A double-chamber furnace for recycling aluminum and an exhaust smoke purification system thereof

Abstract

The application discloses a kind of regenerative aluminum double-chamber furnace smoke exhaust purification system outside furnace, including the flue gas collecting cover of each furnace door of double-chamber furnace, the flue gas collecting cover of each furnace door of double-chamber furnace is communicated with the purification tower air inlet section of purification tower by flue, the purification tower includes from lower to upper purification tower ash storage section, purification tower air inlet section, purification tower venturi section, purification tower reaction section and purification tower air outlet section, purification tower air outlet section is connected with bag filter by flue, pulse dust cleaning system is arranged on bag filter, pulse dust cleaning system is connected with external compressed air equipment by compressed air pipeline, bag filter rotary unloader is arranged on the ash bucket of bag filter, the outlet of bag filter rotary unloader is connected with reversible rotary screw ash conveyor, the present purification system will alleviate environmental protection pressure of enterprise on one hand, on the other hand, it can also reduce production cost, can bring obvious economic and social benefits for enterprise, improve the market competitiveness of enterprise.

Description

Technical Field

[0001] This invention relates to the field of industrial production waste gas purification technology, specifically to an external flue gas purification system for a dual-chamber furnace for recycled aluminum. Background Technology

[0002] The recycled aluminum industry uses scrap aluminum to produce aluminum alloys, which is an encouraged industry as stipulated in the "Guidance Catalogue for Industrial Structure Adjustment". The double-chamber furnace has significant advantages in reducing metal loss and protecting the environment, and is the preferred equipment for smelting scrap aluminum in the industry.

[0003] The raw materials for recycled aluminum production are complex, and the flue gas contains CO2, H2O, SO2, and NO produced during fuel combustion. x In addition to the complex dust generated during the production process, the combustion of organic matter containing F, Cl, and S in the raw materials will also produce acidic gases such as HF, HCl, and SO2. In particular, when the raw materials contain organic matter containing Cl, the flue gas may also contain dioxins, which are highly hazardous.

[0004] Currently, flue gas treatment in dual-chamber recycled aluminum furnaces employs separate treatment processes for in-furnace and external flue gas collection hoods, based on the different pollutant compositions and contents in the flue gas emitted from inside and outside the furnace. The in-furnace flue gas treatment system treats all pollutants generated during the dual-chamber furnace production process, while the external flue gas treatment only involves dust removal. According to actual measurements of the flue gas outlet from the exhaust stacks of the external flue gas purification systems installed in several recycled aluminum companies, acidic gases such as HCl and HF, as well as dioxins, exceed the standards in the external flue gas.

[0005] With increasingly stringent national and local environmental regulations, excessive levels of acidic gases and dioxins in the flue gas emitted from dual-chamber recycled aluminum furnaces have impacted normal production and severely affected enterprise profits. Therefore, there is an urgent need to develop a highly adaptable and cost-effective flue gas purification technology for dual-chamber recycled aluminum furnaces, ensuring that the flue gas meets emission standards. Summary of the Invention

[0006] The technical problem to be solved by this invention is to overcome the existing defects and provide a flue gas purification system for a dual-chamber furnace for recycled aluminum. This system constructs a highly efficient closed-loop process of "reaction-collection-circulation-re-reaction" through a reversible rotary screw conveyor, a circulating ash feeding system, and a Venturi section of the purification tower. This effectively utilizes purified raw materials and reduces the emission of harmful substances. On the one hand, it alleviates the environmental pressure on enterprises; on the other hand, it reduces production costs, bringing significant economic and social benefits to enterprises and enhancing their market competitiveness. This effectively solves the problems in the background technology.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a flue gas purification system for a dual-chamber furnace for recycled aluminum, comprising flue gas collection hoods for each furnace door of the dual-chamber furnace, wherein the flue gas collection hoods for each furnace door are connected to the air inlet section of a purification tower via flues, the purification tower comprising, from bottom to top, a ash storage section, an air inlet section, a Venturi section, a reaction section, and an outlet section, the outlet section being connected to a bag filter via a flue, and the bag filter being equipped with pulse cleaning. The system includes a pulse cleaning system connected to an external compressed air system via a compressed air pipeline. A rotary unloader is installed on the ash hopper of the bag filter. The outlet of the rotary unloader is connected to a reversible rotary screw conveyor. When the reversible screw conveyor rotates forward, it discharges ash into the circulating ash feeding system; when it rotates in reverse, it discharges ash into the external ash discharge system. The Venturi section of the purification tower is connected to the circulating ash feeding system, the fresh quicklime feeding system, and the fresh activated carbon feeding system via pipelines.

[0008] As a preferred embodiment of the present invention, the flue gas collection hood includes a flue gas collection hood for the furnace door of the double-chamber furnace heating chamber, a flue gas collection hood for the furnace door of the double-chamber furnace charging chamber, and a flue gas collection hood for the furnace charging well. The flue is provided with valves for the furnace door of the double-chamber furnace heating chamber, the furnace door of the double-chamber furnace charging chamber, and the furnace charging well, respectively.

[0009] As a preferred embodiment of the present invention, the flue gas temperature regulating valve, the flue gas pressure sensor and the flue gas temperature sensor are respectively installed on the flue gas duct connecting the flue gas collection hood and the purification tower.

[0010] As a preferred embodiment of the present invention, the ash storage section of the purification tower is respectively equipped with a high level gauge, a vibrator, a gate valve at the discharge port, and a rotary unloader.

[0011] As a preferred embodiment of the present invention, the fresh slaked lime feeding system includes a fresh slaked lime storage silo, a dust collector mounted on the silo top, a high-level gauge, a low-level gauge, and a discharge port agitator inside the silo. A discharge port gate valve and a rotary discharger are installed at the discharge port of the silo. The discharge port is connected to a feed silo, which is equipped with a high-level gauge, a low-level gauge, and a discharge port agitator. The outlet of the lime feed silo is connected to a fresh slaked lime screw feeder. A fresh slaked lime rotary feeder is installed at the outlet of the fresh slaked lime screw feeder. The outlet of the fresh slaked lime screw feeder is connected to a fresh slaked lime air-material mixer. One end of the fresh slaked lime air-material mixer is connected to a fresh slaked lime air-material fan through a fresh slaked lime air-material conveying pipeline. A fresh slaked lime air-material valve is installed on the fresh slaked lime air-material conveying pipeline between the fresh slaked lime air-material mixer and the fresh slaked lime air-material fan. The other end of the fresh slaked lime air-material mixer is connected to a fresh slaked lime injector through a fresh slaked lime air-material conveying pipeline. The fresh slaked lime injector is located inside the Venturi section of the purification tower.

[0012] As a preferred embodiment of the present invention, the fresh activated carbon dosing system includes a fresh activated carbon storage silo, a dust collector mounted on the top of the silo, a high-level gauge, a low-level gauge, and a discharge port agitator inside the silo, and a discharge port gate valve and a rotary discharger at the discharge port. The discharge port is connected to a feed silo, which is equipped with a high-level gauge and a discharge port agitator. The feed hopper has a low-level gauge and a mixer at the outlet of the fresh activated carbon feed hopper. The outlet of the fresh activated carbon feed hopper is connected to a fresh activated carbon screw feeder. A fresh activated carbon rotary feeder is installed at the outlet of the fresh activated carbon screw feeder. The outlet of the fresh activated carbon screw feeder is connected to a fresh activated carbon air-material mixer. One end of the fresh activated carbon air-material mixer is connected to a fresh activated carbon pneumatic conveying fan through a fresh activated carbon pneumatic conveying pipeline. The other end of the fresh activated carbon air-material mixer is connected to a fresh activated carbon ejector through a fresh activated carbon pneumatic conveying pipeline. The fresh activated carbon ejector is located inside the Venturi section of the purification tower.

[0013] As a preferred embodiment of the present invention, the circulating ash feeding system includes a circulating ash silo connected to the discharge port of one end of a reversible rotary screw conveyor. A vent pipe is installed on the circulating ash silo. Inside the circulating ash silo, a high-level gauge, a low-level gauge, a discharge port agitator, and a rotary feeder are respectively installed. The discharge port of the circulating ash silo is connected to a circulating ash air-material mixer. One end of the circulating ash air-material mixer is connected to a circulating ash pneumatic conveying fan via a circulating ash pneumatic conveying pipeline. A circulating ash pneumatic conveying valve is installed on the circulating ash pneumatic conveying pipeline between the circulating ash air-material mixer and the circulating ash pneumatic conveying fan. The other end of the circulating ash air-material mixer is connected to a circulating ash ejector via a circulating ash pneumatic conveying pipeline. The circulating ash ejector is located inside the Venturi section of the purification tower.

[0014] As a preferred embodiment of the present invention, the external ash discharge system includes an external ash discharge hopper connected to the discharge port at the other end of the reversible rotary screw conveyor. The external ash discharge hopper is equipped with a dust collector on the top of the hopper, an external ash discharge hopper high level gauge is installed inside the hopper, an external ash discharge port gate valve and an external ash discharge hopper rotary unloader are installed at the bottom, and an external ash discharge hopper vibrator is installed on the outside of the hopper near the discharge port.

[0015] As a preferred embodiment of the present invention, a fresh quicklime conveying air heater is provided on the fresh quicklime pneumatic conveying pipeline between the fresh quicklime air mixer and the fresh quicklime pneumatic conveying air valve, and a circulating ash conveying air heater is provided on the circulating ash pneumatic conveying pipeline between the circulating ash air mixer and the circulating ash pneumatic conveying air valve.

[0016] As a preferred embodiment of the present invention, the exhaust port of the bag filter is connected to the induced draft fan through a flue, the induced draft fan is connected to the exhaust stack through a flue, and a continuous online monitoring system for flue gas is installed on the exhaust stack.

[0017] Compared with existing technologies, the beneficial effects of this invention are as follows: The flue gas collected from each furnace door of the dual-chamber furnace first enters the inlet section of the purification tower and is evenly distributed. Then, it rises to the Venturi section of the purification tower, where the diameter decreases, forming a strong turbulent airflow. The fresh quicklime addition system and the fresh activated carbon addition system respectively inject quicklime and activated carbon into the Venturi section of the purification tower. Relying on the strong turbulent airflow in the Venturi section, the quicklime and activated carbon are evenly distributed in the flue gas, and preliminary deacidification and dioxin adsorption occur. Then, the flue gas carries the quicklime and activated carbon to the reaction section of the purification tower. In the reaction section, the flue gas velocity decreases, the residence time is prolonged, and a stable reaction bed is formed, allowing the quicklime and acidic gases in the flue gas to fully contact and react. The activated carbon fully adsorbs dioxins in the flue gas, improving the deacidification efficiency and dioxin adsorption efficiency of the flue gas. Afterwards, the flue gas continues to rise to the exhaust section of the purification tower and then enters the bag filter. In the bag filter housing and on the filter bags, quicklime continues to react with the acidic gases in the flue gas, and activated carbon continues to adsorb residual dioxin-like substances in the flue gas, further improving the acid removal efficiency and dioxin adsorption efficiency. Finally, the bag filter collects dust, deacidification products, activated carbon adsorbing dioxins, unreacted quicklime, and activated carbon that has not adsorbed dioxins from the flue gas outside the dual-chamber furnace. The dust, deacidification products, activated carbon adsorbing dioxins, unreacted quicklime, and activated carbon that has not adsorbed dioxins adhering to the filter bags are cleaned by the bag filter's pulse cleaning system and fall into the bottom ash hopper. Then, the dust is discharged to the circulating ash feeding system by the bag filter's rotary unloader and reversible rotary screw conveyor. The circulating ash feeding system then re-injects the ash into the Venturi section of the purification tower for reuse. The unreacted quicklime continues to react with acidic gases in the flue gas, and the activated carbon that has not adsorbed dioxins continues to adsorb acidic gases in the flue gas. This improves the utilization rate of quicklime and activated carbon, saves material consumption in the flue gas purification system of the dual-chamber furnace for recycled aluminum, reduces hazardous waste generation, saves operating costs, and improves the economic efficiency of the system operation. After the dust collected by the bag filter is circulated a certain number of times, it is discharged to the external ash discharge system for temporary storage by the bag filter rotary unloader and the reversible rotary screw conveyor, and finally discharged externally for centralized disposal in accordance with regulations. This purification system will alleviate the environmental pressure on enterprises on the one hand, and reduce production costs on the other hand, bringing significant economic and social benefits to enterprises and enhancing their market competitiveness. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention.

[0019] In the diagram: 1. Dual-chamber furnace heating chamber door flue gas collection hood; 2. Dual-chamber furnace heating chamber door flue gas collection hood valve; 3. Dual-chamber furnace charging chamber door flue gas collection hood; 4. Dual-chamber furnace charging chamber door flue gas collection hood valve; 5. Dual-chamber furnace charging well flue gas collection hood; 6. Dual-chamber furnace charging well flue gas collection hood valve; 7. Flue; 8. Flue gas temperature regulating valve; 9. Flue gas pressure sensor; 10. Flue gas temperature sensor; 11. Purification tower ash storage section; 12. Purification tower air inlet section; 13. Purification tower Venturi section; 14. Purification tower reaction section; 15. Purification tower air outlet section; 16. Purification tower high-level gauge; 17. Purification tower ash storage section vibrator; 18. Purification tower ash storage section discharge port slide valve; 19. Purification tower ash storage section rotary unloader; 20. Bag filter; 21. Bag filter differential pressure sensor; 22. Compressed air. Piping, 23 Pulse cleaning system, 24 Bag filter hopper vibrator, 25 Bag filter discharge port gate valve, 26 Bag filter rotary unloader, 27 Reversible rotary screw conveyor, 28 Bag filter hopper high level gauge, 29 Exhaust fan, 30 Exhaust stack, 31 Continuous online flue gas monitoring system, 32 Fresh quicklime storage silo, 33 Fresh quicklime storage silo top dust collector, 34 Fresh quicklime storage silo high level gauge, 35 Fresh quicklime storage silo low level gauge, 36 Fresh quicklime storage silo discharge port agitator, 37 Fresh quicklime storage silo discharge port gate valve, 38 Fresh quicklime storage silo rotary unloader, 39 Fresh quicklime feed silo, 40 Fresh quicklime feed silo high level gauge, 41 Fresh quicklime feed silo low level gauge, 42 Fresh 43 Fresh slaked lime screw feeder, 44 Fresh slaked lime rotary feeder, 45 Fresh slaked lime pneumatic conveying blower, 46 Fresh slaked lime pneumatic conveying air valve, 47 Fresh slaked lime air-material mixer, 48 Fresh slaked lime pneumatic conveying pipeline, 49 Fresh slaked lime injector, 50 Fresh activated carbon storage silo, 51 Fresh activated carbon storage silo top dust collector, 52 Fresh activated carbon storage silo high level gauge, 53 Fresh activated carbon storage silo low level gauge, 54 Fresh activated carbon storage silo discharge port agitator, 55 Fresh activated carbon storage silo discharge port gate valve, 56 Fresh activated carbon storage silo rotary unloader, 57 Fresh activated carbon feed silo, 58 Fresh activated carbon feed silo high level gauge, 59 Fresh activated carbon feed silo low level gauge, 60 Fresh activated carbon feed silo outlet agitator, 61 Fresh activated carbon screw feeder, 62 Fresh activated carbon rotary feeder, 63 Fresh activated carbon pneumatic conveying blower, 64 Fresh activated carbon air-material mixer, 65 Fresh activated carbon pneumatic conveying pipeline, 66 Fresh activated carbon ejector, 67 Circulating ash silo, 68 Venting pipe, 69 Circulating ash silo high level gauge, 70 Circulating ash silo low level gauge, 71 Circulating ash silo outlet agitator, 72 Circulating ash rotary feeder, 73 Circulating ash pneumatic conveying blower, 74 Circulating ash pneumatic conveying air valve, 75 Circulating ash air-material mixer, 76 Circulating ash pneumatic conveying pipeline, 77 Circulating ash ejector, 78 External ash discharge silo, 79 External ash discharge silo top dust collector, 80 External ash discharge silo high level gauge, 81 External ash discharge silo vibrator.82. External ash discharge silo discharge port gate valve; 83. External ash discharge silo rotary unloader; 84. Fresh quicklime conveying air heater; 85. Circulating ash conveying air heater. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1 The present invention provides a technical solution: a flue gas purification system for a double-chamber furnace for recycled aluminum, comprising flue gas collection hoods for each furnace door of the double-chamber furnace. The flue gas collection hoods include a flue gas collection hood 1 for the heating chamber door of the double-chamber furnace, a flue gas collection hood 3 for the charging chamber door of the double-chamber furnace, and a flue gas collection hood 5 for the charging well of the double-chamber furnace, which are respectively used to collect the flue gas generated when the furnace door of the heating chamber of the double-chamber furnace is opened, the flue gas generated when the furnace door of the charging chamber of the double-chamber furnace is opened, and the flue gas generated when the charging well of the double-chamber furnace is used for charging.

[0022] Flue 7 is used to connect various equipment and transport flue gas.

[0023] The flue 7 is equipped with two valves corresponding to the flue gas collection hoods 1, 3, and 5 of the double-chamber furnace heating chamber, charging chamber, and charging shaft, respectively. Valve 2 is a double-chamber furnace heating chamber door flue gas collection hood valve, valve 4 is a double-chamber furnace charging chamber door flue gas collection hood valve, and valve 6 is a double-chamber furnace charging shaft flue gas collection hood valve. Valve 2 is an on / off valve, controlling the exhaust of flue gas from the double-chamber furnace heating chamber door flue gas collection hood 1. This valve is interlocked with the double-chamber furnace heating chamber door; it opens before the double-chamber furnace heating chamber door opens and closes after the double-chamber furnace heating chamber door closes, ensuring the proper functioning of the double-chamber furnace heating chamber door flue gas collection hood valve. The double-chamber furnace charging chamber door flue gas collection hood valve 4 is an on / off valve, which controls the exhaust of flue gas from the double-chamber furnace charging chamber door flue gas collection hood 3. This valve is interlocked with the double-chamber furnace charging chamber door. This valve opens earlier than the double-chamber furnace charging chamber door and closes later than the double-chamber furnace charging chamber door, in order to ensure that the flue gas from the double-chamber furnace charging chamber door does not escape. The double-chamber furnace charging well flue gas collection hood valve 6 is an on / off valve, which controls the exhaust of flue gas from the double-chamber furnace charging well flue gas collection hood 5. This valve is interlocked with the double-chamber furnace charging belt. It opens synchronously when the charging belt starts and closes after a delay after the charging belt stops, in order to ensure that the flue gas from the double-chamber furnace charging well does not escape.

[0024] The flue gas collection hoods of each furnace door of the dual-chamber furnace are connected to the purification tower inlet section 12 of the purification tower via flue 7. The purification tower includes, from bottom to top, a purification tower ash storage section 11, a purification tower inlet section 12, a purification tower Venturi section 13, a purification tower reaction section 14, and a purification tower outlet section 15. The purification tower ash storage section 11 is used to store the mixed dust from the original flue gas settling in the purification tower, deacidification products, activated carbon adsorbing dioxins, unreacted quicklime, and unadsorbed activated carbon. The purification tower inlet section 12 is the device for flue gas to enter the purification tower and to even out the flow of flue gas. The purification tower Venturi section 13 contains fresh quicklime, fresh activated carbon, and recycled ash. The addition section relies on the high-speed turbulent airflow of the Venturi section to uniformly mix fresh quicklime, fresh activated carbon, circulating ash, and flue gas, improving the deacidification efficiency and dioxin adsorption efficiency of the flue gas in the purification tower. At the same time, the high-speed turbulent airflow of the Venturi section maintains a stable reaction bed in the reaction section 14 of the purification tower, preventing powder collapse and affecting the normal operation of the equipment. The stable reaction bed formed by fresh quicklime, fresh activated carbon, circulating ash, and flue gas in the reaction section 14 of the purification tower uses quicklime to remove acidic gases from the flue gas and activated carbon to adsorb dioxin-like substances in the flue gas. The exhaust section 15 of the purification tower is the flue gas outlet of the purification tower.

[0025] The exhaust section 15 of the purification tower is connected to the bag filter 20 via the flue 7. The bag filter 20 is used to remove dust from the furnace door and feeding well, as well as deacidification products, unreacted quicklime, activated carbon that has adsorbed dioxins, and unadsorbed activated carbon from the flue gas, so that the particulate matter emission concentration in the flue gas is lower than the emission limit. At the same time, flue gas deacidification and dioxin adsorption continue on the bag filter, further improving the flue gas deacidification efficiency and dioxin adsorption efficiency.

[0026] The bag filter 20 is equipped with a pulse-jet cleaning system 23. During operation, the pulse-jet cleaning system 23 cleans the dust adhering to the outer surface of the filter bags, reducing the operating resistance of the bag filter 20 and lowering the load on the filter bags. It is a component that ensures the continuous and stable operation of the bag filter 20. The pulse-jet cleaning system 23 is connected to an external compressed air system via a compressed air pipeline 22, which supplies compressed air for cleaning the bag filter 20.

[0027] The dust collector 20 is equipped with a rotary unloader 26 on its ash hopper. The rotary unloader 26 is used to discharge the dust in the ash hopper of the dust collector 20 and to lock the air in the ash hopper of the dust collector 20. It is a component that ensures the continuous and stable operation of the dust collector.

[0028] The outlet of the rotary unloader 26 of the bag filter is connected to the reversible rotary screw conveyor 27. The reversible rotary screw conveyor 27 is used to discharge the dust collected by the bag filter 20 and is a component that ensures the continuous and stable operation of the bag filter 20. The reversible rotary screw conveyor 27 has two discharge ports, one leading to the circulating ash feeding system and the other leading to the external ash discharge system. When the reversible rotary screw conveyor 27 rotates forward, it discharges ash to the circulating ash feeding system; when it rotates in reverse, it discharges ash to the external ash discharge system. Simultaneously, by combining multiple rotary unloaders of the bag filter and connecting them to the reversible rotary screw conveyor 27, the amount of ash collection equipment in the bag filter can be reduced, saving equipment investment and maintenance costs, and also reducing the labor intensity of workers.

[0029] The Venturi section 13 of the purification tower is connected to a circulating ash feeding system, a fresh slaked lime feeding system, and a fresh activated carbon feeding system via pipelines. The fresh slaked lime feeding system and the fresh activated carbon feeding system are used to add fresh slaked lime and fresh activated carbon to the purification tower, respectively, for initial deacidification and adsorption of dioxins. The circulating ash feeding system is used to re-inject dust, deacidification products, activated carbon adsorbing dioxins, unreacted slaked lime, and activated carbon that has not adsorbed dioxins from the flue gas outside the dual-chamber furnace, collected by the bag filter 20, into the Venturi section 13 of the purification tower for recycling. The unreacted slaked lime continues to react with acidic gases in the flue gas, and the activated carbon that has not adsorbed dioxins continues to adsorb acidic gases in the flue gas, improving the utilization rate of slaked lime and activated carbon.

[0030] This invention constructs a highly efficient closed-loop process of "reaction-collection-circulation-re-reaction" through a reversible rotary screw conveyor 27, a circulating ash feeding system, and a Venturi section 13 of the purification tower. According to process requirements, the reversible rotary screw conveyor 27 transports the dust rich in unreacted quicklime and unsaturated activated carbon collected by the bag filter 20 to the circulating ash feeding system. The circulating ash feeding system re-injects the unreacted quicklime and activated carbon that have not adsorbed dioxins into the Venturi section 13 of the purification tower through pneumatic conveying. The strong turbulent airflow generated in the Venturi section 13 of the purification tower not only mixes the fresh material with the flue gas evenly, but also provides strong kinetic energy and dispersing force for the circulating ash, which may have a high density and high humidity, so that it is fully dispersed, gasified, and regains its active reaction and adsorption capacity.

[0031] The high-speed turbulent environment of the Venturi section 13 is a prerequisite for the effective reuse of recycled ash, making it less prone to settling and improving the mixing effect. The recycled ash feeding system transports materials to the Venturi section 13, while the reversible rotary screw conveyor 27 ensures that materials usable for recycling are stably and controllably supplied to the recycled ash feeding system. Simultaneously, by controlling the rotation direction of the reversible rotary screw conveyor 27, unused materials can be returned to the Venturi section 13 for further reaction and adsorption, while materials that have undergone complete reaction or multiple cycles can be discharged through the external ash discharge system. This significantly improves the utilization rate of quicklime and activated carbon, reducing the consumption of fresh materials and the discharge of hazardous waste at the source, achieving a win-win situation for both economic and environmental benefits. Furthermore, compared to the complex layout of existing technology centers that require separate conveyor lines for recycling and external discharge, this greatly simplifies the structure of the dust treatment system, reducing the number of equipment, floor space, and corresponding investment and maintenance costs.

[0032] After being reactivated in the Venturi section, the circulating ash enters the reaction section 14 of the purification tower and the surface of the filter bags in the bag filter 20 along with the flue gas. This provides more sufficient reaction time and contact opportunities for the acid removal and dioxin adsorption reactions, forming a dual purification barrier of "initial reaction in the tower + deep reaction on the filter bag surface". At the same time, the addition of circulating ash helps to form a more stable fluidized bed in the reaction section 14 of the purification tower, enhancing the system's ability to resist flue gas flow fluctuations and ensuring continuous and stable operation.

[0033] Optionally, a torque sensor is installed in the drive mechanism of the reversible rotary screw conveyor 27 to detect the torque when the reversible rotary screw conveyor 27 rotates forward. The torque is used to infer whether the fresh quicklime has reacted completely. The operator can make an online judgment or the control system can make an automatic judgment through a preset program. When the reaction is determined to be complete, the reversible rotary screw conveyor 27 reverses and discharges the ash to the external ash discharge system.

[0034] Unreacted quicklime is a dry, fine powder with good flowability and a relatively low coefficient of friction with the screw conveyor blades and pipe walls. The reaction products, such as gypsum and calcium chloride, undergo significant changes in physical properties. Gypsum, for example, is crystalline and has a stronger granular texture; calcium chloride is highly hygroscopic and deliquescent, making the material damp and sticky. The mixed products after the reaction typically have poorer flowability and easily adhere to the blades and pipe walls, leading to a sharp increase in the coefficient of friction and adhesion force. The more complete the quicklime reaction, the more viscous and hygroscopic components are in the products, resulting in poorer material flowability, greater frictional resistance, and higher torque required for the screw conveyor to propel the material. Therefore, torque detection can be used to help determine whether the material needs to continue circulating or be discharged.

[0035] Torque sensors can be flange-type reactive torque sensors mounted in series in the drive train, shaft-type torque sensors that directly replace the original drive shaft, or wireless torque sensors. These wireless torque sensors and batteries are directly attached to the helical spindle where the torque needs to be measured, transmitting data wirelessly. Alternatively, based on the principle that the current of an AC asynchronous motor is directly proportional to its output torque within a certain range, the motor torque can be determined by detecting the motor current using a frequency converter or current transmitter.

[0036] The preferred technical solution involves monitoring and controlling key system operating parameters such as flue gas temperature, flue pressure, bag filter differential pressure, and storage bin level, and implementing corresponding protection measures to ensure the safe and stable operation of the system.

[0037] The flue duct 7 connecting the flue gas collection hood and the purification tower is equipped with a flue gas temperature regulating valve 8, a flue gas pressure sensor 9, and a flue gas temperature sensor 10. The flue gas temperature regulating valve 8 is used to regulate the flue gas temperature and prevent the system flue gas temperature from becoming too high. The flue gas pressure sensor 9 is used to monitor the pressure of the flue gas in front of the purification tower and will alarm when the pressure exceeds a certain set value. The flue gas temperature sensor 10 is used to monitor the flue gas temperature in front of the purification tower and control the flue gas temperature regulating valve 8. It will alarm when the flue gas temperature exceeds a certain set value. If the temperature continues to rise and exceeds a certain set value, it will automatically open the flue gas temperature regulating valve 8 to cool down and protect the equipment.

[0038] The bag filter 20 is equipped with a differential pressure sensor 21 on its inlet and outlet pipes to monitor the differential pressure of the bag filter 20. An alarm is triggered when the differential pressure exceeds a certain set value.

[0039] The bag filter 20 is equipped with a bag filter hopper vibrator 24, a bag filter discharge port gate valve 25, and a bag filter hopper high level gauge 28. The bag filter hopper vibrator 24 vibrates the bag filter hopper to promote dust flow and break up dust arches at the discharge port. The bag filter discharge port gate valve 25 is closed during maintenance of the bag filter rotary unloader 26 to prevent dust leakage. The bag filter hopper high level gauge 28 alarms when the hopper level reaches the high level and discharges ash to the circulating ash hopper 67 or the external ash discharge hopper 78.

[0040] In a preferred embodiment, the ash storage section 11 of the purification tower is equipped with a high-level gauge 16, a vibrator 17, a gate valve 18 at the discharge port, and a rotary unloader 19. The high-level gauge 16 monitors the ash level in the ash storage section 11 and alarms when the level reaches the high level, prompting the operator to discharge ash. The vibrator 17 vibrates the ash storage section 11 to promote dust flow and break up any arches formed at the discharge port. The gate valve 18 closes during maintenance of the rotary unloader to prevent dust leakage. The rotary unloader 19 discharges dust from the ash storage section 11 and locks the air in the ash storage section, ensuring continuous and stable operation of the purification tower.

[0041] In a preferred embodiment, the fresh quicklime addition system includes a fresh quicklime storage silo 32 for storing fresh quicklime for deacidification. A dust collector 33 is installed on the top of the fresh quicklime storage silo 32 to purify and recover dust in the exhaust gas from the fresh quicklime storage silo 32, prevent exhaust gas from polluting the environment, and reduce material loss.

[0042] The fresh slaked lime storage silo 32 is equipped with a high-level gauge 34, a low-level gauge 35, and a mixer 36 at the discharge port. The high-level gauge 34 and low-level gauge 35 monitor the high and low levels of the slaked lime storage silo 32, respectively. When the slaked lime level reaches the high level, the high-level gauge 34 alarms, prompting the operator to stop feeding. When the slaked lime level reaches the low level, the low-level gauge 35 alarms, prompting the operator to add more material. The mixer 36 at the discharge port breaks up any arched slaked lime at the discharge port, loosens the lime at the discharge port, promotes its flow, and facilitates discharge.

[0043] The discharge port of the fresh quicklime storage silo 32 is equipped with a discharge port gate valve 37 and a rotary unloader 38. The discharge port gate valve 37 is closed when the rotary unloader 38 is under maintenance to prevent quicklime leakage. The rotary unloader 38 feeds quicklime into the fresh quicklime feed silo 39. Its start and stop are controlled by the high level gauge 40 and the low level gauge 41 of the fresh quicklime feed silo. The unloader starts when the fresh quicklime feed silo 39 reaches the low level and stops when the fresh quicklime feed silo 39 reaches the high level.

[0044] The discharge port of the fresh quicklime storage silo 32 is connected to the fresh quicklime feed silo 39. The fresh quicklime supplied to the purification system is temporarily stored in the fresh quicklime feed silo 39, and then fed to the purification tower according to the emission of acidic gas from the exhaust stack 30 outlet and the material level in the bag filter hopper.

[0045] The fresh quicklime feeding silo 39 is equipped with a high level gauge 40, a low level gauge 41, and a discharge agitator 42. The high level gauge 40 and the low level gauge 41 are used to monitor the high and low levels of the fresh quicklime feeding silo 39, respectively. When the level is high, the rotary unloader 38 of the fresh quicklime storage silo is stopped, and when the level is low, the rotary unloader 38 of the fresh quicklime storage silo is started.

[0046] The agitator 42 at the outlet of the fresh quicklime feed silo breaks up the arched quicklime at the outlet of the fresh quicklime feed silo 39 by agitation, loosens the quicklime at the outlet, promotes the flow of quicklime, and facilitates its discharge from the outlet.

[0047] The outlet of the fresh quicklime feeding silo 39 is connected to the fresh quicklime screw feeder 43. The fresh quicklime screw feeder 43 starts and stops according to the emission of acidic gas from the exhaust stack 30 and the material level in the bag filter hopper. During operation, the feed rate is controlled by frequency conversion to achieve the effect of saving materials and reducing operating costs.

[0048] A fresh slaked lime rotary feeder 44 is installed at the outlet of the fresh slaked lime screw feeder 43. Its main function is to lock the airflow and prevent the airflow blown by the fresh slaked lime pneumatic conveying fan 45 from forming an airlock at the fresh slaked lime screw feeder 43, which would prevent the fresh slaked lime from entering the fresh slaked lime air-material mixer 47, thus preventing the supply of slaked lime to the purification system and the removal of acidic gases from the flue gas. It operates synchronously with the fresh slaked lime screw feeder 43 to ensure the supply of slaked lime to the purification system.

[0049] The outlet of the fresh quicklime screw feeder 43 is connected to the fresh quicklime air mixer 47, and the fresh quicklime and the pneumatic conveying airflow are mixed in the device.

[0050] One end of the fresh quicklime air mixer 47 is connected to the fresh quicklime pneumatic conveying fan 45 through the fresh quicklime pneumatic conveying pipeline 48. The high-pressure airflow blown out by the fan transports the fresh quicklime through the fresh quicklime pneumatic conveying pipeline 48 to the Venturi section 13 of the purification tower.

[0051] A fresh quicklime pneumatic conveying valve 46 is installed on the fresh quicklime pneumatic conveying pipeline 48 between the fresh quicklime pneumatic mixer 47 and the fresh quicklime pneumatic conveying blower 45. The fresh quicklime pneumatic conveying valve 46 is opened before the fresh quicklime pneumatic conveying blower 45 is started and closed after the fresh quicklime pneumatic conveying blower 45 is stopped, preventing outside air from entering the fresh quicklime pneumatic conveying pipeline 48, keeping the fresh quicklime pneumatic conveying pipeline 48 dry, and preventing the quicklime from absorbing moisture and caking when the fresh quicklime feeding system is restarted.

[0052] The other end of the fresh quicklime air mixer 47 is connected to the fresh quicklime injector 49 through the fresh quicklime pneumatic conveying pipe 48. The fresh quicklime injector 49 is located inside the Venturi section 13 of the purification tower. The fresh quicklime is evenly injected into the flue gas of the Venturi section 13 of the purification tower by means of this device, thereby improving the uniformity of the mixing of flue gas and fresh quicklime.

[0053] In a preferred embodiment, the fresh activated carbon dosing system includes a fresh activated carbon storage silo 50 for storing and adsorbing dioxins, and a dust collector 51 is installed on the top of the fresh activated carbon storage silo 50 to purify and recover dust in the exhaust gas from the fresh activated carbon storage silo 50, prevent exhaust gas from polluting the environment, and reduce material loss.

[0054] The fresh activated carbon storage silo 50 is equipped with a high-level gauge 52, a low-level gauge 53, and a mixer 54 at the discharge port. The high-level gauge 52 and the low-level gauge 53 are used to monitor the high and low levels of the fresh activated carbon storage silo 50, respectively. When the high level is reached, the high-level gauge 52 alarms, prompting the operator to stop feeding. When the low level is reached, the low-level gauge 53 alarms, prompting the operator to feed.

[0055] The agitator 54 at the discharge port of the fresh activated carbon storage silo breaks up the arched activated carbon at the discharge port of the fresh activated carbon storage silo 50 by agitation, loosens the activated carbon at the discharge port, promotes the flow of activated carbon, and facilitates discharge from the discharge port.

[0056] The discharge port of the fresh activated carbon storage silo 50 is equipped with a discharge port gate valve 55 and a rotary unloader 56. The discharge port gate valve 55 is closed when the rotary unloader 56 is under maintenance to prevent activated carbon leakage. The rotary unloader 56 is used to feed material into the fresh activated carbon feed silo 57. Its start and stop are controlled by the high level gauge 58 and the low level gauge 59 of the fresh activated carbon feed silo. The unloader starts when the fresh activated carbon feed silo 57 reaches the low level and stops when the fresh activated carbon feed silo 57 reaches the high level.

[0057] The discharge port of the fresh activated carbon storage silo 50 is connected to the fresh activated carbon feed silo 57. The fresh activated carbon supplied to the purification system is temporarily stored in the fresh activated carbon feed silo 57 and then fed to the purification tower.

[0058] The fresh activated carbon feeding hopper 57 is equipped with a high level gauge 58, a low level gauge 59, and an agitator 60 at the outlet of the fresh activated carbon feeding hopper. The high level gauge 58 and the low level gauge 59 are used to monitor the high and low levels of the fresh activated carbon feeding hopper 57, respectively. When the level is high, the rotary unloader 56 of the fresh activated carbon storage hopper is stopped, and when the level is low, the rotary unloader 56 of the fresh activated carbon storage hopper is started.

[0059] The agitator 60 at the outlet of the fresh activated carbon feed hopper breaks up the arched activated carbon at the outlet of the fresh activated carbon feed hopper 57 by agitation, loosens the activated carbon at the outlet, promotes the flow of activated carbon, and facilitates its discharge from the outlet.

[0060] The outlet of the fresh activated carbon feeding hopper 57 is connected to the fresh activated carbon screw feeder 61. The fresh activated carbon screw feeder 61 is frequency-controlled and runs continuously. It monitors the incoming raw materials to obtain the corresponding activated carbon feeding amount when the dioxin-like substances in the flue gas meet the emission standards for different raw materials. Multiple operating frequencies are set, and the operator switches the operating frequency according to different raw materials to achieve the effect of saving materials and reducing operating costs.

[0061] A rotary feeder 62 for fresh activated carbon is installed at the outlet of the fresh activated carbon screw feeder 61. The main function of the rotary feeder 62 is to lock the airflow, preventing the airflow blown by the pneumatic conveying fan 63 from forming an airlock at the screw feeder 61, which would prevent the fresh activated carbon from entering the air-material mixer 64 and thus prevent the supply of activated carbon to the purification system, thus hindering the adsorption of dioxins in the flue gas. The rotary feeder 62 operates synchronously with the screw feeder 61 to ensure the supply of activated carbon to the purification system.

[0062] The outlet of the fresh activated carbon screw feeder 61 is connected to the fresh activated carbon air-material mixer 64, and the fresh activated carbon and the pneumatic conveying airflow are mixed in the fresh activated carbon air-material mixer 64.

[0063] One end of the fresh activated carbon air mixer 64 is connected to the fresh activated carbon pneumatic conveying fan 63 via the fresh activated carbon pneumatic conveying pipe 65. The high-pressure airflow blown out by the fan transports the fresh activated carbon through the fresh activated carbon pneumatic conveying pipe 65 to the Venturi section 13 of the purification tower.

[0064] The other end of the fresh activated carbon air-fuel mixer 64 is connected to the fresh activated carbon injector 66 through the fresh activated carbon pneumatic conveying pipe 65. The fresh activated carbon injector 66 is located inside the Venturi section 13 of the purification tower. The fresh activated carbon is evenly injected into the flue gas of the Venturi section 13 of the purification tower by means of this device, thereby improving the uniformity of the mixing of flue gas and fresh activated carbon.

[0065] In a preferred embodiment, the circulating ash feeding system includes a circulating ash silo 67 connected to the discharge port of one end of the reversible rotary screw conveyor 27. The circulating ash silo 67 stores the collected ash from the bag filter 20 and re-introduces the collected ash containing unreacted quicklime and activated carbon that has not adsorbed dioxins into the Venturi section 13 of the purification tower, thereby improving the utilization rate of quicklime and activated carbon, saving material consumption, reducing the amount of hazardous waste generated, and saving operating costs.

[0066] A ventilation pipe 68 is installed on the top of the circulating ash silo 67 to ventilate the circulating ash silo 67, facilitating the entry and exit of circulating ash.

[0067] Inside the circulating ash silo 67, there are respectively a circulating ash silo high level gauge 69, a circulating ash silo low level gauge 70, a circulating ash silo outlet agitator 71, and a circulating ash rotary feeder 72. The circulating ash silo high level gauge 69 and the circulating ash silo low level gauge 70 are used to monitor the high and low levels of the circulating ash silo 67, respectively. When the level is high, the reversible rotating screw conveyor 27 is stopped rotating in the forward direction. When the level is low, the reversible rotating screw conveyor 27 is started rotating in the forward direction.

[0068] The agitator 71 at the outlet of the circulating ash silo breaks up the arched circulating ash at the outlet of the circulating ash silo 67 by agitation, loosens the circulating ash at the outlet, promotes the flow of circulating ash, and facilitates its discharge from the outlet.

[0069] The rotary feeder 72 for circulating ash is used to add circulating ash to the circulating ash air-material mixer 75, and is frequency-controlled.

[0070] The outlet of the circulating ash hopper 67 is connected to the circulating ash air-material mixer 75, and the circulating ash and the pneumatic conveying airflow are mixed in the circulating ash air-material mixer 75.

[0071] One end of the circulating ash air-material mixer 75 is connected to the circulating ash pneumatic conveying fan 73 through the circulating ash pneumatic conveying pipe 76. The high-pressure airflow blown out by the fan transports the circulating ash through the circulating ash pneumatic conveying pipe 76 to the Venturi section 13 of the purification tower.

[0072] A circulating ash pneumatic conveying valve 74 is installed on the circulating ash pneumatic conveying pipeline 76 between the circulating ash air-material mixer 75 and the circulating ash pneumatic conveying fan 73. The circulating ash pneumatic conveying valve 74 is opened before the circulating ash pneumatic conveying fan 73 is started and closed after the circulating ash pneumatic conveying fan 73 is stopped, preventing outside air from entering the circulating ash pneumatic conveying pipeline 76, keeping the circulating ash pneumatic conveying pipeline dry, and preventing the circulating ash from absorbing moisture and caking when the circulating ash feeding system is restarted.

[0073] The other end of the circulating ash air-material mixer 75 is connected to the circulating ash injector 77 through the circulating ash pneumatic conveying pipe 76. The circulating ash injector 77 is located inside the Venturi section 13 of the purification tower. The circulating ash is uniformly injected into the flue gas of the Venturi section 13 of the purification tower by means of this device, thereby improving the uniformity of the mixing of flue gas and circulating ash.

[0074] In a preferred embodiment, the external ash discharge system includes an external ash discharge silo 78 connected to the discharge port at the other end of the reversible rotary screw conveyor 27. The quicklime, activated carbon, and dust from the original flue gas added to the purification system are collected by the bag filter 20 and, after multiple cycles, are finally discharged into the external ash discharge silo 78 for temporary storage and eventual external discharge, and disposed of in accordance with regulations.

[0075] The external ash silo 78 is equipped with an external ash silo top dust collector 79, which is used to purify the dust in the exhaust gas of the external ash silo 78 and prevent exhaust gas from polluting the environment.

[0076] The outer ash silo 78 is equipped with an outer ash silo high level gauge 80, an outer ash silo ash discharge port slide valve 82 and an outer ash silo rotary unloader 83. The outer ash silo high level gauge 80 is used to monitor the high level of the outer ash silo 78 and control the reversible rotary screw conveyor 27 to stop in the reverse direction.

[0077] The ash discharge port gate valve 82 of the external ash discharge silo is closed during maintenance of the external ash discharge silo rotary unloader 83 to prevent dust leakage.

[0078] The rotary unloader 83 for external ash silos is used to discharge dust and air locks from the external ash silos 78 and is a component that ensures the continuous and stable operation of the purification system.

[0079] An external ash discharge hopper vibrator 81 is installed on the outside of the external ash discharge hopper 78 near the discharge port. It is used to vibrate the ash hopper of the external ash discharge hopper 78 to promote the flow of dust and break up the arched dust at the discharge port.

[0080] In a preferred embodiment, a fresh quicklime conveying air heater 84 is provided on the fresh quicklime pneumatic conveying pipeline 48 between the fresh quicklime air mixer 47 and the fresh quicklime pneumatic conveying air valve 46. This heater is used to heat the fresh quicklime conveying air and prevent the quicklime from caking due to dampness in the conveying air, thus blocking the conveying pipeline.

[0081] A circulating ash conveying air heater 85 is installed on the circulating ash pneumatic conveying pipe 76 between the circulating ash air mixer 75 and the circulating ash pneumatic conveying air valve 74. This heater is used to heat the circulating ash conveying air and prevent the circulating ash from becoming caking due to moisture in the conveying air, thus blocking the conveying pipe.

[0082] In a preferred embodiment, the exhaust port of the bag filter 20 is connected to the induced draft fan 29 via the flue 7. The induced draft fan 29 is used to transport flue gas and is frequency-controlled. Its speed is adjusted according to the number of valves opening in the flue gas collection hood and the flue gas temperature, allowing the fan's operating parameters to adapt to the actual production conditions of the dual-chamber furnace. This not only meets the requirements for discharging low-temperature flue gas from the dual-chamber furnace but also saves system energy consumption and reduces operating costs. The induced draft fan 29 is connected to the exhaust stack 30 via the flue 7, and the exhaust stack discharges the purified flue gas, which meets emission standards, into the atmosphere.

[0083] A continuous online flue gas monitoring system 31 is installed on the exhaust stack 30. This system monitors the concentration of particulate matter and acidic gases emitted into the atmosphere at the exhaust stack 30 outlet and displays the monitoring results visually on a real-time monitoring platform. This allows staff to monitor the particulate matter and acidic gas levels emitted into the atmosphere at any time, enabling them to take timely control measures to ensure that flue gas emissions meet standards and prevent environmental pollution. The system also controls the start / stop and feed rate of the fresh quicklime feeding system based on the monitored acidic gas concentration.

[0084] This invention's low-resistance Venturi scrubbing tower efficiently removes acid and adsorbs dioxins while exhibiting minimal increase in system resistance. The dosage of fresh quicklime is automatically adjusted based on the concentration of acidic gas emissions, while the dosage of fresh activated carbon is adjusted according to the type of raw materials used (requiring manual intervention from operators). The quicklime and activated carbon added to the scrubbing system are recycled, maximizing the number of cycles while ensuring that pollutant emissions in the flue gas do not exceed standards. The bag filter 20 utilizes a reversible rotary screw conveyor 27 to achieve both dust recycling and external discharge functions. This invention is highly adaptable to flue gas from dual-chamber furnaces, ensuring effective collection of flue gas and efficient pollutant purification while saving system operating energy, improving material utilization in the flue gas purification system, reducing material consumption, decreasing hazardous waste generation, simplifying system configuration, and enhancing system reliability. This results in low investment and operating costs for the entire system, enabling enterprises to achieve a win-win situation in terms of both environmental and economic benefits.

[0085] All parts not disclosed in this invention are prior art, and their specific structures, materials, and working principles will not be described in detail. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dual chamber furnace off-gas exhaust purification system for recycling aluminum, characterized by: The flue gas collecting cover of each furnace door of the double-chamber furnace is communicated with the purification tower inlet air section (12) of the purification tower through the flue (7), the purification tower comprises, from bottom to top, a purification tower ash storage section (11), a purification tower inlet air section (12), a purification tower Venturi section (13), a purification tower reaction section (14) and a purification tower outlet air section (15), the purification tower outlet air section (15) is connected with the bag-type dust collector (20) through the flue (7), the bag-type dust collector (20) is provided with a pulse dust cleaning system (23), the pulse dust cleaning system (23) is connected with external compressed air equipment through a compressed air pipeline (22), a bag-type dust collector rotary unloader (26) is arranged on the ash bucket of the bag-type dust collector (20), the outlet of the bag-type dust collector rotary unloader (26) is connected with a reversible rotary screw ash conveying machine (27), the reversible rotary screw ash conveying machine (27) has two discharge ports, one of which leads to a circulating ash feeding system, and the other of which leads to an external ash discharge system, when the reversible rotary screw ash conveying machine (27) rotates forward, ash is discharged to the circulating ash feeding system, when the reversible rotary screw ash conveying machine (27) reverses, ash is discharged to the external ash discharge system, a torque sensor is arranged in the driving mechanism of the reversible rotary screw ash conveying machine (27) for detecting the torque when the reversible rotary screw ash conveying machine (27) rotates forward, whether fresh quicklime is completely reacted is inferred by the torque, whether the material needs to continue to participate in the cycle or be discharged externally is judged by the torque detection, when it is judged that the reaction is complete, the reversible rotary screw ash conveying machine (27) reverses to discharge ash to the external ash discharge system, the purification tower Venturi section (13) is connected with the circulating ash feeding system, a fresh quicklime feeding system and a fresh activated carbon feeding system through pipelines.

2. The exhaust gas purification system for a secondary aluminum two-chamber furnace according to claim 1, characterized in that: The flue gas collecting cover comprises a double-chamber furnace heating chamber furnace door flue gas collecting cover (1), a double-chamber furnace charging chamber furnace door flue gas collecting cover (3) and a double-chamber furnace charging well flue gas collecting cover (5), the flue (7) is provided with a double-chamber furnace heating chamber furnace door flue gas collecting cover valve (2), a double-chamber furnace charging chamber furnace door flue gas collecting cover valve (4) and a double-chamber furnace charging well flue gas collecting cover valve (6) corresponding to the double-chamber furnace heating chamber furnace door flue gas collecting cover (1), the double-chamber furnace charging chamber furnace door flue gas collecting cover (3) and the double-chamber furnace charging well flue gas collecting cover (5) respectively.

3. The exhaust gas purification system for a double chamber furnace for recycling aluminum according to claim 1, characterized in that: The flue (7) connected with the flue gas collecting cover and the purification tower is respectively provided with a flue gas temperature adjusting valve (8), a flue pressure sensor (9) and a flue gas temperature sensor (10).

4. The exhaust gas purification system for a secondary aluminum two-chamber furnace according to claim 1, characterized in that: The purification tower ash storage section (11) is respectively provided with a purification tower high material level meter (16), a purification tower ash storage section vibrator (17), a purification tower ash storage section unloading port plug valve (18) and a purification tower ash storage section rotary unloader (19).

5. The exhaust gas purification system for a secondary aluminum two-chamber furnace according to claim 1, characterized in that: The fresh hydrated lime adding system comprises a fresh hydrated lime storage bin (32), a fresh hydrated lime storage bin top dust remover (33) arranged on the fresh hydrated lime storage bin (32), a fresh hydrated lime storage bin high material level meter (34), a fresh hydrated lime storage bin low material level meter (35) and a fresh hydrated lime storage bin discharge port stirrer (36) arranged in the fresh hydrated lime storage bin (32), a fresh hydrated lime storage bin discharge port plug valve (37) and a fresh hydrated lime storage bin rotary discharger (38) arranged at the discharge port of the fresh hydrated lime storage bin (32), the discharge port of the fresh hydrated lime storage bin (32) being connected with a fresh hydrated lime feeding bin (39), the fresh hydrated lime feeding bin (39) being provided with a fresh hydrated lime feeding bin high material level meter (40), a fresh hydrated lime feeding bin low material level meter (41) and a fresh hydrated lime feeding bin discharge port stirrer (42) respectively, the discharge port of the fresh hydrated lime feeding bin (39) being connected with a fresh hydrated lime screw feeder (43), the fresh hydrated lime screw feeder (43) being provided with a fresh hydrated lime rotary feeder (44) at the discharge port, the discharge port of the fresh hydrated lime screw feeder (43) being connected with a fresh hydrated lime air and material mixer (47), one end of the fresh hydrated lime air and material mixer (47) being connected with a fresh hydrated lime pneumatic conveying fan (45) through a fresh hydrated lime pneumatic conveying pipeline (48), the fresh hydrated lime pneumatic conveying pipeline (48) between the fresh hydrated lime air and material mixer (47) and the fresh hydrated lime pneumatic conveying fan (45) being provided with a fresh hydrated lime pneumatic conveying air valve (46), the other end of the fresh hydrated lime air and material mixer (47) being connected with a fresh hydrated lime injector (49) through the fresh hydrated lime pneumatic conveying pipeline (48), and the fresh hydrated lime injector (49) being arranged inside the purification tower Venturi section (13).

6. The exhaust gas purification system for a double chamber furnace for recycling aluminum according to claim 5, characterized in that: The fresh activated carbon feeding system comprises a fresh activated carbon storage bin (50), a fresh activated carbon storage bin top dust remover (51) arranged on the fresh activated carbon storage bin (50), a fresh activated carbon storage bin high material level meter (52), a fresh activated carbon storage bin low material level meter (53) and a fresh activated carbon storage bin discharge port stirrer (54) arranged in the fresh activated carbon storage bin (50), a fresh activated carbon storage bin discharge port flap valve (55) and a fresh activated carbon storage bin rotary discharger (56) arranged at the discharge port of the fresh activated carbon storage bin (50), and the discharge port of the fresh activated carbon storage bin (50) is connected with a fresh activated carbon feeding bin (57), the fresh activated carbon feeding bin (57) is provided with a fresh activated carbon feeding bin high material level meter (58), a fresh activated carbon feeding bin low material level meter (59) and a fresh activated carbon feeding bin discharge port stirrer (60) respectively, the discharge port of the fresh activated carbon feeding bin (57) is connected with a fresh activated carbon screw feeder (61), the discharge port of the fresh activated carbon screw feeder (61) is provided with a fresh activated carbon rotary feeder (62), the discharge port of the fresh activated carbon screw feeder (61) is connected with a fresh activated carbon air and material mixer (64), one end of the fresh activated carbon air and material mixer (64) is connected with a fresh activated carbon pneumatic conveying fan (63) through a fresh activated carbon pneumatic conveying pipeline (65), the other end of the fresh activated carbon air and material mixer (64) is connected with a fresh activated carbon injector (66) through a fresh activated carbon pneumatic conveying pipeline (65), and the fresh activated carbon injector (66) is arranged in the inside of the purification tower Venturi section (13).

7. The exhaust gas purification system for a double chamber furnace for recycling aluminum according to claim 6, characterized in that: The circulating ash feeding system comprises a circulating ash bin (67) connected with one end of a reversible rotary screw ash conveying machine (27), the circulating ash bin (67) is provided with a breather pipe (68), the inside of the circulating ash bin (67) is provided with a circulating ash bin high material level meter (69), a circulating ash bin low material level meter (70), a circulating ash bin discharge port stirrer (71) and a circulating ash rotary feeder (72) respectively, the discharge port of the circulating ash bin (67) is connected with a circulating ash air and material mixer (75), one end of the circulating ash air and material mixer (75) is connected with a circulating ash pneumatic conveying fan (73) through a circulating ash pneumatic conveying pipeline (76), a circulating ash pneumatic conveying air valve (74) is arranged on the circulating ash pneumatic conveying pipeline (76) between the circulating ash air and material mixer (75) and the circulating ash pneumatic conveying fan (73), the other end of the circulating ash air and material mixer (75) is connected with a circulating ash injector (77) through the circulating ash pneumatic conveying pipeline (76), and the circulating ash injector (77) is arranged in the inside of the purification tower Venturi section (13).

8. The exhaust gas purification system for a double chamber furnace for recycling aluminum according to claim 7, characterized in that: The outer ash discharge system comprises an outer ash discharge bin (78) connected with the discharge port of the reversible rotary screw ash conveyor (27), an outer ash discharge bin top dust collector (79) is arranged on the outer ash discharge bin (78), an outer ash discharge bin high material level meter (80) is arranged on the inner side of the outer ash discharge bin (78), an outer ash discharge bin ash discharge port plug valve (82) and an outer ash discharge bin rotary unloader (83) are arranged on the bottom of the outer ash discharge bin (78), and an outer ash discharge bin vibrator (81) is arranged on the outer side of the outer ash discharge bin (78) close to the discharge port.

9. The exhaust gas purification system for a double chamber furnace for recycling aluminum according to claim 7 or 8, characterized in that: A fresh hydrated lime conveying air heater (84) is arranged on the fresh hydrated lime pneumatic conveying pipeline (48) between the fresh hydrated lime pneumatic conveying pipeline (48) and the fresh hydrated lime pneumatic conveying air valve (46), and a circulating ash conveying air heater (85) is arranged on the circulating ash pneumatic conveying pipeline (76) between the circulating ash pneumatic conveying pipeline (76) and the circulating ash pneumatic conveying air valve (74).

10. The exhaust gas purification system for a secondary aluminum two-chamber furnace according to claim 9, characterized in that: The exhaust port of the bag-type dust collector (20) is connected with the induced draft fan (29) through the flue (7), the induced draft fan (29) is connected with the exhaust cylinder (30) through the flue (7), and the exhaust cylinder (30) is provided with a continuous online monitoring system (31) for flue gas.

Images