Incineration type flue gas purification system and method

Abstract

The present invention discloses an incineration type flue gas purification system and method. The disclosed incineration type flue gas purification system includes a dust removal device, a denitrification device and an exhaust pipe which are sequentially connected through a flue gas pipeline; and also includes an incineration device connected to the exhaust pipe through the flue gas pipeline; the incineration device is used to remove pollutants in the flue gas to be treated by incinerating the combustible components of the flue gas to be treated. In this way, the combustible components in the flue gas to be treated can be utilized, and the energy consumption of flue gas purification can be greatly reduced. In the process of incinerating the flue gas, carbon monoxide, VOCs and dioxins can be converted into non-pollutants such as carbon dioxide or water, and pollutants in the flue gas to be treated can be removed, and pollutants can be avoided or reduced from entering the absorption slurry such as desulfurization, eliminating the subsequent treatment process of the slurry, and reducing the cost of flue gas purification.

Description

Technical Field

[0001] The invention relates to a flue gas purification technology, and in particular to an incineration type flue gas purification system and a flue gas purification method. Background Art

[0002] The flue gas emitted by combustion furnaces (sintering furnaces, shaft furnaces, rotary kilns and blast furnaces) includes dust, NO X , SOx, CO, VOCs, dioxins and other harmful pollutants. In order to reduce harmful pollutants in flue gas, it is usually necessary to purify the flue gas.

[0003] The flue gas purification process generally includes dust removal, desulfurization, denitrification, and then emptying, so that nitrate and sulfur can be removed before emptying to achieve flue gas purification. Among them, volatile organic compounds (VOCs) and dioxins often enter the absorption slurry during the desulfurization and denitrification process and become components of the absorption slurry. During the filtration process of the absorption slurry, harmful substances formed by VOCs and dioxins will remain in the filter cake, which will make the filter cake difficult to handle and become an important obstacle to the use of the filter cake. In the prior art, either the absorption slurry is specially treated or the filter cake is specially treated, and these treatments lead to complex processes and increased costs.

[0004] In addition, according to the existing flue gas treatment process, after dust removal, the flue gas temperature is relatively low, which is not conducive to denitrification treatment. It is necessary to set up special heating or temperature-increasing means to increase the flue gas temperature entering the denitrification device, resulting in higher energy consumption for flue gas treatment.

[0005] How to further improve the flue gas purification effect, reduce the adverse effects of harmful pollutants, reduce the cost of flue gas purification treatment, and reduce the energy consumption of flue gas purification are technical problems that technical personnel in this field need to solve. Summary of the invention

[0006] The object of the present invention is to provide an incineration type flue gas purification system, which can better purify flue gas and avoid or reduce the shortcomings of complex process and high treatment cost caused by the presence of VOCs and dioxins.

[0007] At the same time, correspondingly, the present invention also provides an incineration type flue gas purification method, through which the same effect can be achieved.

[0008] The incineration type flue gas purification system provided by the present invention comprises a dust removal device, a denitrification device and an exhaust pipe which are sequentially connected through a flue gas pipeline; and also comprises an incineration device which is connected to the exhaust pipe through the flue gas pipeline; the incineration device is used to remove pollutants such as VOCs and dioxins in the flue gas to be treated by incinerating the combustible components of the flue gas to be treated. In this way, the pollutants in the flue gas can be purified by utilizing the combustible components in the flue gas to be treated, the addition of external fuel can be reduced, and the energy consumption of flue gas purification can be greatly reduced. In the process of incinerating the flue gas, pollutants such as VOCs and dioxins in the flue gas to be treated can be removed, and VOCs and dioxins can be avoided or reduced from entering other devices and then entering slurry or other substances, thereby eliminating the subsequent treatment process of slurry and reducing the cost of flue gas purification.

[0009] In the preferred technical solution, the incineration device is connected between the dust removal device and the denitration device through the flue gas duct. Since the flue gas to be treated needs to be heated to a certain temperature when the denitration device performs denitration treatment, and the temperature of the flue gas discharged from the combustion furnace after the dust removal treatment is lower than the temperature required for denitration. After the VOCs and dioxins are removed by the incineration device, the temperature of the flue gas to be treated is increased, which can provide good conditions for the denitration treatment, reduce the energy consumption of heating the flue gas before denitration, and thus reduce the cost, that is, the incineration treatment can achieve the function and effect of denitration preheating.

[0010] A further preferred technical solution also includes a preheating heat exchanger; the preheating heat exchanger includes a first passage and a second passage for heat exchange; the smoke inlet of the first passage is connected to the smoke outlet of the dust removal device through a smoke pipe, and the smoke outlet is connected to the smoke inlet of the incineration device through a smoke pipe; the smoke inlet of the second passage is connected to the smoke outlet of the denitration device through a smoke pipe, and the smoke outlet is connected to the exhaust pipe through a smoke pipe. Through the preheating heat exchanger, the heat in the flue gas after denitration treatment can be used to preheat the flue gas entering the incineration device, making full use of the system heat, reducing or lowering the consumption of the incineration device, and improving the overall efficiency of the system.

[0011] In a further technical solution, the incineration type flue gas purification system further comprises a desulfurization device, and the desulfurization device is connected between the exhaust port of the denitrification device and the exhaust pipe through a flue gas pipeline;

[0012] It also includes a whitening heat exchanger: the whitening heat exchanger includes a whitening flue gas channel and a whitening gas channel for heat exchange; the smoke inlet of the whitening flue gas channel is communicated with the smoke outlet of the dust removal device through a flue gas pipeline, and the smoke outlet is communicated with the smoke inlet of the desulfurization device through a flue gas pipeline; the inlet of the whitening gas channel is communicated with the outlet of the whitening fan through a flue gas pipeline to introduce whitening gas, and the outlet is communicated with the exhaust pipe through a flue gas pipeline. The whitening heat exchanger can use the heat in the flue gas after denitrification to preheat the whitening gas. The preheated whitening gas is mixed with the gas to be exhausted, which can increase the exhaust flue gas temperature, reduce the flue gas humidity, reduce or eliminate the white smoke phenomenon of the exhaust flue gas, and reduce the corrosion of the exhaust pipe by the exhaust flue gas.

[0013] In the preferred technical solution, the incineration device includes an incinerator and multiple energy storage oxidation furnaces connected to the incinerator; each energy storage oxidation furnace includes an oxidation chamber, a smoke inlet branch pipe and a smoke outlet branch pipe connected to the oxidation chamber; the smoke inlet branches of multiple energy storage oxidation furnaces are connected to the smoke inlet of the incineration device; and the smoke outlet branches of multiple energy storage oxidation furnaces are connected to the smoke outlet of the incineration device. In this way, each energy storage oxidation furnace can work intermittently, keep the temperature of each energy storage oxidation furnace within a suitable range, avoid overheating of the energy storage oxidation furnace, and improve the reliability and service life of the incineration device.

[0014] In a further preferred technical solution, an ignition device is provided for each oxidation chamber; the incineration device includes an incineration controller connected to the signals of the multiple ignition devices, so that the automatic control of multiple incinerators can be realized.

[0015] In the preferred technical solution, in the incineration device, the upper parts of the plurality of energy storage oxidation furnaces are connected to the incinerator, and the incinerator is provided with a fuel inlet.

[0016] In a further optional technical solution, a heat insulation structure is provided between the plurality of oxidation chambers.

[0017] In an optional technical solution, an exhaust dust collector is provided in the exhaust pipe, and the exhaust dust collector is located between the outlet of the white elimination gas channel and the connecting position of the exhaust pipe.

[0018] In an optional technical solution, a demister is further provided in the exhaust pipe, and the demister is located before the exhaust dust collector.

[0019] The incineration flue gas purification method provided by the present invention includes a dust removal step and a denitrification step to treat the flue gas to be treated and then empty it, and also includes an incineration step before emptying; the incineration step removes pollutants such as VOCs and dioxins in the flue gas by burning the combustible components of the flue gas to be treated. Corresponding to the above-mentioned incineration flue gas purification system, the incineration flue gas purification method can convert carbon monoxide, VOCs and dioxins into carbon dioxide or water, avoid or reduce VOCs and dioxins from entering other devices and then entering absorption slurry or other substances, save subsequent treatment processes, and reduce the cost of flue gas purification.

[0020] In the preferred technical solution, the incineration step is before the denitration step; after the temperature of the flue gas to be purified is raised to the denitration temperature through the incineration step, the denitration preparation temperature is between 250 and 450 degrees. While removing VOCs and dioxins through the incineration device, the temperature of the flue gas to be treated can be raised to between 250 and 450 degrees, providing suitable temperature conditions for denitration treatment, and eliminating the process and steps of heating the flue gas before denitration, thereby reducing energy consumption, simplifying the treatment process, and reducing the cost of flue gas purification.

[0021] In the preferred technical solution, the flue gas treated in the denitration step is used to heat the flue gas to be treated in the incineration step. The heat in the flue gas treated with denitration can be used to preheat the flue gas entering the incineration step, making full use of the system heat, reducing or lowering the consumption of the incineration step, and improving the overall efficiency of the system.

[0022] In the preferred technical solution, after the denitration step and before the exhaust, a desulfurization step is also included; the flue gas after the denitration treatment is desulfurized by the desulfurization step; and the step of heating the predetermined whitening gas by using the flue gas after the denitration step and between the desulfurization steps, and mixing the heated whitening gas with the flue gas in the desulfurization step is also included. In this way, the heat in the flue gas after the denitration treatment can be used to preheat the whitening gas, and the preheated whitening gas is mixed with the gas to be exhausted, which can increase the exhaust gas temperature, reduce the white smoke phenomenon of the exhaust flue gas, and reduce the corrosion of the exhaust pipe by the exhaust flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of an embodiment of an incineration type flue gas purification system of the present invention.

[0024] Figure 2 The present invention is a flow chart of an embodiment of the incineration type flue gas purification method of the present invention. DETAILED DESCRIPTION

[0025] In the following, in conjunction with the accompanying drawings, the embodiments of the incineration type flue gas purification system and the incineration type flue gas purification method provided by the present invention are described. In this document, the meanings of the directional words such as "front" and "back" used are determined by considering the implementation status and process sequence of the incineration type flue gas purification system and the incineration type flue gas purification method, and should not be understood as any limitation to this patent.

[0026] Please refer to Figure 1 , which is a schematic structural diagram of an embodiment of an incineration type flue gas purification system of the present invention. The incineration type flue gas purification system comprises a dust removal device 100, an incineration device 400, a denitration device 200 and an exhaust pipe 300 which are sequentially connected through a flue gas pipeline.

[0027] The dust removal device 100 can select existing dust removal equipment or utilize existing dust removal methods to remove dust from the flue gas to be treated. In one embodiment, the dust removal device 100 can include a cyclone dust collector and a pulse bag dust collector. Of course, according to actual needs, multiple dust collectors can be selected for combined use.

[0028] The denitration device 200 can utilize existing denitration equipment or denitration methods to eliminate or reduce NOx in the flue gas, such as oxidation method or reduction method. In this embodiment, the selective catalytic reduction (SCR) method is used for denitration, that is, hot ammonia is added, and the catalyst in the reactor is used to convert NOx into nitrogen to achieve the purpose of flue gas denitration.

[0029] After the flue gas reaches the emission standard through purification, it can be discharged into the air through the exhaust pipe 300. The exhaust pipe 300 can be selected to have a suitable height, and a chimney can be formed to discharge the gas that reaches the emission standard into the atmosphere at a suitable height.

[0030] The incineration device 400 may include an incinerator, which may be a direct-fired incinerator or a regenerative thermal oxidizer (RTO). In one embodiment, a regenerative thermal oxidizer may be selected to reduce energy consumption and ensure safety. The incineration device 400 may be used to heat and incinerate carbon monoxide, VOCs, and dioxins, and convert them into harmless components such as carbon dioxide or water, thereby ensuring a combustion effect.

[0031] In one embodiment, an incineration device 400 is provided between the dust removal device 100 and the denitration device 200 through an appropriate flue gas pipeline. The CO content in the flue gas to be treated is 5601-6201 mg / Nm 3 , VOCs content is 100-500 mg / Nm 3, dioxin content is 1-5ng TEQ / Nm 3 , using an incinerator, while maintaining a temperature of 800-1100°C, to burn the CO in the flue gas to be treated. After testing, the CO content in the flue gas after incineration is 20-800mg / Nm3, and the VOCs content is 5-10mg / Nm 3 , dioxin content is <0.1ng TEQ / Nm 3 That is, after incineration, CO is converted into CO2, VOCs and dioxins are converted into water and carbon dioxide, and pollutants are removed. Generally speaking, flue gas itself contains a large amount of H2O (about 15-18% by volume) and CO2 (about 5-8% by volume), and the H2O produced by the combustion of VOCs is relatively small (such as 0.05% by volume). Flue gas itself contains a large amount of CO2, and the CO2 produced by combustion is relatively small (such as 0.5% by volume).

[0032] At the same time, since the denitrification device 200 needs to heat the flue gas to be treated to a certain temperature when performing denitrification treatment, the temperature of the flue gas discharged from the combustion furnace after dust removal treatment is lower than the temperature required for denitrification. By using the embodiment of the present invention, after removing VOCs and dioxins through the incineration device 400, the temperature of the flue gas to be treated can be increased, providing good conditions for denitrification treatment, and the process and steps of specially heating the flue gas before denitrification can be omitted, that is, the incineration treatment can achieve the function and effect of denitrification preheating; this can also reduce costs, and avoid or reduce VOCs and dioxins from entering the denitrification device, eliminating subsequent treatment processes, and reducing the cost of flue gas purification treatment. Generally speaking, for a project with a flue gas volume of 100,000 Nm3 / h, using existing technology, the annual fuel cost is about 8 million yuan when the flue gas to be treated is increased by adding fuel; using the technology provided by this patent, the annual fuel cost is only 1.8 million yuan, which greatly reduces the cost of flue gas purification.

[0033] It can be understood that the combustible components in the flue gas to be treated are not only CO, VOCs and dioxins, but also other combustible components. According to the above description, it can also be determined that the higher the combustible components in the flue gas to be treated, the better the combustion performance; according to the different flue gases to be treated, the amount of fuel added, the fuel addition speed and the temperature in the combustion furnace can be controlled to balance the heat resistance of the incineration device 400 and the flue gas purification efficiency.

[0034] Of course, the main purpose of the present invention is to avoid or reduce the shortcomings of complex process and high treatment cost caused by the presence of VOCs and dioxins in the flue gas purification process. Therefore, the setting position of the incineration device 400 can be determined according to actual needs, as long as it is connected before the exhaust pipe 300 through the flue gas pipeline, and it does not have to be set between the dust removal device 100 and the denitrification device 200.

[0035] As shown in the figure, the incineration type flue gas purification system provided in this embodiment may also include a preheating heat exchanger 500; the preheating heat exchanger 500 is arranged between the dust collector device 100 and the incineration device 400. The preheating heat exchanger 500 includes a first passage and a second passage for heat exchange. The first passage provides a flue gas passage, including a smoke inlet 511 and a smoke outlet 512. The smoke inlet 511 is communicated with the smoke outlet 102 of the dust collector 100 through a smoke pipe, and the smoke outlet 512 is communicated with the smoke inlet 401 of the incineration device 400 through a smoke pipe. The second passage provides a passage for the flue gas discharged from the denitration device 200, and its smoke inlet 521 is communicated with the smoke outlet 202 of the denitration device 200 through a smoke pipe, and the smoke outlet 522 is directly or indirectly communicated with the exhaust pipe 300 through a smoke pipe. The temperature of the flue gas discharged from the denitration device 200 is relatively high, while the temperature of the flue gas discharged from the dust removal device 100 is relatively low; the two can exchange heat through the preheating heat exchanger 500, thereby increasing the temperature of the flue gas entering the incineration device 400 and reducing the temperature of the flue gas discharged from the denitration device 200. The preheating heat exchanger 500 can be used to preheat the flue gas entering the incineration device 400 using the heat in the flue gas after denitration treatment, making full use of the system heat, reducing or lowering the consumption of the incineration device 400, and improving the overall efficiency of the system. All equipment with flue gas heat exchange function can be used as the preheating heat exchanger 500 in the present invention, and the present invention has no special restrictions on this.

[0036] In order to promote the smooth flow of smoke, a corresponding induced draft fan may be provided in the smoke passage in front of the first passage of the preheating heat exchanger 500 to promote the flow of smoke.

[0037] like Figure 1 As shown, the incineration flue gas purification system provided in this embodiment also includes a desulfurization device 600 and a whitening heat exchanger 700.

[0038] The desulfurization device 600 is connected between the exhaust port 202 of the denitrification device 200 and the exhaust pipe 300 through a flue gas pipeline. In this way, the flue gas after denitrification can enter the desulfurization device 600 for desulfurization. The desulfurization device 600 can use existing desulfurization equipment, such as a multiphase reactor or a spray tower; wet desulfurization can be selected, or dry desulfurization can be selected. In order to control the flue gas entering the desulfurization device 600 and ensure smooth flow of the flue gas, an appropriate induced draft fan can be set in the flue gas introduction pipeline of the desulfurization device 600.

[0039] The desulphurization heat exchanger 700 can be connected after the denitrification device 200. In this embodiment, the desulphurization heat exchanger 700 is arranged after the preheating heat exchanger 500. The desulphurization heat exchanger 700 includes a desulphurization flue gas channel and a desulphurization gas channel for heat exchange. The smoke inlet 711 of the desulphurization flue gas channel is communicated with the smoke outlet 202 of the denitrification device 200 through an appropriate smoke pipe, and the smoke outlet 712 is communicated with the smoke inlet of the desulfurization device 600 through a smoke pipe. The desulphurization gas is introduced into the inlet 721 of the desulphurization gas channel, and the outlet 722 is communicated with the exhaust pipe 300 through a smoke pipe. The desulphurization gas can be air, and of course it can also be other gases. In order to control the introduction of the desulphurization gas, an appropriate induced draft fan can be provided at the inlet 721 of the desulphurization gas channel to control the introduction of the desulphurization gas (air).

[0040] In this embodiment, the principle of using the de-whitening heat exchanger 700 is: using the heat in the flue gas after denitrification treatment to preheat the air, the preheated air is mixed with the purified gas to be exhausted, which can increase the temperature of the exhaust gas, reduce the white smoke phenomenon of the exhaust gas, and reduce the corrosion of the exhaust pipe 300 by the exhaust body.

[0041] In order to avoid overheating of the incineration device 400 and affect the reliability and service life of the incineration device 400, the incineration device 400 in the incineration flue gas purification system includes a plurality of energy storage oxidation furnaces 410 and an incineration furnace 420, each energy storage oxidation furnace 410 includes an oxidation chamber 411, a smoke inlet branch pipe 412 and a smoke outlet branch pipe 413 communicating with the oxidation chamber 411, the smoke inlet branch pipes 412 of the plurality of energy storage oxidation furnaces 410 communicate with the smoke inlet port 401 of the incineration device 400, and the smoke outlet branch pipes 413 of the plurality of energy storage oxidation furnaces 410 communicate with the smoke outlet 402 of the incineration device 400. The smoke inlet branch pipe 412 and the smoke outlet branch pipe 413 are provided with switch valves to control the on-off of the pipelines, realize the entry and exhaust of smoke, and further control the smoke entry, smoke cleaning and exhaust process of each energy storage oxidation furnace 410, and further control the working cycle of each energy storage oxidation furnace 410. In this embodiment, the energy storage oxidation furnace 410 is operated intermittently by controlling the switch valve, so that the temperature of each energy storage oxidation furnace 410 is maintained within a suitable range, thereby avoiding overheating of the energy storage oxidation furnace 410 and improving the reliability and service life of the incineration device 400.

[0042] In this embodiment, the switch valve corresponding to each energy storage oxidation furnace 410 is an electrically controlled switch valve. The incineration device 400 includes an incineration controller connected to multiple electrically controlled switch valves, that is, the control end of the incineration controller is respectively connected to the signal input end of the electrically controlled switch valve, so as to realize automatic control of multiple energy storage oxidation furnaces 410, so that the energy storage oxidation furnaces 410 work intermittently.

[0043] In the incineration device 400, the incinerator 420 is located above the plurality of oxidation chambers 411 and is kept in communication with each other. The incinerator 420 is provided with a suitable burner and a fuel inlet to facilitate the addition of fuel and ignition and incineration. A heat insulation structure is provided between the oxidation chambers 411 of the plurality of energy storage oxidation furnaces 410, such as filling with heat insulation materials, etc., so that the oxidation chambers 411 can be prevented from affecting each other, thereby further improving the reliability and service life of the incineration device 400.

[0044] It is understandable that the incineration device 400 may include only one energy storage oxidation furnace 410 or multiple energy storage oxidation furnaces 410 .

[0045] In order to further purify the flue gas and ensure that the exhaust gas meets the standard, in this embodiment, an exhaust dust collector 310 and a demister 320 are also provided in the exhaust pipe 300. The exhaust dust collector 310 is located between the outlet 722 of the white gas elimination channel and the connection position of the exhaust pipe 300. The demister 320 can be located before the exhaust dust collector 310 to reduce the water content in the gas and reduce the corrosive effect on the dust collector 310. Of course, an online monitoring device can also be provided in the exhaust pipe 300 to monitor the pollutant content of the exhaust gas in real time.

[0046] Based on the above incineration type flue gas purification system, the present invention also provides an incineration type flue gas purification method. Of course, the incineration type flue gas purification method provided by the present invention can be implemented in the above incineration type flue gas purification system, but is not limited to the above incineration type flue gas purification system.

[0047] Please refer to Figure 2 , which is a schematic diagram of the principle of an embodiment of the incineration type flue gas purification method of the present invention. In this embodiment, the incineration type flue gas purification method comprises the following steps for treating the flue gas to be treated:

[0048] S100, dust removal step, that is, dust removal treatment of the flue gas discharged from the combustion furnace to avoid clogging of subsequent flue gas preheating and denitration process equipment. After dust removal treatment, the flue gas to be treated may contain predetermined CO or other combustible components.

[0049] S200, the incineration flue gas preheating step, i.e. using the flue gas treated in the denitration step to preheat the flue gas to be treated in the incineration step, and transferring the heat of the flue gas treated in the denitration step to the flue gas to be treated in the incineration step, so as to reduce the energy consumption in the incineration step.

[0050] S300, the incineration step, is to remove pollutants in the flue gas by incinerating the combustible components of the flue gas to be treated.

[0051] S400, a denitration step, removes NOx from the flue gas to be treated.

[0052] S500, the step of heating the white gas, i.e., using the flue gas to be treated after the denitration step to perform heat exchange with the air (white gas). Through this step, the temperature of the flue gas to be treated entering the desulfurization step can be reduced, and the temperature of the white gas can be increased. The reduction of the flue gas to be treated can reduce the evaporation amount in the desulfurization step; the increase of the white gas temperature can reduce the condensed water vapor during the flue gas discharge and reduce the white smoke phenomenon of the flue gas after exhaust.

[0053] S600, a desulfurization step, removes sulfur dioxide from the flue gas to be treated.

[0054] After being purified and meeting the exhaust conditions, it is discharged into the atmosphere through the exhaust pipe.

[0055] For specific content, please refer to the description of the embodiment of the incineration flue gas purification system. With the incineration flue gas purification method, the denitration step treats the flue gas to be treated and then empties it. Before the denitration step, it includes an incineration step. The incineration step removes pollutants such as carbon monoxide, VOCs and dioxins in the flue gas by incinerating the flue gas to be treated, and after the temperature of the flue gas to be purified is increased to the denitration temperature, the denitration preparation temperature is between 250 degrees and 450 degrees. Corresponding to the above-mentioned incineration flue gas purification system, on the one hand, VOCs and dioxins can be converted into carbon dioxide or water, avoiding or reducing VOCs and dioxins from entering other devices and then entering the absorption slurry or other substances, eliminating the subsequent treatment process and reducing the cost of flue gas purification. On the other hand, since the incineration step is set before the denitration step, after the VOCs and dioxins are removed by the incineration device, the temperature of the flue gas to be treated is increased to between 250 degrees and 450 degrees, the process and steps of heating the flue gas between denitration can be omitted, thereby reducing costs and reducing flue gas purification energy consumption.

[0056] It is understandable that the incineration step only needs to be performed before the emptying, and does not necessarily have to be performed before the denitration step. The specific steps can be arranged and set accordingly according to the type and composition of the flue gas to be treated and the requirements of the application environment.

[0057] In order to utilize the heat in the flue gas after denitration to preheat the flue gas entering the incineration step, fully utilize the system heat, reduce or lower the consumption of the incineration step, and improve the overall efficiency of the system, the flue gas treated in the denitration step is used to preheat the flue gas to be treated in the incineration step. This can be achieved by the preheating heat exchanger 500.

[0058] Of course, in the case where the flue gas to be treated needs to be desulfurized, a desulfurization step can be included after the denitration step and before the exhaust. The desulfurization step is used to desulfurize the flue gas after the denitration treatment. In order to eliminate white smoke during exhaust, the flue gas after the denitration step and between the desulfurization steps can be used to heat the air (white smoke elimination gas), and the heated air can be introduced into the exhaust pipe 300, and then mixed with the gas of the desulfurization step (gas to be exhausted). In this way, the exhaust gas temperature can be increased, the exhaust gas white smoke phenomenon can be eliminated or reduced, and the exhaust gas corrosion to the exhaust pipe can be reduced.

[0059] The above is a detailed introduction to the specific implementation of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An incineration type flue gas purification system, comprising a dust removal device (100), a denitrification device (200) and an exhaust pipe (300) which are sequentially connected through a flue gas pipeline, characterized in that: It also includes an incineration device (400) connected to the exhaust pipe (300) through a flue gas pipeline; The incineration device (400) is connected between the dust removal device (100) and the denitration device (200) via the flue gas duct; The incineration device (400) is used to remove pollutants in the flue gas to be treated by incinerating the combustible components of the flue gas to be treated; The incineration device (400) comprises an incineration furnace (420) and a plurality of energy storage oxidation furnaces (410) connected to the incineration furnace (420); each of the energy storage oxidation furnaces (410) comprises an oxidation chamber (411), a smoke inlet branch pipe (412) and a smoke outlet branch pipe (413) connected to the oxidation chamber (411); the smoke inlet branch pipes (412) of the plurality of energy storage oxidation furnaces (410) are connected to the smoke inlet (401) of the incineration device (400); the smoke outlet branch pipes (413) of the plurality of energy storage oxidation furnaces (410) are connected to the smoke outlet (402) of the incineration device (400); It also includes an incineration controller; the smoke inlet branch pipe (412) and the smoke outlet branch pipe (413) are provided with electrically controlled switch valves; the control end of the incineration controller is respectively connected to the signal input end of the electrically controlled switch valve; A heat insulation structure is arranged between the plurality of oxidation chambers.

2. The incineration type flue gas purification system according to claim 1, characterized in that: It also includes a preheating heat exchanger (500); the preheating heat exchanger (500) includes a first passage and a second passage for heat exchange; the smoke inlet (511) of the first passage is communicated with the smoke exhaust port (102) of the dust removal device (100) through a smoke duct, and the smoke outlet (512) is communicated with the smoke inlet (401) of the incineration device (400) through a smoke duct; the smoke inlet (521) of the second passage is communicated with the smoke exhaust port (202) of the denitration device (200) through a smoke duct, and the smoke outlet (522) is communicated with the exhaust pipe (300) through a smoke duct.

3. The incineration type flue gas purification system according to claim 1 or 2, characterized in that: It also includes a desulfurization device (600), wherein the desulfurization device (600) is connected between the smoke exhaust port (202) of the denitrification device (200) and the exhaust pipe (300) through a smoke duct; Also includes descaling heat exchanger (700): The desulfurization heat exchanger (700) comprises a desulfurization flue gas channel and a desulfurization gas channel for heat exchange; the smoke inlet (711) of the desulfurization flue gas channel is communicated with the smoke outlet (102) of the dust removal device (100) through a smoke duct, and the smoke outlet (712) is communicated with the smoke inlet of the desulfurization device (600) through a smoke duct; the desulfurization gas is introduced into the inlet (721) of the desulfurization gas channel, and the outlet (722) is communicated with the exhaust pipe (300) through a smoke duct.

4. An incineration flue gas purification method using the incineration flue gas purification system according to any one of claims 1 to 3, comprising treating the flue gas to be treated through a dust removal step and a denitration step and then emptying the flue gas, characterized in that: It also includes an incineration step before emptying; The incineration step removes pollutants in the flue gas to be treated by incinerating the combustible components of the flue gas to be treated; The incineration step is before the denitration step; Through the incineration step, after the temperature of the flue gas to be purified is raised to the denitration temperature, the denitration preparation temperature is between 250 degrees and 450 degrees.

5. The incineration flue gas purification method according to claim 4, characterized in that: The flue gas treated in the denitration step is used to heat the flue gas to be treated in the incineration step.

6. The incineration flue gas purification method according to claim 4 or 5, characterized in that: After the denitrification step and before emptying, a desulfurization step is also included; Desulfurization is performed on the flue gas after denitration through the desulfurization step; The method further comprises the steps of heating a predetermined denitrification gas using the flue gas after being processed in the denitrification step and before being processed in the desulfurization step, and mixing the heated denitrification gas with the flue gas processed in the desulfurization step.

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