Pure dry purification treatment system for flue gas of electric furnace

Abstract

The utility model provides an electric furnace flue gas pure dry method purification treatment system which comprises an electric furnace, a continuous preheating device, a mixed combustion settling cylinder, a waste heat boiler and a dust remover which are sequentially communicated, and the electric furnace is communicated with the mixed combustion settling cylinder through a first extraction pipeline. The continuous preheating device is communicated with the mixed combustion settling barrel through a second extraction pipeline; the waste heat boiler receives high-temperature flue gas output by the mixed combustion settling cylinder, the high-temperature flue gas and cooling water are shunted to complete the heat exchange process, and then the flue gas is converged and input into the bag type dust collector to complete the dust removal process and is discharged from the chimney. According to the utility model, the electric furnace flue gas is extracted into the mixed combustion settling barrel through the additionally arranged first extraction pipeline, and after the flue gas is mixed with preheated flue gas, the flue gas is retained in the mixed combustion settling barrel for 2-3 seconds under the action of the auxiliary combustor while the temperature of the flue gas is kept at 800 DEG C or above, so that toxic substances such as dioxin / furan are decomposed; and the waste heat boiler is used for quenching the mixed flue gas, so that the secondary synthesis of toxic substances is effectively avoided.

Description

Technical Field

[0001] This utility model relates to the field of electric furnace flue gas purification technology, and in particular to a pure dry purification system for electric furnace flue gas. Background Technology

[0002] To effectively reduce flue gas temperature and eliminate toxic substances such as dioxins and furans, the process of the CONSTEEL electric arc furnace steelmaking internal high-temperature flue gas purification system, which is widely used both domestically and internationally, is as follows: the high-temperature flue gas generated during the CONSTEEL electric arc furnace smelting process is preheated with scrap steel (approximately 450-650°C) → combustion settling chamber → evaporative cooler (rapid cooling) → mixing tower (mixing with roof hood flue gas to reduce flue gas temperature) → bag filter (filtration and purification) → fan → chimney discharge.

[0003] However, the existing CONSTEEL electric arc furnace steelmaking dust removal system has the following drawbacks:

[0004] 1. The flue gas temperature in the CONSTEEL electric arc furnace continuous scrap preheating system is sometimes too low (450-650℃ < 800℃). Due to steel companies' pursuit of high power consumption targets and high scrap preheating temperatures in electric arc furnace steelmaking, the temperature entering the quenching unit is generally not high (450-650℃ < 800℃). Much dioxin is not fully combusted and remains in the electric arc furnace flue gas, and the quenching unit cannot eliminate this portion of toxic dioxin substances. Purifying the electric arc furnace flue gas using an evaporative cooler (quenching) + bag / cartridge dust collector cannot reliably and stably remove dioxins from the flue gas, and it cannot guarantee that the dioxin content in the electric arc furnace exhaust gas meets standards.

[0005] 2. To ensure that harmful substances such as dioxins / furans contained in the CONSTEEL electric arc furnace flue gas are completely burned and decomposed, it is necessary to continuously inject a certain amount of combustible gas to increase the temperature of the CONSTEEL electric arc furnace flue gas (>800℃), which to some extent increases the cost of steelmaking in the CONSTEEL electric arc furnace.

[0006] 3. This CONSTEEL electric furnace flue gas purification process loses a large amount of waste heat in the electric furnace flue gas; in addition, it consumes a large amount of water; and causes the "plume" problem.

[0007] 4. During peak oxygen blowing smelting, the CONSTEEL electric furnace produces high-temperature flue gas. When passing through the continuous scrap preheating device, the scrap steel is often preheated to an excessively high temperature, causing the scrap steel to soften and stick (or due to the presence of certain low-temperature alloys in the scrap steel). This has a certain impact on the stable operation of the continuous scrap preheating conveying device. Utility Model Content

[0008] The technical problem to be solved by this utility model is to overcome the defects of the existing technology. This utility model proposes a pure dry purification treatment system for electric furnace flue gas, which avoids the sticking of scrap steel during continuous preheating of CONSTEEL electric furnace caused by excessively high temperature flue gas, takes into account the decomposition of dioxins / furans contained in electric furnace flue gas and avoids their resynthesis, and at the same time avoids the occurrence of "plume" problem.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a pure dry purification system for electric furnace flue gas, comprising an electric furnace, a continuous preheating device, a mixing combustion settling cylinder, a waste heat boiler, and a dust collector connected in sequence.

[0010] The electric furnace and the mixed combustion settling cylinder are connected by a first extraction pipe, and the continuous preheating device is connected to the mixed combustion settling cylinder by a second extraction pipe. The output ends of the first extraction pipe and the second extraction pipe are fixed based on different positions of the upper section of the mixed combustion settling cylinder.

[0011] The waste heat boiler receives high-temperature flue gas from the mixed combustion settling cylinder, and the high-temperature flue gas is diverted to cool water to complete the heat exchange process through a heat transfer medium. Then, the flue gas is merged and fed into a bag filter to complete the dust removal process before being discharged from the chimney.

[0012] Furthermore, the output end of the second extraction pipe is connected to the top of the mixing combustion settling cylinder, and a second regulating valve for controlling its on / off state is provided on the second extraction pipe. The output end of the first extraction pipe is connected to the mixing combustion settling cylinder based on the side of the upper section of the mixing combustion settling cylinder, and a first regulating valve for controlling its on / off state is provided on the first extraction pipe. An auxiliary burner is fixedly provided on the side wall of the mixing combustion settling cylinder, close to the lower part of the output end of the first extraction pipe.

[0013] Furthermore, the mixed combustion settling cylinder includes a first chamber and a settling ash hopper. The settling ash hopper is fixedly disposed below the first chamber. The width of the settling ash hopper is greater than the width of the first chamber. The lower end of the first chamber is smoothly connected to the upper edge of the settling ash hopper.

[0014] Furthermore, the waste heat boiler includes a main flue pipe, a boiler body, and a main flue pipe. The main flue pipe and the main flue pipe are fixedly installed at both ends of the boiler body. A dry ice descaling device is also installed on the main flue pipe. The dry ice descaling device is located on the same axis as the boiler body, and the dry ice descaling device can move vertically into the boiler body.

[0015] Furthermore, the boiler body comprises multiple boiler bodies, each including a bundled sleeve and nozzles located at both ends of the bundled sleeve. The bundled sleeve consists of an inner tube and an outer tube, with fixed-distance ribs fixedly arranged between the inner and outer tubes. The nozzles are fixedly arranged at both ends of the inner tube. High-temperature flue gas flows in the inner tube, while cooling water flows in the gap between the inner and outer tubes.

[0016] Furthermore, the number of dry ice descaling devices is the same as that of the boiler body. Each dry ice descaling device includes a driving device and a spray head fixedly installed at a certain distance below the driving device. The spray head can reciprocate along the length of the inner tube with the driving device. The spray head is supplied with block or spherical dry ice by a dry ice sending device.

[0017] The spray head is fixedly mounted below the drive device by a dry ice descaling rod, and also includes a conveying channel for conveying dry ice, the conveying channel being arranged within the dry ice descaling rod along its length.

[0018] Furthermore, the dust collector includes several bag filters, which are arranged laterally and combined into one unit, with adjacent bag filters being connected and interconnected.

[0019] Furthermore, the waste heat boiler and the dust collector are connected by an electric furnace flue gas main pipeline, and a flue gas temperature detection device is installed on the electric furnace flue gas main pipeline.

[0020] A fan and a chimney are connected sequentially above the output end of the dust collector.

[0021] It also includes a first pipe and a second pipe;

[0022] One end of the first pipe is connected between the flue gas temperature detection device and the input end of the dust collector, and the other end is connected between the output end of the dust collector and the fan. A first differential pressure detection device is installed on the first pipe.

[0023] One end of the second pipe is connected between the flue gas temperature detection device and the input end of the dust collector. The same number of test branches as the bag filter are provided on the second pipe, and a second differential pressure detection device is provided on each of the test branches.

[0024] Furthermore, a pneumatic conveying device is fixedly installed at the lower end of the mixed combustion settling cylinder, the waste heat boiler, and each of the bag filters to transport the accumulated ash in the bag filters to a centralized ash silo.

[0025] Furthermore, a method for purifying electric furnace flue gas using a pure dry purification system includes the following steps:

[0026] S1. The electric furnace flue gas located in the electric furnace and the preheating flue gas located in the continuous preheating device are mixed to obtain mixed flue gas, wherein the temperature of the high-temperature flue gas is not less than 800°C and the temperature of the preheating flue gas is 450-650°C.

[0027] S2. The resulting mixed flue gas is subjected to combustion in a mixed combustion settling cylinder at an environment of not less than 800℃ for 2-3 seconds.

[0028] S3. The high-temperature flue gas obtained is diverted in the waste heat boiler to the boiler body and after non-contact heat exchange with the cooling water, it is discharged after merging.

[0029] S4. After the flue gas is cleaned in the dust collector, it flows to the chimney and is discharged into the atmosphere.

[0030] Compared with the prior art, the beneficial effects of this utility model include:

[0031] 1) The high-temperature flue gas from the electric furnace is extracted into the mixing combustion settling tank through the newly added first extraction pipe. After mixing with the preheated flue gas from the continuous preheating device, the flue gas temperature is maintained at no less than 800℃ under the action of the auxiliary burner. The flue gas stays in the mixing combustion settling tank for 2-3 seconds to ensure that the toxic substances such as dioxins / furans contained in the flue gas are burned and decomposed. The high-temperature mixed flue gas is then rapidly cooled by the waste heat boiler, which effectively avoids the resynthesis of toxic substances.

[0032] 2) By adding a first extraction pipe above the electric furnace, the high-temperature flue gas inside the electric furnace can be extracted, which can appropriately reduce the temperature inside the electric furnace, thereby effectively avoiding the sticking problem of scrap steel charge in the electric furnace scrap steel continuous preheating device caused by excessively high flue gas temperature.

[0033] 3) Through the clustered sleeve installed in the boiler body, the high-temperature flue gas and cooling water are located in different areas of the clustered sleeve and complete the heat exchange, effectively recovering the waste heat of the high-temperature flue gas without causing the heat of the high-temperature flue gas to be wasted. Moreover, there is no contact between the high-temperature flue gas and the cooling water during the heat exchange process, so that even if the cooling water vaporizes during the flue gas cooling process, it will not mix with the flue gas, thus effectively avoiding the problem of "plume". Attached Figure Description

[0034] The disclosure of this utility model is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. In the drawings, the same reference numerals are used to refer to the same parts. Wherein:

[0035] Figure 1 The schematic diagram shows the overall structure of the electric furnace flue gas pure dry purification system;

[0036] Figure 2 The schematic diagram shows the overall structure of the waste heat boiler;

[0037] Figure 3 The schematic diagram shows the cross-sectional structure of the boiler body;

[0038] Figure 4 The schematic diagram shows the transverse cross-sectional structure of the bundled sleeve;

[0039] Figure 5 The schematic diagram shows the overall structure of the dry ice descaling device.

[0040] Numbering in the diagram: 1-Electric furnace, 2-Continuous preheating device, 3-Mixed combustion settling cylinder, 4-Waste heat boiler, 5-Dust collector, 6-First extraction pipe, 7-Second extraction pipe, 8-First regulating valve, 9-Second regulating valve, 10-Auxiliary burner, 11-First chamber, 12-Settling ash hopper, 13-Main flue gas inlet pipe, 14-Main flue gas outlet pipe, 15-Boiler body, 16-Inner pipe, 17-Outer pipe, 18-Nozzle, 19 - Fixed-distance stiffener, 20- Dry ice descaling device, 21- Drive device, 22- Spray head, 23- Dry ice sending device, 24- Dry ice descaling rod, 25- Bag filter, 26- Electric furnace flue gas main pipeline, 27- Flue gas temperature detection device, 28- Fan, 29- Chimney, 30- First pipeline, 31- Second pipeline, 32- First differential pressure detection device, 33- Second differential pressure detection device, 34- Pneumatic conveying device. Detailed Implementation

[0041] It is readily understood that, based on the technical solution of this utility model, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of this utility model. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative descriptions of the technical solution of this utility model and should not be considered as the entirety of this utility model or as limitations or restrictions on the technical solution of this utility model.

[0042] Figure 1 The schematic diagram illustrates the overall structure of a pure dry purification system for electric furnace flue gas. A pure dry purification system for electric furnace flue gas, such as... Figure 1As shown, the system includes an electric furnace 1, a continuous preheating device 2, a mixing combustion settling cylinder 3, a waste heat boiler 4, and a dust collector 5, which are connected in sequence. The electric furnace 1 and the mixing combustion settling cylinder 3 are connected by a first extraction pipe 6, and the continuous preheating device 2 and the mixing combustion settling cylinder 3 are connected by a second extraction pipe 7. The output ends of the first extraction pipe 6 and the second extraction pipe 7 are fixed at different positions on the upper section of the mixing combustion settling cylinder 3. That is, the electric furnace flue gas in the electric furnace 1 and the preheated flue gas in the continuous preheating device 2 are input into the mixing combustion settling cylinder 3 from different input ends to facilitate the mixing between the electric furnace flue gas and the preheated flue gas. Specifically, the output end of the aforementioned second extraction pipe 7 is connected to the top of the mixing combustion settling cylinder 3, and a second regulating valve 9 for controlling its on / off state is installed on the second extraction pipe 7; the output end of the first extraction pipe 6 is connected to the side of the upper section of the mixing combustion settling cylinder 3, and a first regulating valve 8 for controlling its on / off state is installed on the first extraction pipe 6; an auxiliary burner 10 is fixedly installed on the side wall of the mixing combustion settling cylinder 3, close to the lower part of the output end of the first extraction pipe 6. It is worth noting that the opening and closing of the aforementioned first regulating valve 8 and second regulating valve 9 are both controlled by a PLC to regulate the mixing ratio of electric furnace flue gas and preheated flue gas with the mixing combustion settling cylinder 3.

[0043] During the operation of the electric furnace 1, the extracted flue gas is divided into two streams: electric furnace flue gas located in the first extraction pipe 6 and preheated flue gas located in the second extraction pipe 7. The preheated flue gas preheats the scrap steel in the continuous preheating device 2, and its temperature is 450-650℃, which is lower than the decomposition temperature of dioxins. Therefore, a large amount of dioxins in the preheated flue gas are not fully combusted and remain in the electric furnace flue gas. Therefore, after the preheated flue gas is introduced into the mixing combustion settling tank 3 through the second extraction pipe 7, a certain proportion of the electric furnace flue gas (temperature > 800℃) is extracted and injected into the mixing combustion settling tank 3 through the first extraction pipe 6. This electric furnace flue gas can increase the temperature of the mixed flue gas after mixing with the preheated flue gas, thereby facilitating the ignition of the mixed flue gas and removing the dioxins in the flue gas. After the electric furnace flue gas and the preheated flue gas are mixed, the flue gas temperature in the mixed combustion settling cylinder 3 is ensured to be no less than 800°C and remain in the mixed combustion settling cylinder 3 for 2-3 seconds through the auxiliary burner 10. This ensures that the toxic substances such as dioxins / furans contained in the mixed flue gas are effectively burned and decomposed at high temperature, and reduces the consumption of combustible gas in the auxiliary burner 10, thereby effectively reducing the steelmaking cost of CONSTEEL electric furnace 1.

[0044] The aforementioned mixed flue gas flows into the waste heat boiler 4 for rapid cooling. Impurities in the mixed flue gas and those generated during combustion fall directly to the bottom of the combustion settling tank. During the rapid cooling process, if the cooling effect is poor, heavy metal dust in the impurities will catalyze the substances in the flue gas to regenerate some dioxins. Therefore, burning the mixed flue gas in the combustion settling tank allows impurities (furnace ash containing heavy metal dust) and combustion-generated impurities in the mixed flue gas to fall directly to the bottom of the combustion settling tank. This can initially remove impurities from the flue gas, reduce heavy metal dust in the mixed flue gas during rapid cooling, and thus reduce the amount of dioxins regenerated during rapid cooling. Therefore, it is only necessary to ensure the rapid cooling effect on the mixed flue gas, cooling it to a temperature below 200℃ to effectively avoid the dioxin reaction temperature range (300-500℃).

[0045] It is worth noting that the aforementioned mixed combustion settling cylinder 3 includes a first chamber 11 and a settling ash hopper 12. The settling ash hopper 12 is fixedly disposed below the first chamber 11. The width of the settling ash hopper 12 is greater than the width of the first chamber 11, and the lower end of the first chamber 11 is smoothly connected to the upper edge of the settling ash hopper 12. That is, opposite to the junction of the lower end of the first chamber 11 and the upper edge of the settling ash hopper 12 is a separate settling ash hopper 12. The structure of the first chamber 11 and the settling ash hopper 12 forms a vertical bending structure. This structure can effectively affect the movement trajectory of the mixed flue gas in the mixed combustion settling cylinder 3, which is conducive to the falling of impurities mixed in the mixed flue gas into the settling ash hopper 12.

[0046] To ensure the rapid cooling effect of the flue gas input from the self-mixing combustion settling tank 3 to the waste heat boiler 4, such as Figure 2 As shown, the waste heat boiler 4 includes a main flue gas inlet pipe 13, a boiler body 15, and a main flue gas outlet pipe 14, wherein the main flue gas inlet pipe 13 and the main flue gas outlet pipe 14 are fixedly installed at both ends of the boiler body 15. The high-temperature mixed flue gas from the mixed combustion settling cylinder 3 enters the waste heat boiler 4 through the main flue gas inlet pipe 13, and after being diverted, it enters several boiler bodies 15 located between the main flue gas inlet pipe 13 and the main flue gas outlet pipe 14. Compared with directly quenching the entire high-temperature mixed flue gas, the difficulty of quenching is significantly reduced and the quenching effect is significantly enhanced by diverting the high-temperature mixed flue gas to several boiler bodies 15. After quenching, the mixed flue gas merges in the main flue gas outlet pipe 14 and is then output.

[0047] The aforementioned rapid cooling process mainly takes place within the boiler body 15, and is essentially a heat exchange process, such as... Figure 3-4As shown, the boiler body 15 includes a bundled sleeve and nozzles 18 located at both ends of the bundled sleeve. The bundled sleeve consists of an inner tube 16 and an outer tube 17, and a spacer rib 19 is fixedly provided between the inner tube 16 and the outer tube 17 to ensure the gap width between the inner tube 16 and the outer tube 17 while also supporting the inner tube 16 and the outer tube 17. The nozzles 18 are fixedly provided at both ends of the inner tube 16. High-temperature flue gas flows in the inner tube 16, and cooling water flows in the gap between the inner tube 16 and the outer tube 17. To facilitate the flow of cooling water, an upper pipe manifold and a lower pipe manifold are installed on the boiler body 15. The upper pipe manifold is fixedly installed based on the spray pipe 18 and outer pipe 17 at the upper end of the boiler body 15, while the lower pipe manifold is fixedly installed based on the spray pipe 18 and outer pipe 17 at the lower end of the boiler body 15. Cooling water is introduced into the lower pipe manifold through a separate pipeline and discharged from the upper pipe manifold. To reduce the number of pipelines, multiple upper pipe manifolds of the boiler body 15 can be connected together, and multiple lower pipe manifolds of the boiler body 15 can be connected together in parallel to allow the cooling water to flow in the aforementioned gaps. Through the aforementioned bundled sleeve configuration, contact between the cooling water (such as cooling water) and the mixed flue gas can be effectively avoided. On the one hand, this prevents moisture from contacting the mixed flue gas, thus avoiding the consumption of cooling water; on the other hand, it allows for the recovery of a large amount of waste heat from the mixed flue gas.

[0048] By dividing the high-temperature flue gas of the aforementioned CONSTEEL electric furnace 1 into multiple flue gas columns, which pass through the boiler body 15 with a smaller cross-section, the high-temperature flue gas of the electric furnace 1 is rapidly cooled and waste heat is recovered, effectively controlling the re-synthesis of dioxins in the flue gas. However, during the rapid cooling process of the high-temperature mixed flue gas, some new debris in the mixed flue gas inevitably falls into the waste heat boiler 4. This debris adheres to the waste heat boiler 4 and forms ash. The presence of ash inevitably affects the rapid cooling effect of the subsequent mixed flue gas. Therefore, it is necessary to clean the ash inside the waste heat boiler 4 regularly. Thus, the waste heat boiler 4 also includes a dry ice descaling device 20. The dry ice descaling device 20 is installed on the main flue pipe 14, and the dry ice descaling device 20 and the boiler body 15 are located on the same axis. The dry ice descaling device 20 can move vertically into the boiler body 15 to clean the ash on the inner wall of the boiler body 15. The cleaning process of the aforementioned dry ice descaling device 20 can be controlled by a PLC.

[0049] Figure 5 The schematic diagram illustrates the overall structure of the dry ice descaling device. The following is a combination of... Figure 5The dry ice descaling device 20 is described in detail below. The number of dry ice descaling devices 20 is the same as that of the boiler body 15. It includes a drive unit 21 and spray heads 22 fixedly disposed at a certain distance below the drive unit 21. The spray heads 22 can reciprocate along the length of the inner tube 16 with the drive unit 21. A guide rail frame can be used to guide the drive unit 21 to move along the length of the guide rail frame, which is parallel to the length of the boiler body 15 and positioned above the main flue pipe 14. The aforementioned spray heads 22 can be fixedly disposed below the drive unit 21 by a dry ice descaling rod 24. The drive unit 21 can drive the dry ice descaling rod 24 to rotate, and the spray heads 22 fixed on the dry ice descaling rod 24 can rotate synchronously with the rotation of the dry ice descaling rod 24. Because during the descaling process of the inner wall of the inner tube 16, if the aforementioned spray head 22 is only oriented in a fixed direction, it can descaling one side of the inner wall of the inner tube 16, but it is difficult to achieve descaling on the other side due to its orientation problem, it is necessary to give the spray head 22 the function of rotation so as to adjust its orientation and complete the descaling process of the inner wall of the inner tube 16. This is achieved by setting a servo motor and a transmission device on the drive device 21.

[0050] The aforementioned spray head 22 is supplied with dry ice by a dry ice delivery device 23. A delivery channel is formed along the length of the aforementioned dry ice descaling rod 24, with one end connected to the output of the dry ice delivery device 23 and the other end connected to the input of the spray head 22. The dry ice delivery device 23 propels block or spherical dry ice through the delivery channel, propelled by nitrogen, from the spray head 22 to contact the inner wall of the inner tube 16. This causes the accumulated dust adhering to it to freeze and become brittle, and under the action of the dry ice, it is peeled off from the inner wall of the inner tube 16. This method has high cleaning efficiency and does not involve any chemical solvents or water, effectively avoiding dust accumulation and structural damage. In some embodiments, to ensure a constant temperature of the aforementioned dry ice descaling rod 24, a circulation pipe can be provided to circulate cooling water, ensuring a constant temperature for the dry ice descaling rod 24. Furthermore, the inner diameter of the aforementioned dry ice descaling rod 24 is smaller than the inner diameter of the inner tube 16.

[0051] The following combination Figure 1 The dust collector 5 is described in detail. It includes several bag filters 25, which are arranged horizontally and connected to each other. An air inlet and an air outlet are respectively provided on the front and rear sides of the dust collector 5. Specifically, the air inlet is located on the side of the bag filter 25 closest to the waste heat boiler 4, and the air outlet is located on the side of the bag filter 25 furthest from the waste heat boiler 4. This allows the mixed flue gas entering the dust collector 5 to undergo multi-stage adsorption of impurities by multiple bag filters 25, so that the resulting flue gas can meet the requirements for direct emission.

[0052] The aforementioned waste heat boiler 4 and dust collector 5 are connected by an electric furnace flue gas main duct 26. A flue gas temperature detection device 27 is installed on the electric furnace flue gas main duct 26 to detect the temperature data of the mixed flue gas input from the waste heat boiler 4 into the dust collector 5. The detected temperature data is uploaded to a PLC for judgment and storage. On the one hand, it can determine whether the temperature of the mixed flue gas input into the dust collector 5 meets the requirements for its long-term operation. On the other hand, it can determine the rapid cooling effect of the waste heat boiler 4 and decide whether descaling is required inside the waste heat boiler 4. A fan 28 and a chimney 29 are connected sequentially to the output end of the dust collector 5 to discharge the mixed flue gas after the dust removal process into the atmosphere through the chimney 29.

[0053] The aforementioned dust collector 5 also includes a first pipe 30 and a second pipe 31; one end of the first pipe 30 is connected between the flue gas temperature detection device 27 and the input end of the dust collector 5, and the other end is connected between the output end of the dust collector 5 and the fan 28. A first differential pressure detection device 32 is installed on the first pipe 30; one end of the second pipe 31 is connected between the flue gas temperature detection device 27 and the input end of the dust collector 5. The second pipe 31 has the same number of test branches as the bag filter 25, and a second differential pressure detection device 33 is installed on each test branch. The aforementioned first differential pressure detection device 32 and second differential pressure detection device 33 are used to detect the differential pressure data of the mixed flue gas flow before and after passing through the dust collector 5 and each bag filter 25. If the differential pressure data before and after passing through the dust collector 5 or a certain bag filter 25 is too large, it indicates that the bag filter 25 is blocked and needs to be cleaned and maintained. By setting the aforementioned first differential pressure detection device 32 and second differential pressure detection device 33, the blockage status of each bag filter 25 can be known in real time and in a timely manner. The differential pressure data obtained by the aforementioned first differential pressure detection device 32 and second differential pressure detection device 33 is transmitted to the PLC in real time for judgment and storage. The PLC can also take into account the operation process of the electric furnace 1, continuous preheating device 2, mixed combustion settling cylinder 3, waste heat boiler 4, and dust collector 5, and regulate the subsequent emission process.

[0054] It is worth noting that it also includes an ash silo. A pneumatic conveying device 34 is fixedly installed at the lower end of the mixed combustion settling cylinder 3, the waste heat boiler 4, and each bag filter 25 to transport the accumulated ash in the bag filter 25 to the centralized ash silo for collection.

[0055] The technical scope of this utility model is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this utility model, and all such modifications and variations should fall within the protection scope of this utility model.

Claims

1. An electrically heated furnace flue gas pure dry method cleaning treatment system characterized by, The electric furnace (1), the continuous preheating device (2), the mixed combustion settling cylinder (3), the waste heat boiler (4) and the dust remover (5) are sequentially communicated, The first extraction pipeline (6) is communicated between the electric furnace (1) and the mixed combustion settling cylinder (3), and the second extraction pipeline (7) is communicated between the continuous preheating device (2) and the mixed combustion settling cylinder (3), and the output ends of the first extraction pipeline (6) and the second extraction pipeline (7) are fixed based on different positions of the upper section of the mixed combustion settling cylinder (3). The waste heat boiler (4) receives high-temperature flue gas output from the mixed combustion settling cylinder (3), divides the high-temperature flue gas and the cooling water to complete the heat exchange process through the heat conduction medium, and then combines to input the bag-type dust remover (25) to complete the dust removal process and then is discharged from the chimney (29).

2. The system for flue gas cleaning by pure dry method of an electric furnace according to claim 1, characterized in that, The output end of the second extraction pipeline (7) is connected and penetrates the top of the mixed combustion settling cylinder (3), a second regulating valve (9) for regulating the on-off of the second extraction pipeline (7) is arranged above the second extraction pipeline (7), the output end of the first extraction pipeline (6) is connected and penetrates the mixed combustion settling cylinder (3) based on the side of the upper section of the mixed combustion settling cylinder (3), a first regulating valve (8) for regulating the on-off of the first extraction pipeline (6) is arranged above the first extraction pipeline (6), and an auxiliary burner (10) is fixedly arranged on the side wall of the mixed combustion settling cylinder (3) close to the lower side of the output end of the first extraction pipeline (6).

3. The system for flue gas cleaning by pure dry method of an electric furnace according to claim 2, characterized in that, The mixed combustion settling cylinder (3) comprises a first chamber (11) and a settling ash hopper (12), the settling ash hopper (12) is fixedly arranged below the first chamber (11), the width of the settling ash hopper (12) is greater than the width of the first chamber (11), and the lower end of the first chamber (11) is smoothly connected with the upper section edge of the settling ash hopper (12).

4. The system for flue gas cleaning by pure dry method of an electric furnace according to claim 1, characterized in that, The waste heat boiler (4) comprises a total smoke inlet pipe (13), a boiler body (15) and a total smoke outlet pipe (14), the total smoke inlet pipe (13) and the total smoke outlet pipe (14) are fixedly arranged at the two ends of the boiler body (15), a dry ice descaling device (20) is further arranged above the total smoke outlet pipe (14), the dry ice descaling device (20) is located on the same axis as the boiler body (15), and the dry ice descaling device (20) can move vertically into the inside of the boiler body (15).

5. The system for flue gas cleaning by pure dry method of an electric furnace according to claim 4, characterized in that, The boiler body (15) is a plurality of, the boiler body (15) comprises a cluster sleeve and a spray pipe (18) located at the two ends of the cluster sleeve, the cluster sleeve is composed of an inner pipe (16) and an outer pipe (17), and a distance rib plate (19) is fixedly arranged between the inner pipe (16) and the outer pipe (17), the spray pipe (18) is fixedly arranged at the two ends of the inner pipe (16), high-temperature flue gas flows in the inner pipe (16), and cooling water flows in the gap between the inner pipe (16) and the outer pipe (17).

6. The system for flue gas cleaning by pure dry method of an electric furnace according to claim 5, characterized in that, The dry ice descaling device (20) is equal in number to the boiler furnace body (15), and comprises a driving device (21) and a spray head (22) fixedly arranged at a distance below the driving device (21), which can reciprocate along the length direction of the inner tube (16) with the driving device (21); the spray head (22) is provided with a dry ice sending device (23) for conveying blocky or spherical dry ice; The spray head (22) is fixedly arranged below the driving device (21) and comprises a conveying channel for conveying dry ice, which is arranged in the dry ice descaling rod (24) based on the length direction of the dry ice descaling rod (24).

7. The system for flue gas cleaning by pure dry method of electric furnaces according to claim 1, characterized in that, The dust collector (5) comprises a plurality of bag-type dust collectors (25), which are arranged in combination in the transverse direction and connected between adjacent bag-type dust collectors (25).

8. The system for flue gas cleaning by pure dry method of an electric furnace according to claim 7, characterized in that, The waste heat boiler (4) and the dust collector (5) are connected by an electric furnace flue gas main pipeline (26), and a flue gas temperature detection device (27) is arranged above the electric furnace flue gas main pipeline (26); The output end of the dust collector (5) is sequentially connected with a fan (28) and a chimney (29), Further comprising a first pipeline (30) and a second pipeline (31); One end of the first pipeline (30) is connected between the flue gas temperature detection device (27) and the input end of the dust collector (5), and the other end is connected between the output end of the dust collector (5) and the fan (28), and a first differential pressure detection device (32) is arranged above the first pipeline (30); One end of the second pipeline (31) is connected between the flue gas temperature detection device (27) and the input end of the dust collector (5), and a test branch equal in number to the bag-type dust collectors (25) is arranged above the second pipeline (31), and a second differential pressure detection device (33) is arranged above each test branch.

9. The system for flue gas cleaning by pure dry method of electric furnaces according to claim 7, characterized in that, A pneumatic conveying device (34) is fixedly arranged at the lower end of the mixed combustion settling cylinder (3), the waste heat boiler (4), and each bag-type dust collector (25), for conveying accumulated ash in the bag-type dust collector (25) to a centralized ash storage.

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