CN216144144U

CN216144144U - Fly ash and scrap steel recovery unit in coordination

Info

Publication number: CN216144144U
Application number: CN202122050475.XU
Authority: CN
Inventors: 许群惟; 沈毅; 周友信; 曹熠; 陈俊宇; 靳晓鹏; 胡波; 李蕾蕾
Original assignee: Hangzhou Zhenglong Environmental Protection Technology Co ltd
Current assignee: Hangzhou Zhenglong Environmental Protection Technology Co ltd
Priority date: 2020-10-28
Filing date: 2021-08-27
Publication date: 2022-03-29
Anticipated expiration: 2031-08-27
Also published as: CN112648618B; CN114485144A; CN214223108U; CN112648618A; CN112747604B; CN214223157U; CN214223156U; CN216144147U; CN114472472B; CN214223107U; CN216144143U; CN114485187A; CN114485144B; CN114472472A; CN112747604A

Abstract

The utility model provides a fly ash and waste steel cooperative recovery device, which solves the problems of low heat recovery efficiency and difficult equipment service life in the existing waste steel recovery through a specific umbrella-shaped feeding control system, a fly ash feeding system, a first pipeline for constant-temperature exhaust gas and a second pipeline for circularly recovering the exhaust gas, can realize uniform feeding of waste steel in high-temperature exhaust gas, green recovery of waste steel, cooperative disposal of dust-removing fly ash and vitrification treatment of fly ash, and has the advantages of simple structure, firmness, durability and low cost; by controlling constant-temperature discharge and recycling of constant-temperature flue gas, dioxin in the flue gas is reduced to the maximum extent, and the dioxin generated in the incineration flue gas can be inhibited; the waste heat of high-temperature flue gas can be fully utilized, the heat recovery efficiency is high, and the energy loss is greatly reduced.

Description

Fly ash and scrap steel recovery unit in coordination

The present application claims the prior application of China, application number: 202011171476.3, priority of claim 2020, 10/18, all of which are intended to be part of this invention.

Technical Field

The utility model belongs to the field of metallurgy and environmental protection, relates to a fly ash and waste steel cooperative recovery device, and particularly relates to a fly ash and waste steel cooperative recovery device which can inhibit dioxin generated in incineration flue gas, utilize energy as high as possible and reduce energy loss.

Background

Fly ash generated by waste incineration and hazardous waste treatment is listed in a hazardous waste management directory in the national hazardous waste directory of 2016 in China because the fly ash contains dioxin and other heavy metal harmful substances, and the fly ash cannot enter a household garbage landfill site without being treated according to the hazardous waste management requirement. The high-temperature slag vitrification technology is one of effective ways for realizing fly ash harmless treatment, has the advantages of wide application range, high treatment capacity, high organic substance burning removal rate, high flue gas purification degree and the like, is not popularized and applied in China at present, and has more research results but less practical application.

In the prior art, the recovery treatment of the fly ash is most thorough by a high-temperature melting method, because the treatment temperature of the high-temperature melting method can reach 1600 ℃, harmful organic matters such as dioxin and the like can be thoroughly decomposed into micromolecules, heavy metals and other inorganic matters are vitrified, and the dissolved matters are reduced to a minimum value. However, the melting method has relatively high energy consumption, and the implementation process needs to utilize the waste heat as much as possible, especially the waste heat of the flue gas. When the fly ash is treated at high temperature in a smelting furnace, the generated high-temperature flue gas can reach 1000 ℃, the energy carried by the high-temperature flue gas reaches 20-30% of the total energy consumed by the high-temperature furnace, so that the part of energy is very necessary to be recycled, and the waste heat of the high-temperature flue gas is used for preheating the feeding material, which is one of the most direct methods and the highest efficiency method. In the process of utilizing the high-temperature flue gas waste heat, the temperature of the flue gas is reduced, when the temperature is reduced to a temperature range of 250-500 ℃, decomposed dioxin is easy to regenerate, and the regeneration speed of the dioxin is high, so that the flue gas waste heat utilization process is avoided from the temperature range as far as possible. In the existing treatment of the flue gas generated by burning the household garbage, in order to avoid the generation of dioxin, a large amount of water spray quenching modes are adopted to rapidly reduce the temperature of the flue gas from about 1000 ℃ to 800 ℃ to 250 ℃, the method can not recover the energy in the flue gas, wastes a large amount of water resources, and the corrosion effect of a large amount of generated water gas on the subsequent equipment is increased.

In the waste iron smelting technology, because various inorganic and organic preservatives are contained on the surface of the existing metal, dioxin pollution is easily generated in the recovery process, and a surface anticorrosive layer is removed by adopting a solvent or a mechanical method at the present stage. Not only the working procedure is complex, but also the secondary pollution is easy to cause.

Energy conservation, consumption reduction and environmental protection in the process of recovering scrap steel by using an electric arc furnace are always one of core technologies of the technical development of the electric arc furnace all over the world. In the prior art, the energy conservation and consumption reduction of the electric arc furnace are mainly researched from two directions, one is to develop the discontinuous production to the continuous production; the other is to preheat the scrap steel, in particular to preheat the scrap steel by using high-temperature flue gas of an electric arc furnace (the high-temperature flue gas generated by the electric arc furnace can reach more than 1000 ℃) so as to reduce the consumption of electric energy.

The technology for preheating the scrap steel by using the flue gas of the electric arc furnace is a technology which is researched at home and abroad for more than twenty years, but has great technical difficulty due to the fact that the technology operates at high temperature, so that the schemes which are put into practical use up to now are few, and typically represent technologies such as vibration continuous charging Consteel (US5400358-1992), finger shaft furnace (DE4025294A1-1992) and shaft side-push charging (US2007/0013112A 1). However, the prior art has major defects: the Consteel (US5400358-1992) furnace only contacts the surface of the feeding scrap steel layer with the flue gas, the heat exchange between the flue gas and the scrap steel is insufficient, and the scrap steel layer is relatively static, so that the scrap steel is heated unevenly; in the finger shaft furnace, flue gas and waste steel are in full contact for heat exchange, the utilization rate of waste heat is high, but finger cooling water is easy to leak due to the complex structure of the finger valve and the large impact force of the waste steel, so that the service life of the finger valve at high temperature is seriously influenced, and the finger valve is easy to break and lose efficacy to interrupt production; in addition, the two processes have the environmental protection problem that the waste steel is often mixed with impurities such as plastics, paint and the like and is easy to generate highly toxic dioxin in the preheating process. The other difficulty is that the flue gas exchanges heat with materials, when the temperature is reduced to 300-500 ℃, decomposed dioxin has regeneration conditions, has proper temperature and various metal ions, and then the dioxin is regenerated and needs to be treated again to become a non-decomposition cycle.

At present, an effective device which can realize uniform feeding of waste steel in high-temperature flue gas, can cooperatively treat dust removal fly ash, can inhibit dioxin from being generated again in incineration flue gas and can fully utilize waste heat of the high-temperature flue gas is lacked.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems, the utility model provides a fly ash and waste steel cooperative recovery device, which solves the problems of low heat recovery efficiency and difficult equipment service life in the existing waste steel recovery through a specific umbrella-shaped feeding control system and a fly ash feeding system and arranging a first pipeline for constant-temperature exhaust gas and a second pipeline for circularly recovering the exhaust gas, can simultaneously realize vitrification treatment of the fly ash, has simple structure and low cost, inhibits the generation of dioxin in incineration flue gas, and greatly reduces the energy loss.

The utility model provides a special feeding preheating device capable of uniformly distributing scrap steel and an acid-removing slagging additive, which is provided with a feeding vertical shaft and an electric arc furnace melting device, wherein an umbrella-shaped grate valve with a cooling device is arranged in the feeding vertical shaft, and a cooling system in the umbrella-shaped grate valve has a double-layer structure and is not easy to leak; the charging shaft wall is provided with a magnetic extension body with cooling, and the heat recovered by the cooling system is recycled by the device for preheating the fly ash; and a movable magnet is arranged outside the feeding vertical shaft, and scrap steel is continuously and uniformly added into the electric arc furnace by moving the magnet outside the feeding vertical shaft and matching with the umbrella-shaped grate valve.

The high-temperature flue gas generated by the electric arc furnace is in full contact heat exchange with the scrap steel layer through a gap in the umbrella-shaped grate valve, after the high-temperature flue gas exchanges heat with the scrap steel and additives at the lower part of the scrap steel feeder, partial constant-temperature flue gas is led out at a specific position (the constant-temperature flue gas refers to that the temperature of the flue gas led out at the specific position is constant), and the flue gas at the temperature can control the regeneration of dioxin. The part of constant-temperature flue gas is guided out and then rapidly cooled through the quenching tower, so that the temperature of a resynthesis window of dioxin is avoided, and the cooled part of flue gas is subjected to ultra-clean emission after being purified by a special purification system. And the other part of constant-temperature flue gas which is not led out continuously rises, further exchanges heat with the scrap steel and the additive on the upper part of the scrap steel feeder to reduce the temperature, the cooled flue gas is connected with a high-temperature fan, is pressurized by the high-temperature fan and then is blown into a specific fly ash feeding system, and is fully exchanged heat with the fly ash and then enters an electric arc furnace melting system.

The method comprises the following steps of heating the fume and the fly ash at high temperature by an electric arc furnace, thoroughly decomposing dioxin contained in the fume and the fly ash under the continuous action of ultrahigh temperature, enabling components such as carbon in the fly ash to participate in recycling of waste steel, enabling other solid matters to form heavy-component and light-component scum melts, enabling the heavy metals in the fume and the fly ash to enter the melts, enabling the light-component scum melts to enter a water quenching tank through an upper-layer light-component discharger, comprehensively utilizing glassy slag formed after water quenching, comprehensively recycling steam formed by water quenching through a specific device, recycling water quenching cooling water, enabling the heavy-component melts formed in the electric arc furnace to enter a heavy-component recycling container through a lower-layer heavy-component discharger after accumulation, and recycling after cooling, so that green recycling of the waste steel and harmless cooperative disposal of the fly ash are realized.

In one aspect, the utility model provides a fly ash and scrap steel cooperative recovery device, which comprises a charging vertical shaft, an umbrella-shaped charging control system, a fly ash charging system and an electric arc furnace; the lower end of the charging vertical shaft is connected with an electric arc furnace; the umbrella-shaped feeding control system is positioned at the lower side of the feeding vertical shaft; the fly ash loading system is located on one side of the loading shaft.

Further, the umbrella-shaped feeding control system comprises an umbrella-shaped grate valve and a magnetic control system; the umbrella-shaped grate valve is arranged at the lower side of the feeding vertical shaft; the magnetic control system is arranged around the wall of the charging vertical shaft and is positioned at the periphery of the umbrella-shaped grate valve.

Further, the umbrella-shaped grate valve comprises an umbrella-shaped base, a positioning pipeline, an umbrella-shaped grate valve cooler and a moving track; the top of the umbrella-shaped base is connected with a positioning pipeline, and the positioning pipeline is connected with an umbrella-shaped grate valve cooler; the umbrella-shaped base and the positioning pipeline can move along the moving track.

In some modes, the umbrella-shaped base is a conical device with a downward opening, the top of the umbrella-shaped base is connected with a positioning pipeline, and the other end of the positioning pipeline is connected with an umbrella-shaped grate valve cooler and used for cooling the umbrella-shaped grate valve and recycling heat; the movable track is used for controlling the positions of the umbrella-shaped base and the positioning pipeline, and the umbrella-shaped base and the positioning pipeline can move up and down or left and right along the movable track so as to control the distance between the movable track and the wall ring at the lower end of the feeding vertical shaft and achieve the purpose of controlling the size of the feeding opening.

In some modes, the umbrella-shaped base and the positioning pipeline are of a double-layer jacketed cooling structure, and the inner layer is communicated with the umbrella-shaped grate valve cooler.

In some modes, the outer layer of the double-layer jacket type cooling structure of the umbrella-shaped grate valve is made of materials with good heat resistance and strength and can bear the impact force during charging, the inner layer of the double-layer jacket type cooling structure is made of materials with good ductility such as copper and the like, so that water seepage can be avoided even if the outer layer is damaged to a certain extent, and meanwhile, the supporting layer of the outer layer is cooled due to the good heat-conducting property of the copper, so that the strength is guaranteed.

The utility model changes the finger valve into the umbrella-shaped grate valve with simple structure for the first time, the umbrella-shaped grate valve body has no movement mechanism, adopts the umbrella-shaped structure, reduces the free falling time during charging, and guides the formula material to the periphery of the charging vertical shaft by utilizing the taper of the umbrella-shaped grate valve, thereby slowing down the impact of the formula material on the umbrella-shaped grate valve. The clamping sleeve type cooling system is adopted to cool the umbrella-shaped grate valve, so that the service life of the umbrella-shaped grate valve is further ensured.

Further, the magnetic control system comprises a magnetic extension and a permanent magnet; the permanent magnet is arranged outside the charging shaft wall and positioned at the periphery of the magnetic extension body; the magnetic extension body is arranged on the charging shaft wall; the magnetic extension bodies are arranged in a layered mode by adopting soft magnetic heat-resistant materials, and the layers are isolated by adopting nonmagnetic heat-resistant materials; the magnetic extension body is also provided with a magnetic extension body cooler; the permanent magnet can move up and down along the moving track.

In some forms, the magnetic extensions and the permanent magnets are both annular structures.

In some embodiments, a thin layer of non-magnetic material may be used to isolate the permanent magnet from the magnetic extensions when the permanent magnet needs to be moved.

Because the permanent magnet and the magnetic extension body have larger attraction force and are difficult to move, an adjustable thin non-magnetic body can be arranged between the permanent magnet and the magnetic extension body for local isolation, and when the permanent magnet needs to move, the position of the thin non-magnetic body is adjusted to isolate the thin non-magnetic body between the permanent magnet and the magnetic extension body, so that the permanent magnet can move conveniently; after the permanent magnet is moved, the position of the non-thin layer magnetic body can be adjusted again to ensure that the non-thin layer magnetic body is no longer positioned between the permanent magnet and the magnetic extension body, so that the magnetic effect of the permanent magnet is better exerted.

In some embodiments, the thin non-magnetic body may be made of stainless steel.

In some modes, the magnetic extension bodies are arranged in a layered mode, the layers are isolated by nonmagnetic heat-resistant materials with proper thicknesses, the magnetic extension materials are not magnetic, but can transmit magnetic force when being subjected to the magnetic force of an external magnet, and the magnetic extension materials mainly adopt soft magnetic materials with relatively good heat resistance and magnetic conductivity.

The magnetic extension body cooler is arranged for ensuring that the temperature of the magnetic extension body is lower than the Curie temperature of the magnetic extension body and recovering waste heat.

In some modes, a permanent magnet controller is arranged below the permanent magnet, and the permanent magnet controller can control the up-and-down displacement of the permanent magnet.

In some forms, the permanent magnet controller controls the up and down displacement of the permanent magnets via a hydraulic system.

Furthermore, a first pipeline and a second pipeline are further arranged on the charging vertical shaft, and the position of the second pipeline is higher than that of the first pipeline; the first pipeline is used for discharging part of the flue gas out of the charging vertical shaft, and the second pipeline is connected with the fly ash charging system and used for returning the rest of the flue gas to the electric arc furnace; the temperature in the first pipeline is higher than the regeneration temperature of dioxin in the flue gas.

In some modes, a first temperature measuring and controlling device is arranged at the position of the first pipeline and used for monitoring the temperature of the smoke discharged by the first pipeline.

In some modes, the first pipeline is provided with a first fan for helping to control the temperature of the discharged flue gas.

In some aspects, the first conduit is coupled to a quench tower.

In some modes, a second temperature measuring and controlling device is arranged at the position of the second pipeline and used for monitoring the temperature of the smoke discharged by the second pipeline, and a second fan is arranged at the position of the second pipeline and used for pressurizing the smoke in the second pipeline.

Through adjusting the motor frequency of first fan and second fan, can realize controlling the circulation volume and the emission of flue gas to reach the control and derive the purpose of flue gas temperature.

The first pipeline, the first temperature measuring and controlling device and the first fan jointly form a constant-temperature flue gas leading-out system of the scrap steel recovery and treatment device.

The constant temperature smoke means that the temperature of the smoke led out at the specific position is constant.

The second pipeline, the second temperature measuring and controlling device and the second fan jointly form a smoke circulating system of the processing device.

In the normal production process, the temperature of the flue gas generated in the electric arc furnace reaches thousands of degrees, and the high-temperature flue gas exchanges heat with scrap steel, a feeding valve and the like in the process of ascending along the feeding vertical shaft, so that the temperature is gradually reduced. When the smoke rises to the position near the constant-temperature smoke leading-out system, the temperature of the smoke is basically reduced to the temperature range required by the smoke leading-out.

In some modes, the constant-temperature flue gas leading-out system is provided with an upper gate valve and a lower gate valve, and under the assistance of the first temperature measuring and controlling device and the first fan, the position of leading-out flue gas can be adjusted in a proper range, so that the temperature of leading-out flue gas can be adjusted.

In some embodiments, the temperature range is controlled between 500 ℃ and 580 ℃.

In some embodiments, the temperature range is controlled to be 520 ℃ to 560 ℃.

The smoke in the temperature range can avoid the re-synthesis of dioxin. The temperature of the derived flue gas is rapidly reduced to 250-300 ℃ through a quenching tower, so that a temperature (300-500 ℃) window for re-synthesizing the dioxin is avoided, the dioxin in the derived flue gas is reduced to the maximum extent, and the waste heat of the flue gas is fully recycled.

The constant-temperature flue gas leading-out system mainly controls the circulating amount and the discharge amount of flue gas by adjusting the motor frequency of the first fan and the second fan so as to achieve the purpose of controlling the temperature of the flue gas. The first fan and the second fan are both variable frequency motors, the circulating flue gas volume in the feeding vertical shaft can be adjusted by matching of the two fans, the fed scrap steel formula material is heated sufficiently, and meanwhile, the temperature of the flue gas discharged by the first pipeline is ensured to be 500-580 ℃. After partial heat exchange, adjusting the first fan and the second fan to adjust the exhaust volume, so that a part of flue gas is discharged from the constant-temperature flue gas guiding system at a constant temperature of 500-580 ℃, and performing next flue gas purification; the residual constant temperature flue gas continuously exchanges heat with the scrap steel formula material, so that the purpose of gasifying organic matters in the scrap steel formula material by using waste heat is achieved.

And leading out part of the rising flue gas left after the constant temperature flue gas is guided out to enter a flue gas circulating system, removing organic substances in the rising flue gas after the rising flue gas exchanges heat with the scrap steel formula material entering the feeding shaft, pressurizing the generated mixed flue gas through a second fan which is a frequency modulation motor, adjusting the temperature of the flue gas in the feeding shaft within a certain range, and returning the rest flue gas to the electric arc furnace for continuous purification treatment.

Furthermore, the feeding vertical shaft is of a multilayer structure, each layer is separated by a feeding valve, and the volume of each layer is increased progressively from top to bottom; the umbrella-shaped feeding control system forms a feeding valve at the lowest layer of the feeding vertical shaft; except the feeding valve at the lowest layer, other feeding valves of the feeding vertical shaft are all inserting plate type feeding valves or split type feeding valves; the top end of the charging vertical shaft is also provided with a charging hopper and a charging box.

In some modes, the loading hopper, the loading box and the loading vertical shaft are sequentially connected from top to bottom through loading valves respectively.

In some forms the charging shaft has a lowermost internal diameter greater than an upper internal diameter.

In some embodiments, the cartridge feed valve is a hollow cartridge valve.

The feeding vertical shaft is of a layered type, the volume of each layer gradually increases from top to bottom, the upper layers are relatively low in temperature, a hollow-out inserting plate type (or split) valve is adopted, and the lowest layer is an umbrella-shaped grate valve. The scrap steel is fed from top to bottom layer by layer when the furnace is opened, and during normal production, the produced smoke gas is from bottom to top and from layer to layer, so that the impact of the scrap steel on the feeding valve can be further lightened.

Further, the fly ash charging system comprises a fly ash charging box, a wind-closing discharge valve, a fly ash charging pipe and an injection pipe; the fly ash charging box is connected with a first connecting port of the fly ash charging pipe through an air-closing discharge valve; the injection pipe is connected with a second connecting port of the fly ash feeding pipe; the lower end of the fly ash charging pipe is connected with an electric arc furnace.

The upper end of the fly ash feeding pipe is provided with a first connecting port and a second connecting port; the fly ash charging box is positioned above the air-closing discharge valve, and the lower part of the air-closing discharge valve is connected with a first connecting port of the fly ash charging pipe.

In some modes, the lower part of the fly ash charging box is in an inverted cone shape, and an inverted cone-shaped opening is in sealing connection with an air-tight discharge valve; the air-closing discharge valve is hermetically connected with a first connecting port of the fly ash charging pipe.

Furthermore, the injection port end of the injection pipe is hermetically connected with a second connecting port of the fly ash charging pipe, and the injection port area of the injection pipe is positioned below the air-seal discharge valve; the tail end of the injection pipe is connected with a second pipeline of the feeding vertical shaft.

The injection port end of the injection pipe is hermetically connected with a second connecting port of the fly ash charging pipe, and the injection port area of the injection pipe is positioned below the air-closing discharge valve; when the spraying pipe sprays high-temperature flue gas to the fly ash charging pipe, a negative pressure area is formed in the spraying opening area, the air-closing discharge valve is opened, and fly ash is sucked into the fly ash charging pipe from the fly ash charging box.

Further, the fly ash charging system also comprises a fan, wherein the fan is positioned at a second pipeline of the charging vertical shaft and is used for heating the flue gas injected by the injection pipe; and the fly ash charging box is also provided with a fly ash preheater. The fly ash preheater utilizes waste heat led out by the umbrella-shaped grate valve and the cooler of the magnetic extension body for preheating and drying the fly ash, thereby not only ensuring the fluidity of the fly ash, but also fully utilizing the waste heat.

Further, the fly ash charging box is provided with a charging valve. The charging valve is used for facilitating charging of the fly ash.

Further, the fly ash charging box is provided with a first charging valve and a second charging valve.

In some embodiments, the first feed valve is located at the top end of the fly ash feed box, and the second feed valve is located at the middle upper part of the fly ash feed box. The arrangement of a plurality of feeding valves is beneficial to uniform feeding of the fly ash.

In some embodiments, the fan of the fly ash loading system is the same fan as the second fan in the second duct of the loading shaft. The second fan is a frequency modulation motor, can adjust the temperature of the flue gas in the charging shaft within a certain range, and can pressurize the flue gas. After the ascending flue gas enters the flue gas circulating system, the ascending flue gas is pressurized by the second fan, the pressurized flue gas is accelerated by the injection pipe to form a negative pressure area, and the fly ash added by the ash hopper and the air-closing discharge valve is sucked and enters the electric arc furnace through the distribution pipe.

In some modes, the scrap steel needs to be properly crushed, the diameter of the scrap steel is not more than 150mm, dechlorination slagging agents (such as lime, calcium hydroxide, dolomite, flying ash and the like) are arranged in a formula, the particle size of the dechlorination slagging agents is controlled, feeding is convenient and smooth, and on the other hand, the addition of the dechlorination slagging agents can greatly reduce the content of chlorine in the constant-temperature flue gas, so that precursors for dioxin synthesis in the constant-temperature flue gas are greatly reduced, and the possibility of synthesizing dioxin again in the derived constant-temperature flue gas is further reduced.

Further, the electric arc furnace is provided with an electrode controller for controlling voltage stabilization; the electric arc furnace is also provided with a light component discharger and a heavy component discharger.

The electric arc furnace is particularly suitable for feeding of scrap steel formula materials and fly ash and flue gas circulation and export; meets the requirements of recovery of waste steel entering the furnace and vitrification slagging treatment of fly ash. The electric arc furnace electrode controller is lifted up and down to control the voltage stabilization of the electric arc and improve the temperature of the whole electric arc furnace, the high temperature generated by the electric arc furnace can reach 1300-1600 ℃, dioxin contained in flue gas and fly ash is thoroughly decomposed under the continuous action of ultra-high temperature (the highest temperature is 1600 ℃ and the duration is dozens of minutes), components such as carbon in the fly ash participate in the recycling and comprehensive utilization of waste steel, other solid matters form heavy component and light component scum melts, heavy metals in the flue gas and the fly ash enter the melts, the light component scum melts enter a water quenching tank through an upper layer light component discharger, and the heavy component melts enter a heavy component recycling container through a lower layer heavy component discharger.

In another aspect, the present invention provides a method for performing a fly ash and steel scrap recycling process by using the apparatus, the method mainly comprises the following steps:

(1) crushing the scrap steel to the diameter of not more than 150mm, adding a dechlorination slagging agent, mixing, and putting into a feeding vertical shaft;

(2) putting the fly ash into a fly ash charging system;

(3) and starting the device, and controlling the temperature in the first pipeline of the feeding vertical shaft to be 500-580 ℃.

The fly ash and scrap steel cooperative recovery processing device provided by the utility model has the following beneficial effects:

1. the waste steel can be uniformly fed in the high-temperature flue gas, the waste steel is recycled in an environment-friendly manner, the dedusting fly ash can be treated cooperatively, the fly ash is vitrified, and the device has a simple structure, is firm and durable and is low in cost;

2. by controlling constant-temperature discharge and recycling of constant-temperature flue gas, dioxin in the flue gas can be reduced to the maximum extent, and the dioxin generated in the incineration flue gas can be inhibited;

3. the waste heat of the high-temperature flue gas can be fully utilized, the heat recovery efficiency is high, and the energy loss is greatly reduced.

Drawings

FIG. 1 is a schematic diagram showing the overall structure of a fly ash and scrap steel cooperative recycling apparatus provided in example 1;

FIG. 2 is a schematic structural diagram of an umbrella-type feed control system provided in example 1;

FIG. 3 is a schematic structural view of a fly ash charging system provided in example 3.

Detailed Description

In the following, preferred embodiments of the utility model are described in further detail with reference to the accompanying drawings, it being noted that the following embodiments are intended to facilitate the understanding of the utility model without limiting it in any way, and that all features disclosed in the embodiments of the utility model, or all steps of the disclosed methods or processes, may be combined in any way, except for mutually exclusive features and/or steps.

Embodiment 1 the present invention provides a fly ash and scrap steel cooperative recovery apparatus

Fig. 1 to 3 show the cooperative recovery device for fly ash and steel scrap provided in this embodiment, where fig. 1 is a schematic view of an overall structure of the cooperative recovery device for fly ash and steel scrap, fig. 2 is a schematic view of an umbrella-shaped feeding control system, and fig. 3 is a schematic view of a fly ash feeding system.

As shown in fig. 1, the fly ash and scrap steel cooperative recovery apparatus comprises a charging shaft 7, an umbrella-shaped charging control system 30, a fly ash charging system 48 and an electric arc furnace 31; the lower end of the charging shaft 7 is connected to an electric arc furnace 31; the umbrella-shaped feeding control system 30 is positioned at the lower side of the feeding vertical shaft 7; the fly ash loading system 48 is located on one side of the loading shaft 7. The umbrella-shaped feeding control system 30 comprises an umbrella-shaped grate valve 1 and a magnetic control system 2; the umbrella-shaped grate valve 1 is arranged at the lower side of the charging vertical shaft 7; the magnetic control system 2 is arranged around the wall of the charging vertical shaft 7 and is positioned at the periphery of the umbrella-shaped grate valve 1.

As shown in fig. 2, the umbrella-shaped grate valve 1 comprises an umbrella-shaped base 3, a positioning pipeline 4, an umbrella-shaped grate valve cooler 5 and a moving track 6; the umbrella-shaped base 3 is a conical device with a downward opening, the top of the umbrella-shaped base 3 is connected with a positioning pipeline 4, and the other end of the positioning pipeline 4 is connected with an umbrella-shaped grate valve cooler 5 for cooling the umbrella-shaped grate valve 1 and simultaneously recycling heat; the umbrella-shaped base 3 and the positioning pipeline 4 can move along the moving track 6, including moving up and down or moving left and right, so as to control the distance between the umbrella-shaped grate valve 1 and the wall ring at the lower end of the charging vertical shaft 7 and achieve the purpose of controlling the size of the charging opening. Umbrella-type base 3 and positioning tube 4 all are double-deck jacketed cooling structure, and the inlayer communicates with each other with umbrella-type comb valve cooler 5, and outer heat-resisting and the better material of intensity of adopting can bear the impact force when feeding in raw material, and the inlayer adopts the better material of ductility such as copper, even can guarantee not the infiltration under the outer impaired circumstances of certain degree, thereby the good heat conductivility of copper guarantees that outer supporting layer obtains the cooling and guarantees intensity simultaneously. The waste heat recovered by the umbrella-shaped grate valve cooler 5 can be used for the waste heat of fly ash, thereby fully utilizing the waste heat and improving the heat recovery efficiency.

The umbrella-shaped grate valve 1 body has no movement mechanism, adopts an umbrella-shaped structure, reduces the free falling time during charging, and guides the formula material to the periphery of the charging vertical shaft 7 by utilizing the taper of the umbrella-shaped grate valve 1, thereby slowing down the impact of the formula material on the umbrella-shaped grate valve 1. The clamping sleeve type cooling system is adopted to cool the umbrella-shaped grate valve 1, and the service life of the umbrella-shaped grate valve 1 is further ensured.

As shown in fig. 2, the magnetic control system 2 comprises a magnetic extension 8 and a permanent magnet 9; (ii) a The magnetic extension body 8 and the permanent magnet 9 are both of annular structures; the permanent magnet 9 is arranged outside the wall of the charging vertical shaft 7, surrounds the wall of the charging vertical shaft 7 for a circle and is positioned at the periphery of the magnetic extension body 8; the magnetic extension body 8 is arranged in the wall of the charging shaft 7. The magnetic extension body 8 is formed by layering magnetic extension materials 11, the magnetic extension materials 11 are not magnetic, but can transmit magnetic force when receiving the magnetic force of an external magnet, and the magnetic extension materials 11 mainly adopt soft magnetic materials with relatively good heat resistance and magnetic conductivity; the layers are isolated by nonmagnetic heat-resistant materials 12.

Preferably, the magnetic extension 8 is further provided with a magnetic extension cooler 13. The magnetic extension cooler 13 is set up to ensure that the temperature of the magnetic extension 8 is below its curie temperature and also to recover waste heat. The waste heat obtained by the magnetic extension body cooler 13 can also be used for preheating the fly ash, thereby fully utilizing the waste heat and improving the heat recovery efficiency.

Preferably, the permanent magnet 9 is movable up and down along the moving rail 15. In this embodiment, a permanent magnet controller 16 is disposed below the permanent magnet 9, and the permanent magnet controller 16 can control the vertical displacement of the permanent magnet 9. In the present embodiment, the permanent magnet controller 16 controls the vertical displacement of the permanent magnet 9 by a hydraulic system.

Preferably, when the permanent magnet 9 needs to move, the permanent magnet 9 and the magnetic extension 8 can be isolated by a thin non-magnetic body 10, so as to facilitate the movement of the permanent magnet 9, and in this embodiment, the thin non-magnetic body 10 is preferably made of stainless steel.

Preferably, the charging shaft 7 is also provided with a first pipeline 40 and a second pipeline 41, and the second pipeline 41 is arranged at a higher position than the first pipeline 40; a first duct 40 for discharging part of the fumes from the charging shaft 7, a second duct 41 connected to a fly ash charging system 48 for returning the rest of the fumes to the electric arc furnace 31; the temperature in the first duct 40 is higher than the regeneration temperature of dioxin in flue gas.

Dioxins are the general names of polychlorinated diphenyl-one-to-one dioxins (PCDDS) and polychlorinated dibenzofurans (PCDFS), and have 210 kinds of isomers in total, wherein 75 kinds of PCDDS exist, 135 kinds of PCDFS exist, dioxins are difficult to dissolve in water, easy to dissolve in organic solvents, generally white solids are in a standard state, colorless and odorless, the melting point is about 305 ℃, and when the temperature reaches above 705 ℃, the dioxins begin to decompose. When monitoring the temperature in the first pipeline 40, we mainly pay attention to the regeneration of dioxin through low-temperature dissimilation catalytic reaction, and at the temperature of 200-. This is not considered to be that dioxin is not regenerated at 400 ℃ to 500 ℃ but is considered to be reduced in the rate of production. There are also data that suggest that 300 ℃ to 500 ℃ is the active temperature for low temperature catalytic regeneration of dioxins. In order to avoid the generation of dioxins and to utilize as much as possible the heat of the flue gas, the temperature in the first duct 40 is not lower than 500 ℃, for example controlled between 500 ℃ and 580 ℃. Preferably, the temperature in the first conduit 40 is not lower than 520 deg.C, such as 520 deg.C to 560 deg.C.

Preferably, the first duct 40 is provided with a first temperature sensor 42, and the first temperature sensor 42 is used for monitoring the temperature of the flue gas discharged from the first duct 40. The first duct 40 is further provided with a first fan 43 for helping to control the temperature of the discharged flue gas. The first pipeline 40 is externally connected with a quenching tower 44, and is used for rapidly cooling the discharged flue gas with the temperature of 520-560 ℃ to be below 200 ℃ so as to avoid the temperature of the dioxin generated again, and then carrying out next purification treatment and discharging.

Preferably, a second temperature measuring and controlling device 45 is arranged at the position of the second pipeline 41, and the second temperature measuring and controlling device 45 is used for monitoring the temperature of the flue gas discharged from the second pipeline 41; the second duct 41 is provided with a second fan 46, and the second fan 46 can be used for pressurizing the flue gas in the second duct 41. By adjusting the motor frequency of the first fan 43 and the second fan 46, the circulation volume and the discharge volume of the flue gas can be controlled, so that the purpose of controlling the temperature of the derived flue gas is achieved. The first pipeline 40, the first temperature measuring and controlling device 42 and the first fan 43 together form a constant-temperature flue gas guiding-out system of the scrap steel recovery processing device; the second pipeline 41, the second temperature measuring and controlling device 45 and the second fan 46 together form a flue gas circulation system of the scrap steel recovery and treatment device.

The constant temperature flue gas refers to the flue gas temperature led out at a specific position is constant, and in the embodiment, the constant temperature flue gas is 500-580 ℃, and preferably 520-560 ℃. The smoke in the temperature range can avoid the re-synthesis of dioxin. The temperature of the derived flue gas is rapidly reduced to 250-300 ℃ through the quenching tower 44, so that a temperature (300-500 ℃) window for re-synthesizing the dioxin is avoided, the dioxin in the derived flue gas is reduced to the maximum extent, and the waste heat of the flue gas is fully recycled.

In the normal production process, the temperature of the flue gas generated in the electric arc furnace 31 reaches thousands of degrees, and the high-temperature flue gas exchanges heat with scrap steel, a charging valve and the like in the process of ascending along the charging vertical shaft 7, so that the temperature gradually drops. When the smoke rises to the position near the constant-temperature smoke leading-out system, the temperature of the smoke is basically reduced to the temperature range required by the smoke leading-out.

Preferably, the constant temperature flue gas leading-out system can also be provided with an upper gate valve and a lower gate valve, and under the assistance of the first temperature measuring and controlling device 42 and the first fan 43, the position of the leading-out flue gas can be adjusted in a proper range, so that the temperature of the leading-out flue gas can be adjusted.

Preferably, the constant temperature flue gas discharging system of the embodiment mainly adjusts the motor frequency of the first fan 43 and the second fan 46, so as to control the circulation volume and the discharge volume of the flue gas to achieve the purpose of controlling the temperature of the flue gas. The first fan 43 and the second fan 46 both adopt variable frequency motors, the circulating flue gas volume in the feeding vertical shaft can be adjusted by matching of the two fans, the fed scrap steel formula material is heated sufficiently, and meanwhile, the constant temperature of the flue gas discharged by the first pipeline 40 is ensured to be 500-580 ℃. After partial heat exchange, the first fan 43 and the second fan 46 are adjusted to adjust the exhaust air volume so that a part of the flue gas is discharged from the constant temperature flue gas guiding system at a constant temperature of 500-580 ℃ for next flue gas purification; the residual constant temperature flue gas continuously exchanges heat with the scrap steel formula material, so that the purpose of gasifying organic matters in the scrap steel formula material by using waste heat is achieved. The residual rising flue gas after leading out part of the constant temperature flue gas enters a flue gas circulating system, organic substances in the rising flue gas are removed after the rising flue gas exchanges heat with the scrap steel formula material entering the feeding shaft 7, the generated mixed flue gas is pressurized by a second fan 46, the second fan 46 is a frequency modulation motor, the temperature of the flue gas in the feeding shaft 7 can be controlled within a certain range, the pressurized flue gas is accelerated by an injection pipe 20 to form a negative pressure area, and fly ash added by a fly ash feeding box 17 and an air-closing discharge valve 18 is sucked in and enters an electric arc furnace 31 through a fly ash feeding pipe 19 for purification treatment.

Preferably, the position of the constant-temperature flue can be determined according to the heat exchange effect between the flue gas of the electric arc furnace 31 and the formula materials, the temperature of the flue gas generated by the electric arc furnace 31 is high and can reach 1000 ℃ when entering the charging shaft 7, the constant-temperature flue gas outlet is generally arranged in the middle of the whole charging shaft 7, and the standard for leading out the flue gas temperature is set to be 500-600 ℃. The export flue mouth can set up the filter layer, and it is flush with reinforced hard well 7 to filter the inlayer, prevents that the formula material from following the flue gas of deciding the temperature and overflowing. Two channels are arranged on the upper portion and the lower portion of the guide flue port to be communicated with the interior of the vertical shaft, and the upper channel or the lower channel can be selectively guided out through the gate valve, so that the temperature of the guided flue gas can be adjusted within a certain range. Leading out the flue gas and passing through the formula material layer, most chlorine reacts with dechlorinating agent therein and is fixed, thereby leading out less precursors of dioxin in the flue gas with fixed temperature, and then leading out the flue gas with fixed temperature and passing through the quenching tower 44 to be rapidly cooled to (250 ℃ -300 ℃), thereby avoiding the window of temperature (300 ℃ -500 ℃) for the second synthesis of dioxin, and further reducing the resynthesis of dioxin in the leading out flue gas to the maximum extent.

Preferably, the feeding shaft 7 is of a multilayer structure, each layer is separated by a first feeding valve 32, a second feeding valve 33, a third feeding valve 34 and a fourth feeding valve 35 respectively, the volume of each layer is increased from top to bottom, and therefore the formula materials of the upper layer can be completely added to the lower layer at one time; the umbrella-shaped feed control system 30 constitutes the feed valve of the lowermost layer of the feed shaft 7. Except that the lowest layer adopts the umbrella-shaped feeding control system 30 as a feeding valve, other feeding valves of the feeding shaft 7 can adopt a plug-in plate type feeding valve or a split type feeding valve, and a hollow-out plug-in plate type feeding valve is preferably adopted in the embodiment; the top end of the feeding vertical shaft 7 is also provided with a feeding hopper 36 and a feeding box 37; the charging hopper 36, the charging box 37 and the charging shaft 7 are respectively connected from top to bottom in sequence through a first charging valve 32 and a second charging valve 33; the inner diameter of the lowermost layer 38 of the charging shaft 7 is larger than the inner diameter of the upper layer 39, so that when the umbrella-shaped grate valve 1 is lowered to the lowermost layer, the passage between the lowermost layer and the wall of the charging shaft 7 becomes larger, and the material can conveniently enter the electric arc furnace 31. The scrap steel is fed from top to bottom layer by layer when the furnace is opened, and during normal production, the produced smoke gas is from bottom to top and from layer to layer, so that the impact of the scrap steel on the feeding valve can be further lightened.

As shown in FIG. 3, the fly ash charging system 48 includes a fly ash charging box 17, an airlock discharge valve 18, a fly ash charging pipe 19, and an injection pipe 20; the fly ash charging box 17 is positioned above the air-closing discharge valve 18, and the fly ash charging box 17 is sequentially connected with a fly ash charging pipe 19 from top to bottom through the air-closing discharge valve 18; the upper end of the fly ash feeding pipe 19 is provided with a first connecting port 22 and a second connecting port 23; the first connecting port 22 of the fly ash charging pipe 19 is connected below the air-closing discharge valve 18.

Preferably, the lower part of the fly ash charging box 17 is in an inverted cone shape, and an inverted cone-shaped opening 21 is in sealing connection with an air-closing discharge valve 18; the airlock discharge valve 18 is hermetically connected with a first connection port 22 of the fly ash charging pipe 19.

Preferably, the injection port end of the injection pipe 20 is hermetically connected with the second connection port 23 of the fly ash feeding pipe 19. The injection port area 24 of the injection pipe 20 is positioned below the air-seal discharge valve 18, when the injection pipe 20 injects high-temperature flue gas to the fly ash charging pipe 19, a negative pressure area is formed in the injection port area 24, the air-seal discharge valve 18 is opened, and fly ash is sucked into the fly ash charging pipe 19 from the fly ash charging box 17.

Preferably, the fly ash charging box 17 is provided with a fly ash preheater 25 for receiving high-temperature hot water or water vapor after recovering waste heat to preheat fly ash for preheating and drying the fly ash, thereby not only ensuring the fluidity of the fly ash, but also fully utilizing the waste heat. The top end of the fly ash charging box 17 is provided with a first charging valve 26, and the middle upper position of the fly ash charging box 17 is provided with a second charging valve 27. In this embodiment, the first charging valve 26 is a plate-inserting type charging valve, so as to facilitate charging of fly ash; the provision of the first and

second feed valves

26, 27 helps to make the fly ash more uniform in the fly ash feed tank 17. The tail end of the injection pipe 20 is connected to the second duct 41 of the charging shaft 7, and the second fan 46 on the second duct 41 can be used for both temperature control of the flue gas in the charging shaft 7 and pressurization of the flue gas injected by the injection pipe 20.

Preferably, the fly ash preheater 25 is connected to the grate cooler 5 and the magnetic extension cooler 13, so that the waste heat from the grate 1 and the magnetic extension 8 is utilized.

Preferably, the scrap steel is properly crushed, the diameter of the scrap steel is not more than 150mm, dechlorination slagging agents (such as lime, calcium hydroxide, dolomite, flying ash and the like) are arranged in the formula, the particle size of the dechlorination slagging agents is controlled, on one hand, the materials can be conveniently and smoothly fed, on the other hand, the addition of the dechlorination slagging agents can greatly reduce the content of chlorine in the constant-temperature flue gas, so that precursors for dioxin synthesis in the constant-temperature flue gas are greatly reduced, and the possibility of secondary dioxin synthesis in the derived constant-temperature flue gas is further reduced.

Preferably, scrap steel such as thin materials and miscellaneous materials which are not easy to recover is appropriately crushed, limestone, dolomite and the like required in the formula are crushed and sieved, and are mixed with calcium hydroxide qualified by analysis to form a formula material, and the formula material is lifted into the loading hopper 36 through the lifting travelling crane 53. When feeding, the second feeding valve 33 is closed, the first feeding valve 32 is opened, the formula in the feeding hopper 36 is fed into the feeding box 37, the first feeding valve 32 is closed, the formula is sealed in the feeding box 37, and after normal production, the formula is fed downwards layer by layer.

Preferably, the lower end of the fly ash charging pipe 19 is connected with the electric arc furnace 31. The electric arc furnace 31 is provided with an electrode controller 47, the voltage stabilization of the electric arc furnace 31 is controlled by the up-and-down lifting of the electrode controller 47, the temperature of the whole electric arc furnace 31 is improved, the high temperature generated by the electric arc furnace 31 can reach 1300-1600 ℃, and dioxin contained in flue gas and fly ash is thoroughly decomposed due to the continuous action of ultrahigh temperature (up to 1600 ℃ and lasting for dozens of minutes). The components such as carbon in the fly ash participate in the recycling and comprehensive utilization of the scrap steel, other solid matters form heavy component and light component scum melts, heavy metals in the flue gas and the fly ash enter the heavy component melts, the light component scum melts enter a water quenching tank 51 through an upper layer light component discharger 49, and the heavy component melts enter a heavy component recycling container 52 through a lower layer heavy component discharger 50.

(1) crushing the scrap steel to the diameter of not more than 150mm, adding a dechlorination slagging agent, mixing and putting into a feeding hopper 36 of a feeding vertical shaft 7;

(2) putting the fly ash into a fly ash charging box 17 of a fly ash charging system 48;

(3) starting the device, and controlling the temperature in the first pipeline 40 of the feeding vertical shaft 7 to be 500-580 ℃.

Example 2 fly ash and scrap steel cooperative recovery device with finger valve

The present example provides a fly ash and scrap steel cooperative recovery apparatus, which is different from example 1 in that the umbrella-shaped feed control system 30 in example 1 is changed to a finger valve in DE4025294A 1-1992.

EXAMPLE 3 scrap Recycling device without Secondary pipe

The scrap steel recycling device provided in this embodiment is different from that of embodiment 1 in that it does not include the second duct 41, and there is no fly ash charging system 48, and all the flue gas generated by the electric arc furnace is discharged from the first duct 40.

Example 4 flue gas treatment effectiveness comparison

Dioxin is not a single pure substance, has 210 isomers, is complex in synthesis mechanism and is difficult to detect. The method adopts the determination of dioxins in HJ77.2-2008 ambient air and waste gas (isotope dilution high resolution gas chromatography-high resolution mass spectrometry) to detect the dioxins in the flue gas;

the following sets of experiments were set up:

experimental group 1: the equipment in the embodiment 1 is adopted, and the temperature in the first pipeline is controlled to be 500 ℃;

experimental group 2: the equipment in the embodiment 1 is adopted, and the temperature in the first pipeline is controlled to be 550 ℃;

experimental group 3: the equipment in the embodiment 1 is adopted, and the temperature in the first pipeline is controlled to be 600 ℃;

experimental group 4: the equipment in the embodiment 2 is adopted, and the temperature in the first pipeline is controlled to be 550 ℃;

experimental group 5: the equipment in example 3 is adopted, and the temperature in the first pipeline is controlled to be 550 ℃;

the comparison of the flue gas treatment effects is performed for the experimental group/the control group, the treatment time is 24 hours, and the comparison result of the flue gas treatment effects is obtained by measuring the content of dioxin after the flue gas comes out of the quenching tower 44, as shown in the following table:

TABLE 1 flue gas treatment effect comparison List

National dioxin emission standard is less than 0.1ngTEQ/m³As can be seen from table 1, the apparatus of the present invention has the ability to treat dioxins as qualified and discharge them. According to the above experimental data, under the condition that other conditions are consistent, the dioxin content in the flue gas discharged from the

experimental groups

1, 2, 3 and 4 is obviously lower than that in the experimental group 5, which is promoted by the second pipeline 41, and the second pipeline 41 sends part of the flue gas back to the furnace again for pyrolysis, so that the emission of dioxin is reduced.

The power consumption of the experiment group 5 is higher than that of the experiment groups 1-3, the experiment groups 1-3 promote the cyclic recycling of the high-temperature flue gas, and the purpose of energy conservation is achieved by utilizing waste heat. Experiment group 5 could not treat fly ash simultaneously and was not conducive to reducing costs.

Through comparison of the experimental groups 1-3, the exhaust temperature of 500 ℃ in the experimental group 1 is more energy-saving than the exhaust temperature of 600 ℃ in the experimental group 5, which shows that the exhaust heat of high-temperature flue gas can be better utilized by the temperature of 500 ℃; however, the content of dioxin in the flue gas discharged at 550 ℃ is lower, which shows that the regeneration of dioxin can be better inhibited.

The test group 4 adopts a finger valve, which has obviously higher cost, mainly because the finger valve has a complex structure, is easy to leak water, has short service life and is more power-consuming.

Therefore, the cooperative recovery device for the fly ash and the waste steel provided by the utility model greatly improves the energy utilization rate, reasonably and efficiently utilizes the waste heat of the flue gas, obviously inhibits the emission of pollutants dioxin, and really realizes cooperative recovery treatment of the fly ash and the waste steel.

The application of the present invention is not limited thereto. Such as expansion according to the application range in the aspect of environmental protection. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the utility model as defined in the appended claims.

Claims

1. The fly ash and scrap steel cooperative recovery device is characterized by comprising a charging vertical shaft, an umbrella-shaped charging control system, a fly ash charging system and an electric arc furnace; the lower end of the charging vertical shaft is connected with an electric arc furnace; the umbrella-shaped feeding control system is positioned at the lower side of the feeding vertical shaft; the fly ash loading system is located on one side of the loading shaft.

2. The apparatus of claim 1, wherein the umbrella-shaped feed control system comprises an umbrella-shaped grate valve and a magnetic control system; the umbrella-shaped grate valve is arranged at the lower side of the feeding vertical shaft; the magnetic control system is arranged around the wall of the charging vertical shaft and is positioned at the periphery of the umbrella-shaped grate valve.

3. The apparatus of claim 2, wherein the umbrella grate valve comprises an umbrella base, a positioning pipe, an umbrella grate cooler, and a moving track; the top of the umbrella-shaped base is connected with a positioning pipeline, and the positioning pipeline is connected with an umbrella-shaped grate valve cooler; the umbrella-shaped base and the positioning pipeline can move along the moving track.

4. The apparatus of claim 2, wherein the magnetic control system comprises a magnetic extension and a permanent magnet; the permanent magnet is arranged outside the charging shaft wall and positioned at the periphery of the magnetic extension body; the magnetic extension body is arranged on the charging shaft wall; the magnetic extension bodies are arranged in a layered mode by adopting soft magnetic heat-resistant materials, and the layers are isolated by adopting nonmagnetic heat-resistant materials; the magnetic extension body is also provided with a magnetic extension body cooler; the permanent magnet can move up and down along the moving track.

5. The apparatus according to any one of claims 1 to 4, wherein the charging shaft is further provided with a first pipe and a second pipe, the second pipe being arranged higher than the first pipe; the first pipeline is used for discharging part of the flue gas out of the feeding preheater, and the second pipeline is connected with the fly ash feeding system and used for returning the rest of the flue gas to the electric arc furnace; the temperature in the first pipeline is higher than the regeneration temperature of dioxin in the flue gas.

6. The apparatus according to claim 5, characterized in that the charging shaft is of a multi-layer structure, each layer is separated by a charging valve, and the volume of each layer increases from top to bottom; the umbrella-shaped feeding control system forms a feeding valve at the lowest layer of the feeding vertical shaft; except the feeding valve at the lowest layer, other feeding valves of the feeding vertical shaft are all inserting plate type feeding valves or split type feeding valves; the top end of the charging vertical shaft is also provided with a charging hopper and a charging box.

7. The apparatus according to any one of claims 1 to 6, wherein the fly ash charging system comprises a fly ash charging box, an airlock discharge valve, a fly ash charging pipe and an injection pipe; the fly ash charging box is connected with a first connecting port of the fly ash charging pipe through an air-closing discharge valve; the injection pipe is connected with a second connecting port of the fly ash feeding pipe; the lower end of the fly ash charging pipe is connected with an electric arc furnace.

8. The apparatus of claim 7, wherein the injection port end of the injection pipe is in sealing connection with the second connection port of the fly ash charging pipe, and the injection port area of the injection pipe is located below the airlock discharge valve; the tail end of the injection pipe is connected with a second pipeline of the feeding vertical shaft.

9. The apparatus according to claim 8, wherein the fly ash charging system further comprises a fan located at the second duct of the charging shaft for pressurizing the flue gas injected by the injection pipes; and the fly ash charging box is also provided with a fly ash preheater.

10. The apparatus of claim 9, wherein the electric arc furnace is provided with an electrode controller for controlling the voltage stabilization; the electric arc furnace is also provided with a light component discharger and a heavy component discharger.