Activated carbon flue gas purification system
By setting up a return air flue in the activated carbon flue gas purification system to dilute the flue gas with high SO2 concentration, the problem of high SO2 concentration flue gas treatment in the existing technology is solved, and efficient and economical desulfurization and denitrification effects are achieved.
Patent Information
- Application Number
- CN202422660286.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-01
- Publication Date
- 2025-09-26
- Estimated Expiration
- 2034-11-01
AI Technical Summary
The existing activated carbon desulfurization and denitrification process is only suitable for treating flue gas with low SO2 concentration. When the SO2 concentration is high, it is easy to cause the activated carbon bed to heat up, become blocked, and increase NH3 consumption.
A first return air duct is set before the secondary adsorption tower to circulate the flue gas purified once by the primary adsorption tower to the original flue gas conveying pipeline to mix with the original flue gas to dilute the SO2 concentration. A second return air duct is set after the secondary adsorption tower to circulate the clean flue gas to the inlet of the primary adsorption tower. The return air volume is adjusted to ensure that the SO2 concentration is within an appropriate range.
It effectively treats flue gas with high SO2 concentration, avoids heating and clogging of the activated carbon bed, reduces NH3 consumption, improves purification efficiency and is economical and energy-saving.
Smart Images
Figure CN223381351U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an activated carbon desulfurization and denitrification process, in particular to an activated carbon flue gas purification system, and belongs to the field of comprehensive treatment of flue gas pollutants. Background Art
[0002] Activated carbon desulfurization has the advantages of high desulfurization rate, simultaneous denitrification, dioxin removal, dust removal, and no wastewater or waste residue generation. Therefore, for industrial flue gas, especially sintering pellet flue gas in the steel industry, the use of activated carbon desulfurization and denitrification process is relatively ideal. At present, sintering pellet flue gas must meet ultra-low emission standards, so the existing activated carbon desulfurization and denitrification technology generally requires a two-stage activated carbon process to meet the emission standards. The existing two-stage activated carbon desulfurization and denitrification process is as follows:
[0003] The sintering flue gas from the sintering main exhaust first enters the primary activated carbon adsorption tower. After preliminary purification, it is sent to the secondary activated carbon adsorption tower by the primary booster fan for further purification. The flue gas purified by the secondary activated carbon adsorption tower can meet the ultra-low emission requirements and is sent to the chimney by the secondary booster fan for discharge. x Ammonia is injected as a reducing agent before the entrance of the first and second adsorption towers to reduce the NO in the flue gas. x Under the action of activated carbon, a redox reaction occurs with NH3 to convert NO x To prevent excessively high flue gas temperatures from entering the adsorption tower, which could cause safety accidents, a cold air inlet is installed above the flue before the first-stage adsorption tower. This inlet draws in air to lower the sintering flue gas temperature to around 135°C. A cold air valve is installed on the cold air inlet to adjust the amount of cold air entering the flue.
[0004] When the SO2 concentration in the sintering flue gas is 3000 mg / m 3 When the concentration of SO2 in flue gas is greater than 3000mg / m 3 Because the adsorption of SO2 by activated carbon is an exothermic reaction, when the SO2 concentration is too high, the heat generated in the activated carbon bed will be far greater than the heat removed by the flue gas, causing the bed to heat up, thereby causing system failures. In addition, in the operation of existing activated carbon desulfurization and denitrification devices, it has been found that if ammonia is sprayed before the primary adsorption tower, NH3 will first react with SO2 in the flue gas to produce ammonium sulfate and ammonium sulfite particles. After these particles are adsorbed by the activated carbon, the viscosity of the activated carbon increases, causing the activated carbon to agglomerate, affecting its fluidity, causing the activated carbon bed to clog and increase the risk of temperature rise. In addition, SO2 consumes NH3, which serves as a denitrification reducing agent, resulting in increased NH3 consumption. Utility Model Content
[0005] To address the technical issue that existing activated carbon desulfurization and denitrification processes are only suitable for treating flue gas with low SO2 concentrations, the present invention proposes a novel activated carbon flue gas purification system. This system incorporates a first return air duct before the secondary adsorption tower, recycling a portion of the flue gas that has undergone primary purification in the primary adsorption tower back into the raw flue gas delivery duct before the primary adsorption tower's inlet. This portion of the primary purified flue gas mixes with the raw flue gas, thereby diluting the SO2 concentration in the raw flue gas and ensuring that the flue gas entering the primary adsorption tower meets the optimal treatment conditions for the adsorption tower. This means that the activated carbon flue gas purification system of the present invention is capable of treating flue gas with high SO2 concentrations.
[0006] According to an embodiment of the present utility model, an activated carbon flue gas purification system is provided.
[0007] An activated carbon flue gas purification system includes a primary adsorption tower and a secondary adsorption tower. The primary adsorption tower is provided with a raw flue gas inlet and a primary purified flue gas outlet. The secondary adsorption tower is provided with a primary purified flue gas inlet and a clean flue gas outlet. The raw flue gas inlet of the primary adsorption tower is connected to a raw flue gas delivery pipeline. The primary purified flue gas outlet of the primary adsorption tower is connected to the primary purified flue gas inlet of the secondary adsorption tower via the primary purified flue gas pipeline. A first return air duct branches off from the primary purified flue gas pipeline and is connected to the raw flue gas delivery pipeline.
[0008] In the present invention, the clean flue gas outlet of the secondary adsorption tower is connected to a clean flue gas exhaust pipe, a second return air flue is branched from the clean flue gas exhaust pipe, and the second return air flue is connected to the original flue gas delivery pipe.
[0009] Preferably, the second return air flue is merged into the first return air flue, and is connected to the original flue gas conveying duct via the first return air flue.
[0010] In the present invention, a smoke mixer is provided on the original smoke delivery pipeline and is located downstream of the connection position between the first return air duct and the original smoke delivery pipeline.
[0011] In the present invention, a SO2 online concentration analyzer is provided on the raw flue gas conveying pipeline and near the raw flue gas inlet of the first-stage adsorption tower.
[0012] In the present invention, a first online pressure gauge is further provided on the original flue gas delivery pipeline, and is located between the connection position between the first return air duct and the original flue gas delivery pipeline and the location where the flue gas mixer is provided.
[0013] In the present invention, a second online pressure gauge is provided on the primary purified flue gas pipeline, and the second online pressure gauge is located upstream of the position where the primary purified flue gas pipeline branches off from the first return air duct.
[0014] In the present invention, a booster fan is further provided on the primary purified flue gas pipeline and is located upstream of the second online pressure gauge.
[0015] In the utility model, a first return air regulating valve is provided on the first return air flue.
[0016] In the utility model, a second return air regulating valve is provided on the second return air flue.
[0017] In the present invention, an ammonia injection pipe is connected to the primary purified flue gas pipe and close to the primary purified flue gas inlet of the secondary adsorption tower.
[0018] In the present invention, a cold air duct is further connected to the original flue gas delivery duct. The connection point between the cold air duct and the original flue gas delivery duct is located upstream of the connection point between the first return air duct and the original flue gas delivery duct. Preferably, a cold air valve is provided on the cold air duct.
[0019] In view of the technical problem that the existing activated carbon desulfurization and denitrification process is only suitable for treating flue gas with low SO2 concentration, the utility model proposes a new activated carbon flue gas purification system. The system includes a primary adsorption tower and a secondary adsorption tower, and a first return air flue is set before the secondary adsorption tower. The part of the flue gas that has been purified once by the primary adsorption tower is circulated to the original flue gas conveying pipeline before the entrance of the primary adsorption tower. The part of the once purified flue gas is mixed with the original flue gas to dilute the SO2 concentration in the original flue gas, so that the SO2 concentration in the mixed flue gas is within 3000mg / m 3 As a result, the flue gas to be treated entering the primary adsorption tower reaches the appropriate treatment conditions of the adsorption tower, that is, the utility model can treat flue gas with high SO2 concentration.
[0020] The utility model transports the primary purified flue gas after passing through the primary adsorption tower to the original flue gas conveying pipeline. This part of the primary purified flue gas is mixed with the original flue gas and then enters the primary adsorption tower for purification. In this process, the mixing of the primary purified flue gas can dilute the SO2 concentration in the original flue gas and reduce the SO2 concentration in the original flue gas (≥3000mg / m 3 ) diluted to 3000mg / m 3 This allows the mixed flue gas to reach optimal processing conditions in the adsorption tower, thus avoiding the problem of existing desulfurization and denitrification processes, where the heat generated in the activated carbon bed is far greater than the heat removed by the flue gas when treating flue gas with high SO2 concentrations, causing the bed to heat up and even cause system failures. At the same time, this portion of the once-purified flue gas is recycled back to the primary adsorption tower to further treat residual pollutants in the flue gas, improving flue gas purification efficiency and reducing the processing load of the subsequent secondary adsorption tower.
[0021] It is worth noting that in the technical solution of the present invention, there is no need to change or adjust the structure of the first-level adsorption tower or the second-level adsorption tower. The SO2 concentration of the flue gas to be treated can be diluted to a treatment concentration suitable for the adsorption tower only by setting up a return air flue. This effectively solves the technical problem that the existing activated carbon desulfurization and denitrification process is only suitable for treating flue gas with low SO2 concentration, and is economical and energy-saving.
[0022] Preferably, the present invention further provides a flue gas mixer on the original flue gas conveying pipeline after merging with the first return air duct. The flue gas mixer allows the primary purified flue gas circulated to the original flue gas conveying pipeline to be mixed more evenly with the original flue gas, thereby evenly distributing the SO2 in the mixed flue gas. A SO2 online concentration analyzer is also provided on the original flue gas conveying pipeline, downstream of the flue gas mixer, and near the original flue gas inlet of the first adsorption tower. The SO2 online concentration analyzer is used to monitor the SO2 concentration in the mixed flue gas in real time, and cooperates with the first return air regulating valve provided on the first return air duct to regulate the return air volume (i.e., the volume of the primary purified flue gas circulated to the original flue gas conveying pipeline) in real time, thereby ensuring that the SO2 concentration of the flue gas to be treated entering the first adsorption tower meets the treatment conditions suitable for the adsorption tower.
[0023] The process flow of using the activated carbon flue gas purification system described in this utility model to purify flue gas with high SO2 concentration is as follows:
[0024] Original flue gas (e.g. SO2 concentration from sintering main exhaust ≥ 3000mg / m 3 The sintering flue gas first enters the primary activated carbon adsorption tower, and after preliminary purification (i.e. primary purification), it is sent to the secondary activated carbon adsorption tower by the desulfurization and denitrification booster fan for further purification (i.e. secondary purification). The flue gas purified by the secondary activated carbon adsorption tower can meet the ultra-low emission requirements and is sent to the chimney for discharge. A first return air flue is set after the desulfurization and denitrification booster fan and before the secondary activated carbon adsorption tower, and a part of the flue gas after the desulfurization and denitrification booster fan is led to the original flue gas conveying pipeline before the primary activated carbon adsorption tower. The first return air regulating valve is set on the first return air flue to adjust the return air volume. After the sintering flue gas is preliminarily purified by the primary activated carbon adsorption tower, the SO2 content in the flue gas is greatly reduced. This part of the flue gas is returned to the front of the primary activated carbon adsorption tower and mixed with the original flue gas, which can reduce the flue gas with high SO2 concentration (SO2 concentration ≥3000mg / m 3 ) "diluted" to 3000mg / m 3Below, so as to achieve the appropriate treatment conditions of the adsorption tower. The mixed flue gas passes through the flue gas mixer to make the SO2 in the flue gas evenly distributed in the flue gas, which is more conducive to the adsorption tower to remove SO2 in the flue gas. A SO2 online concentration analyzer is set after the flue gas mixer and before the first-level activated carbon adsorption tower to monitor the SO2 concentration in the flue gas in real time. When the SO2 concentration in the flue gas is ≥3000mg / m 3 , increase the opening of the first return air regulating valve to make the SO2 concentration in the flue gas close to 3000mg / m 3 When the SO2 concentration in the flue gas is far less than 3000mg / m 3 , reduce the opening of the first return air regulating valve to make the SO2 concentration in the flue gas close to 3000mg / m 3 The thickness of the activated carbon bed in the first-stage activated carbon adsorption tower must be ≥1.8m to ensure that the SO2 concentration of the flue gas is reduced to 200 mg / m after passing through the first-stage activated carbon adsorption tower. 3 The following is the procedure. A second online pressure gauge, P2, is installed on the primary purified flue gas duct after the desulfurization and denitrification booster fan and before the first return air duct intake. A first online pressure gauge, P1, is installed on the raw flue gas delivery duct before the flue gas mixer and after the first return air duct junction. A variable frequency fan is required for the desulfurization and denitrification booster fan. During system operation, the desulfurization and denitrification booster fan frequency and fan damper are adjusted to maintain P1 between -1000 Pa and -200 Pa, and P2 between 500 Pa and 2000 Pa, ensuring optimal system operation. To prevent excessively high flue gas temperatures entering the adsorption tower, potentially causing safety accidents, a cooling air outlet (connected to the cooling air outlet duct) is installed on the raw flue gas delivery duct before the first adsorption tower. Air is drawn in to reduce the sintering flue gas temperature to approximately 135°C. A cooling air valve is installed on the cooling air outlet to adjust the amount of cooling air entering the raw flue gas delivery duct. An NH3 injection port is set on the primary flue gas purification pipeline after the first return air duct intake and before the secondary activated carbon adsorption tower to make NO in the flue gas x Under the action of activated carbon, a redox reaction occurs with NH3 to convert NO x Reduced to N2 and H2O.
[0025] Furthermore, the present invention also sets a second return air flue after the secondary adsorption tower, which guides a portion of the clean flue gas after the secondary purification in the secondary adsorption tower to the original flue gas conveying pipeline before the entrance of the primary adsorption tower. This portion of clean flue gas is mixed with the original flue gas, so that the SO2 concentration of the mixed flue gas reaches the treatment condition suitable for the adsorption tower. Compared with the once purified flue gas discharged from the primary adsorption tower, the SO2 concentration of the clean flue gas discharged from the secondary adsorption tower is lower. Based on this, when the SO2 concentration of the original flue gas transported to the primary adsorption tower is very high (far higher than 3000mg / m 3), the utility model adds a second return air flue to circulate part of the clean flue gas on the basis of purifying the flue gas once through the first return air flue, which can dilute the SO2 concentration of the original flue gas more efficiently and quickly, and cooperates with the second return air regulating valve arranged on the second return air duct to adjust the return air volume (that is, the amount of clean flue gas circulated to the original flue gas conveying pipeline) in real time, thereby ensuring that the mixed flue gas can reach the appropriate treatment conditions of the adsorption tower.
[0026] In addition, the present application can also set up a second return air duct separately instead of the first return air duct, and lead part of the clean flue gas to the original flue gas conveying pipeline through the second return air duct. This part of the clean flue gas is mixed with the original flue gas, which can also dilute the concentration of SO2 in the original flue gas, so that the mixed flue gas can meet the appropriate treatment conditions of the adsorption tower.
[0027] It should be noted that if a selective catalytic reduction denitrification system (ie, SCR) is used to replace the secondary adsorption tower in the aforementioned activated carbon flue gas purification system, this solution is also within the scope of protection of this application.
[0028] In this application, “primary adsorption tower” and “primary activated carbon adsorption tower”, and “secondary adsorption tower” and “secondary activated carbon adsorption tower” can be used interchangeably.
[0029] Compared with the prior art, the present invention has the following beneficial effects:
[0030] 1. The utility model sets a first return air flue before the secondary adsorption tower, and circulates part of the flue gas that has been purified once by the primary adsorption tower to the original flue gas conveying pipeline before the entrance of the primary adsorption tower. This part of the once purified flue gas is mixed with the original flue gas to dilute the SO2 concentration in the original flue gas, so that the flue gas to be treated entering the primary adsorption tower reaches the treatment conditions suitable for the adsorption tower. That is, the utility model can treat flue gas with high SO2 concentration.
[0031] 2. The utility model does not require any changes or adjustments to the structure of the primary adsorption tower or the secondary adsorption tower. It can dilute the SO2 concentration of the flue gas to be treated to a treatment concentration suitable for the adsorption tower by simply setting up a return air flue. This effectively solves the technical problem that the existing activated carbon desulfurization and denitrification process is only suitable for treating flue gas with low SO2 concentration, and is economical and energy-saving.
[0032] 3. The utility model also sets a second return air flue after the secondary adsorption tower, and guides a part of the clean flue gas after the secondary purification in the secondary adsorption tower to the original flue gas conveying pipeline before the entrance of the primary adsorption tower. That is, on the basis of circulating part of the purified flue gas once through the first return air flue, the second return air flue is added to circulate part of the clean flue gas, which can dilute the SO2 concentration of the original flue gas more efficiently and quickly, thereby ensuring that the mixed flue gas can reach the appropriate treatment conditions of the adsorption tower.
[0033] 4. The utility model sets a flue gas mixer on the original flue gas conveying pipeline after merging with the first return air flue. The flue gas mixer makes the primary purified flue gas circulated to the original flue gas conveying pipeline and the original flue gas mixed more evenly, so that the SO2 in the mixed flue gas can also be evenly distributed.
[0034] 5. The utility model is further provided with a SO2 online concentration analyzer on the original flue gas conveying pipeline and downstream of the flue gas mixer, near the original flue gas inlet of the first-stage adsorption tower. The SO2 online concentration analyzer is used to monitor the SO2 concentration in the mixed flue gas in real time, and cooperates with the return air regulating valve arranged on the return air duct to adjust the return air volume in real time to ensure that the SO2 concentration of the flue gas to be treated entering the first-stage adsorption tower meets the appropriate treatment conditions of the adsorption tower.
[0035] 6. The utility model sets a first online pressure gauge and a second online pressure gauge on the original flue gas conveying pipeline and the primary purified flue gas pipeline respectively, and monitors and controls the pressure at the corresponding positions in real time to ensure that the system is in the best operating state and improve the safety of the system.
[0036] 7. The utility model only needs to set up one desulfurization and denitrification booster fan, which reduces one booster fan compared with the existing technology and reduces investment; the utility model only sets up ammonia injection after the first-level adsorption tower, which reduces the consumption of SO2 on NH3 and makes the utilization of NH3 more efficient. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] Figure 1 This is a schematic structural diagram of an activated carbon flue gas purification system of the utility model;
[0038] Figure 2 This is a schematic structural diagram of another activated carbon flue gas purification system of the present invention;
[0039] Figure 3 This is a simplified diagram of the two-stage activated carbon desulfurization and denitrification process in the existing technology.
[0040] Reference numerals:
[0041] 1: First-stage adsorption tower; 2: Second-stage adsorption tower; 3: Flue gas mixer; 4: SO2 online concentration analyzer; 501: First online pressure gauge; 502: Second online pressure gauge; 6: Booster fan; 701: First return air regulating valve; 702: Second return air regulating valve; 8: Cold air valve;
[0042] L1: original flue gas conveying pipeline; L2: primary purified flue gas pipeline; L3: first return air flue; L4: clean flue gas discharge pipeline; L5: second return air flue; L6: ammonia injection pipeline; L7: cold air pipeline. DETAILED DESCRIPTION
[0043] The technical solution of the present invention is illustrated below with examples, and the scope of protection requested by the present invention includes but is not limited to the following embodiments.
[0044] According to an embodiment of the present utility model, an activated carbon flue gas purification system is provided.
[0045] An activated carbon flue gas purification system includes a primary adsorption tower 1 and a secondary adsorption tower 2. The primary adsorption tower 1 is provided with a raw flue gas inlet and a primary purified flue gas outlet. The secondary adsorption tower 2 is provided with a primary purified flue gas inlet and a clean flue gas outlet. The raw flue gas inlet of the primary adsorption tower 1 is connected to a raw flue gas conveying pipeline L1. The primary purified flue gas outlet of the primary adsorption tower 1 is connected to the primary purified flue gas inlet of the secondary adsorption tower 2 via a primary purified flue gas pipeline L2. A first return air duct L3 is branched from the primary purified flue gas pipeline L2 and is connected to the raw flue gas conveying pipeline L1.
[0046] In the present invention, the clean flue gas outlet of the secondary adsorption tower 2 is connected to a clean flue gas exhaust pipe L4. A second return air flue L5 is branched from the clean flue gas exhaust pipe L4, and the second return air flue L5 is connected to the original flue gas delivery pipe L1.
[0047] Preferably, the second return air duct L5 is merged into the first return air duct L3, and is connected to the original flue gas conveying duct L1 via the first return air duct L3.
[0048] In the present invention, the original smoke delivery pipe L1 is provided with a smoke mixer 3. The smoke mixer 3 is located downstream of the connection position between the first return air duct L3 and the original smoke delivery pipe L1.
[0049] In the present invention, a SO2 online concentration analyzer 4 is provided on the raw flue gas conveying pipeline L1 and near the raw flue gas inlet of the first-stage adsorption tower 1 .
[0050] In the present invention, the original flue gas delivery pipe L1 is further provided with a first online pressure gauge 501. The first online pressure gauge 501 is located between the connection position between the first return air duct L3 and the original flue gas delivery pipe L1 and the location of the flue gas mixer 3.
[0051] In the present invention, the primary clean flue gas duct L2 is provided with a second online pressure gauge 502. The second online pressure gauge 502 is located upstream of the location where the primary clean flue gas duct L2 branches off from the first return air duct L3.
[0052] In the present invention, a booster fan 6 is further provided on the primary purified flue gas duct L2 . The booster fan 6 is located upstream of the second online pressure gauge 502 .
[0053] In the present invention, a first return air regulating valve 701 is provided on the first return air flue L3.
[0054] In the present invention, a second return air regulating valve 702 is provided on the second return air flue L5.
[0055] In the present invention, an ammonia gas injection pipe L6 is connected to the primary purified flue gas pipe L2 and close to the primary purified flue gas inlet of the secondary adsorption tower 2 .
[0056] In the present invention, a cooling air duct L7 is also connected to the original flue gas delivery duct L1. The connection point between the cooling air duct L7 and the original flue gas delivery duct L1 is located upstream of the connection point between the first return air duct L3 and the original flue gas delivery duct L1. Preferably, a cooling air valve 8 is provided on the cooling air duct L7. Example 1
[0057] like Figure 1 As shown, an activated carbon flue gas purification system includes a primary adsorption tower 1 and a secondary adsorption tower 2. The primary adsorption tower 1 is provided with a raw flue gas inlet and a primary purified flue gas outlet. The secondary adsorption tower 2 is provided with a primary purified flue gas inlet and a clean flue gas outlet. The raw flue gas inlet of the primary adsorption tower 1 is connected to the raw flue gas conveying pipeline L1. The primary purified flue gas outlet of the primary adsorption tower 1 is connected to the primary purified flue gas inlet of the secondary adsorption tower 2 via the primary purified flue gas pipeline L2. A first return air duct L3 is branched from the primary purified flue gas pipeline L2, and the first return air duct L3 is connected to the raw flue gas conveying pipeline L1. Example 2
[0058] like Figure 2 As shown, Example 1 is repeated, except that the clean flue gas outlet of the secondary adsorption tower 2 is connected to a clean flue gas exhaust pipe L4. A second return air flue L5 is branched from the clean flue gas exhaust pipe L4, and the second return air flue L5 is connected to the original flue gas conveying pipe L1. Example 3
[0059] Example 2 is repeated, except that the second return air duct L5 is merged into the first return air duct L3 and connected to the original flue gas conveying duct L1 via the first return air duct L3. Example 4
[0060] Example 3 is repeated, except that the original smoke conveying pipe L1 is provided with a smoke mixer 3. The smoke mixer 3 is located downstream of the connection position between the first return air duct L3 and the original smoke conveying pipe L1. Example 5
[0061] Example 4 was repeated, except that a SO 2 online concentration analyzer 4 was installed on the raw flue gas delivery pipeline L1 and near the raw flue gas inlet of the primary adsorption tower 1 . The SO 2 online concentration analyzer 4 was located downstream of the flue gas mixer 3 . Example 6
[0062] Repeat Example 5, except that the original flue gas delivery pipe L1 is further provided with a first online pressure gauge 501. The first online pressure gauge 501 is located between the connection point between the first return air duct L3 and the original flue gas delivery pipe L1 and the location of the flue gas mixer 3. Example 7
[0063] Example 6 is repeated, except that the primary purified flue gas duct L2 is provided with a second online pressure gauge 502. The second online pressure gauge 502 is located upstream of the location where the primary purified flue gas duct L2 branches off from the first return air duct L3. Example 8
[0064] Example 7 is repeated, except that a booster fan 6 is further provided on the primary purified flue gas duct L2. The booster fan 6 is located upstream of the second online pressure gauge 502. The booster fan 7 is a variable frequency fan. Example 9
[0065] Repeat Example 8, except that a first return air regulating valve 701 is provided on the first return air flue L3. Example 10
[0066] Repeat Example 9, except that a second return air regulating valve 702 is provided on the second return air flue L5. Example 11
[0067] Example 10 was repeated, except that an ammonia injection pipe L6 was connected to the primary purified flue gas duct L2 near the primary purified flue gas inlet of the secondary adsorption tower 2. The ammonia injection pipe L6 was located downstream of the location where the primary purified flue gas duct L2 branches off from the first return air duct L3. Example 12
[0068] Repeat Example 11, except that a cold air duct L7 is also connected to the original flue gas delivery duct L1. The connection point between the cold air duct L7 and the original flue gas delivery duct L1 is located upstream of the connection point between the first return air duct L3 and the original flue gas delivery duct L1. A cold air valve 8 is installed on the cold air duct L7.
Claims
1. An activated carbon flue gas purification system, characterized by: The system comprises a primary adsorption tower (1) and a secondary adsorption tower (2); the primary adsorption tower (1) is provided with a raw flue gas inlet and a primary purified flue gas outlet; the secondary adsorption tower (2) is provided with a primary purified flue gas inlet and a clean flue gas outlet; wherein the raw flue gas inlet of the primary adsorption tower (1) is connected to a raw flue gas delivery pipeline (L1); the primary purified flue gas outlet of the primary adsorption tower (1) is connected to the primary purified flue gas inlet of the secondary adsorption tower (2) via a primary purified flue gas pipeline (L2); a first return air flue (L3) is branched from the primary purified flue gas pipeline (L2), and the first return air flue (L3) is connected to the raw flue gas delivery pipeline (L1).
2. The activated carbon flue gas purification system according to claim 1, characterized in that: The clean flue gas outlet of the secondary adsorption tower (2) is connected to a clean flue gas exhaust pipe (L4); a second return air flue (L5) is branched from the clean flue gas exhaust pipe (L4), and the second return air flue (L5) is connected to the original flue gas delivery pipe (L1); Preferably, the second return air duct (L5) is merged into the first return air duct (L3), and is connected to the original flue gas conveying duct (L1) via the first return air duct (L3).
3. The activated carbon flue gas purification system according to claim 1 or 2, characterized in that: A smoke mixer (3) is provided on the original smoke delivery pipeline (L1); the smoke mixer (3) is located downstream of the connection position between the first return air duct (L3) and the original smoke delivery pipeline (L1).
4. The activated carbon flue gas purification system according to any one of claims 1 to 3, characterized in that: An SO2 online concentration analyzer (4) is provided on the original flue gas conveying pipeline (L1) and at a position close to the original flue gas inlet of the first-stage adsorption tower (1).
5. The activated carbon flue gas purification system according to claim 3 or 4, characterized in that: The original flue gas delivery pipe (L1) is also provided with a first online pressure gauge (501); the first online pressure gauge (501) is located between the connection position between the first return air flue (L3) and the original flue gas delivery pipe (L1) and the installation position of the flue gas mixer (3).
6. The activated carbon flue gas purification system according to any one of claims 3 to 5, characterized in that: A second online pressure gauge (502) is provided on the primary purified flue gas duct (L2); the second online pressure gauge (502) is located upstream of the position where the primary purified flue gas duct (L2) branches off from the first return air duct (L3).
7. The activated carbon flue gas purification system according to claim 6, characterized in that: A booster fan (6) is also provided on the primary purified flue gas duct (L2); the booster fan (6) is located upstream of the second online pressure gauge (502).
8. The activated carbon flue gas purification system according to any one of claims 2 to 7, characterized in that: A first return air regulating valve (701) is provided on the first return air flue (L3); and / or A second return air regulating valve (702) is provided on the second return air flue (L5).
9. The activated carbon flue gas purification system according to any one of claims 1 to 8, characterized in that: An ammonia injection pipe (L6) is connected to the primary purified flue gas pipe (L2) and at a position close to the primary purified flue gas inlet of the secondary adsorption tower (2).
10. The activated carbon flue gas purification system according to any one of claims 1 to 9, characterized in that: The original flue gas delivery pipe (L1) is also connected to a cold air exchange pipe (L7); the connection position of the cold air exchange pipe (L7) and the original flue gas delivery pipe (L1) is located upstream of the connection position of the first return air flue (L3) and the original flue gas delivery pipe (L1); preferably, a cold air valve (8) is provided on the cold air exchange pipe (L7).