strongest adsorption force.

[0036] Of course, all the fillers can be replaced at the same time, but in the structure of the present invention, this utilization rate is not as good as the above method, because the filler at the lower part of the filler inner bucket 9 is not a part that the smoke must pass through, so replacing all of them will cause waste.

[0037] The above are only preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope defined by the claims.

[0038] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

Claims

1. A desulfurization sintering flue gas dioxin treatment system, characterized by: The invention comprises a fixed bed activated carbon adsorption tower (4), which is provided with a flue gas inlet (6) and a flue gas outlet (12), wherein the flue gas inlet (6) is connected to a tubular heat exchanger (2) via a connecting pipe, and an electric air mixing valve (3) is also installed at the connecting pipe for emergency cooling; the fixed bed activated carbon adsorption tower (4) is divided into three parts: upper, middle and lower parts, wherein the lower part is used for air intake and adsorption, the lower end of the lower part is an air intake outer bucket (7) with a coarse upper part and a thin lower part, the upper part of the lower part is fixed with a filler inner bucket (9) covered with air holes, the upper end outer periphery of the filler inner bucket (9) is in close contact with the inner wall of the lower part, and the lower end is provided with an activated carbon discharge port (15) which passes through the lower end of the air intake outer bucket (7) The flue gas inlet (6) is provided on one side below the filler inner bucket (9); the middle part of the fixed bed activated carbon adsorption tower (4) is a straight section (10) of the adsorption tower, the lower end of which is directly connected to the lower part, and the upper end of which is separated from the upper part by a uniform distributor (11); the middle part of the uniform distributor (11) is provided with an activated carbon feeding port (13) connected to the upper part; the flue gas outlet (12) is provided on one side above the middle part; the upper part of the fixed bed activated carbon adsorption tower (4) is used to supplement the filler downward through the activated carbon feeding port (13); the filler inner bucket (9) is filled with granular activated carbon filler (21), and the loading height is higher than the upper end of the filler inner bucket (9).

2. A desulfurization sintering flue gas dioxin treatment system according to claim 1, characterized in that: The fixed bed activated carbon adsorption tower (4) is provided with a plurality of them according to the flue gas treatment capacity, and the connecting pipe is provided with a plurality of gas outlet ends, and the flue gas inlet (6) of any fixed bed activated carbon adsorption tower (4) is connected to a gas outlet end of the connecting pipe or the flue gas outlet (12) of another fixed bed activated carbon adsorption tower (4).

3. A desulfurization sintering flue gas dioxin treatment system according to claim 1 or 2, characterized in that: In the lower part of the fixed bed activated carbon adsorption tower (4), a porous plate (8) is fixedly arranged between the flue gas inlet (6) and the filler inner bucket (9) for reinforcing the filler inner bucket (9) loaded with filler, and a plurality of gas distribution holes are opened on the porous plate for rectifying and evenly distributing the flue gas; a plurality of guide plates are fixedly arranged between the porous plate (8) and the air inlet outer bucket (7) for guiding the flue gas to be evenly distributed.

4. A desulfurization sintering flue gas dioxin treatment system according to claim 1 or 2, characterized in that: The activated carbon feeding port (13) is provided with an activated carbon feeding port plug valve (14) for controlling the opening when feeding is required and separating the upper part and the middle part of the fixed bed activated carbon adsorption tower (4) when feeding is not required; the lower end of the activated carbon discharging port (15) is connected with an electric discharger (16) for discharging the granular activated carbon filler (21).

5. A desulfurization sintering flue gas dioxin treatment system according to claim 1 or 2, characterized in that: The upper end of the upper part of the fixed bed activated carbon adsorption tower (4) is equipped with a loading electric hoist (18) and a lifting rail (19) for lifting the packaged granular activated carbon filler (21) above the activated carbon feeding port (13).

6. A desulfurization sintering flue gas dioxin treatment system according to claim 1 or 2, characterized in that: The uniform distributor (11) comprises a conical distribution surface, and its center line is collinear with the center line of the activated carbon feeding port (13) and the center line of the filler inner bucket (9).

7. A desulfurization sintering flue gas dioxin treatment system according to claim 1 or 2, characterized in that: The flue gas inlet (6) and the flue gas outlet (12) are respectively arranged on two opposite sides of the fixed bed activated carbon adsorption tower (4).

8. A desulfurization sintering flue gas dioxin treatment system according to claim 1 or 2, characterized in that: The fixed bed activated carbon adsorption tower (4) is provided with a top canopy (17) at the upper end and an adsorption tower bottom support frame (20) at the lower end.

9. A method for treating dioxins in desulfurized sintering flue gas, using the treatment system according to any one of claims 1 to 8, characterized in that: The invention comprises the following specific contents: connecting the air inlet end of the tubular heat exchanger (2) to the air outlet end of the bag filter of the desulfurization system of the sintering machine through the air inlet flue (1); connecting the flue gas outlet (12) to the desulfurization fan and chimney of the desulfurization system of the sintering machine through the air outlet flue (5), completing the air path connection, so that the flue gas after desulfurization and dust removal passes through the treatment system; controlling the temperature of the sintering flue gas entering the fixed bed activated carbon adsorption tower (4) to be no higher than 70°C through the tubular heat exchanger (2) and the electric air mixing valve (3); discharging a portion of the old granular activated carbon filler (21) located at the lower end of the filler inner bucket (9) through the activated carbon discharge port (15) at regular intervals, and replenishing the same amount of new filler to the upper end surface of the filler inner bucket (9) from the activated carbon feeding port (13), so that the uppermost end is always the filler with the strongest adsorption force.

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