System for removing dioxin in waste incineration fly ash through online desorption

Abstract

The utility model relates to the technical field of waste incineration fly ash treatment, in particular to an online desorption system for removing dioxin in waste incineration fly ash, which comprises a waste incinerator, a feeding device, a gas-ash separating device, a thermal desorption device, an ash collecting device and a high-temperature circulating fan, the feeding device is used for inputting fly ash generated by waste incineration to the thermal desorption device, and a hot air inlet and a hot air outlet of the thermal desorption device communicate with a smoke outlet of the waste incinerator and an air inlet of the gas-ash separation device correspondingly. An air inlet and an air outlet of the high-temperature circulating fan communicate with an air outlet of the gas-ash separation device and an air inlet of the garbage incinerator correspondingly, and an ash outlet of the gas-ash separation device communicates with the ash collecting device. High-temperature flue gas generated by the garbage incinerator exchanges heat with fly ash entering the thermal desorption device, efficient thermal desorption of dioxin in the fly ash is achieved, the dioxin is gasified and discharged from the exhaust port of the gas-ash separation device along with the high-temperature flue gas, and the dioxin is fed into the garbage incinerator to be thoroughly burned and removed.

Description

Technical Field

[0001] This utility model relates to the field of waste incineration fly ash treatment technology, and in particular to an online desorption system for removing dioxins from waste incineration fly ash. Background Technology

[0002] Municipal solid waste incineration is the most common method of waste disposal in my country. However, waste incineration may cause secondary pollution. The fly ash produced by incineration is the main carrier of secondary pollution, because the fly ash contains heavy metals and toxic and harmful substances such as dioxins.

[0003] Currently, fly ash from waste incineration is typically treated using cement solidification. Cement solidification involves mixing fly ash into cement, where a hydration reaction occurs under the presence of water, forming hydrated calcium silicate that encapsulates heavy metals and reduces the leaching of toxic substances. However, cement solidification requires large amounts of cement, occupies significant landfill space, and cannot effectively remove dioxin pollution. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides an online desorption system for removing dioxins from fly ash from waste incineration. It aims to solve the pollution problems of existing methods that use cement solidification to treat fly ash, which require a large amount of cement, occupy a large amount of landfill space, and cannot effectively remove dioxins.

[0005] To achieve the above objectives, this utility model provides an online desorption system for removing dioxins from fly ash from waste incineration, comprising a waste incinerator, a feeding device, a gas-ash separation device, a thermal desorption device, an ash collection device, and a high-temperature circulating fan. The gas-ash separation device is provided with an air inlet, an air outlet, and an ash outlet. The thermal desorption device is provided with a hot air inlet, a hot air outlet, and an ash inlet. The feeding device's inlet is used to feed fly ash generated from waste incineration. The feeding device's outlet is connected to the ash inlet of the thermal desorption device. The hot air inlet and hot air outlet of the thermal desorption device are respectively connected to the flue gas outlet of the waste incinerator and the air inlet of the gas-ash separation device. The air outlet of the gas-ash separation device is connected to the air inlet of the high-temperature circulating fan. The air outlet of the high-temperature circulating fan is connected to the air inlet of the waste incinerator. The ash outlet of the gas-ash separation device is connected to the ash collection device.

[0006] Furthermore, the ash collection device includes a discharge conveying device and an ash collection hopper. The inlet end of the discharge conveying device is connected to the ash outlet of the gas-ash separation device, and the outlet end of the discharge conveying device is connected to the ash collection hopper, for conveying the fly ash discharged from the ash outlet of the gas-ash separation device into the ash collection hopper.

[0007] Furthermore, the fly ash fed into the feeding device comes from fly ash generated by the waste incinerator.

[0008] Furthermore, it also includes a fly ash conveying device, the inlet and outlet of which are respectively connected to the ash outlet of the waste incinerator and the inlet of the feeding device. The fly ash conveying device is used to input the fly ash generated by the waste incinerator into the feeding device.

[0009] Furthermore, the thermal desorption device is an electromagnetically heated screw conveyor, which is a frequency-controlled electromagnetically heated screw conveyor 4, and the fly ash undergoes heat exchange within the electromagnetically heated screw conveyor for 5 to 30 minutes.

[0010] Furthermore, the thermal desorption device is a rotary kiln, which is configured as a variable frequency speed-controlled rotary kiln, and the heat exchange time of the fly ash in the rotary kiln is 5 to 30 minutes.

[0011] Furthermore, the thermal desorption device is a thermal desorption airflow pipe 41, and the fly ash exchanges heat within the thermal desorption airflow pipe for 2 to 30 seconds.

[0012] Furthermore, the gas-ash separation device is a high-temperature ceramic dust collector or a high-temperature metal membrane dust collector.

[0013] Furthermore, the fly ash is heated to a temperature greater than or equal to 500°C after heat exchange with hot flue gas from the waste incinerator in the thermal desorption device.

[0014] Furthermore, the temperature of the flue gas produced by the waste incinerator is 600–900°C.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] 1. This utility model's online desorption system for removing dioxins from fly ash in waste incineration utilizes the high-temperature flue gas generated by existing waste incinerators to exchange heat with the fly ash entering the thermal desorption device. After the high-temperature flue gas heats the fly ash, the dioxins in the fly ash are gasified, achieving efficient thermal desorption of dioxins from the fly ash. At this point, the flue gas after heat exchange contains gaseous dioxins. Under the condition of negative pressure created by the high-temperature circulating fan, the flue gas and fly ash after heat exchange enter the gas-ash separation device for gas-ash separation. After gas-ash separation, the fly ash enters the ash collection device from the ash outlet of the gas-ash separation device for collection, and the flue gas is sent from the gas outlet of the gas-ash separation device into the waste incinerator for high-temperature combustion, completely incinerating and removing dioxins.

[0017] 2. The flue gas after heat exchange enters the waste incinerator as the circulating combustion air, which helps the waste incinerator burn the waste and facilitates the drying and complete combustion of the waste in the waste incinerator. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a system for online desorption and removal of dioxins from fly ash of waste incineration, according to Embodiment 1 of this utility model.

[0019] Figure 2 This is a schematic diagram of the structure of a system for online desorption and removal of dioxins from fly ash of waste incineration, according to Embodiment 2 of this utility model.

[0020] Figure 3 This is a schematic diagram of the structure of a system for online desorption and removal of dioxins from fly ash of waste incineration, according to Embodiment 3 of this utility model.

[0021] Numbering in each attached figure:

[0022] 1. Waste incinerator; 2. Feeding device; 3. Gas-ash separation device; 4. Electromagnetic heating screw conveyor; 40. Rotary kiln; 41. Thermal desorption gas flow duct; 5. Ash collection device; 50. Discharge conveying device; 51. Ash collection hopper; 6. High-temperature circulating fan. Detailed Implementation

[0023] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0024] In the description of this utility model, it should be understood that the terms "width", "upper", "lower", "front", "rear", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] Example 1

[0028] Please refer to Figure 1 This utility model provides an online desorption system for removing dioxins from fly ash from waste incineration, including a waste incinerator 1, a fly ash conveying device, a feeding device 2, a gas-ash separation device 3, a thermal desorption device, an ash collection device 5, and a high-temperature circulating fan 6. The fly ash conveying device (not shown) has its inlet and outlet connected to the ash outlet of the waste incinerator 1 and the inlet of the feeding device 2, respectively. The fly ash conveying device is used to input the fly ash generated by the waste incinerator 1 into the feeding device 2. The outlet of the feeding device 2 is connected to the ash inlet of the thermal desorption device. The feeding device 2 is used to feed the fly ash generated by the waste incinerator 1 from the incineration of waste. The hot gas inlet and hot gas outlet of the thermal desorption device are connected to the flue gas outlet of the waste incinerator 1 and the air inlet of the gas-ash separation device 3, respectively. The air outlet of the gas-ash separation device 3 is connected to the air inlet of the high-temperature circulating fan 6. The air outlet of the high-temperature circulating fan 6 is connected to the air inlet of the waste incinerator 1. The ash outlet of the gas-ash separation device 3 is connected to the ash collection device 5.

[0029] The waste incinerator 1 in this embodiment adopts an existing waste incinerator. The flue gas temperature generated by the waste incinerator 1 in this embodiment is 600-900°C, specifically 900°C. In other embodiments, the flue gas temperature generated by the waste incinerator 1 incinerating waste can also be 600°C or 800°C.

[0030] In this embodiment, the feeding device 2 uses a feeding hopper, which is beneficial for fly ash feeding. Of course, in other embodiments, the feeding device 2 can also be a feeding cylinder, and this is not limited here.

[0031] In this embodiment, the fly ash conveying device is a pneumatic conveyor. Of course, in other embodiments, a screw conveyor may also be used, and this is not a limitation here. Pneumatic conveyors are existing technology, and their specific working principle will not be described in detail here.

[0032] In this embodiment, the gas-ash separation device 3 is a high-temperature metal membrane dust collector. Of course, in other embodiments, the gas-ash separation device 3 can also be a high-temperature ceramic dust collector; this is not a limitation here. The high-temperature metal membrane dust collector is prior art, and its specific working principle will not be described in detail here.

[0033] In this embodiment, the thermal desorption device is an electromagnetically heated screw conveyor 4. The electromagnetically heated screw conveyor 4 is a variable frequency speed-regulating electromagnetically heated screw conveyor 4, allowing it to adjust the speed at which it conveys fly ash. It should be noted that since the electromagnetically heated screw conveyor 4 is an existing structure, its specific working principle will not be described in detail here.

[0034] The ash collection device 5 in this embodiment includes a discharge conveying device 50 and an ash collection hopper 51. The inlet end of the discharge conveying device 50 is connected to the ash outlet of the gas-ash separator 3, and the outlet end of the discharge conveying device 50 is connected to the ash collection hopper 51. It is used to convey the fly ash discharged from the ash outlet of the gas-ash separator 3 into the ash collection hopper 51. The structure of the discharge conveying device 50 in this embodiment is the same as that of the fly ash conveying device, and will not be described in detail here.

[0035] Of course, in other embodiments, the discharge conveying device 50 may also be a screw conveyor.

[0036] In summary, the fly ash produced by the waste incinerator 1 is directly conveyed into the feeding device 2 via the fly ash conveying device, and then enters the electromagnetically heated screw conveyor 4 to exchange heat with the high-temperature flue gas generated from the combustion of waste in the waste incinerator 1. The temperature of the high-temperature flue gas is 600-900℃ (controlled by the waste incinerator 1), and the heat exchange time between the high-temperature flue gas and fly ash in the electromagnetically heated screw conveyor 4 is 5-30 minutes. After heat exchange with the hot flue gas from the waste incinerator 1 in the electromagnetically heated screw conveyor 4, the fly ash is heated to ≥500℃. The high-temperature flue gas and fly ash then... After the thermal desorption spiral mixing, the dioxins in the fly ash are gasified, achieving efficient thermal desorption of dioxins from the fly ash. At this time, the flue gas after heat exchange contains gaseous dioxins. Under the condition of negative pressure formed by the high-temperature circulating fan 6, the flue gas and fly ash after heat exchange enter the high-temperature metal membrane dust collector to achieve gas-ash separation. After gas-ash separation, the fly ash enters the discharge conveying device 50 from the ash outlet of the gas-ash separation device 3 and is transported into the ash collection hopper 51 for collection. The flue gas is sent into the waste incinerator 1 from the gas outlet of the gas-ash separation device 3 for high-temperature incineration to completely burn and remove dioxins.

[0037] In one application scenario, the fly ash produced by the waste incinerator 1 is directly conveyed into the feeding device 2 via a fly ash conveying device, and then enters the electromagnetically heated screw conveyor 4 to exchange heat with the high-temperature flue gas generated from the combustion of waste in the waste incinerator 1. The temperature of the high-temperature flue gas is 900℃, and the heat exchange time between the high-temperature flue gas and the fly ash in the electromagnetically heated screw conveyor 4 is 30 minutes. After heat exchange with the hot flue gas from the waste incinerator 1 in the electromagnetically heated screw conveyor 4, the fly ash is heated to 500℃. After the high-temperature flue gas and fly ash are mixed in a thermal desorption screw, the fly ash... Dioxins in the ash are gasified, achieving efficient thermal desorption of dioxins from fly ash. At this point, the flue gas after heat exchange contains gaseous dioxins. Under the negative pressure state created by the high-temperature circulating fan 6, the flue gas and fly ash after heat exchange enter the high-temperature metal membrane dust collector to achieve gas-ash separation. After gas-ash separation, the fly ash enters the discharge conveying device 50 from the ash outlet of the high-temperature metal membrane dust collector and is transported into the ash collection hopper 51 for collection. The flue gas is sent from the gas outlet of the high-temperature metal membrane dust collector into the waste incinerator 1 for high-temperature incineration to completely destroy and remove dioxins.

[0038] In another application scenario, the fly ash produced by the waste incinerator 1 is directly conveyed into the feeding device 2 via a fly ash conveying device, and then enters the electromagnetically heated screw conveyor 4 to exchange heat with the high-temperature flue gas generated from the combustion of waste in the waste incinerator 1. The temperature of the high-temperature flue gas is 600℃, and the heat exchange time between the high-temperature flue gas and the fly ash in the electromagnetically heated screw conveyor 4 is 5 minutes. After heat exchange with the hot flue gas from the waste incinerator 1 in the electromagnetically heated screw conveyor 4, the fly ash is heated to 550℃. The high-temperature flue gas and fly ash are then mixed in a thermal desorption screw conveyor. Dioxins in fly ash are gasified, achieving efficient thermal desorption of dioxins from fly ash. At this point, the flue gas after heat exchange contains gaseous dioxins. Under the negative pressure state created by the high-temperature circulating fan 6, the flue gas and fly ash after heat exchange enter the high-temperature metal membrane dust collector to achieve gas-ash separation. After gas-ash separation, the fly ash enters the discharge conveying device 50 from the ash outlet of the high-temperature metal membrane dust collector and is conveyed into the ash collection hopper 51 for collection. The flue gas is sent from the gas outlet of the high-temperature metal membrane dust collector into the waste incinerator 1 for high-temperature incineration to completely burn and remove dioxins.

[0039] It should be noted that the high-temperature flue gas generated by the waste incinerator 1 does not contain dioxins. The fly ash generated by the waste incinerator 1 is discharged from the ash outlet of the waste incinerator 1, and the high-temperature flue gas generated by the waste incinerator 1 is discharged from the exhaust outlet. In this embodiment, the high-temperature flue gas discharged from the exhaust outlet of the waste incinerator 1 is divided into two parts: one part is treated by the flue gas purification system to meet emission standards, and the other part serves as a heat source for heat exchange with the fly ash entering the thermal desorption device.

[0040] This utility model's online desorption system for removing dioxins from waste incineration fly ash fully utilizes the existing resources of the waste incinerator 1, removing dioxins from the fly ash and improving the resource utilization rate of the waste incinerator 1. Furthermore, the flue gas after heat exchange is used as the circulating combustion air in the waste incinerator 1, assisting in the incineration of waste and promoting the drying and complete combustion of the waste within the incinerator 1. Additionally, the fly ash fed by the feeding device 2 comes from the fly ash generated during the incineration of waste in the waste incinerator 1, achieving the effect of online desorption and removal of dioxins from the fly ash.

[0041] It should be noted that the high-temperature metal membrane dust collector in this invention not only plays a role in dust removal, but also achieves the purpose of solid-gas separation.

[0042] The principle of dioxin desorption: Dioxins are toxic organic compounds with a boiling point of 300-500℃. Dioxins in fly ash are adsorbed in solid form within the fly ash particles. When the fly ash is heated to the corresponding temperature, the dioxin particles will "vaporize" and migrate to the gas phase, thus achieving the purpose of dioxin desorption from the fly ash.

[0043] Currently, high-temperature combustion methods are also used to treat dioxins in waste incineration fly ash. However, existing methods typically employ multi-stage cyclone separators, such as the device disclosed in patent publication number CN215523357U. This device includes multiple cyclone separators, each functioning as a gas-solid mixer, heat exchanger, and gas-solid separator. Heated flue gas is introduced into the flue gas inlet of the final cyclone separator, entering from bottom to top. This heats the fly ash entering from top to bottom within the separator, causing the dioxins to pyrolyze and vaporize at high temperatures, effectively removing them. However, using multi-stage cyclone separators to treat dioxins in fly ash has at least the following drawbacks: the fly ash must pass through each stage of the cyclone separator sequentially from top to bottom. Uneven particle size distribution, low density, or high viscosity can easily accumulate inside each stage of the cyclone separator, causing blockage and affecting the treatment efficiency. In the online desorption system for removing dioxins from waste incineration fly ash in this embodiment, the main method is to use the waste incinerator 1 to remove dioxins from the fly ash. Therefore, it is clear that using a multi-stage cyclone separator to treat dioxins in fly ash is significantly less effective than the system of this invention.

[0044] This utility model's online desorption system for dioxins from waste incineration fly ash can be used as a standard configuration for waste incineration power plants. After treatment by this system, the dioxin levels in the raw ash produced by waste incineration can meet the regulatory requirements. Subsequent water washing and desalination are all that's needed to modify the fly ash for use as general solid waste, thereby significantly reducing the investment and operating costs for the harmless disposal and resource utilization of fly ash.

[0045] Example 2

[0046] The difference between this embodiment and Embodiment 1 is that the structure of the thermal desorption device is different.

[0047] Please refer to Figure 2 The thermal desorption device is a rotary kiln 40, which is configured as a variable frequency speed control rotary kiln 40. The heat exchange time of fly ash in the rotary kiln 40 is 5 to 30 minutes. In this embodiment, the heat exchange time of fly ash in the rotary kiln 40 is 30 minutes, which can greatly improve the thermal desorption efficiency of dioxins in fly ash.

[0048] In other embodiments, the heat exchange time of fly ash in rotary kiln 40 can also be 5 minutes.

[0049] Specifically, in one application scenario, high-temperature flue gas generated by the incinerator 1 from the combustion of waste is introduced into the air inlet of the rotary kiln 40. The temperature of the high-temperature flue gas is 900℃. After the high-temperature flue gas mixes with the fly ash, the high-temperature flue gas heats the fly ash. The heat source for the fly ash to rise in temperature comes from the direct heat transfer of the high-temperature flue gas, and the fly ash temperature rises to 500℃. After the flue gas and fly ash mix and exchange heat in the rotary kiln 40, the residence time of the fly ash in the rotary kiln 40 is 30 minutes by controlling the variable frequency speed regulation of the rotary kiln 40. After the high-temperature flue gas and fly ash are mixed in the rotary kiln 40, the high-temperature circulating fan 6 draws air to form a negative pressure and sends it to the high-temperature metal membrane dust collector to achieve gas-ash separation. After gas-ash separation, the fly ash enters the discharge conveying device 50 from the ash outlet of the gas-ash separation device 3 and is transported into the ash collection hopper 51 for collection. The flue gas is sent into the waste incinerator 1 from the air outlet of the gas-ash separation device 3 for high-temperature combustion to completely incinerate and remove dioxins.

[0050] In another application scenario, high-temperature flue gas generated by the incinerator 1 from the combustion of waste is introduced into the air inlet of the rotary kiln 40. The temperature of the high-temperature flue gas is 600℃. After the high-temperature flue gas mixes with the fly ash, the high-temperature flue gas heats the fly ash. The heat source for the fly ash to rise in temperature comes from the direct heat transfer of the high-temperature flue gas, and the fly ash temperature rises to 550℃. After the flue gas and fly ash mix and exchange heat in the rotary kiln 40, the residence time of the fly ash in the rotary kiln 40 is controlled by the frequency conversion speed regulation of the rotary kiln 40 to ensure that the residence time of the fly ash in the rotary kiln 40 is 2 minutes. After the high-temperature flue gas and fly ash are mixed in the rotary kiln 40, the high-temperature circulating fan 6 draws air to form a negative pressure and sends it to the high-temperature metal membrane dust collector to achieve gas-ash separation. After gas-ash separation, the fly ash enters the discharge conveying device 50 from the ash outlet of the gas-ash separation device 3 and is transported into the ash collection hopper 51 for collection. The flue gas is sent into the waste incinerator 1 from the air outlet of the gas-ash separation device 3 for high-temperature combustion to completely incinerate and remove dioxins.

[0051] Example 3

[0052] The difference between this embodiment and the above embodiments is that the structure of the thermal desorption device is different.

[0053] Please refer to Figure 3 The thermal desorption device is a thermal desorption gas flow duct 41. The heat exchange time of fly ash in the thermal desorption gas flow duct 41 is 2 to 30 seconds. In this embodiment, the heat exchange time of fly ash in the thermal desorption gas flow duct 41 is 30 seconds. In other embodiments, the heat exchange time of fly ash in the thermal desorption gas flow duct 41 is 2 seconds.

[0054] The flue gas velocity in the thermal desorption gas flow duct 41 is 4-10 m / s. In this embodiment, the flue gas velocity in the thermal desorption gas flow duct 41 is 4 m / s; in other embodiments, the flue gas velocity in the thermal desorption gas flow duct 41 is 10 m / s.

[0055] Specifically, in one application scenario, high-temperature flue gas generated by the incinerator 1 from the combustion of waste is introduced into the inlet of the thermal desorption gas flow duct 41. The temperature of the high-temperature flue gas is 900℃. After the high-temperature flue gas mixes with the fly ash, the high-temperature flue gas heats the fly ash. The heat source for the fly ash to rise in temperature comes from the direct heat transfer of the high-temperature flue gas, and the fly ash temperature rises to 550℃. The flue gas velocity in the thermal desorption gas flow duct 41 is 10m / s. The residence time of the fly ash in the thermal desorption gas flow duct 41 is 30s. After the flue gas and fly ash are fully mixed and heat exchanged in the thermal desorption gas flow duct 41, they are drawn by the high-temperature circulating fan 6 to form a negative pressure and sent to the high-temperature metal membrane dust collector to achieve gas-ash separation. After gas-ash separation, the fly ash enters the discharge conveying device 50 from the ash outlet of the gas-ash separation device 3 and is transported into the ash collection hopper 51 for collection. The flue gas is sent into the waste incinerator 1 from the outlet of the gas-ash separation device 3 for high-temperature combustion to completely incinerate and remove dioxins.

[0056] In another application scenario, high-temperature flue gas generated by the incinerator 1 from the combustion of waste is introduced into the inlet of the thermal desorption gas flow duct 41. The temperature of the high-temperature flue gas is 600℃. After the high-temperature flue gas mixes with the fly ash, the high-temperature flue gas heats the fly ash. The heat source for the fly ash to rise in temperature comes from the direct heat transfer of the high-temperature flue gas, and the fly ash temperature rises to 500℃. The flue gas velocity in the thermal desorption gas flow duct 41 is 4m / s. The residence time of the fly ash in the thermal desorption gas flow duct 41 is 2s. After the flue gas and fly ash are fully mixed and heat exchanged in the thermal desorption gas flow duct 41, they are drawn by the high-temperature circulating fan 6 to form a negative pressure and sent to the high-temperature metal membrane dust collector to achieve gas-ash separation. After gas-ash separation, the fly ash enters the discharge conveying device 50 from the ash outlet of the gas-ash separation device 3 and is transported into the ash collection hopper 51 for collection. The flue gas is sent into the waste incinerator 1 from the outlet of the gas-ash separation device 3 for high-temperature combustion to completely destroy and remove dioxins.

[0057] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural or procedural transformations made based on the content of the present utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present utility model.

Claims

1. A system for on-line desorption removal of dioxins in waste incineration fly ash, characterized by, The device comprises a waste incinerator, a feeding device, a gas and ash separation device, a thermal desorption device, an ash collecting device and a high-temperature circulating fan, the gas and ash separation device is provided with an air inlet, an air outlet and an ash outlet, the thermal desorption device is provided with a hot gas inlet, a hot gas outlet and an ash inlet, the feeding port of the feeding device is used for feeding fly ash generated by waste incineration, the ash outlet of the gas and ash separation device is in communication with the ash inlet of the thermal desorption device, the hot gas inlet and the hot gas outlet of the thermal desorption device are in communication with the smoke outlet of the waste incinerator and the air inlet of the gas and ash separation device respectively, the air outlet of the gas and ash separation device is in communication with the air inlet of the high-temperature circulating fan, the air outlet of the high-temperature circulating fan is in communication with the air inlet of the waste incinerator, and the ash outlet of the gas and ash separation device is in communication with the ash collecting device.

2. The system for removing dioxins from waste incineration fly ash by online desorption according to claim 1, characterized in that, The ash collecting device comprises a discharging conveying device and an ash collecting hopper, the feeding end of the discharging conveying device is in communication with the ash outlet of the gas and ash separation device, and the discharging end of the discharging conveying device is in communication with the ash collecting hopper, so as to convey the fly ash discharged from the ash outlet of the gas and ash separation device into the ash collecting hopper.

3. The system for removing dioxins from waste incineration fly ash by online desorption according to claim 1, characterized in that, The fly ash fed by the feeding device is generated by the waste incinerator.

4. The system for removing dioxins from waste incineration fly ash by online desorption according to claim 3, characterized in that, The device further comprises a fly ash conveying device, the feeding end and the discharging end of the fly ash conveying device are in communication with the ash outlet of the waste incinerator and the feeding port of the feeding device respectively, and the fly ash conveying device is used for inputting the fly ash generated by the waste incinerator into the feeding device.

5. The system for removing dioxins from waste incineration fly ash by online desorption according to any one of claims 1-4, characterized in that, The thermal desorption device is an electromagnetic heating screw conveyor, the electromagnetic heating screw conveyor is a frequency conversion speed-regulating electromagnetic heating screw conveyor, and the fly ash exchanges heat in the electromagnetic heating screw conveyor for 5-30 minutes.

6. The system for removing dioxins from waste incineration fly ash by online desorption according to any one of claims 1-4, characterized in that, The thermal desorption device is a rotary kiln, the rotary kiln is a frequency conversion speed-regulating rotary kiln, and the fly ash exchanges heat in the rotary kiln for 5-30 minutes.

7. The system for removing dioxins from waste incineration fly ash by online desorption according to any one of claims 1-4, characterized in that, The thermal desorption device is a thermal desorption airflow pipe, and the fly ash exchanges heat in the thermal desorption airflow pipe for 2-30 seconds.

8. The system for removing dioxins from waste incineration fly ash by online desorption according to claim 1, characterized in that, The gas and ash separation device is a high-temperature ceramic dust collector or a high-temperature metal membrane dust collector.

9. The system for removing dioxins from waste incineration fly ash by online desorption according to claim 1, characterized in that, The fly ash is heated to greater than or equal to 500 DEG C after heat exchange with hot flue gas from the waste incinerator in the thermal desorption device.

10. The system for removing dioxins from waste incineration fly ash by online desorption according to claim 1, characterized in that, The temperature of flue gas generated by the waste incinerator is 600-900 DEG C.

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