CN112747604B

CN112747604B - Flue gas treatment device

Info

Publication number: CN112747604B
Application number: CN202011504625.3A
Authority: CN
Inventors: 周友信; 沈毅; 曹熠; 胡波; 王倩; 陈俊宇; 靳晓鹏; 许群惟; 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: 2020-12-18
Publication date: 2022-07-19
Anticipated expiration: 2040-12-18
Also published as: CN114485187A; CN214223107U; CN216144147U; CN216144143U; CN114472472A; CN114485144B; CN216144144U; CN112648618A; CN112747604A; CN214223156U; CN214223157U; CN114485144A; CN112648618B; CN214223108U; CN114472472B

Abstract

The invention provides a flue gas treatment device which comprises a feeding preheater capable of preheating materials, wherein a first pipeline and a second pipeline are arranged on the feeding preheater, the second pipeline is higher than the first pipeline in arrangement position, the first pipeline is used for discharging part of flue gas out of the feeding preheater, the second pipeline is used for returning the rest of flue gas to a smelting furnace, a first temperature measuring and controlling device is arranged at the position of the first pipeline, and the first temperature measuring and controlling device is used for monitoring the temperature of the flue gas discharged by the first pipeline. By controlling the constant-temperature discharge of the constant-temperature flue gas, the regeneration of dioxin can be reduced; secondly, organic matters in the materials entering the smelting furnace can be fully gasified; energy consumption can be reduced; fourthly, the emission of dioxin can be reduced; the flue gas treatment device adopts flue gas shunting and constant temperature flue gas discharging, and adds a dioxin precursor remover in a feeding formula, thereby inhibiting the generation of dioxin in incineration flue gas and greatly reducing energy loss.

Description

Flue gas treatment device

Technical Field

The invention belongs to the field of environmental protection, relates to a flue gas treatment device, and particularly relates to a flue gas treatment device which can inhibit dioxin generated in incineration flue gas, utilize energy as high as possible and reduce energy loss.

Background

With the development of cities, the total amount of domestic garbage is continuously increased, the existing treatment mode of domestic garbage is mainly incineration, but flue gas generated in the incineration process inevitably carries fly ash, and the fly ash generated by incineration contains harmful substances such as dioxin and the like due to the particularity of the domestic garbage, so that the fly ash is listed as dangerous waste by the nation.

In the prior art, the fly ash generated by burning the household garbage is treated most thoroughly 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 substances 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 by a smelting furnace, the generated high-temperature flue gas can reach 1000 ℃, the energy carried by the high-temperature flue gas can reach 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 methods. 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 higher, so that the process of utilizing the flue gas waste heat 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 spraying and quenching modes are adopted to rapidly reduce the temperature of the flue gas from 1000 ℃ to about 800 ℃ to 250 ℃, the method can not recover the energy in the flue gas, wastes a large amount of water resources, and increases the corrosion effect of a large amount of generated water gas on the subsequent equipment.

Firstly, the feeding is difficult, when the feeding is fully preheated to more than 500 ℃ and is directly contacted with the flue gas which rises to 1000 ℃, no effective feeding control valve solution exists at present, the technical difficulty is large because the feeding control valve operates at high temperature, so that the scheme which is actually put into use so far is few, and the typical representation is as in the U.S. patent: "application number: US07/959733, filing date: 1992-10-13, title of the invention: continuous batch preheating ", discloses a vibrating Continuous-feed electric arc furnace, which has major drawbacks: the surface of the material layer of the furnace feeding material is only contacted with the flue gas, the heat exchange between the flue gas and the material is insufficient, the material is heated unevenly due to the relative static state of the material layer, the energy recovery rate of the flue gas is not high, and the regenerated dioxin is easy to generate due to the uneven heating and the existence of a local low-temperature area. German patent: "application number: DE4025294, filing date: 1990-08-09, title of the invention: steuervorticichung fur ein elektrolosyve Bearbeitung' discloses a finger shaft furnace which has the advantages that smoke and materials 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 and large impact force of the materials of a finger valve, so that the service life of the finger valve at high temperature is seriously influenced, the finger valve is easy to break and lose efficacy to interrupt production, and the environmental protection problem that dioxin which is a highly toxic substance is easy to generate in the preheating process also exists; the other difficulty is that the flue gas and the materials exchange heat, when the temperature is reduced to 300-500 ℃, decomposed dioxin has regeneration conditions, and the dioxin is regenerated at a proper temperature and with various metal ions, and then needs to be treated again to become a non-decomposition cycle.

At present, an effective device which can inhibit the secondary generation of dioxin in incineration flue gas and can fully utilize the waste heat of high-temperature flue gas is lacked.

Disclosure of Invention

In order to solve the problems, the invention provides a flue gas treatment device.

The invention provides a flue gas treatment device which comprises a feeding preheater capable of preheating materials, wherein a first pipeline and a second pipeline are arranged on the feeding preheater, the second pipeline is higher than the first pipeline in arrangement position, the first pipeline is used for discharging part of flue gas out of the feeding preheater, and the second pipeline is used for returning the rest of flue gas to a smelting furnace.

Further, 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.

Further, a first fan is arranged at the position of the first pipeline, and the temperature in the first pipeline is higher than the regeneration temperature of the harmful substances.

Further, the harmful substance is dioxin.

Further, the feed preheater is a shaft feed preheater, the feed preheater being connected to the furnace.

Furthermore, 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, a second fan is arranged at the position of the second pipeline and used for pressurizing the smoke in the second pipeline and then blowing the smoke into the smelting furnace.

Further, an electromagnetic heater is arranged on the feeding preheater and located between the first pipeline and the second pipeline.

Further, the feed preheater adds alkaline calcium salt and/or lime to the material as it is added.

Further, the first pipeline is connected with a flue gas purification system, and the flue gas purification system comprises a quencher, a desulfurization and deacidification tower, a dust remover, an SCR reactor and a chimney.

Further, be equipped with the division board in the feeding preheater, be equipped with the hole on the division board, the diameter in hole is less than the diameter of material, the division board separates the feeding preheater for the first interlayer of preheater and preheater second interlayer, the first interlayer of preheater is located the upside position of preheater second interlayer, first pipeline is located the first interlayer of preheater, the second pipeline is located the preheater second interlayer, be equipped with the pusher on the division board, be equipped with the material passageway or the interlayer of intercommunication between the first interlayer of preheater and the preheater second interlayer.

Has the advantages that:

the constant-temperature exhaust of the constant-temperature flue gas is controlled, so that the regeneration of dioxin can be reduced; secondly, organic matters in the materials entering the smelting furnace can be fully gasified; thirdly, energy consumption can be reduced; fourthly, the emission of dioxin can be reduced; the flue gas treatment device adopts flue gas shunting and constant temperature flue gas discharging, and adds a dioxin precursor remover in a feeding formula, thereby inhibiting the generation of dioxin in incineration flue gas, greatly reducing the energy loss, ensuring the temperature of entering SCR by adopting dry desulfurization and ceramic fiber pipe dust removal for the flue gas treatment, greatly simplifying the process and improving the energy utilization rate.

Drawings

Fig. 1 is a schematic view of the overall structure of a flue gas treatment apparatus provided in embodiment 1;

fig. 2 is a schematic view of the overall structure of the flue gas treatment device provided in embodiment 2;

fig. 3 is a schematic view of the overall structure of a flue gas treatment apparatus provided in embodiment 3;

fig. 4 is a schematic view of the overall structure of a flue gas treatment apparatus provided in embodiment 4;

FIG. 5 is a schematic view of the overall structure of a flue gas treatment apparatus provided in example 5;

fig. 6 is a schematic structural diagram of a flue gas treatment device in the prior art.

Detailed Description

In the following, preferred embodiments of the invention 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 invention without limiting it in any way, and that all features disclosed in the embodiments of the invention, or all steps of the disclosed methods or processes, may be combined in any way, except for mutually exclusive features and/or steps.

Example 1, reference is made to figure 1.

A flue gas treatment device comprises a feeding preheater 10, wherein the feeding preheater 10 is connected with a smelting furnace, materials enter the smelting furnace through the feeding preheater 10, after the materials are combusted in the smelting furnace, high-temperature flue gas is generated, and the high-temperature flue gas enters the feeding preheater 10 again to preheat the materials in the feeding preheater 10. Be equipped with first pipeline 11 on the feeding preheater 10, first pipeline 11 is used for giving the high temperature flue gas discharge feeding preheater 10 after the material preheats, and first pipeline 11 position is equipped with first temperature measurement and control ware 12, and first temperature measurement and control ware 12 can the temperature in the first pipeline 11 of real time monitoring, and this temperature will be higher than the palingenetic temperature of dioxin, can avoid the regeneration of dioxin like this. The flue gas coming out of the first duct 11 is subjected to a further flue gas cleaning.

The dioxins are the general names of polychlorinated diphenyl one-to-one dioxins (PCDDS) and polychlorinated dibenzofuran (PCDFS), and have 210 kinds of isomers in total, wherein 75 kinds of PCDDS exist, 135 kinds of PCDFS exist, the 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 the dioxins begin to decompose when the temperature reaches above 705 ℃. When monitoring the temperature in the first pipeline 11, we mainly pay attention to the regeneration of dioxin through low-temperature dissimilatory catalytic reaction, and at the temperature of 200-. This is not to say 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 dioxin. In order to avoid the generation of dioxin and to utilize as much heat of the flue gas as possible, the temperature in the first duct 11 is not lower than 400 ℃, for example, controlled at 400 ℃ to 600 ℃. Further, the temperature in the first pipe 11 is not lower than 500 ℃, for example, 500 ℃ to 600 ℃.

Preferably, the position of feeding preheater 10 upside is equipped with loading hopper 15, is equipped with feed valve 16 between loading hopper 15 and the feeding preheater 10, through feed valve 16, accomplishes reinforced back at loading hopper 15, and feeding system such as loading hopper 15 can realize keeping apart with feeding preheater 10 inside air, avoids the high temperature flue gas to flow out from loading hopper 15 position in the device working process.

Preferably, the feeding preheater 10 is a shaft type feeding preheater, which facilitates sufficient heat exchange between the fed material and the flue gas, and simultaneously realizes that the material in the feeding preheater 10 has a temperature gradient, which gradually increases from top to bottom (closer to the furnace), and the temperature at a certain position in the feeding preheater 10 can be kept constant, which is beneficial to the first pipeline 11 to discharge the high-temperature flue gas with constant temperature.

After the high-temperature flue gas heats the materials in the feed preheater 10, organic matters in the materials are heated and gasified to form harmful gas. For example, PVDC single resin films (paint films) start to decompose at 110-130 ℃; most of gasification decomposition of common biomass (such as corn stalks) is realized at the temperature of 260 ℃ and 420 ℃, the gasification speed is high, and the gasification can be completed within a few minutes; the high-grade baking varnish of the automobile is decomposed at about 420 ℃. Therefore, the organic matters in the fly ash and the waste steel can be decomposed and gasified at the temperature of more than 400 ℃, and the temperature in the first pipeline 11 is not lower than 400 ℃; if the temperature in the first pipeline 11 is set to be not lower than 500 ℃, a certain temperature margin exists, and the organic matters are ensured to be basically completely gasified by heating. The gas components generated are generally HCL, CmHn (hydrocarbon), CO, and the like. Preferably, still be equipped with second pipeline 13 on the feeding preheater 10, second pipeline 13 position is equipped with second temperature measurement and control ware 14, second temperature measurement and control ware 14 can the temperature in the second pipeline 13 of real time monitoring, the position that sets up of second pipeline 13 will be higher than the position that sets up of first pipeline 11, according to temperature gradient, the temperature of second pipeline 13 will be less than first pipeline 11, and simultaneously, because second pipeline 13 highly will be higher than first pipeline 11, the flue gas of going out in the second pipeline 13 is more abundant with the material heat transfer, consequently, the flue gas of going out from this pipeline contains the harmful gas that regenerated dioxin and organic matter thermal gasification produced, because dioxin and harmful gas have not been handled yet, gas in the second pipeline 13 can not directly carry out gas cleaning like first pipeline 11. Further, the second pipe 13 is connected to the furnace, and the gas discharged from the second pipe 13 is introduced into the furnace again for the purpose of detoxification treatment. Since the gas in the second pipe 13 is sufficiently contacted with the material, the flow rate thereof is greatly reduced, and it is preferable that the second pipe 13 is provided with a second fan 19, and the gas in the second pipe 13 is pressurized by the fan and then circulated and blown into the furnace.

Since the temperature at the location of the first duct 11 is influenced by various factors such as the feed rate of the feed preheater 10, the rate at which the furnace burns the material to produce flue gases, etc. In order to control the temperature of the first pipeline 11 more conveniently, the dioxin regeneration is avoided. Preferably, the first duct 11 is provided with a first fan 18, and the first fan 18 is used for controlling the gas flow speed in the first duct 11, so as to control the gas temperature at the position of the first duct 11, and on the premise that dioxin is not regenerated, the heat of the high-temperature flue gas is utilized as much as possible. The dioxin is easy to regenerate in the range of 250 ℃ to 400 ℃ usually, the temperature in the first pipeline 11 is controlled to be higher than 400 ℃, when the temperature in the first pipeline 11 is measured by the first temperature measuring and controlling device 12 to be far higher than 400 ℃, for example, the measured temperature is 700 ℃, at this time, the working rotating speed of the first fan 18 can be reduced, and the working rotating speed of the second fan 19 can be increased, so that the heat of the high-temperature flue gas can be utilized more; when the first temperature detector 12 detects that the temperature in the first duct 11 is higher than the critical value of the dioxin regeneration temperature, for example, only higher than the critical regeneration temperature by 10 ℃, 20 ℃ and 30 ℃ … …, the operating speed of the first fan 18 is controlled to be increased, and the operating speed of the second fan 19 is controlled to be decreased. Through the control mode, the temperature in the first pipeline 11 can be kept relatively constant within a certain range, meanwhile, the heat of high-temperature flue gas is greatly utilized, the energy loss is reduced as far as possible, and the generation of dioxin in incineration flue gas can be inhibited. The flue gas treatment device of the invention mainly controls the circulation quantity (flue gas returned to the smelting furnace by the second pipeline) and the discharge quantity (flue gas discharged by the first pipeline) of the flue gas by adjusting the motor frequency (rotating speed) of the first fan 18 and the second fan 19 so as to achieve the purpose of controlling the temperature of the flue gas. First fan, second fan all adopt inverter motor, and the inside circulation flue gas volumn of the adjustable feeding pre-heater of two fan cooperations guarantees that the material of advancing receives sufficient heating, guarantees simultaneously that the exhaust flue gas is decided the temperature at 500 ~ 600 ℃. After partial heat exchange, adjusting the exhaust volume by adjusting a second fan and a first fan, so that part of the flue gas is discharged from a first pipeline 11 at a constant temperature of 500-600 ℃ for next step of flue gas purification; the residual constant temperature flue gas continuously exchanges heat with the feeding material to achieve the purpose of gasifying organic matters in the flue gas.

Preferably, the feeding preheater 10 is located at the upper side of the first pipeline 11, the electromagnetic heater 17 is located at the lower side of the second pipeline 13, the electromagnetic heater 17 is used for further ensuring that organic matters in the feeding materials are thoroughly heated and gasified, and can prevent the phenomenon that the electromagnetic heater 17 is used in abnormal working conditions (such as startup and shutdown), the smoke temperature is too low, so that the gasification of the organic matters in the feeding materials is insufficient, and the dioxin precursor in the derived smoke (the smoke coming out from the first pipeline 11) is increased, at the moment, the electromagnetic heater 17 can heat the smoke and the materials above the first pipeline 11, so that the organic matters in the materials are completely gasified, and the smoke and the materials are brought into the melting furnace through the second pipeline 13 for harmless treatment. Furthermore, a first temperature measuring and controlling device 12 and a second temperature measuring and controlling device 14 are respectively arranged in the first pipeline 11 and the second pipeline 13, and the operation of the electromagnetic heater 17 is regulated and controlled through the temperatures measured by the first temperature measuring and controlling device 12 and the second temperature measuring and controlling device 14.

The first and second temperature controllers are provided to regulate the operation of the electromagnetic heater 17 to control the smoke temperature. Wherein the temperature of the first pipeline is controlled to be 500-600 ℃ by the first temperature controller, and the temperature of the second pipeline is controlled to be slightly lower by the second temperature controller and is maintained at 200-250 ℃.

Preferably, in order to further improve the efficiency of removing the dioxin precursor from the material, the feed preheater 10 adds the dioxin precursor removing agent to the feed formula during the material feeding process, so that the dioxin precursor in the flue gas can be solidified, and the possibility of leading out the dioxin in the flue gas at a constant temperature is reduced. For example, one or more of alkaline calcium salt or lime is selected.

Example 2, see figure 2.

In example 2, the flue gas discharged from the first duct 11 is further treated based on example 1, and other embodiments of this example are the same as example 1.

The flue gas treatment device provided by the embodiment further comprises a flue gas purification system, and the flue gas purification system is connected with the first pipeline 11. The flue gas purification system comprises a quencher 40, a desulfurization and deacidification tower 41, a dust remover 42, an SCR reactor 23 and a chimney 30 which are connected into a whole in sequence.

Wherein, the first pipeline 11 is connected with a flue gas quenching air inlet 43 of the quencher 40 through a flue, and in the quencher 40, the flue gas and cooling water sprayed by a quenching water sprayer 44 in the quencher 40 exchange heat rapidly to ensure that the temperature of the constant-temperature flue gas is rapidly reduced to 250 ℃, thereby reducing the retention time in a dioxin regeneration temperature range (250-500 ℃) and inhibiting the regeneration of dioxin.

The flue gas quenched by the quencher 40 is connected with the desulfurization and deacidification tower 41 through the quenching air outlet 31 on the quencher 40, and the flue gas after being cooled is generally treated by wet desulfurization or semi-dry desulfurization at present. Preferably, the desulfurization and deacidification tower 41 is a dry desulfurization and deacidification tower which adopts active alkali and active carbon as a removing agent to perform dry desulfurization and deacidification, thereby avoiding the generation of waste water, ensuring the temperature of the flue gas and being beneficial to the purification of the subsequent flue gas. The dry desulfurization and deacidification tower 41 is provided with a desulfurization and deacidification agent spraying port 45 which can spray quantitative desulfurization and deacidification agent with enough fineness, the desulfurization and deacidification agent is selected from calcium hydroxide, sodium bicarbonate and the like according to the components of the flue gas, and the dry desulfurization and deacidification tower 41 is provided with an activated carbon spraying port 46 which can be added with activated carbon to achieve the aim of further removing harmful substances in the flue gas.

Preferably, the dust collector 42 is a ceramic fiber filter tube high temperature dust collector 42, which adopts a temperature-resistant ceramic fiber filter tube 49 as dust collecting equipment, and the temperature resistance can reach 600 ℃. The desulfurized and deacidified flue gas is connected with a dust collector air inlet 48 of the ceramic fiber tube high-temperature dust collector 42 through a flue, and a great part of dust is removed under the action of a ceramic fiber filter tube 49 and the blowback tube 20.

The dust collector 42 is not suitable for bag dust collection, if the dust collector 42 adopts bag dust collection, the temperature must be reduced to below 200 ℃ in order to meet the bag dust collection requirement, then the flue gas temperature needs to be increased again in order to denitrate, the requirement of white removal of the flue gas needs to be ensured, complicated energy conversion needs to be carried out, and additional energy needs to be supplemented to meet the relevant requirements. The invention adopts the heat-resistant ceramic fiber filter tube as the dust removal equipment, the dust removal principle of the ceramic fiber filter tube is the same as that of a cloth bag, but the temperature resistance of the ceramic fiber filter tube can reach 600 ℃, the dust removal in the flue gas at the temperature of nearly 250 ℃ in the scheme can be ensured, the stable dust removal can be realized, the fluctuation of the dust removal efficiency is reduced, and the process contradiction and the energy waste of temperature rise for the use of the cloth bag for dust removal and the subsequent denitration and dioxin removal are avoided. The dust remover 42 is provided with an ash discharging port 22 at the lower side.

The flue gas is kept at 220-250 ℃ through dust removal smoke temperature, the flue gas can be directly connected with an SCR air inlet 24 of an SCR reactor 23 through a dust remover air outlet 21 on a dust remover 42, ammonia gas sprayed out of an SCR ammonia spraying pipe 27 on the SCR reactor 23 is mixed with the flue gas, nitrogen oxides are purified and removed through an SCR catalyst layer 26 on the SCR reactor 23, meanwhile, trace amount of dioxin in the flue gas is further removed, and the flue gas is discharged through a first fan 18 and a chimney 30 after the ultra-clean discharge requirement is met. Wherein, the SCR reactor 23 is also provided with an access door 25 and a hot water pump outlet valve 28.

Since the constant temperature flue gas is further purified after being discharged, the first fan 18 of this embodiment is preferably installed at the connecting pipe between the chimney 30 and the SCR reactor 23, and is used for controlling the outward discharge amount of the first pipe 11. In some other embodiments, the first fan 18 is mounted at any location behind the first duct 11.

In the embodiment, dry desulfurization and ceramic fiber pipe dedusting are adopted for treating the flue gas, so that the temperature of the flue gas entering the SCR reaches about 230 ℃, the process is greatly simplified, and the energy utilization rate is improved.

Example 3, see figure 3.

Example 3 is a modification of the feed preheater 10 based on example 1, and other embodiments of this example are the same as example 1.

In this embodiment, a partition plate 77 is disposed in the feed preheater 10, the partition plate 77 partitions the feed preheater 10 into an upper and lower structure of a first partition 74 of the preheater and a second partition 75 of the preheater, wherein the first partition 74 of the preheater is located on the upper side of the second partition 75 of the preheater, a hopper 15 is disposed on the first partition 74 of the preheater, a second pipeline 13 is disposed on the first partition 74 of the preheater, a second pipeline 11 is disposed on the second partition 75 of the preheater, a hole is disposed on the partition plate 77, the second partition 75 of the preheater is communicated with the melting furnace 50, the high temperature flue gas of the melting furnace 50 exchanges heat with the material located on the second partition 75 of the preheater to a specific temperature range, the high temperature flue gas is guided out by the first pipeline 11, and the rest of the high temperature flue gas can enter the first partition 74 of the preheater through the hole on the partition plate 77 in the second partition 75 of the preheater, exchanges heat with the material located on the first partition 74 of the preheater, and is guided out by the second pipeline 13, the second fan 19 brings the flue gas in the second duct 13 into the melting furnace 50 again to decompose the dioxin at high temperature. The setting of division board 77 can be isolated in the top position of first pipeline 11 with not preheating abundant material, can avoid having the precursor gas and the palingenetic dioxin of dioxin in first pipeline 11, realizes high-efficient purification flue gas.

Preferably, the material is pretreated and made into small blocks for facilitating feeding and ventilation and heat exchange, and it should be noted that the aperture of the holes on the partition plate 77 needs to be smaller than the diameter of the material, so that the material cannot directly pass through the partition plate 77 and enter the second partition 75 of the preheater, and the high-temperature flue gas in the second partition 75 of the preheater can smoothly enter the first partition 74 of the preheater through the partition plate 77.

Preferably, the feed preheater 10 is provided with a material passage 80 for communicating the first partition 74 with the second partition 75, and the material in the first partition 74 can enter the second partition 75 through the material passage 80. Further, the material passage 80 is inclined, and the material entering the material passage 80 can automatically enter the second partition 75 of the preheater under the action of gravity.

Preferably, the isolation plate 77 is horizontally configured, a first pusher 78 is arranged on the isolation plate 77, the first pusher 78 can push the material at the bottom of the first interlayer 74 of the preheater into the material channel 80, the first pusher 78 can be a perforated pusher, the perforated pusher consists of a pushing controller for controlling the feeding speed and a pushing plate for pushing, and holes are arranged on the pushing plate; the first pusher 78 can also be a pusher of other types such as a screw conveyer commonly used in the chemical field, as long as it can ensure that the space between the isolation plate 77 and the first pusher 78 is not completely sealed, so that the high-temperature flue gas in the second interlayer 75 of the preheater can not enter the first interlayer 74 of the preheater.

Preferably, the height of the connecting position of the material channel 80 and the first partition 74 of the preheater is matched with the height of the first pusher 78, so that the material pushed by the first pusher 78 can enter the material channel 80, and the material blockage between the connecting position of the material channel 80 and the first partition 74 of the preheater and the first pusher 78 is avoided.

Preferably, the material passage 80 is provided with a valve which can be opened and closed at the position where the first pusher 78 is connected to the first partition 74 of the preheater, and the valve is closed when the first pusher 78 is not activated, so as to isolate the material passage 80 from the first partition 74 of the preheater, thereby preventing the material from entering the material passage 80, and the valve is opened when the first pusher 78 is activated. Furthermore, a valve which can be opened and closed is also arranged at the connecting position of the material channel 80 and the second partition 75 of the preheater.

Preferably, the first pusher 78 is adapted to block the connection between the material passage 80 and the first compartment 74 of the preheater, and the first pusher 78 is adapted to block the material from entering the material passage 80 when the first pusher 78 is not activated.

Example 4, see figure 4.

Example 4 is based on example 3, and the material passage 80 is optimized, and other embodiments of this example are the same as example 3.

The material passage 80 is improved to be the interlayer 90, the first pusher 78 can push the materials in the first interlayer 74 of the preheater to the interlayer 90, the interlayer 90 has enough space relative to the largest difference of the material passage 80, the temporary storage of the materials can be realized, especially, the speed of heating the materials by high-temperature flue gas is high, the interlayer 90 can temporarily store the preheated materials, and the heat utilization rate of the high-temperature flue gas can be greatly improved.

Preferably, a second pusher 91 is also disposed at the bottom of the partition 90, and the second pusher 91 can push the material in the partition 90 into the second partition 75 of the preheater.

Example 5, see figure 5.

Example 5 is based on example 4, and is an optimization of the material passage 80 and the feeding portion, and other embodiments of this example are the same as example 4.

The embodiment provides a flue gas treatment device, which comprises a charging hopper 15, a charging shaft 71, a charging preheater 10 and a smelting furnace 50, wherein the charging preheater 10 is positioned at one side of the charging shaft 71, the charging shaft 71 is of a multilayer structure, a charging shaft first isolation plate 66 and a charging shaft second isolation plate 63 are fixedly arranged in the charging shaft 71, the isolation layer of the charging shaft 71 is designed into a three-layer layered structure through the charging shaft first isolation plate 66 and the charging shaft second isolation plate 63, specifically, a charging shaft first interlayer 67 positioned at the upper layer, a charging shaft second interlayer 65 positioned at the middle layer and a charging shaft third interlayer 64 positioned at the lower layer are respectively arranged in each charging shaft interlayer, and a charging pusher is respectively arranged in each charging shaft interlayer, and sequentially from top to bottom, a charging first low-temperature pusher 62 positioned in the charging shaft first interlayer 67, a charging shaft second intermediate-temperature pusher 61 positioned in the charging shaft second interlayer 65 and a charging pusher 64 positioned in the charging shaft third interlayer 64 The shaft third high temperature pusher 60, which is capable of controlling the feed rate separately in each charging shaft compartment. Further, the first partition layer 67 of the feeding shaft, the second partition layer 65 of the feeding shaft and the third partition layer 64 of the feeding shaft are arranged in a staggered mode with the first partition layer 74 of the preheater and the second partition layer 75 of the preheater, a first material channel 92 is formed between the first partition layer 67 of the feeding shaft and the first partition layer 74 of the preheater, a second material channel 93 is formed between the first partition layer 74 of the preheater and the second partition layer 65 of the feeding shaft, and a third material channel 94 is formed between the second partition layer 65 of the feeding shaft and the second partition layer 75 of the preheater, so that materials are conveyed between the feeding shaft 71 and the feeding preheater 10. Preferably, the second preheater partition 75 is in communication with the furnace 50, the connection between the second preheater partition and the furnace 50 is the furnace feed port 29, the third feed shaft partition 64 is flush with the lower end surface of the second preheater partition 75, and the third high temperature pusher 60 of the feed shaft is capable of pushing the material located in the second preheater partition 75 into the furnace 50 through the furnace feed port 29.

Preferably, a feeding box 69 is arranged below the feeding hopper 15, the feeding box 69 is connected with the first interlayer 67 of the feeding shaft, the feeding hopper 15 is of an open structure, a feeding valve 16 is arranged at the position, connected with the feeding hopper 15, of the upper side of the feeding box 69, the feeding valve 16 controls the communication state of the feeding box 69 and the feeding hopper 15, specifically, the feeding valve 16 is opened, the feeding box 69 and the feeding hopper 15 are in a communication state, the material is guided into the feeding box 69 through the feeding hopper 15 at the moment, the feeding valve 16 is closed, the feeding box 69 and the feeding hopper 15 are in an isolation state, and the material is sealed in the feeding box 69 at the moment. The lower side of the feeding box 69 is connected with a first interlayer 67 of the feeding vertical shaft in the feeding vertical shaft 71, a lower gate valve 68 is arranged at the connection position of the feeding box 69 and the feeding vertical shaft 71, the lower gate valve 68 controls the communication state of the feeding box 69 and the feeding vertical shaft 71, specifically, the lower gate valve 68 is opened, the feeding box 69 and the feeding vertical shaft 71 are in the communication state, the material in the feeding box 69 is guided into the feeding vertical shaft 71, and the lower gate valve 68 is closed after feeding is finished. Normally, the charging valve 16 and the lower gate valve 68 are not opened at the same time, so as to avoid the leakage of the flue gas. In addition, after the material is introduced into the feeding box 69 by the feeding hopper 15 and is introduced into the feeding shaft 71 by the material in the feeding box 69, the feeding hopper 15 and the feeding box 69 are both fed in time, and the feeding hopper 15 and the feeding box 69 are ensured to be in a sufficient state. Preferably, the volume of the first partition 67 of the charging shaft and the volume of the second partition 65 of the charging shaft are both larger than the charging amount of one charging hopper 15, and the pusher is positioned at the bottom of the partitions, so as to improve the pushing efficiency of the material. The charging shaft first low-temperature pusher 62, the charging shaft second intermediate-temperature pusher 61 and the charging shaft third high-temperature pusher 60 can be formed by the above-mentioned pusher controller and pusher plate, and the pusher is slightly different from the above-mentioned first pusher 78, and since the high-temperature flue gas does not need to pass through the pusher, holes are not required to be formed on the pusher plates of the charging shaft first low-temperature pusher 62, the charging shaft second intermediate-temperature pusher 61 and the charging shaft third high-temperature pusher 60. In addition, the first low-temperature pusher 62, the second medium-temperature pusher 61 and the third high-temperature pusher 60 of the feeding shaft can also be commonly used pushers in the chemical field such as packing augers.

Preferably, the height of the stripper plate of the charging shaft first low-temperature stripper 62 is matched to the height of the first material channel 92, so that the charging shaft first low-temperature stripper 62 can close off the first material channel 92. Likewise, the height of the pusher plate of the first pusher 78 matches the height of the second material passage 93, and the height of the pusher plate of the second warm pusher 61 of the feeding shaft matches the height of the third material passage 94.

Preferably, the material pushing plate of the third high-temperature pusher 60 of the feeding shaft is positioned in the third interlayer 64 of the feeding shaft and extends into the second interlayer 75 of the preheater, so that the material can be prevented from entering the third interlayer 64 of the feeding shaft, and meanwhile, when the third high-temperature pusher 60 of the feeding shaft does not push the material, the third high-temperature pusher 60 of the feeding shaft can be taken into the third interlayer 64 of the feeding shaft or most of the material can be taken into the third interlayer 64 of the feeding shaft, and preferably, the right end of the third high-temperature pusher 60 of the feeding shaft is flush with the right side of the third interlayer 64 of the feeding shaft, so that the contact time of the third high-temperature pusher 60 of the feeding shaft and the ultrahigh-temperature flue gas generated by the smelting furnace 50 can be shortened, the service life of the equipment is prolonged, and the difficult feeding problem is well solved. Further, the front end of the material pushing plate of the third high-temperature material pusher 60 of the feeding shaft is made of heat-resistant material.

For a better understanding of the solution of the invention, the material flow path is described in the following in a simple manner, the material is fed into the first partition 67 of the charging shaft by means of the feeder, the material is pushed into the first partition 74 of the preheater by means of the first low-temperature pusher 62 of the charging shaft, the predetermined conditions are met (for example, the material temperature in the first partition 74 of the preheater reaches 500 ℃), the material in the first partition 74 of the preheater is pushed into the second partition 65 of the charging shaft by means of the first pusher 78 of the preheater, the material in the second partition 65 of the charging shaft is pushed into the second partition 75 of the preheater by means of the second medium-temperature pusher 61 of the charging shaft, the second partition 75 of the preheater is connected to the furnace 50, the connecting channel between the two is the feed inlet 29 of the preheater, the third high-temperature pusher 60 of the shaft pushes the material in the second partition 75 of the preheater into the furnace 50 by means of the feed inlet 29 of the furnace, the feeding speed of each pusher is controlled according to the operating condition of the melting furnace 50, so that the materials can be controllably, continuously and uniformly fed into the melting furnace 50, and in addition, when the materials positioned in the previous procedure are guided into the next procedure, the materials are supplemented in time in the previous procedure.

The first pipeline 11 is located on the upper side of the second interlayer 75 of the preheater, the first pipeline 11 is provided with a first temperature measuring and controlling device 12 and a constant temperature flue gas control valve 76, the first pipeline 11 is connected with a first fan 18, the high temperature flue gas generated by the smelting furnace 50 is subjected to sufficient convective contact heat transfer with the material in the second interlayer 75 of the preheater through a smelting furnace feed inlet 29, when the temperature of the flue gas is reduced to a specific temperature range (500 ℃ -600 ℃), the first temperature measuring and controlling device 12 and the constant temperature flue gas control valve 76 lead out the part of the flue gas, and the first pipeline 11 is connected with the flue gas purification system in the embodiment 2.

The second pipeline 13 is provided with a second temperature measuring and controlling device 14 and a circulating flue gas control valve 73, the second pipeline 13 is connected with a second fan 19, the flue gas which is subjected to heat exchange in a second interlayer 75 of the preheater but not led out through the first pipeline 11 continuously rises, the rising flue gas is further subjected to heat exchange with the material in the first interlayer 74 of the preheater mainly through a partition plate 77 and a first pusher 78, after the material in the first interlayer 74 of the preheater is heated and heated, controlling the temperature to be above 500 ℃ to fully gasify the organic matters contained in the flue gas, wherein the flue gas is mixed flue gas with gasified organic gas, and the mixed flue gas continuously rises to the second pipeline 13, because the temperature of the mixed flue gas is reduced and the dioxin is regenerated, the mixed flue gas is guided out of the second pipeline 13, is pressurized by the second fan 19 and is blown into the smelting furnace 50, the dioxin in the mixed flue gas is thoroughly decomposed by the continuous action of the ultrahigh temperature through the high-temperature (more than 1000 ℃) heating of the furnace 50. Thereby reducing the amount of dioxin and the precursor thereof contained in the materials, particularly in the discharged flue gas, and achieving the purposes of controlling the discharge of the dioxin and the precursor thereof and fully utilizing the energy of the flue gas.

When the first temperature measuring and controlling device 12 and the second temperature measuring and controlling device 14 monitor the temperature change of the flue gas, the temperature of each position can be kept constant through the rotation speed control of the first fan 18 and the second fan 19.

Materials of the present invention include, but are not limited to, fly ash, which is either pre-treated to make it granular before addition, or the fly ash itself is granular, so that the fly ash does not fall directly into the second compartment 75 through the holes in the partition plate 77 during the first compartment 74.

Example 6 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 'HJ 77.2-2008 ambient air and waste gas dioxin (isotope dilution high resolution gas chromatography-high resolution mass spectrometry)' to detect the dioxin in the smoke;

the following sets of experiments were set up:

experimental group 1: the apparatus of example 2 (and controlling the temperature in the first conduit to 500 ℃);

experimental group 2: the apparatus of example 3 in combination with the flue gas cleaning system provided in example 2 (and controlling the temperature in the first pipe to 500 ℃);

experimental group 3: the apparatus of example 4 in combination with the flue gas cleaning system provided in example 2 (and controlling the temperature in the first pipe to 500 ℃);

experimental group 4: the apparatus of example 5 in combination with the flue gas cleaning system provided in example 2 (and controlling the temperature in the first pipe at 500 ℃);

experimental group 5: the apparatus of example 5 in combination with the flue gas cleaning system provided in example 2 (and controlling the temperature in the first pipe to 600 ℃);

control group: the apparatus of example 6 in combination with the flue gas cleaning system provided in example 2.

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 is discharged from the dust remover 42, as shown in the following table:

TABLE 1 flue gas treatment effect comparison List

The national dioxin discharge standard is less than 0.1ngTEQ/m³As can be seen from Table 1, the apparatus of the present invention has the capability of discharging the qualified dioxin after treatment. According to the above experimental data, under the condition of consistent other conditions, the dioxin content in the flue gas discharged from the experimental group 1, the experimental group 2, the experimental group 3, the experimental group 4 and the experimental group 5 is obviously lower than that in the control group (prior art), which is promoted by the second pipeline 13, and the second pipeline 13 returns part of the flue gas to the furnace for pyrolysis, so that the emission of dioxin is reduced. In addition, the power consumption required by the experiment groups 1, 2, 3, 4 and 5 for processing the same material is obviously reduced compared with the control group, which is promoted by the utilization of the high-temperature flue gas by the equipment, and the purpose of saving energy is realized by utilizing the waste heat. Again, the ratio of experiment group 4 to experiment group 5 was usedIn comparison, the dioxin content in the exhaust flue gas of the two is basically the same, but the exhaust temperature of 500 ℃ in the experimental group 4 is more energy-saving than the exhaust temperature of 600 ℃ in the experimental group 5, which shows that the exhaust heat of the high-temperature flue gas can be better utilized by the temperature of 500 ℃, so in practice, the exhaust temperature of 500 ℃ in the first pipeline 13 is preferred. It should be noted that the temperature of 500 ℃ is only a preferred temperature point, and is not a limitation on the temperature of the flue gas discharged from the first duct 13, and the optimal temperature may be … … 480.1 ℃, 480.2 ℃, … … 485 ℃, 38485 ℃, … … 499.9 ℃, … … 516.3, 516.3 ℃ … …, and the temperature around the optimal temperature does not have a great influence on the power consumption of the furnace and the dioxin content of the discharged flue gas. Meanwhile, the optimal temperature is influenced by environmental factors such as the external air pressure and the like, and is not constant, so any further limitation on the temperature on the basis of the invention is considered to be included in the protection scope of the invention.

Therefore, the flue gas treatment device provided by the invention greatly improves the energy utilization rate, reasonably and efficiently utilizes the flue gas waste heat, and obviously inhibits the emission of pollutants dioxin.

The invention provides a flue gas treatment device which is suitable for controlling harmful substances and recovering heat of high-temperature flue gas. Such as expansion according to the application range in the aspect of environmental protection. Various changes and modifications may be effected by one skilled in the art without departing from the spirit and scope of the invention, as defined in the appended claims.

Claims

1. A flue gas treatment device is characterized by comprising a feeding preheater capable of preheating materials, wherein the feeding preheater is provided with a first pipeline and a second pipeline, the second pipeline is higher than the first pipeline in arrangement position, the first pipeline is used for discharging part of flue gas out of the feeding preheater, and the second pipeline is used for returning the rest of flue gas to a smelting furnace;

wherein, be equipped with the division board in the feeding preheater, be equipped with the hole on the division board, the diameter in hole is less than the diameter of material, and the division board separates the feeding preheater for the first interlayer of preheater and preheater second interlayer, and the first interlayer of preheater is located the upside position of preheater second interlayer, and the second pipeline is located the first interlayer of preheater, and first pipeline is located the preheater second interlayer.

2. The flue gas treatment device according to claim 1, wherein the first duct is provided with a first temperature measuring and controlling device for monitoring the temperature of the flue gas discharged from the first duct.

3. The flue gas treatment device according to claim 2, wherein the first pipeline is provided with a first fan, and the temperature in the first pipeline is higher than the regeneration temperature of the harmful substances.

4. The flue gas treatment device according to claim 3, wherein the harmful substance is dioxin.

5. The flue gas treatment device of claim 1, wherein the feed preheater is a shaft feed preheater, the feed preheater being connected to the furnace.

6. The flue gas treatment device according to claim 1, wherein the second duct is provided with a second temperature sensor for monitoring the temperature of the flue gas discharged from the second duct, and a second blower for pressurizing the flue gas in the second duct and blowing the pressurized flue gas into the furnace.

7. The flue gas treatment device of claim 1, wherein the feed preheater is provided with an electromagnetic heater at a position between the first duct and the second duct.

8. The flue gas treatment device according to claim 1, wherein the feed preheater adds alkaline calcium salt and/or lime to the material as the material is added.

9. The flue gas treatment device according to claim 1, wherein the first pipeline is connected with a flue gas purification system, and the flue gas purification system comprises a quencher, a desulfurization and deacidification tower, a dust remover, an SCR reactor and a chimney.

10. The flue gas treatment device according to claim 1, wherein the separator is provided with a pusher, and a material passage or a material passage is provided between the first partition and the second partition.