Device for removing dioxin in flue gas of sintering machine

Abstract

The utility model discloses a sintering machine flue gas dioxin removal device, 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 adsorption tower is divided into upper, middle and lower parts; the lower end of the lower part is a gas inlet outer hopper, the upper part is fixedly provided with a filler inner hopper, the filler inner hopper is filled with granular activated carbon filler, the lower end of the filler inner hopper 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 is directly communicated with the lower part, and the upper end is separated from the upper part through a uniform distributor; the 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 the activated carbon feeding hole; the device is simple in structure, easy in filler replacement and flexible in arrangement, and is suitable for removing dioxin pollutants in the flue gas of the sintering machine in iron and steel enterprises.

Description

TECHNICAL FIELD

[0001] The utility model relates to sintering flue gas dioxin treatment technical field, concretely is a kind of sintering machine flue gas dioxin removal device. BACKGROUND

[0002] Dioxin is the collective term of a class of organic compounds, including more than 200 substances, of which 17 are internationally recognized as toxic, and 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 under high temperature. The main generation pathway is that organic precursors are converted into dioxins during the cooling process; and organic matter is decomposed and recombined into dioxins during incineration. Due to the high toxicity and wide range of dioxins, it has become a difficult problem that needs to be solved in the waste incineration industry, steel industry and other industries.

[0003] At present, the dioxin emission standard of most countries in the world is 0.1 ng TEQ / m 3 . Among them, the European Union is revising the new emission standard, which is expected to be around 0.05 ng TEQ / m 3 ; The standard in many cities and suburbs of Japan is much lower than 0.1 ng TEQ / m 3 ; Singapore currently implements a standard of 0.1 ng TEQ / m 3 , but the future goal will be much lower than 0.1 ng TEQ / m 3 ; The current emission standard of the United States is 0.059 ng TEQ / m 3 . From the overall trend, the international emission standard of dioxin tends to be 0.05 ng TEQ / m 3 and below. The continuously improving emission standard puts higher requirements on the control of dioxin, which is a great challenge to existing technology.

[0004] The current standards of China, "Steel Sintering and Pelletizing Industry Atmospheric Pollutant Emission Standard" (GB 28662-2012) and "Steelmaking Industry Atmospheric Pollutant Emission Standard" (GB 28664-2012), stipulate the emission standard of dioxin in the flue gas of sintering machine, pelletizing equipment, electric furnace, converter and other equipment in the steel industry, and the emission limit of dioxin is 0.5 ng TEQ / Nm 3 .

[0005] Today, end-of-pipe treatment of dioxin in flue gas has been widely carried out in many fields such as domestic waste incineration, medical waste incineration, chemical plant waste incineration and other fields, but the treatment of dioxin in sintering machine flue gas in the steel industry is still in the initial stage of research and development. With the increasingly stringent emission standards of steel enterprises, the dioxin emission indicators in sintering flue gas will be strictly examined in the future.

[0006] The activated carbon injection technology is widely used in the world to treat dioxin. The principle of pollution treatment is to inject activated carbon powder into the gas, and the activated carbon is used to adsorb dioxin in the waste gas. The activated carbon technology has low overall difficulty and high popularity, but it also has certain limitations: first, the emission of dioxin is unstable, and its concentration is difficult to be effectively predicted, so the amount of activated carbon used cannot be accurately estimated when injection. In actual operation, a fixed amount is usually used for injection. If the injection amount is reduced or stopped due to improper operation of the device, the dioxin will exceed the standard, and the emission control is not accurate enough. Second, the essence of the activated carbon technology is to adsorb dioxin from the waste gas onto the solid and mix it into the by-product of the sintering flue gas desulfurization, which causes secondary pollution to the by-product of the desulfurization. Third, the injection process of activated carbon has high requirements for the reliability of the equipment and the operation level of the personnel, and the actual operation effect is easily affected and lacks stability. On the other hand, the online monitoring equipment technology of dioxin at home and abroad is not mature enough, and it cannot effectively detect dioxin in real time, which leads to the inability to control the emission in normal times. In view of the future emission reduction trend, the activated carbon injection and adsorption removal of dioxin technology will face many challenges in practical application.

[0007] Up to now, there is basically no special treatment technology for dioxin in sintering flue gas in China. The sintering flue gas treatment projects using wet or semi-dry desulfurization process basically have not started to set up dioxin treatment facilities. In other fields such as domestic waste incineration, cement kiln co-incineration treatment of hazardous waste, etc., the activated carbon injection and bag dust collector dust removal technology are still widely used to treat dioxin. However, the injection technology is not suitable for wet or semi-dry desulfurization technology, because a large amount of desulfurization ash (or desulfurization gypsum) mixed with waste activated carbon powder will be produced. If other forms of activated carbon adsorption filler boxes commonly used in small gas fields are used, there are many problems such as large equipment size and large amount of activated carbon loading, which are not suitable for direct application to large sintering flue gas purification projects. Therefore, a sintering machine flue gas dioxin removal device is needed to solve this problem. Practical new type content

[0008] The purpose of the present application is to provide a sintering machine flue gas dioxin removal device to solve the problems mentioned in the background art.

[0009] To achieve the above object, the utility model provides the following technical scheme: A sintering machine flue gas dioxin removal device, it is provided with flue gas import and flue gas export including fixed bed activated carbon adsorption tower, flue gas import is connected with tubular heat exchanger through connecting pipeline, and electric air mixing valve is also installed at connecting pipeline place for emergency cooling, fixed bed activated carbon adsorption tower divides into three parts of upper, middle and lower, wherein lower part is used for air inlet and adsorption, the lower end of lower part is air inlet outer bucket of upper thick lower thin, the upper part in lower part is fixed with the filler inner bucket that is full of air hole, and it is equipped with granular activated carbon filler, the lower end of filler inner bucket is equipped with activated carbon discharge port and passes the lower end of air inlet outer bucket, flue gas import is equipped with in the lower side of filler inner bucket, the middle part of fixed bed activated carbon adsorption tower is adsorption tower straight cylinder section, and its lower end is directly communicated with lower part, and its upper end is separated through even distributor with upper part, and the middle part of even distributor is equipped with activated carbon feeding port and is communicated with upper part, and flue gas export is equipped with in the upper side of middle part, and the upper part of fixed bed activated carbon adsorption tower is used to supplement and add filler to the lower through activated carbon feeding port.

[0010] Preferably, the fixed bed activated carbon adsorption tower is provided with multiple according to the flue gas treatment capacity, the connecting pipeline is provided with several gas outlets, and the flue gas inlet of any fixed bed activated carbon adsorption tower is connected with one gas outlet of the connecting pipeline or the flue gas outlet of another fixed bed activated carbon adsorption tower.

[0011] Preferably, a perforated plate is fixedly arranged in the lower part of the fixed bed activated carbon adsorption tower between the flue gas inlet and the filler inner bucket, for reinforcing the filler inner bucket loaded with the filler, and a plurality of gas distribution holes are arranged on the perforated plate for rectifying and distributing the flue gas; a plurality of guide plates are fixedly arranged between the perforated plate and the air inlet outer bucket for guiding the uniform distribution of the flue gas.

[0012] Preferably, a plug valve is arranged in the activated carbon feeding port for controlling the opening when the filler needs to be added, and separating the upper part from the middle part of the fixed bed activated carbon adsorption tower when the filler does not need to be added; an electric unloader is connected to the lower end of the activated carbon discharge port for discharging the granular activated carbon filler.

[0013] Preferably, an upper end of the upper part of the fixed bed activated carbon adsorption tower is provided with a feeding electric hoist and a hoisting track for hoisting the packaged granular activated carbon filler above the activated carbon feeding port.

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

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

[0016] Preferably, the gas inlet end of the tube heat exchanger is connected to the gas outlet end of the bag-type dust collector of the sintering machine desulfurization system through a gas inlet flue, and the flue gas outlet is communicated to the desulfurization fan and the chimney of the sintering machine desulfurization system through a gas outlet flue.

[0017] Preferably, a top rain shed is fixedly arranged at the upper end of the fixed bed activated carbon adsorption tower, and an adsorption tower bottom support frame is fixedly arranged at the lower end of the fixed bed activated carbon adsorption tower.

[0018] Compared with the prior art, the sintering machine flue gas dioxin removal device has the following beneficial effects:

[0019] 1. The sintering machine flue gas dioxin removal device can be independently arranged after the desulfurization and dust removal device, the semi-dry desulfurization device and other purification process equipment, and the dry flue gas after purification does not need corrosion prevention and does not produce white smoke, thereby avoiding the pollution of activated carbon powder to by-products such as desulfurization ash and not affecting the original purification process.

[0020] 2. The sintering machine flue gas dioxin removal device has the form that the upper and lower inner buckets of the filler are respectively provided with inlet and outlet penetrating through the flue gas area, which is convenient for online replacement of the filler, and even a part of the filler can be replaced each time. In this case, the flue gas always passes through the old filler in the lower part first, and finally passes through the new filler in the uppermost layer to reach the straight cylinder section, so that the utilization rate of the filler supplemented each time can be further improved, the removal capacity of the device for dioxin in the flue gas is relatively consistent, and the device does not need to be stopped for replacement of the filler.

[0021] 3. The sintering machine flue gas dioxin removal device is composed of two or more fixed bed activated carbon adsorption towers according to different flue gas amounts, is suitable for a large flue gas amount range, is not limited in theory by the scale of the flue gas amount, has flexible structural design of the adsorption tower, and has obvious advantages in site arrangement and online switching control; the overall resistance of the system of the adsorption tower is small, any transmission equipment does not need to be arranged in the activated carbon adsorption tower, the failure rate is low, the energy consumption is low, the device does not need to be attended during normal operation, and the workload of personnel inspection and maintenance is extremely small.

[0022] 4. The sintering machine flue gas dioxin removal device has simple structure and reliable technical process, has high freedom, is easy to realize industrial design parameterization, is beneficial to industrialized batch production, greatly reduces the difficulty of dioxin removal facility design, and greatly saves the design and installation period of the engineering project. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a top view structural schematic diagram of the utility model;

[0024] Figure 2 It is a front view structural schematic diagram of the utility model;

[0025] Figure 3The utility model discloses a fixed bed activated carbon adsorption tower internal structure schematic view.

[0026] Figure 4 It is structure schematic view of one implementation mode of the porous plate.

[0027] In the drawing: 1, inlet flue; 2, tubular heat exchanger; 3, electric air mixing valve; 4, fixed bed activated carbon adsorption tower; 5, outlet flue; 6, flue gas inlet; 7, inlet outer hopper; 8, porous plate; 9, filler inner hopper; 10, adsorption tower straight cylinder section; 11, uniform distributor; 12, flue gas outlet; 13, activated carbon feeding port; 14, activated carbon feeding port plug valve; 15, activated carbon discharge port; 16, electric discharger; 17, top canopy; 18, loading electric hoist; 19, hoisting track; 20, adsorption tower bottom support frame; 21, granular activated carbon filler. DETAILED DESCRIPTION

[0028] Referring to Figures 1 to 4 A sintering machine flue gas dioxin removal device, including fixed bed activated carbon adsorption tower 4, it is provided with flue gas inlet 6 and flue gas outlet 12, flue gas inlet 6 is connected with tubular heat exchanger 2 through connecting pipeline, and electric air mixing valve 3 is also installed at connecting pipeline for emergency cooling;Fixed bed activated carbon adsorption tower 4 is divided into upper, middle and lower three parts, wherein the lower part is used for inlet and adsorption, the lower end of the lower part is inlet outer hopper 7 with upper thick and lower thin, the upper part in the lower part is fixedly provided with filler inner hopper 9 with gas holes, and granular activated carbon filler 21 is loaded in it, the lower end of filler inner hopper 9 is provided with activated carbon discharge port 15 and passes through the lower end of inlet outer hopper 7, flue gas inlet 6 is arranged on the lower side of filler inner hopper 9, the middle part of fixed bed activated carbon adsorption tower 4 is adsorption tower straight cylinder section 10, and the lower end thereof is directly communicated with the lower part, and the upper end thereof is separated from the upper part through uniform distributor 11, the middle part of uniform distributor 11 is provided with activated carbon feeding port 13 and is communicated with the upper part, flue gas outlet 12 is arranged on the upper side of the middle part (in order to make the utilization of each filler in filler inner hopper 9 more average, flue gas inlet 6 and flue gas outlet 12 are preferably arranged on the opposite sides of fixed bed activated carbon adsorption tower 4, referring to Figure 3 ), the upper part of fixed bed activated carbon adsorption tower 4 is used for supplementing and adding filler downward through activated carbon feeding port 13.

[0029] Depending on the amount of sintering flue gas to be processed, the fixed-bed activated carbon adsorption tower 4 can be composed of multiple combinations. The internal structure of the combined adsorption towers can be interconnected or independently partitioned, allowing for flexible configuration. Specifically, in a preferred embodiment, multiple fixed-bed activated carbon adsorption towers 4 are provided, with several gas outlets opened in the connecting pipes. The flue gas inlet 6 of any fixed-bed activated carbon adsorption tower 4 is connected to one gas outlet of the connecting pipe or the flue gas outlet 12 of another fixed-bed activated carbon adsorption tower 4. Of course, combinations of two or three sets of multiple fixed-bed activated carbon adsorption towers 4 can also be set up for easy switching during maintenance or failure.

[0030] In the lower part of the fixed-bed activated carbon adsorption tower 4, a perforated plate 8 can be further fixed between the flue gas inlet 6 and the packing hopper 9 to reinforce and support the packing hopper 9 containing the packing. At the same time, multiple gas distribution holes are opened on it for rectifying and equalizing the flue gas. Similarly, in order to make the flue gas distribution more uniform, several guide plates can also be fixed between the perforated plate 8 and the inlet hopper 7 to guide the flue gas to distribute evenly. The direction, form and number of the guide plates are all well-known technologies in the field of gas transportation, so they will not be described in detail.

[0031] An activated carbon feed port gate valve 14 can be further installed inside the activated carbon feed port 13 to control the opening when feeding is needed, and to separate the upper and middle parts of the fixed bed activated carbon adsorption tower 4 when feeding is not needed; an electric unloader 16 can be further connected to the lower end of the activated carbon discharge port 15 to discharge the granular activated carbon packing 21. Specifically, the electric unloader 16, because it has an active motor, can not only avoid discharge blockage compared to natural discharge, but also easily control the discharge speed of the packing by controlling the rotation speed, which is a more convenient control method.

[0032] like Figure 3 As shown, optionally, the upper part of the fixed-bed activated carbon adsorption tower 4 is equipped with a feeding electric hoist 18 and a lifting track 19, 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 position of the feeding electric hoist 18 and the lifting track 19 is relatively arbitrary. Generally speaking, for reference, the lifting track 19 can be placed directly above the activated carbon feeding port 13 to facilitate the replenishment of filler. However, it can also be used if the position is not directly aligned. 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 for convenient 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 up a chute, funnel, etc.

[0033] In addition, the uniform feeder 11 mentioned above can adopt a structure that is commonly found on the market. For specific reference, please refer to [link / reference needed]. Figure 3It includes a conical fabric surface, and its center line is collinear with the center line of the activated carbon feed port 13 and the center line of the packing hopper 9. The purpose is to make the falling packing more evenly distributed on the upper surface of the packing hopper 9 below.

[0034] The dioxin removal device for sintering machine flue gas of this utility model can be connected to the desulfurization system in the following way: the inlet end of the tubular heat exchanger 2 is connected to the outlet end of the bag filter of the sintering machine desulfurization system through the inlet flue 1, and the flue gas outlet 12 is connected to the desulfurization fan and chimney of the sintering machine desulfurization system through the outlet flue 5, so that the flue gas after dust removal passes through this device before being discharged.

[0035] Finally, if installed outdoors, the fixed bed activated carbon adsorption tower 4 should preferably be equipped with a roof canopy 17 at the top. In addition, the bottom of the fixed bed activated carbon adsorption tower 4 generally needs to be equipped with a bottom support frame 20, which can be made of steel structure frame or reinforced concrete frame, and equipped with necessary ladders, guardrails and maintenance platforms, etc. Of course, other forms of fixation can also be used, such as welding the outer perimeter of the junction between the middle part and the upper part to the steel structure foundation, and setting an operating platform on the outer side of the upper part, etc., as needed.

[0036] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the scope of protection of this utility model. Therefore, the scope of protection of this utility model should be determined by the scope defined in the claims.

[0037] Any aspects of this utility model not described in detail are known to those skilled in the art.

Claims

1. A dioxin removal device for sintering machine flue gas, characterized in that: The fixed bed activated carbon adsorption tower (4) is provided with a plurality of smoke inlets (6) according to the smoke treatment amount, and a plurality of gas outlet ends are arranged in the connecting pipeline.

2. The sintering machine off-gas dioxin removal device according to claim 1, characterized in that: The lower part of the fixed bed activated carbon adsorption tower (4) is fixedly provided with a perforated plate (8) between the smoke inlet (6) and the filler inner bucket (9) for reinforcing the filler inner bucket (9) loaded with the filler, and a plurality of gas distribution holes are arranged on the perforated plate (8) for rectifying and distributing the smoke.

3. A device for removing dioxins from sintering machine flue gas 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 needed, and the upper part of the fixed bed activated carbon adsorption tower (4) is separated from the middle part when feeding is not needed.

4. The sintering machine flue gas dioxin removal device 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 provided with an upper feeding electric hoist (18) and a hoisting track (19) for hoisting the packaged granular activated carbon filler (21) above the activated carbon feeding port (13).

5. The sintering machine off-gas dioxin removal device according to claim 1 or 2, characterized in that: The uniform distributor (11) comprises a conical distribution surface, and the center line thereof is collinear with the center line of the activated carbon feeding port (13) and the center line of the filler inner bucket (9).

6. The sintering machine off-gas dioxin removal device according to claim 1 or 2, characterized in that: The smoke inlets (6) and the smoke outlets (12) are arranged on opposite sides of the fixed bed activated carbon adsorption tower (4).

7. The sintering machine off-gas dioxin removal device according to claim 1 or 2, characterized in that: The gas inlet end of the tubular heat exchanger (2) is connected to the gas outlet end of the bag-type dust collector of the sintering machine desulfurization system through a gas inlet flue (1), and the smoke outlet (12) is communicated to the desulfurization fan and the chimney of the sintering machine desulfurization system through a gas outlet flue (5).

8. The sintering machine off-gas dioxin removal device according to claim 1 or 2, characterized in that: ​ 9. The sintering machine off-gas dioxin removal device according to claim 1 or 2, characterized in that: The fixed bed activated carbon adsorption tower (4) is fixed with a top awning (17) at the upper end and an adsorption tower bottom support frame (20) at the lower end.

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