Sintering flue gas waste heat utilization and pollutant collaborative treatment system

Abstract

The utility model relates to a sintering flue gas waste heat utilization and pollutant collaborative treatment system, which comprises a circulating fluidized bed boiler, a denitration device and a desulfurization and dust removal device which are connected in sequence, and further comprises a sintering flue gas source which is communicated with the circulating fluidized bed boiler. The flue gas inlet is used for introducing sintering flue gas into the circulating fluidized bed boiler as a combustion improver; sintering flue gas is fed into the circulating fluidized bed boiler to serve as combustion-supporting gas to participate in combustion reaction, combustible pollutants such as carbon monoxide and dioxin in the sintering flue gas are converted in a high-temperature combustion environment in a hearth, additional thermal gain is brought to combustion of the circulating fluidized bed boiler, coal gas consumption is reduced, the operation cost is reduced, and meanwhile, energy is saved. Sulfur dioxide and nitrogen oxide in the sintering flue gas are subjected to desulfurization, denitrification, dust removal and the like under the action of the denitration device and the desulfurization and dust removal device, so that comprehensive treatment of pollutants in the sintering flue gas is completed.

Description

Technical Field

[0001] The utility model relates to the technical field of pollutant treatment, and in particular to a sintering fume waste heat utilization and pollutant coordinated treatment system. Background Art

[0002] At present, the treatment of sintering flue gas mainly adopts the purification process of "dust removal (electrostatic precipitator) + wet or semi-dry desulfurization + gas supplementary combustion + GGH heat exchanger + SCR denitrification".

[0003] However, the boiler in the above system uses coal gas as fuel, which has high operating costs. At the same time, it can only remove sulfur dioxide, nitrogen oxides and dust in the sintering flue gas, but cannot utilize the waste heat in the sintering flue gas. Utility Model Content

[0004] In view of this, it is necessary to provide a sintering flue gas waste heat utilization and pollutant coordinated treatment system to solve the problem that the boiler in the existing sintering flue gas treatment system uses coal gas as fuel, has high operating costs, and can only remove sulfur dioxide, nitrogen oxides and dust in the sintering flue gas, but cannot utilize the waste heat in the sintering flue gas.

[0005] The utility model provides a system for utilizing waste heat from sintering flue gas and coordinating pollutant treatment thereof, comprising a circulating fluidized bed boiler, a denitrification device and a desulfurization and dust removal device connected in sequence, and also comprising a sintering flue gas source, which is connected to the circulating fluidized bed boiler and is used for introducing the sintering flue gas into the circulating fluidized bed boiler as a combustion aid.

[0006] Furthermore, it also includes a first fan and a first pipeline, and the sintering flue gas source is connected to the circulating fluidized bed boiler via the first fan and the first pipeline in sequence.

[0007] Furthermore, a limestone injection device is installed in the circulating fluidized bed boiler.

[0008] Furthermore, it also includes a second pipe and a third pipe arranged vertically, the circulating fluidized bed boiler is connected to the top of the second pipe, the bottom of the second pipe is connected to the bottom of the third pipe, the top of the third pipe is connected to the desulfurization and dust removal device, and the denitrification device is installed in the second pipe.

[0009] Furthermore, it also includes two air preheaters respectively installed in the second pipeline and the third pipeline, and the first pipeline is connected to the two air preheaters in sequence.

[0010] Furthermore, it also includes a cyclone separator, which is connected to the top of the circulating fluidized bed boiler and has an exhaust port and a waste outlet. The exhaust port of the cyclone separator is connected to the top of the second pipeline, and the waste outlet of the cyclone separator is connected to the bottom of the circulating fluidized bed boiler.

[0011] Furthermore, it also includes a steam system, a first economizer and a second economizer, and the steam system, the first economizer, the denitrification device and the second economizer are arranged in sequence in the second pipeline along a vertical downward direction.

[0012] Furthermore, it also includes a condensate heat exchanger installed in the third pipeline.

[0013] Furthermore, it also includes a second fan, and the exhaust end of the desulfurization and dust removal device is externally connected to the second fan.

[0014] Furthermore, there are multiple first fans and one-to-one corresponding first pipelines.

[0015] Compared with the existing technology, the sintering flue gas is sent into the circulating fluidized bed boiler to act as a combustion-supporting gas to participate in the combustion reaction. The combustible pollutants such as carbon monoxide and dioxins in the sintering flue gas are converted in the high-temperature combustion environment in the furnace, which brings additional heat gain to the combustion of the circulating fluidized bed boiler, reduces gas consumption, and reduces operating costs. At the same time, the sulfur dioxide and nitrogen oxides in the sintering flue gas are desulfurized, denitrified and dusted under the action of the denitrification device and the desulfurization and dust removal device, thereby completing the comprehensive treatment of pollutants in the sintering flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall structure of the system for utilizing sintering flue gas waste heat and coordinating pollutants provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0017] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0018] The utility model provides a system for utilizing waste heat from sintering flue gas and coordinating pollutant treatment thereof, comprising a circulating fluidized bed boiler 100, a denitrification device 200 and a desulfurization and dust removal device 300 connected in sequence, and also comprising a sintering flue gas source 400, which is connected to the circulating fluidized bed boiler 100 and is used to introduce the sintering flue gas into the circulating fluidized bed boiler 100 as a combustion aid.

[0019] During implementation, the sintering flue gas is sent to the circulating fluidized bed boiler 100 to act as a combustion-supporting gas and participate in the combustion reaction. Combustible pollutants such as carbon monoxide and dioxins in the sintering flue gas are converted in the high-temperature combustion environment in the furnace, which brings additional heat gain to the combustion of the circulating fluidized bed boiler 100, reduces gas consumption, and reduces operating costs. At the same time, the sulfur dioxide and nitrogen oxides in the sintering flue gas are desulfurized, denitrified, and dusted under the action of the denitrification device 200 and the desulfurization and dust removal device 300, thereby completing the comprehensive treatment of pollutants in the sintering flue gas.

[0020] In addition, the waste heat and waste energy of sintering flue gas can be effectively utilized in the boiler. On the one hand, the carbon monoxide in the sintering flue gas burns in the furnace to bring additional heat gain; on the other hand, the sintering flue gas with a higher temperature is used as a combustion-supporting gas, and the sensible heat of the sintering flue gas can be further utilized in the boiler. Through these two effects, the boiler efficiency is significantly improved.

[0021] The circulating fluidized bed boiler 100 in this embodiment uses coal gas as fuel, which is a structure that can be imagined by those skilled in the art and will not be further elaborated and illustrated here.

[0022] The sintering flue gas source 400 in this embodiment is connected to the circulating fluidized bed boiler 100 to introduce the sintering flue gas into the circulating fluidized bed boiler 100 as a combustion aid.

[0023] In order to facilitate the introduction of sintering flue gas into the circulating fluidized bed boiler 100 , in one embodiment, a first fan 410 and a first pipeline 420 are further included, and the sintering flue gas source 400 is connected to the circulating fluidized bed boiler 100 via the first fan 410 and the first pipeline 420 in sequence.

[0024] In one embodiment, there are multiple first fans 410 and first pipelines 420 in one-to-one correspondence, so as to increase the delivery rate of the sintering fume.

[0025] The sintering flue gas introduced into the circulating fluidized bed boiler 100 has a certain amount of thermal energy, which can be supplied to the circulating fluidized bed boiler 100 to save gas loss. At the same time, combustible pollutants such as carbon monoxide and dioxins in the sintering flue gas are converted as combustion aids in the high-temperature combustion environment of the circulating fluidized bed boiler 100, further saving gas loss. At the same time, combustible pollutants such as carbon monoxide and dioxins are effectively removed.

[0026] To facilitate the removal of sulfur dioxide gas in the circulating fluidized bed boiler 100, in one embodiment, a limestone injection device 110 is installed in the circulating fluidized bed boiler 100 to achieve desulfurization treatment. At the same time, the carbon monoxide gas in the circulating fluidized bed boiler 100 reacts with nitrogen oxides to reduce the nitrogen oxides to generate nitrogen.

[0027] In one embodiment, the system further includes a cyclone separator 500, which is connected to the top of the circulating fluidized bed boiler 100 and has an exhaust port and a waste outlet. The exhaust port of the cyclone separator 500 is connected to the top of the second pipeline 120, and the waste outlet of the cyclone separator 500 is connected to the bottom of the circulating fluidized bed boiler 100, so as to separate the lime particles and the solid particles mixed in the sintering flue gas.

[0028] After completing the preliminary desulfurization and denitrification treatment in the circulating fluidized bed boiler 100, in order to ensure the accuracy of the desulfurization and denitrification treatment of the sintering flue gas, the present embodiment also includes a denitrification device 200 and a desulfurization and dust removal device 300. The sintering flue gas discharged from the circulating fluidized bed boiler 100 passes through the denitrification device 200 and the desulfurization and dust removal device 300 in sequence, and the secondary denitrification and desulfurization treatment has been completed.

[0029] Among them, the working principle of the denitrification device 200 is mainly based on the selective catalytic reduction (SCR) technology and the selective non-catalytic reduction (SNCR) technology, which is a denitrification structure that can be thought of by those skilled in the art.

[0030] Among them, the desulfurization and dust removal device 300 mainly includes a desulfurization cylinder and a dust collector which are connected in sequence. The desulfurization cylinder can be filled with iron oxide, silica gel, activated carbon and other materials. The sintering flue gas enters through the bottom of the desulfurization cylinder and is discharged from the top to the dust collector for dust removal.

[0031] This embodiment also includes a second pipe 120 and a third pipe 130 which are vertically arranged. The circulating fluidized bed boiler 100 is connected to the top of the second pipe 120 , the bottom of the second pipe 120 is connected to the bottom of the third pipe 130 , the top of the third pipe 130 is connected to the desulfurization and dust removal device 300 , and the denitrification device 200 is installed in the second pipe 120 .

[0032] In one embodiment, two air preheaters 430 are further included which are respectively installed in the second pipeline 120 and the third pipeline 130 , and the first pipeline 420 is connected to the two air preheaters 430 in sequence.

[0033] There may be a plurality of air preheaters 430 located in the first duct 420 and the second duct 120 to achieve the function of gradually preheating the sintering flue gas.

[0034] In order to realize the reasonable utilization of the thermal energy of the sintering flue gas, in one embodiment, the system further comprises a steam system 600, a first economizer 700 and a second economizer 800, and the steam system 600, the first economizer 700, the denitrification device 200 and the second economizer 800 are sequentially arranged in the second pipeline 120 along the vertical downward direction. The flue gas temperature at the boiler outlet is reduced to improve the economic efficiency of the thermal system.

[0035] The heating surface of the steam system 600 is located at the second pipeline 120 to absorb the heat energy contained in the sintering flue gas, and the first economizer 700 and the second economizer 800 are used to recover the waste heat in the sintering flue gas.

[0036] In one embodiment, the system further includes a condensate heat exchanger 900 installed in the third pipe 130. The flue gas temperature at the boiler outlet is further reduced, and the economic efficiency of the thermal system is further improved.

[0037] In one embodiment, a second fan 420 is further included, and the exhaust end of the desulfurization and dust removal device 300 is externally connected to the second fan 420 .

[0038] Compared with the prior art: the sintering flue gas is sent into the circulating fluidized bed boiler 100 to act as a combustion-supporting gas to participate in the combustion reaction. Combustible pollutants such as carbon monoxide and dioxins in the sintering flue gas are converted in the high-temperature combustion environment in the furnace, which brings additional heat gain to the combustion of the circulating fluidized bed boiler 100, reduces gas consumption, and reduces operating costs. At the same time, the sulfur dioxide and nitrogen oxides in the sintering flue gas are desulfurized, denitrified, and dusted under the action of the denitrification device 200 and the desulfurization and dust removal device 300, thereby completing the comprehensive treatment of pollutants in the sintering flue gas.

[0039] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention.

Claims

1. A system for utilizing waste heat from sintering flue gas and coordinating pollutants therefrom, characterized in that: It comprises a circulating fluidized bed boiler, a denitrification device and a desulfurization and dust removal device which are connected in sequence, and also comprises a sintering flue gas source which is connected to the circulating fluidized bed boiler and is used for introducing the sintering flue gas as a combustion aid into the circulating fluidized bed boiler.

2. The sintering flue gas waste heat utilization and pollutant coordinated treatment system according to claim 1 is characterized in that: It also includes a first fan and a first pipeline, and the sintering flue gas source is connected to the circulating fluidized bed boiler via the first fan and the first pipeline in sequence.

3. The sintering flue gas waste heat utilization and pollutant coordinated treatment system according to claim 1 is characterized in that: A limestone injection device is installed in the circulating fluidized bed boiler.

4. The sintering flue gas waste heat utilization and pollutant coordinated treatment system according to claim 2 is characterized in that: It also includes a second pipe and a third pipe arranged vertically, the circulating fluidized bed boiler is connected to the top of the second pipe, the bottom of the second pipe is connected to the bottom of the third pipe, the top of the third pipe is connected to the desulfurization and dust removal device, and the denitrification device is installed in the second pipe.

5. The sintering flue gas waste heat utilization and pollutant coordinated treatment system according to claim 4 is characterized in that: It also includes two air preheaters respectively installed in the second pipeline and the third pipeline, and the first pipeline is connected to the two air preheaters in sequence.

6. The sintering flue gas waste heat utilization and pollutant coordinated treatment system according to claim 4 is characterized in that: It also includes a cyclone separator, which is connected to the top of the circulating fluidized bed boiler and has an exhaust port and a waste outlet. The exhaust port of the cyclone separator is connected to the top of the second pipeline, and the waste outlet of the cyclone separator is connected to the bottom of the circulating fluidized bed boiler.

7. The sintering flue gas waste heat utilization and pollutant coordinated treatment system according to claim 4 is characterized in that: It also includes a steam system, a first economizer and a second economizer. The steam system, the first economizer, the denitrification device and the second economizer are arranged in sequence in the second pipeline along a vertical downward direction.

8. The sintering flue gas waste heat utilization and pollutant coordinated treatment system according to claim 4 is characterized in that: It also includes a condensate heat exchanger installed in the third pipeline.

9. The sintering flue gas waste heat utilization and pollutant coordinated treatment system according to claim 1 is characterized in that: It also includes a second fan, and the exhaust end of the desulfurization and dust removal device is externally connected to the second fan.

10. The sintering flue gas waste heat utilization and pollutant coordinated treatment system according to claim 2 is characterized in that: There are multiple first fans and one-to-one corresponding first pipelines.

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