CN109999656B - Combined treatment system and flue gas treatment method for realizing full-working-condition desulfurization and denitration of flue gas circulating fluidized bed desulfurization and SCR denitration - Google Patents
Combined treatment system and flue gas treatment method for realizing full-working-condition desulfurization and denitration of flue gas circulating fluidized bed desulfurization and SCR denitration Download PDFInfo
- Publication number
- CN109999656B CN109999656B CN201910374857.2A CN201910374857A CN109999656B CN 109999656 B CN109999656 B CN 109999656B CN 201910374857 A CN201910374857 A CN 201910374857A CN 109999656 B CN109999656 B CN 109999656B
- Authority
- CN
- China
- Prior art keywords
- flue gas
- flue
- gas treatment
- desulfurization
- fluidized bed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 title claims abstract description 566
- 239000003546 flue gas Substances 0.000 title claims abstract description 566
- 238000011282 treatment Methods 0.000 title claims abstract description 182
- 238000006477 desulfuration reaction Methods 0.000 title claims abstract description 123
- 230000023556 desulfurization Effects 0.000 title claims abstract description 123
- 238000000034 method Methods 0.000 title claims abstract description 27
- 238000004064 recycling Methods 0.000 claims abstract description 43
- 239000000428 dust Substances 0.000 claims description 62
- 238000010438 heat treatment Methods 0.000 claims description 39
- 238000010521 absorption reaction Methods 0.000 claims description 38
- 239000002250 absorbent Substances 0.000 claims description 24
- 230000002745 absorbent Effects 0.000 claims description 24
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 18
- 238000005507 spraying Methods 0.000 claims description 17
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 15
- 238000006243 chemical reaction Methods 0.000 claims description 12
- 229910021529 ammonia Inorganic materials 0.000 claims description 9
- 238000002347 injection Methods 0.000 claims description 4
- 239000007924 injection Substances 0.000 claims description 4
- 238000011284 combination treatment Methods 0.000 claims 1
- 230000007613 environmental effect Effects 0.000 abstract description 4
- 239000007789 gas Substances 0.000 abstract description 4
- 238000005245 sintering Methods 0.000 description 25
- 239000000779 smoke Substances 0.000 description 13
- 230000001360 synchronised effect Effects 0.000 description 7
- 239000006227 byproduct Substances 0.000 description 6
- 229910000831 Steel Inorganic materials 0.000 description 4
- 239000011575 calcium Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 238000002955 isolation Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- 235000011114 ammonium hydroxide Nutrition 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 239000003344 environmental pollutant Substances 0.000 description 2
- 239000004744 fabric Substances 0.000 description 2
- 230000017525 heat dissipation Effects 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 231100000719 pollutant Toxicity 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 238000005496 tempering Methods 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000005453 pelletization Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/02—Particle separators, e.g. dust precipitators, having hollow filters made of flexible material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
- B01D53/1456—Removing acid components
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
- B01D53/1456—Removing acid components
- B01D53/1481—Removing sulfur dioxide or sulfur trioxide
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/8621—Removing nitrogen compounds
- B01D53/8625—Nitrogen oxides
- B01D53/8631—Processes characterised by a specific device
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2062—Ammonia
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2252/00—Absorbents, i.e. solvents and liquid materials for gas absorption
- B01D2252/10—Inorganic absorbents
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2257/00—Components to be removed
- B01D2257/20—Halogens or halogen compounds
- B01D2257/204—Inorganic halogen compounds
- B01D2257/2045—Hydrochloric acid
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/02—Other waste gases
- B01D2258/0283—Flue gases
Abstract
The invention belongs to the field of environmental protection, and particularly relates to a combined treatment system and a flue gas treatment method for realizing full-working-condition desulfurization and denitration of a flue gas circulating fluidized bed. The invention provides a treatment system which comprises a primary flue, first flue gas treatment equipment, second flue gas treatment equipment and a clean flue which are sequentially connected along the movement direction of flue gas, wherein the primary flue is sequentially provided with a windshield and a recycling flue gas inlet; the clean flue is sequentially provided with an induced draft fan, a recycling flue gas outlet and a clean flue gas discharge port, the gas outlet end of the recycling flue gas outlet is connected with the gas inlet end of the recycling flue gas inlet through the recycling flue, and the recycling flue is provided with a windshield. The treatment system provided by the invention can utilize the recycling flue to lead the high-temperature flue gas at the outlet of the induced draft fan back to the flue gas inlet of the first flue gas treatment equipment, so that the flue gas treatment system is quickly preheated, and the desulfurization and denitrification of the flue gas generating equipment under full working conditions such as a startup and shutdown stage, a low-load working condition and the like are realized.
Description
Technical Field
The invention belongs to the field of environmental protection, and particularly relates to a combined treatment system and a flue gas treatment method for realizing full-working-condition desulfurization and denitration of a flue gas circulating fluidized bed.
Background
The steel sintering and pelletizing are SO 2 And NO x The important source of emission is that part of 2018 area begins to require steel sintering and pellet to realize ultra-low emission, and the emission limit values of particulate matters, sulfur dioxide and nitrogen oxides are respectively 10mg/Nm under the condition that the standard oxygen content of the flue gas of a sintering machine head (pellet roasting) is 16 percent 3 、35mg/Nm 3 、50mg/Nm 3 。
At present, semi-dry process and dry process are mainly selected for desulfurization in non-electric industries such as steel sintering and the like, and SCR denitration is mainly selected for denitration. The Chinese patent with the patent number of CN201320565147 discloses a sintering flue gas desulfurization and denitrification device, and the working flow of the device is as follows: the flue gas to be purified is firstly treated in a pre-deduster, then enters an SCR denitration device after being heated by a GGH heat exchanger and a burner, and then is treated in a desulfurization device and a dedusting device in sequence and finally is discharged into a chimney. Although the device has good desulfurization and denitrification effects under the normal operation working condition of the sintering machine, the device can not meet the emission requirements at the starting stage of the sintering machine. The reason is that the temperature of smoke is low (generally about 10 ℃) within 2-4 hours of starting the sintering machine, and the technology is provided with a heating device such as a smoke heat exchanger, a burner and the like, but the heating device cannot quickly heat the smoke to the required temperature due to the excessively low temperature of inlet smoke at the starting stage, so that desulfurization and desulfurization equipment cannot be put into operation.
In recent years, environmental problems are increasingly serious, and the technical problem to be solved by the technicians in the field is how to realize the full-working-condition operation of desulfurization and denitrification equipment in the non-electric industries such as steel sintering and the like in the face of increasingly strict environmental requirements.
Disclosure of Invention
Therefore, the invention aims to provide a combined treatment system and a flue gas treatment method for realizing full-working-condition desulfurization and denitrification of a flue gas circulating fluidized bed desulfurization and SCR denitrification, and the treatment system provided by the invention can be used in a flue gas generating deviceThe rapid preheating is carried out before the starting, SO that the operation desulfurization and denitrification of the flue gas generating equipment in the starting and stopping stage, the low-load working condition and other full working conditions are realized, and the SO in the whole process from the starting to the closing of the flue gas generating equipment is ensured 2 And NO x The emission meets the emission requirements.
The invention provides a combined treatment system for realizing full-working-condition desulfurization and denitration of a flue gas circulating fluidized bed, which comprises a primary flue, first flue gas treatment equipment, second flue gas treatment equipment and a clean flue, wherein the primary flue, the first flue gas treatment equipment, the second flue gas treatment equipment and the clean flue are sequentially connected along the movement direction of flue gas, and the primary flue is sequentially provided with a windshield and a recycling flue gas inlet; the air outlet end of the recycling flue gas outlet is connected with the air inlet end of the recycling flue gas inlet through the recycling flue, and a windshield is arranged on the recycling flue;
the first flue gas treatment equipment is circulating fluidized bed desulfurization dust removal equipment, and the second flue gas treatment equipment is SCR denitration equipment; or the first flue gas treatment equipment is SCR denitration equipment, and the second flue gas treatment equipment is circulating fluidized bed desulfurization dust removal equipment;
the SCR denitration device includes: the flue gas heat exchanger is provided with a raw flue gas inlet, a raw flue gas outlet, a clean flue gas inlet and a clean flue gas outlet; the flue gas heating device is arranged on a connecting flue of the SCR denitration reactor connected with an original flue gas outlet of the flue gas heat exchanger, and a denitration flue gas outlet of the SCR denitration reactor is connected with a clean flue gas inlet of the flue gas heat exchanger.
Preferably, the recycling flue is provided with a recycling branch flue, the air outlet end of the recycling branch flue is connected with the flue gas inlet of the second flue gas treatment device, and the recycling branch flue is provided with a windshield.
Preferably, a windshield and a recirculation branch flue gas inlet are sequentially arranged on a flue connecting the first flue gas treatment device and the second flue gas treatment device along the flue gas movement direction, and the air outlet end of the recirculation branch flue is connected with the recirculation branch flue gas inlet.
Preferably, the heat source of the flue gas heating device is hot flue gas.
Preferably, the circulating fluidized bed desulfurization dust removal device comprises:
a circulating fluidized bed desulfurization absorption tower which is provided with a flue gas inlet and a desulfurization flue gas outlet,
an absorbent feeding device for feeding absorbent into the circulating fluidized bed desulfurization absorption tower;
atomized water injection means for injecting atomized water into the circulating fluidized bed desulfurization absorption tower;
and the dust remover is connected with the desulfurization flue gas outlet.
Preferably, an air chute is arranged at the bottom of the dust remover, and the air chute is connected with the circulating fluidized bed desulfurization absorption tower.
Preferably, the dust remover is a cloth bag dust remover.
Preferably, no induced draft fan is arranged on a flue connecting the first flue gas treatment device and the second flue gas treatment device.
Preferably, the flue gas purification device further comprises a chimney, wherein a flue gas inlet of the chimney is connected with a clean flue gas discharge port of the clean flue.
The invention provides a flue gas treatment method in the treatment system according to the technical scheme, which comprises the following steps:
a) Closing a windshield arranged on the original flue, opening the windshield arranged on the recycling flue, and simultaneously opening the induced draft fan, the flue gas heat exchanger and the flue gas heating device to circularly heat the flue gas in the system;
b) After the flue gas at the inlet of the SCR denitration reactor reaches the reaction temperature allowing ammonia spraying, starting flue gas generating equipment connected with the original flue, starting a windshield arranged on the original flue, and then sequentially treating the flue gas generated by the flue gas generating equipment in the first flue gas treatment equipment and the second flue gas treatment equipment to obtain purified flue gas.
And at presentCompared with the prior art, the invention provides a combined treatment system and a flue gas treatment method for realizing full-working-condition desulfurization and denitration of a flue gas circulating fluidized bed. The treatment system provided by the invention comprises an original flue, first flue gas treatment equipment, second flue gas treatment equipment and a clean flue which are sequentially connected along the movement direction of flue gas, wherein the original flue is sequentially provided with a windshield and a recycling flue gas inlet; the air outlet end of the recycling flue gas outlet is connected with the air inlet end of the recycling flue gas inlet through the recycling flue, and a windshield is arranged on the recycling flue; the first flue gas treatment equipment is circulating fluidized bed desulfurization dust removal equipment, and the second flue gas treatment equipment is SCR denitration equipment; or the first flue gas treatment equipment is SCR denitration equipment, and the second flue gas treatment equipment is circulating fluidized bed desulfurization dust removal equipment; the SCR denitration device includes: the flue gas heat exchanger is provided with a raw flue gas inlet, a raw flue gas outlet, a clean flue gas inlet and a clean flue gas outlet; the flue gas heating device is arranged on a connecting flue of the SCR denitration reactor connected with an original flue gas outlet of the flue gas heat exchanger, and a denitration flue gas outlet of the SCR denitration reactor is connected with a clean flue gas inlet of the flue gas heat exchanger. The main flow of the flue gas treatment system for treating the flue gas is as follows: a) Closing a windshield arranged on the original flue, opening the windshield arranged on the recycling flue, and simultaneously opening the induced draft fan, the flue gas heat exchanger and the flue gas heating device to circularly heat the flue gas in the system; b) After the flue gas at the inlet of the SCR denitration reactor reaches the reaction temperature allowing ammonia spraying, starting flue gas generating equipment connected with the original flue, starting a windshield arranged on the original flue, and then sequentially treating the flue gas generated by the flue gas generating equipment in the first flue gas treatment equipment and the second flue gas treatment equipment to obtain purified flue gas. The system provided by the invention is provided with the recycling flue at the outlet of the induced draft fan of the clean flue, and the recycling flue can be used for guiding the high-temperature flue gas at the outlet of the induced draft fan back to the first flue gas by adjusting the opening and closing of each windshield in the systemThe flue gas inlet of the gas treatment equipment is used for quickly preheating the flue gas treatment system, SO that the operation desulfurization and denitrification of the flue gas generation equipment under full working conditions such as a startup and shutdown stage, a low-load working condition and the like are realized, and the SO (SO) in the whole process from startup to shutdown of the flue gas generation equipment is ensured 2 And NO x The emission meets the emission requirement, and the problem that the denitration ultralow emission cannot be realized because the smoke temperature is low in the initial stage of starting the engine in the prior art is avoided. In the preferred technical scheme provided by the invention, the first flue gas treatment equipment and the second flue gas treatment equipment are directly connected by adopting a flue (namely, no induced draft fan is arranged between the first flue gas treatment equipment and the second flue gas treatment equipment), so that the energy is saved; meanwhile, as the flue is directly connected, the flue gas inlet flue of the SCR denitration reactor is high in negative pressure, the problem of tempering and positive pressure emission can not occur in a direct hot-blast stove hearth matched with the flue gas heating device, and the control is simpler. In another preferred technical scheme provided by the invention, the isolation baffle is additionally arranged at the hearth outlet flue of the direct hot blast stove for controlling the hearth negative pressure, so that the problem that the hot blast stove is easy to flameout and difficult to ignite due to high hearth negative pressure can be avoided.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of a flue gas treatment system provided by an embodiment of the present invention;
FIG. 2 is a schematic structural view of a circulating fluidized bed desulfurization dust-removing device provided by an embodiment of the invention;
fig. 3 is a schematic structural diagram of an SCR denitration device according to an embodiment of the present invention;
FIG. 4 is a flow diagram of a flue gas treatment system provided with a recirculation bypass flue according to an embodiment of the present invention;
FIG. 5 is a flow chart of a flue gas treatment system with desulfurization followed by denitrification provided in example 1 of the present invention;
fig. 6 is a flow chart of a flue gas treatment system for denitration followed by desulfurization according to embodiment 1 of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention provides a combined treatment system for realizing full-working-condition desulfurization and denitration of a flue gas circulating fluidized bed, which comprises a primary flue, first flue gas treatment equipment, second flue gas treatment equipment and a clean flue, wherein the primary flue, the first flue gas treatment equipment, the second flue gas treatment equipment and the clean flue are sequentially connected along the movement direction of flue gas, and the primary flue is sequentially provided with a windshield and a recycling flue gas inlet; the air outlet end of the recycling flue gas outlet is connected with the air inlet end of the recycling flue gas inlet through the recycling flue, and a windshield is arranged on the recycling flue;
the first flue gas treatment equipment is circulating fluidized bed desulfurization dust removal equipment, and the second flue gas treatment equipment is SCR denitration equipment; or the first flue gas treatment equipment is SCR denitration equipment, and the second flue gas treatment equipment is circulating fluidized bed desulfurization dust removal equipment;
the SCR denitration device includes: the flue gas heat exchanger is provided with a raw flue gas inlet, a raw flue gas outlet, a clean flue gas inlet and a clean flue gas outlet; the flue gas heating device is arranged on the connecting flue of the SCR denitration reactor connected with the original flue gas outlet of the flue gas heat exchanger, and the gas outlet of the SCR denitration reactor is connected with the clean flue gas inlet of the flue gas heat exchanger.
Referring to fig. 1 to 4, fig. 1 is a flow chart of a flue gas treatment system provided by an embodiment of the present invention, in fig. 1, 1 represents a primary flue, 2 represents a primary flue windshield, 3 represents a recirculated flue gas inlet, 4 represents a first flue gas treatment device, 5 represents a flue connecting the first flue gas treatment device and the second flue gas treatment device, 6 represents a second flue gas treatment device, 7 represents a clean flue, 8 represents an induced draft fan, 9 represents a recirculated flue gas outlet, 10 represents a clean flue gas discharge port, 11 represents a recirculated flue, and 12 represents a recirculated flue windshield; fig. 2 is a schematic structural diagram of a circulating fluidized bed desulfurization dust-removing device provided by the embodiment of the invention, in fig. 2, A1 represents an absorbent feeding device, A2 represents an atomized water spraying device, A3 represents a circulating fluidized bed desulfurization absorption tower, A4 represents a dust remover, A5 represents a dust remover flue gas outlet, A6 represents an air chute, and A7 represents a desulfurization by-product discharge port; fig. 3 is a schematic structural diagram of an SCR denitration device according to an embodiment of the present invention, in fig. 3, B1 represents a flue gas heat exchanger (abbreviated as GGH), B2 represents a flue gas heating device, B3 represents an SCR denitration reactor, a represents an original flue gas inlet, B represents an original flue gas outlet, c represents a clean flue gas inlet, and d represents a clean flue gas outlet; fig. 4 is a flowchart of a flue gas treatment system provided with a recirculation bypass flue according to an embodiment of the present invention, and in fig. 4, reference numerals 1 to 12 refer to fig. 1, 13 denote recirculation bypass flue, 14 denote recirculation bypass flue damper, and 15 denote flue damper connection between a first flue gas treatment device and a second flue gas treatment device.
Along the motion direction of the flue gas, the flue gas treatment system provided by the invention comprises a primary flue 1, a first flue gas treatment device 4, a second flue gas treatment device 6 and a clean flue 7 which are sequentially connected. Wherein, a windshield 2 and a recirculated flue gas inlet 3 are sequentially arranged on the original flue 1.
In the invention, a first flue gas treatment device 4 is provided with a flue gas inlet and a flue gas outlet, the flue gas inlet of the first flue gas treatment device 4 is connected with the air outlet end of the original flue 1, and the first flue gas treatment device 4 is specifically a circulating fluidized bed desulfurization dust removal device or an SCR denitration device. In one embodiment provided by the invention, the circulating fluidized bed desulfurization dust removal device comprises an absorbent feeding device A1, an atomized water spraying device A2, a circulating fluidized bed desulfurization absorption tower A3 and a dust remover A4, wherein the absorbent feeding device A1 is used for feeding absorbent into the circulating fluidized bed desulfurization absorption tower A3; the atomized water injection device A2 is used for injecting atomized water into the circulating fluidized bed desulfurization absorption tower A3; the circulating fluidized bed desulfurization absorption tower A3 is provided with a flue gas inlet and a desulfurization flue gas outlet. In one embodiment provided by the invention, along the movement direction of the flue gas, the position of the absorbent feeding device A1 for feeding the absorbent and the position of the atomized water spraying device A2 for spraying the atomized water are sequentially arranged in the tower body. In one embodiment provided by the invention, the flue gas inlet of the circulating fluidized bed desulfurization absorption tower A3 is positioned at the bottom of the tower, the desulfurization flue gas outlet is positioned at the top of the tower, the position of the atomized water spraying device A2 for spraying atomized water is close to the flue gas inlet of the circulating fluidized bed desulfurization absorption tower A3, and the position of the absorbent feeding device A1 for feeding the absorbent is positioned above. In the invention, a flue gas inlet and a flue gas outlet A5 of the dust remover are arranged on the dust remover A4, and the flue gas inlet of the dust remover A4 is connected with a desulfurization flue gas outlet of the circulating fluidized bed desulfurization absorption tower A3. In one embodiment provided by the invention, the bottom of the dust remover A4 is provided with an air chute A6, and the air chute A6 is connected with the circulating fluidized bed desulfurization absorption tower A3 and is used for conveying unreacted materials trapped by the dust remover back to the circulating fluidized bed desulfurization absorption tower A3 to continuously participate in the reaction. In one embodiment provided by the invention, the connection position of the air chute A6 and the circulating fluidized bed desulfurization absorption tower A3 is positioned at the upstream of the position where the absorbent is added by the absorbent feeding device A1 along the movement direction of the flue gas. In one embodiment provided by the invention, the bottom of the dust remover A4 is provided with a desulfurization by-product outlet A7. In one embodiment provided by the invention, the dust remover A4 is a bag-type dust remover. In the invention, when the first flue gas treatment device 4 is a circulating fluidized bed desulfurization dust removal device, the flue gas inlet of the circulating fluidized bed desulfurization absorption tower A3 is the flue gas inlet of the first flue gas treatment device 4, and the dust remover flue gas outlet A5 of the dust remover A4 is the flue gas outlet of the first flue gas treatment device 4.
In the invention, the SCR denitration device comprises a flue gas heat exchanger B1, a flue gas heating device B2 and an SCR denitration reactor B3. The flue gas heat exchanger B1 is provided with a raw flue gas inlet a, a raw flue gas outlet B, a clean flue gas inlet c and a clean flue gas outlet d. In the invention, a flue gas inlet and a denitration flue gas outlet are arranged in the SCR denitration reactor B3, the flue gas inlet of the SCR denitration reactor B3 is connected with the raw flue gas outlet B, and the denitration flue gas outlet of the SCR denitration reactor B3 is connected with the clean flue gas inlet c. In the invention, a flue gas heating device B2 is arranged on a connecting flue of an original flue gas outlet B and a flue gas inlet of the SCR denitration reactor B3 and is used for heating flue gas entering the SCR denitration reactor B3. In one embodiment provided by the invention, the heat source of the flue gas heating device B2 is hot flue gas, the hot flue gas is provided by a direct hot blast stove, and a hearth outlet flue of the direct hot blast stove is provided with an isolation baffle. In the invention, when the first flue gas treatment device 4 is an SCR denitration device, the raw flue gas inlet a is a flue gas inlet of the first flue gas treatment device 4, and the clean flue gas outlet d is a flue gas outlet of the first flue gas treatment device 4.
In the invention, the second flue gas treatment device 6 is provided with a flue gas inlet and a flue gas outlet, and the flue gas inlet of the second flue gas treatment device 6 is connected with the flue gas outlet of the first flue gas treatment device 4 through a flue 5. In the invention, when the first flue gas treatment device 4 is a circulating fluidized bed desulfurization dust removal device, the second flue gas treatment device 6 is an SCR denitration device; when the first flue gas treatment device 4 is an SCR denitration device, the second flue gas treatment device 6 is a circulating fluidized bed desulfurization dust removal device. In the present invention, the circulating fluidized bed desulfurization dust removal device and the SCR denitration device have been described above, and are not described herein, and it should be noted that, when the second flue gas treatment device 6 is the circulating fluidized bed desulfurization dust removal device, the flue gas inlet of the circulating fluidized bed desulfurization absorption tower A3 is the flue gas inlet of the second flue gas treatment device 6, and the flue gas outlet of the dust remover A4 is the flue gas outlet of the second flue gas treatment device 6; when the second flue gas treatment device 6 is an SCR denitration device, the raw flue gas inlet a is a flue gas inlet of the second flue gas treatment device 6, and the clean flue gas outlet d is a flue gas outlet of the second flue gas treatment device 6. In one embodiment provided by the invention, no induced draft fan is arranged on the flue 5 connecting the first flue gas treatment device 4 and the second flue gas treatment device 6.
In the invention, the air inlet end of the clean flue 7 is connected with the flue gas outlet of the second flue gas treatment equipment 6, and an induced draft fan 8, a recirculated flue gas outlet 9 and a clean flue gas discharge port 10 are sequentially arranged on the clean flue 7 along the flue gas movement direction. Wherein, the air outlet end of the recirculation flue gas outlet 9 is connected with the air inlet end of the recirculation flue gas inlet 3 through a recirculation flue 11, and a windshield 12 is arranged on the recirculation flue 11. In one embodiment provided by the invention, the recycling flue 11 is further provided with a recycling branch flue 13, the air outlet end of the recycling branch flue 13 is connected with the flue gas inlet of the second flue gas treatment device 6, and the recycling branch flue 13 is provided with a windshield 14. In one embodiment provided by the invention, a windshield 15 and a recycling branch flue gas inlet are sequentially arranged on a flue 5 connecting the first flue gas treatment device 4 and the second flue gas treatment device 6 along the flue gas movement direction, and the air outlet end of the recycling branch flue 13 is connected with the recycling branch flue gas inlet.
For the sake of clarity, the following describes the main flow of flue gas treatment in the flue gas treatment system provided by the present invention, taking the first flue gas treatment device 4 as a circulating fluidized bed desulfurization dust removal device and the second flue gas treatment device 6 as an SCR denitration device as an example:
1) The flue gas that flue gas generating equipment (like sintering machine) produced can get into flue gas processing system from former flue 1, and the flue gas is through circulating fluidized bed desulfurization dust collecting equipment in proper order, and former flue gas of flue gas heat exchanger B1 advances, exports, flue gas heating device B2, SCR denitration reactor B3, and the clean flue gas of flue gas heat exchanger B1 advances, exports, outwards discharges through draught fan 8 again, and the low reaches of draught fan 8 are connected with recycle flue 11, and the flue gas can directly utilize both ends pressure differential, returns circulating fluidized bed desulfurization dust collecting equipment's entry flue.
2) In order to meet the requirement of synchronous denitration during start-up, before the flue gas generating equipment starts up for 2-4 hours (the time for starting up in advance is determined according to the reaction temperature condition required by denitration), the flue gas heat exchanger B1 is started, the original flue damper 2 is closed, the recirculation flue damper 12 is fully opened, the induced draft fan 8 is slowly started, and the air quantity is slowly pulled up to the required flue gas quantity by the induced draft fan. Simultaneously, the flue gas heating device B2 is started to heat the flue gas entering the SCR denitration reactor B3, the heating rate is controlled in a proper range (50-90 ℃/h, and is specifically determined according to the maximum heating rate of the GGH), and the GGH is ensured not to be blocked due to rapid thermal deformation.
3) Along with the continuous cyclic heating of the flue gas, the flue gas is heated up quickly, and simultaneously, a proper absorbent bed layer is built in a desulfurization absorption tower of the circulating fluidized bed desulfurization dust removal device in advance before the flue gas generation device is started. After 2-4 hours, the temperature at the flue gas inlet of the SCR denitration reactor B3 reaches the reaction temperature (200-280 ℃) of the catalyst for allowing ammonia spraying, at the moment, the main exhaust fan of the flue gas generating device is started slowly, the original flue windshield 2 is opened, and the recirculation flue windshield 12 is regulated and closed slowly, so that the flue gas to be treated by the flue gas generating device is introduced slowly, and ammonia spraying can be performed at the flue gas inlet of the SCR denitration reactor B3 as required to perform synchronous denitration.
4) SO in flue gas 2 、SO 3 、HCl、NO 2 And the pollutants are quickly reacted with the absorbent in the circulating fluidized bed desulfurization dust-removing equipment for removal.
5) The flue gas after desulfurization and dust removal from the circulating fluidized bed desulfurization and dust removal equipment passes through a flue gas heat exchanger B1, exchanges heat with hot flue gas from an SCR denitration reactor B3, heats the flue gas to 20-30 ℃ through a flue gas heating device B2, compensates heat exchange loss, enters the SCR denitration reactor B3 for denitration, enters the flue gas heat exchanger B1 after denitration, and the hot flue gas after heat exchange is discharged outwards through a draught fan 8. Meanwhile, the recirculation flue 11 arranged at the outlet of the induced draft fan can guide the heat-exchanged hot smoke back to the circulating fluidized bed desulfurization dust removal equipment, and the stability of the system under different load working conditions is ensured by adjusting the opening degree of the recirculation flue windshield 12.
6) In the technical scheme provided with the recirculation branch flue 13, if the system needs to be heated more quickly before the flue gas generating equipment is started, after the GGH is started, the first flue gas treatment equipment and the second flue gas treatment equipment are firstly closed to connect the flue windshield 15 and the recirculation flue windshield 12, the recirculation branch flue windshield 14 is opened, the induced draft fan 8 is opened, the flue gas heating device B2 is opened, the recirculation hot flue gas does not pass through the circulating fluidized bed desulfurization dust removal equipment to cool down, the SCR denitration reactor B3 is preheated more quickly, the recirculation flue windshield 12 is opened again before the flue gas generating equipment is started, the first flue gas treatment equipment and the second flue gas treatment equipment are connected with the flue windshield 15, the recirculation branch flue windshield 14 is closed or reduced, the desulfurization bed is built in advance, and the time required by bed building is met. On the one hand, when the SCR denitration reactor is preheated, the heat dissipation loss of the recirculated hot flue gas is smaller, the recirculated flue gas can be preheated more quickly, on the other hand, during the preheating period, the recirculated flue gas does not pass through desulfurization dust removal equipment, the resistance is smaller, and the energy consumption during denitration preheating can be saved.
7) When the flue gas generating device is stopped, the flue gas amount and the flue gas temperature are slowly reduced, and the reverse operation of starting the device is performed, so that the recirculation flue can be utilized, the circulated hot flue gas can be utilized to maintain certain flue gas flow and temperature, the requirement of denitration temperature is met, and full-load desulfurization and denitration are realized.
The system provided by the invention is provided with the recirculation flue at the outlet of the induced draft fan of the clean flue, and the high-temperature flue gas at the outlet of the induced draft fan can be led back to the flue gas inlet of the first flue gas treatment device by utilizing the recirculation flue by adjusting the opening and closing of each windshield in the system, SO that the flue gas treatment system is quickly preheated, the operation desulfurization and denitrification of the flue gas generation device under all working conditions such as a startup and shutdown stage, a low-load working condition and the like are realized, and the SO in the whole process from startup to shutdown of the flue gas generation device is ensured 2 And NO x The emission meets the emission requirement, and the problem that the denitration ultralow emission cannot be realized because the smoke temperature is low in the initial stage of starting the engine in the prior art is avoided.
In the preferred technical scheme provided by the invention, the first flue gas treatment equipment and the second flue gas treatment equipment are directly connected by adopting a flue (namely, no induced draft fan is arranged between the first flue gas treatment equipment and the second flue gas treatment equipment), so that the energy is saved; meanwhile, the flue is directly connected, the negative pressure of the flue gas inlet flue of the SCR denitration reactor is high, the problem of tempering and positive pressure emission can not occur in a direct hot-blast stove hearth matched with the flue gas heating device, and the control is simpler.
In the preferred technical scheme provided by the invention, the isolation baffle is additionally arranged at the hearth outlet flue of the direct hot blast stove for controlling the hearth negative pressure, so that the problem that the hot blast stove is easy to flameout and difficult to ignite due to high hearth negative pressure can be avoided.
The invention also provides a flue gas treatment method in the treatment system according to the technical scheme, which comprises the following steps:
a) Closing a windshield arranged on the original flue, opening the windshield arranged on the recycling flue, and simultaneously opening the induced draft fan, the flue gas heat exchanger and the flue gas heating device to circularly heat the flue gas in the system;
b) After the flue gas at the inlet of the SCR denitration reactor reaches the reaction temperature allowing ammonia spraying, starting flue gas generating equipment connected with the original flue, starting a windshield arranged on the original flue, and then sequentially treating the flue gas generated by the flue gas generating equipment in the first flue gas treatment equipment and the second flue gas treatment equipment to obtain purified flue gas.
In the method, firstly, the opening and closing of each windshield in the system are adjusted to form a smoke circulation loop in the system, so that smoke is circularly heated by a smoke heat exchanger and a smoke heating device arranged in the system.
And after the flue gas at the inlet of the SCR denitration reactor reaches the reaction temperature allowing ammonia spraying, the flue gas generated by the flue gas generating equipment is slowly introduced into the flue gas treatment system by adjusting the opening and closing degree of each windshield in the system under the condition of ensuring that the inlet amount of the flue gas of the first flue gas treatment equipment is stable, and the flue gas generated by the flue gas generating equipment is sequentially treated in the first flue gas treatment equipment and the second flue gas treatment equipment to obtain purified flue gas.
In the present invention, specific conditions for the first flue gas treatment device and the second flue gas treatment device to treat the flue gas are not particularly limited, and a person skilled in the art may select the flue gas based on technical knowledge and actual working conditions.
The flue gas treatment method provided by the invention is carried out in the system, and the method can be used for quickly preheating the whole flue gas treatment system before starting the flue gas generating equipment, so that the flue gas generating equipment is put into operation for desulfurization and denitrification under full working conditions such as a starting and stopping stage, a low-load working condition and the like, and the generation of flue gas is ensuredSO in the whole process from starting up to shutting down of the equipment 2 And NO x The emission meets the emission requirements.
For clarity, the following examples are provided in detail.
Example 1
The present embodiment provides a flue gas treatment system as shown in fig. 5, fig. 5 is a flowchart of a flue gas treatment system with desulfurization followed by denitration provided in embodiment 1 of the present invention, where the flue gas treatment system provided in the present embodiment includes: the connection relationship of the primary flue (not shown in the figure), the primary flue windshield 2, the recycled flue gas inlet 3, the absorbent feeding device A1, the atomized water spraying device A2, the circulating fluidized bed desulfurization absorption tower A3, the dust remover A4 (a bag-type dust remover is selected in the embodiment), the air chute A6, the desulfurization byproduct outer discharge port A7, the first flue gas treatment device and the second flue gas treatment device connection flue 5, the first flue gas treatment device and the second flue gas treatment device connection flue windshield 15, the flue gas heat exchanger B1, the flue gas heating device B2, the SCR denitration reactor B3, the clean flue 7, the induced draft fan 8, the recycled flue gas outlet 9, the clean flue gas discharge port 10, the recycled flue 11, the recycled flue windshield 12, the recycled bypass flue 13 and the recycled bypass flue windshield 14 is shown in fig. 5, and will not be repeated here.
The main flow of the flue gas treatment system provided by the implementation in operation comprises:
1) The flue gas enters from the original flue, then sequentially passes through the original flue gas side of the circulating fluidized bed desulfurization absorption tower A3, the dust remover A4 and the flue gas heat exchanger B1, the flue gas heating device B2, the SCR denitration reactor B3 and the clean flue gas side of the flue gas heat exchanger B1, and then is discharged to a chimney through a draught fan 8 arranged on the clean flue 7, the downstream of the draught fan 8 is connected with a recirculation flue 11 and a recirculation branch flue 13, and the flue gas can directly utilize the pressure difference of two ends to return to the inlet flue of the circulating fluidized bed desulfurization absorption tower A3 and the original flue gas inlet a of the flue gas heat exchanger B1.
2) In order to meet the requirement of synchronous denitration during start-up, before a flue gas generating device (such as a sintering machine) starts up for 2-4 hours (the time for starting up in advance is determined according to the reaction temperature condition required by denitration), a flue gas heat exchanger B1 is started, an original flue gas windshield 2 is closed, a first flue gas treatment device and a second flue gas treatment device are fully opened to be connected with a flue gas windshield 15, a recirculation flue gas windshield 12 is fully opened, a draught fan 8 is slowly opened, and the air quantity is slowly pulled up to the required flue gas quantity by adjusting the draught fan. Simultaneously, the flue gas heating device B2 is started to heat the flue gas entering the SCR denitration reactor B3, the heating rate is controlled in a proper range (50-90 ℃/h, and is specifically determined according to the maximum heating rate of the GGH), and the GGH is ensured not to be blocked due to rapid thermal deformation.
3) Along with the continuous cyclic heating of the flue gas, the flue gas is heated up quickly, and simultaneously, a proper absorbent bed layer is built in the circulating fluidized bed desulfurization absorption tower A3 in advance before the flue gas generating equipment is started. After 2-4 hours, the temperature at the flue gas inlet of the SCR denitration reactor B3 reaches the reaction temperature (200-280 ℃) of the catalyst for allowing ammonia spraying, at the moment, the main exhaust fan of the flue gas generating device is started slowly, the original flue windshield 2 is opened, and the recirculation flue windshield 12 is regulated and closed slowly, so that the flue gas to be treated by the flue gas generating device is introduced slowly, and ammonia spraying can be performed at the flue gas inlet of the SCR denitration reactor B3 as required to perform synchronous denitration.
4) SO in flue gas 2 、SO 3 、HCl、NO 2 And the pollutants are quickly reacted and removed with the calcium-based absorbent in the circulating fluidized bed desulfurization absorption tower A3, and the calcium-based absorbent in the tower is added into the absorption tower through the absorbent feeding device A1. Meanwhile, as the smoke temperature rises, the atomized water injection device A2 is started as required, the temperature of the outlet of the absorption tower is controlled to be 70-110 ℃, and the high-temperature smoke is prevented from damaging the rear cloth bag while high-efficiency desulfurization is ensured.
5) The unreacted materials are collected by a dust remover A4 connected with a desulfurization flue gas outlet of the circulating fluidized bed desulfurization absorption tower A3, most of the unreacted materials are returned to the circulating fluidized bed desulfurization absorption tower A3 through an air chute A4 to continuously participate in the reaction, and a small amount of byproducts after the reaction are discharged through a desulfurization byproduct discharge port A7.
6) Flue gas discharged from a dust-removing flue gas outlet of the dust remover A4 enters a flue gas heat exchanger B1 through an original flue gas inlet a, heat exchange and temperature rise are carried out on the flue gas and hot flue gas discharged from the SCR denitration reactor B3, the heated flue gas is discharged through an original flue gas outlet B and then heated to 20-30 ℃ through a flue gas heating device B2, heat exchange loss is compensated, the flue gas enters the SCR denitration reactor B3 for denitration, the flue gas after denitration enters the flue gas heat exchanger B1 through a clean flue gas inlet c, heat exchange and temperature reduction are carried out on the dust-removing flue gas discharged from the dust remover A4, and the flue gas subjected to heat exchange enters a clean flue 7 after being discharged through a clean flue gas outlet d and then is discharged into a chimney through a draught fan 8. Meanwhile, the opening degree of the recirculated flue damper 12 can be adjusted according to the change condition of the front-end load flue gas quantity, and the clean flue gas is led back to the flue gas inlet of the circulating fluidized bed desulfurization absorption tower A3, so that the stability of the system under different load working conditions is ensured.
7) Except that the clean flue gas after desulfurization and denitrification is led back to the flue gas inlet of the circulating fluidized bed desulfurization absorption tower A3, if the system needs to be heated more quickly before the flue gas generating equipment is started, the first flue gas processing equipment and the second flue gas processing equipment are firstly closed to connect the flue damper 15 and the recirculation flue damper 12 after the GGH is started, the recirculation branch flue damper 14 is opened, the induced draft fan 8 is opened, the flue gas heating device B2 is opened, the recirculation hot flue gas does not pass through the circulating fluidized bed desulfurization and dust removal equipment to cool down, the SCR denitration reactor B3 is preheated more quickly, the recirculation flue damper 12 is opened again before the flue gas generating equipment is started, the first flue gas processing equipment and the second flue gas processing equipment are opened to connect the flue damper 15, the recirculation branch flue damper 14 is closed or reduced, the bed is built in advance, and the time needed by bed building is met. On the one hand, when the SCR denitration reactor is preheated, the heat dissipation loss of the recirculated hot flue gas is smaller, the recirculated flue gas can be preheated more quickly, on the other hand, during the preheating period, the recirculated flue gas does not pass through desulfurization dust removal equipment, the resistance is smaller, and the energy consumption during denitration preheating can be saved.
8) When the flue gas generating device is stopped, the flue gas amount and the flue gas temperature are slowly reduced, and the reverse operation of starting the device is performed, so that the recirculation flue can be utilized, the circulated hot flue gas can be utilized to maintain certain flue gas flow and temperature, the requirement of denitration temperature is met, and full-load desulfurization and denitration are realized.
Example 2
The present embodiment provides a flue gas treatment system as shown in fig. 6, fig. 6 is a flowchart of a flue gas treatment system for denitration followed by desulfurization provided in embodiment 2 of the present invention, where the flue gas treatment system provided in the present embodiment includes: the connection relation of the primary flue (not marked in the figure), the primary flue windshield 2, the recycled flue gas inlet 3, the flue gas heat exchanger B1, the flue gas heating device B2, the SCR denitration reactor B3, the first flue gas treatment device and the second flue gas treatment device is shown in the figure, the absorbent feeding device A1, the atomized water spraying device A2, the circulating fluidized bed desulfurization absorption tower A3, the dust remover A4 (a bag-type dust remover is selected in the embodiment), the air chute A6, the desulfurization byproduct outer discharge port A7, the clean flue 7, the induced draft fan 8, the recycled flue gas outlet 9, the clean flue gas discharge port 10, the recycled flue 11, the recycled flue windshield 12, the recycled branch flue 13 and the recycled branch flue 14 is shown in the figure 6, and is not repeated here.
The main flow of the flue gas treatment system provided by the implementation in operation comprises:
1) The flue gas enters from the original flue, then sequentially passes through the original flue gas side of the flue gas heat exchanger B1, the flue gas heating device B2, the SCR denitration reactor B3, the clean flue gas side of the flue gas heat exchanger B1, the circulating fluidized bed desulfurization absorption tower A3 and the dust remover A4, and then is discharged to a chimney through the induced draft fan 8 arranged on the clean flue 7, the downstream of the induced draft fan 8 is connected with the recirculation flue 11 and the recirculation branch flue 13, and the flue gas can directly utilize the pressure difference of two ends to return to the original flue gas inlet a of the flue gas heat exchanger B1 and the inlet flue of the circulating fluidized bed desulfurization absorption tower A3.
2) In this embodiment, other procedures of the flue gas treatment system during operation may refer to embodiment 1, and will not be described herein.
Example 3
Some 180m 2 The sintering machine uses the flue gas treatment system of the invention, and the flue gas amount is 760000Nm 3 H (standard condition); the temperature of the inlet flue gas under normal working condition is about 100-160 ℃, and the concentration of NOx in the flue gas is about 200-300 mg/Nm 3 ，SO 2 500-1000 mg/Nm 3 . Ca (OH) was used 2 As an absorbent and ammonia water as a denitration reducing agent.
The minimum temperature of flue gas is about 20 ℃ when the sintering machine is started, and the sintering machine is startedAfter the flue gas treatment system is started, the temperature is slowly increased to 100 ℃ in two hours, and according to the conventional device and method, denitration cannot be put into, and before the flue gas treatment system is put into the flue gas treatment system, the NOx emission is 50-200 mg/Nm during the starting period 3 。
After the flue gas treatment system provided by the embodiment 1 of the invention is adopted, the flue gas heat exchanger B1, the induced draft fan 8 and the flue gas heating device B2 are started in advance 2 hours before starting, and the recirculation flue 11 at the outlet of the induced draft fan 8 is utilized for preheating quickly in advance, so that the flue gas temperature at the flue gas inlet of the SCR denitration reactor B3 is preheated to 260-280 ℃. After the sintering is started, sintering flue gas is slowly introduced, the flue gas inlet amount of a system is maintained to be stable by adjusting the opening degree of the recirculated flue damper 12, the temperature at the flue gas inlet of the SCR denitration reactor B3 is always maintained at 260-280 ℃ during the period of introducing sintering cold flue gas, meanwhile, the current of the flue gas heat exchanger B1 is stable, the flue gas heat exchanger B1 is synchronously put into desulfurization and denitration, and the synchronous ultralow emission under the full working condition of starting the machine is realized. During shutdown, the hot flue gas led back by the recirculation flue 11 is also utilized to keep the flue gas temperature and the flue gas quantity of the flue gas inlet of the circulating fluidized bed desulfurization absorption tower A3, so that the desulfurization and denitrification ultralow emission is realized during the shutdown, the desulfurization efficiency can reach more than 99 percent, the denitrification efficiency can reach more than 90 percent, and the dust concentration is less than 5mg/Nm 3 。
Example 4
Some 230m 2 The sintering machine uses the flue gas treatment system of the invention, and the flue gas amount is 920000Nm 3 H (standard condition); the inlet flue gas temperature under normal working condition is about 120-160 ℃, and the concentration of NOx in the flue gas is about 200-350 mg/Nm 3 ，SO 2 500-1000 mg/Nm 3 . Ca (OH) was used 2 As an absorbent and ammonia water as a denitration reducing agent.
The sintering temperature is slowly increased to 90 ℃ after two hours after starting the sintering machine, and according to the conventional device and method, denitration cannot be put into, and before the flue gas treatment system is put into the invention, NOx emission is 50mg/Nm during starting the machine 3 ～250mg/Nm 3 。
After the flue gas treatment system provided by the embodiment 1 of the invention is adopted, the flue gas heat exchanger B1, the induced draft fan 8 and the flue gas heating device B2 are started in advance 2 hours before starting the machine, and the SC is preheated quickly in advance by utilizing the recirculation flue 11 at the outlet of the induced draft fan 8The flue gas temperature at the flue gas inlet of the R denitration reactor B3 is preheated to 260-280 ℃, after sintering is started, sintering flue gas is slowly introduced, the flue gas inlet amount of a system is maintained stable by adjusting the opening degree of a recirculated flue damper 12, and during the period of introducing sintering cold flue gas, the temperature at the flue gas inlet of the SCR denitration reactor B3 is always maintained at 260-280 ℃, meanwhile, the current of a flue gas heat exchanger B1 is stable, and the synchronous investment in desulfurization and denitration is realized, so that the synchronous ultra-low emission is realized. During shutdown, the hot flue gas led back by the recirculation flue 11 is also utilized to keep the flue gas temperature and the flue gas quantity of the flue gas inlet of the circulating fluidized bed desulfurization absorption tower A3, so that the desulfurization and denitrification ultralow emission is realized during the shutdown, the desulfurization efficiency can reach more than 99 percent, the denitrification efficiency can reach more than 90 percent, and the dust concentration is less than 5mg/Nm 3 . At the same time compare other 230m of the same factory area 2 Sintering machine, other two sets of 230m 2 The sintering machine adopts the same dry desulfurization dust removal equipment and SCR denitration equipment, but the desulfurization and denitration equipment is respectively provided with an induced draft fan, no recirculation pipeline is arranged, but the desulfurization and denitration of the full working condition cannot be satisfied, and the power consumption is 20% higher.
The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.
Claims (9)
1. A flue gas treatment method is characterized in that flue gas treatment is carried out in a combined treatment system for realizing full-working-condition desulfurization and denitration of a flue gas circulating fluidized bed desulfurization and SCR denitration;
along the flue gas motion direction, the combination treatment system includes: the original flue, the first flue gas treatment device, the second flue gas treatment device and the clean flue are sequentially connected; the original flue is sequentially provided with a windshield and a recirculated flue gas inlet; the air outlet end of the recycling flue gas outlet is connected with the air inlet end of the recycling flue gas inlet through the recycling flue, and a windshield is arranged on the recycling flue; the first flue gas treatment equipment is circulating fluidized bed desulfurization dust removal equipment, and the second flue gas treatment equipment is SCR denitration equipment; or the first flue gas treatment equipment is SCR denitration equipment, and the second flue gas treatment equipment is circulating fluidized bed desulfurization dust removal equipment; the SCR denitration device includes: the flue gas heat exchanger is provided with a raw flue gas inlet, a raw flue gas outlet, a clean flue gas inlet and a clean flue gas outlet; an SCR denitration reactor connected with an original flue gas outlet of the flue gas heat exchanger is provided with a flue gas heating device on a connecting flue, and a denitration flue gas outlet of the SCR denitration reactor is connected with a clean flue gas inlet of the flue gas heat exchanger;
the specific steps for carrying out the flue gas treatment comprise:
a) Closing a windshield arranged on the original flue, opening the windshield arranged on the recycling flue, and simultaneously opening the induced draft fan, the flue gas heat exchanger and the flue gas heating device to circularly heat the flue gas in the system;
b) After the flue gas at the inlet of the SCR denitration reactor reaches the reaction temperature allowing ammonia spraying, starting flue gas generating equipment connected with the original flue, starting a windshield arranged on the original flue, and then sequentially treating the flue gas generated by the flue gas generating equipment in the first flue gas treatment equipment and the second flue gas treatment equipment to obtain purified flue gas.
2. The flue gas treatment method according to claim 1, wherein the recirculation flue is provided with a recirculation bypass flue, the outlet end of the recirculation bypass flue being connected to the flue gas inlet of the second flue gas treatment device, the recirculation bypass flue being provided with a damper.
3. The flue gas treatment method according to claim 2, wherein a windshield and a recirculation branch flue gas inlet are sequentially arranged on a flue connecting the first flue gas treatment device and the second flue gas treatment device along the flue gas movement direction, and an air outlet end of the recirculation branch flue gas is connected with the recirculation branch flue gas inlet.
4. The flue gas treatment method according to claim 1, wherein the heat source of the flue gas heating device is hot flue gas.
5. The flue gas treatment method according to claim 1, wherein the circulating fluidized bed desulfurization dust removal apparatus comprises:
a circulating fluidized bed desulfurization absorption tower which is provided with a flue gas inlet and a desulfurization flue gas outlet,
an absorbent feeding device for feeding absorbent into the circulating fluidized bed desulfurization absorption tower;
atomized water injection means for injecting atomized water into the circulating fluidized bed desulfurization absorption tower;
and the dust remover is connected with the desulfurization flue gas outlet.
6. The flue gas treatment method according to claim 5, wherein an air chute is provided at the bottom of the dust remover, and the air chute is connected to the circulating fluidized bed desulfurization absorption tower.
7. The flue gas treatment method according to claim 5, wherein the dust remover is a bag-type dust remover.
8. The flue gas treatment method according to claim 1, wherein no induced draft fan is provided on a flue connecting the first flue gas treatment apparatus and the second flue gas treatment apparatus.
9. The flue gas treatment method of claim 1, wherein the combined treatment system further comprises a chimney, the flue gas inlet of the chimney being connected to the clean flue gas discharge of the clean flue.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910374857.2A CN109999656B (en) | 2019-05-07 | 2019-05-07 | Combined treatment system and flue gas treatment method for realizing full-working-condition desulfurization and denitration of flue gas circulating fluidized bed desulfurization and SCR denitration |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910374857.2A CN109999656B (en) | 2019-05-07 | 2019-05-07 | Combined treatment system and flue gas treatment method for realizing full-working-condition desulfurization and denitration of flue gas circulating fluidized bed desulfurization and SCR denitration |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109999656A CN109999656A (en) | 2019-07-12 |
| CN109999656B true CN109999656B (en) | 2024-03-08 |
Family
ID=67175922
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910374857.2A Active CN109999656B (en) | 2019-05-07 | 2019-05-07 | Combined treatment system and flue gas treatment method for realizing full-working-condition desulfurization and denitration of flue gas circulating fluidized bed desulfurization and SCR denitration |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109999656B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101254394A (en) * | 2008-04-25 | 2008-09-03 | 武汉凯迪电力环保有限公司 | Sintering device flue gas multiple pollutant removing process and system thereof |
| CN101695627A (en) * | 2009-10-31 | 2010-04-21 | 福建龙净脱硫脱硝工程有限公司 | Dry-method fume gas purification method and device for synchronous desulfurization and denitrification |
| CN204952670U (en) * | 2015-09-23 | 2016-01-13 | 广州创能环保科技有限公司 | Glass melting furnace flue gas dust removal SOx/NOx control concurrent processing system |
| WO2017045602A1 (en) * | 2015-09-15 | 2017-03-23 | 中冶焦耐(大连)工程技术有限公司 | Coke oven flue gas desulfurization and denitrification combined purification process and apparatus |
| CN106669418A (en) * | 2015-11-09 | 2017-05-17 | 湖南中冶长天节能环保技术有限公司 | Device and method for comprehensively carrying out desulfurization, denitration and dioxin removing on steel sintering flue gas |
| CN208727151U (en) * | 2018-08-16 | 2019-04-12 | 北京晨晰环保工程有限公司 | A kind of new Type Coke Oven flue gas desulfurization and denitrification system |
| CN210021738U (en) * | 2019-05-07 | 2020-02-07 | 福建龙净脱硫脱硝工程有限公司 | Combined treatment system for realizing desulfurization and denitration of flue gas circulating fluidized bed under all working conditions |
-
2019
- 2019-05-07 CN CN201910374857.2A patent/CN109999656B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101254394A (en) * | 2008-04-25 | 2008-09-03 | 武汉凯迪电力环保有限公司 | Sintering device flue gas multiple pollutant removing process and system thereof |
| CN101695627A (en) * | 2009-10-31 | 2010-04-21 | 福建龙净脱硫脱硝工程有限公司 | Dry-method fume gas purification method and device for synchronous desulfurization and denitrification |
| WO2017045602A1 (en) * | 2015-09-15 | 2017-03-23 | 中冶焦耐(大连)工程技术有限公司 | Coke oven flue gas desulfurization and denitrification combined purification process and apparatus |
| CN204952670U (en) * | 2015-09-23 | 2016-01-13 | 广州创能环保科技有限公司 | Glass melting furnace flue gas dust removal SOx/NOx control concurrent processing system |
| CN106669418A (en) * | 2015-11-09 | 2017-05-17 | 湖南中冶长天节能环保技术有限公司 | Device and method for comprehensively carrying out desulfurization, denitration and dioxin removing on steel sintering flue gas |
| CN208727151U (en) * | 2018-08-16 | 2019-04-12 | 北京晨晰环保工程有限公司 | A kind of new Type Coke Oven flue gas desulfurization and denitrification system |
| CN210021738U (en) * | 2019-05-07 | 2020-02-07 | 福建龙净脱硫脱硝工程有限公司 | Combined treatment system for realizing desulfurization and denitration of flue gas circulating fluidized bed under all working conditions |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109999656A (en) | 2019-07-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109136545B (en) | Grate-rotary kiln pellet low NOxProduction process and system thereof | |
| CN107014217B (en) | Coke oven gas utilization and flue gas treatment system of coking plant and treatment method thereof | |
| CN107191963B (en) | Rotary air preheater and method for preventing ammonium bisulfate from being blocked by rotary air preheater | |
| CN108704463B (en) | Comprehensive treatment system and process for desulfurization and denitrification of sintering flue gas and whitening of flue gas | |
| CN112403258B (en) | System and method for removing carbon monoxide and denitration of flue gas | |
| CN109381990A (en) | A kind of steel sintering flue gas denitrification system and the method for denitration using system progress | |
| CN110420558A (en) | A kind of denitrating system for grate-kiln pelletizing equipment | |
| CN109721259B (en) | Lime kiln hot air circulation system | |
| CN111821852A (en) | Device and process for jointly removing carbon monoxide and nitrogen oxides in sintering flue gas | |
| CN106705090A (en) | SCR system based on flue gas waste heat gradient utilization and SCR denitration method | |
| CN111482086A (en) | Boiler flue gas cooperative treatment environmental protection equipment and treatment process | |
| CN206198975U (en) | A kind of desulphurization denitration energy saving integral cleaning system of flue gases of cock oven | |
| CN210021738U (en) | Combined treatment system for realizing desulfurization and denitration of flue gas circulating fluidized bed under all working conditions | |
| CN109999656B (en) | Combined treatment system and flue gas treatment method for realizing full-working-condition desulfurization and denitration of flue gas circulating fluidized bed desulfurization and SCR denitration | |
| CN107899413A (en) | A kind of exhaust gas of hot-blast stove desulphurization denitration cooperates with administering method | |
| CN111804138A (en) | Biomass boiler flue gas denitration system and application process thereof | |
| CN111482085A (en) | Desulfurization and denitrification dust removal system based on heat supply of waste heat of flue gas of biomass boiler | |
| CN109028986B (en) | Sinter sensible heat and sintering flue gas waste heat comprehensive utilization system of belt sintering machine | |
| CN215233222U (en) | Removal system for ultralow emission of nitric oxides of household garbage incinerator | |
| CN112403223B (en) | Heat exchange type system and method for removing carbon monoxide and denitration from flue gas | |
| CN210584405U (en) | Dry desulfurization and denitrification device suitable for cement kiln flue gas | |
| CN112403224B (en) | CO oxidation and denitration system and method | |
| CN211462742U (en) | Self-analysis SCR denitration system | |
| CN210602852U (en) | Low-nitrogen combustion equipment for aluminum kiln | |
| CN112403221B (en) | Flue gas denitration and decarburization treatment system and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |