CN211274179U - Nitric acid chemical industry nitrogen oxide containing tail gas processing apparatus - Google Patents
Nitric acid chemical industry nitrogen oxide containing tail gas processing apparatus Download PDFInfo
- Publication number
- CN211274179U CN211274179U CN201921104962.6U CN201921104962U CN211274179U CN 211274179 U CN211274179 U CN 211274179U CN 201921104962 U CN201921104962 U CN 201921104962U CN 211274179 U CN211274179 U CN 211274179U
- Authority
- CN
- China
- Prior art keywords
- absorption
- absorption liquid
- absorption tower
- spraying
- tower
- 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
Images
Abstract
The utility model discloses a nitric acid chemical nitrogen oxide-containing tail gas treatment device, which comprises a first-stage pre-absorption tower, a second-stage oxidation absorption tower, a third-stage reduction absorption tower and a fourth-stage reduction absorption tower which are connected in series, wherein each absorption tower comprises a tower body, a storage box arranged in the tower body and a spraying layer; the spraying layer is communicated with respective storage tanks, the storage tank of the primary pre-absorption tower is communicated with a first storage device filled with acidic absorption liquid, the storage tank of the secondary oxidation absorption tower is communicated with a second storage device filled with alkaline absorption liquid and a third storage device filled with oxidation absorption liquid, and the storage tanks of the tertiary and quaternary reduction absorption towers are communicated with the alkaline absorption liquid storage device and the reduction absorption liquid storage device, so that ammonia nitride realizes pre-absorption, oxidation absorption, reduction absorption and further reduction absorption treatment under different acidic and alkaline conditions, secondary pollution is avoided, visible yellow smoke can be eliminated, ammonia nitride removal efficiency is high, and exhaust gas reaches the standard.
Description
Technical Field
The utility model relates to an industrial waste gas treatment technical field especially relates to a nitric acid chemical industry nitrogen oxide containing tail gas processing apparatus.
Background
In the process of nitric acid and nitrate production, nitric acid is required to be produced, and nitric acid solution is used as a production raw material of nitrate, so that a large amount of tail gas containing nitrogen oxides in high concentration is generated, and the main component of the tail gas contains nitrogen oxides NOXAnd NOXIncluding nitric oxide (NO, colorless), nitrogen dioxide (pure NO)2Reddish brown), nitrous oxide (N)2O, colorless), dinitrogen tetroxide (N)2O4Colorless), dinitrogen pentoxide, and the like, wherein except for dinitrogen pentoxide which is solid in the normal state, other nitrogen oxides are gaseous in the normal state, and other mixed gases are in the form of yellow smoke, which is commonly called 'yellow dragon'. At present, the method for purifying the nitrogen oxide tail gas mainly adopts alkali liquor for neutralization and absorption. In practical applications, this approach has the following disadvantages: neutralizing and absorbing with alkali solution, and NO2Can react under alkaline conditions to generate NO again, and NO can not be converted into fixed form N2And secondary pollution is easy to generate, so that the removal efficiency of nitrogen oxides is low, the nitrogen oxides are discharged along with yellow smoke, and the treated gas cannot reach the emission standard.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to overcome above-mentioned shortcoming, provide a nitric acid chemical industry contains nitrogen oxide tail gas processing apparatus, its nitrogen oxide gets rid of efficiently, can eliminate visible yellow cigarette, and gas after the processing can reach emission standard.
In order to achieve the above object, the utility model adopts the following technical scheme:
the nitric acid chemical nitrogen oxide-containing tail gas treatment device comprises a first-stage pre-absorption tower, a second-stage oxidation absorption tower, a third-stage reduction absorption tower and a fourth-stage reduction absorption tower which are connected in series, wherein the first-stage pre-absorption tower, the second-stage oxidation absorption tower, the third-stage reduction absorption tower and the fourth-stage reduction absorption tower respectively comprise a tower body, an air outlet and an air inlet which are respectively arranged on the upper side and the lower side of the tower body, a storage box arranged at the lower end of the inner side of the tower body, and a demisting device arranged in the upper side of the tower body, and the first-stage pre-absorption tower further comprises a plurality; the second-stage oxidation absorption tower, the third-stage reduction absorption tower and the fourth-stage reduction absorption tower respectively comprise a plurality of layers of second absorption liquid spraying layers and absorption packing layers which are arranged between the storage box and the demisting device and alternately arranged at intervals, and the plurality of layers of first absorption liquid spraying layers and a first storage device filled with acidic absorption liquid are communicated with the storage box of the first-stage pre-absorption tower through pipelines; the second absorption liquid spraying layers of the second-stage oxidation absorption tower, the third-stage reduction absorption tower and the fourth-stage reduction absorption tower are respectively communicated with respective storage tanks through pipelines, and the storage tanks of the second-stage oxidation absorption tower are also communicated with a second storage device and a third storage device which are respectively filled with acidic absorption liquid and oxidation absorption liquid; and the storage tanks of the third-stage reduction absorption tower and the fourth-stage reduction absorption tower are communicated with an alkaline absorption liquid storage device and a reduction absorption liquid storage device.
Still be provided with the air-supply line in second grade oxidation absorption tower or/and tertiary reduction absorption tower or/and the level four reduction absorption tower, the air-supply line include with communicating main tuber pipe of air intake and upper end with the branch pipe of main tuber pipe switch-on, in the storage case was stretched into to the branch pipe downside, just be provided with the through-hole on the lateral wall of branch pipe downside.
The first absorption liquid spraying layer and the second absorption liquid spraying layer respectively comprise a spraying main pipe, a plurality of spraying branch pipes communicated with the spraying main pipe and one or more nozzles arranged on each spraying branch pipe, and the spraying main pipes of the first-stage pre-absorption tower, the second-stage oxidation absorption tower, the third-stage reduction absorption tower and the fourth-stage reduction absorption tower are respectively communicated with respective storage tanks through pipelines.
In the multiple first absorption liquid spraying layers, the central axes of the spraying main pipes of two adjacent first absorption liquid spraying layers form a different-surface included angle, and the angle of the different-surface included angle is set to be 10-20 degrees.
The multiple first absorption liquid spraying layers are arranged in such a way that a spraying main pipe of any first absorption liquid spraying layer can rotate in the same direction by the angle of the included angle between different surfaces and then can be parallel to a spraying main pipe of the first absorption liquid spraying layer above the adjacent first absorption liquid spraying layer.
The included angle of the different surfaces is set to be 17.5 degrees.
In the multiple second absorption liquid spraying layers, the central axes of the spraying main pipes of two adjacent second absorption liquid spraying layers form a different-surface included angle, and the angle of the different-surface included angle is set to be 25-35 degrees.
The multiple layers of second absorption liquid spraying layers are arranged in such a way that a spraying main pipe of any second absorption liquid spraying layer rotates in the same direction, and after the angle of the included angle between the different surfaces is formed, the spraying main pipe of the second absorption liquid spraying layer above the spraying main pipe can be parallel to the spraying main pipe of the adjacent second absorption liquid spraying layer.
The included angle of the different surfaces of the central axes of the spraying main pipes of the two adjacent second absorption liquid spraying layers is set to be 30 degrees.
And acid absorption liquid in the first storage device is set to be dilute nitric acid solution.
The defogging device comprises a random packing defogging layer, a back-washing two-way washing layer and a wire mesh defogger which are sequentially arranged from bottom to top, wherein the back-washing two-way washing layer comprises a fixing piece fixedly connected with an inner cavity of the tower body, a pipeline connected with the fixing piece, and an upper nozzle and a lower nozzle which are arranged on the pipeline and are respectively used for washing the wire mesh defogger and the random packing defogging layer.
Compared with the prior art, the utility model, following beneficial effect has:
1. the utility model discloses a mode that one-level sprayed absorption tower, second grade oxidation absorption tower, tertiary reduction absorption tower, level four reduction absorption tower in advance, one-level sprayed absorption tower in advance and absorbed partial NO in advanceXThe second-stage oxidation absorption tower converts the residual NO into NO under the acidic condition2And NO2Does not hydrolyze to NO again under acidic conditions,the three-stage reduction absorption tower carries out NO reduction under the alkaline condition2Conversion to a fixed form of N2The four-stage reduction absorption tower further reduces NO under the alkaline conditionXConversion to a fixed form of N2Therefore, the utility model discloses a under different acidity, alkaline condition, adopt the mode of absorbing in advance, oxidation absorption, reduction absorption, the absorptive level four series connection of reduction once more to nitrogen oxide tail gas to handle to prevent to turn into NO's NO2Convert into NO again to avoid secondary pollution and directly convert NO into NOXConversion to fixed form and harmless N2Thereby ensuring the high-efficiency removal of the nitrogen oxide tail gas and eliminating visible yellow smoke, so that the treated gas reaches the emission standard;
2. the air inlet pipes communicated with the air inlets are arranged in the second-stage oxidation absorption tower, the third-stage reduction absorption tower and the fourth-stage reduction absorption tower, the lower sides of all branch pipes of the air inlet pipes extend into the storage boxes of all the absorption towers, and through holes are formed in the pipe walls of the lower sides of the air inlet pipes, so that waste gas enters all the absorption towers, passes through the main air pipes of the air inlet pipes, enters all the branch pipes, flows out of the through holes of the branch pipes and is mixed with liquid in the storage boxes of all the absorption towers, and the liquid in the storage boxes is liquid to be sprayed out of all the absorption spray layers, so that the contact reaction time of tail gas and liquid is prolonged, the gas-liquid phase reaction power is improved, the reaction efficiency of absorption liquid and tail gas is improved, the treatment efficiency is better, and the effect is better;
3. dilute nitric acid solution is used as acidic absorption liquid to be sprayed out of each spraying layer of the primary pre-spraying absorption tower, so that the dilute nitric acid solution can absorb NO in tail gas of the liquidXThe nitric acid solution is converted into a high-concentration nitric acid solution, and the high-concentration nitric acid solution can be used as a production raw material, so that the recycling of waste gas is realized, and the treatment cost is reduced;
4. in the multi-layer absorption spraying layer of the primary pre-spraying absorption tower, the included angle of the different surfaces of the main pipes of the adjacent absorption spraying layers is set to be 10-20 degrees, and the arrangement can ensure that the spraying coverage area of the nozzles is larger than 350 percent of the sectional area of the absorption tower, thereby realizing large spraying coverage area, large liquid-gas ratio, small spraying resistance and large empty tower wind speed, so that the absorption efficiency of absorption liquid is high, the energy consumption loss is low, the tower diameter can be set to be smaller, the occupied area of the primary pre-spraying absorption tower is smaller, and the primary pre-spraying absorption tower is convenient to arrange;
5. second grade oxidation absorption tower, tertiary reduction absorption tower, in the level four reduction absorption tower, the multilayer absorption of each absorption tower sprays in the layer, adjacent absorption sprays the contained angle of the female pipe on layer and sets up to 25-35, so set up, can guarantee that the nozzle sprays the 250% that coverage area is greater than the absorption tower sectional area, thereby it is big to spray the coverage area, can effectively improve gas-liquid area of contact, extension reaction time, thereby improve the absorption and should with the reaction efficiency of tail gas, can make the treatment effeciency better, the effect is better.
Drawings
FIG. 1 is a schematic view of a treatment apparatus of the present invention;
FIG. 2 is an enlarged schematic view of a first-stage pre-spray absorption tower of the treatment device of the present invention;
FIG. 3 is an enlarged schematic view of a second stage oxidation absorption tower of the treatment apparatus of the present invention;
FIG. 4 is an enlarged schematic view of the air inlet pipe and the storage box of the treatment apparatus of the present invention;
FIG. 5 is an enlarged schematic view of a first absorbent spray layer of the present invention;
fig. 6 to 10 are schematic views showing the reduction of the multi-layer first absorption liquid spray layer of the present invention;
FIG. 11 is an enlarged view of portion A of FIG. 2;
fig. 12 to 14 are schematic views showing the reduction of the multi-layer second absorption liquid spray layer according to the present invention;
FIG. 15 is an enlarged schematic top view of the porous flow equalization plate of the treatment device of the present invention;
fig. 16 is an enlarged schematic top view of the circulating liquid buffering grid plate of the treatment device of the present invention.
Detailed Description
As shown in fig. 1 to 4, the nitrogen oxide-containing tail gas treatment device of nitric acid chemical industry of the present invention includes a first-stage pre-absorption tower 1, a second-stage oxidation absorption tower 2, a third-stage reduction absorption tower 3, and a fourth-stage reduction absorption tower 4 connected in series, wherein each of the first-stage pre-absorption tower 1, the second-stage oxidation absorption tower 2, the third-stage reduction absorption tower 3, and the fourth-stage reduction absorption tower 4 includes a tower body 11, an air outlet 12 and an air inlet 13 respectively disposed at the upper side and the lower side of the tower body 11, a storage tank 14 disposed at the lower end of the inner side of the tower body 11, and a defogging device 15 disposed in the upper side of the tower body 11, and the first-stage pre-absorption tower 1; the second-stage oxidation absorption tower 2, the third-stage reduction absorption tower 3 and the fourth-stage reduction absorption tower 4 also respectively comprise a plurality of layers of second absorption liquid spraying layers 17 and absorption filler layers 18 which are arranged between the storage tank 14 and the demisting device 15 and alternately arranged at intervals, and the plurality of layers of first absorption liquid spraying layers 16 and a first storage device 5 filled with acidic absorption liquid are respectively communicated with the storage tank 14 of the first-stage pre-absorption tower 1 through pipelines; the second absorption liquid spraying layers 17 of the second-stage oxidation absorption tower 2, the third-stage reduction absorption tower 3 and the fourth-stage reduction absorption tower 4 are respectively communicated with respective storage tanks 14 through pipelines, and the storage tanks 14 of the second-stage oxidation absorption tower 2 are also communicated with a second storage device 6 and a third storage device 7 which are respectively filled with acidic absorption liquid and oxidation absorption liquid; and the storage tanks 14 of the third-stage reduction absorption tower 3 and the fourth-stage reduction absorption tower 4 are communicated with an alkaline absorption liquid storage device 8 and a reduction absorption liquid storage device 9.
Preferably, an air inlet pipe 19 is further arranged in the secondary oxidation absorption tower 2 or/and the tertiary reduction absorption tower 3 or/and the quaternary reduction absorption tower 4, the air inlet pipe 19 comprises a main air pipe 191 communicated with the air inlet 13 and a branch pipe 192 with the upper end communicated with the main air pipe 191, the lower side of the branch pipe 192 extends into the storage box 14, and a through hole 193 is arranged on the side wall of the lower side of the branch pipe 192.
The oxidizing absorption liquid can be set to be sodium hypochlorite solution or other solution with the same function, the alkaline absorption liquid can be set to be sodium hydroxide solution or other solution with the same function, and the reducing absorption liquid can be set to be sodium hydrosulfide solution or other solution with the same function.
In this embodiment, each of the first absorption liquid spray layer 16 and the second absorption liquid spray layer 17 includes a main spray pipe 161, a plurality of branch spray pipes 162 communicated with the main spray pipe 161, and one or more nozzles 163 disposed on each branch spray pipe 162, and the main spray pipes of the first-stage pre-absorption tower, the second-stage oxidation absorption tower, the third-stage reduction absorption tower, and the fourth-stage reduction absorption tower are respectively communicated with their respective storage tanks through pipelines.
Preferably, in the multiple first absorption liquid spraying layers 16, the central axes of the spraying main pipes 161 of two adjacent first absorption liquid spraying layers 16 form an included angle with different planes, and the included angle with different planes is set to be 10-20 °. Further, from bottom to top, the spraying main pipes 161 of the multiple first absorbing liquid spraying layers 16 are arranged to rotate in one direction, that is, the multiple first absorbing liquid spraying layers 16 are arranged such that any spraying main pipe 161 of a first absorbing liquid spraying layer 16 can be parallel to the spraying main pipe 161 of the adjacent upper first absorbing liquid spraying layer 16 after rotating in the same direction by the angle of the included angle between different surfaces. Specifically, if the spray header 161 of the lowermost first absorbent liquid spray layer 16 is rotated clockwise by 10 to 20 °, i.e., is parallel to the spray header 161 of the second first absorbent liquid spray layer 16, the spray header 161 of the second first absorbent liquid spray layer 16 is rotated clockwise by 10 to 20 °, i.e., is parallel to the spray header 161 of the third first absorbent liquid spray layer 16, and so on for the other layers. The direction of rotation may also be counter-clockwise.
In this embodiment, the included angle between the different planes of the central axes of the main spray pipes 161 of the two adjacent first absorption liquid spray layers 16 is set to be 17.5 °.
So set up, can guarantee that the nozzle sprays the area of coverage and is greater than 350% of absorption tower sectional area to can realize spraying the area of coverage big, the liquid-gas ratio is big, spray resistance is little, empty tower wind speed is big, so, not only absorption liquid's absorption efficiency is high, the energy consumption loss is low, and the tower footpath also can set up to be smaller moreover, so the area of one-level preliminary spray absorption tower is also smaller, is convenient for settle.
Preferably, in the multiple second absorption liquid spraying layers 17, a different surface included angle is formed between central axes of the spraying main pipes 161 of two adjacent second absorption liquid spraying layers 17, and the angle of the different surface included angle is set to be 25-35 °. Similarly, the multiple second absorption liquid spraying layers 17 are arranged in such a way that the spraying main pipe 161 of any second absorption liquid spraying layer 17 rotates in the same direction, and after the angle of the included angle between the different surfaces is formed, the spraying main pipe 161 of the second absorption liquid spraying layer 17 above the adjacent spraying main pipe can be parallel to the spraying main pipe 161 of the second absorption liquid spraying layer 17 above the adjacent spraying main pipe.
In this embodiment, the included angle between the different planes of the central axes of the main spray pipes 161 of the two adjacent second absorption liquid spray layers 17 is set to be 30 °.
In this embodiment, the first absorption liquid spray layer 16 and the second absorption liquid spray layer 17 further include a fixed disk 164 fixedly connected to the inner wall of the tower body 11, and the spray header 161 is fixedly connected to the fixed disk 164.
In this embodiment, five first absorption liquid spray layers 16 are disposed in the first-stage pre-absorption tower 1, three second absorption liquid spray layers 17 and two absorption filler layers 18 are disposed in each of the second-stage oxidation absorption tower 2, the third-stage reduction absorption tower 3 and the fourth-stage reduction absorption tower 4, and the two absorption filler layers 18 are alternately disposed between the three second absorption liquid spray layers 17, that is, from bottom to top, are integrally formed into a manner of disposing a second absorption liquid spray layer, an absorption filler layer, a second absorption liquid spray layer, and a second absorption liquid spray layer.
In other embodiments, the number of the first absorption liquid spraying layer 16, the second absorption liquid spraying layer 17 and the absorption filler layer 18 can be set as required.
In this embodiment, the demister 15 includes a random packing defogging layer 151, a back-washing bidirectional flushing layer 152, and a wire mesh demister 153 arranged in sequence from bottom to top. The back-washing bidirectional washing layer 152 comprises a fixing member (not shown) fixedly connected with the inner cavity of the tower body 11, a pipeline 1521 connected with the fixing member, and an upper nozzle 1522 and a lower nozzle 1523 which are arranged on the pipeline 1521 and are respectively used for washing the wire mesh demister 153 and the random packing defogging layer 151, wherein the pipeline 1521 is communicated with a washing water tank 10 through a pipeline. The random packing defogging layer 151 and the wire mesh demister 153 can absorb water mist in gas, so that the water vapor content of the discharged gas is low, namely the liquid-gas ratio is low, the use amount of the medicament required by the secondary oxidation absorption tower 2, the tertiary reduction absorption tower 3 and the quaternary reduction absorption tower 4 is low, and the normal operation of subsequent online monitoring equipment is facilitated, and the corrosion of the water vapor to the equipment is avoided. The two-way layer of back flush can spray the washing to silk screen mist eliminator 153 and the defogging layer 151 of random packing to can avoid the silk screen mist eliminator 153 to take place with the condition that the defogging layer 151 of random packing blockked up, make waste gas resistance little when the defogging layer 151 of random packing and silk screen mist eliminator 153, thereby defogging efficiency is higher, can further reduce the medicament use amount moreover.
Preferably, the back-flushing bidirectional flushing layer 152 of the first-stage neutralization absorption tower 1, the second-stage oxidation absorption tower 2, the third-stage reduction absorption tower 3 and the fourth-stage reduction absorption tower 4 is communicated with the same flushing water tank 9 through pipelines, so that water can be better managed and controlled.
In this embodiment, preferably, the primary pre-absorption tower 1 further comprises a first pH meter (not shown) and a first liquid level meter 201 connected to the storage tank 14. When the first pH meter 201 detects that the pH value in the first-stage preliminary absorption tower 1 is decreasing, it indicates that the absorption liquid sprayed from the first spray absorption layer has a preliminary absorption effect. When the first pH meter 201 detects that the pH value of the liquid in the storage tank 14 of the primary pre-absorption tower 1 is greater than or equal to 7.5, the first storage device 4 injects the acidic absorption liquid into the storage tank 14 through the dosing pump, and when the pH meter detects that the pH value of the liquid in the storage tank 14 is less than or equal to 6.5, the acidic absorption liquid is stopped to be added; the first liquid level meter 202 is used for detecting the liquid level of the storage tank 14, and when the liquid level drops to a set value, water is supplemented into the storage tank 14.
The secondary oxidation absorption tower 2 further comprises a second pH meter (not shown) connected with the storage tank 14, a second liquid level meter 203 and a second ORP meter 204 communicated with the interior of the tower body 11, wherein the OPR meter can be used for controlling the addition of an oxidant. When the pH meter detects that the pH of the liquid in the storage box 14 is less than or equal to 5, the second storage device 6 starts to add the acidic absorption liquid into the storage box 14 through the dosing pump, and when the pH is detected to be more than or equal to 6, the acidic absorption liquid is stopped to be added; when the ORP meter detects that the ORP of the gas is less than or equal to 575ms, the third storage device adds the oxidant absorption liquid into the storage tank 14 through the dosing pump, and when the ORP is detected to be more than or equal to 595ms, the oxidant absorption liquid addition is stopped. In this embodiment, the oxidizing agent absorbing liquid is a liquid mixed with a strong oxidizing agent. The second liquid level meter 201 is used for detecting the liquid level of the storage tank 14 of the secondary oxidation absorption tower 2, and when the liquid level drops to a set value, water is supplemented into the storage tank 14.
The third-stage reduction absorption tower 3 further comprises a third pH meter and a third liquid level meter which are connected with the storage tank 14, and a third ORP meter which is communicated with the interior of the tower body 11. When the third pH meter detects that the pH of the liquid in the storage tank 14 is less than or equal to 12, the alkaline absorption liquid storage device 8 such as sodium hydroxide injects alkaline absorption liquid such as sodium hydroxide into the storage tank 14 of the three-stage reduction absorption tower 3 through the dosing pump, and when the third pH meter detects that the pH of the liquid in the storage tank 14 is more than or equal to 13, the alkaline absorption liquid such as sodium hydroxide stops being added; when the second ORP meter detects that the ORP of the gas is more than or equal to 495ms, the sodium hydrosulfide and other reducing absorption liquid storage device 98 adds sodium hydrosulfide and other reducing absorption liquids into the storage tank 14 of the three-stage reducing absorption tower 3 through the dosing pump, and when the ORP is detected to be less than or equal to 545ms, the sodium hydrosulfide and other reducing absorption liquids are stopped.
The fourth-stage reduction absorption tower 4 further comprises a fourth pH meter and a fourth liquid level meter which are connected with the storage tank 14 of the fourth-stage reduction absorption tower, and a fourth ORP meter which is communicated with the interior of the tower body 116. When the fourth pH meter detects that the pH of the liquid in the storage tank 141 is less than or equal to 11.5, the storage device 8 for alkaline absorption liquid such as sodium hydroxide injects the alkaline absorption liquid such as sodium hydroxide into the storage tank 141 through the dosing pump, and when the pH meter detects that the pH of the liquid in the storage tank 141 is greater than or equal to 12.5, the addition of the alkaline absorption liquid such as sodium hydroxide is stopped; when the ORP meter detects that the ORP of the gas is more than or equal to 485ms, the sodium hydrosulfide and other reduction absorption liquid storage device 98 adds sodium hydrosulfide and other reduction absorption liquids into the storage tank 141 through a dosing pump, and when the ORP is detected to be less than or equal to 535ms, the sodium hydrosulfide and other reduction absorption liquids are stopped being added; the fourth level gauge is used for detecting the liquid level of the material storage tank 141, and when the liquid level drops to a set value, water is supplied into the material storage tank 141.
The utility model discloses a theory of operation does:
1. first-order pre-absorption
Nitrogen oxide-containing tail gas in a nitric acid chemical production workshop enters a primary pre-spraying absorption tower from an air inlet 13 of the primary pre-spraying absorption tower and sequentially passes through a plurality of first absorption liquid spraying layers 16 upwards, because the first absorption liquid spraying layers 16 are communicated with a first storage tank 14, the first storage tank 14 is communicated with a first storage device filled with dilute nitric acid absorption liquid, dilute nitric acid absorption liquid is sprayed out from each spraying layer, and nitrogen oxide tail gas entering the primary pre-spraying absorption tower is dedusted and cooled firstly under an acidic condition and is absorbed by reacting with the dilute nitric acid absorption liquid under the acidic condition, so that the pre-absorption tower finishes the pre-absorption of the tail gas nitrogen oxide;
the pre-absorbed waste gas continuously flows upwards, passes through the demisting device 15, namely sequentially passes through the random packing demisting layer, the back-washing bidirectional washing layer and the wire mesh demister, the random packing demisting layer and the wire mesh demister absorb water mist in the gas, and the gas demisted by the demisting device 15 is discharged from the air outlet 12 and enters the secondary oxidation absorption tower.
In this embodiment, preferably, the acidic absorption liquid in the first storage device is set to be a dilute nitric acid solution, so that after the acidic absorption liquid reacts with the tail gas, the acidic absorption liquid can react with nitrogen oxide NO in the tail gasXThe nitric acid solution with high concentration is formed by reaction, and the nitric acid solution with high concentration can be used as a production raw material, so that the recycling of waste gas is realized, and the treatment cost is reduced.
2. Secondary oxidation absorption
Gas exhausted from the air outlet 12 of the primary pre-spraying absorption tower enters the secondary oxidation absorption tower through the air inlet 13 of the secondary oxidation absorption tower, the gas firstly enters the main air pipe 191 of the air pipe and is shunted to each branch pipe 192 from the main air pipe 191, the gas entering the branch pipe 192 flows out of the side wall through hole 193 of the branch pipe 192 and contacts with liquid in the storage tank 14, the gas contacting with the liquid flows upwards and sequentially passes through the first absorption liquid spraying layer 16, the first absorption packing layer 18, the second absorption liquid spraying layer 17, the second absorption packing layer 18 and the third absorption liquid spraying layer, and the gas enters the secondary oxidation absorption tower through the secondary oxidation absorptionThe first absorption liquid of tower sprays layer 16, the second absorption liquid sprays layer 17, what the third absorption liquid sprays the layer is equipped with second storage device and third storage device of oxidation absorption liquid such as weak nitric acid absorption liquid and sodium hypochlorite respectively, thereby first absorption liquid sprays layer 16, the second absorption liquid sprays layer 17, the third absorption liquid sprays that the layer sprays out and is the oxidation absorption liquid such as weak nitric acid absorption liquid and sodium hypochlorite, thereby make the nitrogen oxide tail gas that gets into in the second grade oxidation absorption tower further by the dust removal cooling under the acid condition, and NO wherein also accomplishes strong oxidation reaction under the acid condition and converts into NO and reduce the temperature to NO2And under acidic conditions, NO2Nor is it converted to NO.
The gas passing through the second absorption liquid spraying layer 1710 continuously flows upwards, passes through the demisting device 15, sequentially passes through the random packing demisting layer, the backwashing bidirectional flushing layer and the wire mesh demister, and is discharged through the air outlet 12, and the random packing demisting layer and the wire mesh demister absorb water mist in the gas.
The arrangement of the air pipe can prolong the contact reaction time of the tail gas and the liquid and also improve the gas-liquid phase reaction power, thereby improving the reaction efficiency of the absorption liquid and the tail gas, so that the treatment efficiency is better and the effect is better;
3. three-stage reduction absorption
The gas exhausted from the air outlet 12 of the secondary oxidation absorption tower enters the tertiary reduction absorption tower through the air inlet 13 of the tertiary reduction absorption tower, the gas firstly enters the main air pipe 191 of the air pipe, and is diverted from main duct 191 into each branch 192, and the gas entering branch 192 flows out of side wall apertures 193 of branch 192 into contact with the liquid in holding tank 14, the gas contacted with the liquid flows upwards and passes through a first absorption liquid spraying layer 16, a first absorption filler layer 18, a second absorption liquid spraying layer 17, a second absorption filler layer 18 and a third absorption liquid spraying layer in sequence, because the first absorption liquid spraying layer 16, the first absorption liquid spraying layer 16 and the second absorption liquid spraying layer 17 of the secondary oxidation absorption tower are connected with the third storage device and the fourth storage device which are respectively provided with alkaline absorption liquid such as sodium hydroxide and reducing absorption liquid such as sodium hydrosulfide, the first absorption is realized.The liquid spraying layer 16, the second absorption liquid spraying layer 17 and the third absorption liquid spraying layer spray alkaline absorption liquid such as sodium hydroxide and reducing absorption liquid such as sodium hydrosulfide, so that nitrogen oxide tail gas entering the three-stage reducing absorption tower is further dedusted and cooled under alkaline conditions, and NO in the nitrogen oxide tail gas is reduced2And other NOXConversion to harmless N by performing strong reduction reaction under alkaline condition2；
The gas passing through the third absorption liquid spraying layer continuously flows upwards, passes through the demisting device 15, sequentially passes through the random packing demisting layer, the backwashing bidirectional flushing layer and the wire mesh demister, and is discharged through the air outlet 12, and the random packing demisting layer and the wire mesh demister absorb water mist in the gas.
4. Four-stage further reduction absorption
Gas exhausted from the air outlet 12 of the three-stage reduction absorption tower enters the four-stage reduction absorption tower 4 through the air inlet 13 of the four-stage reduction absorption tower 4, the gas firstly enters the main air pipe 191 of the air pipe and is shunted to each branch pipe 192 from the main air pipe 191, the gas entering the branch pipes 192 flows out from the side wall through holes 193 of the branch pipes 192 to be contacted with liquid in the storage box 14, the gas contacted with the liquid flows upwards and sequentially passes through the first absorption liquid spraying layer 16, the first absorption packing layer 18, the second absorption liquid spraying layer 17, the second absorption packing layer 18 and the third absorption liquid spraying layer, and because the first absorption liquid spraying layer 16, the first absorption liquid spraying layer 16 and the second absorption liquid spraying layer 17 of the two-stage oxidation absorption tower are connected with the third storage device and the fourth storage device which are respectively provided with alkaline absorption liquid such as sodium hydroxide and the like and reduction absorption liquid such as sodium hydrosulfide and the like, the first absorption liquid spraying layer 16, the second absorption liquid spraying layer 16, the, The second absorption liquid spraying layer 17 and the third absorption liquid spraying layer spray alkaline absorption liquid such as sodium hydroxide and reducing absorption liquid such as sodium hydrosulfide, so that nitrogen oxide tail gas entering the four-stage reducing absorption tower 4 is further dedusted and cooled under alkaline conditions, and the residual NO is2And other NOXConversion to harmless N by performing strong reduction reaction under alkaline condition2。
The gas passing through the third absorption liquid spraying layer continuously flows upwards, passes through the demisting device 15, namely sequentially passes through the random packing demisting layer, the backwashing bidirectional flushing layer and the wire mesh demister, the random packing demisting layer and the wire mesh demister absorb water mist in the gas, and the gas passing through the demisting device 15 is discharged into the air through the air outlet 12.
Thus, the nitrogen oxide tail gas is sequentially subjected to series treatment of pre-absorption, oxidation absorption, reduction absorption and re-reduction absorption under different acidic and alkaline conditions, thereby avoiding NO and NO2Mutual conversion is carried out, thereby avoiding secondary pollution and leading most of NO to beXAre all converted into harmless N2Therefore, the removal efficiency of the nitrogen oxide tail gas is high, and visible yellow smoke is eliminated, so that the treated gas reaches the emission standard.
Referring to fig. 15, porous flow equalizing plates 31 are further disposed in the first-stage neutralization absorption tower 1, the second-stage oxidation absorption tower 2, the third-stage reduction absorption tower 3, and the fourth-stage reduction absorption tower 4, edges of the porous flow equalizing plates 31 are fixedly connected to an inner wall of the tower body 11, and the porous flow equalizing plates 31 are disposed at an upper side of the air inlet 13, so that gas flows upward through the porous flow equalizing plates 31, and thus the gas entering the towers is uniformly distributed and has a stable flow velocity, a contact area between sprayed absorption liquid and waste gas is increased, reaction efficiency is increased, and a removal rate of ammonia nitride in the waste gas is increased.
Preferably, the porous flow equalizing plate 31 is provided with a plurality of through holes 193 radially outward from the center of the circle, and the aperture ratio of the porous plate is greater than or equal to 80%, so that the flow equalizing effect is very good.
Combine fig. 16 to show, still all be provided with circulation liquid buffering grid plate 32 in one-level neutralization absorption tower 1, second grade oxidation absorption tower 2, tertiary reduction absorption tower 3, the level four reduction absorption tower 4, circulation liquid buffering grid plate 32 edge and 11 inner wall fixed connection of tower body, and circulation liquid buffering grid plate 32 are located storage tank 14 upper portion to can make the liquid of whereabouts can not too splash, and can prevent the utility model discloses circulation liquid in the storage tank 14 flows back to in the air intake 13 when processing apparatus stops.
Claims (18)
1. The utility model provides a nitric acid chemical industry nitrogen oxide containing tail gas processing apparatus which characterized in that: the device comprises a first-stage pre-absorption tower, a second-stage oxidation absorption tower, a third-stage reduction absorption tower and a fourth-stage reduction absorption tower which are connected in series, wherein the first-stage pre-absorption tower, the second-stage oxidation absorption tower, the third-stage reduction absorption tower and the fourth-stage reduction absorption tower respectively comprise a tower body, air outlets and air inlets which are respectively arranged at the upper side and the lower side of the tower body, a storage box arranged at the lower end of the inner side of the tower body and a demisting device arranged in the upper side of the tower body, and the first-stage pre-absorption tower also comprises a plurality of layers of first absorption liquid; the second-stage oxidation absorption tower, the third-stage reduction absorption tower and the fourth-stage reduction absorption tower respectively comprise a plurality of layers of second absorption liquid spraying layers and absorption packing layers which are arranged between the storage box and the demisting device and alternately arranged at intervals, and the plurality of layers of first absorption liquid spraying layers and a first storage device filled with acidic absorption liquid are communicated with the storage box of the first-stage pre-absorption tower through pipelines; the second absorption liquid spraying layers of the second-stage oxidation absorption tower, the third-stage reduction absorption tower and the fourth-stage reduction absorption tower are respectively communicated with respective storage tanks through pipelines, and the storage tanks of the second-stage oxidation absorption tower are also communicated with a second storage device and a third storage device which are respectively filled with acidic absorption liquid and oxidation absorption liquid; and the storage tanks of the third-stage reduction absorption tower and the fourth-stage reduction absorption tower are communicated with an alkaline absorption liquid storage device and a reduction absorption liquid storage device.
2. The nitric acid chemical nitrogen oxide-containing tail gas treatment device according to claim 1, wherein: still be provided with the air-supply line in second grade oxidation absorption tower or/and tertiary reduction absorption tower or/and the level four reduction absorption tower, the air-supply line include with communicating main tuber pipe of air intake and upper end with the branch pipe of main tuber pipe switch-on, in the storage case was stretched into to the branch pipe downside, just be provided with the through-hole on the lateral wall of branch pipe downside.
3. The nitric acid chemical industry nitrogen oxide-containing tail gas treatment device according to claim 1 or 2, characterized in that: the first absorption liquid spraying layer and the second absorption liquid spraying layer respectively comprise a spraying main pipe, a plurality of spraying branch pipes communicated with the spraying main pipe, and one or more nozzles arranged on the spraying branch pipes or/and the spraying main pipe, and the spraying main pipes of the first-stage pre-absorption tower, the second-stage oxidation absorption tower, the third-stage reduction absorption tower and the fourth-stage reduction absorption tower are respectively communicated with respective storage boxes through pipelines.
4. The nitric acid chemical nitrogen oxide-containing tail gas treatment device according to claim 3, wherein: in the multiple first absorption liquid spraying layers, a first different-surface included angle is formed between the central axes of the spraying main pipes of two adjacent first absorption liquid spraying layers, and the angle of the first different-surface included angle is set to be 10-20 degrees.
5. The nitric acid chemical industry nitrogen oxide-containing tail gas treatment device according to claim 4, wherein: the multiple first absorption liquid spraying layers are arranged in such a way that a spraying main pipe of any first absorption liquid spraying layer can be parallel to a spraying main pipe of a first absorption liquid spraying layer above the adjacent spraying main pipe after rotating in the same direction by the angle of the first different-surface included angle.
6. The nitric acid chemical industry nitrogen oxide-containing tail gas treatment device of claim 4 or 5, which is characterized in that: the included angle of the first different surface is set to be 17.5 degrees.
7. The nitric acid chemical industry nitrogen oxide-containing tail gas treatment device of claim 4 or 5, which is characterized in that: in the multiple second absorption liquid spraying layers, a second different-surface included angle is formed between the central axes of the spraying main pipes of two adjacent second absorption liquid spraying layers, and the angle of the second different-surface included angle is set to be 25-35 degrees.
8. The apparatus of claim 7, wherein: the multiple layers of second absorption liquid spraying layers are arranged in such a way that a spraying main pipe of any second absorption liquid spraying layer rotates in the same direction, and after the angle of the included angle of the second different surfaces is formed, the spraying main pipe can be parallel to the spraying main pipe of the second absorption liquid spraying layer above the adjacent layer.
9. The nitric acid chemical industry nitrogen oxide-containing tail gas treatment device according to claim 8, wherein: and a second different-surface included angle of a central shaft of the spraying main pipe of each two adjacent second absorption liquid spraying layers is set to be 30 degrees.
10. The nitric acid chemical industry nitrogen oxide-containing tail gas treatment device according to claim 6, wherein: in the multiple second absorption liquid spraying layers, a second different-surface included angle is formed between the central axes of the spraying main pipes of two adjacent second absorption liquid spraying layers, and the angle of the second different-surface included angle is set to be 25-35 degrees.
11. The nitric acid chemical industry nitrogen oxide-containing tail gas treatment device according to claim 10, wherein: the multiple layers of second absorption liquid spraying layers are arranged in such a way that a spraying main pipe of any second absorption liquid spraying layer rotates in the same direction, and after the angle of the included angle of the second different surfaces is formed, the spraying main pipe can be parallel to the spraying main pipe of the second absorption liquid spraying layer above the adjacent layer.
12. The apparatus of claim 11, wherein: and a second different-surface included angle of a central shaft of the spraying main pipe of each two adjacent second absorption liquid spraying layers is set to be 30 degrees.
13. The nitric acid chemical nitrogen oxide-containing tail gas treatment device according to any one of claims 1 to 2, 4 to 5, and 8 to 12, wherein: and acid absorption liquid in the first storage device is set to be dilute nitric acid solution.
14. The apparatus of claim 13, wherein: the defogging device comprises a random packing defogging layer, a back-washing two-way washing layer and a wire mesh defogger which are sequentially arranged from bottom to top, wherein the back-washing two-way washing layer comprises a fixing piece fixedly connected with an inner cavity of the tower body, a pipeline connected with the fixing piece, and an upper nozzle and a lower nozzle which are arranged on the pipeline and are respectively used for washing the wire mesh defogger and the random packing defogging layer.
15. The nitric acid chemical nitrogen oxide-containing tail gas treatment device according to claim 3, wherein: and acid absorption liquid in the first storage device is set to be dilute nitric acid solution.
16. The nitric acid chemical industry nitrogen oxide-containing tail gas treatment device according to claim 6, wherein: and acid absorption liquid in the first storage device is set to be dilute nitric acid solution.
17. The apparatus of claim 7, wherein: and acid absorption liquid in the first storage device is set to be dilute nitric acid solution.
18. The apparatus for treating nitric acid chemical industry nitrogen oxide-containing tail gas according to any one of claims 15 to 17, comprising: the defogging device comprises a random packing defogging layer, a back-washing two-way washing layer and a wire mesh defogger which are sequentially arranged from bottom to top, wherein the back-washing two-way washing layer comprises a fixing piece fixedly connected with an inner cavity of the tower body, a pipeline connected with the fixing piece, and an upper nozzle and a lower nozzle which are arranged on the pipeline and are respectively used for washing the wire mesh defogger and the random packing defogging layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921104962.6U CN211274179U (en) | 2019-07-15 | 2019-07-15 | Nitric acid chemical industry nitrogen oxide containing tail gas processing apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921104962.6U CN211274179U (en) | 2019-07-15 | 2019-07-15 | Nitric acid chemical industry nitrogen oxide containing tail gas processing apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211274179U true CN211274179U (en) | 2020-08-18 |
Family
ID=72025348
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921104962.6U Active CN211274179U (en) | 2019-07-15 | 2019-07-15 | Nitric acid chemical industry nitrogen oxide containing tail gas processing apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211274179U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117000026A (en) * | 2023-08-28 | 2023-11-07 | 江苏源一工程科技有限公司 | Nitrogen-containing waste gas treatment system |
-
2019
- 2019-07-15 CN CN201921104962.6U patent/CN211274179U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117000026A (en) * | 2023-08-28 | 2023-11-07 | 江苏源一工程科技有限公司 | Nitrogen-containing waste gas treatment system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102580496B (en) | Liquid-phase oxidation multistage absorbed flue gas desulfurization and denitrification technology and device | |
| CN202315673U (en) | Equipment for treating waste gas containing nitric oxide | |
| CN103801176B (en) | A kind of ozone oxidation is in conjunction with the flue-gas denitration process of spraying cooling and device | |
| CN107754599B (en) | High-low temperature gas phase composite desulfurization and denitrification method | |
| CN105854547B (en) | Ammonia process oxidation and denitration technique and reaction unit | |
| CN204891568U (en) | Distributed SOx/NOx control device of boiler flue gas integration | |
| CN105056746A (en) | Implementing method for integrated distributed desulfurization and denitrification process of boiler flue gas | |
| CN205832945U (en) | A kind of nitrous oxides exhaust gas that reclaims prepares the device of dust technology | |
| CN104258715A (en) | Technology for treating nitric oxide waste gas by urea treatment and treatment equipment | |
| CN105536467A (en) | Flue gas purification device and method combining photo-catalytic oxidization and double cyclic absorption | |
| CN104056538B (en) | Flue gas purifying system and method with integration of desulfurization and denitrification | |
| CN102160961A (en) | Dielectric barrier discharge reactor, fume desulfurization and denitration system and desulfurizating and denitrating process | |
| CN203935765U (en) | A kind of flue gas purification system of integrated desulfurizing denitration | |
| CN112058048A (en) | Flue gas desulfurization and denitrification system device and method with cooperation of ozone oxidation and multi-stage spraying | |
| CN211274179U (en) | Nitric acid chemical industry nitrogen oxide containing tail gas processing apparatus | |
| CN106512681A (en) | Denitrification device | |
| CN103170232B (en) | A kind of integrating device of wet oxidation denitration | |
| CN107626195A (en) | The tail gas treatment process of red phosphorus purification | |
| CN102553416A (en) | Method for denitrating flue gas of power plant and absorption liquid used by method | |
| CN205361021U (en) | Wet -type oxidation absorption's denitrification facility | |
| CN210410149U (en) | High-efficient desorption equipment of nitrogen oxide that gaseous phase oxidation liquid phase reduction allies oneself with usefulness | |
| CN212440674U (en) | Integrated desulfurization and denitrification system for ship tail gas | |
| CN107684810A (en) | Flue gas minimum discharge device and application method | |
| CN208878244U (en) | A kind of device of removal of nitrogen oxide | |
| CN106823752A (en) | A kind of novel liquid-phase oxidative absorption method of denitration and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |