CN214764541U - Energy-saving SCR denitration system for mixed acid roasting waste gas - Google Patents
Energy-saving SCR denitration system for mixed acid roasting waste gas Download PDFInfo
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- CN214764541U CN214764541U CN202120105374.5U CN202120105374U CN214764541U CN 214764541 U CN214764541 U CN 214764541U CN 202120105374 U CN202120105374 U CN 202120105374U CN 214764541 U CN214764541 U CN 214764541U
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- 239000002253 acid Substances 0.000 title claims abstract description 32
- 239000002912 waste gas Substances 0.000 title claims abstract description 14
- 239000003546 flue gas Substances 0.000 claims abstract description 114
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims abstract description 112
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical group N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 58
- 239000007789 gas Substances 0.000 claims abstract description 31
- 238000001354 calcination Methods 0.000 claims abstract description 12
- 238000002485 combustion reaction Methods 0.000 claims abstract description 9
- 238000000034 method Methods 0.000 claims description 28
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- 238000002347 injection Methods 0.000 description 10
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- 239000002699 waste material Substances 0.000 description 9
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 6
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- 238000010438 heat treatment Methods 0.000 description 4
- 229910001220 stainless steel Inorganic materials 0.000 description 4
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- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 3
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
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- 238000005260 corrosion Methods 0.000 description 2
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- 230000000694 effects Effects 0.000 description 2
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- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 1
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- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
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- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
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- GFNGCDBZVSLSFT-UHFFFAOYSA-N titanium vanadium Chemical compound [Ti].[V] GFNGCDBZVSLSFT-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
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- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
The utility model relates to a mixed acid calcination waste gas energy-saving SCR denitration system, the combustion chamber on the connecting flue communicates with each other with the flue that admits air, the combustor is the combustor in the flue, the flue gas inlet of SCR denitration unit communicates with each other with the outlet connection of connecting the flue, the clean flue gas export communicates with each other with the thermal path entry connection of gas heater, be equipped with mixed flow grid and spout the ammonia unit in the connecting flue, one side of spouting the ammonia unit still is equipped with wild wind unit, or spout the ammonia unit and communicate with each other with the air-supply line connection; the system is characterized by also comprising a circulating fan and a backflow preheating pipe, wherein the circulating fan is used for circulating partial hot clean flue gas discharged by the SCR denitration unit, the inlet of the circulating fan is communicated with the clean flue gas outlet of the SCR denitration unit, the outlet of the circulating fan is communicated with the backflow preheating pipe, and two outlets of the backflow preheating pipe are communicated with the cold stroke inlet of the flue gas heat exchanger and the air inlet flue. The utility model discloses can avoid the overtemperature that high concentration NOx arouses, can reduce the corruption to gas heater again, can practice thrift the running cost.
Description
Technical Field
The utility model relates to an energy-saving SCR deNOx systems of mixed acid calcination waste gas belongs to mixed acid calcination waste gas treatment technical field.
Background
HF-HNO adopted by stainless steel factories3The mixed acid removes oxide skin, oil stain and welding slag on the surface of stainless steel, a large amount of waste liquid containing metal salt ions is generated in production, the waste acid treatment efficiency is low by the traditional methods of neutralization and precipitation, chemical recovery, ion exchange resin, extraction and the like, and most of waste acid cannot be recycled. The emerging acid roasting process of waste acid can not only recover the iron oxide powder with economic output value, but also recover HF and HNO with certain concentration3The waste acid can be recycled, the recovery rate of the waste acid reaches 60-70%, the high-concentration NOx is transferred from the waste liquid to the flue gas, and the part of the flue gas is in a large amount in the form of NO after being washed by water.
Conventionally, for high-concentration NOx treatment, neutral gas NO cannot be absorbed by alkali liquor, and NO is converted into NO which cannot be detected by a conventional flue gas analyzer by adopting oxidation technologies such as ozone and the like2Even if the denitration catalyst is matched with alkali liquor for absorption, the denitration efficiency is only 60 percent.The SNCR needs a temperature of 900 +/-50 ℃, and the efficiency is only 30-50%. Therefore, SCR with high removal rate is the first choice for denitration of acid-roasted exhaust gas, but working conditions such as low temperature of 40 ℃, small flue gas amount, high-concentration NOx and the like have various factor restrictions on SCR, for example, SCR denitration needs to ensure that the catalyst activity temperature is at least 240 ℃, and heat generated by heat release of denitration reaction is enough to ensure that the temperature of pretreated raw flue gas is raised to more than 200 ℃ and exceeds the temperature resistance range of the catalyst.
At present, aiming at the SCR denitration technology of stainless steel pickling mixed acid regeneration flue gas, the process route of heat exchange and combustion heating of cold and hot flue gas and the process route of high-temperature circulating air to a cold path outlet of a flue gas heat exchanger are adopted, so that the problems of high-temperature inactivation of a catalyst and high energy consumption of flue gas heating denitration can be successfully solved. In the treatment process of the stainless steel pickling mixed acid regeneration flue gas, the concentration of NOx generated by acid regeneration is generally divided into three working conditions, namely about 19640mg/Nm of NOx under the minimum working condition3(@8％O2) NOx in normal working condition is about 29308mg/Nm3(@8％O2) And maximum operating mode NOx of about 47181mg/Nm3(@8％O2) In order to prevent the system from overheating when meeting high-concentration NOx, the flue gas heat exchanger with the minimum heat transfer area designed according to the maximum working condition NOx concentration is adopted, but in the actual operation process, more low-concentration working conditions such as water operation, acid operation water switching operation, gun lifting operation and the like exist, at the moment, the denitration reaction heat is lower, and in order to ensure the concentration of the exhaust gas NOx and NH3Escape reaches the standard, and the required denitration temperature of SCR denitration needs to be maintained, resulting in that the heat supplementing gas consumption rises by a wide margin, still can cause the problem that the flue gas heat exchanger cold stroke entry is corroded because of acidizing fluid drippage in addition.
Disclosure of Invention
The utility model aims at providing a structure closes can, can avoid the overtemperature that high concentration NOx arouses, can reduce the corruption to gas heater again, can practice thrift running cost's mixed acid calcination waste gas energy-saving SCR deNOx systems.
The utility model discloses a technical scheme who reaches above-mentioned purpose is: the utility model provides a mix energy-saving SCR deNOx systems of sour calcination waste gas, includes the gas heater who is used for carrying out the heat transfer to cold flue gas and hot clean flue gas, is used for carrying out the combustor that heats to cold flue gas, is used for carrying out denitration treatment's SCR deNOx systems and connection flue to hot flue gas, its characterized in that: the combustion chamber on the connecting flue is communicated with the air inlet flue, the combustor is a combustor in the flue and is connected with the combustion chamber, a cold process inlet of the flue gas heat exchanger is used for introducing cold flue gas, a cold process outlet is communicated with the air inlet flue, a flue gas inlet of the SCR denitration unit is communicated with an outlet of the connecting flue, a clean flue gas outlet is communicated with a hot process inlet of the flue gas heat exchanger, and a mixed flow grid and an ammonia spraying unit are arranged in the connecting flue; a wild wind unit is arranged on one side of the ammonia spraying unit in the connecting flue, or the ammonia spraying unit is communicated with the air inlet pipe; the system is characterized by also comprising a circulating fan and a backflow preheating pipe, wherein the circulating fan is used for circulating part of hot clean flue gas discharged by the SCR denitration unit, the inlet of the circulating fan is communicated with the clean flue gas outlet of the SCR denitration unit, the outlet of the circulating fan is communicated with the backflow preheating pipe, and two outlets of the backflow preheating pipe are respectively communicated with the cold stroke inlet of the flue gas heat exchanger and the air inlet flue.
The utility model discloses a SCR deNOx systems has adopted circulating fan and backward flow preheater tube, through circulating fan with SCR denitration unit exhaust part heat clean flue gas through the backward flow preheater tube reflux, make heat clean flue gas mix with former preliminary treatment flue gas on the one hand, can promote the flue gas temperature of gas heater cold stroke entry, the sour dew point of rising, reduce gas heater's cold stroke entry low temperature corrosion, extension gas heater life, on the other hand further improves the temperature of heat transfer back preliminary treatment flue gas, and reduce gas heater's heat transfer area, can reduce fuel's use simultaneously, practice thrift the running cost. The utility model discloses be equipped with wild wind unit in connecting the flue, or spout ammonia unit and air-supply line and communicate with each other, consequently can sneak into wild wind between combustor and SCR denitration unit, can the temperature of lowering system, can avoid the overtemperature that high concentration NOx arouses and cause the high temperature sintering inactivation of SCR catalyst, keep the treatment effect of SCR deNOx system to NOx. The utility model discloses rational in infrastructure, can avoid the overtemperature that high concentration NOx arouses, can reduce the corruption to gas heater again, with in the waste gas up to 20000-'s ability of standing for well 50000 mg/Nm-3To harmless nitrogen, with a final NOx of less than 100mg/Nm3And (5) discharging.
Drawings
Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.
FIG. 1 is the structural schematic diagram of the energy-saving SCR denitration system for mixed acid roasting exhaust gas.
Fig. 2 is a schematic top view of the structure of fig. 1.
FIG. 3 is a schematic sectional view A-A of FIG. 1.
Wherein: 1-connecting flue, 1-combustion chamber, 1-2-air inlet flue, 2-mixed flow grid, 3-SCR denitration unit, 3-1-flue gas inlet, 3-2-SCR denitration body, 3-clean flue gas outlet, 4-electric heater, 5-three-way flue, 6-backflow preheating pipe, 7-backflow valve, 8-flue gas heat exchanger, 8-1-hot process inlet, 8-2-cold process inlet, 8-3-hot process outlet, 8-4-cold process outlet, 9-support, 10-ammonia injection unit, 11-wild wind unit, 12-circulating smoke pipe, 13-circulating fan and 14-burner.
Detailed Description
See fig. 1 ~ 3 shown, the utility model discloses a mix acid calcination waste gas energy-saving SCR deNOx systems, including being used for cold flue gas and clean flue gas to carry out the flue gas heat exchanger 8 of heat transfer, be used for carrying out the combustor 14 that heats to cold flue gas, be used for carrying out denitration treatment's SCR deNOx systems unit 3 and connection flue 1 to the flue gas after the heating, can install flue gas heat exchanger 8, SCR deNOx systems unit 3 and connection flue 1 on a support 9.
See fig. 1 ~ 3 and show, the utility model discloses combustion chamber 1-1 on the connection flue 1 communicates with each other with inlet flue 1-2, and combustor 14 is combustor 14 in the flue and is connected with combustion chamber 1-1, and its fuel can be natural gas or producer gas, the utility model discloses combustor 14's rated power can possess under circulating fan 13 closed condition, promotes the preliminary treatment flue gas to 280 ℃ of ability, and normal denitration in-process is exothermic because of high concentration NOx denitration, and is high more and more high when NOx concentration, and required fuel is less, can reduce the gas consumption, reduces running cost.
See fig. 1-3 shown, the utility model discloses flue gas heat exchanger 8's cold stroke entry 8-2 is used for letting in cold flue gas, cold stroke export 8-4 is connected with the flue that admits air and communicates with each other, be connected with cold flue gas pipe on the cold stroke entry 8-2, SCR denitration unit 3's flue gas import 3-1 and connection flue 1, clean flue gas export 3-3 is connected with flue gas heat exchanger's hot stroke entry 8-13 and is communicated with each other, let in the preliminary treatment flue gas through flue gas heat exchanger 8's cold stroke entry 8-2, rethread cold stroke export 8-4 gets into in the flue of admitting air 1-2, heat transfer after the preliminary treatment flue gas through combustor 14 intensifies to the denitration temperature, and get into SCR denitration unit 3, clean flue gas is discharged the chimney by hot stroke export 8-3 after the flue gas heat exchanger 8 cooling after the denitration.
See that 1 ~ 3 is shown, the utility model discloses flue gas heat exchanger 8 is the maximum heat transfer area's under minimum operating mode NOx concentration dividing wall type heat exchanger, and 8 bottoms of flue gas heat exchanger set up the drain, can adopt plate heat exchanger or shell and tube heat exchanger, the utility model discloses a flue gas heat exchanger 8 operation can correspond respectively and mix the regenerated three different operating modes operation of sour calcination, and flue gas heat exchanger 8's heat transfer area adopts 20000mg/Nm under the minimum operating mode3The maximum heat transfer area is designed.
See fig. 1 ~ 3 shown, the utility model discloses be equipped with mixed flow grid 2 in connecting flue 1 and spout ammonia unit 10, can adopt a plurality of mixed flow grids 2, the absolute flue gas velocity before guaranteeing to get into the catalyst has less deviation, makes the sparge into denitrifier can with the flue gas intensive mixing simultaneously. As shown in the figure 1-3, the utility model discloses connect that the flue 1 is inherent to spout ammonia unit 10 one side and have wild wind unit 11, or spout ammonia unit 10 and air-supply line connection and communicate with each other, this wild wind unit is the matrix ammonia injection grid. When the concentration is high, 30000-50000 mg/Nm3During the process, partial wild wind can be mixed in the connecting flue 1, the wild wind amount is about 10-30% of the pretreatment gas amount, the wild wind amount can be adjusted, and the SCR catalyst is prevented from being lost after exceeding 430 ℃.
See fig. 1 shown, the utility model discloses wild wind unit 11 is located the front side of spouting ammonia unit 10, and wild wind unit 11 and air-supply line connection, spout ammonia unit 10 and advance the pencil and be connected, the connecting pipe is connected on the air-supply line with advance the pencil, the connecting pipe, be equipped with the control valve that corresponds on air-supply line and the pencil, through the control valve on each pipeline, make wild wind can let in through wild wind unit 11 and connect in flue 1, can also let in through spouting ammonia unit 10 and connect in flue 1, and when NOx concentration is not high, still can not let in wild wind, and it is nimble convenient to use. The utility model discloses ammonia injection unit 10 is matrix ammonia injection grid or two-fluid spray gun, matches with denitration agent form, and denitration agent can adopt the denitrifier of injection, adopts the ammonia of different concentration or 10% -25% aqueous ammonia or 40% -50% urea solution, and the ammonia injection is the pure ammonia of 10-25kPa, and when using pure ammonia, adopts detachable ammonia injection grid; when ammonia water or urea solution is adopted, a double-fluid spray gun can be adopted, the gas pressure is 3-5 bar, and the liquid pressure is 2-4 bar. The injection amount of ammonia gas, ammonia water and urea is adjusted according to the feedback of NOx value discharged by a chimney, and when the ammonia injection is urea injection solution, the temperature of urea before the urea is pyrolyzed and enters the SCR denitration unit 3 is not lower than 320 ℃.
See fig. 1 ~ 3 and show, the utility model discloses SCR denitration unit 3 includes that horizontal SCR denitration body 3-2 who arranges more than three, and SCR denitration body 3-2 loads the industry vanadium titanium catalyst module of certain volume, catalyst module and with the body between strictly sealed, SCR denitration unit 3 is at the catalyst volume under 280 ℃, possesses NOx from 50000/(1+ circulation multiple) mg/Nm with 1.5 ~ 2.5 times under the preliminary treatment flue gas volume3Down to 100mg/Nm3The following concentrations were used. See fig. 1 and show, the utility model discloses be equipped with electric heater 4 between each SCR denitration body 3-2, open electric heater 4 at SCR deNOx systems start or shut down the in-process to keep needing to maintain the required denitration temperature of SCR. The utility model discloses still can adopt a reserve SCR denitration body 3-2.
As shown in figures 1-3, the utility model also has a circulating fan 13 and a backflow preheating pipe 6 which circulate the partial hot clean flue gas discharged by the SCR denitration unit 3, the hot clean flue gas which accounts for 10% -25% of the pre-treatment flue gas can be circulated, the inlet of the circulating fan 13 is communicated with the clean flue gas outlet 3-3 of the SCR denitration unit 3, the outlet is communicated with the backflow preheating pipe 6, two outlets on the backflow preheating pipe 6 are respectively communicated with the cold process inlet 8-2 of the flue gas heat exchanger 8 and the gas inlet flue 1-2, the part of hot clean flue gas after denitration flows back to the cold process inlet 8-2 of the flue gas heat exchanger 8 to be mixed with the pre-treatment raw flue gas to enter the flue gas heat exchanger 8, the temperature of the flue gas at the cold process inlet 8-2 of the flue gas heat exchanger 8 can be increased, the acid dew point is raised, the low temperature corrosion at the cold process inlet 8-2 of the flue gas heat exchanger 8 is reduced, the rest flue gas enters the air inlet flue 1-2 through the reflux preheating pipe 6 and is mixed with the heat-exchanged raw flue gas for heating.
As shown in the figures 1-3, the utility model discloses be connected with tee bend flue 5 between the clean flue gas export 3-3 of SCR denitration unit 3 and the hot stroke entry 8-1 of gas heater 8, tee bend flue 5 communicates with each other through circulation tobacco pipe 12 and circulating fan 13's entry linkage, and is equipped with the backflow valve 7 of flue gas flow distribution on the backward flow preheater tube 6, makes the hot clean flue gas a small part flue gas connect to the cold stroke entry 8-2 of gas heater 8, and the former flue gas after most flue gas and the cold stroke export 8-4 discharge heat transfer of gas heater 8 mixes the intensification. The utility model discloses a circulating fan 13 is the frequency conversion draught fan, and circulating fan 13's air intake department is provided with very air door, and circulating fan 13 is 35% ~ 80% aperture under the operating mode, and circulating fan 13's the total amount of wind is 2.5 times of the standard condition amount of wind of preliminary treatment, and the total pressure is 2000Pa, and operating temperature is between 350 ~ 430 ℃.
The initial concentration of NOx in the waste gas of mixed acid roasting is 22218mg/Nm3(@8％O2) 100% pure ammonia gas is adopted for denitration, the fuel of the combustor 14 is natural gas, and the heat exchange area of the flue gas heat exchanger 8 under the maximum working condition is 38m2The treated air volume is 10477Nm 3/h. Adopt the utility model discloses the SCR denitration system is handled mixed acid calcination waste gas, with 31 ℃ mixed acid calcination waste flue gas, gets into heat transfer to 197 ℃ through 8 cold stroke entries of gas heater ware, through 50m3The natural gas burner 14 of the/h supplies heat to 250 ℃, and the heat is sprayed into 107m by the ammonia spraying unit 103100% ammonia gas of/h and 5.28kPa uniformly distributed by the mixed flow grid 2 and then enters the SCR denitration unit 3 for denitration treatment, the inlet temperature of the SCR denitration unit 3 is 250 ℃, the temperature of the SCR body catalyst is 375 ℃, and the air volume of the circulating fan is 13 16000Nm3H, leading hot smoke at the outlet of the SCR denitration unit 3 to be about 1050Nm3H to the cold process inlet 8-2 of the flue gas heat exchanger 8, mixing the rest most hot flue gas with the flue gas discharged from the cold process outlet 8-4 of the flue gas heat exchanger 8 after heat exchange, discharging the cleaned flue gas at 259 ℃ to a chimney after heat exchange, and discharging NOx with the concentration of 58mg/Nm3。
The initial concentration of NOx in the waste gas of mixed acid roasting is 50000mg/Nm3(@8％O2) 100% pure ammonia gas is adopted for denitration, the fuel of the combustor 14 is natural gas, and the maximum heat exchange area of the flue gas heat exchanger 8 under the lowest working condition NOx concentration is 280m2The treated air volume is 10000Nm3H is used as the reference value. Adopt the utility model discloses the SCR denitration system is handled mixed acid calcination waste gas, with 31 ℃ mixed acid calcination waste flue gas, gets into heat transfer to 197 ℃ through 8 cold stroke entries of gas heater ware, through 10m3The natural gas burner 14 of the/h supplies heat to 250 ℃, and the heat is sprayed into 187m through the ammonia spraying unit 103100% ammonia gas at a pressure of 5.28kPa and a wild air volume of 2500N m3H, uniformly distributing the mixed flow grids 2, and then enabling the mixed flow grids to enter an SCR denitration unit 3 for denitration treatment, wherein the inlet temperature of the SCR denitration unit 3 is 349 ℃, the temperature of an SCR body catalyst is 420 ℃, and the 13 air volume of a circulating fan is 15000Nm3H, leading hot smoke at the outlet of the SCR denitration unit 3 to be about 1050Nm3H to the cold process inlet 8-2 of the flue gas heat exchanger 8, mixing the rest most hot flue gas with the flue gas discharged from the cold process outlet 8-4 of the flue gas heat exchanger 8 after heat exchange, discharging the 249 ℃ purified flue gas into a chimney after heat exchange, and discharging NOx with the concentration of 23mg/Nm3。
Claims (8)
1. The utility model provides a mix energy-saving SCR deNOx systems of sour calcination waste gas, is including being used for carrying out flue gas heat exchanger (8) of heat transfer to cold flue gas and hot clean flue gas, being used for carrying out combustor (14) that heat to cold flue gas, being used for carrying out SCR denitration unit (3) and connection flue (1) that denitration was handled to hot flue gas, its characterized in that: the combustion chamber (1-1) on the connecting flue (1) is communicated with the air inlet flue (1-2), the combustor (14) is a combustor (14) in the flue and is connected with the combustion chamber (1-1), a cold process inlet (8-2) of the flue gas heat exchanger (8) is used for introducing cold flue gas, a cold process outlet (8-4) is communicated with the air inlet flue (1-2), a flue gas inlet (3-1) of the SCR denitration unit (3) is communicated with an outlet of the connecting flue (1), a clean flue gas outlet (3-3) is communicated with a hot process inlet (8-1) of the flue gas heat exchanger (8), and a mixed flow grid (2) and an ammonia spraying unit (10) are arranged in the connecting flue (1); a wild wind unit (11) is further arranged on one side of the ammonia spraying unit (10) in the connecting flue (1), or the ammonia spraying unit (10) is communicated with an air inlet pipe; the device is characterized by further comprising a circulating fan (13) and a backflow preheating pipe (6), wherein the circulating fan (13) is used for circulating part of hot clean flue gas discharged by the SCR denitration unit (3), the inlet of the circulating fan (13) is communicated with a clean flue gas outlet (3-3) of the SCR denitration unit (3), the outlet of the circulating fan is communicated with the backflow preheating pipe (6), and two outlets of the backflow preheating pipe (6) are respectively communicated with a cold stroke inlet (8-2) and an air inlet flue (1-2) of the flue gas heat exchanger (8).
2. The mixed acid roasting exhaust gas energy-saving SCR denitration system of claim 1, characterized in that: wild wind unit (11) be located the front side of spouting ammonia unit (10), and wild wind unit (11) are connected with the air-supply line, spout ammonia unit (10) and advance the pencil and be connected, the connecting pipe is connected on the air-supply line and advance the pencil, and is equipped with corresponding control valve on connecting pipe, air-supply line and the pencil of advancing respectively.
3. The mixed acid roasting exhaust gas energy-saving SCR denitration system of claim 1 or 2, characterized in that: the ammonia spraying unit (10) is a matrix type ammonia spraying grid or a double-fluid spray gun.
4. The mixed acid roasting exhaust gas energy-saving SCR denitration system of claim 1 or 2, characterized in that: the wild wind unit (11) is a matrix ammonia spraying grid.
5. The mixed acid roasting exhaust gas energy-saving SCR denitration system of claim 1, characterized in that: a three-way flue (5) is connected between a clean flue gas outlet (3-3) of the SCR denitration unit (3) and a hot process inlet (8-1) of the flue gas heat exchanger (8), the three-way flue (5) is communicated with an inlet of a circulating fan (13) through a circulating flue pipe (12), and a return valve (7) for distributing flue gas flow is arranged on the return preheating pipe (6).
6. The mixed acid roasting exhaust gas energy-saving SCR denitration system of claim 1 or 5, characterized in that: circulating fan (13) are the frequency conversion draught fan, and the air intake department of circulating fan (13) is equipped with adjustable air door.
7. The mixed acid roasting exhaust gas energy-saving SCR denitration system of claim 1, characterized in that: the flue gas heat exchanger (8) is a dividing wall type heat exchanger with the largest heat exchange area under the lowest working condition NOx concentration, and a drain outlet is formed in the bottom of the flue gas heat exchanger (8).
8. The mixed acid roasting exhaust gas energy-saving SCR denitration system of claim 1, characterized in that: the SCR denitration unit (3) comprises more than three SCR denitration bodies (3-2) which are horizontally arranged, and an electric heater (4) is arranged between the SCR denitration bodies (3-2).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
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| CN115414780A (en) * | 2022-09-05 | 2022-12-02 | 中国矿业大学 | High concentration NO x Flue gas denitration system and control method |
| CN115414780B (en) * | 2022-09-05 | 2023-11-24 | 中国矿业大学 | High concentration NO x Flue gas denitration system and control method |
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